Female autonomy as a contributing factor to women's HIV-related knowledge and behaviour in three culturally contrasting States in India

Factors contributing to India's vulnerability to the AIDS epidemic include pervasive poverty, low levels of education and high gender stratification. This study uses data collected in the 1998-99 National Family Health Survey-2 (NFHS-2) to investigate the relationship between aspects of women's autonomy and four measures of HIV-related knowledge and behaviour--awareness and knowledge of HIV/AIDS, condom awareness and condom use--in three culturally contrasting states in India: Kerala (n=2884), Karnataka (n=4357) and Uttar Pradesh (n=8981). The NFHS-2 is a nationally representative survey of India, with a sampling scheme that was designed such that each state sample can be generalized back to represent ever-married women aged 15-49 living in the state. Kerala scores highest in the four health outcome measures, followed by Karnataka and then Uttar Pradesh, but condom use is lowest in Karnataka. Kerala also leads in the four dimensions of autonomy examined and in socio-demographic status, followed again by Karnataka and Uttar Pradesh. Despite these observed differences, in all three states, women with greater autonomy as measured by this study were more likely to be knowledgeable about AIDS and condoms and to use condoms, after controlling for socio-demographic factors. These results concur with other studies focusing on women's autonomy and health outcomes around the world, and point to the importance of incorporating a gender-based approach to AIDS prevention programmes in India.     

Differential sex allocation in sand lizards: bright males induce daughter production in a species with heteromorphic sex chromosomes

In sand lizards (Lacerta agilis), males with more and brighter nuptial coloration also have more DNA fragments visualized in restriction fragment length polymorphism analysis of their major histocompatibility complex class I loci (and, hence, are probably more heterozygous at these loci). Such males produce more viable offspring, with a particularly strong viability effect on daughters. This suggests that females should adjust both their reproductive investment and offspring sex ratio in relation to male coloration (i.e. differential allocation). Our results show that experimental manipulation of partner coloration in the wild results in significantly higher maternal effort and a 10% higher proportion of daughters than sons. This supports the hypothesis that females increase their maternal energetic expenditure and adjust their offspring sex ratio in response to high-quality partners. However, it also suggests that this has probably evolved through natural selection for increased offspring viability (primarily through production of daughters), rather than through increased mate attraction (e.g. sexy sons).     

Age and sex variation in measures of body composition among the elderly Bengalee Hindus of Calcutta, India

In the present cross-sectional study we examined 332 (171 men and 161 women) elderly (60 years and above) urban Bengalee Hindu resident in south Calcutta, India. Individuals were selected by random sampling procedure using local voter's registration list. Skin folds measures were used to compute body composition measures among them. There existed significant sex differences in various anthropometric body composition measures. Age had significant (p < 0.001) negative association with all anthropometric body composition measures namely percentage of body fat (PBF), fat mass (FM), arm muscle circumference (AMC), arm muscle area (AMA) and arm fat area (AFA) in both sexes. Fat free mass (FFM) in contrast had negative but not significant age impact. Regression analyses demonstrated that age had explained substantial amount of variance of PBF (men = 32%; women = 18.2%), FM (men = 18.2%; women = 12.8%), AMC (men = 23.4%; women = 19.2%), AMA (men = 22.2%; women = 10.2%) and AFA (men = 34%; women = 31%) in both sexes. Two-way ANOVA revealed age-sex interaction only had significant effect on FFM. The present investigation vindicated that there is a significant inverse age trends in anthropometric body composition measures among the Bengalee Hindus. Moreover, there existed sexual dimorphism in the effect of age on various anthropometric body composition measures.     

Polyandrous females benefit by producing sons that achieve high reproductive success in a competitive environment

Females of many taxa often copulate with multiple males and incite sperm competition. On the premise that males of high genetic quality are more successful in sperm competition, it has been suggested that females may benefit from polyandry by accruing 'good genes' for their offspring. Laboratory studies have shown that multiple mating can increase female fitness through enhanced embryo viability, and have exposed how polyandry influences the evolution of the ejaculate. However, such studies often do not allow for both female mate choice and male-male competition to operate simultaneously. Here, I took house mice (Mus domesticus) from selection lines that had been evolving with (polygamous) and without (monogamous) sperm competition for 16 generations and, by placing them in free-ranging enclosures for 11 weeks, forced them to compete for access to resources and mates. Parentage analyses revealed that female reproductive success was not influenced by selection history, but there was a significant paternity bias towards males from the polygamous selection lines. Therefore, I show that female house mice benefit from polyandry by producing sons that achieve increased fitness in a semi-natural environment.     

