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Premenstrual syndrome (PMS) affects up to 80% of women, often leading to significant personal, social and economic costs. When apparently maladaptive states are widespread, they sometimes confer a hidden advantage, or did so in our evolutionary past. We suggest that PMS had a selective advantage because it increased the chance that infertile pair bonds would dissolve, thus improving the reproductive outcomes of women in such partnerships. We confirm predictions arising from the hypothesis: PMS has high heritability; gene variants associated with PMS can be identified; animosity exhibited during PMS is preferentially directed at current partners; and behaviours exhibited during PMS may increase the chance of finding a new partner. Under this view, the prevalence of PMS might result from genes and behaviours that are adaptive in some societies, but are potentially less appropriate in modern cultures. Understanding this evolutionary mismatch might help depathologize PMS, and suggests solutions, including the choice to use cycle‐stopping contraception.  相似文献   

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Instrumental social support, or aid in the form of labor or money, may exert a positive influence on economic welfare and food security. Several investigators have found a positive relationship between social support and nutritional status, while others have found a negative association between social support and central adiposity. In the rural Andes, extra‐household economic cooperation has long been an important adaptive strategy, and the breakdown of these relationships is one reason for high rates of rural‐to‐urban migration, including to the Bolivian city of El Alto. This research investigates the influence of instrumental support on women's body composition. Information was collected on individual perception of instrumental support and anthropometric indicators of nutritional status including percent body fat (bioelectrical impedance analysis (BIA)), BMI, and distribution of fat on trunk relative to limbs (Ratio of subscapular to triceps skinfold (STR)), and multiple linear regression analysis used to test the prediction that instrumental social support is positively related to body fat stores. Controlling for age and household socioeconomic status, perceived access to one or more sources of instrumental support was positively and significantly related to overall levels of adiposity. There is no evidence that STR mediates the relationship between instrumental social support and body composition. This analysis offers support for the prediction that economic social support has direct effects on women's energy stores. The interpretation of these results is somewhat ambiguous given the high levels of overweight and obesity in this population. Am J Phys Anthropol 152:51–57, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   

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Kathryn MacKay 《Bioethics》2020,34(4):346-353
This paper imagines what the liberatory possibilities of (full) ectogenesis are, insofar as it separates woman from female reproductive function. Even before use with human infants, ectogenesis productively disrupts the biological paradigm underlying current gender categories and divisions of labour. I begin by presenting a theory of women’s oppression drawn from the radical feminisms of the 1960s, which sees oppression as deeply rooted in biology. On this view, oppressive social meanings are overlaid upon biology and body, as artefacts of culture and history. I then argue that ectogenesis should be pursued to replace two modes of assisted gestation that can be seen as outgrowths of oppressive assumptions about women's function, ectogenesis should be pursued to replace two modes of assisted gestation. These are gestational surrogacy and uterine transplant, which arise partly from gendered, pronatalist, and geneticist norms. These practices are supported by assumptions about women’s identity and value. Pursuing technologies such as ectogenesis, which weaken the presumed link between biology and gender, is beneficial to (trans-inclusionary radical) feminist aims, as part of a broad project of challenging dominant power relations resting on and maintaining gender categories. By allowing the conceptual separation of female reproductive function from ‘woman’, ectogenesis raises questions about how we determine who counts in this gender identity, and also how we value those who claim the identity ‘woman’. I conclude that ectogenesis has the potential to challenge traditional patriarchal family structures, and thence all other male-dominated structures (of work, education, cultural production), allowing a reimagining of the family and society in more radical ways than we have yet achieved.  相似文献   

