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1.
As urbanization in the landscape increases, some urban centers are setting aside habitat for wildlife. This habitat may be particularly valuable to declining or conservation-priority species. One group in particular need of conservation actions that may benefit from habitat located in urban areas is grassland birds. Declines of grassland bird species have been particularly severe in the Midwestern U.S., where most grassland cover has been lost, fragmented, and surrounded by unsuitable habitat. Conservation efforts have focused on protecting large grasslands surrounded by minimal amounts of trees and development. Although urban development is considered hostile to grassland birds, this assumption has received little attention. In heavily fragmented landscapes where habitat is limited, urban grasslands may be of significant value to grassland birds. We examined grassland bird response to development and additional landscape and habitat variables in the greater Chicago metropolitan area. In 2012 and 2013, we surveyed bird communities in grassland patches along a gradient of urbanization and patch sizes. Density of Savannah Sparrows (Passerculus sandwichensis) increased with amount of development, while density of Sedge Wrens (Cistothorus platensis) decreased. Development did not appreciably impact Bobolinks (Dolichonyx oryzivorus), Dickcissels (Spiza americana), Eastern Meadowlarks (Sturnella magna), Grasshopper Sparrows (Ammodramus savannarum), or Henslow’s Sparrows (Ammodramus henslowii). Patch size had a positive effect on species densities. These results indicate that for many conservation-priority grassland birds, urban landcover surrounding grasslands generally has neutral rather than negative effects on habitat use. Therefore, grasslands in developed landscapes may provide valuable contributions to regional conservation efforts.  相似文献   

2.
Modern medicine faces fundamental challenges that various approaches to the philosophy of medicine have tried to address. One of these approaches is based on the ancient concept of phronesis. This paper investigates whether this concept can be used as a moral basis for the challenges facing modern medicine and, in particular, analyses phronesis as it is applied in the works of Pellegrino and Thomasma. It scrutinises some difficulties with a phronesis-based theory, specifically, how it presupposes a moral community of professionals. It is argued that Pellegrino and Thomasma's concept of phronesis corresponds to a Hippocratic concept of téchnê, and that this latter concept seems to address many of the challenging issues Pellegrino and Thomasma also address. Thus, if modern medicine is to find its philosophical model in ancient concepts, it appears that the Hippocratic téchnê is closer to the ancient concept of medicine than the Aristotelian phronesis, and that it might avoid many of the pitfalls of a phronesis-based approach.  相似文献   

3.
Growing human populations make it imperative for ecologists to identify strategies to conserve biodiversity in human-dominated landscapes, such as cities. Effects of urbanization on birds are particularly well-studied, but questions remain regarding the best conservation approaches. Debate about the relative utility of focusing conservation efforts on nature reserves versus developed lands has focused largely on comparing species abundance or presence, with few studies addressing underlying behavioral or demographic mechanisms. Here we evaluated differences in avian reproductive success in nature reserves and matrix habitats to test the assumption that nest predation is lower within areas protected from development. Specifically, we investigated 1) whether nest survival differed in replicated pairs of forest parks and residential neighborhoods and 2) whether differences in nest survival were associated with changes in which species most frequently depredated nests. From April–August 2007–2014, we monitored nests of two native birds, American robin (Turdus migratorius) and northern cardinal (Cardinalis cardinalis), and video-documented nest predators in paired forest-matrix habitats in the Columbus, Ohio metropolitan area. We found similar rates of nest survival in the two habitats for both robins (Χ21?=?0.715, p?=?0.398, n?=?741 nests) and cardinals (Χ21?=?0.926, p?=?0.336, n?=?1156 nests), but interactions between predators and prey differed. In particular, domestic cats (Felis catus) were over five times as likely to depredate cardinal nests in matrix habitats versus forest parks (Χ21?=?7.24, simulated p?=?0.010; nforest?=?3, nmatrix?=?7). Our results suggest that at least in some circumstances, nest success of native birds may be equivalent between nature reserves and adjacent residential matrix habitats, and thus residential neighborhoods may contribute positively to bird conservation in urban landscapes.  相似文献   

