No description available.

El presente trabajo busca analizar los discursos de feminidad que se construyen alrededor de una banda femenina de metal, considerando el caso de Strógena, que es una banda peruana formada en el año 2013. En el 2017 lanzaron su primer disco, y actualmente se encuentran grabando el segundo. Dado su posicionamiento en la escena, resulta un buen referente para analizar las lógicas que subyacen tras su incursión en el escenario, sus redes de contactos y su relación con el público. Se busca entender los conflictos de género que atraviesan las mujeres en la esfera más pública de la cultura metalera, es decir en el escenario, en contraste con la homosocialidad del entorno metalero. Para ello, se han utilizado entrevistas, y observación participante en conciertos, ensayos, redes sociales y otros espacios donde las integrantes de la banda se mueven, analizando las situaciones en las que pudieran encontrarse por su condición de mujeres, con dificultades mayores de las que ya deben sortear los hombres en cualquier escenario musical de la realidad peruana.

Alternating copolymers represent a special class of copolymers in which the two comonomers copolymerize in a regular alternating sequence along the polymer chain. Of particular interest in our group are the stilbene-maleic anhydride/maleimide alternating copolymers. These copolymers possess sterically congested backbones and precisely placed functional groups arising from the strictly alternating copolymerization. The research in this dissertation is focused on the synthesis, characterization, and potential application of functionalized copolymers that contain semi-rigid alternating copolymer sequences. The fluorescence properties of a series of non-conjugated, tert-butyl carboxylate functionalized alternating copolymers were investigated. Extraordinarily high fluorescent intensity with excellent linearity was observed for the di-tert-butyl group-containing stilbene and maleic anhydride alternating copolymer in THF. We attributed the origin of the strong fluorescence to the “through space” π – π interactions between the phenyl rings from the stilbene and C=O groups from the anhydride. The fluorescence was maintained when the copolymer was deprotected and hydrolyzed and the resulting carboxylic acid-functionalized copolymer was dissolved in water at neutral pH. The tert-butyl carboxylate functionalized alternating copolymer sequences were incorporated into highly crosslinked polymer networks using suspension polymerization. After removing the tert-butyl groups by acidic hydrolysis, the surface area of the networks increased significantly. Using this facile two-step strategy, we were able to achieve nanoporous polymers with BET surface area up to 817 m2/g and carboxylic acid-functionalized surfaces. The BET surface area of deprotected polymers increased with increasing crosslinking density, and the stilbene-containing polymers showed systematically higher BET surface area than the styrene-containing polymers due to the stiffness of the alternating sequences. The resulting nanoporous polymers have potential to be employed as solid sorbents for CO2. The same tert-butyl carboxylate functionalized alternating copolymer sequences were also incorporated into microgels via miniemulsion polymerization. The miniemulsion technique ensured the successful synthesis of microgels with ~100 nm diameter using solid stilbene and maleimide monomers. The resulting tert-butyl carboxylate-containing microgels were converted into carboxylic acid-containing aqueous microgels by acid hydrolysis. These aqueous microgels showed good and reversible lead and copper ion adsorption capacities. Amine-functionalized nanoporous polymers were synthesized by the post-modification of highly-crosslinked divinylbenzene-maleic anhydride polymers. High amine-contents were achieved by covalently attaching multiamines to the acid-chloride functionalized polymer surface. The resulting polymers showed medium to high BET surface areas (up to 500 m2/g) and high CO2 capture capacities. / PHD / Copolymers are polymers that consist of two or more different monomers in the polymer chain. Research on copolymers can be traced back to the 1930s. Since the early discoveries, the research on copolymers has received considerable attention because of the ease of synthesis and the versatile properties and applications of these materials. Alternating copolymers are one of the most studied types of copolymers. In an