• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • 1
  • Tagged with
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Composition et fonctionnement d'une communauté microbienne au sein d'un drainage minier acide : approches culturales et fonctionnelles / Composition and functioning of a microbial community in an acid mine drainage : cultural and functional approaches

Delavat, François 05 October 2012 (has links)
Le drainage minier acide de Carnoulès est caractérisé par un pH très acide et une forte concentration en métaux et en arsenic. Par différentes approches moléculaires, des études précédentes ont montré une faible biodiversité et ont permis d'établir un modèle de fonctionnement de la communauté bactérienne. Le but de ce travail de thèse a été de préciser la composition et le fonctionnement de cette communauté bactérienne, en utilisant pour cela des approches culturales et fonctionnelles, en se focalisant particulièrement sur le recyclage de la matière organique. L'élaboration de différents milieux a permis l'isolement de 49 souches bactériennes appartenant à 19 genres, augmentant ainsi de 10 % la diversité bactérienne détectée à Carnoulès par rapport aux approches métagénomiques précédentes. Parmi les 19 genres, 3 sont nouveaux dont un, inféodé aux écosystèmes acides, a été caractérisé taxonomiquement et dénommé Acidiminas carnoulesii. La capacité de l'isolat Q8 appartenant au genre Paenibacillus à dégrader I'amidon et la xylane, dans de larges gammes de pH et de concentrations en arsenic, a permis d'attribuer à Paenibacillus un rôle dans la résilience de la communauté pour ces fonctions. Un criblage fonctionnel de I'ADN de Q8 dans Escherichia coli apermis d'isoler les gènes codant les protéines de dégradation de ces polymères. Par ailleurs, un criblage de 80000 clones de la banque d'ADN métagénomique de Carnoulès a permis la détection de 28 clones positifs pour l'activité amylolytique. Deux protéines ne présentant aucune similarité de séquence avec des amylases connues ont été caractérisées in vitro, confirmant leurs activités amylolyiques et démontrant que la bioprospection dans des sites a priori incongrus, autorise des découvertes insoupçonnées. Ces travaux ont ainsi permis de montrer que les approches culturales et fonctionnelles apportent des informations nouvelles par rapport à celles obtenues par les approches moléculaires. La complémentarité de ces approches est vérifiée, et elle apparaît indispensable dans l'analyse de la complexité des écosystèmes. Cependant, la compréhension de leur fonctionnement exigera des efforts redoublés. / The Carnoulès acid mine drainage is characterized by an acidic pH and high metal and arsenic concentrations. Based on the low bacterial biodiversity, molecular approaches allowed the determination of a bacterial community functioning model. The aim of the PhD work was to clariff both the composition andthe functioning of this community, using cultural and functional approaches, focusing on the organic matter recycling. Different media were designed that allowed the isolation of 49 bacterial strains belonging to 19 genera,leading to a 70 o  increase in the bacterial diversity compared with previous metagenomic approaches. Among the 19 genera,3 are new, one of which, a previously uncultured genus frequently detected in acidic environments, has been taxonomically characterized and named Acidiminos cornoulesii.The ability of strain Q8, belonging to the genus Paenibacillus, to degrade starch and xylan over a wide rangeof pH values as well as 4rsenic concentrations allows to assign to Paenibacillus a role in the resilience of the community for these functions. A function-based screening of the Q8-DNA in Escherichia coli led to isolatethe genes encoding the polymer-degrading proteins.Moreover, a function-based screening of 80,000 clones from a Carnoulès metagenomic DNA library led to the detection of 28 positive clones for the amylolyic activity. Two proteins sharing no sequence similarity with known amylases were characterized in vitro, demonstrating that bioprospecting in a priori incongruous sites can lead to unsuspected discoveries.These works show that new informations using cultural and functional approaches can be obtained compared to those gained with molecular approaches. Results confirmed the complementarity between both approachesis crucial to analyze complex ecosystems. Nevertheless, more research efforts still have to be undertaken tounderstand their functioning.
2

社區發展協會與鄰里組織、政府單位互動關係對其社區功能影響性分析-以臺北市為例 / The community function influential analysis of the relationship between the community association and neighborhood office、Government-A case study of Taipei city,Taiwan.

