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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.
81

Diseño de una embarcación tipo catamarán polivalente para resolver el problema de contaminación por derrame de hidrocarburos y por residuos plásticos en el mar peruano

Ruiz Rios, Hanny Aracelly January 2018 (has links)
Considerando que la seguridad en el mar, y del ambiente, ya no es más un tema ajeno, en esta investigación se propone una solución a las distintas emergencias que ocurren en el mar. Consiste en el diseño de una embarcación tipo catamarán polivalente con la función principal, de lucha contra la contaminación marina por derrames de hidrocarburos y por residuos plásticos; y otras posibles funciones como la asistencia y el remolque a embarcaciones en emergencia, salvamento de personas, etc. En el presente trabajo se analizan las distintas emergencias ocurridas en el mar, entre las cuales, las más sobresalientes son los desechos de basura, y los constantes derrames de petróleos registrados en los últimos años. Por ello se realiza la propuesta de diseño en software Naval, obteniendo como resultado una embarcación semi desplazante, a la que se realiza el análisis de estabilidad, análisis de pesos y análisis de estructuras respetando las normas y los Registros de Clasificación. De ese modo, se espera un control más específico en el recojo de desechos y limpieza del mar en la actualidad, y en un futuro por los posibles derrames de hidrocarburos o las diferentes emergencias que se puedan presentar.
82

Parathyroid hormone and calcium interactions in the periparturient mare

Martin, Kelly L. 11 June 2009 (has links)
The initiation of lactation involves an increased flow of Ca into mammary secretions, which leads to responses of serum concentrations of Ca and parathyroid hormone (PTH) that may be influenced by dietary Ca. Eight light mares from Farm A and eight Thoroughbred mares from Farm B were bled and milked 10 d pre-foaling, and eight mares (four from each farm) were bled and milked 5 d post-foaling. Milk Ca was measured by two commercial tests, one for [Ca + Mg] and the other [Ca]. Serum PTH and total Ca were measured in 16 mares, and ionized Ca in four mares. Parturition was induced in all mares with fenoprostalene on Farm A, and in four mares with oxytocin on Farm B; no significant difference was found between induction methods or between induced and spontaneous foaling mares. Dietary Ca was 34% DM on Farm A and .79% on Farm B. Mean serum total Ca concentrations decreased from 12.5 mg/dl to a nadir of 11 mg/dl on d 2 post-partum, and mean PTH increased from 46 pg/ml to a peak of 186 pg/ml on d 2 post-partum. Mean serum PTH concentrations were lower (P = .03) and total Ca concentrations were higher (P = -01) on Farm B in comparison to Farm A, probably reflecting the difference in Ca intake. The nadir in mean ionized Ca and total Ca concentrations was reached on d 2 post-partum, 1 day later than has been observed previously in the dairy cow. Milk Ca concentrations increased from 50 ppm 7 d pre-foaling to 350 ppm on the day of foaling, with no difference between farms. The [Ca + Mg] test reached a critical level of 200 ppm 4.5 d pre-foaling, the [Ca] test 2 d pre-foaling. The [Ca + Mg] and [Ca] tests reached 250 ppm 2.5 and 1 d pre-partum, respectively. In short, serum Ca and PTH concentrations showed periparturient changes which reflected dietary Ca pre-partum. Foaling date was more closely associated with milk [Ca] than with [Ca + Mg] and by a critical level of 250 ppm than by 200 ppm. / Master of Science
83

Diversité microbienne associée au cycle du méthane dans les mares de fonte du pergélisol subarctique

