The quality of stored blood can be deteriorated by hemolysis caused by free radicals. The purpose of this study was to elucidate whether neutrophile leukocytes are the source of free radicals in stored blood as in hemodialyzed patients. Resuspensions with low (LL) or high (HL) leukocyte concentrations were prepared from samples of twenty healthy volunteers. The samples were incubated for 10 days at 4 °C and then for one day at 37 °C. Markers of hemolysis and free radical metabolism were examined before and after incubation in LL and HL samples. In spite of the difference of leukocytes counts in LL and HL resuspensions (p<0.0001), the pre-incubation values of all laboratory parameters were practically identical. In post-storage samples, superoxide dismutase and glutathione peroxidase activities did not differ in either group. Reduced glutathione in erythrocytes and extracellular antioxidant capacity were insignificantly lower in HL resuspensions, but the increase of malondialdehyde was much more pronounced in the HL samples (p<0.0001). The degree of hemolysis, expressed as the extracellular increase of potassium (p<0.001), hemoglobin (p<0.05) and lactate dehydrogenase (p<0.05), was higher in the HL samples. Our results support the hypothesis that leukocytes participate in free radical production in stored blood., J. Racek, R. Herynková, V. Holeček, J. Faltysová, I. Krejčová., and Obsahuje bibliografii
Polycystic ovary syndrome (PCOS), the most common endocrinopathy in women (with a prevalence of 5-10 %), is characterized by hormonal and metabolic imbalance. Complexity of symptoms of close relatives of women with PCOS and genetic autosomal trait initiated a hypothesis about the existence of a male equivalent of PCOS. Premature alopecia was suggested as one of the signs of a male phenotype of this syndrome. The present study investigated a group of 30 men, in which premature hair loss started before 30 years of age. In all patients, their hormonal profile was determined. It was possible to form two subgroups. The first one showed similar hormonal changes as women with PCOS, the other had either no anomalies in steroid spectrum or just only lower level of sexual hormones binding globulin (SHBG). Both subgroups did not differ in either BMI or age. In all men with premature alopecia insulin tolerance test was also carried out and the occurrence of allele 3 INS VNTR was investigated, which is one of the candidate genes for PCOS. The subgroup with hormonal changes resembling those of women with PCOS showed a significantly higher insulin resistance than the group without these changes. About one third of the premature balding men showed the combination of hormonal shifts and higher insulin resistance. This frequency corresponds to the prevalence of PCOS in women. There was no significant difference between the two subgroups in the occurrence of allele 3 INS VNTR.
We tested the hypothesis that males of meadow pipits (Anthus pratensis) respond differentially to simulated territorial intrusions (song playback + bird model) by conspecific, related (tree pipit, Anthus trivialis), and unrelated individuals (willow warbler, Phylloscopus trochilus), and evaluated the effect of playback order. All tested males responded aggressively to the conspecific playback; reactions to heterospecific stimuli occurred only after previous excitation by the conspecific song and dummy, and were usually weaker. Apparently, although males were able to discriminate between playbacks, excitation by intrusion of a conspecific rival elicited an aggressive reaction to otherwise neutral stimuli. Reactions to heterospecific playbacks closely following the conspecific one did not differ significantly between congeneric and unrelated species. The response to a subsequent heterospecific stimulus, however, was taxon-dependent: congeneric species elicited a significantly stronger reaction than an unrelated one. We presume that this was due to the morphological similarity between pipits, and that the more intensive reaction could have been caused by stronger visual stimulus from the respective model. We discuss the potential benefits as well as limitations of using models (dummies) in playback experiments, and suggest that overexcitation by previous stimuli should be considered during experimental setup and data analysis in studies focusing both on interspecific aggressiveness and on neighbour-stranger interactions.
Když benevolence zraňuje ženy a favorizuje muže: účinky ambivalentního sexismu na aspirace na vůdcovství Literatura o ambivalentním sexismu ukázala, že benevolence vůči ženám může být dokonce škodlivější než otevřené nepřátelství, protože není jasně rozpoznatelná jako druh předsudku, a tak je obtížnější s ní bojovat. Podobně benevolence vůči mužům predikuje vnímanou oprávněnost genderové hierarchie. Účinek sexismu na mužské a ženské aspirace na vůdcovství však ještě nebyl zkoumán. Účastníci studie (N = 101) byli poučeni o sexismu (hostilním vs. benevolentním) vůči vlastnímu pohlaví. Výsledky ukázaly, že benevolence podporuje možnost udržení vůdcovské role u mužů, ale odrazuje ženy od vůdcovských pozic. Ženy dokonce považují benevolentní a hostilní postoje vůči ženám za podobné předsudky. Muži naopak vymezují hostilní sexismus vůči mužům jako více předsudečný než benevolentní postoje., Literature on ambivalent sexism has shown that benevolence toward women can be even more pernicious than explicit hostility because it is not clearly recognizable as a form of prejudice and thus it is more difficult to combat. Similarly, benevolence toward men predicts the perceived legitimacy of gender hierarchy. However, the effects of sexism on men’s and women’s leadership aspiration have not been studied yet. In the present study participants (N = 101) were primed with sexism (Hostile vs. Benevolent) toward their own gender. Results showed that benevolence fosters the possibility of holding a leadership role for men, but harms women from leader positions. Moreover, women consider benevolent and hostile attitudes toward women as similarly prejudiced. On the contrary, men define hostile sexism toward men as more prejudiced than benevolent attitudes., Chiara Rollero, Angela Fed., and Obsahuje seznam literatury
Leucorrhinia caudalis is a dragonfly species threatened throughout Europe. Despite evidence of the recent extension of its distribution range, it is unknown whether L. caudalis regularly or hardly ever migrates among ponds. The contemporary migration patterns of the species were investigated using Bayesian assignment tests and the migration rates related to landscape structural and thematic variables (distance between ponds, forest area, area of water body, area of hedgerow). Migration rates of L. caudalis are independent of any landscape element. Thus, landscape structure is not a barrier or corridor for migration in this species. The tendency of L. caudalis to disperse is largely independent of the nature of the landscape, at least at the scale of the present study. and Janine Bolliger, Daniela Keller, Rolf Holderegger.
Socialisation in a single-parent family has been associated with negative consequences both in previous research and popular discourse. This article investigates whether this association may be different in a society with a high rate of divorce and extramarital fertility. Using data from the Czech contribution to the EU-SILC survey, it tests hypotheses concerning the difference between the current situation of adults who grew up in single-parent families and those who were raised in intact families. We look for the influence of socialisation on single-parent families in three areas—educational attainment, current partnership situation, and current family income. The results of regression analyses show that the differences between children from single-parent families and those from intact ones are very small in the area of education (the influence is apparent only at the secondary school graduation level, no difference is present at the tertiary education level), relatively weak in the area of partnership situation, and imperceptible from the viewpoint of family income. These results exclude a causal explanation for the influence of single-parent families on outcomes, cast doubt on selective principles, and open space for interpretation in terms of mechanisms of family de-institutionalisation.