917 resultados para Sexual Behavior, Animal


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This book situates current research into the sexual cultures of South Asia within a cross-cultural perspective. The book argues that in societies undergoing rapid social and cultural change, the construction of sexuality and the discourses that gather around it have a fundamental connection with an entire range of processes - social, cultural, economic, political and global - with which people must engage. The contributors have studied sexuality as a site around which social and cultural ideas may be expressed.

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The use of alternative medicines and herbal remedies is an increasing trend in Western societies. For years, people have taken products made of deer velvet for their alleged beneficial effects on sexual function. There has been no scientific investigation of the effects of deer velvet powder on the sexual functioning of human males. This study investigated sexual function in men during a 12-week double-blind, placebo-controlled trial of deer velvet. Thirty-two volunteer male participants, aged 45–65 years, and their partners, were randomly assigned to either the deer velvet or placebo study group. The males took capsules containing ground deer velvet or placebo everyday for 12 weeks. Two sexual function questionnaires (the International Index of Erectile Function and the Brief Index of Sexual Function for Women) used at pre- and posttreatment assessed changes in sexual functioning in males and their partners. Blood tests at baseline, and end of study, determined levels of sex-related hormones in male participants. There were no significant differences in the sexual behavior of the men taking deer velvet compared with the men taking placebo capsules. There were no significant hormone changes from baseline to the end of the study in either group of men. We conclude that in normal males there was no advantage in taking deer velvet to enhance sexual function. All alternative health products or nutritional supplements should be subjected to randomized placebo-controlled trials to determine efficacy.

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Sexual arousal is a complex and dynamic element of women’s sexuality. Accounts vary, however most multidimensional models highlight the cognitive, affective and physiological components of the female sexual arousal response. While literature examining the peripheral physiological changes that occur during female sexual arousal abounds, there has been a dearth of literature pertaining to the cognitive and affective components. Thus, while many authors have included cognitive and emotions as independent components of the female sexual arousal response, there has been little empirical research to validate this approach. The aim of the current thesis was to examine the cognitive and affective components of female sexual arousal in more depth, investigating the nature of the relationship between these components under various experimental conditions. In order to do so, two integrated studies were conducted, each highlighting the effects of either external or internal variables on women’s subjective sexual arousal, absorption, positive affect and negative affect. Study One was designed to evaluate women’s emotional and cognitive processing of two elements of erotic film – foreplay and erotic context. 60 women were asked to report their subjective sexual arousal, absorption, positive affect and negative affect in response to one of four erotic film excerpts. The erotic excerpts varied in accordance with the degree of foreplay (low vs. high) depicted and the context in which the sexual activities took place (novel vs. habitual context). Women in the study responded more favourably to the high foreplay erotic film excerpt, subsequently reporting higher degrees of subjective sexual arousal, absorption and positive affect. Women also responded favourably to the erotic excerpt filmed in a novel context, reporting greater subjective sexual arousal as a result. The environment in which the sexual encounters were filmed failed to have an effect however, on women’s absorption or their positive or negative affect. The results of Study One suggest that stimulus specific variables, such as the degree of foreplay depicted, have a significant influence on female cognitive and emotional processing of erotic film. The results also suggest that a relationship exists between absorption, subjective sexual arousal and positive affect, albeit a correlational one. Specifically, there was evidence of parallel processing during sexual arousal, as participant reported sexual arousal, absorption and positive affect all increased and decreased in unison. Based on the results it was suggested that future research attempt to experimentally manipulate one of these variables, to examine its direct effect on the remaining variable. Thus, Study Two aimed to examine the effects of absorption on women’s cognitive and emotional processing of erotica. Study Two manipulated absorption at two levels (high vs. low), examining the impact of these states on participants’ subsequent absorption, subjective sexual arousal and positive and negative affect. 62 women were asked to read one of two sets of test session instructions. The first, participant-oriented instruction set, instructed participants to immerse themselves in the erotic film excerpt, as if they were active participants in the sexual exchange. The second, spectator-oriented instruction set, directed participants to observe and evaluate the erotic film. These instructions were designed to elicit high and low degrees of absorption, respectively. The utility of this approach when manipulating female absorption, was demonstrated by self reported ratings of absorption, given at the conclusion of the film presentation. Participants were also asked to report their subjective sexual arousal and positive and negative affect at the conclusion of the erotic film presentation. The findings of this study suggest that the adoption of a participant-oriented (high absorption) perspective elicits more favourable responses from participants than a spectator-oriented (low absorption) perspective, with participants in the former experimental group reporting greater degrees of subjective sexual arousal and positive affect. Negative affect was equivalent across experimental conditions, with the participants reporting that they experienced little to no aversive feelings during either of the experimental conditions. The results suggest that the degree to which a women immerses and absorbs herself in a sexual stimulus has a significant impact in her subsequent cognitive and affective processing of that stimulus. More specifically, it appears that women respond more favourably when they are highly absorbed and immersed in a stimulus, reporting greater subjective sexual arousal and positive affect. Overall, the results of Studies One and Two highlight the dynamic and complex nature of female sexual arousal. It appears that women have definite cognitive and affective responses to sexual stimuli. The magnitude of these responses may be mediated by a number of factors however, including the intrinsic qualities of the stimulus and the degree to which the woman attends to the stimulus. Both these variables act to either enhance or inhibit the sexual arousal response. There results have important implications for current sexuality literature. While women’s cognitions and emotions in response to erotic film were generally highly correlated, in some instances they differed, warranting their inclusion as separate elements in models of female sexual arousal. Furthermore, it might be suggested that the inclusion of an additional variable – absorption – into current models of female sexual arousal would prove beneficial, aiding researchers to better understand and predict the arousal process. As such, recommendations are made for a revised model of female sexual arousal. In terms of future directions, the results of the present thesis have implications for the treatment of sexual dysfunctions, suggesting that clinicians need to understand the internal and external variables that might contribute to the aetiology and maintenance of their presenting problems.

