46 resultados para historical and perspectives


Relevância:

90.00% 90.00%

Publicador:

Resumo:

Biological invasions and land-use changes are two major causes of the global modifications of biodiversity. Habitat suitability models are the tools of choice to predict potential distributions of invasive species. Although land-use is a key driver of alien species invasions, it is often assumed that land-use is constant in time. Here we combine historical and present day information, to evaluate whether land-use changes could explain the dynamic of invasion of the American bullfrog Rana catesbeiana (=Lithobathes catesbeianus) in Northern Italy, from the 1950s to present-day. We used maxent to build habitat suitability models, on the basis of past (1960s, 1980s) and present-day data on land-uses and species distribution. For example, we used models built using the 1960s data to predict distribution in the 1980s, and so on. Furthermore, we used land-use scenarios to project suitability in the future. Habitat suitability models predicted well the spread of bullfrogs in the subsequent temporal step. Models considering land-use changes predicted invasion dynamics better than models assuming constant land-use over the last 50 years. Scenarios of future land-use suggest that suitability will remain similar in the next years. Habitat suitability models can help to understand and predict the dynamics of invasions; however, land-use is not constant in time: land-use modifications can strongly affect invasions; furthermore, both land management and the suitability of a given land-use class may vary in time. An integration of land-use changes in studies of biological invasions can help to improve management strategies.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Most airborne microorganisms are natural components of our ecosystem. Soil, vegetation and animals, including humans, are sources for aerial release of these living or dead cells. In the past, assessment of airborne microorganisms was mainly restricted to occupational health concerns. Indeed, in several occupations, exposure to very high concentrations of non-infectious airborne bacteria and fungi, result in allergenic, toxic or irritant reactions. Recently, the threat of bioterrorism and pandemics have highlighted the urgent need to increase knowledge of bioaerosol ecology. More fundamentally, airborne bacterial and fungal communities begin to draw much more consideration from environmental microbiologists, who have neglected this area for a long time. This increased interest of scientists is to a great part due to the development and use of real-time PCR techniques to identify and quantify airborne microorganisms. Even if the advantages of the PCR technology are obvious, researchers are confronted with new problems. This review describes the methodological state of the art in bioaerosols field and emphasizes the future challenges and perspectives of the real-time PCR-based methods for airborne microorganism studies.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Disability, especially if related to a psychiatric disorder, such as somatoform pain disorder, is characterized by medical, psychological, relational, social and societal, as well as financial and political aspects. This manuscript, part of a PhD thesis which reflects on a possible dialogue between an ancient text and the modern conceptualization of disability, tries to address the phenomenological, historical and political dimensions of disability.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The subject "Value and prices in Russian economic thought (1890--1920)" should evoke several names and debates in the reader's mind. For a long time, Western scholars have been aware that the Russian economists Tugan-Baranovsky and Bortkiewicz were active participants to the Marxian transformation problem, that the mathematical models of Dmitriev prefigured forthcoming neoricardian based models, and that many Russian economists were either supporting the Marxian labour theory of value or being revisionists. Moreover, these ideas were preparing the ground for Soviet planning. Russian scholars additionally knew that this period was the time of introduction of marginalism in Russia, and that, during this period, economists were active in thinking the relation of ethics with economic theory. All these issues are well covered in the existing literature. But there is a big gap that this dissertation intends to fill. The existing literature handles these pieces separately, although they are part of a single, more general, history. All these issues (the labour theory of value, marginalism, the Marxian transformation problem, planning, ethics, mathematical economics) were part of what this dissertation calls here "The Russian synthesis". The Russian synthesis (in the singular) designates here all the attempts at synthesis between classical political economy and marginalism, between labour theory of value and marginal utility, and between value and prices that occurred in Russian economic thought between 1890 and 1920, and that embraces the whole set of issues evoked above. This dissertation has the ambition of being the first comprehensive history of that Russian synthesis. In this, this contribution is unique. It has always surprised the author of the present dissertation that such a book has not yet been written. Several good reasons, both in terms of scarce availability of sources and of ideological restrictions, may accounted for a reasonable delay of several decades. But it is now urgent to remedy the situation before the protagonists of the Russian synthesis are definitely classified under the wrong labels in the pantheon of economic thought. To accomplish this task, it has seldom be sufficient to gather together the various existing studies on aspects of this story. It as been necessary to return to the primary sources in the Russian language. The most important part of the primary literature has never been translated, and in the last years only some of them have been republished in Russian. Therefore, most translations from the Russian have been made by the author of the present dissertation. The secondary literature has been surveyed in the languages that are familiar (Russian, English and French) or almost familiar (German) to the present author, and which are hopefully the most pertinent to the present investigation. Besides, and in order to increase the acquaintance with the text, which was the objective of all this, some archival sources were used. The analysis consists of careful chronological studies of the authors' writings and their evolution in their historical and intellectual context. As a consequence, the dissertation brings new authors to the foreground - Shaposhnikov and Yurovsky - who were traditionally confined to the substitutes' bench, because they only superficially touched the domains quoted above. In the Russian synthesis however, they played an important part of the story. As a side effect, some authors that used to play in the foreground - Dmitriev and Bortkiewicz - are relegated to the background, but are not forgotten. Besides, the dissertation refreshes the views on authors already known, such as Ziber and, especially, Tugan-Baranovsky. The ultimate objective of this dissertation is to change the opinion that one could have on "value and prices in Russian economic thought", by setting the Russian synthesis at the centre of the debates.