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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Some new localized quality of service models and algorithms for communication networks : the development and evaluation of new localized quality of service routing algorithms and path selection methods for both flat and hierarchical communication networks

Mustafa, Elmabrook B. M. January 2009 (has links)
The Quality of Service (QoS) routing approach is gaining an increasing interest in the Internet community due to the new emerging Internet applications such as real-time multimedia applications. These applications require better levels of quality of services than those supported by best effort networks. Therefore providing such services is crucial to many real time and multimedia applications which have strict quality of service requirements regarding bandwidth and timeliness of delivery. QoS routing is a major component in any QoS architecture and thus has been studied extensively in the literature. Scalability is considered one of the major issues in designing efficient QoS routing algorithms due to the high cost of QoS routing both in terms of computational effort and communication overhead. Localized quality of service routing is a promising approach to overcome the scalability problem of the conventional quality of service routing approach. The localized quality of service approach eliminates the communication overhead because it does not need the global network state information. The main aim of this thesis is to contribute towards the localised routing area by proposing and developing some new models and algorithms. Toward this goal we make the following major contributions. First, a scalable and efficient QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated. Second, we have developed a path selection technique that can be used with existing localized QoS routing algorithms to enhance their scalability and performance. Third, a scalable and efficient hierarchical QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated.
192

Stage-dependent prognostic impact of molecular signatures in clear cell renal cell carcinoma

Weber, Thomas, Meinhardt, Matthias, Zastrow, Stefan, Wienke, Andreas, Erdmann, Kati, Hofmann, Jörg, Füssel, Susanne, Wirth, Manfred P. 09 July 2014 (has links) (PDF)
Purpose: To enhance prognostic information of protein biomarkers for clear cell renal cell carcinomas (ccRCCs), we analyzed them within prognostic groups of ccRCC harboring different tumor characteristics of this clinically and molecularly heterogeneous tumor entity. Methods: Tissue microarrays from 145 patients with primary ccRCC were immunohistochemically analyzed for VHL (von Hippel-Lindau tumor suppressor), Ki67 (marker of proliferation 1), p53 (tumor protein p53), p21 (cyclin-dependent kinase inhibitor 1A), survivin (baculoviral IAP repeat containing 5), and UEA-1 (ulex europaeus agglutinin I) to assess microvessel-density. Results: When analyzing all patients, nuclear staining of Ki67 (hazard ratio [HR] 1.08, 95% confidence interval [CI] 1.04–1.12) and nuclear survivin (nS; HR 1.04, 95% CI 1.01–1.08) were significantly associated with disease-specific survival (DSS). In the cohort of patients with advanced localized or metastasized ccRCC, high staining of Ki67, p53 and nS predicted shorter DSS (Ki67: HR 1.07, 95% CI 1.02–1.11; p53: HR 1.05, 95% CI 1.01–1.09; nS: HR 1.08, 95% CI 1.02–1.14). In organ-confined ccRCC, patients with high p21-staining had a longer DSS (HR 0.96, 95% CI 0.92–0.99). In a multivariate model with stepwise backward elimination, tumor size and p21-staining showed a significant association with DSS in patients with "organ-confined" ccRCCs. The p21-staining increased the concordance index of tumor size from 0.75 to 0.78. In patients with "organ-confined" ccRCC, no disease-related deaths occurred in the group with p21-expression below the threshold of 32.5% p21-positive cells (log rank test: P=0.002). Conclusion: The prognostic information of the studied protein biomarkers depended on anatomic tumor stages, which displayed different acquired biological tumor characteristics. Analysis of prognostic factors within different clinical ccRCC groups could help to enhance their prognostic power. The p21-staining was an independent prognostic factor and increased prognostic accuracy in a predictive model in "organ-confined" ccRCC.
193

Les bâtisseurs de Mésoamérique : le plan Puebla Panama, une politique de développement transnationale au défi de ses opposants : Mexique - Nicaragua (2000-2010)

