Dissertations / Theses: 'Cat fish'

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Sinha, Asha. "Study of immune system and responses in an air breathing cat fish : Clarias batrachus." Thesis, University of North Bengal, 1993. http://hdl.handle.net/123456789/988.

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GONZAGA, M. V. M. "Rendimento de carcaça em diferentes tempos de depuração e aspectos sanitários em tilápia do Nilo e cat fish." Universidade Federal do Espírito Santo, 2015. http://repositorio.ufes.br/handle/10/7754.

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A Tilápia do Nilo (Oreochromisniloticus) e o Catfish (Ictaluruspunctatus) são dois dos peixes mais consumidos no Brasil. Devido a este fato, as pisciculturas ou empresas ligadas diretamente aos produtos derivados do pescado, se empenham em conseguir valores de rendimentos de carcaça e filé que seja lucrativo. Entretanto tal empenho não adianta de nada, se o produto tambémnão respeitar padrões e regras para o processamento de forma sanitária adequada. Com isto, o objetivo deste estudo foi verificar a relação entre rendimento de carcaça e filé de Tilápia e Catfish em relação ao tempo de depuração, analisando também a composição bromatológica e microbiológica do filé. Foram utilizados 60 peixes de cada espécie, coletados ao acaso (com massa média de 0,536 ± 0,066 Kg para Tilápia e 0,88 ± 0,13 Kg para Catfish), pertencentes ao Instituto Federal do Espírito Santo Campus de Alegre. Tais animais foram alocados em um tanque por espécie e mantidos em depuração por 0, 24, 48 e 72 horas para abate. Foi realizado biometria inicial, verificando massa, largura do corpo, massa do corpo eviscerado, massa da carcaça limpa, massa do filé, massa da víscera, massa da nadadeira, massa de nadadeira adiposa (no Catfish), massa do fígado, massa da gordura visceral, massa da cabeça e massa da pele. Foram verificados padrões relacionados a rendimento de carcaça, índice viscerossomático, rendimento de nadadeiras, rendimento de nadadeira adiposa (no Catfish), índice hepatossomático, índice gordura viscerossomático, rendimento de carcaça sem cabeça, rendimento de pele, rendimento de carcaça limpa e rendimento de filé. Amostras do filé de cada espécie, após coletado, foram encaminhadas para análise bromatológica e microbiológica em laboratórios da mesma instituição. A análise microbiológica foi realizada em dois ambientes, um considerado próprio e outro impróprio para o abate. Houve diferença significativa na massa da víscera e rendimentos de filé, de carcaça com e sem cabeça e no índice viscerossomático na Tilápia em função do tempo de depuração. Em relação ao Catfish, o tempo de depuração interferiu significativamente em sua massa do filé, largura do corpo e rendimento de carcaça e de nadadeira adiposa. Apesar disso o percentual do rendimento do filé e carcaça se mantiveram altos em ambos os peixes. Na análise bromatologia, houve redução nos níveis de extrato não nitrogenado na Tilápia e extrato etéreo em ambas espécies. Com relação à análise microbiológica, foi notada influência dos tratamentos para o processamento do pescado em relação à presença ou não de Salmonellasp e Staphylococcus aureus, isto é, no ambiente em que não se teve cuidado com a higienedo local de abate e dos manipuladores houve maior contaminação dos microorganismos citados, fato que não ocorreu quando aumentou se o cuidado sanitário para o processamento dos produtos. Conclui se que o tempo de depuração influencia em características físico-químicas do filé e do rendimento de carcaça em ambas as espécies. Percebe-se também que as condições do ambiente de abate e manipulação do pescado influenciam sobre a carga microbiológica presente no produto final.

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Ladrick, Alice. "Isotope." Miami University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=miami1345326739.

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Chong, Samuel Siong Chuan. "Evaluation of a fish gene transfer system : expression, fate, and germline transmission of CAT recombinant plasmid and phage sequences microinjected into newly fertilized eggs of the Japanese medaka, Oryzias latipes (Temminck & Schlegel)." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27407.

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The creation of 'transgenic' animals has provided insights into mechanisms of gene regulation, as well as opened up a new avenue for genetic improvement of livestock, including fish. In this thesis, the suitability of the Japanese ricefield fish or 'medaka' (Oryzias latipes) as a gene expression system was evaluated. The procaryotic chloramphenicol acetyltransferase (CAT) gene regulated by a double eucaryotic promoter-enhancer region was chosen as a reporter. This reporter was introduced as either a supercoiled or linear recombinant plasmid (pUSVCAT), as a phage, or as purified phage DNA. DNA or phage was microinjected into the cytoplasm of newly fertilized medaka eggs at the 1-2 cell stage. Expression and fate of the injected DNA or phage were monitored by harvesting medaka at various developmental stages and performing CAT enzyme assays and Southern blot analyses, respectively. Several injected eggs were allowed to develop to sexual maturity, and their offspring were pooled and tested by CAT enzyme assay for inheritance of the CAT sequences. The patterns of expression of injected supercoiled and linear pUSVCAT DNA were very similar, indicating that DNA conformation does not affect the efficiency of expression. CAT enzyme activity was detectible from the early high blastula stage (4 hr post-injection), was strongest at the late gastrula/early neurula stage (1 day post-injection), and was sustained but slightly weaker in the one-week old embryo. Expression was significantly reduced in hatchlings (2 weeks post-injection), varying noticeably among the individuals analysed. CAT expression was still detectible in free-swimming fish (4 weeks post-injection). Recombinant CAT phage particles or purified CAT phage DNA were also able to express the CAT gene up to the free-swimming fish stage. However, in these treatments, the strongest CAT expression was seen in the one-week old embryo instead of in the gastrula/neurula, raising the possibility of a role played by different vector sequences on gene expression. Studies on the fate of injected supercoiled and linear pUSVCAT revealed conversion of the input forms to high molecular weight head-to-tail and randomly oriented concatemers respectively. Total plasmid DNA increased rapidly during cleavage and gastrulation, indicative of plasmid replication, whereas degradation of plasmid sequences was observed by the early high blastula stage. In the gastrula/neurula derived from injection of supercoiled pUSVCAT, total plasmid DNA increased ten-fold, whereas injection of linear pUSVCAT resulted in a 12-fold increase at the same stage. In both cases, most of the observed increase was contributed by the high molecular weight concatemers. The amount of plasmid DNA decreased after the gastrula/neurula stage, and this DNA was exclusively of the high molecular weight form at hatching and could persist to the free-swimming stage. Neither the DNA from injected CAT phage particles nor the injected purified CAT phage DNA appeared to be concatenated during early embryogenesis. In both cases, however, the phage DNA appeared as higher molecular weight DNA by the one-week old embryonic stage, probably formed by covalent end-to-end ligations. DNA of CAT phage particles did not increase until after the early high blastula stage, but by the flat blastula stage (10 hr post-injection) a three-fold increase over the input amount was observed. There was no significant increase at the gastrula/neurula stage, nor was there an immediate decrease thereafter. Injected purified CAT phage DNA increased through the stages of cleavage and gastrulation, the gastrula/neurula having seven-fold more CAT phage DNA than that injected, and decreased thereafter. Both DNA of injected phage particles and injected phage DNA could persist to the free-swimming stage. CAT gene expression was detected in a number of pooled offspring from several DNA and phage-treated fish, indicating inheritance of the input sequences. The data in this study suggest that the germline-positive parents are probably mosaic for the presence of the CAT sequences, and that germline transmission is possible with plasmid DNA of both conformations, DNA-carrying phage particles, or purified phage DNA. The above results, coupled with the ease of handling and manipulation of the medaka embryo, strongly favour the use of the medaka as a transient expression and transgenic animal model.
Science, Faculty of
Zoology, Department of
Graduate

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Pennock, Casey A. "Fragmentation and fish passage: can fishways mitigate discontinuities in Great Plains fish communities?" Thesis, Kansas State University, 2016. http://hdl.handle.net/2097/34557.

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Master of Science
Department of Biology
Keith B. Gido
Fishways are a common tool for mitigating the effects of habitat fragmentation on fish communities, but their utility in low-gradient, sand-bed rivers of the Great Plains is not well studied. The Lincoln Street Fishway on the Arkansas River became operational in 2015 and was built specifically to pass small-bodied threatened fishes. We used a combination of surveys up-and downstream of the barrier and tagging experiments to test the ability of fishes to move into and through the fishway. Differences in fish community structure up- and downstream of the dam were more pronounced prior to the construction and operation of the fishway. In particular, Emerald Shiner Notropis atherinoides was absent from collections upstream of the dam before fishway construction, but commonly collected upstream in 2015 and 2016 surveys. Surveys within the fishway structure revealed 29 species, or 74% of the total species captured during our study were using the fishway. To further quantify fishway passage, we used a VIE experiment to assess if fish marked downstream of the fishway moved into or upstream of the fishway. Although we did not recapture marked fish upstream of the fishway, some marked individuals moved into the fishway. Finally, we conducted a PIT tag experiment to evaluate short distance movements within the fishway for three species of small-bodied minnow and were able to document upstream movement across a gradient of flows through the fishway. Results from our study illustrate the potential for fishways to mitigate the effects of habitat fragmentation on small-bodied fishes in sand-bed rivers.

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Vaz, Marcela Carraro de Melo. "Thiocyanate excretion can reveal cyanide caught fish." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/8326.

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Mestrado em Biologia Marinha
A pesca com cianeto (CN-) e uma técnica destrutiva utilizada na colheita de peixes vivos de recifes de coral. Estes organismos apresentam elevado valor económico e são destinados tanto para o consumo humano como para o abastecimento da indústria mundial de aquários marinhos. Diversas são as tecnicas capazes de detectar a presenca do cianeto (CN-) em peixes, contudo ainda não há um consenso entre a comunidade científica e os comerciantes sobre qual destas técnicas será a mais eficaz, uma vez que as mais utilizadas ainda são de caráter invasivo. Neste trabalho foi utilizada uma técnica não invasiva e não destrutiva, e mais eficiente, no que diz respeito ao tempo de análise, onde através do uso da fibra óptica (FO) podem ser detectados peixes contaminados com cianeto num tempo médio < 6 min. por meio da excrecão de tiocianato (SCN-). Produto de excreção do (CN-), esse metabolito permite a desintoxicação dos peixes marinhos expostos ao contaminante pelas vias urinárias e os níveis anormais de SCN- presentes na agua marinha indicarão se os exemplares foram ou não expostos ao envenenamento por CN-. A metodologia (FO) foi capaz de detectar níveis ainda que residuais de SCN(> 3; 16mgL - 1) na agua marinha e os níveis base para os organismos não contaminados foram utilizados como referência para classi ficação de presença ou ausência de contaminação. Nesse estudo exemplares de Amphiprion clarkii cultivados em cativeiro foram expostos a um pulso de solução de CN- durante 60 s para as concentrações de 12,5e25, 0mgL - 1 e os resultados obtidos para o CN- excretado, pós-exposição ao longo de 28 dias, foram de até 6,96 ± 0,03 e 9,84 ± 0,03mgL - 1 de SCN- (respectivamente). Apesar da necessidade de mais investigação para diminuir a ocorrência de falsos negativos e positivos, a metodologia testada permite uma rápida detecção do SCN- sem o sacrifício dos espécimes analisados.

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Mello, Lucas Rosolen de Almeida. "MECANISMOS ENVOLVIDOS NA ORIGEM DOS CROMOSSOMOS SEXUAIS GIGANTES NO GENERO OMOPHOITA (COLEOPTERA, CHRYSOMELIDAE)." Universidade Estadual de Ponta Grossa, 2015. http://tede2.uepg.br/jspui/handle/prefix/2378.

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A ordem Coleoptera é a mais diversificada entre todos os seres vivos, existindo ampla possibilidades de estudos no que diz respeito à diversidade cariotípica e aos mecanismos de diferenciação. As espécies da subtribo Oedionychina (Alticinae; Chrysomelidae) são interessantes para estudos evolutivos, pois possuem cromossomos sexuais gigantes e assinápticos durante a meiose, podendo ser considerados altamente derivados. Assim, o objetivo do presente estudo foi propor os mecanismos moleculares envolvidos no processo de diferenciação e evolução dos cromossomos sexuais em espécies do gênero Omophoita. A análise de mapeamento, utilizando sondas de DNA C0t-1 total (cinética de reassociação de DNA altamente e moderadamente repetitivo) mostrou marcações distribuídas em todos os cromossomos, especialmente nos cromossomos sexuais. A hibridação cruzada entre as espécies produziu um padrão de localização muito semelhante, evidenciando que a maior parte do genoma é compartilhada entre as espécies de Omophoita. Análise em conjunto dos resultados obtidos com bandas C, fluorocromos e C0t-1 mostram que a heterocromatina das espécies em grande parte é composta de DNA repetitivo distribuída ao longo dos cromossomos sexuais e autossomos. O mapeamento cromossômico com sondas de microssatélites (SSRs) mostrou marcações conservadas para os autossomos e diversificadas para os cromossomos sexuais, evidenciando uma diferença de composição de SSRs dos cromossomos sexuais entre as espécies. Os resultados de hibridação com clones de elementos de transposição mostraram alguns padrões semelhantes aos obtidos com SSRs, podendo indicar que ao longo do processo evolutivo das espécies esses elementos estiveram presentes no processo de diferenciação. Considerando todos os resultados, pode se propor uma diferença de constituição nos cromossomos sexuais das espécies e, desta forma, inferir que os DNAs repetitivos tiveram um papel evolutivo na diferenciação desses cromossomos na subtribo.
The order Coleoptera is the most diverse of all living beings, with a wide possibilities of studies with regards to the karyotype diversity and the mechanisms of differentiation. The species of the subtribe Oedionychina (Alticinae; Chrysomelidae) are interesting for evolutionary studies due to the giant sex chromosomes and asynaptic during meiosis, can be considered highly derivate. The objective of this study was to propose the molecular mechanisms involved in the differentiation process and evolution of sex chromosomes in the Omophoita genus. The Mapping analysis using DNA C0t-1 total (reassociation kinetics highly and moderately repetitive DNA) showed marks distributed in all chromosomes, especially in the sex chromosomes. The cross-hybridization among species produced a very similar location pattern, indicating that most of the genome is shared among species Omophoita. Analysis of the results obtained in conjunct with C-bands, fluorochromes and C0t-1 together show that the heterochromatin of the species is largely composed of repetitive DNA distributed throughout the autosomes and sex chromosomes. Chromosome mapping with microsatellite (SSRs) probes showed conserved patterns for autosomes, but diversified to sex chromosomes, showing difference in SSRs composition in the sex chromosomes, of the species. The results of hybridization with transposition element clones showed some similarities patterns to the SSRs markers, which may indicate that throughout the evolutive process of species these elements were present. Considering all results we can propose differences in the constitution of sex chromosomes of the species studied, thus, we can infer an evolutionary role of repetitive DNA in the differentiation of chromosomes in the subtribe.

