13 resultados para Australia -- Social life and customs
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
According to life-history theory age-dependent investments into reproduction are thought to co-vary with survival and growth of animals. In polygynous species, in which size is an important determinant of reproductive success, male reproduction via alternative mating tactics at young age are consequently expected to be the less frequent in species with higher survival. We tested this hypothesis in male Alpine ibex (Capra ibex), a highly sexually dimorphic mountain ungulate whose males have been reported to exhibit extremely high adult survival rates. Using data from two offspring cohorts in a population in the Swiss Alps, the effects of age, dominance and mating tactic on the likelihood of paternity were inferred within a Bayesian framework. In accordance with our hypothesis, reproductive success in male Alpine ibex was heavily biased towards older, dominant males that monopolized access to receptive females by adopting the 'tending' tactic, while success among young, subordinate males via the sneaking tactic 'coursing' was in general low and rare. In addition, we detected a high reproductive skew in male Alpine ibex, suggesting a large opportunity for selection. Compared with other ungulates with higher mortality rates, reproduction among young male Alpine ibex was much lower and more sporadic. Consistent with that, further examinations on the species level indicated that in polygynous ungulates the significance of early reproduction appears to decrease with increasing survival. Overall, this study supports the theory that survival prospects of males modulate the investments into reproduction via alternative mating tactics early in life. In the case of male Alpine ibex, the results indicate that their life-history strategy targets for long life, slow and prolonged growth and late reproduction.
Resumo:
BACKGROUND Infectious diseases and social contacts in early life have been proposed to modulate brain tumour risk during late childhood and adolescence. METHODS CEFALO is an interview-based case-control study in Denmark, Norway, Sweden and Switzerland, including children and adolescents aged 7-19 years with primary intracranial brain tumours diagnosed between 2004 and 2008 and matched population controls. RESULTS The study included 352 cases (participation rate: 83%) and 646 controls (71%). There was no association with various measures of social contacts: daycare attendance, number of childhours at daycare, attending baby groups, birth order or living with other children. Cases of glioma and embryonal tumours had more frequent sick days with infections in the first 6 years of life compared with controls. In 7-19 year olds with 4+ monthly sick day, the respective odds ratios were 2.93 (95% confidence interval: 1.57-5.50) and 4.21 (95% confidence interval: 1.24-14.30). INTERPRETATION There was little support for the hypothesis that social contacts influence childhood and adolescent brain tumour risk. The association between reported sick days due to infections and risk of glioma and embryonal tumour may reflect involvement of immune functions, recall bias or inverse causality and deserve further attention.
Resumo:
This book addresses two developments in the conceptualisation of citizenship that arise from the 'war on terror', namely the re-culturalisation of membership in a polity and the re-moralisationof access to rights. Taking an anthropological perspective, it traces the ways in which the trans-nationalisation of the 'war on terror' has affected notions of 'the dangerous other' in different political and social contexts, asking what changes in the ideas of the state and of the nation have been promoted by the emerging culture of security, and how these changes affect practices of citizenship and societal group relations.
Resumo:
Background Recent work on the complexity of life highlights the roles played by evolutionary forces at different levels of individuality. One of the central puzzles in explaining transitions in individuality for entities ranging from complex cells, to multicellular organisms and societies, is how different autonomous units relinquish control over their functions to others in the group. In addition to the necessity of reducing conflict over effecting specialized tasks, differentiating groups must control the exploitation of the commons, or else be out-competed by more fit groups. Results We propose that two forms of conflict – access to resources within groups and representation in germ line – may be resolved in tandem through individual and group-level selective effects. Specifically, we employ an optimization model to show the conditions under which different within-group social behaviors (cooperators producing a public good or cheaters exploiting the public good) may be selected to disperse, thereby not affecting the commons and functioning as germ line. We find that partial or complete dispersal specialization of cheaters is a general outcome. The propensity for cheaters to disperse is highest with intermediate benefit:cost ratios of cooperative acts and with high relatedness. An examination of a range of real biological systems tends to support our theory, although additional study is required to provide robust tests. Conclusion We suggest that trait linkage between dispersal and cheating should be operative regardless of whether groups ever achieve higher levels of individuality, because individual selection will always tend to increase exploitation, and stronger group structure will tend to increase overall cooperation through kin selected benefits. Cheater specialization as dispersers offers simultaneous solutions to the evolution of cooperation in social groups and the origin of specialization of germ and soma in multicellular organisms.