4.
Dominant social theories have rarely placed migration at the center of our understanding of society and social change. Classical theories in the Western tradition have been more preoccupied with the impact of economic and political revolutions on social change, stratification and class conflict, and have paid far less attention to other important aspects of society. Contemporary theories have expanded the theoretical gaze to include a much wider set of issues, from racial and gender divisions to warfare and the environment. In an era of globalization, we argue that such a marginalization of the migrant, and the failure to better integrate both internal and external migration into a more nuanced interpretation of social change, is a significant shortcoming. By examining some of the key elements linked to such human movement in Europe, North America and China -- in the light of five recent studies in this field -- we argue that migration is a vital factor in changing the world as we know it and consequently a central concern for social theory. This is a review essay on:Richard Alba and Nancy Foner. Strangers No More: Immigration and the Challenges of Integration in North America and Western Europe. Princeton: Princeton University Press, 2015.Louis DeSipio and Rodolfo de la Garza. US Immigration in the Twenty-First Century: Making Americans, Remaking America. Boulder, CO: Westview Press, 2015.Adrian Favell. Immigration, Integration and Mobility: New Agendas in Migration Studies. Colchester: ECPR Press, 2015.Zhongshan Yue. Social Integration of Rural-Urban Migrants in China: Current Status, Determinants and Consequences. Singapore: World Scientific Publishers, 2015.Robyn R Iredale and Fei Guo. Handbook of Chinese Migration: Identity and Wellbeing. Cheltenham: Edward Elgar Publishing, 2015.  相似文献   

5.
Understanding the factors determining the occupancy and detection probability of birds in human dominated environments is important for their conservation. In this study we investigated various environmental variables believed to influence the site occupancy and detection probability of Trumpeter Hornbill (Bycanistes bucinator) in urban-forest mosaics of KwaZulu-Natal, South Africa. Presence/absence data were collected from a total of 50 point count stations established between September 2014 and March 2015 in urban-forest mosaics of Durban, Eshowe and Mtunzini. Mean occupancy rate of Trumpeter Hornbill was 0.40 ± 0.09 with a low detection probability of 0.28 ± 0.04. For Trumpeter Hornbills, large trees influenced their occupancy positively (sum AIC weight (ω i ) = 79%) while relative human abundance negatively influenced their occupancy (ω i = 91%). Model selection suggested that housing density had a strong negative influence on detection probability of Trumpeter Hornbills (ω i ?=?82?%?) and availability of fruiting trees influenced their detection positively (ω i ?=?29%). With continued changing land use in KwaZulu-Natal, these finding are important for conservation of Trumpeter Hornbills as we provide insight into landscape variables or features that influence Trumpeter Hornbill’s occupancy and detection in areas of urban-forest mosaics.  相似文献   

6.
Ligustrum lucidum, a tree native to China has naturalized in Japan where it is often planted in parks and along roads. Naturalized individuals in urban woodlands have uncertain competitiveness against native species, particular in light of the frequent pruning undertaken in these woodlands. We compared fitness-related traits of Ligustrum against two co-occurring native species: a pioneer tree (Mallotus japonicus) and an understory tree (Eurya japonica) under pruned and un-pruned settings. A growth experiments where we assessed the leaf and whole plant characteristics of the 3 species under two environments simulating forest edge and forest interior, and two pruning treatments (with or without) was conducted. Under simulated forest edge without pruning, Ligustrum had lower stem growth and Amax (maximum photosynthetic rate) than Mallotus, suggesting that native species can competitively suppress invasive expansion. With pruning, however, Ligustrum resprouted vigorously in both spring and summer with significantly higher apical growth and total shoots than Mallotus and Eurya in forest edge and interior, respectively. Also, with similar Amax between resprouts of Ligustrum and Mallotus, we see a reversal of competitive advantage in favor of Ligustrum in forest edge. In the forest interior, Ligustrum exhibited shade tolerant properties (i.e., Amax, chlorophyll a/b, and leaf density) similar to Eurya but had more resprout shoots, suggesting that the invader also maintains an advantage under low light. The competitiveness of Ligustrum clearly increased with human disturbance in the form of park pruning. Such management practice can inadvertently enhance the invasiveness of exotic species in urban settings.  相似文献   