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In the last thirty years there have been many research studies which have examined the reasons why adolescents and young adults engage in sexual behaviours. Most of these studies have lacked a theoretical basis, Consequently there are many links made between variables, but no consistency across studies, or attempts to develop an underlying theory to explain the results. However, there have been theoretical models developed to explain adolescents’ and young adults’ sexual decision making. Unfortunately, many of these models have not been empirically validated. This thesis attempts to address these deficiencies in the literature by utilising a theory of behaviour and applying it to adolescent and young adult sexual decision making. This theory is the Theory of Planned Behaviour (TPB). Two longitudinal studies were conducted to examine the utility of an adaptation of the TPB to sexual decision making among adolescents and young adults. In the first study 58 adolescent males, aged between 14 years and 18 years participated in a longitudinal study using a questionnaire adapted from the Depth of Sexual Involvement Scale. In the second study, 194 young adults (156 female, 38 male) aged between 18 years and 21 years participated in a similar study. The first study found that intention to engage in behaviour was well predicted, although some of the variables in the model, did not in fact, contribute significantly to the prediction. The prediction of behaviour was less strong than that of intention. Study two found that intention to engage in behaviours was well predicted by the model. However, the degree to which intention led to behaviour was not well predicted. Overall, the results of these studies suggest that the TPB is a good theoretical basis from which to launch a systematic and theoretically informed explanation of adolescent and young adult sexual decision making. However, other factors may need to be added to the model to fully describe the decision making process and accurately predict behaviour. Suggestions are made for future research, as well as interventions that may arise as more knowledge is gathered using this paradigm.

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Interviews with women regarding their experiences of sexual desire informed the development of the Female Sexual Desire Questionnaire. A validation sample of 741 women completed this questionnaire, with six interrelated factors found. These components of sexual desire were labelled: Dyadic Desire, Solitary Desire, Resistance, Positive Relationship, Sexual Self-image, and Concern. The portfolio concludes that a standard evaluation process is needed to assess the effectiveness of men's behaviour change groups (MBCGs), and that such programs should comprise only one component of a comprehensive multifaceted intervention strategy against intimate partner violence (IPV). Four case studies are presented.

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This study investigated the association between sexual practices and duration of a sexual encounter. Using data from a population-based computer-assisted telephone survey of 8,656 Australians aged 16 to 64 years, four distinct patterns of sexual practices among respondents were found: “basic sexual encounter” (involving mainly kissing, cuddling, stroking one's partner and being stroked, and vaginal intercourse), “basic sexual encounter plus oral sex,” “all assessed sexual practices” (all sexual behaviors included in the survey), and “mainly vaginal intercourse” (characterized by lower levels of kissing, cuddling, and stroking). For both men and women, respondents classified in the basic sexual encounter plus oral sex, and all assessed sexual practices clusters reported significantly longer durations than those in the basic sexual encounter group, whereas respondents in the mainly vaginal intercourse cluster reported shorter durations. These differences were found even after allowing for demographic differences in sexual duration—specifically, age and partner type of the most recent opposite-sex partner. These findings add to the understanding of what typically happens in a sexual encounter. Overall, longer sexual encounters appear to be associated with the inclusion of the least common sexual practices—namely, oral sex and self-stimulation.