Crevecoeur, Sophie 24 April 2018 (has links)
La fonte et l’effondrement du pergélisol riche en glace dans la région subarctique du Québec ont donné lieu à la formation de petits lacs (mares de thermokarst) qui émettent des gaz à effet de serre dans l’atmosphère tels que du dioxyde de carbone et du méthane. Pourtant, la composition de la communauté microbienne qui est à la base des processus biogéochimiques dans les mares de fonte a été très peu étudiée, particulièrement en ce qui concerne la diversité et l’activité des micro-organismes impliqués dans le cycle du méthane. L’objectif de cette thèse est donc d’étudier la diversité phylogénétique et fonctionnelle des micro-organismes dans les mares de fonte subarctiques en lien avec les caractéristiques de l’environnement et les émissions de méthane. Pour ce faire, une dizaine de mares ont été échantillonnées dans quatre vallées situées à travers un gradient de fonte du pergélisol, et disposant de différentes propriétés physico-chimiques. Selon les vallées, les mares peuvent être issues de la fonte de palses (buttes de tourbe, à dominance organique) ou de lithalses (buttes de sol à dominance minérale) ce qui influence la nature du carbone organique disponible pour la reminéralisation microbienne. Durant l’été, les mares étaient fortement stratifiées; il y avait un fort gradient physico-chimique au sein de la colonne d’eau, avec une couche d’eau supérieure oxique et une couche d’eau profonde pauvre en oxygène ou anoxique. Pour identifier les facteurs qui influencent les communautés microbiennes, des techniques de séquençage à haut débit ont été utilisées ciblant les transcrits des gènes de l’ARNr 16S et des gènes impliqués dans le cycle du méthane : mcrA pour la méthanogenèse et pmoA pour la méthanotrophie. Pour évaluer l’activité des micro-organismes, la concentration des transcrits des gènes fonctionnels a aussi été mesurée avec des PCR quantitatives (qPCR). Les résultats montrent une forte dominance de micro-organismes impliqués dans le cycle du méthane, c’est-à-dire des archées méthanogènes et des bactéries méthanotrophes. L’analyse du gène pmoA indique que les bactéries méthanotrophes n’étaient pas seulement actives à la surface, mais aussi dans le fond de la mare où les concentrations en oxygène étaient minimales; ce qui est inattendu compte tenu de leur besoin en oxygène pour consommer le méthane. En général, la composition des communautés microbiennes était principalement influencée par l’origine de la mare (palse ou lithalse), et moins par le gradient de dégradation du pergélisol. Des variables environnementales clefs comme le pH, le phosphore et le carbone organique dissous, contribuent à la distinction des communautés microbiennes entre les mares issues de palses ou de lithalses. Avec l’intensification des effets du réchauffement climatique, ces communautés microbiennes vont faire face à des changements de conditions qui risquent de modifier leur composition taxonomique, et leurs réponses aux changements seront probablement différentes selon le type de mares. De plus, dans le futur les conditions d’oxygénation au sein des mares seront soumises à des modifications majeures associées avec un changement dans la durée des périodes de fonte de glace et de stratification. Ce type de changement aura un impact sur l’équilibre entre la méthanogenèse et la méthanotrophie, et affectera ainsi les taux d’émissions de méthane. Cependant, les résultats obtenus dans cette thèse indiquent que les archées méthanogènes et les bactéries méthanotrophes peuvent développer des stratégies pour survivre et rester actives au-delà des limites de leurs conditions d’oxygène habituelles. / The thawing and collapse of ice-rich permafrost in the subarctic region of Quebec has given rise to thaw ponds (thermokarst ponds) that emit the greenhouse gases carbon dioxide and methane to the atmosphere. However, the microbial community composition that underlies biogeochemical processes in thaw ponds has been little investigated, particularly concerning the diversity and activity of micro-organisms involved in the methane cycle. The objective of this thesis study was to determine the phylogenetic and functional diversity of micro-organisms in subarctic thaw ponds, and the relationships with environmental properties and methane emission. To that aim, we sampled ten thaw ponds in four different valleys located across a permafrost degradation gradient with distinct physico-chemical properties. Depending on valley, the ponds were derived either from the thawing of a palsa (peat-mound) or lithalsa (mineral-mound), which influenced the nature of organic carbon available for microbial remineralization. During summer, the ponds were observed to be well-stratified; there were with strong physico-chemical gradients down the water column, with an upper oxic layer and a bottom low oxygen or anoxic layer. To identify the factors influencing microbial community composition, we used high throughput sequencing techniques targeting transcripts of 16S rRNA gene, and additionally targeted genes involved in the methane cycle: mcrA for methanogenesis and pmoA for methanotrophy. As a proxy of microbial activity, we also measured the concentration of functional gene transcripts using with quantitative PCR (qPCR). The results showed a striking dominance of micro-organisms involved in the methane cycle, namely methanogenic Archaea and methanotrophic Bacteria. The pmoA analyses implied that methanotrophic Bacteria were not only active in the surface, but also in the bottom waters where oxygen concentrations were minimal; this was unexpected given their need for oxygen in methane consumption. In general, the microbial community properties were largely determined by the origin of the ponds (palsa versus lithalsa), and much less so by the extent of permafrost degradation. The key environmental variables pH, phosphorus and dissolved organic carbon likely contributed to the differentiation of microbial community between the palsa and lithalsa valleys. With intensification of climate warming, these microbial communities will face changing conditions that are likely to modify their taxonomic composition, and these responses are likely to differ between ponds in the two landscape types. Oxygenation of the ponds will likely be subject to major shifts in the future associated with changes in the duration of the ice-free season and the extent of stratification. Such changes will impact the balance between methanogenesis and methanotrophy, and thereby affect the net rates of methane emission. However, the results obtained here indicate that methanogenic Archaea and methanotrophic Bacteria have strategies to survive and remain active beyond the limit of their usual oxygen preferences.
84

A methodology for analyzing data from long-term passive acoustic monitoring. / Metodologia para análise de dados de monitoramentos acústicos passivos de longa duração.

Sánchez Gendriz, Ignacio 23 March 2017 (has links)
Despite the extensive Brazilian coast areas, little is known on underwater acoustic environments in Brazil. Acoustic environments (or soundscape) are composed by biological, geological and man-made sound sources. Soundscapes are strongly linked to ecosystems dynamics, and follow temporal patters that can vary at daily and seasonal scales. Thus, for soundscape characterization, it is necessary to undertake sound recordings for long periods, which demands innovative analyzing methods. Accordingly, the present research focuses in two principal objectives: (1) to develop methods for analyzing long-term acoustic recordings and, (2) to characterize marine soundscapes of selected points in São Paulo State. Four deployment sites were selected for the underwater acoustic monitoring: a point located at the channel entrance of the Santos Harbor, and three marine Protected Areas (PAs) in Sao Paulo state. As a result, the largest underwater acoustic database from Brazilian seas was acquired. The present work used Power Spectral Density (PSD), Sound Pressure Level (SPL) and Spectrograms to develop an innovative methodology for analyzing long-term acoustic data. In addition, a new visualization tool and a method for automatic detection of dawn and dusk choruses are presented. The achieved results validated the proposed methodology as an effective tool for analyzing long-term acoustic data. The area close to the first site, the vicinity of Santos Harbor, was dominated by ship noise, which values reach levels that can affect some species of fish and marine mammals. The soundscapes of the other three remaining measurement sites were dominated by fish and crustacean choruses, with daily and seasonal patterns (related to sunrise and sunset). For the monitored regions, the present work signifies the first contribution for cataloguing fish choruses, and establishes a baseline for the study of their underwater acoustic environment. Although the proposed methodology has used long-term undersea acoustic datasets as case-study, it can also be extended for monitoring other aquatic or terrestrial ecosystems. Finally, the research indicates to Brazilian environmental agencies and to the related scientific community that passive acoustic monitoring is a noninvasive and cost-effective tool that can be used for the management of PAs and points of economic relevance. / Apesar da ampla área dos mares brasileiros, pouco se conhece sobre paisagens acústicas submarinas no Brasil. Estas paisagens são compostas por sons de origens biológicas, geológicas e as produzidas pelo homem. As paisagens acústicas estão fortemente ligadas à dinâmica dos ecossistemas, mostrando padrões temporais diários e sazonais. Para caracterizar paisagens acústicas é necessário realizar gravações de sons por períodos de tempos prolongados, o que demanda métodos de análise inovadores. Neste sentido, a presente pesquisa visa dois objetivos principais: (1) desenvolver métodos para a análise de gravações acústicas de longa duração, (2) caracterizar a paisagem acústica do litoral do estado de São Paulo. Quatro pontos de coleta foram selecionados para monitoramento acústico passivo: um ponto situado no canal de entrada do Porto de Santos e os outros três em áreas de proteção marinhas (APM) do estado de São Paulo. Como resultado foi obtida a base de dados de sons submarinhos mais extensa dos mares brasileiros. Do ponto de vista da análise destes dados, o presente trabalho baseia-se no cálculo da Densidade Espectral de Potência, Níveis de Pressão Sonora e Espectrogramas, obtendo métodos de análise novedosos a partir técnicas tradicionais. Neste contexto a tese apresenta uma ferramenta para a visualização de dados acústicos e um método para a detecção automática de coros biológicos matutinos e vespertinos. Os resultados obtidos permitiram validar a efetividade dos métodos propostos na descrição e análise de dados acústicos de longa duração. O ambiente acústico nas proximidades do Porto de Santos foi dominado por ruído de embarcações, alcançando valores de níveis sonoros capazes de afetar algumas espécies de peixes e mamíferos marinhos. As paisagens acústicas dos três pontos restantes foram dominadas por coros de peixes e crustáceos, com padrões diários e sazonais (relacionados ao nascer e pôr do sol). O presente trabalho constitui a primeira pesquisa que cataloga coro de peixes e que estabelece uma referência para o estudo do ambiente acústico das regiões monitoradas. Embora os métodos apresentados usaram como estudo de caso dados de sons submarinos, a sua aplicação pode ser estendida para o monitoramento de outros ambientes aquáticos ou terrestres. Por último, a pesquisa mostra aos órgãos ambientais brasileiros que o monitoramento acústico passivo é uma ferramenta eficaz para o manejo e monitoramento de áreas protegidas e pontos de relevância econômica.
85

