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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.
41

Evaluation of IN SITU synthesis route of layered hydroxides in the presence of amphiphilic polymers in comparison with their corresponding physical mixtures / Evaluation d'une voie de synthèse IN SITU d'hydroxydes lamellaires en présence de polymères à caractère amphiphiles en comparaison avec leurs mélanges physiques correspondants

Langry, Arthur 07 October 2015 (has links)
L’originalité du manuscrit de thèse est basée sur une preuve de concept selon laquelle il peut être possible de générer IN SITU des matériaux plaquettaires au sein même d’une matrice polymère à renforcer. Cette approche est basée sur une nouvelle voie de préparation de matériaux hybrides à base d’hydroxydes lamellaires. Cette méthode combine une voie de synthèse par polyol et la génération IN SITU de plaquettes inorganiques, en présence d’oligomères BOLA à caractère amphiphile. La voie polyol consiste en l’hydrolyse en milieu alcoolique d’un ou de plusieurs sels acétate métalliques comme précurseur, en vue de former les phases LSH et HDL suivantes, LSH-Zn, LDH-Zn2Al ;-LiAl2. Les BOLA possèdent des segments téléchéliques composés de chaînes hydrophobes terminées par deux groupes anioniques hydrophiles, l’ensemble est neutralisé par un cation ammonium. L'impact de la voie de synthèse IN SITU, les systèmes plaquettaires choisis ainsi que les contre-ions organiques à partir de la morphologie des phases hybrides obtenues, est étudié en comparaison aux mélanges physiques correspondants (EX SITU). Ce manuscrit présente une étude structurale des différents nanocomposites formés ; par le biais d’analyses DRX, complétées par du SAXS (ligne de lumière SWING à Soleil) et de l’imagerie MET. Des bilans matière sur les différentes synthèses IN SITU sont aussi réalisés pour déterminer les rendements de formation et taux de conversion des précurseurs en matériaux lamellaires. Concernant l’approche EX SITU ; les chaines polymère diffusent entre les plaquettes inorganiques, ceci principalement lié à une réaction d’échange entre les anions acétate des phases lamellaires et les fonctions carboxylates des chaines polymère, conservant l’intégrité des feuillets à par un processus topotactique. L’efficacité du processus d’intercalation a été trouvée décroissante suivant LDH-Zn2Al > LDH- LiAl2 >> LSH-Zn. Dans le cas du LSH-Zn, un ensemble stratifié à plusieurs échelles a été observé alliant charpente inorganique initiale intercalé acétate et une partie diffusée du BOLA, conduisant à une structuration dite biphasique. Contre intuitivement, dans le cas des HDL, la voie EX SITU, basée sur la réaction topotactique d'échange, et la voie IN SITU, basée sur la réaction de templating ont donné dans de nombreux cas des résultats similaires en terme d'états de dispersion, et ceci indépendamment du polymère ou du BOLA utilisé ainsi que de la composition des plaquettes. L’observation de plaquettes isolées LSH-Zn, n’a jamais été reportée dans la littérature, ce qui rend alors le processus de synthèse polyol/IN SITU intéressant pour l’obtention d’état de dispersion exfolié pour ce type de particules. La combinaison polyol/IN SITU permet la génération de plaquette LSH ou LDH de taille latérale comprise entre 10 à 200 nm. Cependant, les plaquettes générées se sont révélées poreuses, un inconvénient pour les propriétés de type barrière. Ce résultat ouvre toutefois des perspectives nouvelles en intégrant ces plaquettes 2D poreuses avec des particules de type 1D pour une approche en architecture « tectonique ». / Layered particle based nano-composites have recently been shown to impart stone impact resistance to automotive coatings by making use of polymer intercalated Layered Double Hydroxide (LDH) platelets in a variety of different film morphologies. However the LDH particles used were obtained via coprecipitation of the metal salts in the presence of small organic anions in order to render the Layered Hydroxide particles organophilic and to facilitate the intercalation of carboxylate group bearing matrix polymers. Thus anion exchange in the course of colloidal processing and during film formation leads to the release of ionic species which may deteriorate the coatings barrier function. In order to circumvent objectionable counter ions (involved in the synthesis and the coatings formulation), a novel preparation route for layered hydroxide based hybrid phases has been here investigated combining the polyol route with the IN SITU generation of inorganic platelets, in the presence of amphiphilic polymer as well as bola-amphiphiles. The polyol route consists in hydrolysis in an alcoholic medium containing acetate metal cation as precursor(s), to yield LDH (Zn2Al, LiAl2 cation composition) or LSH-Zn (Layered Single Hydroxide). Bola amphiphile descripts as being some hydrophobic polymer segment-telechelic-chains terminated by two anionic hydrophilic end groups, using of volatile ammonium cation as counter ion. The impact of both process conditions as well as the chosen system with regard to the metal hydroxide framework and the organic counter ions on the morphology of the obtained hybrid phases are presented, discussed and compared to corresponding physical mixture. For the EX SITU approach, the diffusion of large cumbersome polymers or amphiphilic bolas between the inorganic platelets was found to be efficient, mostly driven by an anion exchange reaction between interleaved acetate anions and carboxylate functions of the molecular backbones, and keeping intact the inner-sheet integrity through a topotactic process. The efficiency of the intercalation process was found decreasing to range as LDH-Zn2Al > LDH-LiAl2 >> LSH-Zn, more or less regardless of the guest organic species. Aggregation may happen and cannot be discarded especially when using LiAl2 type platelets and non-neutralized bola. In particular with LSH-Zn, a multi stratified assembly has been observed combining acetate pristine structure and partly bola diffused structure, leading to a biphasic structure, aggregated and intercalated. To the best of our knowledge, observation of LSH-Zn single platelets has never been reported, making of the combined process Polyol/IN SITU an interesting new route in reaching exfoliation. Indeed, it yields to the generation of platelets either LSH or LDH of lateral size ranging between 10 up to 200 nm. However, the platelets were found to be porous; it is considered as a drawback for barrier properties. It is our belief that such porosity may open new insights in “tectonic” architecture by intertwining 2D and 1D-type filler. Rather counter intuitively, EX SITU based on topotactic exchange reaction matches the IN SITU templating reaction in many cases as a function of the dispersion state regardless of the polymer or bolas as well as the platelets cation composition.
42

