Why similar people have different patterns of wealth accumulation is puzzling. The behavioral life-cycle hypothesis indicates self-control is an important aspect of household saving behavior. This study investigated if household wealth creation from 1994 to 2008 could be predicted by self-control among a sample of young baby boomers using National Longitudinal Survey of Youth (NLSY79) data. Variables that significantly predicted 2008 net worth included homeownership, 1994 net worth, income, bankruptcy filing, inheritance, education level, race, marital status, children, retirement planning activities, locus of control, and self-mastery. The addition of self-control predictors to a regression model improved the model’s ability to predict net worth by 1.3 % above and beyond the human capital, financial status, and demographic predictor variables. In total, the model explained 60 % of the variance in net worth. Findings indicated that individuals who invested in their human capital, were homeowners, and had higher self-control, accumulated more wealth. 相似文献
Recent studies suggest that songbird communication is negatively affected by anthropogenic noise. However, much of the current literature focuses on inter- and intra-sexual communication. Songbirds also use acoustic cues for many other functional behaviors. One example associated with fitness consequences is the identification of predatory threats through acoustic cues. To test the effect of anthropogenic noise on detection of acoustic cues, we compared the rates of seven anti-predator behavioral responses in urban dwelling songbirds foraging at bird feeders when exposed to playback of calls from predatory Cooper’s hawks under quiet conditions, and when overlapped with road noise. Only a single behavior, freeze response, decreased significantly when calls were overlapped with noise. However, freeze responses occurred in only a small percentage of playback trials, raising some question regarding the biological relevance of this observed difference. Overall, our results suggest that common urban songbirds are relatively successful at perceiving acoustic signals associated with predator presence. Whether this ability is commonplace amongst songbird species is unknown and warrants additional study. However, if this trait is not widespread, it may be an additional characteristic determining which bird species can inhabit noisy areas.
Urbanization has been identified as a threat to biodiversity due to landscape modifications. Studies of parasite ecology in urbanized areas lagged behind those made on macro organisms. Here we studied infection prevalence of haemosporidian parasites in an avian community of an urban forest from Germany, and its relationship with bird abundance and body mass. We used PCR to amplify a fragment of the mtDNA cyt b gene to determine the infection status of birds, and bird point counts to determine bird relative abundances. The avifauna was dominated by two small sized insectivore passerines (Parus major, Cyanistes caeruleus), representing ~40 % of the total bird records. The highest haemosporidian prevalence was recorded for Turdus philomelos (100 %) and for Fringilla coelebs (75 %). Bird abundance and body mass were positively associated with infection status for two haemosporidian genera: Plasmodium and Leucocytozoon. Infection rate was lower in juveniles compared to adult birds. We recorded a total of 7 Plasmodium, 26 Haemoproteus, and 10 Leucocytozoon lineages. Avian malaria (P. relictum) was detected infecting 5 individuals of P. major, the most abundant species in the community. These results, together with those of previous studies at the same site, suggest that potentially any of the genetic haemosporidian lineages detected in this urban forest can be transmitted across native and pet bird species, and to species of conservation concern housed at aviaries. 相似文献
Species that successfully inhabit urban ecosystems are rare, and urbanisation often drives localised extinctions of native species. Nonetheless, some species take advantage of the novel conditions available in cities and increase in abundance. Trends in the abundance and distribution of species in urban areas have received much attention, but the precise elements of urban ecosystems that affect the survival of urban-dwelling species are largely unknown. Animals that successfully exploit urban environments may do so because of increases in the availability of resources or habitats. Here we assess the effects of anthropogenic landscapes and prey abundance on the persistence of an orb-weaving spider, Nephila plumipes. We assessed spider persistence for six months in situ along an urban gradient in Sydney. We then transplanted spiders from a common garden into sites along the gradient, monitored their persistence in the new environment and measured a suite of environmental variables at local and landscape scales. The abundance of prey was closely linked with spider persistence, in both the survey and the transplant experiment, and was positively associated with anthropogenic habitats. The surveyed spiders survived longer when located closer to the coast and transplanted spiders persisted longer in smaller sites with more impervious surfaces and reduced vegetation cover. Our study shows that urbanisation has a strong effect on potential prey abundance and can lead to increased persistence of N. plumipes, demonstrating the broad impacts that habitat disturbance can have on the life history and trophic interactions of city-dwelling animals. 相似文献
Urbanization poses threats to earth’s biota, and retention of remnant native habitat in protected areas within expanding urban boundaries may help alleviate threats to wildlife. However, it is unclear for nearly all nonsynanthropic (i.e., not benefiting from an association with humans) species whether vital rates in urban habitats can sustain populations or if populations persist only through immigration from outside the urban boundary. We conducted a three-year study of spotted towhees (Aves: Pipilo maculatus) breeding in four undeveloped parks in Portland, OR, USA, to measure park-specific seasonal reproductive output (F) and annual adult survival (SA). We developed a stochastic model that combined F and SA with an estimate of first-year survival to measure population growth rate (λ) in all parks assumed to be closed to immigration. F differed among parks but SA did not. Relatively high F was possible because many pairs raised >1 brood/season. When combined with empirical estimates of survival through the 30-day period of post-fledging parental care (SD = 0.645), only 2 of 4 parks were self-sustaining (i.e., λ > 1.0). However, SD reflected substantial loss of fledglings to domestic cats (Felis catus). Assuming no loss to cats and either partial compensatory or additive mortality of fledglings substantially improved prospects of population persistence for declining (sink) populations. Moreover, allowing low levels of immigration to sinks reversed population declines in most parks even when vital rates were insufficient to maintain populations. Our results suggest that nonsynanthropic bird species can persist in urban landscapes, but also that offspring mortality in the post-fledging period may be a critical determinant of population viability. 相似文献
