93 research outputs found
Étude des principaux facteurs influençant l'activité de la dégradation biologique des hydrocarbures dans le sol
No full textCe présent travail avait pour but d'étudier et de comprendre l'action de certains paramètres biologiques et climatiques sur le processus de biodégradation des rejets huileux d'une raffinerie. Dans un premier temps, l'étude a porté sur le rôle joué par l'eau et le rôle joué par l'aération du sol en fonction de la vitesse de dégradation biologique des hydrocarbures. Plusieurs chaudières et carrés expérimentaux étaient disponibles pour ces expériences. Pour chacune de celles-ci, le seul paramètre variant entre les carrés ou les chaudières était le paramètre étudié. Il a ainsi été démontré qu'une quantité excessive d'eau inhibait effectivement dans une bonne mesure la biodégradation des hydrocarbures. De plus, la terre est plus apte à s'imbiber d'eau qu'elle ne l'est à s'imbiber d'huile, ce qui constitue évidemment un autre facteur de nuisance. Les bactéries telluriques responsables de la biodégradation de l'huile sont dans une très large mesure aérobies. Nous nous sommes donc intéressés au rôle joué par le mélange mécanique de la terre dans le but de visualiser les effets de l'aération dans le processus étudié. Incidemment, le fait de retourner mécaniquement la terre est utile à condition de ne pas dépasser une fréquence optimale. Cette fréquence doit être déterminée pour chaque site en fonction du climat local et de la quantité de déchets traités par semaine. En second lieu, nous nous sommes intéressés aux effets provoqués par des variations du pourcentage d'hydrocarbures dans le sol au niveau de la vitesse de biodégradation des huiles. En plaçant un volume de liquide constant de carré expérimental en carré expérimental, mais en faisant varier la quantité d'huile (donc le pourcentage d'huile entre chaque carré, nous en sommes venus à la conclusion que plus un sol est riche en hydrocarbures, plus la biodégradation est efficace. La diminution des volumes de déchets huileux par des processus d'élimination d'une forte quantité d'eau contenue dans ceux-ci nous ont amené à déterminer si les hydrocarbures contenus dans des boues huileuses épaissies étaient tout aussi bien biodégradables que les hydrocarbures contenus dans de l'huile brute. En incorporant différentes quantités de boues dans la terre, nous avons pu constater que les hydrocarbures des déchets concentrés étaient très bien biodégradables. Enfin, en étudiant le rôle que pourrait jouer la tourbe dans le processus de dégradation biologique des huiles, nous en sommes venus à la conclusion que non seulement celle-ci n'était pas efficace, mais qu'elle pouvait même être nuisible à la biodégradation
TaskNav: task-based navigation of software documentation
No full textTo help developers navigate documentation, we introduce TaskNav, a tool that automatically discovers and indexes task descriptions in software documentation. With TaskNav, we conceptualize tasks as specific programming actions that have been described in the documentation. TaskNav presents these extracted task descriptions along with concepts, code elements, and section headers in an auto-complete search interface. Our preliminary evaluation indicates that search results identified through extracted task descriptions are more helpful to developers than those found through other means, and that they help bridge the gap between documentation structure and the information needs of software developers.Christoph Treude, Mathieu Sicard, Marc Klocke, and Martin Robillar
Platinum-Based Anticancer DrugsBased in part on the article Platinum-Based Anticancer Drugs by Steven J. Brown, Christine S. Chow & Stephen J. Lippard which appeared in the<i>Encyclopedia of Inorganic Chemistry, First Edition</i>.
