947 resultados para Teenagers Sexual behavior
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Specialized setae placed on proximal segments of appendages in tarantulas have been related to sound production (stridulation), used in defense or sexual communication. The surface structure of called stridulatory setae of Acanthoscurria suina Pocock, 1903 was studied by SEM. Three morphological types of setae were recognized and at least two of them could be involved in stridulation. Their role in sexual communication was tested by experimental removal. Our results showed no differences in the sexual success between the setaeless and control individuals. Consequently, a defensive function for stridulatory setae seems to be more likely than a sexual function.
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We describe the mating behavior of Adelosgryllus rubricephalus Mesa & Zefa, 2004. In trials carried out in laboratory we verified the following mating sequence: (1) sexual recognition by antennation; (2) courtship with male turning his abdomen towards the female, performing mediolateral antennae vibration, jerking its body antero-posteriorly and stridulating intermittently, while receptive female drums on the male's abdomen tip, cerci and hind-tibia with her palpi or foretarsi; the male then stops and stays motionless for some seconds, extrudes the spermatophore and both restart the behavioral sequence described above; (3) copulation: male underneath female; with his tegmina inclined forward, and joins his genitalia to the female's to promote sperm transference ; the female steps off the male, occurring a brief end-to-end position; (4) postcopulation: without guarding behavior; male retains the spermatophore and eats it. We quantified elapsed time of each behavioral sequence and discussed its implications in the observed mating behavior.
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OBJECTIVE: To describe food habits and dietary intakes of athletic and non-athletic adolescents in Switzerland. SETTING: College, high schools and professional centers in the Swiss canton of Vaud. METHOD: A total of 3,540 subjects aged 9-19 y answered a self-reported anonymous questionnaire to assess lifestyles, physical plus sports activity and food habits. Within this sample, a subgroup of 246 subjects aged 11-15 also participated in an in-depth ancillary study including a 3 day dietary record completed by an interview with a dietician. RESULTS: More boys than girls reported engaging in regular sports activities (P<0.001). Adolescent food habits are quite traditional: up to 15 y, most of the respondents have a breakfast and eat at least two hot meals a day, the percentages decreasing thereafter. Snacking is widespread among adolescents (60-80% in the morning, 80-90% in the afternoon). Food habits among athletic adolescents are healthier and also are perceived as such in a higher proportion. Among athletic adolescents, consumption frequency is higher for dairy products and ready to eat (RTE) cereals, for fruit, fruit juices and salad (P<0.05 at least). Thus the athletic adolescent's food brings more micronutrients than the diet of their non-athletic counterparts. Within the subgroup (ancillary study), mean energy intake corresponds to requirements for age/gender group. CONCLUSIONS: Athletic adolescents display healthier food habits than non-athletic adolescents: this result supports the idea that healthy behavior tends to cluster and suggests that prevention programs among this age group should target simultaneously both sports activity and food habits.
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Trait decay may occur when selective pressures shift, owing to changes in environment or life style, rendering formerly adaptive traits non-functional or even maladaptive. It remains largely unknown if such decay would stem from multiple mutations with small effects or rather involve few loci with major phenotypic effects. Here, we investigate the decay of female sexual traits, and the genetic causes thereof, in a transition from haplodiploid sexual reproduction to endosymbiont-induced asexual reproduction in the parasitoid wasp Asobara japonica. We take advantage of the fact that asexual females cured of their endosymbionts produce sons instead of daughters, and that these sons can be crossed with sexual females. By combining behavioral experiments with crosses designed to introgress alleles from the asexual into the sexual genome, we found that sexual attractiveness, mating, egg fertilization and plastic adjustment of offspring sex ratio (in response to variation in local mate competition) are decayed in asexual A. japonica females. Furthermore, introgression experiments revealed that the propensity for cured asexual females to produce only sons (because of decayed sexual attractiveness, mating behavior and/or egg fertilization) is likely caused by recessive genetic effects at a single locus. Recessive effects were also found to cause decay of plastic sex-ratio adjustment under variable levels of local mate competition. Our results suggest that few recessive mutations drive decay of female sexual traits, at least in asexual species deriving from haplodiploid sexual ancestors.