Temperature-related birth sex ratio bias in historical Sami: warm years bring more sons

The birth sex ratio of vertebrates with chromosomal sex determination has been shown to respond to environmental variability, such as temperature. However, in humans the few previous studies on environmental temperature and birth sex ratios have produced mixed results. We examined whether reconstructed annual mean temperatures were associated with annual offspring sex ratio at birth in the eighteenth to nineteenth century Sami from northern Finland. We found that warm years correlated with a male-biased sex ratio, whereas a warm previous year skewed sex ratio towards females. The net effect of one degree Celsius increase in mean temperature during these 2 years corresponded to approximately 1% more sons born annually. Although the physiological and ecological mechanisms mediating these effects and their evolutionary consequences on parental fitness remain unknown, our results show that environmental temperature may affect human birth sex ratio.     

Otter scent signals age, sex, and reproductive status

Scent is used across taxa to communicate information about signaler identity. Eurasian otters Lutra lutra are mainly solitary and thought to use scent as their primary means of communication. Little is known, however, about what information otters communicate through scent or what social function this performs. Headspace solid-phase microextraction and gas chromatography-mass spectrometry were used to sample and analyze volatile organic compounds from anal scent gland secretion from 158 otters of differing sex, age, and female reproductive status. Univariate and multivariate differences were clear between adult and juvenile otters. Complex sex differences were apparent in adult otters but not in younger individuals, suggesting the use of this scent secretion in mate attraction. The scent of pregnant and lactating females was highly differentiated from male and juvenile scent, but anecdotal reports suggest females avoid communication during these times.     

Sexual behaviour: a receptor for sex control in Drosophila females

Male Drosophila manipulate the sexual behaviour of their female mating partners by release of a Sex-peptide, but how does this work? A G-protein-coupled receptor has now been identified which acts in the female flies to detect male Sex-peptide and trigger increased egg laying and reduced sexual receptivity.     

A model of fertility motivation, desires, and expectations early in women's reproductive careers

We propose a general model of the relationships connecting fertility motivations, desires, and expectations in which motivations are antecedent to desires, which in turn are antecedent to expectations. We describe differences in the model as it applies to women early in their reproductive careers, specifically, after marriage but before their 1st birth and after their 1st birth but before their 2nd. We test the model with data from 311 just-married and 318 just-mothered US women enrolled in a prospective psychology of reproduction study, using LISREL (analysis of linear structural relationships by the method of maximum likelihood) software to estimate structural equations for both groups. The general model fits the data well. There are 3 primary differences in the model with respect to the 2 groups of married women. How soon a woman expects her next child affects how many children she expects only among the just-married woman. The number of children expected by the woman is the only antecedent to how soon she expects her next child among the just-mothered women. Both positive and negative maternal motivation has effects among the just-married women, but only negative maternal motivation has effects among the just-mothered women. These and other differences are discussed in terms of psychological and situational developments occurring early in women's reproductive careers.     

Fetal sex determination in infants in Punjab,India: correlations and implications.

