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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.
61

A grammatical analysis of the Tswana adverbial

Le Roux, J. C. 31 October 2007 (has links)
Adverbial constructions are a problematic subject in Tswana grammatical studies. Traditionally termed descriptives, it is not clear what the defining features of this category are. It is also a very vast category. There seems to be many different structures functioning as adverbials in Tswana, including particles, words, prepositional phrases and clauses. Tswana grammars in general often have little to say about the syntax of adverbials, in respect of, for instance, the propensity of Tswana adverbials for multiple occurrences in the same clause and the range of possible positions of Tswana adverbials in clause structure. Because of the vastness of the adverbial category we only deal with adverbials as elements of clause structure. A typical feature of adverbials is the considerable mobility they enjoy in relation to other elements in clause structure which affects their grammatical and semantic status in relation to such elements. By distinguishing different categories of adverbials, in clause structure it becomes clear that the same structural element may function within different adverbial categories. This necessitates a definition of adverbials which is based on their specific semantic functions within clause structure. The study is divided into five chapters. When dealing with the adverbial as a clause element in Tswana, we realise that it is not sufficiently described. The first two chapters therefore serve as an introduction to central theoretical issues where some relevant research is critically examined and related to the present study. In the next chapter, that is Chapter 3, we establish formal and semantic frameworks for the classification and descriptive treatment of adverbials in Tswana. In Chapter 4 we implement the structural, syntactic and semantic properties as well as the features adverbials have as modifiers to make a functional classification of adverbials in clause structure. The classification of adverbials as adjuncts, subjuncts, disjuncts and conjuncts from A Comprehensive grammar of the English language by Quirk, et al. (1985) (CGEL) is taken as the basis for this classification. Chapter 5 presents the overall conclusions and implications of the study. / African Languages / D.litt. et Phil. (African Languages)
62

CALLED TO TEACH: A MIXED METHODS EXPLORATION OF COMMUNITY COLLEGE ADJUNCT FACULTY’S TEACHING SELF-EFFICACY

Tyndall, Christy L. 01 January 2017 (has links)
Adjunct faculty teach over 50% of courses in U.S. higher education but little is known about them as educators. Strong evidence has been found in the K-12 literature demonstrating the link between teachers’ beliefs, instructional practices, and subsequent student outcomes. Teaching self-efficacy, beliefs in one’s capabilities to perform specific tasks in a particular context, is an important contributor to motivation and performance (Tschannen-Moran et al., 1998). This research advances teaching and learning literature in higher education and provides insight into an understudied population of educators by exploring adjunct faculty’s teaching self-efficacy and factors that influence those beliefs. In this mixed methods study, an explanatory sequential design was used to explore teaching-self efficacy among adjunct faculty at a Mid-Atlantic community college. Adjunct faculty were surveyed using the College Teaching Self-Efficacy Scale (Prieto Navarro, 2006). Data were selected from the surveys for further explanation in subsequent interviews. Quantitative and qualitative data were merged to form an overall interpretation of teaching self-efficacy and factors that influenced those beliefs. Teaching self-efficacy was highest in creating a positive learning environment, followed by overall teaching self-efficacy, and then instructional skills. Assessing student learning was rated lowest. Adjunct faculty with fewer than five years teaching experience had lower self-efficacy scores than those teaching for six or more years. Mastery experiences and feedback from students and full-time faculty mentors emerged as the most influential sources of teaching self-efficacy. Student evaluations and attending Convocation were positively correlated with scores in overall teaching self-efficacy, instructional skills, and creating a positive learning environment. Adjunct faculty identified working to accommodate the needs of a diverse range of learners as the most significant challenge to teaching self-efficacy followed by challenges related to working conditions including inadequate pay and job insecurity. Key recommendations for promoting adjunct faculty’s teaching self-efficacy beliefs include increasing opportunities for interaction with departmental colleagues to share best practices and teaching resources, and offering trainings at flexible times and in creative formats on instructional skills, assessment practices, and learning theories. Improving onboarding processes, recognizing different needs of adjunct faculty based on experience, and reassessing pay and employment structures are also needed.
63