alternating copolymer, the two different monomers arrange in a regular alternating sequence along the polymer backbone. Of special interest in our group are the alternating copolymers that contain stilbene (1,2- diphenylethylene). The stilbene-containing alternating copolymers have relatively rigid (semi-rigid) structures, which lead to unusual and interesting properties. The research described in this dissertation is focused on incorporating these semi-rigid alternating copolymers into different types of systems and studying their structure/property relationships. Three different polymeric materials and their properties were explored. Fluorescent materials can glow when irradiated by a certain wavelength of light. This property is very useful in biomedical sensing, imaging and labeling. The semi-rigid stilbene-containing alternating copolymer exhibited fluorescence with extraordinarily high intensity, solely due to the conjugation from the exact juxtaposition of molecular orbitals. This high intensity fluorescence suggests potential application as novel light-emitting materials. The increasing atmospheric CO₂ concentrations due to human activities like transportation and manufacturing have caused public concerns. Currently, liquid amine scrubbing is one of the most well established methods for CO₂ capture in industry. However, due to the solvent evaporation, degradation, and the high energy demand during the solvent regeneration, solid polymeric materials are considered as attractive alternative CO₂ capture materials. We designed two kinds of polymers based on our semi-rigid alternating copolymer sequences, and they both exhibited pores smaller than 2 nm. With the help of different functional groups designed to interact with CO₂, these polymers showed enhancement in CO₂ capture properties, and show the viability as solid sorbents for atmospheric CO₂. Heavy metal contamination in water is a severe environmental and public health problem. The recent Flint water crisis raised the public awareness of this problem. We synthesized a series of hydrogel beads with diameters in the range of 100-200 nm. The incorporation of these functional alternating copolymer sequence into the microgels led to fast and reversible adsorption of the lead and copper ions in water.

A room temperature procedure for the partial extraction of heavy metals from soils was investigated in order to find an optimum combination of acid type, acid strength and digestion period. Hydrochloric and nitric acids were compared. The optimum set of variables would produce a maximum amount of adsorbed metal extraction, with a minimum amount of damage to the soil crystal structures, in the shortest possible time span. Samples were analyzed for aluminum, iron, lead, manganese and zinc. In addition, the amounts of metals extracted by the room temperature procedure were compared with the amounts of metals obtained from both a total extraction and a partial extraction procedure involving heat. The chosen optimum combination technique was performed on a known metals trend area. No clearly optimal combination of acid strength and digestion time was found which would be applicable to varying types of soils; statistical analysis yielded a compromise point of 1.4N hydrochloric acid and 10.5 hour digestion period, as the most suitable combination. This combination of variables proved suitable since predicted results were obtained from the known metals trend area. Nitric acid was eliminated due to the acid’s lower reactivity. Room temperature extractions using strong acids at extended contact times were found to attack silicate minerals, but solutions stronger than have previously been used may be utilized without damage to the soil structure. Extractions utilizing heat and concentrated acids were too destructive to be considered true partial extractions. / M.S.