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Background: Emerging evidence indicates that consumers of alcohol mixed with energy drink (AmED) self-report lower odds of risk-taking after consuming AmED versus alcohol alone. However, these studies have been criticized for failing to control for relative frequency of AmED versus alcohol-only consumption sessions. These studies also do not account for quantity of consumption and general alcohol-related risk-taking propensity. The aims of the present study were to (i) compare rates of risk-taking in AmED versus alcohol sessions among consumers with matched frequency of use and (ii) identify consumption and person characteristics associated with risk-taking behavior in AmED sessions. Methods: Data were extracted from 2 Australian community samples and 1 New Zealand community sample of AmED consumers (n = 1,291). One-fifth (21%; n = 273) reported matched frequency of AmED and alcohol use. Results: The majority (55%) of matched-frequency participants consumed AmED and alcohol monthly or less. The matched-frequency sample reported significantly lower odds of engaging in 18 of 25 assessed risk behaviors in AmED versus alcohol sessions. Similar rates of engagement were evident across session type for the remaining behaviors, the majority of which were low prevalence (reported by <15%). Regression modeling indicated that risk-taking in AmED sessions was primarily associated with risk-taking in alcohol sessions, with increased average energy drink (ED) intake associated with certain risk behaviors (e.g., being physically hurt, not using contraception, and driving while over the legal alcohol limit). Conclusions: Bivariate analyses from a matched-frequency sample align with past research showing lower odds of risk-taking behavior after AmED versus alcohol consumption for the same individuals. Multivariate analyses showed that risk-taking in alcohol sessions had the strongest association with risk-taking in AmED sessions. However, hypotheses of increased risk-taking post-AmED consumption were partly supported: Greater ED intake was associated with increased likelihood of specific behaviors, including drink-driving, sexual behavior, and aggressive behaviors in the matched-frequency sample after controlling for alcohol intake and risk-taking in alcohol sessions. These findings highlight the need to consider both personal characteristics and beverage effects in harm reduction strategies for AmED consumers.

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Although females rarely experience strong mate limitation, delays or lifelong problems of mate acquisition are detrimental to female fitness. In systems where males search for females via pheromone plumes, it is often difficult to assess whether female signaling is costly. Direct costs include the energetics of pheromone production and attention from unwanted eavesdroppers, such as parasites, parasitoids, and predators. Suboptimal outcomes are also possible from too many or too few mating events or near-simultaneous arrival of males who make unwanted mating attempts (even if successfully thwarted). We show that, in theory, even small costs can lead to a scenario where young females signal less intensely (lower pheromone concentration and/or shorter time spent signaling) and increase signaling effort only as they age and gather evidence (while still virgin) on whether sperm limitation threatens their reproductive success. Our synthesis of the empirical data available on Lepidoptera supports this prediction for one frequently reported component of signaling-time spent calling (often reported as the time of onset of calling at night)-but not for another, pheromone titer. This difference is explicable under the plausible but currently untested assumption that signaling earlier than other females each night is a more reliable way of increasing the probability of acquiring at least one mate than producing a more concentrated pheromone plume.

