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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

Coopération, conflits et décisions reproductives individuelles dans les sociétés annuelles de bourdons (Bombus terrestris) / Cooperation, conflicts and individual reproductive decisions in the annual societies of bumble bees (Bombus terrestris)

Blacher, Pierre 12 February 2014 (has links)
L’existence de conflits est une caractéristique inhérente aux sociétés animales dont la structure génétique est non clonale. L’objectif principal de cette thèse était d’étudier les décisions reproductives individuelles des ouvrières en lien avec la dynamique coopération/conflit dans les sociétés annuelles du bourdon Bombus terrestris. Les colonies de B. terrestris présentent la particularité de se développer selon deux phases distinctes : une phase sociale caractérisée par une coopération altruiste des ouvrières et une phase de compétition durant laquelle les ouvrières entrent en conflit entre elles et avec la reine pour la production des mâles. L’analyse détaillée du comportement de dérive en conditions semi-naturelles a permis de démontrer l’existence d’une stratégie de reproduction supplémentaire pour les ouvrières ; quand le conflit s’exprime, certaines ouvrières fertiles quittent leur nid pour se reproduire dans les colonies voisines de la même espèce. Cette stratégie alternative de reproduction permet aux ouvrières d’éviter l’inhibition reproductive au sein de leur nid et d’optimiser ainsi leur inclusive fitness. Nos études ont de plus révélé que les ouvrières ajustent de façon adaptée leur comportement reproducteur à l’environnement social. La grande plasticité reproductive des ouvrières repose sur leur capacité à détecter et à traiter de multiples informations pertinentes de leur environnement social. Enfin, les résultats de cette thèse suggèrent l’existence d’une stratégie de défense coloniale contre le parasitisme reproductif des ouvrières. De part leur signature chimique spécifique, les parasites potentiels sont reconnus et discriminés comportementalement à l‘entrée du nid par les gardes. Cette pluralité de stratégie de reproduction à la disposition des ouvrières est marginale au sein des hyménoptères sociaux, et les résultats obtenus de ce travail nous conduisent à discuter les traits d’histoire de vie de B. terrestris qui ont pu favoriser leur évolution. / Conflicts are inherent characteristics of non-clonal animal societies. The main goal of this thesis was to study the individual reproductive decisions of workers in relation with the cooperation/conflict dynamics in the annual bumblebee Bombus terretris. Colonies of B. terretris have the particularity to go through two distinct phases : a social phase characterized by an altruistic cooperation from workers and a competition phase during which the queen and workers compete for the production of males. The study of worker's behaviour in semi-natural conditions allowed to demonstrate the existence of an additional reproductive strategy for workers ; when the conflict is expressed, some fertile workers leave their nest to reproduce in neighbouring colonies of the same species. This alternative reproductive strategy allows workers to avoid reproductive inhibition in their nest and thus to optimize their inclusive fitness. Workers also adjust their reproductive behaviour to their social environment, in line with their reproductive interests. This high reproductive plasticity of workers relies on their ability to detect and process the multiple relevant signals of their social environment. Finally, the results of this thesis suggest the existence of a colonial defence strategy against worker reproductive parasitism. By their specific chemical signature, potential parasites are recognized and behaviourlly discriminated by guards at the nest-entrance. The multiple reproductive strategies of bumble bee workers appear marginal in social Hymenoptera, and the life history traits of B. terretris which could have promoted this diversification are discussed.
2

Séquençage du génome mitochondrial de l'algue verte Leptosira terrestris /

Gagnon, Jonathan. January 2006 (has links) (PDF)
Thèse (M.Sc.)--Université Laval, 2006. / Bibliogr.: f. [99]-104. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.
3

Nitrogen-mustard induced variability in Pyrenochaeta terrestris

Gasiorkiewicz, Eugene C., January 1951 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1951. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 49-51).
4