This Master’s thesis explores a relatively under-researched area within (popular) musicology, the art of record production, and metal music studies: the phenomenon of private music production in metal music. The thesis is coherently structured: it begins with a brief overview of the history of record production and discussions of the terms heavy metal and home production (chapter 1); states the research questions and objectives (chapter 2); presents a literature review of phono-musicology, rock and metal music studies, and music industries research (chapter 3); the theoretical framework, consisting of the Frankfurt School and French sociology, amongst others (chapter 4); the study’s methodology (triangulation of theoretical research, qualitative interviews, participant observation, autoethnography) (chapter 5); then the three main parts of the investigation. The empirical study deals with the interrelationship between digital production practices, sound and aesthetics, and economics, which is examined in three extensive chapters (6 to 8). These chapters are followed by a detailed discussion with further theoretical considerations, which discuss the differences between private and commercial (metal) music production as well as the hypothesis/observation of music production as a product and reflection of society as a whole.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal / L'objectif principal de cette thèse est d'explorer les liens existant entre la préférence pour la musique heavy metal et le risque suicidaire chez les adolescents québécois à la lumière des théories récentes sur l'aliénation (Arnett, 1996; Roe, 1995). Deux études furent réalisées afin de répondre à ces objectifs. Les deux études ont été réalisées auprès d'un même échantillon provenant d'une école de la région de Montréal. Cet échantillon est constitué de 275 adolescents âgés entre 14 et 18 ans issus d'un milieu socio-économique moyen. Les deux articles traitent de variables et de sujets différents bien qu'ils partagent une épistémologie et un contexte théorique communs. Le premier article examine la validité du construit et la validité concomitante du concept d'aliénation. Le deuxième article explore les liens existant entre la préférence musicale pour la musique heavy metal et le risque suicidaire. Les résultats du premier article démontrent que les items associés à l'ensemble de l'échelle peuvent être modélisés à partir de deux facteurs corrélés de second ordre; ces facteurs ont été nommés a posteriori Aliénation et Anomie. Les dimensions de premier ordre représentant l'Aliénation sont l'aliénation de soi/impuissance et l'isolement social, celles représentant l'Anomie sont l'absence de normes et l'absence de sens. On a constaté que l'Aliénation était plutôt associée à des comportements intériorisés (détresse psychologique et risque suicidaire) alors que l'Anomie était plus associée à des comportements extériorisés (consommation de drogues). Les résultats du deuxième article indiquent la présence d'un lien entre la préférence musicale pour le heavy metal et le risque suicidaire chez les filles, mais cette association devient non significative lorsque l'on considère d-autres facteurs de risque des comportements suicidaires. Cette étude démontre également qu'il existe des liens entre la vénération musicale, l'écoute cathartique et les facteurs de risque des comportements suicidaires. Malgré ces associations positives avec certains facteurs de risque, l'écoute cathartique de la musique est associée négativement au risque suicidaire lorsque l'on considère l'ensemble des facteurs de risque dans un modèle de régression.

This dissertation focuses on the development, characterization, and analysis of luminescent materials and coatings for sensing applications, including CO2, heavy metals, and silver. Chapter 2 involves the use of a gold(I) pyrazolate trimer that is able to detect silver ions with an AgNP medium. Detection of silver is vital, because there is an influx of silver into our environment caused by the increased use of AgNP. Therefore, having a sensor that is able to differentiate between and detect only Ag ions is an important first step to solving the toxicity mystery of AgNPs. Chapter 3 focuses on the development of sensor coatings containing a Eu(III) based luminescent system for sensing dissolved CO2 without the aid of an absorption-based dye. It is well-known that monitoring CO2 levels in our environment is important since even at low concentrations it can cause adverse health effects to the human body. This work demonstrates a pH-sensitive Eu complex being used directly as a CO2 sensor without the aid of any other absorption-based dye. Chapter 4 explores the idea of developing a heavy metal sensor for lead and its ability to detect lead in wide concentration range upon changing the pH of the medium and the polymer matrix. Different heavy metals have toxicity at different concentrations, therefore, being able to change the dynamic range of the sensor is advantageous. This research is the first step towards developing a luminescent Pb sensor with a tunable dynamic range.

