Effects Of Sex Composition Research Articles

The complexity of coffee and its impact on metabolism.

Coffee is one of the three most consumed beverages in the world. It is made by first roasting coffee beans, and then grinding and boiling or steeping the roasted beans in water (brewing). The process of roasting and brewing produces a complex mix of bioactive compounds, including methylxanthines (caffeine, theobromine, theophylline), diterpenes, chlorogenic acid, trigonelline, flavonoids, and hydroxycinnamic acid. In the body, these compounds may be metabolized to produce other bioactive compounds. For example, caffeine is primarily (80%) broken down by demethylation to produce paraxanthine. In the post-ingestion period, levels of paraxanthine may be higher than caffeine due to its slower elimination. Hence, while paraxanthine is not found in coffee itself, it has many of the same properties as caffeine and may be a major contributor to its metabolic effects. The impacts of caffeine and paraxanthine on metabolism relate to their impact on adenosine receptors (notably the A2A receptor). It has been known for almost 100 years that intake of coffee stimulates metabolism by between 5% and 20% for at least 3 h. About half of the increase in metabolic rate after drinking coffee is due to caffeine and derivatives, but the source of the other half is unclear. There are large differences in the response to the same amount of coffee in different individuals, which may be related to caffeine clearance rates, effects of other unknown pathways, genetic polymorphism, age, sex, and body composition.

Sex and landscape influence spatial genetic variation in a large fossorial mammal, the Bare-nosed Wombat (Vombatus ursinus).

Dispersal is an important process that is widely studied across species, and it can be influenced by intrinsic and extrinsic factors. Intrinsic factors commonly assessed include the sex and age of individuals, while landscape features are frequently-tested extrinsic factors. Here, we investigated the effects of both sex and landscape composition and configuration on genetic distances among bare-nosed wombats (Vombatus ursinus)-one of the largest fossorial mammals in the world and subject to habitat fragmentation, threats from disease, and human persecution including culling as an agricultural pest. We analyzed a data set comprising 74 Tasmanian individuals (30 males and 44 females), genotyped for 9,064 single-nucleotide polymorphisms. We tested for sex-biased dispersal and the influence of landscape features on genetic distances including land use, water, vegetation, elevation, and topographic ruggedness. We detected significant female-biased dispersal, which may be related to females donating burrows to their offspring due to the energetic cost of excavation, given their large body sizes. Land use, waterbodies, and elevation appeared to be significant landscape predictors of genetic distance. Land use potentially reflects land clearing and persecution over the last 200 years. If our findings based on a limited sample size are valid, retention and restoration of nonanthropogenic landscapes in which wombats can move and burrow may be important for gene flow and maintenance of genetic diversity.

Children's sex composition and modern contraceptive use among mothers in Bangladesh.

The stagnation and relatively low use of modern contraceptives are ongoing public health concerns in Bangladesh and other low- and middle-income countries. Although a cultural preference for sons may be linked to the current use of contraceptives, this linkage has not been adequately explored in the Bangladesh context. We investigated the effects of child sex composition on the current use of modern contraceptives. We extracted and analysed data from 17,333 women who participated in the 2017/18 Bangladesh Demographic and Health Survey. The outcome variable was the current use of modern contraceptive methods. The study factor was the parity and sex composition of the living children. We used multilevel logistic regressions to determine the association between the study factor and outcome variables, adjusting for potential covariates at the individual-, household-, and community-levels. Women with relatively high parity had higher odds of currently using modern contraceptives. Among the individual parities, compared to women with no live sons, women with one or more live sons were more likely to report currently using modern contraceptives. However, this association is significant for women up to three children. When examining both parity and children's sex composition in a regression model, in each parity category, the likelihood of using modern contraceptives tend to rise with an increasing number of sons compared to women with just one daughter. The findings of this study suggest that while the use of modern contraceptives by women increases with the increasing number of children and son preference is prevalent in Bangladesh, women also want to have a mixed composition of son and daughter. The study findings can be used in family planning programmes to customise contraceptive promotion and counselling messages.