No full textBioresponsive molecular imaging probes
No full textMolecular imaging is recognized as a powerful tool to visualize and characterize biological processes at the cellular and molecular level in vivo. In most imaging approaches, molecular probes are used to bind to disease-specific biomarkers highlighting disease target sites. In recent years, a new subset of molecular imaging probes, known as bioresponsive molecular probes, has been developed. Chapter 1 reviews the several types of these activatable imaging probes and its potential in vivo applicability. The goal of this thesis was the design, synthesis, and in vitro and in vivo characterization of novel bioresponsive imaging probes based on the elegant concept of activatable cell penetrating peptides (ACPPs). The experimental part of this thesis starts with the development of radiolabeled matrix metalloproteinase-2, -9 (MMP-2/9) activatable cell penetrating peptides. The matrix metalloproteinases -2 and -9 play an important role in angiogenesis and metastasis in cancer, and in adverse cardiac remodeling after myocardial infarction. In Chapter 2, it is shown that the proposed MMP-2/9 sensitive peptide-based imaging probes were successfully synthesized on the solid phase, and could be efficiently labeled with radio-isotopes. A dual-isotope labeled ACPP is presented that could discriminate between uptake of the activated probe and the integral probe and this ACPP was used to follow the activation process in vivo. Despite the probe showed specific sensitivity towards MMP-2 and MMP-9 in vitro, in vivo studies in tumor-bearing mice demonstrated that the ACPP was not activated in MMP-expressing tumor tissue, but most likely already in the circulation. Chapter 3 describes the in vivo characterization of the radiolabeled MMP-2/9 ACPPs in a mouse model of myocardial infarction. In this model, infarct-specific activation and retention of the MMP-2/9 ACPP was observed, as was assessed by biodistribution studies using the dual-isotope labeled ACPP. A significant correlation was found between MMP-2/9 expression and the degree of probe activation in infarcted and remote areas of the hearts. Furthermore, ACPP retention in infarcted regions was successfully visualized ex vivo using autoradiography. Nevertheless, also ACPP activation in the circulation resulted in retention of the activated probe in the surrounding tissues, especially in the liver. Consequently, a strong background signal was observed. Chapter 4 focuses on the development of long circulating MMP-2/9 sensitive ACPPs to achieve an extended exposure time to the target proteases. Incorporation of two different albumin ligands i.e. palmitic acid (Palm) and deoxycholic acid (DOCA), in the ACPPs resulted in a strong increase in circulation time of these albumin-binding ACPPs compared to the ACPP without albumin ligand. In vivo biodistribution studies in a mouse model of myocardial infarction pointed towards local activation of a DOCA-conjugated ACPP in areas of cardiac remodelling. Despite the increased circulation time of this probe, the infarct-to-remote ratios and absolute probe uptake in infarcted areas of the heart was comparable to dACPP. In view of the findings discussed in Chapters 2 and 3, we hypothesized that ACPPs sensitive for tissue-specific biomarkers should exhibit reduced activation in the vasculature and background probe uptake of the activated ACPP in all tissues. Consequently, this should improve the signal-to-background ratios of these probes. Therefore, Chapter 5 and Chapter 6 are dedicated to the development of radiolabeled ACPPs activatable by membrane-type matrix metalloproteinase-1 (MMP-14), and the transmembrane protein angiotensin converting enzyme (ACE), respectively. In Chapter 5, the design and synthesis of MMP-14 sensitive ACPPs (ACPP-14) is addressed. MMP-14, like MMP-2 and -9, plays an important role in adverse cardiac remodeling. The most effective ACPP-14 probe was selected by employing MMP-14 sensitivity and enzyme specificity assays. This probe showed efficient cellular uptake upon activation. In a pilot in vivo biodistribution study, the level of in vivo background activation in the vasculature was decreased compared to MMP-2/9 ACPP (Chapters 2 and 3), while an increased uptake in infarcted heart tissue was observed compared to remote heart tissue, warranting further research into the in vivo biodistribution of this probe. Chapter 6 presents the development of an ACPP sensitive for the carboxy exopeptidase angiotensin converting enzyme (ACE). Upregulated heart-associated ACE activity has been related to adverse cardiac remodeling in nearly all cardiovascular diseases. Using molecular modeling approaches, various ACE ACPPs were designed to fit into the catalytic pocket of ACE. These probes were subsequently synthesized, but unfortunately showed no in vitro sensitivity towards ACE. Chapter 7 deals with the design of an ACPP that responds to hydrogen peroxide (H2O2). Production of reactive oxygen species like H2O2 typically occurs during elevated oxidative stress and contributes to the pathogenesis of several diseases, including cardiac ischemia-reperfusion injury. In this Chapter, we propose to extend the application of the ACPP imaging concept to the detection and imaging of H2O2 after cardiac ischemia-reperfusion injury. The suggested H2O2 ACPP uses a H2O2 self-immolative linker moiety to which the cell penetrating polycationic peptide and the polyanionic peptide are conjugated. H2O2-triggering initiates self-immolation of the linker, and thereby releases the polycationic cell penetrating peptide in H2O2-producing tissues. This H2O2 ACPP probe is currently in development. Finally, Chapter 8 concludes with a general discussion on the preceding chapters, followed by some future perspectives of activatable cell penetrating peptide imaging probe
MOLECULAR AGENTS FOR TARGETED IMAGING AND THERAPY Trends and Concepts in Agent Development
No full textAbstract: Molecular Imaging allows the visualization of biological processes in vivo, offering new chances for healthcare with respect to early diagnosis and improved therapy. The new field of molecular imaging has been boosted by more sensitive imaging systems and the emergence of targeted imaging agents that home in on molecules of interest. This chapter describes the principles of molecular imaging and the different strategies to design targeted agents. Each imaging modality offers certain strong points but also shortcomings, which impact targeted agent design and their potential area of application
Literacy and the vernacular : a case study based on the post-colonial history of Mauritius, with particular reference to Mauritian Creole
No full textThis thesis examines the process of the literization of the vernacular, and seeks to establish the island of Mauritius as a case study of this process. The concept of literization equates standardization of the vernacular with its use as a written language. Four issues are established as central to this process: ideological, educational, sociocultural and technical.