Resumo:
Time is one of the scarcest resources in modern parliaments. In parliamentary systems of government the control of time in the chamber is a significant power resource enjoyed – to varying degrees – by parliamentary majorities and the governments they support. Minorities may not be able to muster enough votes to stop bills, but they may have – varying degrees of – delaying powers enabling them to extract concessions from majorities attempting to get on with their overall legislative programme. This paper provides a comparative analysis of the dynamics of the legislative process in 17 West European parliaments from the formal initiation of bills to their promulgation. The ‘biographies’ of a sample of bills are examined using techniques of event-history analysis (a) charting the dynamics of the legislative process both across the life-times of individual bills and different political systems and (b) examining whether, and to what extent, parliamentary rules and some general regime attributes influence the dynamics of this process, speeding up or delaying the passage of legislation. Using a veto-points framework and transaction cost politics as a theoretical framework, the quantitative analyses suggest a number of counter-intuitive findings (e.g., the efficiency of powerful committees) and cast doubt on some of the claims made by Tsebelis in his veto-player model.
Resumo:
ABSTRACT Hope is increasingly recognized as an important psychological resource for career development, yet the empirical research on its functioning in this domain is sparse. This paper describes an investigation of how dispositional hope is related to career decidedness, career planning, and career self-efficacy beliefs and whether these more proximal career attitudes mediate the effects of hope on proactive career behaviors, life satisfaction, and job satisfaction. This investigation was conducted using two independent samples of university students (N = 1,334) and working professionals (N = 233). The results showed that in both samples, hope was significantly related but empirically distinct from career variables. In both samples, hope had a direct effect on proactive career behaviors, partially mediated by more career planning. Hope had significant direct and indirect effects on life satisfaction among students, mediated by the three career development attitudes. Although hope was significantly correlated with job satisfaction among employees, no direct effect of hope was found in the mediation model, but an indirect effect through career decidedness was found. The results suggest that hope is an important resource for proactive career development at different career stages and that the positive relation of hope to life and job satisfaction can partially be attributed to the positive relation between hope and favorable career development attitudes.
Resumo:
This study investigated whether vocational identity achievement mediates the relation between basic personality dispositions (i.e. core self-evaluations) and career and well-being outcomes in terms of job and life satisfaction. Two studies with Swiss adolescents were conducted. Study 1 (N= 310) investigated students in eighth grade, prior to making the transition to vocational education and training (VET); it showed that vocational identity related positively to life satisfaction but that this relationship disappeared once core self-evaluations were controlled. Study 2 (N= 150) investigated students in their second year of VET; it showed that job satisfaction was unrelated to identity and self-evaluations. However, identity fully mediated the relation between self-evaluations and life satisfaction.
Resumo:
Since 1947, Australia has formally resettled more than 750,000 refugees. During that time, researchers have successfully completed more than 150 Masters and doctoral theses and published more than 900 articles, books and reports about issues of refugee settlement in Australia, with about half of them being published in the past 10 years. In this paper, we discuss the development of the production of knowledge about refugee resettlement. We identify trends in the literature, such as the emergence of an ethno-specific focus, and the concern with settlement's psychological and emotional impact, and relate them to policy changes. We suggest that scholars need critically to take stock of the knowledge produced so far and be more cognisant of the international scholarly debate.
Resumo:
The unicellular parasite Trypanosoma brucei shuttles between its definitive host, the tsetse fly, and various mammals including humans. In the fly digestive tract, T. brucei must first migrate to the ectoperitrophic space, establish a persistent infection of the midgut and then migrate to the salivary glands before being transmitted to a new mammalian host. In 2010, it was shown that insect stages of the parasite (procyclic forms) exhibit social motility (SoMo) when cultured on a semi-solid surface, and it was postulated that this behaviour might reflect a migration step in the tsetse fly. Now, almost 5 years after the initial report, several new publications shed some light on the biological function of SoMo and provide insights into the underlying signalling pathways.