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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.
91

Perfil antipsicótico de alstonina : ação em modelos de sintomas negativos, alterações em aminas biogênicas e efeitos adversos em camundongos / Antipsychotic profile of alstonine : action in animal models of negative symptoms, alterations in biogenic amines and side effects in mice.

Linck, Viviane de Moura January 2008 (has links)
A esquizofrenia é um transtorno psiquiátrico grave, caracterizado por distúrbios do pensamento, prejuízo da lógica, alterações cognitivas e emocionais, e/ou isolamento social. Apesar da introdução de novos antipsicóticos, um grupo considerável de pacientes ainda é refratário aos tratamentos disponíveis. Além disso, a alta incidência de efeitos adversos leva à baixa adesão ao tratamento em esquizofrênicos. O desenvolvimento de tratamentos mais eficazes e com menor incidência de efeitos adversos, que aumentem a adesão ao tratamento e melhorem a qualidade de vida destes pacientes, é assim altamente desejável. Em uma expedição etnofarmacológica entre os Igbo na Nigéria identificou-se uma preparação a base de plantas usada no tratamento de pacientes com distúrbios mentais. O alcalóide indólico alstonina é o componente majoritário desta preparação, e possui um claro perfil comportamental de antipsicótico atípico em modelos animais de sintomas positivos, com aparentes vantagens em relação à clozapina. Este trabalho teve o objetivo principal de dar continuidade à caracterização de alstonina como fármaco antipsicótico. Demonstramos que este alcalóide aumenta a interação social e previne o déficit de interação social induzido por MK801 em camundongos, sugerindo utilidade da alstonina no manejo de sintomas negativos da esquizofrenia. Quanto ao mecanismo de ação, a avaliação do efeito de alstonina sobre as aminas biogênicas em córtex frontal e estriado de camundongos sugere que este alcalóide potencia a transmissão serotonérgica e aumenta o catabolismo intraneuronal de dopamina. Quanto aos possíveis efeitos adversos, dados preliminares mostram que alstonina não altera os níveis de prolactina, não induz ganho de peso corporal, mas impede a diminuição da glicemia induzida por jejum. Este trabalho confirma o perfil antipsicótico de alstonina bem como a possibilidade de um mecanismo de ação inovador. Os resultados justificam investimento em novos estudos, quer seja para o desenvolvimento de alstonina como fármaco, quer no sentido de trazer inovação farmacodinâmica tão necessária para avançar no tratamento da esquizofrenia. / Schizophrenia is a serious psychiatric illness, characterized by alterations in thought, deficits in logical thinking, changes in cognition and emotion, and/or social isolation. Despite the introduction of newer antipsychotic drugs, a sizable number of patients are still refractory to the available medication. Moreover, the high incidence of side effects determines the low adhesion of patients to treatments. The development of more efficacious treatments with lower incidence of side effects, ameliorating adhesion to treatment and improving patient’s quality of life is, therefore, sorely wanted. During an ethnopharmacological expedition among the Igbo in Nigeria, a plant based treatment to mentally ill patients was identified. The indole alkaloid alstonine is the major component of this remedy and shown to have a clear behavioral profile of an atypical antipsychotic in rodent models, apparently with advantages in comparison to clozapine. This study had the main purpose of continuing the characterization of alstonine as an antipsychotic drug. We show that this alkaloid increases social interaction and prevents MK801-induced social withdrawal in mice, pointing to its utility in managing negative symptoms of schizophrenia. Regarding its mechanism of action, the effects of alstonine on biogenic amines in mice frontal cortex and striatum suggest that it enhances serotonergic neurotransmission and increases the intra neuronal catabolism of dopamine. In relation to possible side effects, preliminary data suggest that alstonine does not affect prolactin levels, does not induce gains in body weight, but prevents the expected fasting-induced decrease in glucose levels. This study corroborates the antipsychotic profile of alstonine, as well as the possibility of an innovative mechanism of action. These results justify further studies either to develop alstonine as a medication, or to bring pharmacodynamic innovation so sorely needed to move forward in the treatment of schizophrenia.
92

Estudo de compostos orgânicos voláteis biogênicos nas florestas tropicais da Amazônia, da Guiana Francesa e da Mata Atlântica / Study of biogenic volatile organic compounds in the Amazon, French Guiana and Mata Atlântica Tropical Forests