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En la actualidad, los adolescentes son uno de los grupos que por sus características conductuales, cognitivas y sociales, se encuentran en mayor riesgo frente al posible contagio con el VIH. Esta amenaza para la salud y el bienestar de los adolescentes, se ha venido a sumar a otros problemas ya existentes en este colectivo: los embarazos no deseados y las enfermedades de transmisión sexual (ETS), que también se derivan de la no utilización de precauciones en las relaciones sexuales. En este trabajo se exponen diversos factores biológicos, psicológicos (conductuales y cognitivos) y sociales que pueden facilitar, dificultar o impedir los comportamientos sexuales de prevención de los adolescentes, y se revisan y valoran algunas de las intervenciones preventivas realizadas. A partir de esta revisión se argumenta sobre la conveniencia de unificar los programas para la prevención simultánea de los tres trastornos, maximizando de esta forma los recursos disponibles
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In this work, we have developed the first free software for mobile devices with the Android operating system that can preventively mitigate the number of contagions of sexually transmitted infections (STI), associated with risk behavior. This software runs in two modes. The normal mode allows the user to see the alerts and nearby health centers. The second mode enables the service to work in the background. This software reports the health risks, as well as the location of different test centers.
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Triatomines have been important model organisms for behavioural research. Diverse reports about triatomine host search, pheromone communication in the sexual, shelter and alarm contexts, daily cycles of activity, refuge choice and behavioural plasticity have been published in the last two decades. In recent times, a variety of molecular genetics techniques has allowed researchers to investigate elaborate and complex questions about the genetic bases of the physiology of insects. This, together with the current characterisation of the genome sequence of Rhodnius prolixus allows the resurgence of this excellent insect physiology model in the omics era. In the present revision, we suggest that studying the molecular basis of behaviour and sensory ecology in triatomines will promote a deeper understanding of fundamental aspects of insect and, particularly, vector biology. This will allow uncovering unknown features of essential insect physiology questions for a hemimetabolous model organism, promoting more robust comparative studies of insect sensory function and cognition.
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En una muestra de 119 estudiantes de cuarto de Educación Secundaria Obligatoria (ESO) y primerode Bachillerato (52,6% mujeres) se analizan los conocimientos sobre la prevención de latransmisión sexual del virus del sida, las expectativas de resultados y de autoeficacia respecto a losmétodos preventivos y el tipo de prevención utilizada durante la última relación sexual. Para evitarlas respuestas inducidas respecto a los comportamientos preventivos se emplea un formato de preguntaabierta. Los resultados muestran que sólo el 23,5% de los estudiantes han dado dos respuestastotalmente correctas sobre estrategias consideradas eficaces en la prevención sexual del VIH:uso del preservativo y abstinencia (por este orden). El 70,5% valoran totalmente o muy eficaz elpreservativo para evitar la transmisión sexual del VIH y el 95% de los que dan la segunda respuestajuzgan totalmente eficaz la práctica de la abstinencia con la misma finalidad. En el caso del preservativose sienten totalmente o muy capaces de usarlo el 64,3%, mientras que cuando se trata de laabstinencia sólo se perciben con esa competencia el 20%. Por lo que se refiere al uso autoinformadode métodos preventivos en la última relación, por parte de los 29 estudiantes que tuvieronactividad sexual durante el mes anterior, se observa que 21 de ellos emplearon el preservativo, dosla píldora anticonceptiva, otros dos no precisan el tipo de precaución y el resto no tomó ninguna.Tanto el reducido nivel de conocimientos sobre prevención, como la baja percepción de autoeficaciapara mantenerse abstinentes, nos alertan sobre la necesidad de hacer un mayor esfuerzo de informaciónpara eliminar creencias equivocadas, como por ejemplo: sobre la pretendida eficacia protectorade tener relaciones sexuales con una pareja estable o conocida. Así mismo, conviene insistiren el uso del preservativo como anticonceptivo de elección entre los adolescentes
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The sexes of Pseudometocha melanocephala (Perty, 1833) and of a new species of Anomophotopsis are associated based on mating pairs found in the field and also in laboratory mating trials. The previously unknown male of Pseudomethoca melanocephala (Perty, 1833) and both sexes of Anomophotopsis quinteroi Cambra, sp. nov., are described. We present the first distribution record of P. melanocephala from Argentina. Anecdotal data on their mating behavior are also discussed.