Tang Wai Lun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 199-220). / Abstracts in English and Chinese. / Abstract --- p.ii / 摘要 --- p.iv / Acknowledgements --- p.vi / Table of contents --- p.vii / List of Abbreviations --- p.xi / List of Tables --- p.xii / List of Figures --- p.xv / Chapter Chapter One --- Literature Review --- p.1 / Chapter 1.1 --- Marine pollution in Hong Kong --- p.1 / Chapter 1.2 --- Contamination of sediments --- p.3 / Chapter 1.2.1 --- Metals contamination in coastal sediments in Hong Kong --- p.4 / Chapter 1.2.2 --- Other contaminants in sediments --- p.7 / Chapter 1.3 --- Sediment toxicity assessment --- p.9 / Chapter 1.4 --- Fish as examples for the measurement of biological responses to contaminants --- p.9 / Chapter 1.5 --- Biomarkers for toxicity assessment --- p.11 / Chapter 1.5.1 --- Metallothionein (MT) --- p.11 / Chapter 1.5.2 --- Cytochrome P450 1A (CYP1A) --- p.13 / Chapter 1.5.3 --- Vitellogenin (Vtg) --- p.13 / Chapter 1.5.4 --- Enzyme biomarkers: Alanine transaminase (ALT); aspartate transaminase (AST) and creatine kinase (CK) --- p.14 / Chapter 1.5.5 --- DNA damage detected by the comet assay --- p.16 / Chapter 1.6 --- Multi biomarkers for sediment toxicity assessments --- p.16 / Chapter 1.7 --- Objectives --- p.16 / Chapter Chapter Two --- "Concentrations of Heavy Metals and Trace Organics in Coastal Sediments Collected from Victoria Harbour, Deep Bay, Tolo Harbour and Lai Chi Wo" --- p.18 / Chapter 2.1 --- Introduction --- p.18 / Chapter 2.2 --- Materials and Methods --- p.19 / Chapter 2.2.1 --- Sediment collection --- p.19 / Chapter 2.2.2 --- Treatment of sediment samples --- p.21 / Chapter 2.2.3 --- Acid wash of apparatus --- p.21 / Chapter 2.2.4 --- Acid digestion of sediment sample --- p.21 / Chapter 2.2.5 --- Sequential extraction of heavy metals in sediment samples --- p.22 / Chapter 2.2.6 --- Heavy metals measurement --- p.23 / Chapter 2.2.7 --- Trace organic measurement in sediments --- p.24 / Chapter 2.2.8 --- Statistical Analysis --- p.24 / Chapter 2.3 --- Results --- p.25 / Chapter 2.3.1 --- Concentrations of total Metals in sediments --- p.25 / Chapter 2.3.2 --- Speciation of metals in sediments --- p.27 / Chapter 2.3.3 --- Metal abundance in different fractions of sediment --- p.33 / Chapter 2.3.4 --- Concentrations of trace organic in sediments --- p.33 / Chapter 2.3.5 --- Results summary --- p.36 / Chapter 2.4 --- Discussion --- p.36 / Chapter 2.4.1 --- Comparison with international standards --- p.38 / Chapter 2.4.2 --- Comparison with international studies of coastal sediments --- p.39 / Chapter 2.4.3 --- Comparison of the present study with other studies concerning Hong Kong coastal sediments --- p.45 / Chapter Chapter Three --- "Heavy Metals Accumulation in Tissues of Tilapia Exposed to Coastal Sediments Collected from Victoria Harbour, Deep Bay, Tolo Harbour, and Lai Chi Wo" --- p.51 / Chapter 3.1 --- Introduction --- p.51 / Chapter 3.2 --- Materials and Methods --- p.52 / Chapter 3.2.1 --- Collection and treatment of coastal sediments --- p.52 / Chapter 3.2.2 --- Sediment exposure tests with Tilapia --- p.53 / Chapter 3.2.3 --- Dissection of fish samples --- p.54 / Chapter 3.2.4 --- Acid digestion of fish samples --- p.54 / Chapter 3.2.5 --- Statistical Analysis --- p.55 / Chapter 3.3 --- Results --- p.55 / Chapter 3.3.1 --- Metal accumulation --- p.55 / Chapter 3.3.2 --- "Dose, duration and source of sediments affecting metals uptake" --- p.95 / Chapter 3.3.3 --- Results summary --- p.99 / Chapter 3.4 --- Discussion --- p.99 / Chapter 3.4.1 --- Site comparison --- p.99 / Chapter 3.4.2 --- Comparison with other studies --- p.100 / Chapter 3.4.3 --- Safety