Paula Regina Corain Lopes 17 September 2014 (has links)
A atmosfera terrestre contém nitrogênio e oxigênio, sendo este último, um composto altamente reativo e fundamental ao desenvolvimento e manutenção da vida. Além desses gases, diversos outros compostos em pequenas concentrações, os quais podem atuar como reagentes e/ou catalisadores também a compõe. Os compostos gasosos variados e material particulado (orgânico e inorgânico) de diferentes dimensões lançados constantemente à atmosfera são provenientes de fontes diversas. Tais fontes podem ser de origem natural ou antrópica e ainda, podem ser pontuais, difusas, primárias, secundárias, móveis e/ou estacionárias. Os processos envolvendo transformações químicas na atmosfera são extremamente importantes porque tendem a manter a sua composição em estado estacionário. A vegetação, que constitui uma fonte natural, é responsável pela emissão de grandes quantidades de compostos carbonados para a atmosfera. Dentre os vários compostos orgânicos emitidos da superfície do planeta, destacam-se em particular, alguns gases traços, denominados compostos orgânicos voláteis (COVs). A emissão dos compostos orgânicos voláteis pela vegetação ocorre, em escala global, predominantemente nos trópicos ou nos meses de verão em outras regiões. As reações fotoquímicas dos compostos orgânicos voláteis desempenham um papel diferenciado e importante na química da troposfera, podendo alterar de forma significativa a concentração de ozônio em áreas tanto urbanas quanto rurais. O presente projeto contempla o estudo de alguns dos inúmeros compostos orgânicos voláteis de origem biogênica (COVBs) emitidos pela vegetação constituinte, das regiões da Floresta Amazônica, da Mata Atlântica e da floresta Tropical da Guiana Francesa, comparando-se os dados de saída gerados pelos Modelos MOZART-4 e CAM-Chem. A escolha dos sítios experimentais para realização deste estudo se deu em parte em função da importância dos locais em termos de biodiversidade, extensão territorial, influência na climatologia (local e/ou regional), bem como também em função da acessibilidade, proximidade a centros urbanos e alterações devido à influência humana. O procedimento metodológico adotado para coleta das amostras de COVBs se deu por meio da técnica conhecida como acumulação de vórtices turbulentos (Relaxed Eddy Accumulation - REA), a qual faz uso de um dispositivo coletor denominado acumulador compacto de vórtices turbulentos (Compact Relaxed Eddy Accumulator - CREA). As amostras gasosas de COVBs foram coletadas por meio de cartuchos comerciais apropriados, compostos por diferentes materiais adsorvedores que apresentavam afinidade química também diferenciada para os variados compostos aos quais foram expostos. Estudos primários para determinação da natureza dos cartuchos que foram utilizados neste projeto foram realizados, a fim de se obter dispositivos adequados a este propósito. Os resultados evidenciam, como esperado, que a presença de isopreno é predominante em todos os sítios experimentais, sendo sua concentração média diária máxima de 5,0 ± 0,3 μg/cm3 registrada na Amazônia e de 8,0 ± 0,4 μg/cm3 (concentração diária) na floresta da Guiana Francesa, seguido pelo alfa-pineno cuja concentração máxima obtida foi de aproximadamente 1,6 ± 0,08 μg/cm3 no último sítio experimental, ambos detectados na estação seca. A emissão de isopreno e dos monoterpenos ocorreu de forma mais acentuada na época seca em comparação ao período úmido. Contudo, observou-se em algumas situações uma pequena discrepância. De maneira geral os resultados gerados pelos modelos estão subestimados, como exceção do parâmetro de radiação fotossinteticamente ativa (PAR), o que indica que a defasagem entre os resultados observados e os simulados pode estar relacionada parâmetros de OH-, NOx e em algumas reações químicas fotoquímicas envolvendo o ozônio. / The Earth\'s atmosphere contains nitrogen and oxygen, the last one being a highly reactive compound and fundamental to the development and maintenance of life. Besides these gases, many other compounds in small concentrations, which can act as reactants and /or catalysts can be found in the atmosphere. Various gaseous compounds and particulate matter (organic and inorganic) of different dimensions constantly released into the atmosphere come from various sources. Such sources can be natural or anthropogenic and still be punctual, diffuse, primary, secondary, mobile and or stationary. Processes involving chemical transformations in the atmosphere are extremely important because they tend to maintain their steady-state composition. The vegetation, which is a natural source, is responsible for producing large amounts of carbon compounds in the atmosphere. Among the various organic compounds emitted from the planet\'s surface, stand out in particular, some trace gases, called volatile organic compounds (VOCs). The emission of volatile organic compounds by vegetation occurs on a global scale, predominantly in the tropics or in the summer months in other regions. The photochemical reactions of volatile organic compounds play an important and unique role in the chemistry of the troposphere, which can significantly change the concentration of ozone in both urban and rural areas. This project involves the study of some of the numerous biogenic volatile organic compounds (BVOC) emitted by vegetation from the Amazon Forest, the Mata Atlântica forest and the Tropical forest of French Guiana, comparing the output data generated by MOZART -4 and CAM-Chem models. The choice of experimental sites for this study was in part due to the importance of local biodiversity , territorial extent , influence the weather (local and/or regional), and also because of accessibility, proximity to urban centers and changes due to human influence . The methodological procedures for collecting samples of VOCs was through the technique known as eddy accumulation (Relaxed Eddy Accumulation - REA), which uses an equipment known as compact relaxed eddy accumulator (CREA). The gas samples were collected from BVOCs through appropriate commercial cartridges, composed of different materials showed that chemical affinity adsorbents also differentiated for the various compounds which were exposed. Primary studies to determine the nature of cartridges that were used in the field campaigns were conducted in order to obtain devices suitable for this purpose. The results show, as expected, the presence of isoprene as a prevalent compound in all experimental sites, with maximum daily average concentration of 5,0 ± 0,3 μg/cm3 registered on the Amazon basin and 8,0 ± 0,4 μg/cm3 (daily concentration) in the forest of French Guiana, followed by alpha-pinene, whose maximum concentration obtained was approximately 1,6 ± 0,08 μg/cm3 in the last experimental site, both detected in the dry season. The emission of isoprene and monoterpenes occurred sharply in the dry season compared to the wet season. However, it was observed in some situations a small discrepancy. In general, the results generated by the models are underestimated, as an exception of photosynthetically active radiation parameter (PAR), indicating that the gap between the observed and simulated results can be related to OH- and NOx parameters and some chemical reactions involving photochemical ozone.
93

