925 resultados para sex role
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Mutations in the ATRX gene on the human X chromosome cause X-linked α-thalassemia and mental retardation. XY patients with deletions or mutations in this gene display varying degrees of sex reversal, implicating ATRX in the development of the human testis. To explore further the role of ATRX in mammalian sex differentiation, the homologous gene was cloned and characterized in a marsupial. Surprisingly, active homologues of ATRX were detected on the marsupial Y as well as the X chromosome. The Y-borne copy (ATRY) displays testis-specific expression. This, as well as the sex reversal of ATRX patients, suggests that ATRY is involved in testis development in marsupials and may represent an ancestral testis-determining mechanism that predated the evolution of SRY as the primary mammalian male sex-determining gene. There is no evidence for a Y-borne ATRX homologue in mouse or human, implying that this gene has been lost in eutherians and its role supplanted by the evolution of SRY from SOX3 as the dominant determiner of male differentiation.
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Hereditary hemochromatosis (HH) is a common chronic human genetic disorder whose hallmark is systemic iron overload. Homozygosity for a mutation in the MHC class I heavy chain paralogue gene HFE has been found to be a primary cause of HH. However, many individuals homozygous for the defective allele of HFE do not develop iron overload, raising the possibility that genetic variation in modifier loci contributes to the HH phenotype. Mice deficient in the product of the β2-microglobulin (β2M) class I light chain fail to express HFE and other MHC class I family proteins, and they have been found to manifest many characteristics of the HH phenotype. To determine whether natural genetic variation plays a role in controlling iron overload, we performed classical genetic analysis of the iron-loading phenotype in β2M-deficient mice in the context of different genetic backgrounds. Strain background was found to be a major determinant in iron loading. Sex played a role that was less than that of strain background but still significant. Resistance and susceptibility to iron overload segregated as complex genetic traits in F1 and back-cross progeny. These results suggest the existence of naturally variant autosomal and Y chromosome-linked modifier loci that, in the context of mice genetically predisposed by virtue of a β2M deficiency, can profoundly influence the severity of iron loading. These results thus provide a genetic explanation for some of the variability of the HH phenotype.
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Recent studies of Saccharomyces cerevisiae have significantly advanced our understanding of the molecular mechanisms of meiotic chromosome behavior. Structural components of the synaptonemal complex have been identified and studies of mutants defective in synapsis have provided insight into the role of the synaptonemal complex in homolog pairing, genetic recombination, crossover interference, and meiotic chromosome segregation. There is compelling evidence that most or all meiotic recombination events initiate with double-strand breaks. Several intermediates in the double-strand break repair pathway have been characterized and mutants blocked at different steps in the pathway have been identified. With the application of genetic, molecular, cytological, and biochemical methods in a single organism, we can expect an increasingly comprehensive and unified view of the meiotic process.
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The vitamin D endocrine system is regulated reciprocally by renal 25-hydroxyvitamin D3 1 alpha- and 24-hydroxylases. Previously, we reported that renal proximal convoluted tubules, the major site of 1 alpha, 25-dihydroxyvitamin D3 production, have vitamin D receptors. In the presence of vitamin D receptors, renal proximal convoluted tubules cannot maintain the state of enhanced production of 1 alpha, 25-dihydroxyvitamin D3. To clarify this discrepancy, we proposed a working hypothesis for the reciprocal control of renal 25-hydroxyvitamin D3 1 alpha- and 24-hydroxylase activities. In rat models of enhanced renal production of 1 alpha, 25-dihydroxyvitamin D3, expression of vitamin D receptors and 25-hydroxyvitamin D3 24-hydroxylase mRNAs was strikingly suppressed in renal proximal convoluted tubules but not in the cortical collecting ducts. In vitamin D-deficient rats with up-regulated renal 25-hydroxyvitamin D3 1 alpha-hydroxylase activity, expression of vitamin D receptor mRNA in renal proximal convoluted tubules was also down-regulated, indicating that the down-regulation of vitamin D receptor mRNA is not the result of the enhanced production of 1 alpha, 25-dihydroxyvitamin D3. In Japanese quail models with up-regulated renal 25-hydroxyvitamin D3 1 alpha-hydroxylase activity by sex steroids, expression of vitamin D receptor mRNA was also down-regulated in the kidney but not in the duodenum. These results suggest that the down-regulation of vitamin D receptors plays a critical role in production of 1 alpha, 25-dihydroxyvitamin D3 in renal proximal convoluted tubules.