limits --- p.112 / Chapter Chapter Four --- "Expression of Biomarker Genes (MT, CYP1 A, Vtg) in Tissues of Male Tilapia After Eexposure to Coastal Sediments Collected from Victoria Harbour, Deep Bay, Tolo Harbour and Lai Chi Wo" --- p.115 / Chapter 4.1 --- Introduction --- p.115 / Chapter 4.2 --- Materials and Methods --- p.116 / Chapter 4.2.1 --- Sample collection --- p.116 / Chapter 4.2.2 --- Preparation of apparatus --- p.117 / Chapter 4.2.3 --- mRNA expression analysis --- p.117 / Chapter 4.2.3.1 --- Isolation of RNA --- p.117 / Chapter 4.2.3.2 --- Reverse transcription --- p.118 / Chapter 4.2.3.3 --- Real time PCR --- p.118 / Chapter 4.2.4 --- Vitellogenin (Vtg) --- p.120 / Chapter 4.2.5 --- Statistics analysis --- p.121 / Chapter 4.3 --- Results --- p.121 / Chapter 4.3.1 --- MT mRNA expression in tissues of male Tilapia exposed to sediments --- p.121 / Chapter 4.3.2 --- CYP1A mRNA expression in tissues of male Tilapia exposed to sediments --- p.129 / Chapter 4.3.3 --- Vtg expression in tissues of male Tilapia exposed to sediments --- p.137 / Chapter 4.3.4 --- Dose and time dependent relationships --- p.137 / Chapter 4.3.5 --- Results summary --- p.137 / Chapter 4.4 --- Discussion --- p.142 / Chapter 4.4.1 --- Correlation of MT and CYP1A expression with metals uptake in gills and liver --- p.142 / Chapter 4.4.2 --- MT as a biomarker of metals exposure --- p.144 / Chapter 4.4.3 --- CYP1A as a biomarker of trace organics exposure --- p.145 / Chapter 4.4.4 --- Real-time PCR --- p.147 / Chapter 4.4.5 --- Vtg as a biomarker of xenoestrogen exposure --- p.147 / Chapter Chapter Five --- "Expression of Enzyme Biomarkers (ALT, AST and CK) in Tissues of Male Tilapia After Exposure to Coastal Sediments Collected From Victoria Harbour, Deep Bay, Tolo Harbour and Lai Chi Wo" --- p.149 / Chapter 5.1 --- Introduction --- p.149 / Chapter 5.2 --- Materials and Methods --- p.150 / Chapter 5.2.1 --- Samples collection --- p.150 / Chapter 5.2.2 --- Alanine transaminase (ALT) and Aspartate transaminase (AST) --- p.151 / Chapter 5.2.3 --- Creatine kinase (CK) --- p.152 / Chapter 5.2.4 --- Statistical analysis --- p.153 / Chapter 5.3 --- Results --- p.153 / Chapter 5.3.1 --- ALT --- p.153 / Chapter 5.3.2 --- AST --- p.157 / Chapter 5.3.3 --- CK in gills --- p.157 / Chapter 5.3.4 --- CK in muscle --- p.164 / Chapter 5.3.5 --- "Dose, duration and source of sediments affecting metals uptake" --- p.164 / Chapter 5.3.6 --- Results summary --- p.169 / Chapter 5.4 --- Discussion --- p.169 / Chapter Chapter Six --- "DNA Damage in Liver of Male Tilapia After Exposure to Coastal Sediments Collected from Victoria Harbour, Deep Bay, Tolo Harbour and Lai Chi Wo" --- p.174 / Chapter 6.1 --- Introduction --- p.174 / Chapter 6.2 --- Materials and Methods --- p.176 / Chapter 6.2.1 --- Samples collection --- p.176 / Chapter 6.2.2 --- Tissue Preparation --- p.176 / Chapter 6.2.3 --- Single Cell Gel Electrophoresis (Comet) Assay --- p.176 / Chapter 6.2.4 --- Image analysis --- p.177 / Chapter 6.2.5 --- Statistical analysis --- p.178 / Chapter 6.3 --- Results --- p.180 / Chapter 6.4 --- Discussion --- p.187 / Chapter Chapter Seven --- General Discussion and Conclusion --- p.190 / Chapter 7.1 --- General discussion --- p.190 / Chapter 7.2 --- Conclusion --- p.198 / References --- p.199 / Appendix --- p.221

