Perils and pitfalls of reporting sex differences

PubMed Central

Maney, Donna L.

2016-01-01

The idea of sex differences in the brain both fascinates and inflames the public. As a result, the communication and public discussion of new findings is particularly vulnerable to logical leaps and pseudoscience. A new US National Institutes of Health policy to consider both sexes in almost all preclinical research will increase the number of reported sex differences and thus the risk that research in this important area will be misinterpreted and misrepresented. In this article, I consider ways in which we might reduce that risk, for example, by (i) employing statistical tests that reveal the extent to which sex explains variation, rather than whether or not the sexes ‘differ’, (ii) properly characterizing the frequency distributions of scores or dependent measures, which nearly always overlap, and (iii) avoiding speculative functional or evolutionary explanations for sex-based variation, which usually invoke logical fallacies and perpetuate sex stereotypes. Ultimately, the factor of sex should be viewed as an imperfect, temporary proxy for yet-unknown factors, such as hormones or sex-linked genes, that explain variation better than sex. As scientists, we should be interested in discovering and understanding the true sources of variation, which will be more informative in the development of clinical treatments. PMID:26833839

Editorial: Let's talk about sex - the gender binary revisited.

PubMed

Oldehinkel, Albertine J

2017-08-01

Sex refers to biological differences and gender to socioculturally delineated masculine and feminine roles. Sex or gender are included as a covariate or effect modifier in the majority of child psychology and psychiatry studies, and differences found between boys and girls have inspired many researchers to postulate underlying mechanisms. Empirical tests of whether including these proposed explanatory variables actually reduces the variance explained by gender are lagging behind somewhat. That is a pity, because a lot can be gained from a greater focus on the active agents of specific gender differences. As opposed to biological sex as such, some of the processes explaining why a specific outcome shows gender differences may be changeable and so possible prevention targets. Moreover, while the sex binary may be reasonable adequate as a classification variable, the gender binary is far from perfect. Gender is a multidimensional, partly context-dependent factor, and the dichotomy generally used in research does not do justice to the diversity existing within boys and girls. © 2017 Association for Child and Adolescent Mental Health.

Sex Differences in the Effects of Unilateral Brain Damage on Intelligence

NASA Astrophysics Data System (ADS)

Inglis, James; Lawson, J. S.

1981-05-01

A sexual dimorphism in the functional asymmetry of the damaged human brain is reflected in a test-specific laterality effect in male but not in female patients. This sex difference explains some contradictions concerning the effects of unilateral brain damage on intelligence in studies in which the influence of sex was overlooked.

Sex differences in gingivitis relate to interaction of oral health behaviors in young people.

PubMed

Furuta, Michiko; Ekuni, Daisuke; Irie, Koichiro; Azuma, Tetsuji; Tomofuji, Takaaki; Ogura, Toshio; Morita, Manabu

2011-04-01

Although many epidemiologic surveys have shown that gingivitis is more prevalent in males than in females, few studies have clearly explained what causes this difference. The objective of the present study is to explain the sex difference in gingivitis based on the interaction between oral health behaviors and related factors, such as knowledge, attitude, and lifestyle, in young people. The study was comprised of 838 subjects (440 males and 398 females), aged 18 and 19 years. Gingivitis was assessed by the percentage of bleeding on probing (%BOP). Additional information was collected regarding oral hygiene status, oral health behaviors, and related factors. Structural equation modeling was used to test pathways from these factors to %BOP. Multiple-group modeling was also conducted to test for sex differences. Females had greater knowledge, a more positive attitude, a healthier lifestyle, and higher level of oral health behaviors than males. There were significant differences in the paths (i.e., from lifestyle, knowledge, and attitude to %BOP) through oral health behaviors and oral health status. Sex-based differences in gingivitis in young people can be explained by oral health behaviors and hygiene status, which are influenced by lifestyle, knowledge, and attitude. To prevent gingivitis, different approaches to males and females may be useful.

Stereotype Threat as Validity Threat: The Anxiety-Sex-Threat Interaction

ERIC Educational Resources Information Center

Delgado, Ana R.; Prieto, Gerardo

2008-01-01

Stereotype threat has been invoked to explain underperformance on a variety of groups for whom the stereotypes allege inferior cognitive abilities. In math testing, stereotype threat has been used to explain sex differences in test performance. This paper describes an experimental study on a large sample (n = 313), in which the role of anxiety and…

Sex differences in perceived stress and early recovery in young and middle-aged patients with acute myocardial infarction.

PubMed

Xu, Xiao; Bao, Haikun; Strait, Kelly; Spertus, John A; Lichtman, Judith H; D'Onofrio, Gail; Spatz, Erica; Bucholz, Emily M; Geda, Mary; Lorenze, Nancy P; Bueno, Héctor; Beltrame, John F; Krumholz, Harlan M

2015-02-17

Younger age and female sex are both associated with greater mental stress in the general population, but limited data exist on the status of perceived stress in young and middle-aged patients presenting with acute myocardial infarction. We examined sex difference in stress, contributing factors to this difference, and whether this difference helps explain sex-based disparities in 1-month recovery using data from 3572 patients with acute myocardial infarction (2397 women and 1175 men) 18 to 55 years of age. The average score of the 14-item Perceived Stress Scale at baseline was 23.4 for men and 27.0 for women (P<0.001). Higher stress in women was explained largely by sex differences in comorbidities, physical and mental health status, intrafamily conflict, caregiving demands, and financial hardship. After adjustment for demographic and clinical characteristics, women had worse recovery than men at 1 month after acute myocardial infarction, with mean differences in improvement score between women and men ranging from -0.04 for EuroQol utility index to -3.96 for angina-related quality of life (P<0.05 for all). Further adjustment for baseline stress reduced these sex-based differences in recovery to -0.03 to -3.63, which, however, remained statistically significant (P<0.05 for all). High stress at baseline was associated with significantly worse recovery in angina-specific and overall quality of life, as well as mental health status. The effect of baseline stress on recovery did not vary between men and women. Among young and middle-aged patients, higher stress at baseline is associated with worse recovery in multiple health outcomes after acute myocardial infarction. Women perceive greater psychological stress than men at baseline, which partially explains women's worse recovery. © 2015 American Heart Association, Inc.

Explaining sex differences in reactions to relationship infidelities: comparisons of the roles of sex, gender, beliefs, attachment, and sociosexual orientation.

PubMed

Brase, Gary L; Adair, Lora; Monk, Kale

2014-02-04

To the extent that sex differences are mediated by mechanisms such as sex-roles and beliefs, individual differences in these more proximate traits should account for significant portions of relevant sex differences. Differences between women and men in reactions to sexual and emotional infidelity were assessed in a large sample of participants (n = 477), and these target reactions were evaluated as a function of many potential proximate mediators (infidelity implications beliefs, gender-role beliefs, interpersonal trust, attachment style, sociosexuality, and culture of honor beliefs) and as a function of participant sex. Results found a consistent sex difference that was not mediated by any other variables, although a handful of other variables were related to male, but not female, individual differences. These findings suggest particularly promising directions for future research on integrating evolutionarily based sex differences and proximate individual differences.

Explaining sex differences in managerial career satisfier preferences: the role of gender self-schema.

PubMed

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.

Using Physiological Principles to Explain Sex Differences in Running and Swimming Performances

ERIC Educational Resources Information Center

Dollman, Jim

2005-01-01

Demonstrated sex differences in physical characteristics are used to know the performance differences between first-placed males and females from latest world championships in swimming and running. The performance comparisons (PCs) reveal smaller differences between males and females in running sprint events than longer distance running and the…

Cigarette Smoking in Same-Sex and Different-Sex Unions: The Role of Socioeconomic and Psychological Factors

PubMed Central

Liu, Hui; Brown, Dustin

2014-01-01

Cigarette smoking has long been a target of public health intervention because it substantially contributes to morbidity and mortality. Individuals in different-sex marriages have lower smoking risk (i.e., prevalence and frequency) than different-sex cohabiters. However, little is known about the smoking risk of individuals in same-sex cohabiting unions. We compare the smoking risk of individuals in different-sex marriages, same-sex cohabiting unions, and different-sex cohabiting unions using pooled cross-sectional data from the 1997–2010 National Health Interview Surveys (N = 168,514). We further examine the role of socioeconomic status (SES) and psychological distress in the relationship between union status and smoking. Estimates from multinomial logistic regression models reveal that same-sex and different-sex cohabiters experience similar smoking risk when compared to one another, and higher smoking risk when compared to the different-sex married. Results suggest that SES and psychological distress factors cannot fully explain smoking differences between the different-sex married and same-sex and different-sex cohabiting groups. Moreover, without same-sex cohabiter’s education advantage, same-sex cohabiters would experience even greater smoking risk relative to the different-sex married. Policy recommendations to reduce smoking disparities among same-sex and different-sex cohabiters are discussed. PMID:25346559

Attentional Bias for Pain and Sex, and Automatic Appraisals of Sexual Penetration: Differential Patterns in Dyspareunia vs Vaginismus?

PubMed

Melles, Reinhilde J; Dewitte, Marieke D; Ter Kuile, Moniek M; Peters, Madelon M L; de Jong, Peter J

2016-08-01

Current information processing models propose that heightened attention bias for sex-related threats (eg, pain) and lowered automatic incentive processes ("wanting") may play an important role in the impairment of sexual arousal and the development of sexual dysfunctions such as genitopelvic pain/penetration disorder (GPPPD). Differential threat and incentive processing may also help explain the stronger persistence of coital avoidance in women with vaginismus compared to women with dyspareunia. As the first aim, we tested if women with GPPPD show (1) heightened attention for pain and sex, and (2) heightened threat and lower incentive associations with sexual penetration. Second, we examined whether the stronger persistence of coital avoidance in vaginismus vs dyspareunia might be explained by a stronger attentional bias or more dysfunctional automatic threat/incentive associations. Women with lifelong vaginismus (n = 37), dyspareunia (n = 29), and a no-symptoms comparison group (n = 51) completed a visual search task to assess attentional bias, and single target implicit-association tests to measure automatic sex-threat and sex-wanting associations. There were no group differences in attentional bias or automatic associations. Correlational analysis showed that slowed detection of sex stimuli and stronger automatic threat associations were related to lowered sexual arousal. The findings do not corroborate the view that attentional bias for pain or sex contributes to coital pain, or that differences in coital avoidance may be explained by differences in attentional bias or automatic threat/incentive associations. However, the correlational findings are consistent with the view that automatic threat associations and impaired attention for sex stimuli may interfere with the generation of sexual arousal. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Variability of Sex Disparities in Cancer Incidence over 30 Years: The Striking Case of Kidney Cancer.

PubMed

Scelo, Ghislaine; Li, Peng; Chanudet, Estelle; Muller, David C

2017-01-31

It is well established that men are at higher risk of most non-sex-specific cancers than women, but there has been surprisingly little research investigating these differences. This is possibly because differences in exposure to established risk factors and hypothesised protection by female sex hormones are thought to account for the totality of the sex differences. These explanations remain somewhat speculative, as the magnitude of the sex ratio in cancer incidence has not been systematically studied, with no quantitative estimate of the variability of the sex ratio across countries, age groups, and periods of diagnosis. We analysed worldwide cancer incidence data for the years 1978-2007 in terms of sex disparities, and explicitly quantified the variability in sex disparities by age, year, and geographical region. Our analysis highlights several cancer types for which suspected and commonly accepted factors are unlikely to fully explain the observed sex disparity. In particular, kidney cancer showed a 2:1 male/female case incidence ratio that was constant by age, year, and region, suggesting that factors other than sociocultural habits and health behaviours are responsible for this sex disparity. We quantified the difference in the incidence of various cancer types between men and women across the world over 30 years. While the trends for some cancers such as lung cancer are clearly correlated with known variations in lifestyle habits, we found that the sex disparity observed for others such as kidney cancer is unlikely to be explained by known risk factors. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Looking behind the score: Skill structure explains sex differences in skilled video game performance

PubMed Central

Boot, Walter R.; Ericsson, K. Anders

2018-01-01

Some have explained large sex differences in visuospatial abilities by genetic adaptations to different roles in primitive hunter-gatherer societies and the interaction of innate biological differences and environmental factors. We explored the extent to which variations in behavior and acquired skills can provide alternative accounts for sex differences in the performance of a complex spatially-demanding video game (Space Fortress). Men and women with limited video game experience were given 30 hours of training, and latent curve analyses examined the development of their ship control performance and behavior. Men had significantly better control performance than women before and after training, but differences diminished substantially over the training period. An analysis of participants’ joystick behaviors revealed that initially men and women relied on different patterns of control behaviors, but changes in these behaviors over time accounted for the reduced sex differences in performance. When we controlled for these differences in behavior, sex effects after training were no longer significant. Finally, examining the development of control performance and control behaviors of men and women categorized as initially high and low performers revealed the lower-performing women may have been controlling their ship using an approach that was very different from the men and higher-performing women. The potential problems of analyzing men and women’s spatial performance as homogenous groups are discussed, as well as how these issues may account for sex differences in skilled video game performance and perhaps other domains involving spatial abilities. PMID:29847565

Looking behind the score: Skill structure explains sex differences in skilled video game performance.

PubMed

Harwell, Kyle W; Boot, Walter R; Ericsson, K Anders

2018-01-01

Some have explained large sex differences in visuospatial abilities by genetic adaptations to different roles in primitive hunter-gatherer societies and the interaction of innate biological differences and environmental factors. We explored the extent to which variations in behavior and acquired skills can provide alternative accounts for sex differences in the performance of a complex spatially-demanding video game (Space Fortress). Men and women with limited video game experience were given 30 hours of training, and latent curve analyses examined the development of their ship control performance and behavior. Men had significantly better control performance than women before and after training, but differences diminished substantially over the training period. An analysis of participants' joystick behaviors revealed that initially men and women relied on different patterns of control behaviors, but changes in these behaviors over time accounted for the reduced sex differences in performance. When we controlled for these differences in behavior, sex effects after training were no longer significant. Finally, examining the development of control performance and control behaviors of men and women categorized as initially high and low performers revealed the lower-performing women may have been controlling their ship using an approach that was very different from the men and higher-performing women. The potential problems of analyzing men and women's spatial performance as homogenous groups are discussed, as well as how these issues may account for sex differences in skilled video game performance and perhaps other domains involving spatial abilities.

Family Structure and Child Health: Does the Sex Composition of Parents Matter?

PubMed Central

Reczek, Corinne; Spiker, Russell; Liu, Hui; Crosnoe, Robert

2016-01-01

The children of different-sex married couples appear to be advantaged on a range of outcomes relative to the children of different-sex cohabiting couples. Despite the legalization of same-sex marriage in the United States, whether and how this general pattern extends to the children of same-sex married and cohabiting couples is unknown. This study examines this question with nationally representative data from the 2004–2013 pooled National Health Interview Survey (NHIS). Results reveal that children in cohabiting households have poorer health outcomes than children in married households regardless of the sex composition of their parents. Children in same-sex and different-sex married households are relatively similar to each other on health outcomes, as are children in same-sex and different-sex cohabiting households. These patterns are not fully explained by socioeconomic differences among the four different types of families. This evidence can inform general debates about family structure and child health as well as and policy interventions aiming to reduce child health disparities. PMID:27553617

Family Structure and Child Health: Does the Sex Composition of Parents Matter?

PubMed

Reczek, Corinne; Spiker, Russell; Liu, Hui; Crosnoe, Robert

2016-10-01

The children of different-sex married couples appear to be advantaged on a range of outcomes relative to the children of different-sex cohabiting couples. Despite the legalization of same-sex marriage in the United States, whether and how this general pattern extends to the children of same-sex married and cohabiting couples is unknown. This study examines this question with nationally representative data from the 2004-2013 pooled National Health Interview Survey (NHIS). Results reveal that children in cohabiting households have poorer health outcomes than children in married households regardless of the sex composition of their parents. Children in same-sex and different-sex married households are relatively similar to each other on health outcomes, as are children in same-sex and different-sex cohabiting households. These patterns are not fully explained by socioeconomic differences among the four different types of families. This evidence can inform general debates about family structure and child health as well as policy interventions aiming to reduce child health disparities.

Same-sex cohabitors and health: the role of race-ethnicity, gender, and socioeconomic status.

PubMed

Liu, Hui; Reczek, Corinne; Brown, Dustin

2013-03-01

A legacy of research finds that marriage is associated with good health. Yet same-sex cohabitors cannot marry in most states in the United States and therefore may not receive the health benefits associated with marriage. We use pooled data from the 1997 to 2009 National Health Interview Surveys to compare the self-rated health of same-sex cohabiting men (n = 1,659) and same-sex cohabiting women (n = 1,634) with that of their different-sex married, different-sex cohabiting, and unpartnered divorced, widowed, and never-married counterparts. Results from logistic regression models show that same-sex cohabitors report poorer health than their different-sex married counterparts at the same levels of socioeconomic status. Additionally, same-sex cohabitors report better health than their different-sex cohabiting and single counterparts, but these differences are fully explained by socioeconomic status. Without their socioeconomic advantages, same-sex cohabitors would report similar health to nonmarried groups. Analyses further reveal important racial-ethnic and gender variations.

Intersexual and temporal variation in foraging ecology of prothonotary warblers during the breeding season

USGS Publications Warehouse

Petit, L.J.; Petit, D.R.; Petit, K.E.; Fleming, W.J.

1990-01-01

We studied foraging ecology of Prothonotary Warblers (Protonotaria citrea) over four breeding seasons to determine if this species exhibited sex-specific or temporal variation in foraging behavior. Significant differences between sexes during the prenestling period were found for foraging height and substrate height (foraging method, plant species/substrate, perch diameter, horizontal location from trunk, and prey location were not significantly different). During the nestling period, this divergence between sexes was evident for foraging height, substrate height, substrate / tree species, and prey location. Additionally, male warblers significantly altered their behavior for all seven foraging variables between the two periods, whereas females exhibited changes similar to those of males for five of the foraging variables. This parallel shift suggests a strong behavioral response by both sexes to proximate factors (such as vegetation structure, and prey abundance and distribution) that varied throughout the breeding season. Sex-specific foraging behavior during the prenestling period was best explained by differences in reproductive responsibilities rather than by the theory of intersexual competition for limited resources. During the nestling period, neither hypothesis by itself explained foraging divergences adequately. However, when integrated with the temporal responses of the warblers to changes in prey availability, reproductive responsibilities seemed to be of primary importance in explaining intersexual niche partitioning during the nestling period. We emphasize the importance of considering both intersexual and intraseasonal variation when quantifying a species' foraging ecology.

Sex differences in stress-related psychiatric disorders: neurobiological perspectives.

PubMed

Bangasser, Debra A; Valentino, Rita J

2014-08-01

Stress is associated with the onset and severity of several psychiatric disorders that occur more frequently in women than men, including posttraumatic stress disorder (PTSD) and depression. Patients with these disorders present with dysregulation of several stress response systems, including the neuroendocrine response to stress, corticolimbic responses to negatively valenced stimuli, and hyperarousal. Thus, sex differences within their underlying circuitry may explain sex biases in disease prevalence. This review describes clinical studies that identify sex differences within the activity of these circuits, as well as preclinical studies that demonstrate cellular and molecular sex differences in stress responses systems. These studies reveal sex differences from the molecular to the systems level that increase endocrine, emotional, and arousal responses to stress in females. Exploring these sex differences is critical because this research can reveal the neurobiological underpinnings of vulnerability to stress-related psychiatric disorders and guide the development of novel pharmacotherapies. Copyright © 2014 Elsevier Inc. All rights reserved.

Sex Differences in Stress-Related Psychiatric Disorders: Neurobiological Perspectives

PubMed Central

Bangasser, Debra A.; Valentino, Rita J.

2014-01-01

Stress is associated with the onset and severity of several psychiatric disorders that occur more frequently in women than men, including posttraumatic stress disorder (PTSD) and depression. Patients with these disorders present with dysregulation of several stress response systems, including the neuroendocrine response to stress, corticolimbic responses to negatively valenced stimuli, and hyperarousal. Thus, sex differences within their underlying circuitry may explain sex biases in disease prevalence. This review describes clinical studies that identify sex differences within the activity of these circuits, as well as preclinical studies that demonstrate cellular and molecular sex differences in stress responses systems. These studies reveal sex differences from the molecular to the systems level that increase endocrine, emotional, and arousal responses to stress in females. Exploring these sex differences is critical because this research can reveal the neurobiological underpinnings of vulnerability to stress-related psychiatric disorders and guide the development of novel pharmacotherapies. PMID:24726661

Sex Differences in the Development of Moral Reasoning: A Rejoinder to Baumrind.

ERIC Educational Resources Information Center

Walker, Lawrence J.

1986-01-01

Addresses the criticisms of Diana Baumrind's review of his research on sex differences in moral reasoning development. Discusses issues such as the nature of moral development, the focus on adulthood, the choice of statistics, the effect of differing sample sizes and scoring systems, and the role of sexual experiences in explaining variability in…

In hindsight: urban exposure explains the association between prior migration and current health of older adults in Mexico.

PubMed

Wheaton, Felicia V; Crimmins, Eileen M

2013-04-01

This study examines sex differences in the association between migration and exposure to an urban environment and overweight, hypertension and diabetes in later life. Interviews were conducted with 3,604 adults aged 50 and older in the Mexican Family Life Survey (MxFLS). Logistic regression analyses were used to examine the association between previous migration, urban exposure, and risk of overweight, hypertension, and diabetes. Migration itself was not associated with health outcomes after controlling for urban exposure. The risk of overweight and diabetes associated with urban exposure appeared to be greater for men. Sex differences were found in the covariates that helped explain differences in health between those with high and low urban exposure. These findings underscore the need to consider heterogeneity in health by urban exposure and by sex.

Correcting a Longstanding Misconception about Social Roles and Personality: A Case Study in the Psychology of Science.

PubMed

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.

Differences in habitat selection of male and female megrim ( Lepidorhombus whiffiagonis, Walbaum) to the west of Ireland. A result of differences in life-history strategies between the sexes?

NASA Astrophysics Data System (ADS)

Gerritsen, H. D.; McGrath, D.; Lordan, C.; Harlay, X.

2010-11-01

The sex ratio in the catches of megrim ( Lepidorhombus whiffiagonis, Walbaum) varied systematically with depth on three independent trawl survey series off the west coast of Ireland. Female megrim dominated the shallow catches, while males were more common in catches from deeper waters. The size difference between the sexes alone cannot explain this pattern because it remained evident when fish length was taken into account. Therefore size-specific habitat preferences or size-selective fishing mortality cannot fully explain the observed trend in the sex ratio of megrim. Female megrim grow to a larger size, at a faster rate than males and it is likely that their differences in habitat preferences are related to this. Shallower waters are warmer during the growing season and are likely to provide better conditions for fast growth. An understanding of the mechanisms behind these patterns is an important consideration in the management and conservation of this fish stock, which might be particularly vulnerable because the commercial landings are to a large extent dominated by female megrim.

Sex differences in sensation-seeking: a meta-analysis.

PubMed

Cross, Catharine P; Cyrenne, De-Laine M; Brown, Gillian R

2013-01-01

Men score higher than women on measures of sensation-seeking, defined as a willingness to engage in novel or intense activities. This sex difference has been explained in terms of evolved psychological mechanisms or culturally transmitted social norms. We investigated whether sex differences in sensation-seeking have changed over recent years by conducting a meta-analysis of studies using Zuckerman's Sensation Seeking Scale, version V (SSS-V). We found that sex differences in total SSS-V scores have remained stable across years, as have sex differences in Disinhibition and Boredom Susceptibility. In contrast, the sex difference in Thrill and Adventure Seeking has declined, possibly due to changes in social norms or out-dated questions on this sub-scale. Our results support the view that men and women differ in their propensity to report sensation-seeking characteristics, while behavioural manifestations of sensation-seeking vary over time. Sex differences in sensation-seeking could reflect genetically influenced predispositions interacting with socially transmitted information.

Conscientiousness as a Mediator of the Association between Masculinized Finger-Length Ratios and Attention-Deficit Hyperactivity Disorder (ADHD)

ERIC Educational Resources Information Center

Martel, Michelle M.

2009-01-01

Background: One often-overlooked biological risk factor that may help explain sex-biased prevalence rates in psychopathology is sex hormones. Personality traits, which also show sex differences, may mediate relations between biological risk factors like hormones and childhood psychopathology such as ADHD (or, alternatively, be independent risk…

A prospective study of sex differences in the lifetime risk of posttraumatic stress disorder among abused and neglected children grown up.

PubMed

Koenen, Karestan C; Widom, Cathy Spatz

2009-12-01

In the general population, women's lifetime risk of developing posttraumatic stress disorder (PTSD) is twice that of men's. However, evidence is contradictory as to whether this sex difference is present among child abuse/neglect victims. The authors examined sex differences in PTSD among a sample of 674 individuals with documented child abuse/neglect histories assessed for PTSD in adulthood. Across all types of abuse/neglect, women were more than twice as likely to develop PTSD as men. The sex difference was greatest among sexual abuse victims. Female victims' greater revictimization explained a substantial proportion (39%) of the sex differences in PTSD risk. Future research should identify mechanisms that make female victims particularly vulnerable to revictimization and the development of PTSD.

Preadolescent Clues to Understanding Depression in Girls

PubMed Central

Keenan, Kate; Hipwell, Alison E.

2010-01-01

Between the ages of 10 and 15, increases in depression among girls result in a rate that is twice as high as the rate of depression in boys. This sex difference remains throughout early and middle adulthood. Prior to early adolescence, there is essentially no sex difference in the rate of depression. The aim of the present review is to examine whether the preadolescent period is a time during which precursors to depression in girls can be identified. First, existing areas of research on explaining sex differences in depression, including cognitive and affiliative style and the socialization of emotion, are reviewed. Second, the hypothesis that for some girls, preadolescent precursors to depression take the form of excessive empathy, compliance and regulation of negative emotions is articulated. Third, ways of building on existing models by including the proposed preadolescent precursors are proposed. Finally, approaches to testing the hypotheses that individual differences in these domains during preadolescence may explain later individual differences in adolescent onset depression are explored. PMID:15984082

The Role of Sex in Memory Function: Considerations and Recommendations in the Context of Exercise.

PubMed

Loprinzi, Paul D; Frith, Emily

2018-05-31

There is evidence to suggest that biological sex plays a critical role in memory function, with sex differentially influencing memory type. In this review, we detail the current evidence evaluating sex-specific effects on various memory types. We also discuss potential mechanisms that explain these sex-specific effects, which include sex differences in neuroanatomy, neurochemical differences, biological differences, and cognitive and affect-related differences. Central to this review, we also highlight that, despite the established sex differences in memory, there is little work directly comparing whether males and females have a differential exercise-induced effect on memory function. As discussed herein, such a differential effect is plausible given the clear sex-specific effects on memory, exercise response, and molecular mediators of memory. We emphasize that future work should be carefully powered to detect sex differences. Future research should also examine these potential exercise-related sex-specific effects for various memory types and exercise intensities and modalities. This will help enhance our understanding of whether sex indeed moderates the effects of exercise and memory function, and as such, will improve our understanding of whether sex-specific, memory-enhancing interventions should be developed, implemented, and evaluated.

Sex differences in the pharmacokinetics of antidepressants: influence of female sex hormones and oral contraceptives.

PubMed

Damoiseaux, Valérie A; Proost, Johannes H; Jiawan, Vincent C R; Melgert, Barbro N

2014-06-01

Women are twice as likely to develop depression as men. Moreover, the symptoms they experience also show sex differences: women tend to develop depression at an earlier age and show more severe symptoms than men. Likewise, the response to antidepressant pharmacotherapy appears to have sex differences. These differences can partially be explained by differences in pharmacokinetic properties (i.e., absorption, distribution, metabolism, and excretion) of drugs in males and females. More recent research has shown that sex hormones may influence all these previously named pharmacokinetic processes. As concentrations of sex hormones vary throughout the female lifespan, these hormonal variations can have effects on therapeutic responses to antidepressants as well as the occurrence of adverse events. The purpose of this paper is therefore to review the literature reporting on the effects of female sex hormones on the pharmacokinetics of antidepressants and to discuss and evaluate the implications of changes in levels of sex hormones throughout life for the treatment of depression.

Body composition explains sex differential in physical performance among older adults.

PubMed

Tseng, Lisa A; Delmonico, Matthew J; Visser, Marjolein; Boudreau, Robert M; Goodpaster, Bret H; Schwartz, Ann V; Simonsick, Eleanor M; Satterfield, Suzanne; Harris, Tamara; Newman, Anne B

2014-01-01

Older women have higher percent body fat, poorer physical function, lower strength, and higher rates of nonfatal chronic conditions than men. We sought to determine whether these differences explained physical performance differences between men and women. Physical performance was assessed in the Health, Aging and Body Composition study in 2,863 men and women aged 70-79 with a composite 0-4 point score consisting of chair stands, standing balance including one-leg stand, and 6-m usual and narrow walk tests. Total body composition was measured by dual x-ray absorptiometry, thigh composition by computed tomography, and knee extensor strength by isokinetic dynamometer. Analysis of covariance estimated least square mean performance scores for men and women. Men had higher performance scores than women (least square means: 2.33±0.02 vs 2.03±0.02, p < .0001), adjusted for race, study site, age, and height. Body composition measures (total body fat and thigh muscle area, muscle density, subcutaneous fat, and intermuscular fat) accounted for differences between men and women (least square means: 2.15±0.02 vs 2.17±0.02, p = .53). Higher strength in men partly explained the sex difference (least square means: 2.28±0.02 vs 2.12±0.02, p < .0001). Strength attenuated the association of thigh muscle mass with performance. Chronic health conditions did not explain the sex difference. In a well-functioning cohort, poorer physical function in women compared with men can be explained predominantly by their higher fat mass, but also by other body composition differences. The higher proportion of body fat in women may put them at significant biomechanical disadvantage for greater disability in old age.

Mapping QTL for Sex and Growth Traits in Salt-Tolerant Tilapia (Oreochromis spp. X O. mossambicus).

PubMed

Lin, Grace; Chua, Elaine; Orban, Laszlo; Yue, Gen Hua

2016-01-01

In aquaculture, growth and sex are economically important traits. To accelerate genetic improvement in increasing growth in salt-tolerant tilapia, we conducted QTL mapping for growth traits and sex with an F2 family, including 522 offspring and two parents. We used 144 polymorphic microsatellites evenly covering the genome of tilapia to genotype the family. QTL analyses were carried out using interval mapping for all individuals, males and females in the family, respectively. Using all individuals, three suggestive QTL for body weight, body length and body thickness respectively were detected in LG20, LG22 and LG12 and explained 2.4% to 3.1% of phenotypic variance (PV). When considering only males, five QTL for body weight were detected on five LGs, and explained 4.1 to 6.3% of PV. Using only females from the F2 family, three QTL for body weight were detected on LG1, LG6 and LG8, and explained 7.9-14.3% of PV. The QTL for body weight in males and females were located in different LGs, suggesting that in salt-tolerant tilapia, different set of genes 'switches' control the growth in males and females. QTL for sex were mapped on LG1 and LG22, indicating multigene sex determination in the salt-tolerant tilapia. This study provides new insights on the locations and effects of QTL for growth traits and sex, and sets the foundation for fine mapping for future marker-assisted selection for growth and sex in salt-tolerant tilapia aquaculture.

Mapping QTL for Sex and Growth Traits in Salt-Tolerant Tilapia (Oreochromis spp. X O. mossambicus)

PubMed Central

Lin, Grace; Chua, Elaine; Orban, Laszlo; Yue, Gen Hua

2016-01-01

In aquaculture, growth and sex are economically important traits. To accelerate genetic improvement in increasing growth in salt-tolerant tilapia, we conducted QTL mapping for growth traits and sex with an F2 family, including 522 offspring and two parents. We used 144 polymorphic microsatellites evenly covering the genome of tilapia to genotype the family. QTL analyses were carried out using interval mapping for all individuals, males and females in the family, respectively. Using all individuals, three suggestive QTL for body weight, body length and body thickness respectively were detected in LG20, LG22 and LG12 and explained 2.4% to 3.1% of phenotypic variance (PV). When considering only males, five QTL for body weight were detected on five LGs, and explained 4.1 to 6.3% of PV. Using only females from the F2 family, three QTL for body weight were detected on LG1, LG6 and LG8, and explained 7.9–14.3% of PV. The QTL for body weight in males and females were located in different LGs, suggesting that in salt-tolerant tilapia, different set of genes ‘switches’ control the growth in males and females. QTL for sex were mapped on LG1 and LG22, indicating multigene sex determination in the salt-tolerant tilapia. This study provides new insights on the locations and effects of QTL for growth traits and sex, and sets the foundation for fine mapping for future marker-assisted selection for growth and sex in salt-tolerant tilapia aquaculture. PMID:27870905

Sex, Intelligence and Educational Achievement in a National Cohort of over 175,000 11-Year-Old Schoolchildren in England

ERIC Educational Resources Information Center

Calvin, Catherine M.; Fernandes, Cres; Smith, Pauline; Visscher, Peter M.; Deary, Ian J.

2010-01-01

General cognitive ability ("g") does not explain sex differences in academic test performance by the end of compulsory education. Instead, individual differences in specific reasoning abilities, after removing the effects of "g," may contribute to the observed gender gaps. Associations between general or specific cognitive…

The Impact of Gender, Perceived Female Isolation and Beliefs in Traditional Roles for Women on Job Satisfaction.

ERIC Educational Resources Information Center

Barclay, Lizabeth A.; And Others

Past research has detailed conflicting results in investigations of sex differences and job satisfaction. To explain sex differences and job satisfaction within the framework of subtle treatment discrimination (a situation variable) and beliefs about roles for women (a person variable), 1578 employees of a large corporation completed demographic…

The new science of cognitive sex differences.

PubMed

Miller, David I; Halpern, Diane F

2014-01-01

Surprising new findings indicate that many conclusions about sex differences and similarities in cognitive abilities need to be reexamined. Cognitive sex differences are changing, decreasing for some tasks whereas remaining stable or increasing for other tasks. Some sex differences are detected in infancy, but the data are complex and depend on task characteristics. Diverse disciplines have revolutionized our understanding of why these differences exist. For instance, fraternal-twin studies align with earlier literature to help establish the role of prenatal androgens and large international datasets help explain how cultural factors such as economic prosperity and gender equity affect females and males differently. Understanding how biological and environmental factors interact could help maximize cognitive potential and address pressing societal issues. Copyright © 2013 Elsevier Ltd. All rights reserved.

Intra- Versus Intersex Aggression: Testing Theories of Sex Differences Using Aggression Networks.

PubMed

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.

Discriminant Analysis Between Four Different Self Measures and Sex-Role Identity with Junior Year College Students.

ERIC Educational Resources Information Center

Wallace, Gaylen R.; Goodwin-Adam, Sharon

A review of the literature concerning the relationship between sex role and self measure identity includes a discussion of issues confronted in measurement. The methodology and analyses of data for the study are explained. The research was designed to determine which self referent measure most effectively discriminates among sex role identities.…

Sex differences in visuospatial and navigational working memory: the role of mood induced by background music.

PubMed

Palmiero, Massimiliano; Nori, Raffaella; Rogolino, Carmelo; D'amico, Simonetta; Piccardi, Laura

2016-08-01

Sex differences in visuospatial abilities are long debated. Men generally outperform women, especially in wayfinding or learning a route or a sequence of places. These differences might depend on women's disadvantage in underlying spatial competences, such as mental rotation, and on the strategies used, as well as on emotions and on self-belief about navigational skills, not related to actual skill-levels. In the present study, sex differences in visuospatial and navigational working memory in emotional contexts were investigated. Participants' mood was manipulated by background music (positive, negative or neutral) while performing on the Corsi Block-tapping Task (CBT) and Walking Corsi (WalCT) test. In order to assess the effectiveness of mood manipulation, participants filled in the Positive and Negative Affect Schedule before and after carrying out the visuospatial tasks. Firstly, results showed that after mood induction, only the positive affect changed, whereas the negative affect remained unconfounded by mood and by sex. This finding is in line with the main effect of 'group' on all tests used: the positive music group scored significantly higher than other groups. Secondly, although men outperformed women in the CBT forward condition and in the WalCT forward and backward conditions, they scored higher than women only in the WalCT with the negative background music. This means that mood cannot fully explain sex differences in visuospatial and navigational working memory. Our results suggest that sex differences in the CBT and WalCT can be better explained by differences in spatial competences rather than by emotional contexts.

Sex selection: treating different cases differently.

PubMed

Dickens, B M; Serour, G I; Cook, R J; Qiu, R-Z

2005-08-01

This paper contrasts ethical approaches to sex selection in countries where discrimination against women is pervasive, resulting in selection against girl children, and in countries where there is less general discrimination and couples do not prefer children of either sex. National sex ratio imbalances where discrimination against women is common have resulted in laws and policies, such as in India and China, to deter and prevent sex selection. Birth ratios of children can be affected by techniques of prenatal sex determination and abortion, preconception sex selection and discarding disfavored embryos, and prefertilization sperm sorting, when disfavored sperm remain unused. Incentives for son preference are reviewed, and laws and policies to prevent sex selection are explained. The elimination of social, economic and other discrimination against women is urged to redress sex selection against girl children. Where there is no general selection against girl children, sex selection can be allowed to assist families that want children of both sexes.

Sex Chromosome Translocations in the Evolution of Reproductive Isolation

PubMed Central

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

Explaining sex differences in mental rotation: role of spatial activity experience.

PubMed

Nazareth, Alina; Herrera, Asiel; Pruden, Shannon M

2013-05-01

Males consistently outperform females on mental rotation tasks, such as the Vandenberg and Kuse (1978) Perceptual and Motor Skills, 47(2), 599-604, mental rotation test (MRT; e.g. Voyer et al. 1995) in Psychological Bulletin, 117, 250-265. The present study investigates whether these sex differences in MRT scores can be explained in part by early spatial activity experience, particularly those spatial activities that have been sex-typed as masculine/male-oriented. Utilizing an online survey, 571 ethnically diverse adult university students completed a brief demographic survey, an 81-item spatial activity survey, and the MRT. Results suggest that the significant relation between sex of the participant and MRT score is partially mediated by the number of masculine spatial activities participants had engaged in as youth. Closing the gap between males and females in spatial ability, a skill linked to science, technology, engineering, and mathematics success, may be accomplished in part by encouraging female youth to engage in more particular kinds of spatial activities.

Sex Differences and Sex Steroids in Lung Health and Disease

PubMed Central

Townsend, Elizabeth A.; Miller, Virginia M.

2012-01-01

Sex differences in the biology of different organ systems and the influence of sex hormones in modulating health and disease are increasingly relevant in clinical and research areas. Although work has focused on sex differences and sex hormones in cardiovascular, musculoskeletal, and neuronal systems, there is now increasing clinical evidence for sex differences in incidence, morbidity, and mortality of lung diseases including allergic diseases (such as asthma), chronic obstructive pulmonary disease, pulmonary fibrosis, lung cancer, as well as pulmonary hypertension. Whether such differences are inherent and/or whether sex steroids play a role in modulating these differences is currently under investigation. The purpose of this review is to define sex differences in lung structure/function under normal and specific disease states, with exploration of whether and how sex hormone signaling mechanisms may explain these clinical observations. Focusing on adult age groups, the review addresses the following: 1) inherent sex differences in lung anatomy and physiology; 2) the importance of certain time points in life such as puberty, pregnancy, menopause, and aging; 3) expression and signaling of sex steroid receptors under normal vs. disease states; 4) potential interplay between different sex steroids; 5) the question of whether sex steroids are beneficial or detrimental to the lung; and 6) the potential use of sex steroid signaling as biomarkers and therapeutic avenues in lung diseases. The importance of focusing on sex differences and sex steroids in the lung lies in the increasing incidence of lung diseases in women and the need to address lung diseases across the life span. PMID:22240244

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

PubMed Central

Huddy, Timothy F.; Ogawa-Okada, Maya; Adkins, Jamie L.

2018-01-01

Recent studies in mice have demonstrated a sexual dimorphism in circadian entrainment to scheduled feeding. On a time restricted diet, males tend to develop food anticipatory activity (FAA) sooner than females and with a higher amplitude of activity. The underlying cause of this sex difference remains unknown. One study suggests that sex hormones, both androgens and estrogens, modulate food anticipatory activity in mice. Here we present results suggesting that the sex difference in FAA is unrelated to gonadal sex hormones. While a sex difference between males and females in FAA on a timed, calorie restricted diet was observed there were no differences between intact and gonadectomized mice in the onset or magnitude of FAA. To test other sources of the sex difference in circadian entrainment to scheduled feeding, we used sex chromosome copy number mutants, but there was no difference in FAA when comparing XX, XY-, XY-;Sry Tg, and XX;Sry Tg mice, demonstrating that gene dosage of sex chromosomes does not mediate the sex difference in FAA. Next, we masculinized female mice by treating them with 17-beta estradiol during the neonatal period; yet again, we saw no difference in FAA between control and masculinized females. Finally, we observed that there was no longer a sex difference in FAA for older mice, suggesting that the sex difference in FAA is age-dependent. Thus, our study demonstrates that singular manipulations of gonadal hormones, sex chromosomes, or developmental patterning are not able to explain the difference in FAA between young male and female mice. PMID:29385171

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

PubMed

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

2018-01-01

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

Sex/Gender Differences in Cotinine Levels Among Daily Smokers in the Pennsylvania Adult Smoking Study.

PubMed

Chen, Allshine; Krebs, Nicolle M; Zhu, Junjia; Sun, Dongxiao; Stennett, Andrea; Muscat, Joshua E

2017-11-01

This study was conducted to determine sex/gender differences in smoke exposure and to quantify the role of potential predictors including puffing behaviors, nicotine dependence, and non-nicotinic factors. The Pennsylvania Adult Smoking Study (PASS) of 332 adult cigarette smokers utilized portable handheld topography devices to capture the smokers' profiles in a naturalistic environment. Sex/gender differences in salivary biomarkers were modeled using ANCOVA to account for measures of dependence (Fagerstrom Test for Nicotine Dependence, nicotine metabolite ratio [3-hydroxycotinine/cotinine]), and nondependence covariates including anthropomorphic factors and stress. The Blinder-Oaxaca method was used to decompose the sex/gender differences in nicotine uptake due to covariates. Men had significantly higher cotinine levels (313.5 ng/mL vs. 255.8 ng/mL, p < 0.01), cotinine +3-hydroxycotinine levels, (0.0787 mol/L vs. 0.0675 mol/L, p = 0.01), puff volumes (52.95 mL vs. 44.77 mL, p < 0.01), and a lower nicotine metabolite ratio (0.396 vs. 0.475, p = 0.01) than women. The mean Fagerström Test for Nicotine Dependence score did not differ between men and women (p = 0.24). Women had a higher mean Hooked on Tobacco Checklist score than men (7.64 vs. 6.87, p < 0.01). In multivariate analysis, nicotine metabolite levels were not significantly different by sex. Decomposition results show that ten predictors can explain 83% of the sex/gender differences in cotinine uptake. Height was the greatest contributor to these differences, followed by average puff volume. Conclusion and Impact: The higher levels of nicotine metabolites in men, compared to women, can be explained by height, weight, puff volume, and nicotine metabolism.

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

PubMed

Hausmann, Markus

2017-01-02

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

Genetic regulation of sex differences in songbirds and lizards.

PubMed

Wade, Juli

2016-02-19

Sex differences in the morphology of neural and peripheral structures related to reproduction often parallel the frequency of particular behaviours displayed by males and females. In a variety of model organisms, these sex differences are organized in development by gonadal steroids, which also act in adulthood to modulate behavioural expression and in some cases to generate parallel anatomical changes on a seasonal basis. Data collected from diverse species, however, suggest that changes in hormone availability are not sufficient to explain sex and seasonal differences in structure and function. This paper pulls together some of this literature from songbirds and lizards and considers the information in the broader context of taking a comparative approach to investigating genetic mechanisms associated with behavioural neuroendocrinology. © 2016 The Author(s).

Relevant Sex Appeals in Advertising: Gender and Commitment Context Differences

PubMed Central

Lanseng, Even J.

2016-01-01

This research investigates differences in men's and women's attitudes toward ads featuring product-relevant sex appeals. It is found that women, but not men, were more negative toward an ad featuring an attractive opposite-sex model when their commitment thoughts were heightened. Women were also more negative toward an ad with an attractive same-sex model in the presence of commitment thoughts, but only when they scored high on sociosexuality. Men appeared unaffected, regardless of their level of sociosexuality. Commitment thoughts were manipulated by two types of prime, a parenting prime (study1) and a romantic prime (study 2). Results are explained by differences in how men and women react to sexual material and by differences in men's and women's evolved mating preferences. PMID:27746749

Relevant Sex Appeals in Advertising: Gender and Commitment Context Differences.

PubMed

Lanseng, Even J

2016-01-01

This research investigates differences in men's and women's attitudes toward ads featuring product-relevant sex appeals. It is found that women, but not men, were more negative toward an ad featuring an attractive opposite-sex model when their commitment thoughts were heightened. Women were also more negative toward an ad with an attractive same-sex model in the presence of commitment thoughts, but only when they scored high on sociosexuality. Men appeared unaffected, regardless of their level of sociosexuality. Commitment thoughts were manipulated by two types of prime, a parenting prime (study1) and a romantic prime (study 2). Results are explained by differences in how men and women react to sexual material and by differences in men's and women's evolved mating preferences.

Genetic regulation of sex differences in songbirds and lizards

PubMed Central

Wade, Juli

2016-01-01

Sex differences in the morphology of neural and peripheral structures related to reproduction often parallel the frequency of particular behaviours displayed by males and females. In a variety of model organisms, these sex differences are organized in development by gonadal steroids, which also act in adulthood to modulate behavioural expression and in some cases to generate parallel anatomical changes on a seasonal basis. Data collected from diverse species, however, suggest that changes in hormone availability are not sufficient to explain sex and seasonal differences in structure and function. This paper pulls together some of this literature from songbirds and lizards and considers the information in the broader context of taking a comparative approach to investigating genetic mechanisms associated with behavioural neuroendocrinology. PMID:26833833

Size Matters: Cerebral Volume Influences Sex Differences in Neuroanatomy

PubMed Central

Towler, Stephen; Welcome, Suzanne; Halderman, Laura K.; Otto, Ron; Eckert, Mark A.; Chiarello, Christine

2008-01-01

Biological and behavioral differences between the sexes range from obvious to subtle or nonexistent. Neuroanatomical differences are particularly controversial, perhaps due to the implication that they might account for behavioral differences. In this sample of 200 men and women, large effect sizes (Cohen's d > 0.8) were found for sex differences in total cerebral gray and white matter, cerebellum, and gray matter proportion (women had a higher proportion of gray matter). The only one of these sex differences that survived adjustment for the effect of cerebral volume was gray matter proportion. Individual differences in cerebral volume accounted for 21% of the difference in gray matter proportion, while sex accounted for an additional 4%. The relative size of the corpus callosum was 5% larger in women, but this difference was completely explained by a negative relationship between relative callosal size and cerebral volume. In agreement with Jancke et al., individuals with higher cerebral volume tended to have smaller corpora callosa. There were few sex differences in the size of structures in Broca's and Wernicke's area. We conclude that individual differences in brain volume, in both men and women, account for apparent sex differences in relative size. PMID:18440950

Role of corticosteroid binding globulin in emotional reactivity sex differences in mice.

PubMed

Minni, A M; de Medeiros, G F; Helbling, J C; Duittoz, A; Marissal-Arvy, N; Foury, A; De Smedt-Peyrusse, V; Pallet, V; Moisan, M P

2014-12-01

Sex differences exist for stress reactivity as well as for the prevalence of depression, which is more frequent in women of reproductive age and often precipitated by stressful events. In animals, the differential effect of stress on male's and female's emotional behavior has been well documented. Crosstalk between the gonadal and stress hormones, in particular between estrogens and glucocorticoids, underlie these sex differences on stress vulnerability. We have previously shown that corticosteroid binding globulin (CBG) deficiency in a mouse model (Cbg k.o.) leads, in males, to an increased despair-like behavior caused by suboptimal corticosterone stress response. Because CBG displays a sexual dimorphism and is regulated by estrogens, we have now investigated whether it plays a role in the sex differences observed for emotional reactivity in mice. By analyzing Cbg k.o. and wild-type (WT) animals of both sexes, we detected sex differences in despair-like behavior in WT mice but not in Cbg k.o. animals. We showed through ovariectomy and estradiol (E2) replacement that E2 levels explain the sex differences found in WT animals. However, the manipulation of E2 levels did not affect the emotional behavior of Cbg k.o. females. As Cbg k.o. males, Cbg k.o. females have markedly reduced corticosterone levels across the circadian cycle and also after stress. Plasma free corticosterone levels in Cbg k.o. mice measured immediately after stress were blunted in both sexes compared to WT mice. A trend for higher mean levels of ACTH in Cbg k.o. mice was found for both sexes. The turnover of a corticosterone bolus was increased in Cbg k.o. Finally, the glucocorticoid-regulated immediate early gene early growth response 1 (Egr1) showed a blunted mRNA expression in the hippocampus of Cbg k.o. mutants while mineralocorticoid and glucocorticoid receptors presented sex differences but equivalent mRNA expression between genotypes. Thus, in our experimental conditions, sex differences for despair-like behavior in WT mice are explained by estrogens levels. Also, in both sexes, the presence of CBG is required to attain optimal glucocorticoid concentrations and normal emotional reactivity, although in females this is apparent only under low E2 concentrations. These findings suggest a complex interaction of CBG and E2 on emotional reactivity in females. Copyright © 2014 Elsevier Ltd. All rights reserved.

A father effect explains sex-ratio bias.

PubMed

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).

Sex differences in neonatal mortality in Sarlahi, Nepal: the role of biology and environment.

PubMed

Rosenstock, Summer; Katz, Joanne; Mullany, Luke C; Khatry, Subarna K; LeClerq, Steven C; Darmstadt, Gary L; Tielsch, James M

2013-12-01

Studies in South Asia have documented increased risk of neonatal mortality among girls, despite evidence of a biological survival advantage. Associations between gender preference and mortality are cited as reasons for excess mortality among girls. This has not, however, been tested in statistical models. A secondary analysis of data from a population-based randomised controlled trial of newborn infection prevention conducted in rural southern Nepal was used to estimate sex differences in early and late neonatal mortality, with girls as the reference group. The analysis investigated which underlying biological factors (immutable factors specific to the newborn or his/her mother) and environmental factors (mutable external factors) might explain observed sex differences in mortality. Neonatal mortality was comparable by sex (Ref=girls; OR 1.06, 95% CI 0.92 to 1.22). When stratified by neonatal period, boys were at 20% (OR 1.20, 95% CI 1.02% to 1.42%) greater risk of early and girls at 43% (OR 0.70, 95% CI 0.51% to 0.94%) greater risk of late neonatal mortality. Biological factors, primarily respiratory depression and unconsciousness at birth, explained excess early neonatal mortality among boys. Increased late neonatal mortality among girls was explained by a three-way environmental interaction between ethnicity, sex and prior sibling composition (categorised as primiparous newborns, infants born to families with prior living boys or boys and girls, and infants born to families with only prior living girls). Risk of neonatal mortality inverted between the early and late neonatal periods. Excess risk of early neonatal death among boys was consistent with biological expectations. Excess risk for late neonatal death among girls was not explained by overarching gender preference or preferential care-seeking for boys as hypothesised, but was driven by increased risk among Madeshi girls born to families with only prior girls.

Sex differences in attachment to spouses among older Japanese couples.

PubMed

Yokoyama, Katsunori; Shirakawa, Kazutoyo; Hirao, Tomohiro; Nakatsu, Morihito; Yoda, Takeshi; Suzuki, Hiromi; Okabe, Yugo; Shirakami, Gotaro

2017-05-01

Attachment among older adults can partially explain sex differences in bereavement outcomes, but there is currently little evidence regarding this. The aim was to quantify sex differences in the proportion of spouses as attachment figures among older couples. We carried out a secondary analysis of cross-sectional questionnaire survey data. The dataset included information about 5137 respondents aged 65 years or older in Kanonji and Mitoyo, two rural cities in Kagawa prefecture, Japan; those who were never married or were widowed or divorced were excluded. The questionnaire asked participants whom they most want to be close by when they die (this person was defined as an "attachment figure"), and compared the proportion of older people of each sex who named their spouse. We used multiple logistic regression analyses to examine the independent association of sex with the proportion of spouses as attachment figures. Of the 2513 male respondents, 1494 (59.5%) answered "spouse." Of the 2624 female respondents, 904 (34.5%) answered "spouse." Multiple logistic regression analyses adjusted for age, live-in children, annual income, participation in community activities, presence of a long-term primary care doctor, anxiety about death and preferences for place of death showed that men had a higher probability of attachment to spouses than women (odds ratio 2.83, 95% confidence interval 2.43-3.31). Spouses are more likely to be attachment figures for men than for women. The present study supports the theory that sex differences in attachment might partially explain the differences in the bereavement effect between sexes among older people. Geriatr Gerontol Int 2017; 17: 834-838. © 2016 Japan Geriatrics Society.

Targeted metabolomic profiling in rat tissues reveals sex differences.

PubMed

Ruoppolo, Margherita; Caterino, Marianna; Albano, Lucia; Pecce, Rita; Di Girolamo, Maria Grazia; Crisci, Daniela; Costanzo, Michele; Milella, Luigi; Franconi, Flavia; Campesi, Ilaria

2018-03-16

Sex differences affect several diseases and are organ-and parameter-specific. In humans and animals, sex differences also influence the metabolism and homeostasis of amino acids and fatty acids, which are linked to the onset of diseases. Thus, the use of targeted metabolite profiles in tissues represents a powerful approach to examine the intermediary metabolism and evidence for any sex differences. To clarify the sex-specific activities of liver, heart and kidney tissues, we used targeted metabolomics, linear discriminant analysis (LDA), principal component analysis (PCA), cluster analysis and linear correlation models to evaluate sex and organ-specific differences in amino acids, free carnitine and acylcarnitine levels in male and female Sprague-Dawley rats. Several intra-sex differences affect tissues, indicating that metabolite profiles in rat hearts, livers and kidneys are organ-dependent. Amino acids and carnitine levels in rat hearts, livers and kidneys are affected by sex: male and female hearts show the greatest sexual dimorphism, both qualitatively and quantitatively. Finally, multivariate analysis confirmed the influence of sex on the metabolomics profiling. Our data demonstrate that the metabolomics approach together with a multivariate approach can capture the dynamics of physiological and pathological states, which are essential for explaining the basis of the sex differences observed in physiological and pathological conditions.

Small Business Success in Rural Communities: Explaining the Sex Gap.

ERIC Educational Resources Information Center

Bird, Sharon R.; Sapp, Stephen G.; Lee, Motoko Y.

2001-01-01

Supporting a "structural relational" view of small business success, data from 423 small business owners in Iowa suggest that links between owner characteristics, social relational processes, business structure, and success operate differently depending on urban-rural location and owner sex. Female owners had more professional training…

A longitudinal analysis of sex differences in bone mineral accrual in healthy 8-19-year-old boys and girls.

PubMed

Baxter-Jones, A D G; Mirwald, R L; McKay, H A; Bailey, D A

2003-01-01

Although early in life there is little discernible difference in bone mass between boys and girls, at puberty sex differences are observed. It is uncertain if these differences represent differences in bone mass or just differences in anthropometric dimensions. The study aimed to identify whether sex independently affects bone mineral content (BMC) accrual in growing boys and girls. Three sites are investigated: total body (TB), femoral neck (FN) and lumbar spine (LS). 85 boys and 67 girls were assessed annually for seven consecutive years. BMC was assessed by dual energy X-ray absorptiometry (DXA). Biological age was defined as years from age at peak height velocity (PHV). Data were analysed using a hierarchical (random effects) modelling approach. When biological age, body size and body composition were controlled, boys had statistically significantly higher TB and FN BMC at all maturity levels (p < 0.05). No independent sex differences were found at the LS (p > 0.05). Although a statistical significant sex effect is observed, it is less than the error of the measurement, and thus sex difference are debatable. In general, sex difference are explained by anthropometric difference.

Stress and the Development of Cognitive Vulnerabilities to Depression Explain Sex Differences in Depressive Symptoms during Adolescence

PubMed Central

Hamilton, Jessica L.; Stange, Jonathan P.; Abramson, Lyn Y.; Alloy, Lauren B.

2014-01-01

Although cognitive vulnerabilities to depression have received considerable empirical support, little research has evaluated the differential development of cognitive vulnerabilities in adolescent girls and boys. The current study examined the role of stressful life events, as well as sex differences in reactivity and exposure to stress, in the development of negative cognitive style and rumination in a multi-wave study of 382 adolescents. Path analyses indicated that interpersonal dependent stress predicted higher prospective levels of negative cognitive styles and rumination. Additionally, girls’ greater exposure to interpersonal dependent stress explained their higher levels of rumination, which accounted for girls’ higher levels of depressive symptoms than boys. These findings suggest that interpersonal dependent stress is a significant risk factor for the formation of cognitive vulnerabilities to depression during adolescence, and that the sex difference in depressive symptoms may result from girls’ greater exposure to interpersonal dependent stress and ruminative response style than boys. PMID:26509106

Doing gender in sex and sex research.

PubMed

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.

Paraphilic Interests: An Examination of Sex Differences in a Nonclinical Sample.

PubMed

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.

Sex Ideologies in China: Examining Interprovince Differences.

PubMed

Hu, Yang

2016-01-01

In recent decades, premarital sex, extramarital sex, and homosexuality have become increasingly visible in China, leading scholars to claim that a national "sex revolution" is under way. However, China's internal sociocultural diversity calls this nation-level generalization into question. How do sex ideologies vary across China's distinct provinces? To what extent are interprovince variations in sex ideologies associated with distinct macrolevel social factors in China? In this research, data from the 2010 China General Social Survey and the 2011 Chinese Statistics Yearbook were analyzed using multilevel models to test four contending theories of interprovince differences in sex ideologies in China: modernization, Westernization, deindustrialization, and the "rice theory." The modernization theory was unsupported by the results, as socioeconomic development is not significantly associated with sex ideologies. Higher levels of deindustrialization and Westernization were associated with less traditional sex ideologies, but the strength of association varied across the domains of premarital sex, extramarital sex, and homosexuality. The rice theory was consistently supported, as the distinction between rice and wheat agriculture explained up to 30% of the province-level variance in sex ideologies. The findings underline the roles of both long-standing geographic differences and recent social changes in shaping China's ideational landscape of sex.

Sex-Specific Differences in the Association Between Childhood Adversity and Cardiovascular Disease in Adulthood: Evidence From a National Cohort Study.

PubMed

Garad, Yasmin; Maximova, Katerina; MacKinnon, Nathalie; McGrath, Jennifer J; Kozyrskyj, Anita L; Colman, Ian

2017-08-01

Childhood adversity increases the risk for cardiovascular disease (CVD) in adulthood. Previously proposed mechanisms suggest that the association is mediated by stress reactivity-known to be higher in women-and is aggravated by adult stress, but this has not yet been confirmed. Therefore, we investigated sex differences to better understand possible pathways from childhood adversity to CVD. The National Population Health Survey, a 15-year cohort study of Canadians aged 18-49 years at baseline was used. Logistic regression with interaction terms for sex and stressful life events was used to assess the risk of CVD after childhood adversity. In secondary analyses, we assessed mediation effects of depression, smoking, alcohol, exercise, and diet using the product of coefficient approach. Mediated moderation was subsequently used to explain sex-moderated effects. There was a strong association between childhood adversity and CVD (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.56-2.94) for 3+ childhood adversities. The association was stronger with increasing stressful events, and female patients with 3+ stressful events exhibited the highest risk of CVD (OR, 4.40; 95% CI, 1.98-9.75). No association was found in men. Depression, smoking, and poor diet partially mediated the relationship between childhood adversity and CVD (14%, 9%, and 9%, respectively), but differences in these behaviours did not fully explain the sex-specific differences in the mediated moderation analysis. The effect of childhood adverse events on CVD is heightened among women, particularly women with stressful adulthoods, and this difference is not mediated by depression, smoking, or poor diet. These findings have important implications for understanding sex differences in CVD risk. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Genetic Liability to Disability Pension in Women and Men: A Prospective Population-Based Twin Study

PubMed Central

Narusyte, Jurgita; Ropponen, Annina; Silventoinen, Karri; Alexanderson, Kristina; Kaprio, Jaakko; Samuelsson, Åsa; Svedberg, Pia

2011-01-01

Background Previous studies of risk factors for disability pension (DP) have mainly focused on psychosocial, or environmental, factors, while the relative importance of genetic effects has been less studied. Sex differences in biological mechanisms have not been investigated at all. Methods The study sample included 46,454 Swedish twins, consisting of 23,227 complete twin pairs, born 1928–1958, who were followed during 1993–2008. Data on DP, including diagnoses, were obtained from the National Social Insurance Agency. Within-pair similarity in liability to DP was assessed by calculating intraclass correlations. Genetic and environmental influences on liability to DP were estimated by applying discrete-time frailty modeling. Results During follow-up, 7,669 individuals were granted DP (18.8% women and 14.1% men). Intraclass correlations were generally higher in MZ pairs than DZ pairs, while DZ same-sexed pairs were more similar than opposite-sexed pairs. The best-fitting model indicated that genetic factors contributed 49% (95% CI: 39–59) to the variance in DP due to mental diagnoses, 35% (95% CI: 29–41) due to musculoskeletal diagnoses, and 27% (95% CI: 20–33) due to all other diagnoses. In both sexes, genetic effects common to all ages explained one-third, whereas age-specific factors almost two-thirds, of the total variance in liability to DP irrespective of diagnosis. Sex differences in liability to DP were indicated, in that partly different sets of genes were found to operate in women and men, even though the magnitude of genetic variance explained was equal for both sexes. Conclusions The findings of the study suggest that genetic effects are important for liability to DP due to different diagnoses. Moreover, genetic contributions to liability to DP tend to differ between women and men, even though the overall relative contribution of genetic influences does not differ by sex. Hence, the pathways leading to DP might differ between women and men. PMID:21850258

Differential Experience and Degree of Selection: A Comment on "Schooling and Sex Roles: The Case of GCE 'O' Level Mathematics."

ERIC Educational Resources Information Center

Cooper, Barry

1982-01-01

Presents an alternative hypothetical explanation of the results obtained in Sharma and Meighan's research. The study did not control for intelligence, social class, and other relevant variables which might explain the difference between the sexes in mathematical attainment in secondary schools. (AM)

Can variation in HIV/STD-related risk be explained by individual SES? Findings from female sex workers in a rural Chinese county

PubMed Central

Fang, Xiaoyi; Li, Xiaoming; Yang, Hongmei; Hong, Yan; Stanton, Bonita; Zhao, Ran; Dong, Baiqing; Liu, Wei; Zhou, Yuejiao; Liang, Shaoling

2007-01-01

Low socioeconomic status (SES) has been linked to HIV and sexually transmitted disease (STD) at a macro level because the majority of new cases of HIV infection in the world have been reported in underdeveloped or developing countries. However, empirical data on the relationship between individual SES and HIV/STD related risk have been mixed. Employing quantitative data from 454 female sex workers, this study was designed to examine the profile of the study sample in terms of their individual SES, HIV/STD-related sexual risk across work locations with different social, cultural and economic conditions; and examine the relationship between work location and HIV-related risk behaviors, controlling for individual SES. We have shown in the current study that both SES and HIV/STD-related risk behaviors significantly differed by work location. However, the difference in individual SES was not sufficient to explain the difference of HIV/STD-related risk across the work locations. The findings underscore the need for effective prevention intervention efforts targeting female sex workers in rural area. Based on the findings, we also suggest that HIV/STD intervention efforts among female sex workers should take the social and cultural contextual factors of their working environment (and sexual risks) into consideration. PMID:18350430

[Sex and gender: Two different scientific domains to be clarified].

PubMed

Fernández, Juan

2010-05-01

Nowadays, the word sex and its related terms (sexual differences, sexual roles and stereotypes), so common not long ago, seems to have been replaced by gender and its related terms (gender differences, gender roles and stereotypes). We can sometimes find both sex and gender sharing the same space in scientific articles, although referring to different domains. In this paper, I try to explain the need for a model that can integrate both of these complex domains of sex and gender, leading to two independent, although complementary, disciplines: Sexology and Genderology. In both cases, I start from a functional standpoint, which will give meaning to both disciplines' specificities, as it is meant to link contributions from different fields of knowledge. This approach can have consequences for research, education, the experience of women, men, and ambiguous individuals, and therapy.

Teacher Styles in Questioning and Explaining. Technical Report No. 39.

ERIC Educational Resources Information Center

Moore, Carol Ann

The primary purpose of this study was to identify and describe individual differences in teaching style (i.e., teachers' patterns of questioning and explaining) in a standardized teaching situation. The secondary purpose was to explore relationships between teaching behavior and other teacher characteristics: teaching experience; sex and selected…

Sex differences in health care consumption in Sweden: A register-based cross-sectional study.

PubMed

Osika Friberg, Ingrid; Krantz, Gunilla; Määttä, Sylvia; Järbrink, Krister

2016-05-01

Generally, health care consumption, especially primary care, is greater among women than men. The extent to which this sex difference is explained by reproduction and sex-specific morbidity is unclear. We examined age- and sex-specific health care service utilization and costs in the western region of Sweden. Data were retrieved from a regional health care database of information on total health care consumption in the population. Use of health care resources was divided into the following diagnosis categories: health care associated with reproduction; health care received for sex-specific morbidity; and health care provided for all other conditions. Total per capita cost for health care was 20% higher for women than for men. When adjusted for reproduction and sex-specific morbidity, the cost-difference decreased to 8%. The remaining cost-difference could be explained by women's substantially higher costs for mental and behavioral disorders and diseases of the musculoskeletal system. Women were more likely to receive more accessible, less expensive primary care, while men were more likely to receive specialist inpatient care. The substantially greater use of reproduction-associated care among women, which largely occurs within primary care, might make it easier to also seek health care for other reasons. Efforts to eliminate barriers that prevent men from investing in their health and seeking primary care could reduce future morbidity and costs for specialist care. More studies and appropriate actions are needed to determine why women are overrepresented in mental, behavioral and musculoskeletal disorders. © 2015 the Nordic Societies of Public Health.

Coevolution of parental investment and sexually selected traits drives sex-role divergence.

PubMed

Fromhage, Lutz; Jennions, Michael D

2016-08-18

Sex-role evolution theory attempts to explain the origin and direction of male-female differences. A fundamental question is why anisogamy, the difference in gamete size that defines the sexes, has repeatedly led to large differences in subsequent parental care. Here we construct models to confirm predictions that individuals benefit less from caring when they face stronger sexual selection and/or lower certainty of parentage. However, we overturn the widely cited claim that a negative feedback between the operational sex ratio and the opportunity cost of care selects for egalitarian sex roles. We further argue that our model does not predict any effect of the adult sex ratio (ASR) that is independent of the source of ASR variation. Finally, to increase realism and unify earlier models, we allow for coevolution between parental investment and investment in sexually selected traits. Our model confirms that small initial differences in parental investment tend to increase due to positive evolutionary feedback, formally supporting long-standing, but unsubstantiated, verbal arguments.

Coevolution of parental investment and sexually selected traits drives sex-role divergence

PubMed Central

Fromhage, Lutz; Jennions, Michael D.

2016-01-01

Sex-role evolution theory attempts to explain the origin and direction of male–female differences. A fundamental question is why anisogamy, the difference in gamete size that defines the sexes, has repeatedly led to large differences in subsequent parental care. Here we construct models to confirm predictions that individuals benefit less from caring when they face stronger sexual selection and/or lower certainty of parentage. However, we overturn the widely cited claim that a negative feedback between the operational sex ratio and the opportunity cost of care selects for egalitarian sex roles. We further argue that our model does not predict any effect of the adult sex ratio (ASR) that is independent of the source of ASR variation. Finally, to increase realism and unify earlier models, we allow for coevolution between parental investment and investment in sexually selected traits. Our model confirms that small initial differences in parental investment tend to increase due to positive evolutionary feedback, formally supporting long-standing, but unsubstantiated, verbal arguments. PMID:27535478

The influence of sex steroids on structural brain maturation in adolescence.

PubMed

Koolschijn, P Cédric M P; Peper, Jiska S; Crone, Eveline A

2014-01-01

Puberty reflects a period of hormonal changes, physical maturation and structural brain reorganization. However, little attention has been paid to what extent sex steroids and pituitary hormones are associated with the refinement of brain maturation across adolescent development. Here we used high-resolution structural MRI scans from 215 typically developing individuals between ages 8-25, to examine the association between cortical thickness, surface area and (sub)cortical brain volumes with luteinizing hormone, testosterone and estradiol, and pubertal stage based on self-reports. Our results indicate sex-specific differences in testosterone related influences on gray matter volumes of the anterior cingulate cortex after controlling for age effects. No significant associations between subcortical structures and sex hormones were found. Pubertal stage was not a stronger predictor than chronological age for brain anatomical differences. Our findings indicate that sex steroids are associated with cerebral gray matter morphology in a sex specific manner. These hormonal and morphological differences may explain in part differences in brain development between boys and girls.

Mechanisms of rapid sympatric speciation by sex reversal and sexual selection in cichlid fish.

PubMed

Lande, R; Seehausen, O; van Alphen, J J

2001-01-01

Mechanisms of speciation in cichlid fish were investigated by analyzing population genetic models of sexual selection on sex-determining genes associated with color polymorphisms. The models are based on a combination of laboratory experiments and field observations on the ecology, male and female mating behavior, and inheritance of sex-determination and color polymorphisms. The models explain why sex-reversal genes that change males into females tend to be X-linked and associated with novel colors, using the hypothesis of restricted recombination on the sex chromosomes, as suggested by previous theory on the evolution of recombination. The models reveal multiple pathways for rapid sympatric speciation through the origin of novel color morphs with strong assortative mating that incorporate both sex-reversal and suppressor genes. Despite the lack of geographic isolation or ecological differentiation, the new species coexists with the ancestral species either temporarily or indefinitely. These results may help to explain different patterns and rates of speciation among groups of cichlids, in particular the explosive diversification of rock-dwelling haplochromine cichlids.

Sex differences in parental care: Gametic investment, sexual selection, and social environment.

PubMed

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

2015-11-01

Male and female parents often provide different type and amount of care to their offspring. Three major drivers have been proposed to explain parental sex roles: (1) differential gametic investment by males and females that precipitates into sex difference in care, (2) different intensity of sexual selection acting on males and females, and (3) biased social environment that facilitates the more common sex to provide more care. Here, we provide the most comprehensive assessment of these hypotheses using detailed parental care data from 792 bird species covering 126 families. We found no evidence for the gametic investment hypothesis: neither gamete sizes nor gamete production by males relative to females was related to sex difference in parental care. However, sexual selection correlated with parental sex roles, because the male share in care relative to female decreased with both extra-pair paternity and frequency of male polygamy. Parental sex roles were also related to social environment, because male parental care increased with male-biased adult sex ratios (ASRs). Taken together, our results are consistent with recent theories suggesting that gametic investment is not tied to parental sex roles, and highlight the importance of both sexual selection and ASR in influencing parental sex roles. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Explaining the Relationship Between Sexually Explicit Internet Material and Casual Sex: A Two-Step Mediation Model.

PubMed

Vandenbosch, Laura; van Oosten, Johanna M F

2018-07-01

Despite increasing interest in the implications of adolescents' use of sexually explicit Internet material (SEIM), we still know little about the relationship between SEIM use and adolescents' casual sexual activities. Based on a three-wave online panel survey study among Dutch adolescents (N = 1079; 53.1% boys; 93.5% with an exclusively heterosexual orientation; M age  = 15.11; SD = 1.39), we found that watching SEIM predicted engagement in casual sex over time. In turn, casual sexual activities partially predicted adolescents' use of SEIM. A two-step mediation model was tested to explain the relationship between watching SEIM and casual sex. It was partially confirmed. First, watching SEIM predicted adolescents' perceptions of SEIM as a relevant information source from Wave 2 to Wave 3, but not from Wave 1 to Wave 2. Next, such perceived utility of SEIM was positively related to stronger instrumental attitudes toward sex and thus their views about sex as a core instrument for sexual gratification. Lastly, adolescents' instrumental attitudes toward sex predicted adolescents' engagement in casual sex activities consistently across waves. Partial support emerged for a reciprocal relationship between watching SEIM and perceived utility. We did not find a reverse relationship between casual sex activities and instrumental attitudes toward sex. No significant gender differences emerged.

