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1.
    
Gender bias against girls in nineteenth-century England has received much interest but establishing its existence has proved difficult. We utilise data on heights of 16,402 children working in northern textile factories in 1837 to examine whether gender bias was evident. Current interpretations argue against any difference. Here our comparisons with modern height standards reveal greater deprivation for girls than for boys. Discrimination is measured in girls’ height-for-age score (HAZ) falling eight standard errors below boys’ at ages 11, 11.5 and 12 years of age, capturing the very poor performance of factory girls. But this result cannot be taken at face value. We query whether modern standards require adjustment to account for the later timing of puberty in historical populations and develop an alternative. We also test the validity of the age data, considering whether parents were more prone to lie about the ages of their daughters, and question whether the supply of girls was fundamentally different from that of boys. We conclude that neither proposition is justified. Disadvantage to girls remains, although its absence amongst younger children precludes an indictment of culturally founded gender bias. The height data must remain mute on the source of this discrimination but we utilise additional information to examine some hypotheses: occupational sorting, differential susceptibility to disease, poorer nutrition for girls, disproportionate stunting from the effects of nutritional deprivation, and type and amount of work undertaken. Of these we suggest that girls had to do arduous physical labour in the home alongside their factory work. The only (unsubstantiated) alternative is that girls were more likely than boys to be put into factory work below the legal age limit. Both represent forms of gender bias.  相似文献   

2.
    
This paper aims to shed some light on the labour market implications of thyroid disease. Undetected hypothyroidism has adverse effects on wages for female workers,thus widening the existing gender wage gap. However, once female individuals are diagnosed (and therefore assumed to be treated) with hypothyroidism, they experience wage gains and have a higher employment probability. In relation to other labour market outcomes, thyroid disease does not appear to play a significant role on individuals’ labour force participation decision and their working hours. Results suggest that productivity gains may drive the improvement in wages.  相似文献   

3.
Synopsis Mass spawning of Caesio teres occurred between March and August, 1983 on a reef emerging from deep water just inside the East Channel of Enewetak Atoll, Marshall Islands. Aggregations and spawning were observed from one day before until three days after the full moon. Spawning aggregations were not observed during the new or quarter moons. Spawning commenced after high tide, when the current began to flow out the pass from lagoon to ocean. The spawning aggregation of close to 1000 individuals migrated to the spawning site. Spawning occurred when the aggregate ascended to near the water's surface. Subgroups dashed horizontally within the aggregate, releasing a highly visible gamete cloud. Predation on spawning adults was not observed. Predation on spawned eggs was noted. The eggs of C. teres are described. Mid-Pacific Research Laboratory, Enewetak Atoll, Republic of the Marshall Islands Present address: Motupore Island Research Station, P.O. Box 320, University of Papua New Guinea, Papua New Guinea  相似文献   

4.
    
Around the world, and in spite of their higher life expectancy, women tend to report worse health than men until old age. Explanations for this gender gap in self-perceived health may be different in China than in other countries due to the traditional phenomenon of son preference. We examine several possible reasons for the gap using the Chinese SAGE data. We first rule out differential reporting by gender as a possible explanation, exploiting information on anchoring vignettes in eight domains of health functioning. Decomposing the gap in general self-assessed health, we find that about 31% can be explained by socio-demographic factors, most of all by discrimination against women in education in the 20th century. A more complete specification including chronic conditions and health functioning fully explains the remainder of the gap (about 69%). Adding chronic conditions and health functioning also explains at least two thirds of the education contribution, suggesting how education may affect health. In particular, women's higher rates of arthritis, angina and eye diseases make the largest contributions to the gender health gap, by limiting mobility, increasing pain and discomfort, and causing sleep problems and a feeling of low energy.  相似文献   

5.
If mothers take care of children more than fathers, then after the onset of COVID-19 mothers’ employment is expected to drop more than that of fathers. This gender gap is likely to be larger where women are less concerned about the financial repercussions of opting out of the labor force, and therefore the gender gap in employment is likely to grow more where community property or homemaking provisions give more protection to homemakers in case of union dissolution. Difference-in-differences and dynamic study estimations applied to CPS data for 2019–2020 show that after the onset of COVID-19 the labor force participation of mothers of school-age children—but not of fathers--dropped more in states with marital property laws more generous to parental caregivers. These results stand in contrast to how these groups’ labor force participation changed after the Great Recession, compared to pre-recession levels.  相似文献   