謝明峰, Hsieh, Min Feng Unknown Date (has links)
本研究為研究者由實務工作所遭遇之問題出發,企圖了解社區發展協會之學理上社區功能與政策上社區功能為何?而該社區功能受哪些因素所影響(以社區類型、社區發展協會與里辦公處互動關係、社區發展協會與政府單位互動關係來檢視)?學理上社區功能與政策上社區功能有何落差?經由本研究之研究問題,擬訂出本研究假設: 研究假設一:學理上的社區功能與政策上的社區功能是有相關的。 研究假設二:不同的社區類型會影響學理上之社區功能。 研究假設三:不同的社區類型會影響政策上之社區功能。 研究假設四:社區發展協會與里辦公處之互動關係越好,其學理上社區功能發展越好。 研究假設五:社區發展協會與政府單位之互動關係越好,其學理上之社區功能發展越好。 研究假設六:社區發展協會與里辦公處之互動關係越好,其政策上之社區功能發展越好。 研究假設七:社區發展協會與政府單位之互動關係越好,其政策上之社區功能發展越好。 本研究採量化方式進行,針對臺北市331家社區發展協會(以98年11月統計數為母群體),利用臺北市政府社會局每年例行性辦理之補助說明會、臺北市社區發展工作評鑑輔導營及社區人才培訓活動發放問卷,本研究問卷共發放256份,其中回收187份,總計有效問卷161份,無效問卷26份,回收率為62%,惟本研究研究對象為社區發展協會,有效問卷中計有60份為重複填答,經剔除後本研究問卷共調查101家社區發展協會,其中理事長填答者共35份,總幹事填答者共38份,其他填答者28份(含理事、監事、會計、志工)。 經統計分析結果後發現未來在里辦公處與社區發展協會兩者組織發展情形,多數協會認為兩者仍應持續共存,且社區發展協會與里辦公處之互動關係良好的仍佔多數。而在與政府單位互動情形,整體而言,社區發展協會與政府單位之互動關係是良好的,另在整體滿意度與政府發展方向上,協會對於政府之施政、政策認為是滿意的、發展方向也與政府方向是一致的。本研究發現學理上社區功能與政策上社區功能兩者是無完全相關;而不同的社區類型是會影響社區發展協會學理上與政策上之社區功能;另外當協會與里辦公的互動關係越好時,其政策上社區功能會發展的越好。 / This thesis is started from the problem which the researcher met in practice work. The researcher would like to know what the community function in theory and policy is?And it is effected by what factors(Use the community type、the relationship in the community association and neighborhood office、the relationship in the community association and government to confer)?What is the difference between community function in theory and in policy?According to these questions,this thesis have seven assumptions: Assumption 1:The community function in theory is related to the community function in policy. Assumption 2:Different community type influence community function in theory. Assumption 3:Different community type influence community function in policy. Assumption 4:The better the relationship of the community association and neighborhood office is, the better the community function in theory is. Assumption 5:The better the relationship in the community association and the government is, the more is the community function in theory is. Assumption 6:The better the relationship in the community association and neighborhood office is, the better the community function in policy is. Assumption 7:The better the relationship in the community association and the government is, the better the community function in the policy is. This thesis is a quantification research, The population is 331 community associations(On a basis of September 2009).The questionnaire survey delivered 256 pieces. There are 161 pieces is applicable,26pieces are not in 187 recycled questionnaires. A Recycled ratio is 62%. Anyhow, we survey 101 community associations,there are 35 pieces answered by the organization president ,38 pieces answered by the organization manager,the others answered 28 pieces. This survey find out the community association and neighborhood office will exit together in the future. And the relationship of the community association and the neighborhood office is good, and so is the community association and government. In conclusion,the community association is satisfied with the government policy,and the development direction is the same. This survey find that the community function in theory the community function in policy is not related. Different community type influence community function in theory and in policy. Besides the better the relationship of the community association and neighborhood office, the better the community function in theory.

Page generated in 0.0712 seconds