Collombon, Maya 11 December 2012 (has links)
En mai 2001, un mouvement social transnational connecte des acteurs indigènes du sud mexicain et d'Amérique centrale qui s'opposent à une politique publique de développement le Plan Puebla Panama (PPP). L'étude de la promotion et de la contestataion du PPP au Mexique et au Nicaragua vise à interroger le concept de transnationalisation appliqué à l'action publique comme à la protestation collective. La thèse montre que les acteurs indigènes mis sur le devant de la scène par les acteurs contestataires, puis par les acteurs publics en réponse aux mobilisations, ne sont pas les acteurs centraux de la transnationalisation. La sociogenèse de la contestation au PPP permet de saisir les configurations localisées où d'anciennes allégeances continuent de primer sur l'allongement des réseaux à l'international. Ce sont des enjeux agraires, des liens notabilaires et religieux, ou encore le legs zapatiste, qui forgent la matrice du mouvement. Le Chiapas constitue à ce titre un condensé d'une topographie rurale et indigène des luttes dont les connexions à l'international ne sont finalement que secondaires pour une majorité d'acteurs. De même, la transnationalisation de la politique publique ne dépend pas simplement du poids des institutions financières internationales fortement impliquées dans le développement régional mais surtout de reconfigurations élitaires mexicaines qui s'assurent domination sur leurs partenaires centraméricains et maintien de leurs positions politiques, au lendemain de l'alternance de 2000. Ces configurations réticulaires différenciées entre promoteurs et opposants aux politiques de développement n'opèrent pas de connexions explicites. / In May 2001, a transnational social movement connects indigenous actors from southern Mexico and Central America in conflict against a development public policy, the Plan Puebla Panama (PPP). The study of both promotion and contestation to the PPP in Mexico and Nicaragua aims to examine the concept of transnational applied to public policy as to collective protest. The thesis shows that indigenous actors put on the front stage by contentious actors, and by public sector in response to the protests, are not the central actors of transnationalization. The sociogenesis of contention captures localized configurations where old loyalties continue to outweigh the international networks. Agrarian, religious issues, or the Zapatista legacy form the matrix that shape the movement. Chiapas thus constitutes a condensed topography of rural and indigenous struggles where international connections are secondary to a majority of actors. Similarly, the transnationalization of public policy is not simply due to the regional involvement of international financial institutions but also to Mexican elites reconfiguration that ensure their domination on Central American partners and their political positions after the 2000 election's. These reticular and differentiated configurations between promotors and opponents of the development public policy do not operate explicit connections, but they share a set of discursive signifiers that, despite the differentiation of meanings, gradually builds a common reference space: Mesoamerica.
194

Propositions de construction territorialisée de business inclusifs laitiers à l’aide de la gestion de la qualité du lait. Une approche multi-scalaire à partir d’un cas d’étude égyptien. / Proposals to construct territorialized dairy inclusive business using milk quality management. A multi-scalar approach based on an egyptian case study.