The objective of this research is to investigate the possible difference in accumulation of adversity over the life course among decedent gamblers and living control gamblers in the province of Quebec, Canada. A sample of 90 adult men, 41 living participants and 49 suicide decedents, met the criteria for at-risk and problem gambling over the last five years. Data were obtained from informants in the case of suicide and directly from living controls during semi-structured face-to-face interviews using SCID I and II, SOGS, Module K and a recount of life trajectories methodology. The results showed a high level of adversity throughout the life trajectories of both groups. However, the living gamblers faced more difficulties during their lifespan than the suicide victims. In the last six months before their death, suicide victims had a significantly higher number of mental health disorders, especially co-morbid mental health disorders and anxiety, compared to the living controls. We also observed a rapid escalation of difficulties, more life events and more psychological distress in the last six months of their lives among the suicide decedents. Suicidal behaviour needs to be carefully investigated by medical staff and mental health practitioners, especially when gamblers demonstrate evidence of mental health disorders or financial difficulties. 相似文献
This paper draws upon international research evidence that suggests a relationship between protest masculinity and the manifestation of violent crime among young males, and that criminal desistance may be linked to (inter-) subjective processes such as the reconstruction of masculine identity. The paper considers the potential that pugilism (the art and practice of boxing) may have on enabling young, disadvantaged minority male gang members to find avenues for alternative identity construction and to gain transitional experiences which trigger self-confessed desistance actions. Drawing upon an ethnographic study conducted in a boxing rehabilitation centre on the outskirts of Copenhagen, Denmark, the paper reports on data gleaned from participant observation and qualitative interviews with 22 ethnic minority young men. Findings suggest that the masculine context within the rehabilitation programme provided the young men with a safe space to perform broader versions of locally dominated views on masculinity and to reflect on their current situations and dilemmas. The young men were clearly in transition and their desistance journeys were characterized by hope and ambition but also disappointment and despair. In some cases it appeared that the young men's dogged attempts to desist from crime became a new way for them to ‘do masculinity’. The authors draw upon the findings to make recommendations for policy, practice and research. 相似文献
This study addresses the gap in the research for sound multidimensional assessment of social capital and its relationship with risk-taking behaviour among youths living in disadvantaged communities. Social capital and adolescent risk-taking outcomes were studied cross-sectionally in 1371 secondary students living in two disadvantaged communities within Australia. First, a multidimensional measure of social capital was developed and tested using confirmatory factor analysis. Then, the associations between social capital and a range of youth risk-taking behaviours were examined using structural equation modelling across five-year groups (Grades 7–12). With a few exceptions, higher levels of social capital and belongingness within the school and community were generally associated with decreases in smoking, alcohol and drug consumption, and physical violence. Some outcomes were more strongly associated with family and peer social capital, while others associated more with neighbour and community social capital, indicating that attempts to build social capital need to be targeted across the whole community. This study supports the notion that social capital can be measured empirically and is beneficial in alleviating many of the detrimental health outcomes commonly associated with risk-taking behaviours during adolescence. 相似文献
Framed within contextual systems model, this study examines how home and school operate together to shape behavioral and academic outcomes for 544 low-income African American (56%) and Latino/a (44%) elementary school-aged children (mean age?=?7.88 years, SD?=?1.46, 50% male). Using data from Welfare, Children, & Families Study: A Three City Study and multiple group path analysis, we found that for children in kindergarten through third grade, the adequacy of the home resources was positively related to applied problem scores (e.g. math literacy) and negatively associated with externalizing behavior. For fourth- to sixth-graders, the adequacy of classroom resources was negatively associated with applied problem scores. For both age groups positive teacher–child relational quality was also a positive predictor of externalizing behavior. Results revealed that barriers to parental involvement in school were a negative predictor of applied problem scores for low-income children in early and later elementary school. Implications for policy and practice aimed at strengthening opportunities for children and families from marginalized communities are discussed. 相似文献
Silicon Valley, California – home of Apple, Facebook, Twitter, Google, and so on – is widely regarded as the epicentre of the information revolution. However, it is not just a technical or economic phenomenon; it has also made a social revolution. The article evaluates Silicon Valley from a normative perspective, seeking to identify its real societal impact, negative as well as positive. A select review of significant literature is followed by exposition of primary data, based on in situ face-to-face interviews with Valley occupants; these range from the chief technology officer of a global brand to a homeless, unemployed Vietnam War veteran. The article organises its findings under three headings: the nature of information revolution; iCapitalism as a new technoeconomic synthesis; and the normative crisis of the information society. It concludes with a warning about ongoing attempts to clone Silicon Valley around the world. 相似文献