7.
Urbanization is a major global change inducing complex and multiple modifications of landscapes and ecosystems. The spatial distributions of organisms experiencing these modifications will likely shift specifically, depending on each species’ response to each environmental modification induced by urbanization. We sampled two ant genera (Lasius and Tetramorium) at 1248 locations along an urbanization gradient in Lyon, France and used high resolution spatial layers for 18 spatial (e.g., open habitat fragmentation, bioclimatic data and surface temperatures) and temporal (e.g., comparison of Normalized Difference Vegetation Index between 1986 and 2015) environmental variables associated with urbanization. Coupling two different analytical methods (Outlying Mean Index and Boosted Regression Trees), we showed that each species’ distribution was influenced by its own combination of environmental factors. Two morphologically cryptic Tetramorium species (T. sp.E and T. sp.U2) were both highly abundant but with opposite responses to urbanization: while T. sp.E was favored by urbanized habitat, T. sp.U2 avoided urbanized areas. Among Lasius species, we detected 63 occurrences of the invasive ant Lasius neglectus, the distribution of which was favored only by embankments along roads. We found that, even at this reduced spatial scale, climatic effects influenced most species and interacted with urbanization factors.  相似文献   

8.
On the equivalence between progressive taxation and inequality reduction   总被引:1,自引:1,他引:0  
We establish the precise connections between progressive taxation and inequality reduction, in a setting where the level of tax revenue to be raised is exogenously fixed and tax schemes are balanced. We show that, in contrast with the traditional literature on taxation, the equivalence between inequality reduction and the combination of progressivity and income order preservation does not always hold in this setting. However, we show that, among rules satisfying consistency and, either revenue continuity, or revenue monotonicity, the equivalence remains intact.  相似文献   

9.
Israeli environmental non-government organizations (ENGOs) are assessed in light of Resource Mobilization Theory, introducing a new method for dividing ENGOs according to strategic orientation. Based on a national survey, 85 groups are categorized as consensus ENGOs that seek understanding aim at finding common grounds, or as conflict ENGOs working “outside the system.” Results show that conflict ENGOs are more grassroots in orientation and consensus ENGOs are more professionalized. Conflict ENGOs operate primarily in local arenas. Consensus ENGOs appear more stable, with larger annual budgets and paid staff, but with fewer registered members. Consensus ENGOs enjoy a wider variety of income sources; receive more funding from government, foreign, and private donations; and have a broader range of self-generated income sources. Conflict ENGOs depend more on membership fees. Both groups are highly dependent on foundation grants. In general, greater resources are associated with consensus activity than among organizations utilizing conflict tactics.  相似文献   

10.
Urbanization affects the availability and diversity of floral resources (pollen and/or nectar) for wild pollinating insects. For example, urban green areas are characterized by an abundance of ornamental plant species. Increasingly, trees are planted to improve the aesthetics of urban streets and parks. These urban trees might offer important floral resources to pollinating insects. To examine the suitability of urban trees as resources for pollinating insects, we investigated the chemical composition of pollen and nectar as well as the amount of nectar produced by the nine major insect-pollinated tree species planted in cities of Western Europe, namely Acer pseudoplatanus, Aesculus carnea, A. hippocastanum, Robinia pseudoacacia, Tilia cordata, T. x euchlora, T. x europaea, T. platyphyllos and T. tomentosa. The analyses revealed that globally the Tilia trees provide pollen with lower contents of polypeptides, amino acids and phytosterols compared with the other species. Urban tree flowers offer abundant nectar with relatively high sugar contents (0.16–1.28 mg/flower); sucrose was the predominant sugar in all nectars. The investigated tree species could therefore be considered in future city plantings.  相似文献   

11.
As urbanization increases, the identification of nest predators becomes important for avian conservation and management of urban wildlife communities. We investigated bird nest predation using artificial nests in urban areas of the KwaZulu-Natal (KZN) Province of South Africa. From June 2013 through February 2014 we installed seventy-five artificial nests in 25 suburban gardens in the Ethekwini and Msunduzi municipalities of KZN. Euplectes spp. nests were used and baited with two quail-sized, hand-made, silicon eggs. These were placed in residential gardens and monitored by camera traps for 2-weeks in winter, spring and summer respectively. Generally bird nesting occurs throughout the year in KZN’s subtropical climate, with some avoidance during the autumn season. Therefore, experiments were not conducted during autumn, as fresh nests were not available for use. Overall the rate of predation on artificial nests was 25 % (n = 19), with vervet monkeys Ceropithecus aethiops pygerythrus predating 20 % (n = 17) of the nests while domestic cats Felis catus predated 3 % (n = 2) of nests. Nest predation was significantly higher in the winter season, with 79 % of depredations occurring in winter (n = 15), 16 % in spring (n = 3) and 5 % in summer (n = 1), and in areas with less canopy cover. Our results suggest that vervet monkeys may have a negative impact on nesting birds in urban environments, however, in order to assess the rate of predation experiments on natural nests coupled with information on fledgling success is deemed necessary to investigate avian population declines.  相似文献   

