Thèses (M.A.)--Université de Sherbrooke (Canada), 2002. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thèse (M.Sc.)--Université Laval, 2002. / Bibliogr. Publié aussi en version électronique.

Thesis (Ph. D.)--Washington University, 1982. Dept. of History. / Typescript. Includes bibliographical references (leaves 543-568).

Dissertation--Fachbereich Philosophie und Geschichtswissenschaft--Universität Hamburg, 2004. / Bibliogr. p. 302-317.

Beaucoup de données infrmatiques sont structurées de manière arborescente. Dans le contexte du Web, c'est le cas en particulier des données au format XML. De par sa généricité, ce format est rapidement devenu un standard pour l'échange et la sauvegarde d'informations. A l'instar des langages de requêtes pour les bases de données relationnelles, le besoin d'avoir des langages de requêtes pour les documents XML est devenu crucial. On distingue les requêtes unaires (sélection d'un ensemble de sous-parties d'un document) des requêtes n-aires (sélection d'un ensemble de n-uplets de sous-parties d'un document). Beaucoup de formalismes logiques pour les requêtes unaires ont été étudiés, en revanche, peu d'approches logiques existent pour les requêtes n-aires. Cette thèse étudie de manière fondamentale les requêtes n-aires, en proposant et en étudiant principalement deux formalismes logiques pour requêtes n-aires: une extension du paradigme navigationnel du standard W3C XPath au cas n-aire, appelée langage de composition, et une adaptation de la logique spatiale d'arbres TQL, introduite par Cardelli et Ghelli. Les questions de pouvoir d'expressivité, de complexité d'évaluation des requêtes ainsi que leur satisfiabilité sont abordées. L'étude du problème de satisfiabilité pour la logique TQL a nécessité l'introduction de nouveaux automates d'arbres avec tests globaux, dont l'étude est réalisée de manière indépendante. / Ln computer science many data are shaped as trees. ln the context of the Web, it is the case for XML formatted data in particular. XML is a markup language that has rapidly become a standard for information storage and data exchange. As query languages for relational databases are not well-suited to XML data, the need to have query languages specific to XML documents has increased. We distinguish unary queries which select a set of subparts of a document from n-ary queries which select a set of n-tuples of subparts of a document. Many logical formalisms for unary queries have been proposed, but less work has been done on logical formalisms for n-ary queries. This thesis is a fundamental study of n-ary queries that proposes two logical formalisms for n-ary queries: an extension of the navigational paradigm of the W3C standard XPath to n-ary queries, called the composition language, and an adapation of the spatiallogie TQL introduced by Cardelli and Ghelli. The question of expressive power, the complexity of the query evaluation problem as well as the satisfiability problem are considered. ln particular, the satisfiability problem for a TQL fragment is proved to be decidable by reduction to the emptiness test of a new class of tree automata with global constraints that is studied independently.