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Gulameabasse, Ikbal. "Un cas méditerranéen de fish-eye-disease "maladie des yeux de poissons"." Bordeaux 2, 1990. http://www.theses.fr/1990BOR25184.

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Country, Michael. "Ca2+ Dynamics in Retinal Horizontal Cells of Teleost Fish: Ca2+-Based Action Potentials and Tolerance to Hypoxia." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41131.

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Horizontal cells (HCs) are retinal interneurons which provide feedback to photoreceptors to produce visual contrast. They are depolarized by glutamate released from photoreceptors, leading to a constant influx of Ca2+ which would be fatal to most neurons. In addition, HCs present spontaneous Ca2+-based action potentials, which are poorly understood and whose function is unknown. Given these unique Ca2+ dynamics, the present thesis sought to define action potentials (APs) and mechanisms of Ca2+ homeostasis in HCs. APs were observed in isolated goldfish HCs with electrophysiology, Ca2+ imaging, and voltage-sensitive dye imaging. Pharmacological inhibition of ion channels suggests APs required extracellular Ca2+ entry via L-type Ca2+ channels, followed by Ca2+-induced Ca2+ release from ryanodine receptors. Next, we developed a novel system to classify all four HC subtypes in vitro, and validated it with immunocytochemistry for a subtype-specific biomarker. All subtypes presented APs, although frequency and duration varied by subtype. APs were also found in HCs of tissue slices prepared from whole retina, where similar trends were found between subtype, frequency, and duration. This highlights subtype-specific differences in Ca2+ dynamics. Lastly, [Ca2+]i was monitored throughout hypoxia in HCs of the hypoxia-tolerant goldfish and the hypoxia-sensitive rainbow trout. In Ca2+ imaging experiments, hypoxia destabilized [Ca2+]i in HCs of trout; but in goldfish, HCs were resistant to the effects of hypoxia. However, when mitochondrial ATP-dependent K+ (mKATP) channels were inhibited, goldfish HCs lost the ability to maintain [Ca2+]i homeostasis during hypoxia. By contrast, in trout HCs, opening of mKATP stabilized [Ca2+]i during hypoxia. Furthermore, in goldfish, hypoxia protected against increases in [Ca2+]i caused by inhibiting glycolysis, showing that hypoxia is not just tolerated, but is actively protective in goldfish HCs. The present thesis includes the first comprehensive description of spontaneous Ca2+-based APs in HCs, and introduces the first cellular model of intrinsic hypoxic neuroprotection in the vertebrate retina.

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Hitchman, Sean M. "A mosaic approach can advance the understanding and conservation of native biodiversity in natural and fragmented riverscapes." Diss., Kansas State University, 2017. http://hdl.handle.net/2097/38559.

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Doctor of Philosophy
Division of Biology
Martha E. Mather
Understanding the complex relationship between organismal distribution and spatial heterogeneity is central to many ecological questions. This challenge of identifying the biodiversity consequences of spatial patterns is especially critical for resource conservation at the larger riverscape scale because climate- and human-related impacts often act through intricate and spatially-connected organismal-habitat relationships. Specifically, resource managers cannot manage the adverse effects of common disturbances on aquatic ecosystems (e.g. water-withdrawal, dams, urbanization) if the influence of spatial heterogeneity is not recognized and understood. Towards this larger goal, I examined the role of spatial heterogeneity on stream fish biodiversity in the Upper Neosho River, KS in three ways. First, I used a mosaic approach (in which connected, interacting collections of juxtaposed habitat patches were examined) to build the scientific foundation for a general model that aids in the understanding and environmental management of disturbance-related, ecologically-based conservation problems. Second, I examined landscape metrics to quantify the impact of low-head dams on stream habitat and fish diversity. Third, I evaluated multiple quantitative approaches to develop a fuller understanding of how the arrangement of habitats across the riverscape influenced stream fish biodiversity. Related to these questions, the dissertation research provided four key take-home messages that advanced science-based conservation related to stream fish habitat and biodiversity. First, mapping larger-scale patterns of heterogeneity showed that quantitatively-different, physically-distinct pool, riffle, run, and glide habitats were arranged in unique combinations created diverse habitat mosaics across sites. Second, riffles, which comprised < 5% of all habitat patches, acted as keystone habitats that disproportionately increased fish biodiversity (i.e., species richness was significantly higher in mosaics with higher numbers of riffles). Third, mosaic approach metrics provided new insights into the influence of low-head dams on stream fish biodiversity that were not detected with traditional approaches to habitat sampling and statistical analysis. For example, low-head dams dampened the natural habitat diversity that is needed for the maintenance of resilient communities. Furthermore, using path analysis, I found that species richness was higher immediately below low-head dams as mediated through an increase in the proportion of riffle habitat, but this higher species richness was offset by a greater decrease in species richness in the impoundment habitat above low-head dams. Thus, the choice of scale influenced the interpretation of how dams affected habitat heterogeneity and resultant organismal patterns. Finally, landscape approaches to examining compositional and configurational heterogeneity provided new insights about stream fish habitat-biodiversity relationships. For example, riffle patch density had a positive effect on species richness, species richness was higher within shallow, slow flowing riffles, and adjacent neighbor habitats affected riffle species richness as mediated through alterations to within-habitat characteristics. In summary, quantifying the complex patterns of spatial heterogeneity in a range of ways can aid in the understanding of habitat-biodiversity patterns and help conserve stream fishes at a variety of scales.

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Seytre, Catherine. "In situ monitoring of the fish assemblages in the recent Cap Roux marine protected aera (french Mediterranean) : reserve effect, trophic interactions and fish exportation." Nice, 2009. http://www.theses.fr/2009NICE4068.

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Le cantonnement de pêche du Cap Roux (Saint-Raphaël) est une Aire Marine Protégée (AMP) créée en 2003 à la demande des pêcheurs professionnels de la Prud'homie de pêche de Saint-Raphaël. Cette AMP qui s'étend sur une surface de 450 ha, a été créée dans un but de gestion de la pêche côtière locale. Toutes ces caractéristiques : mise en place récente, habitats disponibles et volonté de gestion des pêches, en font un remarquable site d'étude sur la mise en place de l'effet réserve. Pour cette étude, des méthodes d'observation complémentaires : comptages visuels en plongée sous-marine réalisés sur l'herbier à Posidonia oceanica et avec la méthode FAST ainsi que des pêches expérimentales, ont permis d'échantillonner différentes parties du peuplement de poissons. En parallèle, une étude a été réalisée sur une réserve établie depuis 1975 (Scandola, Corse). Les résultats acquis dans la réserve de Scandola sont : une mise en évidence de l'effet réserve sur une longue période avec une stabilisation du peuplement de poissons dans la zone protégée, une relation positive entre la diversité spécifique et la productivité du peuplement de poissons, et une exportation de juvénile de poissons depuis la zone protégée en suivant les courants marins. Le cantonnement de pêche du Cap Roux a montré une augmentation encore faible de l'abondance et de la taille pour les espèces de poissons ciblées par la pêche mais sans modification des interactions trophiques à l'intérieur de la zone protégée. Après 5 ans de protection la restauration des stocks de poissons a commencé mais ne semble pas encore suffisante pour atteindre les objectifs de gestion de la pêche côtière locale
The Cap Roux MPA (Saint-Raphaël) is a Marine Protected Area (MPA) initiated by the commercial fishermen of the Prud'homie de pêche de Saint-Raphaël and created in 2003. This 450-ha MPA was created as a management tool for local fisheries. This MPA is an outstanding site to study the reserve effect due to the following characteristics: recent implementation, availability of habitats and will for fisheries management. For this study, complementary observation methods: underwater visual censuses on Posidonia oceanica beds or with the new FAST method, and experimental fishing, allowed to sample different parts of the fish assemblage. The study of the Cap Roux MPA was combined with a study of the Scandola Marine Reserve (Corsica), created in 1975. The results obtained for the Scandola MPA were: a long-term reserve effect combined with a stabilisation of the fish assemblage structure within the no-take zone, a positive relationship between the fish assemblage diversity and secondary production, and a juvenile fish exportation from the MPA towards fished areas following the marine currents. In the recent Cap Roux MPA, the increase in abundance and size of target fish was still weak and no modification of the trophic structure inside the protected zone was observed. Five years after the MPA implementation, the restoration of fish stocks began but is not strong enough to fulfil the objectives of local fisheries sustaining

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Chantot, Sandrine. "Aspects cytogenetiques des leucemies prolymphocytaires - b (lpl-b) : etude sequentielle en fish - multiplex (m - fish) des anomalies chromosomiques complexes dans un cas de lpl-b evolutive." Paris 5, 1999. http://www.theses.fr/1999PA05N086.

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Nordin, Jonathan. "Highway To Hell: Can a bubble barrier guide descending salmonid kelt to safety?" Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-174689.

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Loss of connectivity in riverine systems due to construction of hydropower dams has resulted in a worldwide decline of anadromous salmonid species such as Atlantic salmon (Salmo salar L.) and sea trout (Salmo trutta L.). The future of these species depend on the presence of available spawning habitat in freshwater river systems. Modern research and mitigation efforts mainly focus on ensuring a successful upstream passage past dams e.g. fish ladders. Atlantic salmon and sea trout are iteroparous, and are thus able to spawn repeatedly during their lifetime. Individuals surviving upstream migration and spawning generally face a hazardous journey back to their marine feeding grounds. In this large scale natural field study I evaluate the possibility of using a bubble barrier as a non-physical structure to guide downstream migrating kelt past the turbines at a large hydropower station in northern Sweden. Results from this study clearly show that kelt effectively can be diverted using a bubble barrier in daylight conditions with a mean water velocity of 1.1 m s-1 (p=0,01). From a fishway managers perspective, increasing survival of salmonid kelt is a substantial step towards achieving a viable population with increased numbers of repeat spawners and large individuals. This study presents new results in a sparsely explored subject; the diversion of post-spawn salmonid migrants using non-physical barriers.

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Olajos, Fredrik. "The post-glacial colonization of fish populations can be dated with DNA in lake sediments." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-125387.

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The age of natural populations is crucial information when studying processes like extinction,colonization, adaptation and evolutionary divergence. Here I evaluate if DNA in lakesediments can be used to date the colonization by whitefish (Coregonus lavaretus) in lakes incentral Sweden. Three species-specific primer pairs were designed to detect the presence orabsence of whitefish DNA in sediments from lake Hotagen where I hypothesized thatwhitefish colonized before 1790 but long after the ice-melt 10 000 years ago. By applyingBayesian estimation on binary PCR results, the colonization of whitefish in lake Hotagen wasdated to 2098 – 2632 BP. To examine if DNA could be detected in 10 000 year old sedimentsand if the detection probability declines over time I also analysed the presence of DNA in acore from lake Stora Lögdasjön. DNA was successfully recovered and amplified throughoutthe sediment core with no loss of detection probability from present time to 9535 – 9480 BP. I conclude that species-specific PCR and lake sediment DNA can be used to reconstruct thehistory of natural populations of aquatic organisms.

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German, Donovan Parks. "Beavers of the fish world can wood-eating catfishes actually digest wood? a nutritional physiology approach /." [Gainesville, Fla.] : University of Florida, 2008. http://purl.fcla.edu/fcla/etd/UFE0023785.

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Hansen, Oliver Kai. "Can cormorants be used as indicators of local fish abundances? : A diet study of cormorants on Gotland." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-447637.

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Human wildlife conflicts can represent missed opportunities for ecological monitoring, including tracking invasive species. The great cormorant Phalacrocorax carbo sinensis is the centre such a conflict, where the lack of concrete scientific evidence is often replaced by anecdotal evidence, leading to the vilification of these birds. The primary aim of this study was to assess the extent of the overlap between cormorant diet and the fish the fishermen are allowed to catch on the North West coast of Gotland, the Baltic seas´ biggest island. To assess cormorant diet, the otoliths in the cormorant pellets were analysed. Secondary aims included assessing the potential to use cormorant diet as a proxy for local fish abundances by comparing it to monitoring fisheries in the same area. Highly contentious species only included cod, herring and flounder, none of which were commonly consumed by cormorants. Cormorants and the monitoring fisheries found comparable proportions of all species except for flatfish herring sprat, sculpin. We conclude that the cormorant poses a relatively low risk to the fishing industry on the North Western coast of Gotland and that they could potentially be used as a sentinel for local fish abundances, including tracking invasive species such as the round goby.

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Furuhjelm, Catrin. "Can fish oil in pregnancy and lactation alter maternal and infant immunological responses and prevent allergy in the offspring?" Doctoral thesis, Linköpings universitet, Pediatrik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-61947.

