Insularity and the evolution of melanism, sexual dichromatism and body size in the worldwide-distributed barn owl.

Abstract Island biogeography has provided fundamental hypotheses in population genetics, ecology and evolutionary biology. Insular populations usually face different feeding conditions, predation pressure, intraspecific and interspecific competition than continental populations. This so-called island syndrome can promote the evolution of specific phenotypes like a small (or large) body size and a light (or dark) colouration as well as influence the evolution of sexual dimorphism. To examine whether insularity leads to phenotypic differentiation in a consistent way in a worldwide-distributed nonmigratory species, we compared body size, body shape and colouration between insular and continental barn owl (Tyto alba) populations by controlling indirectly for phylogeny. This species is suitable because it varies in pheomelanin-based colouration from reddish-brown to white, and it displays eumelanic black spots for which the number and size vary between individuals, populations and species. Females are on average darker pheomelanic and display more and larger eumelanic spots than males. Our results show that on islands barn owls exhibited smaller and fewer eumelanic spots and lighter pheomelanic colouration, and shorter wings than on continents. Sexual dimorphism in pheomelanin-based colouration was less pronounced on islands than continents (i.e. on islands males tended to be as pheomelanic as females), and on small islands owls were redder pheomelanic and smaller in size than owls living on larger islands. Sexual dimorphism in the size of eumelanic spots was more pronounced (i.e. females displayed much larger spots than males) in barn owls living on islands located further away from a continent. Our study indicates that insular conditions drive the evolution towards a lower degree of eumelanism, smaller body size and affects the evolution of sexual dichromatism in melanin-based colour traits. The effect of insularity was more pronounced on body size and shape than on melanic traits.

Opportunity for sexual selection and effective population size in the lek-breeding European treefrog (Hyla arborea).

Sexual selection in lek-breeding species might drastically lower male effective population size, with potentially important consequences for evolutionary and conservation biology. Using field-monitoring and parental-assignment methods, we analyzed sex-specific variances in breeding success in a population of European treefrogs, to (1) help understanding the dynamics of genetic variance at sex-specific loci, and (2) better quantify the risk posed by genetic drift in this species locally endangered by habitat fragmentation. The variance in male mating success turned out to be markedly lower than values obtained from other amphibian species with polygamous mating systems. The ratio of effective breeding size to census breeding size was only slightly lower in males (0.44) than in females (0.57), in line with the patterns of genetic diversity previously reported from H. arborea sex chromosomes. Combining our results with data on age at maturity and adult survival, we show that the negative effect of the mating system is furthermore compensated by the effect of delayed maturity, so that the estimated instantaneous effective size broadly corresponded to census breeding size. We conclude that the lek-breeding system of treefrogs impacts only weakly the patterns of genetic diversity on sex-linked genes and the ability of natural populations to resist genetic drift.

Having a good relationship with their mother: a protective factor against sexual risk behavior among adolescent females?

STUDY OBJECTIVE: To assess whether having a good relationship with their mother was a protective factor against risky sexual behavior for female adolescents and whether it was independent of family structure. DESIGN: Cross-sectional survey of in-school adolescents aged 14-19 years. SETTING: Catalonia, in northeast Spain. PARTICIPANTS: A total of 3677 females divided according on whether they had a good (n=3335) or a bad (n=342) relationship with their mother. MAIN OUTCOME MEASURES: Rates of sexual activity and sexual behavior. RESULTS: Adolescents in the good relationship group were significantly younger, more likely to live in an intact family, to have a good relationship with their father and siblings, and to talk about sexuality and their partner with their mother. They were also less likely to have ever had sexual intercourse. Among those sexually experienced, they were significantly older at first intercourse and less likely to have multiple partners or a history of STI. After adjusting for potential confounders, females in the good relationship group were less likely to be sexually active and to have had multiple partners, independently of family structure. CONCLUSIONS: Having a good relationship with their mother is a protective factor against sexual intercourse and having multiple sexual partners independently of family structure. Communication between generations and having a good relationship with their father and siblings also play an important role.

