943 resultados para Sex-role Stereotypes


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Modern protocols to synchronize ovulations for timed artificial insemination and timed embryo transfer that include manipulations in the proestrus period (i.e., between luteolysis and estrus) affect fertility in cattle. Specifically, stimulating pre-ovulatory follicle growth and exposure to estrogens after CL regression increase the proportion of cows pregnant and decrease late embryo mortality. Such effects may be due to both preovulatory actions of estrogens and post-ovulatory actions of progesterone, as concentrations of the later hormone may be changed in response to manipulations conducted during proestrus. In the first portion of this paper we describe strategies used recently to manipulate the proestrus period in protocols for synchronization of ovulation, and to present evidence of their effects on fertility. Manipulations of timing and prominence of sex steroids during the proestrus and early diestrus that affect fertility may act on targets such as the endometrium. This tissue expresses receptors for both estrogens and progesterone and these hormones change endometrial function to support conceptus growth and pregnancy maintenance. However, specific cellular and molecular mechanisms through which fertility is affected via manipulations of the proestrus are poorly understood. In the second portion of this paper we describe a well-defined animal model to study changes in endometrial function induced by manipulations conducted during the proestrus. Such manipulations induced endometrial changes on sex steroid receptors expression, cell proliferation, oxidative metabolism and eicosanoid synthesis in the uterus, but not on glucose transport to uterine lumen. In summary, evidence is accumulating to support a positive role of increasing duration and estrogen availability during the proestrus on fertility to synchronization protocols. Such positive effects may be through changes in endometrial function to stimulate conceptus growth and survival.

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Homogamy has been suggested as crucial for human mate preferences and mate choice. People are attracted to and choose romantic partners that are similar to them in socio-demographic, physical, and psychological traits. However, only a few studies have shown homogamy in preferences for evolved sex-typical traits. Here, we have investigated male and female preferences for the level of cognitive masculinity-femininity (MF). We tested whether self-reported MF positively correlates with preferences for MF. One hundred men and one hundred women from Brazil filled in questionnaires on their own level of cognitive MF and preferred level of cognitive MF in their ideal partner. Half of the respondents were asked to indicate their preferences for long-term, and the other half for short-term relationships. We found a positive correlation between self-ascribed and preferred level of cognitive MF in women (P = 0.002), but no significant correlation in men (P = 0.309). There was no significant effect of the temporal context of the relationship, but there was a positive correlation between self-ascribed and preferred level of cognitive MF only in women answering about long-term partner. By subtracting the preferred from the selfascribed level of cognitive MF, we created a self-similarity index. We found that women desire potential mates more self-similar and more masculine than men (P < 0.001) and that in men there is greater variation in the self-similarity index than in women. Our results thus add to previous evidence on the role of homogamy in human mating, by showing preferences for self-similarity also in cognitive MF for women, especially for long-term partner preferences. Future studies should cross-culturally test whether the higher self-similar preference found in women is universal.

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The aim of this research was to investigate how the gender representations by young people affect how they interpret and resolve a situation of moral conflict at school. It starts from the references of the Theory of the Organizing Models of Thinking and of critical perspectives on the studies of gender as contributors of conceptual and methodological aspects in the analysis of the psychic functioning. Information was raised with 400 youngsters (15 to 21 years of age) from public and private schools, who answered in writing four questions about feelings, thoughts, and the duty of the characters (boys or girls) before a situation of homophobia at school. The perspective of the gender in the conflict resolution was analyzed taking into account the sex of the characters and the sex of the participants. The results show that the gender representations have an essential role in the manner in which the youngsters resolve interpersonal conflicts, highlighting the reproduction of stereotypes in the social relations among genders at school.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Although there are several studies on morphogenesis in Teleostei, until now there is no research describing the role of the basement membrane in the establishment of the germinal epithelium during gonadal differentiation in Characiformes. In attempt to study these events that result in the formation of ovarian and testicular structures, gonads of Gymnocorymbus ternetzi were prepared for light microscopy. During gonadal development in G. ternetzi, all individuals first developed ovarian tissue. The undifferentiated gonad was formed by somatic cells (SC) and primordial germ cells (PGCs). After successive mitosis, the PGCs became oogonia, which entered into meiosis originating oocytes. An interstitial tissue developed. In half of the individuals, presumptive female, prefollicle cells synthesized a basement membrane around oocyte forming a follicle. Along the ventral region of the ovary, the tissue invaginated to form the ovigerous lamellae, bordered by the germinal epithelium. Stroma developed and the follicle complexes were formed. The gonadal aromatase was detected in interstitial cells in the early steps of the gonadal differentiation in both sexes. In another half of the individuals, presumptive male, there was no synthesis of basement membrane. The interstitium was invaded by numerous granulocytes. Pre-Leydig cells proliferated. Apoptotic oocytes were observed and afterward degenerated. Spermatogonia appeared near the degenerating oocytes and associated to SCs, forming testicular tubules. Germinal epithelium developed and the basement membrane was synthesized. Concomitantly, there was decrease of the gonadal aromatase and increase in the 3β-HSD enzyme expression. Thus, the testis was organized on an ovary previously developed, constituting an indirect gonochoristic differentiation.

