978 resultados para Robespierre, Maximilien, 1758-1794.
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The study of ichthyio-plankton stages and its relations with the environment and other organisms is therefore crucial for a correct use of fishery resources. In this context, the extraction and the analysis of the content of the digestive tract, is a key method for the identification of the diet in early larval stages, the determination of the resources they rely on and possibly a comparison with the diet of other species. Additionally this approach could be useful in determination on occurrence of species competition. This technique is preceded by the analysis of morphometric data (Blackith & Reyment, 1971; Marcus, 1990), that is the acquisition of quantitative variables measured from the morphology of the object of study. They are linear distances, count, angles and ratios. The subsequent application of multivariate statistical methods, aims to quantify the changes in morphological measures between and within groups, relating them to the type and size of prey and evaluate if some changes appear in food choices along the larvae growth.
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The parasites fauna of 491 specimens of Sander lucioperca, Linnaeus 1758 (246 specimens) and catfish, Silurus glanis, Linnaeus 1758 (245 specimens) in different size from Aras Reservoir situated in North —west of the Iran was investigated. During 2006-2007 Totally 16 parasite species were recorded. The most various parasites was found in catfish (10 species) while the lowest number was recorded in Sander lucioperca (6 species). Among them, however three genera of protozoa (Trichodina, Vorticella, Ichthyophthirius), two genera of Monogenea (Gyrodactylus, Silurodiscoides), Digenea, Cestoda, Nematoda, Acanthocephala and Annelida one species each (Diplostomum, Protocephalus, Eustrongylides, Neoechinorhynchus, Pisicola) and two crustacean genera (Argulus and Lernea) recorded and we can come to conclusion in comparison with the earlier data the actual parasite fauna of two hosts has been greatly improved. According to the present study the prevalence, mean abundance and mean intensity of parasites species of both hosts were highly influenced by seasons of the year. Some species found, however show a tendency to be more abundant ides Trichodina sp., Ichthyophthirius multifiliis, Silurodiscoides vistolensis, Protocephalus osculatus respectively. Most parasites species live in gills and skin, where is highly sensitive to some pathogens parasites species (Trichodina, Vorticella, Ichthyophthirius, Pisicola geometra, Argulus foliaceus; Lernea) and While some are specialist (Silurodiscoides vistolensis and Silurodiscoides siluri) other more or less generalist (ichthyophthirius).
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Sturgeons are important because of producing the expensive caviar. With regard to decreasing of natural stocks of these fishes, cultured sturgeons farms are expanding, so infectious or non-infectious agents can cause problems in this industry. One of the most important infectious diseases, are parasitic diseases, like gill parasites. In this study from March 2007 to June 2008, gills of 122 sturgeons of south west of Caspian Sea, 44 samples of juveniles from freshwater farms and 25 samples of cultured fishes in freshwater were collected and examined. Parasites were separated and determination of species and prevalence of them were done. Nitzschia sturionis and Diclybothrium armatum (monogenea) with general prevalence 8.7% in Acipenser persicus and 25.6% in Acipenser stellatus from sea sturgeons and Trichodina (sp.1, sp.2) and Ichthyophthirius multifiliis from freshwater sturgeons, were separated. Statistical analysis was done according to species, sex, length and weight of fishes. Pathology, morphometric and morphological characters of Nitzschia sturionis were also studied. At the end, we have suggested ways for health management of farms for prevention of parasites entry.
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Rezension von: Frank-Michael Kuhlemann: Modernisierung und Disziplinierung. Sozialgeschichte des preußischen Volksschulwesens 1794-1872. (Kritische Studien zur Geschichtswissenschaft. Bd. 96.) Göttingen: Vandenhoeck & Ruprecht 1992. 468 S.
