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41.
Urban Ecosystems - Free-ranging domestic dogs are the world most common exotic carnivore species that could negatively interact with the native wildlife as predators, competitors, and disease...  相似文献   
42.
In this paper we present an axiomatic analysis of several ranking methods for general tournaments. We find that the ranking method obtained by applying maximum likelihood to the (Zermelo-)Bradley-Terry model, the most common method in statistics and psychology, is one of the ranking methods that perform best with respect to the set of properties under consideration. A less known ranking method, generalised row sum, performs well too. We also study, among others, the fair bets ranking method, widely studied in social choice, and the least squares method.  相似文献   
43.
The plant community in the karst forest is influenced by mesoclimatic conditions, such as temperature and humidity and these conditions are in turn influenced by topographic features. Urban areas adjacent to karstic forest remnants also have the potential to influence mesoclimatic variables and may serve as a source of exotic species. We described the temperature and relative humidity of karstic forest remnants at slopes with combinations of either southeast (SE) or northwest (NW) aspect, and adjacent to either urban (URB) or secondary forest (SF). We also compared forest structure and composition on these slopes to understand the interaction between forest aspect and adjacent land use on the plant community. URB-SE slopes had highest temperature and lowest humidity among all adjacent land use-aspect combinations. Understory species in SE slopes had similar richness and diversity independently of adjacent land use, however within NW aspect, slopes adjacent to urban areas showed higher values than slopes adjacent secondary forest. Canopy trees species in slopes adjacent to secondary forest were more diverse and rich in SE than in NW, although no differences between aspects were detected within URB-adjacent slopes. Understory species composition was different among the four land use-aspect combinations. However, composition of canopy trees species was different only between aspect types. Most exotic species in the sites were associated with previous agricultural practices and not with current land use. Our results show a temporal and spatial influence of anthropogenic systems on the plant community in karstic forest remnants at a suburban area of Puerto Rico.  相似文献   
44.
This article presents a definition and characterisation of the ‘European social model’ (ESM), admitting the existence of variants and increasing heterogeneity in institutional and social contexts within the EU in the wake of successive enlargements. The constituent parts of the ESM are compared with data observed in the different countries, in search of empirical evidence of the ESM‘s position as a distinctive model of development, characteristic of Western Europe as opposed to the paths taken by other non‐European developed OECD countries.  相似文献   
45.
Among the various educational models in Latin America that seek to increase parental participation in schooling, perhaps the most far‐reaching is the experiment with self‐managed schools. These are publicly funded schools administered by parents. Broad public powers, such as the capacity to decide the budget and make staffing decisions, are given to parents, many of whom have had very limited prior administrative experience. How does this policy innovation impact on civil society? Does parental participation in school administration empower participating citizens or strain civil society? There are various ways of answering these questions. This article looks at some possible ways to conceptualize and assess the relationship between parental participation in self‐managed schools and civil society. The article draws from the experience of El Salvador, Guatemala, Honduras and Nicaragua, where these reforms have advanced significantly since the 1990s.  相似文献   
46.
Social Indicators Research - This study analyzes the evolution of salary polarization in the Spanish labor market. The paper proposes the use of mixed distributions to examine the consequences of...  相似文献   
47.
\(\alpha \)-Stable distributions are a family of probability distributions found to be suitable to model many complex processes and phenomena in several research fields, such as medicine, physics, finance and networking, among others. However, the lack of closed expressions makes their evaluation analytically intractable, and alternative approaches are computationally expensive. Existing numerical programs are not fast enough for certain applications and do not make use of the parallel power of general purpose graphic processing units. In this paper, we develop novel parallel algorithms for the probability density function and cumulative distribution function—including a parallel Gauss–Kronrod quadrature—, quantile function, random number generator and maximum likelihood estimation of \(\alpha \)-stable distributions using OpenCL, achieving significant speedups and precision in all cases. Thanks to the use of OpenCL, we also evaluate the results of our library with different GPU architectures.  相似文献   
48.
A grounded theory qualitative study was developed to explore how grandparents perceive their role as socializing agents. Forty‐two grandparents with grandchildren aged from 6 to 12 years old participated in this study. Data were collected through focus groups, which were conducted until reaching data saturation and analyzed using the constant comparative method. Four general conclusions emerged from the study: (i) grandparents recognized the importance of getting involved in the socialization of grandchildren as supporters of parents' socializing role, and the need to adapt to social changes; (ii) they emphasized traditional value that were perceived in decline, and combination of warmth and involvement were considered the best way to help grandchildren internalize values; (iii) interaction with grandchildren helped grandparents to feel active and useful, increased their life purpose and gave them a second chance to enjoy what they could not with their own children; and (iv) grandparents also accused burden and role ambiguity. These results show the importance of developing family policies that recognize grandparents' socializing role. Also, interventions that promote strategies that enable grandparents to perform their role more successfully and to cope with possible family conflicts should be developed.  相似文献   
49.
This article examines the interrelations between establishment of territorial quality certification systems (Protected Designations of Origin or PDOs), diffusion of innovations through local agro-food chains, and the role of the institutions overseeing geographical designations. Empirical analysis is applied to olive oil PDOs in Spain and entails a detailed case study of the “Sierra Mágina” PDO in Andalusia. Making use of the neoinstitutional concept of ‘organised proximity’—and focussing specifically on the problematic of organizational quality—the article assesses characteristics that support the competitive positions of local certified-product production systems. In particular, the authors find that collective organisation and coordination between PDO agents who are locally responsible for quality assurance and protection can enhance local competitiveness. Three hypotheses are confirmed. First, PDO labels can, through the action of PDO regulators, become quality assurance systems for distributors. Second, PDO Regulatory Boards can enhance and coordinate local inter-professional activities, particularly with respect to the diffusion of quality-enhancing innovations and knowledge. Third, the study indicates that local certified-product systems are starting to incorporate quality attributes linked to the environment and sustainable development, although much remains to be accomplished in this regard.  相似文献   
50.
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