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111.
Investigations of urbanization effects on birds have focused mainly on breeding traits expressed after the nest-building stage (e.g. first-egg date, clutch size, breeding success, and offspring characteristics). Urban studies largely ignored how and why the aspects of nest building might be associated with the degree of urbanization. As urban environments are expected to present novel environmental changes relative to rural environments, it is important to evaluate how nest-building behavior is impacted by vegetation modifications associated with urbanization. To examine nest design in a Mediterranean city environment, we allowed urban great tits (Parus major) to breed in nest boxes in areas that differed in local vegetation cover. We found that different measures of nest size or mass were not associated with vegetation cover. In particular, nests located adjacent to streets with lower vegetation cover were not smaller or lighter than nests in parks with higher vegetation cover. Nests adjacent to streets contained more pine needles than nests in parks. In addition, in nests adjacent to streets, nests from boxes attached to pine trees contained more pine needles than nests from boxes attached to other trees. We suggest that urban-related alterations in vegetation cover do not directly impose physical limits on nest size in species that are opportunistic in the selection of nesting material. However, nest composition as reflected in the use of pine needles was clearly affected by habitat type and the planted tree species present, which implies that rapid habitat change impacts nest composition. We do not exclude that urbanization might impact other aspects of nest building behaviour not covered in our study (e.g. costs of searching for nest material), and that the strengths of the associations between urbanization and nest structures might differ among study populations or species.  相似文献   
112.
This article identifies the most cohesive multi‐polar regions of the network of world cities, which differ from the unipolar centre–periphery model largely created by the high weight of central city connections. We use a community detection algorithm that outlines the high densities of city networks (in relative weights). Various patterns of industries and services, which are divided into two skill levels, are identified. We use a global database of the network of 1.2 million direct and indirect ownership links between the 800,000 subsidiaries of the top 3000 multinational groups in 2013, allowing us to build four comparable networks of 503 metropolitan areas. Comparing the obtained partitions with continental, regional and economic benchmarks, classes of cities partially correspond to free trade zones (FTZs) but exhibit interesting cross‐continental patterns. A few cities, changing their classes according to the activities, are discussed in the light of the multinational firms' strategies.  相似文献   
113.
We develop a new robust stopping criterion for partial least squares regression (PLSR) component construction, characterized by a high level of stability. This new criterion is universal since it is suitable both for PLSR and extensions to generalized linear regression (PLSGLR). The criterion is based on a non-parametric bootstrap technique and must be computed algorithmically. It allows the testing of each successive component at a preset significance level \(\alpha \). In order to assess its performance and robustness with respect to various noise levels, we perform dataset simulations in which there is a preset and known number of components. These simulations are carried out for datasets characterized both by \(n>p\), with n the number of subjects and p the number of covariates, as well as for \(n<p\). We then use t-tests to compare the predictive performance of our approach with other common criteria. The stability property is in particular tested through re-sampling processes on a real allelotyping dataset. An important additional conclusion is that this new criterion gives globally better predictive performances than existing ones in both the PLSR and PLSGLR (logistic and poisson) frameworks.  相似文献   
114.
Men who have sex with men (MSM) who attend group-sex events often engage in risky sexual behaviors that contribute to the high human immunodeficiency virus (HIV) incidence among this population. We conducted an online survey with 211 New York City MSM who attended sex parties in the prior year and asked them to describe their behaviors and perceptions of risk. We compared responses from HIV-positive-undetectable men (n = 36), HIV-negative men on pre-exposure prophylaxis (PrEP; n = 62), and HIV-negative men never on PrEP (n = 113). In bivariate analyses, undetectable and on-PrEP men had been to more sex parties in the prior six months, had more anal sex partners there, and had higher rates of sexually transmitted infection (STI) diagnoses than men never on PrEP. Although less than the other groups, 43% of the presumably HIV-negative men never on PrEP reported condomless anal sex at a party in the prior six months. About half of participants agreed that, at sex parties, they made assumptions about others’ HIV status, that they sometimes took more risks than intended, and that the atmosphere of these events was conducive to risk taking. Most disagreed that there was discussion of HIV status at sex parties. Implications for sexual health interventions are discussed.  相似文献   
115.
A recent investigation of the British General Household Survey (GHS) found substantial over-reporting of childlessness in recent years, particularly at older ages. We examine the phenomenon in further detail and find that the principal cause was change in survey procedures. To some extent the bias can be corrected for by using information on own children in the household. Revised fertility histories give period estimates of total fertility that are in close agreement with national vital registration statistics, unlike those based on original fertility histories of recent years. Misreporting in fertility histories dates primarily from administrative changes in the GHS in the years 1998-2000, and particularly from 2003, when the option of laptop self-completion (CASI) was introduced for reporting demographic histories.  相似文献   
116.
This paper is about object deformations observed throughout a sequence of images. We present a statistical framework in which the observed images are defined as noisy realizations of a randomly deformed template image. In this framework, we focus on the problem of the estimation of parameters related to the template and deformations. Our main motivation is the construction of estimation framework and algorithm which can be applied to short sequences of complex and highly-dimensional images. The originality of our approach lies in the representations of the template and deformations, which are defined on a common triangulated domain, adapted to the geometry of the observed images. In this way, we have joint representations of the template and deformations which are compact and parsimonious. Using such representations, we are able to drastically reduce the number of parameters in the model. Besides, we adapt to our framework the Stochastic Approximation EM algorithm combined with a Markov Chain Monte Carlo procedure which was proposed in 2004 by Kuhn and Lavielle. Our implementation of this algorithm takes advantage of some properties which are specific to our framework. More precisely, we use the Markovian properties of deformations to build an efficient simulation strategy based on a Metropolis-Hasting-Within-Gibbs sampler. Finally, we present some experiments on sequences of medical images and synthetic data.  相似文献   
117.
The proliferation of reforms in public administration based on the principles and instruments of the “New Public Management” (NPM) have triggered protest from and collective action by many professional groups in various sectors (healthcare, education, justice, social work, research…) and raised questions about the future of professionals working in the public service, particularly as concerns their autonomy. However, after analyzing the situation, it seems that the opposition between NPM and certain professional groups is not the last word in the debate. Should changes be seen as the decline of professional groups and of their autonomy or as a transformation of professional models, an overhaul of professionalism, etc.? Such questions, which current events in France and Europe have brought to the fore, are food for ongoing sociological thought. They are broached here empirically, from the field, applying varied levels of analysis and research. The contributors to this dossier explore the different forms of tension existing between professional groups and NPM.  相似文献   
118.

This paper examines the effect of ethical performance on the value of a company and the attractiveness of its stocks for major owners; institutional investors and insiders. Using the Ethisphere® Institute Ethics Quotient to distinguish between ethical and unethical companies, results show that good ethical performance enhanced company value for a sample of 240 large US companies. Furthermore, strong evidence is found that institutional investors are attracted to ethical companies, but that insiders do not show any investment preferences based on the ethical performance of a company.

  相似文献   
119.
Journal of Management and Governance - The original version of this article contained a mistake. The list of the authors was incorrect. The authors of this article are: Jean-Michel Sahut, Marta...  相似文献   
120.
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