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91.
92.
Urbanization and other land cover changes have been particularly detrimental to wetlands throughout the planet. One wetland specialist that may be sensitive to land cover changes surrounding wetlands is the round-tailed muskrat (Neofiber alleni; hereafter RTM). The RTM is a wetland obligate rodent that appears to have declined over the last half century and is a species of concern in Florida, where it is a near endemic. To determine if urbanization or other land cover influenced the distribution of RTMs we took a multi-scaled approach to examine the occurrence of RTMs and their associated vegetation in North-Central Florida. We detected RTMs on 19 of 72 sample plots and used a Classification And Regression Tree (CART) to determine that dogfennel (Eupatorium capillifolium) was negatively associated with RTMs and maidencane (Panicum hemitomon) was positively associated with their occurrence on sampling plots. Examining the influence of landscape composition for 2 km surrounding our plots we found that RTM occurrence was negatively related to urban land cover. Further, we found that dogfennel increased and maidencane decreased as urbanization increased in the surrounding landscape. Our research suggests that conservation of RTMs and their associated vegetation should focus on limiting urban sprawl at least within 2 km of wetlands.  相似文献   
93.
Does urbanization affect key life-history traits in native organisms? Some studies show that urban areas reduce diversity in certain taxa, but there is little insight into how these environments affect physiological and ecological traits. Urban areas have distinct physical structure and ecological processes compared to original habitats. The environmental changes associated with urban areas can influence the costs and benefits of different traits and behaviors of local organisms. Some of these effects have been explored in groups such as birds, but we might expect stronger effects in animals with reduced mobility, such as amphibians. Importantly, the effects of urban habitats on amphibians have not been explored, in spite that these are the most threatened vertebrate group in the world. Here, we compared three main traits related to the fitness of amphibians in urban and natural habitats: body size, body condition and immune response. To test the generality of our results, we assessed adult males of four amphibian species. We found that the body size was larger in urban environment populations in three of four studied species, while the body condition was better in the urban populations of two aquatic newt species. Finally, we found no effect of urbanization on the immune response of individuals of any species. In conclusion, we show that different species of amphibians may be affected differently by anthropogenic habitat alteration depending on their specific ecology.  相似文献   
94.
A desirable function for terrestrial urban ecosystems is the mitigation of nitrogen (N) pollution associated with cities and suburbs. To assist in maximizing this function, identifying locations of sources and sinks of N in the urban environment is crucial to inform management strategies. Lawns are an extensive land cover in urbanized landscapes, and in general, they have demonstrated the capacity to function as a sink for N inputs. How N is cycled by lawns, however, is likely not uniform across the physical heterogeneity or management activities that exist in lawns. We investigated the influence of heterogeneity in light availability on N cycling in lawns that were irrigated but not fertilized. Light availability is affected by tree canopy and built structures and is, therefore, heterogeneous both within individual lawns and among lawns. Light is expected to control N retention and loss through effects on primary productivity. We experimentally examined N regulation over one calendar year by measuring net primary production (NPP), N retention using an isotopic tracer, and N leaching in existing unfertilized lawns under heterogeneous light conditions. We used a budgetary approach to estimate gaseous N loss which we assume is primarily via denitrification. Light functioned as a limiting resource for primary productivity. From low to high light conditions, annual NPP increased 177 to 430 g C?m?2?y?1 and retention of N isotope tracer increased from 50 to 65% as a result of increased retention in plants. Nitrate leaching losses were low overall and were not affected by light levels. Light availability regulated the fate of N inputs and unfertilized lawns may function as substantial sinks for reactive N through storage in the terrestrial system and N loss by denitrification. However, whether or not denitrification is generally an N sink will depend on the ratio of non-reactive (i.e., N2) to reactive (i.e., N2O, NO) denitrification products. Overall, we find that effective strategies for managing N sources and sinks in cities will likely need to consider light availability, particularly in systems receiving water subsidies via irrigation.  相似文献   
95.
The role of urban expansion on bee diversity is poorly understood, but it may play an important role in restructuring pollinator diversity observed in rural regions at the urban perimeter. We studied bee communities in two habitats essential for pollinators (residential gardens and semi-natural areas) at 42 sites situated at the edge of greater Montreal, Canada. Bee species richness, abundance and functional diversity all increased with urbanization in both habitat types, but gardens and semi-natural areas supported distinct bee communities with unique responses to urbanization in terms of species turnover. Compared to semi-natural sites, residential gardens supported bees that foraged from a greater number but a lower proportion of available plant species. Bees did not discriminate between exotic and indigenous plant species in either gardens or semi-natural sites and were attracted to flowers in either habitat irrespective of their origins. Protecting semi-natural ruderal areas and providing residential garden habitats for pollinators are both effective means of promoting regional bee diversity in urbanizing regions.  相似文献   
96.