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Polythoridae comprise a widespread group of species in the New World tropics, but little is known about their behavior or life history. Here, we described the reproductive behavior of Amazonian Chalchopteryx rutilans, using mark-recapture techniques. Males were resident and territorial, though we found disputes (complex flight manoeuvres) to be rare. Trunks (rotting wood) were important to male persistence in sites, as these are the locations preferred by females for oviposition. The mating system of C. rutilans may be comparable to the resource limitation category, described by Conrad & Pritchard (1992), where males cannot control female access to oviposition sites. So, female choice becomes important and apparently, the observed displays (in which males flash the coppery coloration of their hind wings) may be related to attraction of females to territories, as in a lek system.
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This study deals with the psychological processes underlying the selection of appropriate strategy during exploratory behavior. A new device was used to assess sexual dimorphisms in spatial abilities that do not depend on spatial rotation, map reading or directional vector extraction capacities. Moreover, it makes it possible to investigate exploratory behavior as a specific response to novelty that trades off risk and reward. Risk management under uncertainty was assessed through both spontaneous searching strategies and signal detection capacities. The results of exploratory behavior, detection capacities, and decision-making strategies seem to indicate that women's exploratory behavior is based on risk-reducing behavior while men behavior does not appear to be influenced by this variable. This difference was interpreted as a difference in information processing modifying beliefs concerning the likelihood of uncertain events, and therefore influencing risk evaluation.
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BACKGROUND: Human speech is greatly influenced by the speakers' affective state, such as sadness, happiness, grief, guilt, fear, anger, aggression, faintheartedness, shame, sexual arousal, love, amongst others. Attentive listeners discover a lot about the affective state of their dialog partners with no great effort, and without having to talk about it explicitly during a conversation or on the phone. On the other hand, speech dysfunctions, such as slow, delayed or monotonous speech, are prominent features of affective disorders. METHODS: This project was comprised of four studies with healthy volunteers from Bristol (English: n = 117), Lausanne (French: n = 128), Zurich (German: n = 208), and Valencia (Spanish: n = 124). All samples were stratified according to gender, age, and education. The specific study design with different types of spoken text along with repeated assessments at 14-day intervals allowed us to estimate the 'natural' variation of speech parameters over time, and to analyze the sensitivity of speech parameters with respect to form and content of spoken text. Additionally, our project included a longitudinal self-assessment study with university students from Zurich (n = 18) and unemployed adults from Valencia (n = 18) in order to test the feasibility of the speech analysis method in home environments. RESULTS: The normative data showed that speaking behavior and voice sound characteristics can be quantified in a reproducible and language-independent way. The high resolution of the method was verified by a computerized assignment of speech parameter patterns to languages at a success rate of 90%, while the correct assignment to texts was 70%. In the longitudinal self-assessment study we calculated individual 'baselines' for each test person along with deviations thereof. The significance of such deviations was assessed through the normative reference data. CONCLUSIONS: Our data provided gender-, age-, and language-specific thresholds that allow one to reliably distinguish between 'natural fluctuations' and 'significant changes'. The longitudinal self-assessment study with repeated assessments at 1-day intervals over 14 days demonstrated the feasibility and efficiency of the speech analysis method in home environments, thus clearing the way to a broader range of applications in psychiatry. © 2014 S. Karger AG, Basel.
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The arms race between predators and prey has led to morphological and behavioral adaptations. Different antipredator strategies can coexist within a population if each strategy is the result of a trade-off with competing demands. Antipredator behavior can be associated with morphological traits, like color patterns, either because in the context of sexual selection, coloration signals the ability to avoid predators or because coloration is a naturally selected trait useful in avoiding predators. Because in the barn owl (Tyto alba), heritable eumelanic plumage coloration is associated with the glucocorticoid-dependent response to stress, we tested whether antipredator behavior is also related to this trait. Compared with small-spotted nestlings, individuals displaying larger black spots hissed more intensely in the presence of humans, feigned death longer, had a lower breathing rate under stress, and were more docile when handled. Cross-fostering experiments showed that the covariation between the spot size and the duration of feigning death was inherited from the biological mother, whereas covariation between spot size and docility was inherited from the biological father. Our results confirm that melanin-based coloration is associated with suites of behavioral traits, which are under both genetic and environmental influence. Coloration can thus evolve as a direct or indirect response to predation, but it can also be a signal of antipredator strategies to potential mates.