Perceptions of Exemplary Teaching Attributes of Adjunct Faculty in the Dallas County Community College District: a Case Study

Picquet, James Philip 08 1900 (has links)
The problem of this study involved identifying and ranking perceptions of the attributes of exemplary teaching of adjunct faculty of the Dallas County Community College District. Data was collected by a 75 item opinionnaire and a demographic data sheet which was sent to a population of 3,000 employees of the Dallas County Community College District and 100 exemplary faculty from 39 of the 50 United States. The five chapters were titled Introduction, Review of Literature, Methods, Presentation and Analysis of Findings, and Summary, Discussion, Conclusions, and Recommendations. Revealed through the findings of Chapter 4 was the order of attributes as a Grand grand rank found through the combining of the grand rank order of the Dallas County Community Colleges' employees and the rank order of the nationally recognized exemplary faculty. Findings disclosed that a rank ordering of items represented by Kendall's W at .9654 with a chi-square of 142.8815 at the .001 level of significance. These findings led to the rejection of three null hypotheses and the following related conclusions: (1) perceptions of importance of teaching attributes, can be rank ordered, (2) while a high level of significant values of W may be interpreted as meaning that the observers and judges are applying essentially the same standard in ranking the variables, their pooled ordering may serve as a standard, (3) ordering of perceptions of exemplary teaching attributes is possible, and (4) rankings of attributes provides a usable list of variables that can be employed in evaluation. Recommendations for further study include design of an evaluation instrument incorporating all or part of the attributes for use in adjunct classrooms, and creation of a staff development program designed to help those who are less proficient in the classroom.
64

Cultures antifongiques applicables comme ferments de bioprotection dans les produits laitiers : sélection, évaluation à l'échelle pilote et identification de composés supports de l'activité / Antifungal microorganisms applicable as bioprotectivecultures in diary products : selection, pilot-scale evaluation and identification of the compounds supporting the activity

Leyva Salas, Marcia 06 November 2018 (has links)
La contamination fongique des produits laitiers est à l’origine de pertes économiques conséquentes et de gaspillage alimentaire. Dans un contexte de demande pour plus de « naturalité », les cultures de bioprotection et leurs métabolites représentent une alternative d’intérêt aux conservateurs chimiques pour lutter contre ces contaminants.Les objectifs de cette thèse étaient i) de sélectionner des micro-organismes présentant une activité antifongique, pour élaborer des cultures de bioprotection applicables dans des produits laitiers, et ii) d’étudier les composés potentiellement supports de l’activité antifongique observée. Dans un premier temps, l’activité antifongique de 32 souches de bactéries lactiques et propioniques a été étudiée en modèles « fromage » et « yaourt ». L’étude de combinaisons de souches et de leur innocuité a conduit à sélectionner 2 combinaisons binaires de lactobacilles (A1 et A3). Leur efficacité et applicabilité a été évaluée à l’échelle pilote en fabrication de crème fraîche et de fromage.Les challenges tests et tests d’usages ont montré que selon le produit laitier, A1 et A3 ont une activité antifongique similaire ou supérieure que les cultures bioprotectrices commerciales. Selon l’inoculum ajouté, ces cultures n’impactent pas les caractéristiques technologiques et organoleptiques des produits laitiers. Des méthodes chromatographiques des composés antifongiques suivies d’analyses statistiques ont permis de mettre en évidence des « cocktails » de 2 à 17 composés, selon la matrice et la culture considérée, qui sont probablement supports de l’activité antifongique.Ces travaux contribuent à une meilleure compréhension des mécanismes d’action de l’activité antifongique et devraient conduire au développement de cultures antifongique pour remplacer les conservateurs dans les produits laitiers. / Fungal contamination of dairy products is responsible for economic losses and food waste. In a context of “preservative-free” product demand, bioprotective cultures and their metabolites represe,t an alternative of interest of chemical preservatives to control these spoilers.The objective of this study was i) to select microorganisms exhibiting an antifungal activity, in order to elaborate bioprotectivecultures applicable in dairy products, and ii) to study the compounds potentially supporting the observed activity. Firstly, the antifungal activity of 32 strains of lactic acid and propionic bacteria screened in cheese model and yogurt. Strain combinaison study and safety assessment led to the selection of 2 binary lactobacilli combinations (A1 and A3). Their efficiency and applicability were then evaluated in pilot-scale productions of sour cream and cheese.Challenge and shelf life tests showed that depending on the dairy product, A1 and A3 have a similar or higher antifungal activity than the commercial bioprotective cultures. In addition, depending of inoculum, A1 and A3 did not impact the technological and organoleptic characteristics. Chromatographic methods and statistical analyses allowed identifying cocktails of 2 to 17 compounds, according to the considered dairy product and culture that probably support the antifungal activity.The obtained results contribute to a better understanding of the antifungal activity action mechanisms and should lead to the development of antifungal cultures to replace preservatives in dairy products.
65