Carcajou (Gulo gulo), sociétés et conservation dans le Nord canadien

Bonamy, Morgane 09 1900 (has links)
Cette recherche propose comme objectif d’étudier les relations entre le carcajou et les populations locales et autochtones du Canada, dans différentes régions d’études et dans un site de conservation ex-situ. Ceci afin de mieux comprendre leurs rapports et interactions avec cet animal et de pouvoir adapter les modes de gestion de l’espèce aux besoins des sociétés mais aussi en fonction du contexte socio-culturel local. Plus particulièrement, cette étude explore d’une part les relations entre Premières Nations et le carcajou, ainsi que les perceptions et les représentations sociales que différents groupes de la société (Ainés, chasseur, trappeurs, enfants autochtones/non-autochtones) ont de cet animal, et d’autre part le rôle que joue cette espèce, en contexte de conservation ex-situ : à savoir dans un jardin zoologique, sur les connaissances et la motivation du public envers la protection du carcajou. Pour ce faire, nous avons utilisées différentes méthodes (entrevues semi-dirigées, questionnaires, dessins, observation participante) sur trois sites d’études en fonction de l’absence/présence du carcajou. Ainsi, nous avons étudié les interactions humains-carcajous dans la région North Slave dans les Territoires du Nord-Ouest auprès des populations non autochtones et autochtones (les Premières Nations Dénée et Métis), où le carcajou cohabite avec les sociétés. Nous nous sommes également intéressés à la représentation du carcajou par les membres de la Nation Naskapie au Nord du Québec et de la Nation Dénée dans les Territoires du Nord-Ouest, où le carcajou n’est plus présent depuis 40 ans. Enfin, un dernier terrain au Zoo de St Félicien au Québec nous a permis d’analyser la place de ce carnivore dans la conservation ex-situ pour le public québécois. Les résultats ont mis en évidence, que les Premières Nations Dénées et Métis possèdent des connaissances très approfondies sur cet animal, qu’elles admirent et respectent, et ont souligné l’importance de la participation des populations et des savoirs traditionnels dans les projets de protection et conservation de cette espèce. L’analyse des connaissances et perceptions des enfants a montré que même si le carcajou ne leur est pas inconnu, de nombreuses lacunes sur l’espèce sont présentes reflétant un manque de connaissance général sur cet animal. Cependant, le carcajou reste un animal relativement bien représenté en dessin par les enfants, même si peu d’enfants connaissent son rôle écologique. Il existe quelques différences dans la représentation de l’animal selon le territoire/province dans lequel les enfants habitent. Les données collectées au sein du zoo ont indiqué que le public, d’une région où le carcajou a disparu, ne connait pas bien le carcajou, bien qu’il évalue positivement l’intérêt de cette espèce au sein du zoo. De manière prometteuse, exposer le grand public à cette espèce dans les zoos ou dans des camps d’été pour enfants semble être un moyen efficace pour promouvoir des attitudes positives à l’égard de cette espèce et encourager le soutien des populations envers sa conservation. Ces résultats montrent qu'il est nécessaire de mener des programmes alternatifs de sensibilisation et d'information du public au vu de la conservation et de la gestion du carcajou, en particulier dans les zones où de nouveaux programmes de gestion peuvent être mis en œuvre, afin d'accroître l'acceptation de cette espèce par la société et de sensibiliser le public à ce carnivore incompris. Cette étude souligne aussi l’importance de la participation des populations locales, adultes et enfants dans les programmes de conservation et gestion des espèces afin de garantir leur succès. De plus, les savoirs traditionnels et leur intégration dans la recherche scientifique devraient bénéficier d'une plus grande valeur. Enfin, les programmes de conservation doivent prendre en compte les souhaits des populations locales et collaborer avec elles, afin d’obtenir un plus grand succès. / The objective of this research is to investigate the relationships between local or First Nation people in Canada and wolverines, in different study areas and an ex-situ conservation site. In doing so, we hope to improve our understanding of these relationships and interactions with this species in order to adapt management policies and improve their fit with society’s needs and the local socio-cultural context. On the one hand, this study explores relations between First Nation peoples and the wolverine as well as the perceptions and social representations of this species by different societal groups (Elders, hunters, trappers, Indigenous/non-Indigenous children). On the other hand, it tries to understand the role played by wolverines in the context of ex-situ conservation (i.e. in a zoo) and knowledge and motivation by the public towards the protection of this species. We addressed these goals through the use of multiple different methods: semi-directed interviews, questionnaires, drawings, and participant observation, and applied these techniques in three separate study sites, both with and without wolverines. For example, we studied human-wolverine interactions in the North Slave region of the Northwest Territories with Indigenous populations (Dene and Métis First Nations), where people share the land with wolverines, gathering information from both adults and children alike. We then contrasted the knowledge and perceptions of these children with those of a second group that no longer have regular contact with this species, the Naskapi Nation in northern Quebec. Finally, at the St Félicien Zoo in Quebec, we qualitatively assessed the willingness of the general public to support conservation measures for this carnivorous species. Results indicated that Dene and Métis First Nations have a very deep knowledge of this species, which they admire and respect, which emphasized the importance of participation by First Nation peoples in the implementation of conservation programs for this species. In analyzing children's knowledge and perceptions, we found that while many children possess a basic knowledge about wolverines, there are numerous gaps in that knowledge which, if filled, may benefit future conservation efforts. Despite these gaps, the wolverine was relatively well represented in drawings by children, though their ecological role may remain be cloudy to some, and differences in their portrayal were apparent among territories/provinces in which children live. Data collected in the zoo indicate that the general public, in a region where wolverines have become extirpated, lack some general knowledge about this species and that the level of knowledge is not equal across the greater public. Promisingly, exposure to wolverines at the zoo or through children's camps does seem to promote positive attitudes towards this species and foster support for their conservation. These results shows that there is a need for increased awareness and public information programs for wolverine conservation, particularly in areas where new management programs may be implemented, to increase social acceptance of this species and raise public knowledge about this misunderstood carnivore. An integration of local populations, both children and adults, is necessary for a better legibility of management of the animal; as well as the valorization of traditional knowledge and its integration in scientific research. For the success of a species management program, it is inevitable to ask the people what they want and support the project. This study emphasizes the importance of participation by local populations, both adults and children, in conservation management plans for their success. Additionally, greater value should be assigned to traditional knowledge and its integration into scientific research. Finally, conservation programs must acknowledge the desires of the local populations and work together with local stakeholders if they wish to succeed.
43

Nanostructuration de films nanocomposites amidon / argent et amidon / argent / montmorillonites par procédé de « chimie verte » : influence des voies de génération des nanoparticules métalliques sur la structure et les propriétés de transport / Nanostructuration of starch/silver and starch/silver/montmorillonites nanocomposites films with green process : influence of the silver nanoparticles generation routes on structure and transport properties