6.
Synopsis Shark nurseries, or nursery areas, are geographically discrete parts of a species range where the gravid females of most species of coastal sharks deliver their young or deposit their eggs, and where their young spend their first weeks, months, or years. These areas are usually located in shallow, energy rich coastal areas where the young find abundant food and have little predation by larger sharks. Nurseries are characterized by the presence of both gravid females and free swimming neonates. Neonates are young bearing fresh, unhealed umbilical scars in the case of placental species, or those at or near the birth size in aplacental species. Bulls Bay, South Carolina, is a nursery for the blacknose, spinner, finetooth, blacktip, sandbar, dusky, Atlantic sharpnose, scalloped hammerhead, and smooth dogfish sharks. The lemon shark has its nursery in shallow waters of south Florida and the Bahamas. The bull shark has its nursery in the lagoons of the east coast of central Florida.  相似文献   

7.
    
Synopsis The finetooth shark inhabits shallow coastal waters of the western Atlantic from North Carolina to Brazil. It is common off the southeastern United States, where it spends the summer off Georgia and the Carolinas and winters off Florida. The species appears in the nursery and mating areas of South Carolina when the surface water temperature rises above 20° C in late April and early May. Both adults and juveniles are common in the shallow coastal waters of South Carolina through the summer, where they feed primarily on menhaden. The finetooth shark leaves the Carolinas in early fall and migrates southward as the surface water temperature decreases below 20° C. Females reach maturity at about 1350 mm TL. Males mature at about 1300 mm TL. The finetooth shark has consecutive, year-long ovarian and gestation cycles, like most carcharhinid sharks. Mating occurs from early May to early June. Freshly mated females bear a large spermozeugma at the base of each uterus. The spermozeugmata are large almond shaped masses of individual spermatozoa embedded in a supporting matrix. Embryos are lecithotrophic during their first fifteen weeks of development. Subsequently, the embryos establish a placental connection to the mother. Implantation occurs when the embryos measure about 130 mm or at about the fifteenth week of gestation. Gravid females carrying young 480–550 mm TL enter the shallow water nurseries off South Carolina in late May. Parturition occurs from late May to mid-June, after a gestation period of about twelve months, plus or minus two weeks. The young measure 480–580 mm TL at birth. Oocytes grow little during the gestation cycle. After parturition, a cohort of oocytes begins to develop, that will be ovulated the following May. Thus, the ovarian cycle lasts about a year, although most of the oocyte growth occurs in the months just prior to ovulation.  相似文献   

8.
Flood control, drainage and irrigation (FCDI) schemes are widespread in Bangladesh. They are built to control water levels to improve agricultural production based on high yielding varieties (HYV) of rice that cannot tolerate rapid inundation or that require irrigation, and to provide protection from extreme flood events. The benefits to the agricultural sector can be significant. At some sites in Bangladesh, farmers report up to 80% more agricultural production inside the schemes than outside. However, fish production and species richness is typically lowered by these structures. Fish yields inside a typical flood control compartment can be 50% lower than outside, with up to 25 species of fish absent or less abundant. Lower rates of recruitment of migratory whitefish species, whose lateral migrations are obstructed by the embankments, were found to be largely responsible for these differences. With a risk of more extreme flooding during the monsoon season but hotter and more arid dry season conditions predicted as a consequence of climate change, more FCDI schemes may need to be constructed to provide flood protection and to meet increasing irrigation needs. Based on fisheries monitoring and mark-recapture studies undertaken at 3 sluice gates, nine recommendations for operating sluice gates to mitigate the impacts of FCDI schemes on fish production and biodiversity are described. These recommendations aim to improve the access of migratory whitefish to modified floodplains and to improve or sustain the production of resident (non-migratory) blackfish whilst minimising agricultural sector losses. Guest editors: R. L. Welcomme & G. Marmulla Hydropower, Flood Control and Water Abstraction: Implications for Fish and Fisheries  相似文献   

9.
In this article I examine the state-directed movement of ethnic groups. Such movements include the settlement of majority groups in peripheral regions inhabited by minorities, the relocation of minority groups within the state, and the expulsion of minorities from the state. An important theme of the article is that, while such policies have been implemented for centuries, modern state-directed movements are closely linked to the growth of nationalism. The study seeks to answer three important questions: (1) Why do states move ethnic groups? (2) How do states move ethnic groups? (3) Under what circumstances will states engage in such policies?  相似文献   

10.
In the present study, we examined the migration effects on genetic variabilities and heritabilities patterns between three groups of population like parental population in Punjab, migrant from Pakistan, and migrant from other states of India in Punjab using anthropometric and physiometric traits. A total of 500 adult individuals from 300 families were studied. Statistical comparisons were carried out through mean coefficients, Student’s t test, heritability, and regression analysis. The results suggest a significant migration effect on almost all traits. Correlation coefficient for first-degree relatives, the slope factors, and heritabilities for almost all variables have been found significant among the three groups of populations. However, the discrimination is more prominent among migrant from other states of India because of more genetic heterogeneity.  相似文献   

11.
    
