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Urban environments are often associated with reduced biodiversity, presumably because they are typically more fragmented, warmer, and drier than nearby non-urban environments. However, urban landscapes offer significant complexity that have allowed some taxonomic groups to flourish. Understanding how urban-exploiting animals navigate this spatiotemporal heterogeneity is important given the continued global urban land expansion. Here, we examined the factors influencing resource-use in an urban community of ants, which represent a widespread and important taxon in urban ecosystems. In particular, we sought to integrate ants’ nutritional, thermal, and spatial niches to better understand how urban animals successfully access critical resources throughout their active season. Meteorological season (spring, summer, and fall) and/or species (n?=?9) influenced ants’ preferences for nutrition (ratio of ingested protein-to-carbohydrate ratio), as well as the temperature, type (impervious vs. non-impervious), and shade status (shaded vs. non-shaded) of surfaces used during activity. Our data also indicate links among habitat variables, as well as between nutritional preferences and habitat use. Together, our results suggest that species and seasonality influence ecological (combined nutritional, thermal, and spatial) niches in an urban community. We encourage future work in urban ecosystems that continues to integrate more features of the ecological niche, and to examine the outcomes of variation in niches (e.g., non-overlapping niches may explain both the persistence of some native animals and the success of invaders).  相似文献   
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In this paper, the problem of constant partially accelerated life tests when the lifetime follows the generalized exponential distribution is considered. Based on progressive type-II censoring scheme, the maximum likelihood and Bayes methods of estimation are used for estimating the distribution parameters and acceleration factor. A Monte Carlo simulation study is carried out to examine the performance of the obtained estimates.  相似文献   
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ABSTRACT

This study sheds new light on the role of identity in virtual environments when virtual representation of self is in support of disabled individuals and the potential impact of their virtual identity on work opportunities. It is widely understood that individuals who live with disability often experience a lifetime of bullying, exclusion, marginalization and rejection. They often experience workplace bias and discrimination. Yet, when they can create an identity and experience embodiment in virtual environments, the results can be extraordinarily powerful – even life-changing. This research builds on nearly a decade of ethnographic research in 3D online immersive social virtual worlds; seven of those years working with disability communities to answer the following: RQ1: In a virtual world where one can choose any avatar form, how does that visual sense of self-representation influence one’s ability to gain access to a social network, to be a leader in that network, and to find work? RQ2: How does realism in representation influence work experiences in these digital worlds? The results reveal the importance of choice in online representation of avatars in creating work and online social engagement. Implications contribute to our understanding of visual bias in the workplace and how emerging virtual reality technologies may open new avenues for meaningful work and social interactions for people with disabilities.  相似文献   
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Summary Analysis of data from various phases of a study of post-partum amenorrhoea in Bangladesh illustrated good aggregate consistency of response on menstrual status, but less individual consistency on duration of post-partum amenorrhoea. Using life table techniques, the median duration of amenorrhoea was calculated as 19.9 months for women with births between February and September 1974. There were substantial seasonal variations in duration, with the median decreasing from 21.5 months for women with February births to 16.9 months for those with September births. By contrast, the median duration of post-partum amenorrhoea varies by only two months for women in the lowest and highest quartiles of weight and weight for height. The seasonal pattern was similar for all weight groups.  相似文献   
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ABSTRACT

This study evaluated the success of researcher-generated recruitment, enrollment, data collection, and safety protocols for field research with victims of elder abuse and neglect (EAN) identified from police incident reports in terms of their success including cost-effectiveness, ability to generate a representative sample, and safety. After reviewing 492 police incident reports involving victims age 65 years or older to identify cases of EAN 62 victims were identified. Mail, phone, and in-person recruitment strategies were used. After 259 recruitment attempts, 52 (84%) eligible victims were contacted, of which 24 (46%) consented to participate. Phone calls were the least expensive mechanism to produce a successfully enrolled participant. Findings from a regression show completion of a research interview could not be predicted by victim, suspect, or offense characteristics, indicating that the recruited victims likely represent the population they were drawn from. No safety or adverse events occurred.  相似文献   
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In Macao, the VIP gaming revenue accounts for over two thirds of the total gaming revenue. Since the VIP gaming market is highly competitive, several incentives such as rebates are used to attract the VIP players. There are two commonly used rebate systems in the VIP gaming market: rebate on buy-in and rebate on actual loss. The analysis of rebate on buy-in is relatively easy. However, the analysis of rebate on actual loss is more complicated, which involves the Unit Normal Linear Loss Integral. Using empirical data, MacDonald derived a simple approximation formula for computing the rebate rate on actual loss. In this paper, we use mathematical analysis to derive more accurate approximation formulas for computing the rebate rate on actual loss. Some practical examples are given to compare the accuracies of these formulas. We also discuss how these two rebate systems affect the fluctuations of the results.  相似文献   
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