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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Reconstrucción estructural 3D sinclinal de Barros Arana, cuenca del Salar de Atacama (22°30'S-23°S)

Araya Zuleta, José Antonio January 2016 (has links)
Geólogo / Las rocas clásticas continentales del Grupo Purilactis, han sido depositadas en una cuenca de antepaís, entre el Cretácico Tardío y el Paleoceno, asociadas al alzamiento de la Cordillera de Domeyko durante la Fase Peruana. En la zona del sinclinal de Barros Arana, las excelentes exposiciones de las rocas, hacen que este sea el lugar ideal para analizar los rasgos geométricos de los depósitos sinorogénicos de la Formación Purilactis. Dada las variaciones geométricas del sinclinal de Barros Arana, se hace necesario modelar en 3 dimensiones este pliegue. El modelo es realizado a través de la construcción de secciones geológicas seriadas junto con el análisis posicional de los contactos geológicos, los cuales son llevados a cabo por medio del método de las Isógonas (Ramsay) y el método 3D dip-domain (Ribbon), respectivamente. Finalmente se realiza una restauración del pliegue, mediante el método de Flexural Slip, para así apreciar la geometría interna del sistema previo al plegamiento. Los resultados obtenidos muestran, para los miembros Río Grande y Seilao, pertenecientes a la Formación Purilactis, el desarrollo depocentros con geometrías de cuñas abiertas hacia el oeste, lo cual evidenciaría la subsidencia litosférica en el foredeep de una cuenca de antepaís durante el Cretácico Tardío. Las direcciones de paleocorrientes apuntan hacia los principales depocentros, los cuales podrían estar representando parte las zonas proximales de los sistemas sedimentarios. Por lo tanto, la geometría y ubicación de los depocentros de los miembros de la Formación Purilactis, son controladas en primer orden por la subsidencia tectónica generada en el foredeep de una cuenca de antepaís, durante periodos de actividad tectónica. Esta actividad también produciría variaciones en las facies sedimentarias que componen a los diferentes miembros de la Formación Purilactis, y por consiguiente, en las principales direcciones de paleocorrientes. La evolución estática de los depocentros de los miembros superiores de la Formación Purilactis, muestra que los pulsos tectónicos que componen la Fase Peruana, solo generarían subsidencia en el anteapaís y no mayor deformación durante este periodo, acorde a una posición de foredeep. La compleja organización y geometría del sistema de fallas presentes en el dominio norte del sinclinal, podría ser producto del exceso de rotación horaria del bloque rígido de los Cerros de Tuina. El principal mecanismo de plegamiento para el sinclinal de Barros Arana sería Flexural Slip, sin embargo, también se evidencia la participación de Flexural Flow como también de Orthogonal Flexure.
42

Balance hídrico de la cuenca del Salar del Huasco mediante el modelo hidrológico de simulación TopModel usando información del reanálisis atmosférico

Vega Quintana, Arturo Ignacio January 2016 (has links)
Ingeniero Civil / El Salar del Huasco, ubicado en la Región de Tarapacá, Chile, constituye un sistema de gran relevancia ambiental al albergar ciertos ecosistemas vitales para la sobrevivencia de especies en estado vulnerable, como por ejemplo flamencos, que requieren de lagunas someras para sus nidos, típicas en estos ambientes. El objetivo de este trabajo de título es realizar un balance hídrico histórico en esta cuenca mediante un modelo de simulación hidrológica, en una escala temporal de 30 años y utilizando información meteorológica proveniente del reanálisis atmosférico, para así analizar la disponibilidad del recurso hídrico y su dinámica temporal futura en una escala de tiempo de 94 años. Se escogió el modelo de simulación hidrológica TOPMODEL por la naturaleza distribuida de los procesos considerados, simpleza en los datos de entrada y cantidad reducida de parámetros a calibrar. A los datos de entrada obtenidos del reanálisis atmosférico se les aplicó un proceso de escalamiento espacial a la zona y luego se realizó una corrección de sesgo mediante ajustes probabilísticos a sus curvas de duración. La hidrología de la cuenca del Salar se obtuvo para el periodo comprendido entre los años 1984 y 2014. La calibración de los parámetros se realizó de forma de disminuir el error entre la recarga producto de caudal y flujo subterráneo a través del acuífero al Salar y la descarga por evaporación desde el mismo. Los resultados de esta simulación histórica arrojan que de la precipitación media anual: un 90% se evapora en la cuenca mientras el 10% restante escurre superficial y subsuperficialmente hacia el Salar donde posteriormente se evapora totalmente, mientras que la percolación profunda es despreciable frente a las variables anteriores. Posteriormente se obtuvieron las series futuras de precipitación y evapotranspiración potencial a partir de los resultados del modelo climático HadGEM2-AO, acoplado con un modelo de balance radiativo, bajo los escenarios de cambio climático RCP 2.6, 4.5, 6.0 y 8.5. A estas series se les aplicó un escalamiento espacial, mientras que la corrección del sesgo se determinó a partir del periodo histórico común a las series de cada uno de los escenarios. Luego, ocupando los parámetros ya calibrados, se simuló la hidrología del Salar en el periodo histórico (1984-2005) y futuro (2006-2100) para analizar su dinámica. Con las series de recarga al Salar y evaporación potencial en el mismo, se realizó el balance de volumen de la laguna. Los resultados muestran que al comparar una ventana temporal de los años 2070-2100 con la inicial de la proyección futura (1984-2005), se tiene un aumento estadísticamente significativo de la precipitación de un 55% y 70% para los dos escenarios de mayor forzamiento radiativo, mientras que la recarga al salar como fracción de la precipitación aumenta de un 13% a un 23% para el escenario RCP 6.0. El balance de volumen en el Salar predice aumentos en la altura promedio anual de la laguna entre 36% y 74% mientras que el área de la misma aumenta hasta 1.4 veces para el escenario R.C.P 8.5.
43

