71 resultados para HORMÔNIOS SEXUAIS FEMININOS
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Many behavioral and biological variables of animals are expressed in the form of biological rhytms, down by the Circadian Timing System, that synchronize them with the environment from external stimuli such as light. One of them is the secretion profile of most circulating hormones regulated by the hypothalamuspirtuitary axis, which controls functions essential for the survival and reproduction of organisms. The sagüi, Callithrix jacchus, one of the most studied species about their endocrine physiology, is an appropriate subject for evaluating the profile of plasma prolactin and cortisol of adult males and females born in captivity throughout the year. Three male and two adult femelas were housed individually and subjected to natural environmental conditions over two years. Blood samples were used to measure the circulating levels of both hormones by methods radioimmunoassay (RIA) and immunoassay (ELISA), respectively. The analysis during the year of the plasmatic values of both hormones test was performed by ANOVA for repeated measures, the correlation of Spearman, and the test of Friedman and Student's t-test. The levels of prolactin in plasma were higher during the months in which there is a greater incidence of births of baby in the colony, possibly serving for modulating the expression of the behavior of parental care in both sexes. The plasma cortisol showed a lift in anticipation of the station with the highest birth rate and may be associated with the preparation of individual participation in caring for the baby, and also with the establishment of emotional bond between reproductive partners. Thus, this study shows that, despite the variations observed in the environment in which the animals live, plasma levels of prolactin and cortisol vary little throughout the year.
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Several studies have found different patterns of preferences to men and women for short term and long term relationship romantic partners. It is known that the preferences vary with the sex of individuals, the expected involvement level of the relationship and according to the perceptions that subjects have about themselves. In the present study, we investigate whether the preferences typically founded for sexes are also founded between Brazilian undergraduate students. We also investigated if the individuals choose partners in accord of the sex preferences and if the ideal preferences are really expressed in real choices. For these investigations, 370 undergraduate students described profiles of an ideal partner for a short-term and a long-term relationship, through the joint evaluation of nine characteristics. Each ideal s profile has been described over three simulations, in which the amount of points available to be invested were limited and gradually reduced. After the descriptions of these profiles, the participants described the current or previous partner (if they were not in a relationship) and performed a self-assessment with the same characteristics used in the description of preferences. Overall, the results obtained in several countries were observed in Brazil. For short-term relationships men prioritize physical attributes and women value physical and personal attributes. For long-term, personal traits gained in importance on masculine preferences and women emphasized personal traits and the partner disposition to acquire resources. We also identified similar preferences profiles for both sexes and that the romantic preferences reflect similarities with the own individual s characteristics, in addition to the typical sexual preferences expected for the Parental Investment Theory. When evaluated their real partners, men considerate them more physically attractive than themselves but less intelligent, good humorous and ambi tion/willing to work. Women, in turn, described their partners as good as them. Finally, we observed equivalence between characteristics of the subjects and those of its partners, this effect being more pronounced among men. The last partners were described only as less sincere. The interpretation of the most part of our results was possible from evolutionist s and socio-cultural s explanations and was discussed under the two perspectives. We conclude this study stressing that the traditional romantic preferences occur in Brazil and that the sex, the kind of relationship and the vision that people have about their own characteristics affect the preferences, which are expressed in the real partner choices