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Background: A connection has been proposed between the increase of allergic disease and the altered composition of fatty acids in the diet in the westernised world. Less oily fish and more vegetable oil are consumed today compared to 50-100 years ago. Programming of the immune responses takes place very early in life and environmental factors, such as fish in the diet, have been suggested to protect from infant allergy. Aim: The general aim of this thesis was to assess the effects of maternal dietary supplementation with ω-3 long chain polyunsaturated fatty acids (LCPUFA), i.e. fish oil, in pregnancy and lactation on the development of allergic symptoms and sensitisation in the infants as well as some immunological markers in mothers and infants. Subjects and methods: This thesis is based on the results from a prospective double-blind placebo-controlled multi-centre trial comprising 145 families. Pregnant women, at risk of having an allergic infant, were recruited at the antenatal clinics and randomised to daily supplementation with 1.6 g eicosapentaenoic acid (EPA, C20:5ω-3) and 1.1 g docosahexaenoic acid (DHA, C22:6ω-3) or placebo, starting in the 25th gestational week and continuing through 3.5 months of breastfeeding. Phospholipid fatty acids in maternal and infant plasma were analysed to assess compliance. Maternal prostaglandin E2 (PGE2), leukotriene B4 (LTB4) and cytokines along with infant vaccine induced responses and chemokines were analysed with ELISA and Luminex techniques. Clinical outcomes were allergic disease and positive skin prick test/detectable circulating IgE antibodies to common allergens. Results: Phospholipid proportions of ω-3 LCPUFA increased significantly in the ω-3 supplemented women and their infants. Lipopolysaccharide-induced PGE2 secretion from whole blood culture supernatants decreased in a majority of the ω-3-supplemented mothers (p<0.01). The decrease in PGE2 production was more pronounced among non-atopic than atopic mothers. No difference in the prevalence of allergic symptoms was found between the intervention groups. The cumulative incidence of IgE associated eczema and IgE mediated food allergy was though reduced in the ω-3 group during the first two years (OR=0.2 and 0.3 compared to placebo, p<0.05 for both). The cumulative incidence of any IgE associated disease during the first two years of life was 13% in the ω-3 supplemented group compared to 30% in the placebo group (p=0.01, OR 0.3, p<0.05). This effect was most evident in infants of non-allergic mothers. Higher maternal and infant proportions of DHA and EPA were associated with lower prevalence of IgE associated disease (p=0.01-0.05), in a dose dependent manner. In addition, no allergic symptoms as compared to multiple allergic symptoms in the infants, regardless of sensitisation, were related to higher maternal and infant ω-3 LCPUFA status (p<0.05). In infants without, but not with, maternal history of allergy, the ω-3 supplementation was related to lower CC-chemokine ligand 17 (CCL17)/ CXC-chemokine ligand 11 (CXCL11) (Th2/Th1) ratios (p<0.05). Furthermore in non-allergic, but not in allergic infants, ω-3 supplementation was linked with higher Th1-associated CXCL11 levels (p<0.05), as well as increased IgG titres to diphtheria (p=0.01) and tetanus (p=0.05) toxins. Conclusions: A decreased cumulative incidence of IgE associated disease in the infants was found after maternal ω-3 LCPUFA supplementation as well as a reverse dose response relationship between maternal ω-3 LCPUFA status and infant IgE associated disease. Higher plasma proportions of DHA and EPA in were also associated to less severe allergic disease. A tendency towards strengthened Th1 associated response after maternal ω-3 LCPUFA supplementation was indicated in the analysis of maternal and infant immunological markers. These effects, as well as the clinical outcomes, were more pronounced in non-allergic individuals, suggesting gene-by-environment interactions.

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Midgley, Craig. "Trends in the fish assemblage structure of two South African transition-zone estuaries : can these trends be linked to climate change?" Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1013173.

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Changes in the fish communities of the Breede and Mbashe estuaries were investigated in relation to the environmental variables that influence the fish assemblages in these systems. The Breede Estuary (34° 24’21.6”S, 20° 51’ 08.2”E) occurs within the warm-temperate/cool-temperate transition-zone, while the Mbashe Estuary (32o 14' 55.4"S, 28o 54' 03.7"E) falls within the subtropical/warm-temperate transition-zone along the South African coastline. The Breede Estuary was sampled (seine and gill nets) during summer (January-March) over a period of 10 years (2002-2012), while the Mbashe Estuary was sampled (seine net) during spring (October) over a period of three years (2010-2012). The proportion of tropical fish species was higher in the Mbashe Estuary compared to the Breede Estuary, while the Breede Estuary contained a higher proportion of temperate species than the Mbashe Estuary. Although the abundance of individual species in both estuaries varied, the ranking of species in the Breede Estuary was stable over the 10 year period. Multivariate analysis showed that the fish communities within each reach (upper, middle, lower) of the Breede Estuary remained similar, regardless of year. In contrast, species composition in the Mbashe Estuary differed significantly between years mainly due to differences in the river flow regime during the study period. Environmental variables responsible for structuring the fish assemblage in each estuary differed. Salinity significantly impacted the spatial fish assemblage structure of the Breede Estuary, with most of the species recorded being associated with the more saline lower reaches. The abundance of tropical species near their distributional limit in the Breede Estuary appeared to be impacted by sea surface temperature (SST) as peak total abundance of these species coincided with the warmest SST, while the lowest total abundance coincided with the coldest annual SST during the study period. The fish assemblage structure in the Mbashe Estuary was impacted by differing freshwater input prior to sampling, with flooding negatively impacting the mean total abundance, species composition and diversity in this system. The variables that influenced the fish assemblage structure of both transition-zone estuaries will be affected by climate change in the future. These variables will, in turn, determine the composition, abundance and diversity of species within these important estuarine systems. In order to measure these impacts with any degree of understanding, long-term studies on the abiotic and biotic (including the ichthyofauna) features of these estuaries are required to interpret climate change trends.

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Ben, Messaoud Fatma. "Altérations génétiques dans les phénotypes spermatiques monomorphes : cas de la globozoospermie et de la macrocéphalie." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCB163.

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L'infertilité humaine représente un problème de santé publique qui affecte 10-15% des couples avec des causes masculines retrouvées dans 50% des cas. En raison de la grande diversité des anomalies responsables d'infertilité masculine nous avons choisi de sélectionner des phénotypes spermatiques monomorphes précis (macrocéphalie et globozoospermie) pour faciliter les corrélations génotype - phénotype et l'identification de nouveaux gènes. La globozoospermie est une tératozoospermie monomorphe, rare, secondaire dans 70-75% des cas à une anomalie du gène DPY19L2 qui intervient dans la formation de l'acrosome. La macrocéphalie ou syndrome des spermatozoïdes macrocéphales (SSM) est caractérisée par une augmentation très importante du volume de la tête et la présence inconstante de plusieurs flagelles. Le gène majeur impliqué dans cette pathologie est le gène AURKC. Une proportion de 20-30% des cas de globozoospermie et de SSM demeurent sans cause génétique connue. Les objectifs de notre travail sont d'une part, d'identifier de nouveaux gènes impliqués dans ces deux phénotypes spermatiques précis de manière à améliorer la prise en charge et le conseil génétique de ces patients, et d'autre part d'étudier l'architecture du génome dans les spermatozoïdes globozoocéphales pour mieux comprendre le rôle de DPY19L2 dans l'organisation du génome spermatique. L'étude du phénotype globozoocéphale a été menée sur une cohorte de 10 patients infertiles, maghrébins et européens. L'analyse moléculaire du gène DPY19L2 a révélé la présence d'une délétion à l'état homozygote chez quatre patients. Une délétion à l'état hétérozygote associée à une nouvelle mutation a été mise en évidence chez deux patients non apparentés. Il s'agit d'une mutation faux sens (c.2056A>G) responsable d'une substitution d'une arginine, conservée au cours de l'évolution, par une glycine (p.R 686G). Les études in silico ainsi que l'absence de cette variation chez 100 témoins fertiles d'origine tunisienne suggèrent que cette mutation aurait un effet délétère sur la fonction de la protéine Dpy19l2. Quatre patients restent sans cause génétique identifiée à ce jour. En raison de l'association de Dpy19l2 avec la lamina et de son rôle potentiel de protéine LINC, nous avons recherché en FISH-3D l'existence d'une altération de l'organisation du génome spermatique chez les patients déficients en Dpy19l2 comparée à des témoins fertiles. Nos résultats montrent une augmentation du nombre de chromocentres et une organisation spatiale altérée des régions télomériques et des territoires chromosomiques. Ces résultats renforcent l'hypothèse que Dpy19l2 pourrait être considérée comme une protéine de type LINC et jouerait un rôle crucial dans l'organisation de la chromatine nucléaire dans le noyau spermatique. Ces altérations architecturales du génome pourraient participer à l'arrêt précoce du développement embryonnaire observé après ICSI chez les patients ayant des anomalies du gène DPY19L2. Nous avons par ailleurs recruté une cohorte de 23 patients d'origine nord- africaine et européenne et présentant le phénotype typique ou atypique du SSM. Le séquençage du gène AURKC chez tous les patients a mis en évidence la présence de la mutation récurrente c.144delC chez 18 patients, et la deuxième mutation récurrente p.Y248X chez deux patients, en accord avec les données de la littérature. Un séquençage d'exome a été réalisé chez les trois patients pour lesquels aucune mutation du gène AURKC n'a été retrouvée. Ces trois patients avaient des phénotypes partiels ou atypiques du SSM. Une nouvelle mutation faux sens a été découverte à l'état homozygote au niveau d'un nouveau gène candidat, TNKS1BP1, très fortement exprimé au niveau du testicule et impliqué dans le contrôle du cycle cellulaire, la mitose et la méiose
Human infertility affects 10-15% of couples worldwide and represents a major health issue. Although multifactorial, male infertility has a strong genetic basis which has so far not been fully deciphered. Recent studies of consanguineous families and of small cohorts of phenotypically homogeneous patients have however allowed the identification of new genes causing teratozoospermia, including globozoospermia and macrozoospermia. Globozoospermia is a rare and severe form of teratozoospermia characterized by the presence in the ejaculate of a large majority of round spermatozoa lacking the acrosome. Genetic defects of DPY19L2 represent the main cause of this teratozoospermia by preventing the anchoring of the acrosome to the nucleus. Patients with large-headed multiflagellar spermatozoa, named also macrozoospermia or macrocephalic sperm head syndrome, present with a primary infertility characterized by the presence in the ejaculate of 100% abnormal spermatozoa with an oversized irregular head, abnormal midpiece and acrosome, and multiple flagella. Homozygous mutations of aurora kinase C (AURKC) are responsible for most cases of macrozoospermia. Neverthless 20 to 30% of patients with macrozoopsermia and globozoospermia remain without known genetic causes sugesting that these phenotypes are genetically heterogeneous. The purpose of this study is to identify new genes responsible for globozoospermia and macrozoospermia to improve the management and genetic counseling of these patients, on the one hand, and to explore the three-dimensional (3D) organization of sperm genome in DPY19L2-deficient globozoospermic patients speculating a role for Dpy19l2 in genome organization of sperm nucleus, on the other hand. We screened for DPY19L2 deletion and mutations, as well as mutations in SPATA16 in a cohort of 10 Tunisian and European globozoospermic patients. Molecular analyses performed on 9 genetically independent individuals showed that four (40%) were homozygous for the DPY19L2 deletion, two were heterozygous for the deletion and a new non-synonymous mutation (p.R 686G) in exon 21, and no DPY19L2 or SPATA16 mutations were identified for 4 patients. Because Dpy19l2 protein has been shown to be localized in the inner nuclear membrane and was suggested to have a LINC-like function, we hypothesized that a functional defect of this protein may induce an altered chromatin packaging in DPY19L2-deficient globozoospermic human sperm nuclei. Study of chromatin organization in DPY19L2-deficient globozoospermic patients and healthy donors using three-dimensional fluorescence in situ hybridization (3D-FISH) showed that the absence of Dpy19l2 leads to a disturbance of the overall sperm nuclear architecture. Dpy19l2-deficient nuclei had a altered organization of the chromocenter resulting in an increased number of chromocenters, and an altered spatial organisation of telomeric regions and chromosome territories (CTs). Our findings strengthen the hypothesis that Dpy19l2 might be considered as a LINC-like protein having a crucial role in the organization of nuclear chromatin in sperm nucleus through its interaction with nuclear lamina. Our results might also explain defective embryonic development after intracytoplasmic sperm injection (ICSI) performed with DPY19L2-deficient globozoospermic sperm. Genetic screening for AURKC mutations in a cohort of 23 Tunisian and European macrozoospermic patients, showed that 18 patients had the most frequent recurrent mutation (c.144delC) and two patients had the second most frequent mutation (p.Y248X). Exome sequencing was performed for the remaining three macrozoospermic patiens without AURKC mutations. Bioinformatic analyses showed a new homozygous non-synonymous mutation in a candidate gene, TNKS1BP1, highly expressed in testis and implicated in control of cell cycle, mitosis and meiosis

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Gonçalves, Cátia Vanessa Caetano. "Can the complex mixture of sediment contaminants cause endocrine disruption on a benthic fish? A case study with Solea senegalensis." Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10811.

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Pollution in coastal ecosystems is a serious threat to the biota and human populations there residing. Anthropogenic activities in these ecosystems are the main cause of contamination by endocrine disruption compounds (EDCs), which can interfere with hormonal regulation and cause adverse effects to growth, stress response and reproduction. Although the chemical nature of many EDCs is unknown, it is believed that most are organic contaminants. Under an environmental risk assessment for a contaminated estuary (the Sado, SW Portugal), the present work intended to detect endocrine disruption in a flatsfish, Solea senegalensis Kaup, 1858, and its potential relationship to organic toxicants. Animals were collected from two areas in the estuary with distinct influences (industrial and rural) and from an external reference area. To evaluate endocrine disruption, hepatic vitellogenin (VTG) concentrations in males and gonad histology were analysed. As biomarkers of exposure to organic contaminants, cytochrome P450 (CYP1A) induction and the ethoxyresorufin-O-deethylase (EROD) activity were determined. The results were contrasted to sediment contamination levels, which are overall considered low, although the area presents a complex mixture of toxicants. Either males or females were found sexually immature and showed no significant evidence of degenerative pathologies. However, hepatic VTG concentrations in males from the industrial area in estuary were superior than those from the Reference, even reaching levels comparable to those in females, which may indicate an oestrogenic effect resulting from the complex contaminant mixture. These individuals also presented higher levels of CYP1A induction and EROD activity, which is consistent with contamination by organic substances. The combination of the results suggest that the exposure of flatfish to an environment contaminated by mixed toxicants, even at low levels, may cause endocrine disruption, therefore affecting populations, which implies the need for further research in identification of potential EDCs, their sources and risks at ecosystem scale.
Projecto HERA (PTDC/SAU-ESA/100107/2008)

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Stein, William III. "Fish and decapod community structure in estuarine habitats of the New Orleans Land Bridge, including a description of the life cycle of tarpon (Megalops atlanticus) in southeastern Louisiana." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1673.

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Estuarine marshes are generally considered to be productive but not necessarily diverse ecosystems. During 24 consecutive months, I collected 65,000 fishes and decapods comprising over 65 species from the New Orleans Land Bridge, an estuarine salt marsh. My research details the distribution of nekton across five contiguous but geomorphically different regions, which I defined as “Areas”. This factor “Area” was significant in explaining community composition differences in 11 of the 24 months I evaluated. That is, during those 11 months community structure was different among the Areas. Specific “month” was also found to be a significant factor as community structure was found to differ among the months. No consistent abiotic factors were associated with community structure. These observations imply that a different set of factors are associated with community structure at the Area level than at the microhabitat level. Sampling of nekton in shallow estuarine salt marsh habitats was difficult. The cast net is a useful gear type for this type of sampling and can be readily standardized for each operator. Standardization of the area covered by the net allows density of collected nekton to be calculated. Little is known about the life cycle of one important estuarine dependent sport fish, tarpon (Megalops atlanticus), in southeastern Louisiana. This research details the presence of the major life stages of the species in Louisiana and suggests that it is capable of completing its life cycle in State waters. The presence of a spawning capable female and male tarpon is documented.