Understanding key factors associated with the infection of farmed Atlantic salmon by the salmon louse Lepeophtheirus salmonis

Frenzl, Benedikt January 2015 (has links)
The objective of the work described in the current thesis was to provide a better understanding of some of the key factors associated with sea louse, Lepeophtheirus salmonis, infection of farmed Atlantic salmon. In Chapter 2, initial work focused on establishing the vertical and horizontal distribution of sea lice copepodids and spatial patterns of on-farm infections. The louse distribution was investigated along the main current gradient across adjacent salmon production pens at three commercial sites. A depth profile for the distribution of larval lice was also established for the top 12 m of the water column at three different locations in close proximity to commercial salmon farms. Within all multi-pen sites there were clear patterns of distribution and infection along the main water current gradient with the abundance of lice in end pens at each site appearing to be different from the central pens. The vertical distribution pattern of free swimming L. salmonis larvae (nauplii and copepodids) showed that the surface 6 m harboured 85.5 ± 1.6 % of the lice present in the water body analysed (0 – 12 m depth), irrespective of sampling date and location. In Chapter 3, further environmental effects / influences on attachment success of the copepodids were analysed using controlled infection challenges. A flume with adjustable flow rates, and controlled light conditions was designed for this study. Flume current velocity was observed to be a significant factor in infection success, with higher infection levels observed at lower current velocities, while higher current velocities were demonstrated to reduce settlement success. At fixed velocity, higher copepodid exposure levels gave rise to higher infection levels, this having a linear relationship suggestive of a lack of competitive effects for space on the fish. Light was also shown to play an important role in host settlement. A positive correlation between increasing light intensity and higher louse attachment success was found for all tested light spectra / wavelengths (white - Halogen, blue 455 nm, green 530 nm and red 640 nm). Observation of an infecting cohort of copepodids showed maximal infection at four days post-moulting with a tail-off of infection by six days post-moulting. However, even under the optimal conditions represented by a flume challenge, including linear water flow, the constraint of copepodids to pass close to the salmon host and the very high exposure levels of copepodids per fish, louse attachment success was still relatively low. Chapter 4 examined implementation of a possible management approach based upon some of the environmental influences observed. This chapter described a study in which environmental manipulation of salmon swimming depth was employed on-site in an attempt to reduce farm infection of Atlantic salmon. The effects of submerged artificial lighting in combination with submerged feeding were tested with respect to salmon swimming depth and sea lice infection, following the hypothesis that L. salmonis infection in a commercial salmon population could be reduced through exposure to deep lighting and feeding. The results of the study suggest that swimming depth manipulation can indeed be used at a commercial scale to reduce salmon lice burdens on Atlantic salmon by physically minimising spatial interactions between the two animals. In the final research chapter (Chapter 5), this thesis examines the question of whether ploidy of the host impacts on sea louse infection levels and whether susceptibility of individual fish is consistent between replicate infections. Results showed that triploid salmon are not subject to higher sea louse infection levels under experimental challenge and farm infection conditions compared to diploid hosts. In addition, triploid fish subject to initial infection, did not become more or less resistant to infection compared to diploids when comparing repeated sea louse infections. In summary, this thesis describes work conducted to analyse key infection pathways and factors influencing infection of Atlantic salmon by sea lice and suggestions made as to how findings may be exploited to reduce louse burdens in Atlantic salmon farming. The practical solutions presented to exploit the results found in this work are currently under consideration by the Scottish salmon industry.
44