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Mayflies (Ephemeroptera) are known to have short adult life-spans. Adults are unable to feed, and they utilize reserves stored during their aquatic larval stage. Energy reserves (fat, glycogen, and free sugars) of mature larvae, subimagoes and imagoes of both sexes of Siphlonurus aestivalis Eaton were compared. All the stages of both sexes had low glycogen and free sugar contents, and the only significant change occurred during the transformation of the mature larva to subimago when almost all the reserves of free sugars were used up. Glycogen and free sugars may serve as energy sources permitting individuals to swim and fly out of the water during emergence. Fat made up most of the energy reserves of mature larvae and was the main source of energy used during the final development of both sexes. Young adult males had high fat reserves which they used as a source of energy for their swarming flights. In contrast, females did not seem to use a significant amount of fat for flight. This difference is probably related to the different mating strategies of the sexes in this species. Males perform long flights waiting for females, whereas females perform only brief flights to mate and reproduce.
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Introduction: In 2012, a study by K. Chatziioannidou and S-C. Renteria showed that teenagers chose to undergo a surgical termination of pregnancy (TOP) more often than a medical TOP (mifepristone followed by misoprostol) when they decided to terminate a pregnancy. It also showed that the teenagers' choice for a medical versus surgical method is inversely proportional to the adults' choice although the efficiency of the medical method showed even better results for teenagers than for adults. According to the hypothesis made, the reasons for this choice might be influenced by the following facts: (i) the belated call to make an appointment, the medical procedure not being available after 9 weeks of gestation; (ii) the imperative request for confidentiality; (iii) the beliefs and subjective appreciation of the medical staff. Objectives: The aim of this retrospective and qualitative study is to analyse the reasons why, in case of a TOP, teenagers chose the surgical method more often than their adult counterparts. Material: (i) All teenagers who were admitted for an abortive procedure during 2011 in the in- or outpatient ward. (ii) The professional team (midwives and sexual and reproductive counsellors) in charge in the case of a TOP request. Methods: The information about the patient's history and the biopsycho- social data was retrieved from the patient files filled out by midwives and sexual and reproductive health counsellors during the first appointment for a TOP request or during its process. The professionals' appreciation was evaluated by means of a semi-structured questionnaire. Results: Concerning the choice of the method for a pregnancy termination, the results of our research show that: (i) Out of 47 teenagers, 27 chose the surgical method and 17 the medical method. (ii) Three had a second trimester abortion (which includes use of the medical method). (iii) Fifteen teenagers out of the 27 who chose a surgical method consulted between the 9th and 14th weeks of amenorrhoea and therefore did not have any other choice. The reasons for their 'late arrival' will be explained in detail. The 12 teenagers who arrived before the 8th week of amenorrhoea and chose to undertake abortion by suction & curettage under general anaesthesia did it for the following reasons: (i) Four were afraid of bleeding and pain. (ii) Five thought that the organisation of the surgical procedure was easier. (iii) Two did not trust the abortion pill. (iv) One was taken to her mother's gynaecologist where she had a D&C. Confidentiality was requested nine times out of 27 when choosing the surgical method, and six times out of 17 when choosing the medical method. Therefore, although confidentiality concerns a third of the teenagers' pregnancy termination requests, it does not seem to be a significant element for the choice of the method. As for the subjective appreciation of the professionals, the first results of the discussions seem to show that teenagers were reluctant or resistant towards the medical method. Conclusion: This study shows that the reasons why teenagers still prefer the use of the surgical over the medical method compared to adults, seem to include the late request for an appointment, fear of pain and bleeding and organisational issues. Confidentiality does not seem to greatly influence the teenagers' choice. Nonetheless, medical professionals seem to favour the suction curettage procedure performed under anesthesia because they associate young age with vulnerability and psychological frailty and consequently diminished ability to cope with pain and emotional distress during the medical procedures.