12.
Artificial shiny dark objects reflecting horizontally polarized light (e.g. asphalt roads, black cars, solar panels) can attract polarotactic aquatic insects in mass. Glass buildings on the riverside also lure swarming caddisflies emerging from the river. These caddisfly swarms are a temporary rich food source for certain bird species, such as white wagtails (Motacilla alba), house sparrows (Passer domesticus), magpies (Pica pica) and great tits (Parus major). We report here about our observation of great spotted woodpeckers (Dendrocopos major), hooded crows (Corvus cornix) and black redstarts (Phoenicurus ochruros) feeding atypically on Hydropsyche pellucidula caddisflies swarming at glass buildings placed on the shore of the river Danube in Budapest (Hungary).  相似文献   

13.
We study claims problems in which a certain amount of indivisible units (of an homogeneous good) has to be distributed among a group of agents, when this amount is not enough to fully satisfy agents’ demands. Our aim is to find solutions fulfilling procedural and fairness properties. To do that, we define the M-down methods, which are the unique robust (composition down and consistency) and fair (balancedness and conditional full compensation) rules. Besides, we also establish the relationship between these M-down methods and the constrained equal awards rule.  相似文献   

14.
Since the “Public Library of Science” launched its first open-access journals and the “Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities” has been released in 2003 and found enormous attention, the claim for open access—to make publicly funded journal articles available for the public—started to reach German scientists too. But still no experience has been made with electronic publishing in general and more specifically with open-access publishing. One consequence is that the potential capacity of open access—the (inter) national and (trans) disciplinary visibility and accessibility of scientific output—is not sufficiently used by German researchers. Ways to successfully establish an open-access journal are presented in this article by referring to “Forum Qualitative Sozialforschung/Forum:Qualitative Social Research” (FQS) as an example: after introducing the current state of FQS traditional and innovative ways of publishing are being discussed which had been employed while developing FQS and which helped FQS to become the most important electronic journal in the field of qualitative research.  相似文献   

15.
In order to ensure sustainable development, aid donors need to improve the environmental effectiveness of their whole activity. This improvement seems to be influenced by their interactions with environmental NGOs (ENGOs). Faced with a diversity of interactions between these two kinds of actors, a strategic typology is proposed here to describe this multiplicity and, by doing so, to consider their environmental impact. Four relational postures have been identified: (i) external advocacy and (ii) the cooperation–criticism focus on the antagonistic link that exists between environment and development; (iii) environmental collaboration, and (iv) service provision, which focus on synergies that can exist between environment protection and development issues. Win–win solutions need to be continuously sought and enhanced. However, ENGOs and donors are called to recognize the necessity of maintaining a critical position in actors’ interactions vis-à-vis the implementation of development activities that are detrimental for the environment.  相似文献   

16.
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   

17.

Background

Physical exercise (PE), virtual reality-based exercise (VRE), and brain exercise (BE) can influence physical and cognitive conditions in older persons. However, it is not known which of the three types of exercises provide the best effects on physical and cognitive status, and which exercise is preferred by older persons. This study compared the effects of PE, VRE, and BE on balance, muscle strength, cognition, and fall concern. In addition, exercise effort perception and contentment in older persons was evaluated.

Methods

Eighty-four older persons (n?=?84) were randomly selected for PE, VRE, BE, and control groups. The exercise groups received 8-week training, whereas the control group did not. Balance was assessed by Berg Balance Scale (BBS) and Timed Up and Go test (TUG), muscle strength by 5 Times Sit to Stand (5TSTS) and left and right hand grip strength (HGS), cognition by Montreal Cognitive Assessment (MoCA) and Timed Up and Go test Cognition (TUG-cog), fall concern by Fall Efficacy Scale International (FES-I), exercise effort perception by Borg category ratio scale (Borg CR-10), and exercise contentment by a questionnaire.