Efeitos do anti-inflamatório inibidor COX 2 (meloxicam) associado ao uso da hCG na gestação, características de corpo lúteo, fertilidade e desenvolvimento embrionário em éguas receptoras / Effects of the anti-inflammatory cox2 inhibitor (meloxicam) associated with the use of hCG in gestation, corpus luteum characteristics, fertility and embryonic development in recipient mares

Dercoli, Thyago Escodro 24 May 2017 (has links)
A transferência de embriões (TE) é uma biotecnologia amplamente utilizada na produção de equinos no Brasil, e a égua receptora exerce um papel fundamental nos resultados finais nos programas de reprodução. Alguns tratamentos têm sido preconizados com objetivo de exercer ação luteotrófica, melhorando a função luteal, e com isto aumentando os níveis sistêmicos de progesterona, como também o uso de drogas anti-inflamatórias, que evitam a perda da função luteal causada pela liberação de prostaglandina em processos inflamatórios prévios ou por manipulação na passagem transcervical do embrião no momento da TE. O objetivo deste estudo foi investigar os efeitos do anti-inflamatório inibidor seletivo COX 2 (meloxicam) associado ao uso luteotrófico da hCG na gestação, características de corpo lúteo, fertilidade e desenvolvimento embrionário em éguas receptoras. Para isto, 60 éguas receptoras alojadas em central de reprodução foram aleatoriamente divididas em 4 grupos de 15 animais, de acordo com os seguintes tratamentos: aplicação de 5ml solução fisiológica no dia da ovulação (controle); aplicação de 2500 UI hCG no dia da ovulação; aplicação de 2500 UI hCG no dia da ovulação associado a 0,6 mg/kg de meloxicam; aplicação de 2500 UI hCG no momento da transferência do embrião associado a 0,6 mg/kg meloxicam. No dia da TE, 7 dias após a TE e 21 dias após a TE para as éguas que ficaram gestantes, foi avaliada a irrigação do corpo lúteo por ultrassonografia modo doppler colorido por meio de score do percentual de irrigação (0-100%), e a irrigação do útero avaliado por score (1-4). Por meio da ultrassonografia no modo B, a área do CL em mm2 foi avaliada nos mesmos momentos, a área da vesícula em mm2 aos 15 e 21 dias da gestação e o tamanho do embrião em cm aos 29 dias de gestação. Além disso, foi realizada dosagem plasmática de progesterona no dia da TE, 7 dias após a TE e 21 dias para as éguas gestantes. As comparações entre os grupos foram analisadas para efeitos principais de tratamento e tempo, assim como para efeito de interação tratamento x tempo. Não foi observado influencia da aplicação de hCG e/ou meloxicam nos animais tratados comparados ao controle (P>0,05). No entanto, foi observado um aumento numérico na taxa de gestação para os dois grupos de receptoras que receberam anti-inflamatório meloxicam, correspondendo a um índice superior em 13,3 % de gestação para éguas tratadas. Em conclusão, não há influencia da aplicação de hCG associado ou não meloxicam sobre a perfusão sanguínea uterina, do corpo lúteo, no desenvolvimento embrionário e nas concentrações plasmáticas de progesterona em receptoras de embriões. No entanto, existe, pela aplicação de meloxicam, evidência de melhora nos índices de gestação, podendo estar associado ao efeito anti-inflamatório seletivo COX-2, que pode melhorar resultados em programas comerciais de transferência de embriões em equinos. / Embryo transfer (ET) is a biotechnology widely used in equine production in Brazil, and the recipient mare plays a key role in the final results of breeding programs. Several treatments have been advocated both for the purpose of exerting luteotrophic action, improving luteal function, and thereby increasing systemic levels of progesterone, such as the use of anti-inflammatory drugs, which prevent the loss of luteal function caused by the release of prostaglandin in previous inflammatory processes or by manipulation in the transcervical passage of the embryo at the time of ET. The objective of this study was to investigate the effects of the anti-inflammatory COX 2 inhibitor (meloxicam) associated with luteotrophic use of hCG in gestation, corpus luteum characteristics, fertility and embryonic development in recipient mares. For this, 60 receiving mares housed in a reproduction center were randomly divided into 4 groups of 15 animals, according to the following treatments: application of 5ml physiological solution on the day of ovulation (control group); application of 2500 IU hCG on ovulation day; application of 2500 IU hCG on the day of ovulation associated with 0.6 mg/kg of meloxicam; application of 2500 IU hCG at the time of embryo transfer associated with 0.6 mg/kg meloxicam. On the day of ET, 7 days after ET and 21 days after ET for pregnant mares, corpus luteum irrigation was evaluated by color Doppler ultrasonography using a score of the percentage of irrigation (0-100%), and irrigation of the uterus evaluated by score (1-4). Using B-mode ultrasonography, corpus luteum area in mm2 was assessed at the same time points, the area of the embryonic vesicle in mm2 at 15 and 29 days of gestation, and the size of the embryo in cm at 29 days of gestation. In addition, plasma progesterone dosage was performed on ET day 7 days after ET in all groups and 21 days after ET for pregnant mares. The comparisons between the groups were analyzed for main effects of treatment and time, as well as for interaction effect treatment x time. No influence of application of hCG and / or meloxican was observed on treated animals compared to control (P>0.05). However, a numerical increase in gestation rate was observed for the two groups of recipients who received anti-inflammatory meloxicam, corresponding to an index higher than 13.3% of gestation for treated mares. In conclusion, there is no influence of the application of hCG associated or not to meloxicam on uterine irrigation, corpus luteum, embryo development and plasma concentrations of progesterone in embryo recipients. However, there is evidence of improvement in gestation rates due to the application of meloxicam, which may be associated with the COX-2 selective anti-inflammatory effect of this drug, improving results in commercial embryo transfer programs in horses.
86