Cheviron, Perrine 08 April 2015 (has links)
Des films nanocomposites amidon / argent ont été préparés par deux voies de génération vertes de nanoparticules d'argent. La première voie, dite ex situ, consiste à préparer tout d'abord une solution colloïdale d'argent qui est ensuite redispersée dans une matrice amidon plastifiée glycérol. Les nanoparticules d'argent colloïdales sont synthétisées en solution aqueuse par réduction du nitrate d'argent par du glucose en présence d'amidon stabilisant. La seconde voie, dite in situ, consiste à disperser le nitrate d'argent dans le film amidon plastifié et le réduire directement dans le film par traitement thermique en présence ou non de réducteur. L'influence du taux de glucose réducteur, du temps de synthèse et de la température a été étudiée en termes de taille, distribution de taille et dispersion des nanoparticules d'argent dans les films nanocomposites ex situ et in situ. Tout en gardant des paramètres de procédé comparables, les deux voies de nanostructuration des films amidon/argent ont également été comparées en termes de structure, de propriétés thermiques et de transport. Enfin, l'incorporation de charges montmorillonites a également été étudiée dans les deux voies de génération des nanoparticules métalliques. L'ensemble des travaux a permis de valider les deux voies de génération vertes menant à des nanoparticules d'argent dispersées de manière homogène et de tailles moyennes inférieures à 30 nm. La voie in situ à 85°C se distingue par des nanoparticules d'argent cristallines et de très petites tailles (inférieures à 10 nm) avec une interface amidon/argent cohésive particulière qui permettent d'améliorer les propriétés barrières aux gaz et à l'eau avec une diminution de perméabilité observée jusqu'à 90% / The present work reports a strategy involving the preparation of silver nanoparticles in a biodegradable polymer stemming from either an ex situ or an in situ method, using in both cases a completely green chemistry process. The influence of the reducing agent concentration and the silver nanoparticles generation route is investigated on the structure, the morphology and the properties of the nanocomposite films. In both routes, silver nanoparticles with a diameter below 30 nm were highlighted in the nanocomposite films. For all nanocomposite films, no modification on the crystalline structure of the starch matrix is observed in the presence of silver. The in situ generation route allowed to obtain the smallest silver nanoparticles with a diameter below 10 nm. Crystalline silver nanoparticles were obtained only from the in situ generation route at the temperature of 85°C. The introduction of montmorillonites in both generation routes was also studied. The decrease of the water sorption and the improvement of water and oxygen barrier properties were found to be not dependent on the reducing agent concentration but mainly on the presence of the crystalline structure of the silver nanoparticles. Thus, significant enhancement of the barrier properties were finally obtained for the in situ nanocomposite films thanks to an efficient interaction between the crystalline silver nanoparticles and the starch matrix
44

Development and Application of Techniques for the Control of Captive Breeding in Elasmobranchs