Migration and quality of landlocked Atlantic salmon smolt : Implications for conservation and management

Norrgård, Johnny R January 2014 (has links)
Atlantic salmon Salmo salar has a complex life cycle, including long migrations and habitat shifts for both juveniles and adults. As such, salmon populations are vulnerable to habitat degradation and fragmentation along their migratory routes. This makes management and conservation a complex task requiring knowledge of salmon ecology at different temporal and spatial scales. In this thesis I highlight the use of a holistic life-history based approach in the conservation and management of wild and hatchery-reared salmon in regulated rivers and lakes. Small populations of wild-reproducing landlocked salmon and trout Salmo trutta exist in the regulated River Klarälven, Sweden. Since the 1930s, transportation of adult spawners upstream of eight dams has given the fish access to spawning grounds. The number of returning wild spawners became critically low in the 1960s, but stocking of hatchery smolts resulted in an increase in spawners that continues today. My data show that wild smolt may suffer high mortality due to multiple dam passages. To ensure viable populations of wild populations, future management should include both up- and downstream solutions that ensure connectivity in the system. The recreational and commercial salmonid fishery are maintained by compensatory stockings, yielding annual catches of about 75 tons, and a river return rate of hatchery fish of about 1%. As a large portion of the stocked smolts does not survive downstream migration to the lake, there has been discussion about the quality of the stocked smolt and about stocking strategies. Based on my studies, producing hatchery smolts more closely resembling wild-born conspecifics should result in reduced loss rates. I suggest changes in the hatchery and stocking procedures to increase the survival of stocked smolts. The results of my research should be applicable to other regulated systems, particularly those with mixed stocks of wild and hatchery salmonid populations. / Atlantic salmon Salmo salar has a complex life cycle, including long migrations and habitat shifts for both juveniles and adults. As such, salmon populations are vulnerable to habitat degradation and fragmentation along their migratory routes, which make management and conservation a complex task requiring knowledge of salmon ecology at different temporal and spatial scales. In this thesis, I highlight the use of a holistic approach in the conservation and management of wild and hatchery-reared salmon in regulated rivers and lakes. Small populations of wild-reproducing landlocked salmon and trout Salmo trutta exist in the regulated River Klarälven, Sweden. Since 1930, transportation of adult spawners upstream of eight dams has been done to give the fish access to the spawning grounds. My data indicate that a large proportion of the wild smolts are lost due to multiple dam passages, and future management should include both up- and downstream solutions, ensuring connectivity in the system. The fishery in Klarälven and Lake Vänern is maintained by compensatory stockings, yielding catches of about 75 metric tons and a river return rate of stocked fish of about 1%. I suggest changes in the hatchery and stocking procedures to increase the survival of stocked smolts.
45

Sveriges Kommuner och Landsting (SKL) – en postkorporativ kvarleva eller en kvasistatlig hybrid? : En undersökning av SKL:s roll och inflytande i två politiska beslutsprocesser / The Swedish Association of Local Authorities and Regions (SALAR) – a post-corporatist remnant or a quasigovernment hybrid? : A survey of SALAR’s role and influence in two policy processes

Rönnberg, Nico January 2019 (has links)
The aim of this thesis is to study the role and the influence of the Swedish local government association, SALAR, which is an interest group representing all of the Swedish local authorities and regions. As a result of a change in exercising public power from government to multi-level governance that has reinforced subnational level, including local authorities and regions, SALAR is today a significant actor. It has an intermediating role in the relation between the government and local and regional authorities. SALAR is a hybrid organization that has interest group and governmental characteristics. It is a player competing with other interest groups in a pluralistic system but it is also a corporatist negotiation partner of the government that has a privileged access to central government decision-making. This study uses a comparative case study method analyzing two policy processes to study and describe what kind of role and influence SALAR has in these processes and how the role and the influence of SALAR can be understood from an interest group perspective and a multi-level governance perspective. The described and analyzed policy processes are Kömiljarden, an effectivity effort in Swedish public health care system, and the introduction of the teacher license system in Swedish schools. The empirical material used in this thesis consists of official publications published by public authorities, the parliament and the government as well as interviews with officials representing public authorities, the government and SALAR. The results presented in this thesis show that SALAR in line with previous research on local government associations in other countries, has a role as an intermediator with a privileged access to central government and central decision-making. It is a partner that central government negotiates with and which has the task of informing about the local and regional circumstances. Its influence can also be analyzed in connection to these negotiations. SALAR is in many ways stuck in the structure of decision-making, which is operated by central government while still being in competition with interest groups, such as the teacher unions.
46

DNA extraction comparisons between  fresh and boiled Atlantic Salmon (S. salar) tissues.