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Widener, Ashlee N. "Restoring Streams to Pre-Colonization Conditions in Pennsylvania: What Periphyton, Macroinvertebrates, and Fish can tell us about the Release of Legacy Nutrients." Ohio University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1628853151741668.

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Smith, Lia. "Biodiversity monitoring using environmental DNA: Can it detect all fish species in a waterbody and is it cost effective for routine monitoring?" Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2017. https://ro.ecu.edu.au/theses/1985.

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The challenges associated with environmental monitoring such as the impact on the environment and the financial costs are problems we face when trying to conserve freshwater systems around the world. The need for precise and accurate results that are cost effective is important so that we can achieve our conservation goals. The overall aim of this study was to explore Next-Generation - metabarcoding for the detection of feral and native freshwater fish species based on the DNA shed by individual organisms into the water column. Cytochrome c oxidase I (COI) primers were developed for this study using DNA from six freshwater species expected to be found in the waterbody. These primers, along with 16S rRNA (16S) primers, were assessed to ensure that the molecular method was robust and suitable for use in the field. Along with the cost effectiveness of the molecular method when compared to the more traditional surveying method of Fyke net surveying. This study comprised development of field and lab protocols for the detection of freshwater fish species in a lentic system. Both the COI and 16S primer sets showed results that were comparable to previous Fyke net surveys, though both primer sets detected species that the other did not. Further qPCR analysis showed that there were differences in detection for both primers for each of the species. The molecular surveying of the waterbody has been proven sensitive enough to detect Maccullochella peelii. This species has a very low abundance in the waterbody (believed to be n=1) so these results suggest that this method can be used to target low abundance species. The outcome of this study highlighted the need for multi-location sampling within a waterbody as increasing the number of locations sampled, led to an increase in the number of species detected. Along with the multi-location sampling, it was also important to sample throughout the year to account for seasonal variability. The eDNA study emphasized the importance of having knowledge of both the ecology and the biology of the species targeted so that a robust monitoring method can be implemented. As well as comparing the apparent accuracy of Fyke netting and the eDNA approach in the study waterbody, a cost benefit analysis comparing the relative costs of multiplex DNA surveying, single species molecular surveying, and Fyke net surveying was undertaken. Molecular environmental surveying was found to be a cost effective method for monitoring, as the analysis suggested single species monitoring would break even after only 95 waterbodies were surveyed, and multiplex surveying would break even after 145 waterbodies, under the proposed scenario. The cost benefit analysis explored the costs associated with all three methods, including lab set up costs, along with the number of waterbodies that could be surveyed on both a weekly and yearly basis.

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Wennberg, Maria, Andreas Tornevi, Ingegerd Johansson, Agneta Hörnell, Margareta Norberg, and Ingvar A. Bergdahl. "Diet and lifestyle factors associated with fish consumption in men and women : a study of whether gender differences can result in gender-specific confounding." Umeå universitet, Yrkes- och miljömedicin, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-62237.

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BACKGROUND: Fish consumption and intake of omega-3 fatty acids from fish are associated with a lower risk of cardiovascular disease. However, a prospective study from northern Sweden showed that high consumption of fish is associated with an increased risk of stroke in men, but not in women. The current study aimed to determine if fish consumption is differently related to lifestyle in men compared with women in northern Sweden. METHODS: Lifestyle information on 32,782 men and 34,866 women (aged 30--60 years) was collected between 1992 and 2006 within the Vasterbotten Intervention Programme (a health intervention in northern Sweden). Spearman correlation coefficients (Rs) were calculated for associations between self-reported consumption of fish and other food items or lifestyle variables. RESULTS: Fish consumption was positively associated with other foods considered healthy (e.g., root vegetables, lettuce/cabbage/spinach/broccoli, chicken, and berries; Rs = 0.21-0.30), as well as with other healthy lifestyle factors (e.g., exercise and not smoking) and a higher educational level, in both men and women. The only gender difference found, concerned the association between fish consumption and alcohol consumption. Men who were high consumers of fish had a higher intake of all types of alcohol compared with low to moderate fish consumers. For women, this was true only for wine. CONCLUSIONS: Except for alcohol, the association between fish consumption and healthy lifestyle did not differ between men and women in northern Sweden. It is important to adjust for other lifestyle variables and socioeconomic variables in studies concerning the effect of fish consumption on disease outcome.

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Gullberg, Beata. "The Hate U Give and Interpretive Communities : How Young Adult Fiction Can Strengthen a Political Movement." Thesis, Högskolan i Gävle, Avdelningen för humaniora, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-35864.

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In the wake of the guilty verdict of George Floyd’s murderer, police officer Derek Chauvin, there is hope for change in the pattern of police brutality against black people in the United States. The Hate U Give by Angie Thomas was published three years prior to George Floyd’s death, in 2017, and is a realistic fictional novel in the young adult genre that has gained attention for its relevant contribution in the debate of racism and police violence, as the fictional victim Khalil Harris, an unarmed black teenager, does not receive the same justice as George Floyd. In this essay, reader response to The Hate U Give is analysed in order to examine how it affects the opinions and worldview of the reader during and after the read. A close reading and analysis of pivotal scenes was carried out using affective stylistics, in order to interpret what the text does to the reader word-by-word, and subsequently the reader’s creation of meaning was examined and discussed. The reader’s response was then analysed with Stanley Fish’s theoretical framework of interpretive communities, groups with shared social norms and worldviews, which dictate how individuals create meaning in the first place. The analysis suggests that readers of The Hate U Give, while starting out in different, albeit to a certain extent similar, interpretive communities, will gradually align themselves with the interpretive community of Black Lives Matter through shared ideas and opinions and the increased understanding they develop when they read the novel.

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Faillettaz, Robin. "Estimation des capacités comportementales des larves de poissons et leurs implications pour la phase larvaire : un cas d'étude d'espèces démersales de Méditerranée Nord-Occidentale." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066342/document.

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La majorité des espèces de poissons côtiers a un cycle de vie comprenant une phase juvénile et adulte démersale et une phase larvaire pélagique. Cette seconde phase représente l’unique opportunité de dispersion pour de nombreuses espèces mais est soumise à une forte mortalité. Aujourd’hui, il est toujours délicat de prédire la connectivité entre les populations car tous les processus influençant la survie et le transport des larves durant leur phase pélagique ne sont pas encore décrits. Les larves de poissons possèdent des capacités comportementales non-négligeables (de nage, d’orientation, etc.) qui pourraient leur permettre de contrôler leur dispersion au cours de leur épisode pélagique. Cependant, les observations in situ de ces comportements ont principalement été faites en milieu tropical. Elles sont nettement plus rares en milieu tempéré, notamment chez les poissons Perciformes. Dans cette thèse, nous cherchons à décrire l’écologie et les capacités comportementales des larves de poissons en Mer Méditerranée Nord-Occidentale, un milieu tempéré où elles n’ont pas encore été décrites.La première partie de cette thèse vise à décrire la distribution des jeunes stades larvaires le long d’un transect côte-large traversant un front hydrologique. Nous nous intéressons également à leurs comportements de migration nycthémérale et d’évitement des prédateurs. La méthode d’imagerie utilisée pour décrire leur distribution à microéchelle génèrant des quantités de données considérables, nous avons développé une méthode de classification automatique pour accélérer le traitement de ce type de données. La seconde partie se concentre sur la phase d’installation, c’est-à-dire lorsque les larves arrivent à la côte à la fin de leur phase pélagique. Nous avons suivi l’arrivée des larves à la côte afin de déterminer les périodes d’installation des différentes espèces ainsi que les facteurs influençant leur arrivée. Nous avons également testé in situ les capacités d’orientation des espèces les plus abondantes, en se focalisant sur les mécanismes d’orientation à large échelle. En laboratoire, nous avons mesuré les vitesses de nage de plusieurs espèces, incluant celles testées pour l’orientation. Nous avons ensuite implémenté ces comportements observés dans un modèle biophysique afin de tester leur l’influence combinée sur le taux d’installation. Pour finir, nous discutons de l’influence que peut avoir le comportement sur la survie des larves de poissons tout au long de la phase pélagique, ainsi que de l’importance de sa prise en compte dans les modèles de dispersion
Most coastal fish species have a bipartite life history, with a demersal phase as juvenile and adult and a pelagic larval phase. Dispersal is often limited to this pelagic phase, which is also the phase experiencing the highest mortality rates. Predicting the connectivity between populations remains difficult because not all processes determining larval fish survival and transport during the pelagic phase are understood. Besides the environmental conditions that may influence the journey of fish larvae in the open ocean, these tiny organisms possess high behavioural abilities (swimming, orientating, etc.) that have the potential to shape their dispersal. However, the vast majority of in situ observations of these behaviours have been conducted in tropical environments and very little data exists on temperate Perciformes fish larvae. In this dissertation, we aim to describe the ecology and behavioural abilities of fish larvae from the Mediterranean Sea, a temperate environment where they have never been studied.The first part of this dissertation describes the distribution of young fish larvae along an inshore-offshore transect crossing an hydrological front. We also describe their diel vertical migration and predatoravoidance behaviour. The high-frequency imaging techniques used to capture their distribution at miscroscale generated huge amount of data. It lead us to modify an automatic classification method to reduce the time required to processes these kind of data. The second part focuses on the settlement phase, when fish larvae come back to the coast at the end of their pelagic journey. To shed light on the factors influencing the settlement process, we monitored the supply of fish larvae to a coastal habitat, on a weekly basis for three years and at higher frequency over shorter periods of time. Additionally, we tested the in situ orientation abilities of the most abundant species, focusing on large scale orientation mechanisms. In the laboratory, we measured the swimming speeds of several species, including the ones tested for orientation. Then, we implemented these observed behaviours in a biophysical model to explore their combined influence on settlement rate. To finish, we discuss on how larval fish behaviour may influence survival throughout the pelagic larval phase and insist on the importance of considering behaviour to improve larval dispersal models

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Ferreira, Carlos Miguel Henriques. ""Can fish liver melanomacrophages be modulated by xenoestrogenic and xenoandrogenic pollutants? Experimental studies on the influences of temperature, sex, and ethynylestradiol, using the platyfish as the model organism"." Master's thesis, Instituto de Ciências Biomédicas Abel Salazar, 2011. http://hdl.handle.net/10216/57097.

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Ferreira, Carlos Miguel Henriques. ""Can fish liver melanomacrophages be modulated by xenoestrogenic and xenoandrogenic pollutants? Experimental studies on the influences of temperature, sex, and ethynylestradiol, using the platyfish as the model organism"." Dissertação, Instituto de Ciências Biomédicas Abel Salazar, 2011. http://hdl.handle.net/10216/57097.

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Chevillot, Xavier. "Réponses fonctionnelles des écosystèmes estuariens dans le contexte du changement global : le cas du réseau trophique de l'estuaire de la Gironde." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0030/document.

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Les changements philosophiques et techniques qui ont accompagné l’avènement de notre civilisation «moderne » laissent dans leurs sillages un cortège de bouleversements physiques, chimiques etbiologiques à l’échelle du globe. Aujourd’hui les preuves sont nombreuses pour affirmer que cechangement global modifie le fonctionnement de la « Nature ». La nécessité d’appréhender et decomprendre ce fonctionnement a conduit à interroger les processus de reconfiguration des diversescomposantes et fonctionnalités des éco-sociosystèmes sous l’influence des changements globaux.Concentrant aujourd’hui près de 75 % de la population humaine, les écosystèmes estuariens et côtierssont particulièrement vulnérables, de plus en plus exploités et contaminés et leur biodiversité estlargement impactée. L’estuaire de la Gironde, un des plus grands estuaires d’Europe de l’Ouest, montredepuis au moins trois décennies des signes de ce changement global. C’est dans ce contexte que cettethèse décrit la trajectoire fonctionnelle de l’écosystème estuarien au cours des trente dernières années.Trois aspects du fonctionnement y sont décrits, analysés et discutés. L’étude de la dynamiqueinterannuelle du cortège ichtyologique a permis, tout d’abord, de mettre en avant trois périodes defonctionnement distinctes dans les dernières décennies. L’exploration des rythmes saisonniers despoissons et de leurs proies zooplanctoniques dans chacune d’elle a ensuite permis de montrer desmodifications de la phénologie de ces espèces à même d’engendrer, pour certaines, desdésynchronisations temporelles entre proies et prédateurs questionnant, par conséquent, la stabilité desrelations trophique et la capacité trophique du milieu. Enfin, un modèle holistique du réseau trophique aété réalisé pour chacune des trois périodes. La comparaison des propriétés de chacun d’eux a permisde conclure à une augmentation du stress de l’estuaire de la Gironde et à remettre en question sacapacité à durablement jouer son rôle de nourricerie pour les stocks de poissons marins du Golfe deGascogne. Quatre scénarii d’évolutions prospectifs synthétisent les conclusions de cette étude etdonnent à voir des avenirs possibles de cet écosystème
The philosophical and technical changes associated with the emergence of our "modern" civilizationcaused numbers of physical, chemical and biological changes those led to changes in the functioning of"Nature". The necessity to understand this functioning has led to question the reconfiguration process ofthe various eco-sociosystems’ components and features under the influence of Global Change. TheGironde estuary, one of the largest estuaries in Western Europe, has shown since three decades, signsof this Global Change. In this context, this study highlights the functional trajectory of this estuarineecosystem during the last thirty years. Three aspects of its functioning are described, analyzed anddiscussed. First, the study of the inter-annual fish community evolution highlighted three periods withdistinct functioning. The exploration of the seasonal patterns of the fish and zooplankton dynamicsduring each period shows phenological changes able to cause, in some cases, prey-predator mismatch.This leads to question the stability of trophic interactions and the trophic capacity of the ecosystem forfish. Finally, within each of these three periods, the estuarine food web was modeled within a holisticframework. The comparison of the functional properties of each model highlighted an increase in thestress of the Gironde estuary and questioned the sustainability of its nursery function for Bay of Biscaymarine stocks. Four forecasting scenarios summarize conclusions of this study and let see possiblefutures of this ecosystem

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Leport, Julie. "Dynamiques de changement des modèles alimentaires : le cas du poisson à Dakar." Thesis, Toulouse 2, 2017. http://www.theses.fr/2017TOU20017/document.