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Fibromyalgia (FM) is a non-inflammatory rheumatic syndrome characterized by widespread musculoskeletal pain with palpable tender points, muscle stiffness, fatigue, and sleep disturbances. Patients with FM have hormonal changes that are directly correlated with symptoms of the syndrome. The neuroendocrine regulation may be impaired, with abnormalities in the hypothalamus-pituitary-adrenal (HPA) axis with various hormones showing changes in their levels. In women in fertile period, various gonadal hormones are associated with symptoms of the syndrome, but studies focusing only a population of women in post-menopausal period who do not use hormone replacement are rare. We developed an analytical cross sectional study to assess the plasma levels of cortisol and dehidroepiandrosterona sulfate (DHEA-S) with quimioluminescence method in a group of 17 women with FM and 19 healthy women in post-menopause who do not use hormone replacement and observe the correlation with the symptoms of pain through algometry, depression and physical functional capacity measured from the Beck Depression Index (BDI) and the Fibromyalgia Impact Questionnaire (FIQ). Three blood samples were collected in the morning (between 8:00 9:30) with an interval of 24 hours for the measurements of hormonal levels and biochemical profile. There were no immunological or lipid changes in patients with FM. Comparing the two groups, there is no difference in levels of cortisol and a tangential effect for DHEA-S (p=0,094) with the lowest levels in the FM. DHEA-S also correlated with pain threshold (r=0,7) and tolerance (r=0,65) in group FM. We found the presence of depressive state and low physical functional capacity in FM. It was also evident that women in post-menopausal period, DHEA-S should influence the symptoms of increased sensitivity to pain, but not the presence of depressive status and low physical functional
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The group Callithrichidae is characterized by the flexibility in its mating system. This fact generates questions about the mechanisms that Callithrix jacchus males reach the breeding position in a group and how they prevent the subordinates reproduction, since the competition apparently happens with less intensity when compared to the females. Studies have shown the importance of social interactions and kinship among individuals in the distribution of mating opportunities in a group. This work aimed to evaluate if dyads of Callithrix jacchus males acted socially different due to kinship. We observed the agonistic and affiliative behaviours made by the males when associated in dyads (Phase 1) and when these dyads received a female (Phase 2), which was introduced in the pair`s cage for 45 minutes. In the phase 2, we also accounted for the sexual interactions between males and female in each trio. We used 16 males, 8 related (brothers-R) and 8 nonrelated (NR), as well as 8 females. Each phase lasted 4 weeks, with 3 observations/week, during 15 min/male in phase 1 and 2. In the first phase, two pairs of R males had a contested dominance and the other two, just like in the NR males, had an uncontested dominance. The NR dominant males were more aggressive than the subordinates. With the female`s entrance in the cage, all male pairs began to have an uncontested dominance. The NR males aggression frequency rose along with the subordinates` submission. In the R males, the frequency of grooming and physical contact was higher than in the NR males. So, we conclude that the low levels of agonism presented by the R males, along with the higher tolerance shown amongst them, lead us to believe that kinship attenuate the competition among these males
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This study investigated the influence of intrinsic and extrinsic factors on the feeding ecology and foraging behavior of the whiptail lizard Ameivula aff. ocellifera, a new species widely distributed in the Brazilian Caatinga, and that is in process of description. In attendance to the objectives, the Dissertation was structured in two chapters, which correspond to scientific articles, one already published and the other to be submitted for publication. In Chapter 1 were analyzed the general diet composition, the relationship between lizard size and prey size, and the occurrence of sexual and ontogenetic differences in the diet. Chapter 2 contemplates a seasonal analysis of diet composition during two rainy seasons interspersed with a dry season, and the quantitative analysis of foraging behavior during two distinct periods. The diet composition was determined through stomach analysis of lizards (N = 111) collected monthly by active search, between September 2008 and August 2010, in the Estação Ecológica do Seridó (ESEC Seridó), state of Rio Grande do Norte. Foraging behavior was investigated during a rainy and a dry month of 2012 also in ESEC Seridó, by determining percent of time moving (PTM), number of movements per minute (MPM) and prey capture rate by the lizards (N = 28) during foraging. The main prey category in the diet of Ameivula aff. ocellifera was Insect larvae, followed by Orthoptera, Coleoptera and Araneae. Termites (Isoptera) were important only in numeric terms, having negligible volumetric contribution (<2%) and low frequency of occurrence, an uncommon feature among whiptail lizards. Males and females did not differ neither in diet composition nor in foraging behavior. Adults and juveniles ingested similar prey types, but differed in prey size. Maximum and minimum prey sizes were positively correlated with lizard body size, suggesting that in this population individuals experience an ontogenetic change in diet, eating larger prey items while growing, and at the same time excluding smaller ones. The diet showed significant seasonal differences; during the two rainy seasons (2009 and 2010), the predominant prey in diet were Insect larvae, Coleoptera and Orthoptera, while in the dry season the predominant prey were Insect larvae, Hemiptera, Araneae and Orthoptera. The degree of mobility of consumed prey during the rainy seasons was lower, mainly due to a greater consumption of larvae (highly sedentary prey) during these periods. Population niche breadth was higher in the dry season, confirming the theoretical prediction that when food is scarce, the diets tend to be more generalized. Considering the entire sample, Ameivula aff. ocellifera showed 61,0 ± 15,0% PTM, 2,03 ± 0,30 MPM, and captured 0,13 ± 0,14 per minute. Foraging mode was similar to that found for other whiptail lizards regarding PTM, but MPM was relatively superior. Seasonal differences were verified for PTM, which was significantly higher in the rainy season (66,4 ± 12,1) than in the dry season (51,5 ± 15,6). It is possible that this difference represents a behavioral adjustment in response to seasonal variation in the abundance and types of prey available in the environment in each season
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Natural selection shapes body and behavior of each species. For primates, the social environment constituted one of the greatest selective pressure for the development of their cognition. When we consider gender differences, we see that sexual selection also operates through different selective pressures for men and women not only in physical terms but in terms of cognitive skills. Among these, the primary cognitive abilities - that emerge naturally - and secondary - that rely on an artificial environment for learning - develop differently for each sex, making them suitable for specific tasks in different capacities. Previous studies utilized the Wason Selection Test a conditional logic tool - to measure, among several other things, the ability to recognize violation of rules in abstract contexts and social contexts. Subjects generally had better performance in the latter, however, in these studies possible differences motivated by learning in formal logic or genre were not considered. Our study investigated these two variables, as well as the time spent to solve each task. Furthermore, we used an index to take into account the rights and wrongs of the participants in tasks. We realized that although learning in formal logic does not bring significant differences in solving tests, the gender differences are strongly observed when we consider the social contexts and abstract. Women perform better in social tasks. This can be explained due to different sexual selective pressures for this gender in terms of one-on-one relationships within the group. Men are better at tasks of abstract context and this is probably due to the same reason. Their capabilities for territory defense, habitat navigation and forming coalitions depends on primary cognitive abilities that support secondary cognitive skills of abstraction. Thus, gender differences are a factor to be taken into account in controlling future experiments with the same tool
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Contrary to what is recorded for Callithrix jacchus females, the social interactions and hormonal profiles of males are less studied, and mainly in wild groups. The goal of this study was to investigate the behavioral and endocrine profiles of reproductive (RMs) and non-reproductive (NRs) common marmoset adult free-ranging males living in two natural groups (GC1 and GR2). The groups inhabited the area of the Escola Agrícola de Jundiaí/UFRN, located in Macaíba, Brazil. Fecal collection for cortisol and androgen measurement and behavioral monitoring was carried out during the active phase from April to September, 2005. For behavioral data collection the focal instantaneous method was used every 5 min, for a total of 11.563 records. Statistical analysis was performed using non parametric tests and p < 0.05. Besides showing diurnal variation, the frequency of affiliative behaviors was significantly higher for RMs toward reproductive females than for NRs. Affiliative interactions of RMs with both reproductive females and NRs were similar, probably related to pair bond formation and helper recruitment, respectively. Parental care was also similar for both RMs and NRs. Both androgen and cortisol levels increased after the birth of the infants, mainly in RMs. The longitudinal profile of androgens fluctuates more in response to agonistic encounters and sexual behavior than that of cortisol. The mean basal excretion of both hormones was significantly higher in RMs and seems to reflect their higher participation in territorial vigilance and mate guarding behaviors. Significant positive correlations were found between agonism and cortisol and androgen hormones. These results describe, for the first time, the behavioral and hormonal profiles of common marmosets living in free-ranging groups and suggest that reproductive males are more responsive both behaviorally and hormonally to social group dynamics
