Genetic causes of transitions from sexual reproduction to asexuality in plants and animals.

The persistence of sexual reproduction in the face of competition from asexual invaders is more likely if asexual lineages are produced infrequently or have low fitness. The generation rate and success of new asexual lineages will be influenced by the proximate mechanisms underlying transitions to asexuality. As such, characterization of these mechanisms can help explain the distribution of reproductive modes among natural populations. Here, we synthesize the literature addressing proximate causes of transitions from sexual to asexual reproduction in plants and animals. In cyclical and facultatively asexual taxa, individual mutations can cause obligate asexuality. The evolution of asexuality in obligately sexual groups is more complex, requiring the simultaneous acquisition of two traits generally controlled by different genetic factors: unreduced gamete formation and spontaneous development of unfertilized gametes. At least three 'pre-adaptations' could favour transitions to obligate asexuality in obligate sexuals. First, linkage among loci affecting separate key components of asexuality facilitates its spread, with evidence for these linkage blocks in plants. Second, asexuality should evolve more readily in haplodiploids; support for this hypothesis comes from two examples where a single locus causes transitions to asexuality. Third, standing genetic variation for the production of unreduced gametes could facilitate transitions to asexuality, but whether the ability to produce unreduced gametes contributes to the evolution of obligate asexuality remains unclear. We close by reviewing the associations between asexuality, hybridization and polyploidy, and argue that current data suggest that hybridization is more likely to play a causal role in transitions to asexuality than polyploidy.

Estilos de vida na adolescência: comportamento sexual dos adolescentes portugueses

Estudos recentes têm demonstrado que actualmente os adolescentes iniciam a vida sexual cada vez mais cedo, sem contudo possuírem uma educação sexual consistente. Os objectivos deste estudo foram analisar o comportamento sexual de adolescentes do ensino secundário e identificar os hábitos de vigilância de saúde sexual em adolescentes, do ensino secundário, sexualmente activos. Realizou-se um estudo exploratório em que participaram 680 adolescentes, com idades entre 15 e 19 anos. Os resultados evidenciam que a maioria dos inquiridos ainda não iniciou a actividade sexual; são os rapazes os que mais reportam já ter tido relações sexuais; o preservativo não é um método utilizado por todos os adolescentes nas suas relações sexuais; a maioria dos adolescentes não faz vigilância de saúde sexual. É importante que os adolescentes sexualmente activos recebam cuidados de saúde e aconselhamento. As instituições de saúde e os seus profissionais necessitam de ser pró-activos tentando captar os adolescentes.

Do pornographic websites influence boys' sexual behavior?

Purpose: To compare the sexual behavior of adolescent males who do and do not watch pornographic websites. Methods: This study was presented as a school survey. Data were drawn from the 2002 Swiss Multicenter Adolescent Survey on Health (SMASH02) database, a survey including 7,548 adolescents age 16-20. The setting was post-mandatory schools in Switzerland. A total of 2,891 male students who connected to the internet in the last 30 days were enrolled and distributed into two groups: boys who deliberately watched pornographic websites in the last 30 days (n ¼ 942; 33%) and boys who did not (n ¼ 1,949; 67%). Socio-demographic characteristics; frequency of connection to the internet; sexual behavior parameters (having a girlfriend and if yes, for more or less than 6 months; having had sexual intercourse; age at first sexual intercourse; use of a condom at last sexual intercourse; number of sexual partners; having made a partner pregnant). Results: A logistic regression was performed using STATA 9.2. The only significant socio-demographic variable was having a low socioeconomic status (adjusted odds ratio [AOR] 1.66); no difference was found for age and academic track between the two groups. Boys who watch pornographic websites were also significantly more likely to connect frequently to the internet (one day a week: AOR 1.75; several days a week: AOR 2.36; every day: AOR 3.11), to have had sexual intercourse (AOR 2.06), and to have had their first sexual intercourse before age 15 (AOR 1.48). The stability of the relationship with their girlfriend did not appear to have any influence on the search for pornography on the internet. Conclusions: About one third of boys in our sample report having accessed pornographic websites in the last 30 days, a proportion similar to other studies. Watching such websites increases with the frequency of connection to the internet and seems to be correlated with an earlier sexual activity debut among adolescent males. However, having had first sexual intercourse before age 15 is the only sexual risk behavior that seems to be increased when watching pornographic websites among boys. Further studies should address the causality of this correlation and the factors influencing the search for pornography on the web among boys, in order to explore some new ways of prevention about sexual risk behaviors. Sources of Support: The SMASH02 survey was carried out with the financial support of the Swiss Federal Office of Public Health and the participating cantons.