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Although androgens are commonly seen as male sex hormones, it has been established over the years that in both sexes, androgens also respond to social challenges. To explain the socially driven changes in androgens, two theoretical models have been proposed: the biosocial model and the challenge hypothesis. These models are typically seen as partly overlapping; however, they generate different predictions that are clarified here. In humans, sports competition and nonmetabolic competitive tasks have been used in the laboratory setting, as a proxy for agonistic interactions in animals. The results reviewed here show that the testosterone (T) response to competition in humans is highly variable – the studies present postcompetition T levels and changes in T that depend on the contest outcome and that cannot be predicted by the current theoretical models. These conflicting results bring to the foreground the importance of considering cognitive factors that could moderate the androgen response to competition. Among these variables, we elect cognitive appraisal and its components as a key candidate modulating factor. It is known that T also modulates the cognitive processes that are relevant to performance in competition. In this article, we reviewed the evidence arising from studies investigating the effect of administering exogenous T and compare those results with the findings from studies that measured endogenous T levels. Finally, we summarized the importance of also considering the interaction between androgens and other hormones, such as cortisol, when investigating the social modulation of T, as proposed by the dual-hormone hypothesis.
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Thesis (Master's)--University of Washington, 2016-06
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In Studies I and 21 after reading an acquaintance-rape but not a stranger-rape scenario, higher benevolent. sexist but not hostile sexist participants blamed the victim significantly more. In Study 2, higher hostile sexist but not benevolent sexist male participants showed significantly greater proclivity to commit acquaintance (but not stranger) rape. Studies 3 a effects of nd 4 'slippor,ted the hypothesis that the benevolent sexism and hostile sexism are mediated by different perceptions of the victim, as behaving. inappropriately and as really wanting sex with the rapist. These findings show that benevolent sexism and hostile sexism,underpin different assumptions about women that, generate sexist reactions toward rape victims.
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A critical gene involved in mammalian sex determination and differentiation is the Sty-related gene Sox9. In reptiles, Sox9 resembles that of mammals in both structure and expression pattern in the developing gonad, but a causal role in male sex determination has not been established. A closely related gene, Sox8, is conserved in human, mouse, and trout and is expressed in developing testes and not developing ovaries in mouse. In this study, we tested the possibility of Sox8 being important for sex determination or sex differentiation in the red-eared slider turtle Trachemys scripta, in which sex is determined by egg incubation temperature between stages 15 and 20. We cloned partial turtle Sox8 and anti-Mullerian hormone (Amh) cDNAs, and analyzed the expression patterns of these genes in developing gonads by reverse transcriptase-polymerase chain reaction and whole-mount in situ hybridization. While Amh is expressed more strongly in males than in females at stage 17, Sox8 is expressed at similar levels in males and females throughout the sex-determining period. These observations suggest that differential transcription of Sill is not responsible for regulation of Amh, nor responsible for sex determination in turtle. (C) 2004 Wiley-Liss, Inc.