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Le poisson a une place centrale dans l’alimentation dakaroise. Il est aussi l’un des composants principaux du plat emblématique du pays, le ceebujën, présent dans les habitudes quotidiennes des populations. Pour des raisons écologiques, politiques et économiques, l’accessibilité du poisson sur le marché local diminue ces dernières années. Cette thèse analyse les stratégies d’adaptation mises en place par les Dakarois face à cette situation. Ce projet explore la dimension dynamique de l’alimentation et des processus de décision alimentaire. Une enquête a été réalisée en trois phases principales : 1) une phase d’immersion ethnographique ; 2) une phase qualitative constituée d’entretiens d’experts et de mangeurs dakarois, ainsi que d’observations participantes de séquences alimentaires (approvisionnement, préparation, consommation d’un repas) ; 3) une phase quantitative de passation d’un questionnaire auprès de 820 Dakarois. Les résultats démontrent que les changements alimentaires peuvent autant recouvrir des enjeux de maintien des pratiques à l’intérieur des cadres définis par les modèles alimentaires, qu’ils peuvent se révéler des leviers de redéfinition de ces modèles. Le statut identitaire et social de certains aliments (le poisson), plats (le ceebujën) ou recettes (celle du ceebujën dit plat « à une marmite ») favorise les comportements de maintien à l’intérieur du modèle alimentaire, tandis que la « modernisation » de la société tend à favoriser, au contraire, des pratiques dépassant le modèle. Par conséquent, cette thèse contribue à dynamiser le concept de modèle alimentaire en exposant, d’une part, comment les modèles alimentaires constituent une ressource mobilisée en situation de changement et, d’autre part, sont façonnés par ces mêmes changements
Fish have a central position in food in Dakar. It is also one of the main components of the emblematic dish of the country, the ceebujën, present in the daily habits of the populations. For ecological, political and economic reasons, the accessibility of fish to the local market has been declining in recent years. This thesis analyses the adaptation strategies used by Dakar inhabitants facing this situation. This project considers the dynamic dimension of food and of the food decision processes. Data collection was carried out in three main phases: 1) an ethnographic immersion phase; 2) a qualitative phase consisting of interviews with experts and Dakar eaters, plus participant observation sessions of food sequences (supply, preparation and consumption of a meal); 3) a quantitative phase in which 820 Dakar inhabitants answered a questionnaire. The results show that while food changes can involve a maintaining of the practices defined by the food models, they can also participate in the redefinition of these models. The identity and social statuses of certain food (fish), dishes (the ceebujën) or recipes (the ceebujën is categorised as "one-pot dish") favours the behaviours of maintenance inside the food model, whereas “modernization” tends to allow for the development of practices that go beyond the model. This thesis complicates and revitalises the concept of food model by exposing how food models constitute a resource mobilized in time of change, while they are simultaneously shaped by these same changes

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Katsuragawa, Mario. "Estudos sobre Variabilidade de Amostragem, Distribui-cao e Abundancia de Larvas de Peixes da Regiao Sudes-te do Brasil." Universidade de São Paulo, 1985. http://www.teses.usp.br/teses/disponiveis/21/21131/tde-30062010-132419/.

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Utilizando-se materiais coletados durante qua-tro cruzeiros oceanográficos com o N/Oc .\"Prof. W. Besnard\", na região Sudeste do Brasil, compreendida entre Cabo Frio (RJ) e Florianópolis (SC), de janeiro de 1980 a março de 1982, foram realizados estudos quali quantitativos so-bre ocorrências de larvas de peixes, relacionando-as com fatores abióticos. Problemas concernentes aos processos de amostragem tambem foram verificadas. Realizaram-se dois tipos de arrastos: arrasto oblíquo com a rede Bongo usando-se malhagens de 0,333 mm (fina) e de 0,505 mm (regular), e arrasto horizontal de superfície com a rede de Neuston, de 0,333 mm de malhagem. Em cada estação oceanográfica, alem das amostras biologicas, efetuaram-se as medições de temperatura e coleta de água para determinação de salinidade. Um total de 35.090 larvas foram analisadas, incluíndo as coletas das redes fina e regular da Bongo e a rede de Neuston. Dentre estas, 61 grupos diferentes foram separados, chegando a níveis específicos em alguns casos.- Dois gêneros e quatro especies foram identificados pela primeira vez na região: Saurida spp, Hygophum spp, Trachinocephalus myops, Synodus foetens Bregmaceros can-tori e Maurolicus muelleri. As famílias predominantes foram Clupeidae, Engraulidae, Myctophidae e Gonostomatidae. De uma maneira geral, a região Sudeste apresentou grande riqueza em taxa, mas com o predomínio de poucos grupos, em termos de abundância. Análises da relação entre larvas de peixes e fatores abióticos revelaram a existência de padrões de ocorrência e distribuição próprios para cada espécie, dentro de uma determinada faixa de variaçao de temperatura e de salinidade. Estudos realizados durante uma estação fixa de 36 horas em Cabo Frio, mostraram uma situação típica da estrutura oceanográfica da região, notando-se mudanças de massas de água no local, devido ao fenômeno da ressurgiê-cia. Este fator, associado ao horário de coleta, deve ter exercido influência de maneira complexa sobre o componen-te biológico, induzindo mudanças na ocorrência de diferentes tipos de larvas. Dois transectos, um ao largo de Cabo Frio e ou-tro ao largo de paranaguá, foram analisados com o intuito de obter-se informações a respeito da ocorrência e distribuição de larvas de acordo com a distância da costa. Os dados hidrográficos comprovam a existincia de diferentes massas de água compondo a estrutura oceanográfica daregião, que por sua vez influenciam a ocorrência e distribuição de larvas. A família Gerreidae teve a maior abundância associada à massa costeira. Sardinella brasiliensis, Harenguia jaguna e Engraulis anchoita foram de distribuição tipicamente nerítica, assim como as famílias Sciaenidae, Bleniidae, Ophidiidae, Carangidae e Cynoglossidae. Por ou-tro lado, Myctophidae, Gonostomatidae, Paralepedidae e Scombridae ocorreram preferencialmente na região ocêanica, que sofre influência da Corrente do Brasil. Análise do material coletado com a rede de Neuston comprovam a importância deste tipo de amostragem su-perficial para os estudos relacionados com o ictioplâncton, uma vez que esta rede captura uma porcentagem da população que é subamostrada pela rede Bongo. Observou-se a tendência de estratificação na camada superficial, principalmete de formas jovens, como no caso de Sardinella brasiliensis. Um aspecto especialmente notável foi o caso das fa-mílias Mugilidae e Mullidae em que a captura se deu significativamente em maior número no arrasto de superfície do que no arrasto oblíquo. Comparando-se os materiais coletados com as re-des finas e regular da Bongo, pôde-se verificar dois pro-blemas relacionados com a seletividade: o entupimento da rede e o escape de larvas menores através da malhagem. Ecomparando-se os materiais coletados durante os períodos diurno e noturno, pôde-se verificar o outro problema importante de seletividade, que é a fuga da boca da rede de larvas maiores. As nossas amostragens parecem nao ter sido afetadas pelo problema de entupimento, como mostram as análises do volume de água filtrada. Já o escape de lar-vas menores foi constatado em vários grupos, tendo sido de terminado para três especies o tamanho a partir do qual este problema começa a se tornar evidente: 7,5 mm para Sardinella brasiliensis e 6,5 mm para Harengula jaguana e Engraulis anchoita. A fuga da boca da rede ocorreu em lar-vas maiores durante o dia, concluindo-se que este problema varia conforme a especie, o padrão de migração vertical e o desenvolvimento do sistema visual.
Four oceanographic cruises have heen carried out off the southeastern Brazilian coast from Cabo Frio (23ºS) to Florianópolis (27°S) during the period from January 1980 to March 1982 by the R/V\" Prof. W. Besnard ,\". Fish larvae taken during these cruises were analysed and influences of abiotic factors on their occurrence were discussed.Problems regarding the sampling process were also discussed. Two kinds of sampling gears were used: Bongo nets fitted with a 0.505 mm and 0.333 mm mesh nets for oblique tow and Neuston net with a 0.333 mesh net for surface horizontal tow. At each sampling station, hydrographic data were sampled in addition to biological data. Total of 35,090 larvae were analysed. Sixty one groups were classified and some dominant ones were identified to spec1es level. Larvae belonging to two genera and four species were identified for the first time in the region under observation, i. e. Saurida spp., Hygophum spp., Synodus foetens, Trachinocephalus myops, Bregmaceros cantori and Maurolicus muelleri. The most abundant families were clupeidae, Engraulidae, Myctophidae and Gonostomatidae. In general, the ichthyoplankton from the southeastern Brazilian coast showed a large variety of larvae, but just few groups were outstandingly abundant. Analysing the relations between occurrence of fish larvae and hydrographic parameters, we found specific distri-bution patterns for each species. At the fixed station off Cabo Frio (22°59\'S; 042º05\'7W), 36 hour observations have been done and biological and hydrographic data have been collected every two hours. A change in the local oceanographic structure during the survey period has been observed along with wind induced coastal upwelling. A change of the oceanographic conditions associated with sampling time, may have influenced the occurrence of fish larvae. In order to obtain information on the distribution patterns of fish larvae in relation to distance from the coast, the samples collected on two transects off Cabo Frio and paranaguá were analysed. The presence of four different water masses in this region was confirmed and the occurrence and distribution of larvae seems to have close relationship with those water masses. Larvae of the family Gerreidae were more abundant in the coas tal water mass and those of Sardinella braziliensis, Harengula jaguana and Engraulis anchoita showed typical neritic distribution. Larvae belonging to the families Sciaenidae, Blenniidae, Ophídiidae, Carangidae and Cynoglossidae also showed the same distribution pattern. On the other hand, larvae belonging to the families Myctophidae, Gonostomatidae, Paralepedidae and Scombridae occurred mainly in the oceanic region where the influence of the Brazil Current is eminent. The ichthyoplankton collected at surface layer with Neuston net showed quite different types and size composition of fish larvae, In comparison with those taken with Bongo nets. Clear tendency of stratification in size composition at the surface layer was observed on some species (e.g. S.braziliensis). Larvae belonging to the families Mugilidae and Mullidae seems to be more concentrated at the surface layer, since they were more frequently sampled with the Neuston neto Three problems related to selectivity of plankton net (clogging, extrusion and avoidance) can be studied compar1ng the materials collected with the Bongo ets fitted with different mesh size nets and sampled at different times of the day. As shown in Figs. 23 and 24, there is no evidence of clogging of the fine mesh net during this survey. On the other hand, the extrusion of smaller larvae was confirmed for many groups and it was observed at sizes smaller than 7.5 mm, 6.5 mm, and 6.5 mm, respectively for S.brasiliensis, H.jaguana and E. anchoita. The avoidance was more remarkeble during the day time for larger larvae, but this problem varies depending on spec1es, migration pattern, and development stage of the visual system of each larvae

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Sulpizi, Marialore. "Ab initio studies of targets for pharmaceutical intervention." Doctoral thesis, SISSA, 2001. http://hdl.handle.net/20.500.11767/4280.

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In this thesis we further explore the capability of first principle methods to provide insights on drug/target interactions in different contexts. In the first part of this work, we address the issue whether OFT methods can be used as a potential tool for drug-screening. First principle calculations are particularly interesting for screening the energetics of drug/target interactions, as they do not involve the painstaking procedure of developing each set of new parameters for each novel drug. In this context, we use ab initio_ methods as a novel tool to determine a scoring function in a series of prodrug I target (herpes simplex type 1 thyimidine kinase) complexes for gene-therapy based anticancer approaches. This work, accompanied by experimental data provided by Prof. Folkers' Lab (ETH, Zurich) provides a new, very simple, ab initiobased approach to the construction of scoring functions for drug-screening. In the second part of the thesis we investigate the capability of OFT to describe non trivial interactions which are encountered in several inhibitor/enzyme complexes of pharmaceutical interest. Clearly, the description of these non-trivial phenomena might require the use of electronic structure methods. Here we present an example of cation-n interaction found in the human immunodeficiency virus reverse transcriptase (HIV-1 RT), one of the major targets for anti-AIDS therapy(Furman et al., 2000)). Furthermore, we provide a description of the hydroxyl-n interactions in the active site of μ-glutathione S-transferase(Xiao et al., 1996) (μ-GST), whose differential expression has been implicated in the development of cancers as well as their resistance to chemotherapeutic drugs ((Mccallum et al., 2000) and reference therein). Finally we present a classic problem treated by quantum-chemical methods: the simulation of an enzymatic reaction. We focus on a class of cysteine proteases, the caspases. These enzymes are extremely important targets for pharmaceutical intervention in therapies against Alzheimer's and other neurodegenerative processes, yet very few inhibitors have been so far designed. Since an important class of inhibitors is the given by the transition state analogs, it is of importance to fully understand the · enzymatic reaction, that is the hydrolysis of peptides. Because of the crucial importance of temperature and environment(Karplus, 2000; Glennon and Warshel, 1998; Varnai and Warshel, 2000; Villa et al., 2000) effects for enzymatic catalysis, we use here a hybrid Car-Parrinello Molecular dynamics I Molecular mechanics approach recently developed in the Lab of Prof. U. Roethlisberger (Laio et al., 2001 ). This technique allows to evaluate the intermolecular interactions at the active site from electronic structure calculations as the simulation proceeds(Car and Parrinello, 1985). Steric and electrostatic effects of the protein scaffold on the quantum region are included using classical MD approach on the rest of the system. The free energy of the process is calculated using a thermodynamic integration approach(Ciccotti et al., 1989; Carloni et al., 2000; Piana et al., 2001). This thesis is organized as follows. The first chapter provides a description of the used computational techniques. The following chapter describes the systems investigated here and summarizes our findings. The subsequent three chapters are devoted to a - detailed description of my thesis work. In a final chapter we draw some conclusions and provide a perspective for possible future applications, which could follow this work.

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Bouchoucha, Marc. "Les zones portuaires peuvent-elles servir de nourriceries alternatives pour les poissons marins côtiers ? : cas des sars en Méditerranée Nord-occidentale." Thesis, Perpignan, 2017. http://www.theses.fr/2017PERP0046/document.