OBJECTIVES--To determine the proportion of children whose sex was determined prenatally among those attending one Indian hospital and to identify factors which affect use of fetal sex determination. DESIGN--Cross sectional study using interviews with mothers. SETTING--Medical school hospital in Punjab, India. SUBJECTS--596 children delivered or seen for inpatient or outpatient care. MAIN OUTCOME MEASURES--Fetal sex determination, sex of child, number and sex of siblings, type of care received, socioeconomic status, and maternal education. RESULTS--Sex had been determined prenatally for fewer girls (5/236, 2%) than boys (49/360, 14%). Fetal sex determination had been done for only 2% (3/154) of first born boys compared with 18% (12/66) with one older sister and no older brother and 63% (30/48) with more than one older sister and no older brother. Only four boys whose sex had been determined prenatally had older brothers. The five girls whose sex had been determined prenatally either had a male twin or were incorrectly identified as male. Prenatal sex determination had been done for 21% (26/122) of boys admitted for inpatient care compared with 11% (19/173) seen as outpatients. Use of fetal sex determination increased with increasing monthly income (chi2 for trend = 6.384, P = 0.0115). None of the mothers who had had no education had used fetal sex determination, but among mothers with some education the frequency of use did not change with increasing education. The sex ratio of children born at the hospital rose from 107 boys/100 girls in 1982 to 132 boys/100 girls in 1993. CONCLUSIONS--Fetal sex determination was common, especially if the family already had daughters. Sex determination seems to be driven by a desire to have sons, with socioeconomic status and education having little effect. The lower prevalence of fetal sex determinations for girls is likely to be due to abortion of fetuses found to be female.     

Testes size, testosterone production and reproductive behaviour in a natural mammalian mating system

1. Testosterone (T) is a key mediator in the expression of numerous morphological and behavioural traits in mammals, but the factors underlying individual variation in circulating T levels are poorly understood. 2. The intimate structural integration of sperm and T production within the testes, alongside the dependency of sperm production on high levels of T, suggests that T requirements for spermatogenesis could be an important driver of individual differences in T. 3. To test this hypothesis, we examine how male capacity for sperm production (as indicated by their testes size) is associated with T levels in a feral population of Soay sheep, resident on St. Kilda, Scotland, during their rutting season. 4. We found a strong positive relationship between an individual's testes size (as measured before their seasonal enlargement) and the levels of circulating T during their rut, suggesting that T requirements for spermatogenesis has a prominent influence on the production of this androgen. 5. In contrast, body condition and competitive ability did not independently predict T levels, findings that are inconsistent with conventional 'condition-dependent' and 'challenge' hypotheses of T production. 6. This influence of male's capacity for sperm production on T appeared to be substantial enough to be biologically relevant, as testes size also predicted male aggression and mate-seeking behaviour. 7. Our results suggest that a male's inherent capacity for sperm and T production is tightly phenotypically integrated, with potential consequences for a wide range of other T-mediated reproductive traits.     

A model of fertility motivation,desires, and expectations early in women's reproductive careers

Abstract

We propose a general model of the relationships connecting fertility motivations, desires, and expectations in which motivations are antecedent to desires, which in turn are antecedent to expectations. We describe differences in the model as it applies to women early in their reproductive careers, specifically, after marriage but before their first birth and after their first birth but before their second. We test the model with data from 311 just‐married and 318 just‐mothered women, using LISREL to estimate structural equations for both groups. The general model fits the data well. There are three primary differences in the model with respect to the two groups of married women. How soon a woman expects her next child affects how many children she expects only among the just‐married woman. The number of children expected by the woman is the only antecedent to how soon she expects her next child among the just‐mothered women. Both positive and negative maternal motivation has effects among the just‐married women, but only negative maternal motivation has effects among the just‐mothered women. These and other differences are discussed in terms of psychological and situational developments occurring early in women's reproductive careers.     

Maternal nutrition affects reproductive output and sex allocation in a lizard with environmental sex determination

Life-history traits such as offspring size, number and sex ratio are affected by maternal feeding rates in many kinds of animals, but the consequences of variation in maternal diet quality (rather than quantity) are poorly understood. We manipulated dietary quality of reproducing female lizards (Amphibolurus muricatus; Agamidae), a species with temperature-dependent sex determination, to examine strategies of reproductive allocation. Females maintained on a poor-quality diet produced fewer clutches but massively (twofold) larger eggs with lower concentrations of yolk testosterone than did conspecific females given a high-quality diet. Although all eggs were incubated at the same temperature, and yolk steroid hormone levels were not correlated with offspring sex, the nutrient-deprived females produced highly male-biased sex ratios among their offspring. These responses to maternal nutrition generate a link between sex and offspring size, in a direction likely to enhance maternal fitness if large body size enhances reproductive success more in sons than in daughters (as seems plausible, given the mating system of this species). Overall, our results show that sex determination in these animals is more complex, and responsive to a wider range of environmental cues, than that suggested by the classification of 'environmental sex determination'.     

