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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.
1

Desenvolvimento e implementação de um novo sistema pneumático de transferência para irradiação de materiais no reator IEA-R1 / Development and implementation of a new pneumatic transfer system for materials irradiation at IEA-R1 reactor

Fernando, Alberto de Jesus 28 February 2011 (has links)
Sistemas Pneumáticos de Transferência - \"Pneumatic Transfer Systems\" (PTS) são equipamentos mecânicos amplamente e mundialmente utilizados para o transporte, movimentação e transferência de diversos tipos de materiais, objetos e cargas entre dois ou mais terminais localizados em locais próximos ou distantes um do outro. Devido à sua versatilidade e rapidez, a aplicabilidade do sistema se faz presente em diversas áreas da sociedade tais como medicina (hospitais e laboratórios de análises clínicas); indústria (civil, automobilística, siderúrgica, metalúrgica, mineração, química, de alimentos); comércio (postos de gasolina, cinemas, supermercados, bancos, pedágios, empresas de venda de produtos por internet, cassinos); serviços públicos (repartições públicas, cortes de justiça, correios e telégrafos). Na área nuclear o PTS também tem uma vasta aplicabilidade nas diversas instalações nucleares, destacando-se a sua utilização como parte do processo de produção de radioisótopos e radiofármacos de meia vida curta tais como 67Ga, 201Tl, 18F e 123I-ultra puro, instalações de eliminação e estocagem de resíduos radioativos e áreas de pesquisa que utilizam o método analítico de Análise por Ativação Neutrônica (AAN). O desenvolvimento deste trabalho foi direcionado para o projeto, construção, instalação e implementação de um novo Sistema de Transferência Pneumático para transporte e transferência de materiais que são irradiados no núcleo do reator IEA-R1, localizado no Instituto de Pesquisas Energéticas e Nucleares (IPEN), para aplicação da técnica de AAN. Para sua instalação foi calculado a carga sobre a placa matriz do núcleo do reator e os testes de envio e retorno da amostra em análise. O fluxo neutrônico na posição de irradiação foi determinado utilizando a técnica de folhas de Au (ativação) apresentando um valor de 3,70±0,26.1012 n cm-2 s-1. / Pneumatic Transfer Systems (PTS) are classified as mechanical equipment largely operated all over the world for transport of a huge sort of objects, samples and materials located at nearly terminals or even at separated ones. System applicability is often recognized in many activities, such as medicine (hospital settings, clinical analysis labs), industry (steel, automobiles, mining, chemical, food, construction), trading (gas station, movies, supermarkets, banks, e-commerce) and federal agencies (post services, federal courts, public enterprises). In the nuclear settings, PTS shows also a vast array of applications, being a part of radioisotope production, as well as short-lived radiopharmaceuticals, including 67 Ga, 201 Tl, 18 F and 123 I-ultra pure. Besides, PTS are also used at radioactive waste management plants and research institutes that apply neutron activation analysis (NAA). This work was directed toward the design and operation of a new PTS for the IEA-R1 nuclear research reactor settled at Instituto de Pesquisas Energéticas e Nucleares (IPEN) for NAA application. With this aim, it was calculated the charge of reactor core grid plate and sample transport testing. Neutron flux at irradiating position was determined as 3,70 ± 0,26 1012 n cm-2 s-1.
2

Desenvolvimento e implementação de um novo sistema pneumático de transferência para irradiação de materiais no reator IEA-R1 / Development and implementation of a new pneumatic transfer system for materials irradiation at IEA-R1 reactor