Sex Differences in Type-2 Diabetes: Implications for Cardiovascular Risk Management.

PubMed

Raparelli, Valeria; Morano, Susanna; Franconi, Flavia; Lenzi, Andrea; Basili, Stefania

2017-01-01

Among individuals with Type 2 diabetes (T2DM), cardiovascular disease (CVD) is the leading cause of morbidity and mortality. Sex and gender differences (SGDs) in the cardiovascular consequences of T2DM are relevant suggesting the need for a more aggressive CVD preventive strategy in diabetic women as they lose the so-called &quot;female advantage&quot; in terms of CVD risk comparing with the nondiabetic population. Multiple factors may explain the disproportion in CVD risk among women with diabetes comparing with diabetic men or non-diabetic women. Both genetic and hormonal factors only partially explain SGDs in CVD risk in diabetes. However, women likely reach diagnosis later and in worse conditions, they undergo both diagnostic and therapeutic supports in lower percentage and, finally, they are not able to obtain therapeutic goals recommended by guidelines. Concerning the cardiovascular system, diabetes amplifies the extent of damage at both micro- and macrovascular level differently among sexes. The aim of this review is to clarify, in a sex and gender perspective, the impact of diabetes in CVD risk and to summarize the most important SGDs in CVD primary and secondary prevention strategies such as antiplatelet drugs and statins. The efficacy of ASA and/or statins in secondary prevention is documented in both sexes independently by the presence of T2DM. A different approach to CVD primary prevention with ASA using the age cut-off to discriminate sex differences has been recommended. The use of statins for primary prevention in women should be accurately monitored for the occurrence of myalgia and risk of developing diabetes. A gender approach in CVD prevention strategies is urgently required to achieve a sensible reduction of adverse CV events. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Sexually selected sex differences in competitiveness explain sex differences in changes in drinking game participation.

PubMed

Hone, Liana S E; McCullough, Michael

2015-05-14

Drinking games are a risk factor for behavioral and health problems among university students. Previous cross-sectional research by Hone, Carter, and McCullough (2013) replicated well-established sex differences in drinking game behaviors (i.e., that men are more active drinking game participants than are women) and university drinking problems more generally. Hone et al. (2013) also found that these male-specific behavioral patterns are attributable in part to the fact that men's generally unrestricted sexual strategies, plus their social competitiveness, motivate them to participate in drinking games to display their fortitude and compete with same-sex rivals. Here, the authors conducted a study to evaluate with greater causal rigor whether sex differences in sexual restrictedness and social competitiveness-and sex differences in motivations for participating in drinking games in particular-are partially responsible for the sex differences in university students' drinking game behaviors and drinking problems. Sex differences in changes in frequency of drinking game participation were partially mediated by competitive motivations for participating in drinking games and by the effects of social competitiveness on competitive drinking game motivation. These findings lend additional support to the proposition that participation in drinking games is motivated in part by their suitability as a venue for sexual competition in university students' day-to-day lives.

Territory Quality and Plumage Morph Predict Offspring Sex Ratio Variation in a Raptor

PubMed Central

Chakarov, Nayden; Pauli, Martina; Mueller, Anna-Katharina; Potiek, Astrid; Grünkorn, Thomas; Dijkstra, Cor; Krüger, Oliver

2015-01-01

Parents may adapt their offspring sex ratio in response to their own phenotype and environmental conditions. The most significant causes for adaptive sex-ratio variation might express themselves as different distributions of fitness components between sexes along a given variable. Several causes for differential sex allocation in raptors with reversed sexual size dimorphism have been suggested. We search for correlates of fledgling sex in an extensive dataset on common buzzards Buteo buteo, a long-lived bird of prey. Larger female offspring could be more resource-demanding and starvation-prone and thus the costly sex. Prominent factors such as brood size and laying date did not predict nestling sex. Nonetheless, lifetime sex ratio (LSR, potentially indicative of individual sex allocation constraints) and overall nestling sex were explained by territory quality with more females being produced in better territories. Additionally, parental plumage morphs and the interaction of morph and prey abundance tended to explain LSR and nestling sex, indicating local adaptation of sex allocation However, in a limited census of nestling mortality, not females but males tended to die more frequently in prey-rich years. Also, although females could have potentially longer reproductive careers, a subset of our data encompassing full individual life histories showed that longevity and lifetime reproductive success were similarly distributed between the sexes. Thus, a basis for adaptive sex allocation in this population remains elusive. Overall, in common buzzards most major determinants of reproductive success appeared to have no effect on sex ratio but sex allocation may be adapted to local conditions in morph-specific patterns. PMID:26445010

Sex differences in life span: Females homozygous for the X chromosome do not suffer the shorter life span predicted by the unguarded X hypothesis.

PubMed

Brengdahl, Martin; Kimber, Christopher M; Maguire-Baxter, Jack; Friberg, Urban

2018-03-01

Life span differs between the sexes in many species. Three hypotheses to explain this interesting pattern have been proposed, involving different drivers: sexual selection, asymmetrical inheritance of cytoplasmic genomes, and hemizygosity of the X(Z) chromosome (the unguarded X hypothesis). Of these, the unguarded X has received the least experimental attention. This hypothesis suggests that the heterogametic sex suffers a shortened life span because recessive deleterious alleles on its single X(Z) chromosome are expressed unconditionally. In Drosophila melanogaster, the X chromosome is unusually large (∼20% of the genome), providing a powerful model for evaluating theories involving the X. Here, we test the unguarded X hypothesis by forcing D. melanogaster females from a laboratory population to express recessive X-linked alleles to the same degree as males, using females exclusively made homozygous for the X chromosome. We find no evidence for reduced life span or egg-to-adult viability due to X homozygozity. In contrast, males and females homozygous for an autosome both suffer similar, significant reductions in those traits. The logic of the unguarded X hypothesis is indisputable, but our results suggest that the degree to which recessive deleterious X-linked alleles depress performance in the heterogametic sex appears too small to explain general sex differences in life span. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

The many costs of sex.

PubMed

Lehtonen, Jussi; Jennions, Michael D; Kokko, Hanna

2012-03-01

Explaining the evolution of sex is challenging for biologists. A 'twofold cost' compared with asexual reproduction is often quoted. If a cost of this magnitude exists, the benefits of sex must be large for it to have evolved and be maintained. Focusing on benefits can be misleading, as this sidelines important questions about the cost of sex: what is the source of the twofold cost: males, genome dilution or both? Does the cost deviate from twofold? What other factors make sex costly? How should the costs of sex be empirically measured? The total cost of sex and how it varies in different contexts must be known to determine the benefits needed to account for the origin and maintenance of sex. Copyright © 2011 Elsevier Ltd. All rights reserved.

Sex-role attitudes across two cultures: United States and India.

PubMed

Rao, V V; Rao, V N

1985-12-01

This study tests whether students from India hold more traditional sex role attitudes compared to students from the US, whether women from either country hold more liberal sex role attitudes than males, and whether socioeconomic and demographic factors are better predictors of sex role attitudes among women of either culture. Data were obtained in 1978 from a sample of 409 undergraduate students from three Mississippi colleges in the US and 419 undergraduate and graduate students from three educational institutions in Andhra Pradesh, India. Sex role attitudes are measured by scaling developed by Scanzoni (1975). Out of a total possible score of 100, the mean values are 69.09 for the US sample and 53.62 for the Indian sample. Differences between the means for all 20 sex role attitudes are statistically significant. Results indicate that US females and Indian females had less traditional sex role attitudes than their respective counterparts. Mother role, wife role, father role, and total sex role attitude were more traditional among males in India compared to males in the US and among females in India compared to females in the US. More traditional attitudes were held by males in India with lower educated fathers and unemployed mothers. Religion was the only variable significantly related to Indian female students. In the US, traditional sex role attitudes of males were significantly related to high maternal income and residence in urban areas. More traditional sex role attitudes among US females were related to increasing age and marital status. Stepwise analysis reveals that the most powerful explanatory factors were sex and mother's occupation among Indian students and sex, father's income, and year in college among US students. What little variance was explained was explained by more variables in the US sample, and the best model predictors explained more variance in the US sample.

The Right Ventricle Explains Sex Differences in Survival in Idiopathic Pulmonary Arterial Hypertension

PubMed Central

Jacobs, Wouter; van de Veerdonk, Mariëlle C.; Trip, Pia; de Man, Frances; Heymans, Martijn W.; Marcus, Johannes T.; Kawut, Steven M.; Bogaard, Harm-Jan; Boonstra, Anco

2014-01-01

Background: Male sex is an independent predictor of worse survival in pulmonary arterial hypertension (PAH). This finding might be explained by more severe pulmonary vascular disease, worse right ventricular (RV) function, or different response to therapy. The aim of this study was to investigate the underlying cause of sex differences in survival in patients treated for PAH. Methods: This was a retrospective cohort study of 101 patients with PAH (82 idiopathic, 15 heritable, four anorexigen associated) who were diagnosed at VU University Medical Centre between February 1999 and January 2011 and underwent right-sided heart catheterization and cardiac MRI to assess RV function. Change in pulmonary vascular resistance (PVR) was taken as a measure of treatment response in the pulmonary vasculature, whereas change in RV ejection fraction (RVEF) was used to assess RV response to therapy. Results: PVR and RVEF were comparable between men and women at baseline; however, male patients had a worse transplant-free survival compared with female patients (P = .002). Although male and female patients showed a similar reduction in PVR after 1 year, RVEF improved in female patients, whereas it deteriorated in male patients. In a mediator analysis, after correcting for confounders, 39.0% of the difference in transplant-free survival between men and women was mediated through changes in RVEF after initiating PAH medical therapies. Conclusions: This study suggests that differences in RVEF response with initiation of medical therapy in idiopathic PAH explain a significant portion of the worse survival seen in men. PMID:24306900

Refined genetic maps reveal sexual dimorphism in human meiotic recombination at multiple scales

NASA Astrophysics Data System (ADS)

Bhérer, Claude; Campbell, Christopher L.; Auton, Adam

2017-04-01

In humans, males have lower recombination rates than females over the majority of the genome, but the opposite is usually true near the telomeres. These broad-scale differences have been known for decades, yet little is known about differences at the fine scale. By combining data sets, we have collected recombination events from over 100,000 meioses and have constructed sex-specific genetic maps at a previously unachievable resolution. Here we show that, although a substantial fraction of the genome shows some degree of sexually dimorphic recombination, the vast majority of hotspots are shared between the sexes, with only a small number of putative sex-specific hotspots. Wavelet analysis indicates that most of the differences can be attributed to the fine scale, and that variation in rate between the sexes can mostly be explained by differences in hotspot magnitude, rather than location. Nonetheless, known recombination-associated genomic features, such as THE1B repeat elements, show systematic differences between the sexes.

Female disability disadvantage: a global perspective on sex differences in physical function and disability.

PubMed

Wheaton, Felicia V; Crimmins, Eileen M

2016-07-01

The objectives were to determine whether women always fare more poorly in terms of physical function and disability across countries that vary widely in terms of their level of development, epidemiologic context and level of gender equality. Sex differences in self-reported and objective measures of disability and physical function were compared among older adults aged 55-85 in the United States of America, Taiwan, Korea, Mexico, China, Indonesia and among the Tsimane of Bolivia using population-based studies collected between 2001 and 2011. Data were analysed using logistic and ordinary least-squares regression. Confidence intervals were examined to see whether the effect of being female differed significantly between countries. In all countries, women had consistently worse physical functioning (both self-reported and objectively measured). Women also tended to report more difficulty with activities of daily living (ADL), although differences were not always significant. In general, sex differences across measures were less pronounced in China. In Korea, women had significantly lower grip strength, but sex differences in ADL difficulty were non-significant or even reversed. Education and marital status helped explain sex differences. Overall, there was striking similarity in the magnitude and direction of sex differences across countries despite considerable differences in context, although modest variations in the effect of sex were observed.

Sex Differences in Anxiety Disorders: Interactions between Fear, Stress, and Gonadal Hormones

PubMed Central

Maeng, Lisa Y.; Milad, Mohammed R.

2015-01-01

Women are more vulnerable to stress- and fear-based disorders, such as anxiety and post-traumatic stress disorder. Despite the growing literature on this topic, the neural basis of these sex differences remains unclear, and the findings appear inconsistent. The neurobiological mechanisms of fear and stress in learning and memory processes have been extensively studied, and the crosstalk between these systems is beginning to explain the disproportionate incidence and differences in symptomatology and remission within these psychopathologies. In this review, we discuss the intersect between stress and fear mechanisms and their modulation by gonadal hormones and discuss the relevance of this information to sex differences in anxiety and fear-based disorders. Understanding these converging influences is imperative to the development of more effective, individualized treatments that take sex and hormones into account. PMID:25888456

Mate retention behavior of men and women in heterosexual and homosexual relationships.

PubMed

Vanderlaan, Doug P; Vasey, Paul L

2008-08-01

Comparing the behavior of heterosexual and homosexual persons can provide insight into the origins of heterosexual sex differences in psychology. Evidence indicates that, aside from sexual partner preference, the mating psychology of homosexual men is sex-typical whereas that of homosexual women tends to be more sex-atypical. The current study examined one aspect of mating psychology, mate retention behavior, and tested whether homosexual men and women were sex-typical or sex-atypical for those mate retention tactics where heterosexual men and women differed. Men and women in heterosexual and homosexual relationships were asked to provide information regarding their partners' mate retention behavior by using the Mate Retention Inventory Questionnaire. Heterosexual men and women differed significantly for six of the 19 mate retention tactics considered. With respect to the six mate retention tactics where heterosexual sex differences existed, homosexual men behaved in a sex-typical manner for five of the tactics, whereas homosexual women behaved in a sex-atypical manner for all six tactics. We discuss the significance of these findings for explaining the origins of the mate retention behavior of heterosexual men and women. In addition, we consider what the pattern of sex-typical and sex-atypical mating psychology among homosexual men and women, respectively, suggests in regard to sex differences in the development of mating psychology and the development of homosexual persons.

Mechanisms of gender-linked ischemic brain injury

PubMed Central

Liu, Mingyue; Dziennis, Suzan; Hurn, Patricia D.; Alkayed, Nabil J.

2010-01-01

Biological sex is an important determinant of stroke risk and outcome. Women are protected from cerebrovascular disease relative to men, an observation commonly attributed to the protective effect of female sex hormones, estrogen and progesterone. However, sex differences in brain injury persist well beyond the menopause and can be found in the pediatric population, suggesting that the effects of reproductive steroids may not completely explain sexual dimorphism in stroke. We review recent advances in our understanding of sex steroids (estradiol, progesterone and testosterone) in the context of ischemic cell death and neuroprotection. Understanding the molecular and cell-based mechanisms underlying sex differences in ischemic brain injury will lead to a better understanding of basic mechanisms of brain cell death and is an important step toward designing more effective therapeutic interventions in stroke. PMID:19531872

Explaining the sex difference in depression with a unified bargaining model of anger and depression

PubMed Central

Hagen, Edward H.; Rosenström, Tom

2016-01-01

Background: Women are twice as likely as men to be depressed, a bias that is poorly understood. One evolutionary model proposes that depression is a bargaining strategy to compel reluctant social partners to provide more help in the wake of adversity. An evolutionary model of anger proposes that high upper body strength predisposes individuals to angrily threaten social partners who offer too few benefits or impose too many costs. Here, we propose that when social partners provide too few benefits or impose too many costs, the physically strong become overtly angry and the physically weak become depressed. The sexual dimorphism in upper body strength means that men will be more likely to bargain with anger and physical threats and women with depression. Methodology: We tested this idea using the 2011–12 National Health and Nutrition Examination Survey (NHANES), a large nationally representative sample of US households that included measures of depression and upper body strength. Results: A 2 SD increase in grip strength decreased the odds of depression by more than half (OR=0.4, P=0.0079), which did not appear to be a consequence of confounds with anthropometric, hormonal or socioeconomic variables, but was partially explained by a confound with physical disability. Nevertheless, upper body strength mediated 63% of the effect of sex on depression, but the mediation effect was unexpectedly moderated by age. Conclusions: Low upper body strength is a risk factor for depression, especially in older adults, and the sex difference in body strength appears to explain much of the perplexing sex difference in depression. PMID:26884416

Influence of Sex on Gestational Complications, Fetal-to-Neonatal Transition, and Postnatal Adaptation.

PubMed

Lorente-Pozo, Sheila; Parra-Llorca, Anna; Torres, Begoña; Torres-Cuevas, Isabel; Nuñez-Ramiro, Antonio; Cernada, María; García-Robles, Ana; Vento, Maximo

2018-01-01

Fetal sex is associated with striking differences during in utero development, fetal-to-neonatal transition, and postnatal morbidity and mortality. Male sex fetuses are apparently protected while in utero resulting in a higher secondary sex rate for males than for females. However, during fetal-to-neonatal transition and thereafter in the newborn period, female exhibits a greater degree of maturation that translates into a better capacity to stabilize, less incidence of prematurity and prematurity-associated morbidities, and better long-term outcomes. The present review addresses the influence of sex during gestation and postnatal adaptation that includes the establishment of an adult-type circulation, the initiation of breathing, endurance when confronted with perinatal hypoxia ischemia, and a gender-related different response to drugs. The intrinsic mechanisms explaining these differences in the perinatal period remain elusive and further experimental and clinical research are therefore stringently needed if an individual oriented therapy is to be developed.

Testing Stereotype Threat: Does Anxiety Explain Race and Sex Differences in Achievement?

ERIC Educational Resources Information Center

Osborne, Jason W.

The stereotype threat theory of C. Steele (1992, 1997) attempts to explain the underperformance of minority students in academic domains and of women in mathematics. Steele asserts that situational self-relevance of negative group stereotypes in testing situations increases the anxiety these students experience, and that these differential anxiety…

Towards a New Theory of Gender Inequities in Labour Market Outcomes of Education.

ERIC Educational Resources Information Center

Quinlan, Liz

Attempts to explain sex-related wage differentials generally rely on the human capital and segmentation labor market theories. The human capital theory explains individuals' position in the labor market primarily in terms of factors determining their productivity, whereas segmentation theory focuses on differences among jobs as determinants of the…

Built Environment Influences of Children's Physical Activity: Examining Differences by Neighbourhood Size and Sex.

PubMed

Mitchell, Christine A; Clark, Andrew F; Gilliland, Jason A

2016-01-15

Neighbourhoods can facilitate or constrain moderate-to-vigorous physical activity (MVPA) among children by providing or restricting opportunities for MVPA. However, there is no consensus on how to define a child's neighbourhood. This study examines the influence of the neighbourhood built environment on objectively measured MVPA among 435 children (aged 9-14 years) in London (ON, Canada). As there is no consensus on how to delineate a child's neighbourhood, a geographic information system was used to generate measures of the neighbourhood built environment at two buffer sizes (500 m and 800 m) around each child's home. Linear regression models with robust standard errors (cluster) were used to analyze the relationship between built environment characteristics and average daily MVPA during non-school hours on weekdays. Sex-stratified models assessed sex-specific relationships. When accounting for individual and neighbourhood socio-demographic variables, park space and multi-use path space were found to influence children's MVPA. Sex-stratified models found significant associations between MVPA and park space, with the 800 m buffer best explaining boys' MVPA and the 500 m buffer best explaining girls' MVPA. Findings emphasize that, when designing built environments, programs, and policies to facilitate physical activity, it is important to consider that the size of the neighbourhood influencing a child's physical activity may differ according to sex.

Sex-Related Effects in the Superhydrophobic Properties of Damselfly Wings in Young and Old Calopteryx splendens

PubMed Central

Kuitunen, Katja; Kovalev, Alexander; Gorb, Stanislav N.

2014-01-01

Numerous sex-related morphological adaptations are connected to reproductive behavior in animals. For example, females of some insect species can submerge during oviposition, which may lead to sex-related adaptations in the hydrophobicity (water-repellency) due to specialization of certain morphological structures. On the other hand, ageing can cause changes in hydrophobicity of the surface, because the morphological structures can wear with age. Here, we investigated sex-and age-related differences in wing hydrophobicity and in morphology (spine density, wax cover characteristics, size of females' pseudopterostigma) potentially related to hydrophobicity of Calopteryx splendens damselflies. Hydrophobicity was measured with two methods, by measuring the contact angle (CA) between a wing and water droplet, and by dipping a wing into water and measuring forces needed to submerge, withdraw, and pull-out a wing from water. We found that C. splendens wings are superhydrophobic, having mean CAs of 161°. The only sex and age related difference in the hydrophobicity measurements was that young females had stronger amplitude of force fluctuations during withdrawal of wings from water than young males. This suggests that young females may form less uniform air pockets on their wings while submerged. From the morphological structures measured here, the only sex related finding was that old females had denser spine cover than young females in their wing veins. The difference may be explained by better survival of females with denser spine cover. The most important morphological character that predicted superhydrophobicity was the prevalence of long wax rods on wing veins. In addition, female pseudopterostigma area (a trait present only in females) was negatively related to pull-out force, suggesting that large pseudopterostigmas might help females to emerge from water following oviposition. The subtle sex-related differences in hydrophobicity could be explained by the fact that both sexes must resist rain, and males are occasionally in contact with water. PMID:24520406

An examination of the factors related to dating violence perpetration among young men and women and associated theoretical explanations: a review of the literature.

PubMed

Dardis, Christina M; Dixon, Kristiana J; Edwards, Katie M; Turchik, Jessica A

2015-04-01

This article provides a review of the literature on dating violence (DV) perpetration, specifically sex similarities and differences in the correlates and predictors of DV perpetration and the utility of current theories to explain young men's and women's DV perpetration. Overall, many of the correlates and predictors of DV perpetration are similar among young men and women (e.g., witnessing interparental violence, experiencing child abuse, alcohol abuse, traditional gender roles, relationship power dynamics). However, young women's perpetration of DV is more strongly related to internalizing symptoms (e.g., depression), trait anger and hostility, and experiencing DV victimization than young men's perpetration, whereas young men's perpetration of DV is more consistently related to lower socioeconomic status and educational attainment, antisocial personality characteristics, and increased relationship length than young women's perpetration. Each theory offers insights into but does not fully account for the correlates and predictors of DV perpetration. Sociocultural theories may be useful in explaining the use of coercive control in relationships, and learning/intergenerational transmission of violence theories may be useful in explaining bidirectional couple violence. Future research should focus on integrative theories, such as in the social-ecological theory, in order to explain various forms of DV. Our understanding of young men's and young women's DV perpetration is limited by cross-sectional research designs, methodological inconsistencies, a lack of sex-specific analytic approaches, and a lack of focus on contextual factors; more multivariate and longitudinal studies are needed. Further, as DV prevention programming is often presented in mixed-sex formats, a critical understanding of sex differences and similarities in DV perpetration could ultimately refine and improve effectiveness of programming efforts aimed at reducing DV. © The Author(s) 2014.

Geographical and Temporal Body Size Variation in a Reptile: Roles of Sex, Ecology, Phylogeny and Ecology Structured in Phylogeny

PubMed Central

Aragón, Pedro; Fitze, Patrick S.

2014-01-01

Geographical body size variation has long interested evolutionary biologists, and a range of mechanisms have been proposed to explain the observed patterns. It is considered to be more puzzling in ectotherms than in endotherms, and integrative approaches are necessary for testing non-exclusive alternative mechanisms. Using lacertid lizards as a model, we adopted an integrative approach, testing different hypotheses for both sexes while incorporating temporal, spatial, and phylogenetic autocorrelation at the individual level. We used data on the Spanish Sand Racer species group from a field survey to disentangle different sources of body size variation through environmental and individual genetic data, while accounting for temporal and spatial autocorrelation. A variation partitioning method was applied to separate independent and shared components of ecology and phylogeny, and estimated their significance. Then, we fed-back our models by controlling for relevant independent components. The pattern was consistent with the geographical Bergmann's cline and the experimental temperature-size rule: adults were larger at lower temperatures (and/or higher elevations). This result was confirmed with additional multi-year independent data-set derived from the literature. Variation partitioning showed no sex differences in phylogenetic inertia but showed sex differences in the independent component of ecology; primarily due to growth differences. Interestingly, only after controlling for independent components did primary productivity also emerge as an important predictor explaining size variation in both sexes. This study highlights the importance of integrating individual-based genetic information, relevant ecological parameters, and temporal and spatial autocorrelation in sex-specific models to detect potentially important hidden effects. Our individual-based approach devoted to extract and control for independent components was useful to reveal hidden effects linked with alternative non-exclusive hypothesis, such as those of primary productivity. Also, including measurement date allowed disentangling and controlling for short-term temporal autocorrelation reflecting sex-specific growth plasticity. PMID:25090025

DIFFERENCES IN IMMUNE RESPONSE MAY EXPLAIN LOWER SURVIVAL AMONG OLDER MEN WITH PNEUMONIA

PubMed Central

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

Sex differences in the neural substrates of spatial working memory during adolescence are not mediated by endogenous testosterone

PubMed Central

Alarcón, Gabriela; Cservenka, Anita; Fair, Damien A.; Nagel, Bonnie J.

2014-01-01

Adolescence is a developmental period characterized by notable changes in behavior, physical attributes, and an increase in endogenous sex steroid hormones, which may impact cognitive functioning. Moreover, sex differences in brain structure are present, leading to differences in neural function and cognition. Here, we examine sex differences in performance and blood oxygen level-dependent (BOLD) activation in a sample of adolescents during a spatial working memory (SWM) task. We also examine whether endogenous testosterone levels mediate differential brain activity between the sexes. Adolescents between ages 10 and 16 completed a SWM functional magnetic resonance imaging (fMRI) task, and serum hormone levels were assessed within seven days of scanning. While there were no sex differences in task performance (accuracy and reaction time), differences in BOLD response between girls and boys emerged, with girls deactivating brain regions in the default mode network and boys showing increased response in SWM-related brain regions of the frontal cortex. These results suggest that adolescent boys and girls adopted distinct neural strategies, while maintaining spatial cognitive strategies that facilitated comparable cognitive performance of a SWM task. A nonparametric bootstrapping procedure revealed that testosterone did not mediate sex-specific brain activity, suggesting that sex differences in BOLD activation during SWM may be better explained by other factors, such as early organizational effects of sex steroids or environmental influences. Elucidating sex differences in neural function and the influence of gonadal hormones can serve as a basis of comparison for understanding sexually dimorphic neurodevelopment and inform sex-specific psychopathology that emerges in adolescence. PMID:25312831

Sexing the brain: the science and pseudoscience of sex differences.

PubMed

Rogers, Lesley J

2010-06-01

A recent upsurge in unitary biological explanations for gender differences in behavior (i.e. that they are "hard-wired" in the genetic code), put forward not only in books written for a general audience but also in scientific papers, makes it important to examine the fallacies of these ideas. Such genetic and hormonal explanations of human behavior, formulated with little consideration of the influences of experience, and often without taking experience into account at all, are part of a new wave of genetic explanations for a broad range of human behavior, as explained in the paper. These ideas are far from new; moreover, they are pseudoscientific and are used for political influence under the guise of science. They are a conservative social force that maintains social and educational inequalities between women and men. This paper explains that causal explanations of differences between the sexes are of two completely different types: unitary (genetic determinist) versus interactive explanations. The false reasoning used to support genetic determinist explanations of sex differences in behavior is discussed. To illustrate what biology really tells us about gender differentiation, the paper discusses the interactive roles of genetic, hormonal and environmental influences on the development of gender differences. These interactions are illustrated using two model biological systems (e.g. the intertwined influences of genes, sex hormones and experience on the development of sex differences in behavior in rats, and sex differences in neuronal connections in chickens). There is plenty of scientific evidence to show the complex interactive, and ever changing, influences of experience and genes that take place as an organism develops and throughout its life. Malleability of brain and behavior can be shown clearly using animal models, and the processes involved apply also to the development of brain and behavior in humans. We diminish our understanding of the functions of a host of contributing factors to gender differentiation by parceling out the largest portion of control to the genes. The biology and behavior of humans is dynamic and flexible and need not restrict women to inferior positions in society. 2010 Elsevier. Published by Elsevier B.V. All rights reserved.

Sex differences in lizard escape decisions vary with latitude, but not sexual dimorphism.

PubMed

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.

Effect of age and sex on lacosamide pharmacokinetics in healthy adult subjects and adults with focal epilepsy.

PubMed

Schaefer, Carina; Cawello, Willi; Waitzinger, Josef; Elshoff, Jan-Peer

2015-04-01

Age- and sex-related differences in body composition could affect the pharmacokinetic parameters of administered drugs. The purpose of this post hoc analysis was to investigate the influences of age and sex on the pharmacokinetics of lacosamide. This post hoc analysis used pharmacokinetic data taken at steady state from (i) two phase I studies of oral lacosamide in healthy adult subjects (n = 66), and (ii) a population pharmacokinetic analysis carried out using data from two phase III studies of adjunctive oral lacosamide in adults (n = 565) with focal epilepsy taking 1-3 concomitant anti-epileptic drugs. Phase I data were stratified by age and sex as 'younger female' (aged 18-40 years), 'younger male' (aged 18-45 years) or 'elderly male/female' (aged ≥65 years), then normalized by body weight (lean body weight or fat-free mass), height or volume of distribution, and analysed using non-compartmental analysis. Population pharmacokinetic data were stratified by sex and analysed using a one-compartment model. Minor numerical differences between lacosamide exposure [the area under the concentration-time curve at steady state over the dosage interval (AUCτ,ss)] and the maximum plasma concentration at steady state (C max,ss) in subjects of different ages or sexes were noted. The differences could be explained by a scaling factor between the drug applied and the plasma concentration. Following normalization by lean body weight or volume of distribution, an analysis of relative bioavailability resulted in 90 % confidence intervals of the ratios for AUCτ,ss and C max,ss for age (elderly to younger) or sex (male to female) falling within the range accepted for equivalence (80-125 %); without normalization, the 90 % confidence intervals were outside this range. Minor numerical differences in lacosamide plasma concentrations were noted in the comparison between male and female patients (aged 16-71 years) with focal epilepsy. Simulations using different body weights demonstrated a minimal effect of body weight on lacosamide plasma concentrations in adult patients with focal epilepsy. Age and sex had no relevant effects on the rates of absorption and elimination of lacosamide in this post hoc analysis, as the minor numerical differences could be explained by the main scaling factor for body weight or volume of distribution. The pharmacokinetic profile of lacosamide was unaffected by age or sex in adults with focal epilepsy.

Sex differences in neural and behavioral signatures of cooperation revealed by fNIRS hyperscanning

PubMed Central

Baker, Joseph M.; Liu, Ning; Cui, Xu; Vrticka, Pascal; Saggar, Manish; Hosseini, S. M. Hadi; Reiss, Allan L.

2016-01-01

Researchers from multiple fields have sought to understand how sex moderates human social behavior. While over 50 years of research has revealed differences in cooperation behavior of males and females, the underlying neural correlates of these sex differences have not been explained. A missing and fundamental element of this puzzle is an understanding of how the sex composition of an interacting dyad influences the brain and behavior during cooperation. Using fNIRS-based hyperscanning in 111 same- and mixed-sex dyads, we identified significant behavioral and neural sex-related differences in association with a computer-based cooperation task. Dyads containing at least one male demonstrated significantly higher behavioral performance than female/female dyads. Individual males and females showed significant activation in the right frontopolar and right inferior prefrontal cortices, although this activation was greater in females compared to males. Female/female dyad’s exhibited significant inter-brain coherence within the right temporal cortex, while significant coherence in male/male dyads occurred in the right inferior prefrontal cortex. Significant coherence was not observed in mixed-sex dyads. Finally, for same-sex dyads only, task-related inter-brain coherence was positively correlated with cooperation task performance. Our results highlight multiple important and previously undetected influences of sex on concurrent neural and behavioral signatures of cooperation. PMID:27270754

Sex differences in anxiety disorders: Interactions between fear, stress, and gonadal hormones.

PubMed

Maeng, Lisa Y; Milad, Mohammed R

2015-11-01

This article is part of a Special Issue "SBN 2014". Women are more vulnerable to stress- and fear-based disorders, such as anxiety and post-traumatic stress disorder. Despite the growing literature on this topic, the neural basis of these sex differences remains unclear, and the findings appear inconsistent. The neurobiological mechanisms of fear and stress in learning and memory processes have been extensively studied, and the crosstalk between these systems is beginning to explain the disproportionate incidence and differences in symptomatology and remission within these psychopathologies. In this review, we discuss the intersect between stress and fear mechanisms and their modulation by gonadal hormones and discuss the relevance of this information to sex differences in anxiety and fear-based disorders. Understanding these converging influences is imperative to the development of more effective, individualized treatments that take sex and hormones into account. Published by Elsevier Inc.

Sex differences in the neural circuit that mediates female sexual receptivity

PubMed Central

Flanagan-Cato, Loretta M.

2011-01-01

Female sexual behavior in rodents, typified by the lordosis posture, is hormone-dependent and sex-specific. Ovarian hormones control this behavior via receptors in the hypothalamic ventromedial nucleus (VMH). This review considers the sex differences in the morphology, neurochemistry and neural circuitry of the VMH to gain insights into the mechanisms that control lordosis. The VMH is larger in males compared with females, due to more synaptic connections. Another sex difference is the responsiveness to estradiol, with males exhibiting muted, and in some cases reverse, effects compared with females. The lack of lordosis in males may be explained by differences in synaptic organization or estrogen responsiveness, or both, in the VMH. However, given that damage to other brain regions unmasks lordosis behavior in males, a male-typical VMH is unlikely the main factor that prevents lordosis. In females, key questions remain regarding the mechanisms whereby ovarian hormones modulate VMH function to promote lordosis. PMID:21338620

Individual differences in valuing mates' physical attractiveness.

PubMed

Mathes, Eugene W; Bielser, Abby; Cassell, Ticcarra; Summers, Sarah; Witowski, Aggie

2006-10-01

To investigate correlates of valuing physical attractiveness in a mate, it was hypothesized that valuing physical attractiveness in a mate would correlate with sex and valuing promiscuous sex, status, personal physical attractiveness, beauty, and order. Men and women college students completed measures of the extent to which they valued physical attractiveness in a mate and other variables. Valuing physical attractiveness in a mate was correlated with sex (men valued physical attractiveness in a mate more than did women) and valuing promiscuous sex and status, and, for women, valuing personal physical attractiveness. The results were explained in terms of evolutionary theory.

Association between sex hormones and adiposity: qualitative differences in women and men in the multi-ethnic study of atherosclerosis.

PubMed

Mongraw-Chaffin, Morgana L; Anderson, Cheryl A M; Allison, Matthew A; Ouyang, Pamela; Szklo, Moyses; Vaidya, Dhananjay; Woodward, Mark; Golden, Sherita Hill

2015-04-01

Sex hormones may influence adipose tissue deposition, possibly contributing to sex disparities in cardiovascular disease risk. We hypothesized that associations of sex hormone levels with visceral and subcutaneous fat differ by sex. Participants were from the Multi-Ethnic Study of Atherosclerosis with sex hormone levels at baseline and visceral and subcutaneous fat measurements from computed tomography at visit 2 or 3 (n = 1835). Multivariable linear regression was used to investigate the relationships between sex hormones and adiposity. Testing for interaction by sex, race/ethnicity, and age was conducted. In adjusted models, there was a modest significant positive association between estradiol and visceral fat in both sexes (percent difference in visceral fat for 1% difference in hormone [95% confidence interval] in women, 5.44 [1.82, 9.09]; and in men, 8.22 [0.61, 16.18]). Higher bioavailable T was significantly associated with higher visceral and subcutaneous fat in women and with the reverse in men (women, 14.38 [10.23, 18.69]; men, -7.69 [-13.06, -1.00]). Higher dehydroepiandrosterone was associated with higher visceral fat in women (7.57 [1.71, 13.88]), but not in men (-2.47 [-8.88, 4.29]). Higher SHBG was associated with significantly lower levels of adiposity in both sexes (women, -24.42 [-28.11, -20.55]; men, -27.39 [-32.97, -21.34]). There was no significant interaction by race/ethnicity or age. Sex hormones are significantly associated with adiposity, and the associations of androgens differ qualitatively by sex. This heterogeneity may help explain the complexity of the contribution of sex hormones to sex differences in cardiovascular disease.

Sex-Related Differences in the Effects of the Mediterranean Diet on Glucose and Insulin Homeostasis

PubMed Central

Bédard, Alexandra; Corneau, Louise; Lamarche, Benoît; Dodin, Sylvie; Lemieux, Simone

2014-01-01

Objective. To document sex differences in the impact of the Mediterranean diet (MedDiet) on glucose/insulin homeostasis and to verify whether these sex-related effects were associated with changes in nonesterified fatty acids (NEFA). Methods. All foods were provided to 38 men and 32 premenopausal women (24–53 y) during 4 weeks. Variables were measured during a 180 min OGTT before and after the MedDiet. Results. A sex-by-time interaction for plasma insulin iAUC was found (men: −17.8%, P = 0.02; women: +9.4%, P = 0.63; P for sex-by-time interaction = 0.005). A sex-by-time interaction was also observed for insulin sensitivity (Cederholm index, P = 0.03), for which only men experienced improvements (men: +8.1%, P = 0.047; women: −5.9%, P = 0.94). No sex difference was observed for glucose and C-peptide responses. Trends toward a decrease in NEFA AUC (P = 0.06) and an increase in NEFA suppression rate (P = 0.06) were noted, with no sex difference. Changes in NEFA were not associated with change in insulin sensitivity. Conclusions. Results suggest that the more favorable changes in glucose/insulin homeostasis observed in men compared to women in response to the MedDiet are not explained by sex differences in NEFA response. This clinical trial is registered with clinicaltrials.gov NCT01293344. PMID:25371817

Sex differences in jealousy: a population-based twin study in Sweden.

PubMed

Walum, Hasse; Larsson, Henrik; Westberg, Lars; Lichtenstein, Paul; Magnusson, Patrik K E

2013-10-01

According to the theory of evolved sex differences in jealousy, the challenge for women to ensure paternal investment increased their jealousy response to emotional infidelity, whereas paternal uncertainty exerted selective pressures that shaped men to become more distressed by sexual infidelity. Several studies have investigated whether the effect of these sexually dimorphic selection pressures can be detected in contemporary human populations, with conflicting results. To date, no genetically informed studies of sex differences in jealousy have been conducted. We used data from the Screening Across the Lifespan of Twins Younger (SALTY) sample, containing information concerning self-rated jealousy from 3,197 complete twin pairs collected by the Swedish Twin Registry. Intra-class correlations and structural equation models were used to assess the genetic influence on jealousy and to investigate sex differences at genetic level. We saw a highly significant sex effect on the relationship between infidelity types, indicating that men, relative to women, reported greater jealousy in response to sexual infidelity than in response to emotional infidelity. The twin models revealed significant heritabilities for both sexual (32%) and emotional (26%) jealousy. The heritabilities were of a similar magnitude in both sexes, and no qualitative sex differences could be detected. We show for the first time that variance in jealousy is to some extent explained by genetic factors. Even though our results from the mean value analyses are in line with the theory of evolved sex differences in jealousy, we could not identify any sex differences on a genetic level.

Explaining the sex difference in depression with a unified bargaining model of anger and depression.

PubMed

Hagen, Edward H; Rosenström, Tom

2016-01-01

Women are twice as likely as men to be depressed, a bias that is poorly understood. One evolutionary model proposes that depression is a bargaining strategy to compel reluctant social partners to provide more help in the wake of adversity. An evolutionary model of anger proposes that high upper body strength predisposes individuals to angrily threaten social partners who offer too few benefits or impose too many costs. Here, we propose that when social partners provide too few benefits or impose too many costs, the physically strong become overtly angry and the physically weak become depressed. The sexual dimorphism in upper body strength means that men will be more likely to bargain with anger and physical threats and women with depression. We tested this idea using the 2011-12 National Health and Nutrition Examination Survey (NHANES), a large nationally representative sample of US households that included measures of depression and upper body strength. A 2 SD increase in grip strength decreased the odds of depression by more than half ([Formula: see text],[Formula: see text]), which did not appear to be a consequence of confounds with anthropometric, hormonal or socioeconomic variables, but was partially explained by a confound with physical disability. Nevertheless, upper body strength mediated 63% of the effect of sex on depression, but the mediation effect was unexpectedly moderated by age. Low upper body strength is a risk factor for depression, especially in older adults, and the sex difference in body strength appears to explain much of the perplexing sex difference in depression. © The Author(s) 2016. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.

Sex differences in normal age trajectories of functional brain networks.

PubMed

Scheinost, Dustin; Finn, Emily S; Tokoglu, Fuyuze; Shen, Xilin; Papademetris, Xenophon; Hampson, Michelle; Constable, R Todd

2015-04-01

Resting-state functional magnetic resonance image (rs-fMRI) is increasingly used to study functional brain networks. Nevertheless, variability in these networks due to factors such as sex and aging is not fully understood. This study explored sex differences in normal age trajectories of resting-state networks (RSNs) using a novel voxel-wise measure of functional connectivity, the intrinsic connectivity distribution (ICD). Males and females showed differential patterns of changing connectivity in large-scale RSNs during normal aging from early adulthood to late middle-age. In some networks, such as the default-mode network, males and females both showed decreases in connectivity with age, albeit at different rates. In other networks, such as the fronto-parietal network, males and females showed divergent connectivity trajectories with age. Main effects of sex and age were found in many of the same regions showing sex-related differences in aging. Finally, these sex differences in aging trajectories were robust to choice of preprocessing strategy, such as global signal regression. Our findings resolve some discrepancies in the literature, especially with respect to the trajectory of connectivity in the default mode, which can be explained by our observed interactions between sex and aging. Overall, results indicate that RSNs show different aging trajectories for males and females. Characterizing effects of sex and age on RSNs are critical first steps in understanding the functional organization of the human brain. © 2014 Wiley Periodicals, Inc.

A critical review on physical factors and functional characteristics that may explain a sex/gender difference in work-related neck/shoulder disorders.

PubMed

Côté, Julie N

2012-01-01

The objective of this paper is to critically review recent literature on physical and functional sex/gender (s/g) differences, with focus on physical determinants associated with neck/shoulder musculoskeletal injuries. It is well known that there are s/g differences in anthropometrical and functional body characteristics (e.g. size and strength). However, s/g differences may be wrongly attributed if data analysis does not include appropriate corrections (e.g. by strength for endurance). Recent literature on motor control shows that there may indeed be s/g differences in muscle coordination and movement strategies during upper limb tasks that are not currently explained by methodological inadequacies. Moreover, recent studies have shown differences between men and women in sensory hypersensitivity characteristics associated with neck/shoulder injuries. Taken together, the literature points to the importance of accounting for possible s/g differences at all levels of the biopsychosocial system in order to better understand sex- and gender-specific issues relevant to workplace health. This article critically reviews recent literature and a conceptual model highlighting s/g differences in physical and functional characteristics related to neck/shoulder musculoskeletal disorders (NSMSD). Findings have implications on understanding how personal factors may affect NSMSD risk. With better understanding, practitioners can make more appropriate decisions to prevent work-related NSMSD.

Attitudes Toward Same-Sex Parenting: An Effect of Gender.

PubMed

Webb, Stephanie N; Chonody, Jill M; Kavanagh, Phillip S

2017-01-01

The definition of family in Australia has been continuously changing over the past four decades. The 21 st century has brought with it various images of family, with an increase of awareness to same-sex families; however, the acceptance of such family structures does not appear to be widespread and is often determined by sex. Substantive literature demonstrates differences between men and women in attitudes toward same-sex parenting, with theory suggesting that gender role norms may explain this. Despite large efforts to determine sex differences in attitudes toward same-sex parenting, little research, and even less in Australia, has been done to investigate whether there are differences in reasons behind negative attitudes toward same-sex parenting between men and women. To further this understanding, an Australian sample (N= 790) ranging in age from 18-78 completed a survey regrading attitudes toward same-sex parenting, in addition to relevant demographic information. Participants reported more positive attitudes about parenting by lesbians as compared to parenting by gay men. Reasons behind attitudes toward same-sex parenting also differed between males and females. Results suggested that the impact of socially prescribed gender norms may affect prejudice toward same-sex families. Despite an increase in tolerance for sexual minorities recently, policies that continue to discriminate against same-sex parenting rights demonstrates the importance of continuing to identify potential influences of same-sex family prejudice to reduce the potentially negative impacts associated with the prejudice.

Sex differences in physical and mental functioning of Japanese civil servants: explanations from work and family characteristics.

PubMed

Sekine, Michikazu; Chandola, Tarani; Martikainen, Pekka; Marmot, Michael; Kagamimori, Sadanobu

2010-12-01

Poor physical and mental functioning are more common among women than men and those with disadvantaged work and family characteristics. This study aims to clarify whether sex differences in health functioning can be explained by sex differences in work and family characteristics. The subjects were 3787 civil servants (2525 men and 1262 women), aged 20-65, working in a local government on the west coast of Japan. A questionnaire survey was conducted in January 2003. Low employment grade, high demands, long work hours, shift work, being unmarried, having no young children, high family-to-work conflict and high work-to-family conflict were more common among women than men and were independently associated with poor physical and mental functioning. The age-adjusted odds ratios (ORs) of women for poor health functioning were 1.80 for poor physical functioning and 1.77 for poor mental functioning. When adjusted for employment grade and work characteristics (control, demand, support, work hours, and shift work), the sex differences in health functioning attenuated. When adjusted for family characteristics (family structure and work-family conflicts), the sex differences in health functioning further attenuated and were no longer statistically significant. Sex differences in family characteristics contributed more to sex difference in mental functioning than sex differences in work characteristics. Japan belongs to conservative welfare regimes. In such countries, men are able to concentrate on their work with relative freedom from their family tasks and responsibilities, whereas women feel difficulties in maintaining their work-life balances. Such sex differences in work- and family-related stresses may contribute to sex difference in health. Longitudinal research is necessary to clarify the causal nature of these associations. Copyright © 2010 Elsevier Ltd. All rights reserved.

Sex differences in the neural substrates of spatial working memory during adolescence are not mediated by endogenous testosterone.

PubMed

Alarcón, Gabriela; Cservenka, Anita; Fair, Damien A; Nagel, Bonnie J

2014-12-17

Adolescence is a developmental period characterized by notable changes in behavior, physical attributes, and an increase in endogenous sex steroid hormones, which may impact cognitive functioning. Moreover, sex differences in brain structure are present, leading to differences in neural function and cognition. Here, we examine sex differences in performance and blood oxygen level-dependent (BOLD) activation in a sample of adolescents during a spatial working memory (SWM) task. We also examine whether endogenous testosterone levels mediate differential brain activity between the sexes. Adolescents between ages 10 and 16 years completed a SWM functional magnetic resonance imaging (fMRI) task, and serum hormone levels were assessed within seven days of scanning. While there were no sex differences in task performance (accuracy and reaction time), differences in BOLD response between girls and boys emerged, with girls deactivating brain regions in the default mode network and boys showing increased response in SWM-related brain regions of the frontal cortex. These results suggest that adolescent boys and girls adopted distinct neural strategies, while maintaining spatial cognitive strategies that facilitated comparable cognitive performance of a SWM task. A nonparametric bootstrapping procedure revealed that testosterone did not mediate sex-specific brain activity, suggesting that sex differences in BOLD activation during SWM may be better explained by other factors, such as early organizational effects of sex steroids or environmental influences. Elucidating sex differences in neural function and the influence of gonadal hormones can serve as a basis of comparison for understanding sexually dimorphic neurodevelopment and inform sex-specific psychopathology that emerges in adolescence. Copyright © 2014 Elsevier B.V. All rights reserved.

Secondary analyses of data from four studies with fourth-grade children show that sex, race, amounts eaten of standardized portions, and energy content given in trades explain the positive relationship between BMI and energy intake at school-provided meals

PubMed Central

Baxter, Suzanne Domel; Paxton-Aiken, Amy E.; Tebbs, Joshua M.; Royer, Julie A.; Guinn, Caroline H.; Finney, Christopher J.

2012-01-01

Results from a 2012 article showed a positive relationship between children’s body mass index (BMI) and energy intake at school-provided meals. To help explain that positive relationship, secondary analyses investigated 1) whether the relationship differed by sex and race, and 2) the relationship between BMI and six aspects of school-provided meals—amounts eaten of standardized portions, energy content given in trades, energy intake received in trades, energy intake from flavored milk, energy intake from a la carte ice cream, and breakfast type. Data were from four studies conducted one per school year (1999–2000 to 2002–2003). Fourth-grade children (n=328; 50% female; 54% Black) from 13 schools total were observed eating school-provided breakfast and lunch on one to three days per child for 1,178 total meals (50% breakfast). Children were weighed and measured. Marginal regression models were fit using BMI as the dependent variable. For Purpose One, independent variables were energy intake at school-provided meals, sex, race, age, and study; additional models included interaction terms involving energy intake and sex/race. For Purpose Two, independent variables were the six aspects of school-provided meals, sex, race, age, and study. The relationship between BMI and energy intake at school-provided meals differed by sex (p<0.0001; stronger for females) and race (p=0.0063; stronger for Black children). BMI was positively related to amounts eaten of standardized portions (p<0.0001) and negatively related to energy content given in trades (p=0.0052). Explaining the positive relationship between BMI and energy intake at school-provided meals may contribute to school-based obesity prevention efforts. PMID:23084638

Secondary analyses of data from 4 studies with fourth-grade children show that sex, race, amounts eaten of standardized portions, and energy content given in trades explain the positive relationship between body mass index and energy intake at school-provided meals.

PubMed

Baxter, Suzanne Domel; Paxton-Aiken, Amy E; Tebbs, Joshua M; Royer, Julie A; Guinn, Caroline H; Finney, Christopher J

2012-09-01

Results from a 2012 article showed a positive relationship between children's body mass index (BMI) and energy intake at school-provided meals. To help explain that positive relationship, secondary analyses investigated (1) whether the relationship differed by sex and race and (2) the relationship between BMI and 6 aspects of school-provided meals--amounts eaten of standardized portions, energy content given in trades, energy intake received in trades, energy intake from flavored milk, energy intake from a la carte ice cream, and breakfast type. Data were from 4 studies conducted 1 per school year (1999-2000 to 2002-2003). Fourth-grade children (n = 328; 50% female; 54% black) from 13 schools total were observed eating school-provided breakfast and lunch on 1 to 3 days per child for 1178 total meals (50% breakfast). Children were weighed and measured. Marginal regression models were fit using BMI as the dependent variable. For purpose 1, independent variables were energy intake at school-provided meals, sex, race, age, and study; additional models included interaction terms involving energy intake and sex/race. For purpose 2, independent variables were the 6 aspects of school-provided meals, sex, race, age, and study. The relationship between BMI and energy intake at school-provided meals differed by sex (P < .0001; stronger for females) and race (P = .0063; stronger for black children). BMI was positively related to amounts eaten of standardized portions (P < .0001) and negatively related to energy content given in trades (P = .0052). Explaining the positive relationship between BMI and energy intake at school-provided meals may contribute to school-based obesity prevention efforts. Copyright © 2012 Elsevier Inc. All rights reserved.

Empathy, Intimacy, Loneliness and Locus of Control in Child Sex Offenders: A Comparison between Familial and Non-Familial Child Sexual Offenders.

ERIC Educational Resources Information Center

Parton, Felicity; Day, Andrew

2002-01-01

Compares a group of familial and non-familial child sex offenders on a number of relationship dimensions thought to be important in explaining offending. No statistically significant differences were found between these groups on measures of general empathy, intimacy and loneliness, although non-familial offenders were found to have higher levels…

Sex difference in polychlorinated biphenyl concentrations of burbot Lota lota from Lake Erie

USGS Publications Warehouse

Madenjian, C.P.; Stapanian, M.A.; Rediske, R.R.; O’Keefe, J. P.

2013-01-01

Whole-fish polychlorinated biphenyl (PCB) concentrations were determined for 25 female and 25 male burbot Lota lota from Lake Erie. Bioenergetics modeling was used to investigate whether the sex difference in growth rate resulted in a difference in gross growth efficiency (GGE) between the sexes. For ages 6–13 years, male burbot averaged 28 % greater PCB concentrations than female burbot. The sex difference in PCB concentrations widened for ages 14–17 years, with male burbot having, on average, 71 % greater PCB concentrations than female burbot. Bioenergetics modeling results showed that the faster growth rate exhibited by female burbot did not lead to greater GGE in female individuals of the younger burbot and that the faster growth by female fish led to female GGE being only 2 % greater than male GGE in older burbot. Although our bioenergetics modeling could not explain the observed sex difference in PCB concentrations, we concluded that a sex difference in GGE was the most plausible explanation for the sex difference in PCB concentrations of burbot ages 6–13 years. Not only are male fish likely to be more active than female fish, but the resting metabolic rate of male fish may be greater than that of female fish. We also concluded that the widening of the sex difference in PCB concentrations for the older burbot may be due to many of the older male burbot spending a substantial amount of time in the vicinity of mouths of rivers contaminated with PCBs.

Sex differences in claimed and behavioral self-handicapping and ADHD symptomatology in emerging adults.

PubMed

Jaconis, Maryanne; Boyd, Stephen J; Hartung, Cynthia M; McCrea, Sean M; Lefler, Elizabeth K; Canu, Will H

2016-12-01

Although the research is clear that boys with ADHD have higher symptomatology and impairment than girls with ADHD, for adults the research is mixed. Some studies suggest no sex differences, whereas others suggest that women might have higher symptomatology and impairment. The present study examined sex differences in ADHD symptomatology and impairment, and the possible role of claimed and behavioral self-handicapping as an explanation for any differences. Claimed self-handicapping (CSH) involves reports of performance-inhibiting conditions, whereas behavioral self-handicapping (BSH) involves reporting more objective, intentional acts that could undermine performance. College students (N = 699) completed an online study. Sex differences were found for hyperactivity such that women reported higher levels, but not for inattention or impairment. The test of the indirect effect of sex through CSH was significant, suggesting that higher levels of CSH in women were associated with elevated ADHD symptoms and impairment. The test of the indirect effect of sex through BSH was also significant, suggesting that higher levels of BSH in men are associated with elevated symptoms of ADHD and impairment. These data extend the literature by suggesting that self-handicapping might at least partially explain differential self-reporting of ADHD symptoms and impairment in emerging adults across the sexes.

Sex Differences in Music: A Female Advantage at Recognizing Familiar Melodies.

PubMed

Miles, Scott A; Miranda, Robbin A; Ullman, Michael T

2016-01-01

Although sex differences have been observed in various cognitive domains, there has been little work examining sex differences in the cognition of music. We tested the prediction that women would be better than men at recognizing familiar melodies, since memories of specific melodies are likely to be learned (at least in part) by declarative memory, which shows female advantages. Participants were 24 men and 24 women, with half musicians and half non-musicians in each group. The two groups were matched on age, education, and various measures of musical training. Participants were presented with well-known and novel melodies, and were asked to indicate their recognition of familiar melodies as rapidly as possible. The women were significantly faster than the men in responding, with a large effect size. The female advantage held across musicians and non-musicians, and across melodies with and without commonly associated lyrics, as evidenced by an absence of interactions between sex and these factors. Additionally, the results did not seem to be explained by sex differences in response biases, or in basic motor processes as tested in a control task. Though caution is warranted given that this is the first study to examine sex differences in familiar melody recognition, the results are consistent with the hypothesis motivating our prediction, namely that declarative memory underlies knowledge about music (particularly about familiar melodies), and that the female advantage at declarative memory may thus lead to female advantages in music cognition (particularly at familiar melody recognition). Additionally, the findings argue against the view that female advantages at tasks involving verbal (or verbalizable) material are due solely to a sex difference specific to the verbal domain. Further, the results may help explain previously reported cognitive commonalities between music and language: since declarative memory also underlies language, such commonalities may be partly due to a common dependence on this memory system. More generally, because declarative memory is well studied at many levels, evidence that music cognition depends on this system may lead to a powerful research program generating a wide range of novel predictions for the neurocognition of music, potentially advancing the field.

Sex differences in lung cancer survival: long-term trends using population-based cancer registry data in Osaka, Japan.

PubMed

Kinoshita, Fukuaki Lee; Ito, Yuri; Morishima, Toshitaka; Miyashiro, Isao; Nakayama, Tomio

2017-09-01

Several studies of sex differences in lung cancer survival have been reported. However, large-size population-based studies based on long-term observation are scarce. We investigated long-term trends in sex differences in lung cancer survival using population-based cancer registry data from Osaka, Japan. We analyzed 79 330 cases from the Osaka Cancer Registry (OCR) diagnosed between 1975 and 2007. We calculated 5-year relative survival in the six periods (1975-1980, 1981-1986, 1987-1992, 1993-1997, 1998-2002 and 2003-2007). To estimate the trends in sex differences in lung cancer survival throughout the study period, we applied a multivariate excess hazard model to control for confounders. The proportion of adenocarcinoma (ADC) and 5-year relative relative survival have increased for both sexes. Sex differences in lung cancer survival have widened over the period, especially in ADC and since the late 1990s. The excess hazard ratio of death within 5 years for males was 1.19 (95% CI: 1.16-1.21), adjusting for period at diagnosis, histologic type, stage, age group and treatment. We reported that females have better prognosis in lung cancer than males and the sex differences in lung cancer survival have become wider in Osaka, Japan. This can be partly explained by the sex differences in the proportions of histologic type and stage. Further studies considering other factors that influence sex differences in lung cancer survival are needed. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Evolution of dosage compensation under sexual selection differs between X and Z chromosomes

PubMed Central

Mullon, Charles; Wright, Alison E.; Reuter, Max; Pomiankowski, Andrew; Mank, Judith E.

2015-01-01

Complete sex chromosome dosage compensation has more often been observed in XY than ZW species. In this study, using a population genetic model and the chicken transcriptome, we assess whether sexual conflict can account for this difference. Sexual conflict over expression is inevitable when mutation effects are correlated across the sexes, as compensatory mutations in the heterogametic sex lead to hyperexpression in the homogametic sex. Coupled with stronger selection and greater reproductive variance in males, this results in slower and less complete evolution of Z compared with X dosage compensation. Using expression variance as a measure of selection strength, we find that, as predicted by the model, dosage compensation in the chicken is most pronounced in genes that are under strong selection biased towards females. Our study explains the pattern of weak dosage compensation in ZW systems, and suggests that sexual selection plays a major role in shaping sex chromosome dosage compensation. PMID:26212613

Involvement of the oxytocin system in the bed nucleus of the stria terminalis in the sex-specific regulation of social recognition.

PubMed

Dumais, Kelly M; Alonso, Andrea G; Immormino, Marisa A; Bredewold, Remco; Veenema, Alexa H

2016-02-01

Sex differences in the oxytocin (OT) system in the brain may explain why OT often regulates social behaviors in sex-specific ways. However, a link between sex differences in the OT system and sex-specific regulation of social behavior has not been tested. Here, we determined whether sex differences in the OT receptor (OTR) or in OT release in the posterior bed nucleus of the stria terminalis (pBNST) mediates sex-specific regulation of social recognition in rats. We recently showed that, compared to female rats, male rats have a three-fold higher OTR binding density in the pBNST, a sexually dimorphic area implicated in the regulation of social behaviors. We now demonstrate that OTR antagonist (5 ng/0.5 μl/side) administration into the pBNST impairs social recognition in both sexes, while OT (100 pg/0.5 μl/side) administration into the pBNST prolongs the duration of social recognition in males only. These effects seem specific to social recognition, as neither treatment altered total social investigation time in either sex. Moreover, baseline OT release in the pBNST, as measured with in vivo microdialysis, did not differ between the sexes. However, males showed higher OT release in the pBNST during social recognition compared to females. These findings suggest a sex-specific role of the OT system in the pBNST in the regulation of social recognition. Copyright © 2015 Elsevier Ltd. All rights reserved.

Involvement of the oxytocin system in the bed nucleus of the stria terminalis in the sex-specific regulation of social recognition

PubMed Central

Dumais, Kelly M.; Alonso, Andrea G.; Immormino, Marisa A.; Bredewold, Remco; Veenema, Alexa H.

2015-01-01

Sex differences in the oxytocin (OT) system in the brain may explain why OT often regulates social behaviors in sex-specific ways. However, a link between sex differences in the OT system and sex-specific regulation of social behavior has not been tested. Here, we determined whether sex differences in the OT receptor (OTR) or in OT release in the posterior bed nucleus of the stria terminalis (pBNST) mediates sex-specific regulation of social recognition in rats. We recently showed that, compared to female rats, male rats have a three-fold higher OTR binding density in the pBNST, a sexually dimorphic area implicated in the regulation of social behaviors. We now demonstrate that OTR antagonist (5 ng/0.5 μl/side) administration into the pBNST impairs social recognition in both sexes, while OT (100 pg/0.5 μl/side) administration into the pBNST prolongs the duration of social recognition in males only. These effects seem specific to social recognition, as neither treatment altered total social investigation time in either sex. Moreover, baseline OT release in the pBNST, as measured with in vivo microdialysis, did not differ between the sexes. However, males showed higher OT release in the pBNST during social recognition compared to females. These findings suggest a sex-specific role of the OT system in the pBNST in the regulation of social recognition. PMID:26630388

Sex differences in the locus coeruleus-norepinephrine system and its regulation by stress.

PubMed

Bangasser, Debra A; Wiersielis, Kimberly R; Khantsis, Sabina

2016-06-15

Women are more likely than men to suffer from post-traumatic stress disorder (PTSD) and major depression. In addition to their sex bias, these disorders share stress as an etiological factor and hyperarousal as a symptom. Thus, sex differences in brain arousal systems and their regulation by stress could help explain increased vulnerability to these disorders in women. Here we review preclinical studies that have identified sex differences in the locus coeruleus (LC)-norepinephrine (NE) arousal system. First, we detail how structural sex differences in the LC can bias females towards increased arousal in response to emotional events. Second, we highlight studies demonstrating that estrogen can increase NE in LC target regions by enhancing the capacity for NE synthesis, while reducing NE degradation, potentially increasing arousal in females. Third, we review data revealing how sex differences in the stress receptor, corticotropin releasing factor 1 (CRF1), can increase LC neuronal sensitivity to CRF in females compared to males. This effect could translate into hyperarousal in women under conditions of CRF hypersecretion that occur in PTSD and depression. The implications of these sex differences for the treatment of stress-related psychiatric disorders are discussed. Moreover, the value of using information regarding biological sex differences to aid in the development of novel pharmacotherapies to better treat men and women with PTSD and depression is also highlighted. This article is part of a Special Issue entitled SI: Noradrenergic System. Copyright © 2015 Elsevier B.V. All rights reserved.

Do sex differences in rumination explain sex differences in depression?

PubMed

Shors, Tracey J; Millon, Emma M; Chang, Han Yan M; Olson, Ryan L; Alderman, Brandon L

2017-01-02

It is generally accepted that women tend to ruminate more than men do and these thought patterns are often associated with depressive symptoms (Nolen-Hoeksema et al., ). Based on these findings, we considered whether the relationship between rumination and depression is stronger in women than in men and if so, whether this might explain the higher prevalence of major depressive disorder (MDD) in women and finally, whether the association can be disrupted through a mind/body intervention. Adult men and women, most of whom were clinically depressed, participated in an intervention known as MAP Training, which combines "mental" training with silent meditation and "physical" training with aerobic exercise (Shors et al., ). After eight weeks of training, both men and women reported significantly fewer symptoms of depression and fewer ruminative thoughts (Alderman et al., ). Statistical correlations between depressive symptoms and ruminative thoughts were strong and significant (rho > 0.50; p < 0.05) for both men and women before and after MAP Training. However, only in women did depressive symptoms relate to "reflective" ruminations, which involve analyses of past events, feelings, and behaviors. This is also the only relationship that dissipated after the intervention. In general, these analyses suggest that the strength of the relationship between depressive symptoms and rumination does not necessarily explain sex differences in depression; but because the relationship is strong, targeting rumination through intervention can reduce the incidence of MDD, which is more prevalent among women. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Reconceptualizing sex, brain and psychopathology: interaction, interaction, interaction

PubMed Central

Joel, D; Yankelevitch-Yahav, R

2014-01-01

In recent years there has been a growing recognition of the influence of sex on brain structure and function, and in relation, on the susceptibility, prevalence and response to treatment of psychiatric disorders. Most theories and descriptions of the effects of sex on the brain are dominated by an analogy to the current interpretation of the effects of sex on the reproductive system, according to which sex is a divergence system that exerts a unitary, overriding and serial effect on the form of other systems. We shortly summarize different lines of evidence that contradict aspects of this analogy. The new view that emerges from these data is of sex as a complex system whose different components interact with one another and with other systems to affect body and brain. The paradigm shift that this understanding calls for is from thinking of sex in terms of sexual dimorphism and sex differences, to thinking of sex in terms of its interactions with other factors and processes. Our review of data obtained from animal models of psychopathology clearly reveals the need for such a paradigmatic shift, because in the field of animal behaviour whether a sex difference exists and its direction depend on the interaction of many factors including, species, strain, age, specific test employed and a multitude of environmental factors. We conclude by explaining how the new conceptualization can account for sex differences in psychopathology. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24758640

Sex differences in risk factors for cardiovascular disease: the PERU MIGRANT study.

PubMed

Bernabe-Ortiz, Antonio; Benziger, Catherine Pastorius; Gilman, Robert H; Smeeth, Liam; Miranda, J Jaime

2012-01-01

Although men and women have similar risk factors for cardiovascular disease, many social behaviors in developing countries differ by sex. Rural-to-urban migrants have different cardiovascular risk profiles than rural or urban dwellers. The objective of this study was to evaluate the sex differences with specific cardiovascular risk factors in rural-to-urban migrants. We used the rural-to-urban migrant group of the PERU MIGRANT cross-sectional study to investigate the sex differences in specific cardiovascular risk factors: obesity, hypertension, metabolic syndrome, as well as exposures of socioeconomic status, acculturation surrogates and behavioral characteristics. Logistic regression analysis was used to characterize strength of association between sex and our outcomes adjusting for potential confounders. The sample of migrants was 589 (mean age 46.5 years) and 52.4% were female. In the adjusted models, women were more likely to be obese (OR=5.97; 95%CI: 3.21-11) and have metabolic syndrome (OR=2.22; 95%CI: 1.39-3.55) than men, explaining the greatest variability for obesity and metabolic syndrome but not for hypertension. Our results suggest that interventions for CVD in Peru should be sex-specific and address the unique health needs of migrant populations living in urban shantytowns since the risk factors for obesity and metabolic syndrome differ between males and females.

Do Sexual Networks of Men Who Have Sex with Men in New York City Differ by Race/Ethnicity?

PubMed Central

Nandi, Vijay; Hoover, Donald R.; Lucy, Debbie; Stewart, Kiwan; Frye, Victoria; Cerda, Magdalena; Ompad, Danielle; Latkin, Carl; Koblin, Beryl A.

2016-01-01

Abstract The United States HIV epidemic disproportionately affects black and Hispanic men who have sex with men (MSM). This disparity might be partially explained by differences in social and sexual network structure and composition. A total of 1267 MSM in New York City completed an ACASI survey and egocentric social and sexual network inventory about their sex partners in the past 3 months, and underwent HIV testing. Social and sexual network structure and composition were compared by race/ethnicity of the egos: black, non-Hispanic (N = 365 egos), white, non-Hispanic (N = 466), and Hispanic (N = 436). 21.1% were HIV-positive by HIV testing; 17.2% reported serodiscordant and serostatus unknown unprotected anal/vaginal intercourse (SDUI) in the last 3 months. Black MSM were more likely than white and Hispanic MSM to report exclusively having partners of same race/ethnicity. Black and Hispanic MSM had more HIV-positive and unknown status partners than white MSM. White men were more likely to report overlap of social and sex partners than black and Hispanic men. No significant differences by race/ethnicity were found for network size, density, having concurrent partners, or having partners with ≥10 years age difference. Specific network composition characteristics may explain racial/ethnic disparities in HIV infection rates among MSM, including HIV status of sex partners in networks and lack of social support within sexual networks. Network structural characteristics such as size and density do not appear to have such an impact. These data add to our understanding of the complexity of social factors affecting black MSM and Hispanic MSM in the U.S. PMID:26745143

Sex differences in child and adolescent mortality by parental education in the Nordic countries.

PubMed

Gissler, Mika; Rahkonen, Ossi; Mortensen, Laust; Arntzen, Annett; Cnattingius, Sven; Nybo Andersen, Anne-Marie; Hemminki, Elina

2012-01-01

Socioeconomic position inequalities in infant mortality are well known, but there is less information on how child mortality is socially patterned by sex and age. To assess maternal and paternal socioeconomic inequalities in mortality by sex, whether these differences vary by age and country, and how much of the sex differences can be explained by external causes of death. Data on all live-born children were received from national birth registries for 1981-2000 (Denmark: n=1,184,926; Norway: n=1,090,127; and Sweden n=1,961,911) and for 1987-2000 (Finland: n=841,470). Data on the highest level of education in 2000 were obtained from national education registers, and data on mortality and causes of death were received from the national cause-of-death registers until the end of follow-up (20 years or 2003). Boys had a higher child and adolescent mortality than girls. The children of mothers and fathers who had had the shortest education time had the highest mortality for both sexes and for all ages and countries. The differences between the groups with longer than basic education were smaller, particularly among older children and girls. The gradient in mortality was mostly similar for boys and girls. Among 1-19-year-olds, 32% of boys' deaths and 27% of girls' deaths were due to external causes. Boys' excess mortality was only partly explained by educational inequalities or by deaths from external causes. A more detailed analysis is needed to study whether the share of avoidable deaths is higher among children whose parents have had a shorter education time.

Dysanapsis and the resistive work of breathing during exercise in healthy men and women.

PubMed

Dominelli, Paolo B; Molgat-Seon, Yannick; Bingham, Derek; Swartz, Philippa M; Road, Jeremy D; Foster, Glen E; Sheel, A William

2015-11-15

We asked if the higher work of breathing (Wb) during exercise in women compared with men is explained by biological sex. We created a statistical model that accounts for both the viscoelastic and the resistive components of the total Wb and independently compares the effects of biological sex. We applied the model to esophageal pressure-derived Wb values obtained during an incremental cycle test to exhaustion. Subjects were healthy men (n = 17) and women (n = 18) with a range of maximal aerobic capacities (V̇o2 max range: men = 40-68 and women = 39-60 ml·kg(-1)·min(-1)). We also calculated the dysanapsis ratio using measures of lung recoil and forced expiratory flow as index of airway caliber. By applying the model we found that the differences in the total Wb during exercise in women are due to a higher resistive Wb rather than viscoelastic Wb. We also found that the higher resistive Wb is independently explained by biological sex. To account for the known effect of lung volumes on the dysanapsis ratio we compared the sexes with an analysis of covariance procedures and found that when vital capacity was accounted for the adjusted mean dysanapsis ratio is statistically lower in women (0.17 vs. 0.25 arbitrary units; P < 0.05). Our collective findings suggest that innate sex-based differences may exist in human airways, which result in significant male-female differences in the Wb during exercise in healthy subjects. Copyright © 2015 the American Physiological Society.

The female advantage: sex as a possible protective factor against emotion recognition impairment following traumatic brain injury.