This study investigates the relationship between household wealth and child height utilizing longitudinal data on 7150 children from Ethiopia, India, Peru, and Vietnam. The concept of conditional wealth is applied to separate the influence of wealth in early childhood. Conditional wealth is the change in wealth that was unpredicted at the age of 5 years. This study finds two dimensions of heterogeneity in the wealth-gradient of adolescent height: gender and stunting status at the age of 5 years. For all four countries in the study, the effect of conditional wealth on adolescent height is stronger for boys than for girls. The estimates for the pooled sample indicate that after the age of 5 years, the growth of children who were stunted at that age is significantly more responsive to conditional wealth than the growth of non-stunted children. The analysis results show that for boys in Ethiopia, a one-standard-deviation increase in preadolescence wealth is associated with an increase of 1 cm (standard error [SE]: 0.3) in height at the age of 15 years. For boys in the Indian state of Andhra Pradesh, Peru, and Vietnam, the corresponding figures are 1.1 cm (SE: 0.4), 1.8 cm (SE: 0.4), and 1.2 cm (SE: 0.4), respectively. The effect of preadolescence wealth on adolescent height is not statistically significant for girls, except in some regions. Overall, the results suggest that household wealth in preadolescence disproportionately benefits the male population in these countries when using height as a proxy for health.  相似文献   

12.
13.
The polymorphism of the serum vitamin D binding protein (DBP) in humans is based on the existence of three common alleles, Gc1F, Gc1S, and Gc2, and 84 rare alleles. The geographical distribution of Gc1F, Gc1S, and Gc2 alleles shows north to south clines, together with a balanced equilibrium between the Gc1F or Gc1S allele frequency and the Gc2 frequency. The distribution of the FST values shows high variability within a geographical area. For European and North Asiatic groups, the FST values are the lowest observed, and the reason may be a long process of homogenization. Aboriginal populations from Australia and New Guinea and groups from both North Africa and South America show the greatest heterogeneity of their allele frequencies. Systematic factors such as genetic drift and selection may account for this distribution. In contrast with the three main DBP alleles, the distribution of the rare alleles corresponds to patterns of human migrations that occurred during prehistoric and historic periods. Thus, the rare mutants are of particular relevance to anthropological and genetical investigations.  相似文献   

14.
    
Anthropometric literature on the American territories of the Hispanic monarchy before their independence is still scarce. We attempt to expand the field with a case study that includes some important novelties.Albeit our main source, the military records of the Censo de Revillagigedo (conducted in the early 1790s), has already been used, the sample size and the geographical scope are unprecedented: 19,390 males of four ethnicities (castizos, españoles, mestizos, and mulatos) aged from 16 to 39 from 24 localities, including towns and villages scattered across central regions of the Viceroyalty of New Spain. We build a database that, complemented with information on resource endowments obtained from other sources, permits to analyze the determinants of height.Our results show the importance of spatial differences as well as the significance of ethnicity, occupation, rurality, age and resource endowments as determinants of height. Unprivileged mulatos are only 0.5 cm shorter than, assumedly privileged, españoles in the “first world” (El Bajío) and 1.3 cm taller in the “second world” (Eastern Central Highlands). In turn, living in the “first world” implies being between nearly 1.5 cm and 5 cm taller than the inhabitants of the “second world”. Our estimates of physical statures are placed within an international comparative context and offer a relatively “optimistic” picture.  相似文献   

15.
This article is part of a Special Issue "Puberty and Adolescence".This article aims to provide an outline of what is currently known on trajectories, and contributing factors to gender identity development in adolescence. We give a historical overview of the concept of gender identity, and describe general identity development in adolescence, gender identity development in the general population and in gender variant youth. Possible psychosocial (such as child and parental characteristics) and biological factors (such as the effects of prenatal exposure to gonadal hormones and the role of genetics) contributing to a gender variant identity are discussed.  相似文献   