Adolescentes em cena: uma proposta educativa no campo da saúde sexual e reprodutiva

Objetivou-se descrever a experiência sobre a elaboração de material educativo, no formato de performance teatral criada e encenada por adolescentes, como estratégia para a obtenção de uma atitude reflexiva e autônoma desses sujeitos, no campo afetivo-sexual e reprodutivo. Processo de intervenção e de investigação desenvolvido em uma escola pública de Belo Horizonte - Minas Gerais, Brasil - com 12 estudantes de 14 a 18 anos. A análise baseou-se no método de educação pela experiência, de John Dewey. Foram realizadas 23 oficinas até a produção do espetáculo e do vídeo Sexo sim, Doença Não, exibido para alunos do ensino médio. A produção de tecnologias educativas, construída pelos próprios adolescentes, possibilitou a ampliação de suas vivências e a re-significação de conhecimentos. Também auxiliou a compreensão da realidade cotidiana desses sujeitos, permitindo a ligação entre o interno (o pensamento do adolescente) e o externo (que concretiza os fenômenos sociais) no campo afetivo-sexual e reprodutivo.

A qui li dic? : la detecció de l’abús sexual infantil i el traspàs d’informació entre professionals

Aquest treball s'estructura en una primera part de fonamentació teòrica. El procediment que s'ha seguit ha estat la recerca bibliogràfica. Es basa en els aspectes tècnics a tenir en compte per la detecció de l' Abusos Sexuals Infantils (ASI), la ubicació dels Serveis Bàsics d'Atenció Social (SBAS) dins el sistema català de serveis socials, el marc jurídic dels drets i de la protecció a la infància i l'adolescència així com de qüestions relatives al tractament de dades, de la confidencialitat de les informacions de què disposem els/les professionals, l'obligació de secret, complementat amb la deontologia professional, que ens pot orientar a l'hora de prendre les decisions més adequades a la nostra praxi. La segona part del treball és empírica. El procediment ha estat portar a terme un grup de reflexió ètica amb professionals del Consorci de Benestar Social del Pla de l'Estany-Banyoles. Partint de casos pràctics de sospita d'ASI, les persones participants han concretat els principals problemes (alguns dels quals relacionats amb l'ètica aplicada) davant els quals s'han trobat a la fase de detecció/intervenció. Les aportacions extretes de les diferents sessions en les quals es van treballar part dels objectius d'aquesta recerca ens permeten concretar la realitat i una primera deliberació sobre quina podria ser la bona pràctica general. La tercera part utilitza la fonamentació teòrica i els material del treball de camp per presentar la reflexió final que pretén donar resposta als objectius plantejats en aquesta recerca

Alpha1-adrenoceptors are required for normal male sexual function.

BACKGROUND AND PURPOSE: Alpha(1)-adrenoceptor antagonists are extensively used in the treatment of hypertension and lower urinary tract symptoms associated with benign prostatic hyperplasia. Among the side effects, ejaculatory dysfunction occurs more frequently with drugs that are relatively selective for alpha(1A)-adrenoceptors compared with other drugs of this class. This suggests that alpha(1A)-adrenoceptors may contribute to ejaculation. However, this has not been studied at the molecular level. EXPERIMENTAL APPROACH: The physiological contribution of each alpha(1)-adrenoceptor subtype was characterized using alpha(1)-adrenoceptor subtype-selective knockout (KO) mice (alpha(1A)-, alpha(1B)- and alpha(1D)-AR KO mice) since the subtype-specific drugs available are only moderately selective. We analysed the role of alpha(1)-adrenoceptors in the blood pressure and vascular response as well as ejaculation by determining these variables in alpha(1)-adrenoceptor subtype-selective KO mice and in mice with all their alpha(1)-adrenoceptor subtypes deleted (alpha(1)-AR triple-KO mice). KEY RESULTS: The pregnancy rate was reduced by 50% in alpha(1A)-adrenoceptor KO mice, and this reduction was dramatically enhanced in alpha(1)-adrenoceptor triple-KO mice. Contractile tension of the vas deferens in response to noradrenaline was markedly decreased in alpha(1A)-adrenoceptor KO mice, and this contraction was completely abolished in alpha(1)-adrenoceptor triple-KO mice. This attenuation of contractility was also observed in the electrically stimulated vas deferens. CONCLUSIONS AND IMPLICATIONS: These results demonstrate that alpha(1)-adrenoceptors, particularly alpha(1A)-adrenoceptors, are required for normal contractility of the vas deferens and consequent sperm ejaculation as well as having a function in fertility.

Sexual Harassment in Education: It's Against the Law

An informational sheet about workplace sexual harassment produced by Iowa Commission on the Status of Women.

Sexual Harassment in Housing: It's Against the Law, 2001

An informational sheet about housing and sexual harassment produced by Iowa Commission on the Status of Women.

Sexual Harassment in the Workplace: Sample Policy

An informational sheet about developing and implementing a policy which prohibits sexual harassment in the workplace.