Explaining third birth patterns in India: causal effects of sibling sex composition

Explaining third birth patterns in India: causal effects of sibling sex composition

Sex-Specific Effects of Body Composition on Tumor Microenvironment in Non–Small Cell Lung Cancer

BackgroundThere exists a gap in understanding the interaction between sex and obesity on tumor microenvironment in non–small cell lung cancer (NSCLC). We demonstrate the combined effects of sex and body composition on clinically relevant biomarkers of NSCLC immune response. MethodsA cohort of 409 patients with NSCLC was subdivided into 4 groups jointly defined by body mass index (BMI; cutoff of 25 kg/m2) and sex (male–high BMI, male–low BMI, female–high BMI, female–low BMI). Associations between these sex-BMI groups and tumor inflammation (expression of 161 immune response genes), cell proliferation (expression of 10 cell proliferation genes), and programmed cell death ligand 1 (PD-L1; through immunohistochemistry and targeted RNA sequencing) were assessed by Kruskal-Wallis and Wilcoxon rank sum tests for overall and pairwise tests, respectively. ResultsWe observed an overall significant association of sex-BMI with tumor inflammation (P < .001) and cell proliferation (P = .002). On pairwise analysis, high-BMI females had significantly higher tumor inflammation compared with low-BMI females (P = .002). In addition, women with a high (P = .004) and low (P = .008) BMI had significantly higher tumor inflammation compared with men with a high and low BMI, respectively. Low-BMI females (P = .01) and males (P = .01) had more cell proliferation. PD-L1 expression by RNA sequencing (P = .001) but not by immunohistochemical analysis differed significantly with sex-BMI. High-BMI females had significantly higher PD-L1 expression compared with low-BMI females (P = .01). ConclusionsWe demonstrate that tumor inflammation and PD-L1 expression are more strongly associated with BMI in women than in men. Additional studies are required to better understand the mechanisms underlying these effects and their role in response to checkpoint inhibitors in NSCLC.

Effect of sex and dyad composition on speech and gesture development of singleton and twin children.

Children's early vocabulary shows sex differences - with boys having smaller vocabularies than age-comparable girls - a pattern that becomes evident in both singletons and twins. Twins also use fewer words than their singleton peers. However, we know relatively less about sex differences in early gesturing in singletons or twins, and also how singletons and twins might differ in their early gesture use. We examine the patterns of speech and gesture production of singleton and twin children, ages 0;10-to-3;4, during structured parent-child play. Boys and girls - singleton or twin - were similar in speech and gesture production, but singletons used a greater amount and diversity of speech and gestures than twins. There was no effect of twin dyad type (boy-boy, girl-girl, boy-girl) on either speech or gesture production. These results confirm earlier research showing close integration between gesture and speech in singletons in early language development, and further extend these patterns to twin children.

Does sex composition of offspring relate to fertility in urban areas? The case of Ouagadougou, Burkina Faso.

With the onset of the demographic transition in sub-Saharan Africa, couples' desired number of children and the sex composition of offspring may become conflicted, with potential effects on future fertility. While intuitively expected, this effect has not been observed in studies in sub-Saharan Africa, where the level of fertility is higher than in other African regions. In this study, the hypothesis of a conflicted situation was examined by assessing the effect of sex composition of offspring on women's intentions regarding additional children and their use of modern contraceptives. A mixed-method analysis was performed using quantitative data regarding 2567 women aged 35-49 years drawn from a 2012 Demtrend retrospective longitudinal population survey, supplemented by qualitative data collected through 23 in-depth interviews of men and women in Ouagadougou. Results showed that the absence of one sex (boy or girl) in the existing offspring was associated with additional demand for children and lower contraceptive use. These results suggest that a desire for a combination of both girls and boys may be the driving factor contributing to larger family size; that is, continued fertility may not be determined by son preference, but rather by overall composition of offspring, when existing children are all girls or all boys. This could explain the stalling of the fertility decline observed in recent years in Ouagadougou.

Dyad sex composition effect on inter-brain synchronization in face-to-face cooperation.

Human cooperation behavior based on reciprocal altruism has been a hallmark of ancient and modern societies. Prior studies have indicated that inter-brain synchronization (IBS) between partners could exist during cooperation. However, how the sex composition of dyads influences the neural synchronization is still poorly understood. Here, we adopted functional near-infrared spectroscopy (fNIRS) based hyperscanning and a task of building blocks to investigate the sex composition effect on IBS in face-to-face cooperation in a natural situation, by evaluating brain-to-brain interactions of forty-five same-sex and mixed-sex dyads. Results showed significantly stronger inter-brain synchronization in Brodmann area 10 (BA10) in cooperation. In addition, variance analysis indicated that only male-male dyads showed increased inter-brain synchronization in left inferior frontal region (i.e., BA10) specific to cooperation. More importantly, the inter-brain synchronization in male-male dyads was significantly greater than that in male-female and female-female dyads. These findings provide support for the impact of sex composition on social cooperation in a naturalistic interactive setting and extend our knowledge on the neural basis of face-to-face cooperation.