PubMed

Rigon, Arianna; Turkstra, Lyn; Mutlu, Bilge; Duff, Melissa

2016-10-01

Although moderate to severe traumatic brain injury (TBI) leads to facial affect recognition impairments in up to 39% of individuals, protective and risk factors for these deficits are unknown. The aim of the current study was to examine the effect of sex on emotion recognition abilities following TBI. We administered two separate emotion recognition tests (one static and one dynamic) to 53 individuals with moderate to severe TBI (females = 28) and 49 demographically matched comparisons (females = 22). We then investigated the presence of a sex-by-group interaction in emotion recognition accuracy. In the comparison group, there were no sex differences. In the TBI group, however, females significantly outperformed males in the dynamic (but not the static) task. Moreover, males (but not females) with TBI performed significantly worse than comparison participants in the dynamic task. Further analysis revealed that sex differences in emotion recognition abilities within the TBI group could not be explained by lesion location, TBI severity, or other neuropsychological variables. These findings suggest that sex may serve as a protective factor for social impairment following TBI and inform clinicians working with TBI as well as research on the neurophysiological correlates of sex differences in social functioning.

A Theory of Sex Differences in Technical Aptitude and Some Supporting Evidence.

PubMed

Schmidt, Frank L

2011-11-01

In this article, I present a theory that explains the origin of sex differences in technical aptitudes. The theory takes as proven that there are no sex differences in general mental ability (GMA), and it postulates that sex differences in technical aptitude (TA) stem from differences in experience in technical areas, which is in turn based on sex differences in technical interests. Using a large data set, I tested and found support for four predictions made by this theory: (a) the construct level correlation between technical aptitude and GMA is larger for females than males, (b) the observed and true score variability of technical aptitude is greater among males than females, (c) at every level of GMA females have lower levels of technical aptitude, and (d) technical aptitude measures used as estimates of GMA for decision purposes would result in underestimation of GMA levels for girls and women. Given that GMA carries the weight of prediction of job performance, the support found for this last prediction suggests that, for many jobs, technical aptitude tests may underpredict the job performance of female applicants and employees. Future research should examine this question. © Association for Psychological Science 2011.

Asthma, the sex difference.

PubMed

Kynyk, Jessica A; Mastronarde, John G; McCallister, Jennifer W

2011-01-01

asthma is a common chronic disease with significant clinical impact worldwide. Sex-related disparities in asthma epidemiology and morbidity exist but debate continues regarding the mechanisms for these differences. There is a need to review the recent findings for asthma care providers and to highlight areas in need of additional research. recent data illustrate striking sex-related differences in asthma epidemiology and disease expression. Studies show an increased incidence of asthma in women. Data demonstrate that asthmatic women have a poorer quality of life and increased utilization of healthcare compared to their male counterparts despite similar medical treatment and baseline pulmonary function. Research continues to explore hypotheses for these differences including the potential influences of the female sex hormones, altered perception of airflow obstruction, increased bronchial hyper-responsiveness, and medication compliance and technique. However, no single explanation has been able to fully explain the disparities. women are more likely to be diagnosed with asthma and suffer greater morbidity than men. The physiologic mechanisms for these differences are not well understood. Understanding sex-related differences in asthma and providing patients with education geared toward these disparities are important in establishing effective, individualized asthma management strategies for all patients.

Sex Work Venue and Condom Use among Female Sex Workers in Senggigi, Indonesia

PubMed Central

Safika, Iko; Levy, Judith A.; Johnson, Timothy P.

2013-01-01

This paper examines the structural influence of sex work venues on condom use among female sex workers in the Senggigi area of Lombok, Indonesia. A cross-sectional design employing ethnographic observation, structured interviews and hierarchical linear modeling was used to examine condom use among female sex workers who solicited clients at three types of sex work venues: freelance, brothels, and entertainment places (karaoke bars and massage parlours). The sample consisted of 115 women “nested” within 16 sex work venues drawn from the three venue types. Rate (39%) of condom use varied across sex work venues. Perceived management style, HIV/AIDS-related policies, and risk-reduction services differed by venue, but this variation did not explain differences in condom use. At the individual level, higher condom use was associated with female sex workers having ever been married. At the client level, condoms were more likely to be used with foreign rather than domestic/local Indonesian clients. Low rates of condom use among Indonesian female sex workers during commercial sex suggests the need for increased HIV prevention efforts that acknowledge sex worker characteristics and relationships with clients that place them at risk. Future research into the effects of social context on HIV risk should also be considered. PMID:23472595

Sex work venue and condom use among female sex workers in Senggigi, Indonesia.

PubMed

Safika, Iko; Levy, Judith A; Johnson, Timothy P

2013-01-01

This paper examines the structural influence of sex work venues on condom use among female sex workers in the Senggigi area of Lombok, Indonesia. A cross-sectional design employing ethnographic observation, structured interviews and hierarchical linear modelling was used to examine condom use among female sex workers who solicited clients at three types of sex work venues: (1) freelance locations, (2) brothels and (3) entertainment places (karaoke bars and massage parlours). The sample consisted of 115 women 'nested' within 16 sex work venues drawn from the three venue types. Rate (39%) of condom use varied across sex work venues. Perceived management style, HIV/AIDS-related policies and risk-reduction services differed by venue, but this variation did not explain differences in condom use. At the individual level, higher condom use was associated with female sex workers having ever been married. At the client level, condoms were more likely to be used with foreign rather than domestic/local Indonesian clients. Low rates of condom use among Indonesian female sex workers during commercial sex suggests the need for increased HIV-prevention efforts that acknowledge sex worker characteristics and relationships with clients that place them at risk. Future research into the effects of social context on HIV risk should also be considered.

Sex differences in the association between infant markers and later autistic traits.

PubMed

Bedford, Rachael; Jones, Emily J H; Johnson, Mark H; Pickles, Andrew; Charman, Tony; Gliga, Teodora

2016-01-01

Although it is well established that the prevalence of autism spectrum disorder (ASD) is higher in males than females, there is relatively little understanding of the underlying mechanisms and their developmental time course. Sex-specific protective or risk factors have often been invoked to explain these differences, but such factors are yet to be identified. We take a developmental approach, using a prospective sample of 104 infants at high and low familial risk for ASD, to characterise sex differences in infant markers known to predict emerging autism symptoms. We examine three markers previously shown to be associated with later autistic social-communication symptoms: the Autism Observation Scale for Infants (AOSI) total score, attention disengagement speed and gaze following behaviour. Our aim was to test whether sex differences were already present in these markers at 1 year of age, which would suggest sex-specific mechanisms of risk or protection. While no sex differences were found in any of the three markers investigated, we found sex differences in their relationship to 3-year autism traits; all three markers significantly predicted later autism traits only in the boys. Previously identified 'early autism markers' were associated with later autism symptoms only in boys. This suggests that there may be additional moderating risk or protective factors which remain to be identified. Our findings have important implications for prospective studies in terms of directly testing for the moderating effect of sex on emerging autistic traits.

Sex and race differences in young people's responsiveness to price and tobacco control policies

PubMed Central

Chaloupka, F.; Pacula, R. L.

1999-01-01

OBJECTIVE—To determine if there are differences in young people's responsiveness to price and tobacco control policies for population subgroups and to examine whether or not these differences, if they exist, can explain sex and racial differences in trends in the prevalence of smoking in young people in the United States.
DESIGN—Use cross-sectional and intertemporal variation in local and state tobacco control policies and prices to calculate demand responses to these policies using regression analysis techniques.
SUBJECTS—A nationally representative sample of American eighth grade (ages 13-14 years), 10th grade (15-16 years) and 12th grade (17-18 years) students obtained from the 1992-1994 Monitoring the Future surveys.
MAIN OUTCOME MEASURE—Thirty-day smoking prevalence.
RESULTS—Young men are much more responsive to changes in the price of cigarettes than young women. The prevalence elasticity for young men is almost twice as large as that for young women. Smoking rates of young black men are significantly more responsive to changes in price than young white men. Significant differences in responsiveness to particular tobacco control policies also exist. These differences, however, explain relatively little of the differences in smoking prevalence among young population subgroups.
CONCLUSIONS—Policymakers need to keep in mind that there is not a "one-size fits all" strategy for discouraging smoking among young people.


Keywords: adolescents; tobacco control policies; price; sex differences; racial differences PMID:10629242

Gender Differences in the Perception of Administrative Role Demands.

ERIC Educational Resources Information Center

Estler, Suzanne E.

Efforts to understand the relationship between gender and school administration have usually focused on explaining the limited numbers of women administrators. Explanations of leadership style differences have stressed sex-role socialization theory, though some researchers suggest that the structure of power, opportunity, and social proportions in…

Sex, Productivity and Reward in Academe.

ERIC Educational Resources Information Center

Harlan, Anne; And Others

This study attempts to utilize more refined measures of rewards and productivity than have been employed in past research in an effort to determine whether differences in rewards offered to men and women exist, and if they do, whether such differences can be explained in terms of differing rates of productivity. A 10-page questionnaire was…

Current hypotheses for the evolution of sex and recombination.

PubMed

Hartfield, Matthew; Keightley, Peter D

2012-06-01

The evolution of sex is one of the most important and controversial problems in evolutionary biology. Although sex is almost universal in higher animals and plants, its inherent costs have made its maintenance difficult to explain. The most famous of these is the twofold cost of males, which can greatly reduce the fecundity of a sexual population, compared to a population of asexual females. Over the past century, multiple hypotheses, along with experimental evidence to support these, have been put forward to explain widespread costly sex. In this review, we outline some of the most prominent theories, along with the experimental and observational evidence supporting these. Historically, there have been 4 classes of theories: the ability of sex to fix multiple novel advantageous mutants (Fisher-Muller hypothesis); sex as a mechanism to stop the build-up of deleterious mutations in finite populations (Muller's ratchet); recombination creating novel genotypes that can resist infection by parasites (Red Queen hypothesis); and the ability of sex to purge bad genomes if deleterious mutations act synergistically (mutational deterministic hypothesis). Current theoretical and experimental evidence seems to favor the hypothesis that sex breaks down selection interference between new mutants, or it acts as a mechanism to shuffle genotypes in order to repel parasitic invasion. However, there is still a need to collect more data from natural populations and experimental studies, which can be used to test different hypotheses. © 2012 ISZS, Blackwell Publishing and IOZ/CAS.

The effect of equalizing landing task demands on sex differences in lower extremity energy absorption.

PubMed

Montgomery, Melissa M; Shultz, Sandra J; Schmitz, Randy J

2014-08-01

Less lean mass and strength may result in greater relative task demands on females compared to males when landing from a standardized height and could explain sex differences in energy absorption strategies. We compared the magnitude of sex differences in energy absorption when task demands were equalized relative to the amount of lower extremity lean mass available to dissipate kinetic energy upon landing. Male-female pairs (n=35) were assessed for lower extremity lean mass with dual-energy X-ray absorptiometry. Relative task demands were calculated when landing from a standardized height. Based on the difference in lower extremity lean mass within each pair, task demands were equalized by increasing the drop height for males. Joint energetics were measured while landing from the two heights. Multivariate repeated measures ANOVAs compared the magnitude of sex differences in joint energetics between conditions. The multivariate test for absolute energy absorption was significant (P<0.01). The magnitude of sex difference in energy absorption was greater at the hip and knee (both P<0.01), but not the ankle (P=0.43) during the equalized condition compared to the standardized and exaggerated conditions (all P<0.01). There was no difference in the magnitude of sex differences between equalized, standardized and exaggerated conditions for relative energy absorption (P=0.18). Equalizing task demands increased the difference in absolute hip and knee energy absorption between sexes, but had no effect on relative joint contributions to total energy absorption. Sex differences in energy absorption are likely influenced by factors other than differences in relative task demands. Copyright © 2014 Elsevier Ltd. All rights reserved.

Explaining disparities in HIV infection among black and white men who have sex with men: a meta-analysis of HIV risk behaviors.

PubMed

Millett, Gregorio A; Flores, Stephen A; Peterson, John L; Bakeman, Roger

2007-10-01

To identify factors that contribute to the racial disparity in HIV prevalence between black and white men who have sex with men (MSM) in the United States. A comprehensive literature search of electronic databases, online bibliographies, and publication reference lists yielded 53 quantitative studies of MSM published between 1980 and 2006 that stratified HIV risk behaviors by race. Meta-analyses were performed to compare HIV risks between black and white MSM across studies. Compared with white MSM, black MSM reported less overall substance use [odds ratio (OR), 0.71; 95% confidence interval (CI), 0.53-0.97], fewer sex partners (OR, 0.64; 95% CI, 0.45-0.92), less gay identity (OR, 0.29; 95% CI, 0.17-0.48), and less disclosure of same sex behavior (OR, 0.42; 95% CI, 0.30-0.60). HIV-positive black MSM were less likely than HIV-positive white MSM to report taking antiretroviral medications (OR, 0.43; 95% CI, 0.30-0.61). Sexually transmitted diseases were significantly greater among black MSM than white MSM (OR, 1.64; 95% CI, 1.07-2.53). There were no statistically significant differences by race in reported unprotected anal intercourse, commercial sex work, sex with a known HIV-positive partner, or HIV testing history. Behavioral risk factors for HIV infection do not explain elevated HIV rates among black MSM. Continued emphasis on risk behaviors will have only limited impact on the disproportionate rates of HIV infection among black MSM. Future research should focus on the contribution of other factors, such as social networks, to explain racial disparities in HIV infection rates.

Impaired Health Status, Psychological Distress, and Personality in Women and Men With Nonobstructive Coronary Artery Disease: Sex and Gender Differences: The TWIST (Tweesteden Mild Stenosis) Study.

PubMed

Mommersteeg, Paula M C; Arts, Lindy; Zijlstra, Wobbe; Widdershoven, Jos W; Aarnoudse, Wilbert; Denollet, Johan

2017-02-01

Patients with nonobstructive coronary artery disease (NOCAD; wall irregularities, stenosis <60%), and women with NOCAD in particular, remain underinvestigated. We examined sex and gender (S&G) differences in health status, psychological distress, and personality between patients with NOCAD and the general population, as well as S&G differences within the NOCAD population. In total, 523 patients with NOCAD (61±9 years, 52% women) were included via coronary angiography and computed tomography as part of the TWIST (Tweesteden Mild Stenosis) study. Generic health status (12-item Short Form physical and mental scales and fatigue), psychological distress (Hospital Anxiety and Depression Scale anxiety and depressive symptoms and Global Mood Scale negative and positive affect), and personality (Type D personality) were compared between patients with NOCAD and an age- and sex-matched group of 1347 people from the general population. Frequency matching was performed to obtain a similar sex distribution in each age-decile group. Both men and women with NOCAD reported impaired health status, more psychological distress, and Type D personality compared with men and women in the reference group. Women reported more psychosocial distress compared with men, but no significant sex-by-group interaction effects were observed. Women with NOCAD reported impaired health status, more anxiety, and less positive affect, but no differences in depressive symptoms, angina, or Type D personality when compared with men with NOCAD. Age, education, employment, partner, and alcohol use explained these S&G differences within the NOCAD group. In both men and women, NOCAD was associated with impaired health status, more psychological distress, and Type D personality when compared with a reference population. Factors reflecting S&G differences explained these S&G findings in patient-reported outcomes. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01788241. © 2016 The Authors.

Adolescence and Depression.

ERIC Educational Resources Information Center

Wisconsin Clearinghouse, Madison.

This booklet begins with a poem written by an adolescent undergoing psychotherapy for depression, then goes on to describe what depression is and to examine sex and age differences related to depression. The difference between clinical depression and feeling blue is explained. Various therapies used in the treatment of depression are identified.…

Relationship Between Body Fatness and Performance in Preadolescent Children.

ERIC Educational Resources Information Center

Hensley, Larry D.; And Others

This study investigated the relationship between physical performance tests and body fatness in young children, and the extent to which differences in performance between the sexes could be explained by differences in body fatness. Measurements of age, height, weight, skinfold thicknesses, and performance scores on the vertical jump, standing…

The effects of temperature on sex determination in the bloater Coregonus hoyi: a hypothesis test

USGS Publications Warehouse

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.

Why is infant mortality higher in boys than in girls? A new hypothesis based on preconception environment and evidence from a large sample of twins.

PubMed

Pongou, Roland

2013-04-01

Infant mortality is higher in boys than girls in most parts of the world. This has been explained by sex differences in genetic and biological makeup, with boys being biologically weaker and more susceptible to diseases and premature death. At the same time, recent studies have found that numerous preconception or prenatal environmental factors affect the probability of a baby being conceived male or female. I propose that these environmental factors also explain sex differences in mortality. I contribute a new methodology of distinguishing between child biology and preconception environment by comparing male-female differences in mortality across opposite-sex twins, same-sex twins, and all twins. Using a large sample of twins from sub-Saharan Africa, I find that both preconception environment and child biology increase the mortality of male infants, but the effect of biology is substantially smaller than the literature suggests. I also estimate the interacting effects of biology with some intrauterine and external environmental factors, including birth order within a twin pair, social status, and climate. I find that a twin is more likely to be male if he is the firstborn, born to an educated mother, or born in certain climatic conditions. Male firstborns are more likely to survive than female firstborns, but only during the neonatal period. Finally, mortality is not affected by the interactions between biology and climate or between biology and social status.

Sex differences in the structural connectome of the human brain.

PubMed

Ingalhalikar, Madhura; Smith, Alex; Parker, Drew; Satterthwaite, Theodore D; Elliott, Mark A; Ruparel, Kosha; Hakonarson, Hakon; Gur, Raquel E; Gur, Ruben C; Verma, Ragini

2014-01-14

Sex differences in human behavior show adaptive complementarity: Males have better motor and spatial abilities, whereas females have superior memory and social cognition skills. Studies also show sex differences in human brains but do not explain this complementarity. In this work, we modeled the structural connectome using diffusion tensor imaging in a sample of 949 youths (aged 8-22 y, 428 males and 521 females) and discovered unique sex differences in brain connectivity during the course of development. Connection-wise statistical analysis, as well as analysis of regional and global network measures, presented a comprehensive description of network characteristics. In all supratentorial regions, males had greater within-hemispheric connectivity, as well as enhanced modularity and transitivity, whereas between-hemispheric connectivity and cross-module participation predominated in females. However, this effect was reversed in the cerebellar connections. Analysis of these changes developmentally demonstrated differences in trajectory between males and females mainly in adolescence and in adulthood. Overall, the results suggest that male brains are structured to facilitate connectivity between perception and coordinated action, whereas female brains are designed to facilitate communication between analytical and intuitive processing modes.

Sex, race, and consideration of bariatric surgery among primary care patients with moderate to severe obesity.

PubMed

Wee, Christina C; Huskey, Karen W; Bolcic-Jankovic, Dragana; Colten, Mary Ellen; Davis, Roger B; Hamel, Marybeth

2014-01-01

Bariatric surgery is one of few obesity treatments to produce substantial weight loss but only a small proportion of medically-eligible patients, especially men and racial minorities, undergo bariatric surgery. To describe primary care patients' consideration of bariatric surgery, potential variation by sex and race, and factors that underlie any variation. Telephone interview of 337 patients with a body mass index or BMI > 35 kg/m(2) seen at four diverse primary care practices in Greater-Boston. Patients' consideration of bariatric surgery. Of 325 patients who had heard of bariatric surgery, 34 % had seriously considered surgery. Men were less likely than women and African Americans were less likely than Caucasian patients to have considered surgery after adjustment for sociodemographics and BMI. Comorbid conditions did not explain sex and racial differences but racial differences dissipated after adjustment for quality of life (QOL), which tended to be higher among African American than Caucasian patients. Physician recommendation of bariatric surgery was independently associated with serious consideration for surgery [OR 4.95 (95 % CI 2.81-8.70)], but did not explain variation in consideration of surgery across sex and race. However, if recommended by their doctor, men were as willing and African American and Hispanic patients were more willing to consider bariatric surgery than their respective counterparts after adjustment. Nevertheless, only 20 % of patients reported being recommended bariatric surgery by their doctor and African Americans and men were less likely to receive this recommendation; racial differences in being recommended surgery were also largely explained by differences in QOL. High perceived risk to bariatric surgery was the most commonly cited barrier; financial concerns were uncommonly cited. Single geographic region; examined consideration and not who eventually proceeded with bariatric surgery. African Americans and men were less likely to have considered bariatric surgery and were less likely to have been recommended surgery by their doctors. Differences in how obesity affects QOL appear to account for some of these variations. High perceived risk rather than financial barrier was the major deterrent for patients.

Correlation and sex differences between ankle and knee cartilage morphology determined by quantitative magnetic resonance imaging

PubMed Central

Eckstein, F; Siedek, V; Glaser, C; Al-Ali, D; Englmeier, K; Reiser, M; Graichen, H

2004-01-01

Objective: To study the correlation between ankle and knee cartilage morphology to test the hypothesis that knee joint cartilage loss in gonarthritis can be estimated retrospectively using quantitative MRI analysis of the knee and ankle and established regression equations; and to test the hypothesis that sex differences in joint surface area are larger in the knee than the ankle, which may explain the greater incidence of knee osteoarthritis in elderly women than in elderly men. Methods: Sagittal MR images (3D FLASH WE) of the knee and hind foot were acquired in 29 healthy subjects (14 women, 15 men; mean (SD) age, 25 (3) years), with no signs joint disease. Cartilage volume, thickness, and joint surface area were determined in the knee, ankle, and subtalar joint. Results: Knee cartilage volumes and joint surface areas showed only moderate correlations with those of the ankle and subtalar joint (r = 0.33 to 0.81). The correlations of cartilage thickness between the two joints were weaker still (r = –0.05 to 0.53). Sex differences in cartilage morphology at the knee and the ankle were similar, with surface areas being –17.5% to –23.5% lower in women than in men. Conclusions: Only moderate correlations in cartilage morphology of healthy subjects were found between knee and ankle. It is therefore impractical to estimate knee joint cartilage loss a posteriori in cross sectional studies by measuring the hind foot and then applying a scaling factor. Sex differences in cartilage morphology do not explain differences in osteoarthritis incidence between men and women in the knee and ankle. PMID:15479900

THE FEMALE ADVANTAGE: SEX AS A POSSIBLE PROTECTIVE FACTOR AGAINST EMOTION RECOGNITION IMPAIRMENT FOLLOWING TRAUMATIC BRAIN INJURY

PubMed Central

Rigon, Arianna; Turkstra, Lyn; Mutlu, Bilge; Duff, Melissa

2018-01-01

Although moderate to severe traumatic brain injury (TBI) leads to facial affect recognition impairments in up to 39% of individuals, protective and risk factors for these deficits are unknown. The aim of the current study was to examine the effect of sex on emotion recognition abilities following TBI. We administered two separate emotion recognition tests (one static and one dynamic) to 53 individuals with moderate to severe TBI (Females=28) and 49 demographically matched comparisons (Females=22). We then investigated the presence of a sex-by-group interaction in emotion recognition accuracy. In the comparison group, there were no sex differences. In the TBI group, however, females significantly outperformed males in the dynamic (but not the static) task. Moreover, males (but not females) with TBI performed significantly worse than comparison participants in the dynamic task. Further analysis revealed that sex differences in emotion recognition abilities within the TBI group could not be explained by lesion location, TBI severity, or other neuropsychological variables. These findings suggest that sex may serve as a protective factor for social impairment following TBI and inform clinicians working with TBI as well as research on the neurophysiological correlates of sex differences in social functioning. PMID:27245826

Summer habitat selection by Dall’s sheep in Wrangell-St. Elias National Park and Preserve, Alaska

USGS Publications Warehouse

Roffler, Gretchen H.; Adams, Layne G.; Hebblewhite, Mark

2017-01-01

Sexual segregation occurs frequently in sexually dimorphic species, and it may be influenced by differential habitat requirements between sexes or by social or evolutionary mechanisms that maintain separation of sexes regardless of habitat selection. Understanding the degree of sex-specific habitat specialization is important for management of wildlife populations and the design of monitoring and research programs. Using mid-summer aerial survey data for Dall’s sheep (Ovis dalli dalli) in southern Alaska during 1983–2011, we assessed differences in summer habitat selection by sex and reproductive status at the landscape scale in Wrangell-St. Elias National Park and Preserve (WRST). Males and females were highly segregated socially, as were females with and without young. Resource selection function (RSF) models containing rugged terrain, intermediate values of the normalized difference vegetation index (NDVI), and open landcover types best explained resource selection by each sex, female reproductive classes, and all sheep combined. For male and all female models, most coefficients were similar, suggesting little difference in summer habitat selection between sexes at the landscape scale. A combined RSF model therefore may be used to predict the relative probability of resource selection by Dall’s sheep in WRST regardless of sex or reproductive status.

Sex differences in a shoaling-boldness behavioral syndrome, but no link with aggression.

PubMed

Way, Gregory P; Kiesel, Alexis L; Ruhl, Nathan; Snekser, Jennifer L; McRobert, Scott P

2015-04-01

A behavioral syndrome is observed in a population when specific behaviors overlap at the individual level in different contexts. Here, we explore boldness and aggression personality spectra, the repeatability of shoaling, and possible associated correlations between the behaviors in a population of lab-reared zebrafish (Danio rerio). Our findings describe a sex-specific boldness-shoaling behavioral syndrome, as a link between boldness and shoaling behaviors is detected. The results indicate that bold males are likely to have a stronger shoaling propensity than shy males for unfamiliar conspecifics. Conversely, bold females are more likely to shoal than shy females, but only when presented with heterospecific individuals. Additionally, aggression does not correlate with boldness or shoaling propensity for either sex. A positive relationship between boldness and shoaling that differs by sex is contrary to most of the present literature, but could help to explain population dynamics and may also have evolutionary implications. Copyright © 2015 Elsevier B.V. All rights reserved.

Invited review: sex ratio and rheumatic disease.

PubMed

Lockshin, M D

2001-11-01

Human illnesses affect men and women differently. In some cases (diseases of sex organs, diseases resulting from X or Y chromosome mutations), reasons for sex discrepancy are obvious, but in other cases no reason is apparent. Explanations for sex discrepancy of illness occur at different biological levels: molecular (e.g., imprinting, X-inactivation), cellular (sex-specific receptor activity), organ (endocrine influences), whole organism (size, age), and environmental-behavioral, including intrauterine influences. Autoimmunity represents a prototypical class of illness that has high female-to-male (F/M) ratios. Although the F/M ratios in autoimmune diseases are usually attributed to the influence of estrogenic hormones, evidence demonstrates that the attributed ratios are imprecise and that definitions and classifications of autoimmune diseases vary, rendering at least part of the counting imprecise. In addition, many studies on sex discrepancy of human disease fail to distinguish between disease incidence and disease severity. In April 2001, the Institute of Medicine of the National Academy of Sciences published Exploring the Biological Contributions to Human Health: Does Sex Matter? (Wizemann T and Pardue M-L, editors). This minireview summarizes the section of that report that concerns autoimmune and infectious disease. Some thyroid, rheumatic, and hepatic autoimmune diseases have high F/M ratios, whereas others have low. Those that have high ratios occur primarily in young adulthood. Gonadal hormones, if they play a role, likely do so through a threshold or permissive mechanism. Examples of sex differences that could be caused by environmental exposure, X inactivation, imprinting, X or Y chromosome genetic modulators, and intrauterine influences are presented as alternate, theoretical, and largely unexplored explanations for sex differences of incidence. The epidemiology of autoimmune diseases (young, female) suggests that an explanation for sex discrepancy of these illnesses lies in differential exposure, vulnerable periods, or thresholds. Biologists have an opportunity to inform medical scientists about sex differences that explain different attack rates in specific diseases, and physicians offer biologists experiments of nature to test theories of sex.

The evolution of sex ratio differences and inflorescence architectures in Begonia (Begoniaceae).

PubMed

Twyford, Alex D; Ennos, Richard A; White, Chris D; Ali, Mobina Shaukat; Kidner, Catherine A

2014-02-01

A major benefit conferred by monoecy is the ability to alter floral sex ratio in response to selection. In monoecious species that produce flowers of a given sex at set positions on the inflorescence, floral sex ratio may be related to inflorescence architecture. We studied the loci underlying differences in inflorescence architecture between two monoecious Begonia species and related this to floral sex ratios. We performed trait comparisons and quantitative trait locus (QTL) mapping in a segregating backcross population between Central American Begonia plebeja and B. conchifolia. We focused on traits related to inflorescence architecture, sex ratios, and other reproductive traits. The inflorescence branching pattern of B. conchifolia was more asymmetric than B. plebeja, which in turn affects the floral sex ratio. Colocalizing QTLs of moderate effect influenced both the number of male flowers and the fate decisions of axillary meristems, demonstrating the close link between inflorescence architecture and sex ratio. Additional QTLs were found for stamen number (30% variance explained, VE) and pollen sterility (12.3% VE). One way in which Begonia species develop different floral sex ratios is through modifications of their inflorescence architecture. The potential pleiotropic action of QTL on inflorescence branching and floral sex ratios may have major implications for trait evolution and responses to selection. The presence of a single QTL of large effect on stamen number may allow rapid divergence for this key floral trait. We propose candidate loci for stamen number and inflorescence branching for future characterization.

Helping effort increases with relatedness in bell miners, but ‘unrelated’ helpers of both sexes still provide substantial care

PubMed Central

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

Preferences, constraints, and the process of sex segregation in college majors: A choice analysis.

PubMed

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.

The role of testosterone and estradiol in brain volume changes across adolescence: a longitudinal structural MRI study.

PubMed

Herting, Megan M; Gautam, Prapti; Spielberg, Jeffrey M; Kan, Eric; Dahl, Ronald E; Sowell, Elizabeth R

2014-11-01

It has been postulated that pubertal hormones may drive some neuroanatomical changes during adolescence, and may do so differently in girls and boys. Here, we use growth curve modeling to directly assess how sex hormones [testosterone (T) and estradiol (E₂)] relate to changes in subcortical brain volumes utilizing a longitudinal design. 126 adolescents (63 girls), ages 10 to 14, were imaged and restudied ∼2 years later. We show, for the first time, that best-fit growth models are distinctly different when using hormones as compared to a physical proxy of pubertal maturation (Tanner Stage) or age, to predict brain development. Like Tanner Stage, T and E₂ predicted white matter and right amygdala growth across adolescence in both sexes, independent of age. Tanner Stage also explained decreases in both gray matter and caudate volumes, whereas E₂ explained only gray matter decreases and T explained only caudate volume decreases. No pubertal measures were related to hippocampus development. Although specificity was seen, sex hormones had strikingly similar relationships with white matter, gray matter, right amygdala, and bilateral caudate volumes, with larger changes in brain volume seen at early pubertal maturation (as indexed by lower hormone levels), followed by less robust, or even reversals in growth, by late puberty. These novel longitudinal findings on the relationship between hormones and brain volume change represent crucial first steps toward understanding which aspects of puberty influence neurodevelopment. Copyright © 2014 Wiley Periodicals, Inc.

An fMRI study of sex differences in regional activation to a verbal and a spatial task.

PubMed

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.

Sex Differences in General Knowledge: Meta-Analysis and New Data on the Contribution of School-Related Moderators among High-School Students

PubMed Central

Tran, Ulrich S.; Hofer, Agnes A.; Voracek, Martin

2014-01-01

Research from various countries consistently reported an advantage of boys over girls in general knowledge and was also suggestive of some overall trends regarding specific domains of general knowledge that were speculated to stem from biologically differentiated interests. However, results were heterogeneous and, as of yet, had not been evaluated meta-analytically. Moreover, previous research drew on overly homogeneous high-school or undergraduate samples whose representativeness appears problematic; mostly, likely moderators, such as school type, student age or parental education, were also not directly investigated or controlled for. We provide a meta-analytical aggregation of available results regarding sex differences in general knowledge and present new data, investigating the psychometric properties of the General Knowledge Test (GKT), on which previous research primarily relied, and explored sex differences in a large and heterogeneous Austrian high-school student sample (N = 1088). The aggregated sex effect in general knowledge was of medium size in previous research, but differences in specific domains were heterogeneous across countries and only modest at best. Large sex differences in our data could be explained to a large part by school-related moderators (school type, school, student age, parental education) and selection processes. Boys had a remaining advantage over girls that was only small in size and that was consistent with the magnitude of sex differences in general intelligence. Analysis of the GKT yielded no evidence of biologically differentiated interests, but of a specific interest in the humanities among girls. In conclusion, previous research likely overestimated sex differences in general knowledge. PMID:25347190

Sex differences in general knowledge: meta-analysis and new data on the contribution of school-related moderators among high-school students.

PubMed

Tran, Ulrich S; Hofer, Agnes A; Voracek, Martin

2014-01-01

Research from various countries consistently reported an advantage of boys over girls in general knowledge and was also suggestive of some overall trends regarding specific domains of general knowledge that were speculated to stem from biologically differentiated interests. However, results were heterogeneous and, as of yet, had not been evaluated meta-analytically. Moreover, previous research drew on overly homogeneous high-school or undergraduate samples whose representativeness appears problematic; mostly, likely moderators, such as school type, student age or parental education, were also not directly investigated or controlled for. We provide a meta-analytical aggregation of available results regarding sex differences in general knowledge and present new data, investigating the psychometric properties of the General Knowledge Test (GKT), on which previous research primarily relied, and explored sex differences in a large and heterogeneous Austrian high-school student sample (N = 1088). The aggregated sex effect in general knowledge was of medium size in previous research, but differences in specific domains were heterogeneous across countries and only modest at best. Large sex differences in our data could be explained to a large part by school-related moderators (school type, school, student age, parental education) and selection processes. Boys had a remaining advantage over girls that was only small in size and that was consistent with the magnitude of sex differences in general intelligence. Analysis of the GKT yielded no evidence of biologically differentiated interests, but of a specific interest in the humanities among girls. In conclusion, previous research likely overestimated sex differences in general knowledge.

THE APPARENT NON-SIGNIFICANCE OF SEX IN CHILD UNDERNUTRITION IN INDIA.

PubMed

Mukhopadhyay, Simantini

2016-03-01

The lack of significance of sex in the determination of child nutrition in India, as revealed from the analysis of data from the entire population, is misleading and perplexing. Given that child nutrition is affected by all channels through which sex bias operates, scholars have sought to explain its inconclusive evidence, looking at child-specific household-level factors such as birth order and sex composition of surviving older siblings. The paper points out that sex inequality needs to be examined in the context of its intersection with other consequential social identities such as religious membership, economic status and caste group affiliation. Sex disparity in child stunting is found to be prevalent particularly among upper caste Hindus. However, the relative advantage that poor tribal girls enjoy is reversed with improvement in wealth status. Thus, children in different social settings need customized policy focus.

Epigenetics and Sex Differences in the Brain: A Genome-Wide Comparison of Histone-3 Lysine-4 Trimethylation (H3K4me3) in Male and Female Mice

PubMed Central

Shen, Erica Y.; Ahern, Todd H.; Cheung, Iris; Straubhaar, Juerg; Dincer, Aslihan; Houston, Isaac; de Vries, Geert J.; Akbarian, Schahram; Forger, Nancy G.

2014-01-01

Many neurological and psychiatric disorders exhibit gender disparities, and sex differences in the brain likely explain some of these effects. Recent work in rodents points to a role for epigenetics in the development or maintenance of neural sex differences, although genome-wide studies have so far been lacking. Here we review the existing literature on epigenetics and brain sexual differentiation and present preliminary analyses on the genome-wide distribution of histone-3 lysine-4 trimethylation in a sexually dimorphic brain region in male and female mice. H3K4me3 is a histone mark primarily organized as ‘peaks’ surrounding the transcription start site of active genes. We microdissected the bed nucleus of the stria terminalis and preoptic area (BNST/POA) in adult male and female mice and used ChIP-Seq to compare the distribution of H3K4me3 throughout the genome. We found 248 genes and loci with a significant sex difference in H3K4me3. Of these, the majority (71%) had larger H3K4me3 peaks in females. Comparisons with existing databases indicate that genes and loci with increased H3K4me3 in females are associated with synaptic function and with expression atlases from related brain areas. Based on RT-PCR, only a minority of genes with a sex difference in H3K4me3 has detectable sex differences in expression at baseline conditions. Together with previous findings, our data suggest there may be sex biases in the use of epigenetic marks. Such biases could underlie sex differences in vulnerabilities to drugs or diseases that disrupt specific epigenetic processes. PMID:25131640

Clinical epidemiology of Alzheimer's disease: assessing sex and gender differences.

PubMed

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

PubMed Central

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

Influences of gender role and anxiety on sex differences in temporal summation of pain.

PubMed

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.

A framework for analyzing sex-selective abortion: the example of changing sex ratios in Southern Caucasus

PubMed Central

Hohmann, Sophie A; Lefèvre, Cécile A; Garenne, Michel L

2014-01-01

The paper proposes a socioeconomic framework of supply, demand, and regulation to explain the development of sex-selective abortion in several parts of the world. The framework is then applied to three countries of southern Caucasus (Armenia, Azerbaijan, and Georgia) where sex-selective abortion has developed since the collapse of the Soviet Union. The authors argue that sex-selective abortion cannot be explained simply by patriarchal social systems, sex discrimination, or son preference. The emphasis is put on the long-term acceptability of abortion in the region, on acceptability of sex-screening by both the medical establishment and by the population, on newly imported techniques of sex-screening, and on the changing demand for children associated with the major economic and social changes that followed the dismantlement of the Soviet Union. PMID:25349481

Amygdala subnuclei resting-state functional connectivity sex and estrogen differences.

PubMed

Engman, Jonas; Linnman, Clas; Van Dijk, Koene R A; Milad, Mohammed R

2016-01-01

The amygdala is a hub in emotional processing, including that of negative affect. Healthy men and women have distinct differences in amygdala responses, potentially setting the stage for the observed sex differences in the prevalence of fear, anxiety, and pain disorders. Here, we examined how amygdala subnuclei resting-state functional connectivity is affected by sex, as well as explored how the functional connectivity is related to estrogen levels. Resting-state functional connectivity was measured using functional magnetic resonance imaging (fMRI) with seeds placed in the left and right laterobasal (LB) and centromedial (CM) amygdala. Sex differences were studied in 48 healthy men and 48 healthy women, matched for age, while the association with estrogen was analyzed in a subsample of 24 women, for whom hormone levels had been assessed. For the hormone analyses, the subsample was further divided into a lower and higher estrogen levels group based on a median split. We found distinct sex differences in the LB and CM amygdala resting-state functional connectivity, as well as preliminary evidence for an association between estrogen levels and connectivity patterns. These results are potentially valuable in explaining why women are more afflicted by conditions of negative affect than are men, and could imply a mechanistic role for estrogen in modulating emotion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sex and boldness explain individual differences in spatial learning in a lizard.

PubMed

Carazo, Pau; Noble, Daniel W A; Chandrasoma, Dani; Whiting, Martin J

2014-05-07

Understanding individual differences in cognitive performance is a major challenge to animal behaviour and cognition studies. We used the Eastern water skink (Eulamprus quoyii) to examine associations between exploration, boldness and individual variability in spatial learning, a dimension of lizard cognition with important bearing on fitness. We show that males perform better than females in a biologically relevant spatial learning task. This is the first evidence for sex differences in learning in a reptile, and we argue that it is probably owing to sex-specific selective pressures that may be widespread in lizards. Across the sexes, we found a clear association between boldness after a simulated predatory attack and the probability of learning the spatial task. In contrast to previous studies, we found a nonlinear association between boldness and learning: both 'bold' and 'shy' behavioural types were more successful learners than intermediate males. Our results do not fit with recent predictions suggesting that individual differences in learning may be linked with behavioural types via high-low-risk/reward trade-offs. We suggest the possibility that differences in spatial cognitive performance may arise in lizards as a consequence of the distinct environmental variability and complexity experienced by individuals as a result of their sex and social tactics.

Condom and Substance Use at Last Sex: Differences between MSMO and MSWO High School Youth.

PubMed

Phillips, Gregory; Kalmin, Mariah M; Turner, Blair; Felt, Dylan; Marro, Rachel; Salamanca, Paul; Beach, Lauren B

2018-05-15

HIV disproportionately impacts youth, particularly young men who have sex with men (YMSM), a population that includes subgroups of young men who have sex with men only (YMSMO) and young men who have sex with men and women (YMSMW). In 2015, among male youth, 92% of new HIV diagnoses were among YMSM. The reasons why YMSM are disproportionately at risk for HIV acquisition, however, remain incompletely explored. We performed event-level analyses to compare how the frequency of condom use, drug and/or alcohol use at last sex differed among YMSMO and YMSWO (young men who have sex with women only) over a ten-year period from 2005⁻2015 within the Youth Risk Behavior Survey (YRBS). YMSMO were less likely to use condoms at last sex compared to YMSWO. However, no substance use differences at last sexual encounter were detected. From 2005⁻2015, reported condom use at last sex significantly declined for both YMSMO and YMSWO, though the decline for YMSMO was more notable. While there were no significant differences in alcohol and substance use at last sex over the same ten-year period for YMSMO, YMSWO experienced a slight but significant decrease in reported alcohol and substance use. These event-level analyses provide evidence that YMSMO, similar to adult MSMO, may engage in riskier sexual behaviors compared to YMSWO, findings which may partially explain the increased burden of HIV in this population. Future work should investigate how different patterns of event-level HIV risk behaviors vary over time among YMSMO, YMSWO, and YMSMW, and are tied to HIV incidence among these groups.

Biological and demographic causes of high HIV and sexually transmitted disease prevalence in men who have sex with men

PubMed Central

Goodreau, Steven M; Golden, Matthew R

2007-01-01

Objectives HIV disproportionately affects men who have sex with men (MSM). MSM and heterosexual networks are distinguished by biologically determined sexual role segregation among heterosexual individuals but not MSM, and anal/vaginal transmissibility differences. To identify how much these biological and demographic differences could explain persistent disparities in HIV/sexually transmitted disease prevalence in the United States, even were MSM and heterosexual individuals to report identical numbers of unprotected sexual partnerships per year. Methods A compartmental model parameterized using two population‐based surveys. Role composition was varied between MSM and heterosexual subjects (insertive‐only and receptive‐only versus versatile individuals) and infectivity values. Results The absence of sexual role segregation in MSM and the differential anal/vaginal transmission probabilities led to considerable disparities in equilibrium prevalence. The US heterosexual population would only experience an epidemic comparable to MSM if the mean partner number of heterosexual individuals was increased several fold over that observed in population‐based studies of either group. In order for MSM to eliminate the HIV epidemic, they would need to develop rates of unprotected sex lower than those currently exhibited by heterosexual individuals in the United States. In this model, for US heterosexual individuals to have a self‐sustaining epidemic, they would need to adopt levels of unprotected sex higher than those currently exhibited by US MSM. Conclusions The persistence of disparities in HIV between heterosexual individuals and MSM in the United States cannot be explained solely by differences in risky sexual behavior between these two populations. PMID:17855487

A varied pattern of change of the sex differential in survival in the G7 countries.

PubMed

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.

Sex differences in attention to disgust facial expressions.

PubMed

Kraines, Morganne A; Kelberer, Lucas J A; Wells, Tony T

2017-12-01

Research demonstrates that women experience disgust more readily and with more intensity than men. The experience of disgust is associated with increased attention to disgust-related stimuli, but no prior study has examined sex differences in attention to disgust facial expressions. We hypothesised that women, compared to men, would demonstrate increased attention to disgust facial expressions. Participants (n = 172) completed an eye tracking task to measure visual attention to emotional facial expressions. Results indicated that women spent more time attending to disgust facial expressions compared to men. Unexpectedly, we found that men spent significantly more time attending to neutral faces compared to women. The findings indicate that women's increased experience of emotional disgust also extends to attention to disgust facial stimuli. These findings may help to explain sex differences in the experience of disgust and in diagnoses of anxiety disorders in which disgust plays an important role.

Sex- and Age-Related Differences in Bone Microarchitecture in Men Relative to Women Assessed by High-Resolution Peripheral Quantitative Computed Tomography

PubMed Central

Amin, Shreyasee; Khosla, Sundeep

2012-01-01

The trabecular and cortical compartments of bone each contributes to bone strength. Until recently, assessment of trabecular and cortical microstructure has required a bone biopsy. Now, trabecular and cortical microstructure of peripheral bone sites can be determined noninvasively using high-resolution peripheral quantitative computed tomography (HR-pQCT). Studies that have used HR-pQCT to evaluate cohorts of both men and women have provided novel insights into the changes in bone microarchitecture that occur with age between the sexes, which may help to explain the lower fracture incidence in older men relative to women. This review will highlight observations from these studies on both the sex- and age-related differences in trabecular and cortical microstructure that may underlie the differences in bone strength, and thereby fracture risk, between men and women. PMID:22496983

Polyploidy in animals: effects of gene expression on sex determination, evolution and ecology.

PubMed

Wertheim, B; Beukeboom, L W; van de Zande, L

2013-01-01

Polyploidy is rarer in animals than in plants. Why? Since Muller's observation in 1925, many hypotheses have been proposed and tested, but none were able to completely explain this intriguing fact. New genomic technologies enable the study of whole genomes to explain the constraints on or consequences of polyploidization, rather than focusing on specific genes or life history characteristics. Here, we review a selection of old and recent literature on polyploidy in animals, with emphasis on the consequences of polyploidization for gene expression patterns and genomic network interactions. We propose a conceptual model to contrast various scenarios for changes in genomic networks, which may serve as a framework to explain the different evolutionary dynamics of polyploidy in animals and plants. We also present new insights of genetic sex determination in animals and our emerging understanding of how animal sex determination systems may hamper or enable polyploidization, including some recent data on haplodiploids. We discuss the role of polyploidy in evolution and ecology, using a gene regulation perspective, and conclude with a synopsis regarding the effects of whole genome duplications on the balance of genomic networks. See also the sister articles focusing on plants by Ashman et al. and Madlung and Wendel in this themed issue. Copyright © 2013 S. Karger AG, Basel.

Sex differences in fluctuating asymmetry of body traits in chewing lice Docophorulus coarctatus (Phthiraptera: Ischnocera).

PubMed

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.

Transactional sex risk across a typology of rural and urban female sex workers in Indonesia: a mixed methods study.

PubMed

Puradiredja, Dewi Ismajani; Coast, Ernestina

2012-01-01

Context-specific typologies of female sex workers (FSWs) are essential for the design of HIV intervention programming. This study develops a novel FSW typology for the analysis of transactional sex risk in rural and urban settings in Indonesia. Mixed methods include a survey of rural and urban FSWs (n=310), in-depth interviews (n=11), key informant interviews (n=5) and ethnographic assessments. Thematic analysis categorises FSWs into 5 distinct groups based on geographical location of their sex work settings, place of solicitation, and whether sex work is their primary occupation. Multiple regression analysis shows that the likelihood of consistent condom use was higher among urban venue-based FSWs for whom sex work is not the only source of income than for any of the other rural and urban FSW groups. This effect was explained by the significantly lower likelihood of consistent condom use by rural venue-based FSWs (adjusted OR: 0.34 95% CI 0.13-0.90, p=0.029). The FSW typology and differences in organisational features and social dynamics are more closely related to the risk of unprotected transactional sex, than levels of condom awareness and availability. Interventions need context-specific strategies to reach the different FSWs identified by this study's typology.

A comparison of health-related quality of life in idiopathic pulmonary fibrosis and chronic hypersensitivity pneumonitis.

PubMed

Lubin, Molly; Chen, Hubert; Elicker, Brett; Jones, Kirk D; Collard, Harold R; Lee, Joyce S

2014-06-01

Patients with interstitial lung disease (ILD) have poor health-related quality of life (HRQL). However, whether HRQL differs among different subtypes of ILD is unclear. The aim of this study was to determine whether HRQL was different among patients with idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis (CHP). We identified patients from an ongoing longitudinal cohort of patients with ILD. HRQL was assessed using the Short Form (SF)-36 medical outcomes form (version 2.0). Regression analysis was used to determine the association between clinical covariates and HRQL, primarily the physical component summary (PCS) and mental component summary (MCS) score. A multivariate regression model was created to identify potential covariates that could help explain the association between the ILD subtype and HRQL. Patients with IPF (n = 102) were older, more likely to be men, and more likely to have smoked. Pulmonary function was similar between the groups. The patients with CHP (n = 69) had worse HRQL across all eight domains of the SF-36, as well as the PCS and MCS, compared with patients with IPF (P < .01-.09). This pattern remained after controlling for age and pulmonary function (P < .01-.02). Covariates explaining part of the relationship between disease subtype and PCS score included severity of dyspnea (P < .01) and fatigue (P < .01). Covariates explaining part of the relationship between disease subtype and MCS score included severity of dyspnea (P < .01), female sex (P = .02), and fatigue (P = .02). HRQL is worse in CHP compared with IPF. HRQL differences between ILD subtypes are explained in part by differences in sex, dyspnea, and fatigue.

The Political Divide Over Same-Sex Marriage: Mating Strategies in Conflict?

PubMed

Pinsof, David; Haselton, Martie

2016-04-01

Although support for same-sex marriage has grown dramatically over the past decade, public opinion remains markedly divided. Here, we propose that the political divide over same-sex marriage represents a deeper divide between conflicting mating strategies. Specifically, we propose that opposition to same-sex marriage can be explained in terms of (a) individual differences in short-term mating orientation and (b) mental associations between homosexuality and sexual promiscuity. We created a novel Implicit Association Test to measure mental associations between homosexuality and promiscuity. We found that mental associations between homosexuality and promiscuity, at both the implicit and the explicit levels, interacted with short-term mating orientation to predict opposition to same-sex marriage. Our model accounted for 42.3% of the variation in attitudes toward same-sex marriage, and all predictors remained robust when we controlled for potential confounds. Our results reveal the centrality of mating psychology in attitudes toward same-sex marriage. © The Author(s) 2016.

Life Expectancy and Years of Potential Life Lost After Acute Myocardial Infarction by Sex and Race: A Cohort-Based Study of Medicare Beneficiaries.

PubMed

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.

Gender, multiple roles, role meaning, and mental health.

PubMed

Simon, R W

1995-06-01

This paper examines gender differences in the consequences of combining spouse, parent, and worker roles for mental health. I suggest that work and family roles have different meanings for males and females, and that differences in the meaning of these roles may be partially responsible for why the mental health advantages of holding multiple roles are fewer for women than for men. Based on qualitative analyses of follow-up, in-depth interviews with 40 employed married parents who participated in a community panel study of mental health, I find that sex differences in the perceived relationship between work and family roles may help account for sex differences in distress by contributing to male-female differences in both the extent and nature of work-parent conflicts, attributions of responsibility for marital problems, feelings of guilt, and self-evaluations as parents and spouses. By identifying gender differences in the meaning of roles among individuals who have the same multiple role configuration, and suggesting how these differences can help explain sex differences in well-being; this research may expand existing theories about the mental health consequences of multiple role involvements.

The male handicap: male-biased mortality explains skewed sex ratios in brown trout embryos.

PubMed

Morán, P; Labbé, L; Garcia de Leaniz, C

2016-12-01

Juvenile sex ratios are often assumed to be equal for many species with genetic sex determination, but this has rarely been tested in fish embryos due to their small size and absence of sex-specific markers. We artificially crossed three populations of brown trout and used a recently developed genetic marker for sexing the offspring of both pure and hybrid crosses. Sex ratios (SR = proportion of males) varied widely one month after hatching ranging from 0.15 to 0.90 (mean = 0.39 ± 0.03). Families with high survival tended to produce balanced or male-biased sex ratios, but SR was significantly female-biased when survival was low, suggesting that males sustain higher mortality during development. No difference in SR was found between pure and hybrid families, but the existence of sire × dam interactions suggests that genetic incompatibility may play a role in determining sex ratios. Our findings have implications for animal breeding and conservation because skewed sex ratios will tend to reduce effective population size and bias selection estimates. © 2016 The Authors.

Long-term trends of bloater (Coregonus hoyi) recruitment in Lake Michigan: evidence for the effect of sex ratio

USGS Publications Warehouse

Bunnell, David B.; Madenjian, Charles P.; Croley, Thomas E.

2006-01-01

Long-term population trends are generally explained by factors extrinsic (e.g., climate, predation) rather than intrinsic (e.g., genetics, maternal effects) to the population. We sought to understand the long-term population dynamics of an important native Lake Michigan prey fish, the bloaterCoregonus hoyi. Over a 38-year time series, three 10- to 15-year phases occurred (poor, excellent, and then poor recruitment) without high interannual variability within a particular phase. We used dynamic linear models to determine whether extrinsic (winter and spring temperature, alewife predator densities) or intrinsic factors (population egg production, adult condition, adult sex ratio) explained variation in recruitment. Models that included population egg production, sex ratio, winter and spring temperature, and adult bloater condition explained the most variation. Of these variables, sex ratio, which ranged from 47% to 97% female across the time series, consistently had the greatest effect: recruitment declined with female predominance. Including biomass of adult alewife predators in the models did not explain additional variation. Overall our results indicated that bloater recruitment is linked to its sex ratio, but understanding the underlying mechanisms will require additional efforts.

Genetic and epigenetic architecture of sex-biased expression in the jewel wasps Nasonia vitripennis and giraulti

PubMed Central

Wang, Xu; Werren, John H.; Clark, Andrew G.

2015-01-01

There is extraordinary diversity in sexual dimorphism (SD) among animals, but little is known about its epigenetic basis. To study the epigenetic architecture of SD in a haplodiploid system, we performed RNA-seq and whole-genome bisulfite sequencing of adult females and males from two closely related parasitoid wasps, Nasonia vitripennis and Nasonia giraulti. More than 75% of expressed genes displayed significantly sex-biased expression. As a consequence, expression profiles are more similar between species within each sex than between sexes within each species. Furthermore, extremely male- and female-biased genes are enriched for totally different functional categories: male-biased genes for key enzymes in sex-pheromone synthesis and female-biased genes for genes involved in epigenetic regulation of gene expression. Remarkably, just 70 highly expressed, extremely male-biased genes account for 10% of all transcripts in adult males. Unlike expression profiles, DNA methylomes are highly similar between sexes within species, with no consistent sex differences in methylation found. Therefore, methylation changes cannot explain the extensive level of sex-biased gene expression observed. Female-biased genes have smaller sequence divergence between species, higher conservation to other hymenopterans, and a broader expression range across development. Overall, female-biased genes have been recruited from genes with more conserved and broadly expressing “house-keeping” functions, whereas male-biased genes are more recently evolved and are predominately testis specific. In summary, Nasonia accomplish a striking degree of sex-biased expression without sex chromosomes or epigenetic differences in methylation. We propose that methylation provides a general signal for constitutive gene expression, whereas other sex-specific signals cause sex-biased gene expression. PMID:26100871

Antecedents and sex/gender differences in youth suicidal behavior

PubMed Central

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

Absence of sex differential plasticity to light availability during seed maturation in Geranium sylvaticum.

PubMed

Varga, Sandra; Laaksonen, Ester; Siikamäki, Pirkko; Kytöviita, Minna-Maarit

2015-01-01

Sex-differential plasticity (SDP) hypothesis suggests that since hermaphrodites gain fitness through both pollen and seed production they may have evolved a higher degree of plasticity in their reproductive strategy compared to females which achieve fitness only through seed production. SDP may explain the difference in seed production observed between sexes in gynodioecious species in response to resource (nutrients or water) availability. In harsh environments, hermaphrodites decrease seed production whereas females keep it relatively similar regardless of the environmental conditions. Light availability can be also a limiting resource and thus could theoretically affect differently female and hermaphrodite seed output even though this ecological factor has been largely overlooked. We tested whether the two sexes in the gynodioecious species Geranium sylvaticum differ in their tolerance to light limitation during seed maturation in the field. We used a fully factorial block experiment exposing female and hermaphrodite plants to two different light environments (control and shade) after their peak flowering period. Specifically, we measured fruit and seed production in response to decreased light availability and compared it between the sexes. Shading reduced the number of fruits and seeds produced, but the decrease was similar between the sexes. Furthermore, shading delayed seed production by three days in both sexes, but did not affect seed mass, seed P content, or the probability of re-flowering the following year. Our results give no evidence for reproductive SDP in response to light during seed maturation.

The Evolution of Genome Structure by Natural and Sexual Selection.

PubMed

Kirkpatrick, Mark

2017-01-01

Progress on understanding how genome structure evolves is accelerating with the arrival of new genomic, comparative, and theoretical approaches. This article reviews progress in understanding how chromosome inversions and sex chromosomes evolve, and how their evolution affects species' ecology. Analyses of clines in inversion frequencies in flies and mosquitoes imply strong local adaptation, and roles for both over- and under dominant selection. Those results are consistent with the hypothesis that inversions become established when they capture locally adapted alleles. Inversions can carry alleles that are beneficial to closely related species, causing them to introgress following hybridization. Models show that this "adaptive cassette" scenario can trigger large range expansions, as recently happened in malaria mosquitoes. Sex chromosomes are the most rapidly evolving genome regions of some taxa. Sexually antagonistic selection may be the key force driving transitions of sex determination between different pairs of chromosomes and between XY and ZW systems. Fusions between sex-chromosomes and autosomes most often involve the Y chromosome, a pattern that can be explained if fusions are mildly deleterious and fix by drift. Sexually antagonistic selection is one of several hypotheses to explain the recent discovery that the sex determination system has strong effects on the adult sex ratios of tetrapods. The emerging view of how genome structure evolves invokes a much richer constellation of forces than was envisioned during the Golden Age of research on Drosophila karyotypes. © The American Genetic Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Blind Adolescents' Perceptions of Parental Attitudes.

ERIC Educational Resources Information Center

Agarwal, Rita; Piplani, Rashmi

1990-01-01

This study examined the perception of parental attitudes of 50 blind adolescents in northern India. Results indicated that blind girls perceived their parents as being more accepting and less rejecting than did blind boys, a result explained by culturally determined differences in social sex roles. (DB)

Wage Determination and Discrimination among Older Workers.

ERIC Educational Resources Information Center

Quinn, Joseph F.

1979-01-01

Analyzed determinants of wage rates of older workers and the large discrepancies existing between wage earned by Whites, non-Whites, men, and women. Human capital and geographic variables were important wage determinants. Differences in variables cannot completely explain the wage differentials of race and sex. (Author)

Brain Type or Sex Differences? A structural equation model of the relation between brain type, sex, and motivation to learn science

NASA Astrophysics Data System (ADS)

Zeyer, Albert; Bölsterli, Katrin; Brovelli, Dorothee; Odermatt, Freia

2012-03-01

Sex is considered to be one of the most significant factors influencing attitudes towards science. However, the so-called brain type approach from cognitive science suggests that the difference in motivation to learn science does not primarily differentiate the girls from the boys, but rather the so-called systemisers from the empathizers. The present study investigates this hypothesis by using structural equation modelling on a sex-stratified sample of 500 male and female students of secondary II level. The results show, that the motivation to learn science is directly influenced by the systemizing quotient SQ, but not by sex. The impact of sex on the motivation to learn science, measured by five key concepts, only works indirectly, namely through the influence of sex on the SQ. The empathizing quotient (EQ) has no impact on the motivation to learn science. The SQ explains between 13 and 23 percent of the variation of the five key constructs. In female students, the impact of the SQ is very similar for all key concepts. In male students, it is highest for self-efficacy and lowest for assessment anxiety. The motivation to learn science is significantly larger for male students in all involved SMQ key concepts, but the difference is small. The interpretation of these findings and conclusions for science teaching and further research are discussed.

Height-income association in developing countries: Evidence from 14 countries.

PubMed

Patel, Pankaj C; Devaraj, Srikant

2017-12-28

The purpose of this study was to assess whether the height-income association is positive in developing countries, and whether income differences between shorter and taller individuals in developing countries are explained by differences in endowment (ie, taller individuals have a higher income than shorter individuals because of characteristics such as better social skills) or due to discrimination (ie, shorter individuals have a lower income despite having comparable characteristics). Instrumental variable regression, Oaxaca-Blinder decomposition, quantile regression, and quantile decomposition analyses were applied to a sample of 45 108 respondents from 14 developing countries represented in the Research on Early Life and Aging Trends and Effects (RELATE) study. For a one-centimeter increase in country- and sex-adjusted median height, real income adjusted for purchasing power parity increased by 1.37%. The income differential between shorter and taller individuals was explained by discrimination and not by differences in endowments; however, the effect of discrimination decreased at higher values of country- and sex-adjusted height. Taller individuals in developing countries may realize higher income despite having characteristics similar to those of shorter individuals. © 2017 Wiley Periodicals, Inc.

Segregation distortion causes large-scale differences between male and female genomes in hybrid ants.

PubMed

Kulmuni, Jonna; Seifert, Bernhard; Pamilo, Pekka

2010-04-20

Hybridization in isolated populations can lead either to hybrid breakdown and extinction or in some cases to speciation. The basis of hybrid breakdown lies in genetic incompatibilities between diverged genomes. In social Hymenoptera, the consequences of hybridization can differ from those in other animals because of haplodiploidy and sociality. Selection pressures differ between sexes because males are haploid and females are diploid. Furthermore, sociality and group living may allow survival of hybrid genotypes. We show that hybridization in Formica ants has resulted in a stable situation in which the males form two highly divergent gene pools whereas all the females are hybrids. This causes an exceptional situation with large-scale differences between male and female genomes. The genotype differences indicate strong transmission ratio distortion depending on offspring sex, whereby the mother transmits some alleles exclusively to her daughters and other alleles exclusively to her sons. The genetic differences between the sexes and the apparent lack of multilocus hybrid genotypes in males can be explained by recessive incompatibilities which cause the elimination of hybrid males because of their haploid genome. Alternatively, differentiation between sexes could be created by prezygotic segregation into male-forming and female-forming gametes in diploid females. Differentiation between sexes is stable and maintained throughout generations. The present study shows a unique outcome of hybridization and demonstrates that hybridization has the potential of generating evolutionary novelties in animals.

Explaining sex differences in lifespan in terms of optimal energy allocation in the baboon.

PubMed

King, Annette M; Kirkwood, Thomas B L; Shanley, Daryl P

2017-10-01

We provide a quantitative test of the hypothesis that sex role specialization may account for sex differences in lifespan in baboons if such specialization causes the dependency of fitness upon longevity, and consequently the optimal resolution to an energetic trade-off between somatic maintenance and other physiological functions, to differ between males and females. We present a model in which females provide all offspring care and males compete for access to reproductive females and in which the partitioning of available energy between the competing fitness-enhancing functions of growth, maintenance, and reproduction is modeled as a dynamic behavioral game, with the optimal decision for each individual depending upon his/her state and the behavior of other members of the population. Our model replicates the sexual dimorphism in body size and sex differences in longevity and reproductive scheduling seen in natural populations of baboons. We show that this outcome is generally robust to perturbations in model parameters, an important finding given that the same behavior is seen across multiple populations and species in the wild. This supports the idea that sex differences in longevity result from differences in the value of somatic maintenance relative to other fitness-enhancing functions in keeping with the disposable soma theory. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Individual Differences in Personality Masculinity-Femininity: Examining the Effects of Genes, Environment, and Prenatal Hormone Transfer.

PubMed

Verweij, Karin J H; Mosing, Miriam A; Ullén, Fredrik; Madison, Guy

2016-04-01

Males and females score differently on some personality traits, but the underlying etiology of these differences is not well understood. This study examined genetic, environmental, and prenatal hormonal influences on individual differences in personality masculinity-femininity (M-F). We used Big-Five personality inventory data of 9,520 Swedish twins (aged 27 to 54) to create a bipolar M-F personality scale. Using biometrical twin modeling, we estimated the influence of genetic and environmental factors on individual differences in a M-F personality score. Furthermore, we tested whether prenatal hormone transfer may influence individuals' M-F scores by comparing the scores of twins with a same-sex versus those with an opposite-sex co-twin. On average, males scored 1.09 standard deviations higher than females on the created M-F scale. Around a third of the variation in M-F personality score was attributable to genetic factors, while family environmental factors had no influence. Males and females from opposite-sex pairs scored significantly more masculine (both approximately 0.1 SD) than those from same-sex pairs. In conclusion, genetic influences explain part of the individual differences in personality M-F, and hormone transfer from the male to the female twin during pregnancy may increase the level of masculinization in females. Additional well-powered studies are needed to clarify this association and determine the underlying mechanisms in both sexes.

A potential sex dimorphism in the relationship between bitter taste and alcohol consumption.

PubMed

Beckett, Emma Louise; Duesing, Konsta; Boyd, Lyndell; Yates, Zoe; Veysey, Martin; Lucock, Mark

2017-03-22

Bitterness is an innate aversive taste important in detecting potentially toxic substances, including alcohol. However, bitter compounds exist in many foods and beverages, and can be desirable, such as in beer. TAS2R38 is a well-studied bitter taste receptor with common polymorphisms. Some have reported relationships between TAS2R38 genotypes, bitter taste phenotype and alcohol intake, however results have been mixed. These mixed results may be explained by the varying taste properties of different alcoholic beverages or a sex dimorphism in responses. Bitter taste phenotype was assessed using PROP taste test and TAS2R38-P49A genotype was assessed by RFLP-PCR. Alcohol intake was assessed by food frequency questionnaire and classified by beverage type (beer, wine, spirits or mixed drinks). The relationships between bitter taste phenotype and carriage of the P allele of the TAS2R38-A49P gene and alcohol intake were assessed adjusted for and stratified by sex, and the interaction between taste and sex was evaluated. The relationship between alcohol intake and bitter taste phenotype varied by beverage type, with significant results for beer, spirits and mixed drinks, but not wine. When stratified, results varied by sex, and were only significant in males. Significant interactions were found for taster phenotype and sex (total alcohol intake and intake of beer and spirits). Results were similar for carriage of the TAS2R38-P49A P allele. Sex-specific interactions between bitter taste phenotype, TAS2R38 genotype and alcohol intake may explain variance in previous studies and may have implications for sex-specific disease risk and public health interventions.

The multiple sex chromosomes of platypus and echidna are not completely identical and several share homology with the avian Z.

PubMed

Rens, Willem; O'Brien, Patricia C M; Grützner, Frank; Clarke, Oliver; Graphodatskaya, Daria; Tsend-Ayush, Enkhjargal; Trifonov, Vladimir A; Skelton, Helen; Wallis, Mary C; Johnston, Steve; Veyrunes, Frederic; Graves, Jennifer A M; Ferguson-Smith, Malcolm A

2007-01-01

Sex-determining systems have evolved independently in vertebrates. Placental mammals and marsupials have an XY system, birds have a ZW system. Reptiles and amphibians have different systems, including temperature-dependent sex determination, and XY and ZW systems that differ in origin from birds and placental mammals. Monotremes diverged early in mammalian evolution, just after the mammalian clade diverged from the sauropsid clade. Our previous studies showed that male platypus has five X and five Y chromosomes, no SRY, and DMRT1 on an X chromosome. In order to investigate monotreme sex chromosome evolution, we performed a comparative study of platypus and echidna by chromosome painting and comparative gene mapping. Chromosome painting reveals a meiotic chain of nine sex chromosomes in the male echidna and establishes their order in the chain. Two of those differ from those in the platypus, three of the platypus sex chromosomes differ from those of the echidna and the order of several chromosomes is rearranged. Comparative gene mapping shows that, in addition to bird autosome regions, regions of bird Z chromosomes are homologous to regions in four platypus X chromosomes, that is, X1, X2, X3, X5, and in chromosome Y1. Monotreme sex chromosomes are easiest to explain on the hypothesis that autosomes were added sequentially to the translocation chain, with the final additions after platypus and echidna divergence. Genome sequencing and contig anchoring show no homology yet between platypus and therian Xs; thus, monotremes have a unique XY sex chromosome system that shares some homology with the avian Z.

A Large Pseudoautosomal Region on the Sex Chromosomes of the Frog Silurana tropicalis

PubMed Central

Bewick, Adam J.; Chain, Frédéric J.J.; Zimmerman, Lyle B.; Sesay, Abdul; Gilchrist, Michael J.; Owens, Nick D.L.; Seifertova, Eva; Krylov, Vladimir; Macha, Jaroslav; Tlapakova, Tereza; Kubickova, Svatava; Cernohorska, Halina; Zarsky, Vojtech; Evans, Ben J.

2013-01-01

Sex chromosome divergence has been documented across phylogenetically diverse species, with amphibians typically having cytologically nondiverged (“homomorphic”) sex chromosomes. With an aim of further characterizing sex chromosome divergence of an amphibian, we used “RAD-tags” and Sanger sequencing to examine sex specificity and heterozygosity in the Western clawed frog Silurana tropicalis (also known as Xenopus tropicalis). Our findings based on approximately 20 million genotype calls and approximately 200 polymerase chain reaction-amplified regions across multiple male and female genomes failed to identify a substantially sized genomic region with genotypic hallmarks of sex chromosome divergence, including in regions known to be tightly linked to the sex-determining region. We also found that expression and molecular evolution of genes linked to the sex-determining region did not differ substantially from genes in other parts of the genome. This suggests that the pseudoautosomal region, where recombination occurs, comprises a large portion of the sex chromosomes of S. tropicalis. These results may in part explain why African clawed frogs have such a high incidence of polyploidization, shed light on why amphibians have a high rate of sex chromosome turnover, and raise questions about why homomorphic sex chromosomes are so prevalent in amphibians. PMID:23666865

The Discovery of XY Sex Chromosomes in a Boa and Python.

PubMed

Gamble, Tony; Castoe, Todd A; Nielsen, Stuart V; Banks, Jaison L; Card, Daren C; Schield, Drew R; Schuett, Gordon W; Booth, Warren

2017-07-24

For over 50 years, biologists have accepted that all extant snakes share the same ZW sex chromosomes derived from a common ancestor [1-3], with different species exhibiting sex chromosomes at varying stages of differentiation. Accordingly, snakes have been a well-studied model for sex chromosome evolution in animals [1, 4]. A review of the literature, however, reveals no compelling support that boas and pythons possess ZW sex chromosomes [2, 5]. Furthermore, phylogenetic patterns of facultative parthenogenesis in snakes and a sex-linked color mutation in the ball python (Python regius) are best explained by boas and pythons possessing an XY sex chromosome system [6, 7]. Here we demonstrate that a boa (Boa imperator) and python (Python bivittatus) indeed possess XY sex chromosomes, based on the discovery of male-specific genetic markers in both species. We use these markers, along with transcriptomic and genomic data, to identify distinct sex chromosomes in boas and pythons, demonstrating that XY systems evolved independently in each lineage. This discovery highlights the dynamic evolution of vertebrate sex chromosomes and further enhances the value of snakes as a model for studying sex chromosome evolution. Copyright © 2017 Elsevier Ltd. All rights reserved.

The landscape of sex-differential transcriptome and its consequent selection in human adults.

PubMed

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.

Mother's prior intrauterine position affects the sex ratio of her offspring in house mice.

PubMed

Vandenbergh, J G; Huggett, C L

1994-11-08

Sex ratio alterations related to environmental factors occur in several mammals, but no mechanism has been identified to explain the adjustment. Intrauterine position (IUP) may provide the context in which such alterations occur. Previous studies on house mice and gerbils reveal that the position of a fetus in the uterus in relation to the sex of its neighbors influences its later anatomy, physiology, and behavior. The anogenital distance (AGD) of females located between two males (2M) is longer than that of females not between two males (OM). We have found that the IUP, as determined by cesarean section and by an index of the AGD, correlates with the sex ratio of the litters produced by female mice. The sex ratio of the first litter born to 2M females was 58% males, for 1M females was 51% males and for OM females was 42% males. The effect on sex ratio continues into the second litter. The number of pups produced by mothers of different IUPs in her first two litters did not differ, suggesting that the sex ratio adjustment occurs prior to parturition. These results provide a basis for the natural variability observed in sex ratios of litter-bearing mammals and suggest that one or more intrauterine mechanisms may be responsible for environmentally related sex ratio alterations.

Acute Stress Modulates Feedback Processing in Men and Women: Differential Effects on the Feedback-Related Negativity and Theta and Beta Power

PubMed Central

Banis, Stella; Geerligs, Linda; Lorist, Monicque M.