REDRESSING THE ADJUNCT STAFFING MODEL IN AMERICAN HIGHER EDUCATION

Casto, Andrew C. 01 January 2017 (has links)
Since their advent as supplemental staff at community colleges four decades ago, part-time instructors, or adjuncts, have since been employed with increasing frequency and in escalating numbers across all institutional types of American higher education. Currently comprising approximately forty percent of all postsecondary faculty, part-time instructors now outnumber full-time nontenure-track, tenure-track, and tenured faculty respectively on many campuses. This pervasive trend has created a professional climate of uncertainty and, in some cases, even hostility as American colleges and universities struggle to adapt to ever changing enrollment populations, market demands, technological innovations, and political pressure. As the sustainability of traditional faculty tenure hangs in the balance and as opportunities to secure tenure-track appointments continually diminish, the arguably inequitable working conditions of college faculty hired off the tenure track have fallen under public and political scrutiny since these instructors now provide such a large proportion of undergraduate education. This dissertation offers a comprehensive overview of the adjunct staffing model’s development and consequences as well as a proposed solution particularly to chairpersons of academic departments that have become inordinately dependent upon part-time instructors to teach their undergraduate curriculum. Combining personal experience with recent research, the first chapter offers a detailed description of the typical adjunct’s current working conditions, which include heavy workloads, poor compensation, and insufficient time for preparation and professional development. I briefly review the origins of and dramatically increasing reliance upon postsecondary adjunct employment over the past forty years. I situate the present undervaluing of part-time instructors within the context of colleges’ persistently rising “sticker prices,” which most commonly derive from curricular as well as extracurricular amenities and a drastic increase in non-instructional staff. I suggest that colleges cannot afford to ignore the adjunct problem much longer due to growing public and political awareness of the issue. I conclude by encouraging college governing boards, administrators, and faculty to collaborate in order to arrange respectable and sustainable terms of employment. The second chapter analyzes how the current model of adjunct employment adversely affects higher education. In addition to the first chapter’s grievances pertaining specifically to adjuncts, college faculty as a whole suffers from the deprofessionalization and bifurcation resulting from the widespread overdependence upon part-time instruction. Furthermore, college students suffer from part-time instructors’ compromised ethos and resultant “shielding,” last-minute staffing practices by means of which institutions often hire adjuncts, part-time instructors’ inadequate access to instructional resources, and irrational models for adjunct compensation. Finally, the adjunct problem harms the reputations of postsecondary institutions overall, indicating dysfunction and lack of accountability to an already skeptical public. The chapter closes with a call to action, encouraging all postsecondary institutions to consider improved, sustainable employment for all faculty. The third and final chapter proposes a solution in the form of a standardized college faculty position, which I call the core-survey instructor. Based loosely on a specific definition of contingent faculty, such a professor would assume reasonably heavy teaching loads as a full-time employee of one institution in exchange for a respectable salary, renewable multi-year contracts, and limited benefits. I explain how core-survey instructors will benefit postsecondary institutions not only by resolving the detriments listed in the second essay but also via improved remedial instruction, academic advising, and participation in shared governance.
66

