989 resultados para Investigative activities
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Thesis written in co-mentorship with Robert Michaud.
Pro-inflammatory and angiogenic activities of VEGF and angiopoietins in murine sponge/Matrigel model
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La dérégulation de la formation et l'intégrité des vaisseaux sanguins peut conduire à un état pathologique tel qu’observé dans de nombreuses maladies ischémiques telles que: la croissance de tumeur solide, l’arthrite rhumatoïde, le psoriasis, les rétinopathies et l'athérosclérose. Par conséquent, la possibilité de moduler l'angiogenèse régionale chez les patients souffrant d'ischémie est cliniquement pertinente. Un élément clé dans l'induction de l'angiogenèse pathologique est une inflammation qui précède et accompagne la formation des nouveaux vaisseaux. Ce phénomène est démontré par l'augmentation de la perméabilité vasculaire et le recrutement de monocytes/ macrophages et cellules polynucléaires (neutrophiles). En collaboration avec d'autres groupes, nous avons montré que différents facteurs de croissance tels que le facteur de croissance endothélial vasculaire et les angiopoïétines peuvent non seulement promouvoir l'angiogenèse mais aussi induire diverses étapes connexes au processus de la réaction inflammatoire, y compris la synthèse et la libération des médiateurs inflammatoires et la migration des neutrophiles. Les objectifs de notre étude étaient d'adresser si le vascular endothelial growth factor (VEGF) et les angiopoïétines (Ang1 et Ang2) sont capables de promouvoir la formation des nouveaux vaisseaux sanguins au fil du temps et d'identifier la présence de différentes cellules inflammatoires dans ce processus. Des éponges d'alcool polyvinylique stérilisées et imbibées de Matrigel appauvri en facteur de croissance (contenant PBS, VEGF, Ang1 ou Ang2 (200 ng/200 μl)) ont été insérées sous la peau de souris C57/Bl6 anesthésiées. Les éponges ont ensuite été retirées aux jours 4, 7, 14 ou 21 après la procédure pour des analyses histologiques, immunohistologiques et cytométriques. La formation des nouveaux vaisseaux a été validée par la coloration au Trichrome de Masson et des analyses histologiques et immunohistologiques contre les cellules endothéliales (anti-CD31). De plus, la maturation des vaisseaux a été démontrée par la coloration séquentielle contre les cellules endothéliales (anti-CD31) et musculaires lisses (anti-alpha-actine). Nous avons effectué la même procédure pour caractériser le recrutement de neutrophiles (anti-MPO), et de macrophages (anti-F4/80). Afin de mieux délimiter la présence de différents sous-ensembles de leucocytes recrutés dans les éponges, nous avons utilisé une technique de cytométrie en flux sur des préparations de cellules isolées à partir de ces éponges. Nous avons observé que le VEGF et les angiopoïétines favorisent le recrutement de cellules endothéliales et la formation de nouveaux vaisseaux plus rapidement qu’en présence de PBS. Une fois formé au jour 7, ces nouveaux vaisseaux restent stables en nombre, et ne subissent pas une réorganisation importante de leur surface. Ces vaisseaux maturent grâce au recrutement et au recouvrement par les cellules musculaires lisses des néovaisseaux. En outre, le microenvironnement angiogénique est composé de cellules inflammatoires, principalement de neutrophiles, macrophages et quelques cellules de type B et T. Donc, le VEGF, l’Ang1 et l’Ang2 induisent séparément la formation et la stabilisation de nouveaux vaisseaux sanguins, ainsi que le recrutement de cellules inflammatoires avec des puissances différentes et une action temps-dépendante dans un modèle d’éponge/Matrigel.
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Aquaculture is one of the prime catalysts for the socio-economic development of Indian economy contributing to the nations food and nutritional security, export earnings, income and employment generation. In this study an evaluation of extension activities in the development of aquaculture in Kerala. This study was conducted with a view to examine how the Kerala fisheries department offered extension services to the aquaculture farmers in the freshwater and brackish water sectors of the state through various agencies like Fish Farmers Development Agency(FFDA), Brackish water Fish Farmers Development Agency (BFFDA). In this study there are 3 category of respondent’s fresh water beneficiary farmers, brackish water beneficiary farmers and fisheries extension officers. The main motive of the thesis is to make an attempt to explore the responses of local producers to the extension programs of the state with special reference to the aquaculture sector of Kerala, India. The most important technical constraint faced by the fresh water farmers was lack of knowledge followed by non-availability of quality seeds. In the case of brackish water farming, it was infection of disease followed by lack of knowledge. The overall activities of the department of fisheries were ‘fairly good’. It indicate the need for improvements in the delivery of extension services to various target groups. The state fisheries department has already moving towards evolving these modes of extension activities by community participation.
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One-pot acetalizations of cyclohexanone. acetophenone and benzophenone were carried out using methanol over H-montmorillonite clay (a mesoporous material). silica, alumina, and different zeolites such as HFAU-Y.HBeta, H-ZSM-5, and H-mordenite. In all the cases a single product-the corresponding dimethylacetal-was obtained in high yields. Hemiacetal formation was not observed with any catalyst. A comparison of catalytic activity indicated that montmorillonite K-10 is the most active catalyst for the reaction. As evidenced by the reaction time studies, the catalyst decay is greater over the zeolite catalyst than over the clay.
