Genetic influence on age at first birth of female twins born in the UK, 1919–68

Using a sample of monozygotic (945, 42?per cent) and dizygotic (1,329, 58?per cent) twin pairs born 1919–68 in the UK, we applied innovative tobit models to investigate genetic and environmental influences on age at first birth (AFB). We found that a substantial part (40?per cent) of the variation in AFB is caused by latent family characteristics. Genetic dispositions (26?per cent) play a more important role than the shared environment of siblings (14?per cent), with the non-shared environment/measurement error having the strongest influence (60?per cent). Like previous studies, this study reveals marked changes in estimates over time, and supports the idea that environmental constraints (war or economic crisis) suppress and normative freedom (sexual revolution) promotes the activation of genetic predispositions that affect fertility. We show that the exclusion of censored information (i.e., on the childless) by previous studies biased their results.

Supplementary material for this article is available at: http://dx.doi.org/10.1080/00324728.2015.1056823     

Early life exposures and the occurrence and timing of heart disease among the older adult Puerto Rican population

Few studies have examined the effects of early life conditions on the timing of the onset of heart disease. We use the remarkable example of a representative sample of the population of older Puerto Ricans aged 60– 74 who lived in the countryside during childhood (n = 1,438) to examine the effects of seasonal exposures to poor nutrition and infectious diseases during late gestation on the timing of the onset and the probability of ever experiencing adult heart disease. Cox and log logistic hazard models controlling for childhood conditions (self-reported childhood health status and socioeconomic status [SES], rheumatic fever, and knee height) and adult risk factors (adult SES, obesity, smoking, texercise, and self-reported diabetes) showed that the risk of onset of heart disease was 65% higher among those born during high-exposure periods compared with unexposed individuals. However, there were no significant differences in median time of onset for those ever experiencing heart disease. As a comparison, we found that there were no significant seasonality effects for those who lived in urban areas during childhood. We conclude that early exposures in utero have important ramifications for adult heart disease among the older Puerto Rican population. We show, however, that while exposure is associated with the probability of ever experiencing adult heart disease, it is not associated with the timing of onset among those who do experience it.     

A National Survey on Depression,Internalized Homophobia,College Religiosity,and Climate of Acceptance on College Campuses for Sexual Minority Adults

ABSTRACT

Sexual minority persons have an increased risk for negative mental health outcomes in adulthood. This seems to largely be due to experiences of stigma in social settings. This study sought to understand the relationship between attending a religiously conservative college, internalized homophobia (a measure of sexual stigma), and depressive symptoms for sexual minority adults. Sexual minority adult participants (n = 384) from across the U.S. were recruited and completed a Web-based, anonymous survey. A mediation model predicting depression through college religious conservatism, college acceptance of sexual minority identities, and internalized homophobia was tested using path analysis. Results revealed an indirect effect of increased religious conservatism of a college predicted higher depression through lower college acceptance and higher internalized homophobia. Implications for the mental health of sexual minority adults and future research are examined.     

Social demographic change and autism

Parental age at child’s birth—which has increased for U.S. children in the 1992–2000 birth cohorts—is strongly associated with an increased risk of autism. By turning a social demographic lens on the historical patterning of concordance among twin pairs, we identify a central mechanism for this association: de novo mutations, which are deletions, insertions, and duplications of DNA in the germ cells that are not present in the parents ’ DNA. Along the way, we show that a demographic eye on the rising prevalence of autism leads to three major discoveries. First, the estimated heritability of autism has been dramatically overstated. Second, heritability estimates can change over remarkably short periods of time because of increases in germ cell mutations. Third, social demographic change can yield genetic changes that, at the population level, combine to contribute to the increased prevalence of autism.     