Bernal, Victoria January 2019 (has links)
Barcode identification is a method that uses genetic information to differentiate species. Because of its general versatility it can be applied to contexts from archaeology to the food industry. Atlantic salmon (Salmo salar) is a fish species commonly hunted in modern times and has been found in archaeological settings. However, barcoding requires enough quality DNA for amplification and abiotic exposure tends to degrade it. High temperatures, such as when boiling, can diminish DNA quality. The extent of DNA degradation between fresh and boiled tissues and whether all tissues retain the same amount of DNA is unclear. In this study DNA was extracted from S. salar tissues fins, muscle, bones and scales without treatment and with boiling treatment. DNA concentrations between fresh and boiled bones were not significantly different, nor were comparisons between samples with the same treatments. Muscles had higher DNA concentrations when boiled and fins had higher when fresh. These findings show that regarding certain tissue types can be expected to better retain DNA concentrations after boiling.
47

Transição nutricional em comunidades indígenas do Salar de Atacama, norte do Chile: uma abordagem biocultural das mudanças na dieta e nutrição atacamenha / Nutritional transition in indigenous communities of the Atacama Salt, Northern Chile: a biocultural approach of changes in Atacamenian diet and nutrition

Cerda, Tamara Andrea Pardo 11 December 2014 (has links)
As comunidades indígenas localizadas no de Atacama têm experimentado uma serie de mudanças nos padrões de consumo alimentar como consequência de aceleradas mudanças econômicas, sociais e culturais. Estas mudanças tem contribuído em um paulatino abandono das práticas tradicionais de produção de alimentos, assim como uma rápida incorporação de produtos industrializados na dieta atacamenha. No entanto, não existem estudos que diagnostiquem as mudanças nos padrões de dieta e seu possível impacto nas condições nutricionais dessas populações, em um contexto de mudanças consideráveis a nível local e mundial na dieta e nutrição. Esta pesquisa tem como objetivo identificar as mudanças das práticas alimentares ocorridas durante as últimas três gerações nas comunidades atacamenhas de Toconao e Talabre, assim como avaliar as mudanças no estado nutricional da população adulta nas últimas décadas nestas comunidades. A coleta de dados se realizou utilizando a conjugação de métodos qualitativos e quantitativos. No primeiro caso, foram realizadas entrevistas semi-estruturadas com as pessoas de maior idade de cada comunidade para nos aproximarmos às mudanças desde uma perspectiva local e histórica. Também foram realizadas listagens livres em três gerações para visualizar as preferencias alimentares geracionais. No segundo caso, foram coletadas medidas antropométricas de peso, estatura e Índice de Massa Corporal (IMC) registradas nas fichas clinicas do posto de saúde local, incluindo indivíduos adultos (entre 18 até 90 anos) das comunidades de Toconao e Talabre. Os resultados evidenciam drásticas diferencias no consumo de alimentos entre as três gerações dos atacamenhos de ambas as comunidades, com perda no consumo de alimentos tradicionais por parte das novas gerações devido à substituição de alimentos locais por alimentos forâneos na dieta atacamenha de Toconao e Talabre. Os dados nutricionais apresentam um aumento significativo da estatura ao longo das décadas como resultado de uma maior disponibilidade de alimentos processados e ultraprocessados. O relato histórico obtido das entrevistas semi-estruturadas permitiu uma compressão mais integral das aceleradas mudanças acontecidas nas últimas décadas na dieta e nutrição atacamenha das comunidades de Toconao e Talabre. A partir desta pesquisa se conclui que fatores econômicos e políticos tem contribuído a esta rápidas transformações nos sistemas de subsistência e, consequentemente, na dieta e nutrição destas comunidades indígenas / Native communities from Atacama desert have experienced several changes in their dietary patterns as a consequence of fast economic, social and cultural changes. These changes have contributed in a gradual abandonment of traditional food production activities as well as rapid adoption of industrialized food in their diet. However, there are no studies that provide a diagnosis of these changes of the dietary patterns and their potential impact in the nutritional state of the aforementioned native communities in a context of considerable changes of local and worldwide diet and nutrition. Thus, the goals of this research are to identify the changes in the dietary patterns occurring during the last three generations of the Atacama communities of Toconao and Talabre, and to evaluate the changes of the nutritional state of the adult population at last decades of both communities. The data collection was done using a combination of qualitative and quantitative methods. In the first case, semi-structured interviews with the elderly of each community was performed in order to obtain an approximation to the dietary changes from a local and historical perspective. Additionally, free lists will be performed in people from three generations in order to visualize dietary preferences by generations. In the second case, antropometric measures of weight, height and body mass index was collected of the clinical records in the local heath center, including adults (between 18 to 90 years old) of the Toconao and Talabre communities. The results show drastic differences in food consumption between the three generations of both Atacama communities, with a loss in the consumption of traditional foods by the younger generations due to the substitution of local food for foreign food in the Atacama diet of Toconao and Talabre. From this research it is concluded that economic and political factors have contributed to this rapid change in subsistence systems and, consequently, in the diet and nutrition of these indigenous communities
48