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Objective: Pre‐pregnancy obesity poses risks to both pregnant women and their infants. This study used a large population‐based data source to examine trends, from 1993 through 2003, in the prevalence of pre‐pregnancy obesity among women who delivered live infants. Research Methods and Procedures: Data from the Pregnancy Risk Assessment Monitoring System in nine states were analyzed for trends in pre‐pregnancy obesity (BMI > 29.0 kg/m2) overall and by maternal demographic and behavioral characteristics. Pre‐pregnancy BMI was calculated from self‐reported weight and height on questionnaires administered after delivery, and demographic characteristics were taken from linked birth certificates. The sample of 66,221 births was weighted to adjust for survey design, non‐coverage, and non‐response, and it is representative of all women delivering a live birth in each particular state. The sampled births represented 18.5% of all births in the United States. Results: Pre‐pregnancy obesity increased 69.3% during the study period, from 13.0% in 1993 to 1994 to 22.0% in 2002 to 2003. The percentage increase ranged from 45% to 105% for individual states. Subgroups of women with the highest prevalence of obesity in 2002 to 2003 were those who were 20 to 29 years of age, black, had three or more children, had a high school education, enrolled in Women, Infants, and Children, or were non‐smokers. However, all subgroups of women examined experienced at least a 43% increase in pre‐pregnancy obesity over this time period. Discussion: The prevalence of pre‐pregnancy obesity is increasing among women in these nine states, and this trend has important implications for all stages of reproductive health care.  相似文献   

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Objective: The objective was to assess the relevance of the recommendations of the Institute of Medicine (IOM), regarding gestational weight gain (GWG) for long‐term BMI development. Research Methods and Procedures: The Stockholm Pregnancy and Women's Nutrition is a follow‐up study of 483 women who delivered children in 1984 to 1985. ANOVA was used to examine the change in body weight before pregnancy, at 6 months, and 1 year postpartum and 15 years after childbirth. Multiple linear regression was used to assess the predictors of BMI at 15‐year follow‐up. Results: The weight increase from baseline to 15‐year follow‐up was 6.2 kg for IOM‐insufficient, 6.7 kg for IOM‐recommended, and 10.0 kg for IOM‐excessive weight gain (p < 0.01). ANOVA showed a main effect of time, group and group by time interaction. The weight of the women who had excessive GWG was significantly greater at each time‐point of follow‐up than the weight of those who gained within or below recommendations. GWG was related to BMI at 15‐year follow‐up even after accounting for several confounders. Women who gained excessive weight during pregnancy had an increase of 0.72 kg/m2 in long‐term BMI compared with women who gained within recommendations. Discussion: The findings support the adequateness of IOM guidelines, not only for the pregnancy‐related health matters, but also for preventing long‐term weight retention after delivery. Healthcare providers should give women appropriate advice for controlling GWG and motivate them to lose pregnancy‐related weight during postpartum to prevent future overweight.  相似文献   

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Objective: Obesity has risen to epidemic proportions in the United States, leading to an emerging epidemic of type 2 diabetes. African‐American women are disproportionately affected by both conditions. While an association of overall obesity with increasing risk of diabetes has been documented in black women, the effect of fat distribution, specifically abdominal obesity, has not been studied. We examined the association of BMI, abdominal obesity, and weight gain with risk of type 2 diabetes. Research Methods and Procedures: During eight years of follow‐up of 49,766 women from the Black Women's Health Study, 2472 incident cases of diabetes occurred. Cox proportional hazard models were used to estimate incidence rate ratios (IRRs), with control for age, physical activity, family history of diabetes, cigarette smoking, years of education, and time period of data collection. Results: Sixty‐one percent of participants had a BMI ≥25 kg/m2 (WHO definition of overweight). Compared with a BMI of <23 kg/m2, the IRR for a BMI of >45 kg/m2 was 23 (95% confidence interval, 17.0 to 31.0). The IRR for the highest quintile of waist‐to‐hip ratio relative to the lowest was 2.3 (95% confidence interval, 2.0 to 2.7) after control for BMI. Furthermore, at every level of BMI, an increased risk was observed for high waist‐to‐hip ratio relative to low. Discussion: Central obesity, as well as overall obesity, is a strong risk factor for diabetes in African‐American women. Efforts to reduce the prevalence of obesity in African‐American women are of paramount importance.  相似文献   

