Les PNA (peptide nucleic acids) : Des sondes high-tech pour l’analyse génétique et cytogénétique moléculaire

Les PNA (peptide nucleic acids) sont des molécules de synthèse, analogues des acides nucléiques, dans lesquelles le squelette phosphodiester a été remplacé par une chaîne pseudo-peptidique sur laquelle viennent se fixer les bases puriques et pyrimidiques. Du fait de cette structure, les molécules de PNA ne sont pas chargées et s’apparient aux séquences d’acides nucléiques avec une remarquable affinité et une très forte spécificité. De plus, les PNA présentent une remarquable stabilité et une excellente résistance aux protéases et aux nucléases. Depuis leur mise au point en 1991, les PNA ont été incorporées dans de nombreux protocoles d’études et de diagnostics génétiques pour la recherche de mutations, la coupure dirigée de l’ADN ou la thérapie génique. L’élaboration récente de sondes PNA pour l’identification in situ des chromosomes humains a permis d’adapter avec succès cette nouvelle technologie à l’analyse cytogénétique humaine.The peptide nucleic acids (PNAs) constitute a remarkable new class of synthetic nucleic acids analogs, in which the sugar phosphate backbone is replaced by repeating N-(2-aminoethyl) glycine units linked by amine bonds and to which the nucleobases are fixed. This structure gives to PNAs the capacity to hybridize with high affinity and specificity to complementary RNA and DNA sequences, and a great resistance to nucleases and proteinases. Originally conceived as ligands for the study of double stranded DNA, the unique physico-chemical properties of PNAs have led to the development of a large variety of research and diagnostic assays, including antigene and antisense therapy and genome mapping. Several sensitive and robust PNA-dependent methods have been designed for modulating polymerase chain reactions, detecting genomic polymorphisms and mutations or capturing nucleic acids. Over the last few years, the use of PNAs has proven its powerful usefulness in cytogenetics for the rapid in situ identification of human chromosomes and the detection of aneuploidies. Recent studies have reported the successful use of chromosome-specific PNA probes on human lymphocytes, amniocytes, spermatozoa as well as on isolated oocytes and blastomeres. Muticolor PNA protocols have been described for the identification of several human chromosomes, indicating that PNAs could become a powerful tool for in situ chromosomal investigation

Business Language applied to the didactic of French for Specific Purposes in Lebanon

La volonté d'apporter un nouveau concept dans l'enseignement du français à l'université au Liban issu des recherches les plus récentes effectuées en Français sur Objectifs Spécifiques, les dernières mises à jour du Cadre Européen Commun de Référence pour les Langues ainsi que le souci de l'appuyer par une expérience d'une dizaine d'années sur le terrain et de plusieurs séminaires de formation dans ce domaine, ont amené à effectuer ce travail de recherche basé sur la conciliation de la théorie et de la pratique. Notre travail part de la conviction que si l'étudiant trouvait une réponse à ses demandes, voire à ses besoins que ce soit au niveau universitaire ou professionnel dans un cours de langue, il s'intéresserait beaucoup plus à la langue en question. Partant d'une observation de la méthodologie du Français sur Objectifs Spécifiques, passant par une observation sociolinguistique du terrain libanais permettant de mieux définir les besoins linguistiques de l'étudiant au Liban, ce travail de thèse aboutit à une conception d'une nouvelle méthode d'enseignement du français en proposant une élaboration didactique d'un dossier de français des affaires, considéré comme langue de spécialité.My aim to provide a new concept in teaching French at a Lebanese university is the result of extensive research on French for Specific Purposes based on the Common European Framework for Languages as well as my concern of providing support based on valuable years of experience and many seminars followed in this field. All of those factors contributed to my endeavor to make a worthy attempt at combining theory with practice. My whole work rests on a belief I have long sustained if students could find a language course that would meet their academic or professional needs, they would be keener on learning that language. While studying the methodology adapted by French for Specific Purposes, carrying out a sociolinguistic analysis of the Lebanese community, and analyzing the linguistic needs of the Lebanese students, I managed to come up with a new concept for teaching Business French and to devise a different didactic approach that would be more effective when put into practice

Contributions à l'indexation et à la reconnaissance des manuscrits syriaques

Cette thèse est dédiée à l exploration informatique de manuscrits syriaques, c est la première étude de ce type mise en œuvre. Le syriaque est une langue qui s est développé à l est du bassin méditerranéen, il y a plus de vingt siècles et qui aujourd hui est encore pratiquée. La présentation de l histoire du développement de cette langue fait l objet du premier chapitre. Le syriaque s écrit de droite à gauche, avec un aspect très singulier, un penché d un angle d environ 45 qui rend les algorithmes de traitement et d analyse de documents développés pour les autres écritures inopérants. Dans le second chapitre, après nous être intéressés à la description et l extraction des structures des documents, nous avons élaboré une méthode de segmentation des mots qui prend en compte ce penché ; elle nous conduit à une trentaine de formes stables qui sont des lettres individuelles verticales et des n-grammes constitués par des lettres penchées. Dans la deuxième partie de la thèse, nous nous sommes intéressés au contenu des documents à des fins d indexation. Nous avons développé une méthode de repérage de mots qui permet de retrouver, dans un document, toutes les occurrences d un mot selon plusieurs modes de requêtes (word spotting, word retrieval). Elle repose sur une similarité de forme évaluée à partir d une analyse très fine de l orientation du tracé de l écriture. Le dernier chapitre est une première contribution à la transcription assistée des manuscrits syriaques qui repose sur la segmentation des mots décrite ci-dessus. Nous montrons que la transcription, qui s appuie sur l interaction, est en rupture avec la traditionnelle démarche de reconnaissance par OCR.This thesis is dedicated to the computed exploration of Syriac manuscripts; it is the first study of the sort. Syriac is a language that developed in the eastern region of the Mediterranean coast, about twenty centuries ago, and is still in practice, today. The history as well as the development of the language is presented in the first chapter. Syriac is written from right to left with a distinct feature which is a tilt of about 45 which renders classical signal and document analysis algorithms which were developed for other languages rather useless. In the second chapter, after describing and extracting the documents structure, we developed a word segmentation method that takes this tilt into consideration, this lead us to about thirty stable shapes which are vertical letters and n-grammes made out of titled letters. In the second part of this thesis, we were interested in the content of the documents for indexation purposes. We developed a word spotting method that allowed us to find all the occurrences of a word in a document using several word query approaches (word spotting, word retrieval). It is based on shape similarity evaluated after a thorough analysis of the orientations of the handwriting. The last chapter consists of a first contribution to assisted transcription of Syriac manuscripts which relies on the above described segmentation. We showed that transcription based on interaction, is in conflict with the traditional approaches of OCR recognition.VILLEURBANNE-DOC'INSA LYON (692662301) / SudocSudocFranceF

Résorptions mandibulaires postérieures et solutions a visée pre-implantaire

Les différents rappels embryologiques, histologiques, anatomiques et physiologiques nous permettent de comprendre la situation particulière des édentements mandibulaires postérieurs. Ensuite, nous détaillons les principales techniques et les différents matériaux visant à recouvrer une quantité et une qualité d'os suffisant pour réhabiliter la zone édentée par des prothèses implantaires. Face au manque de prédictibilité et aux échecs de ces techniques, la réflection s'oriente vers la gestion du recouvrement muqueux de cet os au volume augmenté. Nous proposons trois possibilités pour améliorer le pronostic des augmentations osseuses mandibulaires postérieures.The different knowledge of embryology, histology, anatomy and physiology allow us to understand the particular situation of posterior edentulous mandible. Then, we detail the main techniques and thé different materials to recover the sufficient amount and quality ofbone to restore the edentulous area by implant-supported prosthesis. Against the lack of predictability and the failures of these techniques, we focus our interest on the manageIl}-ent of mucosal recovery. We suggest three possibilities to improve the prognostic ofthese ~osterior mandibular bone augmentations.MONTPELLIER-BU Médecine UPM (341722108) / SudocMONTPELLIER-BU Odontologie (341722110) / SudocMONTPELLIER-BU Médecine (341722104) / SudocSudocFranceF

Heat transfer in a rice storage silo: an explicit finite difference method approach for two-dimensional and two-dimensional transient models

