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991.
992.
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   
993.
Studies were carried out in two mining pond complexes in an industrial landscape. The first complex (consisting of six ponds) was located in an urban area and the second one (consisting of six ponds) in a woodland area. The aims of the study were to assess the diversity of benthic oligochaetes and to evaluate which environmental variables are most important in determining variations in the community structure in ponds of varying location. In total, 21 oligochaete species were recorded (7–11 in the urban ponds, 11–15 in the woodland ponds). Aulodrilus pluriseta, Aulodrilus japonicus and Ophidonais serpentina were only found in the woodland ponds, while Potamothrix bavaricus only occurred in the urban ponds. Limnodrilus hoffmeisteri, Limnodrilus claparedeanus, Chaetogaster diaphanus and Ophidonais serpentina dominated in the woodland ponds, whereas Limnodrilus hoffmeisteri, Limnodrilus claparedeanus, Potamothrix bavaricus and Tubifex tubifex prevailed in the urban ponds. The total density of oligochaetes was higher in the urban ponds thought the values of the diversity indices were higher in the woodland ponds. The local diversity of the ponds was high, while the among-site diversity made only a small contribution to the regional diversity. Nonetheless, a cluster analysis divided all of the ponds into two distinct groups depending on their location. CCA analysis showed that conductivity, pH, total hardness, alkalinity, the concentration of chlorides and the content of organic matter in the bottom sediments were most associated with the distribution of some oligochaete species among the ponds studied.  相似文献   
994.
The environmental factors affecting the spatial dynamics of bird communities in urban parks are well understood, but much less attention has been paid to the seasonal dynamics of bird communities. Since migrant and resident human commensal birds might have contrasting responses to environmental factors of urban parks, we expected different seasonal dynamics among parks. On the other hand, because bird species can have different habitat relationships throughout the year, we also expected different responses of bird richness to environmental variables between breeding and non-breeding seasons. Bird surveys were conducted in 14 small urban parks (1–4 Ha) of Mar del Plata city (Argentina) for one full annual cycle. Bird richness changed between seasons, but bird abundance remained constant. Bird community composition did not vary between seasons, but urban parks near the urban center, with the highest pedestrian traffic and isolation to other green areas had the least seasonal change of composition. During the breeding season, bird richness was negatively affected by the percentage cover of high buildings surrounding the immediate limits of parks, whereas during the non-breeding season bird richness was not related with any environmental variable. Bird composition variation among parks was affected by the distance to the urban center during both seasons. Results showed that urbanization promotes a seasonal homogenization of bird communities in urban parks, probably by affecting the presence of migrant species and promoting the temporal stability of human commensal species.  相似文献   
995.
ABSTRACT

Female incarceration rates are increasing at unprecedented rates. The majority of women are poor single mothers, serving sentences for nonviolent drug-related and property offenses. Among challenges faced when transitioning back into society are a history of interpersonal violence and financial instability. This study examines literature with regard to the barriers women experience with an emphasis on financial struggles and explores outcomes of one initiative to begin addressing the financial capability of women in a minimum security prison. Findings reveal women benefited from the class experience. Social workers are called upon for additional financial capability programming and research in this area.  相似文献   
996.
Computer-assisted qualitative data analysis software (CAQDAS) programs are established tools for qualitative research. Making informed decisions when using them requires researchers to understand how they affect research practices and outcomes. In this article we consider the impact of CAQDAS on researcher reflexivity. Reviewing three decades of literature, we identify specific ‘reflexive moments’ experienced by CAQDAS users, the contexts in which they occur, the issues they raise, and the reflexive awareness they generate. The ways in which CAQDAS can enhance or undermine researcher reflexivity are also reported. By doing so, we aim to help researchers and especially research students (and their supervisors) understand the relationship between CAQDAS and reflexivity and the reflexive moments they may encounter when using such software.  相似文献   
997.
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   
998.
The influence of neoliberalism on culture and subjectivity is well documented. This paper contributes to understanding of how neoliberal ideology enters into the production of subjectivity. While subject formation takes place in multiple and contradictory ways and across multiple social sites, we focus on the increasingly popular media discourse of self-development, and examine it as a technology of neoliberal subjectification. Drawing on Foucauldian understandings, we analyze data from two different newspapers from two different national contexts, both of which are heavily influenced by neoliberalism. Based on our analysis, we detail four interrelated discourses—rationality, autonomy and responsibility, entrepreneurship, and positivity and self-confidence—demonstrating how these discourses constitute the neoliberal subject in ways consonant with neoliberal governmentality. There is no observable resistance to subject positions offered within these discourses. Self-development discourse instills stronger individualism in society, while constraining collective identity, and thus provides social control and contributes to preserving status quo of neoliberal societies.  相似文献   
999.
Abstract

In the past decade, security has emerged as a new discourse in water governance beyond transboundary conflicts and cooperation. This paper will examine how security is framed in the context of international river basin organizations (RBOs), key regional organizations in transboundary water governance operating in many international river basins around the world. As an example of cross-border governance, RBOs can promote joint cooperation and information sharing, and serve as a form to bring together diverse stakeholders. This paper focuses on the discursive construction of ‘security’ in a particular context of cross-border river basin governance in the Mekong River Basin. We ask: How is security framed in the discourse of RBOs? We examine how diverse actors frame security in the context of RBOs and at various scales and around certain management actions in a case study of the Mekong River Commission, a well-established RBO. Attention will be paid to the links between water security, food security, and energy security in the broader water and development discourse. We analyze what the findings mean for cross-border governance more broadly.  相似文献   
1000.
We evaluate the effectiveness in empirical migration research of the respondent-driven sampling (RDS) and the quota sampling with regard to four criteria: quality of the data; sociometric diversity of the sample; geographic coverage of the sample; and cost-effectiveness. We review two surveys of ex-USSR migrants, conducted simultaneously in the Warsaw metropolitan area, each undertaken with the use of one of the two sampling methods. We find that although the RDS was considerably costlier, it enabled faster data collection and posed a lower risk of underestimating the cost of the survey. We also find that the RDS generated higher-quality data, and that it was more successful in surveying short-term circular migrants. This comparative evaluation contributes to the literature on social research methods in that it links the sampling methods with the quality and character of the data, and helps assess the usefulness and applicability of RDS in empirical migration studies.  相似文献   
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