Stress, behaviour and reproductive performance in female cattle and pigs

Female farm animals are exposed to a great variety of environmental and management related stressors. As a consequence, their reproductive and maternal abilities may be compromised through mechanisms acting on the hypothalamic, pituitary, ovarian and uterine function. Responses to short- and long-term stressors may differ as short-term stressors often fail to affect reproduction or even may have stimulatory effects. Thus, the stress response induces diverse neuroendocrine reactions that can either increase or decrease the probability of an animal reproducing depending on the specific situation. The aim of the present review is to summarise the current knowledge on the stress concept and its implications on behaviour and reproductive performance in cows and female pigs as phenomena reported in laboratory animals are unable to explain all effects encountered in domesticated farm animals.     

Play behaviour in lowland gorillas: Age differences,sex differences,and possible functions

A study on lowland gorilla (Gorilla gorilla gorilla) play behaviour was conducted on four exhibits at three different zoological parks so that 19 gorillas were observed. Juvenile gorillas played the most, but play continued at fairly high frequencies through adolescence. Most social play occurred between dyads. Triadic groups usually chased each other. No sex differences in type of play were observed, but gender differences in partner preferences were observed. Males played with both other males and females, while females seldom played together. These data support the social skills hypothesis (Baldwin & Baldwin, 1974) of play. Data were gathered while the author was a graduate student at Tulane University and a visiting lecturer at the University of California, Riverside.     

Human behaviour: sex ratio and the city

The ratio of males to females in a population is known to influence the behaviour, life histories and demography of animals. A recent experimental study finds that sex ratio also affects human economic behaviour, and in a manner consistent with evolutionary theory.     

Household extension and reproductive behaviour in Taiwan

The inflence of household type on reproductive behavior is examined for a national probability sample of Taiwanese women. Data were derived from a 1980 national household survey of the labor force in Taiwan, focusing on 10,624 couples. Reproductive variables include measures of current and prospective fertility as well as cumulative fertility. In spite of remarkable social and economic development over the past 3 decades, extended families are still widely found in Taiwan. Women in extended households have only slightly higher fertility preferences and current fertility than women in nuclear families once marital duration is controlled. Although women in extended households marry earlier and receive more family help with child care than women in nuclear families, such factors are no longer considered sufficient to produce major differentials in reproductive behavior. Residence and husband's class of work are the strongest correlates of whether a household is currently extended or nuclear. In general, the husband's characteristics are more strongly related to family type than the wife's. Findings suggest that preferences for smaller families and low fertility need not await a transformation to a nuclear family structue.     

Desire for sons and subsequent fertility in rural India. A 20-year longitudinal study

This paper compares the desired fertility of rural Indian women in 1987 with their actual fertility in 2007. Seventy-one respondents who stated definite fertility intentions and had fewer children than desired in 1987 were re-interviewed 20 years later, as part of a larger study. The results indicated that these women had fewer children than intended and stopped childbearing once they reached, or approximated, their desired number of sons. The majority had been sterilized, indicating broad acceptance of lower fertility among rural women and the success of India's family planning efforts, although the practice of sex determination seems also to have played a role. These findings echo those of an earlier longitudinal study of reproductive intentions and outcomes in the same community, demonstrating the persistence of son preference in determining reproductive behaviour, even in the context of low overall fertility. The paper concludes with a discussion of the policy and programme implications of the study's findings.     

Parental gender preferences and reproductive behaviour: a review of the recent literature

This paper reviews various theoretical approaches towards an explanation of parental gender preferences and empirical findings from developing as well as from industrialized countries, focusing on the role of gender preferences in reproductive decisions. Although various attempts have been made to shed light on the mechanisms underlying the observed patterns of sex preferences for children, a fully satisfying theoretical explanation is still not at hand. Empirically, a distinct and stable preference for at least one child of each sex can be observed as a common pattern of parental sex preferences across many different social, economic and cultural contexts. Further - and ideally multidisciplinary - research that helps to improve our understanding of this phenomenon is highly desirable.