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Recent years have seen an emerging knowledge base and increasing public interest and awareness of sexual-economic relationships between local men and Western women, in different touristic regions around the world. However, to date, Western perspectives on the phenomenon make up the bulk of the existent literature. Questioning the dominant discourse of 'romance tourism' and representations of male participants as 'victims-opportunists', this dissertation explores male beach workers' experiences with, and perspectives on sexual-economic relationships between Kenyan men and visiting Western women in Kenya's South Coast region. The men were not considered in isolation; their experiences and perspectives are situated in relation to their family ties, social networks and the political economy of beach tourism. The study shows that locally these relationships are clearly understood as livelihood strategies for the visited. Men seek to establish long-term intimate relationships with female tourists as a means to accessing life's basic necessities for themselves and for their families and overall to improve their standards of living. It is argued that these relationships are a response to the poverty and inequalities generated by socio-economic changes over time. They are also a response to local gender role prescriptions that hinge male social value on men's capacity to marry, procreate and provide intergenerational social and economic support. The men's parallel quest for non-sexual economically motivated friendships with visiting foreign tourists termed "family friends" is a salient finding, that serves to reinforce the finding that the sexual- economic relationships are above all livelihood strategies. Résumé Ces dernières années ont vu l'émergence d'une base de connaissance, ainsi que d'un intérêt et d'une prise de conscience accrue du public, à l'égard des relations économico-sexuelles entre hommes locaux et femmes occidentales, dans différentes régions touristiques du monde. Cependant, à ce jour, des perspectives occidentales sur ce phénomène constituent l'essentiel de la littérature existante. En remettant en question le discours dominant du «romance tourism» (tourisme sentimental) et les représentations qui conçoivent les hommes participants comme étant 'victimes-opportunistes', cette thèse explore les expériences, et les visions qu'ont les travailleurs de plage sur les relations économico-sexuelles entre hommes Kenyans et femmes Occidentales dans la région de la côte sud du Kenya. Les hommes n'ont pas été considérés de manière isolée; leurs expériences et leurs perspectives sont situées par rapport à leur liens familiaux, leur réseaux sociaux et aussi par rapport à l'économie politique du tourisme balnéaire. L'étude montre que sur place ces relations sont clairement conçues comme des stratégies de survie pour les participants hôtes. Les hommes cherchent à établir des relations de long durée avec des femmes touristes comme moyen d'accéder à des biens et des services qui constituent des nécessités de bases, pour eux et pour leur familles et globalement pour relever leur niveau de vie! L'étude fait valoir que ces relations sont une réponse à la pauvreté et aux inégalités sociales crées par des dynamiques socio-économiques au fil du temps. Elles sont aussi une réponse au prescriptions sociales locales par lesquelles la valeur sociale masculine est définie à travers la capacité des hommes à se marier, à procréer et d'assurer un soutien intergénérationnel social et économique. La quête, en parallèle, de relations d'amitiés non-sexuelles à motivation économique, dénommé « family friends », par des hommes, est un résultat saillant de cette étude qui vient renforcer l'observation que les relations économico-sexuelles relèvent avant tout des stratégies de survie.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Understanding the relative importance of historical and environmental processes in the structure and composition of communities is one of the longest quests in ecological research. Increasingly, researchers are relying on the functional and phylogenetic β-diversity of natural communities to provide concise explanations on the mechanistic basis of community assembly and the drivers of trait variation among species. The present study investigated how plant functional and phylogenetic β-diversity change along key environmental and spatial gradients in the Western Swiss Alps. Methods Using the quadratic diversity measure based on six functional traits: specific leaf area (SLA), leaf dry matter content (LDMC), plant height (H), leaf carbon content (C), leaf nitrogen content (N), and leaf carbon to nitrogen content (C/N) alongside a species-resolved phylogenetic tree, we relate variations in climate, spatial geographic, land use and soil gradients to plant functional and phylogenetic turnover in mountain communities of the Western Swiss Alps. Important findings Our study highlights two main points. First, climate and land use factors play an important role in mountain plant community turnover. Second, the overlap between plant functional and phylogenetic turnover along these gradients correlates with the low phylogenetic signal in traits, suggesting that in mountain landscapes, trait lability is likely an important factor in driving plant community assembly. Overall, we demonstrate the importance of climate and land use factors in plant functional and phylogenetic community turnover, and provide valuable complementary insights into understanding patterns of β-diversity along several ecological gradients.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