La dynamique temporelle des successions de communautés microperforantes et des taux de dissolution associés en milieu récifal. Quelle influence des paramètres biotiques/abiotiques ? / Temporal dynamic of microboring community successions and associated biogenic dissolution rates in coral reefs. What are the impacts of biotic and abiotic factors?

Grange, Julie 12 October 2015 (has links)
La dissolution biogénique réalisée par les microperforants constitue une des principales forces de destruction des récifs coralliens. Ce processus, stimulé par certains facteurs du changement global comme l'acidification, est encore peu connu et donc mal intégré dans les modèles de prédiction du devenir des récifs. Pour mieux comprendre ce processus et sa dynamique temporelle, des blocs de squelette corallien ont été exposés, sur un récif en Nouvelle-Calédonie, aux microperforants entre 1 et 12 mois et au cours de six séries temporelles; trois commençant en été et trois en hiver. Ainsi, les taux de dissolution biogénique ainsi que la diversité et l'abondance des microperforants ont été déterminés. En parallèle, un suivi de paramètres externes, abiotiques et biotiques, a été réalisé. Cette étude a mis en avant i/ trois étapes dans le processus de dissolution biogénique, décrites par un modèle logistique de croissance, contrôlées par les espèces microperforantes et par l'intensité du broutage ; ii/ les interactions entre les paramètres externes et la dynamique des successions de communautés microperforantes décrites dans un modèle conceptuel ; iii/ l'influence de paramètres externes sur la dynamique temporelle de la dissolution biogénique. Ainsi, Ostreobium quekettii, l'agent le plus actif dans la dissolution biogénique, est recruté plus rapidement et la dissolution biogénique augmente lorsque les squelettes sont exposés à des températures plus élevées ou soumis à une augmentation des nutriments. Ces résultats suggéreraient, dans le contexte du changement global, une accélération de la dissolution biogénique fragilisant d'autant plus les récifs coralliens. / Biogenic dissolution of carbonates due to microborers is one of the main destructive forces in coral reefs. Unfortunately this biogeochemical process received low attention and thus is considered as negligible by prediction models of coral reefs future while this process seems to be stimulated by global change factors such as acidification. In this context, dead coral skeletons were exposed, on a reef in New Caledonia, to microborers for six temporal series from 1 to 12 months of exposure (three started in summer and three in winter). Study of coral blocks allowed to determine together biogenic dissolution rates, the diversity and the abundance of microborers. In parallel, external biotic and abiotic parameters were recorded monthly and/or continuously. This experiment highlighted for the first time; I/ three steps in the temporal dynamics of the biogenic dissolution, described by a growth logistic models, driven by microborer communities and grazing intensity; II/ The interactions between microboring community successions and external parameters described by a conceptual model; III/ the influence of external parameters on the dynamic of biogenic dissolution. Thus, results showed an early installation of Ostreobium quekettii, the main agent of the biogenic dissolution and an increase of this process due to higher seawater temperature or nutrients. This suggests, in the context of global change, an acceleration of the biogenic dissolution weakening even more coral reef ecosystems.
94

