Home About us Contact
|
Home About us Contact | ||
|
|
||
Vs. Females (vs + female)
Selected AbstractsGender differences in rival characteristics that evoke jealousy in response to emotional versus sexual infidelityPERSONAL RELATIONSHIPS, Issue 4 2004Bram P. Buunk Previous research has shown that in men jealousy is evoked more by a rival's status-related characteristics than in women, whereas in women jealousy is evoked more by a rival's physical attractiveness than in men. The present study examined whether the occurrence of this gender difference depends upon the type of infidelity one's partner engages in, i.e., emotional or sexual infidelity, and whether these types of jealousy evoke different emotional responses. An experiment was conducted using hypothetical jealousy situations with a 2 (participant gender: male vs. female) × 2 (rival physical attractiveness: high vs. low) × 2 (rival dominance: high vs. low) × 2 (type of infidelity: sexual vs. emotional) mixed-factor design. Jealousy evoked by emotional infidelity was primarily characterized by feelings of threat, and jealousy after sexual infidelity was primarily characterized by feelings of betrayal and anger. Following emotional infidelity, in men, a rival's dominance, and in women, a rival's physical attractiveness, evoked feelings of threat but not feelings of anger-betrayal. In contrast, after sexual infidelity, in men, but not in women, a rival's physical attractiveness evoked feelings of betrayal-anger but not anxiety or suspicion. [source] Dexamethasone administration inhibits skeletal muscle expression of the androgen receptor and IGF-1 , implications for steroid-induced myopathyCLINICAL ENDOCRINOLOGY, Issue 1 2010Warrick J. Inder Summary Context, Glucocorticoids are a well-recognized cause of muscle weakness. The early effects of glucocorticoids on skeletal muscle (SkM) androgen and IGF-1 pathways have not been previously investigated in human subjects. Objective, To determine if administration of the potent glucocorticoid dexamethasone down-regulates SkM androgen receptor and the IGF-1 signalling pathway. Methods and subjects, Twenty-four subjects (12 men and 12 women), including 12 with type 2 diabetes and 12 nondiabetics were enrolled. Venous blood sampling and biopsy of vastus lateralis were performed before and after administration of oral dexamethasone 4 mg/day for 4 days. Main outcome measures, Changes in plasma testosterone and IGF-1, SkM androgen receptor mRNA, SkM IGF-1mRNA and SkM IGF-1 receptor mRNA by quantitative RT-PCR after dexamethasone. Results, Relative expression of SkM androgen receptor was similar in male (1·63 ± 0·37) vs. female (1·57 ± 0·30) subjects, despite the significant difference in plasma testosterone levels. Plasma IGF-1 and SkM expression of IGF-1 and IGF-1 receptor were also similar between males and females. Following dexamethasone, there was a significant down-regulation of SkM androgen receptor (1·60 ± 0·23 vs. 1·11 ± 0·16, P < 0·05) and IGF-1 (1·72 ± 0·29 vs. 1·06 ± 0·14, P < 0·05) mRNA, but no change in expression of the IGF-1 receptor. Plasma testosterone fell significantly in both sexes (male: 15·0 ± 1·3 vs. 11·3 ± 1·2 nmol/l, P < 0·01, female: 1·8 ± 0·5 vs. 0·5 ± 0·1 nmol/l, P < 0·05). Conclusions, Exogenous steroid excess results in relative androgen deficiency at two levels, reduced circulating testosterone and SkM androgen receptor mRNA, along with reduced SkM IGF-1 mRNA. These defects may contribute to the development of steroid-induced myopathy. [source] Evidence against a sexual dimorphism in glucose and fatty acid metabolism in skeletal muscle cultures from age-matched men and post-menopausal womenACTA PHYSIOLOGICA, Issue 3 2009A. Rune Abstract Aim:,In vivo whole body differences in glucose/lipid metabolism exist between men and women. Thus, we tested the hypothesis that intrinsic sex differences exist in skeletal muscle gene expression and glucose/lipid metabolism using cultured myotubes. Methods:, Myotube cultures were prepared for gene expression and metabolic studies from vastus lateralis skeletal muscle biopsies obtained from age-matched men (n = 11; 59 ± 2 years) and post-menopausal women (n = 10; 60 ± 1 years). Results:, mRNA expression of several genes involved in glucose and lipid metabolism was higher in skeletal muscle biopsies from female vs. male donors, but unaltered between the sexes in cultured myotubes. Basal and insulin-stimulated glucose uptake, as well as glucose incorporation into glycogen, was similar in myotube cultures derived from male vs. female donors. In males vs. females, insulin increased glucose uptake (1.3 ± 0.1 vs. 1.5 ± 0.1-fold respectively) and incorporation