MEDEIROS, Abda de Souza. Cosmologias do rock em Fortaleza. 2008. 124f. Dissertação (Mestrado em Sociologia) – Universidade Federal do Ceará, Departamento de Ciências Sociais, Programa de Pós-Graduação em Sociologia, Fortaleza-CE, 2008. / Submitted by nazareno mesquita (nazagon36@yahoo.com.br) on 2011-11-08T12:45:24Z No. of bitstreams: 1 Art_2008_AdeS.Medeiros.pdf: 923279 bytes, checksum: b0d933bf67d6fc4b9fbff9eb73ae46a0 (MD5) / Approved for entry into archive by Maria Josineide Góis(josineide@ufc.br) on 2011-11-10T11:06:37Z (GMT) No. of bitstreams: 1 Art_2008_AdeS.Medeiros.pdf: 923279 bytes, checksum: b0d933bf67d6fc4b9fbff9eb73ae46a0 (MD5) / Made available in DSpace on 2011-11-10T11:06:37Z (GMT). No. of bitstreams: 1 Art_2008_AdeS.Medeiros.pdf: 923279 bytes, checksum: b0d933bf67d6fc4b9fbff9eb73ae46a0 (MD5) Previous issue date: 2008 / Este trabalho tem como objetivo tomar os shows de rock, mais especificamente os shows de Metal, sob a perspectiva dos rituais a fim de identificar e compreender as diferentes linguagens que ordenam e expressam as cosmologias (partes que em conjunto formam um todo dotado de sentidos de acordo com o contexto no qual estão inseridos, Tambiah, 1985) que configuram os referidos shows em determinados espaços na cidade. Do ponto de vista conceitual, algumas definições podem ser consideradas a fim de que compreendamos porquê os shows de Metal podem ser analisados sob a perspectiva dos rituais. Vejamos: a) é algo ordenado, sistemático, cuja lógica obedece a certos princípios em sintonia com o universo do Rock e o contexto social; b) o show se apresenta como um momento de diferenciação das atividades cotidianas e onde se compartilha assuntos de interesses comuns no que se refere a bandas, músicos, instrumentos; c) é um momento de encontros, trocas simbólicas e materiais, circulação e efetivação de espaços; d) e revelam os mecanismos de aceitação e de conflitos inerentes ao universo no qual os participantes seja organizados como banda ou platéia, estão inseridos. Os shows são protagonizados por grupos juvenis e que se denominam metaleiros/metalheads/headbangers, cujo significado é batedores de cabeça. Além disso, esses eventos configuram-se e realizam-se seguindo os princípios da filosofia denominada por eles underground,ou seja, orientam-se pela idéia “faça você mesmo” independente de patrocinadores, apoios institucionais públicos e/ou privados, seguindo uma lógica de mercado diferenciada da difundida pela “cultura de massa”; ainda que em certos ocasiões, na busca por espaços, apoios financeiros para a realização dos eventos, como também nas formas de divulgação e difusão dos trabalhos produzidos pelas bandas e consumidos pela platéia e por outras bandas ligadas ao estilo, recorram às formas de organização, produção, difusão e distribuição características da indústria cultural para o estabelecimento de trocas simbólicas, materiais e novos laços de sociabilidade, o que provoca, na maioria das vezes, um enriquecimento cultural por meio desses contatos, embora antagonismos de interesses venham a surgir. Entre as questões que esta proposta pretende responder, indago se os shows de rock contribuem ou não para o fortalecimento e diferenciação dos “metaleiros” em relação a outros agrupamentos que se ligam à música. E mais, que significados os shows expressam para os participantes e se esses significados permitem repensar as dinâmicas juvenis e mudanças culturais na contemporaneidade. O interesse por esse campo empírico advém de minhas experiências com pesquisa desde 2002, quando então, dediquei-me aos estudos de grupos e manifestações juvenis que se utilizam da música do Rock e do corpo como instrumentos para contarem a si mesmos e aos “outros” suas estórias (Geertz,1978) focando sempre os mecanismos de aceitação e de conflitos inerentes ao universo no qual estão inseridos. Os caminhos traçados por esta pesquisa se utilizaram da observação de palco e platéia, entrevistas realizadas entre os jovens "metaleiros", sites, jornais e revistas referentes aos shows.