Impact des conditions nutritionnelles sur la dissolution de la silice biogénique des diatomées à travers l'étude de la variabilité de la structure biphasique du frustule / No title

Boutorh, Julia 14 February 2014 (has links)
Les diatomées sont des micro-algues qui participent à hauteur de 35 à 75 % à la production primaire océanique et qui sont les acteurs majeurs du cycle biogéochimique du silicium (Si) dans l’océan. Comprendre les mécanismes qui affectent la dissolution de la silice biogénique (bSiO2) constituant le frustule des diatomées est nécessaire afin d’améliorer la compréhension du cycle océanique du Si. En période estivale, la majorité de l’océan ouvert est limitée par de faibles disponibilités en éléments nutritifs. Les travaux réalisés dans cette thèse ont donc pour objectif majeur d’étudier l’effet de l’environnement nutritionnel des diatomées sur la dissolution et l’export de silice biogénique (bSiO2). Cette étude s’est focalisée sur les limitations en fer (Fe), en Si et en azote (N), c'est-à-dire sur les éléments nutritifs dont les faibles concentrations en période estivale limitent la production de diatomées dans une grande majorité de l’océan mondial. Une des originalités de cette thèse consiste en l’étude de la limitation en cuivre (Cu), dont les impacts sur la composition élémentaire et la dissolution des diatomées ont été peu étudiés. Les effets des conditions limitantes en micronutriments ont été étudiés sur la diatomée pennée Pseudo-nitzschia delicatissima tandis que les limitations en macronutriments ont été étudiées sur la diatomée centrique Thalassiosira weissflogii. La première étape de ce travail a consisté en l'étude de l'effet de conditions nutritives limitantes sur deux échelles du frustule des diatomées : celle de la cellule, avec l’étude du degré de silicification des diatomées, et celle du frustule, avec l’étude de sa structure et sa composition fine, au moyen de la spectroscopie InfraRouge à Transformée de Fourier (IRTF). La seconde étape de ce travail a consisté en l’étude du devenir post-mortem de ces cellules à travers l’étude de la cinétique de dissolution de la bSiO2 constituant leur frustule. Les résultats obtenus par IRTF indiquent clairement qu’à la plasticité du contenu global en bSiO2 du frustule des diatomées, s’ajoute la plasticité du frustule à l’échelle moléculaire, en fonction des conditions de croissance. Le degré d’organisation et le degré de réactivité du réseau siliceux sont tous deux affectés par l’environnement nutritif des diatomées. La quantité relative de matière organique associée au frustule varie également avec la disponibilité des éléments nutritifs. A travers ces changements, l’environnement nutritionnel affecte la dissolution du frustule des diatomées qui, dans les six expériences de dissolution, se déroulent en deux étapes, illustrant la composition biphasique du frustule. Les résultats indiquent que les conditions de croissance vont affecter la proportion et les vitesses de dissolution de la bSiO2 de ces phases. Par la modification des propriétés intrinsèques des phases de bSiO2, le frustule des diatomées limitées en nutriments auront une propension à la dissolution moins importante que celle des diatomées non-limitées. De ce fait, l’environnement nutritif des diatomées affecte l’export de bSiO2. Pour P. delicatissima, seuls 9 % de la bSiO2 initiale des cellules non limitées sont préservés après 22 jours de dissolution, tandis qu’environ 25 % sont préservés en cas de carence stricte en Cu ou de limitation en Fe durant la croissance. Les frustules de T. weissflogii limitées en macronutriment sont également mieux préservés après un mois de dissolution, avec 41 % et 51 % de la bSiO2 initiale restante pour les cellules majoritairement limitées en Si ou en N, respectivement, comparés au 20 % de