Sex-Structured Dynamic of Multi-Group Herpes Simplex Virus 2

A 3(n + l)-dimensional ordinary differential equation for HSV-2 includes l groups of men and n groups of women with different risks of infection. Global Lyapunov functions based on graph theory and on LaSalle invariance principle show that the model dynamics are completely determined by the basic reproduction number ?₀. The disease-free equilibrium is globally asymptotically stable when ?₀ ≤ 1; a unique endemic equilibrium is globally asymptotically stable in the interior of the feasible region when ?₀ > 1.     

A distance measure of spatial pattern in a biological population

Summary Suppose thatn individuals locate independently and randomly on a segment of line of finite length (habitat). Let the theoretical and observed ranges of the sites of the individuals on the segment be μ _n-1 andr _n-1, respectively. Then, the degree of dispersion of the individual sites is measured by the ratio, T _n =n _n-1/μ _n-1, as follows: A random spatial pattern forI _r−1 =1 An aggregated spatial pattern for 0≤I _r <1 A uniform spatial pattern for (n+1)/(n−1)≥I _r >1. Another method was derived. Let the probability that an observed range is less thanr _n−1 beI _p , under the hypothesis of a Beta distribution. Then indicates A random spatial pattern forI _p =1/2 An aggregated spatial pattern forI _p <1/2 A uniform spatial pattern forI _p >1/2. The first index can be used for comparing populations having the same number of individuals, whereas the second one can be used for comparing populations with different numbers of individuals.     

Community Cleavages: Gay and Bisexual Men’s Perceptions of Gay and Mainstream Community Acceptance in the Post-AIDS,Post-Rights Era

Changes in gay and bisexual men’s connectedness to the gay community are related to the declining public visibility of HIV/AIDS and greater acceptance for homosexuality and bisexuality in mainstream society. Little work, however, has focused on perceived acceptance for subgroups within the gay community or broader society. Using interviews (n = 20) and a survey (n = 202) of gay and bisexual men in a mid-sized Canadian city, we find perceived hierarchies of acceptance for the various subgroups as well as an age effect wherein middle-aged men perceive the least acceptance for all groups. These differences are linked with the uneven impact of social, political, and institutional changes relevant to gay and bisexual men in Canada.     

Bayesian Estimation for Quantification by Real-time Polymerase Chain Reaction Under a Branching Process Model of the DNA Molecules Amplification Process

The aim of Quantitative Polymerase Chain Reaction is to determine the initial amount X ₀ of specific nucleic acids from an observed trajectory of the amplification process, the amplification being achieved through successive replication cycles. This process depends on the efficiency {p _n } _n of replication of the DNA molecules, p _n being the probability that a molecule will duplicate at replication cycle n. Assuming p _n  = p for all n, Bayesian estimators of the unknown parameter θ = (p, X ₀) are constructed by Markov Chain Monte Carlo methods under a Bienaymé-Galton-Watson branching model of the amplification process. The Bayesian approach takes into account some prior information on the parameter. Relying on simulated data, the proposed Bayesian estimators and their credibility sets are shown to be quite accurate.     

The genetic heterogeneity of deer mouse populations ( Peromyscus maniculatus ) in an insular landscape

A survey of the genetic variability in deer mouse populations was performed using specimens collected from six different islands on a lake covering approximately 50 km². Random amplified polymorphic DNA (RAPD) was used to measure the extent of the genetic differences in this insular system. An analysis of molecular variance (AMOVA) revealed that populations are clearly separated at this microgeographic scale (F _st = 0.13863; P < 0.001). The homogeneity of molecular variance test (HOMOVA) indicated that within-population levels vary greatly (B _p = 0.76831; P < 0.001). The within-population molecular variance was found to be mainly correlated with the accessibility of the islands, computed as the inverse of the geographic distance separating an island from the lakeshore (r = 0.916; P < 0.003). Received: March 5, 1999 / Accepted: July 16, 1999     