Adverbiale Kasus des Deutschen

Egorova, Olga 16 August 2006 (has links)
Adverbiale Kasus sind Substantivgruppen ohne Präposition, die im Satz die Funktion einer temporalen, lokalen oder modalen Adverbialbestimmung erfüllen. Im Satz treten sie in der Regel als Adjunkte auf und sind in ihrer Form syntaktisch unabhängig. Das Ziel der vorliegenden Dissertation ist, adverbiale Kasus des Deutschen anhand zahlreicher Belege sowohl synchron als auch diachron aus verschiedenen Perspektiven zu beschreiben. In den älteren Sprachstufen sind adverbiale Kasus häufig belegt. Bis zum Gegenwartsdeutschen wurden viele davon adverbialisiert, durch Präpositionalphrasen ersetzt oder sind zu Phraseologismen erstarrt. In dieser Arbeit wird auf die semantisch-lexikalischen Restriktionen, Struktur, interne Ausfüllung bzw. Besetzung, Bezugsmöglichkeiten, Bedeutungen und die stilistischen Besonderheiten adverbialer Kasus ausführlich eingegangen. / Adverbial case is a noun phrase without preposition, functioning as the adverbial modifier of time, place or manner in a sentence. Syntactically they usually serve as adjuncts and are independent in their form. The aim of the present investigation was to describe the German adverbial case synchronically and diachronically on the basis of a large number of speech samples from different points of view. Adverbial cases have been very frequent at the earlier stages of German. Many of them have been adverbialised, replaced by prepositional phrases or have turned into phraseologisms in the course of language development up to the modern German. The present doctor thesis provides a detailed study of the lexical-semantic restrictions of the adverbial cases as well as of their structure and inner filling, their relation to other sentence constituents, aspects of their meaning and stylistic peculiarities.
67

Flavor development of cheddar cheese under different manufacturing practices

Lemus, Freddy Mauricio 19 September 2012 (has links)
Cheddar Cheese samples (good cheese, weak cheese, cheese made with pasteurized milk, cheese made with heat-shocked milk, cheese from production plant A, cheese from production plant B, cheese made with adjunct culture, and cheese made without adjunct culture), were evaluated during the ripening stage. Proteolysis was studied by a fractionation scheme, resulting in an insoluble fraction analyzed by urea polyacrylamide gel electrophoresis (Urea-PAGE), and a soluble fraction which was further investigated through water soluble nitrogen (WSN), trichloroacetic acid soluble nitrogen (TCA-SN) and phosphotungstic acid soluble nitrogen (PTA-SN) analyzed by total Kjeldahl nitrogen content (TKN). Reversed phase high performance liquid chromatography (RP-HPLC) was used to study the peptide profile of the water soluble fraction. Lipolyisis was studied by levels of individual free fatty acids determined through gas chromatography-flame ionization detection (GC-FID) after isolation employing solid phase extraction (SPE). Volatile sulfur compounds were studied using head space solid phase micro-extraction (SPME) coupled with gas chromatography-pulsed flame photometric detection (PFPD). It was found that Urea-PAGE is capable to differentiate samples according their age, but cannot discriminate samples regarding the treatment assessed, quality or origin of the samples. However, measurements of total Kjeldahl Nitrogen (TKN) of the WSN, TCA-SN, and PTA-SN fractions, and the principal component analysis of the RP-HPLC peptide profile of the WSN fraction, revealed differences in the rate and pattern of proteolysis for each one of the manufacturing cases. Good cheese, cheese produce in plant TCCA, cheese made in plant CRP with adjunct culture isolated from plant TCCA cheese, and cheese made with heat-shocked milk developed higher level of total nitrogen for the WSN, TCA-SN and PTA-SN fractions, indicating that primary and secondary proteolysis were faster for these samples. This is supported by a PCA model with three principal components that account for the 80-83% of the variability of the data from the RP-HPLC peptide profile analysis, which discriminates the samples according to age and manufacturing practice. In addition, FFA profiles demonstrated higher levels of low and medium chain free fatty acids for good cheese, cheese produce in plant TCCA, cheese made in plant CRP with adjunct culture, and cheese made with heat-shocked milk samples, which suggest faster lipolysis during ripening. The Volatile Sulfur Compounds (VSC) analysis showed higher levels of DMS and MeSH and lower levels of H2S, suggesting faster catabolism of sulfur containing amino acids in good cheese, cheese produce in plant TCCA, cheese made in plant CRP with adjunct culture, and cheese made with heat-shocked milk. / Graduation date: 2013
68