From Local to Global: External Validity in a Fertility Natural Experiment

We study issues related to external validity for treatment effects using over 100 replications of the Angrist and Evans natural experiment on the effects of sibling sex composition on fertility and labor supply. The replications are based on census data from around the world going back to 1960. We decompose sources of error in predicting treatment effects in external contexts in terms of macro and micro sources of variation. In our empirical setting, we find that macro covariates dominate over micro covariates for reducing errors in predicting treatments, an issue that past studies of external validity have been unable to evaluate. We develop methods for two applications to evidence-based decision-making, including determining where to locate an experiment and whether policy-makers should commission new experiments or rely on an existing evidence base for making a policy decision.

Birth Order, Family Size, and Sibling Sex Composition Effects in Entrepreneurship

Family background matters for entrepreneurship. The focus on factors making siblings similar rather than different, however, may understate the total importance of families for occupational choice ...

Child Sex Composition, Parental Sex Preferences, and Marital Outcomes: Evidence From a Matrilineal Context.

The authors study matrilineal settings in rural Malawi, a southeast African country, to assess if women experience better marital outcomes in the presence of daughters and if so whether daughter preference plays a role. A provocative finding in family sociology is that couples with sons experience better marital outcomes relative to those with daughters. Sociologists contend that these marital benefits are attributable to the gender system fostering greater closeness between fathers and sons, a preference for sons, or economic, cultural, and social incentives for fathers to invest more in unions that have produced sons. Extrapolating these arguments beyond son-inspired marital benefits in patriarchal settings suggests that the reverse process-daughter-inspired marital benefits-could prevail in matrilineal contexts. The authors analyze three rounds of the nationally representative Malawi Demographic and Health Survey. They estimate three series of parity-specific, multivariable logistic regression models to assess the associations between child sex composition and marital outcomes (two forms of relationship abuse and polygyny) and model each outcome among the full sample of women with one to four children and control for number of children, thus conveying the average effect of sex composition across parities. Women with daughters-particularly women with only daughters-in predominately matrilineal, rural communities in the central and southern regions of Malawi are more likely to be in monogamous versus polygynous unions and are less likely to have experienced emotionally abusive and controlling behaviors. We find little evidence that women and men explicitly prefer or pursue daughters. The study shows that a matrilineal gender system can influence marital dynamics in the presence of daughters even without fostering an overwhelming preference for them.

Coeducational and single-sex physical education: students’ situational interest in learning tasks centred on technical skills

ABSTRACTBackground: A student’s choice to engage in a learning task is highly related to the student’s environmental stimuli and his or her perception of interest. From this perspective, the construct of situational interest (SI) has been used to interpret students’ motivation in task engagement. SI is assumed to be transitory, environmentally activated, and context specific. It has been conceptualized as a multidimensional construct with five dimensions: instant enjoyment, exploration intention, attention demand, novelty, and challenge. Few prior studies have compared SI between girls and boys in physical education (PE) contexts, and these studies have offered contrasting findings. They were conducted in coeducational (coed) or single-sex contexts and used learning tasks centred on a variety of outcomes: technical or tactical skills, creativity and cultural understanding.Purpose: In the context of the debate on single-sex and coed classes in PE, this study aimed to estimate the effects of single-sex and coed PE classes on students’ situational interest (SI) within learning tasks centred on technical skills. The researchers decided to study learning tasks centred on the development of students’ technical skills, since these tasks are often used by teachers in PE.Participants: The sample consisted of 177 Swiss secondary school students, aged 11–17 years (M = 14.07, SD = 1.41, 96 boys, 81 girls).Data collection: The students completed the French 15-item SI Scale after practising a technical learning task in single-sex and coed PE contexts. The researchers chose five physical activities (i.e. athletics, basketball, dance, gymnastics, and volleyball), which are commonly taught in the state of Vaud (Switzerland) and provide a balance between masculine and feminine activities.Data analysis: A two-way repeated-measures MANOVA was performed to examine the main and interaction effects of student sex and class sex composition on the five SI dimensions.Findings: The results showed a main effect of class sex composition on student SI but no main effect of student sex and no interaction effect of student sex and class sex composition. More precisely, the scores for three SI dimensions (i.e. instant enjoyment, exploration intention, and attention demand) were higher in the coed context than in the single-sex context.Conclusions: This study encourages teachers to propose coed PE classes to enhance students’ motivation and engagement when practising learning tasks centred on technical skills. This study offers supplementary evidence of the teacher’s role in promoting student SI. Beyond accounting for students’ dispositional factors (e.g. sex), PE teachers can significantly impact students’ SI in technical learning tasks through instructional choices.