"O geóide gravimétrico e o nível médio do mar na região do Datum altimétrico brasileiro: um estudo comparativo" / A comparative study on the gravimetric geoid and the brasilian altimetric Datum.

Lopes, Alexandre Bernardino 17 May 2006 (has links)
Um estudo sobre a compatibilidade de um geóide gravimétrico recente com o nível médio do mar no Datum altimétrico do Sistema Geodésico Brasileiro (SGB), foi realizado. A metodologia usada consiste na comparação do geóide gravimétrico com o nível médio do mar, materializado pelo marégrafo de Imbituba (SC), e análise dos desníveis entre os marégrafos da costa brasileira em relação ao de Imbituba, determinados por nivelamento geométrico e dados oceanográficos. A unificação de Data altimétricos, investigada em vários centros de pesquisas geodésicas, visa homogeneizar altitudes ortométricas em escalas regional e global através de técnicas espaciais de posicionamento e modelos geoidais gravimétricos. Entre as propostas para a unificação de Data altimétricos, a utilização de modelos geoidais gravimétricos vem se mostrando adequada tanto do ponto de vista teórico como prático. Assim, foi determinada a componente sistemática no Datum de Imbituba, a partir da comparação de um geóide gravimétrico da América do Sul, obtido através da colocação por mínimos quadrados, e o geóide GPS/nivelamento, determinado através dos dados da Rede GPS do Sul/Sudeste do Brasil (RGSB). Para representar a componente sistemática no Datum altimétrico brasileiro, foram usados três formas: 1) determinação da componente sistemática na RN fundamental da RAFB (RN 4X), 2) cálculo da média ponderada da componente sistemática a partir das RNs mais próximas ao Datum, e 3) modelagem da componente sistemática usando modelo matemático da transformação de similaridade a partir de todos os dados da RGSB. Os resultados, obtidos no cálculo do nível médio do mar a partir de dados oceanográficos, mostram que as diferenças em relação ao marégrafo de Imbituba são, em grande parte, causadas por mudanças das características oceanográficas (salinidade, temperatura, densidade e pressão) ao longo da costa. A remoção da componente sistemática, obtida no Datum, diminuiu significativamente a diferença entre os geóides gravimétrico e GPS/nivelamento nas RNs da RAFB; entretanto o ajuste da componente sistemática, através da transformação de similaridade, utilizando todos os dados da RGSB, apresentou os melhores resultados na compatibilização dos geóides gravimétricos e GPS/nivelamento. ix / A study on the compatibility of a recent gravimetric geoid with the mean sea level in altimetric Datum of the Sistema Geodésico Brasileiro (SGB) was accomplished. The used methodology consists in comparing gravimetric geoid with mean sea level, at the tide gauge of Imbituba (SC), and the analysis of differences among tide gauges of Brazilian coast with respecto Imbituba, obtained by geometric levelling and oceanographic data. The unification of altimetric Data, investigated in several geodetic research centres, aiming the standardization of orthometric heights in regional and global scales by using spatial positioning techniques, and gravimetric geoid models. Among the suggestions for the altimetric Data unification, the use of gravimetric geoid models is adequate in both, theoretical and practical points of view. Thus, a systematic component at Imbituba Datum was determined by comparing a South American gravimetric geoid, obtained by least-squares collocation, and GPS/levelling geoid, determined at stations of the Rede GPS no Sul/Sudeste do Brasil (RGSB). To represent the systematic component in Brazilian altimetric Datum, three aproaches were used: 1) determining the systematic component at the fundamental benchmark of the RAFB (RN 4X); 2) computing the weighted mean from the stations closer to the Datum, and 3) modelling the systematic component by using the similarity transformation model from all stations of the RGSB, The results of mean sea level, computed from oceanographic data, show that differences with respect to Imbituba tide gauge are mostly due to oceanographic characteristics, (salinity, temperature, density, and pressure) along the coast. The removal of systematic component at Datum, has significantly reduced the difference between gravimetric and GPS/levelling geoids; however, the adjustment of systematic component by using the similarity transformation model, has shown the best results in representing the differences between gravimetric and GPS/levelling geoids.
87