2014-01-01

Sex-specific prevalence rates in mental and physical disorders may be partly explained by sex differences in physiological stress responses. Neural networks that might be involved are those underlying feedback processing. Aim of the present EEG study was to investigate whether acute stress alters feedback processing, and whether stress effects differ between men and women. Male and female participants performed a gambling task, in a control and a stress condition. Stress was induced by exposing participants to a noise stressor. Brain activity was analyzed using both event-related potential and time-frequency analyses, measuring the feedback-related negativity (FRN) and feedback-related changes in theta and beta oscillatory power, respectively. While the FRN and feedback-related theta power were similarly affected by stress induction in both sexes, feedback-related beta power depended on the combination of stress induction condition and sex. FRN amplitude and theta power increases were smaller in the stress relative to the control condition in both sexes, demonstrating that acute noise stress impairs performance monitoring irrespective of sex. However, in the stress but not in the control condition, early lower beta-band power increases were larger for men than women, indicating that stress effects on feedback processing are partly sex-dependent. Our findings suggest that sex-specific effects on feedback processing may comprise a factor underlying sex-specific stress responses. PMID:24755943

Childhood trauma and metabolic syndrome in men and women.

PubMed

Lee, Chioun; Tsenkova, Vera; Carr, Deborah

2014-03-01

The long-term effects of childhood trauma on health are well-documented, but few population-based studies have explored how childhood trauma affects the risk of developing metabolic syndrome (MetS) in adulthood. Using data from 1234 adults in the second wave of Midlife in the United States (MIDUS), we investigate (1) the extent to which childhood abuse affects the risk of developing MetS in adulthood; (2) how the severity of different types of abuse (emotional, physical, sexual, or cumulative abuse) affects this risk; and (3) the extent to which adult socioeconomic status (SES), maladaptive stress responses, and unhealthy behaviors mediate the association. We also test whether these associations differ significantly by sex. We find that emotional and physical abuse increase the risk of developing MetS for both sexes, whereas sexual abuse is a predictor for women only. For both sexes, individuals who experienced more cumulative abuse have a greater risk of developing MetS. Adult SES partially explains the association between childhood abuse and MetS. Maladaptive stress responses and unhealthy behaviors further explain the association. Among the potential mediators, poor sleep quality was a significant pathway for men and women, while stress-induced eating was a significant pathway for women only. Our findings suggest that the well-documented health consequences of early life trauma may vary by the nature of the trauma, the victim's sex, and the coping mechanisms that he or she employs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Differential sex-specific effects of oxygen toxicity in human umbilical vein endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yuhao; Lingappan, Krithika

Despite the well-established sex-specific differences in the incidence of bronchopulmonary dysplasia (BPD), the molecular mechanism(s) behind these are not completely understood. Pulmonary angiogenesis is critical for alveolarization and arrest in vascular development adversely affects lung development. Human neonatal umbilical vein endothelial cells (HUVECs) provide a robust in vitro model for the study of endothelial cell physiology and function. Male and Female HUVECs were exposed to room air (21% O{sub 2}, 5% CO{sub 2}) or hyperoxia (95% O{sub 2}, 5% CO{sub 2}) for up to 72 h. Cell viability, proliferation, H{sub 2}O{sub 2} production and angiogenesis were analyzed. Sex-specific differences in the expressionmore » of VEGFR2 and modulation of NF-kappa B pathway were measured. Male HUVECs have decreased survival, greater oxidative stress and impairment in angiogenesis compared to similarly exposed female cells. There is differential expression of VEGFR2 between male and female HUVECs and greater activation of the NF-kappa B pathway in female HUVECs under hyperoxic conditions. The results indicate that sex differences exist between male and female HUVECs in vitro after hyperoxia exposure. Since endothelial dysfunction has a major role in the pathogenesis of BPD, these differences could explain in part the mechanisms behind sex-specific differences in the incidence of this disease. - Highlights: • Cellular sex effects viability and oxidative stress in HUVECs exposed to hyperoxia. • Male HUVECs show greater impairment in angiogenesis compared to female cells. • Sex-specific modulation of VEGFR2 and the NF-kappaB pathway was noted.« less

Higher rates of sex evolve during adaptation to more complex environments

PubMed Central

Luijckx, Pepijn; Ho, Eddie Ka Ho; Gasim, Majid; Chen, Suyang; Stanic, Andrijana; Yanchus, Connor; Kim, Yun Seong; Agrawal, Aneil F.

2017-01-01

A leading hypothesis for the evolutionary maintenance of sexual reproduction proposes that sex is advantageous because it facilitates adaptation. Changes in the environment stimulate adaptation but not all changes are equivalent; a change may occur along one or multiple environmental dimensions. In two evolution experiments with the facultatively sexual rotifer Brachionus calyciflorus, we test how environmental complexity affects the evolution of sex by adapting replicate populations to various environments that differ from the original along one, two, or three environmental dimensions. Three different estimates of fitness (growth, lifetime reproduction, and population density) confirmed that populations adapted to their new environment. Growth measures revealed an intriguing cost of complex adaptations: populations that adapted to more complex environments lost greater amounts of fitness in the original environment. Furthermore, both experiments showed that B. calyciflorus became more sexual when adapting to a greater number of environmental dimensions. Common garden experiments confirmed that observed changes in sex were heritable. As environments in nature are inherently complex these findings help explain why sex is maintained in natural populations. PMID:28053226

Higher rates of sex evolve during adaptation to more complex environments.

PubMed

Luijckx, Pepijn; Ho, Eddie Ka Ho; Gasim, Majid; Chen, Suyang; Stanic, Andrijana; Yanchus, Connor; Kim, Yun Seong; Agrawal, Aneil F

2017-01-17

A leading hypothesis for the evolutionary maintenance of sexual reproduction proposes that sex is advantageous because it facilitates adaptation. Changes in the environment stimulate adaptation but not all changes are equivalent; a change may occur along one or multiple environmental dimensions. In two evolution experiments with the facultatively sexual rotifer Brachionus calyciflorus, we test how environmental complexity affects the evolution of sex by adapting replicate populations to various environments that differ from the original along one, two, or three environmental dimensions. Three different estimates of fitness (growth, lifetime reproduction, and population density) confirmed that populations adapted to their new environment. Growth measures revealed an intriguing cost of complex adaptations: populations that adapted to more complex environments lost greater amounts of fitness in the original environment. Furthermore, both experiments showed that B. calyciflorus became more sexual when adapting to a greater number of environmental dimensions. Common garden experiments confirmed that observed changes in sex were heritable. As environments in nature are inherently complex these findings help explain why sex is maintained in natural populations.

Habitat heterogeneity favors asexual reproduction in natural populations of grassthrips

PubMed Central

Lavanchy, Guillaume; Strehler, Marie; Llanos Roman, Maria Noemi; Lessard‐Therrien, Malie; Humbert, Jean‐Yves; Dumas, Zoé; Jalvingh, Kirsten; Ghali, Karim; Fontcuberta García‐Cuenca, Amaranta; Zijlstra, Bart; Arlettaz, Raphaël; Schwander, Tanja

2016-01-01

Explaining the overwhelming success of sex among eukaryotes is difficult given the obvious costs of sex relative to asexuality. Different studies have shown that sex can provide benefits in spatially heterogeneous environments under specific conditions, but whether spatial heterogeneity commonly contributes to the maintenance of sex in natural populations remains unknown. We experimentally manipulated habitat heterogeneity for sexual and asexual thrips lineages in natural populations and under seminatural mesocosm conditions by varying the number of hostplants available to these herbivorous insects. Asexual lineages rapidly replaced the sexual ones, independently of the level of habitat heterogeneity in mesocosms. In natural populations, the success of sexual thrips decreased with increasing habitat heterogeneity, with sexual thrips apparently only persisting in certain types of hostplant communities. Our results illustrate how genetic diversity‐based mechanisms can favor asexuality instead of sex when sexual lineages co‐occur with genetically variable asexual lineages. PMID:27346066

Gender inequality in New Zealand life expectancy: decomposition by age and cause.

PubMed

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.

Sex differences in physiological reactivity to acute psychosocial stress in adolescence.

PubMed

Ordaz, Sarah; Luna, Beatriz

2012-08-01

Females begin to demonstrate greater negative affective responses to stress than males in adolescence. This may reflect the concurrent emergence of underlying differences in physiological response systems, including corticolimbic circuitries, the hypothalamic-pituitary-adrenal axis (HPAA), and the autonomic nervous system (ANS). This review examines when sex differences in physiological reactivity to acute psychosocial stress emerge and the directionality of these differences over development. Indeed, the literature indicates that sex differences emerge during adolescence and persist into adulthood for all three physiological response systems. However, the directionality of the differences varies by system. The emerging corticolimbic reactivity literature suggests greater female reactivity, particularly in limbic regions densely innervated by gonadal hormone receptors. In contrast, males generally show higher levels of HPAA and ANS reactivity. We argue that the contrasting directionality of corticolimbic and peripheral physiological responses may reflect specific effects of gonadal hormones on distinct systems and also sex differences in evolved behavioral responses that demand different levels of peripheral physiological activation. Studies that examine both subjective reports of negative affect and physiological responses indicate that beginning in adolescence, females respond to acute stressors with more intense negative affect than males despite their comparatively lower peripheral physiological responses. This dissociation is not clearly explained by sex differences in the strength of the relationship between physiological and subjective responses. We suggest that females' greater subjective responsivity may instead arise from a greater activity in brain regions that translate stress responses to subjective awareness in adolescence. Future research directions include investigations of the role of pubertal hormones in physiological reactivity across all systems, examining the relationship of corticolimbic reactivity and negative affect, and sex differences in emotion regulation processes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sex differences in physiological reactivity to acute psychosocial stress in adolescence

PubMed Central

Ordaz, Sarah; Luna, Beatriz

2012-01-01

Summary Females begin to demonstrate greater negative affective responses to stress than males in adolescence. This may reflect the concurrent emergence of underlying differences in physiological response systems, including corticolimbic circuitries, the hypothalamic—pituitary— adrenal axis (HPAA), and the autonomic nervous system (ANS). This review examines when sex differences in physiological reactivity to acute psychosocial stress emerge and the directionality of these differences over development. Indeed, the literature indicates that sex differences emerge during adolescence and persist into adulthood for all three physiological response systems. However, the directionality of the differences varies by system. The emerging corti-colimbic reactivity literature suggests greater female reactivity, particularly in limbic regions densely innervated by gonadal hormone receptors. In contrast, males generally show higher levels of HPAA and ANS reactivity. We argue that the contrasting directionality of corticolimbic and peripheral physiological responses may reflect specific effects of gonadal hormones on distinct systems and also sex differences in evolved behavioral responses that demand different levels of peripheral physiological activation. Studies that examine both subjective reports of negative affect and physiological responses indicate that beginning in adolescence, females respond to acute stressors with more intense negative affect than males despite their comparatively lower peripheral physiological responses. This dissociation is not clearly explained by sex differences in the strength of the relationship between physiological and subjective responses. We suggest that females' greater subjective responsivity may instead arise from a greater activity in brain regions that translate stress responses to subjective awareness in adolescence. Future research directions include investigations of the role of pubertal hormones in physiological reactivity across all systems, examining the relationship of corticolimbic reactivity and negative affect, and sex differences in emotion regulation processes. PMID:22281210

Sex Differences in Occupational Choice, Pay, and Worth: A Supply-Side Approach to Understanding the Male-Female Wage Gap.

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…

Decreased Symptoms of Depression After Mindfulness-Based Stress Reduction: Potential Moderating Effects of Religiosity, Spirituality, Trait Mindfulness, Sex, and Age

PubMed Central

Smoski, Moria J.; Suarez, Edward C.; Brantley, Jeffrey G.; Ekblad, Andrew G.; Lynch, Thomas R.; Wolever, Ruth Quillian

2015-01-01

Abstract Objective: Mindfulness-based stress reduction (MBSR) is a secular meditation training program that reduces depressive symptoms. Little is known, however, about the degree to which a participant's spiritual and religious background, or other demographic characteristics associated with risk for depression, may affect the effectiveness of MBSR. Therefore, this study tested whether individual differences in religiosity, spirituality, motivation for spiritual growth, trait mindfulness, sex, and age affect MBSR effectiveness. Methods: As part of an open trial, multiple regression was used to analyze variation in depressive symptom outcomes among 322 adults who enrolled in an 8-week, community-based MBSR program. Results: As hypothesized, depressive symptom severity decreased significantly in the full study sample (d=0.57; p<0.01). After adjustment for baseline symptom severity, moderation analyses revealed no significant differences in the change in depressive symptoms following MBSR as a function of spirituality, religiosity, trait mindfulness, or demographic variables. Paired t tests found consistent, statistically significant (p<0.01) reductions in depressive symptoms across all subgroups by religious affiliation, intention for spiritual growth, sex, and baseline symptom severity. After adjustment for baseline symptom scores, age, sex, and religious affiliation, a significant proportion of variance in post-MBSR depressive symptoms was uniquely explained by changes in both spirituality (β=−0.15; p=0.006) and mindfulness (β=−0.17; p<0.001). Conclusions: These findings suggest that MBSR, a secular meditation training program, is associated with improved depressive symptoms regardless of affiliation with a religion, sense of spirituality, trait level of mindfulness before MBSR training, sex, or age. Increases in both mindfulness and daily spiritual experiences uniquely explained improvement in depressive symptoms. PMID:25695903

Skating start propulsion: three-dimensional kinematic analysis of elite male and female ice hockey players.

PubMed

Shell, Jaymee R; Robbins, Shawn M K; Dixon, Philippe C; Renaud, Philippe J; Turcotte, René A; Wu, Tom; Pearsall, David J

2017-09-01

The forward skating start is a fundamental skill for male and female ice hockey players. However, performance differences by athlete's sex cannot be fully explained by physiological variables; hence, other factors such as skating technique warrant examination. Therefore, the purpose of this study was to evaluate the body movement kinematics of ice hockey skating starts between elite male and female ice hockey participants. Male (n = 9) and female (n = 10) elite ice hockey players performed five forward skating start accelerations. An 18-camera motion capture system placed on the arena ice surface captured full-body kinematics during the first seven skating start steps within 15 meters. Males' maximum skating speeds were greater than females. Skating technique sex differences were noted: in particular, females presented ~10° lower hip abduction throughout skating stance as well as ~10° greater knee extension at initial ice stance contact, conspicuously followed by a brief cessation in knee extension at the moment of ice contact, not evident in male skaters. Further study is warranted to explain why these skating technique differences exist in relation to factors such as differences in training, equipment, performance level, and anthropometrics.

Sex determination, longevity, and the birth and death of reptilian species.

PubMed

Sabath, Niv; Itescu, Yuval; Feldman, Anat; Meiri, Shai; Mayrose, Itay; Valenzuela, Nicole

2016-08-01

Vertebrate sex-determining mechanisms (SDMs) are triggered by the genotype (GSD), by temperature (TSD), or occasionally, by both. The causes and consequences of SDM diversity remain enigmatic. Theory predicts SDM effects on species diversification, and life-span effects on SDM evolutionary turnover. Yet, evidence is conflicting in clades with labile SDMs, such as reptiles. Here, we investigate whether SDM is associated with diversification in turtles and lizards, and whether alterative factors, such as lifespan's effect on transition rates, could explain the relative prevalence of SDMs in turtles and lizards (including and excluding snakes). We assembled a comprehensive dataset of SDM states for squamates and turtles and leveraged large phylogenies for these two groups. We found no evidence that SDMs affect turtle, squamate, or lizard diversification. However, SDM transition rates differ between groups. In lizards TSD-to-GSD surpass GSD-to-TSD transitions, explaining the predominance of GSD lizards in nature. SDM transitions are fewer in turtles and the rates are similar to each other (TSD-to-GSD equals GSD-to-TSD), which, coupled with TSD ancestry, could explain TSD's predominance in turtles. These contrasting patterns can be explained by differences in life history. Namely, our data support the notion that in general, shorter lizard lifespan renders TSD detrimental favoring GSD evolution in squamates, whereas turtle longevity permits TSD retention. Thus, based on the macro-evolutionary evidence we uncovered, we hypothesize that turtles and lizards followed different evolutionary trajectories with respect to SDM, likely mediated by differences in lifespan. Combined, our findings revealed a complex evolutionary interplay between SDMs and life histories that warrants further research that should make use of expanded datasets on unexamined taxa to enable more conclusive analyses.

Mediating Factors Explaining the Association Between Sexual Minority Status and Dating Violence.

PubMed

Martin-Storey, Alexa; Fromme, Kim

2017-08-01

Dating violence presents a serious threat for individual health and well-being. A growing body of literature suggests that starting in adolescence, individuals with sexual minority identities (e.g., individuals who identify as gay, lesbian, or bisexual) may be at an increased risk for dating violence compared with heterosexuals. Research has not, however, identified the mechanisms that explain this vulnerability. Using a diverse sample of young adults ( n = 2,474), the current study explored how minority stress theory, revictimization theory, sex of sexual partners, and risky sexual behavior explained differences in dating violence between sexual minority and heterosexual young adults. Initial analyses suggested higher rates of dating violence among individuals who identified as bisexual, and individuals who identified as gay or lesbian when compared with heterosexuals, and further found that these associations failed to differ across gender. When mediating and control variables were included in the analyses, however, the association between both sexual minority identities and higher levels of dating violence became nonsignificant. Of particular interest was the role of discrimination, which mediated the association between bisexual identity and dating violence. Other factors, including sex and number of sexual partners, alcohol use, and childhood maltreatment, were associated with higher rates of dating violence but did not significantly explain vulnerability among sexual minority individuals compared with their heterosexual peers. These findings suggest the importance of minority stress theory in explaining vulnerability to dating violence victimization among bisexuals in particular, and generally support the importance of sexual-minority specific variables in understanding risk for dating violence within this vulnerable population.

Linking sex differences in corticosterone with individual reproductive behaviour and hatch success in two species of uniparental shorebirds.

PubMed

Edwards, Darryl B; Chin, Eunice H; Burness, Gary; Gilchrist, H Grant; Schulte-Hostedde, Albrecht I

2013-09-01

In birds, corticosterone (CORT) appears to facilitate reproductive activity because baseline and stress-induced CORT levels are elevated in breeding individuals compared with other times of the year. In particular, CORT is lower in the sex providing most of the parental care (i.e., incubation), which could be an important adaptation to tolerate stressors that result in abandoning reproduction. Therefore, one explanation for sex differences in CORT is that lower levels are favoured during the incubation/parental phase of reproduction. Using two species of uniparental shorebird - polyandrous red phalaropes (Phalaropus fulicarius) and polygynous white-rumped sandpipers (Calidris fuscicollis) - we predicted that the incubating sex would have lower baseline and stress-induced CORT, and incubating individuals with lower CORT would more effectively defend nests against a simulated intrusion, would return more quickly afterwards, and would ultimately have higher hatch success. We found that phalaropes followed the predicted pattern: incubating individuals (males) had lower baseline and stress-induced CORT than females but for baseline CORT these differences existed prior to males commencing incubation. Incubating male phalaropes with lower baseline and stress-induced CORT returned to incubate more quickly after a disturbance and there was non-significant tendency for baseline CORT to be lower in successful nests. In sandpipers, we observed no sex differences and no significant relationships between individual CORT levels and nest defence behaviours or hatch success. Our results demonstrate that in phalaropes at least, selection favours lower baseline and stress-induced CORT during the nesting period. These results can explain sex differences in stress-induced levels of CORT, however sex differences in baseline CORT were present prior to incubation. Copyright © 2013 Elsevier Inc. All rights reserved.

Cognitive function in the oldest old: women perform better than men.

PubMed

van Exel, E; Gussekloo, J; de Craen, A J; Bootsma-van der Wiel, A; Houx, P; Knook, D L; Westendorp, R G

2001-07-01

Limited formal education is associated with poor cognitive function. This could explain sex differences in cognitive function in the oldest old. Whether limited formal education explains differences in cognitive function between elderly women and men was explored. The Leiden 85-plus Study is a population based study investigating all 85 year old inhabitants of Leiden with an overall response rate of 87%. A sample of 599 participants were visited at their place of residence. The mini mental state examination was completed by all participants. Cognitive speed and memory were determined with four neuropsychological tests in participants with a mini mental state examination score higher than 18 points. The proportion of women with limited formal education was significantly higher than that of men (70% v 53%, p=0.001), but women had better scores for cognitive speed and memory than men (p<0.05). After adjustment for differences in limited formal education and the presence of depressive symptoms, the odds ratio for women to have a higher cognitive speed than men was 1.7 (95% CI; 1.0 to 2.6), and for them to have a better memory the odds ratio was 1.8 (95%CI; 1.2 to 2.7). Women have a better cognitive function than men, despite their lower level of formal education. Limited formal education alone, therefore, cannot explain the differences in cognitive function in women and men. These findings support the alternative hypothesis that biological differences, such as atherosclerosis, between women and men account for the sex differences in cognitive decline.

Disgust as a Mechanism for Decision Making Under Risk: Illuminating Sex Differences and Individual Risk-Taking Correlates of Disgust Propensity.

PubMed

Sparks, Adam Maxwell; Fessler, Daniel M T; Chan, Kai Qin; Ashokkumar, Ashwini; Holbrook, Colin

2018-02-01

The emotion disgust motivates costly behavioral strategies that mitigate against potentially larger costs associated with pathogens, sexual behavior, and moral transgressions. Because disgust thereby regulates exposure to harm, it is by definition a mechanism for calibrating decision making under risk. Understanding this illuminates two features of the demographic distribution of this emotion. First, this approach predicts and explains sex differences in disgust. Greater female disgust propensity is often reported and discussed in the literature, but, to date, conclusions have been based on informal comparisons across a small number of studies, while existing functionalist explanations are at best incomplete. We report the results of an extensive meta-analysis documenting this sex difference, arguing that key features of this pattern are best explained as one manifestation of a broad principle of the evolutionary biology of risk-taking: for a given potential benefit, males in an effectively polygynous mating system accept the risk of harm more willingly than do females. Second, viewing disgust as a mechanism for decision making under risk likewise predicts that individual differences in disgust propensity should correlate with individual differences in various forms of risky behavior, because situational and dispositional factors that influence valuation of opportunity and hazard are often correlated across multiple decision contexts. In two large-sample online studies, we find consistent associations between disgust and risk avoidance. We conclude that disgust and related emotions can be usefully examined through the theoretical lens of decision making under risk in light of human evolution. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Detecting depression among adolescents in Santiago, Chile: sex differences.

PubMed

Araya, Ricardo; Montero-Marin, Jesus; Barroilhet, Sergio; Fritsch, Rosemarie; Gaete, Jorge; Montgomery, Alan

2013-04-23

Depression among adolescents is common but most cases go undetected. Brief questionnaires offer an opportunity to identify probable cases but properly validated cut-off points are often unavailable, especially in non-western countries. Sex differences in the prevalence of depression become marked in adolescence and this needs to be accounted when establishing cut-off points. This study involved adolescents attending secondary state schools in Santiago, Chile. We compared the self-reported Beck Depression Inventory-II with a psychiatric interview to ascertain diagnosis. General psychometric features were estimated before establishing the criterion validity of the BDI-II. The BDI-II showed good psychometric properties with good internal consistency, a clear unidimensional factorial structure, and good capacity to discriminate between cases and non-cases of depression. Optimal cut-off points to establish caseness for depression were much higher for girls than boys. Sex discrepancies were primarily explained by differences in scores among those with depression rather than among those without depression. It is essential to validate scales with the populations intended to be used with. Sex differences are often ignored when applying cut-off points, leading to substantial misclassification. Early detection of depression is essential if we think that early intervention is a clinically important goal.

The politics of school sex education policy in England and Wales from the 1940s to the 1960s.

PubMed

Hampshire, James

2005-04-01

This article explores the political history of school sex education policy in England and Wales. Focusing on the period from the 1940s to the 1960s, it shows how sex education developed as a controversial political issue through an analysis of the differing institutional cultures and agendas of health and education administrators. The article argues that serious consideration of school sex education by central government was first prompted by concern about venereal disease during the Second World War. Thereafter, two groups of actors emerged with conflicting ideas about the role of government in prescribing school sex education. The medical establishment, including the Ministry of Health, was broadly supportive of a national policy, whereas the Department of Education, which had ultimate responsibility for any such policy in schools, sought to avoid decision-making about the issue. The article explores how a public health consensus on sex education developed and then explains why the Department of Education resisted this consensus.

Eye tracking, strategies, and sex differences in virtual navigation.

PubMed

Andersen, Nicolas E; Dahmani, Louisa; Konishi, Kyoko; Bohbot, Véronique D

2012-01-01

Reports of sex differences in wayfinding have typically used paradigms sensitive to the female advantage (navigation by landmarks) or sensitive to the male advantage (navigation by cardinal directions, Euclidian coordinates, environmental geometry, and absolute distances). The current virtual navigation paradigm allowed both men and women an equal advantage. We studied sex differences by systematically varying the number of landmarks. Eye tracking was used to quantify sex differences in landmark utilisation as participants solved an eight-arm radial maze task within different virtual environments. To solve the task, participants were required to remember the locations of target objects within environments containing 0, 2, 4, 6, or 8 landmarks. We found that, as the number of landmarks available in the environment increases, the proportion of time men and women spend looking at landmarks and the number of landmarks they use to find their way increases. Eye tracking confirmed that women rely more on landmarks to navigate, although landmark fixations were also associated with an increase in task completion time. Sex differences in navigational behaviour occurred only in environments devoid of landmarks and disappeared in environments containing multiple landmarks. Moreover, women showed sustained landmark-oriented gaze, while men's decreased over time. Finally, we found that men and women use spatial and response strategies to the same extent. Together, these results shed new light on the discrepancy in landmark utilisation between men and women and help explain the differences in navigational behaviour previously reported. Copyright © 2011 Elsevier Inc. All rights reserved.

Mental Stress-Induced-Myocardial Ischemia in Young Patients With Recent Myocardial Infarction: Sex Differences and Mechanisms.

PubMed

Vaccarino, Viola; Sullivan, Samaah; Hammadah, Muhammad; Wilmot, Kobina; Al Mheid, Ibhar; Ramadan, Ronnie; Elon, Lisa; Pimple, Pratik M; Garcia, Ernest V; Nye, Jonathon; Shah, Amit J; Alkhoder, Ayman; Levantsevych, Oleksiy; Gay, Hawkins; Obideen, Malik; Huang, Minxuan; Lewis, Tené T; Bremner, J Douglas; Quyyumi, Arshed A; Raggi, Paolo

2018-02-20

Mental stress-induced myocardial ischemia (MSIMI) is frequent in patients with coronary artery disease and is associated with worse prognosis. Young women with a previous myocardial infarction (MI), a group with unexplained higher mortality than men of comparable age, have shown elevated rates of MSIMI, but the mechanisms are unknown. We studied 306 patients (150 women and 156 men) ≤61 years of age who were hospitalized for MI in the previous 8 months and 112 community controls (58 women and 54 men) frequency matched for sex and age to the patients with MI. Endothelium-dependent flow-mediated dilation and microvascular reactivity (reactive hyperemia index) were measured at rest and 30 minutes after mental stress. The digital vasomotor response to mental stress was assessed using peripheral arterial tonometry. Patients received 99m Tc-sestamibi myocardial perfusion imaging at rest, with mental (speech task) and conventional (exercise/pharmacological) stress. The mean age of the sample was 50 years (range, 22-61). In the MI group but not among controls, women had a more adverse socioeconomic and psychosocial profile than men. There were no sex differences in cardiovascular risk factors, and among patients with MI, clinical severity tended to be lower in women. Women in both groups showed a higher peripheral arterial tonometry ratio during mental stress but a lower reactive hyperemia index after mental stress, indicating enhanced microvascular dysfunction after stress. There were no sex differences in flow-mediated dilation changes with mental stress. The rate of MSIMI was twice as high in women as in men (22% versus 11%, P =0.009), and ischemia with conventional stress was similarly elevated (31% versus 16%, P =0.002). Psychosocial and clinical risk factors did not explain sex differences in inducible ischemia. Although vascular responses to mental stress (peripheral arterial tonometry ratio and reactive hyperemia index) also did not explain sex differences in MSIMI, they were predictive of MSIMI in women only. Young women after MI have a 2-fold likelihood of developing MSIMI compared with men and a similar increase in conventional stress ischemia. Microvascular dysfunction and peripheral vasoconstriction with mental stress are implicated in MSIMI among women but not among men, perhaps reflecting women's proclivity toward ischemia because of microcirculatory abnormalities. © 2018 American Heart Association, Inc.

Sex differences in the inference and perception of causal relations within a video game

PubMed Central

Young, Michael E.

2014-01-01

The learning of immediate causation within a dynamic environment was examined. Participants encountered seven decision points in which they needed to choose, which of three possible candidates was the cause of explosions in the environment. Each candidate was firing a weapon at random every few seconds, but only one of them produced an immediate effect. Some participants showed little learning, but most demonstrated increases in accuracy across time. On average, men showed higher accuracy and shorter latencies that were not explained by differences in self-reported prior video game experience. This result suggests that prior reports of sex differences in causal choice in the game are not specific to situations involving delayed or probabilistic causal relations. PMID:25202293

Sex differences in the inference and perception of causal relations within a video game.

PubMed

Young, Michael E

2014-01-01

The learning of immediate causation within a dynamic environment was examined. Participants encountered seven decision points in which they needed to choose, which of three possible candidates was the cause of explosions in the environment. Each candidate was firing a weapon at random every few seconds, but only one of them produced an immediate effect. Some participants showed little learning, but most demonstrated increases in accuracy across time. On average, men showed higher accuracy and shorter latencies that were not explained by differences in self-reported prior video game experience. This result suggests that prior reports of sex differences in causal choice in the game are not specific to situations involving delayed or probabilistic causal relations.

Bateman's principle is reversed in a cooperatively breeding bird.

PubMed

Apakupakul, Kathleen; Rubenstein, Dustin R

2015-04-01

Bateman's principle is not only used to explain sex differences in mating behaviour, but also to determine which sex has the greater opportunity for sexual selection. It predicts that the relationship between the number of mates and the number of offspring produced should be stronger for males than for females. Yet, it is unclear whether Bateman's principle holds in cooperatively breeding systems where the strength of selection on traits used in intrasexual competition is high in both sexes. We tested Bateman's principle in the cooperatively breeding superb starling (Lamprotornis superbus), finding that only females showed a significant, positive Bateman gradient. We also found that the opportunity for selection was on average higher in females, but that its strength and direction oscillated through time. These data are consistent with the hypothesis that sexual selection underlies the female trait elaboration observed in superb starlings and other cooperative breeders. Even though the Bateman gradient was steeper for females than for males, the year-to-year oscillation in the strength and direction of the opportunity for selection likely explains why cooperative breeders do not exhibit sexual role reversal. Thus, Bateman's principle may not hold in cooperative breeders where both sexes appear to be under mutually strong sexual selection. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Unusually dynamic sex roles in a fish.

PubMed

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

2004-06-03

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

Transactional Sex Risk across a Typology of Rural and Urban Female Sex Workers in Indonesia: A Mixed Methods Study

PubMed Central

Puradiredja, Dewi Ismajani; Coast, Ernestina

2012-01-01

Context-specific typologies of female sex workers (FSWs) are essential for the design of HIV intervention programming. This study develops a novel FSW typology for the analysis of transactional sex risk in rural and urban settings in Indonesia. Mixed methods include a survey of rural and urban FSWs (n = 310), in-depth interviews (n = 11), key informant interviews (n = 5) and ethnographic assessments. Thematic analysis categorises FSWs into 5 distinct groups based on geographical location of their sex work settings, place of solicitation, and whether sex work is their primary occupation. Multiple regression analysis shows that the likelihood of consistent condom use was higher among urban venue-based FSWs for whom sex work is not the only source of income than for any of the other rural and urban FSW groups. This effect was explained by the significantly lower likelihood of consistent condom use by rural venue-based FSWs (adjusted OR: 0.34 95% CI 0.13–0.90, p = 0.029). The FSW typology and differences in organisational features and social dynamics are more closely related to the risk of unprotected transactional sex, than levels of condom awareness and availability. Interventions need context-specific strategies to reach the different FSWs identified by this study's typology. PMID:23285205

Influence of gender constancy and social power on sex-linked modeling.

PubMed

Bussey, K; Bandura, A

1984-12-01

Competing predictions derived from cognitive-developmental theory and social learning theory concerning sex-linked modeling were tested. In cognitive-developmental theory, gender constancy is considered a necessary prerequisite for the emulation of same-sex models, whereas according to social learning theory, sex-role development is promoted through a vast system of social influences with modeling serving as a major conveyor of sex role information. In accord with social learning theory, even children at a lower level of gender conception emulated same-sex models in preference to opposite-sex ones. Level of gender constancy was associated with higher emulation of both male and female models rather than operating as a selective determinant of modeling. This finding corroborates modeling as a basic mechanism in the sex-typing process. In a second experiment we explored the limits of same-sex modeling by pitting social power against the force of collective modeling of different patterns of behavior by male and female models. Social power over activities and rewarding resources produced cross-sex modeling in boys, but not in girls. This unexpected pattern of cross-sex modeling is explained by the differential sex-typing pressures that exist for boys and girls and socialization experiences that heighten the attractiveness of social power for boys.

A genome scan revealed significant associations of growth traits with a major QTL and GHR2 in tilapia

PubMed Central

Liu, Feng; Sun, Fei; Xia, Jun Hong; Li, Jian; Fu, Gui Hong; Lin, Grace; Tu, Rong Jian; Wan, Zi Yi; Quek, Delia; Yue, Gen Hua

2014-01-01

Growth is an important trait in animal breeding. However, the genetic effects underpinning fish growth variability are still poorly understood. QTL mapping and analysis of candidate genes are effective methods to address this issue. We conducted a genome-wide QTL analysis for growth in tilapia. A total of 10, 7 and 8 significant QTLs were identified for body weight, total length and standard length at 140 dph, respectively. The majority of these QTLs were sex-specific. One major QTL for growth traits was identified in the sex-determining locus in LG1, explaining 71.7%, 67.2% and 64.9% of the phenotypic variation (PV) of body weight, total length and standard length, respectively. In addition, a candidate gene GHR2 in a QTL was significantly associated with body weight, explaining 13.1% of PV. Real-time qPCR revealed that different genotypes at the GHR2 locus influenced the IGF-1 expression level. The markers located in the major QTL for growth traits could be used in marker-assisted selection of tilapia. The associations between GHR2 variants and growth traits suggest that the GHR2 gene should be an important gene that explains the difference in growth among tilapia species. PMID:25435025

Sex-specific phenotypes of hyperthyroidism and hypothyroidism in mice.

PubMed

Rakov, Helena; Engels, Kathrin; Hönes, Georg Sebastian; Strucksberg, Karl-Heinz; Moeller, Lars Christian; Köhrle, Josef; Zwanziger, Denise; Führer, Dagmar

2016-01-01

Thyroid dysfunction is more common in the female population, however, the impact of sex on disease characteristics has rarely been addressed. Using a murine model, we asked whether sex has an influence on phenotypes, thyroid hormone status, and thyroid hormone tissue response in hyper- and hypothyroidism. Hypo- and hyperthyroidism were induced in 5-month-old female and male wildtype C57BL/6N mice, by LoI/MMI/ClO4 (-) or T4 i.p. treatment over 7 weeks, and control animals underwent sham treatment (N = 8 animals/sex/treatment). Animals were investigated for impact of sex on body weight, food and water intake, body temperature, heart rate, behaviour (locomotor activity, motor coordination, and strength), liver function, serum thyroid hormone status, and cellular TH effects on gene expression in brown adipose tissue, heart, and liver. Male and female mice showed significant differences in behavioural, functional, metabolic, biochemical, and molecular traits of hyper- and hypothyroidism. Hyperthyroidism resulted in increased locomotor activity in female mice but decreased muscle strength and motor coordination preferably in male animals. Hypothyroidism led to increased water intake in male but not female mice and significantly higher serum cholesterol in male mice. Natural sex differences in body temperature, body weight gain, food and water intake were preserved under hyperthyroid conditions. In contrast, natural sex differences in heart rate disappeared with TH excess and deprivation. The variations of hyper- or hypothyroid traits of male and female mice were not explained by classical T3/T4 serum state. TH serum concentrations were significantly increased in female mice under hyperthyroidism, but no sex differences were found under eu- or hypothyroid conditions. Interestingly, analysis of expression of TH target genes and TH transporters revealed little sex dependency in heart, while sex differences in target genes were present in liver and brown adipose tissue in line with altered functional and metabolic traits of hyper- and hypothyroidism. These data demonstrate that the phenotypes of hypo- and hyperthyroidism differ between male and female mice and indicate that sex is an important modifier of phenotypic manifestations.

Epigenetics and sex differences in the brain: A genome-wide comparison of histone-3 lysine-4 trimethylation (H3K4me3) in male and female mice.

PubMed

Shen, Erica Y; Ahern, Todd H; Cheung, Iris; Straubhaar, Juerg; Dincer, Aslihan; Houston, Isaac; de Vries, Geert J; Akbarian, Schahram; Forger, Nancy G

2015-06-01

Many neurological and psychiatric disorders exhibit gender disparities, and sex differences in the brain likely explain some of these effects. Recent work in rodents points to a role for epigenetics in the development or maintenance of neural sex differences, although genome-wide studies have so far been lacking. Here we review the existing literature on epigenetics and brain sexual differentiation and present preliminary analyses on the genome-wide distribution of histone-3 lysine-4 trimethylation in a sexually dimorphic brain region in male and female mice. H3K4me3 is a histone mark primarily organized as 'peaks' surrounding the transcription start site of active genes. We microdissected the bed nucleus of the stria terminalis and preoptic area (BNST/POA) in adult male and female mice and used ChIP-Seq to compare the distribution of H3K4me3 throughout the genome. We found 248 genes and loci with a significant sex difference in H3K4me3. Of these, the majority (71%) had larger H3K4me3 peaks in females. Comparisons with existing databases indicate that genes and loci with increased H3K4me3 in females are associated with synaptic function and with expression atlases from related brain areas. Based on RT-PCR, only a minority of genes with a sex difference in H3K4me3 has detectable sex differences in expression at baseline conditions. Together with previous findings, our data suggest that there may be sex biases in the use of epigenetic marks. Such biases could underlie sex differences in vulnerabilities to drugs or diseases that disrupt specific epigenetic processes. Copyright © 2014 Elsevier Inc. All rights reserved.

Sex-biased survivorship and differences in migration of wild steelhead (Oncorhynchus mykiss) smolts from two coastal Oregon rivers

USGS Publications Warehouse

Thompson, Neil F.; Leblanc, Camille A.; Romer, Jeremy D.; Schreck, Carl B.; Blouin, Michael S.; Noakes, David L. G.

2016-01-01

In salmonids with partial migration, females are more likely than males to undergo smoltification and migrate to the ocean (vs. maturing in freshwater). However, it is not known whether sex affects survivorship during smolt migration (from fresh water to entry into the ocean). We captured wild steelhead (Oncorhynchus mykiss) smolts in two coastal Oregon rivers (USA) and collected fin tissue samples for genetic sex determination (2009; N = 70 in the Alsea and N = 69 in the Nehalem, 2010; N = 25 in the Alsea). We implanted acoustic tags and monitored downstream migration and survival until entry in to the Pacific Ocean. Survival was defined as detection at an estuary/ocean transition array. We found no effect of sex on smolt survivorship in the Nehalem River in 2009, or in the Alsea River in 2010. However, males exhibited significantly lower survival than females in the Alsea River during 2009. Residency did not influence this result as an equal proportion of males and females did not reach the estuary entrance (11% of males, 9% of females). The sexes did not differ in timing or duration of migration, so those variables seem unlikely to explain sex-biased survivorship. Larger males had higher odds of survival than smaller males in 2009, but the body size of females did not affect survivorship. The difference in survivorship between years in the Alsea River could be due to flow conditions, which were higher in 2010 than in 2009. Our findings suggest that sex may affect steelhead smolt survival during migration, but that the difference in survivorship may be weak and not a strong factor influencing adult sex ratios.

Sex biased survival and differences in migration of wild steelhead (Oncorhynchus mykiss) smolts from two coastal Oregon rivers

USGS Publications Warehouse

Thompson, Neil F.; Leblanc, Camille A.; Romer, Jeremy D.; Schreck, Carl B.; Blouin, Michael S.; Noakes, David L. G.

2016-01-01

In salmonids with partial migration, females are more likely than males to undergo smoltification and migrate to the ocean (vs. maturing in freshwater). However, it is not known whether sex affects survivorship during smolt migration (from fresh water to entry into the ocean). We captured wild steelhead (Oncorhynchus mykiss) smolts in two coastal Oregon rivers (USA) and collected fin tissue samples for genetic sex determination (2009; N = 70 in the Alsea and N = 69 in the Nehalem, 2010; N = 25 in the Alsea). We implanted acoustic tags and monitored downstream migration and survival until entry in to the Pacific Ocean. Survival was defined as detection at an estuary/ocean transition array. We found no effect of sex on smolt survivorship in the Nehalem River in 2009, or in the Alsea River in 2010. However, males exhibited significantly lower survival than females in the Alsea River during 2009. Residency did not influence this result as an equal proportion of males and females did not reach the estuary entrance (11% of males, 9% of females). The sexes did not differ in timing or duration of migration, so those variables seem unlikely to explain sex-biased survivorship. Larger males had higher odds of survival than smaller males in 2009, but the body size of females did not affect survivorship. The difference in survivorship between years in the Alsea River could be due to flow conditions, which were higher in 2010 than in 2009. Our findings suggest that sex may affect steelhead smolt survival during migration, but that the difference in survivorship may be weak and not a strong factor influencing adult sex ratios.

The multiple sex chromosomes of platypus and echidna are not completely identical and several share homology with the avian Z

PubMed Central

Rens, Willem; O'Brien, Patricia CM; Grützner, Frank; Clarke, Oliver; Graphodatskaya, Daria; Tsend-Ayush, Enkhjargal; Trifonov, Vladimir A; Skelton, Helen; Wallis, Mary C; Johnston, Steve; Veyrunes, Frederic; Graves, Jennifer AM; Ferguson-Smith, Malcolm A

2007-01-01

Background Sex-determining systems have evolved independently in vertebrates. Placental mammals and marsupials have an XY system, birds have a ZW system. Reptiles and amphibians have different systems, including temperature-dependent sex determination, and XY and ZW systems that differ in origin from birds and placental mammals. Monotremes diverged early in mammalian evolution, just after the mammalian clade diverged from the sauropsid clade. Our previous studies showed that male platypus has five X and five Y chromosomes, no SRY, and DMRT1 on an X chromosome. In order to investigate monotreme sex chromosome evolution, we performed a comparative study of platypus and echidna by chromosome painting and comparative gene mapping. Results Chromosome painting reveals a meiotic chain of nine sex chromosomes in the male echidna and establishes their order in the chain. Two of those differ from those in the platypus, three of the platypus sex chromosomes differ from those of the echidna and the order of several chromosomes is rearranged. Comparative gene mapping shows that, in addition to bird autosome regions, regions of bird Z chromosomes are homologous to regions in four platypus X chromosomes, that is, X1, X2, X3, X5, and in chromosome Y1. Conclusion Monotreme sex chromosomes are easiest to explain on the hypothesis that autosomes were added sequentially to the translocation chain, with the final additions after platypus and echidna divergence. Genome sequencing and contig anchoring show no homology yet between platypus and therian Xs; thus, monotremes have a unique XY sex chromosome system that shares some homology with the avian Z. PMID:18021405

Sexual Conflict in Hermaphrodites

PubMed Central

Schärer, Lukas; Janicke, Tim; Ramm, Steven A.

2015-01-01

Hermaphrodites combine the male and female sex functions into a single individual, either sequentially or simultaneously. This simple fact means that they exhibit both similarities and differences in the way in which they experience, and respond to, sexual conflict compared to separate-sexed organisms. Here, we focus on clarifying how sexual conflict concepts can be adapted to apply to all anisogamous sexual systems and review unique (or especially important) aspects of sexual conflict in hermaphroditic animals. These include conflicts over the timing of sex change in sequential hermaphrodites, and in simultaneous hermaphrodites, over both sex roles and the postmating manipulation of the sperm recipient by the sperm donor. Extending and applying sexual conflict thinking to hermaphrodites can identify general evolutionary principles and help explain some of the unique reproductive diversity found among animals exhibiting this widespread but to date understudied sexual system. PMID:25237131

Adolescent Same-Sex Attraction and Academic Outcomes: The Role of School Attachment and Engagement

PubMed Central

Pearson, Jennifer; Muller, Chandra; Wilkinson, Lindsey

2010-01-01

Schools create environments in which some sexual feelings, behaviors, and relationships are stigmatized, and this may have negative consequences for adolescents with nonheterosexual romantic attractions. This stigma can lead them to withdraw and disengage from school at a critical time of preparation for adulthood, which can compromise opportunities for future success. Previous research has demonstrated that sexual minority youth report greater levels of school-related problems, including a weaker sense of attachment to school and more trouble with teachers and peers. This lack of social integration is likely to affect their educational success. Data from the National Longitudinal Study of Adolescent Health and the newly collected Adolescent Health and Academic Achievement study provide the first opportunity to fully explore whether and to what extent same-sex attracted youth enter adulthood with an educational disadvantage. In this study, we examine (1) whether same-sex attracted adolescents have lower levels of academic success, (2) if their lower academic success is explained by a lack of social integration at school, and (3) whether these relationships differ for boys and girls. Results suggest that same-sex attracted students, particularly boys, do suffer academically, and that this is in part a result of school-related problems and risk factors such as emotional distress and substance use; however, a great deal of the disadvantage fails to be explained by these factors. Additionally, while same-sex attracted boys show poorer academic performance, same-sex attracted girls do not, suggesting that gender may shape how sexual minority youth experience and respond to marginalizing school environments PMID:20221417

Adolescent Same-Sex Attraction and Academic Outcomes: The Role of School Attachment and Engagement.

PubMed

Pearson, Jennifer; Muller, Chandra; Wilkinson, Lindsey

2007-11-01

Schools create environments in which some sexual feelings, behaviors, and relationships are stigmatized, and this may have negative consequences for adolescents with nonheterosexual romantic attractions. This stigma can lead them to withdraw and disengage from school at a critical time of preparation for adulthood, which can compromise opportunities for future success. Previous research has demonstrated that sexual minority youth report greater levels of school-related problems, including a weaker sense of attachment to school and more trouble with teachers and peers. This lack of social integration is likely to affect their educational success. Data from the National Longitudinal Study of Adolescent Health and the newly collected Adolescent Health and Academic Achievement study provide the first opportunity to fully explore whether and to what extent same-sex attracted youth enter adulthood with an educational disadvantage. In this study, we examine (1) whether same-sex attracted adolescents have lower levels of academic success, (2) if their lower academic success is explained by a lack of social integration at school, and (3) whether these relationships differ for boys and girls. Results suggest that same-sex attracted students, particularly boys, do suffer academically, and that this is in part a result of school-related problems and risk factors such as emotional distress and substance use; however, a great deal of the disadvantage fails to be explained by these factors. Additionally, while same-sex attracted boys show poorer academic performance, same-sex attracted girls do not, suggesting that gender may shape how sexual minority youth experience and respond to marginalizing school environments.

Adult sex ratios and their implications for cooperative breeding in birds.

PubMed

Komdeur, Jan; Székely, Tamás; Long, Xiaoyan; Kingma, Sjouke A

2017-09-19

Cooperative breeding is a form of breeding system where in addition to a core breeding pair, one or more usually non-breeding individuals provide offspring care. Cooperative breeding is widespread in birds, but its origin and maintenance in contemporary populations are debated. Although deviations in adult sex ratio (ASR, the proportion of males in the adult population) have been hypothesized to influence the occurrence of cooperative breeding because of the resulting surplus of one sex and limited availability of breeding partners, this hypothesis has not been tested across a wide range of taxa. By using data from 188 bird species and phylogenetically controlled analyses, we show that cooperatively breeding species have more male-biased ASRs than non-cooperative species. Importantly, ASR predicts helper sex ratio: in species with more male-biased ASR, helper sex ratio is also more male biased. We also show that offspring sex ratios do not predict ASRs, so that the skewed ASRs emerge during the period when individuals aim to obtain a breeding position or later during adulthood. In line with this result, we found that ASR (among both cooperatively and non-cooperatively breeding species) is inversely related to sex bias in dispersal distance, suggesting that the cost of dispersal is more severe for the further-dispersing sex. As females usually disperse further in birds, this explains the generally male-biased ASR, and in combination with benefits of philopatry for males, this probably explains why ASR is more biased in cooperatively breeding species. Taken together, our results suggest that a sex bias in helping in cooperatively breeding species relates to biased ASRs. We propose that this relationship is driven by sex-specific costs and benefits of dispersal and helping, as well as other demographic factors. Future phylogenetic comparative and experimental work is needed to establish how this relationship emerges.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 Author(s).

Considering risk contexts in explaining the paradoxical HIV increase among female sex workers in Mumbai and Thane, India.

PubMed

Bandewar, Sunita V S; Bharat, Shalini; Kongelf, Anine; Pisal, Hemlata; Collumbien, Martine

2016-01-28

The period 2006-2009 saw intensive scale-up of HIV prevention efforts and an increase in reported safer sex among brothel and street-based sex workers in Mumbai and Thane (Maharashtra, India). Yet during the same period, the prevalence of HIV increased in these groups. A better understanding of sex workers' risk environment is needed to explain this paradox. In this qualitative study we conducted 36 individual interviews, 9 joint interviews, and 10 focus group discussions with people associated with HIV interventions between March and May 2012. Dramatic changes in Mumbai's urban landscape dominated participants' accounts, with dwindling sex worker numbers in traditional brothel areas attributed to urban restructuring. Gentrification and anti-trafficking efforts explained an escalation in police raids. This contributed to dispersal of sex work with the sex-trade management adapting by becoming more hidden and mobile, leading to increased vulnerability. Affordable mobile phone technology enabled independent sex workers to trade in more hidden ways and there was an increased dependence on lovers for support. The risk context has become ever more challenging, with animosity against sex work amplified since the scale up of targeted interventions. Focus on condom use with sex workers inadvertently contributed to the diversification of the sex trade as clients seek out women who are less visible. Sex workers and other marginalised women who sell sex all strictly prioritise anonymity. Power structures in the sex trade continue to pose insurmountable barriers to reaching young and new sex workers. Economic vulnerability shaped women's decisions to compromise on condom use. Surveys monitoring HIV prevalence among 'visible' street and brothel-bases sex workers are increasingly un-representative of all women selling sex and self-reported condom use is no longer a valid measure of risk reduction. Targeted harm reduction programmes with sex workers fail when implemented in complex urban environments that favour abolition. Increased stigmatisation and dispersal of risk can no longer be considered as unexpected. Reaching the increasing proportion of sex workers who intentionally avoid HIV prevention programmes has become the main challenge. Future evaluations need to incorporate building 'dark logic' models to predict potential harms.

[Sex differences in sexual versus emotional jealousy: evolutionary approach and recent discussions].

PubMed

Demirtaş Madran, H Andaç

2008-01-01

Sex differences in jealousy have been reported widely in the social psychological, clinical psychological, psychiatric, and anthropological literature. Many of the studies conducted on jealousy have focused on the sex differences in the level of reported jealousy. Most research has reported that there is no difference between men and women regarding the level of reported jealousy, but there are some sex differences between sexual and emotional jealousy. Evolutionary psychologists divide jealousy into 2 dimensions based on their observations and empirical research findings: Sexual jealousy and emotional jealousy. Sexual jealousy is knowing or suspecting that one's partners has had sexual relationship with a third person, whereas emotional jealousy is triggered by partner's emotional involvement with and/or love for another person. The parental investment model, which extended Darwin's explanations of sexual selection, provides a useful theoretical framework for studying sexual and emotional jealousy. According to this model sexual selection is driven by differential parental investment by men and women; men should experience more sexual jealousy than women and women should experience more emotional jealousy than men. Considerable research has focused on testing this hypothesis and, with a few exceptions, the results are generally consistent with the evolutionary account. In this study, firstly, a brief definition of the sexual and emotional jealousy will be given. Then, sex differences in sexual and emotional jealousy will be explained according to the evolutionary theory. Finally, the results of empirical studies and critiques of the evolutionary model will be given.

A comparison of female and male oral health in skeletal populations from late Roman Britain: implications for diet.

PubMed

Bonsall, L

2014-12-01

Textual sources from the Roman period point to the existence of dietary differences between the sexes. The aim of this study was to assess the palaeopathological evidence for such gender differences in dietary habits in Roman Britain by comparing the oral health of sexed individuals from two late Romano-British sites (Ancaster, Lincolnshire, and Winchester, Hampshire, England). Eighty-seven females (1243 teeth and 1950 sockets) and 112 males (1984 teeth and 2903 sockets) were examined for the presence of five dento-alveolar conditions, namely caries, calculus, periapical lesions, periodontal disease, and antemortem tooth loss. The frequency of each condition was calculated at the per individual and per tooth/socket level, and the results were compared between the sexes using Fisher's exact tests. Caries and antemortem tooth loss were slightly more common among women, but differences between the sexes were generally not significant. Males experienced higher rates of calculus and periodontal disease. There were no sex differences in the frequency of periapical lesions. Comparable rates of caries, periapical lesions and antemortem tooth loss in females and males indicate broad similarity in the diets of men and women. The greater levels of calculus and periodontal disease in males might point to some dietary differences, but could also be explained by non-dietary factors. Overall, the findings suggest that significant gender differences in diet, described in some contemporaneous textual sources, were not widely observed in Roman Britain. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sexual Violence in the Backlands: Toward a Macro-Level Understanding of Rural Sex Crimes.

PubMed

Braithwaite, Jeremy

2015-10-01

This research focuses on structural covariates of sex crimes in rural communities (using urban and urbanizing communities as comparison groups), with particular analysis on exploring how the magnitude and direction of such covariates differ with respect to type of sex crime. Using 2000 sex crime data from the National Incident-Based Reporting System (NIBRS) for the population of reporting U.S. cities, negative binomial and logistic regression procedures were used to explore the relationship between resource disadvantage, local investment, and economic inequality and sex crime subtypes. For sex crimes that occurred almost exclusively in the home, urban and urbanizing community rates were largely influenced by resource disadvantage and local investment, while these measures did not reach significance for explaining rural rates. Conversely, local investment was a significant predictor of sex crimes that occurred outside the home in rural communities. This research indicates that a structural analysis of sexual victimization (widely absent from the scientific literature) does yield significant findings and that disaggregation of crime into subtypes allows for a more detailed differentiation between urban and rural communities. © The Author(s) 2014.

Sex differences in adolescent white matter architecture.

PubMed

Bava, Sunita; Boucquey, Veronique; Goldenberg, Diane; Thayer, Rachel E; Ward, Megan; Jacobus, Joanna; Tapert, Susan F

2011-02-23

Sex-specific trajectories in white matter development during adolescence may help explain cognitive and behavioral divergences between males and females. Knowledge of sex differences in typically developing adolescents can provide a basis for interpreting sexual dimorphisms in abilities and actions. We examined 58 healthy adolescents (12-14years of age) with diffusion tensor imaging (DTI). Diffusion parameters fractional anisotropy (FA), and mean (MD), radial (RD), and axial diffusivities (AD) were subjected to whole-brain voxel-wise group comparisons using tract-based spatial statistics. Sex differences in white matter microstructure were examined in relation to pubertal development. Early adolescent females (n=29) evidenced higher FA in the right superior corona radiata, higher FA and AD in bilateral corticospinal tracts (≥164μl, p<.01), and lower MD in the right inferior longitudinal fasciculus (ILF) and left forceps major (≥164μl, p<.01) than age-matched males (n=29). Males did not show any areas of higher FA or lower MD than females, but had higher AD in the right superior longitudinal fasciculus, ILF, and forceps minor (≥ 164μl, p<.01). Pubertal stage did not account for sex disparities. In early adolescence, females' motor tracts may reflect widespread changes, while males may undergo relatively more microstructural change in projection and association fibers. Copyright © 2010 Elsevier B.V. All rights reserved.

12-months metabolic changes among gender dysphoric individuals under cross-sex hormone treatment: a targeted metabolomics study

PubMed Central

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

Female song is widespread and ancestral in songbirds.

PubMed

Odom, Karan J; Hall, Michelle L; Riebel, Katharina; Omland, Kevin E; Langmore, Naomi E

2014-03-04

Bird song has historically been considered an almost exclusively male trait, an observation fundamental to the formulation of Darwin's theory of sexual selection. Like other male ornaments, song is used by male songbirds to attract females and compete with rivals. Thus, bird song has become a textbook example of the power of sexual selection to lead to extreme neurological and behavioural sex differences. Here we present an extensive survey and ancestral state reconstruction of female song across songbirds showing that female song is present in 71% of surveyed species including 32 families, and that females sang in the common ancestor of modern songbirds. Our results reverse classical assumptions about the evolution of song and sex differences in birds. The challenge now is to identify whether sexual selection alone or broader processes, such as social or natural selection, best explain the evolution of elaborate traits in both sexes.

Ploidy, sex and crossing over in an evolutionary aging model

NASA Astrophysics Data System (ADS)

Lobo, Matheus P.; Onody, Roberto N.

2006-02-01

Nowadays, many forms of reproduction coexist in nature: Asexual, sexual, apomictic and meiotic parthenogenesis, hermaphroditism and parasex. The mechanisms of their evolution and what made them successful reproductive alternatives are very challenging and debated questions. Here, using a simple evolutionary aging model, we give a possible scenario. By studying the performance of populations where individuals may have diverse characteristics-different ploidies, sex with or without crossing over, as well as the absence of sex-we find an evolution sequence that may explain why there are actually two major or leading groups: Sexual and asexual. We also investigate the dependence of these characteristics on different conditions of fertility and deleterious mutations. Finally, if the primeval organisms on Earth were, in fact, asexual individuals we conjecture that the sexual form of reproduction could have more easily been set and found its niche during a period of low-intensity mutations.

Sex Differences: A Resultant of an Evolutionary Pressure?

PubMed

Della Torre, Sara; Maggi, Adriana

2017-03-07

Spurred by current research policy, we are witnessing a significant growth in the number of studies that observe and describe sexual diversities in human physiology and sex prevalence in a large number of pathologies. Yet we are far from the comprehension of the mechanisms underpinning these differences, which are the result of a long evolutionary history. This Essay is meant to underline female reproductive function as a driver for the positive selection of the specific physiological features that explain male and female differential susceptibility to diseases and metabolic disturbances, in particular. A clear understanding of the causes underlying sexual dimorphisms in the physio-pathology is crucial for precision medicine. Copyright © 2017 Elsevier Inc. All rights reserved.

Countries with Higher Levels of Gender Equality Show Larger National Sex Differences in Mathematics Anxiety and Relatively Lower Parental Mathematics Valuation for Girls

PubMed Central

2016-01-01

Despite international advancements in gender equality across a variety of societal domains, the underrepresentation of girls and women in Science, Technology, Engineering, and Mathematics (STEM) related fields persists. In this study, we explored the possibility that the sex difference in mathematics anxiety contributes to this disparity. More specifically, we tested a number of predictions from the prominent gender stratification model, which is the leading psychological theory of cross-national patterns of sex differences in mathematics anxiety and performance. To this end, we analyzed data from 761,655 15-year old students across 68 nations who participated in the Programme for International Student Assessment (PISA). Most importantly and contra predictions, we showed that economically developed and more gender equal countries have a lower overall level of mathematics anxiety, and yet a larger national sex difference in mathematics anxiety relative to less developed countries. Further, although relatively more mothers work in STEM fields in more developed countries, these parents valued, on average, mathematical competence more in their sons than their daughters. The proportion of mothers working in STEM was unrelated to sex differences in mathematics anxiety or performance. We propose that the gender stratification model fails to account for these national patterns and that an alternative model is needed. In the discussion, we suggest how an interaction between socio-cultural values and sex-specific psychological traits can better explain these patterns. We also discuss implications for policies aiming to increase girls’ STEM participation. PMID:27100631

Countries with Higher Levels of Gender Equality Show Larger National Sex Differences in Mathematics Anxiety and Relatively Lower Parental Mathematics Valuation for Girls.

PubMed

Stoet, Gijsbert; Bailey, Drew H; Moore, Alex M; Geary, David C

2016-01-01

Despite international advancements in gender equality across a variety of societal domains, the underrepresentation of girls and women in Science, Technology, Engineering, and Mathematics (STEM) related fields persists. In this study, we explored the possibility that the sex difference in mathematics anxiety contributes to this disparity. More specifically, we tested a number of predictions from the prominent gender stratification model, which is the leading psychological theory of cross-national patterns of sex differences in mathematics anxiety and performance. To this end, we analyzed data from 761,655 15-year old students across 68 nations who participated in the Programme for International Student Assessment (PISA). Most importantly and contra predictions, we showed that economically developed and more gender equal countries have a lower overall level of mathematics anxiety, and yet a larger national sex difference in mathematics anxiety relative to less developed countries. Further, although relatively more mothers work in STEM fields in more developed countries, these parents valued, on average, mathematical competence more in their sons than their daughters. The proportion of mothers working in STEM was unrelated to sex differences in mathematics anxiety or performance. We propose that the gender stratification model fails to account for these national patterns and that an alternative model is needed. In the discussion, we suggest how an interaction between socio-cultural values and sex-specific psychological traits can better explain these patterns. We also discuss implications for policies aiming to increase girls' STEM participation.

Shaping attitudes about homosexuality: the role of religion and cultural context.

PubMed

Adamczyk, Amy; Pitt, Cassady

2009-06-01

Across the globe, the debate over homosexuality continues, with great variation in public opinion about the acceptability of homosexuality, laws regulating same-sex unions and penalties for homosexual sex behaviors. Religion is often seen as an important predictor of attitudes about homosexuality. However, cross-national differences in cultural orientations suggest that the role religion has in explaining homosexual attitudes may depend on a nation's cultural context. In this study, we merge ideas from cultural sociology and religious contextual effects to explain cross-national variation in public opinion about homosexuality. Using data from the fourth wave of the World Values Survey and Hierarchical Modeling techniques, we find support for the micro and macro effects of religion and a survival vs. self-expressive cultural orientation. Moreover, we find that personal religious beliefs have a greater effect on attitudes about homosexuality in countries like the United States, which have a strong self-expressive cultural orientation.

Comparison of phenotype in uniparental disomy and deletion Prader-Willi syndrome: Sex specific differences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell, J.; Langlois, S.; Robinson, W.P.

1996-10-16

Prader-Willi syndrome (PWS) results primarily from either a paternal deletion of 15q11-q13 or maternal uniparental disomy (UPD) 15. Birth parameters and clinical presentation of 79 confirmed UPD cases and 43 deletion patients were compared in order to test whether any manifestations differ between the two groups. There were no major clinical differences between the two classes analyzed as a whole, other than the presence of hypopigmentation predominantly in the deletion group. However, there was a significant bias in sex-ratio (P<.001) limited to the UPD group with a predominance (68%) of males. An equal number of males and females was observedmore » in the deletion group. When analyzed by sex, several significant differences between the UPD and deletion groups were observed. Female UPD patients were found to be less severely affected than female deletion patients in terms of length of gavage feeding and a later onset of hyperphagia. Although these traits are likely to be influenced by external factors, they may reflect a milder presentation of female UPD patients which could explain the observed sex bias by causing under-ascertainment of female UPD. Alternatively, there may be an effect of sex on either early trisomy 15 survival or the probability of somatic loss of a chromosome from a trisomic conceptus. 26 refs., 1 tab.« less

Sex differences in case fatality before and after admission to hospital after acute cardiac events: analysis of community based coronary heart disease register.

PubMed Central

Sonke, G. S.; Beaglehole, R.; Stewart, A. W.; Jackson, R.; Stewart, F. M.

1996-01-01

OBJECTIVE: To determine whether the reported higher case fatality in hospital after an acute cardiac event in women can be explained by sex differences in mortality before admission and in baseline risk factors. DESIGN: Analyses of data from a community based coronary heart disease register. SETTING: Auckland region, New Zealand. SUBJECTS: 5106 patients aged 25-64 years with an acute cardiac event leading to coronary death or definite myocardial infarction within 28 days of onset, occurring between 1986 and 1992. MAIN OUTCOME MEASURES: Case fatality before admission, 28 day case fatality for patients in hospital, and total case fatality after an acute cardiac event. RESULTS: Despite a more unfavourable risk profile women tended to have lower case fatality before admission than men (crude odds ratio 0.88; 95% confidence interval 0.77 to 1.02). Adjustment for age, living arrangements, smoking, medical history, and treatment increased the effect of sex (0.72; 0.60 to 0.86). After admission to hospital, women had a higher case fatality than men (1.76; 1.43 to 2.17), but after adjustment for confounders this was reduced to 1.18 (0.89 to 1.58). Total case fatality 28 days after an acute cardiac event showed no significant difference between men and women (0.85; 0.70 to 1.02) CONCLUSIONS: The higher case fatality after an acute cardiac event in women admitted to hospital is largely explained by differences in living status, history, and medical treatment and is balanced by a lower case fatality before admission. PMID:8870571

The Effects of Sex and Size on Status Ranking.

ERIC Educational Resources Information Center

Crosbie, Paul V.

1979-01-01

Sex, body size, several sociocultural variables, and status rank were measured in mixed-sex small groups. The intervening sociocultural variables explained some but not all of the interrelationships. Results underscore the empirical vulnerability of social-psychological explanations of sex-role behavior and signal the need for further research.…

In Defense of Tradition: Religiosity, Conservatism, and Opposition to Same-Sex Marriage in North America

PubMed Central

van der Toorn, Jojanneke; Jost, John T.; Packer, Dominic J.; Noorbaloochi, Sharareh; Van Bavel, Jay J.

2017-01-01

Arguments opposing same-sex marriage are often made on religious grounds. In five studies conducted in the United States and Canada (combined N = 1,673), we observed that religious opposition to same-sex marriage was explained, at least in part, by conservative ideology and linked to sexual prejudice. In Studies 1 and 2, we discovered that the relationship between religiosity and opposition to same-sex marriage was mediated by explicit sexual prejudice. In Study 3, we saw that the mediating effect of sexual prejudice was linked to political conservatism. Finally, in Studies 4a and 4b we examined the ideological underpinnings of religious opposition to same-sex marriage in more detail by taking into account two distinct aspects of conservative ideology. Results revealed that resistance to change was more important than opposition to equality in explaining religious opposition to same-sex marriage. PMID:28918711

Synergy from reproductive division of labor and genetic complexity drive the evolution of sex.

PubMed

Jaffe, Klaus

2018-04-16

Computer experiments that mirror the evolutionary dynamics of sexual and asexual organisms as they occur in nature were used to test features proposed to explain the evolution of sexual recombination. Results show that this evolution is better described as a network of interactions between possible sexual forms, including diploidy, thelytoky, facultative sex, assortation, bisexuality, and division of labor between the sexes, rather than a simple transition from parthenogenesis to sexual recombination. Diploidy was shown to be fundamental for the evolution of sex; bisexual reproduction emerged only among anisogamic diploids with a synergistic division of reproductive labor; and facultative sex was more likely to evolve among haploids practicing assortative mating. Looking at the evolution of sex as a complex system through individual-based simulations explains better the diversity of sexual strategies known to exist in nature, compared to classical analytical models.

In Defense of Tradition: Religiosity, Conservatism, and Opposition to Same-Sex Marriage in North America.

PubMed

van der Toorn, Jojanneke; Jost, John T; Packer, Dominic J; Noorbaloochi, Sharareh; Van Bavel, Jay J

2017-10-01

Arguments opposing same-sex marriage are often made on religious grounds. In five studies conducted in the United States and Canada (combined N = 1,673), we observed that religious opposition to same-sex marriage was explained, at least in part, by conservative ideology and linked to sexual prejudice. In Studies 1 and 2, we discovered that the relationship between religiosity and opposition to same-sex marriage was mediated by explicit sexual prejudice. In Study 3, we saw that the mediating effect of sexual prejudice was linked to political conservatism. Finally, in Studies 4a and 4b we examined the ideological underpinnings of religious opposition to same-sex marriage in more detail by taking into account two distinct aspects of conservative ideology. Results revealed that resistance to change was more important than opposition to equality in explaining religious opposition to same-sex marriage.

The Effect of Sex and Gender on Diabetic Complications.

PubMed

Seghieri, Giuseppe; Policardo, Laura; Anichini, Roberto; Franconi, Flavia; Campesi, Ilaria; Cherchi, Sara; Tonolo, Giancarlo

2017-01-01

While in non-diabetic people the risk for cardiovascular disease is higher in men, diabetes completely reverts this sex-gender difference conferring to women a greater burden of cardiovascular complications. Additionally, all risk factors associated with cardiovascular disease appear to be more active in diabetic females than in their male counterparts. The reasons of this different impact of diabetes between genders are not completely clear. The aim of this review is trying to clarify these issues in a sex and gender perspective. Both genetic and hormonal factors are at the basis of sex-gender differences in diabetes, even do not explain the totality of data. Possibly women arrive later and in worse conditions to the diagnosis of diabetes, receive both diagnostic and therapeutic supports in a lesser measure and, finally, reach therapeutic goals as recommended by guidelines in a lesser extent. Further aspects of sex-gender differences in diabetic complications are represented by a more frequent prevalence of drug side effects in women, as well as by increased resistance to the action of drugs used in prevention or in the therapy of cardiovascular diseases. As to microvascular complications, the issue of sex-gender differences is even more complex, with some important differences emerging in experimental models 'in vitro', as well as in human pathology 'in vivo'. The main problem, however, also in this case, is that it is difficult to differentiate how common pathogenetic mechanisms acting in diabetes may differently impact between genders. In conclusion what is evident is that diabetes represents a 'risk magnifier' for the damage of both micro and macrovessels differently in men and in women. This issue deserves, therefore, a more careful approach from people involved in both clinical aspects and research regarding diabetes and its complications, in a sex-gender oriented perspective. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Sex and gender differences in chronic kidney disease: progression to end-stage renal disease and haemodialysis.

PubMed

Cobo, Gabriela; Hecking, Manfred; Port, Friedrich K; Exner, Isabella; Lindholm, Bengt; Stenvinkel, Peter; Carrero, Juan Jesús

2016-07-01

Sex and gender differences are of fundamental importance in most diseases, including chronic kidney disease (CKD). Men and women with CKD differ with regard to the underlying pathophysiology of the disease and its complications, present different symptoms and signs, respond differently to therapy and tolerate/cope with the disease differently. Yet an approach using gender in the prevention and treatment of CKD, implementation of clinical practice guidelines and in research has been largely neglected. The present review highlights some sex- and gender-specific evidence in the field of CKD, starting with a critical appraisal of the lack of inclusion of women in randomized clinical trials in nephrology, and thereafter revisits sex/gender differences in kidney pathophysiology, kidney disease progression, outcomes and management of haemodialysis care. In each case we critically consider whether apparent discrepancies are likely to be explained by biological or psycho-socioeconomic factors. In some cases (a few), these findings have resulted in the discovery of disease pathways and/or therapeutic opportunities for improvement. In most cases, they have been reported as merely anecdotal findings. The aim of the present review is to expose some of the stimulating hypotheses arising from these observations as a preamble for stricter approaches using gender for the prevention and treatment of CKD and its complications. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Risk Taking in Community College Students: Age and Sex Differences.

ERIC Educational Resources Information Center

Okun, Morris A.; Johnston, Lynn D.

To determine the relationship between age and risk taking for community college students, 74 male and 72 female students, ranging from 18-79 years of age, took a vocabulary test in which six "nonsense" items were interspersed among 54 legitimate items (following Slakter's procedure). Test instructions explained a penalty would be levied for…

"Drunkorexia": Exploring the Who and Why of a Disturbing Trend in College Students' Eating and Drinking Behaviors

ERIC Educational Resources Information Center

Eisenberg, Miriam H.; Fitz, Caroline C.

2014-01-01

Objective: "Drunkorexia," limiting food intake before alcohol consumption, increases college students' risk for negative alcohol-related health consequences. The current study tested whether (1) women engage in drunkorexia more frequently than men; (2) weight control motivations explain sex differences in drunkorexia; and (3) among…

Mumbling: Macho or Morphoogy?