Same-Sex Parents and Children's School Progress: An Association That Disappeared Over Time.

Research is divided as to whether children living in same-sex parent families achieve different outcomes compared with their peers. In this article, we improve on earlier estimates of such differences and subsequently study whether and why the association between parental union sex composition and children's school progress changed over time. Data from the American Community Survey waves 2008-2015 (N = 1,952,490 including 7,792 children living with a same-sex couple) indicate that children living with same-sex couples were historically more likely to be behind in school but that this association disappeared over time. Changes in socioeconomic characteristics of same-sex couples played a minor role. In 2008, it was only in areas with unfavorable laws and attitudes toward same-sex couples that children living with same-sex couples were more likely to be behind in school. This was especially the case for adopted children. In more recent periods, no effect of parental union sex composition on school progress is observed within any area or among any group studied. Based on where and when these changes took place, it is suggested that changing attitudes toward same-sex couples might have played an important role in equalizing school progress across groups.

Birth Order and Sibling Sex Composition Effects Among Surviving Children in India: Enrollment Status and Test Scores

While the birth of later‐born girls seems least welcome in India, where gender discrimination persists, birth order and sibling sex composition effects among surviving children are less known. The current study investigates whether later‐born girls are discriminated from their siblings once children survive up to primary school age in India. Examining the effects on test scores reveals that there is no negative later‐born effect for girls among surviving children. Instead, girls seem to be consistently at an advantage if they have elder sisters. Furthermore, gender bias among primary school age children is detected only in households of larger size. This implies that gender discrimination is severe in terms of survival, but once children survive up to primary school age they are treated equally.

The glorified mothers of sons: Evidence from child sex composition and parental time allocation in rural China

We study the effects of sons versus daughters on parental joint time allocation between the labor market and the household. Using data from the China Health and Nutrition Survey from 1989 to 2006, we apply a fixed-effects model to control for cross-household heterogeneity in son preference. We find that the birth of sons rather than daughters significantly reduces maternal time spent on household chores, which we argue represents an increase in maternal intra-household bargaining power. However, the effects of sex composition of children on paternal time allocation and maternal time on labor-market activities are weak or mixed. Results are robust to a series of sensitive analyses.

Premarital birth, children’s sex composition and marital instability among women in sub-Saharan Africa

Anecdotal evidence in sub-Saharan Africa (SSA) suggests that it is unlikely for marriages with children to break up, especially when the children are male. To provide new empirical evidence, this study was conducted to investigate the effect of premarital birth and sex composition of children on marital instability (divorce or separation) among ever-married women in SSA. Data from a weighted sample of 205,997 women from Demographic and Health Surveys conducted in 26 sub-Saharan African countries between 2011 and 2014 were analysed. Stratified by sub-region, analysis involved the use of descriptive statistics and multiple logistic regression models with robust standard errors. Parity-specific logistic regression models were fitted to investigate the association between sex composition and marital instability at parities 1, 2, 3 and 4+. The percentage of women with experience of marital instability in the four sub-regions was: Western (4.6%), Central (12.0%), Eastern (10.5%) and Southern Africa (11.4%). Premarital birth was significantly associated with marital instability in Western (OR = 1.52, p < 0.05), Central (OR = 1.22, p < 0.05), Eastern (OR = 1.39, p < 0.05) and Southern Africa (OR = 1.25, p < 0.05). In Western Africa, at parities 1–2, women with female children were significantly more likely to be divorced or separated. At parities 3 and above, there was no significant difference in the odds of marital instability between women with majority male and those with majority female children. This study extends current knowledge about family dynamics by providing a wider view on the relationship between premarital birth, children’s sex composition and marital instability in the four sub-regions of sub-Saharan Africa.

Effect of Sex Composition of Children on the Gender of Next Birth in the Context of Low Fertility in Rural China

China currently has the world’s most skewed national sex ratio at birth. In this paper, we use data from China’s 2001 National Family Planning and Reproductive Health Survey and employ hierarchical logistic models to study how macro factors (mainly fertility policy and economic indicators, as represented by per capita GDP of the village units sampled in this research) and micro factors (mainly fertility intention and sex composition of children) affect the gender of the next birth. We find that the effect of fertility policies is intertwined with the sex composition of children already born. For those couples who have had a son (or sons), fertility policy exerts no effect; but for those with only daughters, the effect is significant. Furthermore, fertility intention, independent from fertility policy, has a significant effect on the gender of the next birth.