Daburon, Annabelle 20 October 2017 (has links)
Des groupes agro-alimentaires se tournent vers les filières laitières artisanales pour assurer leur approvisionnement. De cette tendance émergent des business inclusifs (BI). Malgré l’engouement qu’ils suscitent auprès des acteurs du développement agricole, ils restent délicats à mettre en œuvre. Mais dans quelle mesure la coordination de ces BI relève de démarches inclusives ? Quelles sont les barrières à leur adoption et les conséquences sur leur durabilité? Un cas d’étude est analysé pour explorer ces questions, le projet DEEP (Danone Egypt Ecosystem Project). Initié en 2011 par le fond Danone Ecosystème, en partenariat avec Danone Egypte et l’ONG CARE, il promeut un business model réplicable de centres de collecte de lait (CCL) de vache auprès des petits producteurs, dans des coopératives agricoles publiques. Ce BI tente de sécuriser l’approvisionnement de la laiterie Danone et de contribuer au développement socio-économique des villages hôtes. Dans la thèse, un cadre analytique transdisciplinaire est élaboré ; la gestion de la qualité permet d’associer une approche chaîne de valeur (CV) et une approche système agroalimentaire localisée (SYAL). Des données socio-économiques sont collectées entre 2014 et 2016, individuellement et collectivement, auprès des acteurs directement ou indirectement impliqués dans ce BI. Si l’extrême diversité des activités, des objectifs et des ressources des acteurs qui « gravitent » autour du produit lait et du BI est mise en évidence, améliorer la qualité du lait semble être un but partagé. La distance et les asymétries de pouvoirs entre les partenaires limitent la promotion de stratégies répondant à la complexité et à la variabilité du contexte égyptien. Au dépend de la collaboration, des logiques d’intégration et de coercition s’installent dans la chaîne de valeur inclusive (CVI), pilotée en aval par l’entreprise avec l’ONG. Si la qualité sanitaire du lait fourni par les CCL s’améliore, la qualité compositionnelle se dégrade. L’entreprise rejette fréquemment les livraisons des CCL sans mécanisme de compensation et la CVI construite est fragile. Le BI est alors abordé en examinant l’évolution du SYAL laitier d’Halabeya. Après 6 années d’interventions, le CCL y est un acteur central des réseaux de collecte de lait. Il influence la qualité sanitaire via les institutions qui l’organisent (analyses de la qualité du lait, fixation des prix ou connaissances sur l’hygiène). La promotion d’un pôle concentrant l’offre de services agricoles pour les fournisseurs du CCL échoue. Une multitude d’entreprises familiales de proximité, organisées en réseaux spécialisés mais non coordonnés, l’assurent. Il semble que la généricité de la construction de CVI durable doive passer par la systématisation de processus de partenariat. En Egypte, une cellule de coordination villageoise pourrait être créée. Réunissant divers acteurs clef du SYAL, elle pourrait activer les ressources territoriales aux profits des habitants et du BI, en l’associant dans un comité de pilotage avec des représentants de l’état, de l’entreprise investisseuse et de l’ONG. Ce comité de pilotage s’attacherait à bâtir un business model adapté au territoire et aux besoins des partenaires, puis à piloter la CVI construite. L’utilisation de l’amélioration de la qualité du lait pourrait catalyser l’action collective. Par la sensibilisation des partenaires, l’implication de l’état, le recours à des facilitateurs et la possibilité pour les territoires de communiquer sur ces interventions, limiter les asymétries de pouvoir devient envisageable. Original par son utilisation de la gestion de la qualité comme un facteur d’inclusion, le cadre d’analyse permet d’aborder des échelles variées et plus ou moins distantes et pose les bases d’un cadre d’action favorisant la territorialisation des partenariats de BI. Ainsi, bâtir des CVI durables, c’est contribuer à l’émergence de territoires autonomes, voie prometteuse dans les pays du Sud comme du Nord. / Agri-food companies turn to traditional dairy sector to ensure their supply of milk. Inclusivebusinesses (IB) have emerged from this trend. Despite the enthusiasm raised among the playersof agricultural development, such businesses remain difficult to implement. But to what extentdoes IB coordination fall into an inclusive approach? What are the obstacles to the adoption ofsuch processes and the consequences for their sustainability? A case study is analyzed to explorethese issues, the DEEP project (Danone Egypt Ecosystem Project). Initiated in 2011 by the DanoneEcosystem fund, in partnership with Danone Egypt and the NGO CARE, it promotes a replicablebusiness model of cow milk collection centers (MCC) in public agricultural cooperatives targetingsmall producers. This IB’s aims are to secure the sourcing of Danone’s dairy and to contribute tothe socio-economic development of associated villages. In this thesis, a transdisciplinary analyticalframework is developed; the quality management has been used to link a value chain (VC)approach and a localized agri-food system (SYAL) approach. Socio-economic data were collectedbetween 2014 and 2016, individually and collectively, directly or indirectly from the playersinvolved in this IB. While the extreme diversity of the activities, objectives and resources of actorsevolving around the milk product and the IB is highlighted, improving the quality of the milk seemsto be a common goal. Both the distance and the differences in power between partners limit thepromotion of strategies responding to the complexity and variability of the Egyptian situation.Logics of integration and coercion take place within the inclusive value chain (IVC) drivendownstream by the company with the NGO, to the detriment of collaboration. If the sanitaryquality of the milk provided by the MCC is improving, its compositional quality deteriorates. Thecompany frequently rejects deliveries from MCCs, without a mechanism for compensation, whichlead to the precarity of such built IVC. The IB is therefore discussed by examining the evolution ofthe dairy SYAL from Halabeya. After 6 years of interventions, the MCC became a central playerwithin the milk collection networks. It influences milk sanitary quality through the institutions thatorganize it (milk quality analyses, pricing or hygiene knowledge). The promotion of a hubdelivering agricultural services to MCC suppliers fails. Numerous local family businesses, organizedin specialized networks lacking of coordination, ensure it. It seems that the genericity of theconstruction of sustainable IVC must go through the systematization of partnership processes. InEgypt, a coordination cell in the village could be established. Bringing together various key actorsof the SYAL, this cell could activate the territorial resources in favour of the inhabitants and the IB,by associating it in a steering committee with representatives of the state, the investing companyand the NGO. This steering committee would work on building a business model adapted to theterritory and to the needs of the partners, before piloting the IVC built. Using milk qualityimprovement could catalyze the collective action. By raising awareness of partners, involving thestate, using facilitators and giving the capacity for the territories to communicate on theseinterventions, therefore limiting the differences in power becomes possible. Through its use ofquality management as an inclusion factor, the analytical framework allows approaching distantscales, and lays the foundations for an action framework fostering the territorialization of IBpartnerships. Therefore building sustainable IVCs go hand in hand with the emergence ofautonomous territories, a promising path towards the Southern countries as well as the Northern.
195

Envolvimento de CD200 na infectividade de isolados de Leishmania (Leishmania) amazonensis associados à leishmaniose cutânea localizada e leishmaniose cutânea difusa. / Involvement of CD200 in the infectivity of Leishmania (Leishmania) amazonenses isolates associated with localized cutaneous leishmaniasis and diffuse cutaneous leishmaniasis.