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Objective: To examine the relation of body mass index (BMI), cardiorespiratory fitness (CRF), and all‐cause mortality in women. Research Methods and Procedures: A cohort of women (42.9 ± 10.4 years) was assessed for CRF, height, and weight. Participants were divided into three BMI categories (normal, overweight, and obese) and three CRF categories (low, moderate, and high). After adjustment for age, smoking, and baseline health status, the relative risk (RR) of all‐cause mortality was determined for each group. Further multivariate analyses were performed to examine the contribution of each predictor (e.g., age, BMI, CRF, smoking status, and baseline health status) on all‐cause mortality while controlling for all other predictors. Results: During follow‐up (113,145 woman‐years), 195 deaths from all causes occurred. Compared with normal weight (RR = 1.0), overweight (RR = 0.92) and obesity (RR = 1.58) did not significantly increase all‐cause mortality risk. Compared with low CRF (RR = 1.0), moderate (RR = 0.48) and high (RR = 0.57) CRF were associated significantly with lower mortality risk (p = 0.002). In multivariate analyses, moderate (RR = 0.49) and high (RR = 0.57) CRF were strongly associated with decreased mortality relative to low CRF (p = 0.003). Compared with normal weight (RR = 1.0), overweight (RR = 0.84) and obesity (RR = 1.21) were not significantly associated with all‐cause mortality. Discussion: Low CRF in women was an important predictor of all‐cause mortality. BMI, as a predictor of all‐cause mortality risk in women, may be misleading unless CRF is also considered.  相似文献   

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1 Using a combination of observational and experimental approaches, both allocation of resources to reproduction (often called the direct cost of reproduction) and the subsequent long-term costs (the indirect, delayed or demographic cost) associated with reproductive allocation to male and female function in Siparuna grandiflora (Siparunaceae), a tropical dioecious shrub, were examined.
2 The objectives were to determine whether females allocate more biomass or nitrogen per reproductive episode than males, and whether there is a long-term cost of reproduction in terms of subsequent growth or reproduction for either sex. If there is no long-term cost of reproduction, then reproduction may be viewed as free in an evolutionary sense.
3 As is generally the case in dioecious species, females allocated more biomass and nitrogen to reproduction than males. Females also showed delayed costs of reproduction in terms of decreased growth and subsequent reproduction, whereas males did not.
4 The lack of measurable delayed costs in males suggests that with the evolution of dioecy, selection has reduced delayed costs of reproduction in S. grandiflora males. In contrast, females that were prevented from reproducing were able to re-allocate resources to growth, and produced more stem length on average than males. This re-allocation response may have evolved to reduce delayed costs of reproduction in females over time frames longer than that considered in the present study.  相似文献   

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Somatic cell nuclear transfer (SCNT) research, otherwise known as therapeutic cloning, requires large numbers of research oocytes, placing pressure on an already limited supply. In the UK, Canada, Australia, Singapore and most of Western Europe, oocytes are made available through modestly reimbursed donation, and, owing to the onerous nature of donation, the existing demand for reproductive oocytes far outstrips availability. SCNT research will place this system under even greater pressure. This paper investigates the growth in a global market for oocytes, where transnational IVF clinics broker sales between generally poor, female vendors and wealthy purchasers, beyond the borders of national regulation, and with little in the way of clinical or bioethical scrutiny. It considers the possible impact that SCNT research will have on this global market. It argues that oocyte vending could be understood as a kind of reproductive labor in the bioeconomy, and suggests some ways to improve the protection, security and power of vendors.  相似文献   

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The Tsimane Health and Life History Project, an integrated bio‐behavioral study of the human life course, is designed to test competing hypotheses of human life‐history evolution. One aim is to understand the bidirectional connections between life history and social behavior in a high‐fertility, kin‐based context lacking amenities of modern urban life (e.g. sanitation, banks, electricity). Another aim is to understand how a high pathogen burden influences health and well‐being during development and adulthood. A third aim addresses how modernization shapes human life histories and sociality. Here we outline the project's goals, history, and main findings since its inception in 2002. We reflect on the implications of current findings and highlight the need for more coordinated ethnographic and biomedical study of contemporary nonindustrial populations to address broad questions that can situate evolutionary anthropology in a key position within the social and life sciences.  相似文献   