García Salinas, Pablo 03 January 2024 (has links)
Tesis por compendio / [ES] Los tiburones y rayas aparecieron hace 420 millones de años, conformando el antiguo y ecológicamente diverso, grupo de vertebrados acuáticos conocido como elasmobranquios. Este variado grupo posee unas estrategias vitales que los hace muy vulnerables a los cambios rápidos del entorno, como los derivados de la acción antrópica. Pese a ser elementos clave en la regulación de los ecosistemas en los que habitan, en la actualidad, se trata de uno de los grupos vertebrados más amenazados del planeta. Paralelamente a la conservación in situ, los programas de conservación ex situ se pueden utilizar para mejorar la situación de algunas especies sensibles. Entre estos programas, los planes de cría en cautividad aumentarían la sostenibilidad de acuarios públicos y centros de investigación, además de permitir el desarrollo de estrategias de conservación en estado salvaje. Sin embargo, para que sean efectivos, estos planes deberían incluir el uso de técnicas de reproducción asistida. Desafortunadamente, estas técnicas apenas se han desarrollado en el pasado, por lo que su utilidad no se ha demostrado adecuadamente. Esta tesis aborda el uso de técnicas de reproducción en elasmobranquios, con énfasis en la obtención y preservación del esperma. Inicialmente, se centró en dos especies modelo, Scyliorhinus canicula y Raja radula, pero luego se incluyeron otras especies. Esto reveló variabilidad en las estructuras reproductivas, lo que puede afectar la eficacia y calidad de las técnicas. Los capítulos 1 y 2 se enfocaron en catalogar y describir estas estructuras en diversas especies, destacando las mejores prácticas de obtención de gametos e inseminación. La conservación a corto, medio y largo plazo del esperma es esencial para planes ex situ, reduciendo el transporte de machos, conflictos durante el cortejo y endogamia. El Capítulo 3 detalla fórmulas para mantener el esperma fresco y un medio para su supervivencia por más de 30 días. Luego, se describe la criopreservación del esperma de varias especies de rayas y tiburones mediante crioprotectores. El Capítulo 4 aborda desafíos en la manipulación de espermatozoides elasmobranquios debido a su morfología helicoidal y la formación de agregaciones llamadas espermatozeugma. Se resalta la importancia de la viscosidad en las técnicas de reproducción asistida. En la Discusión, se compara la eficacia de los métodos y se exploran nuevas oportunidades al tener acceso a diversas especies. Esto incluye descripciones detalladas con análisis de imagen, evaluación de viscosidad y agregados en la preservación, y la consideración de inseminaciones artificiales. / [CA] Els taurons i les ratjades van aparèixer fa 420 milions d'anys, formant el grup conegut com a elasmobranquis. Aquest grup divers posseeix estratègies vitals que els fan molt vulnerables als canvis ràpids de l'entorn. Malgrat ser elements clau en la regulació dels ecosistemes on habiten, actualment són un dels grups més amençats del planeta. Els programes de conservació ex situ es poden utilitzar per millorar la situació d'algunes espècies. Entre aquests programes, els plans de cria en captivitat augmentarien la sostenibilitat dels aquaris públics i els centres de recerca, a més de permetre el desenvolupament d'estratègies de conservació a l'estat salvatge. No obstant això, aquests plans haurien d'incloure l'ús de tècniques de reproducció assistida. Desafortunadament, aquestes tècniques gairebé no s'han desenvolupat en el passat. Davant d'aquesta situació, aquesta tesi pretén omplir certes mancances en el coneixement sobre l'ús d'aquestes tècniques en diverses espècies d'elasmobranquis. La nostra investigació va començar centrant-se especialment en dues espècies model, el tauró gat Scyliorhinus canicula i la ratjada peluda Raja radula, però al llarg de l'estudi es va aconseguir tenir accés a altres espècies. Aquest accés ens va permetre ser conscients de la gran variabilitat en la disposició de les estructures del sistema reproductor. Malgrat que en la literatura hi ha descripcions generals i, en ocasions, detallades dels sistemes reproductors de certes espècies, aquestes descripcions mai s'han centrat en l'aplicació pràctica de les tècniques de reproducció assistida. Per aquest motiu, els capítols 1 i 2 es van centrar en la catalogació i descripció de les diferents estructures d'espècies que abasten un ampli espectre taxonòmic. La conservació de l'esperma juga un paper clau per poder desenvolupar plans de conservació en condicions ex situ. Disposar d'esperma de qualitat permet limitar el transport de mascles entre institucions, minimitzar problemes derivats de la manca de sincronia entre adults reproductors, reduir conflictes durant èpoques d'aparellament i reduir l'endogàmia. El