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Among a variety of learning conceptions, David Kolb´s Experiential Learning Theory proposes four different learning styles: diverging, characterized by orientation towards people and multi-perspective vision; assimilating, concerned with ideas and abstract concepts as well as theory formulation; converging, expert in dealing with technical tasks and problem solving; and accommodating, risk taker and good at getting things done. Interesting correlations have been pointed out between Kolb s learning styles, professional careers and genders. With respect to behaviors, specific cognitive skills and interests, sex differences are widely known, and explained by Evolutionary Psychology as the result of distinct selective pressures acting on each gender. The aim of this research was to assess adolescents learning styles and their relation with interests on school and career choices, analyzing possible gender differences. We distributed questionnaires to 221 senior high school students to research their preferences for school disciplines, professional activities and career choices. The Learning Style Inventory specified the learning style of each individual. Our results showed a high frequency of reflective styles, with predominance of females as diverging and males as assimilating. Concerning school and professional interests, there were correlations between styles oriented towards the abstract and technical interests. Moreover, females preferred disciplines related to languages and interpersonal activities while males preferred disciplines related to science and technical activities. There were more males in exact science and engineering careers, and more females in social science and applied social science. Correlations found between learning styles, school and professional interests corroborate Kolb´s propositions, and the findings about gender differences are supported by Evolutionary Psychology theories
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The prostitution is known as the world's oldest "profession", according to some historians, "the contemporary civilization itself." However, to refer it that way, we can systematically emptying it of expressions of violence that permeate. Furthermore, this statement tries to legitimize prostitution as a practical historically related to the natural condition of women. The main objective of the research is to examine how the activity prostitucional potentiates in different forms of violence in everyday development of prostitution in the city of Natal. Accordingly, the spot of the categories of gender relations and patriarchal violence against women, refute the thesis advocated by much of feminist studies on of prostitution as an expression of autonomy of women and overcoming the patriarchal order of gender. Procedures as set methodological quali-quantitative approach, guided by the method historicalmaterialist dialectic that allows us to apprehend the object of study beyond their immediate, unmasking its contradictions. We conducted nine interviews with prostitutes belonging to the classes of People who develop the activities in the streets and prostitutes Natals` cabarets. We hand with the systematic observation activities promoted by the Association of Prostitutes in Rio Grande do Norte ASPRORN, as the visits to cabarets, as well as participation in seminars held by this entity, at which establish contacts with informants-c which have facilitated access to interviewed. We note that the economic dimension is the factor determinant for their inclusion in prostitution, all to recognize as who found an alternative for survival, since most do not has no professional training and education. Another issue important to be emphasized concerns the areas where unhealthy develop programs which by itself is characterized as a denial of rights, expressed in the socioeconomic inequality that are subject. As the expressions of violence in their daily lives, the main forms identified were the physical and social, however, there is a trend in naturalizes them, the secondary-over other issues identified as most pressing, such as not service payment by the customers. The determinants of violence identified by respondents were assigned to the woman, or is its boldness. We also, the omission of the State in the issue of prostitution, mainly embodied in absence of public policies directed to sexual rights and reproductive and generation of employment and income. Regarding the regulation of prostitution, the majority of the interviewees is contrary, arguing that exacerbate the stigma in this practice
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Considerando o caráter multifacetado e socialmente heterogêneo da epidemia do HIV/AIDS, gostaria de refletir sobre as formas pragmáticas de apropriação, negociação e conflito de gênero em termos das disposições possíveis de masculinidade e feminilidade ou, ainda, suas amplas combinações entre homens e mulheres de diferentes identidades sexuais e diversos status sorológicos. Os contextos a serem explorados e descritos são aqueles particulares ao mundo social da AIDS, incluindo tanto o cotidiano de uma ONG AIDS específica, bem como os que se apresentam em situações tanto públicas como privadas na cidade do Rio de Janeiro. Pretendo discutir como novas subjetividades podem se constituir a partir dos usos de categorias sexuais e sorológicas, valores morais e de expressões performativas de gênero.