Estudo duplo-cego, randomizado e controlado com placebo da eficácia do Tribulus terrestris no tratamento da disfunção erétil e no aumento dos níveis séricos da testosterona total / Double-blind, randomized and controlled with placebo study about the effectiveness of Tribulus terrestris in the treatment of erectile dysfunction and increase of serum levels of total testosterone

Santos Junior, Carlos Alberto dos, 1976- 21 August 2018 (has links)
Orientador: Adriano Fregonesi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T14:29:00Z (GMT). No. of bitstreams: 1 SantosJunior_CarlosAlbertodos_M.pdf: 1616257 bytes, checksum: d70350f8e901a282f84ace52fff8b42d (MD5) Previous issue date: 2012 / Resumo: Introdução e Objetivo: A disfunção erétil (DE) é a incapacidade de ter e/ou manter uma ereção para um intercurso sexual satisfatório. Dentre os diversos fatores ligados a ela pode-se citar a queda dos níveis de testosterona na corrente sanguínea. Apesar da evolução representada pela descoberta dos inibidores da enzima PDE5 no tratamento da DE, muitos homens ainda procuram tratamentos alternativos através do uso dos fitoterápicos. Este estudo avaliou a eficácia do Tribulus terrestris no tratamento da disfunção erétil e nos níveis da testosterona sanguínea. Pacientes e Métodos: Trinta homens foram inscritos no estudo. Todos eles tinham 40 anos ou mais, não eram tabagistas, não haviam sido submetidos a nenhum tratamento para câncer de próstata, não apresentavam dislipidemia e podiam ter diabetes e/ou hipertensão controladas. Os pacientes responderam ao IIFE-5 e sua testosterona total foi medida. Os pacientes foram randomizados em dois grupos de quinze indivíduos. O grupo tratamento recebeu Tribulus na dose de 400 mg duas vezes ao dia por 30 dias. O grupo controle recebeu placebo com a mesma orientação de ingestão. Após este período, os pacientes responderam ao questionário e tiveram sua testosterona medida novamente. Resultados: Antes do tratamento os indivíduos do grupo Tribulus apresentaram IIFE-5 médio de 13,2 pontos (variação 5 -18) (dp 3,5) e testosterona total média de 417,1ng/dl (variação 270,7ng/dl - 404,7ng/dl) (dp 89,4). Após o tratamento o grupo Tribulus apresentou IIFE-5 médio de 15,3 pontos (variação 5 -21) (dp 4,3) p=0,2463 e testosterona total média de 409,3ng/dl (variação 216,9ng/dl e 760,8ng/dl) (dp 125,8) p=0,3551. Conclusões: O Tribulus terrestris na dose de 800mg dia durante 30 dias não foi superior ao placebo, estatisticamente, quando comparado o IIEF-5 e aumento da testosterona total sérica / Abstract: Introduction and Objective: Erectile dysfunction (ED) is the inability to have and/or maintain an erection sufficient for a sexual intercourse. It could be linked to many factors. Among them could be pointed low testosterone levels. Despite the huge revolution of PDE5 inhibitors in the treatment of ED, many men have been looking for alternative treatments with herbs. This study evaluated the efficacy of Tribulus terrestris in the treatment of erectile dysfunction and in the serum levels of testosterone. Patients and Methods: Thirty men were enrolled to the study. All of them had 40 years old or later, non-smoking, not have been submitted to any treatment for prostate cancer, without dyslipidemia and they could have controlled diabetes and/or hypertension. The patients answered to the IIEF-5 and the total testosterone was measured. All the patients were randomized in two groups of fifteen. The treatment group received 400mg of Tribulus twice a day during 30 days. The control group received placebo at the same way. After this period, the patients answered the questionnaire and total testosterone was measured again. Results: Both groups were statistically equivalent. Before the treatment, the patients from Tribulus group presented mean IIEF-5 of 13.2 points (variation 5 - 18) (sd 3,5) and mean total testosterone of 417.1 ng/dl (variation 270,7 - 404,7) (sd 89,4). After the treatment, the Tribulus group presented mean IIEF-5 of 15.3 points (variation 5 - 21) (sd 4,3) p=0,2463 and mean total testosterone of 409.3ng/dl (variation 216,9 - 760.8) (sd 125,8) p=0,3551. Conclusion: Daily 800 mg Tribulus terrestris during 30 days was not statistically superior to placebo when compared IIEF-5 and serum total testosterone / Mestrado / Fisiopatologia Cirúrgica / Mestre em Ciências
5