Samper, Lina Borda 19 November 2015 (has links)
Leishmania (Leishmania) amazonenses está associada à leishmaniose cutânea difusa (DCL) e localizada (LCL). LCL se apresenta como uma lesão única com cura espontânea e DCL apresenta nódulos não ulcerativos que se espalham pela pele. Até o momento não se conhecem os fatores que influenciam na apresentação destas manifestações. A virulência do parasito tem sido associada com a capacidade de sobreviver no macrófago ativado. CD200 é uma glicoproteína reguladora que ativa o CD200R, gerando a inibição da resposta próinflamatória do macrófago. Recentemente foi demonstrado que no processo de infecção por L. (L.) amazonenses, há indução de CD200 no começo da infecção, aumentando a supervivência do parasito. O objetivo principal foi determinar a associação da expressão de CD200 na infecção de macrófagos com isolados de L. (L.) amazonenses associados à LCL ou DCL. Observamos que o aumento da expressão da proteína nos tempos avançados de infecção está relacionado com um aumento na infectividade dos isolados e um maior número de parasitos por célula infectada. / Leishmania (Leishmania) amazonenses is one of the etiologic agents of two forms of leishmaniasis: diffuse (DCL) and localized (LCL) cutaneous leishmaniasis. LCL is presents a unique ulcerated lesion and DCL multiple non-ulcerative nodules. Until now, it is not well known which factors influence the development of LCL or DCL. The parasites virulence has been associated with the ability to survive inside the activated macrophage. CD200 is a glycoprotein that interacts with CD200R inhibiting the proinflammatory response of the cell. Recently it was revealed during the infection process in macrophages L. (L.) amazonenses enhances CD200 expression in the early stages of infection resulting in the intracellular survival of amastigotes. The aim of this study was to determine the association between the induction of CD200 during infection with L. (L.) amazonenses isolates associated with LCL or DCL. An increase in CD200 expression was noteworthy in the late stages of infection, which was also related to a higher infectivity rate of L. (L.) amazonenses isolates.
196

Optische elektronische Eigenschaften leitender Polymere

Dhaibi, Youssef 21 December 2000 (has links)
In dieser Arbeit wird unter Verwendung des Su-Schrieffer-Heeger-Modells die Dynamik des einfachsten konjugierten Polymers Trans-Polyacetylen in Mean-Field-Approximation untersucht. Dazu wird erstmalig von einer dimerisierten Peierls-Kette im Grundzustand ausgegangen, die durch einen gaußförmigen Laserpuls angeregt wird. Sowohl bei subresonanter Anregung als auch bei Anregungen hoch im Band bilden sich geladene Solitonpaare mit gemischten Gap-Zuständen, für die ein Phasendiagramm in Abhängigkeit vom Mischungsparameter abgeleitet wird. Diese Zustände werden im Rahmen des Takayama-Lin-Liu-Maki-Modells erfolgreich beschrieben.Um einen Ladungstransfer zwischen benachbarten Ketten zu untersuchen, werden die Rechnungen auf zwei gekoppelte Peierls-Ketten ausgedehnt. In Abhängigkeit von der Kopplungsstärke und der Kettenlänge ergibt sich eine Reihe von Grundzustandskonfigurationen. Bei einer Anregung mit einem transversalen Laserpuls findet ein Ladungstransfer zwischen den beiden Ketten mit einer Frequenz statt, die der doppelten Kopplungsstärke entspricht. Zur Einbeziehung der Coulomb-Wechselwirkung der Pi-Elektronen wird das Pariser-Parr-Pople-Modell verwendet. Durch Anpassung an möglichst viele experimentelle Größen wird ein geeigneter Satz von Modell-Parametern berechnet. Die von der Kette aufgenommene Energie und deren Dynamik werden diskutiert. / In the framework of the Su-Schrieffer-Heeger model the dynamics of the most simple conjugated polymer trans-polyacetylene is investigated in mean field approximation. Starting with a dimerized Peierls chain in the ground state, a femtosecond laser pulse with a gaussian enveloppe is applied. For subresonant and high band excitation charged soliton pairs are created and are related to mixed gap states. For different values of the mixing strength a phase diagram can be drawn. The creation of the mixed gap states can be also explained within the continuum approximation with the Takayama-Lin-Liu-Maki model. In order to investigate charge transfer between two Peierls chains, the calculations are extended to a system with two coupled chains. Different ground state configurations occur, depending on the coupling stength and the chain length. In the case of an excitation perpendicular to the chain axis, a strong charge transfer between the chains is observed. Furthermore the Pariser-Parr-Pople model is used to take into account the Coulomb interaction between the Pi-electrons. A model parameter set can be determined by fitting the experimental values. The energy absorbed by the chain and the soliton dynamics are discussed in this model.
197