Julia Lum 《Visual Studies》2017,32(2):111-123
This essay examines the roles of photographic and oral testimony in the construction of Chinese Canadian family identity during a period of discriminatory immigration laws and family separation. Extending Marianne Hirsch’s idea of the ‘familial look’, I argue that Chinese Canadians deployed photography to serve as visual proxies that could transcend physical border restrictions. By examining the interplay between visual and verbal cues and the entanglement of selective framing and storytelling, I posit that the strategic use of photography was a means of building a material trace of family presence in the face of absence and loss. However, as a medium where distance and absence are inherent properties, photography – when paired with oral history – also reveals gaps and discontinuities in the construction of memory. Containing and activating trans-temporal and transnational narratives, family photographs and oral histories act upon each other, changing the way we interpret each mode of articulating the past. Deployed as forms of énoncés, photographs in this period declared Chinese Canadians as members of a visible citizenry, in spite of barriers preventing their achievement of full rights as Canadians. This research draws from the development of the project Chinese Canadian Women, 1923–1967, an online multimedia resource and digital repository that brings together oral histories and photographic collections of families across Canada.  相似文献   
97.
Female genital cutting (FGC) is a persistent social norm in the Liben district of southern Ethiopia. This study explores whether the sexual experiences of married men and women differ by women's FGC status. Qualitative in-depth interviews were conducted with 28 women with different types of FGC (or no FGC) and 21 husbands. Compared to others, women with more severe FGC reported traumatic sexual experiences and decreased sexual desire. Nonetheless, participants largely endorsed FGC for daughters, revealing pressure to maintain the practice. Opportunities for change exist, as women and men recognized the sexual pleasure and healthy birth experiences of uncut women.  相似文献   
98.
In 2011 6.4 million children in the United States ages four to 17 years had a diagnosis of ADHD. Quantitative studies have indicated that parenting stress for parents of children diagnosed with ADHD is high. The purpose of the current meta-synthesis was to conduct a comprehensive review of both the published and unpublished qualitative studies involving the experience of parents raising children diagnosed with ADHD. Searches in online scholarly databases yielded an initial 1217 hits, which were narrowed down to eighty studies that met the criteria. A “meta-ethnography” framework was used for the synthesis. Results of the first part of the analysis were reported in Corcoran et al. (2016) and had to do with the personal impact on parents. The themes in Part II have to do with the processes parents go through in accepting the diagnosis of ADHD and in deciding whether their children should take medication. Parents struggled to make sense of their child’s problems and came to terms with the diagnosis in a series of stages. Regarding medication use, parental attitudes varied greatly, with both costs and benefits noted. Though there was considerable ambivalence towards medication use, some parents reported relief after their child began using medication. Implications from this study are that providers should recognize the processes involved in making decisions about an ADHD diagnosis and the use of medication. Social workers should allow sensitive exploration of parents’ attributions and understanding of their children’s behavior and level of acceptance of the diagnosis. Keeping an ethical and critical stance toward the use of medication, social workers should also have full exploration with parents around the potential benefits and risks associated with the treatment of their children’s ADHD, taking into account parents’ preferences.  相似文献   
99.
The premise of this paper is that effective supervision and proper internal control system (ICS) can promote accountability and transparency, and this will attract more donors. However, in a developing country like Malaysia, it is common that proper accounting standards are not available, the laws are not enforced, and charities often struggle for survival. Debates on regulating nonprofit organizations (NPOs) have been sensitive to many and are often left unresolved, and some quarters believe that NPOs should be left to handle their own affairs. This paper provides evidence from a survey of 60 charities on the status of their ICS. It briefly describes the current state of regulations in Malaysia and makes a case for better monitoring of the sector, as this might be the reason NPOs are lacking in their ICS. We propose what type of regulation and assistance can be provided by the authorities to this sector, not only in Malaysia but also in other developing countries facing similar challenges.  相似文献   
100.
本文是对清华大学教授葛兆光新著《中国思想史》第一卷的学术评论。文章认为 ,葛先生“重写”思想史的基本路子即以论带史、以今视昔、以文领义 ,而“基本路子只有一条 ,一分为三 ,乃是方便说法”。事实上 ,思想史领域本来就别有洞天 ,“葛先生自许的突破之处 ,不过是划地为牢 ,然后纵身一跃 ,作突破状而已。”文章还批评了《中国思想史》中存在的理路不清、用词不当的一些“大议论”。本文作者总结道 :如果要我用一句话来评论这本书 ,我将说 :“在这本号称‘思想史’的书里 ,我看不到历史上的思想和知识 ,我只看到现在一位中国人葛兆光的‘思想’”。  相似文献   
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