Séquençage du génome mitochondrial de l'algue verte Leptosira terrestris

Gagnon, Jonathan 11 April 2018 (has links)
Le génome mitochondrial montre une grande variabilité de taille et de contenu génique chez les plantes vertes. Près d'une dizaine de génomes mitochondriaux de chlorophytes ont été complètement séquences, incluant le génome de la trebouxiophyte Prototheca wickerhamii. Cette algue est la seule trebouxiophyte qui a été examinée jusqu'à maintenant; puisqu'elle est non-photosynthétique, l'architecture de son génome mitochondrial pourrait ne pas être représentative de la classe Trebouxiophyceae. C'est pour ces raisons que nous avons entrepris le séquençage du génome mitochondrial de Leptosira terrestris, une autre trebouxiophyte. Ce génome, dont la séquence a été déterminée par la méthode shotgun, possède une taille de 111124 pb. Il contient 57 gènes, dont 27 codant pour des ARN de transfert. Dix-huit introns ont été trouvés, faisant de Leptosira l'algue qui possède le plus d'introns au niveau de son génome mitochondrial. Les données phylogénétiques recueillies placent Leptosira comme un intermédiaire chez les trebouxiophytes.
6

Uppfödning av svenska humlor till pollinering : Med perspektiv från aktörer: humleuppfödare, jordbrukare, offentlig sektor och akademi / Rearing Swedish Bumblebees for Pollination : With Perspectives from Actors: Bumblebee Rearer, Farmer, Government Agency and Academy