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The species-specificity of pairing has been studied in three sympatric Neotropical termites: Cornitermes bequaerti, Cornitermes cumulans and Cornitermes silvestrii (Termitidae, Syntermitinae). Bioassays showed that sex attraction was highly species-specific between C. bequaerti and C cumulans but not between C. cumulans and C. silvestrii. The sex-pairing pheromone of the three species is secreted by the tergal glands of female alates. It consists of a common compound (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. In C. bequaerti, this polyunsaturated alcohol is the only compound of the sex-pairing pheromone, whereas it is associated with the oxygenated sesquiterpene (E)-nerolidol in C. cumulans, and with (E)-nerolidol and (Z)-dodec-3-en-1-ol in C silvestrii. (3Z,6Z,8E)-Dodeca-3,6,8-trien-1-ol is responsible for sexual attraction, whereas (E)-nerolidol, which is inactive in eliciting attraction of male alates, is responsible for the species-specificity of the attraction. This is the first time that a multicomponent sex-pairing pheromone has been identified in termites. The role of (Z)-dodec-3-en-1-ol present on the surface of the tergal glands of the female alates of C. silvestrii could not be definitively determined, but it is suggested that this compound could be involved in the species-specificity of sex attraction with other sympatric species of Cornitermes. Our study shows that the reproductive isolation in termites is due to a succession of factors, as the chronology of dispersal flights, the species-specificity of sex-pairing pheromones and the species-specific recognition. (C) 2011 Elsevier Ltd. All rights reserved.

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Abstract Background Melatonin is associated with direct or indirect actions upon female reproductive function. However, its effects on sex hormones and steroid receptors during ovulation are not clearly defined. This study aimed to verify whether exposure to long-term melatonin is able to cause reproductive hormonal disturbances as well as their role on sex steroid receptors in the rat ovary, oviduct and uterus during ovulation. Methods Twenty-four adult Wistar rats, 60 days old (+/- 250 g) were randomly divided into two groups. Control group (Co): received 0.9% NaCl 0.3 mL + 95% ethanol 0.04 mL as vehicle; Melatonin-treated group (MEL): received vehicle + melatonin [100 μg/100 g BW/day] both intraperitoneally during 60 days. All animals were euthanized by decapitation during the morning estrus at 4 a.m. Results Melatonin significantly reduced the plasma levels of LH and 17 beta-estradiol, while urinary 6-sulfatoximelatonin (STM) was increased at the morning estrus. In addition, melatonin promoted differential regulation of the estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR) and melatonin receptor (MTR) along the reproductive tissues. In ovary, melatonin induced a down-regulation of ER-alpha and PRB levels. Conversely, it was observed that PRA and MT1R were up-regulated. In oviduct, AR and ER-alpha levels were down-regulated, in contrast to high expression of both PRA and PRB. Finally, the ER-beta and PRB levels were down-regulated in uterus tissue and only MT1R was up-regulated. Conclusions We suggest that melatonin partially suppress the hypothalamus-pituitary-ovarian axis, in addition, it induces differential regulation of sex steroid receptors in the ovary, oviduct and uterus during ovulation.