A grammatical analysis of the Tswana adverbial

Le Roux, J. C. 31 October 2007 (has links)
Adverbial constructions are a problematic subject in Tswana grammatical studies. Traditionally termed descriptives, it is not clear what the defining features of this category are. It is also a very vast category. There seems to be many different structures functioning as adverbials in Tswana, including particles, words, prepositional phrases and clauses. Tswana grammars in general often have little to say about the syntax of adverbials, in respect of, for instance, the propensity of Tswana adverbials for multiple occurrences in the same clause and the range of possible positions of Tswana adverbials in clause structure. Because of the vastness of the adverbial category we only deal with adverbials as elements of clause structure. A typical feature of adverbials is the considerable mobility they enjoy in relation to other elements in clause structure which affects their grammatical and semantic status in relation to such elements. By distinguishing different categories of adverbials, in clause structure it becomes clear that the same structural element may function within different adverbial categories. This necessitates a definition of adverbials which is based on their specific semantic functions within clause structure. The study is divided into five chapters. When dealing with the adverbial as a clause element in Tswana, we realise that it is not sufficiently described. The first two chapters therefore serve as an introduction to central theoretical issues where some relevant research is critically examined and related to the present study. In the next chapter, that is Chapter 3, we establish formal and semantic frameworks for the classification and descriptive treatment of adverbials in Tswana. In Chapter 4 we implement the structural, syntactic and semantic properties as well as the features adverbials have as modifiers to make a functional classification of adverbials in clause structure. The classification of adverbials as adjuncts, subjuncts, disjuncts and conjuncts from A Comprehensive grammar of the English language by Quirk, et al. (1985) (CGEL) is taken as the basis for this classification. Chapter 5 presents the overall conclusions and implications of the study. / African Languages / D.litt. et Phil. (African Languages)
69

A sintaxe de constituintes locativos no portugues brasileiro = restrição e predicação / The syntax of locative constituints in brazilian portuguese : restriction and predication