Alberto de Jesus Fernando 28 February 2011 (has links)
Sistemas Pneumáticos de Transferência - \"Pneumatic Transfer Systems\" (PTS) são equipamentos mecânicos amplamente e mundialmente utilizados para o transporte, movimentação e transferência de diversos tipos de materiais, objetos e cargas entre dois ou mais terminais localizados em locais próximos ou distantes um do outro. Devido à sua versatilidade e rapidez, a aplicabilidade do sistema se faz presente em diversas áreas da sociedade tais como medicina (hospitais e laboratórios de análises clínicas); indústria (civil, automobilística, siderúrgica, metalúrgica, mineração, química, de alimentos); comércio (postos de gasolina, cinemas, supermercados, bancos, pedágios, empresas de venda de produtos por internet, cassinos); serviços públicos (repartições públicas, cortes de justiça, correios e telégrafos). Na área nuclear o PTS também tem uma vasta aplicabilidade nas diversas instalações nucleares, destacando-se a sua utilização como parte do processo de produção de radioisótopos e radiofármacos de meia vida curta tais como 67Ga, 201Tl, 18F e 123I-ultra puro, instalações de eliminação e estocagem de resíduos radioativos e áreas de pesquisa que utilizam o método analítico de Análise por Ativação Neutrônica (AAN). O desenvolvimento deste trabalho foi direcionado para o projeto, construção, instalação e implementação de um novo Sistema de Transferência Pneumático para transporte e transferência de materiais que são irradiados no núcleo do reator IEA-R1, localizado no Instituto de Pesquisas Energéticas e Nucleares (IPEN), para aplicação da técnica de AAN. Para sua instalação foi calculado a carga sobre a placa matriz do núcleo do reator e os testes de envio e retorno da amostra em análise. O fluxo neutrônico na posição de irradiação foi determinado utilizando a técnica de folhas de Au (ativação) apresentando um valor de 3,70±0,26.1012 n cm-2 s-1. / Pneumatic Transfer Systems (PTS) are classified as mechanical equipment largely operated all over the world for transport of a huge sort of objects, samples and materials located at nearly terminals or even at separated ones. System applicability is often recognized in many activities, such as medicine (hospital settings, clinical analysis labs), industry (steel, automobiles, mining, chemical, food, construction), trading (gas station, movies, supermarkets, banks, e-commerce) and federal agencies (post services, federal courts, public enterprises). In the nuclear settings, PTS shows also a vast array of applications, being a part of radioisotope production, as well as short-lived radiopharmaceuticals, including 67 Ga, 201 Tl, 18 F and 123 I-ultra pure. Besides, PTS are also used at radioactive waste management plants and research institutes that apply neutron activation analysis (NAA). This work was directed toward the design and operation of a new PTS for the IEA-R1 nuclear research reactor settled at Instituto de Pesquisas Energéticas e Nucleares (IPEN) for NAA application. With this aim, it was calculated the charge of reactor core grid plate and sample transport testing. Neutron flux at irradiating position was determined as 3,70 ± 0,26 1012 n cm-2 s-1.
3

REDUCING THE PEAK TO AVERAGE POWER RATIO OF MIMO-OFDM USING Particle SWARM OPTIMIZATION BASED PTS.

Mazin, Asim Mohamed 01 May 2013 (has links)
Asim M. Mazin, for the Master of Science degree in Electrical and Computer Engineering, presented on Mar 27, 2013, at Southern Illinois University Carbondale. TITLE: REDUCING THE PEAK TO AVERAGE POWER RATIO OF MIMO-OFDM USING PSO BASED PTS. MAJOR PROFESSOR: Dr. Garth V. Crosby, In this thesis we proposed PSO based PTS to accomplish the lowest Peak-to-Average Power Ratio of MIMO-OFDM system. We applied the PSO based PTS on each antenna of the system in order to find the optimal phase factors which is a straightforward method to get the minimum PAPR in such a system. The performance of PSO based PTS algorithm in MIMO-OFDM with a wide range of phase factor tends to give a high performance according to the simulation results. In addition, there is no need to increase the number of particles of the PSO algorithm to enhance the performance of the system, which keeps the complexity of finding the minimum PAPR reasonable.
4

A reasch of strategy map and dynamic strategy goal of nonprofit organization ---Take Public Television Servive as example