Amortissement virtuel pour la conception vibroacoustique des lanceurs futurs / Thin films and heterostructures of LiNbO3 for acoustical / optical integrated devices

Krifa, Mohamed 19 May 2017 (has links)
Dans le dimensionnement des lanceurs spatiaux, la maîtrise de l'amortissement est une problématique majeure. Faute d'essais sur structure réelle très couteux avant la phase finale de qualification, la modélisation de l'amortissement peut conduire à un sur-dimensionnement de la structure alors que le but recherché est de diminuer le coût du lancement d'une fusée tout en garantissant le confort vibratoire de la charge utile.Nos contributions sont les suivantes. Premièrement, une méthode de prédiction par le calcul des niveaux vibratoires dans les structures de lanceurs en utilisant une stratégie d'essais virtuels qui permet de prédire les amortissements en basses fréquences, est proposée. Cette méthode est basée sur l'utilisation de méta-modèles construits à partir de plans d'expériences numériques à l'aide de modèles détaillés des liaisons. Ces méta-modèles peuvent être obtenus grâce à des calculs spécifiques utilisant une résolution 3D par éléments finis avec prise en compte du contact. En utilisant ces méta-modèles, l'amortissement modal dans un cycle de vibration peut être calculé comme étant le ratio entre l'énergie dissipée et l'énergie de déformation. L'approche utilisée donne une approximation précise et peu coûteuse de la solution. Le calcul non-linéaire global qui est inaccessible pour les structures complexes est rendu accessible en utilisant l'approche virtuelle basées sur les abaques.Deuxièmement, une validation des essais virtuels sur la structure du lanceur Ariane 5 a été élaborée en tenant compte des liaisons boulonnées entre les étages afin d'illustrer l'approche proposée. Lorsque la matrice d'amortissement généralisé n'est pas diagonale (car des dissipations localisées), ces méthodes modales ne permettent pas de calculer ou d'estimer les termes d'amortissement généralisé extra-diagonaux. La problématique posée est alors la quantification de l'erreur commise lorsque l'on néglige les termes extra-diagonaux dans le calcul des niveaux vibratoires ; avec un bon ratio précision / coût de calcul.Troisièmement, la validité de l'hypothèse de diagonalité de la matrice d'amortissement généralisée a été examinée et une méthode très peu coûteuse de quantification a posteriori de l'erreur d'estimation de l'amortissement modal par la méthodes des perturbations a été proposée.Finalement, la dernière contribution de cette thèse est la proposition d'un outil d'aide à la décision qui permet de quantifier l'impact des méconnaissances sur l'amortissement dans les liaisons sur le comportement global des lanceurs via l'utilisation de la méthode info-gap. / In the dimensioning of space launchers, controlling depreciation is a major problem. In the absence of very expensive real structural tests before the final qualification phase, damping modeling can lead to over-sizing of the structure while the aim is to reduce the cost of launching a rocket while guaranteeing the vibratory comfort of the payload.[...]
198