ERIC Educational Resources Information Center

Weirich, Melanie; Fuchs, Susanne; Simpson, Adrian; Winkler, Ralf; Perrier, Pascal

2016-01-01

Purpose: Mumbling as opposed to clear speech is a typical male characteristic in speech and can be the consequence of a small jaw opening. Whereas behavioral reasons have often been offered to explain sex-specific differences with respect to clear speech, the purpose of this study is to investigate a potential anatomical reason for smaller jaw…

A population health approach to reducing observational intensity bias in health risk adjustment: cross sectional analysis of insurance claims.

PubMed

Wennberg, David E; Sharp, Sandra M; Bevan, Gwyn; Skinner, Jonathan S; Gottlieb, Daniel J; Wennberg, John E

2014-04-10

To compare the performance of two new approaches to risk adjustment that are free of the influence of observational intensity with methods that depend on diagnoses listed in administrative databases. Administrative data from the US Medicare program for services provided in 2007 among 306 US hospital referral regions. Cross sectional analysis. 20% sample of fee for service Medicare beneficiaries residing in one of 306 hospital referral regions in the United States in 2007 (n = 5,153,877). The effect of health risk adjustment on age, sex, and race adjusted mortality and spending rates among hospital referral regions using four indices: the standard Centers for Medicare and Medicaid Services--Hierarchical Condition Categories (HCC) index used by the US Medicare program (calculated from diagnoses listed in Medicare's administrative database); a visit corrected HCC index (to reduce the effects of observational intensity on frequency of diagnoses); a poverty index (based on US census); and a population health index (calculated using data on incidence of hip fractures and strokes, and responses from a population based annual survey of health from the Centers for Disease Control and Prevention). Estimated variation in age, sex, and race adjusted mortality rates across hospital referral regions was reduced using the indices based on population health, poverty, and visit corrected HCC, but increased using the standard HCC index. Most of the residual variation in age, sex, and race adjusted mortality was explained (in terms of weighted R2) by the population health index: R2=0.65. The other indices explained less: R2=0.20 for the visit corrected HCC index; 0.19 for the poverty index, and 0.02 for the standard HCC index. The residual variation in age, sex, race, and price adjusted spending per capita across the 306 hospital referral regions explained by the indices (in terms of weighted R2) were 0.50 for the standard HCC index, 0.21 for the population health index, 0.12 for the poverty index, and 0.07 for the visit corrected HCC index, implying that only a modest amount of the variation in spending can be explained by factors most closely related to mortality. Further, once the HCC index is visit corrected it accounts for almost none of the residual variation in age, sex, and race adjusted spending. Health risk adjustment using either the poverty index or the population health index performed substantially better in terms of explaining actual mortality than the indices that relied on diagnoses from administrative databases; the population health index explained the majority of residual variation in age, sex, and race adjusted mortality. Owing to the influence of observational intensity on diagnoses from administrative databases, the standard HCC index over-adjusts for regional differences in spending. Research to improve health risk adjustment methods should focus on developing measures of risk that do not depend on observation influenced diagnoses recorded in administrative databases.

Sexually antagonistic selection on genetic variation underlying both male and female same-sex sexual behavior.

PubMed

Berger, David; You, Tao; Minano, Maravillas R; Grieshop, Karl; Lind, Martin I; Arnqvist, Göran; Maklakov, Alexei A

2016-05-13

Intralocus sexual conflict, arising from selection for different alleles at the same locus in males and females, imposes a constraint on sex-specific adaptation. Intralocus sexual conflict can be alleviated by the evolution of sex-limited genetic architectures and phenotypic expression, but pleiotropic constraints may hinder this process. Here, we explored putative intralocus sexual conflict and genetic (co)variance in a poorly understood behavior with near male-limited expression. Same-sex sexual behaviors (SSBs) generally do not conform to classic evolutionary models of adaptation but are common in male animals and have been hypothesized to result from perception errors and selection for high male mating rates. However, perspectives incorporating sex-specific selection on genes shared by males and females to explain the expression and evolution of SSBs have largely been neglected. We performed two parallel sex-limited artificial selection experiments on SSB in male and female seed beetles, followed by sex-specific assays of locomotor activity and male sex recognition (two traits hypothesized to be functionally related to SSB) and adult reproductive success (allowing us to assess fitness consequences of genetic variance in SSB and its correlated components). Our experiments reveal both shared and sex-limited genetic variance for SSB. Strikingly, genetically correlated responses in locomotor activity and male sex-recognition were associated with sexually antagonistic fitness effects, but these effects differed qualitatively between male and female selection lines, implicating intralocus sexual conflict at both male- and female-specific genetic components underlying SSB. Our study provides experimental support for the hypothesis that widespread pleiotropy generates pervasive intralocus sexual conflict governing the expression of SSBs, suggesting that SSB in one sex can occur due to the expression of genes that carry benefits in the other sex.

Risk factors cannot explain the higher prevalence rates of precancerous colorectal lesions in men

PubMed Central

Waldmann, Elisabeth; Heinze, Georg; Ferlitsch, Arnulf; GessI, Irina; Sallinger, Daniela; Jeschek, Philip; Britto-Arias, Martha; Salzl, Petra; Fasching, Elisabeth; Jilma, Bernd; Kundi, Michael; Trauner, Michael; Ferlitsch, Monika

2016-01-01

Background: Prevalence of (pre)cancerous colorectal lesions are higher in men than in women, although transition rates from advanced lesions to cancer is similar in both sexes. Our aim was to investigate whether the sex-specific difference in incidence of premalignant colorectal lesions might be explained by the impact of risk factors. Methods: A cross-sectional study analysing health check-up examinations and screening colonoscopies performed within a national quality assurance program. Results: A total of 25 409 patients were included in this study, 50.8% were women. Median age for both sexes was 60 years (interquartile range (IQR) 54–67). A multivariable model showed that risk factors mediated only 0.6 of the 10.4% gender gap in adenoma and 0.47 of the 3.2% gender gap in advanced adenoma detection rate. Smoking was the only independent risk factor with a varying sex-specific effect (men OR 1.46, CI 1.29, 1.64, women OR 1.76, CI 1.53, 2.06) and advanced adenomas (men OR 1.06, CI 0.80–1.42; women OR 2.08, CI 1.52–2.83). Independent risk factors for adenomas were BMI (OR 1.35 per IQR, CI 1.25–1.47) and triglyceride level (OR 1.03 per IQR, CI 1.00–1.06); for advanced adenomas physical activity (none vs regular: OR 1.54, CI 1.18–2.00, occasional vs regular: OR 1.17, CI 1.00–1.38), cholesterol level (OR 1.13 per IQR, CI 1.02–1.25), blood glucose level (OR 1.05 per IQR, CI 1.01–1.09) and alcohol score (OR 1.09 per IQR, CI 1.01–1.18). Conclusions: Risk factors cannot explain higher prevalence rates in men. Results of this study strongly underline the need for sex-specific screening recommendations. PMID:27764840

Estimating and explaining the effect of education and income on head and neck cancer risk: INHANCE consortium pooled analysis of 31 case-control studies from 27 countries

PubMed Central

Conway, David I.; Brenner, Darren R.; McMahon, Alex D.; Macpherson, Lorna M.D.; Agudo, Antonio; Ahrens, Wolfgang; Bosetti, Cristina; Brenner, Hermann; Castellsague, Xavier; Chen, Chu; Curado, Maria Paula; Curioni, Otávio A.; Maso, Luigino Dal; Daudt, Alexander W.; de Gois Filho, José F.; D'Souza, Gypsyamber; Edefonti, Valeria; Fabianova, Eleonora; Fernandez, Leticia; Franceschi, Silvia; Gillison, Maura; Hayes, Richard B.; Healy, Claire M.; Herrero, Rolando; Holcatova, Ivana; Jayaprakash, Vijayvel; Kelsey, Karl; Kjaerheim, Kristina; Koifman, Sergio; La Vecchia, Carlo; Lagiou, Pagona; Lazarus, Philip; Levi, Fabio; Lissowska, Jolanta; Luce, Daniele; Macfarlane, Tatiana V.; Mates, Dana; Matos, Elena; McClean, Michael; Menezes, Ana M; Menvielle, Gwenn; Merletti, Franco; Morgenstern, Hal; Moysich, Kirsten; Müller, Heiko; Muscat, Joshua; Olshan, Andrew F.; Purdue, Mark P.; Ramroth, Heribert; Richiardi, Lorenzo; Rudnai, Peter; Schantz, Stimson; Schwartz, Stephen M.; Shangina, Oxana; Simonato, Lorenzo; Smith, Elaine; Stucker, Isabelle; Sturgis, Erich M.; Szeszenia-Dabrowska, Neonila; Talamini, Renato; Thomson, Peter; Vaughan, Thomas L.; Wei, Qingyi; Winn, Deborah M.; Wunsch-Filho, Victor; Yu, Guo-Pei; Zhang, Zuo-Feng; Zheng, Tongzhang; Znaor, Ariana; Boffetta, Paolo; Chuang, Shu-Chun; Ghodrat, Marianoosh; Lee, Yuan-Chin Amy; Hashibe, Mia; Brennan, Paul

2015-01-01

Low socioeconomic status has been reported to be associated with head and neck cancer risk. However, previous studies have been too small to examine the associations by cancer subsite, age, sex, global region and calendar time and to explain the association in terms of behavioral risk factors. Individual participant data of 23,964 cases with head and neck cancer and 31,954 controls from 31 studies in 27 countries pooled with random effects models. Overall, low education was associated with an increased risk of head and neck cancer (OR = 2.50; 95% CI = 2.02 – 3.09). Overall one-third of the increased risk was not explained by differences in the distribution of cigarette smoking and alcohol behaviors; and it remained elevated among never users of tobacco and nondrinkers (OR = 1.61; 95% CI = 1.13 – 2.31). More of the estimated education effect was not explained by cigarette smoking and alcohol behaviors: in women than in men, in older than younger groups, in the oropharynx than in other sites, in South/Central America than in Europe/North America and was strongest in countries with greater income inequality. Similar findings were observed for the estimated effect of low versus high household income. The lowest levels of income and educational attainment were associated with more than 2-fold increased risk of head and neck cancer, which is not entirely explained by differences in the distributions of behavioral risk factors for these cancers and which varies across cancer sites, sexes, countries and country income inequality levels. PMID:24996155

Premigrational movements and behavior of young mallards and wood ducks in north-central Minnesota

USGS Publications Warehouse

Kirby, R.E.; Cowardin, L.M.; Tester, J.R.

1989-01-01

Movements and behavior of 89 young mallards (Anas platyrhynchos) and 48 young wood ducks (Aix sponsa) were monitored on a 932-km2 study area in north-central Minnesota in late summer and fall, 1972-74, with telemetry, visual observation, and aerial surveys. Initial flights of both species were confined to the natal (brood) marsh; first flights away from the natal marsh occurred in the third week after fledging in both species. First flights of young mallards and wood ducks away from their natal marshes were not significantly different between the sexes (mallard, mean = 4.95 km for females and 5.83 km for males; wood ducks, mean = 2.31 km for females and 2.64 km for males). However, flights away from the brood marshes by wood ducks were significantly shorter than for mallards.As young mallards and wood ducks grew, their daytime use of the natal marshes decreased in an irregular pattern as both species began daily flights between day- and night-use areas. Locally reared mallards made longer daily flights between use areas than did wood ducks, but wood ducks changed use areas with greater frequency before 1 October. Despite often extensive movements, most locally reared mallards and wood ducks remained in the vicinity of their brood marshes throughout fall until migration.Movement of young birds to new habitat was not the result of random searching and thus fortuitous discovery of nearby areas. Instead, birds seemed to learn of new habitat and develop movement patterns by associating with other birds; locally reared young always moved in the company of flocks of conspecifics that included adults and older immatures.Differences in movement patterns between the sexes of young birds and between young and adult birds cause them to be differentially distributed by age and sex on and near the breeding grounds. These differences are ultimately reflected in the distribution of the hunter harvest. We have interpreted generalizations about such phenomena, developed from analysis of continent-wide mallard banding data, using our data obtained from individually marked birds. We document (a) greater distances moved by early than by late-hatched young in the postbreeding period before migration, (b) differential movement of age and sex cohorts that explains greater hunting mortality of young than adults and of females than males near natal marshes, (c) differences in length and timing of postbreeding movements of adult male mallards and the postfledging movements of immature male mallards that help explain the northerly continental recovery distribution of young males, and (d) differential timing and rate of movement by birds through harvest areas (early departure of males and some return of females to natal marshes after the beginning of hunting) that explain differences in the timing of hunting season recoveries. Behavioral differences between the age and sex cohorts in the fall waterfowl population on and near their breeding grounds in north-central Minnesota can explain observed differences in survival and recovery rates of adult and young birds.The behaviors observed suggest to us that restrictive harvest regulations such as small-area closure may have little or no local benefits at the breeding grounds because premigratory assemblages of birds make extensive movements. In particular, protection of postbreeding adult females and locally reared young might only occur by closing large areas or scheduling extreme delays in the season opening, neither of which may be compatible with equitably apportioning waterfowl harvest at higher latitudes. Additional research on the local effects of restrictive regulations, and on age- and sex-specific differences in the timing, rate, and direction of fall movements of postbreeding waterfowl is needed.

Infarct size, left ventricular function, and prognosis in women compared to men after primary percutaneous coronary intervention in ST-segment elevation myocardial infarction: results from an individual patient-level pooled analysis of 10 randomized trials.

PubMed

Kosmidou, Ioanna; Redfors, Björn; Selker, Harry P; Thiele, Holger; Patel, Manesh R; Udelson, James E; Magnus Ohman, E; Eitel, Ingo; Granger, Christopher B; Maehara, Akiko; Kirtane, Ajay; Généreux, Philippe; Jenkins, Paul L; Ben-Yehuda, Ori; Mintz, Gary S; Stone, Gregg W

2017-06-01

Studies have reported less favourable outcomes in women compared with men after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI). Whether sex-specific differences in the magnitude or prognostic impact of infarct size or post-infarction cardiac function explain this finding is unknown. We pooled patient-level data from 10 randomized primary PCI trials in which infarct size was measured within 1 month (median 4 days) by either cardiac magnetic resonance imaging or technetium-99m sestamibi single-photon emission computed tomography. We assessed the association between sex, infarct size, and left ventricular ejection fraction (LVEF) and the composite rate of death or heart failure (HF) hospitalization within 1 year. Of 2632 patients with STEMI undergoing primary PCI, 587 (22.3%) were women. Women were older than men and had a longer delay between symptom onset and reperfusion. Infarct size did not significantly differ between women and men, and women had higher LVEF. Nonetheless, women had a higher 1-year rate of death or HF hospitalization compared to men, and while infarct size was a strong independent predictor of 1-year death or HF hospitalization (P < 0.0001), no interaction was present between sex and infarct size or LVEF on the risk of death or HF hospitalization. In this large-scale, individual patient-level pooled analysis of patients with STEMI undergoing primary PCI, women had a higher 1-year rate of death or HF hospitalization compared to men, a finding not explained by sex-specific differences in the magnitude or prognostic impact of infarct size or by differences in post-infarction cardiac function. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Female in-nest chatter song increases predation.

PubMed

Kleindorfer, Sonia; Evans, Christine; Mahr, Katharina

2016-01-01

Female song is an ancestral trait in songbirds, yet extant females generally sing less than males. Here, we examine sex differences in the predation cost of singing behaviour. The superb fairy-wren (Malurus cyaneus) is a Southern Hemisphere songbird; males and females provision the brood and produce solo song year-round. Both sexes had higher song rate during the fertile period and lower song rate during incubation and chick feeding. Females were more likely than males to sing close to or inside the nest. For this reason, female but not male song rate predicted egg and nestling predation. This study identifies a high fitness cost of song when a parent bird attends offspring inside a nest and explains gender differences in singing when there are gender differences in parental care. © 2016 The Author(s).

Sex- and Estrus-Dependent Differences in Rat Basolateral Amygdala

PubMed Central

Blume, Shannon R.; Freedberg, Mari; Vantrease, Jaime E.; Chan, Ronny; Padival, Mallika; Record, Matthew J.; DeJoseph, M. Regina; Urban, Janice H.

2017-01-01

Depression and anxiety are diagnosed almost twice as often in women, and the symptomology differs in men and women and is sensitive to sex hormones. The basolateral amygdala (BLA) contributes to emotion-related behaviors that differ between males and females and across the reproductive cycle. This hints at sex- or estrus-dependent features of BLA function, about which very little is known. The purpose of this study was to test whether there are sex differences or estrous cyclicity in rat BLA physiology and to determine their mechanistic correlates. We found substantial sex differences in the activity of neurons in lateral nuclei (LAT) and basal nuclei (BA) of the BLA that were associated with greater excitatory synaptic input in females. We also found strong differences in the activity of LAT and BA neurons across the estrous cycle. These differences were associated with a shift in the inhibition–excitation balance such that LAT had relatively greater inhibition during proestrus which paralleled more rapid cued fear extinction. In contrast, BA had relatively greater inhibition during diestrus that paralleled more rapid contextual fear extinction. These results are the first to demonstrate sex differences in BLA neuronal activity and the impact of estrous cyclicity on these measures. The shift between LAT and BA predominance across the estrous cycle provides a simple construct for understanding the effects of the estrous cycle on BLA-dependent behaviors. These results provide a novel framework to understand the cyclicity of emotional memory and highlight the importance of considering ovarian cycle when studying the BLA of females. SIGNIFICANCE STATEMENT There are differences in emotional responses and many psychiatric symptoms between males and females. This may point to sex differences in limbic brain regions. Here we demonstrate sex differences in neuronal activity in one key limbic region, the basolateral amygdala (BLA), whose activity fluctuates across the estrous cycle due to a shift in the balance of inhibition and excitation across two BLA regions, the lateral and basal nuclei. By uncovering this push–pull shift between lateral and basal nuclei, these results help to explain disparate findings about the effects of biological sex and estrous cyclicity on emotion and provide a framework for understanding fluctuations in emotional memory and psychiatric symptoms. PMID:28954870

Prenatal hormones and postnatal socialization by parents as determinants of male-typical toy play in girls with congenital adrenal hyperplasia.

PubMed

Pasterski, Vickie L; Geffner, Mitchell E; Brain, Caroline; Hindmarsh, Peter; Brook, Charles; Hines, Melissa

2005-01-01

Toy choices of 3- to 10-year-old children with congenital adrenal hyperplasia (CAH) and of their unaffected siblings were assessed. Also assessed was parental encouragement of sex-typed toy play. Girls with CAH displayed more male-typical toy choices than did their unaffected sisters, whereas boys with and without CAH did not differ. Mothers and fathers encouraged sex-typical toy play in children with and without CAH. However, girls with CAH received more positive feedback for play with girls' toys than did unaffected girls. Data show that increased male-typical toy play by girls with CAH cannot be explained by parental encouragement of male-typical toy play. Although parents encourage sex-appropriate behavior, their encouragement appears to be insufficient to override the interest of girls with CAH in cross-sexed toys.

Gendered race: are infants' face preferences guided by intersectionality of sex and race?

PubMed

Kim, Hojin I; Johnson, Kerri L; Johnson, Scott P

2015-01-01

People occupy multiple social categories simultaneously (e.g., a White female), and this complex intersectionality affects fundamental aspects of social perception. Here, we examined the possibility that infant face processing may be susceptible to effects of intersectionality of sex and race. Three- and 10-month-old infants were shown a series of computer-generated face pairs (5 s each) that differed according to sex (Female or Male) or race (Asian, Black, or White). All possible combinations of face pairs were tested, and preferences were recorded with an eye tracker. Infants showed preferences for more feminine faces only when they were White, but we found no evidence that White or Asian faces were preferred even though they are relatively more feminized. These findings challenge the notions that infants' social categories are processed independently of one another and that infants' preferences for sex or race can be explained from mere exposure.

Gendered race: are infants’ face preferences guided by intersectionality of sex and race?

PubMed Central

Kim, Hojin I.; Johnson, Kerri L.; Johnson, Scott P.

2015-01-01

People occupy multiple social categories simultaneously (e.g., a White female), and this complex intersectionality affects fundamental aspects of social perception. Here, we examined the possibility that infant face processing may be susceptible to effects of intersectionality of sex and race. Three- and 10-month-old infants were shown a series of computer-generated face pairs (5 s each) that differed according to sex (Female or Male) or race (Asian, Black, or White). All possible combinations of face pairs were tested, and preferences were recorded with an eye tracker. Infants showed preferences for more feminine faces only when they were White, but we found no evidence that White or Asian faces were preferred even though they are relatively more feminized. These findings challenge the notions that infants’ social categories are processed independently of one another and that infants’ preferences for sex or race can be explained from mere exposure. PMID:26388823

Sex difference in travel is concentrated in adolescence and tracks reproductive interests

PubMed Central

Miner, Emily J.; Gurven, Michael; Kaplan, Hillard; Gaulin, Steven J. C.

2014-01-01

Sexual selection theory suggests that the sex with a higher potential reproductive rate will compete more strongly for access to mates. Stronger intra-sexual competition for mates may explain why males travel more extensively than females in many terrestrial vertebrates. A male-bias in lifetime distance travelled is a purported human universal, although this claim is based primarily on anecdotes. Following sexual maturity, motivation to travel outside the natal territory may vary over the life course for both sexes. Here, we test whether travel behaviour among Tsimane forager–horticulturalists is associated with shifting reproductive priorities across the lifespan. Using structured interviews, we find that sex differences in travel peak during adolescence when men and women are most intensively searching for mates. Among married adults, we find that greater offspring dependency load is associated with reduced travel among women, but not men. Married men are more likely to travel alone than women, but only to the nearest market town and not to other Tsimane villages. We conclude that men's and women's travel behaviour reflects differential gains from mate search and parenting across the life course. PMID:25320169

Hepatitis B surface antigen gene expression is regulated by sex steroids and glucocorticoids in transgenic mice.

PubMed Central

Farza, H; Salmon, A M; Hadchouel, M; Moreau, J L; Babinet, C; Tiollais, P; Pourcel, C

1987-01-01

We have investigated the basis for liver-specific and sex-linked expression of hepatitis B surface antigen (HBsAg) gene in transgenic mice by monitoring the level of liver HBsAg mRNA and serum HBsAg at different stages of development and in response to sex-hormone regulation. Transcription of the HBsAg gene starts at day 15 of development, together with that of the albumin gene, and reaches a comparable level at birth. HBsAg mRNA level and HBsAg production are parallel in males and females during prenatal development and until the first month of life, but HBsAg gene expression increases 5-10 times in males at puberty. After castration, the level of expression decreases dramatically in both males and females and is subsequently increased by injection of testosterone or estradiol. Glucocorticoids also regulated positively expression of the HBsAg gene. Our results suggest that sex hormones play a role in hepatitis B virus gene expression during natural infection and could explain the difference in incidence of chronic carriers between men and women. Images PMID:3469661

Can variation in HIV/STD-related risk be explained by individual SES? Findings from female sex workers in a rural Chinese county.

PubMed

Fang, Xiaoyi; Li, Xiaoming; Yang, Hongmei; Hong, Yan; Stanton, Bonita; Zhao, Ran; Dong, Baiqing; Liu, Wei; Zhou, Yuejiao; Liang, Shaoling

2008-03-01

Low socioeconomic status (SES) has been linked to HIV and sexually transmitted disease (STD) at a macro level because the majority of new cases of HIV infection in the world have been reported in underdeveloped or developing countries. However, empirical data on the relationship between individual SES and HIV/STD related risk have been mixed. Employing quantitative data from 454 female sex workers (FSWs), this study was designed to examine the profile of the study sample in terms of their individual SES, HIV/STD-related sexual risk across work locations with different social, cultural, and economic conditions; and to examine the relationship between work location and HIV-related risk behaviors, controlling for individual SES. We have shown in the current study that both SES and HIV/STD-related risk behaviors significantly differed by work location. However, the difference in individual SES was not sufficient to explain the difference of HIV/STD-related risk across the work locations. The findings underscore the need for effective prevention intervention efforts targeting FSWs in rural areas. Based on the findings, we also suggest that HIV/STD intervention efforts among FSWs should take the social and cultural contextual factors of their working environment (and sexual risks) into consideration.

The ecology and evolution of temperature-dependent reaction norms for sex determination in reptiles: a mechanistic conceptual model.

PubMed

Pezaro, Nadav; Doody, J Sean; Thompson, Michael B

2017-08-01

Sex-determining mechanisms are broadly categorised as being based on either genetic or environmental factors. Vertebrate sex determination exhibits remarkable diversity but displays distinct phylogenetic patterns. While all eutherian mammals possess XY male heterogamety and female heterogamety (ZW) is ubiquitous in birds, poikilothermic vertebrates (fish, amphibians and reptiles) exhibit multiple genetic sex-determination (GSD) systems as well as environmental sex determination (ESD). Temperature is the factor controlling ESD in reptiles and temperature-dependent sex determination (TSD) in reptiles has become a focal point in the study of this phenomenon. Current patterns of climate change may cause detrimental skews in the population sex ratios of reptiles exhibiting TSD. Understanding the patterns of variation, both within and among populations and linking such patterns with the selection processes they are associated with, is the central challenge of research aimed at predicting the capacity of populations to adapt to novel conditions. Here we present a conceptual model that innovates by defining an individual reaction norm for sex determination as a range of incubation temperatures. By deconstructing individual reaction norms for TSD and revealing their underlying interacting elements, we offer a conceptual solution that explains how variation among individual reaction norms can be inferred from the pattern of population reaction norms. The model also links environmental variation with the different patterns of TSD and describes the processes from which they may arise. Specific climate scenarios are singled out as eco-evolutionary traps that may lead to demographic extinction or a transition to either male or female heterogametic GSD. We describe how the conceptual principles can be applied to interpret TSD data and to explain the adaptive capacity of TSD to climate change as well as its limits and the potential applications for conservation and management programs. © 2016 Cambridge Philosophical Society.

Genome-wide meta-analysis of common variant differences between men and women

PubMed Central

Boraska, Vesna; Jerončić, Ana; Colonna, Vincenza; Southam, Lorraine; Nyholt, Dale R.; William Rayner, Nigel; Perry, John R.B.; Toniolo, Daniela; Albrecht, Eva; Ang, Wei; Bandinelli, Stefania; Barbalic, Maja; Barroso, Inês; Beckmann, Jacques S.; Biffar, Reiner; Boomsma, Dorret; Campbell, Harry; Corre, Tanguy; Erdmann, Jeanette; Esko, Tõnu; Fischer, Krista; Franceschini, Nora; Frayling, Timothy M.; Girotto, Giorgia; Gonzalez, Juan R.; Harris, Tamara B.; Heath, Andrew C.; Heid, Iris M.; Hoffmann, Wolfgang; Hofman, Albert; Horikoshi, Momoko; Hua Zhao, Jing; Jackson, Anne U.; Hottenga, Jouke-Jan; Jula, Antti; Kähönen, Mika; Khaw, Kay-Tee; Kiemeney, Lambertus A.; Klopp, Norman; Kutalik, Zoltán; Lagou, Vasiliki; Launer, Lenore J.; Lehtimäki, Terho; Lemire, Mathieu; Lokki, Marja-Liisa; Loley, Christina; Luan, Jian'an; Mangino, Massimo; Mateo Leach, Irene; Medland, Sarah E.; Mihailov, Evelin; Montgomery, Grant W.; Navis, Gerjan; Newnham, John; Nieminen, Markku S.; Palotie, Aarno; Panoutsopoulou, Kalliope; Peters, Annette; Pirastu, Nicola; Polašek, Ozren; Rehnström, Karola; Ripatti, Samuli; Ritchie, Graham R.S.; Rivadeneira, Fernando; Robino, Antonietta; Samani, Nilesh J.; Shin, So-Youn; Sinisalo, Juha; Smit, Johannes H.; Soranzo, Nicole; Stolk, Lisette; Swinkels, Dorine W.; Tanaka, Toshiko; Teumer, Alexander; Tönjes, Anke; Traglia, Michela; Tuomilehto, Jaakko; Valsesia, Armand; van Gilst, Wiek H.; van Meurs, Joyce B.J.; Smith, Albert Vernon; Viikari, Jorma; Vink, Jacqueline M.; Waeber, Gerard; Warrington, Nicole M.; Widen, Elisabeth; Willemsen, Gonneke; Wright, Alan F.; Zanke, Brent W.; Zgaga, Lina; Boehnke, Michael; d'Adamo, Adamo Pio; de Geus, Eco; Demerath, Ellen W.; den Heijer, Martin; Eriksson, Johan G.; Ferrucci, Luigi; Gieger, Christian; Gudnason, Vilmundur; Hayward, Caroline; Hengstenberg, Christian; Hudson, Thomas J.; Järvelin, Marjo-Riitta; Kogevinas, Manolis; Loos, Ruth J.F.; Martin, Nicholas G.; Metspalu, Andres; Pennell, Craig E.; Penninx, Brenda W.; Perola, Markus; Raitakari, Olli; Salomaa, Veikko; Schreiber, Stefan; Schunkert, Heribert; Spector, Tim D.; Stumvoll, Michael; Uitterlinden, André G.; Ulivi, Sheila; van der Harst, Pim; Vollenweider, Peter; Völzke, Henry; Wareham, Nicholas J.; Wichmann, H.-Erich; Wilson, James F.; Rudan, Igor; Xue, Yali; Zeggini, Eleftheria

2012-01-01

The male-to-female sex ratio at birth is constant across world populations with an average of 1.06 (106 male to 100 female live births) for populations of European descent. The sex ratio is considered to be affected by numerous biological and environmental factors and to have a heritable component. The aim of this study was to investigate the presence of common allele modest effects at autosomal and chromosome X variants that could explain the observed sex ratio at birth. We conducted a large-scale genome-wide association scan (GWAS) meta-analysis across 51 studies, comprising overall 114 863 individuals (61 094 women and 53 769 men) of European ancestry and 2 623 828 common (minor allele frequency >0.05) single-nucleotide polymorphisms (SNPs). Allele frequencies were compared between men and women for directly-typed and imputed variants within each study. Forward-time simulations for unlinked, neutral, autosomal, common loci were performed under the demographic model for European populations with a fixed sex ratio and a random mating scheme to assess the probability of detecting significant allele frequency differences. We do not detect any genome-wide significant (P < 5 × 10−8) common SNP differences between men and women in this well-powered meta-analysis. The simulated data provided results entirely consistent with these findings. This large-scale investigation across ∼115 000 individuals shows no detectable contribution from common genetic variants to the observed skew in the sex ratio. The absence of sex-specific differences is useful in guiding genetic association study design, for example when using mixed controls for sex-biased traits. PMID:22843499

Sex-specific phenotypes of hyperthyroidism and hypothyroidism in aged mice.

PubMed

Rakov, Helena; Engels, Kathrin; Hönes, Georg Sebastian; Brix, Klaudia; Köhrle, Josef; Moeller, Lars Christian; Zwanziger, Denise; Führer, Dagmar

2017-12-22

Sex and age play a role in the prevalence of thyroid dysfunction (TD), but their interrelationship for manifestation of hyper- and hypothyroidism is still not well understood. Using a murine model, we asked whether sex impacts the phenotypes of hyper- and hypothyroidism at two life stages. Hyper- and hypothyroidism were induced by i.p. T4 or MMI/ClO 4 -/LoI treatment over 7 weeks in 12- and 20-months-old female and male C57BL/6N mice. Control animals underwent PBS treatment (n = 7-11 animals/sex/treatment). Animals were investigated for impact of sex on body weight, food and water intake, body temperature, heart rate, behaviour (locomotor activity, motor coordination and strength) and serum thyroid hormone (TH) status. Distinct sex impact was found in eu- and hyperthyroid mice, while phenotypic traits of hypothyroidism were similar in male and female mice. No sex difference was found in TH status of euthyroid mice; however, T4 treatment resulted in twofold higher TT4, FT4 and FT3 serum concentrations in adult and old females compared to male animals. Hyperthyroid females consistently showed higher locomotor activity and better coordination but more impairment of muscle function by TH excess at adult age. Importantly and in contrast to male mice, adult and old hyperthyroid female mice showed increased body weight. Higher body temperature in female mice was confirmed in all age groups. No sex impact was found on heart rate irrespective of TH status in adult and old mice. By comparison of male and female mice with TD at two life stages, we found that sex modulates TH action in an organ- and function-specific manner. Sex differences were more pronounced under hyperthyroid conditions. Importantly, sex-specific differences in features of TD in adult and old mice were not conclusively explained by serum TH status in mice.

Different sex ratios of children born to Indian and Pakistani immigrants in Norway

PubMed Central

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

Sex Ratio and Reproductive Effort in the Dioecious Juniperus communis subsp. alpina (Suter) Čelak. (Cupressaceae) Along an Altitudinal Gradient

PubMed Central

ORTIZ, PEDRO LUIS; ARISTA, MONTSERRAT; TALAVERA, SALVADOR

2002-01-01

The hypothesis that reproductive cost differs between sexes was tested in Juniperus communis subsp. alpina along an altitudinal gradient. Sex ratio (male : female) increased significantly with elevation, and above 2600 m it was significantly male‐biased. The reproductive effort was markedly greater for females than for males at all elevations. However, over 3 years of study, the growth of the females, measured as elongation of the main axes, was similar to that of the males. In both sexes, growth decreased with increasing elevation. Neither size of the ripe seed cones, nor the number of developed seeds per cone varied with elevation. The percentage of filled seeds was significantly greater at higher elevations indicating more favourable conditions for wind pollination in these stands. However, cone production decreased with elevation and so, reproductive success of J. communis subsp. alpina in Sierra Nevada decreases towards both upper and lower altitudinal distribution limits. The results do not support the hypothesis of differential reproductive cost between sexes; thus, alternative arguments to explain the altitudinal variation of sex ratio are discussed. PMID:12099351

Sex ratio and reproductive effort in the dioecious Juniperus communis subsp. alpina (Suter) Celak. (Cupressaceae) along an altitudinal gradient.

PubMed

Ortiz, Pedro Luis; Arista, Montserrat; Talavera, Salvador

2002-02-01

The hypothesis that reproductive cost differs between sexes was tested in Juniperus communis subsp. alpina along an altitudinal gradient. Sex ratio (male : female) increased significantly with elevation, and above 2,600 m it was significantly male-biased. The reproductive effort was markedly greater for females than for males at all elevations. However, over 3 years of study, the growth of the females, measured as elongation of the main axes, was similar to that of the males. In both sexes, growth decreased with increasing elevation. Neither size of the ripe seed cones, nor the number of developed seeds per cone varied with elevation. The percentage of filled seeds was significantly greater at higher elevations indicating more favourable conditions for wind pollination in these stands. However, cone production decreased with elevation and so, reproductive success of J. communis subsp. alpina in Sierra Nevada decreases towards both upper and lower altitudinal distribution limits. The results do not support the hypothesis of differential reproductive cost between sexes; thus, alternative arguments to explain the altitudinal variation of sex ratio are discussed.

Science Majors and Degrees among Asian-American Students: Influences of Race and Sex in "model Minority" Experiences

NASA Astrophysics Data System (ADS)

Meng, Yu; Hanson, Sandra L.

Both race and sex continue to be factors that stratify entry into science education and occupations in the United States. Asian-Americans (men and women) have experienced considerable success in the sciences and have earned the label of "model minority." The complexities and patterns involved in this success remain elusive. We use several concepts coming out of the status attainment framework and a multicultural gender perspective to explore the way in which race and sex come together to influence choices of science major and degree. Our sample consists of Asian-American and white students in the National Educational Longitudinal Study. Findings suggest that being male and being Asian-American are both associated with higher chances of pursuing majors and degrees in science. The male advantage is greater than the Asian-American advantage. Findings also suggest that race and sex interact in the science decision. For example, race differences (with an Asian-American advantage) in choice of science major are significant for women but not men. Sex differences (with a male advantage) in choice of science major are significant in the white, but not the Asian-American sample. A different set of race and sex patterns is revealed in the science degree models. Processes associated with family socioeconomic status and student characteristics help to explain race and sex patterns. Findings suggest that when Asian-American youths have closer ties to the Asian culture, they are more likely to choose science majors and degrees. Implications for policy, practice, and research in science education are discussed.

SEX DIFFERENCES IN BIOMECHANICS ASSOCIATED WITH KNEE OSTEOARTHRITIS

PubMed Central

Sims, Ershela L.; Carland, Julie M.; Keefe, Francis J.; Kraus, Virginia B.; Guilak, Farshid; Schmitt, Daniel

2011-01-01

Osteoarthritis of the knee is seen more frequently in females than males. However, few studies have examined the interplay of gender, gait mechanics, pain, and disability in persons with osteoarthritis. This study examines the influence of anthropometrics, radiographic disease severity, pain, and disability on gender differences in gait mechanics in patients with knee osteoarthritis. Gait mechanics for 26 men and 30 women, were collected using 3-D kinematics and kinetics. Women had a significantly lower knee adduction moment than men, and a significantly higher stride frequency. Within female subjects, variations in gait mechanics were primarily explained by weight, BMI, pain, and disability. In males, variations in gait mechanics were primarily explained by age and disability. PMID:20183142

Sex differences in the circadian regulation of sleep and waking cognition in humans.

PubMed

Santhi, Nayantara; Lazar, Alpar S; McCabe, Patrick J; Lo, June C; Groeger, John A; Dijk, Derk-Jan

2016-05-10

The sleep-wake cycle and circadian rhythmicity both contribute to brain function, but whether this contribution differs between men and women and how it varies across cognitive domains and subjective dimensions has not been established. We examined the circadian and sleep-wake-dependent regulation of cognition in 16 men and 18 women in a forced desynchrony protocol and quantified the separate contributions of circadian phase, prior sleep, and elapsed time awake on cognition and sleep. The largest circadian effects were observed for reported sleepiness, mood, and reported effort; the effects on working memory and temporal processing were smaller. Although these effects were seen in both men and women, there were quantitative differences. The amplitude of the circadian modulation was larger in women in 11 of 39 performance measures so that their performance was more impaired in the early morning hours. Principal components analysis of the performance measures yielded three factors, accuracy, effort, and speed, which reflect core performance characteristics in a range of cognitive tasks and therefore are likely to be important for everyday performance. The largest circadian modulation was observed for effort, whereas accuracy exhibited the largest sex difference in circadian modulation. The sex differences in the circadian modulation of cognition could not be explained by sex differences in the circadian amplitude of plasma melatonin and electroencephalographic slow-wave activity. These data establish the impact of circadian rhythmicity and sex on waking cognition and have implications for understanding the regulation of brain function, cognition, and affect in shift-work, jetlag, and aging.

Sex differences in the circadian regulation of sleep and waking cognition in humans

PubMed Central

Santhi, Nayantara; Lazar, Alpar S.; McCabe, Patrick J.; Lo, June C.; Groeger, John A.; Dijk, Derk-Jan

2016-01-01

The sleep–wake cycle and circadian rhythmicity both contribute to brain function, but whether this contribution differs between men and women and how it varies across cognitive domains and subjective dimensions has not been established. We examined the circadian and sleep–wake-dependent regulation of cognition in 16 men and 18 women in a forced desynchrony protocol and quantified the separate contributions of circadian phase, prior sleep, and elapsed time awake on cognition and sleep. The largest circadian effects were observed for reported sleepiness, mood, and reported effort; the effects on working memory and temporal processing were smaller. Although these effects were seen in both men and women, there were quantitative differences. The amplitude of the circadian modulation was larger in women in 11 of 39 performance measures so that their performance was more impaired in the early morning hours. Principal components analysis of the performance measures yielded three factors, accuracy, effort, and speed, which reflect core performance characteristics in a range of cognitive tasks and therefore are likely to be important for everyday performance. The largest circadian modulation was observed for effort, whereas accuracy exhibited the largest sex difference in circadian modulation. The sex differences in the circadian modulation of cognition could not be explained by sex differences in the circadian amplitude of plasma melatonin and electroencephalographic slow-wave activity. These data establish the impact of circadian rhythmicity and sex on waking cognition and have implications for understanding the regulation of brain function, cognition, and affect in shift-work, jetlag, and aging. PMID:27091961

Biological sex and the risk of cerebral palsy in Victoria, Australia.

PubMed

Reid, Susan M; Meehan, Elaine; Gibson, Catherine S; Scott, Heather; Delacy, Michael J

2016-02-01

Males typically outnumber females in cerebral palsy (CP) cohorts. To better understand this 'male disadvantage' and provide insight into causal pathways to CP, this study used 1983 to 2009 Australian CP and population birth cohorts to identify associations and trends with respect to biological sex and CP. Within birth gestation groups, sex ratios were calculated to evaluate any male excess in the CP cohort compared with livebirths, neonatal deaths, neonatal mortality and survival rates, neonatal survivors, and CP rates in survivors. Sex- and gestation-specific trends in neonatal mortality, CP rates, and CP sex ratios were assessed by plotting their annual frequencies and fitting quadratic curves. Over-representation of males in preterm live births partly explained the male excess in the CP cohort after preterm birth, especially at 28 to 31 weeks. Higher CP rates in male neonatal survivors also contributed to the male excess in CP, particularly at <28 and 37+ weeks. Higher neonatal mortality rates in males at all gestations had little impact on the CP sex ratio. There was no clearly discernible change over time in the CP sex ratio. Gestation-specific associations between sex and CP provide insight into causal pathways to CP and suggest sex-specific differences in response to neuroprotective strategies. © 2016 The Authors. Developmental Medicine & Child Neurology © 2016 Mac Keith Press.

Sex Bias in Infectious Disease Epidemiology: Patterns and Processes

PubMed Central

Guerra-Silveira, Felipe; Abad-Franch, Fernando

2013-01-01

Background Infectious disease incidence is often male-biased. Two main hypotheses have been proposed to explain this observation. The physiological hypothesis (PH) emphasizes differences in sex hormones and genetic architecture, while the behavioral hypothesis (BH) stresses gender-related differences in exposure. Surprisingly, the population-level predictions of these hypotheses are yet to be thoroughly tested in humans. Methods and Findings For ten major pathogens, we tested PH and BH predictions about incidence and exposure-prevalence patterns. Compulsory-notification records (Brazil, 2006–2009) were used to estimate age-stratified ♂:♀ incidence rate ratios for the general population and across selected sociological contrasts. Exposure-prevalence odds ratios were derived from 82 published surveys. We estimated summary effect-size measures using random-effects models; our analyses encompass ∼0.5 million cases of disease or exposure. We found that, after puberty, disease incidence is male-biased in cutaneous and visceral leishmaniasis, schistosomiasis, pulmonary tuberculosis, leptospirosis, meningococcal meningitis, and hepatitis A. Severe dengue is female-biased, and no clear pattern is evident for typhoid fever. In leprosy, milder tuberculoid forms are female-biased, whereas more severe lepromatous forms are male-biased. For most diseases, male bias emerges also during infancy, when behavior is unbiased but sex steroid levels transiently rise. Behavioral factors likely modulate male–female differences in some diseases (the leishmaniases, tuberculosis, leptospirosis, or schistosomiasis) and age classes; however, average exposure-prevalence is significantly sex-biased only for Schistosoma and Leptospira. Conclusions Our results closely match some key PH predictions and contradict some crucial BH predictions, suggesting that gender-specific behavior plays an overall secondary role in generating sex bias. Physiological differences, including the crosstalk between sex hormones and immune effectors, thus emerge as the main candidate drivers of gender differences in infectious disease susceptibility. PMID:23638062

Sex-Related Differences in Self-Reported Neurocognitive Impairment among High-Risk Cocaine Users in Methadone Maintenance Treatment Program.

PubMed

Shrestha, Roman; Huedo-Medina, Tania B; Copenhaver, Michael M

2015-01-01

Previous research has suggested possible sex-related differences in executive functioning among cocaine users; however, no studies specifically explain sex-related differences in neurocognitive impairment (NCI) among cocaine users receiving clinical care. Knowledge about this association can aid in the development of targeted prevention strategies to reduce adverse health outcomes. This study was designed to examine the sex-related differences in NCI among high-risk cocaine users receiving substance-abuse treatment. The Neuropsychological Impairment Scale (NIS) was administered to 199 cocaine users (98 men; 101 women), receiving methadone maintainance treatment, to assess self-reported NCI by identifying the patients' awareness of neuropsychological symptoms. We used T-test comparison to find differences in NCI between men and women and multiple regression analysis to explore the relative contribution of sex to NCI. Consistent with prior work, high NCI was evident within this sample, as indicated by high scores on most of the NIS subscales. Women reported greater impairment than men, as evidenced by significantly higher scores on several NIS subscales, after controlling for demographic and other confounding variables. Interestingly, cocaine craving significantly predicted NCI among men but not among women, as suggested by the significant association between cocaine craving and all except one of the NIS subscales. These findings suggest that cocaine users enter into treatment with a range of NCI - with women having significantly more neurocognitive deficits than men - that may contribute to differential treatment outcomes. This highlights the need to include additional services such as neuropsychological screening and sex-specific treatment programs to optimally reduce adverse health outcomes in these high-risk, cognitively impaired patients.

Work and family characteristics as determinants of socioeconomic and sex inequalities in sleep: The Japanese Civil Servants Study.

PubMed

Sekine, Michikazu; Chandola, Tarani; Martikainen, Pekka; Marmot, Michael; Kagamimori, Sadanobu

2006-02-01

To clarify whether socioeconomic and sex inequalities in poor sleep quality are explained by socioeconomic and sex differences in work and family characteristics. A cross-sectional study. Three thousand five hundred fifty-six employees (2397 men and 1159 women) aged 20 to 65 years in local government in Japan. Respondents completed a self-administered questionnaire that asked about sleep quality, as measured by the Pittsburgh Sleep Quality Index; work characteristics, as measured by the job-demand-control-support model, work hours, and shift work; and family characteristics, such as family structure and family-work conflicts. Lower control at work, higher work demands, lower social support, shorter and longer working hours, shift work, being single, higher family-to-work conflict, and higher work-to-family conflict were independently associated with poorer sleep quality in both men and women. In men, the age-adjusted odds ratio (OR) of low-grade employees for poor sleep quality was 1.64 (95% confidence interval: 1.14-2.36) in comparison with high-grade employees. The difference in sleep was attenuated when work and family characteristics were adjusted for (OR=1.25 [0.84-1.86]). Among women, there was no significant grade difference in sleep. Women tended to have poorer sleep quality than men (the age-adjusted OR=1.75 [1.49-2.06]). The sex difference was attenuated and no longer significant when adjustments were made for work and family characteristics (OR=1.04 [0.85-1.27]). The results of this study suggest that work and family characteristics may be important for reducing socioeconomic and sex inequalities in sleep. Sex differences in the pattern of socioeconomic inequalities in sleep deserve further research.

What Should Be the Moral Aims of Compulsory Sex Education?

ERIC Educational Resources Information Center

Steutel, Jan; de Ruyter, Doret J.

2011-01-01

With reference to the unsuccessful attempt of the Labour Government to make sex education a statutory part of the National Curriculum, this paper argues in favour of making liberal sex education compulsory at all state schools. First, the main characteristics of a liberal sex education are briefly explained. Promoting the virtue of respect for…

Homonegativity in the Technical and Vocational Track: A Survey of Secondary School Students in Flanders

ERIC Educational Resources Information Center

Aerts, Saskia; Dewaele, Alexis; Cox, Nele; Van Houtte, Mieke

2014-01-01

Students from the technical and vocational track in Flanders have more homonegative attitudes than other students. We investigate what explains this track difference and if the homonegativity is reflected in more bullying experiences by lesbian, gay, and bisexual (LGB) students in these tracks. The results show that sex-role ideology and religion…

How Much Can Evolutionary Psychology Inform the Educational Sciences?

ERIC Educational Resources Information Center

Halpern, Diane F.

2008-01-01

In response to a stimulating article by David C. Geary on the value of understanding the evolutionary basis of learning as a guide to instruction, I raise several objections. When evolutionary theory is used to explain everything from sex differences in math and reading to why children are bored in school, it loses its explanatory power. There is…

Schizophrenia in High-Risk Children: Sex Differences in Predisposing Factors.

ERIC Educational Resources Information Center

Mednick, Sarnoff A.; And Others

Reported is a research program to observe children at high risk for schizophrenia and explore possibilities of prevention. Characteristics of the high risk group (n=207) observed during 1962 are discussed, and a theory which suggests that schizophrenia is an evasion of life is explained. Among results of a diagnostic assessment conducted 10 years…

The Two Sexes: Growing Up Apart, Coming Together. Family and Public Policy Series.

ERIC Educational Resources Information Center

Maccoby, Eleanor E.

This book seeks to explain how gender affects human development from infancy through adolescence and into adulthood. The book's introduction states the two theses of the book: first, gender differences appear primarily in group, or social, contexts; and second, gender differentiation can be understood only in a developmental context--the sexes…

Differential Exposure and Reactivity to Interpersonal Stress Predict Sex Differences in Adolescent Depression

ERIC Educational Resources Information Center

Shih, Josephine H.; Eberhart, Nicole K.; Hammen, Constance L.; Brennan, Patricia A.

2006-01-01

This study tested the hypothesis that higher rates of depression in adolescent girls are explained by their greater exposure and reactivity to stress in the interpersonal domain in a large sample of 15-year-olds. Findings indicate that adolescent girls experienced higher levels of total and interpersonal episodic stress, whereas boys experienced…

Do Lower-Body Dimensions and Body Composition Explain Vertical Jump Ability?

PubMed

Caia, Johnpaul; Weiss, Lawrence W; Chiu, Loren Z F; Schilling, Brian K; Paquette, Max R; Relyea, George E

2016-11-01

Caia, J, Weiss, LW, Chiu, LZF, Schilling, BK, Paquette, MR, and Relyea, GE. Do lower-body dimensions and body composition explain vertical jump ability? J Strength Cond Res 30(11): 3073-3083, 2016-Vertical jump (VJ) capability is integral to the level of success attained by individuals participating in numerous sport and physical activities. Knowledge of factors related to jump performance may help with talent identification and/or optimizing training prescription. Although myriad variables are likely related to VJ, this study focused on determining if various lower-body dimensions and/or body composition would explain some of the variability in performance. Selected anthropometric dimensions were obtained from 50 university students (25 men and 25 women) on 2 occasions separated by 48 or 72 hours. Estimated body fat percentage (BF%), height, body weight, hip width, pelvic width, bilateral quadriceps angle (Q-angle), and bilateral longitudinal dimensions of the feet, leg, thigh, and lower limb were obtained. Additionally, participants completed countermovement VJs. Analysis showed BF% to have the highest correlation with countermovement VJ displacement (r = -0.76, p < 0.001). When examining lower-body dimensions, right-side Q-angle displayed the strongest association with countermovement VJ displacement (r = -0.58, p < 0.001). Regression analysis revealed that 2 different pairs of variables accounted for the greatest variation (66%) in VJ: (a) BF% and sex and (b) BF% and body weight. Regression models involving BF% and lower-body dimensions explained up to 61% of the variance observed in VJ. Although the variance explained by BF% may be increased by using several lower-body dimensions, either sex identification or body weight explains comparatively more. Therefore, these data suggest that the lower-body dimensions measured herein have limited utility in explaining VJ performance.

Reported masculinity ratio in Pakistan: a triumph of anthropology and economics over biology.

PubMed

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).

The secret life of ground squirrels: accelerometry reveals sex-dependent plasticity in above-ground activity

PubMed Central

Wilsterman, Kathryn; Zhang, Victor; Moore, Jeanette; Barnes, Brian M.; Buck, C. Loren

2016-01-01

The sexes differ in how and when they allocate energy towards reproduction, but how this influences phenotypic plasticity in daily activity patterns is unclear. Here, we use collar-mounted light loggers and triaxial accelerometers to examine factors that affect time spent above ground and overall dynamic body acceleration (ODBA), an index of activity-specific energy expenditure, across the active season of free-living, semi-fossorial arctic ground squirrels (Urocitellus parryii). We found high day-to-day variability in time spent above ground and ODBA with most of the variance explained by environmental conditions known to affect thermal exchange. In both years, females spent more time below ground compared with males during parturition and early lactation; however, this difference was fourfold larger in the second year, possibly, because females were in better body condition. Daily ODBA positively correlated with time spent above ground in both sexes, but females were more active per unit time above ground. Consequently, daily ODBA did not differ between the sexes when females were early in lactation, even though females were above ground three to six fewer hours each day. Further, on top of having the additional burden of milk production, ODBA data indicate females also had fragmented rest patterns and were more active during late lactation. Our results indicate that sex differences in reproductive requirements can have a substantial influence on activity patterns, but the size of this effect may be dependent on capital resources accrued during gestation. PMID:27703706

Sex Bias in Georgia High School Economics Textbooks.

ERIC Educational Resources Information Center

Blankenship, Glen; Hahn, Carole L.

1982-01-01

Analyzes 17 secondary level economics textbooks for sex bias. All of the texts reviewed are on Georgia's approved textbook list. Without exception, each of the texts is guilty of sex bias, although to varying degrees. The method used in analyzing the texts is explained. (RM)

Differences between the sexes in technical mastery of rhythmic gymnastics.

PubMed

Bozanic, Ana; Miletic, Durdica

2011-02-01

The aims of this study were to determine possible differences between the sexes in specific rhythmic gymnastics techniques, and to examine the influence of various aspects of technique on rhythmic composition performance. Seventy-five students aged 21 ± 2 years (45 males, 30 female) undertook four test sessions to determine: coefficients of asymmetry, stability, versatility, and the two rhythmic compositions (without apparatus and with rope). An independent-sample t-test revealed sex-based differences in technique acquisition: stability for ball (P < 0.05; effect size = 0.65) and club (P < 0.05; effect size = 0.79) performance and rhythmic composition without apparatus (P < 0.05; effect size = 0.66). Multiple regression analysis revealed that the variables for assessing stability (beta = 0.44; P < 0.05) and versatility (beta = 0.61; P < 0.05) explained 61% of the variance in the rhythmic composition performance of females, and the variables for assessing asymmetry (beta = -0.38; P < 0.05), versatility (beta = 0.32; P < 0.05), and stability (beta = 0.29; P < 0.05) explained 52% of the variance in the rhythmic composition performance of males. The results suggest that female students dominate in body skill technique, while male students have the advantage with apparatus. There was a lack of an expressive aesthetic component in performance for males. The need for ambidexterity should be considered in the planning of training programmes.

Observed Differences between Males and Females in Surgically Treated Carpal Tunnel Syndrome Among Non-manual Workers: A Sensitivity Analysis of Findings from a Large Population Study

PubMed Central

Farioli, Andrea; Curti, Stefania; Bonfiglioli, Roberta; Baldasseroni, Alberto; Spatari, Giovanna; Mattioli, Stefano; Violante, Francesco Saverio

2018-01-01

Abstract Objectives We aimed at assessing whether differences among males and females in carpal tunnel syndrome (CTS) epidemiology might be attributable to segregation with respect to occupational biomechanical exposures or differential access to care by sex. Methods We analysed surgically treated cases of CTS occurring among non-manual workers in Tuscany between 1997 and 2000. We conducted a Monte Carlo simulation to estimate the difference in occupational biomechanical exposures between males and females necessary to explain the observed incidence rate ratios. We also accounted for the sex-specific probability of receiving surgery after the diagnosis of CTS, as women were reported to be more likely to undergo surgery in a subset of our study population. We quantified the hypothetical biomechanical overload through the hand activity level (HAL) metric proposed by the American Conference of Governmental Industrial Hygienists. To quantify the effect of HAL on CTS risk, we assumed a prior distribution based on findings from two large cohort studies of industrial workers. Results After adjustment for the probability of receiving surgery, women showed a 4-fold incidence of CTS as compared with men. To explain this association among non-manual workers, women should have an average value of HAL at least 5 points higher. Conclusions Our analysis does not support the hypothesis that the difference in CTS incidence between males and females is entirely attributable to occupational risk factors or to differential access to surgery. The causal pathway between sex and CTS might include more determinants such as hormonal factors, anthropometric characteristics, and non-occupational exposure to biomechanical overload (e.g. household tasks). PMID:29579135

What Matters When Children Play: Influence of Social Cognitive Theory and Perceived Environment on Levels of Physical Activity Among Elementary-Aged Youth

PubMed Central

Harmon, Brook E.; Nigg, Claudio R.; Long, Camonia; Amato, Katie; Anwar, Mahabub-Ul; Kutchman, Eve; Anthamatten, Peter; Browning, Raymond C.; Brink, Lois; Hill, James O.

2014-01-01

Objectives Social Cognitive Theory (SCT) has often been used as a guide to predict and modify physical activity (PA) behavior. We assessed the ability of commonly investigated SCT variables and perceived school environment variables to predict PA among elementary students. We also examined differences in influences between Hispanic and non-Hispanic students. Design This analysis used baseline data collected from eight schools who participated in a four-year study of a combined school-day curriculum and environmental intervention. Methods Data were collected from 393 students. A 3-step linear regression was used to measure associations between PA level, SCT variables (self-efficacy, social support, enjoyment), and perceived environment variables (schoolyard structures, condition, equipment/supervision). Logistic regression assessed associations between variables and whether students met PA recommendations. Results School and sex explained 6% of the moderate-to-vigorous PA models' variation. SCT variables explained an additional 15% of the models' variation, with much of the model's predictive ability coming from self-efficacy and social support. Sex was more strongly associated with PA level among Hispanic students, while self-efficacy was more strongly associated among non-Hispanic students. Perceived environment variables contributed little to the models. Conclusions Our findings add to the literature on the influences of PA among elementary-aged students. The differences seen in the influence of sex and self-efficacy among non-Hispanic and Hispanic students suggests these are areas where PA interventions could be tailored to improve efficacy. Additional research is needed to understand if different measures of perceived environment or perceptions at different ages may better predict PA. PMID:24772004

Assessment of Gene-by-Sex Interaction Effect on Bone Mineral Density

PubMed Central

Liu, Ching-Ti; Estrada, Karol; Yerges-Armstrong, Laura M.; Amin, Najaf; Evangelou, Evangelos; Li, Guo; Minster, Ryan L.; Carless, Melanie A.; Kammerer, Candace M.; Oei, Ling; Zhou, Yanhua; Alonso, Nerea; Dailiana, Zoe; Eriksson, Joel; García-Giralt, Natalia; Giroux, Sylvie; Husted, Lise Bjerre; Khusainova, Rita I.; Koromila, Theodora; Kung, Annie WaiChee; Lewis, Joshua R.; Masi, Laura; Mencej-Bedrac, Simona; Nogues, Xavier; Patel, Millan S.; Prezelj, Janez; Richards, J Brent; Sham, Pak Chung; Spector, Timothy; Vandenput, Liesbeth; Xiao, Su-Mei; Zheng, Hou-Feng; Zhu, Kun; Balcells, Susana; Brandi, Maria Luisa; Frost, Morten; Goltzman, David; González-Macías, Jesús; Karlsson, Magnus; Khusnutdinova, Elza K.; Kollia, Panagoula; Langdahl, Bente Lomholt; Ljunggren, Östen; Lorentzon, Mattias; Marc, Janja; Mellström, Dan; Ohlsson, Claes; Olmos, José M.; Ralston, Stuart H.; Riancho, José A.; Rousseau, François; Urreizti, Roser; Van Hul, Wim; Zarrabeitia, María T.; Castano-Betancourt, Martha; Demissie, Serkalem; Grundberg, Elin; Herrera, Lizbeth; Kwan, Tony; Medina-Gómez, Carolina; Pastinen, Tomi; Sigurdsson, Gunnar; Thorleifsson, Gudmar; vanMeurs, Joyce B.J.; Blangero, John; Hofman, Albert; Liu, Yongmei; Mitchell, Braxton D.; O’Connell, Jeffrey R.; Oostra, Ben A.; Rotter, Jerome I; Stefansson, Kari; Streeten, Elizabeth A.; Styrkarsdottir, Unnur; Thorsteinsdottir, Unnur; Tylavsky, Frances A.; Uitterlinden, Andre; Cauley, Jane A.; Harris, Tamara B.; Ioannidis, John P.A.; Psaty, Bruce M.; Robbins, John A; Zillikens, M. Carola; vanDuijn, Cornelia M.; Prince, Richard L.; Karasik, David; Rivadeneira, Fernando; Kiel, Douglas P.; Cupples, L. Adrienne; Hsu, Yi-Hsiang

2012-01-01

Background Sexual dimorphism in various bone phenotypes, including bone mineral density (BMD), is widely observed; however the extent to which genes explain these sex differences is unclear. To identify variants with different effects by sex, we examined gene-by-sex autosomal interactions genome-wide, and performed eQTL analysis and bioinformatics network analysis. Methods We conducted an autosomal genome-wide meta-analysis of gene-by-sex interaction on lumbar spine (LS-) and femoral neck (FN-) BMD, in 25,353 individuals from eight cohorts. In a second stage, we followed up the 12 top SNPs (P<1×10−5) in an additional set of 24,763 individuals. Gene-by-sex interaction and sex-specific effects were examined in these 12 SNPs. Results We detected one novel genome-wide significant interaction associated with LS-BMD at the Chr3p26.1-p25.1 locus, near the GRM7 gene (male effect = 0.02 & p-value = 3.0×10−5; female effect = −0.007 & p-value=3.3×10−2) and eleven suggestive loci associated with either FN- or LS-BMD in discovery cohorts. However, there was no evidence for genome-wide significant (P<5×10−8) gene-by-sex interaction in the joint analysis of discovery and replication cohorts. Conclusion Despite the large collaborative effort, no genome-wide significant evidence for gene-by-sex interaction was found influencing BMD variation in this screen of autosomal markers. If they exist, gene-by-sex interactions for BMD probably have weak effects, accounting for less than 0.08% of the variation in these traits per implicated SNP. PMID:22692763

The predictive validity of ideal partner preferences: a review and meta-analysis.

PubMed

Eastwick, Paul W; Luchies, Laura B; Finkel, Eli J; Hunt, Lucy L

2014-05-01

A central element of interdependence theory is that people have standards against which they compare their current outcomes, and one ubiquitous standard in the mating domain is the preference for particular attributes in a partner (ideal partner preferences). This article reviews research on the predictive validity of ideal partner preferences and presents a new integrative model that highlights when and why ideals succeed or fail to predict relational outcomes. Section 1 examines predictive validity by reviewing research on sex differences in the preference for physical attractiveness and earning prospects. Men and women reliably differ in the extent to which these qualities affect their romantic evaluations of hypothetical targets. Yet a new meta-analysis spanning the attraction and relationships literatures (k = 97) revealed that physical attractiveness predicted romantic evaluations with a moderate-to-strong effect size (r = ∼.40) for both sexes, and earning prospects predicted romantic evaluations with a small effect size (r = ∼.10) for both sexes. Sex differences in the correlations were small (r difference = .03) and uniformly nonsignificant. Section 2 reviews research on individual differences in ideal partner preferences, drawing from several theoretical traditions to explain why ideals predict relational evaluations at different relationship stages. Furthermore, this literature also identifies alternative measures of ideal partner preferences that have stronger predictive validity in certain theoretically sensible contexts. Finally, a discussion highlights a new framework for conceptualizing the appeal of traits, the difference between live and hypothetical interactions, and the productive interplay between mating research and broader psychological theories.

Psychosocial work dimensions, personality, and body mass index: sex differences.

PubMed

Blanch, Angel; Aluja, Anton

2013-08-01

The association between psychosocial work dimensions (i.e. demand and control) and obesity has been found to be inconclusive, indicating that individual differences factors might also contribute to explain the variability in BMI. The interaction between work dimensions and personality variables in a group of male and female workers (N = 506), and its associations with BMI were analyzed with a cross-sectional study with self-report data. Hierarchical regression analyses were used to predict the BMI levels from work and individual differences variables and their interactions for males and females. The main effects of personality variables were not significant, physical workload interacted with neuroticism for males, whereas control interacted with activity for females. Psychosocial work dimensions and personality traits were related to BMI for men and women. These outcomes reinforce the notion that different models might account for the explanatory mechanisms of BMI in regard to sex.

Relationship between birth order of spouses with different degrees of consanguineous relationship.

PubMed

Reddy, B M; Malhotra, K C

1991-08-01

The relationship between birth order of spouses with different degrees of consanguinity is examined in a sample of 1826 couples belonging to the endogamous Vadde Fisherfolk of Kolleru Lake, Andhra Pradesh, India. We attempt to explain the wide variation in the frequency of different kinds of consanguineous marriages through the age-sex structure of the population in general and especially of the related families. This structure may also be manifested in the association between the birth orders of spouses. A highly significant and large correlation between the birth orders of spouses in uncle-niece marriages and a gradual decrease in the correlation with increase in remoteness of the relationship between the spouses were observed. Given the distribution of age differences between the spouses and assuming a standard age-sex structure, it seems possible to estimate the optimum frequency with which at least close consanguineous marriages occur in any particular population.

Good sex/bad sex: the individualised focus of US HIV prevention policy in sub-Saharan Africa, 1995-2005.

PubMed

Esacove, Anne W

2013-01-01

The expanding reliance on the health sciences to address social problems is well documented, as are the effects of the social construction of public (health) problems on 'target' populations, intervention design and broader social systems. Less attention has been given in the literature to the cultural meanings that configure public health efforts themselves. This study demonstrates how the cultural understandings of sex and sexuality that inform US human immunodeficiency virus (HIV) prevention policy in sub-Saharan Africa shape policy recommendations. Based on an analysis of 119 US policy documents, a relatively stable and highly gendered narrative of sexual risk was found across the Clinton and (G.W.) Bush administrations. This narrative locates HIV risk in (what is constructed to be) the inevitable clash between women's sexuality and men's sexuality, and delineates HIV risk by the form of relationship in which sex occurs. The two narratives diverge at this point, offering different definitions of 'bad' sex and 'good' sex. This divergence helps to explain the different prevention foci of the administrations - condoms during the Clinton era and abstinence-outside-of-marriage during the Bush administration. In both cases, the sexual risk narrative points to individual targeted prevention strategies, even as the policy identifies structural factors as driving global HIV epidemics. © 2012 The Author. Sociology of Health & Illness © 2012 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

Great ape origins of personality maturation and sex differences: a study of orangutans and chimpanzees.

PubMed

Weiss, Alexander; King, James E

2015-04-01

Human personality development evinces increased emotional stability, prosocial tendencies, and responsibility. One hypothesis offered to explain this pattern is Social-Investment Theory, which posits that culturally defined social roles, including marriage and employment, are responsible for the increased maturity. Alternatively, Five-Factor Theory emphasizes the role of biological factors, such as those governing physical development, which may predate the emergence of humans. Five-Factor Theory, unlike Social-Investment Theory, predicts that all or some of the human personality developmental trends should be present in great apes, our closest evolutionary relatives. To test this prediction and to better understand the evolutionary origins of sex differences, we examined age and sex differences in the chimpanzee and orangutan personality domains Extraversion, Dominance, Neuroticism, and Agreeableness. We also examined the Activity and Gregariousness facets of Extraversion and the orangutan Intellect domain. Extraversion and Neuroticism declined across age groups in both species, in common with humans. A significant interaction indicated that Agreeableness declined in orangutans but increased in chimpanzees, as it does in humans, though this may reflect differences in how Agreeableness was defined in each species. Significant interactions indicated that male chimpanzees, unlike male orangutans, displayed higher Neuroticism scores than females and maintained higher levels of Activity and Dominance into old age than female chimpanzees, male orangutans, and female orangutans. Personality-age correlations were comparable across orangutans and chimpanzees and were similar to those reported in human studies. Sex differences were stronger in chimpanzees than in humans or orangutans. These findings support Five-Factor Theory, suggest the role of gene-culture coevolution in shaping personality development, and suggest that sex differences evolved independently in different species. (c) 2015 APA, all rights reserved).

Suicide in Castellon, 2009-2015: Do sociodemographic and psychiatric factors help understand urban-rural differences?

PubMed

Suso-Ribera, Carlos; Mora-Marín, Rafael; Hernández-Gaspar, Carmen; Pardo-Guerra, Lidón; Pardo-Guerra, María; Belda-Martínez, Adela; Palmer-Viciedo, Ramón

Studies have pointed to rurality as an important factor influencing suicide. Research so far suggests that several sociodemograpic and psychiatric factors might influence urban-rural differences in suicide. Also, their contribution appears to depend on sex and age. Unfortunately, studies including a comprehensive set of explanatory variables altogether are still scare and most studies have failed to present their analyses split by sex and age groups. Also, urban-rural differences in suicide in Spain have been rarely investigated. The present study aimed at explaining rural-urban differences in suicidality in the province of Castellon (Spain). A comprehensive set of sociodemographic and psychiatric factors was investigated and analyses were split by sex and age. The sample comprised all suicides recorded in the province of Castellon from January 2009 to December 2015 (n=343). Sociodemographic data included sex, age, and suicide method. Psychiatric data included the history of mental health service utilization, psychiatric diagnosis, suicide attempts, and psychiatric hospitalization. Consistent with past research, suicide rates were highest in rural areas, especially in men and older people. We also found that urban-rural differences in sociodemographic and psychiatric variables were sensitive to sex and age. Our results indicated that specialized mental health service use and accessibility to suicide means might help understand urban-rural differences in suicide, especially in men. When exploring urban-rural differences as a function of age, general practitioner visits for psychiatric reasons were more frequent in the older age group in rural areas. Study implications for suicide prevention strategies in Spain are discussed. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

Sex differences in visual-spatial working memory: A meta-analysis.

PubMed

Voyer, Daniel; Voyer, Susan D; Saint-Aubin, Jean

2017-04-01

Visual-spatial working memory measures are widely used in clinical and experimental settings. Furthermore, it has been argued that the male advantage in spatial abilities can be explained by a sex difference in visual-spatial working memory. Therefore, sex differences in visual-spatial working memory have important implication for research, theory, and practice, but they have yet to be quantified. The present meta-analysis quantified the magnitude of sex differences in visual-spatial working memory and examined variables that might moderate them. The analysis used a set of 180 effect sizes from healthy males and females drawn from 98 samples ranging in mean age from 3 to 86 years. Multilevel meta-analysis was used on the overall data set to account for non-independent effect sizes. The data also were analyzed in separate task subgroups by means of multilevel and mixed-effects models. Results showed a small but significant male advantage (mean d = 0.155, 95 % confidence interval = 0.087-0.223). All the tasks produced a male advantage, except for memory for location, where a female advantage emerged. Age of the participants was a significant moderator, indicating that sex differences in visual-spatial working memory appeared first in the 13-17 years age group. Removing memory for location tasks from the sample affected the pattern of significant moderators. The present results indicate a male advantage in visual-spatial working memory, although age and specific task modulate the magnitude and direction of the effects. Implications for clinical applications, cognitive model building, and experimental research are discussed.

Variation in offspring sex ratio of a long-lived sexually dimorphic raptor, the eastern imperial eagle (Aquila heliaca)

Treesearch

Todd E. Katzner; Daniel S. Jackson; Jamie Ivy; Evgeny A. Bragin; Andrew Dewoody

2014-01-01

Sex ratio theory attempts to explain observed variation in offspring sex ratio at both the population and the brood levels. In the context of low-fecundity organisms producing high-investment offspring, the drivers of adaptive variation in sex ratio are incompletely understood. For raptors that display reverse sexual dimorphism (RSD), preferential allocation of...