Chen, Chun-chi 06 February 2006 (has links)
The main idea of strategy map is to compensate for the exceedingly static balance scorecard and to have the four frameworks more logically arranged. Strategic action is a dynamic system existing in the four frameworks of balance scorecard. Policymakers tend to pay too much attention to the variations of the short-time measurements than the long-term structural effect of system. Through time delay and the effect of negative feedback loops, strategic actions may cause the change of loops, leading to some side effects or counterintuition. As a result, managers may fail to correctly analyze situations and make appropriate decisions, have a complete strategic planning, and have the strategic goal expectably achieved. Public Television Service is a nonprofit corporation with properties of wireless television corporation and nonprofit organization simultaneously. Based on article 2 of the law of PTS, governmental donations of foundations for which a budget is prepared in accordance with this Law shall be reduced by ten percent each year until the third fiscal year; according to article 41, the station may not broadcast business commercials¡K This clause brings about an innate problem that it prevents PTS from raising money by dealing with commercial pursuits. With governmental donations barely increased, improving funds-raising ability has become an important object of PTS. With limited financial resource, PTS requires a dynamic managerial tool to keep its balance between the object of public welfare and the budget. The purpose of this article is to discuss the dynamic relations among strategic themes, actions and measurements on the strategy map of PTS, and to map the management system by qualitative and quantitative system dynamics. According to the result of secondary data analysis and the interviews, this research constitutes the strategy map of PTS based on strategic themes of four frameworks, modeling each sub-system. After testing, basic simulating and policy simulating, we can then explore the interaction among all sub-systems. Based on the theory of improving the dynamic alignment of balance scorecard strategy in system dynamics, this research models the system of PTS by intuitional and systematically-thinking methods separately. The results shows: 1. In the systems constructed by BSC and strategy map, dynamic relations exist in each component. Strategies may turn out to be counter-intuitional owing to time delay, and the effects of positive and negative loops. 2. Policy laboratory made by system dynamics can be used to simulate the policies. Leading and lag index of BSC also have dynamic properties. Therefore, when setting strategy goals or KPI, managers have to consider the influence caused by loops and time delay. In addition, the outcome of policy and case simulation reveals: 1. If the quality of TV programs does not progress in company with its service, the system will fall into the crisis of growth limit. 2. Improving service quality one-sidedly may lead to an effect disappointing or being detected after a long time because of time delay. 3. When executing the strategy to improve the quality of TV programs (to increase the budget of TV programs), PTS should manage to raise service capacity and satisfaction to reduce the force of negative feedback loops and maintain the policy effect.
5

Stress Responses and Attachment of Listeria Monocytogenes in Food

Bae, Dongryeoul 12 May 2012 (has links)
The rates of the US hospitalization and mortality caused by Listeria monocytogenes was estimated to be the highest of 31 food-borne pathogens including Salmonella, Escherichia coli, Campylobacter, and Clostridium. This pathogen has an ability to survive under extreme conditions widely found in the natural environment and food. Among 13 serovars L. monocytogenes serovar 4b, 1/2a and 1/2b are mainly associated with human listeriosis outbreaks. The deadliest outbreaks of human listeriosis and massive product recalls in multi-states were associated with ready-to-eat (RTE) food products such as mexican-style cheese, turkey deli meat, cabbage, and cantaloupes contaminated with the bacterium. Thus, contamination of food products with L. monocytogenes is a major concern for the food industry, regulatory agents and consumers. This study used oligonucleotide probe-based DNA array, quantitative real time RT-PCR, gene manipulation, biochemical assays, and electron microscopy techniques to better understand the molecular mechanisms of L. monocytogenes under stress conditions on various food matrices,. The transcriptome profiles of L. monocytogenes via microarray analysis and quantitative PCR identified genes that are involved in adaptation, attachment, or survival and growth of the pathogen under a stress condition on a food matrix. The mechanistic and functional studies further characterized the biological properties of L. monocytogenes in various RTE food products. We showed that specific genes involved in energy metabolism, biosynthesis of proteins, and cellular processes to affect listerial growth or adaptation to a RTE meat matrix were changed with no associated changes in virulence factor expression. We also reported that the effects of salt stress on the expression of genes involved in PTS and its related metabolic enzymes in L. monocytogenes. In addition, a novel gene involved in attachment to RTE vegetables and fruits was discovered. The concern about the prevalence of L. monocytogenes in RTE food has been escalated by recent food-borne outbreaks, suggesting that the prevention of human listeriosis become the top priority for the food industry. Data from these studies help us to better understand the survival, growth and contamination of the bacterium under different conditions. The information will help the development of prevention strategies in RTE meat products, vegetables and fruits.
6

Etude du rôle de l'opéron métabolique frz dans la virulence d'escherichia coli et dans son adaptation aux conditions environnementales / Role of the frz metabolic operon ini the virulence and in the environmental adaptation of Escherichia Coli