tercer capítol es centra en com es van desenvolupar i provar diferents fórmules per aconseguir el manteniment en fresc de l'esperma, fins a aconseguir un medi on diluir l'esperma capaç de mantenir-lo amb vida durant més de 30 dies. Posteriorment, mitjançant l'addició de diversos crioprotectors (ou, DMSO i metanol) en diverses concentracions, s'explica com es va aconseguir la criopreservació de l'esperma de diverses espècies de ralles i, per primer cop, la criopreservació de l'esperma de diverses espècies de taurons. Un dels primers obstacles que es van detectar en treballar amb els espermatozoides es va deure a la morfologia d'aquestes cèl·lules en comparació amb les d'altres espècies. El cap dels espermatozoides presenta una forma helicoidal, amb un nombre variable de voltes en funció de l'espècie. A més, en moltes ocasions les cèl·lules no apareixen lliures en el fluid seminal, sinó que formen agregacions estructurades anomenades espermatotzeugma. Al llarg del capítol 4 s'explora com aquestes dues característiques sorgeixen com a resultat de la fecundació interna i les característiques mecàniques del medi en què han de realitzar la seva funció. Per primer cop, es pot observar com les cèl·lules reaccionen davant mitjans amb diferents propietats, posant de relleu la importància de la viscositat en l'aplicació de tècniques de reproducció assistida. Finalment, a la discussió, es compara l'eficàcia dels mètodes emprats i s'explora nous camins d'acció sorgits de tenir accés a més individus de diferents espècies. Això inclou la possibilitat de fer descripcions detallades mitjançant tècniques d'anàlisi d'imatge, avaluar la importància de la viscositat i els agregats en els processos de preservació i la possibilitat de realitzar inseminacions artificials. / [EN] Sharks and rays emerged 420 million years ago, forming the ancient and ecologically diverse group of aquatic vertebrates known as elasmobranchs. This diverse group possesses vital strategies that make them highly vulnerable to rapid environmental changes, such as those resulting from human activities. Despite being key elements in the regulation of the ecosystems they inhabit, they are currently one of the most threatened vertebrate groups on the planet. In parallel with in-situ conservation efforts, ex-situ conservation programs can be used to improve the status of some sensitive species. Among these programs, captive breeding plans would enhance the sustainability of public aquariums and research centers, as well as enable the development of conservation strategies in the wild. However, for these plans to be effective, they should include the use of assisted reproduction techniques. Unfortunately, these techniques have been scarcely developed in the past, and their utility has not been adequately demonstrated. This thesis addresses the use of reproduction techniques in elasmobranchs, with an emphasis on sperm retrieval and preservation. Initially, it focused on two model species, Scyliorhinus canicula and Raja radula, but later, other species were included. This revealed variability in reproductive structures, which can affect the effectiveness and quality of the techniques. Chapters 1 and 2 focused on cataloging and describing these structures in various species, highlighting best practices for gamete retrieval and insemination. The short, medium, and long-term conservation of sperm is essential for ex-situ plans, reducing the need for transporting males, conflicts during courtship, and inbreeding. Chapter 3 details formulas for maintaining sperm freshness and a medium for its survival for over 30 days. Subsequently, sperm cryopreservation in several species of rays and sharks is described using cryoprotectants. Chapter 4 addresses challenges in handling elasmobranch sperm due to its helical morphology and the formation of aggregates called spermatozeugma. The importance of viscosity in assisted reproduction techniques is emphasized. In the Discussion, the effectiveness of the methods is compared, and new opportunities are explored by having access to various species. This includes detailed descriptions with image analysis, viscosity assessment, and aggregate preservation, as well as the consideration of artificial inseminations. / This research was partially funded by the Fundación Biodiversidad ( ). PGS has a PhD contract from the European Union through the Operational Program of the European Social Fund (ESF) of the Comunitat Valenciana 2014–2020 ACIF 2018 (ACIF/2018/147). VG has a postdoc contract from the MICIU, Programa Juan de la Cierva-Incorporación (IJCI- 2017-34200). / García Salinas, P. (2023). Development and Application of Techniques for the Control of Captive Breeding in Elasmobranchs [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/201494 / Compendio
45