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Although smoking is widely recognized as a major cause of cancer, there is little information on how it contributes to the global and regional burden of cancers in combination with other risk factors that affect background cancer mortality patterns. We used data from the American Cancer Society's Cancer Prevention Study II (CPS-II) and the WHO and IARC cancer mortality databases to estimate deaths from 8 clusters of site-specific cancers caused by smoking, for 14 epidemiologic subregions of the world, by age and sex. We used lung cancer mortality as an indirect marker for accumulated smoking hazard. CPS-II hazards were adjusted for important covariates. In the year 2000, an estimated 1.42 (95% CI 1.27-1.57) million cancer deaths in the world, 21% of total global cancer deaths, were caused by smoking. Of these, 1.18 million deaths were among men and 0.24 million among women; 625,000 (95% CI 485,000-749,000) smoking-caused cancer deaths occurred in the developing world and 794,000 (95% CI 749,000-840,000) in industrialized regions. Lung cancer accounted for 60% of smoking-attributable cancer mortality, followed by cancers of the upper aerodigestive tract (20%). Based on available data, more than one in every 5 cancer deaths in the world in the year 2000 were caused by smoking, making it possibly the single largest preventable cause of cancer mortality. There was significant variability across regions in the role of smoking as a cause of the different site-specific cancers. This variability illustrates the importance of coupling research and surveillance of smoking with that for other risk factors for more effective cancer prevention. (C) 2005 Wiley-Liss, Inc.
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Vertebrates use many different strategies to determine sex, but the Sox9 gene is a common thread, probably acting as the pivotal gene that controls the male-determining pathway. It now appears that Sox9 is not alone in this role, and that a closely related gene, Sox8, can partly substitute for Sox9. But is this a clever backup strategy to safeguard male development, or a relic of the past?
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This paper explores the policy of single-sex classes that is currently being adopted in some schools as a strategy for addressing boys' educational and social needs. It draws on research in one Australian government, coeducational primary school to examine teachers' and students' experiences of this strategy. Interviews with the principal, male and female teachers responsible for teaching the single-sex classes and the students involved in these classes are used to illustrate the impact and effect of the strategy on pedagogical practices in this particular school. The data are used to raise critical questions about the impact and effects of teachers' pedagogical practices in light of the current literature and research about single-sex classes. In this case study, it was found that teachers had a tendency to modify their pedagogical practices and the curriculum to suit stereotypical constructions about boys' and girls' supposed oppositional orientations to learning. It is concluded that teacher knowledges and assumptions about gender play an important role in the execution of their pedagogies in the single-sex classroom.
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Background - Smoking is a major cause of cardiovascular disease mortality. There is little information on how it contributes to global and regional cause-specific mortality from cardiovascular diseases for which background risk varies because of other risks. Method and Results - We used data from the American Cancer Society's Cancer Prevention Study II (CPS II) and the World Health Organization Global Burden of Disease mortality database to estimate smoking-attributable deaths from ischemic heart disease, cerebrovascular disease, and a cluster of other cardiovascular diseases for 14 epidemiological subregions of the world by age and sex. We used lung cancer mortality as an indirect marker for accumulated smoking hazard. CPS-II hazards were adjusted for important covariates. In the year 2000, an estimated 1.62 (95% CI, 1.27 to 2.04) million cardiovascular deaths in the world, 11% of total global cardiovascular deaths, were due to smoking. Of these, 1.17 million deaths were among men and 450 000 among women. There were 670 000 (95% CI, 440 000 to 920 000) smoking-attributable cardiovascular deaths in the developing world and 960 000 (95% CI, 770 000 to 1 200 000) in industrialized regions. Ischemic heart disease accounted for 54% of smoking-attributable cardiovascular mortality, followed by cerebrovascular disease (25%). There was variability across regions in the role of smoking as a cause of various cardiovascular diseases. Conclusions - More than 1 in every 10 cardiovascular deaths in the world in the year 2000 were attributable to smoking, demonstrating that it is an important preventable cause of cardiovascular mortality.
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Why is the public presentation of the war on terror suffused with sexualised racism? What does this tell us about ideas of gender, sexuality, religious and political identity and the role of the state in the Western powers? Can we diffuse inter-ethnic conflicts and change the way the West pursues its security agenda by understanding the role of sexualised racism in the war on terror? In asking such questions, Gargi Bhattacharyya considers how the concepts of imperialism, feminism, terror and security can be applied, in order to build on the influential debates about the sexualised character of colonialism. She examines the way in which western imperial violence has been associated with the rhetoric of rights and democracy - a project of bombing for freedom that has called into question the validity of western conceptions of democracy, rights and feminism. Such rhetoric has given rise to actions that go beyond simply protecting western interests or securing access to scarce resources and appear to be beyond instrumental reason. The articulations of racism that appear with the war on terror are animated by fears and sexual fantasies inexplicable by rational interest alone. There can be no resolution to this seemingly endless conflict without understanding the highly sexualised racism that animates it. Such an understanding threatens to pierce the heart of imperial relations, revealing their intense contradictions and uncovering attempts to normalise violent expropriation.