Differential DNA extraction of challenging simulated sexual assault samples: a Swiss collaborative study.

ABSTRACT: In sexual assault cases, autosomal DNA analysis of gynecological swabs is a challenge, as the presence of a large quantity of female material may prevent the detection of the male DNA. A solution to this problem is differential DNA extraction, but as there are different protocols, it was decided to test their efficiency on simulated casework samples. Four difficult samples were sent to the nine Swiss laboratories active in the forensic genetics. They used their routine protocols to separate the epithelial cell fraction, enriched with the non-sperm DNA, from the sperm fraction. DNA extracts were then sent to the organizing laboratory for analysis. Estimates of male to female DNA ratio without differential DNA extraction ranged from 1:38 to 1:339, depending on the semen used to prepare the samples. After differential DNA extraction, most of the ratios ranged from 1:12 to 9:1, allowing the detection of the male DNA. Compared to direct DNA extraction, cell separation resulted in losses of 94-98% of the male DNA. As expected, more male DNA was generally present in the sperm than in the epithelial cell fraction. However, for about 30% of the samples, the reverse trend was observed. The recovery of male and female DNA was highly variable depending on the laboratories. Experimental design similar to the one used in this study may help for local protocol testing and improvement.

Unwanted sexual experiences among adolescents: shedding light on the gray zone between consensual and non-consensual sex.

This study aimed at exploring adolescents' perceptions of unwanted sexual experiences (USE) in order to set up definitions, categories, and boundaries on the continuum between consensual and non-consensual sex. METHODS: We conducted a qualitative thematic analysis of four focus group discussions gathering a total of 29 male and female adolescents aged 16-20 years. RESULTS: Analysis of participants' discourse revealed three main characteristics that define USE, namely, regret, as most situations discussed were said to be acceptable or not in terms of whether there were regrets after the fact; misperception of sexual intent; and lack of communication between partners. CONCLUSIONS: Our findings revealed that health professionals should be aware of the subtle aspects identifying USE when screening for situations that can have adverse psychological consequences. Where prevention is concerned, it appears important to address these aspects of USE in sex education classes.

A Eclosão do Turismo Sexual em Cabo Verde

O artigo pretende expor a violência resultante das opções desenvolvimentistas dos governos cabo-verdianos pós-coloniais, nomeadamente a aposta no turismo de massa. Parte-se do caso de uma jovem república em vias de ser invadida pelo turismo sexual para se esboçar a prefiguração do que a globalização significa em termos de relações Norte-Sul. Em Cabo Verde, explosões de uma sexualidade e violência juvenil não-domesticáveis, na medida em que agridem o senso moral e os interesses das famílias de classe média em processo de distanciamento sociocultural de suas origens populares, desencadeiam um conjunto de estudos financiados pelas redes internacionais de protecção social. Na esteira de um desses estudos, o artigo parte de um trabalho de campo realizado em 2005 e outro em 2010 em que se entrevista um grande número de crianças em situação de vulnerabilidade.

Efeito da Gonadectomia nos Níveis Hormonais e no Comportamento de Machos de Oreochromis Mossambicus

Nos vertebrados, incluindo os peixes as hormonas activam e modificam o comportamento, e o comportamento por sua vez altera os níveis de hormonas, em particular os androgénios. A principal fonte de hormonas esteróides são as gónadas, mas o cérebro e outros tecidos também as produzem. A castração produz efeitos variados nos níveis hormonais e no comportamento sexual e agonístico dos teleosteos. Os objectivos deste estudo são: verificar a possível razão porque os níveis de androgénios continuam elevados após a gonadectomia, incluindo a possibilidade de contribuição de secreção de esteróides por tecidos extra-gonadais; e ainda de que forma a gonadectomia afecta o comportamento dos animais. Para isso foram efectuadas cirurgias a mais de 20 indivíduos de tilapia moçambicana e foram também retiradas amostras de sangue. Ainda foram retirados e incubados diversos tecidos - como cérebro, rim anterior e posterior, brânquias, fígado e sangue - para a identificação de fontes extragonadais de esteróides. A medição dos níveis hormonais de testosterona, 11- cetotestosterona e 17,20β-progesterona foi realizada através da técnica do radioimunoensaio. Os resultados obtidos monstram que a castração teve um efeito de diminuição muito ténue nos níveis hormonais, sendo que o comportamento dos animais manteve-se praticamente inalterado. O tecido que demonstrou maior capacidade de metabolização do precursor 17-HP foi o rim. Esses resultados podem ser explicados por regeneração do tecido das gónadas, e hipertrofia com consequente feedback positivo, ou ainda pela produção extragonadal de androgénios.

Sexual associations for two species of mutillid wasps (Hymenoptera, Mutillidae), with the description of a new species of Anomophotopsis

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.