Feeling Close to Fellow Citizens in Hong Kong,Korea, Taiwan,and Thailand

Feeling close to fellow citizens in the city is a feature of social cohesion that is worth investigation among East Asian societies for exploring societal conditions for the closeness. Because of the variation of such conditions among the societies, differentials in the closeness among the societies are possible. As the variation of societal conditions can translate into differences in personal characteristics and experiences, such differences are likely to explain differentials in the closeness. This likelihood is a focus for the present study, which surveyed 4,087 adult citizens in Hong Kong (n = 681), South Korea (n = 1,006), Taiwan (n = 1,200), and Thailand (n = 1,200). Results revealed significant differentials in the closeness among the societies, showing that it was highest in Thailand and lowest in Taiwan. Furthermore, these differentials were largely due to differences in personal and characteristics among citizens in the four societies. Among the significant predictors of the closeness, work-family conflict and the costliness of medical expense are two experiences. The two experiences, as well as other predictors, champion a conflict or social force explanation for citizens’ closeness. Accordingly, conflict or social force that is incapacitating would estrange the incapacitated individual from others. The results and explanation imply that relieving work and family conflicts is relevant to lifting citizens’ closeness. In conclusion, the East Asian societies manifested differentials in citizens’ social cohesion, and the differentials are explicable by differentials in resources and conflicts among the societies.     

Social Problem Solving as a Predictor of Well-being in Adolescents and Young Adults

Social problem solving is the cognitive-affective-behavioral process by which people attempt to resolve real-life problems in a social environment, and is of key importance in the management of emotions and well-being. This paper reviews a series of studies on social problem solving conducted by the authors. First, we developed and validated the Chinese version of the Social Problem-Solving Inventory Revised (C-SPSI-R) which demonstrated very good psychometric properties. Second, we identified the scope of stressful social situations faced by young adults and their self-efficacy in facing such situations (N = 179). Young adults were generally confident about their basic social skills but found it much more stressful to relate to family members, handle conflicts, handle negative behaviors from others, self-disclose to others, and to express love. Third, in two separate studies, we found that social problem solving was closely linked to measures of depression (n = 200), anxiety (n = 235), and family well-being (N = 1462). Measures of anxiety and depression were found to be significantly related to aspects of social problem solving in expected directions and expected strength. In another study, higher parental social problem solving behavior and lower avoidance behavior were found to be related to indicators of family well-being, including better overall family functioning, and fewer parent–adolescent conflicts.     

A mixed methods study: Midlife African American women’s knowledge,beliefs, and barriers to well-woman visit,flu vaccine,and mammogram use

ABSTRACT

African American women (AAW) are particularly at risk for deleterious health outcomes that might be mitigated through increased preventive care use. A mixed methods study that examined relationships between knowledge of, beliefs about, and barriers to well-woman visits, flu vaccines, and mammograms was conducted with midlife AAW who participated in an online survey (n = 124) and in-depth interviews (n = 19). Findings showed that greater knowledge of preventive service recommendations and positive patient-provider relationships were associated with greater preventive service use. Flu vaccines were significantly underused. Study implications inform strategies to increase preventive care utilization among AAW and increase capacities to improve health disparities.     

Preliminary studies on the respiratory energy loss of a spider,Lycosa pseudoannulata

Summary To elucidate the basic food requirement of spiders, the important polyphagous predators of rice-plant insect pests, an attempt was made to measure the respiratory energy loss of fasting spiders,Lycosa pseudoannulata. Relationship between fresh (y) and dry (x) weights of spiders inhabiting the bottom layer of the rice-plant community was represented by the following allometric equation:y=0.428x ^0.872. The carbon dioxide production by previously fed and unfed females under the dark at 29°C 100% R. H. was measured by a titration technique. The relationship between fresh body weight and CO₂ production by unfed animals could be represented by the equationM=aW ^b, M being the CO₂ output per individual per day andW the fresh body weight. The constantb, which determines the slope of curve, was 0.808. Respiration of the adult female with 100 mg fresh weight was 1.155±0.250 mg CO₂/100 g fresh weight/day or 48.69 mg CO₂/g dry weight/day. This value corresponds to 35.81 cal/g fresh weight/day or 150.94 cal/g dry weight/day. Supposing the calorific content of spiders to be 5820 cal/g dry weight, rate of the respiratory energy loss to total energy of the body was estimated to be 2.60%. This rate did not strongly contradict with the loss of fresh body weight before and after the measurement. The metabolic rate showed remarkable fluctuation with changing food supply. The CO₂ production of starved individuals decreased to 83.63±16.34% as compared with individuals which were fed before the measurement.     