Cupriavidus metallidurans CH34 est la bactérie Gram négative considérée comme organisme-modèle pour l’étude de la résistance aux métaux lourds. Notre travail a porté sur sa résistance au cuivre, codée par les gènes cop du plasmide pMOL30. Ces gènes, responsables des différentes étapes de la résistance (compartimentation des systèmes d’efflux entre périplasme et cytoplasme, modification de valence, et d’autres fonctions totalement inconnues) ont suscité notre intérêt.<p><p>On distingue dans l’îlot cop des gènes codant pour des fonctions de résistance proprement dite (essentiellement par détoxication active du cytoplasme et du périplasme). En effet, les mutants de copSRABCD, copF, et dans une moindre mesure copJ et copE deviennent sensibles. Les phénotypes des mutants divergent toutefois suivant que la mutation soit sur un cosmide qui ne porte que l’îlot (pMOL1024) ou dans son plasmide d’origine (pMOL30). Un second groupe de mutants (copVTMK, copG, copL, copQ) se distingue par un phénotype plus résistant ou identique à la souche parente, sauf autour de la CMI. Ces gènes interviendraient donc à la CMI pour assurer la résistance la plus élevée et le maintien d'un état viable latent.<p><p>La présence de l’îlot cop permet de contenir le taux d’oxygène radicalaire qui reste à un taux basal lorsque les cellules sont adaptées au cuivre environnent. Après un choc de Cu (ou stress aigu), l’îlot cop répond de façon « explosive » au stress, en consommant l’énergie du potentiel membranaire et en augmentant fortement l’activité de la chaîne respiratoire.<p><p>La résistance au cuivre est inductible, mais de façon différenciée pour la souche sauvage (CH34) et celle qui ne porte qu l’îlot cop (AE1744) :la CMI de CH34 triple après adaptation au cuivre, alors que celle d’AE1744 est inchangée. Après un choc de Cu, la résistance au cuivre est plus fortement induite pour AE1744 que pour CH34. Ces observations suggèrent que l’îlot cop ait été sélectionné pour sa capacité à répondre à un stress aigu puis intégré dans un ensemble de gènes plus vaste qui répond à des impératifs de stress chronique.<p><p>L’analyse biochimique de CopI, une petite protéine bleue à cuivre, montre qu’elle porte un site analogue à celui des oxydases multicuivre. Son rôle pourrait dès lors être celui d’une réductase multicuivre. La protéine CopK lie de façon très spécifique le Cu(I) et il semble que la liaison du cuivre modifie sa structure. L’analyse écologique a montré que des homologues de copK pourraient être présents dans l’ADN extrait de la terre de biotopes chargés en cuivre, et dans les souches cuprorésistantes qu’on y trouve. <p><p>La contribution majeure de cette thèse est de montrer que l’effet d’un stress métallique ne se résume pas à deux états physiologiques « mort ou vif ». Il y a lieu de considérer des états transitoires (choc de Cu, adaptation au métal, survie autour de la CMI, persistance) où interviennent des gènes spécifiques dans un ou plusieurs états donnés. Les résultats biochimiques et physiologiques ne nous éclairent pas encore assez sur les interconversions Cu(I)/Cu(II) ni sur les flux de cations notamment vers l'espace extracellulaire. Cette thèse ouvre des perspectives sur des mécanismes (protection à la CMI, phénotype persistant) assurant la survie des bactéries ou leur potentiel de recolonisation lors d'une diminution de la pression toxique :les gènes copT, copV, copK, copM, copB, copG, copL et copQ semblent impliqués dans ces fonctions. <p> / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished