845 resultados para historical comparative research


Relevância:

40.00% 40.00%

Publicador:

Resumo:

In diesem Arbeitspapier will ich zur künftigen Forschung über soziale Stratifikation in Afrika beitragen, indem ich die theoretischen Implikationen und empirischen Herausforderungen der Konzepte "Elite" und "Mittelklasse" untersuche. Diese Konzepte stammen aus teilweise miteinander konkurrierenden Theorietraditionen. Außerdem haben Sozialwissenschaftler und Historiker sie zu verschiedenen Zeiten und mit Bezug auf verschiedene Regionen unterschiedlich verwendet. So haben Afrikaforscher und -forscherinnen soziale Formationen, die in anderen Teilen der Welt als Mittelklasse kategorisiert wurden, meist als Eliten aufgefasst und tun dies zum Teil noch heute. Elite und Mittelklasse sind aber nicht nur Begriffe der sozialwissenschaftlichen Forschung, sondern zugleich Kategorien der sozialen und politischen Praxis. Die Art und Weise, wie Menschen diese Begriffe benutzen, um sich selbst oder andere zu beschreiben, hat wiederum Rückwirkungen auf sozialwissenschaftliche Diskurse und umgekehrt. Das Arbeitspapier setzt sich mit beiden Aspekten auseinander: mit der Geschichte der theoretischen Debatten über Elite und Mittelklasse und damit, was wir aus empirischen Studien über die umstrittenen Selbstverortungen sozialer Akteure lernen können und über ihre sich verändernden Auffassungen und Praktiken von Elite- oder Mittelklasse-Sein. Weil ich überzeugt bin, dass künftige Forschung zu sozialer Stratifikation in Afrika außerordentlich viel von einer historisch und regional vergleichenden Perspektive profitieren kann, analysiert dieses Arbeitspapier nicht nur Untersuchungen zu afrikanischen Eliten und Mittelklassen, sondern auch eine Fülle von Studien zur Geschichte der Mittelklassen in Europa und Nordamerika sowie zu den neuen Mittelklassen im Globalen Süden.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The BLEVE, acronym for Boiling Liquid Expanding Vapour Explosion, is one of the most dangerous accidents that can occur in pressure vessels. It can be defined as an explosion resulting from the failure of a vessel containing a pressure liquefied gas stored at a temperature significantly above its boiling point at atmospheric pressure. This phenomenon frequently appears when a vessel is engulfed by a fire: the heat causes the internal pressure to raise and the mechanical proprieties of the wall to decrease, with the consequent rupture of the tank and the instantaneous release of its whole content. After the breakage, the vapour outflows and expands and the liquid phase starts boiling due to the pressure drop. The formation and propagation of a distructive schock wave may occur, together with the ejection of fragments, the generation of a fireball if the stored fluid is flammable and immediately ignited or the atmospheric dispersion of a toxic cloud if the fluid contained inside the vessel is toxic. Despite the presence of many studies on the BLEVE mechanism, the exact causes and conditions of its occurrence are still elusive. In order to better understand this phenomenon, in the present study first of all the concept and definition of BLEVE are investigated. A historical analysis of the major events that have occurred over the past 60 years is described. A research of the principal causes of this event, including the analysis of the substances most frequently involved, is presented too. Afterwards a description of the main effects of BLEVEs is reported, focusing especially on the overpressure. Though the major aim of the present thesis is to contribute, with a comparative analysis, to the validation of the main models present in the literature for the calculation and prediction of the overpressure caused by BLEVEs. In line with this purpose, after a short overview of the available approaches, their ability to reproduce the trend of the overpressure is investigated. The overpressure calculated with the different models is compared with values deriving from events happened in the past and ad-hoc experiments, focusing the attention especially on medium and large scale phenomena. The ability of the models to consider different filling levels of the reservoir and different substances is analyzed too. The results of these calculations are extensively discussed. Finally some conclusive remarks are reported.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Comparative effectiveness research in spine surgery is still a rarity. In this study, pain alleviation and quality of life (QoL) improvement after lumbar total disc arthroplasty (TDA) and anterior lumbar interbody fusion (ALIF) were anonymously compared by surgeon and implant.