16.
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Adults, larvae and pupae of Levitinia freidbergi n. sp. are described from a tiny winter stream at Merom Golan in the Golan Heigths. The relation of the new species to L. tacobi and to the primitive genera of Prosimuliini is discussed.https://doi.org/10.1051/parasite/198762159  相似文献   

17.
Jenny Audring 《Morphology》2008,18(2):93-116
In research on grammatical gender, assignment and agreement are the two central notions. Genders are defined as systems of agreement classes, and the assignment of nouns to genders is reflected in the agreement they consistently trigger on associated elements. Yet, gender assignment and gender agreement are often discussed quite separately. This paper investigates the possibility that gender agreement is not only an overt manifestation of gender assignment, but that properties of agreement systems can themselves constrain the assignment systems they express. The paper discusses typological and diachronic evidence for the fact that not every type of assignment system can be expressed in every type of agreement system.  相似文献   

18.
一种测量林窗面积的改良方法:等角椭圆扇形法   总被引:7,自引:0,他引:7  
目前测量林窗面积较精确的方法为:测量从林窗中心沿8或16个罗盘方向到林窗林冠边缘的距离,再将林窗近似成等角8或16边形估测其面积(本文称这类方法为等角多边形法)。研究表明,等角8或16边形法均会低估林窗面积,本文提出一种改良方法:等角椭圆扇形法,野外测量与前者相同,计算时将相邻距离间的部分近似为椭圆扇形,以所有椭圆扇形面积之和估测林窗面积。用配对t检验对等角多边形法和等角椭圆扇形法的林窗面积进行比较,结果表明:(1)等角16边形法与等角8或4边形法存在极显著差异(P<0.001),比后两者,分别高10.96%和61.66%,这表明等角条边形法均会低估林窗面积;(2)等角椭圆扇形16分法比等角16边形法大10.16%,且二者之间存在极显著差异(P<0.001),因此,等角16边形法的测量值位于等角椭圆扇形16分法和等角8边形法之间;由(1)和(2)可推断等角椭圆扇形16分法比等角8边形法更准确;(3)等角椭圆扇形8分法与等角椭圆扇形16分法没有显著差异(P=0.715),但与等角8边形法存在显著差异(P<0.05),因此,等角椭圆扇形8分法比等角8边形法更准确。另外,本文的两个等角8边形法(基于两组不同罗盘方位的测量距离)求得的林窗面积之间存在极显著差异(P<0.01),而两个等角椭圆扇形8分法之间却没有差异(P=0.778),这表明等角椭圆扇形8分法的结果更稳定。  相似文献   

19.
    
Cattle on the Golan Heights are kept in enclosures and some of these enclosures have guard dogs. We studied the effect of such dogs on the behavior and breeding success of mountain gazelles Gazella gazella living within enclosures. We found that guard dogs have both direct and indirect effects on gazelles. Gazelles living in enclosures with dogs spent more time in vigilance behavior and running, and less time resting and walking, in comparison with gazelles in dog-free enclosures. In the absence of dogs, gazelle female herds in enclosures tended to stay closer to the cattle, but shunned away from them in the presence of the dogs, which, in turn, remained near the cattle. The percentage of fawns per female was higher in enclosures without dogs in comparison with those with dogs, but the difference was not significant. However, the largest of the enclosures with dogs, which had the largest number of gazelles, had only an average number of dogs in it. Hence, the gazelles in this enclosure were better able to avoid the dogs in comparison with those in smaller enclosures. Removing this enclosure from the overall calculation revealed that guard dogs have a significant negative effect on gazelle reproductive success. In two of the four enclosures with dogs no fawn still survived 6 months after birth, while in each of the four enclosures without dogs some fawns did survive to that age and beyond, suggesting that the dogs themselves may predate the fawns.  相似文献   

20.
Clinical investigators have been forced primarily to use experiments of nature (e.g., cloacal exstrophy; androgen insensitivity, congenital adrenal hyperplasia) to assess the contribution of fetal sex hormone exposure to the development of male- and female-typical profiles of gender identity and role behavior as well as sexual orientation. In this review, I summarize the results of numerous correlative as well as mechanistic animal experiments that shed significant light on general neuroendocrine mechanisms controlling the differentiation of neural circuits controlling sexual partner preference (sexual orientation) in mammalian species including man. I also argue, however, that results of animal studies can, at best, provide only indirect insights into the neuroendocrine determinants of human gender identity and role behaviors.  相似文献   

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