Rochas geradoras da Formação Guia, Neoproterozoico do sul do Cráton Amazônico, região de Cáceres e Nobres, estado do Mato Grosso

BEZERRA JUNIOR, Alexandre Castelo Branco 24 October 2018 (has links)
Submitted by Fernanda Costa (fernandaclaudiasilva19@gmail.com) on 2019-01-03T16:58:01Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_RochasGeradorasFormacao.pdf: 6064715 bytes, checksum: f254a827da436827a60145a06dcd1803 (MD5) / Approved for entry into archive by Cleide Dantas (cleidedantas@ufpa.br) on 2019-02-01T16:12:27Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_RochasGeradorasFormacao.pdf: 6064715 bytes, checksum: f254a827da436827a60145a06dcd1803 (MD5) / Made available in DSpace on 2019-02-01T16:12:27Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_RochasGeradorasFormacao.pdf: 6064715 bytes, checksum: f254a827da436827a60145a06dcd1803 (MD5) Previous issue date: 2018-10-24 / ANP - Agência Nacional do Petróleo / Extensos mares epíricos instalados na porção oeste do Gondwana, no final do Neoproterozoico, foram influenciados pelo último evento glacial global Marinoano (635 Ma) ligado a hipótese de Snowball Earth. A rápida mudança nas condições de icehouse para greenhouse favoreceu o desenvolvimento de extensas plataformas carbonáticas na margem sudeste do Cráton Amazônico, num contexto de Bacia Intracratônica, invertida no início do Paleozoico. Nesta região, estão expostos os depósitos do Grupo Araras, que registram a evolução das plataformas carbonáticas pós-glaciais. O Grupo Araras é composto, da base para o topo, pelas formações Mirassol d’Oeste (capa dolomítica), Guia (capa calcária), Serra do Quilombo e Nobres. A Formação Guia, objeto deste estudo, tem a sua base interpretada como capa calcária com até 30 metros de espessura nas ocorrências sobre o Cráton e depósitos de plataforma com até 225 metros na Bacia Intracratônica. Esta unidade consiste em calcários micríticos e folhelhos transgressivos ricos em matéria orgânica apresentando excelentes exposições nas regiões de Cáceres e Nobres, Estado do Mato Grosso, consistindo nas seguintes fácies/microfácies: mudstone calcífero (Mc); wackestone com terrígenos (Wt); mudstone com instraclastos (Mi); e brecha calcária (Bc). Este monótono conjunto de fácies/microfácies foi interpretado como um paleoambiente de plataforma marinha rasa abaixo do nível de ondas de tempestades, na zona offshore, sob condições redutoras. Estilólitos e dissolution seams são frequentes nas microfácies Mc e Wt, assim como, a presença de betume e pirita preenchendo poros intercristalinos. A fácies Wt apresenta conteúdo de terrígenos acima de 10%, representados por grãos de quartzo e muscovita, ambos variando de silte a areia fina. A análise dos grãos de quartzo por catodoluminescência indicam proveniência de fontes ígneas e metamórficas de médio a alto grau. A quantidade anômala de terrígenos disseminados nas fácies micríticas, considerada uma inversão textural, sugere influxo siliciclástico de margens próximas da bacia condizentes com um contexto paleogeogr fico de mares epíricos proposto para o núcleo do Gondwana Oeste. A análisede Conteúdo Orgânico Total (COT) indicou na sucessão aflorante na região de Cáceres valores de COT entre 0,06% a 0,23%, enquanto na região de Nobres, os depósitos apresentam valores entre 0,05 e 0,27%, condizentes com acumulações neoproterozoicas ao redor do mundo (geralmente inferiores a 1%). Esta acumulação de hidrocarboneto, apesar de inviável economicamente, compõe um sistema petrolífero não-convencional denominado de Araras. De tal forma que a sucessão estudada (Fm. Guia) constitui a rocha geradora e reservatório deste sistema e os dolomitos da Formação Serra do Quilombo representam a rocha selante. São registradas pelo menos duas fases de migração de hidrocarboneto, associados aos eventos tectônicos no Ediacarano superior e início do Paleozoico, com a abertura das bacias do Parecis e Paraná. / Extensive epeiric seas installed in the western Gondwana at the Upper Neoproterozoic were influenced by the last global glacial Marinoan event (635 Ma) linked to the Snowball Earth hypothesis. The rapid change in icehouse for greenhouse conditions favored the development of wide carbonaceous platforms on the southeastern margin of the Amazonian Craton, in the context of the Intracratonic Basin, reversed at the beginning of the Paleozoic. In this region, the deposits of the Araras Group are exposed, which record the evolution of the post-glacial carbonaceous platforms. The Araras Group is composed, from the base to the top, by the Mirassol d'Oeste (cap dolomitic), Guia (cap limestone), Serra do Quilombo and Nobres formations. The Guia Formation, object of this study, has its base interpreted as limestone cap with up to 30 meters thickness in the occurrences on the Craton and platform deposits with up to 225 meters in the Intracratonic Basin. This unit consists of micritic limestones and transgressive shales rich in organic matter presenting excellent exposures in the regions of Cáceres and Nobres, State of Mato Grosso, consisting of the following facies/microfacies: limemudstone; wackestone with terrigenous; mudstone with intraclastic; and limestone breccia. This monotonous set of facies/microfacies was interpreted as a shallow marine platform paleoenvironment below the level of storm waves in the offshore zone under reducing conditions. Stilolytes and dissolution seams are common in Mc and Wt microfacies, as well as the presence of bitumen and pyrite filling inter-crystalline pores. The facies Wt presents a variation of terrigenous content of 5% to 35%, represented by grains of quartz and muscovite, both varying from silt to fine sand. The analysis of the quartz grains by cathodoluminescence indicate the origin of igneous and metamorphic sources from medium to high grade. The anomalous amount of terrigenous disseminated in the micritic facies, considered a textural inversion, suggests siliciclastic influx of margins close to the basin, consistent with a paleogeographic context of epeiric seas proposed by previous studies for the core of West Gondwana. The analysis of Total Organic Content (TOC) indicated in the outcropping succession in the region of Cáceres TOC values between 0.06% and 0.23%, while in the Nobres region, the deposits presented values between 0.05 and 0.27%, consistent with neoproterozoic accumulations around the world (generally less than 1%). This hydrocarbon accumulation, although economically irrelevant, composes an unconventional petroleum system called Araras. In such a way that the studied succession (Fm. Guia) constitutes the generating and reservoir rock of this system and the dolomites of the Serra do Quilombo Formation represent the sealing rock. At least two stages of hydrocarbon migration are recorded, associated to the tectonic events in the Upper Ediacaran and Early Paleozoic, with the opening of the Parecis and Paraná basins.
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Dinâmica ovariana e uterina em éguas da raça crioula durante a estação reprodutiva / Ovarian and uterine dynamics in criollo breed mares during the reproductive season