Rice is one of the most consumed cereals in the world, being one of the most important crops in southern Brazil, however, it is a grain susceptible to thermal and mechanical damage and, mainly, to the attack of pests and fungi when subjected to inadequate temperature conditions. and humidity. Because of this, it needs a lot of care in its harvesting and post-harvesting processes, so that it reaches the consumer in good condition. Among these precautions is the need for careful storage in your silo, as poor storage can lead to irreparable damage to producers, such as total or partial loss of grain and, consequently, monetary loss. In this sense, mathematical modeling makes it possible to evaluate and predict within certain parameters, not free of errors, the internal temperature of a silo and, thus, to analyze the best preventive tool for the grain to maintain its ideal physical and nutritional properties. In this sense, through the relations of mathematical models, it is aimed to reduce the damages resulting from the bad conducts of the process related to the storage of the grain. Thus, the main objective of the present work is to model the heat transfer process by the explicit method of finite differences, applied to a prototype of a silo containing grains of paddy rice, and to compare the simulated data with the experimental ones in the literature. Seeking to carry out this comparison, two transient mathematical models will be presented, namely: one-dimensional and two-dimensional. In both models, the thermal diffusivity of the grains will be analyzed with mean and variable value (with grain moisture and temperature). The numerical simulations were obtained through the Google Collaboratory platform and, through these, the graphs between the approximations of order two and four were analyzed for the unidimensional model with thermal diffusivity with average value and, for approximation of order two the one-dimensional models with variable thermal diffusivity and two-dimensional models with mean and variable values. In addition, statistical indices, correlation coefficients and determination between observed and predicted temperatures were analyzed. The chosen methodology proved to be satisfactory, as the data obtained are close to literature data, adapting to the physical process of the system. In this sense, the methodology is of paramount importance for more complex problems, as in the case of variable thermal diffusivity, since for non-linear partial differential equations such resolution is not feasible analytically, which is the differential of the research. Furthermore, the statistical indices are close to the ideal values, with a very strong positive correlation for both cables of the one-dimensional and two-dimensional models (average and variable value).Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESO arroz e um dos cereais mais consumidos no mundo, sendo uma das culturas mais importantes no Sul do Brasil, porém, é um grão suscetível ao dano térmico, mecânico e, principalmente, ao ataque de pragas e fungos quando submetido a condições inadequadas de temperatura e umidade. Devido a isso, necessita de muitos cuidados em seus processos de colheita e pós-colheita, para que chegue em bom estado ao consumidor. Dentre esses cuidados, está a necessidade de um armazenamento cuidadoso em seu silo, pois uma má estocagem pode acarretar em prejuízos irreparáveis aos produtores, como perda total ou parcial dos grãos e, por consequência, prejuízo monetário. Nesse sentido, a modelagem matemática permite avaliar e prever dentro de certos parâmetros, não livre de erros, a temperatura interna de um silo e, assim, analisar a melhor ferramenta preventiva para que o grão mantenha suas propriedades físicas e nutricionais ideais. Nesse sentido, através das relações de modelos matemáticos, visa-se reduzir os danos provenientes das más conduções do processo relacionado a armazenagem do grão. Assim, o principal objetivo do presente trabalho é modelar o processo de transferência de calor pelo método explícito das diferenças finitas, aplicado a um protótipo de silo contendo grãos de arroz em casca, e comparar os dados simulados com os experimentais existentes na literatura. Buscando realizar essa comparação, apresentar-se-á dois modelos matemáticos transientes, sendo eles: unidimensional e bidimensional. Nos dois modelos, serão analisados a difusividade térmica dos grãos com valor médio e variável (com a umidade e a temperatura do grão). As simulações numéricas foram obtidas através da plataforma ´ Google Colaboratory e, por meio destas, foram analisados os gráficos entre as aproximações de ordem dois e quatro para o modelo unidimensional com difusividade térmica com valor médio e, para aproximação de ordem dois os modelos unidimensional com difusividade térmica variável e bidimensional com valor médio e variável. Além disso, foram analisados os índices estatísticos, os coeficientes de correlação e determinação entre as temperaturas observadas e a predita. A metodologia escolhida mostrou-se satisfatória, pois os dados obtidos aproximam-se dos dados da literatura, se adequando ao processo físico do sistema. Nesse sentido, a metodologia é de suma importância para problemas mais complexos, como no caso da difusividade térmica variável, uma vez que para equações diferenciais parciais não lineares não é viável tal resolução de forma analítica, sendo esse o diferencial da pesquisa. Ademais, os índices estatísticos são próximos aos valores ideais, tendo correlação positiva muito forte para ambos os cabos dos modelos unidimensional e bidimensional (valor médio e variável)

[Monnaie : Bronze, Pétra, Arabie, Élagabale]

Ancien possesseur : Seyrig, Henri (1895-1973). Ancien possesseurAppartient à l’ensemble documentaire : MonnGr

[Monnaie : Bronze, Pétra, Arabie, Élagabale]

Appartient à l’ensemble documentaire : MonnGr