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Au cours de leur cycle de vie, la plupart des espèces de poissons marins côtiers passent par des nourriceries littorales dont la qualité influence largement le succès du recrutement et donc le maintien de l’abondance de leurs populations. Or, la construction de ports entrain irrémédiablement une perte de fonction pour les habitats côtiers impactés. Dans ce contexte,l’objectif général de cette thèse était de voir si les zones portuaires peuvent malgré tout servir de nourriceries alternatives pour les poissons marins côtiers. Pour cela, les abondances des juvéniles de quatre espèces de sars, du genre Diplodus, ont d’abord été suivies dans cinq ports méditerranéens. Ceci a permis de montrer que ces espèces côtières peuvent s’installer et grandir avec succès dans les ports. La complexification de la structure 3D de l’habitat augmente sensiblement les abondances de juvéniles. Dans un second temps, la croissance, la condition et les niveaux de contamination desjuvéniles de deux espèces de sars (D. sargus et D. vulgaris) ont été comparés entre différents ports et habitats naturels de la rade de Toulon. Ceci a montré que la croissance et la condition des juvéniles peut être équivalente dans certains ports et dans les zones naturelles adjacentes, avec des niveaux de contamination faibles, même dans les zones les plus polluées. Enfin, la composition multi- élémentaire des otolithes des juvéniles de D. sargus et D. vulgaris a été comparée entre trois ports et deux zones naturelles de la rade de Toulon. Aucun élément chimique lié aux activités portuaires n’aété retrouvé en plus forte concentration dans les otolithes des juvéniles issus des ports. Il n’existe donc pas une signature unique caractéristique de l’ensemble des ports. La composition chimique des otolithes peut néanmoins être utilisée pour étudier la contribution relative des ports aux stocks d’adultes à condition de caractériser la signature de l’ensemble des habitats juvéniles potentiels. L’ensemble des résultats acquis indiquent que les ports peuvent être utilisés comme nourriceries alternatives par plusieurs espèces de poissons marins côtiers. Les projets d’ingénierie écologiquevisant à augmenter la complexité structurale des habitats portuaires sont des pistes intéressantes pour maintenir la biodiversité côtières et les stocks de poissons
During their life cycle, most of the marine coastal fish species use nursery grounds which quality influence their recruitment and then the conservation of their populations. However, the construction of ports impair irremediably fish nursery function of the coastal areas impacted. The ultimate aim of the PhD research was to assess if ports could provide suitable alternative nursery habitats for coastal fish species. Firstly, abundances of the juveniles of four Diplodus species were surveyed in five marinas located along the French Mediterranean coast. This showed that coastal fishes can successfully settle and grow inside these artificialized coastal areas. Moreover, increasing the complexity of port habitats can considerably enhance their suitability for juveniles, especially at the youngest stages. Secondly, body condition, growth rate and metal contamination in the juveniles of two Diplodus species (D. sargus and D. vulgaris) were compared between different ports and natural areas in the Bay of Toulon. Juvenile growth and condition can be equivalent between fish collected from ports and from adjacent natural areas. Contamination levels in fish were low, even in highly polluted areas. Finally, otolith composition in the juveniles of D. sargus and D. vulgaris was investigated in three ports and two natural areas in the Bay of Toulon. None of the port related had systematically higher concentrations in otoliths from Diplodus juveniles collected in ports. Therefore, otolith microchemistry cannot provide a unique and reliable fingerprint discriminating ports and natural areas. Nevertheless, otolith microchemistry could provide an effective natural tag to determine the contribution of ports to adult stocks provided that a library of all potential juvenile habitat fingerprints is established. All these results confirm that ports can be used as alternative nursery habitats by marine coastal fishes. Ecological engineering projects aiming at increasing structural complexity of port habitats seem promising for biodiversity and fish stock conservation

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Ferreira, Francesca Werner. "Sobrevivência e crescimento de juvenis de jundiá Rhamdia quelen expostos a diferentes níveis de amônia, oxigênio e ca2+ na dieta e na água." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/4308.

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The present study examined the effect of experimentally elevating dietary Ca2+ and water hardness on survival and growth of silver catfish, Rhamdia quelen, exposed to different waterborne NH3 and O2 levels. In the dietary Ca2+ experiment of determination of NH3 lethal concentration in 96 h (LC50-96h) juveniles (4.06±0.27g and 7.82±1.2cm) were exposed to five different NH3 levels (in mg.L-1): 0.107±0.007 (control), 0.36±0.021, 0.773±0.074, 1.170±0.071 and 1.63±0.315 and four dietary Ca2+ levels (in % Ca2+): 0.45, 0.95, 1.45, and 2.45. In the waterborne Ca2+ experiment of LC50-96h juveniles (1.85±0.6g and 6.0±0.54cm) were maintained at five different NH3 levels (mg.L-1): 0.097±0.017 (control), 0.356±0.037, 0.779±0.141, 1.459±0.185 and 1.770±0.070 and four water hardness levels (in mg CaCO3.L-1): 34.5±4.4, 62.0±5.7, 116.0±9.3, and 174.0±22.42. In the dietary Ca2+ experiment of determination of O2 lethal concentration in 96 h (LC50-96h) juveniles (4.75 + 0.65 g e 7.56 + 0.61 cm) were exposed to five different O2 levels (in mg.L-1): (0.41±0.13, 0.71±0.15, 0.97±0.13, 1.44±0.35 e 6.41±0.60 mg/L) and four dietary Ca2+ levels (in % Ca2+): 0.45, 0.95, 1.45, and 2.45. In the waterborne Ca2+ experiment of LC50-96h juveniles (3.66 ± 0.75 g e 7.32± 0.5 cm) were maintained at five different O2 levels (mg.L-1): (0.27±0.10, 0.74±0.26, 1.33±0.14, 1.74±0.32 e 6.55±0.02 mg.L-1) and four water hardness levels (in mg CaCO3.L-1): (28, 116, 116 e 180). In the growth experiment juveniles (2.27±0.14g and 6.9±0.13cm) were exposed to two NH3 levels (mg.L-1), 0.021±0.001 and 0.623±0.039, and four water hardness levels (mg CaCO3.L-1): 32.1±4.6, 63.1±5.9, 119.9±10.0, and 177.3±8.1 for 40 days. In the growth experiment juveniles (3.66±0.75g and 7.32±0.5cm) were exposed to two O2 levels (1.47±0.04 and 6.46±0.06 mg.L-1), and four water hardness levels (mg CaCO3.L-1): 30±2.0, 61±2.5, 121±3.0 e 180±3.0 for 15 days. The NH3 LC50-96h was 0.73 mg.L-1 (0.63 - 0.84) in the dietary Ca2+ experiment, and LC50-96h was significantly higher in juveniles fed 0.45 and 0.95% dietary Ca2+. Water hardness did not change significantly NH3 LC50-96h, which was1.20 mg.L-1 (1.10 - 1.24). Weight gain, biomass and specific growth rate at end of the growth experiment were significantly higher in juveniles exposed to 0.021 mg.L-1 NH3 than those exposed to 0.623 mg.L- NH3. The increase of water hardness impaired all measured parameters in juveniles exposed to the lowest NH3 level, but increased them in those exposed to the highest NH3 level. The O2 LC50-96h was 0.89 mg/L (CI 0.64 1.34 mg/L) in the dietary Ca2+ experiment, and LC50-96h was significantly higher in juveniles fed 2.45 e 0.45% dietary Ca2+. Weight gain, biomass, length and specific growth rate at end of the growth experiment were significantly higher in juveniles exposed to 6.46±0.06 than those exposed to 1.47±0.04 mg.L-1O2 . The increase of water hardness increased all measured parameters in juveniles exposed to the lowest O2 level, but them impaired in those exposed to the highest O2 level. This study indicates that low dietary Ca2+ enhanced survival of silver catfish exposed to high NH3 and low O2 levels, and that the increase of water hardness is recommended only when this species is raised in waters with high growth NH3 and low O2 levels.
Este trabalho teve como objetivos verificar os efeitos da adição de Ca2+ na ração e na água na sobrevivência e crescimento de juvenis de jundiá (Rhamdia quelen) submetidos a diferentes níveis de amônia e oxigênio dissolvido. No experimento para verificar a eficácia da adição de Ca2+ na ração sobre a concentração letal 96h (CL50-96h) da amônia (NH3) os juvenis (4.06±0.27g e 7.82±1.2cm) foram expostos a cinco níveis de NH3 (em mg/L): 0,107±0,007 (controle); 0,360±0,021; 0,773±0,074; 1,170±0,071 e 1,630±0,315 e quatro níveis de Ca2+ na dieta (em % Ca2+): 0,45; 0,95; 1,45 e 2,45. Para verificar a eficácia do Ca2+ na água sobre a CL50-96h da NH3 , os juvenis (1,85±0,6g e 6,0±0,54cm) foram mantidos em cinco níveis de NH3 (mg/L): 0,097±0,017 (controle); 0,356±0,037; 0,779±0,141; 1,459±0,185 e 1,770±0,070 e quatro níveis de dureza (em mg CaCO3/L): 34,5±4,4; 62,0±5,7; 116,0±9,3 e 174,0±22,42. No experimento para avaliar a eficácia da adição de Ca2+ na ração sobre a CL50-96h do O2, os juvenis (4,75±0,65g e 7,56±0,61cm) foram expostos a cinco níveis de O2 (em mg/L): (0,41±0,13; 0,71±0,15; 0,97±0,13; 1,44±0,35 e 6,41±0,60 mg/L) e quatro níveis de Ca2+ na dieta (em % Ca2+): 0,45; 0,95; 1,45 e 2,45. Para verificar a eficácia do Ca2+ na água sobre a CL50-96h do O2, os juvenis (3,66±0,75g e 7,2±0,5cm) foram mantidos em cinco níveis de O2 (mg/L): 0,27±0,10; 0,74±0,26; 1,33±0,14; 1,74±0,32 e 6,55±0,02 mg.L-1) e quatro níveis de dureza (em mg CaCO3/L): (28, 116, 116 e 180). Para verificar a influência do Ca2+ na água sobre a sobrevivência e o crescimento, os juvenis (2,27±0,14g e 6,9cm) foram mantidos em dois níveis de NH3 (mg/L), 0,021±0,001 e 0,623±0,039, e quatro níveis de dureza na água (mg CaCO3/L): 32,1±4,6; 63,1±5,9; 119,9±10,0 e 177,3±8,1 por 40 dias. No segundo experimento de crescimento, os juvenis (3,66±0,75g e 7,32±0,5cm) foram mantidos dois níveis de O2 (1,47±0,04 e 6,46±0,06 mg/L), e quatro níveis de dureza na água (mg CaCO3/L): 30±2,0; 61±2,5; 121±3,0 e 180±3,0 por 15 dias. A CL50-96h para NH3 foi de 0,73 mg.L-1 (CI 0,63 0,84) no experimento com Ca2+ na dieta, com uma diferença significativa nos juvenis alimentados com 0,45 e 0,95% de Ca2+ na dieta. A dureza na água não influenciou a LC50-96h NH3, que foi de 1,20 mg/L (CI 1,10 - 1,24). No experimento para avaliar a influência dos níveis de NH3 no crescimento, o ganho de peso, biomassa e taxa de crescimento específico foram significativamente maiores nos juvenis expostos ao nível mais baixo de NH3 , do que naqueles mantidos no nível mais alto de NH3. Nesse experimento o aumento da dureza prejudicou os juvenis expostos ao nível mais baixo de NH3, mas o aumento beneficiou os juvenis mantidos no nível mais alto de NH3 em todos os parâmetros avaliados. A CL50-96h para o O2 foi de 0.89 mg/L (CI 0,64 1,34 mg/L) no experimento com Ca2+ na dieta e foi maior nos juvenis alimentados com 2.45 e 0.45% de Ca2+ na dieta. O ganho de peso, a biomassa, o comprimento e a taxa de crescimento específico foram significativamente maiores nos juvenis mantidos nas concentrações de 1,47±0,04 mg/L O2 do que os expostos a 6,46±0,06 mg/L O2. O aumento da dureza foi positivo para todos os parâmetros medidos nos juvenis expostos ao nível mais baixo de O2, mas prejudicou aqueles submetidos ao nível mais alto de O2. Este estudo indicou que dietas com baixos níveis de Ca2+ aumentam a sobrevivência de juvenis de jundia expostos a altos níveis de NH3 e baixas concentrações de O2, e ao aumento da dureza da água pode ser recomendada somente quando essa espécie é submetida a situações de hipóxia e altos níveis de NH3.

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Le, Croizier Gaël. "Variabilité et déterminants de la bioaccumulation des métaux par les poissons marins : cas du Grand Ecosystème Marin du Courant des Canaries." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0047/document.

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Le Grand Ecosystème Marin du Courant des Canaries est un des principaux systèmes mondiaux d’upwelling et assure une des plus importantes productions de pêche parmi les grands écosystèmes marins d’Afrique. Cet écosystème est soumis à des apports en éléments métalliques entraînant leur accumulation par les organismes marins et notamment les poissons. En termes de bioaccumulation, une forte variabilité est observée entre les espèces exploitées mais également entre individus d’une même espèce. Ce travail de thèse se propose de caractériser les paramètres majeurs qui déterminent l’accumulation des métaux par les poissons marins, en prenant pour cas d’étude l’écosystème du courant des Canaries. Deux approches ont été adoptées, l’une portant sur les particularités physiologiques et l’autre sur les mécanismes écologiques régissant la bioaccumulation. A un premier niveau d’intégration, les caractéristiques physiologiques spécifiques telles que l’efficacité d’assimilation, les concentrations en métallothionéines et le mode de séquestration des métaux agissent sur la bioaccumulation. Ensuite, à un second niveau, la nature des proies joue un rôle crucial sur l’exposition aux métaux du fait de la dominance de la voie de transfert trophique chez les poissons marins. A un dernier niveau d’intégration, l’habitat représente un paramètre déterminant, principalement en influant sur les niveaux de contamination des proies soumis au cycle des métaux dans l’environnement marin. Cette thèse a présenté une approche innovante, en proposant une étude intégrée de la cellule à l’écosystème en passant par l’individu, dédiée à la compréhension d’un mécanisme impliquant des répercutions tant sur la préservation des ressources marines que sur la santé des consommateurs
The Canary Current Large Marine Ecosystem in West Africa is one of the most productive upwelling ecosystems. It is subjected to anthropogenic inputs leading to metal accumulation by marine fish species, which show a great variability in terms of metal concentrations. This PhD work aims to characterize the major parameters determining metal accumulation by marine fish, based on the case study of the Canary current. Two main approaches were developed concerning physiological and ecological features. At a first integration level, physiological characteristics such as assimilation efficiency, metallothionein concentrations and subcellular metal partitioning influence bioaccumulation. At a second level, prey composition plays a key role due to the dominance of metal accumulation through dietary intakes in marine fish. Finally, habitat drives metal exposure to fish due to the biogeochemical cycle of the metal elements.This study proposed an innovating approach, combining analyses from the cellular level to the ecosystem one, including the individual level, and aiming for a thorough comprehension of a mechanism implying consequences on marine resource conservation and human safety

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VIVONA, Letizia. "A physical-computational modelling for analysis of Centromere patterns in IIF images." Doctoral thesis, Università degli Studi di Palermo, 2014. http://hdl.handle.net/10447/90902.