Duval, Luzia Hallal January 2017 (has links)
O cavalo Crioulo é originário de raças de cavalos espanhóis trazidos há quatro séculos e reproduziu-se livremente no sul do continente da América.A seleção natural que ocorreu durante séculos fez o cavalo Crioulo ser conhecido por sua rusticidade e resistência, o que pode ter influenciado positivamente a fertilidade e longevidade desta raça, mas informações sobre fertilidade e performance reprodutiva da égua Crioula sob manejo natural ou controlado ainda são escassas. Os objetivos do presente estudo foram: (1) elucidar a dinâmica folicular das éguas Crioulas; (2) caracterizar o desenvolvimento e a regressão do corpo lúteo; e (3)estudar as mudanças de tônus e de ecotextura uterina ultrassonográfica durante dois ciclos estrais consecutivos. No experimento, 26 intervalos interovulatórios (IIO) foram estudados em 13 éguas. O ciclo estral natural foi caracterizado por: (i) o comprimento do IIO foi de 21 dias; (ii) os folículos dominante e subordinado emergem juntos no dia 5 e a taxa de crescimento é lenta até o momento do divergência; (iii) o divergência folicular ocorreu quando o folículo dominante atingiu o diâmetro de 22mm; (iv) o diâmetro pré-ovulatório foi de 43 mm; (v) o corpo lúteo atingiu o tamanho máximo 1,5 dias depois da ovulação e no dia 15 já não pode ser mais visualizado por ultrassonografia transretal; e (vi) a forte correlação de repetibilidade demonstrou que o tônus uterino e cervical podem ser usados para determinar a fase do ciclo estral. Os resultados apresentados neste trabalho possuem grande importância para melhor compreensão das características reprodutivas naturais do ciclo estral da égua Crioula. / The Criollo horse originates from breeds of spanish horses that were brought four centuries ago and reproduced freely in the southern part of the American continent. The natural selection that occurred over the centuries made the Criollo horse known for its roughness and resistance, which may have influenced positively the fertility and longevity of this breed, but information regarding fertility and reproductive performance of Criollo breed mare under natural or controlled management conditions is scarce. The objectives of the present study were to: (1) elucidate the follicular dynamics of Criollo breed mares; (2) characterize growth and regression of the corpus luteum; and (3) study the tone and ultrasonographic uterine echotexture changes during two consecutive estrous cycles. In this trial, 26 interovulatory intervals (IOI) were evaluated in 13 mares. The spontaneous estrous cycles were characterized by: (i) the length of the IOI was 21 days; (ii) dominant and subordinate follicles emerge together at day 5 and their growth rate were slower until the deviation moment; (iii) deviation occurred when the dominant follicle has achieved 22 mm; (iv) diameter of the preovulatory follicle was 43 mm; (v) corpus luteum has achieved its maximum diameter 1.5 days after ovulation and at day 15 it can no longer be visualized by transrectal ultrasonography; and (vi) the strong correlation for repeatability demonstrated that the uterine and cervical tonus can be used to determine the phase of the estrous cycle. The results presented are of fundamental importance for a better understanding of the reproductive physiological patterns of the estrous cycle in the Criollo mare.
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Diversité, distribution spatiale et dynamique temporelle des petits eucaryotes dans des écosystèmes d'eau douce peu profond / Diversity, spatial distribution and temporal dynamics of small eukaryotes in shallow freshwater ecosystems