Sistema agroalimentario del maíz blanco en Ciudad Arce, municipio de El Salvador

Ayala Durán, Carlos Ernesto January 2018 (has links)
Aiming to understand interrelations surrounding maize culture in El Salvador, the present work addresses white maize agri food system in Ciudad Arce. To do so, this thesis has used localized agrifood systems as theoretical framework. Thereof, historical, technical, institutional and food aspects compounding the localized agrifood system have been studied. Seemingly, this thesis has carried out a dense fieldwork, spreading through direct interviews with 82 maize producers in Ciudad Arce. Additionally, a number of actors, both public and private, have been interviewed, including: Rural extentionists, researchers, inputs providers, food retailers among others. This thesis begins with a theoretical analysis of territory. Thereof, the territorial perspective developed in the present work has been enriched from Geography, since it was originally within this science where territory emerged and where it has been more rigorously studied. This theoretical discussion of territory has paved the way to analyze its appropriation by productive agglomeration approaches such as: Industrial districts, clusters, local productive arrangements, local productive systems, rural agoindustry and localized agrifood systems. Given our above mentioned analysis on territory, it is highlighted that all these theoretical perspectives conceive the territorial concept with a positive bias, leaving aside the historical power relations accompanying territory from a geographical perspective. Subsequently, and given a lack of detailed and trustworthy statistics and databases in El Salvador, this thesis profoundly describes maize producers in Ciudad Arce. To do so, the framework of localized agrifood systems is implemented, describing producers in terms of their historical, technical, institutional and food peculiarities. This characterization paved the way to conceptualize and analyze how the maize localized agrifood system is structured in Ciudad Arce. Besides this conceptualization and analysis, the present work has exposed power relations at different levels, some of which are not conscripted to the usual economic and political arena. Hence, it has been possible to identify and discuss at least two power relations in each of the four dimensions that form the above mentioned localized agrifood system (LAFS). This qualitative analysis set the way to move onto a quantitative discussion. Within it, a system of four regressions (one for each LAFS dimension) was performed to predict and quantify maize productivity variations. Likewise a system of four regressions was used to predict and quantify variations in total production of this cereal. In general terms, regressions having productivity as dependent variable showed more modest results. Afterwards, another multiple regression was used to predict the variations of maize production including variables from all four different dimensions form the LAFS. At this point selected variables were combined into only one multiple regression in order to integrate the previous isolated dimensions. This regression was able to predict 83% of variations in maize production (R²: 0.830/ R² Adjusted: 0.782). These results identified many variables that influence total production, among the three most relevant in decreasing importance are: Area planted, commercial motivation to produce maize and the possession of an irrigation system. At the end, this thesis elaborates final considerations at both theoretical and practical level. Likewise, it also points to new research lines. / Con el objetivo de entender las inter-relaciones y el entramado alrededor de la cultura del maíz en El Salvador, el presente trabajo aborda el sistema agroalimentario del maíz blanco en Ciudad Arce. Para tal fin, el presente trabajo se ha valido de los sistemas agroalimentarios localizados como marco teórico. Con ello, se ha estudiado aspectos históricos, técnicos, institucionales y alimenticios del mencionado sistema. De tal suerte, esta tesis se ha valido de un nutrido trabajo de campo, que abarcó entrevistas directas con 82 agricultores que producen maíz, además de un número elevado de actores públicos y privados relacionados al tema, entre ellos: extensionistas rurales, investigadores, proveedores de insumos, comerciantes agrícolas. Esta tesis parte de una revisión teórica que aborda el territorio como concepto central. En tal sentido, la visión del territorio ha sido nutrida con aportes desde la geografía, ya que en esa ciencia se ha tratado históricamente este concepto de forma más rigurosa. La discusión sobre el territorio ha permitido evaluar su aplicación a la hora de ser retomada por enfoques teóricos que estudian aglomeraciones productivas, como los distritos industriales, los clúster, arreglos productivos locales, sistemas productivos locales, agro industrias rurales y los propios sistemas agroalimentarios localizados. A la luz de nuestro análisis sobre el territorio, se ha podido evidenciar que todos estos enfoques teóricos se apropian del territorio con un sesgo positivo, dejando de lado las históricas relaciones de poder circundantes a este concepto geográfico. Posteriormente, ante una ausencia de datos pormenorizados y estadísticas confiables, se caracteriza de forma profunda a los agricultores que producen maíz en Ciudad Arce De tal suerte, y al amparo del marco teórico de los sistemas agroalimentarios localizados, se destacan características históricas, técnicas, institucionales y alimenticias de los agricultores. Esto da paso a poder conceptualizar y analizar, cómo está formado el sistema agroalimentario del maíz en Ciudad Arce. Paralela a esta conceptualización y análisis, se ha explicitado cuáles son las relaciones de poder en diversa escala que han sido identificadas. De tal suerte, ha sido posible problematizar al menos dos relaciones de poder en cada una de las diferentes dimensiones del SIAL. Todo este análisis de cuño más cualitativo, da paso a un análisis cuantitativo. Al respecto, se realiza en primer lugar un sistema de cuatro regresiones (una por cada dimensión del SIAL) para predecir y cuantificar las variaciones en la productividad del maíz. Similarmente se emplea otro sistema de cuatro regresiones teniendo como variable dependiente producción de maíz. En términos generales, las regresiones que tienen a la productividad del maíz como variable dependiente, muestran resultados mucho más modestos. En un segundo momento, se opta por realizar una regresión múltiple que integre variables de las diferentes dimensiones abordadas, mismas que habían sido estudiadas hasta ahora de forma aislada. Esta regresión integrada consigue dar cuenta del 83% (R²: 0.830/ R² Ajustado: 0.782) de las variaciones en la producción. Se pudo identificar numerosas variables que influían en la producción total de maíz, siendo las tres más importantes en orden decreciente: superficie plantada, motivación para la producción de maíz es el comercio y la posesión de un sistema de riego. Finalmente, la tesis concluye con consideraciones a nivel teórico y práctico, no sin antes apuntar sobre nuevas líneas de investigación a ser exploradas.
199