Pires, Marcos Eroni, 1985- 15 August 2018 (has links)
Orientador: Juanito Ornelas de Avelar / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-08-15T21:58:29Z (GMT). No. of bitstreams: 1 Pires_MarcosEroni_M.pdf: 658766 bytes, checksum: 0d51879d2d0dee80f48bf84667a72f87 (MD5) Previous issue date: 2010 / Resumo: Seguindo a versão minimalista da Teoria de Princípios e Parâmetros (Chomsky, 1995 e obras posteriores), esta dissertação tem como objetivo propor um quadro formal para capturar propriedades sintáticas e semânticas demonstradas por sintagmas preposicionados locativos (PPLocs do tipo (lá) em cima de, (aqui) debaixo de, (ali) em frente a, (aí) por trás de, (lá) por dentro de, (aqui) para fora de etc.) em sua relação com constituintes nominais no português brasileiro. Assumindo uma configuração clausal para os PP-Locs (Koopman, 1997; Dikken, 2003; Avelar, 2006; Svenonius, 2007), o estudo aborda casos em que o sintagma locativo funciona ou como um modificador restritivo do nome (quando é tradicionalmente classificado como adjunto adnominal), ou como um elemento que estabelece com a categoria nominal uma predicação secundária (quando assume uma função predicativa). A análise explora a ideia de que, para ter uma função restritiva e funcionar como um adjunto adnominal, o PP-Loc precisa ser complemento de uma categoria que codifique informações sobre referencialidade, de modo a atender requerimentos da interface semântica. A abordagem explora algumas consequências do modelo proposto por Kayne (1994), especificamente no que diz respeito ao estatuto das relações especificador-núcleo, assim como a proposta de Starke (1995), segundo a qual as relações de predicação que caracterizam small clauses envolvem uma projeção LexP. Adotando uma estrutura expandida para os sintagmas nominais de acordo com Vangsnes (2001), o estudo conclui que para um PP-Loc ser [+restritivo] precisa ser obrigatoriamente tomado como um complemento de D(eterminante) na computação sintática, portando consigo um traço de dêixis / Abstract: Following the minimalist version of the Principles and Parameters Theory (Chomsky, 1995 and following works), this thesis aims at proposing a formal framework to capture syntactic and semantic properties displayed by prepositional locative phrases (PP-Locs as (lá) em cima de, (aqui) debaixo de, (ali) em frente a, (aí) por trás de, (lá) por dentro de, (aqui) para fora de etc.) in their interaction with nominal constituents in Brazilian Portuguese. Assuming a clausal configuration for PP-Locs (Koopman, 1997; Dikken, 2003; Avelar, 2006; Svenonius, 2007), the study addresses cases in which the locative phrase works either as a restrictive modifier of the name (when it is traditionally classified as an adnominal adjunct), or as an element that provides a secondary predication together with the nominal category (when it assumes a predicative function). The analysis explores the idea that in order to have a restrictive function and to operate as an adnominal adjunct, PP-Loc needs to be a complement of a category that encodes information about referentiality so as to meet the requirements of the semantic interface. The approach explores some consequences of Kayne's (1994) especifically with respect to the status of Spec-head relations; and also Starke's (1995) proposal, according to which predication relations that characterize small clauses involve a LexP projection. Adopting na expanded structure for nominal phrases following Vangsnes (2001), the study concludes that in order to a PP-Loc to be [+restrictive] it must necessarily be taken as a complement of D(eterminant) in the syntactic computation, carrying with it a deixis feature / Mestrado / Gramatica / Mestre em Linguística
70

Etude d'un modèle de neuropaludisme chez le rat et évaluation des effets pharmacologiques d'un candidat-médicament / Study of a cerebral malaria model in rats and pharmacological effects assessment of a drug-candidate