Adolescent Same-Sex Attraction and Mental Health: The Role of Stress and Support

This study draws on the social stress model from the sociology of mental health to examine the impact of same-sex attraction on depressed mood and suicidal tendencies. Specifically, we hypothesize that across multiple contexts, adolescents with same-sex attractions are likely to experience more social stress and less social support than heterosexual adolescents. In turn, these experiences increase the likelihood of negative mental health outcomes. Using data from the National Longitudinal Study of Adolescent Health (n = 11,911), we find that adolescents with same-sex attraction are more likely than their heterosexual counterparts to report depressed mood and suicidal tendencies. Moreover, stress and social support were found to mediate a substantial part of the relationship between same-sex attraction and depressed mood. In addition, stress and social support mediated about one third of the relationship between same-sex attraction and suicidal tendencies. These findings give strong support for the social stress model. We conclude with a discussion of the role that alienation plays in same-sex-attracted adolescent mental health.     

What Kind of Self-Care Strategies Do People Report Using and is There an Association with Well-Being?

Objectives: The aim of this study was to describe what kind of self-care strategies people report using to improve or maintain their well-being. Furthermore, we also wanted to investigate whether reports of using self-care strategies were associated with well-being. Methods: A selected sample (n=871), aged between 20 and 64 years, living in Stockholm County, answered an open-ended question about self-care strategies. Well-being was assed using the WHO (Ten) well-being index. Results: Ten different categories were found. The most commonly reported self-care strategy was physical exercise, followed by social support and engaging in pleasurable activities. Physical exercise, social support, relaxation, and physical health were associated with a better well-being, social support being strongest correlated. Conclusion: The results suggest that reports of using certain self-care strategies are associated with a better well-being.     

Paving the way for successful twinning:: Using grounded theory to understand the contribution of twin pairs in twinning collaborations

BackgroundTwinning collaborations, where two groups — from educational institutions, hospitals or towns — work together cross-culturally on joint goals, are increasingly common worldwide. Pairing up individuals, so-called twin pairs, is thought to contribute to successful collaboration in twinning projects, but as yet, there is no empirical evidence or theory that offers insight into the value of the pair relationship for twinning.AimTo explore the contribution of one-to-one relationships between twins to twinning projects, as exemplified in projects between Dutch and Moroccan, and Dutch and Sierra Leone midwives.MethodsWe conducted thirteen in-depth interviews with midwives from two twinning collaborations. Interviews were transcribed and analysed using an iterative, grounded theory process, yielding a theoretical understanding of one-to-one twinning relationships for twinning collaborations.FindingsParticipant comments fell into four substantive categories: 1) Being named a twin, 2) moving beyond culture to the personal level, 3) searching for common ground to engage, 4) going above and beyond the twinning collaboration. Their interplay demonstrates the value of twin pairs in paving the way for successful twinning.DiscussionA complex combination of contextual inequities, personality, and cultural differences affect the twin relationship. Trusting relationships promote effective collaboration, however, as ‘trust’ cannot be mandated, it must be built by coaching twins in personal flexibility and (cultural) communication.ConclusionBy offering original insights into the ways twinning relationships are built, our research explores how twin pairs can enhance the success of twinning projects.     