Recuperação da qualidade de águas contaminadas por gasolina usando reator anaeróbio de leito fixo / Recovery of the quality of water contaminated with gasoline using horizontal anaerobic immobilized biomass (HAIB) reactor

Ribeiro, Rogers 25 February 2005 (has links)
Em razão da intensa atividade industrial e da ampla utilização de compostos derivados do petróleo pela indústria, compostos aromáticos, principalmente os BTEX (benzeno, tolueno, etilbenzeno e xilenos) são freqüentemente encontrados em aqüíferos contaminados, em especial em casos de contaminação por vazamento de tanques de armazenagem subterrânea de combustíveis. Nesse sentido, o presente trabalho foi proposto com o intuito de desenvolver um sistema capaz de remover tanto os BTEX quanto à matéria orgânica presente e efluentes e aqüíferos contaminados com gasolina. Foi constatada a viabilidade técnica da aplicação do RAHLF sob condições metanogênicas operando com TDH de 16 horas em que foi verificada a remoção de 99% da matéria orgânica e em torno de 95% dos BTX, apresentando as seguintes concentrações no efluente (benzeno - 0,62 +/- 0,41 mg/L; tolueno - 0,71 +/- 0,46 mg/L; meta-xileno - 0,28 +/- 0,19 mg/L). Os valores estimados para as constantes cinéticas pelo modelo cinético de primeira ordem com residual para a remoção dos BTX foram muito superiores, cerca de cem vezes maiores do que os encontrados na literatura. A caracterização microbiana do RAHLF metanogênico mostrou a estratificação ao longo do leito. Segundo as análises empregando a técnica de FISH, verificou-se o predomínio dos domínios Archaea no primeiro trecho do reator o que ocorreu, provavelmente, devido a presença de ácido acético proveniente da degradação do etanol, constituinte principal da gasolina vendida no Brasil. Já de acordo com os padrões de bandas de DGGE obtidos a partir dos primers universais para o domínio Bacteria e para o domínio Archaea, estes permitiram constatar certa diferença na diversidade genética entre o ponto zero e o resto do reator. Em relação ao RAHLF sob condições desnitrificantes a remoção quase total de nitrato e BTX ocorreu praticamente no primeiro trecho do reator levando a uma operação em um regime de metabolismo misto (metanogênico e desnitrificante). Em virtude do esgotamento do íon nitrato no primeiro trecho do reator e da ausência de biomassa adaptada ao processo de metanogênese acetoclástica, o RAHLF apresentou desbalanceamento do metabolismo anaeróbio levando ao acúmulo de ácido acético nos primeiros 140 dias de operação. O estudo cinético da degradação dos BTX em solução etanólica realizado no reator anaeróbio com biomassa imobilizada operado em bateladas seqüenciais levou a construção de modelo que descreveu com grande precisão os processos físicos e metabólicos principais envolvidos na degradação do etanol e remoção dos BTX. Tal modelo proporciona uma ferramenta adequada para o dimensionamento de reatores em escala piloto. / Due to the intense industrial activity and the wide range of applications for the petroleum-derived substances by the industry, several aromatic compounds, mainly the BTEX (benzene, toluene, ethylbenzene and xylenes), are often found in contaminated aquifers, specially in the cases of spilling of oil storage tanks. In this sense, the present work intended to develop a system useful for simultaneous BTEX and organic matter removal present in wastewaters and aquifers contaminated with gasoline. The technical viability of the HAIB (horizontal anaerobic immobilized biomass) reactor was evidenced when it was operated with a HDT of 16 hours, condition where removal percentages of about 99% of organic matter and 95% of BTX were reached. The kinetic constants were calculated employing the apparent first-order model with residual concentration, and the results showed that the constants estimated for the BTX were approximately 100 times higher than the ones found in the literature. According to the analysis employing the FISH technique, it was verified a predominance of Archaea in the first part of the reactor, probably due to the high concentrations of acetic acid produced by the degradation of ethanol. As for the DGGE-profile obtained from the universal primers for the Bacteria and Archaea, they showed some differences among the different sample points of the reactor. As for the denitrifying HAIB, there was almost total removal of nitrate and BTX in the first section of the reactor, fact that probably led it to operate in a mixed metabolism (methanogenic and denitrifying). Due to this depletion and to the absence of biomass adapted to the acetoclastic methanogenesis, the HAIB presented disequilibria in the anaerobic metabolism, fact that caused an accumulation of acetic acid in the first 140 days of operation. The kinetic study of BTX degradation in the ethanolic solution carried out in the anaerobic reactor with immobilized biomass operated in batch mode led to a mathematical model that described with great accuracy the main physical and metabolic processes involved in the ethanol degradation and removal of BTX. This model probably provides a suitable tool for the design of pilot scale reactors.
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Effects of the captive environment and enrichment on the daily activity of European Bison (<em>Bison bonasus</em>)