Results

After exercise, PE significantly enhanced TUG and 5TSTS to a greater extent than VRE (TUG; p?=?0.004, 5TSTS; p?=?0.027) and BE (TUG; p?=?0,012, 5TSTS; p?<?0.001). VRE significantly improved MoCA (p?<?0.001) and FES-I (p?=?0.036) compared to PE, and 5TSTS (p?<?0.001) and FES-I (p?=?0.011) were improved relative to BE. MoCA was significantly enhanced by BE compared to PE (p?<?0.001) and both MoCA and TUG-cog were improved compared to VRE (p?=?0.04). PE and VRE significantly (p < 0.001) increased Borg CR-10 in all exercise sessions, whereas BE showed a significant improvement (p?< 0.001) in the first 4 sessions. Participants had a significantly greater satisfaction with BE than controls (p?=?0.006), and enjoyed VRE and BE more than PE (p?< 0.001). Subjects in all exercise groups exhibited benefits compared to the control group (p?< 0.001).

Conclusions

PE provided the best results in physical tests, VRE produced measurable improvements in physical and cognition scores, while BE enhanced cognition ability in older persons. Older persons preferred VRE and BE compared to PE. Both exercises are suggested to older persons to improve physical and cognitive conditions.
  相似文献   

18.
In this paper, we theoretically characterize robust empirically implementable normative criteria for evaluating socially risky situations. Socially risky situations are modeled as distributions, among individuals, of lotteries on a finite set of state-contingent pecuniary consequences. Individuals are assumed to have selfish Von Neumann–Morgenstern preferences for these socially risky situations. We provide empirically implementable criteria that coincide with the unanimity, over a reasonably large class of such individual preferences, of anonymous and Pareto-inclusive Von Neuman Morgenstern social rankings of risks. The implementable criteria can be interpreted as sequential expected poverty dominance. An illustration of the usefulness of the criteria for comparing the exposure to unemployment risk of different segments of the French and US workforce is also provided.  相似文献   

19.
Although much overlooked by both sociologists and educators, Emile Durkheim’s The Evolution of Educational Thought (EET; lectures from 1904–1905) not only provides extended insight into the developmental flows and disjunctures of Western education and scholarship from the classical Greek era to Durkheim’s own time but also indicates the fundamentally sociological nature of these transformations. As well, and in contrast to the more heavily structuralist, Cartesian rationalist approach that Durkheim adopts in his earlier, better known works (especially The Division of Labor in Society, Rules of the Sociological Method, and Suicide), Durkheim’s EET may be better characterized as a historically informed, sociological pragmatist approach to the study of education as a humanly engaged process. Given the extended amount of material covered in EET and the necessity of establishing in some detail Durkheim’s position on the development of educational thought over the preceding 2000 years, it has been necessary to divide this material into smaller packages for the purpose of presentation. In the first six chapters of EET Durkheim addresses (a) the Greek and Latin foundations of educational thought in France, (b) the role that the early Christian church assumed in shaping and preserving education and scholarship, and (c) the nature and emphasis of the Carolingian Renaissance (8th and 9th centuries), along with its relevance for the development of universities in Europe. Following (1) an introduction to Durkheim’s EET, (2) a synopsis of the first six chapters of EET, and (3) a highly compacted overview of the remaining 21 chapters of this volume, this paper concludes with (4) a commentary on the necessity of attending to the historical development of Western social thought for a sociological analysis of knowing and acting. An epilogue briefly considers (5) some ways that sociologists, classicists, and other students of the human condition may contribute to this exceptionally consequential venture  相似文献   

20.
We used data from the Birth to Twenty Cohort study to understand children’s receipt of financial support from their fathers in a low income, Black community in urban South Africa. Specifically, we (1) described fathers’ financial support over the life course of children; (2) estimated survival probabilities of receiving support for all children and not receiving support for children who experienced a parental union dissolution; and (3) identified factors that explained variation in the receipt of support after a union dissolution. Results suggest that most children received full or partial support throughout the life course. Furthermore, a high proportion of children received support after a union dissolution with much of the variation driven by pre-dissolution support, father’s education and the presence of extended kin.  相似文献   

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