The Impact of Sex, Puberty, and Hormones on White Matter Microstructure in Adolescents

PubMed Central

Herting, Megan M.; Maxwell, Emily C.; Irvine, Christy

2012-01-01

Background: During adolescence, numerous factors influence the organization of the brain. It is unclear what influence sex and puberty have on white matter microstructure, as well as the role that rapidly increasing sex steroids play. Methods: White matter microstructure was examined in 77 adolescents (ages 10–16) using diffusion tensor imaging. Multiple regression analyses were performed to examine the relationships between fractional anisotropy (FA) and mean diffusivity (MD) and sex, puberty, and their interaction, controlling for age. Follow-up analyses determined if sex steroids predicted microstructural characteristics in sexually dimorphic and pubertal-related white matter regions, as well as in whole brain. Results: Boys had higher FA in white matter carrying corticospinal, long-range association, and cortico-subcortical fibers, and lower MD in frontal and temporal white matter compared with girls. Pubertal development was related to higher FA in the insula, while a significant sex-by-puberty interaction was seen in superior frontal white matter. In boys, testosterone predicted white matter integrity in sexually dimorphic regions as well as whole brain FA, whereas estradiol showed a negative relationship with FA in girls. Conclusions: Sex differences and puberty uniquely relate to white matter microstructure in adolescents, which can partially be explained by sex steroids. PMID:22002939

Sex Differences in Academic Rank in US Medical Schools in 2014.

PubMed

Jena, Anupam B; Khullar, Dhruv; Ho, Oliver; Olenski, Andrew R; Blumenthal, Daniel M

2015-09-15

The proportion of women at the rank of full professor in US medical schools has not increased since 1980 and remains below that of men. Whether differences in age, experience, specialty, and research productivity between sexes explain persistent disparities in faculty rank has not been studied. To analyze sex differences in faculty rank among US academic physicians. We analyzed sex differences in faculty rank using a cross-sectional comprehensive database of US physicians with medical school faculty appointments in 2014 (91,073 physicians; 9.1% of all US physicians), linked to information on physician sex, age, years since residency, specialty, authored publications, National Institutes of Health (NIH) funding, and clinical trial investigation. We estimated sex differences in full professorship, as well as a combined outcome of associate or full professorship, adjusting for these factors in a multilevel (hierarchical) model. We also analyzed how sex differences varied with specialty and whether differences were more prevalent at schools ranked highly in research. Physician sex. Academic faculty rank. In all, there were 30,464 women who were medical faculty vs 60,609 men. Of those, 3623 women (11.9%) vs 17,354 men (28.6%) had full-professor appointments, for an absolute difference of -16.7% (95% CI, -17.3% to -16.2%). Women faculty were younger and disproportionately represented in internal medicine and pediatrics. The mean total number of publications for women was 11.6 vs 24.8 for men, for a difference of -13.2 (95% CI, -13.6 to -12.7); the mean first- or last-author publications for women was 5.9 vs 13.7 for men, for a difference of -7.8 (95% CI, -8.1 to -7.5). Among 9.1% of medical faculty with an NIH grant, 6.8% (2059 of 30,464) were women and 10.3% (6237 of 60,609) were men, for a difference of -3.5% (95% CI, -3.9% to -3.1%). In all, 6.4% of women vs 8.8% of men had a trial registered on ClinicalTrials.gov, for a difference of -2.4% (95% CI, -2.8% to -2.0%). After multivariable adjustment, women were less likely than men to have achieved full-professor status (absolute adjusted difference in proportion, -3.8%; 95% CI, -4.4% to -3.3%). Sex-differences in full professorship were present across all specialties and did not vary according to whether a physician's medical school was ranked highly in terms of research funding. Among physicians with faculty appointments at US medical schools, there were sex differences in academic faculty rank, with women substantially less likely than men to be full professors, after accounting for age, experience, specialty, and measures of research productivity.

Treatment and Response to Statins: Gender-related Differences.

PubMed

Raparelli, Valeria; Pannitteri, Gaetano; Todisco, Tommaso; Toriello, Filippo; Napoleone, Laura; Manfredini, Roberto; Basili, Stefania

2017-01-01

Response to drug administration is a primary determinant for treatment success. Sex and gender disparities play a role in determining the efficacy and safety of the most commonly used medications suggesting the need for a sex-tailored approach in prescription. Statins are a cost-effective strategy for cardiovascular disease (CVD) prevention. While statins are similarly effective in secondary CVD prevention, some concerns raised by conflicting data reported in primary CVD prevention clinical trials. The small representation of women in clinical trials and the fewer rates of events due to the lower female baseline CVD risk may have conditioned contradictory meta-analysis findings. Specifically, benefits outweigh disadvantages of statin therapy in women with a high CVD risk, while several doubts exist for the primary prevention of women at low-intermediate CVD risk. Furthermore, disparities between women and men in medication adherence may influence statin efficacy in CVD prevention. The sex-dependent impact of adverse side effects is one of the reasons advocated for explaining the gender gap, but it is not evidence-proved. The present review summarizes the sex and gender differences in the use of statins, pointing out new perspectives and opening issues in sex-tailored CVD prevention strategy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Sex- and age-dependent patterns of survival and breeding success in a long-lived endangered avian scavenger

NASA Astrophysics Data System (ADS)

Sanz-Aguilar, Ana; Cortés-Avizanda, Ainara; Serrano, David; Blanco, Guillermo; Ceballos, Olga; Grande, Juan M.; Tella, José L.; Donázar, José A.

2017-01-01

In long-lived species, the age-, stage- and/or sex-dependent patterns of survival and reproduction determine the evolution of life history strategies, the shape of the reproductive value, and ultimately population dynamics. We evaluate the combined effects of age and sex in recruitment, breeder survival and breeding success of the globally endangered Egyptian vulture (Neophron percnopterus), using 31-years of exhaustive data on marked individuals in Spain. Mean age of first reproduction was 7-yrs for both sexes, but females showed an earlier median and a larger variance than males. We found an age-related improvement in breeding success at the population level responding to the selective appearance and disappearance of phenotypes of different quality but unrelated to within-individual aging effects. Old males (≥8 yrs) showed a higher survival than both young males (≤7 yrs) and females, these later in turn not showing aging effects. Evolutionary trade-offs between age of recruitment and fitness (probably related to costs of territory acquisition and defense) as well as human-related mortality may explain these findings. Sex- and age-related differences in foraging strategies and susceptibility to toxics could be behind the relatively low survival of females and young males, adding a new concern for the conservation of this endangered species.

A population health approach to reducing observational intensity bias in health risk adjustment: cross sectional analysis of insurance claims

PubMed Central

Sharp, Sandra M; Bevan, Gwyn; Skinner, Jonathan S; Gottlieb, Daniel J

2014-01-01

Objective To compare the performance of two new approaches to risk adjustment that are free of the influence of observational intensity with methods that depend on diagnoses listed in administrative databases. Setting Administrative data from the US Medicare program for services provided in 2007 among 306 US hospital referral regions. Design Cross sectional analysis. Participants 20% sample of fee for service Medicare beneficiaries residing in one of 306 hospital referral regions in the United States in 2007 (n=5 153 877). Main outcome measures The effect of health risk adjustment on age, sex, and race adjusted mortality and spending rates among hospital referral regions using four indices: the standard Centers for Medicare and Medicaid Services—Hierarchical Condition Categories (HCC) index used by the US Medicare program (calculated from diagnoses listed in Medicare’s administrative database); a visit corrected HCC index (to reduce the effects of observational intensity on frequency of diagnoses); a poverty index (based on US census); and a population health index (calculated using data on incidence of hip fractures and strokes, and responses from a population based annual survey of health from the Centers for Disease Control and Prevention). Results Estimated variation in age, sex, and race adjusted mortality rates across hospital referral regions was reduced using the indices based on population health, poverty, and visit corrected HCC, but increased using the standard HCC index. Most of the residual variation in age, sex, and race adjusted mortality was explained (in terms of weighted R2) by the population health index: R2=0.65. The other indices explained less: R2=0.20 for the visit corrected HCC index; 0.19 for the poverty index, and 0.02 for the standard HCC index. The residual variation in age, sex, race, and price adjusted spending per capita across the 306 hospital referral regions explained by the indices (in terms of weighted R2) were 0.50 for the standard HCC index, 0.21 for the population health index, 0.12 for the poverty index, and 0.07 for the visit corrected HCC index, implying that only a modest amount of the variation in spending can be explained by factors most closely related to mortality. Further, once the HCC index is visit corrected it accounts for almost none of the residual variation in age, sex, and race adjusted spending. Conclusion Health risk adjustment using either the poverty index or the population health index performed substantially better in terms of explaining actual mortality than the indices that relied on diagnoses from administrative databases; the population health index explained the majority of residual variation in age, sex, and race adjusted mortality. Owing to the influence of observational intensity on diagnoses from administrative databases, the standard HCC index over-adjusts for regional differences in spending. Research to improve health risk adjustment methods should focus on developing measures of risk that do not depend on observation influenced diagnoses recorded in administrative databases. PMID:24721838

Sex-based differences in lymphocyte proliferation in the spleen after vanadium inhalation.

PubMed

Rodriguez-Lara, Vianey; Muñiz-Rivera Cambas, Angelica; González Villalva, Adriana; Fortoul, Teresa I

2016-07-01

Vanadium (V) is a transition metal often adhered to particulate matter and released into the atmosphere as vanadium pentoxide (V2O5) by the burning of fossil fuels. This air pollutant causes adverse effects in the immune system. Lymphocytosis and splenomegaly have been reported with increased white pulp in mice after V inhalation. The effect of V on the immune system as related to sex has been poorly investigated. This study sought to determine if V inhalation (a) produced lymphoproliferation that could explain the changes previously observed in the spleen and in peripheral blood lymphocyte counts and (b) whether any observed effects differed due to gender. Immunohistochemical analyses of Ki-67, a specific proliferation marker, was made in the spleens of CD-1 male and female mice exposed for 1 h, twice a week, over a 12-week period to V2O5 (at 1.4 mg V2O5/m(3)) by whole-body inhalation; similar analyses were performed on spleens of control mice exposed to vehicle (filtered air). The results showed that in male mice there was a significant increase in percentage of Ki-67 immunopositive lymphocytes starting from the second week and until the end of the exposure. The Ki-67 signal was cytoplasmic and nuclear in the exposed males, while in controls the signal was only nuclear. In female mice, V inhalation singificantly increased the percentage of proliferating lymphocytes only after 1 week of exposure. Ki-67 signal was observed only in the nucleus of lymphocytes from the control and exposed females. The results here help to explain the splenomegaly and lymphocytosis observed previously in male mice and support the lymphoproliferative effect induced by V. Lastly, the finding that there was a sex difference in the effect of vanadium on lymphocyte proliferation suggests a role for sex hormones in potential protection against V immunotoxicity; however, further studies are needed to support this hypothesis.

Media's contribution to sexual knowledge, attitudes, and behaviors for adolescents and young adults in three Asian cities.

PubMed

Lou, Chaohua; Cheng, Yan; Gao, Ersheng; Zuo, Xiayun; Emerson, Mark R; Zabin, Laurie S

2012-03-01

Evidence in western countries indicates that the media have associations with adolescents' and young people's sexual behavior that may be as important as family, school, and peers. In this new study of Asian adolescents and young adults in the three cities of Hanoi, Shanghai, and Taipei, the associations between exposure to sexual content in the media and adolescents' and young adults' sex-related knowledge, attitudes, and behaviors are explored in societies with traditional Confucian culture, but at different stages in the process of modernization. The data are from a questionnaire-based cross-sectional study conducted from 2006 to 2007, where a sample of 17,016 adolescents and young adults aged 15-24 years from Shanghai, Hanoi, and Taipei completed face-to-face interviews coupled with computer-assisted self-interviews for sensitive questions. For the objectives of this article, analysis was restricted to the 16,554 unmarried respondents. Exposure to sexual content in the mass media (including the Internet and traditional media), pornographic videos, and a preference for western/Asian movies/videos were the main media influence measures. Sex-related knowledge, premarital sexual permissiveness (PSP), and sex-related behaviors were the main outcome measures. The impact of each of four contexts including family, peer, school, and media on sex-related knowledge, attitudes, and behaviors were assessed using multiple linear regression stratified by gender and city, controlling for age, urban/rural residence, education, and economic status. The change in adjusted R(2) from the multiple linear regression analysis was adopted to indicate the contribution of family, peer, school, and media variables to respondents' sex-related knowledge, attitudes, and behaviors. The contextual factors, including family, peer, school, and media, explained 30%-50% of the variance in sex-related knowledge, 8%-22% of the variance in PSP, and 32%-41% of the variance in sex-related behaviors. Media variables explained 13%-24% of the variance in sexual knowledge, 3%-13% in PSP, and 3%-13% in sex-related behaviors, which was comparable with that of family, peer, and school variables. These associations differed by city and gender. Access to and use of mass media and the messages they present are influential factors on sex-related knowledge, attitudes, and behaviors of unmarried Asian adolescents and young adults, and should be considered in future research and intervention programs attempting to improve reproductive health outcomes. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Media’s Contribution to Sexual Knowledge, Attitudes and Behaviors for Adolescents and Young Adults in Three Asian Cities

PubMed Central

Lou, Chaohua; Cheng, Yan; Gao, Ersheng; Zuo, Xiayun; Emerson, Mark R.; Zabin, Laurie S.

2014-01-01

Background Evidence in western countries indicates that the media have associations with adolescents’ and young people’ sexual behavior that may be as important as family, school and peers. In this new study of Asian adolescents and young adults in the three cities of Hanoi, Shanghai and Taipei, the associations between exposure to sexual content in the media and adolescents’ and young adults’ sex-related knowledge, attitudes and behaviors are explored in societies with traditional Confucian culture, but at different stages in the process of modernization. Method The data are from a questionnaire-based cross-sectional study conducted from 2006 to 2007 where a sample of 17,016 adolescents and young adults aged 15–24 years from Shanghai, Hanoi and Taipei completed face-to-face interviews coupled with computer-assisted self-interviews (CASI) for sensitive questions. For the objectives of this paper, analysis was restricted to the 16,554 unmarried respondents. Exposure to sexual content in the mass media (including the Internet and traditional media), pornographic videos, and a preference for western/Asian movies/videos were the main media influence measures. Sex-related knowledge, premarital sexual permissiveness, and sex-related behaviors were the main outcome measures. The impact of each of four contexts including family, peer, school and media on sex-related knowledge, attitudes and behaviors were assessed using multiple linear regression stratified by gender and city, controlling for age, urban/rural residence, education and economic status. The change in adjusted R2 from the multiple linear regression analysis was adopted to indicate the contribution of family, peer, school and media variables to respondents’ sex-related knowledge, attitudes and behaviors. Results The contextual factors, including family, peer, school and media, explained 30–50% of the variance in sex-related knowledge, 8–22% of the variance in premarital sexual permissiveness and 32–41% of the variance in sex-related behaviors. Media variables explained 13–24% of the variance in sexual knowledge, 3–13% in premarital sexual permissiveness and 3–13% in sex-related behaviors, which was comparable to that of family, peer and school variables. These associations differed by city and gender. Conclusion Access to and use of mass media and the messages it presents are influential factors on sex-related knowledge, attitudes and behaviors of unmarried Asian adolescents and young adults, and should be considered in future research and intervention programs attempting to improve reproductive health outcomes. PMID:22340853

Gender differences in chemical carcinogenesis in National Toxicology Program two-year bioassays

PubMed Central

Kadekar, Sandeep; Peddada, Shyamal; Silins, Ilona; French, John E; Högberg, Johan; Stenius, Ulla

2016-01-01

Differences in cancer incidences between men and women are often explained by either differences in environmental exposures or by influences of sex hormones. However, there are few studies on intrinsic gender differences in susceptibility to chemical carcinogens. We have analyzed the National Toxicology Program (NTP) database for sex differences in rat responses to chemical carcinogens. We find that the odds that male rat bioassays were assigned a higher level of evidence than female rat bioassays was 1.69 (p<0.001). Of 278 carcinogenic chemicals in the database, 201 (72%) exhibited statistical gender differences (p = 0.05) in at least one non-reproductive organ. 130 of these 201 chemicals induced gender-specific tumors in male rats and 59 in female rats. 68 chemicals induced tumors in males but no tumors in females. Less than one third, i.e. 19 chemicals, induced tumors in females but not males. Male-specific tumors included pancreatic tumor and skin tumor, and female-specific tumors included lung tumors. For some tumor types these differences in gender susceptibility can be associated with literature data on sex hormone receptor expression. In conclusion, gender-specific tumors were common. The male dominance is in line with human data and the male susceptibility to carcinogens should be further studied. PMID:22585941

Allelic incompatibility can explain female biased sex ratios in dioecious plants.

PubMed

Pucholt, Pascal; Hallingbäck, Henrik R; Berlin, Sofia

2017-03-23

Biased sex ratios are common among dioecious plant species despite the theoretical prediction of selective advantage of even sex ratios. Albeit the high prevalence of deviations from even sex ratios, the genetic causes to sex biases are rarely known outside of a few model species. Here we present a mechanism underlying the female biased sex ratio in the dioecious willow species Salix viminalis. We compared the segregation pattern of genome-wide single nucleotide polymorphism markers in two contrasting bi-parental pedigree populations, the S3 with even sex ratio and the S5 with a female biased sex ratio. With the segregation analysis and comparison between the two populations, we were able to demonstrate that sex determination and sex ratio distortion are controlled by different genetic mechanisms. We furthermore located the sex ratio distorter locus to a Z/W-gametologous region on chromosome 15, which was in close linkage with the sex determination locus. Interestingly, all males in the population with biased sex ratio have in this sex ratio distorter locus the same genotype, meaning that males with the Z 1 /Z 3 -genotype were missing from the population, thereby creating the 2:1 female biased sex ratio. We attribute the absence of Z 1 /Z 3 males to an allelic incompatibility between maternally and paternally inherited alleles in this sex ratio distorter locus. Due to the tight linkage with the sex determination locus only male individuals are purged from the population at an early age, presumably before or during seed development. We showed that such allelic incompatibility could be stably maintained over evolutionary times through a system of overdominant or pseudooverdominant alleles. Thus, it is possible that the same mechanism generates the female biased sex ratio in natural willow populations.

Relationships between Circulating and Intraprostatic Sex Steroid Hormone Concentrations.

PubMed

Cook, Michael B; Stanczyk, Frank Z; Wood, Shannon N; Pfeiffer, Ruth M; Hafi, Muhannad; Veneroso, Carmela C; Lynch, Barlow; Falk, Roni T; Zhou, Cindy Ke; Niwa, Shelley; Emanuel, Eric; Gao, Yu-Tang; Hemstreet, George P; Zolfghari, Ladan; Carroll, Peter R; Manyak, Michael J; Sesterhann, Isabell A; Levine, Paul H; Hsing, Ann W

2017-11-01

Background: Sex hormones have been implicated in prostate carcinogenesis, yet epidemiologic studies have not provided substantiating evidence. We tested the hypothesis that circulating concentrations of sex steroid hormones reflect intraprostatic concentrations using serum and adjacent microscopically verified benign prostate tissue from prostate cancer cases. Methods: Incident localized prostate cancer cases scheduled for surgery were invited to participate. Consented participants completed surveys, and provided resected tissues and blood. Histologic assessment of the ends of fresh frozen tissue confirmed adjacent microscopically verified benign pathology. Sex steroid hormones in sera and tissues were extracted, chromatographically separated, and then quantitated by radioimmunoassays. Linear regression was used to account for variations in intraprostatic hormone concentrations by age, body mass index, race, and study site, and subsequently to assess relationships with serum hormone concentrations. Gleason score (from adjacent tumor tissue), race, and age were assessed as potential effect modifiers. Results: Circulating sex steroid hormone concentrations had low-to-moderate correlations with, and explained small proportions of variations in, intraprostatic sex steroid hormone concentrations. Androstane-3α,17β-diol glucuronide (3α-diol G) explained the highest variance of tissue concentrations of 3α-diol G (linear regression r 2 = 0.21), followed by serum testosterone and tissue dihydrotestosterone ( r 2 = 0.10), and then serum estrone and tissue estrone ( r 2 = 0.09). There was no effect modification by Gleason score, race, or age. Conclusions: Circulating concentrations of sex steroid hormones are poor surrogate measures of the intraprostatic hormonal milieu. Impact: The high exposure misclassification provided by circulating sex steroid hormone concentrations for intraprostatic levels may partly explain the lack of any consistent association of circulating hormones with prostate cancer risk. Cancer Epidemiol Biomarkers Prev; 26(11); 1660-6. ©2017 AACR . ©2017 American Association for Cancer Research.

Fertility transition and adverse child sex ratio in districts of India.

PubMed

Mohanty, Sanjay K; Rajbhar, Mamta

2014-11-01

Demographic research in India over the last two decades has focused extensively on fertility change and gender bias at the micro-level, and less has been done at the district level. Using data from the Census of India 1991-2011 and other sources, this paper shows the broad pattern of fertility transition and trends in the child sex ratio in India, and examines the determinants of the child sex ratio at the district level. During 1991-2011, while the Total Fertility Rate (TFR) declined by 1.2 children per woman, the child sex ratio fell by 30 points in the districts of India. However, the reduction in fertility was slower in the high-fertility compared with the low-fertility districts. The gender differential in under-five mortality increased in many districts of India over the study period. The decline in the child sex ratio was higher in the transitional compared with the low-fertility districts. The transitional districts are at higher risk of a low child sex ratio due to an increased gender differential in mortality and increase in the practice of sex-selective abortions. The sex ratio at birth and gender differential in mortality explains one-third of the variation, while region alone explains a quarter of the variation in the child sex ratio in the districts of India.

Changing trend? Sex ratios of children born to Indian immigrants in Norway revisited.

PubMed

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.

The genetic architecture of liver enzyme levels: GGT, ALT and AST.

PubMed

van Beek, Jenny H D A; de Moor, Marleen H M; de Geus, Eco J C; Lubke, Gitta H; Vink, Jacqueline M; Willemsen, Gonneke; Boomsma, Dorret I

2013-07-01

High levels of liver enzymes GGT, ALT and AST are predictive of disease and all-cause mortality and can reflect liver injury, fatty liver and/or oxidative stress. Variation in GGT, ALT and AST levels is heritable. Moderation of the heritability of these liver enzymes by age and sex has not often been explored, and it is not clear to what extent non-additive genetic and shared environmental factors may play a role. To examine the genetic architecture of GGT, ALT and AST, plasma levels were assessed in a large sample of twins, their siblings, parents and spouses (N = 8,371; age range 18-90). For GGT and ALT, but not for AST, genetic structural equation modeling showed evidence for quantitative sex differences in the genetic architecture. There was no evidence for qualitative sex differences, i.e. the same genes were expressed in males and females. Both additive and non-additive genetic factors were important for GGT in females (total heritability h(2) 60 %) and AST in both sexes (total h(2) 43 %). The heritability of GGT in males and ALT for both sexes was due to additive effects only (GGT males 30 %; ALT males 40 %, females 22 %). Evidence emerged for shared environmental factors influencing GGT in the male offspring generation (variance explained 28 %). Thus, the same genes influence liver enzyme levels across sex and age, but their relative contribution to the variation in GGT and ALT differs in males and females and for GGT across age. Given adequate sample sizes these results suggest that genome-wide association studies may result in the detection of new susceptibility loci for liver enzyme levels when pooling results over sex and age.

Exploring mechanisms underlying sex-specific differences in mortality of Lake Michigan bloaters

USGS Publications Warehouse

Bunnell, D.B.; Madenjian, C.P.; Rogers, M.W.; Holuszko, J.D.; Begnoche, L.J.

2012-01-01

Sex-specific differences in mortality rates have been observed among freshwater and marine fish taxa, and underlying mechanisms can include sex-specific differences in (1) age at maturity, (2) growth rate, or (3) activity or behavior during the spawning period. We used a long-term (1973–2009) Lake Michigan data set to evaluate whether there were sex-specific differences in catch per unit effort, mortality, age at maturity, and length at age in bloaters Coregonus hoyi. Because bloater population biomass varied 200-fold during the years analyzed, we divided the data into three periods: (1) 1973–1982 (low biomass), (2) 1983–1997 (high biomass), and (3) 1998–2009 (low biomass). Mortality was higher for males than for females in periods 2 and 3; the average instantaneous total mortality rate (Z) over these two periods was 0.71 for males and 0.57 for females. Length at age was slightly greater (2–6%) for females than for males in different age-classes (3–6 years) during each period. Age at maturity was earlier for males than for females in periods 1 and 2, but the mean difference was only 0.2–0.4 years. To test the hypothesis that somatic lipids declined more in males than in females during spawning (perhaps due to increased activity or reduced feeding), we estimated sex-specific percent somatic lipids for fish sampled in 2005–2006 and 2007–2008. During 2005–2006, somatic lipids declined from prespawning to postspawning for males but were unchanged for females. During 2007–2008, however, somatic lipids were unchanged for males, whereas they increased for females. We found that sex-specific differences in Z occurred in the Lake Michigan bloater population, but our hypotheses that sex-specific differences in maturity and growth could explain this pattern were generally unsupported. Our hypothesis that somatic lipids in males declined during spawning at a faster rate than in females will require additional research to clarify its importance.

Sea lice population and sex differences in P-glycoprotein expression and emamectin benzoate resistance on salmon farms in the Bay of Fundy, New Brunswick, Canada.

PubMed

Igboeli, Okechukwu O; Burka, John F; Fast, Mark D

2014-06-01

Parasitic sea lice are a major challenge for salmon aquaculture. This is especially due to the recent development of resistance to emamectin benzoate (EMB) in the parasite. We investigated: (1) whether EMB treatment success in Grand Manan, Bay of Fundy, NB, Canada can be explained through EMB bioassay and P-glycoprotein (P-gp) mRNA expression studies; (2) if other populations of sea lice not under EMB selective pressure possess similar EMB sensitivity as Grand Manan sea lice populations; and (3) the heritability of EMB resistance in Lepeophtheirus salmonis. EMB bioassay results indicated population, species, sex and temporal differences in EMB EC50 values. RT-qPCR analyses revealed population and sex differences in P-gp mRNA levels, correlating with the bioassay results. Laboratory-reared sea lice maintained their EMB sensitivity status up to the F3 generation. Caligus elongatus, collected from Grand Manan showed more than twofold lower EMB EC50 values compared with L. salmonis collected from the same site. Concurrent exposure to EMB and verapamil yielded no increase in C. elongatus sensitivity to the parasiticide. Sea lice bioassay and P-gp mRNA studies can be used to track EMB resistance and sex differences in EMB sensitivity and P-gp mRNA levels exist in the parasite. © 2013 Society of Chemical Industry.

Sex differences in paradoxical sleep: influences of estrus cycle and ovariectomy.

PubMed

Fang, J; Fishbein, W

1996-09-23

Previously, we reported that paradoxical sleep (PS) is sexually dimorphic in mice and rats. Since some early studies indicate that PS is suppressed during proestrus night, it is important to know whether the estrus cycle and accompanying circulating ovarian hormones could explain the sexual dimorphism of PS. To examine this, sleep patterns of male rats were compared with those of normal cycling female rats and ovariectomized females in a 12:12 h light/dark cycle. Slow wave sleep and total sleep time are indistinguishable between the males, cycling females and ovariectomized females. However, normal males display significantly more PS than cycling females during both daytime and nighttime (average of all estrus stages). On the other hand, while ovariectomy has no visible effect on daytime sleep--the sexual dimorphism of PS is unchanged by ovariectomy--during nighttime, ovariectomy produces a selective increase of PS, eliminating the sex difference during the night. In sum, normal cycling females show no change in daytime sleep patterns across the estrus cycle, but have significantly less PS during proestrus nights than during metestrus and diestrus nights. The results indicate that the sex difference in nighttime PS is due to the suppression of PS by ovarian hormones during proestrus and, to a less extent, estrus nights. The sex difference in daytime PS, on the other hand, appears to be independent of circulating ovarian hormones.

Women and vulnerability to depression: some personality and clinical factors.

PubMed

Carrillo, Jesús M; Rojo, Nieves; Staats, Arthur W

2004-05-01

The purpose of this study is to explore the role of sex differences and personality in vulnerability to depression. Sex differences in personality and some clinical variables are described. We also assess the value of the variables that revealed significant sex differences as predictors of vulnerability to depression. In a group of adult participants (N = 112), 50% males and 50% females (mean age = 41.30; SD = 15.09; range 17-67), we studied sex differences in the three-factor personality model, using the Eysenck Personality Questionnaire, Form A (EPQ-A; Eysenck & Eysenck, 1975), and in the Five-Factor Personality Model, with the NEO Personality Inventory (NEO-PI; Costa & McCrae, 1985). The following clinical scales were used: the Beck Depression Inventory (BDI; Beck, Rush, Shaw, & Emery, 1979), the Schizotypy Questionnaire (STQ; Claridge & Broks, 1984; Spanish version, Carrillo & Rojo, 1999), the THARL Scales (Dua, 1989, 1990; Spanish version, Dua & Carrillo, 1994) and the Adjustment Inventory (Bell, 1937; Spanish version, Cerdá, 1980). Subsequently, simple linear regression analysis, with BDI scores as criterion, were performed to estimate the value of the variables as predictors of vulnerability to depression. The results indicate that a series of personality variables cause women to be more vulnerable to depression than men and that these variables could be explained by a negative emotion main factor. Results are discussed within the framework of the psychological behaviorism theory of depression.

Sex differences in genetic and environmental influences on educational attainment and income.

PubMed

Orstavik, Ragnhild E; Czajkowski, Nikolai; Røysamb, Espen; Knudsen, Gun Peggy; Tambs, Kristian; Reichborn-Kjennerud, Ted

2014-12-01

In many Western countries, women now reach educational levels comparable to men, although their income remains considerably lower. For the past decades, it has become increasingly clear that these measures of socio-economic status are influenced by genetic as well as environmental factors. Less is known about the relationship between education and income, and sex differences. The aim of this study was to explore genetic and environmental factors influencing education and income in a large cohort of young Norwegian twins, with special emphasis on gender differences. National register data on educational level and income were obtained for 7,710 twins (aged 29-41 years). Bivariate Cholesky models were applied to estimate qualitative and quantitative gender differences in genetic and environmental influences, the relative contribution of genetic and environmental factors to the correlation between education and income, and genetic correlations within and between sexes and phenotypes. The phenotypic correlation between educational level and income was 0.34 (0.32-0.39) for men and 0.45 (0.43-0.48) for women. An ACE model with both qualitative and quantitative sex differences fitted the data best. The genetic correlation between men and women (rg) was 0.66 (0.22-1.00) for educational attainment and 0.38 (0.01-0.75) for income, and between the two phenotypes 0.31 (0.08-0.52) for men and 0.72 (0.64-0.85) for women. Our results imply that, in relatively egalitarian societies with state-supported access to higher education and political awareness of gender equality, genetic factors may play an important role in explaining sex differences in the relationship between education and income.

Schizophrenic delusions in Seoul, Shanghai and Taipei: a transcultural study.

PubMed Central

Kim, K.; Hwu, H.; Zhang, L. D.; Lu, M. K.; Park, K. K.; Hwang, T. J.; Kim, D.; Park, Y. C.

2001-01-01

In this transcultural study of schizophrenic delusions among patients in Seoul, Shanghai and Taipei, we discovered that both the frequency and content of delusions differed among the three groups; and that these differences could perhaps be explained by varying sociocultural and political situations. Delusional themes that are sensitive to sociocultural or political situations include guilt, love/sex, religion, somatic damage, economy/business and politics. Delusions regarding longevity, love/sex, dysmorphophobia/dysosmophobia, religion or supernatural matters, and espionage/spy stories were most frequent in Seoul patients. Those in Taipei predominantly had delusions about possession, religion or supernatural matters, hypnotism, and mass media/computers. Shanghai patients often had delusions of poisons, being prickled by poisoned needles, their brain and viscera extracted and being a family member of political authorities. PMID:11289407

Schizophrenic delusions in Seoul, Shanghai and Taipei: a transcultural study.

PubMed

Kim, K; Hwu, H; Zhang, L D; Lu, M K; Park, K K; Hwang, T J; Kim, D; Park, Y C

2001-02-01

In this transcultural study of schizophrenic delusions among patients in Seoul, Shanghai and Taipei, we discovered that both the frequency and content of delusions differed among the three groups; and that these differences could perhaps be explained by varying sociocultural and political situations. Delusional themes that are sensitive to sociocultural or political situations include guilt, love/sex, religion, somatic damage, economy/business and politics. Delusions regarding longevity, love/sex, dysmorphophobia/dysosmophobia, religion or supernatural matters, and espionage/spy stories were most frequent in Seoul patients. Those in Taipei predominantly had delusions about possession, religion or supernatural matters, hypnotism, and mass media/computers. Shanghai patients often had delusions of poisons, being prickled by poisoned needles, their brain and viscera extracted and being a family member of political authorities.

The importance of having two X chromosomes

PubMed Central

Arnold, Arthur P.; Reue, Karen; Eghbali, Mansoureh; Vilain, Eric; Chen, Xuqi; Ghahramani, Negar; Itoh, Yuichiro; Li, Jingyuan; Link, Jenny C.; Ngun, Tuck; Williams-Burris, Shayna M.

2016-01-01

Historically, it was thought that the number of X chromosomes plays little role in causing sex differences in traits. Recently, selected mouse models have been used increasingly to compare mice with the same type of gonad but with one versus two copies of the X chromosome. Study of these models demonstrates that mice with one X chromosome can be strikingly different from those with two X chromosomes, when the differences are not attributable to confounding group differences in gonadal hormones. The number of X chromosomes affects adiposity and metabolic disease, cardiovascular ischaemia/reperfusion injury and behaviour. The effects of X chromosome number are likely the result of inherent differences in expression of X genes that escape inactivation, and are therefore expressed from both X chromosomes in XX mice, resulting in a higher level of expression when two X chromosomes are present. The effects of X chromosome number contribute to sex differences in disease phenotypes, and may explain some features of X chromosome aneuploidies such as in Turner and Klinefelter syndromes. PMID:26833834

Global differences between women and men in the prevalence of obesity: is there an association with gender inequality?

PubMed

Garawi, F; Devries, K; Thorogood, N; Uauy, R

2014-10-01

In most populations the prevalence of obesity is greater in women than in men; however, the magnitude of the difference between the sexes varies significantly by country. We considered the role of gender inequality in explaining these disparities. We undertook an ecological analysis of internationally comparable obesity prevalence data to examine the association between indicators of gender inequality and the differences between men and women in obesity prevalence. Gender inequality was assessed using three measures: the Gender Inequality Index, the Global Gender Gap Index and the Social Institutions and Gender Index. We fitted multiple regression models to examine the association. We found that the prevalence of obesity across countries shows gendered patterning with greater prevalence and greater heterogeneity in women than in men (P<0.001). We also found that two of three measures of gender inequality were significantly associated with the sex differences in obesity prevalence across countries. The patterning of obesity across countries is gendered. However, the association between global measures of gender inequality and the sex gap in obesity is dependent on the measure used. Further research is needed to investigate the mechanisms that underpin the gendered nature of obesity prevalence.

Females exceed males in mercury concentrations of burbot Lota lota

USGS Publications Warehouse

Madenjian, Charles P.; Stapanian, Martin A.; Cott, Peter A.; Krabbenhoft, David P.; Edwards, William; Ogilvie, Lynn M.; Mychek-Londer, Justin G.; DeWild, John F.

2015-01-01

Examination of differences in contaminant concentrations between sexes of fish, across several fish species, may reveal clues for important behavioral and physiological differences between the sexes. We determined whole-fish total mercury (Hg) concentrations of 25 male and 25 female adult burbot Lota lota captured in Lake Erie during summer 2011, and of 14 male and 18 female adult burbot captured in Great Slave Lake (Northwest Territories, Canada) during winter 2013. On average, females were 22 % greater in Hg concentration than males. This difference was probably not due to a greater feeding rate by females, because results from previous studies based on polychlorinated biphenyl (PCB) determinations of these same burbot indicated that males fed at a substantially greater rate than females. Based on our determinations of Hg concentrations in the gonads and somatic tissue of five ripe females and five ripe males, this difference was not attributable to changes in Hg concentration immediately after spawning due to release of gametes. Further, bioenergetics modeling results from previous studies indicated that growth dilution would not explain any portion of this observed difference in Hg concentrations between the sexes. We, therefore, conclude that this difference was most likely due to a substantially faster rate of Hg elimination by males compared with females. Male burbot exhibit among the greatest gonadosomatic indices (GSIs) of all male fishes, with their testes accounting for between 10 and 15 % of their body weight when the fish are in ripe condition. Androgens have been linked to enhanced Hg elimination rates in other vertebrates. If androgen production is positively related to GSI, then male burbot would be expected to have among the greatest androgen levels of all fishes. Thus, we hypothesize that male burbot eliminate Hg from their bodies faster than most other male fishes, and this explains the greater Hg concentration in females compared with males.

Marriage season, promptness of successful pregnancy and first-born sex ratio in a historical natural fertility population - evidence for sex-dependent early pregnancy loss?

NASA Astrophysics Data System (ADS)

Nonaka, K.; Desjardins, Bertrand; Charbonneau, Hubert; Légaré, Jacques; Miura, Teiji

We investigated population-based vital records of the seventeenth and eighteenth century French Canadian population to assess the effects of marriage season on the outcome of the first births under natural fertility conditions (n=21,698 marriages). Promptness of the first successful conception after marriage differed according to marriage season; the proportion of marriages with a marriage-first birth interval of 8.0-10.0 months was lowest (34%) for marriages in August-October (P=0.001). Although the male/female sex ratio of the babies born with an interval of 8.0-10.0 months was generally higher (1.10) than those with an interval of 10.0-24.0 months (1.05), the marriages in August-October resulted in a significantly reduced sex ratio (0.96) among only the prompt conceptions (P=0.026). We discuss whether this seasonal reduction of the sex ratio could be partly explained by a clustered pregnancy loss of male zygotes in early pregnancy.

Age- and sex-specific reference values of a test of neck muscle endurance.

PubMed

Peolsson, Anneli; Almkvist, Cecilia; Dahlberg, Camilla; Lindqvist, Sara; Pettersson, Susanne

2007-01-01

This study evaluates age- and sex-specific reference values for neck muscle endurance (NME). In this cross-sectional study, 116 randomly selected, healthy volunteers (ages 25-64 years) stratified according to age and gender participated. Dorsal and ventral NME was measured in seconds until exhaustion in a laying-down position. A weight of 4 kg for men or 2 kg for women was used in the dorsal procedure. The ventral procedure was performed without external load. Background and physical activity data were obtained and used in the analysis of NME performance. Mean values for dorsal and ventral NME were about 7 and 2.5 minutes for men and 8.5 and 0.5 minutes for women, respectively. The cutoff values for subnormal dorsal and ventral NME were 157 and 56 seconds for men and 173 and 23 seconds for women, respectively. Women's NME was 122% of men's NME in the dorsal (P = .17) and 24% of men's NME in the ventral (P < .0001) procedure. There were no significant differences among age groups. In multiple regression analysis, physical activity explained 4% of variability in the performance of the dorsal NME; and sex explained 37% of the variability in the performance of ventral NME. The reference values and the cutoff points obtained could be used in clinical practice to identify patients with a subnormal NME. Sex is an important consideration when using both the test procedure and the reference values.

Sex difference in travel is concentrated in adolescence and tracks reproductive interests.

PubMed

Miner, Emily J; Gurven, Michael; Kaplan, Hillard; Gaulin, Steven J C

2014-12-07

Sexual selection theory suggests that the sex with a higher potential reproductive rate will compete more strongly for access to mates. Stronger intra-sexual competition for mates may explain why males travel more extensively than females in many terrestrial vertebrates. A male-bias in lifetime distance travelled is a purported human universal, although this claim is based primarily on anecdotes. Following sexual maturity, motivation to travel outside the natal territory may vary over the life course for both sexes. Here, we test whether travel behaviour among Tsimane forager-horticulturalists is associated with shifting reproductive priorities across the lifespan. Using structured interviews, we find that sex differences in travel peak during adolescence when men and women are most intensively searching for mates. Among married adults, we find that greater offspring dependency load is associated with reduced travel among women, but not men. Married men are more likely to travel alone than women, but only to the nearest market town and not to other Tsimane villages. We conclude that men's and women's travel behaviour reflects differential gains from mate search and parenting across the life course. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

The Stress-Metabolic Syndrome Relationship in Adolescents: An Examination of the Moderating Potential of Physical Activity.

PubMed

Holmes, Megan E; Pivarnik, Jim; Pfeiffer, Karin; Maier, Kimberly S; Eisenmann, Joey C; Ewing, Martha

2016-10-01

The role of psychosocial stress in the development of obesity and metabolic syndrome is receiving increased attention and has led to examination of whether physical activity may moderate the stress-metabolic syndrome relationship. The current study examined relationships among physical activity, stress, and metabolic syndrome in adolescents. Participants (N = 126; 57 girls, 69 boys) were assessed for anthropometry, psychosocial stress, physical activity, and metabolic syndrome variables; t tests were used to examine sex differences, and regression analysis was used to assess relationships among variables controlling for sex and maturity status. Mean body mass index approached the 75th percentile for both sexes. Typical sex differences were observed for systolic blood pressure, time spent in moderate and vigorous physical activity, and perceived stress. Although stress was not associated with MetS (β = -.001, P = .82), a modest, positive relationship was observed with BMI (β = .20, P = .04). Strong relationships between physical activity and stress with MetS or BMI were not found in this sample. Results may be partially explained by overall good physical health status of the participants. Additional research in groups exhibiting varying degrees of health is needed.

The effects of mating status and time since mating on female sex pheromone levels in the rice leaf bug, Trigonotylus caelestialium

NASA Astrophysics Data System (ADS)

Yamane, Takashi; Yasuda, Tetsuya

2014-02-01

Although mating status affects future mating opportunities, the biochemical changes that occur in response to mating are not well understood. This study investigated the effects of mating status on the quantities of sex pheromone components found in whole-body extracts and volatile emissions of females of the rice leaf bug, Trigonotylus caelestialium. When sampled at one of four time points within a 4-day postmating period, females that had copulated with a male had greater whole-body quantities of sex pheromone components than those of virgin females sampled at the same times. The quantities of sex pheromone components emitted by virgin females over a 24-h period were initially high but then steadily decreased, whereas 24-h emissions were persistently low among mated females when measured at three time points within the 4 days after mating. As a result, soon after mating, the mated females emitted less sex pheromones than virgin females, but there were no significant differences between mated and virgin females at the end of the experiment. Thus, postmating reduction in the rate of emission of sex pheromones could explain previously observed changes in female attractiveness to male T. caelestialium.

Social influences on physical activity in Anglo- and Vietnamese-Australian adolescent males in a single sex school.

PubMed

Wilson, Andrew N; Dollman, James

2007-06-01

Understanding factors that influence physical activity levels of adolescents can assist the design of more effective interventions. Social support is a consistent correlate of youth physical activity but few studies have examined this in different cultural settings. Male adolescents (n=180, age=13.58+/-0.97 years) from a metropolitan single sex private school participated in this study. Habitual physical activity was estimated using the 3-day physical activity recall (3dPAR), and aspects of social support to be physically active using a specifically designed questionnaire. Comparisons were made between Anglo-Australians (n=118), whose parents were both born in Australia, and Vietnamese-Australians (n=62), whose parents were both born in Vietnam. There was a trend towards higher physical activity among Anglo-Australians, particularly on weekends. Anglo-Australians reported significantly more parental and peer support across most items pertaining to these constructs. Among the whole sample, social support variables explained 5-12% of the total explained variance in physical activity, with items pertaining to father and best friend support emerging as the strongest and most consistent predictors in multiple regression models. Among Anglo-Australians, the prediction models were relatively weak, explaining 0-9% of the total explained variance in physical activity. Prediction models for physical activity among Vietnamese-Australians were much stronger, explaining 11-32% of the total explained variance, with father's support variables contributing consistently to these models. The strong paternal influence on physical activity among Vietnamese-Australians needs to be confirmed in more diverse population groups, but results from this study suggest that interventions promoting physical activity among adolescent boys need to take into account cultural background as a moderator of widely reported social influences.

Intrafamily and intragenomic conflicts in human warfare

PubMed Central

2017-01-01

Recent years have seen an explosion of multidisciplinary interest in ancient human warfare. Theory has emphasized a key role for kin-selected cooperation, modulated by sex-specific demography, in explaining intergroup violence. However, conflicts of interest remain a relatively underexplored factor in the evolutionary-ecological study of warfare, with little consideration given to which parties influence the decision to go to war and how their motivations may differ. We develop a mathematical model to investigate the interplay between sex-specific demography and human warfare, showing that: the ecology of warfare drives the evolution of sex-biased dispersal; sex-biased dispersal modulates intrafamily and intragenomic conflicts in relation to warfare; intragenomic conflict drives parent-of-origin-specific patterns of gene expression—i.e. ‘genomic imprinting’—in relation to warfare phenotypes; and an ecological perspective of conflicts at the levels of the gene, individual, and social group yields novel predictions as to pathologies associated with mutations and epimutations at loci underpinning human violence. PMID:28228515

Intrafamily and intragenomic conflicts in human warfare.

PubMed

Micheletti, Alberto J C; Ruxton, Graeme D; Gardner, Andy

2017-02-22

Recent years have seen an explosion of multidisciplinary interest in ancient human warfare. Theory has emphasized a key role for kin-selected cooperation, modulated by sex-specific demography, in explaining intergroup violence. However, conflicts of interest remain a relatively underexplored factor in the evolutionary-ecological study of warfare, with little consideration given to which parties influence the decision to go to war and how their motivations may differ. We develop a mathematical model to investigate the interplay between sex-specific demography and human warfare, showing that: the ecology of warfare drives the evolution of sex-biased dispersal; sex-biased dispersal modulates intrafamily and intragenomic conflicts in relation to warfare; intragenomic conflict drives parent-of-origin-specific patterns of gene expression-i.e. 'genomic imprinting'-in relation to warfare phenotypes; and an ecological perspective of conflicts at the levels of the gene, individual, and social group yields novel predictions as to pathologies associated with mutations and epimutations at loci underpinning human violence. © 2017 The Authors.

Crowding, sex ratio and horn evolution in a South African beetle community.

PubMed

Pomfret, Joanne C; Knell, Robert J

2008-02-07

Sexually selected ornaments and weapons are exceptionally variable, even between closely related species. It has long been recognized that some of this diversity can be explained by differences in mating systems between species, but there remains substantial variation between species with similar mating systems. We investigated the roles of sex ratio (measured as operational sex ratio, OSR) and population density (measured as mean male crowding, a measure indicating the average number of conspecific males that an individual male animal will encounter) in determining horn presence in a community of South African dung beetles. Analysis of data from 14 species using a generalized least-squares model incorporating phylogenetic influences found that both OSR and mean crowding were significant predictors of horn presence, with hornless species tending to show female-biased sex ratios and high levels of crowding. The influence of mean crowding on horn diversity between species probably reflects the difficulty of guarding and monopolizing females when many competitors are present, meaning that males who adopt 'scramble' tactics tend to be favoured.

The Impact of PTSD Symptoms on Women's Safer-Sex Negotiation: Influence of Ethnicity

PubMed Central

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

On the association between sexual attraction and adolescent risk behavior involvement: Examining mediation and moderation.

PubMed

Busseri, Michael A; Willoughby, Teena; Chalmers, Heather; Bogaert, Anthony F

2008-01-01

On the basis of a large-scale survey of high-school youth, the authors compared adolescents reporting exclusively heterosexual, mostly heterosexual, bisexual, and predominately same-sex attraction based on high-risk involvement across a range of risk behaviors. Bisexual and same-sex attracted groups were characterized by heightened high-risk involvement relative to the other two groups. Mediation analysis was used to determine whether these group disparities were explained by a set of normative predictive factors spanning multiple life domains. Differences among a combined exclusively/mostly heterosexual attraction group and both the bisexual and same-sex attraction groups were attenuated (66% and 50%, respectively) after incorporating the hypothesized intervening predictive factors, providing evidence of partial mediation. Primary mediators included intrapersonal (attitudes toward risk-taking; academic orientation), interpersonal (peer victimization; parental relationships; unstructured activities), and environmental (substance availability) factors. Mediation results were consistent across participant age and sex. Implications, limitations, and directions for future research are discussed. Copyright (c) 2008 APA.

Does the Theory of Planned Behaviour Explain Condom Use Behaviour Among Men Who have Sex with Men? A Meta-analytic Review of the Literature.

PubMed

Andrew, Benjamin J; Mullan, Barbara A; de Wit, John B F; Monds, Lauren A; Todd, Jemma; Kothe, Emily J

2016-12-01

The aim of this meta-analysis was to explore whether the constructs in the theory of planned behaviour (TPB; i.e., attitude, subjective norm, perceived behavioural control, intention) explain condom use behaviour among men who have sex with men (MSM). Electronic databases were searched for studies that measured TPB variables and MSM condom use. Correlations were meta-analysed using a random effects model and path analyses. Moderation analyses were conducted for the time frame of the behavioural measure used (retrospective versus prospective). Attitude, subjective norm and perceived behavioural control accounted for 24.0 % of the variance in condom use intention and were all significant correlates. Intention and PBC accounted for 12.4 % of the variance in condom use behaviour. However, after taking intention into account, PBC was no longer significantly associated with condom use. The strength of construct relationships did not differ between retrospective and prospective behavioural assessments. The medium to large effect sizes of the relationships between the constructs in the TPB, which are consistent with previous meta-analyses with different behaviours or target groups, suggest that the TPB is also a useful model for explaining condom use behaviour among MSM. However, the research in this area is rather small, and greater clarity over moderating factors can only be achieved when the literature expands.

Can evolutionary principles explain patterns of family violence?

PubMed

Archer, John

2013-03-01

The article's aim is to evaluate the application of the evolutionary principles of kin selection, reproductive value, and resource holding power to the understanding of family violence. The principles are described in relation to specific predictions and the mechanisms underlying these. Predictions are evaluated for physical violence perpetrated by (a) parents to unrelated children, (b) parents to genetic offspring, and (c) offspring to parents and between (d) siblings and (e) sexual partners. Precise figures for risks have been calculated where possible. The major conclusions are that most of the evidence is consistent with evolutionary predictions derived from kin selection and reproductive value: There were (a) higher rates of violence to stepchildren, (b) a decline in violence with the age of offspring, and (c) an increase in violence with parental age, while (d) violence between siblings was generally at a low level and concerned resource disputes. The issue of distinguishing evolutionary from alternative explanations is addressed throughout and is problematic for predictions derived from reproductive value. The main evolutionary explanation for male partner violence, mate guarding as a result of paternity uncertainty, cannot explain Western studies where sex differences in control and violence between partners were absent, although other aspects of male partner violence are consistent with it, and it may explain sex differences in traditional cultures. Recurrent problems in evaluating the evidence were to control for possible confounds and thus to distinguish evolutionary from alternative explanations. Suggestions are outlined to address this and other issues arising from the review. © 2013 American Psychological Association

Muscle Damage following Maximal Eccentric Knee Extensions in Males and Females

PubMed Central

2016-01-01

Aim To investigate whether there is a sex difference in exercise induced muscle damage. Materials and Method Vastus Lateralis and patella tendon properties were measured in males and females using ultrasonography. During maximal voluntary eccentric knee extensions (12 reps x 6 sets), Vastus Lateralis fascicle lengthening and maximal voluntary eccentric knee extensions torque were recorded every 10° of knee joint angle (20–90°). Isometric torque, Creatine Kinase and muscle soreness were measured pre, post, 48, 96 and 168 hours post damage as markers of exercise induced muscle damage. Results Patella tendon stiffness and Vastus Lateralis fascicle lengthening were significantly higher in males compared to females (p<0.05). There was no sex difference in isometric torque loss and muscle soreness post exercise induced muscle damage (p>0.05). Creatine Kinase levels post exercise induced muscle damage were higher in males compared to females (p<0.05), and remained higher when maximal voluntary eccentric knee extension torque, relative to estimated quadriceps anatomical cross sectional area, was taken as a covariate (p<0.05). Conclusion Based on isometric torque loss, there is no sex difference in exercise induced muscle damage. The higher Creatine Kinase in males could not be explained by differences in maximal voluntary eccentric knee extension torque, Vastus Lateralis fascicle lengthening and patella tendon stiffness. Further research is required to understand the significant sex differences in Creatine Kinase levels following exercise induced muscle damage. PMID:26986066

The Vanderbilt Expertise Test Reveals Domain-General and Domain-Specific Sex Effects in Object Recognition

PubMed Central

McGugin, Rankin W.; Richler, Jennifer J.; Herzmann, Grit; Speegle, Magen; Gauthier, Isabel

2012-01-01

Individual differences in face recognition are often contrasted with differences in object recognition using a single object category. Likewise, individual differences in perceptual expertise for a given object domain have typically been measured relative to only a single category baseline. In Experiment 1, we present a new test of object recognition, the Vanderbilt Expertise Test (VET), which is comparable in methods to the Cambridge Face Memory Task (CFMT) but uses eight different object categories. Principal component analysis reveals that the underlying structure of the VET can be largely explained by two independent factors, which demonstrate good reliability and capture interesting sex differences inherent in the VET structure. In Experiment 2, we show how the VET can be used to separate domain-specific from domain-general contributions to a standard measure of perceptual expertise. While domain-specific contributions are found for car matching for both men and women and for plane matching in men, women in this sample appear to use more domain-general strategies to match planes. In Experiment 3, we use the VET to demonstrate that holistic processing of faces predicts face recognition independently of general object recognition ability, which has a sex-specific contribution to face recognition. Overall, the results suggest that the VET is a reliable and valid measure of object recognition abilities and can measure both domain-general skills and domain-specific expertise, which were both found to depend on the sex of observers. PMID:22877929

Comparison of telomere length in black and white teachers from South Africa: the sympathetic activity and ambulatory blood pressure in Africans study.

PubMed

von Känel, Roland; Malan, Nico T; Hamer, Mark; Malan, Leoné

2015-01-01

Telomere length is a marker of biological aging that has been linked to cardiovascular disease risk. The black South African population is witnessing a tremendous increase in the prevalence of cardiovascular disease, part of which might be explained through urbanization. We compared telomere length between black South Africans and white South Africans and examined which biological and psychosocial variables played a role in ethnic difference in telomere length. We measured leukocyte telomere length in 161 black South African teachers and 180 white South African teachers aged 23 to 66 years without a history of atherothrombotic vascular disease. Age, sex, years having lived in the area, human immunodeficiency virus (HIV) infection, hypertension, body mass index, dyslipidemia, hemoglobin A1c, C-reactive protein, smoking, physical activity, alcohol abuse, depressive symptoms, psychological distress, and work stress were considered as covariates. Black participants had shorter (median, interquartile range) relative telomere length (0.79, 0.70-0.95) than did white participants (1.06, 0.87-1.21; p < .001), and this difference changed very little after adjusting for covariates. In fully adjusted models, age (p < .001), male sex (p = .011), and HIV positive status (p = .023) were associated with shorter telomere length. Ethnicity did not significantly interact with any covariates in determining telomere length, including psychosocial characteristics. Black South Africans showed markedly shorter telomeres than did white South African counterparts. Age, male sex, and HIV status were associated with shorter telomere length. No interactions between ethnicity and biomedical or psychosocial factors were found. Ethnic difference in telomere length might primarily be explained by genetic factors.

Allometry of sexual size dimorphism in turtles: a comparison of mass and length data.

PubMed

Regis, Koy W; Meik, Jesse M

2017-01-01

The macroevolutionary pattern of Rensch's Rule (positive allometry of sexual size dimorphism) has had mixed support in turtles. Using the largest carapace length dataset and only large-scale body mass dataset assembled for this group, we determine (a) whether turtles conform to Rensch's Rule at the order, suborder, and family levels, and (b) whether inferences regarding allometry of sexual size dimorphism differ based on choice of body size metric used for analyses. We compiled databases of mean body mass and carapace length for males and females for as many populations and species of turtles as possible. We then determined scaling relationships between males and females for average body mass and straight carapace length using traditional and phylogenetic comparative methods. We also used regression analyses to evalutate sex-specific differences in the variance explained by carapace length on body mass. Using traditional (non-phylogenetic) analyses, body mass supports Rensch's Rule, whereas straight carapace length supports isometry. Using phylogenetic independent contrasts, both body mass and straight carapace length support Rensch's Rule with strong congruence between metrics. At the family level, support for Rensch's Rule is more frequent when mass is used and in phylogenetic comparative analyses. Turtles do not differ in slopes of sex-specific mass-to-length regressions and more variance in body size within each sex is explained by mass than by carapace length. Turtles display Rensch's Rule overall and within families of Cryptodires, but not within Pleurodire families. Mass and length are strongly congruent with respect to Rensch's Rule across turtles, and discrepancies are observed mostly at the family level (the level where Rensch's Rule is most often evaluated). At macroevolutionary scales, the purported advantages of length measurements over weight are not supported in turtles.

Sex-Based Differences as a Predictor of Recovery Trajectories in Young Athletes After a Sports-Related Concussion.

PubMed

Ono, Kim E; Burns, Thomas G; Bearden, Donald J; McManus, Susan M; King, Harold; Reisner, Andrew

2016-03-01

To date, few studies have delineated clear sex-based differences in symptom resolution after a sports-related concussion (SRC), and equivocal results have been identified in sex-based differences on baseline assessments. To assess whether female athletes displayed prolonged recovery and more symptoms at baseline and after an SRC compared with male athletes. Cohort study; Level of evidence, 3. The current study assessed 135 male and 41 female athletes (10-18 years old) who participated in high-impact sports in metropolitan Atlanta middle and high schools. All athletes completed a baseline assessment and at least 1 postconcussion assessment from the Immediate Post-Concussion Assessment and Cognitive Testing battery. Longitudinal hierarchical linear modeling was employed to examine individual-level variables and their associations with adolescents' rates of recovery in concussive symptoms after controlling for age and number of prior concussions. Aggregate symptoms were rated as higher in female athletes compared with male athletes at baseline (mean ± SD: females, 13.49 ± 11.20; males, 4.88 ± 8.74; F(1,175) = 10.59, P < .001) and immediately after a concussion (females: 16.75 ± 18.08; males: 10.58 ± 14.21; F(1,175) = 3.99, P = .05). There were no group differences in the slope of recovery between male and female athletes, indicating generally similar trajectories of change for both groups. Post hoc analyses revealed higher baseline levels of migraine and neuropsychological symptoms in female athletes. Although female athletes in the current study reported increased symptoms, identical recovery patterns were observed in both sexes, suggesting that sex-based differences in concussion recovery are better explained by increased symptom frequency among female athletes when compared with their male counterparts. © 2015 The Author(s).

Sex-specific morphological and physiological differences in the moss Ceratodon purpureus (Dicranales).

PubMed

Slate, Mandy L; Rosenstiel, Todd N; Eppley, Sarah M

2017-11-10

Dioecy and sexual dimorphism occur in many terrestrial plant species but are especially widespread among the bryophytes. Despite the prevalence of dioecy in non-vascular plants, surprisingly little is known about how fine-scale sex-specific cell and leaf morphological traits are correlated with sex-specific physiology and population sex ratios. Such data are critical to understanding the inter-relationship between sex-specific morphological and physiological characters and how their relationship influences population structure. In this study, these data types were assessed to determine how they vary across three populations within one moss species and whether fine-scale morphological traits scale up to physiological and sex ratio characteristics. Twenty cell-, leaf- and canopy-level traits and two photochemical measurements were compared between sexes and populations of the dioecious moss Ceratodon purpureus . Field population-expressed sex ratios were obtained for the same populations. Male and female plants differed in cell, leaf and photochemical measures. These sexual dimorphisms were female biased, with females having larger and thicker leaves and greater values for chlorophyll fluorescence-based, leaf photochemistry measurements than males. Female traits were also more variable than male traits. Interestingly, field population sex ratios were significantly male biased in two study populations and female biased in the third study population. The results demonstrate that the larger morphology and the greater physiological output of female C. purpureus gametophytes compared with males occurs across populations and is likely to have significant effects on resource allocation and biotic interactions. However, this high level of dimorphism does not explain population sex ratio variation in the three study populations tested. This research lays the groundwork for future studies on how differential sex-specific variation in cell and leaf traits influences bryophyte plant fitness. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Exploring the Myth of Unhappiness in Former Communist Countries: The Roles of the Sex Gap in Life Expectancy and the Marital Status Composition

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…

Sex differences in a chronometric mental rotation test with cube figures: a behavioral, electroencephalography, and eye-tracking pilot study.

PubMed

Scheer, Clara; Mattioni Maturana, Felipe; Jansen, Petra

2018-05-07

In chronometric mental rotation tasks, sex differences are widely discussed. Most studies find men to be more skilled in mental rotation than women, which can be explained by the holistic strategy that they use to rotate stimuli. Women are believed to apply a piecemeal strategy. So far, there have been no studies investigating this phenomenon using eye-tacking methods in combination with electroencephalography (EEG) analysis: the present study compared behavioral responses, EEG activity, and eye movements of 15 men and 15 women while solving a three-dimensional chronometric mental rotation test. The behavioral analysis showed neither differences in reaction time nor in the accuracy rate between men and women. The EEG data showed a higher right activation on parietal electrodes for women and the eye-tracking results indicated a longer fixation in a higher number of areas of interest at 0° for women. Men and women are likely to possess different perceptual (visual search) and decision-making mechanisms, but similar mental rotation processes. Furthermore, men presented a longer visual search processing, characterized by the greater saccade latency of 0°-135°. Generally, this study could be considered a pilot study to investigate sex differences in mental rotation tasks while combining eye-tracking and EEG methods.

Interpopulation Comparison of Sex-Biased Mortality and Sexual Size Dimorphism in Sea-Run Masu Salmon, Oncorhynchus masou.

PubMed

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.

Human ethology: age and sex differences in mall walking.

PubMed

Hangland, A; Cimbalo, R S

1997-12-01

Well-controlled experimental research has examined the biomechanical aspects of walking in homo sapiens on a track. The research reported here also examined cadence, velocity, and stride length for estimated ages ranging from 15 to over 55 years but in a shopping mall. Women at all ages walked faster than men in the mall setting which was opposite to what was found in the track research. Apparently context may influence how fast people walk. Hunter-gatherer differences could explain these results.

The Anterolateral Ligament: An Anatomic Study on Sex-Based Differences

PubMed Central

Daggett, Matt; Helito, Camilo; Cullen, Matthew; Ockuly, Andrew; Busch, Kyle; Granite, Joseph; Wright, Barth; Sonnery-Cottet, Bertrand

2017-01-01

Background: The anterolateral ligament (ALL) has been shown to have an important role in rotatory stability of the knee. While there is abundant research on sex-based differences related to anterior cruciate ligament (ACL) rupture, there is a paucity of literature related to such differences in the ALL. Purpose: To define any sex-based differences in the ALL with regard to length, width, and thickness. Study Design: Descriptive laboratory study. Methods: The ALL was initially evaluated in 165 unpaired knees (92 males and 65 females after exclusion criteria applied). The length, width, and thickness of the ALL were measured using a digital caliper. Width and thickness were measured at the joint line just superior to the lateral meniscus. The Mann-Whitney test and Student t tests were used to compare measurements between males and females. The Pearson product-moment correlation was subsequently used to determine the correlation between height and weight and the statistically different morphometric variables. Results: The mean (±SD) thickness of the ALL in males was 2.09 ± 0.56 mm, almost twice as thick as females (1.05 ± 0.49 mm; P = 8.8 × 10−20). There was also a statistically significant difference in ALL length (P = 3.8 × 10−7), but no significant difference was found for width. A moderate association was found between donor height and ALL thickness and length. Conclusion: The anatomic measurements of the ALL demonstrate a difference between sexes, and the ALL is significantly thicker in males than females. Clinical Relevance: As the role of the ALL in rotatory stability of the knee becomes better understood, the difference in the thickness of the ALL we have found between the sexes may be another factor why female athletes have an increased incidence of ACL rupture compared with males. This may also help explain why females have issues with knee laxity and rotatory instability. PMID:28321423

Poorer right ventricular systolic function and exercise capacity in women after repair of tetralogy of fallot: a sex comparison of standard deviation scores based on sex-specific reference values in healthy control subjects.

PubMed

Sarikouch, Samir; Boethig, Dietmar; Peters, Brigitte; Kropf, Siegfried; Dubowy, Karl-Otto; Lange, Peter; Kuehne, Titus; Haverich, Axel; Beerbaum, Philipp

2013-11-01

In repaired congenital heart disease, there is increasing evidence of sex differences in cardiac remodeling, but there is a lack of comparable data for specific congenital heart defects such as in repaired tetralogy of Fallot. In a prospective multicenter study, a cohort of 272 contemporary patients (158 men; mean age, 14.3±3.3 years [range, 8-20 years]) with repaired tetralogy of Fallot underwent cardiac magnetic resonance for ventricular function and metabolic exercise testing. All data were transformed to standard deviation scores according to the Lambda-Mu-Sigma method by relating individual values to their respective 50th percentile (standard deviation score, 0) in sex-specific healthy control subjects. No sex differences were observed in age at repair, type of repair conducted, or overall hemodynamic results. Relative to sex-specific controls, repaired tetralogy of Fallot in women had larger right ventricular end-systolic volumes (standard deviation scores: women, 4.35; men, 3.25; P=0.001), lower right ventricular ejection fraction (women, -2.83; men, -2.12; P=0.011), lower right ventricular muscle mass (women, 1.58; men 2.45; P=0.001), poorer peak oxygen uptake (women, -1.65; men, -1.14; P<0.001), higher VE/VCO2 (ventilation per unit of carbon dioxide production) slopes (women, 0.88; men 0.58; P=0.012), and reduced peak heart rate (women, -2.16; men -1.74; P=0.017). Left ventricular parameters did not differ between sexes. Relative to their respective sex-specific healthy control subjects, derived standard deviation scores in repaired tetralogy of Fallot suggest that women perform poorer than men in terms of right ventricular systolic function as tested by cardiac magnetic resonance and exercise capacity. This effect cannot be explained by selection bias. Further outcome data are required from longitudinal cohort studies.

Sex-specific effects of dehydroepiandrosterone (DHEA) on glucose metabolism in the CNS.

PubMed

Vieira-Marques, Claudia; Arbo, Bruno Dutra; Cozer, Aline Gonçalves; Hoefel, Ana Lúcia; Cecconello, Ana Lúcia; Zanini, Priscila; Niches, Gabriela; Kucharski, Luiz Carlos; Ribeiro, Maria Flávia M

2017-07-01

DHEA is a neuroactive steroid, due to its modulatory actions on the central nervous system (CNS). DHEA is able to regulate neurogenesis, neurotransmitter receptors and neuronal excitability, function, survival and metabolism. The levels of DHEA decrease gradually with advancing age, and this decline has been associated with age related neuronal dysfunction and degeneration, suggesting a neuroprotective effect of endogenous DHEA. There are significant sex differences in the pathophysiology, epidemiology and clinical manifestations of many neurological diseases. The aim of this study was to determine whether DHEA can alter glucose metabolism in different structures of the CNS from male and female rats, and if this effect is sex-specific. The results showed that DHEA decreased glucose uptake in some structures (cerebral cortex and olfactory bulb) in males, but did not affect glucose uptake in females. When compared, glucose uptake in males was higher than females. DHEA enhanced the glucose oxidation in both males (cerebral cortex, olfactory bulb, hippocampus and hypothalamus) and females (cerebral cortex and olfactory bulb), in a sex-dependent manner. In males, DHEA did not affect synthesis of glycogen, however, glycogen content was increased in the cerebral cortex and olfactory bulb. DHEA modulates glucose metabolism in a tissue-, dose- and sex-dependent manner to increase glucose oxidation, which could explain the previously described neuroprotective role of this hormone in some neurodegenerative diseases. Copyright © 2016. Published by Elsevier Ltd.

Why is bidirectional sex change rare?

PubMed

Yamaguchi, Sachi; Iwasa, Yoh

2018-09-14

Various species of fish living in coral reef communities show sequential hermaphroditism, or sex change. In a typical case, an individual first matures as a female, and later, when it becomes dominant in the mating group, it becomes a male (i.e., protogynous sex change). Many species show only unidirectional changes but some of coral reef fishes exhibit bidirectional sex changes, in which even a dominant male may revert to female when a socially more dominant competitor arrives. However, bidirectional sex change has rarely been observed in natural conditions, even among those species exhibiting it under experimental conditions. Here we explain the rarity of bidirectional sex change by studying dynamics of hormones controlling sex expression. We consider social status factor, S F , which is elevated when the individual becomes more dominant in the mating group. When the S F level is high, the dynamics would culminate with low estradiol expression and high testosterone expression, suggesting a male phenotype. In contrast, when S F level is low, the system converges to an equilibrium with high estradiol expression and low testosterone expression, suggesting a female phenotype. There is a parameter region in which the dynamics exhibit bistability. The model demonstrates hysteresis: as S F increases smoothly, the system undergoes a sudden transition in the levels of sex hormones. The model can explain why species show unidirectional sex change, in that an individual's switch to a new sex is irreversible, even if the individual's social situation returns to the original subdominant status. Copyright © 2018 Elsevier Ltd. All rights reserved.

Are Females More Resistant to Extreme Neuromuscular Fatigue?

PubMed

Temesi, John; Arnal, Pierrick J; Rupp, Thomas; Féasson, Léonard; Cartier, Régine; Gergelé, Laurent; Verges, Samuel; Martin, Vincent; Millet, Guillaume Y

2015-07-01

Despite interest in the possibility of females outperforming males in ultraendurance sporting events, little is known about the sex differences in fatigue during prolonged locomotor exercise. This study investigated possible sex differences in central and peripheral fatigue in the knee extensors and plantar flexors resulting from a 110-km ultra-trail-running race. Neuromuscular function of the knee extensors and plantar flexors was evaluated via transcranial magnetic stimulation (TMS) and electrical nerve stimulation before and after an ultra-trail-running race in 20 experienced ultraendurance trail runners (10 females and 10 males matched by percent of the winning time by sex) during maximal and submaximal voluntary contractions and in relaxed muscle. Maximal voluntary knee extensor torque decreased more in males than in females (-38% vs -29%, P = 0.006) although the reduction in plantar flexor torque was similar between sexes (-26% vs -31%). Evoked mechanical plantar flexor responses decreased more in males than in females (-23% vs -8% for potentiated twitch amplitude, P = 0.010), indicating greater plantar flexor peripheral fatigue in males. Maximal voluntary activation assessed by TMS and electrical nerve stimulation decreased similarly in both sexes for both muscle groups. Indices of knee extensor peripheral fatigue and corticospinal excitability and inhibition changes were also similar for both sexes. Females exhibited less peripheral fatigue in the plantar flexors than males did after a 110-km ultra-trail-running race and males demonstrated a greater decrease in maximal force loss in the knee extensors. There were no differences in the magnitude of central fatigue for either muscle group or TMS-induced outcomes. The lower level of fatigue in the knee extensors and peripheral fatigue in the plantar flexors could partly explain the reports of better performance in females in extreme duration running races as race distance increases.

Young Adult Risk Factors for Cancer: Obesity, Inflammation, and Sociobehavioral Mechanisms.

PubMed

Yang, Yang Claire; Johnson, Moira P; Schorpp, Kristen M; Boen, Courtney E; Harris, Kathleen Mullan

2017-09-01

The paper assesses social disparities in the burdens of metabolic and inflammatory risks for cancer in the U.S. young adult population and examines psychosocial and behavioral mechanisms in such disparities. Using data of 7,889 individuals aged 12-32 years from the National Longitudinal Study of Adolescent to Adult Health from 1994 to 2009, generalized linear models were used to assess the sex, race/ethnicity, and SES differences in the risks of obesity and inflammation, measured by C-reactive protein. Further tests examined the extent to which social isolation, smoking, physical inactivity, alcohol abuse, and illicit drug use explain social differentials in each biomarker outcome. Women, blacks, Hispanics, and socioeconomically disadvantaged groups had higher risks of obesity and elevated C-reactive protein, with the SES gradients being more pronounced in female participants. Health-related behaviors showed large variation across sex, race, and SES strata. After adjusting for these behavioral variables, sex, and race disparities in obesity and excess inflammation in blacks diminished, whereas the adolescent SES disparity in obesity remained. The associations of adolescent and young adult SES disadvantage and inflammation were also explained by behavioral mechanisms. Behavioral factors associated with higher risks of obesity and inflammation differed, with the exception of fast food consumption, a risk factor for both. This study provides new knowledge of social distribution of early life exposures to physiologic precedents to cancer development later in life with implications for prevention and early intervention of modifiable risky behaviors in adolescents and young adults. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Wage determination and discrimination among older workers.