Envolvimento de CD200 na infectividade de isolados de Leishmania (Leishmania) amazonensis associados à leishmaniose cutânea localizada e leishmaniose cutânea difusa. / Involvement of CD200 in the infectivity of Leishmania (Leishmania) amazonenses isolates associated with localized cutaneous leishmaniasis and diffuse cutaneous leishmaniasis.

Lina Borda Samper 19 November 2015 (has links)
Leishmania (Leishmania) amazonenses está associada à leishmaniose cutânea difusa (DCL) e localizada (LCL). LCL se apresenta como uma lesão única com cura espontânea e DCL apresenta nódulos não ulcerativos que se espalham pela pele. Até o momento não se conhecem os fatores que influenciam na apresentação destas manifestações. A virulência do parasito tem sido associada com a capacidade de sobreviver no macrófago ativado. CD200 é uma glicoproteína reguladora que ativa o CD200R, gerando a inibição da resposta próinflamatória do macrófago. Recentemente foi demonstrado que no processo de infecção por L. (L.) amazonenses, há indução de CD200 no começo da infecção, aumentando a supervivência do parasito. O objetivo principal foi determinar a associação da expressão de CD200 na infecção de macrófagos com isolados de L. (L.) amazonenses associados à LCL ou DCL. Observamos que o aumento da expressão da proteína nos tempos avançados de infecção está relacionado com um aumento na infectividade dos isolados e um maior número de parasitos por célula infectada. / Leishmania (Leishmania) amazonenses is one of the etiologic agents of two forms of leishmaniasis: diffuse (DCL) and localized (LCL) cutaneous leishmaniasis. LCL is presents a unique ulcerated lesion and DCL multiple non-ulcerative nodules. Until now, it is not well known which factors influence the development of LCL or DCL. The parasites virulence has been associated with the ability to survive inside the activated macrophage. CD200 is a glycoprotein that interacts with CD200R inhibiting the proinflammatory response of the cell. Recently it was revealed during the infection process in macrophages L. (L.) amazonenses enhances CD200 expression in the early stages of infection resulting in the intracellular survival of amastigotes. The aim of this study was to determine the association between the induction of CD200 during infection with L. (L.) amazonenses isolates associated with LCL or DCL. An increase in CD200 expression was noteworthy in the late stages of infection, which was also related to a higher infectivity rate of L. (L.) amazonenses isolates.
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Sistema agroalimentar da avicultura fundada em princípios da Agricultura Natural: multifuncionalidade, desenvolvimento territorial e sustentabilidade / Agrifood System of chicken meat and egg production based on principles of Nature Farming method: multifunctionality, local development and sustainability