Godoy, Erika January 2009 (has links)
<p>When breeding wild species in captivity, the animals may gradually become more adapted to captivity and therefore less suited for reintroduction which is the ultimate goal for some species. This study measured the activity budget of European bison (<em>Bison bonasus</em>) in six enclosures in Sweden with the aim to find out how the characteristics of the enclosures – with and without pasture - influenced the activity budget. The results show that there were significant differences in the activity budget, i.e. the activity was higher in the enclosures with pasture than in enclosures with barren ground. However, since barren enclosures were smaller than naturalistic, it was not possible to exclude the effect of size. Judged from observations of bison in the wild, there seems to be a direct correlation between food availability and ranging, indicating that enclosure characteristics affect activity more than size. The bison foraged differently in the two enclosure categories, but the total amount of time spent on feeding did not differ. A feeding enrichment experiment showed to have more positive effects in the barren enclosures than in the naturalistic ones, as the amount of time of inactivity decreased in the former. Since the genetic characteristics of all Swedish bison are very similar, the differences between the two enclosure groups indicate that the animals still have the ability to respond appropriately to improved environmental quality. Hence the next step in the assessment of the suitability of these bison for release would be to study them during an acclimatisation program.</p>
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Effects of the captive environment and enrichment on the daily activity of European Bison (Bison bonasus)

Godoy, Erika January 2009 (has links)
When breeding wild species in captivity, the animals may gradually become more adapted to captivity and therefore less suited for reintroduction which is the ultimate goal for some species. This study measured the activity budget of European bison (Bison bonasus) in six enclosures in Sweden with the aim to find out how the characteristics of the enclosures – with and without pasture - influenced the activity budget. The results show that there were significant differences in the activity budget, i.e. the activity was higher in the enclosures with pasture than in enclosures with barren ground. However, since barren enclosures were smaller than naturalistic, it was not possible to exclude the effect of size. Judged from observations of bison in the wild, there seems to be a direct correlation between food availability and ranging, indicating that enclosure characteristics affect activity more than size. The bison foraged differently in the two enclosure categories, but the total amount of time spent on feeding did not differ. A feeding enrichment experiment showed to have more positive effects in the barren enclosures than in the naturalistic ones, as the amount of time of inactivity decreased in the former. Since the genetic characteristics of all Swedish bison are very similar, the differences between the two enclosure groups indicate that the animals still have the ability to respond appropriately to improved environmental quality. Hence the next step in the assessment of the suitability of these bison for release would be to study them during an acclimatisation program.
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Sexual conditioning in the dyeing poison dart frog (Dendrobates tinctorius)

Gaalema, Diann E. 15 January 2010 (has links)
Amphibian populations worldwide are currently in decline. One approach to preventing extinction of some of the affected species is to create assurance colonies. These sustainable captive populations might some day be used to reestablish wild populations. One issue with creating assurance colonies is successful breeding; often difficulties arise when attempting to breed exotic animals in captivity. Sexual conditioning, a form of Pavlovian conditioning, has been shown to improve breeding behavior. In this project the efficacy of sexual conditioning to improve breeding behavior in the dyeing dart frog (Dendrobates tinctorius) was tested. The frogs were trained with a stimulus that was either predictive of or independent of exposure to a member of the opposite sex. The group trained with the predictive stimulus showed shorter latencies to a variety of breeding behaviors and produced more eggs than the control groups. The sexual conditioning procedure also increased expression of various breeding behaviors allowing for careful examination of calls and visual signaling within this species.
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PAPRASTOJO KMYNO (CARUM CARVI L.) LIETUVOS POPULIACIJOS FENOTIPINĖ IR GENETINĖ ĮVAIROVĖ / PHENOTYPIC AND GENETIC DIVERSITY OF CARAWAY (CARUM CARVI L.) POPULATION IN LITHUANIA