Kornfeld, Ellen, Nibelius, Rebecca January 2021 (has links)
I dagsläget importeras omkring 4600 humlebon årligen från Europa till Sverige för att öka produktionen av grönsaker och då framförallt tomater. Sverige har i dagsläget ingen egen produktion av humlor men bolaget Svenska Humlor AB ämnar att starta en försäljning under 2021. Att humlorna är svenskuppfödda och närda på svensk pollen är en ny produkt på marknaden som kan medföra nya intressen och intressekonflikter från olika aktörsperspektiv. Syftet med denna studie är att skapa en ögonblicksbild av åsikter som finns kring att starta en inhemsk försäljning av humlor av arten Bombus terrestris. Vidare är ett mål är att utreda hur en framtida svensk humleproduktion kan utformas och hur det kan relatera till hållbar utveckling. Studien kopplar till FN:s Agenda 2030 och målet att bevara biodiversitet och ekosystem. Humlor påverkas av klimatförändringar och flyttar därför till nya områden. Vidare hotas vissa humlearter av antropogen påverkan av landskapen. Humlornas pollinering möjliggör större skördar, som i sin tur bidrar till en ökad matproduktion som också är en målsättning i Agenda 2030. Humlesamhällen föds därför upp och placeras i jordbrukarnas odlingar.  Studien berör både för- och nackdelar med en potentiell svensk produktion av humlor. Intervjuer genomfördes med fyra för ämnet viktiga aktörer; humleuppfödare, jordbrukare, myndighet och akademi. De har ombetts diskutera de största styrkorna, svagheterna, möjligheterna och hoten med att införa svenska humlor som en ny produkt. Dessa åsikter presenteras i SWOT-diagram. SWOT är en metod för att analysera en organisation eller verksamhet där argument delas in efter styrkor (S), svagheter (W) möjligheter (O) och hot (T). Intervjuerna och SWOT-analysen struktureras med fyra huvudteman: ekonomi, teknik, ekologi och övrigt. En litteraturstudie utfördes för att få fördjupade kunskaper i ämnet inför intervjuerna. Litteraturen användes också för att styrka vissa fakta som påståtts av intervjupersonerna. I studien analyseras och diskuteras de huvudämnen som lyftes av de olika aktörerna, för att skapa en bild av vad en framtida svensk humleproduktion kan innebära.  Det framkommer bland annat att det kan vara fördelaktigt att producera svenska humlor jämfört med att importera, då det minskar risken att föra in sjukdomar som kan drabba de vilda pollinerarna. De importerade humlorna från Europa är av en annan underart än de svenska vilda humlorna, varför svenskuppfödda humlor även har mindre påverkan på den vilda genetiken. Vidare lyfts att även fler insekter kan vara relevanta för kommersiell pollinering. Andra diskussionspunkter är bland annat hur ny lagstiftning kan påverka svensk humleuppfödning, möjligheter till lönsamhet, svensk självförsörjningsgrad, inavel i uppfödningen, jämförelser med norsk humleuppfödning, återanvändning av material samt samhällsopinion kring att ha humlor som ett produktionsdjur. Studien avser att samla åsikter kring temat i en uppstartsfas av svensk humleuppfödning, för att kunna användas som diskussionsunderlag och ligga till grund för framtida studier. / Sweden imports around 4600 bumblebee colonies per year from Europe to increase the production of vegetables, primarily tomatoes. Sweden currently lacks a domestic bumblebee rearer, however the company Svenska Humlor AB plans to start selling colonies by 2021. Swedish bumblebees reared on swedish pollen is a new type of product that opens a whole new market. This can cause new undocumented interests and conflicts from different actor’s perspectives. The objective of this study is to portray a current view of opinions regarding a domestic market for bumblebees of the species Bombus terrestris. Furthermore, the study aims to investigate the future of Swedish bumblebee rearing and how it relates to sustainable development. The study integrates the United Nations’ Agenda 2030 Sustainable Development Goals since it includes conservation of biodiversity and ecosystems. Bumblebees are affected by climate change and therefore migrate to new areas. In addition, anthropogenic influence of the landscapes affects their functions. A great advantage is that bumblebee pollination contributes to food production which is included in the Agenda 2030, since bumblebee pollination increases the harvest. Hence, bumblebee colonies are bred and placed in the plantations.  The study covers advantages and disadvantages regarding a potential start-up of swedish reared bumblebees. To achieve this, interviews were conducted with four different actors; a bumblebee rearer, a farmer, authority and academy. They were asked to discuss the greatest strengths, weaknesses, opportunities and threats regarding a Swedish domestic bumblebee rearing. These opinions are presented in SWOT-diagrams, which is a method used to analyse an organisation or business model where strengths (S), weaknesses (W), opportunities (O) and threats (T) are identified and discussed. The interviews and SWOT-analysis are structured around four main themes; economy, technology, ecology and other. Additional literature was also used to strengthen facts that were brought up by the interviewees. The study aims to discuss the main themes raised by the different actors in relation to literature to create a picture of a future Swedish production.  During the interviews it was discussed that Swedish bumblebees might be beneficial in comparison to imported bumblebees as they lower the risk of spreading pathogens to wild pollinators. The imported bumblebees from Europe are of a different sub-species than the indigenous bumblebees. Due to this the Swedish bred bumblebees affect the native genetics less than their imported counterparts. It was also noted that other insects could be used as pollinators in the future. Other points of discussion related to a future Swedish bumblebee rearing were: new regulations, profitability, Swedish self-sufficiency, reusable materials for nests, inbreeding and opinions regarding the usage of bumblebees in production. The study provides opinions regarding these topics which are meant to be used for discussion as well as in future work.
7

Determination of the inheritance of resistance in the onion, Allium cepa L., to the pink root fungus, Pyrenochaeta terrestris