préservation pour les cellules non-limitées. Ces résultats suggèrent que la dissolution de la silice dans les modèles globaux de l’océan pourrait être mieux paramétrée en tenant compte (i) de la cinétique de dissolution des deux phases de silice biogénique et (ii) de la meilleure préservation de la bSiO2 des cellules limitées en nutriments. / Diatoms are microalgae that contribute up to 75% of oceanic primary production and are major players in the oceanic biogeochemical silicon (Si) cycle. Understanding the mechanisms affecting the biogenic silica (bSiO2), constituting the diatom frustule, is necessary to improve the understanding of oceanic Si cycling. In summer, most of the open ocean is limited by low nutrient availability. Thus, the main objective of this thesis is to study the effect of diatom nutritional environment on biogenic silica (bSiO2) dissolution and export. This study focused on iron (Fe), Si and nitrogen (N) limitations, i.e. nutrients whose low concentrations during summer limit diatom production in the majority of the world ocean. One originality of this thesis is to study the copper (Cu) limitation, whose impact on the elemental composition and dissolution of diatoms has rarely been studied. The effects of micronutrient limiting conditions were studied on the pennate diatom Pseudo-nitzschia delicatissima while macronutrient limiting conditions were studied on the centric diatom Thalassiosira weissflogii. The first stage of this work was to study the effect of nutrient limiting conditions at two different scales of diatoms frustule: the cell scale, with the study of the silicification degree of diatoms, and the frustule scale, with the study of its structure and composition using Fourier Transform InfraRed spectroscopy (FTIR). The second stage of this work consisted of the study of the diatom post-mortem fate through the study of the dissolution kinetics of bSiO2 from diatom frustule. The FTIR results clearly indicate that, in addition to the plasticity of global bSiO2 content, diatom frustule also has plasticity at the molecular scale, depending on growth conditions. The organization degree and the reactivity degree of the silica lattice are both affected by diatom nutritional environment. The relative amount of organic matter associated with frustule is also affected by nutrient availability. Through these changes, the nutritional environment affects the dissolution of diatom frustules, which showed a two-stage dissolution in all six dissolution experiments, illustrating the biphasic composition of the frustule. The results indicate that the growth conditions affect both the proportion and the dissolution rates of these bSiO2 phases. By changing the intrinsic properties of the bSiO2 phases, nutrient limited-frustules will be dissolving less than non-limited diatom frustule. Therefore, the diatom nutrient environment affects bSiO2 export. In P. delicatissima, only 9 % of the initial bSiO2 remained from replete cells at the end of the twenty-two days dissolution experiment, while about 25 % remained from Cu-starved and Fe-limited cells. Macronutrient-limited T. weissflogii were also more preserved after one month of dissolution with 41 % and 51 % of the initial bSiO2 remaining for cells predominantly Si- or N-limited, respectively, whereas 20% of the initial bSiO2 was preserved in replete cells. These results suggest that the biogenic silica dissolution in global ocean models could be better parameterized taking into account (i) the dissolution kinetics of the two bSiO2 phases and (ii) an enhanced bSiO2 preservation of nutrient-limited cells.
95

The Impact of Ageing, Gamma(γ)-irradiation, and Varying Concentrations of Phosphate on the Stability and Solubility of Biogenic Iron Oxides (BIOS) in the Presence of Shewanella putrefaciens CN32