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Hirst et al. (2013; Mar Ecol Prog Ser 489:297-298) suggest that Gusmão et al. (2013; Mar Ecol Prog Ser 482:279-298) misinterpreted the findings of Hirst et al. (2010; Limnol Oceanogr 55:2193-2206). They restate that the major factors determining sex ratio in pelagic copepods act upon the adult stage, but they place less emphasis on the idea that predation on male copepods is a likely determinant, and highlight the role of physiological longevity. Here we reconsider the data and confirm our position that at present there is limited evidence to support the theory of male-skewed predation. However, we agree that sex determination is governed by a combination of factors, with the relative emphasis being the main point of contention between the 2 parties.

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[EN] Leptin and osteocalcin play a role in the regulation of the fat-bone axis and may be altered by exercise. To determine whether osteocalcin reduces fat mass in humans fed ad libitum and if there is a sex dimorphism in the serum osteocalcin and leptin responses to strength training, we studied 43 male (age 23.9 2.4 yr, mean +/- SD) and 23 female physical education students (age 23.2 +/- 2.7 yr). Subjects were randomly assigned to two groups: training (TG) and control (CG). TG followed a strength combined with plyometric jumps training program during 9 wk, whereas the CG did not train. Physical fitness, body composition (dual-energy X-ray absorptiometry), and serum concentrations of hormones were determined pre- and posttraining. In the whole group of subjects (pretraining), the serum concentration of osteocalcin was positively correlated (r = 0.29-0.42, P < 0.05) with whole body and regional bone mineral content, lean mass, dynamic strength, and serum-free testosterone concentration (r = 0.32). However, osteocalcin was negatively correlated with leptin concentration (r = -0.37), fat mass (r = -0.31), and the percent body fat (r = -0.44). Both sexes experienced similar relative improvements in performance, lean mass (+4-5%), and whole body (+0.78%) and lumbar spine bone mineral content (+1.2-2%) with training. Serum osteocalcin concentration was increased after training by 45 and 27% in men and women, respectively (P < 0.05). Fat mass was not altered by training. Vastus lateralis type II MHC composition at the start of the training program predicted 25% of the osteocalcin increase after training. Serum leptin concentration was reduced with training in women. In summary, while the relative effects of strength training plus plyometric jumps in performance, muscle hypertrophy, and osteogenesis are similar in men and women, serum leptin concentration is reduced only in women. The osteocalcin response to strength training is, in part, modulated by the muscle phenotype (MHC isoform composition). Despite the increase in osteocalcin, fat mass was not reduced.