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Objective: The objective was to assess the effect of a low‐fat, vegan diet compared with the National Cholesterol Education Program (NCEP) diet on weight loss maintenance at 1 and 2 years. Research Methods and Procedures: Sixty‐four overweight, postmenopausal women were randomly assigned to a vegan or NCEP diet for 14 weeks, and 62 women began the study. The study was done in two replications. Participants in the first replication (N = 28) received no follow‐up support after the 14 weeks, and those in the second replication (N = 34) were offered group support meetings for 1 year. Weight and diet adherence were measured at 1 and 2 years for all participants. Weight loss is reported as median (interquartile range) and is the difference from baseline weight at years 1 and 2. Results: Individuals in the vegan group lost more weight than those in the NCEP group at 1 year [?4.9 (?0.5, ?8.0) kg vs. ?1.8 (0.8, ?4.3); p < 0.05] and at 2 years [?3.1 (0.0, ?6.0) kg vs. ?0.8 (3.1, ?4.2) kg; p < 0.05]. Those participants offered group support lost more weight at 1 year (p < 0.01) and 2 years (p < 0.05) than those without support. Attendance at meetings was associated with improved weight loss at 1 year (p < 0.001) and 2 years (p < 0.01). Discussion: A vegan diet was associated with significantly greater weight loss than the NCEP diet at 1 and 2 years. Both group support and meeting attendance were associated with significant weight loss at follow‐up.  相似文献   

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牧区妇女社会地位的高低对草地生态系统健康具有重要的影响。以祁连山区的天祝藏族自治县抓喜秀龙乡为调查研究区域,随机抽取100户藏族牧户为研究对象,采用问卷、座谈和关键人物座谈等形式,对妇女在社会生产中充当的角色、日常生活中承担的家务状况、受教育程度、参与社会活动情况以及对草地政策的认知等方面进行了系统调查和分析。研究结果表明:在农村社会变革中,女性是畜牧业生产的主力军,承担着将近80%的生产管理工作,74.3%的日常家务。其在家庭经济中的决策权和农村社会中的地位也在逐渐提高,在经济方面占36.5%的支配权,拥有14.5%的决策权。但是,妇女的受教育的程度普遍较低,女性的文盲率达14.4%。因此,妇女对草地生产管理技术的接受程度较低,对草原管理方面的政策及相关的法规缺乏认识,这将会对牧区草地畜牧业的可持续发展产生潜在影响。  相似文献   

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Life-history theory states that reproductive events confer costs upon mothers. Many studies have shown that reproduction causes a decline in maternal condition, survival or success in subsequent reproductive events. However, little attention has been given to the prospect of reproductive costs being passed onto subsequent offspring, despite the fact that parental fitness is a function of the reproductive success of progeny. Here we use pedigree data from a pre-industrial human population to compare offspring life-history traits and lifetime reproductive success (LRS) according to the cost incurred by each individual's mother in the previous reproductive event. Because producing a son versus a daughter has been associated with greater maternal reproductive cost, we hypothesize that individuals born to mothers who previously produced sons will display compromised survival and/or LRS, when compared with those produced following daughters. Controlling for confounding factors such as socio-economic status and ecological conditions, we show that those offspring born after elder brothers have similar survival but lower LRS compared with those born after elder sisters. Our results demonstrate a maternal cost of reproduction manifested in reduced LRS of subsequent offspring. To our knowledge, this is the first time such a long-term intergenerational cost has been shown in a mammal species.  相似文献   