Simon, Marianne 26 September 2014 (has links)
La diversité des très petits eucaryotes (<5 µm) a essentiellement été étudiée par des méthodes moléculaires dans les océans ou de grands lacs. La diversité dans les écosystèmes d'eau douce peu profonds reste très peu explorée, bien que ces systèmes soient très nombreux et écologiquement importants en régions tempérées. Dans ce travail, nous avons voulu explorer la diversité et certains aspects de l'écologie des micro-organismes eucaryotes dans ce type d'écosystèmes, à l'aide de méthodes moléculaires ciblant l'ADNr 18S de cellules planctoniques de surface, dans la fraction de taille théorique 0,2-5 µm. Nous nous sommes d'abord concentrés sur les haptophytes, un groupe important en milieu marin mais beaucoup moins bien connu en eaux douces. Nous avons exploré leur diversité à l'aide d'amorces spécifiques pour amplifier les gènes des ARNr 18S du groupe suivi du clonage / séquençage Sanger de ces marqueurs, dans 17 écosystèmes continentaux et 2 colonnes d'eau marines pour comparer la diversité dans différents milieux, ainsi qu'à l'aide du pyroséquençage de ce même marqueur dans 4 mares et 1 ru au cours d'un suivi mensuel sur 2 ans. La diversité des haptophytes était moindre en eau douce qu'en milieu marin, mais nous avons pu y détecter un nouveau groupe, divergeant au sein des Isochrysidales, présentant une saisonnalité marquée. Les phylotypes d'eau douce étaient majoritairement distincts de ceux détectés en milieu marin, et ont confirmé l'existence de plusieurs transitions marin/eau douce dans l'histoire des haptophytes. Dans un second temps, nous avons exploré par pyroséquençage 454 des ADNr 18S la diversité des micro-organismes eucaryotes dans 4 mares et 1 ru, échantillonnés au printemps, et différant par leur taille, leur forme et leur environnement proche. Nous avons détecté une grande diversité dans chaque système étudié, avec des séquences affiliées à tous les supergroupes reconnus (Archaeplastida, Stramenopiles, Alveolata, Rhizaria, Excavata, Amoebozoa et Opisthokonta), ainsi qu'à des taxa de position phylogénétique mal résolue (i.e. Cryptophyta, Haptophyta, Centroheliozoa Katablepharida). Notamment, certaines OTU étaient affiliées au groupe MAST-3 (MArine STramenopiles) jusque-là considéré comme exclusivement marin. Les communautés de petits eucaryotes étaient différentes dans chacun des écosystèmes ; ces différences ne corrélaient pas avec les distances géographiques entre sites (test de Mantel), et des analyses multivariées n'ont pas mis en évidence de relation claire entre la distribution d'un groupe et un paramètre environnemental. Par la suite, nous avons suivi la diversité des eucaryotes microbiens sur 2 ans dans les mêmes 5 écosystèmes. Nous avons collecté des échantillons de plancton et mesuré différents paramètres physico-chimiques chaque mois, sauf pour 2 des écosystèmes lorsqu'ils étaient à sec. La diversité détectée sur 2 ans était bien plus grande que celle identifiée lors de l'étude ponctuelle. Cryptophytes, ciliés, chrysophytes et champignons stricto sensu étaient globalement les plus abondants. La composition et la structure des communautés différaient d'un écosystème à l'autre sur l'ensemble du suivi. Ces communautés étaient très dynamiques, et montraient une saisonnalité claire. La distribution spatio-temporelle des champignons sensu stricto était clairement corrélée aux hautes valeurs de conductivité. Enfin, nous avons décrit la dynamique des communautés de petits eucaryotes dans l'une des mares et le ru lors d'épisodes de sécheresse. Nous avons collecté du sédiment dans le lit asséché des écosystèmes lors des sécheresses, et du plancton le reste du temps. Les communautés du sédiment présentaient une signature différente des assemblages planctoniques. Ces derniers montraient une résilience élevée, et retrouvaient une signature planctonique moins d'un mois après que les écosystèmes soient de nouveau en eau. / The diversity of very small eukaryotes (<5 µm) has mainly been studied by molecular methods in marine systems or in large lakes. However, that of small shallow systems remains practically unexplored, despite the fact that these systems are extensive and ecologically important in temperate regions. We thus aimed at describing the diversity and community composition of small eukaryotes in shallow freshwater systems, using molecular methods targeting the 18S rRNA gene of planktonic cells in the 0.2-5 µm size range. We first focused on haptophytes, an important group in marine environments but much less known in freshwaters. We explored their diversity using newly designed specific primers to amplify haptophyte 18S rRNA genes, followed by their subsequent cloning and Sanger sequencing in seventeen continental ecosystems and in two marine water columns to allow comparisons between different environments, as well as using 454-pyrosequencing in 4 ponds and one brook during a 2-years monthly survey. Even if freshwater haptophytes were less diverse than marine lineages, we revealed the presence of a divergent lineage belonging to the Isochrysidales never recorded so far, which presented a marked seasonality. Freshwater phylotypes were usually distinct from their marine counterparts, and confirmed the occurrence of multiple marine–freshwater transitions in haptophyte evolution. In a second step, we explored the microbial eukaryote diversity in 5 distinct shallow ecosystems sampled at spring and that differ in size, shape and surrounding environment, by 454-pyrosequencing their 18S rDNA. Diversity was high in the studied systems, with sequences affiliated to the 7 recognized eukaryotic supergroups (Archaeplastida, Stramenopiles, Alveolata, Rhizaria, Excavata, Amoebozoa and Opisthokonta) as well as groups of unresolved phylogenetic position including, among others, Cryptophyta, Haptophyta, Centroheliozoa or Katablepharida. Especially, we detected OTUs affiliated to the previously thought exclusively marine lineage MAST-3 (MArine STramenopiles), and potentially to other MAST groups with no known representative from freshwaters. Small eukaryote community structures were different in the five ecosystems. Differences in community compositions did not correlate with geographical distances (Mantel test), and multivariate statistical analyses did not reveal clear relationships between any group distribution and specific environmental parameters. Then, we conducted a 2-years survey of eukaryotic micro-organisms diversity in the same 5 small ecosystems. To do so, we collected plankton and measured several physical and chemical parameters on a monthly basis, except for two systems when they were totally dry. The total diversity encountered during the 24 months was much broader than that identified in the previous snapshot study. The most abundant detected groups were Cryptophytes, Ciliates, Chrysophytes and Fungi sensu stricto. Community structures and compositions were different in the five systems along the two years. In all systems, communities were highly dynamic, and revealed a marked seasonality, notably with summer and winter communities being always distinct. Multivariate statistical analyses were used to analyze simultaneously physico-chemical data and community compositions. The clearest correlation associated fungi distribution and high conductivity. Finally, we described the dynamics of small-eukaryote communities in a pond and a brook through drought events. We collected sediment on the system beds when they were dry, and plankton the rest of time. Communities in the sediment and in the water presented distinct signatures. Surface water communities presented (a high) resilience, and recovered a planktonic signature within a month after the systems were filled up again with water.
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Efeitos do anti-inflamatório inibidor COX 2 (meloxicam) associado ao uso da hCG na gestação, características de corpo lúteo, fertilidade e desenvolvimento embrionário em éguas receptoras / Effects of the anti-inflammatory cox2 inhibitor (meloxicam) associated with the use of hCG in gestation, corpus luteum characteristics, fertility and embryonic development in recipient mares