into glycogen (2.3 ± 0.3 vs. 2.0 ± 0.3-fold respectively) to the same extent. Basal fatty acid oxidation and rate of uptake/accumulation was similar between sexes. In response to the 5,AMP-activated protein kinase activator AICAR, lipid oxidation was increased to the same extent in myotubes established from male vs. female donors (1.6 ± 0.6 vs. 2.0 ± 0.3-fold respectively). Moreover, the AICAR-induced rate of uptake/accumulation was similar between sexes. Conclusion:, Differences in metabolic parameters and gene expression profiles between age-matched men and post-menopausal women noted in vivo are not observed in cultured human skeletal muscle cells. Thus, the sexual dimorphism in glucose and lipid metabolism is likely a consequence of systemic whole body factors, rather than intrinsic differences in the skeletal muscle proper. [source] Sex differences in grey seal diet reflect seasonal variation in foraging behaviour and reproductive expenditure: evidence from quantitative fatty acid signature analysisJOURNAL OF ANIMAL ECOLOGY, Issue 3 2007CARRIE A. BECK Summary 1Intraspecific variation in diet can be an important component of a species niche breadth. We tested the hypothesis that sex differences in seasonal foraging behaviour and energy storage of sexually size dimorphic grey seals Halichoerus grypus (Fabrisius 1971) are reflected in differences in the diet and niche breadth. Diet composition was estimated for 496 adult (226 males, 270 females) and 91 juvenile (46 males/45 females; all 6 months old) grey seals sampled between 1993 and 2000 using quantitative fatty acid signature analysis. Niche breadth and overlap were estimated using the Shannon,Weaver diversity index (H,) and the Morisita,Horn index (CH), respectively. 2Sand lance Ammodytes dubius (Reinhardt 1837) and redfish Sebastes sp. (Cuvier 1829) accounted for a high proportion of the diet in both sexes and age groups. However, the diets of adult males were significantly more diverse across all seasons (H,: males 0·36 ± 0·007 vs. females 0·28 ± 0·007) and less energy dense in spring (male 5·3 ± 0·07 kJ g,1 vs. females 5·6 ± 0·09 kJ g,1) than those of adult females. 3Season and sex explained most of the observed variation in adult diets, but there were significant sex,season interactions. These differences were most evident during the post-breeding (spring) foraging period when energy acquisition is important to female recovery of nutrient stores needed to support pregnancy. Females selected fewer and higher quality prey species in spring than males. 4There were no sex differences in the diets of juvenile grey seals. Although many of the species overlapped with those eaten by adults, juvenile niche breadth (H,: 0·41 ± 0·014, n = 91) was significantly broader than that of adults (H,: 0·30 ± 0·011, n = 115). Juvenile diets were also of lower energy density (5·3 ± 0·04 kJ g,1) than those of adults (5·6 ± 0·09 kJ g,1), suggesting less selectivity in these young and relatively naïve predators. 5Sex-specific seasonal changes in diet correspond to seasonal changes in diving behaviour and rate of body energy accumulation of adult males and females. Sex-specific reproductive requirements appear to be a primary factor generating the intraspecific variation in the seasonal foraging ecology of this large marine carnivore. However, sex differences in the breadth and energy content of diets also suggest the influence of body-size dimorphism as a factor shaping the diet of this species. [source] Social group norms, school norms, and children's aggressive intentionsAGGRESSIVE BEHAVIOR, Issue 3 2010Christian Nipedal Abstract This study examined whether the effect of social group norms on 7- and 10-year-old children's aggression can be moderated or extinguished by contrary school norms. Children (n=384) participated in a simulation in which they were assigned membership in a social group for a drawing competition against an outgroup. Participants learnt that their group had a norm of inclusion, exclusion, or exclusion-plus-relational aggression, toward non-group members, and that the school either had a norm of inclusion, or no such norm. Findings indicated that group norms influenced the participants' direct and indirect aggressive intentions, but that the school norm moderated the group norm effect, with the school's norm effect tending to be greater for indirect vs. direct aggression, males vs. females, and younger vs. older participants. Discussion focused on how school norms can be developed, endorsed, and presented so that they have their most lasting effect on children. Aggr. Behav. 36:195,204, 2010. © 2010 Wiley-Liss, Inc. [source] | |||||||||||||