The thesis investigates the particular sociolinguistic situation of Mauritius, and examines each of these issues in relation to Mauritian Creole. It demonstrates the role that Mauritian Creole plays in Mauritian society, and how, since independence, issues relating to ideology, education, and the cultural and technical aspects of standardization, have been involved in the promotion of the language. The interaction between these issues is apparent throughout the thesis, and manifested in the work of Ledikasyon pu Travayer (LPT), the only organization in Mauritius to provide literacy tuition in Mauritian Creole. The thesis seeks to show that their unified approach to literacy, standardization, and the promotion of Mauritian Creole exemplifies the issues involved, and provides the best basis for the establishment of Mauritian Creole as a standard language.
The analysis of the situation in Mauritius within the framework of wider issues of the literization of the vernacular permits a comparison to other former colonies facing problems of language choice, and places these issues within the wider sociolinguistic context of standardization
Construire une didactique interculturelle du français juridique (approche sociolinguistique, historique et épistémologique.)
No full textCette thèse se propose de réfléchir à l intégration d une démarche interculturelle dans un enseignement-apprentissage de français juridique. Axé sur le public des étudiants étrangers venant suivre un cursus de droit en France, ce travail constitue une contribution à la didactique du français sur objectifs universitaires (FOU). Les questions didactiques abordées sont étayées par une mise en perspective sociolinguistique, historique et épistémologique approfondie : éclairer la manière dont s articulent le linguistique et le juridique permet en effet de mieux comprendre la relative difficulté à concevoir un enseignement interculturel du français juridique. Pour (ré)introduire cette dimension interculturelle, il paraît pertinent de partir de certaines propositions herméneutiques existant en droit et en sciences du langage. L herméneutique interculturelle développée dans ce travail vise à améliorer la préparation et l accompagnement de l insertion des étudiants juristes étrangers, en proposant une perspective véritablement relationniste.This thesis explores the idea of integrating a cross-cultural approach into the teaching-learning process of legal French. Focused on the foreign student public who are studying Law in France, this work constitutes a contribution to French for Academic Purposes. The didactic questions raised here are backed up by a thorough putting into perspective of sociolinguistic, historic and epistemic factors : clarifying the manner in which Linguistics and Law are articulated to each other allows to better understand the relative difficulty of setting up a cross-cultural teaching program of legal French. In order to (re)introduce this cross-cultural dimension, it would seem appropriate to start with certain formerly-established hermeneutic propositions in Law and Language Sciences. The cross-cultural hermeneutics developed in this work aims at improving the preparation and accompaniment of foreign students integration, by proposing a truly relationist perspective.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF
« Interlecte » : Outil ou point de vue épistémologique sur « la » linguistique et les langues ? Sémiotique ou herméneutique ?
No full textInternational audienceStarting from the seminal notion of interlect coined by L.-F. Prudent for Creole situations, the author wonders whether, upon reflection, this notion would not gain from seeing its scope of relevance broadened and its status changed. Indeed, the question posed by L.-F. Prudent suggests that the notion of "language" deserves in-depth critical reflection that has consequences on the way in which we conceive of linguistics itself (should it remain strictly semiotic?), and, hence, sociolinguistics.A partir de la notion séminale d'interlecte forgée par L.-F. Prudent pour les situations créoles, l'auteur se demande si, à la réflexion, cette notion ne gagnerait pas à voir son champ de pertinence élargi, et son statut changé. En effet, la question posée par L.-F. Prudent suggère que la notion de "langue" mérite une réflexion critique approfondie qui a des conséquences sur la façon dont on conçoit la linguistique elle-même (doit-elle demeurer strictement sémiotique ?), et la sociolinguistique
- …