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The original aim of this project was to describe and analyse the higher education acts in force in five Central and Eastern European countries at present, trying to understand the dependence of higher education on the historical traditions, national peculiarities and all-European tendencies. The description and comparison of the main aspects of higher education was supplemented by a study of the possibilities of transferring experience in the field between the five countries and possible solutions to implementing foreign structural and functional models. Questions covered included the role of the state in the management of higher education, the structures of the higher education systems and the organisation of institutions, academic autonomy and the classifications of academic teaching staff, the main trends in the recent development of research, academic degrees, the accreditation of higher education institutions, and the financing of higher education. Popov found that it was almost impossible to understand the dependence of higher education on historical traditions and national peculiarities purely through a study of the relevant legislation. Education traditions in these countries have twice been broken, once with the start of communism (1917 in Russia and 1944-45 in Bulgaria, Hungary, Poland and Romania) and for a second time at the beginning of the 1990s. The most recent higher education acts in all five countries studied have abandoned many of their historical and national traditions, following instead all-European trends as determined by Western Europe, and the project included a study of the dependence on these trends. There were also difficulties in comparing some aspects of higher education as it depended on how far a given aspect has different or common features in the different countries and to what extent the application is comparable. While many possible areas for transferring experience between the five countries were identified, Popov concentrated on those where he felt that there was a real practical possibility of application in view of national academic differences. He concluded by defining some of the challenges facing each country in the field of higher education and by making some predictions as to the developments in the different countries.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Cerebrovascular diseases are significant causes of death and disability in humans. Improvements in diagnostic and therapeutic approaches strongly rely on adequate gyrencephalic, large animal models being demanded for translational research. Ovine stroke models may represent a promising approach but are currently limited by insufficient knowledge regarding the venous system of the cerebral angioarchitecture. The present study was intended to provide a comprehensive anatomical analysis of the intracranial venous system in sheep as a reliable basis for the interpretation of experimental results in such ovine models. We used corrosion casts as well as contrast-enhanced magnetic resonance venography to scrutinize blood drainage from the brain. This combined approach yielded detailed and, to some extent, novel findings. In particular, we provide evidence for chordae Willisii and lateral venous lacunae, and report on connections between the dorsal and ventral sinuses in this species. For the first time, we also describe venous confluences in the deep cerebral venous system and an 'anterior condylar confluent' as seen in humans. This report provides a detailed reference for the interpretation of venous diagnostic imaging findings in sheep, including an assessment of structure detectability by in vivo (imaging) versus ex vivo (corrosion cast) visualization methods. Moreover, it features a comprehensive interspecies-comparison of the venous cerebral angioarchitecture in man, rodents, canines and sheep as a relevant large animal model species, and describes possible implications for translational cerebrovascular research.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

​This book presents an up-to-date portrait of the characteristics of sport clubs in various European countries and their role in society and the national sport system. Furthermore, it offers a cross-national comparative perspective of sport clubs in twenty European countries. Containing both empirical data and information on the political and historical backgrounds of sport clubs, the book is organized in three parts. First, the authors provide an overview of the theoretical approach of the book and a description of the framework used for the country chapters. Second, the country chapters, written by experts within the field, provide a systematic overview of the available information on sport clubs in each country. These chapters are structured to answer the following questions: (1) What is the position of sport clubs within the national sport structure? (2) Which role do they fulfil in policy and society? (3) What are their basic characteristics and what factors influence the development of sport clubs? The book is concluded with a systematic comparison of the participating countries with the purpose of forging a clear link between the functioning of policy systems, observed problems, and possible solutions, and with a future research agenda on sport clubs. In an era of increased collaboration between European states, sport provides a natural vehicle through which to compare changes in culture, economics, and policy across nations. Sport Clubs in Europe will appeal to scholars of nonprofit management, sports management and sports sociology as well as administrators and policy makers in the international sports community.