Nichols, Courtland Geoffrey, January 1963 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 55-58).
8

Padrão de frugivoria por Tapirus terrestris na Mata Atlântica do norte do Espírito Santo, Brasil

SEIBERT, J. B. 27 March 2015 (has links)
Made available in DSpace on 2016-08-29T15:09:23Z (GMT). No. of bitstreams: 1 tese_8639_Jardel Brandão.pdf: 1114041 bytes, checksum: ebbe36929aceba4b45127ed193641dd9 (MD5) Previous issue date: 2015-03-27 / A anta Tapirus terrestris (Linnaeus, 1758), último representante da megafauna Pleistocênica na região Neotropical, representa um importante grupo funcional, pois se alimentam de uma grande variedade de espécies vegetais, especialmente frutos. No entanto, o padrão de frugivoria da espécie pode variar entre diferentes áreas. Dessa forma, nosso interesse foi investigar o grau de frugivoria da espécie em duas diferentes áreas no estado do Espírito Santo e a sua importância para a dinâmica florestal. Para isso, foram coletadas amostras fecais, através de busca ativa em diferentes ambientes na Reserva Biológica do Córrego do Veado (Rebio Córrego do Veado) e na Reserva Particular do Patrimônio Natural Recanto das Antas (RPPN Recanto das Antas), durante o período de janeiro de 2011 a novembro de 2013. Após a triagem do material biológico, as sementes foram individualizadas, classificadas quanto às características e grupos ecológicos e identificadas até o menor nível taxonômico possível. Foi obtido um esforço amostral de 130 dias, resultando em 325 amostras fecais coletadas, sendo 53,2% da Rebio Córrego do Veado e 46,8% da RPPN Recanto das Antas. Do total de amostras, 41,8% estavam depositadas dentro ou próximas a corpos dágua e 58,2% na serrapilheira/substrato seco. A dieta da anta foi composta por 94,1% de fibras e 5,9% de frutos. Foram encontradas duas vezes mais amostras contendo sementes na RPPN Recanto das Antas do que na Rebio Córrego do Veado. Das 30 morfoespécies encontradas nas amostras, 15 foram identificadas em nível específico, as quais estão distribuídas em oito famílias. As famílias mais representativas foram Anacardiaceae, Fabaceae e Myrtaceae. As espécies mais freqüentemente encontradas nas amostras foram Spondias macrocarpa Engl. e S. venulosa (Engl.) Engl. Do total de sementes encontradas 60% apresentam dispersão zoocórica e 46,7% são sementes grandes e muito grandes e 50% possuem fruto do tipo carnoso. Das morfoespécies encontradas, sete foram registradas em ambas as unidades de conservação, 21 foram encontradas apenas na RPPN Recanto das Antas e duas foram encontradas na Rebio Córrego do Veado. Isso pode indicar que o ambiente na RPPN Recanto das Antas pode fornecer mais frutos que na Rebio Córrego do Veado, o que pode ser um resultado do histórico de perturbações da última 8 reserva. Na década de 1980, 80% da Rebio Córrego do Veado foi queimada em um incêndio e, atualmente, o entorno da reserva é composto principalmente por pastagens. Ao contrário, a RPPN Recanto das Antas, apesar de sua área ter sofrido extração seletiva na década de 50, está inserida no maior remanescente de Mata Atlântica do Espírito Santo. Ainda que a anta possua uma dieta composta por uma variedade de frutos nas áreas de estudo, ela aparenta ser menos frugívora do que em outras áreas da Mata Atlântica. Contudo, é evidente a importância de T. terrestris na dispersão de um grande número de espécies vegetais, especialmente as espécies com sementes grandes, aumentando o recrutamento de espécies de plantas que não são dispersadas por outras espécies animais.
9