BACKGROUND: The treatment of status epilepticus (SE) is based on relatively little evidence although several guidelines have been published. A recent study reported a worse SE prognosis in a large urban setting as compared to a peripheral hospital, postulating better management in the latter. The aim of this study was to analyse SE episodes occurring in different settings and address possible explanatory variables regarding outcome, including treatment quality. METHODS: Over six months we prospectively recorded consecutive adults with SE (fit lasting five or more minutes) at the Centre Hospitalier Universitaire Vaudois (CHUV) and in six peripheral hospitals (PH) in the same region. Demographical, historical and clinical variables were collected, including SE severity estimation (STESS score) and adherence to Swiss SE treatment guidelines. Outcome at discharge was categorised as "good" (return to baseline), or "poor" (persistent neurological sequelae or death). RESULTS: Of 54 patients (CHUV: 36; PH 18), 33% had a poor outcome. Whilst age, SE severity, percentage of SE episodes lasting less than 30 minutes and total SE duration were similar, fewer patients had a good outcome at the CHUV (61% vs 83%; OR 3.57; 95% CI 0.8-22.1). Mortality was 14% at the CHUV and 5% at the PH. Most treatments were in agreement with national guidelines, although less often in PH (78% vs 97%, P = 0.04). CONCLUSION: Although not statistically significant, we observed a slightly worse SE prognosis in a large academic centre as compared to smaller hospitals. Since SE severity was similar in the two settings but adherence to national treatment guidelines was higher in the academic centre, further investigation on the prognostic role of SE treatment and outcome determinants is required.

Relevância:

90.00% 90.00%

Publicador:

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The Economics of Urban Diversity explores ethnic and religious minorities in urban economies. In this exciting work, the contributors develop an integrative approach to urban diversity and economy by employing concepts from different studies and linking historical and contemporary analyses of economic, societal, demographic, and cultural development. Contributors from a variety of disciplines-geography, economics, history, sociology, anthropology, and planning-make for a transdisciplinary analysis of past and present migration-related economic and social issues, which helps to better understand the situation of ethnic and religious minorities in metropolitan areas today.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This paper analyses the early modern transformations of South Asian literary cultures through the production of historiography in Persian, English, and Urdu. In the 18th-19th centuries, South Asian communities experienced and participated in a major restructuring of the languages of the subcontinent. Urdu and English were institutionalized as governmental languages and utilized in new literary productions as Persian was gradually marginalized from the centre of literary and governmental polities. Three interrelated colonial policies reshaped the historical consciousness of South Asia and Britain: the production of new Persian histories commissioned under British patronage, the initiation of Urdu historiography through the translation of Persian and English histories, and the construction of the British history of India written in English. This article explores the historical and social dynamics of these events and situates the origins and evolution of the colonial historiographical project. Major works discussed are the Tārīkh-i Bangālah of Salīm Allāh Munshī (fl. 1763), James Mill's (1773-1836) The History of British India first published in 1817, Mīr Sher ʿAlī Afsos' the Ārāʾish-i mahfil, as well as the production of original Urdu histories such as Muḥammad Zakāʾ-Allāh's (1832-1910) the Tārīkh-i Hindustān.