PubMed

Quinn, J F

1979-09-01

In this study, the determinants of the wage rates of a large sample of individuals aged 58 to 63 are first analyzed. Second, an explanation for the large discrepancies existing between the average wage rates earned by whites and nonwhites and by men and women is attempted. Human capital and geographic variables were found to be important wage determinants. Education, vocational training, years of job tenure, health, region of residence and local cost of living were significant explanators, especially for whites. Differences in these variables, however, cannot completely explain the wage differentials that exist by race and sex. There is a large unexplained component (especially in the male-female comparison) offering evidence of race and sex discrimination among older workers. In the case of sex discrimination, much of the problem appears to be occupational segregation--the crowding of women into low paying industries and occupations.

Sex differences in theory-based predictors of leisure time physical activity in a population-based sample of adults with spinal cord injury.

PubMed

Stapleton, Jessie N; Martin Ginis, Kathleen A

2014-09-01

To examine sex differences in theory-based predictors of leisure time physical activity (LTPA) among men and women with spinal cord injury, and secondarily, to identify factors that might explain any sex differences in social cognitions. A secondary analysis of Study of Health and Activity in People with Spinal Cord Injury survey data. Community. Community-dwelling men (n=536) and women (n=164) recruited from 4 rehabilitation and research centers. Not applicable. Subjective norms, attitudes, barrier self-efficacy, perceived controllability (PC), and intentions. Men had stronger PC and barrier self-efficacy than women. Hierarchical regression analyses revealed that social support significantly predicted PC for both sexes, and health, pain, and physical independence also significantly predicted PC for men. Social support, health, and pain significantly predicted barrier self-efficacy for men. Social support was the only significant predictor of barrier self-efficacy for women. Women felt significantly less control over their physical activity behavior and had lower confidence to overcome barriers to physical activity than did men. Although social support predicted PC and barrier self-efficacy in both men and women, men seemed to take additional factors into consideration when formulating their control beliefs for LTPA. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Explaining ethnic disparities in lung function among young adults: A pilot investigation

PubMed Central

Patel, Jaymini; Minelli, Cosetta; Burney, Peter G. J.

2017-01-01

Background Ethnic disparities in lung function have been linked mainly to anthropometric factors but have not been fully explained. We conducted a cross-sectional pilot study to investigate how best to study ethnic differences in lung function in young adults and evaluate whether these could be explained by birth weight and socio-economic factors. Methods We recruited 112 university students of White and South Asian British ethnicity, measured post-bronchodilator lung function, obtained information on respiratory symptoms and socio-economic factors through questionnaires, and acquired birth weight through data linkage. We regressed lung function against ethnicity and candidate predictors defined a priori using linear regression, and used penalised regression to examine a wider range of factors. We reviewed the implications of our findings for the feasibility of a larger study. Results There was a similar parental socio-economic environment and no difference in birth weight between the two ethnic groups, but the ethnic difference in FVC adjusted for sex, age, height, demi-span, father’s occupation, birth weight, maternal educational attainment and maternal upbringing was 0.81L (95%CI: -1.01 to -0.54L). Difference in body proportions did not explain the ethnic differences although parental immigration was an important predictor of FVC independent of ethnic group. Participants were comfortable with study procedures and we were able to link birth weight data to clinical measurements. Conclusion Studies of ethnic disparities in lung function among young adults are feasible. Future studies should recruit a socially more diverse sample and investigate the role of markers of acculturation in explaining such differences. PMID:28575113

Assessment of gene-by-sex interaction effect on bone mineral density.

PubMed

Liu, Ching-Ti; Estrada, Karol; Yerges-Armstrong, Laura M; Amin, Najaf; Evangelou, Evangelos; Li, Guo; Minster, Ryan L; Carless, Melanie A; Kammerer, Candace M; Oei, Ling; Zhou, Yanhua; Alonso, Nerea; Dailiana, Zoe; Eriksson, Joel; García-Giralt, Natalia; Giroux, Sylvie; Husted, Lise Bjerre; Khusainova, Rita I; Koromila, Theodora; Kung, Annie Waichee; Lewis, Joshua R; Masi, Laura; Mencej-Bedrac, Simona; Nogues, Xavier; Patel, Millan S; Prezelj, Janez; Richards, J Brent; Sham, Pak Chung; Spector, Timothy; Vandenput, Liesbeth; Xiao, Su-Mei; Zheng, Hou-Feng; Zhu, Kun; Balcells, Susana; Brandi, Maria Luisa; Frost, Morten; Goltzman, David; González-Macías, Jesús; Karlsson, Magnus; Khusnutdinova, Elza K; Kollia, Panagoula; Langdahl, Bente Lomholt; Ljunggren, Osten; Lorentzon, Mattias; Marc, Janja; Mellström, Dan; Ohlsson, Claes; Olmos, José M; Ralston, Stuart H; Riancho, José A; Rousseau, François; Urreizti, Roser; Van Hul, Wim; Zarrabeitia, María T; Castano-Betancourt, Martha; Demissie, Serkalem; Grundberg, Elin; Herrera, Lizbeth; Kwan, Tony; Medina-Gómez, Carolina; Pastinen, Tomi; Sigurdsson, Gunnar; Thorleifsson, Gudmar; Vanmeurs, Joyce Bj; Blangero, John; Hofman, Albert; Liu, Yongmei; Mitchell, Braxton D; O'Connell, Jeffrey R; Oostra, Ben A; Rotter, Jerome I; Stefansson, Kari; Streeten, Elizabeth A; Styrkarsdottir, Unnur; Thorsteinsdottir, Unnur; Tylavsky, Frances A; Uitterlinden, Andre; Cauley, Jane A; Harris, Tamara B; Ioannidis, John Pa; Psaty, Bruce M; Robbins, John A; Zillikens, M Carola; Vanduijn, Cornelia M; Prince, Richard L; Karasik, David; Rivadeneira, Fernando; Kiel, Douglas P; Cupples, L Adrienne; Hsu, Yi-Hsiang

2012-10-01

Sexual dimorphism in various bone phenotypes, including bone mineral density (BMD), is widely observed; however, the extent to which genes explain these sex differences is unclear. To identify variants with different effects by sex, we examined gene-by-sex autosomal interactions genome-wide, and performed expression quantitative trait loci (eQTL) analysis and bioinformatics network analysis. We conducted an autosomal genome-wide meta-analysis of gene-by-sex interaction on lumbar spine (LS) and femoral neck (FN) BMD in 25,353 individuals from 8 cohorts. In a second stage, we followed up the 12 top single-nucleotide polymorphisms (SNPs; p < 1 × 10(-5) ) in an additional set of 24,763 individuals. Gene-by-sex interaction and sex-specific effects were examined in these 12 SNPs. We detected one novel genome-wide significant interaction associated with LS-BMD at the Chr3p26.1-p25.1 locus, near the GRM7 gene (male effect = 0.02 and p = 3.0 × 10(-5) ; female effect = -0.007 and p = 3.3 × 10(-2) ), and 11 suggestive loci associated with either FN- or LS-BMD in discovery cohorts. However, there was no evidence for genome-wide significant (p < 5 × 10(-8) ) gene-by-sex interaction in the joint analysis of discovery and replication cohorts. Despite the large collaborative effort, no genome-wide significant evidence for gene-by-sex interaction was found to influence BMD variation in this screen of autosomal markers. If they exist, gene-by-sex interactions for BMD probably have weak effects, accounting for less than 0.08% of the variation in these traits per implicated SNP. © 2012 American Society for Bone and Mineral Research. Copyright © 2012 American Society for Bone and Mineral Research.

Divergent hypoxia tolerance in adult males and females of the plainfin midshipman (Porichthys notatus).

PubMed

LeMoine, Christophe M R; Bucking, Carol; Craig, Paul M; Walsh, Patrick J

2014-01-01

In the summer, the plainfin midshipman (Poricththys notatus) migrates to reproduce in the nearshore environment, where oxygen levels are influenced by the tidal cycles. Parental males establish nests under rocks in the intertidal zone, where they reside until the eggs they guard are fully developed. In contrast, females and sneaker males leave the nests shortly after spawning. We examined the physiological resistance and metabolic response of parental male and female adult midshipman to hypoxia to test whether they exhibited sex-specific differences reflecting their reproductive strategies. Further, we assessed whether metabolic enzymes and metabolites were differentially enriched in tissues of parental males and females to explain the differences observed in their hypoxia tolerance. While parental males and females exhibited similar depression of their oxygen consumption in response to graded hypoxia, parental males could withstand significantly longer exposures to severe hypoxic stress. At the biochemical level, parental males showed higher hepatic glycogen reserves and higher glycolytic enzyme capacities in gills and skeletal muscles than females. Although some of these enzymatic variations could be explained by differences in body size, we also observed a significant effect of sex on some of these factors. These results suggest that parental male midshipman may benefit from sexual dimorphism at the whole-organismal (larger body size) and biochemical (enzyme activities) levels, conferring on them a higher glycolytic potential to sustain the extensive hypoxia bouts they experience in nature.

Concussion reporting, sex, and conformity to traditional gender norms in young adults.

PubMed

Kroshus, Emily; Baugh, Christine M; Stein, Cynthia J; Austin, S Bryn; Calzo, Jerel P

2017-01-01

This study assessed whether between-sex differences in concussion reporting intention and behavior among young adults are explained by the extent to which the individual conforms to traditional masculine norms that often characterize contemporary sport culture. A survey of college athletes in the United States (n = 328) found greater symptom reporting intention among females as compared to males, but no difference in their likelihood continued play while experiencing symptoms of a possible concussion. Greater conformity to the norms of risk-taking was associated with greater likelihood of continued play while symptomatic among female athletes but not among male athletes. These findings suggest that gendered behavior, rather than biologically determined sex, is an important consideration for concussion safety in this age group. Addressing elements of the contemporary sport ethos that reinforce risk taking in service of athletic achievement may be a relevant direction for interventions aimed at improving injury reporting among all athletes. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Sex-biased phoretic mite load on two seaweed flies: Coelopa frigida and Coelopa pilipes.

PubMed

Gilburn, Andre S; Stewart, Katie M; Edward, Dominic A

2009-12-01

Two hypotheses explain male-biased parasitism. Physiological costs of male sexually selected characteristics can reduce immunocompetence. Alternatively, ecological differences could generate male-biased parasitism. One method of comparing the importance of the two theories is to investigate patterns of phoresy, which are only likely to be generated by ecological rather than immunological differences between the sexes. Here we studied the pattern of phoresy of the mite, Thinoseius fucicola, on two species of seaweed fly hosts, Coelopa frigida and Coelopa pilipes. We found a highly male-biased pattern of phoresy of T. fucicola on both species. These are the first reported instances of sex-biased phoresy in a solely phoretic parasite. We also show the first two cases of size-biased phoresy. We suggest that ecological factors, particularly, male mate searching, generated male biased patterns of phoresy. We highlight the potential importance of studies of phoresy in determining the relative roles of the immunocompetence and ecological theories in generating male-biased parasitism. We suggest that more studies of patterns of phoresy are carried out to allow detailed comparisons with patterns of parasitism.

Sulcal morphology and volume of Broca's area linked to handedness and sex.

PubMed

Powell, Joanne L; Kemp, Graham J; Roberts, Neil; García-Finaña, Marta

2012-06-01

We investigated the effect of handedness and sex on: (i) sulcal contours defining PO and PTR and (ii) volume estimates of PO and PTR subfields in 40 left- and 42 right-handers. Results show an effect of handedness on discontinuity of the inferior frontal sulcus (IFS: P<0.01). Discontinuity of IFS was observed in: 43% left- and 62% right hemispheres in right-handers and in 65% left- and 48% right-hemispheres in left-handers. PO volume asymmetry was rightward in left-handed males (P=0.007) and females (P=0.02), showed a leftward trend in right-handed males (P=0.06), and was non-asymmetrical in right-handed females (P=0.96, i.e. left- and right-hemisphere PO volumes did not differ significantly). PO volume asymmetry in males differed significantly between handedness groups (P=0.001). Findings indicate a high degree of variability in the sulcal contours of PO and PTR and volume asymmetry of PO: the factors sex and handedness can explain some of this variability. Copyright © 2012 Elsevier Inc. All rights reserved.

Locus of control and academic efficacy in the thoughts of life and death of young Quebec university students.

PubMed

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.

Cognition in Males and Females with Autism: Similarities and Differences

PubMed Central

Lai, Meng-Chuan; Lombardo, Michael V.; Ruigrok, Amber N. V.; Chakrabarti, Bhismadev; Wheelwright, Sally J.; Auyeung, Bonnie; Allison, Carrie; Baron-Cohen, Simon

2012-01-01

The male bias in autism spectrum conditions (ASC) has led to females with ASC being under-researched. This lack of attention to females could hide variability due to sex that may explain some of the heterogeneity within ASC. In this study we investigate four key cognitive domains (mentalizing and emotion perception, executive function, perceptual attention to detail, and motor function) in ASC, to test for similarities and differences between males and females with and without ASC (n = 128 adults; n = 32 per group). In the mentalizing and facial emotion perception domain, males and females with ASC showed similar deficits compared to neurotypical controls. However, in attention to detail and dexterity involving executive function, although males with ASC showed poorer performance relative to neurotypical males, females with ASC performed comparably to neurotypical females. We conclude that performance in the social-cognitive domain is equally impaired in male and female adults with ASC. However, in specific non-social cognitive domains, performance within ASC depends on sex. This suggests that in specific domains, cognitive profiles in ASC are modulated by sex. PMID:23094036

Sexual and Emotional Infidelity: Evolved Gender Differences in Jealousy Prove Robust and Replicable.

PubMed

Buss, David M

2018-03-01

Infidelity poses threats to high-investment mating relationships. Because of gender differences in some aspects of reproductive biology, such as internal female fertilization, the nature of these threats differs for men and women. Men, but not women, for example, have recurrently faced the problem of uncertainty in their genetic parenthood. Jealousy is an emotion hypothesized to have evolved to combat these threats. The 1992 article Sex Differences in Jealousy: Evolution, Physiology, and Psychology reported three empirical studies using two different methods, forced-choice and physiological experiments. Results supported the evolution-based hypotheses. The article became highly cited for several reasons. It elevated the status of jealousy as an important emotion to be explained by any comprehensive theory of human emotions. Subsequent meta-analyses robustly supported the evolutionary hypotheses. Moreover, the work supported the evolutionary meta-theory of gender differences, which posits differences only in domains in which the sexes have recurrently faced distinct adaptive problems. It also heralded the newly emerging field of evolutionary psychology as a useful perspective that possesses the scientific virtues of testability, falsifiability, and heuristic value in discovering previously unknown psychological phenomena.

Sex and life expectancy.

PubMed

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.

The Role of Sex, Gender, Health Factors, and Job Context in Workplace Accommodation Use Among Men and Women with Arthritis

PubMed Central

Gignac, Monique A M; Ibrahim, Selahadin; Smith, Peter M; Kristman, Vicki; Beaton, Dorcas E; Mustard, Cameron A

2018-01-01

Abstract Background With the aging of populations in many countries, workers are expected to remain employed longer but may struggle with the onset of common, chronic conditions like arthritis. To date, few studies have examined workplace policies and practices that could help accommodate individuals with arthritis, and fewer still have used a sex and gender-based approach to explore similarities and differences between women and men. Objectives This study compared the health and work contexts of workers aged ≥50 years to better understand similarities and differences between women and men in accommodation availability, need, use, and unmet needs. Methods A cross-sectional survey of men and women with osteoarthritis (OA), inflammatory arthritis (IA), or both OA and IA was administered online or by telephone and assessed demographics (e.g. age, education), health (e.g. pain, fatigue, workplace activity limitations), work context factors (e.g. job sector, full/part-time work, job control), and workplace accommodations (e.g. health benefits, flexible hours, special equipment/adaptations, modified duties). Sex and gender-based analyses examined similarities and differences between men and women and included descriptive statistics, multivariable multinomial analyses, and nested regression analyses. Results There was a 58.9% response rate and final sample of 463 participants (women, n = 266; men, n = 197; OA = 59.0%; IA/both IA and OA = 23.7%; unsure = 17.3%). Women and men were significantly different in a number of health (e.g. fatigue, health variability, workplace activity limitations) and work context factors (e.g. job sector, part-time work, job stress). However, in other respects, they were similar (e.g. pain, job involving physical demands, size of organization, shift work, union membership, job control). There were no differences between men and women in the availability or use of workplace accommodations. However, women reported significantly more accommodation needs and had greater unmet needs. Multivariable multinomial analyses found male/female as a binary variable did not explain differences in accommodation need, use, and unmet need. Nested analyses highlighted that differences in health variables explained male/female differences in accommodation need, while work context differences explained male/female differences in whether needs were met. Conclusions The findings highlight that women and men draw on a range of existing accommodation policies and practices to help manage their arthritis and that most have their accommodation needs met. Decomposing the context within which men and women with arthritis work suggests that women may face health and work context challenges that differ from men and that are related to greater accommodation needs and unmet need. This highlights potential vulnerabilities in the work of women that need to be addressed. PMID:29420700

The Role of Sex, Gender, Health Factors, and Job Context in Workplace Accommodation Use Among Men and Women with Arthritis.

PubMed

Gignac, Monique A M; Ibrahim, Selahadin; Smith, Peter M; Kristman, Vicki; Beaton, Dorcas E; Mustard, Cameron A

2018-04-18

With the aging of populations in many countries, workers are expected to remain employed longer but may struggle with the onset of common, chronic conditions like arthritis. To date, few studies have examined workplace policies and practices that could help accommodate individuals with arthritis, and fewer still have used a sex and gender-based approach to explore similarities and differences between women and men. This study compared the health and work contexts of workers aged ≥50 years to better understand similarities and differences between women and men in accommodation availability, need, use, and unmet needs. A cross-sectional survey of men and women with osteoarthritis (OA), inflammatory arthritis (IA), or both OA and IA was administered online or by telephone and assessed demographics (e.g. age, education), health (e.g. pain, fatigue, workplace activity limitations), work context factors (e.g. job sector, full/part-time work, job control), and workplace accommodations (e.g. health benefits, flexible hours, special equipment/adaptations, modified duties). Sex and gender-based analyses examined similarities and differences between men and women and included descriptive statistics, multivariable multinomial analyses, and nested regression analyses. There was a 58.9% response rate and final sample of 463 participants (women, n = 266; men, n = 197; OA = 59.0%; IA/both IA and OA = 23.7%; unsure = 17.3%). Women and men were significantly different in a number of health (e.g. fatigue, health variability, workplace activity limitations) and work context factors (e.g. job sector, part-time work, job stress). However, in other respects, they were similar (e.g. pain, job involving physical demands, size of organization, shift work, union membership, job control). There were no differences between men and women in the availability or use of workplace accommodations. However, women reported significantly more accommodation needs and had greater unmet needs. Multivariable multinomial analyses found male/female as a binary variable did not explain differences in accommodation need, use, and unmet need. Nested analyses highlighted that differences in health variables explained male/female differences in accommodation need, while work context differences explained male/female differences in whether needs were met. The findings highlight that women and men draw on a range of existing accommodation policies and practices to help manage their arthritis and that most have their accommodation needs met. Decomposing the context within which men and women with arthritis work suggests that women may face health and work context challenges that differ from men and that are related to greater accommodation needs and unmet need. This highlights potential vulnerabilities in the work of women that need to be addressed.

Brief Highlights of Major Federal Laws and Order on Sex Discrimination in Employment.

ERIC Educational Resources Information Center

Employment Standards Administration (DOL), Washington, DC. Women's Bureau.

The following laws and order are explained in this pamphlet: (1) Equal Pay Act of 1963 (concerns prohibiting employers from paying workers of one sex less than workers of the other sex for equal work on jobs that require equal skill, effort, and responsibility and that are performed under similar working conditions), (2) Title VII of the Civil…

Attitudes toward same-sex marriage: the case of Scandinavia.

PubMed

Jakobsson, Niklas; Kotsadam, Andreas; Jakobsson, Siri Støre

2013-01-01

The purpose of this study was to examine the variables that explain attitudes toward same-sex marriage. Using recently collected Scandinavian data (from Norway and Sweden) with a high response rate, this study shows that gender, regular participation in religious activities, political ideology, education, whether the respondent lived in the capital city, and attitudes toward gender equality were important for attitudes toward same-sex marriage. Age and income were not important for attitudes toward same-sex marriage. Although both Norwegians and Swedes clearly favor same-sex marriage, Swedes are significantly more positive than Norwegians.

Disability in long-term care residents explained by prevalent geriatric syndromes, not long-term care home characteristics: a cross-sectional study.

PubMed

Lane, Natasha E; Wodchis, Walter P; Boyd, Cynthia M; Stukel, Thérèse A

2017-02-10

Self-care disability is dependence on others to conduct activities of daily living, such as bathing, eating and dressing. Among long-term care residents, self-care disability lowers quality of life and increases health care costs. Understanding the correlates of self-care disability in this population is critical to guide clinical care and ongoing research in Geriatrics. This study examines which resident geriatric syndromes and chronic conditions are associated with residents' self-care disability and whether these relationships vary across strata of age, sex and cognitive status. It also describes the proportion of variance in residents' self-care disability that is explained by residents' geriatric syndromes versus long-term care home characteristics. We conducted a cross-sectional study using a health administrative cohort of 77,165 long-term care home residents residing in 614 Ontario long-term care homes. Eligible residents had their self-care disability assessed using the RAI-MDS 2.0 activities of daily living long-form score (range: 0-28) within 90 days of April 1st, 2011. Hierarchical multivariable regression models with random effects for long-term care homes were used to estimate the association between self-care disability and resident geriatric syndromes, chronic conditions and long-term care home characteristics. Differences in findings across strata of sex, age and cognitive status (cognitively intact versus cognitively impaired) were examined. Geriatric syndromes were much more strongly associated with self-care disability than chronic conditions in multivariable models. The direction and size of some of these effects were different for cognitively impaired versus cognitively intact residents. Residents' geriatric syndromes explained 50% of the variation in their self-care disability scores, while characteristics of long-term care homes explained an additional 2% of variation. Differences in long-term care residents' self-care disability are largely explained by prevalent geriatric syndromes. After adjusting for resident characteristics, there is little variation in self-care disability associated with long-term care home characteristics. This suggests that residents' geriatric syndromes-not the homes in which they live-may be the appropriate target of interventions to reduce self-care disability, and that such interventions may need to differ for cognitively impaired versus unimpaired residents.

The Army Family Research Program: Program Development Increment Package Defense Information and General Officer Steering Committee Materials

DTIC Science & Technology

1990-08-01

If you want more, call us.] IBI. 6% of enlisted personnel and 5% of officers are riiarried to another soldier. This varies by sex and pay grade. For...societal openness about sex and accessibility pregnancy-related rates for teenagers. The Only one measure of sex education-the of contraceptive services...headed households correlates positively receiving sex educalion--proved signifi- betveen countries in explaining variation ir with abortion and pr

Gender differences in sexual risk and sexually transmitted infections correlate with gender differences in social networks among San Francisco homeless youth.

PubMed

Valente, Annie M; Auerswald, Colette L

2013-10-01

To explore whether gender differences in sexual risk and sexually transmitted infections (STIs) among homeless youth may be explained in part by gender differences in their social networks. Our sample includes 258 youth (64% male) recruited in San Francisco from street venues and transitional programs. Participants completed an audio computer-administered self-interview survey regarding their housing status and risk behaviors and an interviewer-administered survey regarding their social networks, and were tested for STIs (chlamydia and gonorrhea). We examined relationships between sexual risk and STI rates and social network characteristics by gender. Condom use was lower in young women than in young men, whereas young women were more likely to have an injection drug user (IDU) sex partner and to be diagnosed with an STI. Homeless young men were more likely to have stably housed contacts and same-sex friendships in their social networks than were young women. Stably housed network contacts were associated with increased condom use and decreased STI prevalence in young men. Same-sex friends were associated with increased condom use in young women. No young woman with a family member in her network had an IDU sex partner. Having a network member who had been recently incarcerated was associated with having an IDU sex partner for young women. Homeless young women's networks may place them at greater risk for STIs than young men. Increasing mainstream contacts and same-gender friendships may protect all homeless youth from STIs. Interventions addressing homeless young women's social networks may decrease their gender-disparate STI risk. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Breed, sex, and litter effects in 2-month old puppies' behaviour in a standardised open-field test.

PubMed

Barnard, Shanis; Marshall-Pescini, Sarah; Pelosi, Annalisa; Passalacqua, Chiara; Prato-Previde, Emanuela; Valsecchi, Paola

2017-05-11

A considerable number of studies have reported differences among dog breeds with respect to their genetic profile, cognitive abilities or personality traits. Each dog breed is normally treated as a homogeneous group, however, researchers have recently questioned whether the behavioural profile of modern breeds still reflects their historical function or if the intense divergent selective pressures and geographical barriers have created a more fragmented picture. The majority of studies attempting to assess and compare modern breeds' personality focused on the evaluation of adult dogs where the potential effects of environmental/human factors on the dogs' behaviour are hard to discern from their genetic heritage. In the following study, we aimed at investigating between- and within-breed differences in the personality of two-months-old puppies by direct behavioural observation of 377 puppies from 12 breeds. Results showed that there was no effect of sex, however both breed and litter, significantly affected all personality traits. Breed on average explained 10% of the variance, whereas the effect of litter was noticeably higher, explaining on average 23% of the variance. Taken together, our results suggest that breed does have some influence on personality traits, but they also highlight the importance of taking litter effects into account.

Females roam while males patrol: divergence in breeding season movements of pack-ice polar bears (Ursus maritimus).

PubMed

Laidre, Kristin L; Born, Erik W; Gurarie, Eliezer; Wiig, Øystein; Dietz, Rune; Stern, Harry

2013-02-07

Intraspecific differences in movement behaviour reflect different tactics used by individuals or sexes to favour strategies that maximize fitness. We report movement data collected from n = 23 adult male polar bears with novel ear-attached transmitters in two separate pack ice subpopulations over five breeding seasons. We compared movements with n = 26 concurrently tagged adult females, and analysed velocities, movement tortuosity, range sizes and habitat selection with respect to sex, reproductive status and body mass. There were no differences in 4-day displacements or sea ice habitat selection for sex or population. By contrast, adult females in all years and both populations had significantly more linear movements and significantly larger breeding range sizes than males. We hypothesized that differences were related to encounter rates, and used observed movement metrics to parametrize a simulation model of male-male and male-female encounter. The simulation showed that the more tortuous movement of males leads to significantly longer times to male-male encounter, while having little impact on male-female encounter. By contrast, linear movements of females are consistent with a prioritized search for sparsely distributed prey. These results suggest a possible mechanism for explaining the smaller breeding range sizes of some solitary male carnivores compared to females.

Sex-based memory advantages and cognitive aging: a challenge to the cognitive reserve construct?

PubMed

Caselli, Richard J; Dueck, Amylou C; Locke, Dona E C; Baxter, Leslie C; Woodruff, Bryan K; Geda, Yonas E

2015-02-01

Education and related proxies for cognitive reserve (CR) are confounded by associations with environmental factors that correlate with cerebrovascular disease possibly explaining discrepancies between studies examining their relationships to cognitive aging and dementia. In contrast, sex-related memory differences may be a better proxy. Since they arise developmentally, they are less likely to reflect environmental confounds. Women outperform men on verbal and men generally outperform women on visuospatial memory tasks. Furthermore, memory declines during the preclinical stage of AD, when it is clinically indistinguishable from normal aging. To determine whether CR mitigates age-related memory decline, we examined the effects of gender and APOE genotype on longitudinal memory performances. Memory decline was assessed in a cohort of healthy men and women enriched for APOE ɛ4 who completed two verbal [Rey Auditory Verbal Learning Test (AVLT), Buschke Selective Reminding Test (SRT)] and two visuospatial [Rey-Osterrieth Complex Figure Test (CFT), and Benton Visual Retention Test (VRT)] memory tests, as well as in a separate larger and older cohort [National Alzheimer's Coordinating Center (NACC)] who completed a verbal memory test (Logical Memory). Age-related memory decline was accelerated in APOE ɛ4 carriers on all verbal memory measures (AVLT, p=.03; SRT p<.001; logical memory p<.001) and on the VRT p=.006. Baseline sex associated differences were retained over time, but no sex differences in rate of decline were found for any measure in either cohort. Sex-based memory advantage does not mitigate age-related memory decline in either APOE ɛ4 carriers or non-carriers.

Gender differences in patients with heart failure.

PubMed

Strömberg, Anna; Mårtensson, Jan

2003-04-01

The aim of this literature review was to review and discuss the differences between men and women with heart failure with regard to epidemiology, aetiology, diagnostics, prognosis, pharmacological and non-pharmacological treatment, and the impact of heart failure on psychosocial factors and healthcare utilisation. Two primary health care resources, MEDLINE and CINAHL, were selected to review the current literature. In MEDLINE, 234 abstracts dealing with heart failure and gender/sex were found and in CINAHL, 20 abstracts. Men have a higher incidence of heart failure, but the overall prevalence rate is similar in both sexes, since women survive longer after the onset of heart failure. Women tend to be older when diagnosed with heart failure and more often have diastolic dysfunction than men. The extent of sex differences in treatment, hospital cost and quality of care can partly be explained by age differences. The life situations for men and women with heart failure are different. Physical and social restrictions affecting daily life activities are experienced as most bothersome for men, whereas restrictions affecting the possibility to support family and friends are most difficult to accept for women. Women with heart failure ascribe more positive meanings to their illness. Despite this, women seem to experience a lower overall quality of life than men. The known gender differences in patients with heart failure need to be highlighted in guidelines as well as implemented in standard care.

Using signals associated with safety in avoidance learning: computational model of sex differences

PubMed Central

Beck, Kevin D.; Pang, Kevin C.H.; Myers, Catherine E.

2015-01-01

Avoidance behavior involves learning responses that prevent upcoming aversive events; these responses typically extinguish when the aversive events stop materializing. Stimuli that signal safety from aversive events can paradoxically inhibit extinction of avoidance behavior. In animals, males and females process safety signals differently. These differences help explain why women are more likely to be diagnosed with an anxiety disorder and exhibit differences in symptom presentation and course compared to men. In the current study, we extend an existing model of strain differences in avoidance behavior to simulate sex differences in rats. The model successfully replicates data showing that the omission of a signal associated with a period of safety can facilitate extinction in females, but not males, and makes novel predictions that this effect should depend on the duration of the period, the duration of the signal itself, and its occurrence within that period. Non-reinforced responses during the safe period were also found to be important in the expression of these patterns. The model also allowed us to explore underlying mechanisms for the observed sex effects, such as whether safety signals serve as occasion setters for aversive events, to determine why removing them can facilitate extinction of avoidance. The simulation results argue against this account, and instead suggest the signal may serve as a conditioned reinforcer of avoidance behavior. PMID:26213650

Epigenetics of sex determination and gonadogenesis.

PubMed

Piferrer, Francesc

2013-04-01

Epigenetics is commonly defined as the study of heritable changes in gene function that cannot be explained by changes in DNA sequence. The three major epigenetic mechanisms for gene expression regulation include DNA methylation, histone modifications, and non-coding RNAs. Epigenetic mechanisms provide organisms with the ability to integrate genomic and environmental information to modify the activity of their genes for generating a particular phenotype. During development, cells differentiate, acquire, and maintain identity through changes in gene expression. This is crucial for sex determination and differentiation, which are among the most important developmental processes for the proper functioning and perpetuation of species. This review summarizes studies showing how epigenetic regulatory mechanisms contribute to sex determination and reproductive organ formation in plants, invertebrates, and vertebrates. Further progress will be made by integrating several approaches, including genomics and Next Generation Sequencing to create epigenetic maps related to different aspects of sex determination and gonadogenesis. Epigenetics will also contribute to understand the etiology of several disorders of sexual development. It also might play a significant role in the control of reproduction in animal farm production and will aid in recognizing the environmental versus genetic influences on sex determination of sensitive species in a global change scenario. Copyright © 2013 Wiley Periodicals, Inc.

How sex and age affect immune responses, susceptibility to infections, and response to vaccination

PubMed Central

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

Factors influencing soft tissue profile changes following orthodontic treatment in patients with Class II Division 1 malocclusion.

PubMed

Maetevorakul, Suhatcha; Viteporn, Smorntree

2016-01-01

Several studies have shown soft tissue profile changes after orthodontic treatment in Class II Division 1 patients. However, a few studies have described factors influencing the soft tissue changes. The purpose of this study was to investigate the factors influencing the soft tissue profile changes following orthodontic treatment in Class II Division 1 patients. The subjects comprised 104 Thai patients age 8-16 years who presented Class II Division 1 malocclusions and were treated with different orthodontic modalities comprising cervical headgear, Class II traction and extraction of the four first premolars. The profile changes were evaluated from the lateral cephalograms before and after treatment by means of the X-Y coordinate system. Significant soft tissue profile changes were evaluated by paired t test at a 0.05 significance level. The correlations among significant soft tissue changes and independent variables comprising treatment modality, age, sex, pretreatment skeletal, dental and soft tissue morphology were evaluated by stepwise multiple regression analysis at a 0.05 significance level. The multiple regression analysis indicated that different treatment modalities, age, sex, pretreatment skeletal, dental and soft tissue morphology were related to the profile changes. The predictive power of these variables on the soft tissue profile changes ranged from 9.9 to 40.3%. Prediction of the soft tissue profile changes following treatment of Class II Division 1 malocclusion from initial patient morphology, age, sex and types of treatment was complicated and required several variables to explain their variations. Upper lip change in horizontal direction could be found only at the stomion superius and was less predictable than those of the lower lip. Variations in upper lip retraction at the stomion superius were explained by types of treatment (R(2) = 0.099), whereas protrusion of the lower lip at the labrale inferius was correlated with initial inclination of the lower incisor (L1 to NB), jaw relation (ANB angle), lower lip thickness and sex (R(2) = 0.403). Prediction of chin protrusion at the soft tissue pogonion was also low predictable (R(2) = 0.190) depending upon sex, age and initial mandibular plane angle (SN-GoGn). Additionally, age and sex also had mainly effect on change of the soft tissue profile in the vertical direction.

COHORT EFFECTS OF SUICIDE MORTALITY ARE SEX SPECIFIC IN THE RAPIDLY DEVELOPED HONG KONG CHINESE POPULATION, 1976-2010.

PubMed

Chung, Roger Y; Yip, Benjamin H K; Chan, Sandra S M; Wong, Samuel Y S

2016-06-01

To examine temporal variations of age, period, and cohort on suicide mortality rate in Hong Kong (HK) from 1976 to 2010, and speculate the macroenvironmental mechanisms of the observed trends. Poisson age-period-cohort modeling was used to delineate the effects of age, period, and cohort on suicide mortality. Analysis by sex was also conducted to examine if gender difference exists for suicidal behaviours. Age-cohort model provides the best fit to the mortality data, implying that the cohort effect is likely to explain more of the contributions to HK's suicide mortality pattern than the period effect. Risk of suicide mortality increases nonlinearly with age and accelerates after age 65-69 for both sexes. Moreover, the cohort effects differ between the sexes-risk of mortality increases continually for men born after 1961, but no change is observed for women since the 1941 cohort. With increased risk of suicide mortality in younger cohorts and the age effect of suicide mortality, we may see future increase in suicide mortality as these younger cohorts age. Further studies are needed to clarify plausible associations between broader sociohistorical changes in the population impacting psychological risk factors and suicidal behaviour to better inform suicide prevention strategies. © 2015 Wiley Periodicals, Inc.

Higher risk of incident hepatitis C virus among young women who inject drugs compared with young men in association with sexual relationships: a prospective analysis from the UFO Study cohort.

PubMed

Tracy, Daniel; Hahn, Judith A; Fuller Lewis, Crystal; Evans, Jennifer; Briceño, Alya; Morris, Meghan D; Lum, Paula J; Page, Kimberly

2014-05-29

Female injection drug users (IDUs) may report differences in injection behaviours that put them at greater risk for hepatitis C virus (HCV). Few studies have examined these in association with HCV incidence. Longitudinal data from a cohort of 417 HCV-uninfected IDU aged 30 or younger were analysed. Cox proportional hazards was used to model female sex as a predictor of new HCV infection. General estimating equation (GEE) analysis was used to model female sex as a predictor of HCV-associated risk behaviour prospectively. Women were significantly more likely than men to become infected with HCV during study follow-up (HR 1.4, p<0.05), and were also more likely than men to report high-risk injecting behaviours, especially in the context of sexual and injecting relationships. Sex differences in injecting behaviours appeared to explain the relationship between sex and HCV infection. Young women's riskier injection practices lead to their higher rates of HCV infection. Further study on the impact of intimate partnership on women's risk behaviour is warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

HABITAT-SPECIFIC FORAGING AND SEX DETERMINE MERCURY CONCENTRATIONS IN SYMPATRIC BENTHIC AND LIMNETIC ECOTYPES OF THE THREESPINE STICKLEBACK

PubMed Central

Willacker, James J.; Von Hippel, Frank A.; Ackerly, Kerri L.; O’Hara, Todd M.

2013-01-01

Mercury (Hg) is a widespread environmental contaminant known for the neurotoxicity of its methylated forms, especially monomethylmercury, which bioaccumulates and biomagnifies in aquatic food webs. Mercury bioaccumulation and biomagnification rates are known to vary among species utilizing different food webs (benthic vs limnetic) within and between systems. The authors assessed whether carbon and nitrogen stable isotope values and total Hg (THg) concentrations differed between sympatric benthic and limnetic ecotypes and sexes of threespine stickleback fish (Gasterosteus aculeatus) from Benka Lake, Alaska, USA. The mean THg concentration in the limnetic ecotype was significantly higher (26 mg/kg dry wt, 16.1%) than that of the benthic ecotype. Trophic position and benthic carbon percentage utilized were both important determinants of THg concentration; however, the 2 variables were of approximately equal importance in females, whereas trophic position clearly explained more of the variance than benthic carbon percentage in males. Additionally, strong sex effects (45 mg/kg dry wt, 29.4%) were observed in both ecotypes, with female fish having lower THg concentrations than males. These results indicate that trophic ecology and sex are both important determinants of Hg contamination even within a single species and lake and likely play a role in governing Hg concentrations in higher trophic levels. PMID:23456641

The Effects of Gender Differences in Patients with Depression on Their Emotional Working Memory and Emotional Experience

PubMed Central

Li, Mi; Lu, Shengfu; Wang, Gang; Zhong, Ning

2015-01-01

A large amount of research has been conducted on the effects of sex hormones on gender differences in patients with depression, yet research on cognitive differences between male and female patients with depression is insufficient. This study uses emotion pictures to investigate the differences of the emotional working memory ability and emotional experience in male and female patients with depression. Despite identifying that the working memory of patients with depression is impaired, our study found no significant gender differences in emotional working memory. Moreover, the research results revealed that memory effects of mood congruence are produced in both men and women, which may explain why the depression state can be maintained. Furthermore, female patients have more emotional experiences than male patients, which is particularly significant in terms of negative emotional experiences. This result provides cognitive evidence to explain why women suffer from longer terms of depression, are more susceptible to relapse, and can more easily suffer from major depressive disorder in the future. PMID:26578820

Higher skeletal muscle α2AMPK activation and lower energy charge and fat oxidation in men than in women during submaximal exercise

PubMed Central

Roepstorff, Carsten; Thiele, Maja; Hillig, Thore; Pilegaard, Henriette; Richter, Erik A; Wojtaszewski, Jørgen F P; Kiens, Bente

2006-01-01

5′AMP-activated protein kinase (AMPK) is an energy sensor activated by perturbed cellular energy status such as during muscle contraction. Activated AMPK is thought to regulate several key metabolic pathways. We used sex comparison to investigate whether AMPK signalling in skeletal muscle regulates fat oxidation during exercise. Moderately trained women and men completed 90 min bicycle exercise at 60% V̇O2peak. Both AMPK Thr172 phosphorylation and α2AMPK activity were increased by exercise in men (∼200%, P < 0.001) but not significantly in women. The sex difference in muscle AMPK activation with exercise was accompanied by an increase in muscle free AMP (∼164%, P < 0.01), free AMP/ATP ratio (159%, P < 0.05), and creatine (∼42%, P < 0.001) in men but not in women (NS), suggesting that lack of AMPK activation in women was due to better maintenance of muscle cellular energy balance compared with men. During exercise, fat oxidation per kg lean body mass was higher in women than in men (P < 0.05). Regression analysis revealed that a higher proportion of type 1 muscle fibres (∼23%, P < 0.01) and a higher capillarization (∼23%, P < 0.05) in women than in men could partly explain the sex difference in α2AMPK activity (r = −0.54, P < 0.05) and fat oxidation (r = 0.64, P < 0.05) during exercise. On the other hand, fat oxidation appeared not to be regulated via AMPK. In conclusion, during prolonged submaximal exercise at 60% V̇O2peak, higher fat oxidation in women cannot be explained by higher AMPK signalling but is accompanied by improved muscle cellular energy balance in women probably due to sex specific muscle morphology. PMID:16600998

The distribution of pain activity across the human neonatal brain is sex dependent.

PubMed

Verriotis, Madeleine; Jones, Laura; Whitehead, Kimberley; Laudiano-Dray, Maria; Panayotidis, Ismini; Patel, Hemani; Meek, Judith; Fabrizi, Lorenzo; Fitzgerald, Maria

2018-05-12

In adults, there are differences between male and female structural and functional brain connectivity, specifically for those regions involved in pain processing. This may partly explain the observed sex differences in pain sensitivity, tolerance, and inhibitory control, and in the development of chronic pain. However, it is not known if these differences exist from birth. Cortical activity in response to a painful stimulus can be observed in the human neonatal brain, but this nociceptive activity continues to develop in the postnatal period and is qualitatively different from that of adults, partly due to the considerable cortical maturation during this time. This research aimed to investigate the effects of sex and prematurity on the magnitude and spatial distribution pattern of the long-latency nociceptive event-related potential (nERP) using electroencephalography (EEG). We measured the cortical response time-locked to a clinically required heel lance in 81 neonates born between 29 and 42 weeks gestational age (median postnatal age 4 days). The results show that heel lance results in a spatially widespread nERP response in the majority of newborns. Importantly, a widespread pattern is significantly more likely to occur in females, irrespective of gestational age at birth. This effect is not observed for the short latency somatosensory waveform in the same infants, indicating that it is selective for the nociceptive component of the response. These results suggest the early onset of a greater anatomical and functional connectivity reported in the adult female brain, and indicate the presence of pain-related sex differences from birth. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Mechanical Contributions of the Cortical and Trabecular Compartments Contribute to Differences in Age-Related Changes in Vertebral Body Strength in Men and Women Assessed by QCT-Based Finite Element Analysis

PubMed Central

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

An Underlying Common Factor, Influenced by Genetics and Unique Environment, Explains the Covariation Between Major Depressive Disorder, Generalized Anxiety Disorder, and Burnout: A Swedish Twin Study.

PubMed

Mather, Lisa; Blom, Victoria; Bergström, Gunnar; Svedberg, Pia

2016-12-01

Depression and anxiety are highly comorbid due to shared genetic risk factors, but less is known about whether burnout shares these risk factors. We aimed to examine whether the covariation between major depressive disorder (MDD), generalized anxiety disorder (GAD), and burnout is explained by common genetic and/or environmental factors. This cross-sectional study included 25,378 Swedish twins responding to a survey in 2005-2006. Structural equation models were used to analyze whether the trait variances and covariances were due to additive genetics, non-additive genetics, shared environment, and unique environment. Univariate analyses tested sex limitation models and multivariate analysis tested Cholesky, independent pathway, and common pathway models. The phenotypic correlations were 0.71 (0.69-0.74) between MDD and GAD, 0.58 (0.56-0.60) between MDD and burnout, and 0.53 (0.50-0.56) between GAD and burnout. Heritabilities were 45% for MDD, 49% for GAD, and 38% for burnout; no statistically significant sex differences were found. A common pathway model was chosen as the final model. The common factor was influenced by genetics (58%) and unique environment (42%), and explained 77% of the variation in MDD, 69% in GAD, and 44% in burnout. GAD and burnout had additive genetic factors unique to the phenotypes (11% each), while MDD did not. Unique environment explained 23% of the variability in MDD, 20% in GAD, and 45% in burnout. In conclusion, the covariation was explained by an underlying common factor, largely influenced by genetics. Burnout was to a large degree influenced by unique environmental factors not shared with MDD and GAD.

Sex differences in mortality following acute coronary syndromes.

PubMed

Berger, Jeffrey S; Elliott, Laine; Gallup, Dianne; Roe, Matthew; Granger, Christopher B; Armstrong, Paul W; Simes, R John; White, Harvey D; Van de Werf, Frans; Topol, Eric J; Hochman, Judith S; Newby, L Kristin; Harrington, Robert A; Califf, Robert M; Becker, Richard C; Douglas, Pamela S

2009-08-26

Conflicting information exists about whether sex differences modulate short-term mortality following acute coronary syndromes (ACS). To investigate the relationship between sex and 30-day mortality in ACS, and to determine whether this relationship was modified by clinical syndrome or coronary anatomy using a large database across the spectrum of ACS and adjusting for potentially confounding clinical covariates. A convenience sample of patients pooled from 11 independent, international, randomized ACS clinical trials between 1993 and 2006 whose databases are maintained at the Duke Clinical Research Institute, Durham, North Carolina. Of 136 247 patients, 38 048 (28%) were women; 102 004 (26% women) with ST-segment elevation myocardial infarction (STEMI), 14 466 (29% women) with non-STEMI (NSTEMI), and 19 777 (40% women) with unstable angina. Thirty-day mortality following ACS. Thirty-day mortality was 9.6% in women and 5.3% in men (odds ratio [OR], 1.91; 95% confidence interval [CI], 1.83-2.00). After multivariable adjustment, mortality was not significantly different between women and men (adjusted OR, 1.06; 95% CI, 0.99-1.15). A significant sex by type of ACS interaction was demonstrated (P < .001). In STEMI, 30-day mortality was higher among women (adjusted OR, 1.15; 95% CI, 1.06-1.24), whereas in NSTEMI (adjusted OR, 0.77; 95% CI, 0.63-0.95) and unstable angina, mortality was lower among women (adjusted OR, 0.55; 95% CI, 0.43-0.70). In a cohort of 35 128 patients with angiographic data, women more often had nonobstructive (15% vs 8%) and less often had 2-vessel (25% vs 28%) and 3-vessel (23% vs 26%) coronary disease, regardless of ACS type. After additional adjustment for angiographic disease severity, 30-day mortality among women was not significantly different than men, regardless of ACS type. The relationship between sex and 30-day mortality was similar across the levels of angiographic disease severity (P for interaction = .70). Sex-based differences existed in 30-day mortality among patients with ACS and vary depending on clinical presentation. However, these differences appear to be largely explained by clinical differences at presentation and severity of angiographically documented disease.

Genetic and environmental influences on growth from late childhood to adulthood: a longitudinal study of two Finnish twin cohorts.

PubMed

Jelenkovic, Aline; Ortega-Alonso, Alfredo; Rose, Richard J; Kaprio, Jaakko; Rebato, Esther; Silventoinen, Karri

2011-01-01

Human growth is a complex process that remains insufficiently understood. We aimed to analyze genetic and environmental influences on growth from late childhood to early adulthood. Two cohorts of monozygotic and dizygotic (same sex and opposite sex) Finnish twin pairs were studied longitudinally using self-reported height at 11-12, 14, and 17 years and adult age (FinnTwin12) and at 16, 17, and 18 years and adult age (FinnTwin16). Univariate and multivariate variance component models for twin data were used. From childhood to adulthood, genetic differences explained 72-81% of the variation of height in boys and 65-86% in girls. Environmental factors common to co-twins explained 5-23% of the variation of height, with the residual variation explained by environmental factors unique to each twin individual. Common environmental factors affecting height were highly correlated between the analyzed ages (0.72-0.99 and 0.91-1.00 for boys and girls, respectively). Genetic (0.58-0.99 and 0.70-0.99, respectively) and unique environmental factors (0.32-0.78 and 0.54-0.82, respectively) affecting height at different ages were more weakly, but still substantially, correlated. The genetic contribution to height is strong during adolescence. The high genetic correlations detected across the ages encourage further efforts to identify genes affecting growth. Common and unique environmental factors affecting height during adolescence are also important, and further studies are necessary to identify their nature and test whether they interact with genetic factors. Copyright © 2011 Wiley-Liss, Inc.

Parent-of-origin Effect in Schizophrenia and Non-affective Psychoses: Evidence from Dermatoglyphics

PubMed Central

Divakaran, Anjith; Narayanaswamy, Janardhanan C.; Kalmadi, Sunil V.; Narayan, Vidya; Rao, Naren P.; Venkatasubramanian, Ganesan

2013-01-01

Objective: This study aims at examining “parent-of-origin effect” (POE) in dermatoglyphic patterns among patients with schizophrenia and non-affective psychoses. Materials and Methods: Dermatoglyphic comparison was carried out for schizophrenia patients (n=200) and healthy controls (HC) (n=100). In addition, the effect of family history and POE was examined in the dermatoglyphic pattern. Results: Schizophrenia patients compared to HC had significantly lower left total finger ridge count (LTFRC) (t=3.63, P<0.001), right total finger ridge count (RTFRC) (t=4.86, P<0.001), and absolute finger ridge count (ATFRC) (t=4.80, P<0.001) compared to HC. It was also noted that patient group had significantly higher average number of arches (t=2.20, P=0.03). The comparison between the same sex POE group and the opposite sex POE group revealed that significant differences exist in LTFRC (t=2.91, P<0.01) and ATFRC (t=2.30, P=0.02). The same sex group also had lesser number of whorls compared to opposite sex group (t=2.04, P=0.04). Conclusions: The same sex parental inheritance group seem to be more developmentally compromised than the opposite sex parental inheritance group indicating a significant POE. Complex epigenetic mechanisms along with hormonal modulation could explain the sex specific disease phenotype expression, which is a plausible explanation as in the present study. PMID:24249928

Parent-of-origin Effect in Schizophrenia and Non-affective Psychoses: Evidence from Dermatoglyphics.

PubMed

Divakaran, Anjith; Narayanaswamy, Janardhanan C; Kalmadi, Sunil V; Narayan, Vidya; Rao, Naren P; Venkatasubramanian, Ganesan

2013-07-01

This study aims at examining "parent-of-origin effect" (POE) in dermatoglyphic patterns among patients with schizophrenia and non-affective psychoses. Dermatoglyphic comparison was carried out for schizophrenia patients (n=200) and healthy controls (HC) (n=100). In addition, the effect of family history and POE was examined in the dermatoglyphic pattern. Schizophrenia patients compared to HC had significantly lower left total finger ridge count (LTFRC) (t=3.63, P<0.001), right total finger ridge count (RTFRC) (t=4.86, P<0.001), and absolute finger ridge count (ATFRC) (t=4.80, P<0.001) compared to HC. It was also noted that patient group had significantly higher average number of arches (t=2.20, P=0.03). The comparison between the same sex POE group and the opposite sex POE group revealed that significant differences exist in LTFRC (t=2.91, P<0.01) and ATFRC (t=2.30, P=0.02). The same sex group also had lesser number of whorls compared to opposite sex group (t=2.04, P=0.04). The same sex parental inheritance group seem to be more developmentally compromised than the opposite sex parental inheritance group indicating a significant POE. Complex epigenetic mechanisms along with hormonal modulation could explain the sex specific disease phenotype expression, which is a plausible explanation as in the present study.

Hypothalamic-pituitary-adrenal axis response to acute psychosocial stress: Effects of biological sex and circulating sex hormones

PubMed Central

Stephens, Mary Ann C.; Mahon, Pamela B.; McCaul, Mary E.; Wand, Gary S.

2016-01-01

Summary Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis influences the risk for developing stress-related disorders. Sex-dependent differences in the HPA axis stress response are believed to contribute to the different prevalence rates of stress-related disorders found in men and women. However, studies examining the HPA axis stress response have shown mixed support for sex differences, and the role of endogenous sex hormones on HPA axis response has not been adequately examined in humans. This study utilized the largest sample size to date to analyze the effects of biological sex and sex hormones on HPA axis social stress responses. Healthy, 18- to 30- year-old community volunteers (N=282) completed the Trier Social Stress Test (TSST), a widely used and well-validated stress-induction laboratory procedure. All women (n=135) were tested during the follicular phase of their menstrual cycle (when progesterone levels are most similar to men). Adrenocorticotropic hormone (ACTH) and cortisol measures were collected at multiple points throughout pre- and post-TSST. Testosterone and progesterone (in men) and progesterone and estradiol (in women) were determined pre-TSST. Following the TSST, men had greater ACTH and cortisol levels than women. Men had steeper baseline-to-peak and peak-to-end ACTH and cortisol response slopes than women; there was a trend for more cortisol responders among men than women. Testosterone negatively correlated with salivary cortisol response in men, while progesterone negatively correlated with ACTH and cortisol responses in women. These data confirm that men show more robust activation of the HPA axis response to the TSST than do women in the follicular phase of the menstrual cycle. Testosterone results suggest an inhibitory effect on HPA axis reactivity in men. Progesterone results suggest an inhibitory effect on HPA axis reactivity in women. Future work is needed to explain why men mount a greater ACTH and cortisol response to the TSST than do women during the follicular phase of the menstrual cycle. PMID:26773400

Flower development and sex specification in wild grapevine.

PubMed

Ramos, Miguel Jesus Nunes; Coito, João Lucas; Silva, Helena Gomes; Cunha, Jorge; Costa, Maria Manuela Ribeiro; Rocheta, Margarida

2014-12-12

Wild plants of Vitis closely related to the cultivated grapevine (V. v. vinifera) are believed to have been first domesticated 10,000 years BC around the Caspian Sea. V. v. vinifera is hermaphrodite whereas V. v. sylvestris is a dioecious species. Male flowers show a reduced pistil without style or stigma and female flowers present reflexed stamens with infertile pollen. V. vinifera produce perfect flowers with all functional structures. The mechanism for flower sex determination and specification in grapevine is still unknown. To understand which genes are involved during the establishment of male, female and complete flowers, we analysed and compared the transcription profiles of four developmental stages of the three genders. We showed that sex determination is a late event during flower development and that the expression of genes from the ABCDE model is not directly correlated with the establishment of sexual dimorphism. We propose a temporal comprehensive model in which two mutations in two linked genes could be players in sex determination and indirectly establish the Vitis domestication process. Additionally, we also found clusters of genes differentially expressed between genders and between developmental stages that suggest a role involved in sex differentiation. Also, the detection of differentially transcribed regions that extended existing gene models (intergenic regions) between sexes suggests that they may account for some of the variation between the subspecies. There is no evidence of differences of expression levels in genes from the ABCDE model that could explain the shift from hermaphroditism to dioecy. We propose that sex specification occurs after floral organ identity has been established and therefore, sex determination genes might be having an effect downstream of the ABCDE model genes.For the first time a full transcriptomic analysis was performed in different flower developmental stages in the same individual. Our experimental approach enabled us to create a comprehensive catalogue of transcribed genes across developmental stages and genders that will contribute for future work in sex determination in seed plants.

Integrating the dimensions of sex and gender into basic life sciences research: methodologic and ethical issues.

PubMed

Holdcroft, Anita

2007-01-01

The research process -- from study design and selecting a species and its husbandry, through the experiment, analysis, peer review, and publication -- is rarely subject to questions about sex or gender differences in mainstream life sciences research. However, the impact of sex and gender on these processes is important in explaining biological variations and presentation of symptoms and diseases. This review aims to challenge assumptions and to develop opportunities to mainstream sex and gender in basic scientific research. Questions about the mechanisms of sex and gender effects were reviewed in relation to biological, environmental, social, and psychological interactions. Gender variations, in respect to aging, socializing, and reproduction, that are present in human populations but are rarely featured in laboratory research were considered to more effectively translate animal research into clinical health care. Methodologic approaches to address the present lack of a gender dimension in research include actively reducing variations through attention to physical factors, biological rhythms, and experimental design. In addition, through genomic and acute nongenomic activity, hormones may compound effects through multiple small sex differences that occur during the course of an acute pathologic event. Furthermore, the many exogenous sex steroid hormones and their congeners used in medicine (eg, in contraception and cancer therapies) may add to these effects. The studies reviewed provide evidence that sex and gender are determinants of many outcomes in life science research. To embed the gender dimension into basic scientific research, a broad approach -- gender mainstreaming -- is warranted. One example is the use of review boards (eg, animal ethical review boards and journal peer-review boards) in which gender-related standardized questions can be asked about study design and analysis. A more fundamental approach is to question the relevance of present-day laboratory models to design methods to best represent the age-related changes, comorbidity, and variations experienced by each sex in clinical medicine.

Condom use among Swedes while traveling internationally: A qualitative descriptive study.

PubMed

Lejelind, Eva; Westerling, Ragnar; Sjögren Fugl-Meyer, Kerstin; Larsson, Kjerstin

2017-06-01

This study explores factors influencing condom use among Swedish women and men who visited a sexual health clinic after unprotected sex during international travel. Semi-structured interviews were conducted with 25 women and 25 men. The data were analyzed using conventional content analysis. The informants' narratives were categorized as strategies and barriers. Strategies found were: risk assessment, testing, and treatment for sexually transmitted infections. The barriers were characterized as technical and personal or emotional. The findings indicate that sexual behavior may be different while traveling internationally, and that a release of social constraints and increased alcohol consumption were risk factors for practicing unprotected sex. Some of the strategies may be appropriate for the prevention of sexually transmitted infections, but several strategies and most barriers were used to explain why unprotected sex was practiced. Thus, people need the opportunity to reconsider strategies and strengthen confidence in their ability to use condoms. An individual-based approach employed within routine health care may support the practice of safer sex and prevent further transmission of sexually transmitted infections. © 2017 John Wiley & Sons Australia, Ltd.

Sex differences in episodic memory: the impact of verbal and visuospatial ability.

PubMed

Herlitz, A; Airaksinen, E; Nordström, E

1999-10-01

The impact of verbal and visuospatial ability on sex differences in episodic memory was investigated. One hundred men and 100 women, 2040 years old, participated in a series of verbal and visuospatial tasks. Episodic memory was assessed in tasks that, to a greater or lesser extent, were verbal or visuospatial in nature. Results showed that women excelled in verbal production tasks and that men performed at a superior level on a mental rotation task. In addition, women tended to perform at a higher level than men on most episodic memory tasks. Taken together, the results demonstrated that (a) women perform at a higher level than men on most verbal episodic memory tasks and on some episodic memory tasks with a visuospatial component, and (b) women's higher performance on episodic memory tasks cannot fully be explained by their superior performance on verbal production tasks.

SATISFACTION WITH LIFE AMONG YOUNG ADULTS IN FOUR ARAB COUNTRIES.

PubMed

Abdel-Khalek, Ahmed M; El Nayal, Mayssah A

2015-12-01

This study sought to explore the sex and cultural differences in satisfaction with life between undergraduate men and women recruited from four Arab countries, i.e., Egypt, Kuwait, Lebanon, and Qatar (N = 1,322); ages ranged from 18 to 27 years. The participants responded to the Arabic version of the Satisfaction with Life Scale. Egyptian and Lebanese women obtained significantly higher mean scores on satisfaction with life than did their male counterparts, whereas there were no significant sex differences in the Kuwaiti and Qatari samples. For men, the Qatari and Kuwaiti samples obtained the high mean scores on satisfaction with life, whereas the Egyptian and Lebanese samples obtained the low mean scores. For women, the Qatari sample had the higher mean score, whereas the Egyptian sample obtained the lowest mean score. The results were explained in light of the positive association between gross domestic product and satisfaction with life.

Sexual Dimorphism and Sexual Selection: A Unified Economic Analysis1

PubMed Central

Chu, C. Y. Cyrus; Lee, Ronald D.

2012-01-01

We develop a life history model with two sexes, and study the optimal energy allocation strategy of males and females. We join Darwin and others in suggesting that the origin of sexual dimorphism and sexual selection is the difference between male and female reproduction costs. Due to this assumed cost difference, the resulting Bellman equations of gene dynamics in our two-sex life history model imply a large “energy surplus” on the part of males. This allows the male form to devote energy to the development of some costly male traits that help the males to compete for access to females. These costly male traits are sexually dimorphic. Using this life history model, we are able to explain important features of sexual dimorphism, as well as why males often transfer less to their offspring than do females, and why only females have menopause. PMID:22699007

Variations in Dream Recall Frequency and Dream Theme Diversity by Age and Sex

PubMed Central

Nielsen, Tore

2012-01-01

We assessed dream recall frequency (DRF) and dream theme diversity (DTD) with an internet questionnaire among a cohort of 28,888 male and female participants aged 10–79 years in a cross-sectional design. DRF increased from adolescence (ages 10–19) to early adulthood (20–29) and then decreased again for the next 20 years. The nature of this decrease differed for males and females. For males, it began earlier (30–39), proceeded more gradually, and reached a nadir earlier (40–49) than it did for females. For females, it began later (40–49), dropped more abruptly, and reached nadir later (50–59). Marked sex differences were observed for age strata 10–19 through 40–49 and year-by-year analyses estimated the window for these differences to be more precisely from 14 to 44 years. DTD decreased linearly with age for both sexes up to 50–59 and then dropped even more sharply for 60–79. There was a sex difference favoring males on this measure but only for ages 10–19. Findings replicate, in a single sample, those from several previous studies showing an increase in DRF from adolescence to early adulthood, a subsequent decrease primarily in early and middle adulthood, and different patterns of age-related decrease in the two sexes. Age-related changes in sleep structure, such as decreasing %REM sleep which parallel the observed dream recall changes, might help explain these findings, but these sleep changes are much smaller and more gradual in nature. Changes in the phase and amplitude of circadian rhythms of REM propensity and generational differences in life experiences may also account for some part of the findings. That decreases in DTD parallel known age-related decreases in episodic and autobiographical memory may signify that this new diversity measure indexes an aspect of autobiographical memory that also influences dream recall. PMID:22783222

Can Foraging Ecology Drive the Evolution of Body Size in a Diving Endotherm?

PubMed Central

Cook, Timothée R.; Lescroël, Amélie; Cherel, Yves; Kato, Akiko; Bost, Charles-André

2013-01-01

Within a single animal species, different morphs can allow for differential exploitation of foraging niches between populations, while sexual size dimorphism can provide each sex with access to different resources. Despite being potentially important agents of evolution, resource polymorphisms, and the way they operate in wild populations, remain poorly understood. In this study, we examine how trophic factors can select for different body sizes between populations and sexes in a diving endotherm. Dive depth and duration are positively related to body size in diving birds and mammals, a relationship explained by a lower mass-specific metabolic rate and greater oxygen stores in larger individuals. Based on this allometry, we predict that selection for exploiting resources situated at different depths can drive the evolution of body size in species of diving endotherms at the population and sexual level. To test this prediction, we studied the foraging ecology of Blue-eyed Shags, a group of cormorants with male-biased sexual size dimorphism from across the Southern Ocean. We found that mean body mass and relative difference in body mass between sexes varied by up to 77% and 107% between neighbouring colonies, respectively. Birds from colonies with larger individuals dived deeper than birds from colonies with smaller individuals, when accounting for sex. In parallel, males dived further offshore and deeper than females and the sexual difference in dive depth reflected the level of sexual size dimorphism at each colony. We argue that body size in this group of birds is under intense selection for diving to depths of profitable benthic prey patches and that, locally, sexual niche divergence selection can exaggerate the sexual size dimorphism of Blue-eyed Shags initially set up by sexual selection. Our findings suggest that trophic resources can select for important geographic micro-variability in body size between populations and sexes. PMID:23409169

Age-sex analysis for the diet of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in Shennongjia National Nature Reserve, China.

PubMed

Liu, Xuecong; Li, Fang; Jiang, Jun; Wang, Xiaoju; Li, Yiming

2016-10-01

Age-sex differences in diet have been reported in many nonhuman primates, and body size, reproductive costs, and growth are three mutually non-exclusive factors often proposed to explain such differences. Smaller animals tend to feed on high quality foods (high in protein/energy) more often than larger animals due to their higher metabolic requirements per body weight. Animals of different sizes tend to use different substrate levels, leading to dietary differences if food resources are unevenly distributed along substrate levels. Adult females and juveniles experience additional metabolic requirements for reproduction and growth, respectively, and tend to feed on high quality foods more frequently than adult males. We conducted an age-sex analysis for the diet of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in Shennongjia, China. In spite of general age-sex similarities, we found that adult males ate herbs more frequently than juveniles and adult females, most likely because they were more terrestrial. As predicted, juveniles ate high quality foods (young leaves, fruits, seeds, and buds) more frequently, and meanwhile ate low quality foods (barks and lichens) less frequently than adult males across the study year or in some seasons when these food types were eaten. However, we found high similarities in diet between adult females and adult males. The most likely reason was that the low diversity of food sources and strong phenological synchrony did not allow adult females to select foods based on quality to cope with their higher metabolic constraints compared to adult males. Surprisingly, the only sex difference in diet except herbs was that adult females ate lichens more frequently in autumn. One plausible reason was that lactating females experienced their highest metabolic requirements in the middle period of infant care (autumn), and had to disproportionately increase the intake of lichens due to the limited availability of plant foods.

Can foraging ecology drive the evolution of body size in a diving endotherm?

PubMed

Cook, Timothée R; Lescroël, Amélie; Cherel, Yves; Kato, Akiko; Bost, Charles-André

2013-01-01

Within a single animal species, different morphs can allow for differential exploitation of foraging niches between populations, while sexual size dimorphism can provide each sex with access to different resources. Despite being potentially important agents of evolution, resource polymorphisms, and the way they operate in wild populations, remain poorly understood. In this study, we examine how trophic factors can select for different body sizes between populations and sexes in a diving endotherm. Dive depth and duration are positively related to body size in diving birds and mammals, a relationship explained by a lower mass-specific metabolic rate and greater oxygen stores in larger individuals. Based on this allometry, we predict that selection for exploiting resources situated at different depths can drive the evolution of body size in species of diving endotherms at the population and sexual level. To test this prediction, we studied the foraging ecology of Blue-eyed Shags, a group of cormorants with male-biased sexual size dimorphism from across the Southern Ocean. We found that mean body mass and relative difference in body mass between sexes varied by up to 77% and 107% between neighbouring colonies, respectively. Birds from colonies with larger individuals dived deeper than birds from colonies with smaller individuals, when accounting for sex. In parallel, males dived further offshore and deeper than females and the sexual difference in dive depth reflected the level of sexual size dimorphism at each colony. We argue that body size in this group of birds is under intense selection for diving to depths of profitable benthic prey patches and that, locally, sexual niche divergence selection can exaggerate the sexual size dimorphism of Blue-eyed Shags initially set up by sexual selection. Our findings suggest that trophic resources can select for important geographic micro-variability in body size between populations and sexes.

Lack of sex-related differences in saquinavir pharmacokinetics in an HIV-seronegative cohort

PubMed Central

Robertson, Sarah M; Formentini, Elizabeth; Alfaro, Raul M; Natarajan, Ven; Falloon, Judith; Penzak, Scott R

2006-01-01

Aims To examine the influence of sex on steady-state saquinavir pharmacokinetics in HIV-seronegative volunteers administered saquinavir without a concomitant protease inhibitor. Methods Thirty-eight healthy volunteers (14 female) received saquinavir soft-gel capsules 1200 mg three times daily for 3 days to achieve steady-state conditions. Following administration of the 10th dose, blood was collected serially over 8 h for measurement of saquinavir plasma concentrations. Saquinavir pharmacokinetic parameter values were determined using noncompartmental methods and compared between males and females. CYP3A phenotype (using oral midazolam) and MDR-1 genotypes at positions 3435 and 2677 were determined for all subjects in order to characterize possible mechanisms for any observed sex-related differences. Results There was no significant difference in saquinavir AUC0−8 or any other pharmacokinetic parameter value between the sexes. These findings persisted after mathematically correcting for total body weight. The mean weight-normalized AUC0−8 was 29.9 (95% confidence interval 15.5, 44.3) and 29.8 (18.6, 40.9) ng h−1 ml−1 kg−1 for males and females, respectively. No significant difference in CYP3A phenotype was observed between the groups; likewise, the distribution of MDR-1 genotypes was similar for males and females. Conclusion In contrast to previous study findings, results from this investigation showed no difference in saquinavir pharmacokinetics between males and females. The discrepancy between our findings and those previously reported may be explained by the fact that we evaluated HIV-seronegative volunteers and administered saquinavir in the absence of concomitant protease inhibitors such as ritonavir. Caution must be exercised when extrapolating pharmacokinetic data from healthy volunteer studies (including sex-based pharmacokinetic differences) to HIV-infected populations or to patients receiving additional concurrent medications. PMID:16542198

What Contributes to the (Im)Balanced Division of Family Work Between the Sexes?

PubMed Central

Lothaller, Harald; Mikula, Gerold; Schoebi, Dominik

2011-01-01

This study examines a comprehensive set of variables that have been proposed as explaining the imbalance of the division of family work between the sexes. The analyses use survey data of 735 dual-earner couples from Austria, the Netherlands, and Portugal. The results support theoretical explanations referring to time availability, gender ideology, relative resources, and the importance of characteristics of the family system. No support was obtained for the doing-gender perspective. Additional findings suggest that increased consideration of psychological concepts adds to the understanding of why women do more family work than men. The analyses revealed similarities, but also differences between the factors that contribute to the division of household labor and childcare. PMID:22318972

[The banishment of the marvellous. Hermaphrodites and sexual mutants in Enlightenment Spain].

PubMed

Vásquez, Francisco; Cleminson, Richard

2011-01-01

This article presents a historical synthesis in order to trace how the collective belief in the existence of hermaphrodites and sex-changes was slowly eroded in the changing medical and cultural context of Enlightenment Spain. In order to explain this change, three interlinked processes are outlined. First, the naturalization of the monster and the disappearance of the "marvellous" in Enlightenment science. Second, the consolidation of modern legal or forensic science and the rise of the medical specialist as the relevant authority in the determination of sexual identity. Third, the emergence of the notion of fundamental biological differences between the sexes. The article concludes by discussing the consequences of these shifts for early nineteenth-century Spanish medicine.

Getting back the missing men of Aotearoa: declining gender inequality in NZ life expectancy.

PubMed

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.

Exploring attentional biases towards facial expressions of pain in men and women.

PubMed

Keogh, E; Cheng, F; Wang, S

2018-05-14

Interpersonal factors may help explain why men and women differ in their perception and expression of pain. Whilst the focus is often on the person in pain, how observers respond to those in pain is important. This study explored whether male-female differences exist in the way observers attend to expressions of pain in others. Fifty-three adults (26 females) completed a visual dot-probe task, to measure selective attentional biases to facial expressions of pain and fear. Expression pairs (e.g. pain/neutral) were displayed by either the same male or female actor, and in two different viewing duration conditions: 150 and 1250 ms. Dot-probes appeared in either a congruent or incongruent location to the target expression. No evidence was found for sex-related attentional biases towards pain or fear. However, when examining congruency and incongruency indexes separately, differences emerged. The congruency index analysis indicated that in the 150-ms presentation condition, both men and women were slower during congruent female pain/neutral trials when compared to neutral/neutral trials, and relatively faster at responding during congruent male pain/neutral trials. There is utility in exploring the attentional processes involved in the decoding of pain-related expressions to understand the influence of sex and gender differences in pain. Although male-female differences were found, this was most clearly related to the actor. Our results point to an early attentional mechanism that orients attention away from female expressions of pain. Future consideration of sex- and gender-related contextual factors in attentional processing is warranted. Sex-related factors seem to affect how observers view the pain of others. Our results point to an early attentional mechanism that orients the attention of observers away from female expressions of pain. © 2018 European Pain Federation - EFIC®.

Hierarchical analysis of cardiovascular risk factors in relation to the development of acute coronary syndromes, in different parts of Greece: the CARDIO2000 study.