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This thesis Entitled Internet Utilization and Academic Activities of Faculty Members in the Universities of kerala: an analytical study. Today, scientific research is throwing up new discoveries, inventions and vistas by the hour. We are witnessing a veritable knowledge explosion. It is important for members of university faculty members to keep abreast of it for giving up-t-date information to their students about the new development in the subject of their study. The internet is an invaluable tool for achieving it. Most of the universities have sufficient internet facility, but the accessibility to all the faculty members is not adequate. University Libraries also provides standard supplementary service in the internet area. This study indicates differential level of awareness and utilization of the internet services by the faculty members in the areas of teaching, research and publication. However the overall impression is that the awareness and utilization is inadequate. This point to the urgent need to devise programs and schemes to promote internet utilization among the faculty members. The suggestions indicate the key areas that deserve attention by policy makers and administrators. Thanks to the internet, every new development in every field of study is just a click away for faculty members, research scholars and students.
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In the present study we address the issue on gut associated lactic acid bacteria (LAB) isolated from the intestine of estuarine fish Mugil cephalus using de Man Rogossa and Sharpe (MRS) agar. LAB isolates were identified biochemically and screened for their ability to inhibit in vitro growth of various fish, shrimp and human pathogens. Most of the LAB isolates displayed an improved antagonism against fish pathogens compared to shrimp and human pathogens. Selected representative strains displaying high antibacterial activity were identified using 16S rRNA gene sequence analysis. Of the selected strains Lactobacillus brevis was the most predominant. Four other species of Lactobacillus, Enterobacter hormaechei and Enterobacter ludwigii were also identified. It was also observed that even among same species, considerable diversity with respect to substrate utilization persisted. Considering the euryhaline nature of grey mullet (Mugil cephalus), the LAB isolated from the gut possessed good tolerance to varying salt concentrations. This finding merits further investigation to evaluate whether the isolated LAB could be used as probiotics in various fresh and sea water aquaculture
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A more widespread use of cereal/legume rotations has been suggested as a means to sustainably meet increasing food demands in sub-Saharan West Africa. Enhanced cereal yields following legumes have been attributed to chemical and biological factors such as higher levels of mineral nitrogen (Nmin) and arbuscular mycorrhizae (AM) but also to lower amounts of plant parasitic nematodes. This study was conducted under controlled conditions to examine the relative contribution of AM, plant parasitic nematodes and increased nitrogen (N) and phosphorus (P) availability to cereal/legume rotation effects on two West African soils. Sample soils were taken from field experiments at Gaya (Niger) and Fada (Burkina Faso) supporting continuous cereal and cereal/legume rotation systems and analysed for chemical and biological parameters. Average increases in cereal shoot dry matter (DM) of rotation cereals compared with continuous cereals were 490% at Gaya and 550% at Fada. Shoot P concentration of rotation millet was significantly higher than in continuous millet and P uptake in rotation cereals was on average 62.5-fold higher than in continuous cereals. Rotation rhizosphere soils also had higher pH at both sites. For the Fada soil, large increases in Bray1-P and organic P were observed in bulk and rhizosphere soils. Plant parasitic nematodes in roots of continuous cereals were 60–80-fold higher than in those of rotation cereals. In both cropping systems mycorrhizal infection rates were similar at 37 days after sowing (DAS) but at 57 DAS AM infection was 10–15% higher in rotation sorghum than in continuous sorghum. This study provides strong evidence that cereal/legume rotations can enhance P nutrition of cereals through improved soil chemical P availability and microbiologically increased P uptake.
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Aquest quadern és el quart lliurement de la Guia per a l'adaptació a l'espai europeo superior. Té l'origen en el debat de la Comissió de Seguiment del Pla Pilot d'adaptació a l'Espai Europeu d'Educació Superior de la UdG i del grup de treball que s'ha constituït l'estiu del 2006 expressament per tractar el tema de les activitats d'aprenentatge
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Resumen basado en la publicación
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El auténtico protagonismo de los centros educativos tiene que dirigirse a ayudar a pensar a sus alumnos y a enseñarlos a aprender, es decir, el docente tiene que enseñar estrategias de aprendizaje y debe promover el esfuerzo del estudiante para facilitar la construcción de esquemas y el aprendizaje permanente. El profesor debe utilizar cualquier situación de aprendizaje para enseñar dichas estrategias de aprendizaje, incluso en las situaciones de evaluación; por lo tanto, en este trabajo se sugiere que en las evaluaciones de los alumnos y alumnas se tenga en cuenta la metacognición como factor fundamental en el aprendizaje y la enseñanza
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Notes, slides and activities which students can use/refer to when developing their CV. This is pitched at entry level students, but may be useful to students at all levels for general reference.
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A quick skim through Learning Outcomes, pedagogic methods and preparing and describing a learning activity.
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collection of resources specifying presentation tasks and providing guidance
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Description of a set student activity to create summaries of selected academic papers. Also contains small set of selected papers from which to choose two papers to read and summarise
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Use across a series of lectures to introduce the module, focus on the topic of interdisciplinarity and get to know the group. Includes link to mendeley group