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Autoimmune diseases are a family of more than 80 chronic, and often disabling, illnesses that develop when underlying defects in the immune system lead the body to attack its own organs, tissues, and cells. Diagnosing autoimmune diseases can be particularly difficult because these disorders can affect any organ or tissue in the body, and produce highly diverse clinical manifestations, depending on the site of autoimmune attack. Moreover, disease symptoms are often not apparent until the disease has reached a relatively advanced stage. These observations suggested us to develop an automated method to support the diagnosis. Developing an automated procedure for diagnosis of autoimmune diseases, generally authors focus their attention on cells detection, fluorescence intensity determination or pattern classification. Since different patterns correspond to different diseases, it is really important to be able to distinguish among different pattern, so we chosen to deal with the pattern recognition. Particularly we propose here a method to automatically classify the Centromere pattern based on the grouping of centromeres present on the cells through a clustering algorithm.

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Carbonnel, Anna. "Engagement de la recherche agronomique dans l'action. Le cas d'une Recherche-Action en Partenariat au Cameroun." Phd thesis, Université Paul Valéry - Montpellier III, 2012. http://tel.archives-ouvertes.fr/tel-00839985.

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La Recherche-Action en Partenariat (R.A.P.) est une démarche de recherche conçue par des chercheurs du Centre de coopération Internationale en Recherche Agronomique pour le Développement (C.I.R.A.D.). D'après les concepteurs de la R.A.P., les inventions proposées par les chercheurs agronomes ne sont pas suffisamment prises en compte par les potentiels utilisateurs et ne se transforment pas forcément en innovation. Inspirée des sciences sociales et présentée comme une démarche capable d'élaborer des conditions favorables à la co-construction des innovations, la R.A.P. doit améliorer le passage entre l'invention des chercheurs et l'adoption de ces inventions par les utilisateurs. Cette thèse se focalise sur les conditions d'émergence de la R.A.P. au C.I.R.A.D. puis sur son application à deux terrains vivants : le Cameroun et le Burkina Faso. La question principale posée dans ce travail est de savoir si effectivement et concrètement,la R.A.P. s'inspire des sciences sociales pour favoriser la co-construction des innovations et atteindre l'un de ses objectifs : résoudre les problèmes des acteurs. Cette thèse est une réflexion sur la place et les actions possibles des sciences sociales en collaboration avec d'autres disciplines pour se mettre au service d'une telle démarche et de tels projets de développement. L'observation de la R.A.P. comme un objet de recherche socio-anthropologique donne à voir une multitude de questionnements essentiels tant pour le milieu de la recherche que pour les situations locales rencontrées.

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Oliveira, M?nica Rocha de. "Estrat?gia reprodutiva do peixe-voador, Hirundichthys affinis e do peixe agulha preta, Hemiramphus brasiliensis no litoral de Cai?ara do Norte, Rio Grande do Norte, Brasil." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17244.

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Made available in DSpace on 2014-12-17T15:36:44Z (GMT). No. of bitstreams: 1 MonicaRO_TESE.pdf: 9199361 bytes, checksum: c0ccdbb9830c327846e159e62e15732a (MD5) Previous issue date: 2014-07-03
Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
The flyingfish, Hirundichthys affinis (G?nther, 1866) (Exocoetidae) and ballyhoo half beak, Hemiramphus brasiliensis (Linnaeus, 1758) (Hemiramphidae) are marine fish species of commercial value, which contribute to artisanal fishery production of Rio Grande do Norte, Brazil. Besides the economic importance, these fish are important from an ecological point of view, being components in pelagic food chain, where they are the preferred prey of larger predators of high commercial value. This study aimed to determine the reproductive strategies of H. affinis and H. brasiliensis and the fishery production of H. affinis in the northern coast of Rio Grande do Norte. The results are presented in the form of six cientific articles and a review paper. The first article presents the morphometric measurements and meristic counts which confirmed the taxonomic status, population structure in length-weight and the gonad development of H. affinis through macroscopic observations of the ovaries and testes. Females of this species were bigger and heavier than males. The second article describes the reproductive tactics, such as, sex ratio, length at first sexual maturity, histological aspects of gonads, fecundity and spawning season, that indicate the reproductive strategy of H. affinis. The third article shows annual changes in the fishery production of H. affinis in Cai?ara do Norte, during the period of 1993 to 2010, emphasizing the relevance of this fish in total fishery production of Rio Grande do Norte, besides registering the fall in production in the years 2008 to 2010. The fourth article describes the population structure, with respect to the length and weight, the length-weight relationship, growth type and sex ratio of Hemiramphus brasiliensis. The fifth article describes the reproductive biology of H. brasiliensis, with details about sex ratio, length at first sexual maturity, fecundity, type of breeding and spawning season. The sixth article deals with the reproductive strategy of H. brasiliensis. The review paper presents the topic of age determination of tropical fish using analysis of otoliths. Both species use the coastal waters of Cai?ara do Norte for reproductive purposes. The flying fish, H. affinis migrates from the oceanic waters to the coastal waters to reproduce, coinciding with the rainy season. H. affinis presents total spawning and a seasonal reproductive strategy. However, H. brasiliensis lives and reproduces in the coastal waters displaying partial spawning and an equilibrium reproductive strategy
O peixe-voador, Hirundichthys affinis (G?nther, 1866) (Exocoetidae) e a agulha preta, Hemiramphus brasiliensis (Linnaeus,1758) (Hemiramphidae) s?o peixes marinhos de valor comercial, que contribuem para a produ??o pesqueira artesanal do Rio Grande do Norte, Brasil. Esses peixes s?o importantes na teia alimentar pel?gica, pois constituem as principais presas preferidas de predadores de alto valor comercial. Este trabalho teve como objetivo determinar as estrat?gias reprodutivas de H. affinis e de H. brasiliensis e a produ??o pesqueira de H. affinis no litoral Norte do Rio Grande do Norte. Os resultados est?o apresentados sob a forma de seis artigos cient?ficos e um artigo de revis?o. O primeiro artigo aborda as medidas morfom?tricas e contagens mer?sticas que confirmaram a taxonomia da esp?cie, a estrutura da popula??o em peso-comprimento e o desenvolvimento das g?nadas de H. affinis, atrav?s de observa??es macrosc?picas dos ov?rios e test?culos. Foi verificado que as f?meas s?o maiores e mais pesados do que os machos. O segundo artigo descreve ?s t?ticas reprodutivas, tais como, propor??o sexual, comprimento da primeira matura??o sexual, aspectos histol?gicos das g?nadas, fecundidade e per?odo de desova, que indicam a estrat?gia reprodutiva de H. affinis. O terceiro artigo mostra a varia??o anual da produ??o de H. affinis em Cai?ara do Norte, durante o per?odo de 1993 a 2010, dando ?nfase a relev?ncia desse peixe na produ??o pesqueira no RN, incluindo o registro da queda na produ??o durante os anos de 2008 a 2010. O quarto artigo apresenta a estrutura populacional, no que tange ao comprimento e peso, a rela??o peso-comprimento, o tipo de crescimento e a propor??o sexual de Hemiramphus brasiliensis. O quinto artigo apresenta a biologia reprodutiva de H. brasiliensis, com detalhes sobre a propor??o sexual, o comprimento da primeira matura??o sexual, a fecundidade, o tipo e o per?odo de desova. O sexto artigo descreve a estrat?gia reprodutiva de H. brasiliensis. O artigo de revis?o aborda o tema de determina??o da idade dos peixes tropicais atrav?s de ot?litos. As duas esp?cies utilizam o litoral de Cai?ara do Norte para fins reprodutivos. H. affinis migra das ?guas oce?nicas para as ?guas costeiras, coincidindo com o per?odo chuvoso. H. affinis apresenta desova total e a estrat?gia reprodutiva do tipo sazonal. Enquanto, H. brasiliensis vive e reproduz nas ?guas costeiras apresentando desova parcelada e uma estrat?gia reprodutiva do tipo de equil?brio

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Cordier, Mateo. "Ecosystème estuarien et système économique régional: faisabilité d'une intégration par modélisation input-output : application au cas de l'habitat halieutique dans l'estuaire de la Seine." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209905.

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Le modèle input-output régional environnementalisé développé dans la thèse de M. Cordier suggère qu’il serait possible de restaurer 25% des surfaces naturelles de nourriceries de poissons détruites dans l’estuaire de la Seine entre 1834 et 2004. Le modèle suggère que la mesure de restauration pourrait augmenter de 15% à 23% la biomasse de soles produite dans l’estuaire par rapport à une situation sans mesure. Quant à l’effet des coûts de restauration sur les agrégats macroéconomiques (PIB, emploi, etc.), il génère une diminution qui ne dépasse pas 0,5% par rapport à une situation sans mesure. Le modèle montre cependant que trois secteurs sont particulièrement touchés par la mesure, leur bénéfice étant considérablement réduit. Cela indique le compromis à réaliser entre les objectifs écologiques à long terme et les objectifs économiques sectoriels à court terme. La quantification des compromis par le modèle constitue un atout utile aux processus de décision participatifs multicritère / The regional green input-output model developed in Mateo Cordier's PhD shows that it seems possible to restore 25% of the natural areas of fish nurseries destroyed in the Seine estuary between 1834 and 2004. The model suggests that the restoration measure could increase between 15% and 23% the biomass of sole generated by the estuary compared to a situation without measure. Regarding the impact of restoration costs on macro-economic indicators (GDP, employment, etc.), it generates a decrease that does not exceed 0,5% compared to a situation without measure. However, the model shows that three sectors are particularly impacted by the measure. Their benefits are considerably reduced. This shows the trade-off that occurs between ecological targets on the long run and economic targets on the short run. The quantification of such trade-offs in the model is particularly useful to public participation in decision-making.
Doctorat en Sciences agronomiques et ingénierie biologique
info:eu-repo/semantics/nonPublished

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Roy, Allison Hunt. "Can riparian forests mediate impacts of urbanization on stream fish assemblages?" 2004. http://purl.galileo.usg.edu/uga%5Fetd/roy%5Fallison%5Fh%5F200408%5Fphd.

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Thesis (Ph. D.)--University of Georgia, 2004.
Directed by Mary C. Freeman. Includes articles submitted to Canadian journal of fisheries and acquatic sciences, Landscape ecology, and Environmental management, and an article accepted by The journal of the North American Benthlogical Society. Includes bibliographical references.

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41

Singh, Gurjeet. "Design and development of an automated can filling system for fish." Thesis, 1996. http://hdl.handle.net/2429/5692.

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Salmon processing is a five hundred million dollar industry in British Columbia. This research is a part of the work undertaken in the Industrial Automation Laboratory at the University of British Columbia to develop advanced, low-cost technology for flexible automation in the fish processing industry. The scope of the research reported in this thesis is limited to the design' and development of an automated can-filling system for fish. Higher operating speeds, improved filling accuracy and waste reduction, better versatility and process flexibility, improved product quality and presentation, and a greater level of automation are some of the key objectives of the research. These are addressed in the thesis. The performance of the existing special purpose machines is examined in detail to identify problem areas and their possible causes. Alternative conceptual designs are studied, that would eliminate these problems. An appropriate design is chosen and further analyzed and developed. The particular design chosen uses weight-based portion control of fish as opposed to the existing volume-based processing and portion compacting. This new approach is expected to provide improved accuracy and product quality. The proposed design for an automated canfilling system is developed up to the stage of component specification and selection that would meet the industrial requirements. Also, a cost-benefit analysis is made for the proposed can filling system, with a critical comparison with the existing technology. Laboratory experiments have been carried out to check the suitability of the design. In particular, an experimental prototype for the filling system has been designed, built and employed to test the filling effectiveness of the proposed system. The experimental results are evaluated and further improvements are recommended for the can-filling system.

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Crawford, Kathryn Anna. "Healthy fish, healthy people: how fish can inform our understanding of effects of metabolism disrupting compound exposure on wildlife and human health." Thesis, 2018. https://hdl.handle.net/2144/33045.

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Biologists have traditionally studied adverse health effects of contaminants on wildlife, whereas public health researchers have independently studied effects of the same chemicals on humans. This siloed approach limits maximal progress towards understanding and managing pollution if relevant findings are not translated between fields. A new threat to human health, and potentially ecological health, is metabolic disruption. Metabolism disrupting chemicals (MDCs) are environmental chemicals that can act at systemic and molecular levels across the lifespan to interfere with normal adipose tissue development, lipid storage in the liver, and alter whole-body energetics. Using fish from New Bedford Harbor (NBH), Massachusetts, a marine Superfund site, this research demonstrates the benefit of using a holistic approach to examine exposures to and effects of contaminants in urban waterways. The overall goals of this dissertation were to investigate trends in polychlorinated biphenyl (PCB) contamination in NBH and to test the hypothesis that PCB and/or organotin exposure has resulted in metabolic disruption in Atlantic killifish (Fundulus heteroclitus) resident in New Bedford Harbor. First, trends in PCBs in seafood harvested throughout NBH since 2003 were characterized over time and space. PCBs declined in shellfish, but not finfish, over time. My risk assessment shows that human health risks associated with seafood consumption have decreased, but safe levels in seafood are not likely to be reached by the end of NBH sediment remediation, in the early 2020s. PCBs and tributyltin (TBT), a pollutant also commonly found in commercial harbors because of its use as an antifouling agent in marine paints, act as MDCs by distinct mechanisms. Dioxin-like PCBs act through the aryl hydrocarbon receptor. TBT acts through nuclear receptors, particularly PPARγ and RXR. In the second aim, using historical sediments and current sediments, I document the presence of tin in NBH above background levels. Biological investigations show that adult killifish two generations removed from NBH have more adipose tissue and higher levels of liver triglycerides than killifish from an uncontaminated location. Initial analyses show that changes in PPAR signaling may be particularly important in male killifish. In the third aim, I demonstrate that killifish embryos are minimally responsive to changes in PPARγ-regulated gene expression when treated with TBT or mammalian agonists. However, embryonic TBT exposure interferes with caudal fin development, likely through RXR activation and a reduction in bone formation signaling. Overall, these findings demonstrate metabolic disruption is occurring in a fish species resident to a highly polluted harbor and support the use of sentinel species not only for addressing potential human exposures but also potential adverse human health effects.

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Nguyen, Van Trai. "The influences of shrimp farming and fishing practices on natural fish conservation in Can Gio, Ho Chi Minh City, Vietnam." Thesis, 2008. http://hdl.handle.net/1959.13/33064.

