27 research outputs found

    Geographic variation in breeding system and environment predicts melanin-based plumage ornamentation of male and female Kentish plovers

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    Sexual selection determines the elaboration of morphological and behavioural traits and thus drives the evolution of phenotypes. Sexual selection on males and females can differ between populations, especially when populations exhibit different breeding systems. A substantial body of literature describes how breeding systems shape ornamentation across species, with a strong emphasis on male ornamentation and female preference. However, whether breeding system predicts ornamentation within species and whether similar mechanisms as in males also shape the phenotype of females remains unclear. Here, we investigate how different breeding systems are associated with male and female ornamentation in five geographically distinct populations of Kentish plovers Charadrius alexandrinus. We predicted that polygamous populations would exhibit more elaborate ornaments and stronger sexual dimorphism than monogamous populations. By estimating the size and intensity of male (n = 162) and female (n = 174) melanin-based plumage ornaments, i.e. breast bands and ear coverts, we show that plumage ornamentation is predicted by breeding system in both sexes. A difference in especially male ornamentation between polygamous (darker and smaller ornaments) and monogamous (lighter and larger) populations causes the greatest sexual dimorphism to be associated with polygamy. The non-social environment, however, may also influence the degree of ornamentation, for instance through availability of food. We found that, in addition to breeding system, a key environmental parameter, rainfall, predicted a seasonal change of ornamentation in a sex-specific manner. Our results emphasise that to understand the phenotype of animals, it is important to consider both natural and sexual selection acting on both males and females

    A Review of the Status of Brain Structure Research in Transsexualism

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    Latino Mother/Daughter Dyadic Attachment as a Mediator for Substance Use Disorder and Emotional Abuse

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    BACKGROUND: To date, no studies have investigated emotional abuse of adult Latina women by their mothers despite evidence that emotional maternal abuse may significantly contribute to the emotional abuse experienced by Latina women in their lifetime. METHODS: Cross-sectional data including 316 women was analyzed using mediation and logistic regression. RESULTS: Overall, 7.1% of mothers and 24.1% of daughters abused drugs; and, 19.5% of daughters were emotionally abused by their mothers. Mother's attachment to her daughter mediated the association between mother's drug abuse and emotionally abusing her adult daughter (Indirect effect: 0.863). DISCUSSION: Latina women can serve as perpetrators of emotional abuse of their adult children. Since drug-abusing daughters are more likely to be victims of emotional abuse by their mothers and drug-abusing mothers are more likely to abuse their daughters, drug-rehabilitation practitioners should incorporate a family abuse component into rehabilitation programs
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