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Freshwater mussel (Mollusca, Bivalvia, Unionoida) populations are one of the most endangered faunistic groups. Mussels play an important role in the functioning of aquatic ecosystems, because they are responsible for the filtration and purification of water. They have a complex life cycle, with a parasitic larvae and usually limited host fish species. The real status of these populations is still poorly understood worldwide. The objectives of the present work were the study of bioecology of duck mussel (Anodonta anatina L.) populations of Tua Basin (NE Portugal). It was made the characterization of the ecological status of Rabaçal, Tuela and Tua Rivers, selecting 15 sampling sites, equally distributed by the three rivers. Samplings were made in the winter of 2016, and several physico-chemical water parameters measured and two habitat quality indexes calculated (GQC and QBR indexes). Benthic macroinvertebrate communities were sampled based on the protocols established by the Water Framework Directive. Host fish populations for duck mussel were determined in laboratorial conditions, testing several native and exotic fish species. The results showed that several water quality variables (e.g. dissolved oxygen, conductivity, pH, total dissolved solids, and nutrients) can be used for the classification of river typology. Other responsive metrics were also determined to identify environmental degradation. For instances, hydromorphological conditions (GQC and QBR indexes) and biota related metrics (e.g. composition, distribution, abundance, diversity of invertebrate communities) contributed to the evaluation of the ecological integrity. The upper zones of Rabaçal and Tuela rivers were classified with excellent and good ecological integrity, while less quality was found in downstream zones. The host fish tests showed that only native species are effective hosts, essential for the conservation purposes of this mussel species. Threats, like pollution, sedimentation and river regularization (3 big dams are in construction or in filling phase), are the main cause of habitat loss for native mussel and fish populations in the future. Rehabilitation and mitigation measures are essential for these lotic ecosystems in order to preserve the prioritary habitats and the native species heavily threatened.
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Nossa pesquisa consiste no estudo esquemático macroscópico na placenta de gatos e a sua caracterização como tipo, placenta zonária, que 62,5% dos casos apresenta uma fissura na área distal do funículo umbilical. Esse é formado por uma área justa fetal, área justa placentária e área média, encontrando achados histológicos de 2 artérias, uma veia, 2 pedículos vitelínicos e 2 pedículos alantoidianos. Na fissura, encontramos um epitélio alantoidiano cobrindo esta área em 10% dos casos e, em 90% dos achados foram encontrados um trofoblasto diminuído comparado com outras áreas placentárias fora da fissura. Portanto, a placenta felina, com sua relação materno fetal mostra uma placenta zonária incompleta, diferente do ocorrido nos outros carnívoros.
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A incorporação de fontes proteicas alternativas à farinha de peixe na alimentação de espécies piscícolas tem sido objecto de variados estudos no âmbito da nutrição animal. Neste contexto realizou-se o presente trabalho, cujo objectivo foi determinar o nível de substituição ideal de farinha de peixe por glúten de trigo na alimentação de dourada. Foram realizados dois ensaios, um de crescimento e um de digestibilidade. O ensaio de crescimento efectuou-se para determinar qual o nível máximo de substituição sem que os animais apresentassem diferenças significativas em termos de taxa de crescimento. O ensaio de digestibilidade teve como principal objectivo determinar qual das dietas testadas proporcionaria melhores valores de utilização digestiva por parte dos animais. Tendo em conta os resultados dos ensaios e as condições experimentais em que se realizaram, verificou-se que a substituição até 40% não afecta significativamente o desempenho zootécnico das douradas. ABSTRACT; The incorporation of alternative protein sources in fish diets has been the aim of many scientific experiments in animal nutrition. ln this study, the main objective was to evaluate the ideal level of wheat gluten incorporation in substitution of fishmeal in diets for gilthead sea bream (Sparus aurata L). To reach this objective, two experiments were carried out, in which growth and digestibility were studied. The aim of the growth experiment was to evaluate the maximum level of fish meal substitution by wheat gluten (20%, 40%, 60% and 80%), without affecting significantly the animals growth rate. The digestibility experiment took place to evaluate which animals presented better food utilization with the tested diets (20%, 40%, 60% and 80%). Observing the results of these two experiments, it was concluded that the substitution until 40% did not affect significantly the performance of the fishes.