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At the beginning of the 80s new approaches to translation were emerging in such a way that, in the global context of postmodernism and poststructuralism, they provoked a reassessment of Translation Studies (TS), acknowledging ideologies as a relevant concept to TS and considering the political and visible role of the translator. This introduction aims to establish a basic theoretical framework in which we can develop an analysis of the ‘alterations’ that, consciously or unconsciously, translators have imposed on Le deuxième sexe (1949, Gallimard) by Simone de Beauvoir for the last fifty years. Furthermore, it is essential to examine the divergences of the censoring attitude adopted by the first male translators (Parshley, Palant and Milliet) who considered this text to be a sex manual, and the one adopted by more recent female translators (Martorell and Simons) who considered it to be a philosophical book on feminism. Nevertheless, despite this tendency to consider that translators are the only professionals responsible for the translation process, it is necessary to bear in mind the work carried out by the paratranslator, who is the real censor and ‘decider’ of the way a work is presented to the translation community. Paratranslators work with paratexts (also known as ‘analysis-spaces’), and this makes it possible to study the ideological adaptation that a cultural object undergoes when it is incorporated into a new culture and society (covers, volumes, tables of contents, titles, iconic or visual elements and so forth). In short, the analysis of the texts and paratexts of Le deuxième sexe, along with its subsequent translations and rewritings into Spanish, Portuguese and English, will help reveal the function of the censoring apparatus and demonstrate the essential role that –without exception– ideologies play in the professional work of translation and paratranslation, since they have a decisive influence on the reception of the cultural (and ideological) object, in both the society in which it is created and that in which it is received.
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An analysis is made of the conceptions which serving teachers have of their role, though no attempt is made to relate this to their practice of teaching. A series of role items was collected to afford a description of the teacher's role in terms of school and society expectations as well as classroom behaviours. These were taken from the literature and from interviews with teachers, and confirmed in a preliminary survey. Presented as a questionnaire, replies to the main investigation were made by 881 teachers, working in a variety of schools from nurseries to comprehensives. Two attempts have been made to construct a role model. The first, depending on the judgement of items fitting theoretically derived roles, failed, due to diffuseness in the role of teacher. The second used factor analysis; six factors were extracted which represent meaningful and distinct areas of role. The analysis has depended largely on examination of scores taken from these factors. Teachers in all types of school have similar conceptions of discipline. Nursery-infant and junior staff generally agree on the other areas investigated, but the concepts of secondary teachers are distinct. They are more conservative and less child-centered. When the class being taught is held constant, few differences in role conception are found to be related to sex, being a parent, graduate status, or personality, as measured in terms of the extrovert and neurotic dimensions. The first few years of teaching bring considerable changes in role conception, and further changes occur with prolonged experience. Deputy heads in junior schools and nursery nurses have quite distinct role conceptions; those of all other teachers, including those holding senior posts in secondary schools, are similar. The perception of school climate influences the role conception of primary teachers directly, but it does not influence that of secondary teachers. The greatest variation in role conception is related to scores on the radical scale of Oliver and Butcher. Primary school teachers experience little constraint, but that reported by secondary school teachers is considerable, especially that coming from the head. Despite difficulties caused by the wide division between primary and secondary education, teachers have an accurate perception of the roles their colleagues adopt. A few misunderstandings may be due to a feeling of idealism amongst nursery and infant teachers. There is evidence in their conception of role that would enhance the professional standing of teachers, but this is not in a form which is likely to be recognised by the public.