Najem, Tarek January 2017 (has links)
The redox cycling of iron is intimately linked to the cycling of C, S, N, P as well as the speciation, mobility, and bioavailability of various toxic contaminants in soils and sediments. Within these environments, the cycling of iron is catalytically driven by iron-oxidizing (FeOB) and iron reducing bacteria (FeRB) which mediate the formation, transformation, and dissolution of various iron-bearing minerals. Under oxic conditions, FeOB promote the formation of iron oxides on or in close proximity of their cell walls and extracellular polymeric substances, and such composite, termed biogenic iron oxides (BIOS), offers highly reactive heterogenous sites that efficiently immobilize trace metals and contaminants alike. However, under reducing conditions, FeRB mediate the reductive dissolution of BIOS and in turn lead to the remobilization of associated contaminants. Conversely, contaminants may become immobilized by secondary iron minerals that form from the metabolic activity of FeRB. Therefore, determining the factors that influence the reactivity of BIOS, as well as the formation of secondary iron minerals is of critical importance to develop a better understanding of the geochemical cycling of iron and in turn the transport of contaminants in the environment. This thesis investigated (1) the impact of simulated diagenesis (ageing for ~5 years at 4ºC) on the mineral stability and reactivity of BIOS towards reduction by Shewanella putrefaciens CN32, (2) the effects of phosphate at an environmentally relevant (10µM) and excess (3.9mM) concentration on the rates and extent of microbial reduction of synthetic 2-line ferrihydrite and BIOS, as well as the formation of secondary iron minerals, and (3) the impact of sterilization by γ-irradiation on the mineral stability and reactivity of BIOS. It was found that simulated diagenesis did not affect the mineralogical composition of BIOS but significantly lowered the reactivity of BIOS towards microbial reduction. The concentration of phosphate was found to have contrasting effects on the rates of reduction of ferrihydrite and BIOS, but in general, excess concentration of phosphate enhanced the extent of Fe(III) reduction. The formation of a specific secondary iron mineral was also found to depend on the concentration of phosphate, as well as, in the case for BIOS, the presence of intermixed cell derived organic matter. γ-irradiation did not alter the mineralogy and reactivity of BIOS towards microbial reduction, and it was concluded to be a suitable technique to sterilize BIOS.
96

Lake condition changes of a boreal lake over the past ca. 6500 years based on varve geochemistry

Ligtenberg, Jora January 2017 (has links)
The purpose of this study was to assess changes in the in-lake conditions of lake Kassjön, northern Sweden, in response to environmental and climate changes over the past ca. 6500 years. Sediment concentrations of different elements and biogenic silica (bSi) were measured with wavelength dispersive X-ray fluorescence spectrometry (XRF) and Fourier transform infrared spectroscopy (FTIR), respectively. The lake-water total organic carbon (LWTOC) content was inferred based on near-infrared spectroscopy (NIRS). The marine sediment was distinguished from the lacustrine sediment by higher dry bulk density, lithogenic element concentrations and Br content, and lower bSi concentrations. After lake formation, the dry bulk density, lithogenic element concentrations and metal contents decreased, while organic matter (OM), bSi and LWTOC increased. The main reasons for these changes are soil development and vegetation establishment. Spruce immigration around 3000 BP induced considerable changes to the sediment concentrations indicative of increased erosion versus weathering, and LWTOC declined. These changes are mainly related the different characteristics of spruce compared to birch. Human influences in the catchment were also clearly visible, but the rest of the sediment sequence demonstrated that natural changes can be of a similar magnitude. Overall, relatively small-scale, catchment specific processes seem to be more important for changes in the lake conditions than general climate change.
97

Concentration of specific biogenic amines in ventricular CSF of type A and B Parkinson's disease patients on Sinemet

Ahlman, Justin Robert 01 January 2001 (has links)
No description available.
98

Diversity of silicon uptake by tropical forest trees and its implication for biogenic silicon flux through leaf-litter / 熱帯林樹木のケイ素集積多様性とその落葉リターを介しての生物由来ケイ素フラックスとの関係

Nakamura, Ryosuke 23 March 2020 (has links)
付記する学位プログラム名: グローバル生存学大学院連携プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22483号 / 農博第2387号 / 新制||農||1075(附属図書館) / 学位論文||R2||N5263(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 北島 薫, 教授 神﨑 護, 教授 北山 兼弘 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
99

Benefícios do processamento térmico na composição fitoquímica de couves-flores coloridas /