Petraitytė, Nijolė 16 January 2006 (has links)
In 1996-2000 during expeditions were found and described 123 Carum carvi habitats. Mostly common caraway is found in pasture type habitats of Cynosurion cristati confederation communities. Plants of Carum carvi cenopopulations are characterized by wide diversity of phenotypic traits strongly influenced by ecological conditions and anthropogenic activity in natural habitats. The most stable parameters are weight of 1000 fruit and biochemical composition of essential oil. Essential oil synthesis in fruits is positively affected by warm and dry weather at the stage of caraway flowering – fruit ripening, carvone content – by warm and wet weather. The identified morphological types of Carum carvi leaves were as follows: normal, dill and parsley. Early-season caraway forms in comparison to others distinguished for the lowest height, fruit weight and total yield, but had the highest carvone content in fruit essential oil. Pink petals are characteristic for early-season caraway cenopopulations. White petal color, greater pigments amount in leaves, higher fruit productivity, as well as essential oil and carvone output characterize medium late and late forms. Various caraway genotypes with different levels of leaf carotinoids, chlorophyll content and ratio, anthocianins amount in petals, different reaction to cold and lighting stress reveal specific adaptive plasticity of caraway. Caraway intercenopopulation genetic diversity was determined at the molecular level.
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Diversidade genética em populações de Myracrodruon urundeuva Fr. All., sob diferentes tipos de perturbação antrópica /

Perez Viegas, Michele. January 2009 (has links)
Resumo: Os marcadores de microssatélites tem sido utilizados com grande freqüência como ferramenta efetiva para estudos de estrutura genética de populações, fluxo gênico, parentesco e para quantificar os efeitos da fragmentação de habitats e guiar estratégias de conservação e melhoramento genético. Este trabalho teve como objetivo avaliar a diversidade genética e o sistema reprodutivo em progênies de duas populações de Myracrodruon urundeuva, procedentes de Aramina-SP e Selvíria-MS, assim como verificar os efeitos da ação antrópica sobre estas populações. Foram avaliadas 25 progênies de cada população, cada uma com 17 a 20 indivíduos, sendo analisados oito locos polimórficos de regiões microssatélites. Observouse 118 alelos nas duas populações e o número efetivo por loco ( e A ∧ = 4,05) foi inferior ao número médio de alelos por loco ( ∧A= 14,75), indicando elevado número de alelos em baixa freqüência. O índice de fixação (F = 0,210 e 0,107, respectivamente para Aramina e Selvíria) foi positivo, relativamente alto e significativamente diferente de zero. A taxa de cruzamento multilocos ( ∧ m t = 1,000 e ∧ m t = 1,000) e unilocos ( ∧ s t = 0,989 e ∧ s t = 0,999) para as populações de Aramina e Selvíria, respectivamente, foram altos, confirmando que a espécie é obrigatoriamente de cruzamento. A diferença entre a taxa de cruzamento multilocos e unilocos indicam cruzamentos entre indivíduos aparentados na população de Aramina. 9 Entretanto, as duas populações apresentaram alta diversidade genética, o que as qualifica para utilização em programas de conservação e melhoramento genético da espécie. / Abstract: The microsatellite markers has been often employed as effective tool for studies of genetic structure of populations, gene flow, relationship and also for to quantify environmental fragmentation effects and to outline strategies for conservation and breeding. This study aimed to evaluate the genetic diversity and mating system in progenies of two Myracrodruon urundeuva populations from Aramina-SP and Selvíria-MS, as well as verify the effects of antropic action on these populations. From each population were evaluated 25 progenies, with 15-20 individuals each, using genetic data from 8 microsatellite loci. There was 118 alleles in both populations and the actual number per locus ( e A ∧ = 4.05) was lower than the average number of alleles per locus ( ∧A = 14.75), indicating high number of alleles in low frequency. The fixation index (F = 0,210 e 0,107, respectively for Aramina and Selvíria) was positive, relatively high and significantly different from zero. The multilocus outcrossing rate ( ∧ m t = 1,000 e ∧ m t = 1,000) single-locus ( ∧ s t = 0,989 e ∧ s t = 0,999) for the populations for Aramina and Selvíria, respectively, they were high, confirming that the species is obligatorily for outcrossing. The difference between the multilocus outcrossing rates and single-locus outcrossing rate indicates mating among relatives in the Aramina population. Meanwhile, the 11 two populations had high genetic diversity, which qualifies them for use in programs for conservation and breeding of this species. / Orientador: Mário Luiz Teixeira de Moraes / Coorientador: Cristina Lacerda Soares Petrarolha Silva / Banca: Alexandre Magno Sebbenn. / Banca: Karina Martins. / Mestre

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