PubMed

Panagiotakos, Demosthenes B; Pitsavos, Christos; Chrysohoou, Christine; Stefanadis, Christodoulos

2008-01-01

During 2000 to 2002, 700 men (59 +/- 10 years) and 148 women (65 +/- 9 years) patients with first event of an ACS were randomly selected from cardiology clinics of Greek regions. Afterwards, 1078 population-based, age-matched and sex-matched controls were randomly selected from the same hospitals. The frequency ratio between men and women in the case series of patients was about 4:1, in both south and north Greek areas. Hierarchical classification analysis showed that for north Greek areas family history of coronary heart disease, hypercholesterolemia, hypertension, diabetes (explained variability 35%), and less significantly, dietary habits, smoking, body mass index, and physical activity status (explained variability 4%) were associated with the development of ACS, whereas for south Greek areas hypercholesterolemia, family history of coronary heart disease, diabetes, smoking, hypertension, dietary habits, physical activity (explained variability 34%), and less significantly body mass index (explained variability <1%), were associated with the development of the disease.

Are Women's Orgasms Hindered by Phallocentric Imperatives?

PubMed

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.

Sexual dimorphism in obesity-related genes in the epicardial fat during aging.

PubMed

Kocher, Caitlin; Christiansen, Matthew; Martin, Sarah; Adams, Christopher; Wehner, Paulette; Gress, Todd; Santanam, Nalini

2017-05-01

Aging increases the risk of cardiovascular disease and metabolic syndrome. Alterations in epicardial fat play an important pathophysiological role in coronary artery disease and hypertension. We investigated the impact of normal aging on obesity-related genes in epicardial fat. Sex-specific changes in obesity-related genes with aging in epicardial fat (EF) were determined in young (6 months) and old (30/36 months) female and male, Fischer 344 × Brown Norway hybrid (FBN) rats, using a rat obesity RT 2 PCR Array. Circulating sex hormone levels, body and heart weights were determined. Statistical significance was determined using two-tailed Student's t test and Pearson's correlation. Our results revealed sex-specific differences in obesity-related genes with aging. Dramatic changes in the expression profile of obesity-related genes in EF with aging in female, but not in male, FBN rats were observed. The older (30 months) female rats had more significant variations in the abundance of obesity-related genes in the EF compared to that seen in younger female rats or both age groups in male rats. A correlation of changes in obesity-related genes in EF to heart weights was observed in female rats, but not in male rats with aging. No correlation was observed to circulating sex hormone levels. Our findings indicate a dysfunctional EF in female rats with aging compared to male rats. These findings, with further functional validation, might help explain the sex differences in cardiovascular risk and mortality associated with aging observed in humans.

Sex Differences in Reported Adverse Drug Reactions of Selective Serotonin Reuptake Inhibitors.

PubMed

Ekhart, Corine; van Hunsel, Florence; Scholl, Joep; de Vries, Sieta; van Puijenbroek, Eugene

2018-02-26

Several studies have investigated sex as a risk factor for the occurrence of adverse drug reactions (ADRs) and found that women are more likely to experience ADRs than men. The aim of this explorative study was to investigate whether differences exist in reported ADRs of selective serotonin reuptake inhibitors (SSRIs) for men and women in the database of the Netherlands Pharmacovigilance Centre Lareb. A ratio of reports concerning women and men, corrected for the number of users, was calculated for all the ADRs reported on SSRIs. We found that 16 ADRs were statistically significantly more reported in women than men, and four ADRS were reported more in men than women. ADRs more reported in women than men when using SSRIs were usually dose-related ADRs or commonly occurring ADRs. Differences in the pharmacokinetics of SSRIs between men and women may explain why these reports of dose-related ADRs when using SSRIs concern women more than men.

The sight of the peacock's tail makes me sick: the early arguments on sexual selection.

PubMed

Hiraiwa-Hasegawa, M

2000-03-01

Why does a peacock have a beautiful train, while a peahen is sober without such flamboyance? Darwin proposed the theory of sexual selection to explain the differences between the sexes of the same species. Recently the study of sexual selection has been one of the most flourishing areas in evolutionary biology. However, the theory met with great resistance from biologists since the publication of the idea and the history of the theory included a lot of misunderstanding and confusion. There are several reasons for this. First, classical Darwinism failed to recognize social competition as an important selective force. Second, the good-for-the-species argument, which persisted in the days after Darwin, made the sexual selection argument more difficult to under-stand. Compared to the discussions on animals, Darwin's argument on human sex differences is not satisfactory. The reason probably lies in the debate over human racial differences which prevailed in the 19th century.

Internalizing behavior in adolescent girls affects parental emotional overinvolvement: a cross-lagged twin study.

PubMed

Moberg, Therese; Lichtenstein, Paul; Forsman, Mats; Larsson, Henrik

2011-03-01

The aim of this study was to examine the direction and the etiology of the association between different parenting styles (parental emotional overinvolvement [EOI] and parental criticism) and internalizing behavior from adolescence to early adulthood. A longitudinal genetically informative cross-lagged design was applied to a population-based sample of Swedish twins contacted at age 16-17 (n = 2369) and at age 19-20 (n = 1705). Sex-limitation modelling revealed different effects for boys and girls. For girls, genetic influences on internalizing problems at age 16-17 independently explained 2.7% of the heritability in parental EOI at age 19-20. These results suggest that emotionally overinvolved and self-sacrificing parental behavior stems in part from daughters (but not sons) genetic predisposition for internalizing behavior. These findings highlight the importance of genetically influenced child-driven effects underlying the parenting-internalizing association, and clarify that the role of such effects may differ depending on sex, type of parenting and developmental period.

The Association between Pro-Social Attitude and Reproductive Success Differs between Men and Women

PubMed Central

Fieder, Martin; Huber, Susanne

2012-01-01

The evolution of pro-social attitude and cooperation in humans is under debate. Most of the knowledge on human cooperation results from laboratory experiments and theoretic modeling. Evolutionary explanations, however, rest upon fitness consequences. We therefore examined fitness correlates of pro-social behavior in a real life setting, analyzing data from the Wisconsin Longitudinal Study (n = 2545 men, 2967 women). We investigated whether pro-social attitude, proxied by self reported voluntary work, is associated with lifetime reproductive success. We find a sex difference in the association between pro-social attitude and offspring number. In men, a pro-social attitude was associated with higher offspring number, whereas in women, it was associated with lower offspring count. To our knowledge, this is the first study to demonstrate fitness consequences of pro-social behavior towards strangers. We conclude that analysing real life settings may help to explain the evolutionary forces leading to pro-social behavior in humans and speculate that these factors might differ between the sexes. PMID:22496750

Evolution of Drosophila sex comb length illustrates the inextricable interplay between selection and variation.

PubMed

Malagón, Juan N; Ahuja, Abha; Sivapatham, Gabilan; Hung, Julian; Lee, Jiwon; Muñoz-Gómez, Sergio A; Atallah, Joel; Singh, Rama S; Larsen, Ellen

2014-09-30

In spite of the diversity of possible biological forms observed in nature, a limited range of morphospace is frequently occupied for a given trait. Several mechanisms have been proposed to explain this bias in the distribution of phenotypes including selection, drift, and developmental constraints. Despite extensive work on phenotypic bias, the underlying developmental mechanisms explaining why particular regions of morphological space remain unoccupied are poorly understood. To address this issue, we studied the sex comb, a group of modified bristles used in courtship that shows marked morphological diversity among Drosophila species. In many Drosophila species including Drosophila melanogaster, the sex comb rotates 90° to a vertical position during development. Here we analyze the effect of changing D. melanogaster sex comb length on the process of rotation. We find that artificial selection changes the number of bristles per comb without a proportional change in the space available for rotation. As a result, when increasing sex comb length, rather than displaying a similar straight vertical shape observed in other Drosophila species, long sex combs bend because rotation is blocked by a neighboring row of bristles. Our results show ways in which morphologies that would be favored by natural selection are apparently impossible to achieve developmentally. These findings highlight the potential role of development in modifying selectable variation in the evolution of Drosophila sex comb length.

Evolution of Drosophila sex comb length illustrates the inextricable interplay between selection and variation

PubMed Central

Malagón, Juan N.; Ahuja, Abha; Sivapatham, Gabilan; Hung, Julian; Lee, Jiwon; Muñoz-Gómez, Sergio A.; Atallah, Joel; Singh, Rama S.; Larsen, Ellen

2014-01-01

In spite of the diversity of possible biological forms observed in nature, a limited range of morphospace is frequently occupied for a given trait. Several mechanisms have been proposed to explain this bias in the distribution of phenotypes including selection, drift, and developmental constraints. Despite extensive work on phenotypic bias, the underlying developmental mechanisms explaining why particular regions of morphological space remain unoccupied are poorly understood. To address this issue, we studied the sex comb, a group of modified bristles used in courtship that shows marked morphological diversity among Drosophila species. In many Drosophila species including Drosophila melanogaster, the sex comb rotates 90° to a vertical position during development. Here we analyze the effect of changing D. melanogaster sex comb length on the process of rotation. We find that artificial selection changes the number of bristles per comb without a proportional change in the space available for rotation. As a result, when increasing sex comb length, rather than displaying a similar straight vertical shape observed in other Drosophila species, long sex combs bend because rotation is blocked by a neighboring row of bristles. Our results show ways in which morphologies that would be favored by natural selection are apparently impossible to achieve developmentally. These findings highlight the potential role of development in modifying selectable variation in the evolution of Drosophila sex comb length. PMID:25197080

How Does Sex Trafficking Increase the Risk of HIV Infection? An Observational Study From Southern India

PubMed Central

Wirth, Kathleen E.; Tchetgen Tchetgen, Eric J.; Silverman, Jay G.; Murray, Megan B.

2013-01-01

Studies have documented the substantial risk of human immunodeficiency virus (HIV) infection endured by sex-trafficked women, but it remains unclear how exposure to trafficking puts its victims at risk. We assessed whether the association between sex trafficking and HIV could be explained by self-reported forced prostitution or young age at entry into prostitution using cross-sectional data collected from 1,814 adult female sex workers in Karnataka, India, between August 2005 and August 2006. Marginal structural logistic regression was used to estimate adjusted odds ratios for HIV infection. Overall, 372 (21%) women met 1 or both criteria used to define sex trafficking: 278 (16%) began sex work before age 18 years, and 107 (5%) reported being forcibly prostituted. Thirteen (0.7%) met both criteria. Forcibly prostituted women were more likely to be HIV-infected than were women who joined the industry voluntarily, independent of age at entering prostitution (odds ratio = 2.30, 95% confidence interval: 1.08, 4.90). Conversely, after adjustment for forced prostitution and other confounders, no association between age at entry into prostitution and HIV was observed. The association between forced prostitution and HIV infection became stronger in the presence of sexual violence (odds ratio = 11.13, 95% confidence interval: 2.41, 51.40). These findings indicate that forced prostitution coupled with sexual violence probably explains the association between sex trafficking and HIV. PMID:23324332

Explaining the host-finding behavior of blood-sucking insects: computerized simulation of the effects of habitat geometry on tsetse fly movement.

PubMed

Vale, Glyn A; Hargrove, John W; Solano, Philippe; Courtin, Fabrice; Rayaisse, Jean-Baptiste; Lehane, Michael J; Esterhuizen, Johan; Tirados, Inaki; Torr, Stephen J

2014-06-01

Male and female tsetse flies feed exclusively on vertebrate blood. While doing so they can transmit the diseases of sleeping sickness in humans and nagana in domestic stock. Knowledge of the host-orientated behavior of tsetse is important in designing bait methods of sampling and controlling the flies, and in understanding the epidemiology of the diseases. For this we must explain several puzzling distinctions in the behavior of the different sexes and species of tsetse. For example, why is it that the species occupying savannahs, unlike those of riverine habitats, appear strongly responsive to odor, rely mainly on large hosts, are repelled by humans, and are often shy of alighting on baits? A deterministic model that simulated fly mobility and host-finding success suggested that the behavioral distinctions between riverine, savannah and forest tsetse are due largely to habitat size and shape, and the extent to which dense bushes limit occupiable space within the habitats. These factors seemed effective primarily because they affect the daily displacement of tsetse, reducing it by up to ∼70%. Sex differences in behavior are explicable by females being larger and more mobile than males. Habitat geometry and fly size provide a framework that can unify much of the behavior of all sexes and species of tsetse everywhere. The general expectation is that relatively immobile insects in restricted habitats tend to be less responsive to host odors and more catholic in their diet. This has profound implications for the optimization of bait technology for tsetse, mosquitoes, black flies and tabanids, and for the epidemiology of the diseases they transmit.

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

USGS Publications Warehouse

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.

Sex differences in left/right confusion.

PubMed

Jordan, Kirsten; Wüstenberg, Torsten; Jaspers-Feyer, Fern; Fellbrich, Anja; Peters, Michael

2006-01-01

In agreement with the literature, females (n=269) gave themselves significantly poorer ratings than males (n=164) in evaluating their ability to make fast and accurate left/right judgments. In order to evaluate the ecological validity of the self-ratings, subjects were tested on a task that required fast and accurate left/right judgments, on a mental rotation task, and on a task that required navigation of a virtual maze. The correlations between the performances and self-ratings were computed. Both males and females who gave themselves very poor LRC (left/right confusion) ratings had significantly lower accuracy scores on the left/right judgement task than males and females with average ratings, but there was no sex-specific relation between LRC ratings and left/right judgements that would explain why females give themselves lower LRC ratings. For females only, a weak correlation between LRC scores and the learning of the virtual maze was observed, but no significant correlations were observed between LRC scores and mental rotation performance. We conclude that self-ratings on left/right confusion questions, although they yield reliable sex differences, are poor predictors of actual performance on spatial tasks that involve left/right judgements. Thus, and in support of earlier speculations (Sholl and Egeth, 1981; Teng and Lee, 1982; Williams et al., 1993), the principal cause of the marked sex differences in LRC self-ratings likely lies in a greater willingness of females to rate themselves more poorly on questions of this type than is the case for men.

Hypotheses on the stability and variation of human sex ratios at birth.

PubMed

James, William H

2012-10-07

Human sex ratios at birth simultaneously show both significant variation with a number of variables, and striking stability across time. Hypotheses on these features are discussed here. A) The causes of the stability are not established. B) There are several hypotheses which purport to explain sex ratio variation. 1. The Trivers–Willard hypothesis has had only limited success. This may be because (from a methodological standpoint) it has an unusual provenance in that it is not a response to a perceived need for explanation of an observed phenomenon. At present there seems too much evidence in its favour for this hypothesis to be rejected, and too much against it, for it to be accepted. 2. My hypothesis proposes that hormone concentrations (of both parents) around the time of conception partially control the sex of the zygote. A substantial quantity of data has been adduced in favour of this hypothesis. But it cannot explain all types of variation of sex ratios at birth. 3. It has been proposed by Catalano that other variation in sex ratios at birth is associated with maternal stress during pregnancy. He and his co-workers have adduced substantial quantities of data to support this hypothesis too. Copyright © 2012 Elsevier Ltd. All rights reserved.

Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients (VIRGO) Study Design

PubMed Central

Lichtman, Judith H.; Lorenze, Nancy P.; D’Onofrio, Gail; Spertus, John A.; Lindau, Stacy T.; Morgan, Thomas M.; Herrin, Jeph; Bueno, Héctor; Mattera, Jennifer A.; Ridker, Paul M.; Krumholz, Harlan M.

2011-01-01

Background Among individuals with ischemic heart disease, young women with an acute myocardial infarction (AMI) represent an extreme phenotype associated with an excess mortality risk. While women younger than 55 years of age account for less than 5% of hospitalized AMI events, almost 16,000 deaths are reported annually in this group, making heart disease a leading killer of young women. Despite a higher risk of mortality compared with similarly aged men, young women have been the subject of few studies. Methods Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients (VIRGO) is a large, observational study of the presentation, treatment and outcomes of young women and men with AMI. VIRGO will enroll 2,000 women, 18–55 years of age, with AMI and a comparison cohort of 1,000 men with AMI from more than 100 participating hospitals. The aims of the study are: to determine sex differences in the distribution and prognostic importance of biological, demographic, clinical, and psychosocial risk factors; determine whether there are sex differences in the quality of care received by young AMI patients; and determine how these factors contribute to sex differences in outcomes (including mortality, hospitalization and health status). Blood serum and DNA for consenting participants will be stored for future studies. Conclusions VIRGO will seek to identify novel and prognostic factors that contribute to outcomes in this young AMI population. Results from the study will be used to develop clinically useful risk-stratification models for young AMI patients, explain sex differences in outcomes and identify targets for intervention. PMID:21081748

The Opportunity of Adolescence.

ERIC Educational Resources Information Center

Gardner, John F.

1995-01-01

Argues that readiness for sexual activity is achieved years later than suggested by physical development and that premature sexual activity can create diminished vitality and longevity of function. The article discusses the pro's and con's of sex education, explains the tension between intellect and sex, and examines related social issues. (SM)

Gender differences in sport injury risk and types of inju-ries: a retrospective twelve-month study on cross-country skiers, swimmers, long-distance runners and soccer players.

PubMed

Ristolainen, Leena; Heinonen, Ari; Waller, Benjamin; Kujala, Urho M; Kettunen, Jyrki A

2009-01-01

This twelve months survey compared injury risk and injury types by genders (312 females, 262 males) in 15- to 35-year-old cross-country skiers, swimmers, long- distance runners and soccer players. More male than female athletes reported at least one acute injury (44% vs. 35%, p < 0.05), and more male than female runners reported at least one overuse injury (69% vs. 51%, p < 0.05). When the incidence of acute and overuse injuries both separately and combined was calculated per 1000 training hours, per 1000 competition hours and all exposure hours combined we found no gender differences in either of these comparisons. After adjustment for sport event males were at increased risk for posterior thigh overuse injuries compared to females (relative risk (RR) 5.8, 95% confidence interval (CI) 1.3 to 26.4, p < 0.05) while females were at increased risk for overuse injuries in the ankle compared to males (RR 3.1, 95% CI 1.0 to 9.3, p < 0.05). After adjustment for exposure time (injuries/1000 exposure hours) significance of the difference between the sexes in overuse injury to the ankle persisted (female 0.11 vs. male 0.02 injuries/1000 exposure hours, p < 0.05). Six athletes had an anterior cruciate ligament (ACL) injury, of whom four were female soccer players. After combining all reported acute and overuse ankle and knee injuries, the proportion of athletes with such injury was higher in the female compared to male soccer players (75% and 54% respectively; p < 0.05), but no difference was found in such injuries when calculated per 1000 exposure hours. In conclusion, we found some gender differences in sport-related injuries, but most of these differences seemed to be explained at least in part by differences in the amount of training. Key pointsOnly a few sport injury studies have compared in-jury rates between the sexesOverall gender-related risk for acute and overuse injuries in top-level athletes between the sexes was smallSome gender differences in the specific anatomical locations of injuries as well as in specific injuries in sports were foundSome of these differences seem to be explained by the differences in the amount of training.

Sex Differences in Memory for Sexually-Relevant Information

PubMed Central

McCall, Katie M.; Rellini, Alessandra H.; Seal, Brooke N.

2010-01-01

The present study was conducted in an attempt to examine potential differences between men and women in memory for sexually relevant information. A total of 77 undergraduate students (31 men, 46 women) read a sexual story and completed memory tasks in response to the story. Based on previous research, we hypothesized that differences would exist between men and women for different types of sexual information and we hoped to understand whether specific variables (sexual experiences, sexual functioning, and reactions to the sexual story) could explain such differences. Men were more likely to remember erotic or explicit details of the story, whereas women were more likely to remember love and emotional bonding details of the story. Additionally, women were more likely to recall information referencing the characters in the story. Results from regression analyses indicated that sexual desire and satisfaction were related to differences in recall and recognition of the love and emotional bonding aspects of the story, and that frequency of sexual intercourse was related to differences in the recall of erotic or explicit details of the story. The significant results obtained in this study correspond to previously established sex differences in memory for sexual information. PMID:17186127

Mobility predicts change in older adults' health-related quality of life: evidence from a Vancouver falls prevention prospective cohort study.

PubMed

Davis, Jennifer C; Bryan, Stirling; Best, John R; Li, Linda C; Hsu, Chun Liang; Gomez, Caitlin; Vertes, Kelly A; Liu-Ambrose, Teresa

2015-07-15

Older adults with mobility impairments are prone to reduced health related quality of life (HRQoL) is highly associated with mobility impairments. The consequences of falls have detrimental impact on mobility. Hence, ascertaining factors explaining variation among individuals' quality of life is critical for promoting healthy ageing, particularly among older fallers. Hence, the primary objective of our study was to identify key factors that explain variation in HRQoL among community dwelling older adults at risk of falls. We conducted a longitudinal analysis of a 12-month prospective cohort study at the Vancouver Falls Prevention Clinic (n = 148 to 286 depending on the analysis). We constructed linear mixed models where assessment month (0, 6, 12) was entered as a within-subjects repeated measure, the intercept was specified as a random effect, and predictors and covariates were entered as between-subjects fixed effects. We also included the predictors by sex and predictor by sex by time interaction terms in order to investigate sex differences in the relations between the predictor variable and the outcome variable, the EQ-5D. Our primary analysis demonstrated a significant mobility (assessed using the Short Performance Physical Battery and the Timed Up and Go) by time interaction (p < 0.05) and mobility by time by sex interaction (p < 0.05). The sensitivity analyses demonstrated some heterogeneity of these findings using an imputed and a complete case analysis. Mobility may be an important predictor of changes in HRQoL over time. As such, mobility is a critical factor to target for future intervention strategies aimed at maintaining or improving HRQoL in late life.

Factors Associated With Emotional Satisfaction During First Anal Intercourse in a Sample of YMSM.

PubMed

Arrington-Sanders, Renata; Rosenberger, Joshua G; Matson, Pamela; Novak, David S; Fortenberry, J Dennis

2016-07-01

We sought to determine, in a sample of 2,813 HIV seronegative young men who had sex with other men age 18-24, whether physical satisfaction would explain emotional satisfaction during first anal intercourse and whether emotional satisfaction would impact having sex with a partner a second time. Emotional satisfaction was explained mostly by physical satisfaction during the event, but partner type also had direct impact on emotional satisfaction. Our findings suggest that first anal intercourse experiences in young men are both emotionally and physically satisfying and may impact subsequent sexual behavior and partner decision-making.

Sex differences in the MB49 syngeneic, murine model of bladder cancer

PubMed Central

White-Gilbertson, Shai; Davis, Megan; Voelkel-Johnson, Christina; Kasman, Laura M.

2016-01-01

OBJECTIVE The MB49 syngeneic, murine model of bladder cancer has been widely used for more than 35 years. In humans, bladder cancer is one third as prevalent in women as in men, with a trend toward lower prevalence in parous compared to nulliparous women. Our objective was to determine if the MB49 bladder cancer model reproduces the sex differences observed in humans, and to determine its sensitivity to testosterone and the pregnancy hormone, human chorionic gonadotropin (hCG). METHODS Male and female C57BL/6 mice were implanted with MB49 murine bladder cancer cells, and observed for tumor growth. MB49 dose responses to hCG and dihydrotestosterone were determined in vitro. RESULTS MB49 tumor growth was significantly greater in male mice than female mice. Pregnancy did not affect MB49 tumor growth in female mice. MB49 cells did not proliferate in response to hCG in vitro and the functional receptor for gonadotropins was absent. Dihydrotestosterone strongly stimulated growth of MB49 cells in vitro. CONCLUSIONS The MB49 murine model of bladder cancer reproduced some aspects of the sex differences observed in humans. Our results suggest that testosterone may stimulate MB49 cell proliferation, which may explain the more rapid MB49 tumor growth observed in male mice. PMID:26998503

The clinical presentation of acute bacterial meningitis varies with age, sex and duration of illness.

PubMed

Johansson Kostenniemi, Urban; Norman, David; Borgström, Malin; Silfverdal, Sven Arne

2015-11-01

This Swedish study reviewed differences in clinical presentation and laboratory findings of acute bacterial meningitis in children aged one month to 17 years in Västerbotten County, Sweden. A register-based study was performed for the period 1986 to 2013 using the Västerbotten County Council's patient registration and laboratory records at the Department of Laboratory Medicine at Umeå University Hospital. The medical records were reviewed to extract data and confirm the diagnosis. We found 103 cases of acute bacterial meningitis, and Haemophilus influenzae was the most common pathogen, causing 40.8% of all cases, followed by Streptococcus pneumoniae at 30.1% and Neisseria meningitidis at 9.7%. Significant differences in clinical presentation and laboratory findings were found. Younger children were more unwell than older ones and had more diffuse symptoms on admission. In addition, important sex-related differences were found that might explain the higher case fatality rates for boys than girls. For example, boys tended to have a higher disturbance in the blood-brain barrier, which is known to be a negative prognostic factor. This study showed that clinical presentation for acute bacterial meningitis varied with age and sex and, to a lesser extent, on the duration of the illness. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Sex differences in the MB49 syngeneic, murine model of bladder cancer.

PubMed

White-Gilbertson, Shai; Davis, Megan; Voelkel-Johnson, Christina; Kasman, Laura M

The MB49 syngeneic, murine model of bladder cancer has been widely used for more than 35 years. In humans, bladder cancer is one third as prevalent in women as in men, with a trend toward lower prevalence in parous compared to nulliparous women. Our objective was to determine if the MB49 bladder cancer model reproduces the sex differences observed in humans, and to determine its sensitivity to testosterone and the pregnancy hormone, human chorionic gonadotropin (hCG). Male and female C57BL/6 mice were implanted with MB49 murine bladder cancer cells, and observed for tumor growth. MB49 dose responses to hCG and dihydrotestosterone were determined in vitro . MB49 tumor growth was significantly greater in male mice than female mice. Pregnancy did not affect MB49 tumor growth in female mice. MB49 cells did not proliferate in response to hCG in vitro and the functional receptor for gonadotropins was absent. Dihydrotestosterone strongly stimulated growth of MB49 cells in vitro . The MB49 murine model of bladder cancer reproduced some aspects of the sex differences observed in humans. Our results suggest that testosterone may stimulate MB49 cell proliferation, which may explain the more rapid MB49 tumor growth observed in male mice.

Does induced masseter muscle pain affect integrated jaw-neck movements similarly in men and women?

PubMed

Wiesinger, Birgitta; Häggman-Henrikson, Birgitta; Hellström, Fredrik; Englund, Erling; Wänman, Anders

2016-12-01

Normal jaw opening-closing involves simultaneous jaw and head-neck movements. We previously showed that, in men, integrated jaw-neck movements during jaw function are altered by induced masseter muscle pain. The aim of this study was to investigate possible sex-related differences in integrated jaw-neck movements following experimental masseter muscle pain. We evaluated head-neck and jaw movements in 22 healthy women and 16 healthy men in a jaw opening-closing task. The participants performed one control trial and one trial with masseter muscle pain induced by injection of hypertonic saline. Jaw and head movements were registered using a three-dimensional optoelectronic recording system. There were no significant sex-related differences in jaw and head movement amplitudes. Head movement amplitudes were significantly greater in the pain trials for both men and women. The proportional involvement of the neck motor system during jaw movements increased in pain trials for 13 of 16 men and for 18 of 22 women. Thus, acute pain may alter integrated jaw-neck movements, although, given the similarities between men and women, this interaction between acute pain and motor behaviour does not explain sex differences in musculoskeletal pain in the jaw and neck regions. © 2016 Eur J Oral Sci.

Effect of sex on the acute skeletal muscle response to sprint interval exercise.

PubMed

Skelly, Lauren E; Gillen, Jenna B; MacInnis, Martin J; Martin, Brian J; Safdar, Adeel; Akhtar, Mahmood; MacDonald, Maureen J; Tarnopolsky, Mark A; Gibala, Martin J

2017-03-01

What is the central question of this study? Are there sex-based differences in the acute skeletal muscle response to sprint interval training (SIT)? What is the main finding and its importance? In response to a SIT protocol that involved three 20 s bouts of 'all-out' cycling, the expression of multiple genes associated with mitochondrial biogenesis, metabolic control and structural remodelling was largely similar between men and women matched for fitness. Our findings cannot explain previous reports of sex-based differences in the adaptive response to SIT and suggest that the mechanistic basis for these differences remains to be elucidated. A few studies have reported sex-based differences in response to several weeks of sprint interval training (SIT). These findings may relate to sex-specific responses to an acute session of SIT. We tested the hypothesis that the acute skeletal muscle response to SIT differs between sexes. Sedentary but healthy men (n = 10) and women (n = 9) were matched for age (22 ± 3 versus 22 ± 3 years old) and cardiorespiratory fitness [45 ± 7 versus 43 ± 10 ml O 2  (kg fat-free mass) -1  min -1 ], with women tested in the mid-follicular phase of their menstrual cycles. Subjects performed three 20 s 'all-out' cycling efforts against a resistance of 5% of body mass, interspersed with 2 min of recovery. Relative mean power outputs [7.6 ± 0.5 versus 7.5 ± 0.9 W (kg fat-free mass) -1 ] were similar between men and women (P > 0.05). Furthermore, there were no differences in the exercise-induced changes in mRNA expression of PGC-1α, PRC, PPARD, SIRT1, RIP140, HSL, HKII, PDK4, PDP1, FOXO3, MURF-1, Myf5, MyoD and VEGFA at 3 h of recovery versus rest (P < 0.05, main effect of time). The only sex-specific responses to exercise were an increase in the mRNA expression of GLUT4 and LPL in women only and Atrogin-1 in men only (P < 0.05). Women also had higher expression of HKII and lower expression of FOXO3 compared with men (P < 0.05, main effect of sex). We conclude that the acute skeletal muscle response to SIT is largely similar in young men and women. The mechanistic basis for sex-based differences in response to several weeks of SIT that has been previously reported remains to be elucidated. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

Socioeconomic differences in alcohol-related risk-taking behaviours.

PubMed

Livingston, Michael

2014-11-01

There is substantial research showing that low socioeconomic position is a predictor of negative outcomes from alcohol consumption, while alcohol consumption itself does not exhibit a strong social gradient. This study aims to examine socioeconomic differences in self-reported alcohol-related risk-taking behaviour to explore whether differences in risk-taking while drinking may explain some of the socioeconomic disparities in alcohol-related harm. Cross-sectional data from current drinkers (n = 21 452) in the 2010 wave of the Australian National Drug Strategy Household Survey were used. Ten items on risk-taking behaviour while drinking were combined into two risk scores, and zero-inflated Poisson regression was used to assess the relationship between socioeconomic position and risk-taking while controlling for age, sex and alcohol consumption. Socioeconomically advantaged respondents reported substantially higher rates of alcohol-related hazardous behaviour than socioeconomically disadvantaged respondents. Controlling for age, sex, volume of drinking and frequency of heavy drinking, respondents living in the most advantaged quintile of neighbourhoods reported significantly higher rates of hazardous behaviour than those in the least advantaged quintile. A similar pattern was evident for household income. Socioeconomically advantaged Australians engage in alcohol-related risky behaviour at higher rates than more disadvantaged Australians even with alcohol consumption controlled. The significant socioeconomic disparities in negative consequences linked to alcohol consumption cannot in this instance be explained via differences in behaviour while drinking. Other factors not directly related to alcohol consumption may be responsible for health inequalities in outcomes with significant alcohol involvement. © 2014 Australasian Professional Society on Alcohol and other Drugs.

Biochemical markers for cardiovascular disease in recently postmenopausal women with or without hot flashes.

PubMed

Tuomikoski, Pauliina; Mikkola, Tomi S; Hämäläinen, Esa; Tikkanen, Matti J; Turpeinen, Ursula; Ylikorkala, Olavi

2010-01-01

Menopausal hot flashes may affect vascular function and perhaps explain conflicting data on cardiovascular disease (CVD) between observational and randomized hormone therapy (HT) studies. We prospectively assessed hot flash status in recently postmenopausal women and related it to a number of biochemical vascular surrogate markers for CVD. Healthy, nonsmoking women (n = 150) exhibiting a broad range (no, mild, moderate, severe) of hot flashes and an onset of menopause within the previous 0.5 to 3 years were studied with laboratory tests for lipids, lipoproteins, apolipoproteins, high-sensitivity C-reactive protein, and sex hormone-binding globulin. Apart from marked differences in hot flashes, the groups showed comparable levels of estrone, estradiol, or free estradiol index. The levels of total cholesterol (3.7-9.1 mmol/L) were similar between the groups (P = 0.744), and hypercholesterolemia (>6.5 mmol/L) was encountered equally often (P = 0.699). No difference was seen in high-, low-, or very low-density lipoproteins, triglycerides, apolipoprotein A-1, apolipoprotein B (or their ratio), or lipoprotein(a) between the groups. The levels of sex hormone-binding globulin and high-sensitivity C-reactive protein correlated negatively with each other (r = -0.204; P = 0.013) but showed no dependence on hot flashes (P = 0.531 and P = 0.215, respectively). No baseline difference in lipid or nonlipid CVD risk factors was observed between women with hot flashes (potential HT users) and women with no or mild hot flashes (potential HT nonusers). This may imply that hot flash status per se cannot explain the difference between observational and randomized trials.

Female turtles from hot nests: is it duration of incubation or proportion of development at high temperatures that matters?

PubMed

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.

The incorporation of gender perspective into Spanish health surveys.

PubMed

Rohlfs, Izabella; Borrell, Carme; Artazcoz, Lucia; Escribà-Agüir, Vicenta

2007-12-01

Most studies into social determinants of health conducted in Spain based on data from health surveys have focused on social class inequalities. This paper aims to review the progressive incorporation of gender perspective and sex differences into health surveys in Spain, and to suggest design, data collection and analytical proposals as well as to make policy proposals. Changes introduced into health surveys in Spain since 1995 to incorporate gender perspective are examined, and proposals for the future are made, which would permit the analysis of differences in health between women and men as a result of biology or because of gender inequalities. The introduction of gender perspective in health surveys requires the incorporation of questions related to family setting and reproductive work, workplace and society in general to detect gender differences and inequalities (for example, domestic work, intimate partner violence, discrimination, contract type or working hours). Health indicators reflecting differential morbidity and taking into account the different life cycle stages must also be incorporated. Analyses ought to be disaggregated by sex and interpretation of results must consider the complex theoretical frameworks explaining the differences in health between men and women based on sex differences and those related to gender. Analysis of survey data ought to consider the impact of social, political and cultural constructs of each society. Any significant modification in procedures for collection of data relevant to the study of gender will require systematic coordination between institutions generating the data and researchers who are trained in and sensitive to the topic.

Pessimism, Trauma, Risky Sex: Covariates of Depression in College Students

ERIC Educational Resources Information Center

Swanholm, Eric; Vosvick, Mark; Chng, Chwee-Lye

2009-01-01

Objective: To explain variance in depression in students (N = 648) using a model incorporating sexual trauma, pessimism, and risky sex. Method: Survey data collected from undergraduate students receiving credit for participation. Results: Controlling for demographics, a hierarchical linear regression analysis [Adjusted R[superscript 2] = 0.34,…

Stereotyping in the Learning Environment: Teachers' Perceptions and Strategies for Change.

ERIC Educational Resources Information Center

Hoover, Nora Lee

This paper calls for the elimination of sex role stereotyping in classrooms and reading programs and suggests strategies for creating nonsexist learning environments. The first section defines sex role stereotpying, explains its detrimental effects, and points to evidence of its existence in classrooms and instructional materials. The second…

Disparities in herpes simplex virus type 2 infection between black and white men who have sex with men in Atlanta, GA.

PubMed

Okafor, Netochukwu; Rosenberg, Eli S; Luisi, Nicole; Sanchez, Travis; del Rio, Carlos; Sullivan, Patrick S; Kelley, Colleen F

2015-09-01

HIV disproportionately affects black men who have sex with men, and herpes simplex virus type 2 is known to increase acquisition of HIV. However, data on racial disparities in herpes simplex virus type 2 prevalence and risk factors are limited among men who have sex with men in the United States. InvolveMENt was a cohort study of black and white HIV-negative men who have sex with men in Atlanta, GA. Univariate and multivariate cross-sectional associations with herpes simplex virus type 2 seroprevalence were assessed among 455 HIV-negative men who have sex with men for demographic, behavioural and social determinant risk factors using logistic regression. Seroprevalence of herpes simplex virus type 2 was 23% (48/211) for black and 16% (38/244) for white men who have sex with men (p = 0.05). Education, poverty, drug/alcohol use, incarceration, circumcision, unprotected anal intercourse, and condom use were not associated with herpes simplex virus type 2. In multivariate analyses, black race for those ≤25 years, but not >25 years, and number of sexual partners were significantly associated. Young black men who have sex with men are disproportionately affected by herpes simplex virus type 2, which may contribute to disparities in HIV acquisition. An extensive assessment of risk factors did not explain this disparity in herpes simplex virus type 2 infection suggesting differences in susceptibility or partner characteristics. © The Author(s) 2014.

Burnout, working conditions and gender - results from the northern Sweden MONICA Study

PubMed Central

2010-01-01

Background Sick-leave because of mental and behavioural disorders has increased considerably in Sweden since the late nineties, and especially in women. The aim of this study was to assess the level of burnout in the general working population in northern Sweden and analyse it's relation to working conditions and gender. Methods In this cross-sectional study the survey from the MONICA-study (Monitoring of Trends and Determinants in Cardiovascular Disease) in northern Sweden 2004 was used. A burnout instrument, the Shirom Melamed Burnout Questionnaire (SMBQ), was incorporated in the original survey which was sent to a random sample of 2500 individuals with a response rate of 76%. After including only actively working people, aged 25-64 years, our study population consisted of 1000 participants (497 women and 503 men). ANOVA and multiple linear regression models were used. Results The prevalence of a high level of burnout (SMBQ >4.0) was 13%. Women had a higher level of burnout than men with the most pronounced difference in the age group 35-44 years. In both sexes the level of burnout decreased with age. Demand and control at work, and job insecurity were related to burnout. In women the level of education, socioeconomic position, work object, and working varying hours were of importance. Interaction effects were found between sex and work object, and sex and working hours. In a multiple regression analysis almost half of the gender difference could be explained by work related and life situational factors. Conclusions Working life conditions contributed to the level of burnout in this actively working sample from the general population in northern Sweden. Especially in women, socioeconomic position was associated with burnout. The high level of burnout in women compared to men was partly explained by more unfavourable working conditions and life situational factors. Efforts to level out gender differences in burnout should probably focus on improving both working and socioeconomic conditions for women. PMID:20534136

Age, education, and the gender gap in the sense of control.

PubMed

Slagsvold, Britt; Sørensen, Annemette

2008-01-01

High sense of control is related to benefits in many aspects of life, and education is known to be strongly related to sense of control. In this article we explore why women tend to feel a lower sense of control than men, and why the sense of control tends to be lower among the elderly than among younger people. In particular we explore the role played by education in explaining age- and gender differences in sense of control. The analysis is based on data from the first wave of the Norwegian NorLAG study, with a representative sample of adults aged 40-79 in 30 municipalities. We find that education accounts for some of the age and gender differences in sense of control, but the mediating effects of education are rather modest. We find an increasing gender gap in sense of control with age, and this increasing gap is completely explained by differences in education. Gender differences in sense of control is explained completely by four factors, which are related to resources and power; physical health, education, living with a partner, and leadership experience. Age differences in sense of control are only partially explained. Education, physical health and employment status cuts the age effect on sense of control to half. The effect of education on sense of control is partly mediated through what we suggest are tangible benefits of education, namely health, employment, and leadership experience. Education also influences individuals through socialization mechanisms. We view agentive orientation as a psychological benefit of education, and measure this characteristic with Bem's (1981) sex-role scale on masculinity. Agentive orientation completely explains the remaining effect of education on sense of control.

Ethnicity, Sex Work, and Incident HIV/STI Among Transgender Women in New York City: A Three Year Prospective Study.

PubMed

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.

Both cell-autonomous mechanisms and hormones contribute to sexual development in vertebrates and insects.

PubMed

Bear, Ashley; Monteiro, Antónia

2013-08-01

The differentiation of male and female characteristics in vertebrates and insects has long been thought to proceed via different mechanisms. Traditionally, vertebrate sexual development was thought to occur in two phases: a primary and a secondary phase, the primary phase involving the differentiation of the gonads, and the secondary phase involving the differentiation of other sexual traits via the influence of sex hormones secreted by the gonads. In contrast, insect sexual development was thought to depend exclusively on cell-autonomous expression of sex-specific genes. Recently, however, new evidence indicates that both vertebrates and insects rely on sex hormones as well as cell-autonomous mechanisms to develop sexual traits. Collectively, these new data challenge the traditional vertebrate definitions of primary and secondary sexual development, call for a redefinition of these terms, and indicate the need for research aimed at explaining the relative dependence on cell-autonomous versus hormonally guided sexual development in animals. © 2013 The Authors. BioEssays published by WILEY Periodicals, Inc.

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

PubMed Central

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

2013-01-01

Heritability estimates of metabolic syndrome traits vary widely across studies. Some studies have suggested that the contribution of genes may vary with age or sex. We estimated the heritability of 11 metabolic syndrome-related traits and height as a function of age and sex in a large population-based sample of twin families (N = 2,792–27,021, for different traits). A moderate-to-high heritability was found for all traits [from H2 = 0.47 (insulin) to H2 = 0.78 (BMI)]. The broad-sense heritability (H2) showed little variation between age groups in women; it differed somewhat more in men (e.g., for glucose, H2 = 0.61 in young females, H2 = 0.56 in older females, H2 = 0.64 in young males, and H2= 0.27 in older males). While nonadditive genetic effects explained little variation in the younger subjects, nonadditive genetic effects became more important at a greater age. Our findings show that in an unselected sample (age range, ∼18–98 years), the genetic contribution to individual differences in metabolic syndrome traits is moderate to large in both sexes and across age. Although the prevalence of the metabolic syndrome has greatly increased in the past decades due to lifestyle changes, our study indicates that most of the variation in metabolic syndrome traits between individuals is due to genetic differences. PMID:23918046

The Arabic scale of death anxiety: some results from east and west.

PubMed

Abdel-Khalek, Ahmed M; Lester, David; Maltby, John; Tomás-Sábado, Joaquin

2009-01-01

The twofold objectives of the present study were (a) to examine sex-related differences on the Arabic Scale of Death Anxiety (ASDA) in seven Arabic and Western countries, and (b) to compare the mean ASDA scores among Arabic samples (Egypt, Kuwait, Lebanon, and Syria) with Western samples (Spain, the United Kingdom, and the United States). A total sample of 2978 volunteer undergraduates participated in this study. They resided in their countries of origin and responded to the scale in their respective native-speaking languages. Sex-related differences on the ASDA were statistically significant in all countries (except the United Kingdom), with women having higher mean scores than their male peers. It was found that all the Arab samples, except the Lebanese men, had significantly higher mean ASDA scores than their Western counterparts. These differences might be explained either in the light of higher emotionally responsiveness of the Arab samples, differences in individualism and collectivism and in secularism in the countries, and the lower per capita income in the Arab countries except in Kuwait.

Sexual variation in assimilation efficiency: its link to phenotype and potential role in sexual dimorphism.

PubMed

Stahlschmidt, Zachary R; Davis, Jon R; Denardo, Dale F

2011-04-01

Sex-specific variation in morphology (sexual dimorphism) is a prevalent phenomenon among animals, and both dietary intake and resource allocation strategies influence sexually dimorphic traits (e.g., body size or composition). However, we investigated whether assimilation efficiency (AE), an intermediate step between dietary intake and allocation, can also vary between the sexes. Specifically, we tested whether sex-based differences in AE can explain variation in phenotypic traits. We measured morphometric characteristics (i.e., body length, mass, condition, and musculature) and AE of total energy, crude protein, and crude fat in post-reproductive adult Children's pythons (which exhibit a limited female-biased sexual size dimorphism) fed both low and high dietary intakes. Meal size was negatively related to AE of energy. Notably, male snakes absorbed crude protein more efficiently and increased epaxial (dorsal) musculature faster than females, which demonstrates a link between AE and phenotype. However, females grew in body length faster but did not absorb any nutrient more efficiently than males. Although our results do not provide a direct link between AE and sexual size dimorphism, they demonstrate that sexual variation in nutrient absorption exists and can contribute to other types of sex-based differences in phenotype (i.e., sexual dimorphism in growth of musculature). Hence, testing the broader applicability of AE's role in sexually dimorphic traits among other species is warranted.

What does the geography of parthenogenesis teach us about sex?

PubMed

Tilquin, Anaïs; Kokko, Hanna

2016-10-19

Theory predicts that sexual reproduction is difficult to maintain if asexuality is an option, yet sex is very common. To understand why, it is important to pay attention to repeatably occurring conditions that favour transitions to, or persistence of, asexuality. Geographic parthenogenesis is a term that has been applied to describe a large variety of patterns where sexual and related asexual forms differ in their geographic distribution. Often asexuality is stated to occur in a habitat that is, in some sense, marginal, but the interpretation differs across studies: parthenogens might not only predominate near the margin of the sexuals' distribution, but might also extend far beyond the sexual range; they may be disproportionately found in newly colonizable areas (e.g. areas previously glaciated), or in habitats where abiotic selection pressures are relatively stronger than biotic ones (e.g. cold, dry). Here, we review the various patterns proposed in the literature, the hypotheses put forward to explain them, and the assumptions they rely on. Surprisingly, few mathematical models consider geographic parthenogenesis as their focal question, but all models for the evolution of sex could be evaluated in this framework if the (often ecological) causal factors vary predictably with geography. We also recommend broadening the taxa studied beyond the traditional favourites.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'. © 2016 The Author(s).

Genital Evolution: Why Are Females Still Understudied?

PubMed Central

Ah-King, Malin; Barron, Andrew B.; Herberstein, Marie E.

2014-01-01

The diversity, variability, and apparent rapid evolution of animal genitalia are a vivid focus of research in evolutionary biology, and studies exploring genitalia have dramatically increased over the past decade. These studies, however, exhibit a strong male bias, which has worsened since 2000, despite the fact that this bias has been explicitly pointed out in the past. Early critics argued that previous investigators too often considered only males and their genitalia, while overlooking female genitalia or physiology. Our analysis of the literature shows that overall this male bias has worsened with time. The degree of bias is not consistent between subdisciplines: studies of the lock-and-key hypothesis have been the most male focused, while studies of cryptic female choice usually consider both sexes. The degree of bias also differed across taxonomic groups, but did not associate with the ease of study of male and female genital characteristics. We argue that the persisting male bias in this field cannot solely be explained by anatomical sex differences influencing accessibility. Rather the bias reflects enduring assumptions about the dominant role of males in sex, and invariant female genitalia. New research highlights how rapidly female genital traits can evolve, and how complex coevolutionary dynamics between males and females can shape genital structures. We argue that understanding genital evolution is hampered by an outdated single-sex bias. PMID:24802812

Age- and Sex-Specific Causal Effects of Adiposity on Cardiovascular Risk Factors

PubMed Central

Fall, Tove; Hägg, Sara; Ploner, Alexander; Mägi, Reedik; Fischer, Krista; Draisma, Harmen H.M.; Sarin, Antti-Pekka; Benyamin, Beben; Ladenvall, Claes; Åkerlund, Mikael; Kals, Mart; Esko, Tõnu; Nelson, Christopher P.; Kaakinen, Marika; Huikari, Ville; Mangino, Massimo; Meirhaeghe, Aline; Kristiansson, Kati; Nuotio, Marja-Liisa; Kobl, Michael; Grallert, Harald; Dehghan, Abbas; Kuningas, Maris; de Vries, Paul S.; de Bruijn, Renée F.A.G.; Willems, Sara M.; Heikkilä, Kauko; Silventoinen, Karri; Pietiläinen, Kirsi H.; Legry, Vanessa; Giedraitis, Vilmantas; Goumidi, Louisa; Syvänen, Ann-Christine; Strauch, Konstantin; Koenig, Wolfgang; Lichtner, Peter; Herder, Christian; Palotie, Aarno; Menni, Cristina; Uitterlinden, André G.; Kuulasmaa, Kari; Havulinna, Aki S.; Moreno, Luis A.; Gonzalez-Gross, Marcela; Evans, Alun; Tregouet, David-Alexandre; Yarnell, John W.G.; Virtamo, Jarmo; Ferrières, Jean; Veronesi, Giovanni; Perola, Markus; Arveiler, Dominique; Brambilla, Paolo; Lind, Lars; Kaprio, Jaakko; Hofman, Albert; Stricker, Bruno H.; van Duijn, Cornelia M.; Ikram, M. Arfan; Franco, Oscar H.; Cottel, Dominique; Dallongeville, Jean; Hall, Alistair S.; Jula, Antti; Tobin, Martin D.; Penninx, Brenda W.; Peters, Annette; Gieger, Christian; Samani, Nilesh J.; Montgomery, Grant W.; Whitfield, John B.; Martin, Nicholas G.; Groop, Leif; Spector, Tim D.; Magnusson, Patrik K.; Amouyel, Philippe; Boomsma, Dorret I.; Nilsson, Peter M.; Järvelin, Marjo-Riitta; Lyssenko, Valeriya; Metspalu, Andres; Strachan, David P.; Salomaa, Veikko; Ripatti, Samuli; Pedersen, Nancy L.; Prokopenko, Inga; McCarthy, Mark I.

2015-01-01

Observational studies have reported different effects of adiposity on cardiovascular risk factors across age and sex. Since cardiovascular risk factors are enriched in obese individuals, it has not been easy to dissect the effects of adiposity from those of other risk factors. We used a Mendelian randomization approach, applying a set of 32 genetic markers to estimate the causal effect of adiposity on blood pressure, glycemic indices, circulating lipid levels, and markers of inflammation and liver disease in up to 67,553 individuals. All analyses were stratified by age (cutoff 55 years of age) and sex. The genetic score was associated with BMI in both nonstratified analysis (P = 2.8 × 10−107) and stratified analyses (all P < 3.3 × 10−30). We found evidence of a causal effect of adiposity on blood pressure, fasting levels of insulin, C-reactive protein, interleukin-6, HDL cholesterol, and triglycerides in a nonstratified analysis and in the <55-year stratum. Further, we found evidence of a smaller causal effect on total cholesterol (P for difference = 0.015) in the ≥55-year stratum than in the <55-year stratum, a finding that could be explained by biology, survival bias, or differential medication. In conclusion, this study extends previous knowledge of the effects of adiposity by providing sex- and age-specific causal estimates on cardiovascular risk factors. PMID:25712996

What does the geography of parthenogenesis teach us about sex?

PubMed Central

Kokko, Hanna

2016-01-01

Theory predicts that sexual reproduction is difficult to maintain if asexuality is an option, yet sex is very common. To understand why, it is important to pay attention to repeatably occurring conditions that favour transitions to, or persistence of, asexuality. Geographic parthenogenesis is a term that has been applied to describe a large variety of patterns where sexual and related asexual forms differ in their geographic distribution. Often asexuality is stated to occur in a habitat that is, in some sense, marginal, but the interpretation differs across studies: parthenogens might not only predominate near the margin of the sexuals' distribution, but might also extend far beyond the sexual range; they may be disproportionately found in newly colonizable areas (e.g. areas previously glaciated), or in habitats where abiotic selection pressures are relatively stronger than biotic ones (e.g. cold, dry). Here, we review the various patterns proposed in the literature, the hypotheses put forward to explain them, and the assumptions they rely on. Surprisingly, few mathematical models consider geographic parthenogenesis as their focal question, but all models for the evolution of sex could be evaluated in this framework if the (often ecological) causal factors vary predictably with geography. We also recommend broadening the taxa studied beyond the traditional favourites. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’. PMID:27619701

Reversing sex steroid deficiency and optimizing skeletal development in the adolescent with gonadal failure.

PubMed

Vanderschueren, Dirk; Vandenput, Liesbeth; Boonen, Steven

2005-01-01

During puberty, the acquisition of skeletal mass and areal bone mineral density (BMD) mainly reflects an increase in bone size (length and perimeters) and not true volumetric BMD. Sexual dimorphism in bone mass and areal BMD is also explained by differences in bone size (longer and wider bones in males) and not by differences in volumetric BMD. Androgens stimulate skeletal growth by activation of the androgen receptor, whereas estrogens (following aromatization of androgens and stimulation of estrogen receptors) have a biphasic effect on skeletal growth during puberty. Recent evidence from clinical cases has shown that many of the growth-promoting effects of the sex steroids are mediated through estrogens rather than androgens. In addition, skeletal maturation and epiphyseal fusion are also estrogen-dependent in both sexes. Nevertheless, independent actions of androgens in these processes also occur. Both sex steroids maintain volumetric BMD during puberty. Androgens interact with the growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis neonatally, resulting in a sexual dimorphic GH pattern during puberty, whereas estrogens stimulate GH and hereby IGF-I in both sexes. Hypogonadism in adolescents impairs not only bone size but also maintenance of volumetric BMD, hereby severely reducing peak areal BMD. Delayed puberty in boys and Turner's syndrome in women impair both bone length and size, reducing areal BMD. Whether volumetric BMD is also reduced and whether fracture risk is increased in these conditions remains controversial. Replacing sex steroids according to a biphasic pattern (starting at low doses and ending at high-normal doses) seems the safest approach to reach targeted height and to optimize bone development.

Determinants of dental health status and dental health behavior among Sana'a University students, Yemen.

PubMed

Halboub, Esam; Dhaifullah, Esam; Yasin, Rasha

2013-11-01

To evaluate the dental health status and toothbrushing behavior among Sana'a University students, and to explore any associations with different factors. In this cross-sectional study, the dental health of 360 students from the dental, medical, and literature faculties (120 each) at Sana'a University were examined using the Decayed, Missing, and Filled Teeth (DMFT) index. Data regarding study field, grade, toothbrushing behavior, parents' education, and smoking and khat chewing habits were recorded. Nearly 76% of students (n = 273) reported regularly brushing their teeth. Excluding fathers' education levels and khat chewing, other factors (faculty, grade, sex, mothers' education, and smoking) were significant independent predictors for this behavior. The overall mean DMFT score (± standard deviation) was 4.13 ± 3.1, and was found to be adversely influenced by smoking, which explained only 1.1% of the variance. Toothbrushing, sex, and smoking were significant independent predictors for the decay score, and explained 10.6% of its variance. Khat chewing was found to be adversely associated with the missing score, with an influence of only 2.9%. The filling score was found to be positively associated with toothbrushing and study grade, which together had an influence of 10%. The dental health and toothbrushing behaviors of Sana'a University students are unsatisfactory, and influenced unequally by different factors. © 2013 Wiley Publishing Asia Pty Ltd.

Genetic and Environmental Influences on Smoking Behavior across Adolescence and Young Adulthood in the Virginia Twin Study of Adolescent Behavioral Development and the Transitions to Substance Abuse Follow-Up

PubMed Central

Do, Elizabeth K.; Prom-Wormley, Elizabeth C.; Eaves, Lindon J.; Silberg, Judy L.; Miles, Donna R.; Maes, Hermine H.

2016-01-01

Little is known regarding the underlying relationship between smoking initiation and current quantity smoked during adolescence into young adulthood. It is possible that the influences of genetic and environmental factors on this relationship vary across sex and age. To investigate this further, the current study applied a common causal contingency model to data from a Virginia-based twin study to determine: (1) if the same genetic and environmental factors are contributing to smoking initiation and current quantity smoked; (2) whether the magnitude of genetic and environmental factor contributions are the same across adolescence and young adulthood; and (3) if qualitative and quantitative differences in the sources of variance between males and females exist. Study results found no qualitative or quantitative sex differences in the relationship between smoking initiation and current quantity smoked, though relative contributions of genetic and environmental factors changed across adolescence and young adulthood. More specifically, smoking initiation and current quantity smoked remain separate constructs until young adulthood, when liabilities are correlated. Smoking initiation is explained by genetic, shared, and unique environmental factors in early adolescence and by genetic and unique environmental factors in young adulthood; while current quantity smoked is explained by shared environmental and unique environmental factors until young adulthood, when genetic and unique environmental factors play a larger role. PMID:25662421

Genetic and Environmental Influences on Smoking Behavior across Adolescence and Young Adulthood in the Virginia Twin Study of Adolescent Behavioral Development and the Transitions to Substance Abuse Follow-Up.

PubMed

Do, Elizabeth K; Prom-Wormley, Elizabeth C; Eaves, Lindon J; Silberg, Judy L; Miles, Donna R; Maes, Hermine H

2015-02-01

Little is known regarding the underlying relationship between smoking initiation and current quantity smoked during adolescence into young adulthood. It is possible that the influences of genetic and environmental factors on this relationship vary across sex and age. To investigate this further, the current study applied a common causal contingency model to data from a Virginia-based twin study to determine: (1) if the same genetic and environmental factors are contributing to smoking initiation and current quantity smoked; (2) whether the magnitude of genetic and environmental factor contributions are the same across adolescence and young adulthood; and (3) if qualitative and quantitative differences in the sources of variance between males and females exist. Study results found no qualitative or quantitative sex differences in the relationship between smoking initiation and current quantity smoked, though relative contributions of genetic and environmental factors changed across adolescence and young adulthood. More specifically, smoking initiation and current quantity smoked remain separate constructs until young adulthood, when liabilities are correlated. Smoking initiation is explained by genetic, shared, and unique environmental factors in early adolescence and by genetic and unique environmental factors in young adulthood; while current quantity smoked is explained by shared environmental and unique environmental factors until young adulthood, when genetic and unique environmental factors play a larger role.

Preparing Your Child for a New Sibling (For Parents)

MedlinePlus

... the child isn't asking you to explain sex but probably wants to know where, literally, they come from. It may be enough to explain: "The baby comes from the uterus, which is inside the mother's belly." A child who wants to know more ...

Human MAMLD1 Gene Variations Seem Not Sufficient to Explain a 46,XY DSD Phenotype.

PubMed

Camats, Núria; Fernández-Cancio, Mónica; Audí, Laura; Mullis, Primus E; Moreno, Francisca; González Casado, Isabel; López-Siguero, Juan Pedro; Corripio, Raquel; Bermúdez de la Vega, José Antonio; Blanco, José Antonio; Flück, Christa E

2015-01-01

MAMLD1 is thought to cause disordered sex development in 46,XY patients. But its role is controversial because some MAMLD1 variants are also detected in normal individuals, several MAMLD1 mutations have wild-type activity in functional tests, and the male Mamld1-knockout mouse has normal genitalia and reproduction. Our aim was to search for MAMLD1 variations in 108 46,XY patients with disordered sex development, and to test them functionally. We detected MAMDL1 variations and compared SNP frequencies in controls and patients. We tested MAMLD1 transcriptional activity on promoters involved in sex development and assessed the effect of MAMLD1 on androgen production. MAMLD1 expression in normal steroid-producing tissues and mutant MAMLD1 protein expression were also assessed. Nine MAMLD1 mutations (7 novel) were characterized. In vitro, most MAMLD1 variants acted similarly to wild type. Only the L210X mutation showed loss of function in all tests. We detected no effect of wild-type or MAMLD1 variants on CYP17A1 enzyme activity in our cell experiments, and Western blots revealed no significant differences for MAMLD1 protein expression. MAMLD1 was expressed in human adult testes and adrenals. In conclusion, our data support the notion that MAMLD1 sequence variations may not suffice to explain the phenotype in carriers and that MAMLD1 may also have a role in adult life.

Human MAMLD1 Gene Variations Seem Not Sufficient to Explain a 46,XY DSD Phenotype

PubMed Central

Audí, Laura; Mullis, Primus E.; Moreno, Francisca; González Casado, Isabel; López-Siguero, Juan Pedro; Corripio, Raquel; Bermúdez de la Vega, José Antonio; Blanco, José Antonio; Flück, Christa E.

2015-01-01

MAMLD1 is thought to cause disordered sex development in 46,XY patients. But its role is controversial because some MAMLD1 variants are also detected in normal individuals, several MAMLD1 mutations have wild-type activity in functional tests, and the male Mamld1-knockout mouse has normal genitalia and reproduction. Our aim was to search for MAMLD1 variations in 108 46,XY patients with disordered sex development, and to test them functionally. We detected MAMDL1 variations and compared SNP frequencies in controls and patients. We tested MAMLD1 transcriptional activity on promoters involved in sex development and assessed the effect of MAMLD1 on androgen production. MAMLD1 expression in normal steroid-producing tissues and mutant MAMLD1 protein expression were also assessed. Nine MAMLD1 mutations (7 novel) were characterized. In vitro, most MAMLD1 variants acted similarly to wild type. Only the L210X mutation showed loss of function in all tests. We detected no effect of wild-type or MAMLD1 variants on CYP17A1 enzyme activity in our cell experiments, and Western blots revealed no significant differences for MAMLD1 protein expression. MAMLD1 was expressed in human adult testes and adrenals. In conclusion, our data support the notion that MAMLD1 sequence variations may not suffice to explain the phenotype in carriers and that MAMLD1 may also have a role in adult life. PMID:26580071

Theories of Suggestion.

PubMed

Brown, W

1928-02-01

The word "suggestion" has been used in educational, scientific and medical literature in slightly different senses. In psychological medicine the use of suggestion has developed out of the earlier use of hypnotic influence.Charcot defined hypnosis as an artificial hysteria, Bernheim as an artificially increased suggestibility. The two definitions need to be combined to give an adequate account of hypnosis. Moreover, due allowance should be made for the factors of dissociation and of rapport in hypnotic phenomena.The relationships between dissociation, suggestibility, and hypnotizability.Theories of suggestion propounded by Pierre Janet, Freud, McDougall, Pawlow and others. Ernest Jones's theory of the nature of auto-suggestion. Janet explains suggestion in terms of ideo-motor action in which the suggested idea, because of the inactivity of competing ideas, produces its maximum effect. Freud explains rapport in terms of the sex instinct "inhibited in its aim" (transference) and brings in his distinction of "ego" and "ego-ideal" (or "super-ego") to supplement the theory. Jones explains auto-suggestion in terms of narcissism. McDougall explains hypnotic suggestion in terms of the instinct of self-abasement. But different instincts may supply the driving power to produce suggestion-effects in different circumstances. Such instincts as those of self-preservation (fear) and gregariousness may play their part. Auto-suggestion as a therapeutic factor is badly named. It supplements, but does not supplant the will, and makes complete volition possible.

Theories of Suggestion

PubMed Central

Brown, William

1928-01-01

The word “suggestion” has been used in educational, scientific and medical literature in slightly different senses. In psychological medicine the use of suggestion has developed out of the earlier use of hypnotic influence. Charcot defined hypnosis as an artificial hysteria, Bernheim as an artificially increased suggestibility. The two definitions need to be combined to give an adequate account of hypnosis. Moreover, due allowance should be made for the factors of dissociation and of rapport in hypnotic phenomena. The relationships between dissociation, suggestibility, and hypnotizability. Theories of suggestion propounded by Pierre Janet, Freud, McDougall, Pawlow and others. Ernest Jones's theory of the nature of auto-suggestion. Janet explains suggestion in terms of ideo-motor action in which the suggested idea, because of the inactivity of competing ideas, produces its maximum effect. Freud explains rapport in terms of the sex instinct “inhibited in its aim” (transference) and brings in his distinction of “ego” and “ego-ideal” (or “super-ego”) to supplement the theory. Jones explains auto-suggestion in terms of narcissism. McDougall explains hypnotic suggestion in terms of the instinct of self-abasement. But different instincts may supply the driving power to produce suggestion-effects in different circumstances. Such instincts as those of self-preservation (fear) and gregariousness may play their part. Auto-suggestion as a therapeutic factor is badly named. It supplements, but does not supplant the will, and makes complete volition possible. PMID:19986306

Reducing voluntary, avoidable turnover through selection.

PubMed

Barrick, Murray R; Zimmerman, Ryan D

2005-01-01

The authors investigated the efficacy of several variables used to predict voluntary, organizationally avoidable turnover even before the employee is hired. Analyses conducted on applicant data collected in 2 separate organizations (N = 445) confirmed that biodata, clear-purpose attitudes and intentions, and disguised-purpose dispositional retention scales predicted voluntary, avoidable turnover (rs ranged from -.16 to -.22, R = .37, adjusted R = .33). Results also revealed that biodata scales and disguised-purpose retention scales added incremental validity, whereas clear-purpose retention scales did not explain significant incremental variance in turnover beyond what was explained by biodata and disguised-purpose scales. Furthermore, disparate impact (subgroup differences on race, sex, and age) was consistently small (average d = 0.12 when the majority group scored higher than the minority group).

The cognitive cost of being a twin: evidence from comparisons within families in the Aberdeen children of the 1950s cohort study

PubMed Central

Ronalds, Georgina A; De Stavola, Bianca L; Leon, David A

2005-01-01

Objectives To determine whether twins have lower IQ scores in childhood than singletons in the same family and, if so, whether differences in fetal growth explain this deficit. Design Cohort study. Setting Scotland. Participants 9832 singletons and 236 twins born in Aberdeen between 1950 and 1956. Results At age 7, the mean IQ score of twins was 5.3 points lower (95% confidence interval 1.5 to 9.1) and at age 9, 6.0 points lower (1.7 to 10.2) than that of singletons in the same family. Adjustment for sex, mother's age, and number of older siblings had little effect on these differences. Further adjustment for birth weight and gestational age attenuated the IQ difference between twins and singletons: the difference in mean IQ was 2.6 points (-1.5 to 6.7) at age 7 and 4.1 points (-0.5 to 8.8) at age 9. Conclusions Twins have substantially lower IQ in childhood than singletons in the same family. This effect cannot be explained by confounding due to socioeconomic, maternal, or other family characteristics, or by recruitment bias. The reduced prenatal growth and shorter gestations of twins may explain an important part of their lower IQ in childhood. PMID:16299014

Towards greater realism in inclusive fitness models: the case of worker reproduction in insect societies

PubMed Central

Wenseleers, Tom; Helanterä, Heikki; Alves, Denise A.; Dueñez-Guzmán, Edgar; Pamilo, Pekka

2013-01-01

The conflicts over sex allocation and male production in insect societies have long served as an important test bed for Hamilton's theory of inclusive fitness, but have for the most part been considered separately. Here, we develop new coevolutionary models to examine the interaction between these two conflicts and demonstrate that sex ratio and colony productivity costs of worker reproduction can lead to vastly different outcomes even in species that show no variation in their relatedness structure. Empirical data on worker-produced males in eight species of Melipona bees support the predictions from a model that takes into account the demographic details of colony growth and reproduction. Overall, these models contribute significantly to explaining behavioural variation that previous theories could not account for. PMID:24132088

Scandalous: Christian identification, sex guilt, and the mediated demonization of the participants in the AshleyMadison scandal.

PubMed

Ashdown, Brien K; Hackathorn, Jana M; Daniels, Jordan

2018-04-06

In 2015, AshleyMadison.com (AshleyMadison) was hacked, leading to the release of site members' personal information. The exposed members faced public scrutiny, judgment, and other negative outcomes. In this study, we examined predictors of the demonization of the AshleyMadison participants (i.e., AshleyMadison members, owners, hackers) to help explain victim derogation. We attempted to discern the role religiosity and sexual guilt played in the demonization of the AshleyMadison hacking participants. We predicted sexual guilt would mediate between religiosity and demonization of the AshleyMadison hacking participants. Our findings indicate that religiosity alone does not predict demonization. Instead, sex guilt was a necessary part of the equation and mediated between participants' religiosity and the amount they demonized the different groups.

Sex-Linked Behavior: Evolution, Stability, and Variability.

PubMed

Fine, Cordelia; Dupré, John; Joel, Daphna

2017-07-29

Common understanding of human sex-linked behaviors is that proximal mechanisms of genetic and hormonal sex, ultimately shaped by the differential reproductive challenges of ancestral males and females, act on the brain to transfer sex-linked predispositions across generations. Here, we extend the debate on the role of nature and nurture in the development of traits in the lifetime of an individual, to their role in the cross-generation transfer of traits. Advances in evolutionary theory that posit the environment as a source of trans-generational stability, and new understanding of sex effects on the brain, suggest that the cross-generation stability of sex-linked patterns of behavior are sometimes better explained in terms of inherited socioenvironmental conditions, with biological sex fostering intrageneration variability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sex-Linked Behavior: Evolution, Stability, and Variability.

PubMed

Fine, Cordelia; Dupré, John; Joel, Daphna

2017-09-01

Common understanding of human sex-linked behaviors is that proximal mechanisms of genetic and hormonal sex, ultimately shaped by the differential reproductive challenges of ancestral males and females, act on the brain to transfer sex-linked predispositions across generations. Here, we extend the debate on the role of nature and nurture in the development of traits in the lifetime of an individual, to their role in the cross-generation transfer of traits. Advances in evolutionary theory that posit the environment as a source of trans-generational stability, and new understanding of sex effects on the brain, suggest that the cross-generation stability of sex-linked patterns of behavior are sometimes better explained in terms of inherited socioenvironmental conditions, with biological sex fostering intrageneration variability. Copyright © 2017 Elsevier Ltd. All rights reserved.

American woodcock winter distribution and fidelity to wintering areas

USGS Publications Warehouse

Diefenbach, D.R.; Derleth, E.L.; Vander Haegen, W. Matthew; Nichols, J.D.; Hines, J.E.

1990-01-01

We examined winter distribution and fidelity to wintering areas for the American Woodcock (Scolopax minor), which exhibits reversed, sexual size dimorphism. Band-recovery data revealed no difference in winter distributions of different age/sex classes for woodcock from the same breeding ares. Similarly, band recoveries from woodcock banded on wintering grounds revealed no difference in fidelity to wintering sites. Males may winter north of a latitude that is optimal for survival based on physiological considerations, but they gain a reproductive advantage if they are among the first to arrive on the breeding grounds. This may explain our results, which indicate males and females have similar distribution patterns during winter.

Feminist activist women are masculinized in terms of digit-ratio and social dominance: a possible explanation for the feminist paradox.

PubMed

Madison, Guy; Aasa, Ulrika; Wallert, John; Woodley, Michael A

2014-01-01

The feminist movement purports to improve conditions for women, and yet only a minority of women in modern societies self-identify as feminists. This is known as the feminist paradox. It has been suggested that feminists exhibit both physiological and psychological characteristics associated with heightened masculinization, which may predispose women for heightened competitiveness, sex-atypical behaviors, and belief in the interchangeability of sex roles. If feminist activists, i.e., those that manufacture the public image of feminism, are indeed masculinized relative to women in general, this might explain why the views and preferences of these two groups are at variance with each other. We measured the 2D:4D digit ratios (collected from both hands) and a personality trait known as dominance (measured with the Directiveness scale) in a sample of women attending a feminist conference. The sample exhibited significantly more masculine 2D:4D and higher dominance ratings than comparison samples representative of women in general, and these variables were furthermore positively correlated for both hands. The feminist paradox might thus to some extent be explained by biological differences between women in general and the activist women who formulate the feminist agenda.

No evidence for faster male hybrid sterility in population crosses of an intertidal copepod (Tigriopus californicus).

PubMed

Willett, Christopher S

2008-06-01

Two different forces are thought to contribute to the rapid accumulation of hybrid male sterility that has been observed in many inter-specific crosses, namely the faster male and the dominance theories. For male heterogametic taxa, both faster male and dominance would work in the same direction to cause the rapid evolution of male sterility; however, for taxa lacking differentiated sex chromosomes only the faster male theory would explain the rapid evolution of male hybrid sterility. It is currently unknown what causes the faster evolution of male sterility, but increased sexual selection on males and the sensitivity of genes involved in male reproduction are two hypotheses that could explain the observation. Here, patterns of hybrid sterility in crosses of genetically divergent copepod populations are examined to test potential mechanisms of faster male evolution. The study species, Tigriopus californicus, lacks differentiated, hemizygous sex chromosomes and appears to have low levels of divergence caused by sexual selection acting upon males. Hybrid sterility does not accumulate more rapidly in males than females in these crosses suggesting that in this taxon male reproductive genes are not inherently more prone to disruption in hybrids.