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My project explores and compares different forms of gender performance in contemporary art and visual culture according to a perspective centered on photography. Thanks to its attesting power this medium can work as a ready-made. In fact during the 20th century it played a key role in the cultural emancipation of the body which (using a Michel Foucault’s expression) has now become «the zero point of the world». Through performance the body proves to be a living material of expression and communication while photography ensures the recording of any ephemeral event that happens in time and space. My questioning approach considers the gender constructed imagery from the 1990s to the present in order to investigate how photography’s strong aura of realism promotes and allows fantasies of transformation. The contemporary fascination with gender (especially for art and fashion) represents a crucial issue in the global context of postmodernity and is manifested in a variety of visual media, from photography to video and film. Moreover the internet along with its digital transmission of images has deeply affected our world (from culture to everyday life) leading to a postmodern preference for performativity over the more traditional and linear forms of narrativity. As a consequence individual borders get redefined by the skin itself which (dissected through instant vision) turns into a ductile material of mutation and hybridation in the service of identity. My critical assumptions are taken from the most relevant changes occurred in philosophy during the last two decades as a result of the contributions by Jacques Lacan, Michel Foucault, Jacques Derrida, Gilles Deleuze who developed a cross-disciplinary and comparative approach to interpret the crisis of modernity. They have profoundly influenced feminist studies so that the category of gender has been reassessed in contrast with sex (as a biological connotation) and in relation to history, culture, society. The ideal starting point of my research is the year 1990. I chose it as the approximate historical moment when the intersection of race, class and gender were placed at the forefront of international artistic production concerned with identity, diversity and globalization. Such issues had been explored throughout the 1970s but it was only from the mid-1980s onward that they began to be articulated more consistently. Published in 1990, the book "Gender trouble: feminism and the subversion of identity" by Judith Butler marked an important breakthrough by linking gender to performance as well as investigating the intricate connections between theory and practice, embodiment and representation. It inspired subsequent research in a variety of disciplines, art history included. In the same year Teresa de Lauretis launched the definition of queer theory to challenge the academic perspective in gay and lesbian studies. In the meantime the rise of Third Wave Feminism in the US introduced a racially and sexually inclusive vision over the global situation in order to reflect on subjectivity, new technologies and popular culture in connection with gender representation. These conceptual tools have enabled prolific readings of contemporary cultural production whether fine arts or mass media. After discussing the appropriate framework of my project and taking into account the postmodern globalization of the visual, I have turned to photography to map gender representation both in art and in fashion. Therefore I have been creating an archive of images around specific topics. I decided to include fashion photography because in the 1990s this genre moved away from the paradigm of an idealized and classical beauty toward a new vernacular allied with lifestyles, art practices, pop and youth culture; as one might expect the dominant narrative modes in fashion photography are now mainly influenced by cinema and snapshot. These strategies originate story lines and interrupted narratives using models’ performance to convey a particular imagery where identity issues emerge as an essential part of fashion spectacle. Focusing on the intersections of gender identities with socially and culturally produced identities, my approach intends to underline how the fashion world has turned to current trends in art photography and in some case turned to the artists themselves. The growing fluidity of the categories that distinguish art from fashion photography represents a particularly fruitful moment of visual exchange. Varying over time the dialogue between these two fields has always been vital; nowadays it can be studied as a result of this close relationship between contemporary art world and consumer culture. Due to the saturation of postmodern imagery the feedback between art and fashion has become much more immediate and then increasingly significant for anyone who wants to investigate the construction of gender identity through performance. In addition to that a lot of magazines founded in the 1990s bridged the worlds of art and fashion because some of their designers and even editors were art-school graduates encouraging innovation. The inclusion of art within such magazines aimed at validating them as a form of art in themselves supporting a dynamic intersection for music, fashion, design and youth culture: an intersection that also contributed to create and spread different gender stereotypes. This general interest in fashion produced many exhibitions of and about fashion itself at major international venues such as the Victoria and Albert Museum in London, the Metropolitan Museum of Art and the Solomon R. Guggenheim Museum in New York. Since then this celebrated success of fashion has been regarded as a typical element of postmodern culture. Owing to that I have also based my analysis on some important exhibitions dealing with gender performance like "Féminin-Masculin" at the Centre Pompidou of Paris (1995), "Rrose is a Rrose is a Rrose. Gender performance in photography" at the Solomon R. Guggenheim Museum of New York (1997), "Global Feminisms" at the Brooklyn Museum (2007), "Female Trouble" at the Pinakothek der Moderne in München together with the workshops dedicated to "Performance: gender and identity" in June 2005 at the Tate Modern of London. Since 2003 in Italy we have had Gender Bender - an international festival held annually in Bologna - to explore the gender imagery stemming from contemporary culture. In few days this festival offers a series of events ranging from visual arts, performance, cinema, literature to conferences and music. Being aware that any method of research is neither race nor gender neutral I have traced these critical paths to question gender identity in a multicultural perspective taking account of the political implications too. In fact, if visibility may be equated with exposure, we can also read these images as points of intersection of visibility with social power. Since gender assignations rely so heavily on the visual, the postmodern dismantling of gender certainty through performance has wide-ranging effects that need to be analyzed. In some sense this practice can even contest the dominance of visual within postmodernism. My visual map in contemporary art and fashion photography includes artists like Nan Goldin, Cindy Sherman, Hellen van Meene, Rineke Dijkstra, Ed Templeton, Ryan McGinley, Anne Daems, Miwa Yanagi, Tracey Moffat, Catherine Opie, Tomoko Sawada, Vanessa Beecroft, Yasumasa Morimura, Collier Schorr among others.

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Repeated Chlamydia trachomatis infections after treatment are common. One reason is reinfection from untreated partners in ongoing sexual partnerships. Mathematical models that are used to predict the impact of screening on reducing chlamydia prevalence often do not incorporate reinfection and might overestimate the expected impact. We describe a pair compartmental model that explicitly incorporates sexual partnership duration and reinfection. The pair model predicts a weaker impact of screening when compared directly with a model that does not accommodate partnerships. Effective management of sex partners to prevent reinfection might need to be strengthened in chlamydia control programs.