Pathologies in Earthworms: Sublethal Biomarkers of Xenobiotic Toxicity

Cikutovic Salas, Marcos A. 05 1900 (has links)
This research is part of an overall program to develop and use a suite of acute and sublethal toxicity biomarkers, and testing protocols for use in assaying potential effects of complex mixtures of xenobiotics such as found in soils containing agricultural biocides and petrochemical wastes dredged sediments, and hazardous waste sites (HWS). The purpose of this study was to evaluate four biomarkers of sublethal pathology that could be used in an integrative model of multiple toxicity endpoints with the earthworm Lumbricus terrestris.
10

Caracterização funcional e estrutural da primeira arabinofuranosidase da família 62 de Thielavia terrestris dimerizada através de domain swapping / Functional and structural characterization of the first arabinofuranosidase of the Thielavia terrestris from family 62 dimerized through the domain swapping

Camargo, Suelen 10 August 2018 (has links)
As enzimas hidrolíticas são consideradas, por plena definição, aquelas com a capacidade de realizar a reação de hidrólise. Devido à sua capacidade de degradar substâncias naturais, as enzimas hidrolíticas são de grande uso industrial e podem ser aplicadas nas indústrias têxtil, alimentar, farmacêutica, biocombustíveis- agrícola, assim como na produção de derivados biotecnológicos de maior valor agregado. Conhecidas como enzimas que liberam arabinose e arabinofuranose, as arabinofuranosidases da família 62 são capazes de quebrar as conexões de arabinoxilanos. A importância biotecnológica de tais proteínas é desde o uso na agricultura à indústria. Elas podem ser utilizadas, por exemplo, em coquetéis na digestão de alimentos para animais, vinhos e para melhorar a eficiência de clarificação de sucos. Além disso, sua ação de deslignificação é promissora na degradação da biomassa para a produção de bicombustíveis. Este projeto procura realizar a clonagem, expressão heteróloga em bactérias e caracterização estrutural de uma α-L-arabinofuranosidase do fungo termofílico Thielavia terrestris. Esta enzima pertence à família 62 das hidrolases de glicosídeos, que é conhecida por melhorar a ação das celulases e, portanto, de interesse na degradação da biomassa lignocelulósica, como o bagaço de cana-de-açúcar. Estudos biofísicos, bioquímicos e estruturais apresentados neste estudo buscam promover a compreensão dos mecanismos de ação desta enzima e sua aplicação na hidrólise do bagaço de cana-de-açúcar. O trabalho destaca uma estrutura tridimensional inédita dentro da família 62 portadora de um fenômeno conhecido como domain swapping, possibilitando maiores investigações dentro do grupo das arabinofuranosidases. / Hydrolytic enzymes are considered, for the full definition, those with the ability to perform the hydrolysis reaction. Because of their ability of degrading natural substances, hydrolytic enzymes are of wide industrial use and can be applied in the textile, food, pharmaceutical, and agricultural industries, in addition to being used in the production of biofuels. Known as enzymes that release arabinose, the arabinofuranosidases from family 62 are able to break arabinoxylans connections. The biotechnological importance of these proteins are used in the agricultural and industry. These enzymes are employed to process as cocktails for animal feed digestion, wines and to improve the efficiency of juices clarification. Moreover, its delignification action is promising in the biomass degradation for biofuel production. This project seeks to carry out cloning, heterologous expression in bacteria and characterization of an α-L-arabinofuranosidase from thermophilic fungus Thielavia terrestris. This enzyme belonging to the glycoside hydrolase family 62, which is known to enhance the action of cellulases, and thus of interest in the lignocellulosic biomass degradation such as sugar cane bagasse. This study will characterize the protein structure and biochemistry in order to understand the mechanism and optimal conditions of action. The biophysical, biochemical and structural tests seek to promote an understanding of the mechanisms of action of this enzyme and its application in the hydrolysis of sugarcane bagasse. The work shows a new three- dimensional structure within the family 62 caused by a phenomenon known as domain swapping. Thus, it is possible to predict further investigations on the arabinofuranosidases group.

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