Prevalencia y características del abuso sexual infantil en estudiantes universitarios españoles

Objective: The purpose of this paper was to compare the prevalence rates of child sexual abuse reported by [Finkelhor, D. (1994). The international epidemiology of child sexual abuse. Child Abuse & Neglect, 18 (5), 409417] with those found in recent publications in order to confirm the widespread prevalence of child sexual abuse. Methods: Relevant articles about prevalence of child sexual abuse were identified through searches of computerized databases and a handsearch of Child Abuse & Neglect and the Journal of Child Sexual Abuse. Results: Thirty-eight independent articles were identified, corresponding to 39 prevalence studies; these articles report the prevalence of childhood sexual abuse in 21 different countries, ranging from 0 to 53% for women and 0 to 60% for men. Conclusions: Comparison of the present study with that of [Finkelhor, D. (1994). The international epidemiology of child sexual abuse. Child Abuse & Neglect, 18 (5), 409417] shows a similarity between prevalence distributions; there appears to be a general pattern that remains more or less constant over the years, especially in women. Practice implications: Twelve years after the first revision study about the international prevalence of child sexual abuse, there is still a need for new data about this topic. The present study shows child sexual abuse is still a widespread problem in the society. In this research, carried out on 38 independent studies, there is new data for 21 countries over the world, being especially relevant the results obtained from other countries different from those pertaining toNorth America or Europe. It is important to point out the high prevalence found in most of the countries, so this information could be a new warning to make society and governments aware of this problem and undertake actions to prevent sexual abuse in childhood. © 2009 Elsevier Ltd. All rights reserved.

Estudio descriptivo de víctimas de abuso sexual infantil

En este trabajo se describen las características principales que presenta la población atendida en un centro de asesoramiento y atención a menores víctimas de abusos sexuales. Este centro, con sede en Barcelona, pertenece a la asociación FADA,creada en 1997 con la finalidad de ofrecer un servicio profesional de asesoramiento, prevención y formación especializada en relación con el abuso sexual acontecido durante la infancia. El presente estudio, meramente descriptivo, muestra la frecuencia del abuso sexual, la dificultad de su descubrimiento durante la infancia, sus consecuencias más comunes, así como la reacción del entorno de la víctima ante su revelación. Para ello se han utilizado los testimonios de 385 personas víctimas de abuso sexual durante su infancia. A través del análisis de dos muestras de usuarios del centro (adultos y menores) se dan a conocer las diferencias más destacadas. Los profesionales de este centro hacen de este modo públicas sus experiencias y recalcan la urgente y necesaria atención especializada que requieren no sólo las víctimas de abuso sexual infantil, sino también sus familias y/o su entorno social.

Uso do feromônio sexual sintético para captura de machos da traça-das-crucíferas

Este trabalho teve como objetivo estudar a atração dos machos da traça-das-crucíferas (Plutella xylostella L., Lepidoptera: Yponomeutidae) por diferentes formulações do feromônio sexual sintético. Os tratamentos consistiram em: 1) formulação comercial; 2) Z11,16:Ald; 3) Z11,16:Ac; 4) mistura 7:3 de 2+3; 5) mistura 5:5 de 2+3; 6) septos de borracha com hexano (testemunha); e 7) cinco fêmeas virgens. A formulação comercial do feromônio sexual sintético propiciou maior captura de machos, não diferindo significativamente de fêmeas virgens e da mistura 5:5 utilizadas como isca. Os componentes isoladamente foram pouco atrativos aos machos. Foram testados cinco modelos de armadilhas. A armadilha Pherocon 1 CP (33,2 machos/armadilha/noite) foi a mais eficiente na captura de machos, seguida pelas armadilhas Cilíndrica Aberta, Cilíndrica Fechada, Delta e Redonda Aberta. Três alturas de instalação da armadilha foram avaliadas. Ocorreu significativamente maior captura de machos na altura do ápice das plantas (30 cm do solo). As alturas de 5 e 60 cm não diferiram entre si.

Neutral and selection-driven decay of sexual traits in asexual stick insects.

Environmental shifts and lifestyle changes may result in formerly adaptive traits becoming non-functional or maladaptive. The subsequent decay of such traits highlights the importance of natural selection for adaptations, yet its causes have rarely been investigated. To study the fate of formerly adaptive traits after lifestyle changes, we evaluated sexual traits in five independently derived asexual lineages, including traits that are specific to males and therefore not exposed to selection. At least four of the asexual lineages retained the capacity to produce males that display normal courtship behaviours and are able to fertilize eggs of females from related sexual species. The maintenance of male traits may stem from pleiotropy, or from these traits only regressing via drift, which may require millions of years to generate phenotypic effects. By contrast, we found parallel decay of sexual traits in females. Asexual females produced altered airborne and contact signals, had modified sperm storage organs, and lost the ability to fertilize their eggs, impeding reversals to sexual reproduction. Female sexual traits were decayed even in recently derived asexuals, suggesting that trait changes following the evolution of asexuality, when they occur, proceed rapidly and are driven by selective processes rather than drift.

Hermenéutica del deseo y género sexual

"La que mis palabras esconden, mi cuerpo lo revela". El interés de esta cita de Roland Barthes1 para una reflexión formal sobre la distinción de género entte 10 femenino y 10 masculino radica en el supuesto de la diferencia hermeneutica entte las palabras y el cuerpo, que se oponen conceptualmente a partir de su función, respectivamente, ocultadora y reveladora en relación con el deseo.