Rouquet, Géraldine 29 June 2010 (has links)
L’opéron métabolique frz code les sous-unités d’un transporteur PTS de la sous-famille du fructose, un activateur transcriptionnel des systèmes PTS de la famille MgA (FrzR), deux cétoses-1,6-bisphosphate aldolases de type II, une kinase spécifique des sucres (famille ROK) et une protéine de la superfamille des cupines. Il est fortement associé aux souches d’Escherichia coli à virulence extra-intestinale. Nous avons montré qu’il procure un avantage aux bactéries lors de conditions de stress (peu d’oxygène, phase stationnaire de croissance, croissance dans le sérum et l’intestin) et qu’il est impliqué dans l’adhérence et l’internalisation de la bactérie dans diverses cellules eucaryotes, en régulant l’expression des fimbriae de type 1. L’activateur (FrzR) est impliqué dans ces phénotypes. A l’aide de microarrays, une série de gènes sous la dépendance du système Frz ont été identifiés. Nos données suggèrent que frz code un senseur de l’environnement permettant à E. coli de s’adapter à un environnement fluctuant en régulant notamment certains gènes de virulence et d’adaptation à l’hôte. Un modèle de régulation est présenté. / The metabolic frz operon codes for three subunits of a PTS transporter of the fructose sub-family, for a transcriptional activator of PTS systems of the MgA family (FrzR), for two type II ketose-1,6-bisphosphate aldolases, for a sugar specific kinase (ROK family) and for a protein of the cupin superfamily. It is highly associated with Extra-intestinal Pathogenic Escherichia coli strains. We proved that frz promotes bacterial fitness under stressful conditions, (such as oxygen restriction, late stationary phase of growth or growth in serum or in the intestinal tract). Furthermore, we showed that frz is involved in adherence to and internalization of E. coli in several eukaryotic cells by regulating the expression of type 1 fimbriae. The FrzR activator is involved in these phenotypes. Microarrays, experiments allowed the identification of several genes under the dependence of the frz system. Our data suggest that frz codes for a sensor of the environment allowing E. coli to adapt to a fluctuating environment by regulating some virulence and host adaptation genes. A regulation model is presented.
7

Caracterização do material particulado inalável na atmosfera e na vegetação urbana na cidade de Goiânia / Characterization of inhalable particulate matter in the atmosphere and urban vegetation in the city of Goiânia

COSTA, Elias Cardoso da 08 September 2011 (has links)
Made available in DSpace on 2014-07-29T15:01:46Z (GMT). No. of bitstreams: 1 Dissertacao parte1 Elias Cardoso da Costa.pdf: 4115792 bytes, checksum: 0a587011d082ae96596c66939ca9bb02 (MD5) Previous issue date: 2011-09-08 / This work had as objective to study the thin particulate material (PM2;5), thick (PM10) suspended in the atmosphere and the PTS adsorved in the vegetation s foliage of the Goiânia city and also study the metals associated with these particulates, especially Pb and Cd, giving subsidies to the city s air quality avaliation. The samples were studied between june of 2010 to june of 2011, using samplers of the type stacker which collects the thin and thick particulate simultaneously in polycarbonate membranes of 47 mm of diameter and pores of 0.4 and 8µm of diameter. The particulates masses were determinated by gravimetria and the metals analysis were done by the Atomic Espectrometry of Absortion(AEA). The thin and thick particulates concentrations showed seasonal variation with a reduction of 80% in the rainy season. The primary standard in the CONAMA resolution, of 150µg.m-³,was not exceeded in any sampled day.The ideal annual average, of 50µg.m-³, was exceeded sometimes during this period and the air quality ranged between goot to regular during the drought season and good during the rainy season. The thin particulate concentrations were above the USEPA s recommended limit in the drought season.The concentrations of the metals associated to the particulate, like Pb, Cu, Cr, Mn and Ni were below the USEPA s and WHO s concentrations. The Cd concentrations, in some samples, were above the WHO s recommended limit. The studied vegetation showed a great adsortion capacity of PTS on their foliage and reached the maximum concentration of 16,97 mg.mm-² on the Monguba s foliage and contributed to the air quality.The species which showed the biggest particulate adsorption capacity per unit of area was Oiti, followed by Monguba.OBS: Estão subscritos 2,5 e 10 em PM. O programa não copia algumas formatações. / Este trabalho teve como objetivo estudar o material particulado fino (MP2,5), grosso (MP10) em suspensão na atmosfera e o PTS adsorvidos em folhagem de vegetação da cidade de Goiânia e bem como os metais associados a esses particulados, principalmente Pb e Cd, dando subsídios para a avaliação da qualidade do ar na cidade. As amostragens foram realizadas entre Junho de 2010 e Junho de 2011, utilizandose amostrador tipo stacker que coleta o particulado fino e grosso simultaneamente em membranas de policarbonato de 47mmde diâmetro e com diâmetros de poros de 0.4 e 8µm. As massas de particulados foram determinadas por gravimetria e as análises de metais foram realizadas empregando-se a técnica da Espectrometria de Absorção Atômica (AAS). As concentrações de particulados finos e grossos apresentaram variação sazonal com uma redução de 80% no período chuvoso. O padrão primário previsto na resolução CONAMA, de 150 µg.m-³, não foi ultrapassado em nenhum dia amostrado. O valor médio anual ideal, de 50 µg.m-³, foi ultrapassado algumas vezes nesse período e a qualidade do ar variou de boa a regular no período de seca e boa durante o período chuvoso. As concentrações de particulado fino ficaram acima do limite recomendado pelo USEPA no período seco. As concentrações de metais associados ao particulado, tais como, Pb, Cu, Cr, Mn e Ni ficaram abaixo do limite recomendado pela USEPA e OMS. As concentrações de Cd, em algumas amostras, ficaram acima do limite recomendado pela OMS. A vegetação estudada apresentou grande capacidade de adsorção de PTS em suas folhagens e alcançou uma concentração máxima de 16,97 mg.mm-² em folha de Monguba e contribui na melhoria da qualidade do ar. A espécie que apresentou maior capacidade de adsorção de particulado por unidade de área foi o Oiti, seguido pela Monguba. OBS: Estão subscritos 2,5 e 10 em PM. O programa não copia algumas formatações.
8