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O presente estudo foi realizado numa área com 156,5 Km/ localizada nos municípios de Évora e Montemor-o-Novo, a Sul de Portugal. Cinco genetas foram seguidas via telemetria durante seis meses visando o estudo do uso do espaço e comportamento relativamente às estradas. Estas, parecem funcionar como limites das áreas vitais da geneta actuando como barreira física e/ou social aos seus movimentos. Contudo, as genetas cruzaram diferentes tipos de estrada embora com frequência reduzida. Por outro lado, as genetas adoptaram uma distância de segurança média das estradas, de 1km, onde se verifica uma aproximação durante a noite e um distanciamento durante o dia. Todos os animais evidenciaram ter uma distribuição não aleatória relativamente às estradas concentrando-se maioritariamente apenas num dos lados da estradão que indica o efeito destas infra-estruturas como barreiras parciais ao movimento. A presença de galerias ripicolas parece promover o uso das bermas e durante o estudo todos os indivíduos seleccionaram positivamente estes habitats. ABSTRACT: The present study, was conducted in a 156,5 Km 2 area, located in the Évora and Montemor-o-Novo counties, southern Portugal. Five genets were radio-tracked for six months with the purpose of studying their space use and behavior towards roads. ln this study, roads seem to be artificial boundaries to genets' home ranges acting as physical and social barrier to their movements. However, genets have crossed different types of roads, although in lower frequencies. They adopted, in average, a security distance of 1km from roads being further during the day and closer at night. Ali animals showed a not random distribution on their activity concerning roads presence and their localizations tend to concentrate on one side of the road which confirms that these infrastructures pose a significant barrier to genets' movements. The existence of riparian galleries seems to promote roadside usage and during the study genets have selected positively these habitats.
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Dietary studies of marine species constitute an important key to improve the understanding of its biology and of its role in the ecosystem. Thus, prey-predator relationships structure and determine population dynamics and the trophic network at the ecosystem scale. Among the major study sites, the marine ecosystem is submitted to natural and anthropogenic constraints. In the North-Eastern part of the Atlantic Ocean, the Bay of Biscay is a large open area surrounded South by Spain and East by France. This bay is an historic place of intense fishery activities for which the main small pelagic species targeted are the pilchard, Sardina pilchardus and the anchovy, Engraulis encrasicolus. The aim of this work is to analyze the trophic ecology of these two small pelagic fish in spring in the Bay of Biscay. To do this, a first section is devoted to their prey composed by the mesozooplanktonic compartment, through a two-fold approach: the characterization of their spatio-temporal dynamics during the decade 2003-2013 and the measurement of their energetic content in spring. For this season, it appears that all prey types are not worth energetically and that the Bay of Biscay represents a mosaic of dietary habitat. Moreover, the spring mesozooplankton community presents a strong spatial structuration, a temporal evolution marked by a major change in abundance and a control by the microphytoplankton biomass. The second section of this work is relative to a methodological approach of the trophic ecology of S. pilchardus and E. encrasicolus. Three different trophic tracers have been used: isotopic ratios of carbon and nitrogen, parasitological fauna and mercury contamination levels. To improve the use of the first of these trophic tracers, an experimental approach has been conducted with S. pilchardus to determine a trophic discrimination factor. Finally, it appears that the use of these three trophic tracers has always been permitted to highlight a temporal variability of the relative trophic ecology of these fish. However, no spatial dynamics could be identified through these three trophic tracers.
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Tesis (Zootecnista). -- Universidad de La Salle. Facultad de Ciencias Agropecuarias. Programa de Zootecnia, 2014
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Eleven expeditions were undertaken to the Saint Peter and Saint Paul Archipelago to study the reproductive biology of Grapsus grapsus, providing additional information on limb mutilation and carapace colour. MATURE software was used to estimate morphological maturity, while gonadal analyses were conducted to estimate physiological maturity. The puberty moult took place at larger size in males (51.4 mm of carapace length) than in females (33.8 mm), while physiological maturity occurred at a similar size in males (38.4 mm) and in females (33.4 mm). Above 50 mm, the proportion of red males increased in the population, indicating that functional maturity is also related to colour pattern. Small habitat and high local population density contributed to the high rate of cannibalism. The low diversity of food items, absence of predators of large crabs and high geographic isolation are the determinants of unique behavioural and biological characteristics observed in the G. grapsus population.
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Tese de dout., Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Univ. do Algarve, 1995
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Dissertação de mest. em Estudos Marinhos e costeiros, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Univ. do Algarve, 1998
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O objetivo deste trabalho foi coletar espécimes de Apis melífera em três tipos de meloeiro em diferentes horários, buscando identificar os horários de coleta de pólen.