The Importance of Team Sex Composition in Team-Training Research Employing Complex Psychomotor Tasks

The relationship between team sex composition and team performance on a complex psychomotor task was examined because these types of tasks are commonly used in the lab-based teams literature. Despite well-documented sex-based differences on complex psychomotor tasks, the preponderance of studies-mainly lab based-that use these tasks makes no mention of the sex composition of teams across or within experimental conditions. A sample of 123 four-person teams with varying team sex composition learned and performed a complex psychomotor task, Steal Beasts Pro PE. Each team completed a 5-hr protocol whereby they conducted several performance missions. The results indicated significant large mean differences such that teams with larger proportions of males had higher performance scores. These findings demonstrate the potential effect of team sex composition on the validity of studies that use complex psychomotor tasks to explore and investigate team performance-related phenomena when (a) team sex composition is not a focal variable of interest and (b) it is not accounted for or controlled. Given the proclivity of complex psychomotor action-based tasks used in lab-based team studies, it is important to understand and control for the impact of team sex composition on team performance. When team sex composition is not controlled for, either methodologically or statistically, it may affect the validity of the results in teams studies using these types of tasks.

Individualising the exposure of −110 °C whole body cryotherapy: The effects of sex and body composition

The purpose of this study was to investigate the effects of whole body cryotherapy (WBC) on a range of thermoregulatory measures. We also sought to examine the influence of sex and body composition. A convenience sample of 18 healthy participants (10 males and 8 females) (27±6yr) volunteered for this study. Temperature (core, tympanic, skin and mean body), heart rate, blood pressure, and thermal comfort and sensation were recorded pre- and post- (immediately and every 5min until 35min post) exposure to a single bout of WBC (30s at −60°C, 150s at 110°C). Anthropometric data (height, weight, body surface area, body mass index, fat mass and fat free mass) were also recorded. No significant differences in temperature (core, tympanic, skin and mean body), heart rate, blood pressure, or thermal comfort / sensation were observed between male and females at baseline. Immediately post WBC mean body (male:31.9±0.8°C; female:31.0±0.9°C; ∆ mean body temperature:0.9±0.1°C; P≤0.05, d=0.64) and mean skin (male:22.1±2.2°C; female:19.6±2.8°C; ∆ mean skin temperature:−2.5±0.6°C; d=0.99, P≤0.05) temperature was significantly different between sexes. Sex differences were also observed in regional skin temperature (male thigh, 20.8±1.1°C; female thigh, 16.7±1.1°C, ∆ mean thigh skin temperature:−4.1°C; d=3.72; male calf, 20.5±1.1°C; female calf, 18.2±1°C, ∆ mean calf skin temperature:−2.3±0.1°C; d=3.61; male arm, 21.7±1°C; female arm, 19±0.4°C, ∆ mean arm skin temperature: −2.7±0.3°C; d=3.54; P≤0.05). Mean arterial pressure was significantly different over time (P≤0.001) and between sexes (male 0mins:94±10mmHg; female 0mins:85±7mmHg; male 35mins:88±7mmHg; female 35mins:80±6mmHg; P≤0.05). Combined data set indicated a strong negative relationship between skin temperature and body fat percentage 35min’ post WBC (r=−0.749, P≤0.001) and for core temperature and body mass index in males only (r=0.726, P≤0.05) immediately after WBC. There were no significant differences between sexes in any other variables (heart rate, tympanic and perceptual variables). We observed sex differences in mean skin and mean body temperature following exposure to whole body cryotherapy. In an attempt to optimise treatment, these differences should be taken into account if whole body cryotherapy is prescribed.

Double take: The effect of sibling sex composition on women’s schooling, earnings, and labor supply

Understanding the role of the family in the production of human capital is a salient question in economics. Using a twin research design that exploits exogenous gender variation in dizygotic twins, this paper investigates the effect of sibling sex composition on schooling, earnings, and labor supply. Women born with a male co-twin have higher earnings and increased rates of high school completion than women born with a female co-twin. Men born with a female co-twin, on the other hand, have outcomes that are statistically indistinguishable from zero. Family attributes provide a limited explanation of the sex composition effect.