Pomacea canaliculata es un gasterópodo dulceacuícola perteneciente a la familia Ampullariidae, cuyo rango natural de distribución se extiende desde el sur de Brasil hasta el sur bonaerense. Esta especie ha sido introducida accidental o intencionalmente en numerosos países, y es considerada uno de los 100 peores invasores a nivel mundial. El objetivo de esta tesis fue analizar los determinantes de la distribución espacial de P. canaliculata a distintas escalas espaciales. Específicamente se estudió el grado de dependencia de la respiración aérea, la velocidad de desprendimiento, el efecto de la corriente sobre la dispersión y el efecto de la temperatu-ra y el tiempo de exposición sobre la actividad. También se caracterizó cuantitativamente su microhábitat y se exploraron la distribución entre y dentro de los arroyos de la cuenca de las Lagunas Encadenadas del Oeste y sus patrones tempora-les de actividad. Los resultados obtenidos aquí mostraron que la restricción en la respiración aérea afecta negativamente la actividad y la supervivencia y que sus efectos empeoran con la temperatura y la polución del agua. La actividad se incre-menta con temperaturas entre 10 y 30C pero el tiempo de exposición carece de importancia, salvo a temperaturas superiores a 30C y en aguas polutas. La velocidad de desprendimiento fluctuó entre 0.07 y 1.64 m.s-1, indicando que P. canaliculata puede soportar, por un período corto, velocidades que se encuentran entre las máximas registradas en los arroyos de la cuenca de las Encadenadas del Oeste. Velocidades de la corriente menores a 0.3 m.s-1 no influyen sobre la tasa y dirección de dispersión por reptación. No hay una respuesta reotáctica positiva que compense los eventos de deriva aguas abajo, probablemente dificultando la coloniza-ción de tramos cercanos a las sierras. Los microhábitats más utilizados por esta especie se caracterizaron por su proximi-dad a la orilla o a sustratos emergentes aptos para ventilar el pulmón, velocidades de la corriente que no interfieren con las actividades de rutina (menores a 0.3 m.s-1) y sedimentos finos ricos en materia orgánica o abundancia de macrófitas y detritos. La efectividad de algunas medidas de control podría incrementarse reuniendo esfuerzos donde se concentran los caracoles debido a su dependencia del acceso al aire. El por-centaje de caracoles activos en la cuenca de las Encadena-das del Oeste fluctuó entre 0 y 100% durante el año. En la estación fría la mayoría de los caracoles estaban inactivos pero aparentemente no entran en un estado letárgico profundo y persistente, sino que muestran una respuesta rápida a cambios de temperatura, reactivándose tan pronto como las condiciones sean favorables. A pesar de que algunas variables ambientales influyeron sobre la distribución de P. canaliculata entre y dentro de los arroyos de la cuenca de las Encadenadas del Oeste, ninguna resultó determinante de su presencia. Todos los arroyos serían habitables para esta especie, aunque sólo en algunos las poblaciones podrían permanecer a largo plazo. Probablemente, las condiciones climáticas e hidrológicas, muy variables e impredecibles en esta región, sean determinantes de eventos de extinción-colonización y, en consecuencia, de su distribución en esta cuenca. / Pomacea canaliculata is a freshwater snail belonging to the family Ampullariidae, whose natural range of distribution extends from southern Brazil to southern Buenos Aires Province in Argentina. This species has been introduced either accidentally or intentionally to many countries and is considered to be one of the 100 worst invaders worldwide. The aim of this thesis was to analyze the determinants of the spatial distribution of P. canaliculata at different spatial scales. Specifically, the dependence on aerial respiration, the effect of water velocity on detachment and dispersal, and the effects of temperature and exposure time on activity were investigated. In addition, its microhabitat was characterized quantitatively and the distribution among and within streams in the Encadenadas del Oeste basin (Buenos Aires Province, Argentina) and the temporal patterns of activity were explored. The experimental results showed that a restriction in aerial respiration negatively affected activity and survival and that its effects worsened with increasing temperatures and water fouling. Activity increased with temperature between 10 and 30C but exposure time was irrelevant, except at temperatures above 30C and in fouled waters. The detachment velocity ranged from 0.07 to 1.64 m.s-1, indicating that P. canaliculata can resist, at least for short periods, velocities that were among the highest recorded in the streams of Encadenadas del Oeste basin. Current velocities below 0.3 m.s-1 did not influence dispersal rate and direction by crawling. A positive rheotactic response able to compensate the natural events of downstream drifting was not evident, so that the colonization of piedmont sections is unlikely. The microhabitats most frequently used by this species were characterized by their proximity to the shore or an emergent substratum suitable for lung ventilation, by water velocities not interfering with routine activities (below 0.3 m.s-1), and by fine sediments rich in organic matter or abundance of macrophytes and detritus. The effectiveness of some control measures could be increased by focusing efforts on areas where the snails are concentrated due to their dependence on access to air. The percentage of active snails in Encadenadas del Oeste basin fluctuated between 0 and 100% along the year. During the cold season most of the snails were inactive though they apparently not enter a deep and persistent lethargic state but show a rather quick response to temperature changes, being able to reactivate as soon as conditions become favorable. Despite the fact that some environmental variables influenced the distribution of P. canaliculata among and within the streams of Encadenadas del Oeste basin, none was determinant of its presence. All streams would be habitable for this species, but only in some of them populations would be able to persist long term. Probably, the climatic and hydrological conditions, which are highly variable and unpredictable in this region, are determi-nants of extinction-colonization events and, consequently, of its distribution in the streams of this basin.

No description available.