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It has been proposed that short-term activation of the hypothalamo-pituitary adrenal axis, with a consequent increase in the secretion of cortisol, amy disrupt the endocrine events prior to ovulation and thereby impair reproduction in females. We investigated this concept in gilts in which oestrus was detected by introduction to boars, where intense physical contact is possible, or by applying pressure to the back of gilts (back-pressure test) during fence-line exposure to boars, where intense physical contact is prohibited. We expected that there would be a greater release of cortisol and that reproduction would be inhibited in gilts introduced to boars compared to gilts in which the back-pressure test was used. As expected, introduction of gilts to boars resulted in a significant transient increase in plasma concentrations of cortisol while there was no significant effect of using the back-pressure test on plasma cortisol. Nevertheless, introduction of gilts to boars did not impair reproduction and there was no effect of method of detecting oestrus on duration of oestrus, sexual receptivity, fertility or fecundity. The length of the oestrous cycle was decreased and ovulation rate increased in gilts that were introduced to boars compared to gilts that underwent the back-pressure test, indicating that introduction of gilts to boars may have stimulated these aspects of reproduction. These stimulatory effects may have been due to an increased exposure of gilts to sexual behaviour and stimuli from boars when introduced to boars and/or to stimulatory effects of the hypothalamo-pituitary adrenal axis on some aspects of reproduction.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The purpose of this study was to validate noninvasive endocrine monitoring techniques for Pampas deer and to evaluate seasonal changes in testicular steroidogenic activity and their correlation to reproductive behavior, antler cycle and group size. Thus, fecal samples, behavioral data and observations of antler status were collected at monthly intervals during 1 year from free-ranging Pampas deer stags (three radio-collared individuals and 15 random individuals) living in Emas National Park, Brazil (18 degrees S latitude). Fecal steroids were extracted using 80% methanol and steroid concentrations were quantified by a commercial enzyme immunoassay (EIA). Fecal testosterone concentrations peaked in December-January (summer), March (early autumn) and in August-September (winter-spring), with minimal values from April-July. Reproductive behavior had two peaks, the first in December-January, characterized by predominately anogenital sniffing, flehmen, urine sniffing, chasing and mounting behavior, and the second peak in July-September (behavior primarily related to gland marking). There were significant correlations between fecal testosterone and reproductive behavior (r = 0.490), and between fecal testosterone and antler phases (r = 0.239). Antler casting and regrowth occurred under low testosterone concentrations, whereas velvet shedding was associated with high concentrations of testosterone. We inferred that Pampas deer stags exhibited a seasonal cycle that modulated sexual behavior and the antler cycle, and we concluded that fecal steroid analysis was a practical and reliable non-invasive method for the evaluation of the endocrine status of free-ranging Pampas deer. (c) 2004 Elsevier B.V. All rights reserved.

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The knowledge of Anastrepha zenildae behavioral aspects combined with the biology of Tephritidae may contribute to monitoring and control programs of this fruit fly that is considered as economically important to the Rio Grande do Norte state. In order to characterize the daily activity profile of this species, we studied the behaviors of resting, locomotion, feeding, cleaning, courtship, copulation and oviposition of animals submitted to an artificial 12:12h light-dark cycle (750:1lux) with controlled temperature (26±2 °C). The observations were made with groups of 16 males and 16 females during 3 consecutive days each generation from parental to F5. Resting, locomotion, feeding and cleaning data were recorded as frequency and time of occurrence by scanning technique in 15 minutes windows per hour, with a record each minute. Courtship, copulation and oviposition were recorded as frequency, time of occurrence and duration by al occurrences technique. Resting was the most frequent behavior with males resting more than females. Locomotion was more evident in the first half of the ligh phase with higher values in females. Cleaning and feeding behaviors were more frequent in the second half of the light phase for both sexes with females eating more frequently than males. During the courtship, males were grouped in lek formations showing wings vibration and pheromone liberation. Courtship occurred more frequently 4 to 7 h after lights on (81,9%) with copulations being more frequent 6 h after lights on with a mean duration of 58,1±40,4 min. Copulation attempts were observed in males inside and outside the lek with aggressive behavior being observed only between males in the lek. Oviposition behavior was similar to that described for other species of the genus with a peak of this activity 2-3 h after the lights on, mean duration of 43, 7±34, 8 sec and 2 to 5 eggs by event. According to the results, sexual behavior of A. zenildae is temporally different of other sympatric species of the genus, being favorable to the reproductive isolation as well as the use of resources as oviposition substrate.

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Why are we attracted to some people but not to other ones? How is this attraction established? Which signs are characteristic of a good partner? These and many other questions concerning how mate attraction and mate selection work out among humans have been intriguing behavioral scientists. It is well-known that beauty indicates something about a potential mate s health. The odor may indicate a similar assessment, if we can assess how pheromones are integrated into human sexual behavior. However, what is the relation between age preference and body scent evaluation? In order to investigate this question, this study´s objective was identifying evidences which show that olfactory cues might reveal the potential mate s age and that it coincides with the ideal mate s profile. To produce the stimuli, men and women had to wear cotton t-shirts for three nights in order to have their body odor impregnated. After that, opposite-sex individuals evaluated the intensity and attractivity of these odor impregnated tshirts according to two Likert scales (4 points scale for intensity; 7 points scale for attractivity). We found differences between men and women on body scent perception, that indicates a better scent discrimination for women when it concerns the perception of potential mate s age. Another finding was the negative correlation between intensity and attractiveness perception for both sexes. We also verified that mate selection strategies are plural, more than one tactic simultaneously fitting in the same strategy, but all of them are related to differential investment of each sex on their own reproductive success