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Objectives : To determine the prevalence of the metabolic syndrome across age strata and cardiorespiratory fitness (CRF) levels in women. Research Methods and Procedures : 7104 women underwent a physical examination, including a maximal treadmill exercise test. Participants were divided into CRF quintiles according to age. The metabolic syndrome was identified using Adult Treatment Panel‐III Guidelines. Tests for trend were performed on demographic variables across CRF quintiles, as well as prevalence of the metabolic syndrome across CRF quintiles, age strata, and maximal workload achieved [maximal metabolic equivalent (MET) level]. Results : The overall prevalence of the metabolic syndrome was 6.5%. Age‐ and smoking‐adjusted prevalence was lower across quintiles of CRF (19.0%, 6.7%, 6.0%, 3.6%, and 2.3% for quintiles I to V, respectively, p for trend = 0.001). Smoking‐adjusted prevalence of the metabolic syndrome was higher across age strata (2.4%, 2.7%, 6.4%, 8.7%, 15.3%, and 16.1% for ages 20 to 29, 30 to 39, 40 to 49, 50 to 59, 60 to 69, and 70 to 80, respectively, p for trend = 0.001). Prevalence of the metabolic syndrome in the different age groups for women who achieved a maximal MET level of 11 or higher was one‐third to one‐fourth that of women who achieved lower maximal MET levels. Discussion : Prevalence of the metabolic syndrome was markedly lower across progressively higher levels of CRF in women of different age strata. Because regular physical activity improves components of the metabolic syndrome, modest increases in CRF among low fit women may ameliorate the metabolic syndrome in some instances.  相似文献   

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Chargaff''s rule of intra-strand parity (ISP) between complementary mono/oligonucleotides in chromosomes is well established in the scientific literature. Although a large numbers of papers have been published citing works and discussions on ISP in the genomic era, scientists are yet to find all the factors responsible for such a universal phenomenon in the chromosomes. In the present work, we have tried to address the issue from a new perspective, which is a parallel feature to ISP. The compositional abundance values of mono/oligonucleotides were determined in all non-overlapping sub-chromosomal regions of specific size. Also the frequency distributions of the mono/oligonucleotides among the regions were compared using the Kolmogorov–Smirnov test. Interestingly, the frequency distributions between the complementary mono/oligonucleotides revealed statistical similarity, which we named as intra-strand frequency distribution parity (ISFDP). ISFDP was observed as a general feature in chromosomes of bacteria, archaea and eukaryotes. Violation of ISFDP was also observed in several chromosomes. Chromosomes of different strains belonging a species in bacteria/archaea (Haemophilus influenza, Xylella fastidiosa etc.) and chromosomes of a eukaryote are found to be different among each other with respect to ISFDP violation. ISFDP correlates weakly with ISP in chromosomes suggesting that the latter one is not entirely responsible for the former. Asymmetry of replication topography and composition of forward-encoded sequences between the strands in chromosomes are found to be insufficient to explain the ISFDP feature in all chromosomes. This suggests that multiple factors in chromosomes are responsible for establishing ISFDP.  相似文献   

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I apply evolutionary perspectives and conceptual tools to analyse central issues underlying child health, with emphases on the roles of human-specific adaptations and genomic conflicts in physical growth and development. Evidence from comparative primatology, anthropology, physiology and human disorders indicates that child health risks have evolved in the context of evolutionary changes, along the human lineage, affecting the timing, growth-differentiation phenotypes and adaptive significance of prenatal stages, infancy, childhood, juvenility and adolescence. The most striking evolutionary changes in humans are earlier weaning and prolonged subsequent pre-adult stages, which have structured and potentiated maladaptations related to growth and development. Data from human genetic and epigenetic studies, and mouse models, indicate that growth, development and behaviour during pre-adult stages are mediated to a notable degree by effects from genomic conflicts and imprinted genes. The incidence of cancer, the primary cause of non-infectious childhood mortality, mirrors child growth rates from birth to adolescence, with paediatric cancer development impacted by imprinted genes that control aspects of growth. Understanding the adaptive significance of child growth and development phenotypes, in the context of human-evolutionary changes and genomic conflicts, provides novel insights into the causes of disease in childhood.  相似文献   

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