Estudi sobre assetjament sexual a la Universitat Pompeu Fabra

La present investigació té com a objectiu analitzar la dimensió d’assetjament sexual en el àmbit de la Universitat Pompeu Fabra. Per poder valorar-ho, s’ha creat una enquesta per analitzar aquest fenomen dirigida exclusivament a la població de la universitat. La investigació es divideix en tres apartats diferents. El primer, pretén valorar la percepció dels membres de la Universitat Pompeu Fabra en relació a l’assetjament sexual. El segon, veure si es produeix assetjament dins de la Universitat. Per últim, es vol valorar la opinió de la població en relació a la implementació d’un mecanisme per atendre a les víctimes d’assetjament sexual.

Perfil sociosanitario sexual y contraceptivo de las mujeres visitadas por primera vez en el Programa Joven del Bages

Objetivos. Conocer las características, el perfil sanitario, sexual y contraceptivo, y los factores de riesgo en las mujeres jóvenes (menores de 24 años) que han acudido por primera vez al Programa Joven del PSAD-ASSIR del Bages. Método. Estudio transversal, descriptivo y observacional, realizado mediante el vaciado de 790 historias clínicas de jóvenes, pertenecientes a la comarca del Bages (Barcelona), que acudieron por primera vez al Programa Joven durante el año 2002. Resultados. La media de edad de las mujeres estudiadas es de 20 años (DE= 3), la mayoría nacidas en España (84%), con estudios secundarios (43%) y que viven la gran mayoría con familiares de primer grado (71%). Factores sexuales de riesgo: la edad media de inicio de relaciones sexuales con penetración es de 18 años (DE= 2,41); un 16% no emplea ningún método anticonceptivo o métodos poco fiables; un 14% tiene más de dos parejas sexuales. El porcentaje de mujeres que manifestaron haber estado embarazadas es del 18%, y habían tenido una interrupción voluntaria del embarazo (IVE) el 7%. Las principales sustancias tóxicas consumidas son tabaco (46%), alcohol (26%) y cannabis (7,2%). La petición de la anticoncepción de emergencia es el principal motivo de consulta (20%). Conclusión. En el momento de plantear políticas preventivas para la población juvenil, debería contemplarse desde una perspectiva global y no individualizada, ya que los factores de riesgo son múltiples y se hallan estrechamente relacionados.

Populations with elevated mutation load do not benefit from the operation of sexual selection.

Theory predicts that if most mutations are deleterious to both overall fitness and condition-dependent traits affecting mating success, sexual selection will purge mutation load and increase nonsexual fitness. We explored this possibility with populations of mutagenized Drosophila melanogaster exhibiting elevated levels of deleterious variation and evolving in the presence or absence of male-male competition and female choice. After 60 generations of experimental evolution, monogamous populations exhibited higher total reproductive output than polygamous populations. Parental environment also affected fitness measures - flies that evolved in the presence of sexual conflict showed reduced nonsexual fitness when their parents experienced a polygamous environment, indicating trans-generational effects of male harassment and highlighting the importance of a common garden design. This cost of parental promiscuity was nearly absent in monogamous lines, providing evidence for the evolution of reduced sexual antagonism. There was no overall difference in egg-to-adult viability between selection regimes. If mutation load was reduced by the action of sexual selection in this experiment, the resultant gain in fitness was not sufficient to overcome the costs of sexual antagonism.

Flight energetics in relation to sexual differences in the mating behaviour of a mayfly, Siphlonurus aestivalis

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.

Actuació d'infermeria en salut afectiva sexual i reproductiva en adolescents: proposta Programa Educatiu en l'àmbit escolar

L'adolescència és un període de transició entre la infància i l'edat adulta, una etapa del cicle de creixement que marca el final de la infància i anuncia la maduresa, aquest terme s'utilitza generalment per referir-se a una persona que es troba entre els 13 i 19 anys d'edat. En aquesta etapa s'inicia la maduració física, cognitiva, social i emocional del nen o nena en la cerca del camí cap a l'adultesa. Per a molts joves l'adolescència és un període d'incertesa i fins i tot de desesperació; per a uns altres, és una etapa d'amistats internes, de desvinculació de les lligadures amb els pares, de somnis sobre el futur, etc. El desenvolupament físic és només una part d'aquest procés de maduració, ja que els adolescents han de superar també una sèrie de canvis psicosocials, com per exemple: independència dels pares, aprenentatge d'estratègies de comunicació per relacionar-se de forma més madura, desenvolupament de les capacitats intel·lectuals, consolidació de la pròpia identitat, inici de les relacions sexuals, actituds i valors, control emocional, entre uns altres.