Typology of Gay Consumers’ Interaction Styles on Complaining Propensity

The purpose of this study is to develop a typology of gay male consumers based on self-concept variables related to social interactions. Openness about sexual orientation, collective self-esteem, stigma-consciousness, and negative evaluation were used to identify clusters of gay male consumers. An initial test sample (n = 125) suggested a three-cluster solution, and a validation sample (n = 247) established reproducibility of the proposed typology. Three clusters with distinct interaction styles emerged: “confident gay,” “diffident gay,” and “guarded gay.” Additionally, the usefulness of the typology is demonstrated by comparing the clusters on the basis of complaining propensity. Typologies of each cluster and implications for research and practice are discussed.     

Is the Association Between Education and Fertility Postponement Causal? The Role of Family Background Factors

A large body of literature has demonstrated a positive relationship between education and age at first birth. However, this relationship may be partly spurious because of family background factors that cannot be controlled for in most research designs. We investigate the extent to which education is causally related to later age at first birth in a large sample of female twins from the United Kingdom (N = 2,752). We present novel estimates using within–identical twin and biometric models. Our findings show that one year of additional schooling is associated with about one-half year later age at first birth in ordinary least squares (OLS) models. This estimate reduced to only a 1.5-month later age at first birth for the within–identical twin model controlling for all shared family background factors (genetic and family environmental). Biometric analyses reveal that it is mainly influences of the family environment—not genetic factors—that cause spurious associations between education and age at first birth. Last, using data from the Office for National Statistics, we demonstrate that only 1.9 months of the 2.74 years of fertility postponement for birth cohorts 1944–1967 could be attributed to educational expansion based on these estimates. We conclude that the rise in educational attainment alone cannot explain differences in fertility timing between cohorts.     

The Influence of the Built Environment and Other Factors on the Physical Activity of Older Women from Different Ethnic Communities

ABSTRACT

Inactivity has been identified as a major contributor to the burden of disease in older women. Study aims were: (a) to assess the personal, social, and environmental facilitators and impediments to physical activity in older women from ethnic communities; and (b) to determine the factors associated with physical activity participation. Older women (aged 60–84 years) were recruited from the local Italian (n = 20), Vietnamese (n = 26) and Anglo-Celtic (n = 26) communities. A survey questionnaire was administered in the participants' preferred language. The most common barriers were: “I am not in good health,” “I am self-conscious about my looks,” “I am too tired,” “I don't have time,” and “The weather is bad.” When comparing the ethnic groups, the Vietnamese women reported fewer barriers than the Italian women (2.6 vs. 5.9). While the Vietnamese women were much more likely to report being “self-conscious about my looks,” the Italian women more commonly reported poor health, being too tired, and not liking exercise as barriers. Overall, those living alone were more likely to be active and those who reported fear of injury, less active. Recognizing ethnospecific differences in the prevalence of barriers may be important when devising strategies to increase activity levels of older women.     

The Association Between Perceived Spirituality, Religiosity, and Life Satisfaction: The Mediating Role of Self-Rated Health

This study examined the mediating role of self-perceived health between perceived spirituality, religiosity, and life satisfaction among a stratified, random sample of college students, while controlling for gender. Although both models displayed excellent fit criteria, the perceived spirituality and life satisfaction model was fully mediated by self-perceived health χ² (n=459, 4) = 1.64, p=0.80, CFI =0.99, TLI=0.99), and the perceived religiosity and life satisfaction model was partially mediated by self-perceived health χ² (n=459, 10) = 22.29, p=0.01 CFI = 0.99, TLI = 0.99). Both models were equal for men and women. Students who describe themselves as spiritual (or religious) are likely to report greater self-perceived health and greater self-perceived health likely influences life satisfaction for both men and women. Results preliminarily support the contention that life satisfaction is related to differing reported health status, whether physical or mental, and that life satisfaction may be influenced by religiosity and spirituality engagement. Implications for colleges and universities are discussed.