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Research Doctorate - Doctor of Philosophy (PhD)
Shrimp farming and capture fishery are two of the major industries of Can Gio district, Ho Chi Minh City, southern Vietnam. These industries have recently developed and contributed to the improvement of local economy. However, they have also raised environmental concerns regarding water pollution and fish stock depletion. The negative impacts of shrimp farm effluents on the water quality of mainstream rivers and fish communities have not been studied in Can Gio. Additionally, there is a lack of research on the influence of the current fisheries management on environmental protection and fish conservation in this district. The goal of this study was to address key issues in fisheries management in Can Gio in regard to the impacts of wastewater from shrimp farming on the water quality of mainstream rivers that affect the local fish communities, and the influence of improper fishing practices that lead to the depletion of local fish stocks. This study also aimed to propose strategies to improve the local fisheries management for more environmentally responsible productions. Two mainstream surveys were developed to obtain data, i.e. environmental surveys for the assessment of water quality and pollution impacts on fish communities; and people interviews for the examination of fisheries management related to shrimp farming and fishing practices. The findings were used as a baseline to develop appropriate strategies for improving the management in terms of promoting sustainable productions both in shrimp farming and capture fishery industries and protecting the environment. This study found that shrimp farming, especially intensive farms have contributed to water pollution in mainstream rivers in Can Gio, and in turn the water pollution has adversely affected the local fish communities. The waters adjacent to the intensive farms were contaminated with high concentrations of organic matter. The number of fish species reduced and tolerant species appeared at higher proportions in these areas. Many improper practices in shrimp farming and fishing as well as weaknesses in government management were addressed to be the key issues leading to environmental pollution and fish depletion. The proposed strategies focused on improving the management at both government and community levels. Promoting community-based management was suggested as a key to the success in fisheries management in Can Gio.

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Nguyen, Van Trai. "The influences of shrimp farming and fishing practices on natural fish conservation in Can Gio, Ho Chi Minh City, Vietnam." 2008. http://hdl.handle.net/1959.13/33064.

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Research Doctorate - Doctor of Philosophy (PhD)
Shrimp farming and capture fishery are two of the major industries of Can Gio district, Ho Chi Minh City, southern Vietnam. These industries have recently developed and contributed to the improvement of local economy. However, they have also raised environmental concerns regarding water pollution and fish stock depletion. The negative impacts of shrimp farm effluents on the water quality of mainstream rivers and fish communities have not been studied in Can Gio. Additionally, there is a lack of research on the influence of the current fisheries management on environmental protection and fish conservation in this district. The goal of this study was to address key issues in fisheries management in Can Gio in regard to the impacts of wastewater from shrimp farming on the water quality of mainstream rivers that affect the local fish communities, and the influence of improper fishing practices that lead to the depletion of local fish stocks. This study also aimed to propose strategies to improve the local fisheries management for more environmentally responsible productions. Two mainstream surveys were developed to obtain data, i.e. environmental surveys for the assessment of water quality and pollution impacts on fish communities; and people interviews for the examination of fisheries management related to shrimp farming and fishing practices. The findings were used as a baseline to develop appropriate strategies for improving the management in terms of promoting sustainable productions both in shrimp farming and capture fishery industries and protecting the environment. This study found that shrimp farming, especially intensive farms have contributed to water pollution in mainstream rivers in Can Gio, and in turn the water pollution has adversely affected the local fish communities. The waters adjacent to the intensive farms were contaminated with high concentrations of organic matter. The number of fish species reduced and tolerant species appeared at higher proportions in these areas. Many improper practices in shrimp farming and fishing as well as weaknesses in government management were addressed to be the key issues leading to environmental pollution and fish depletion. The proposed strategies focused on improving the management at both government and community levels. Promoting community-based management was suggested as a key to the success in fisheries management in Can Gio.

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Williams, Ashley John. "Spatial patterns in population biology of a large coral reef fish: what role can movement play?" Thesis, 2003. https://researchonline.jcu.edu.au/24132/1/01front.pdf.

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Recent empirical studies have demonstrated significant spatial variation in the population biology of coral reef fish. The scales at which this variation occurs often depend on the species and processes that are examined. Most research on coral reef fish population biology has focused on relatively small, site-attached species and results from such research often indicate variations in population biology at localised spatial scales, such as 10's to 100's or 1000's of meters. There have been fewer studies of large reef fish species and, consequently, little is known of the spatial patterns in population biology of large reef fish. Large reef fish are generally thought to be more mobile and have larger home ranges than small reef fish species. Therefore, the spatial scales that define intermixed populations of large reef fish may differ from those at which small reef fish vary. Furthermore, large reef fish species are often the targets for commercial and recreational fisheries. Information on the spatial patterns in population biology of harvested species will be of particular importance for fisheries management, as population responses to fishing pressure and different management strategies will vary among populations with different dynamics. Within this context, the broad objectives of this thesis were to: 1) Estimate a number of reproductive parameters, including spawning season, maturity schedules and size and age at sex change for the red throat emperor (Lethrinus miniatus) and compare the parameters between the northern and southern areas of the distribution of L. miniatus on the Great Barrier Reef (GBR); 2) Estimate rates of growth and mortality for L. miniatus and compare these parameters within and among three regions of the GBR over a temporal scale of five years; and 3) Explore the potential for large-scale movement of post-settlement L. miniatus to explain the observed spatial patterns in population age structures. Estimates of population parameters for these objectives required reliable estimates of age. Accordingly, age estimates of L. miniatus were first validated using marginal increment analysis (MIA) and captive rearing of chemically tagged fish. The MIA was achieved by obtaining monthly samples of L. miniatus from commercial line fishing vessels from the northern and southern areas of the GBR. Fish that were chemically tagged and reared in an aquarium were also collected from a commercial fishing vessel. Opaque increments in the otoliths of L. miniatus were found to be deposited on an annual basis, but the timing of formation varied slightly between years and areas. Reproductive parameters (Objective 1) were derived from the monthly samples collected from the commercial fleet. A peak spawning season was observed between July and October in both the northern and southern areas of the distribution of L. miniatus on the GBR. The proportion of spawning females, however, was greater in the northern area than in the southern area. The size at which L. miniatus changed sex from female to male was significantly larger in the southern area, but there were no spatial differences in the age at sex change. The size and age at maturity were estimated to be 180 mm FL and 1.2 years respectively, but data were insufficient to allow spatial comparisons of these parameters. Spatial patterns in growth and mortality of L. miniatus (Objective 2) were estimated from annual samples of populations of L. miniatus from four reefs within three regions of the GBR (Townsville, Mackay and Storm Cay) over a period of five years. Growth rates were found to vary among years but this variation was consistent among regions and reefs. Mortality rates were consistent among cohorts within each region and reef. Rates of growth and mortality were relatively similar at the spatial scale of individual reefs within regions but differed significantly among regions. This regional variation was consistent over years. The Townsville (northern-most) region was characterised by the smallest maximum size, and lowest rates of mortality. In contrast, the Mackay region was characterised by the largest maximum size, and highest rates of mortality. Rates of growth and mortality for the Storm Cay (southern-most) region were intermediate between the other two regions. The potential for migration of L. miniatus to contribute to the observed patterns in population parameters (Objective 3) was explored by developing an age structured model for L. miniatus populations from the Townsville, Mackay and Storm Cay regions of the GBR, using the empirical data collected from the annual regional samples. Model age structures were compared with observed age structures to determine the net movement that would be required to explain the significant regional variations in age structure. The model predicted significant immigration to the Townsville region of fish aged from three to 10 years and significant emigration of fish aged three and four years from the Mackay region. Predicted net movement in the Storm Cay region was negligible, although immigration of a small number of seven year old fish was predicted under some model scenarios. A number of hypotheses that might explain the model results are discussed. The results from this thesis highlight the need to determine the spatial scales at which all demographic processes operate, including movement, to obtain reliable estimates of population structure and provide the most useful information with which to optimise harvest strategies for reef fish.

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Heron, Carl P., O. E. Craig, A. Luquin, Valerie J. Steele, A. Thompson, and G. Piličlauskas. "Cooking fish and drinking milk? Patterns in pottery use in the southeastern Baltic, 3300–2400 cal BC." 2015. http://hdl.handle.net/10454/7423.

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yes
A study of pottery vessel contents and use was undertaken in order to obtain information on food processed in Subneolithic and Neolithic vessels from Nida and Šventoji (3300–2400 cal BC). The aim is to assess pottery use during major changes in the coastal environment and in material culture. Bulk carbon and nitrogen isotope, lipid biomarker and compound specific carbon isotope analysis was undertaken on ‘foodcrusts’, charred deposits adhering to vessel surfaces, and absorbed residues from different vessel types. In addition, three archaeological seal bones were analysed for bulk collagen and compound specific carbon isotope analysis to establish collagen-lipid offsets to inform interpretation of the data. The results show that the majority of the vessels were used for processing aquatic products. At Nida the data suggest exploitation of freshwater resources and, in the later stages of occupation, dairying. Analysis of a small number of Subneolithic vessels from Šventoji produced results that are also consistent with processing of aquatic products. Other substances identified include Pinaceae sp. resin or tar and beeswax. These data demonstrate that identifying patterns in pottery use contributes to understanding Neolithisation processes.

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BLAŽKOVÁ, Barbora. "Charakterizace molekulárního složení genomu obaleče jablečného, \kur{Cydia pomonella}, s využitím reasociační kinetiky." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-135701.

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In this study, the reassociation kinetics of codling moth (Cydia pomonella) was performed in order to characterize the molecular composition of the codling moth (Cydia pomonella) genome and to isolate highly repetitive and unique DNA components. The effectivity of distinct repetitive DNA fractions as a specific competitor in fluerescence in situ hybridization was tested.

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Dias, Diogo Cabeleira. "How can natural compounds supplemented in eggs improve digestive efficiency in fish larvae? In ovosupplementation of spermine as promoter of early digestive system maturation." Master's thesis, 2020. http://hdl.handle.net/10400.1/15358.

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The world Human population is growing, and it is expected to reach almost 10 billion until 2050. The dietary protein trends in developing countries are changing from vegetable and cereal to animal sources. The superimposition of these anthropogenic factors will, if solutions are not found, increase the pressure on the already fragilized natural resources. Aquaculture is a growing animal production sector that may be the one of the solutions for supplying the world with food, specifically marine products, while reducing the pressure on natural stocks and having the minimum impact on the environment. Nonetheless fish production has some major bottlenecks concerning, for example, sustainable feed production and fish juveniles’ supply. This is mostly due to the need to replace the typically provided live feeds with microdiets, specifically tailored to meet fish larvae´s nutritional needs, but still with constraints derived from fish larvae digestive inability to digest and assimilate the nutrients provided in these diets. For this reason, the objective of this study was to test the viability of early metabolic programing in Solea seneganelensis, a marine fish species with high commercial value, by supplementing eggs with three different amounts of spermine. Spermine, a polyamine shown to promote the maturation of the gut, was delivered through a novel technique for in ovo supplementation named sonophoresis. Each treatment was done in triplicate from egg stage until 35 days after hatching (DAH) larvae. Results demonstrate the short- and long-term safety of both, sonophoresis technique and in ovo supplementation with spermine. Regarding gut maturation, some degree of improvement in terms of lipolytic capacity were observed at 14 DAH in Sole from LOW and MED treatments. In the future, sonophoresis may become a keystone in early metabolic programing and the supplementation of spermine may generate more pronounced results if trials are conducted through longer periods and/or spermine supplementation is done through the dietary route.
A população humana mundial continua em elevado crescimento, é esperado que atinja perto de 10 bilhões até ao ano de 2050. Para além disso, nos países em desenvolvimento é constatada uma modificação dos padrões de consumo de proteína, designadamente no que diz respeito à sua proveniência, verificando-se uma substituição de fontes vegetais por fontes animais. A conjugação destes fatores antropogénicos irá no futuro, caso não sejam encontradas soluções viáveis, incrementar a já existente pressão imputada sobre os recursos naturais. A aquacultura é um dos sectores de produção animal que apresenta um maior crescimento e que poderá ser parte da muito necessária resposta ao fornecimento de alimento à escala mundial, particularmente de peixe e de marisco, e que promova a redução de pressão sob os stocks de pesca e minimize o impacto ambiental. Não obstante, a produção de pescado está sujeita a condicionantes, como a necessidade de uma elaboração mais sustentável de ração e a produção estável de juvenis. Esta última deve-se em parte, à necessidade de substituição de alimento vivo por alimento inerte especificamente formulados, que se adequem às necessidades nutricionais das larvas de peixes marinhos. Todavia, persistem ainda algumas limitações resultantes da incapacidade das larvas de peixes marinhos em digerir e assimilar os nutrientes presentes nestes alimentos. Por esta razão, o objetivo do presente estudo foi verificar a viabilidade da aplicação do conceito de “programação metabólica precoce” em linguado (Solea senegalensis), uma espécie de elevado interesse comercial, através da suplementação de distintas concentrações de espermina no estádio de ovo. A espermina é uma poliamina com resultados validados na promoção do desenvolvimento precoce do sistema digestivo em animais, tendo a sua aplicação sido efetivada com recurso a uma técnica recentemente desenvolvida (sonoforese), que permite suplementação de compostos através de canais criados na membrana do ovo. A suplementação foi realizada com três concentrações diferentes de espermina, sendo que para cada tratamento o cultivo foi feito em triplicado até ao trigésimo quinto dia após eclosão (DAE). Os resultados obtidos comprovam a segurança a curto e longo prazo tanto da utilização de sonoforese como da suplementação de espermina. No que diz respeito à maturação do sistema digestivo, foi verificado um incremento na capacidade lipolítica das larvas dos tratamentos LOW e MED aos 14 DAE. No futuro, a sonoforese poderá tornar-se um dos pontos-chave no contexto de “programação metabólica precoce” e a suplementação com espermina poderá gerar efeitos mais pronunciados em ensaios com uma duração superior e/ou cuja suplementação seja realizada pela via alimentar.

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Tanguay, Louis. "La durabilité de deux systèmes intégrés d'agriculture et d'aquaculture adoptés dans le delta du Mékong au Vietnam : étude de cas." Thèse, 2009. http://hdl.handle.net/1866/7960.

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Barmaki, Fatiha. "Le rôle de la traduction dans le transfert des connaissances juridiques : le cas des codes civils marocain et tunisien." Thèse, 2017. http://hdl.handle.net/1866/21147.

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Dissertations / Theses on the topic 'Cat fish'

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