This thesis analyzes an alternative public evaluation on students' performance which has affected the educational system of the City of Buenos Aires (Argentina) since 1992. This evaluation program intends to solve some key dilemmas of the evaluation policy: issues on equity, participation, trustworthiness, comparability and authenticity of the evaluated information. The study focuses on the potential, insight and barriers of this evaluation program. The relevance of this program lies in the fact that it was designed to make a contribution to the democratization of educational administration and to resist some authoritarian effects of a surrounding regional and global context of neoliberal educational reforms. This work also aims at capturing the perspectives about the hegemonic and alternative public policies of centralized evaluation, and collaborative leadership in education held by the contemporary Argentine leaders in education. / This research makes a contribution to the fields of Policy Studies and Leadership in Education and the arena of public evaluation policies, while maintaining a pedagogic perspective of the issues under analysis. The main contribution of the study is that it shows that it is possible to try alternative ways to solve the current political necessity to evaluate large amounts of students in order to inform the educational politics and policies, and at the same time, to attach the evaluation to teachers' and student's pedagogic needs, by involving educators and administrators in central places of the evaluation design and implementation. / The political and theoretical perspective adopted is consistent with a critical socio-pedagogy. Methodologically, this research is a case study oriented by a qualitative methodology, which combines two main techniques: documentary exploration and interviews to 19 leaders of different rank within the analyzed Argentine jurisdiction. The interpretation process, in both the document review and the interviews, is led by a threefold analysis: comprehensive, ethnographic and critical.

Texte remanié de: Dissertation--Philosophische Fakultät--Bonn--Rheinische Friedrich-Wilhelms-Universität, 2003. / Textes en allemand et espagnol. Bibliogr. p. 335-352.

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-Graduação em Geografia. / Made available in DSpace on 2012-10-24T12:25:35Z (GMT). No. of bitstreams: 1 263811.pdf: 7683593 bytes, checksum: 7c2101acc366cc19318f3ffce19e1763 (MD5) / Esta tese busca apreender os fatores que contribuem na construção do risco a eventos pluviais intensos numa cidade de pequeno porte. Realiza-se estudo aplicado na Bacia do Arroio Castelhano com ênfase na cidade de Venâncio Aires, localizada na porção centro-oriental do estado do Rio Grande do Sul. Das proposições teóricas de Mendonça (2004) e Pigeon (2005) estabeleceu-se que, para compreender as inundações e seus impactos numa cidade, além de avaliar fatores como localização, distâncias, mudanças nas condições ecológicas associadas às características demográficas do ambiente construído, é preciso investigar a história de sua produção, o modelo de desenvolvimento urbano e os padrões internos de diferenciação social na cidade. A análise procurou decifrar as dinâmicas natural e social presentes na materialidade dos espaços da bacia e da cidade. A identificação dessa presença foi registrada através do uso de diversas ferramentas relacionadas às geotecnologias e apresentada em diferentes planos de informação. Além da leitura e do cruzamento de planos de informação, a tese busca avançar nas reflexões sobre as interações possíveis entre estes planos e sobre as diferenciações ocorridas no processo de transformação espacial. O recorte temporal se apresentou em duas dimensões escalares: uma mais genérica, que se estende aos primórdios da povoação ainda no século XIX; outra, de avaliação mais detalhada, conduzida a partir da década de 1970. Observaram-se em mapas, fotografias aéreas e no terreno que a dinâmica natural do Arroio Castelhano e de seus afluentes está marcada na paisagem pela forma original de seus cursos fluviais. Esta forma, porém, foi alterada pela dinâmica social; os cursos de água foram encurtados e mudaram de posição, consequentemente, a alteração na dinâmica fluvial. A partir da década de 1970 se intensificaram as intervenções na organização do espaço estudado. A drenagem das várzeas propiciou o aumento das áreas agricultáveis, no entanto, implicou na necessidade de desobstrução permanente do canal fluvial a jusante. A urbanização e a intensificação do uso da terra que a acompanharam, também alteram o processo físico de escoamento superficial. Registrou-se por mapeamento a ampliação da ocupação urbana sobre a planície de inundação. Também foi constatado um tratamento desigual quanto à regulamentação urbanística para ocupação de áreas inundáveis, na comparação com a desigualdade socioambiental constatada pela espacialização dos dados do Censo 2000 do IBGE, agregados por setor censitário. A tese resgatou ainda a interferência humana sobre os cursos de água urbanos ao longo do tempo e os caminhos naturais da água superficial que foram desaparecendo sob a cidade. Os resultados, por um lado, demonstram o potencial da "Espacialização-periodização" como apoio ao desenvolvimento de estudos integrados do problema das inundações em pequenas cidades, pois ajudam a identificar as variáveis que criam risco e, por outro, levantam questões fundamentais sobre o futuro da cidade.