Dokumentationsmodell för fibernätverk : Utveckling av ett insticksprogram i QGIS / Documentation model for fiber networks : Development of a plug-in for QGIS

Pihl, Petra January 2019 (has links)
Samhällets ökande beroende av bredbandsstruktur och framför allt av digitala tjänster ställer krav på stabilitet och driftsäkerhet. Det innebär att infrastrukturen måste vara robust nog att motstå påfrestningar och ha så god kvalitet att den fungerar och är tillgänglig även vid störningar. Det har hittills inte funnits någon etablerad standard för hur ett nät bör förläggas vilket har lett till en stor variation kring hur nät anläggs och vilken kvalitet de håller. Post- och telestyrelsen (PTS) har på regeringens uppdrag tagit fram föreskrifter som ska leda till att bredbandsnätet byggs upp driftsäkert och robust. Föreskrifter har tagits fram tillsammans med flera av branschens aktörer och beskriver hur en robust fiberanläggning ska anläggas och drivas. Anvisningarna går under samlingsnamnet Robust fiber. I detta examensarbete är det kraven på dokumentation av fibernät som studeras. På grund av Sveriges regerings bredbandsstrategi så har utbyggande av fibernätverket gått i sådan takt att dokumentation släpar efter. Geografiska informationssystem (GIS) är lämpliga att utnyttja för dokumentation och analys av robustheten i fibernät. Syftet med examensarbetet är utveckla en metod till opensource programvaran QGIS för att dokumentera fibernätverk och information om dess beståndsdelar. Metoden för arbetet var att designa en relationsdatabas med stöd för geografiska objekt och implementera detta i QGIS för att modellera upp fibernätverkets struktur och generera en översikt. Databasen sköter information om objekt och utsökningar kan utföras med SQL-frågeuttryckt och kopplas ihop med nätöversikt i QGIS. Resultatet visar att det är möjligt att till stor del uppfylla kraven för dokumentation. Det problem som dock inte lyckades lösas var dokumentationskravet att kunna visa schematiska ritningar för kanalisation.
9

Métabolisme du carbone et virulence chez Neisseria meningitidis / Carbon metabolism and virulence in Neisseria meningitidis