Keita Alassane, Ndeye Sokhna 30 November 2016 (has links)
Le neuropaludisme (NP) est la forme la plus mortelle du paludisme. C'est une complication neurologique observée uniquement dans les cas d'infection par Plasmodium falciparum, principalement chez les enfants de moins de 5 ans vivant en Afrique Sub-saharienne, et les adultes non-immuns, notamment les femmes enceintes et les touristes visitant les zones d'endémie. Les signes cliniques sont à présent bien décrits (prostration, convulsions répétées, difficultés respiratoires, coma,...), mais les mécanismes physiopathologiques conduisant au NP sont encore mal définis. Leur élucidation est rendue difficile par la localisation cérébrale de la pathologie du vivant des patients et la faible disponibilité des données nécropsiques. Bien que l'accès aux tissus humains soit limité en nombre, les résultats d'autopsie ont permis d'établir que le NP résulte d'une séquestration des globules parasités au niveau de l'endothélium intra-vasculaire, associée à une forte réaction immunitaire. La stratégie de prise en charge du NP combine un traitement étiologique à base de dérivés d'artémisinine, ou de quinine et un traitement adjuvant symptomatique destiné à pallier à la défaillance multiorganique qui est à l'origine de l'issue fatale souvent observée. Le modèle de NP expérimental actuellement le plus utilisé est le modèle souris infecté par P. berghei ANKA. La pertinence de ce modèle est toutefois remise en cause en raison notamment des différences histo-pathologiques observées par rapport à la forme humaine. En effet, les souris manifestant les symptômes du NP ne présentent que très rarement le phénomène de séquestration, caractéristique majeure du NP chez l'Homme. Par ailleurs, comparativement à la réponse immunitaire de la souris, le modèle rat s'est également révélé plus proche de la réaction de l'Homme, dans le cas d'une autre parasitose, la schistosomose. L'objectif de la première partie du projet thèse a donc été la mise en place et l'évaluation d'un modèle alternatif de NP chez le rat. Ainsi un modèle de NP chez le rat Sprague Dawley infecté par la souche murine P. berghei K173 a été caractérisé sur les plans clinique, biologique (paramètres hématologiques et biochimiques),histopathologique et du profil cytokinique (cytokines cérébrales et sériques). La forte similarité des symptômes et des lésions associées au NP du rat Sprague Dawley infecté par P. berghei K173 par rapport au NP humain permet de valider la pertinence de ce modèle pour l'étude de la physiopathologie du NP. L'objectif de la deuxième partie de mon projet de thèse a été d'évaluer les effets pharmacologiques d'un candidat-médicament, l'isoflurane, pour le traitement adjuvant du NP. Ce composé présente l'avantage d'être déjà utilisé chez l'Homme à d'autres fins thérapeutiques et dispose donc d'une autorisation de mise sur le marché. Les résultats obtenus montrent une efficacité nette de l'isoflurane avec une rémission totale des signes de paralysie pour 47.8% des rats traités ainsi qu'un gain de survie des rats NP traités de 2 à 10 jours par rapport aux rats NP non traités. Ce gain de survie des animaux traités pourrait permettre un allongement de la fenêtre du temps de traitement étiologique, améliorant ainsi sensiblement le pronostic du NP. L'isoflurane, dont le mécanisme d'action semble être la réversion de la séquestration des globules parasités, limite les complications neurologiques souvent responsables de séquelles liées au NP. Des études ultérieures permettront d'optimiser ce nouveau protocole de traitement adjuvant du NP. / Cerebral malaria (CM) is the most deadly form of malaria. It is a neurological complication observed only in cases of infection with Plasmodium falciparum that affects mainly children under five years living in Sub-Saharan Africa and non-immune adults including pregnant women and tourists visiting endemic areas. Although clinical signs are well described (prostration, respiratory distress convulsions, coma), the pathophysiological mechanisms leading to CM are still unclear. Their elucidation in vivo is made difficult by the cerebral location and the low availability of autopsy data. Instead of limited access to human tissues, autopsy results have shown that CM results from a strong immune response linked to sequestration of infected red blood cells in the intravascular endothelium. Cerebral malaria management combines an etiological treatment with artemisinin derivatives or quinine and adjunct treatment of the multi-visceral failures, responsible of fatal outcome. P. berghei ANKA-infected mouse is widely used as experimental murine model of CM. However the relevance of this model is still questioned because of the histopathologic differences from the human form. Indeed, CM mice rarely exhibit the red blood cell sequestration that is a major feature of human CM. Furthermore, compared to mouse, the rat displays a closer immune response to human in Schistosoma infection. This PhD research project first aimed to implement and assess an alternative rat model of CM. The clinical, biological, histo-pathological features as well as the cytokine profiling of an experimental model of CM were characterized in Sprague Dawley rats infected with P. berghei strain K173. The strong similarity of the symptoms and lesions observed in this model with those reported in human CM confirms its high relevance. The second objective of this thesis project was to assess the pharmacological effects of a drug-candidate in adjunct treatment of CM. Results demonstrated a strong efficacy of the molecule tested with 47.8% of the treated CM rats showing total remission. Moreover we observed a 2- to 10-day survival gain in the treated CM rats group compared to the non-treated CM rat group. Preliminary data suggest that this drug-candidate may reverse the endothelial sequestration of parasitized red blood cells and so limit the neurological sequels related to CM. It is anticipated that the gain in survival associated with this drug-candidate use will extend the window of the etiological treatment time, thus significantly improving the global prognosis of CM. Further studies are needed to optimize this adjunct CM treatment protocol.

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