Demattê Filho, Luiz Carlos 14 August 2014 (has links)
O presente trabalho de pesquisa se refere às atividades e às relações desenvolvidas em torno da agroindústria brasileira Korin Agropecuária Ltda. Essa empresa possui uma origem peculiar uma vez que foi fundada com o propósito de colocar em prática os princípios, conceitos e métodos originados da Agricultura Natural, sistema agrícola preconizado por Mokiti Okada (Japão, 1882-1955). Okada enfatizou a necessidade de um perfeito equilíbrio entre as atividades humanas e as forças da natureza, para se alcançar bons resultados na produção, privilegiando a segurança dos alimentos, a interação e o respeito à natureza e a saúde e o bem estar socioeconômico dos agentes participantes deste sistema. Segundo Okada, a Agricultura Natural é um dos pilares de sustentação de uma civilização e sociedade ideais, onde a saúde, a prosperidade e a paz são predominantes. Assim, enquanto método produtivo enquadra-se perfeitamente na ideia de uma agricultura sustentável, pelo não uso de adubos químicos solúveis, agrotóxicos, antibióticos, melhoradores de desempenho e outros insumos industriais, veiculando uma abordagem socioambiental da atividade agrícola, com enfoque na qualidade diferenciada dos alimentos. Especificamente sobre a produção avícola de corte e postura convencional discutimos os problemas decorrentes do uso excessivo de antibióticos e promotores de crescimento, apresentando a evolução técnico-produtiva deste sistema de integração vertical alternativo no qual estas substâncias não são utilizadas e o bem estar animal é considerado. Prioritariamente abordamos, neste trabalho, a sustentabilidade sob o ponto de vista da multifuncionalidade da agricultura, tratando também do desenvolvimento da empresa sob a ótica dos Sistemas Agroalimentares Localizados - SIAL. Considerando essas abordagens, realizamos pesquisa qualitativa junto a 28 produtores predominantemente familiares integrados à empresa, aplicando questionário semiestruturado para explorar e analisar suas atitudes, percepções e experiências em relação aos conceitos e métodos da empresa, ao meio ambiente, segurança alimentar e suas condições socioeconômicas. No que diz respeito à sede da empresa, apresentamos um estudo, que contou com nossa colaboração, sobre a sustentabilidade de seu sistema de produção através de método que utiliza indicadores socioambientais, desenvolvido pela Embrapa Meio Ambiente. Trata-se do APOIA - Novo Rural, voltado para análise de unidades produtivas rurais. A análise integrada de sustentabilidade avalia a gestão ambiental do estabelecimento rural, tendo como base o contexto local e as práticas de manejo adotadas. A agroindústria em questão obteve um excelente índice integrado de sustentabilidade (0,87), justificado pelo seu histórico de mais de 20 anos de práticas relacionadas à Agricultura Natural. Peculiarmente, este complexo em torno da Agricultura Natural está inserido na confluência das divisas de duas unidades de conservação do estado de São Paulo, as Áreas de Proteção Ambiental - APA Corumbataí e a APA Piracicaba, o que promove sinergias com vistas a alcançar modelos ambientalmente adequados de produção agroalimentar. Os dados obtidos neste estudo junto aos avicultores integrados nos permitiram verificar que a prática da Agricultura Natural tem contribuído sinergicamente para que as dimensões da multifuncionalidade da agricultura sejam reconhecidas no território em questão, dinamizando e consolidando um sistema agroalimentar localizado sob uma perspectiva de sustentabilidade na produção agropecuária. / This research study refers to the activities and relationships developed around a Brazilian agrifood company named Korin Agropecuária Ltda. With a peculiar origin, this company was founded with the purpose of putting into practice the principles, concepts and methods originated from the Nature Farming system. NF is an agricultural approach created and advocated by Mokiti Okada (Japan, 1882-1955). Okada emphasized the necessity of a perfect balance between human activities and the nature forces in order to achieve good results in the production, favouring food safety, nature interaction and respect, health, and the social-economic well-being of all players of this system. According to Okada, Nature Farming is one of the pillars of true civilization and an ideal society where health, prosperity and peace are predominant. Thus, while a productive method, perfectly fits in the idea of sustainable agriculture since its methodological aspects as the non-use of chemical fertilizers, pesticides, antibiotics, growth promoters and other synthetic inputs, leading to a social-environmental approach to agriculture, with a focus on differentiated quality food. Regarding chicken meat and eggs regular production, we discuss the concerns about the overuse of antibiotics and growth promoters, showing the technical evolution of this particularly verticalized system where these substances are not used and the animal welfare is highly take into consideration. As a priority, we address in this work, sustainability from the point of view of the multifunctionality of agriculture and also addressing the company\"s development from the perspective of Localized Agrifood Systems. Considering these approaches, we conducted a qualitative research on twenty eight integrated farmers who are linked to the company, applying semi-structured questionnaire. The objective was to explore and describe their attitudes, perceptions and experiences in relation to the company concepts and methods towards the environment, food safety, and their socio-economic conditions. With regard to corporate headquarters, located in a farm on a rural area, we present a study on the sustainability of the production system through a social-environmental indicator developed by Embrapa, named APOIA - NovoRural. This indicator was designed to analyse rural productive units with focus on the environmental management based on local context. The company have achieved an excellent sustainability index (0.87), due to its history for more than twenty years of Nature Farming\'s handling. Peculiarly this Nature Farming complex is inserted at the confluence of two conservation units of the state of São Paulo, called Environmental Protected Areas of Corumbataí and of Piracicaba, which reinforces the need to search for environmentally suitable models of agrifood production. The data obtained from this study with the integrated farmers have allowed us to verify that the dimensions of multifunctionality of agriculture are being recognized within this particular territory, streamlining and consolidating this agrifood localized system under a sustainability perspective in agriculture.

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