Derkaoui, Meriem 04 September 2015 (has links)
Neisseria meningitidis possède un PTS incomplet. Constitué des composants générales EI et HPr et de deux EIIAs (EIIANtr et EIIAMan), ce système ne permet pas le transport des sucres chez cette bactérie. Cependant, nous avons confirmé que la cascade de phosphorylation (EI HPr EIIANtr) est fonctionnelle et que HPr est aussi phosphorylée sur sa Ser-46 par une HprK/P.Dans l’objectif d’étudier l’effet de HPr sur la virulence de N. meningitidis, nous avons construit un mutant ΔptsH chez N. meningitidis 2C4-3. Le mutant ΔptsH a montré une faible survie chez la souris, une faible production de la capsule, une meilleure adhérence aux cellules épithéliales et un niveau élevé de cellules apoptotiques, par rapport à la souche sauvage. HPr semble intervenir dans la virulence de N. meningitidis en interagissant avec la protéine CrgA. L’interaction HPr/CrgA est plus forte quand HPr est phosphorylée sur sa Ser-46 par HprK/P.N. meningitidis utilise le glucose et le maltose comme seuls sucres. Nous avons identifié une perméase à glucose (GlcP) et une perméase à maltose (MalY), responsables du transport de ces sucres. Une perméase putative à gluconate (GntP) a été également identifiée chez N. meningitidis 2C4-3. Cette perméase n’assure pas le transport du gluconate, dans les conditions testées. La délétion de gntP chez N. meningitidis 2C4-3 induit une meilleure croissance sur glucose et une bonne survie du mutant ΔgntP chez la souris, par rapport à la souche sauvage. La fonction réelle de la perméase GntP chez N. meningitidis reste inconnue et suscite des études ultérieures. / Neisseria meningitidis has an incomplete PTS composed of general proteins EI and HPr and two EIIAs (EIIANtr and EIIAMan). This system does not allow the transport of sugars in this bacterium. However, we confirmed that the phosphorylation cascade (EI HPr EIIANtr) is functional and HPr is also phosphorylated at its Ser-46 by an HprK/P.In order to study the effect of HPr on meningococcal virulence, we constructed a ΔptsH mutant in N. meningitidis 2C4-3. Compared to the wild-type strain, the ΔptsH mutant showed poor survival in mice, low production of capsule, better adherence to epithelial cells and high levels of apoptotic cells. HPr appears to be involved in the virulence of N. meningitidis by interacting with CrgA protein. The HPr/CrgA interaction is stronger when HPr is phosphorylated at its Ser-46 by HprK/P.N. meningitidis uses glucose and maltose as the only sugars. We identified permeases for glucose (GlcP) and maltose (MalY), which catalyze the uptake of these sugars.A putative gluconate permease (GntP) has also been identified in N. meningitidis 2C4-3. Under the conditions tested, this permease did not catalyze the transport of gluconate. Compared to the wild-type strain, deletion of gntP in N. meningitidis 2C4-3 induced faster growth on glucose and a better survival of the mutant in mice. To underst and the function of the GntP permease in N. meningitidis further studies will have to be carried out.
10

Caractérisation de l'opéron métabolique fru2 de Streptococcus agalactiae : phylogénie, induction, et régulation / Characterization of the Streptococcus agalactia fru carbohydrate metabolic operon : phylogeny, induction and regulation

Patron, Kévin 11 December 2015 (has links)
Streptococcus agalactiae est la première cause d’infections néonatales, et est aussi un pathogène émergent chez l’adulte immunodéprimé. L’objectif de ce travail de thèse a été de caractériser l’opéron métabolique fru2 de S. agalactiae (i) en étudiant sa phylogénie, (ii) en identifiant ses inducteurs, et (iii) en élaborant son schéma de régulation. Cet opéron est composé de 7 gènes qui codent un activateur transcriptionnel de la famille DeoR-like (Fru2R), un transporteur PTS (PTSFru2), et trois enzymes qui sont potentiellement impliquées dans la voie non oxydative des pentoses phosphates. Nous avons mis en évidence que cet opéron avait été acquis au cours de l’évolution, et n’était présent que chez les souches de complexes clonaux responsables d’infections chez l’adulte immunodéprimé et la personne âgée. Nous avons ensuite montré que certains milieux complexes, sources de carbone, et liquides biologiques humains permettaient l’activation de cet opéron. Ensuite, nous avons caractérisé le rôle et fonctionnement de la protéine Fru2R (i) en montrant son rôle d’activateur transcriptionnel, (ii) en identifiant les acides aminés essentiels à son activité, et (iii) en démontrant sa capacité à se fixer au niveau de la région promotrice de fru2. / Streptococcus agalactiae, commonly known as group B streptococcus, is a leading cause of neonatal morbidity and mortality. It is also an emergent pathogen in immunocompromised and elderly adults. The objective of this study was to characterize the phylogeny, the induction and the regulation of the S. agalactiae fru2 operon. This operon encodes a PTS transporter of the fructose-mannitol family, a transcriptional activator of the DeoR-like family, an allulose-6 phosphate-3-epimerase, a transaldolase and a transketolase. Our results, concerning the phylogeny, indicate that fru2 was acquired during the evolution of S. agalactiae. Then, we highlighted that the fru2 promoter was active in complex medium, in chemically defined medium with various carbon sources and in human biological fluids. Then, we demonstrated that the Fru2R protein (i) was a transcriptional activator, (ii) contains amino acids which are essential for the activity of the Fru2R and fru2 promoter, and (iii) interacts with the fru2 intergenic region. Then, we demonstrated the role of the PTSFru2 proteins of S. agalactiae A909 fru2.

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