Diamante, Marla Sílvia January 2019 (has links)
Orientador: Giuseppina Pace Pereira Lima / Resumo: O cozimento além de facilitar a digestibilidade e a palatabilidade dos vegetais, pode alterar a biodisponibilidade de micronutrientes. As couves-flores são normalmente consumidas após processamento térmico e apresentam níveis elevados de compostos bioativos que influenciam na saúde humana, especialmente na prevenção as doenças crônicas. Estes compostos possuem atividade antioxidante que confere proteção e auxilia o organismo humano a eliminar os radiacias livres, componentes centrais das regulações metabólicas induzidas por doenças crônicas. Desta forma, o objetivo deste estudo foi avaliar o efeito do tempo e tipo de cozimento (fervura, vapor e micro-ondas) sobre as características bioquímicas de quatro genótipos de couve-flor colorida (‘Verde di Macerata’, ‘Cheddar’, ‘Forata’ e ‘Graffiti’). Em um primeiro momento, foi determinado o perfil físico-químico das couves-flores coloridas. Os floretes foram submetidos aos tratamentos térmicos por 5 e 10 min e após foram realizadas as análises físico-químicas. O processamento em ebulição resultou em perdas significativas de sólidos solúveis totais e carboidratos solúveis totais, diferentemente dos métodos onde foram utilizadas menores quantidades de água para o processamento das inflorescências (i.e., micro-ondas e vapor). Os métodos a vapor e micro-ondas resultaram em valores superiores de sólidos solúveis, independente do genótipo analisado. O cozimento dos floretes em ebulição reduziu significativamente os teores da maioria dos co... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The cooking process, besides facilitating the digestibility and palatability of vegetables, can alter the bioavailability of micronutrients. The cauliflowers are usually consumed after a thermal process and present high levels of bioactive compounds that positively affect the human health, particularly in chronic disease prevention. The compounds possess antioxidant activity that provides protection and assists the human organism in eliminating free radicals, central compounds in metabolic regulations induced by chronic diseases. Thus, the objective of this study was to evaluate the effect of time and cooking procedure (boiling, steaming and microwaving) over the biochemical characteristics of four genotypes of colored cauliflowers (‘Verde di Macerata’, ‘Cheddar’, ‘Forata’ e ‘Gradffiti’). Firstly, the physicochemical profile of the colored cauliflowers was determined. The cauliflowers were subjected to the thermal processes for 5 and 10 minutes and physicochemical analysis were performed. The boiling process resulted in significant losses of total soluble solids and total soluble carbohydrates, unlike the methods where smaller amounts of water were used for processing the inflorescences (i.e., microwaving and steaming). The steaming and microwaving methods resulted in superior values of soluble solids, independently of the analyzed genotype. The cooking of the inflorescences by boiling reduced significantly the contents of the majority of the analyzed chemical compounds (titr... (Complete abstract click electronic access below) / Doutor
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Octopamine Levels Relate to Male Mating Tactic Expression in the Wolf Spider Rabidosa punctulata

Hebets, Eileen A., Hansen, Matthew, Jones, Thomas C., Wilgers, Dustin J. 01 February 2015 (has links)
In the wolf spider Rabidosa punctulata, upon encountering a female, males use one of two distinct strategies: (1) they court the female in an attempt to elicit a mating, or (2) they engage in a direct-mount tactic that involves extensive grappling with the female until a mating is achieved. The latter tactic appears more sexually aggressive, and both tactics come with the risk of being cannibalized. We explored the physiological mechanisms underlying this behavioural variation by assessing the relationship between circulating levels of the biogenic amine octopamine (OA), a neuromodulator suggested to play a role in 'fight or flight' responses of arthropods and male mating tactic expression. We predicted, and found support for, a relationship between OA levels and tactic expression, with males adopting the direct-mount tactic expressing higher OA levels than courting males. Male mating tactic and mass also showed a significant interaction, with a negative trend in direct-mounting males and no relationship in courting males. Males had considerably higher levels of OA circulating in their haemolymph than females and female OA level increased with female mass. Our experimental design cannot disentangle cause from effect, but our results are consistent with the hypothesis that OA plays a role in regulating mating tactic expression in R.punctulata.

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