Thyago Escodro Dercoli 24 May 2017 (has links)
A transferência de embriões (TE) é uma biotecnologia amplamente utilizada na produção de equinos no Brasil, e a égua receptora exerce um papel fundamental nos resultados finais nos programas de reprodução. Alguns tratamentos têm sido preconizados com objetivo de exercer ação luteotrófica, melhorando a função luteal, e com isto aumentando os níveis sistêmicos de progesterona, como também o uso de drogas anti-inflamatórias, que evitam a perda da função luteal causada pela liberação de prostaglandina em processos inflamatórios prévios ou por manipulação na passagem transcervical do embrião no momento da TE. O objetivo deste estudo foi investigar os efeitos do anti-inflamatório inibidor seletivo COX 2 (meloxicam) associado ao uso luteotrófico da hCG na gestação, características de corpo lúteo, fertilidade e desenvolvimento embrionário em éguas receptoras. Para isto, 60 éguas receptoras alojadas em central de reprodução foram aleatoriamente divididas em 4 grupos de 15 animais, de acordo com os seguintes tratamentos: aplicação de 5ml solução fisiológica no dia da ovulação (controle); aplicação de 2500 UI hCG no dia da ovulação; aplicação de 2500 UI hCG no dia da ovulação associado a 0,6 mg/kg de meloxicam; aplicação de 2500 UI hCG no momento da transferência do embrião associado a 0,6 mg/kg meloxicam. No dia da TE, 7 dias após a TE e 21 dias após a TE para as éguas que ficaram gestantes, foi avaliada a irrigação do corpo lúteo por ultrassonografia modo doppler colorido por meio de score do percentual de irrigação (0-100%), e a irrigação do útero avaliado por score (1-4). Por meio da ultrassonografia no modo B, a área do CL em mm2 foi avaliada nos mesmos momentos, a área da vesícula em mm2 aos 15 e 21 dias da gestação e o tamanho do embrião em cm aos 29 dias de gestação. Além disso, foi realizada dosagem plasmática de progesterona no dia da TE, 7 dias após a TE e 21 dias para as éguas gestantes. As comparações entre os grupos foram analisadas para efeitos principais de tratamento e tempo, assim como para efeito de interação tratamento x tempo. Não foi observado influencia da aplicação de hCG e/ou meloxicam nos animais tratados comparados ao controle (P&gt;0,05). No entanto, foi observado um aumento numérico na taxa de gestação para os dois grupos de receptoras que receberam anti-inflamatório meloxicam, correspondendo a um índice superior em 13,3 % de gestação para éguas tratadas. Em conclusão, não há influencia da aplicação de hCG associado ou não meloxicam sobre a perfusão sanguínea uterina, do corpo lúteo, no desenvolvimento embrionário e nas concentrações plasmáticas de progesterona em receptoras de embriões. No entanto, existe, pela aplicação de meloxicam, evidência de melhora nos índices de gestação, podendo estar associado ao efeito anti-inflamatório seletivo COX-2, que pode melhorar resultados em programas comerciais de transferência de embriões em equinos. / Embryo transfer (ET) is a biotechnology widely used in equine production in Brazil, and the recipient mare plays a key role in the final results of breeding programs. Several treatments have been advocated both for the purpose of exerting luteotrophic action, improving luteal function, and thereby increasing systemic levels of progesterone, such as the use of anti-inflammatory drugs, which prevent the loss of luteal function caused by the release of prostaglandin in previous inflammatory processes or by manipulation in the transcervical passage of the embryo at the time of ET. The objective of this study was to investigate the effects of the anti-inflammatory COX 2 inhibitor (meloxicam) associated with luteotrophic use of hCG in gestation, corpus luteum characteristics, fertility and embryonic development in recipient mares. For this, 60 receiving mares housed in a reproduction center were randomly divided into 4 groups of 15 animals, according to the following treatments: application of 5ml physiological solution on the day of ovulation (control group); application of 2500 IU hCG on ovulation day; application of 2500 IU hCG on the day of ovulation associated with 0.6 mg/kg of meloxicam; application of 2500 IU hCG at the time of embryo transfer associated with 0.6 mg/kg meloxicam. On the day of ET, 7 days after ET and 21 days after ET for pregnant mares, corpus luteum irrigation was evaluated by color Doppler ultrasonography using a score of the percentage of irrigation (0-100%), and irrigation of the uterus evaluated by score (1-4). Using B-mode ultrasonography, corpus luteum area in mm2 was assessed at the same time points, the area of the embryonic vesicle in mm2 at 15 and 29 days of gestation, and the size of the embryo in cm at 29 days of gestation. In addition, plasma progesterone dosage was performed on ET day 7 days after ET in all groups and 21 days after ET for pregnant mares. The comparisons between the groups were analyzed for main effects of treatment and time, as well as for interaction effect treatment x time. No influence of application of hCG and / or meloxican was observed on treated animals compared to control (P&gt;0.05). However, a numerical increase in gestation rate was observed for the two groups of recipients who received anti-inflammatory meloxicam, corresponding to an index higher than 13.3% of gestation for treated mares. In conclusion, there is no influence of the application of hCG associated or not to meloxicam on uterine irrigation, corpus luteum, embryo development and plasma concentrations of progesterone in embryo recipients. However, there is evidence of improvement in gestation rates due to the application of meloxicam, which may be associated with the COX-2 selective anti-inflammatory effect of this drug, improving results in commercial embryo transfer programs in horses.

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