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Immigrants from high-burden countries and HIV-coinfected individuals are risk groups for tuberculosis (TB) in countries with low TB incidence. Therefore, we studied their role in transmission of Mycobacterium tuberculosis in Switzerland. We included all TB patients from the Swiss HIV Cohort and a sample of patients from the national TB registry. We identified molecular clusters by spoligotyping and mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) analysis and used weighted logistic regression adjusted for age and sex to identify risk factors for clustering, taking sampling proportions into account. In total, we analyzed 520 TB cases diagnosed between 2000 and 2008; 401 were foreign born, and 113 were HIV coinfected. The Euro-American M. tuberculosis lineage dominated throughout the study period (378 strains; 72.7%), with no evidence for another lineage, such as the Beijing genotype, emerging. We identified 35 molecular clusters with 90 patients, indicating recent transmission; 31 clusters involved foreign-born patients, and 15 involved HIV-infected patients. Birth origin was not associated with clustering (adjusted odds ratio [aOR], 1.58; 95% confidence interval [CI], 0.73 to 3.43; P = 0.25, comparing Swiss-born with foreign-born patients), but clustering was reduced in HIV-infected patients (aOR, 0.49; 95% CI, 0.26 to 0.93; P = 0.030). Cavitary disease, male sex, and younger age were all associated with molecular clustering. In conclusion, most TB patients in Switzerland were foreign born, but transmission of M. tuberculosis was not more common among immigrants and was reduced in HIV-infected patients followed up in the national HIV cohort study. Continued access to health services and clinical follow-up will be essential to control TB in this population.

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In this paper, I will argue that Canadian author Margaret Atwood uses fiscal and socially conservative dystopias to show how sex work and prostitution are choices that women would never have to make in a world with true gender equality. In these radically different worlds, women have no agency beyond their sexuality and no ability to express themselves as equals within either society. And while the structures of both societies, the society of The Handmaid’s Tale and that of both Oryx and Crake and The Year of the Flood, are inherently different, they both stem from modern conservative philosophies: for example, the country of Gilead in The Handmaid’s Tale holds Christian conservative beliefs on the role of religion in the state and the culturally designated roles of women. I define social conservatism as the idea that government organizations are used to pursue an agenda promoting traditional religious values such as “public morality” and opposing “immoralities” such as abortion, prostitution, and homosexuality. I define fiscal conservatism as an agenda promoting privatization of the market, deregulation and lower taxes. In this paper I argue that because these philosophies are incompatible with gender equality, they drive women to occupations such as sex work. Women find that they have no choices and sex work provides something to “trade.” For Offred, this “trading” is more limited, because she is a sex slave. For Oryx, this trading allows her to travel to the West, yet not before her childhood is marked by prostitution and pornography. Sex work allows for Ren to reclaim some agency over her life, yet she only chooses sex work because she is presented with few other options. All of these issues stem from the philosophies that define these dystopias.

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The current study integrates system justification theory with research on mental illness stigma. Stereotypes of both low- and high-status groups in society can be a means of satisfying the system justification motive, or the motive to view societal inequalities as justified (as reviewed in Jost, Banaji, & Nosek, 2004). Corrigan, Watson, and Ottati (2003) proposed that system justification theory may be able to explain the origins of particular stereotypes of people with mental illness, such as dangerousness and incompetence. The primary goal of the present study was to investigate whether the stigmatization of people with mental illness – a specific form of stigmatization of a lowstatus group – can be at least partially attributed to a broader motive to justify societal inequalities. To test this, the current study included both an experimental manipulation of the perceived legitimacy of the social system and a measure of system-justifying beliefs. Stigmatization of individuals with mental illness was measured with both explicit selfreport measures (semantic differentials and the Attribution Questionnaire) and an implicit measure (a computer-based Implicit Association Test). The relationships between participant characteristics, such as personal experience with mental illness, and stigma were also investigated. Consistent with past research demonstrating only modest correlations between explicit and implicit stigma, greater self-reported fear toward a person with a chronic mental illness was weakly associated with increased implicit bias against mental illness in favor of physical disability. There was little support for the involvement of system justification in explicit stigma. Participants with personal experience with mental illness were less likely to self-report fear and avoidance of a person with a chronic mental illness. These findings have implications for stigmareduction efforts.