Transição nutricional em comunidades indígenas do Salar de Atacama, norte do Chile: uma abordagem biocultural das mudanças na dieta e nutrição atacamenha / Nutritional transition in indigenous communities of the Atacama Salt, Northern Chile: a biocultural approach of changes in Atacamenian diet and nutrition

Tamara Andrea Pardo Cerda 11 December 2014 (has links)
As comunidades indígenas localizadas no de Atacama têm experimentado uma serie de mudanças nos padrões de consumo alimentar como consequência de aceleradas mudanças econômicas, sociais e culturais. Estas mudanças tem contribuído em um paulatino abandono das práticas tradicionais de produção de alimentos, assim como uma rápida incorporação de produtos industrializados na dieta atacamenha. No entanto, não existem estudos que diagnostiquem as mudanças nos padrões de dieta e seu possível impacto nas condições nutricionais dessas populações, em um contexto de mudanças consideráveis a nível local e mundial na dieta e nutrição. Esta pesquisa tem como objetivo identificar as mudanças das práticas alimentares ocorridas durante as últimas três gerações nas comunidades atacamenhas de Toconao e Talabre, assim como avaliar as mudanças no estado nutricional da população adulta nas últimas décadas nestas comunidades. A coleta de dados se realizou utilizando a conjugação de métodos qualitativos e quantitativos. No primeiro caso, foram realizadas entrevistas semi-estruturadas com as pessoas de maior idade de cada comunidade para nos aproximarmos às mudanças desde uma perspectiva local e histórica. Também foram realizadas listagens livres em três gerações para visualizar as preferencias alimentares geracionais. No segundo caso, foram coletadas medidas antropométricas de peso, estatura e Índice de Massa Corporal (IMC) registradas nas fichas clinicas do posto de saúde local, incluindo indivíduos adultos (entre 18 até 90 anos) das comunidades de Toconao e Talabre. Os resultados evidenciam drásticas diferencias no consumo de alimentos entre as três gerações dos atacamenhos de ambas as comunidades, com perda no consumo de alimentos tradicionais por parte das novas gerações devido à substituição de alimentos locais por alimentos forâneos na dieta atacamenha de Toconao e Talabre. Os dados nutricionais apresentam um aumento significativo da estatura ao longo das décadas como resultado de uma maior disponibilidade de alimentos processados e ultraprocessados. O relato histórico obtido das entrevistas semi-estruturadas permitiu uma compressão mais integral das aceleradas mudanças acontecidas nas últimas décadas na dieta e nutrição atacamenha das comunidades de Toconao e Talabre. A partir desta pesquisa se conclui que fatores econômicos e políticos tem contribuído a esta rápidas transformações nos sistemas de subsistência e, consequentemente, na dieta e nutrição destas comunidades indígenas / Native communities from Atacama desert have experienced several changes in their dietary patterns as a consequence of fast economic, social and cultural changes. These changes have contributed in a gradual abandonment of traditional food production activities as well as rapid adoption of industrialized food in their diet. However, there are no studies that provide a diagnosis of these changes of the dietary patterns and their potential impact in the nutritional state of the aforementioned native communities in a context of considerable changes of local and worldwide diet and nutrition. Thus, the goals of this research are to identify the changes in the dietary patterns occurring during the last three generations of the Atacama communities of Toconao and Talabre, and to evaluate the changes of the nutritional state of the adult population at last decades of both communities. The data collection was done using a combination of qualitative and quantitative methods. In the first case, semi-structured interviews with the elderly of each community was performed in order to obtain an approximation to the dietary changes from a local and historical perspective. Additionally, free lists will be performed in people from three generations in order to visualize dietary preferences by generations. In the second case, antropometric measures of weight, height and body mass index was collected of the clinical records in the local heath center, including adults (between 18 to 90 years old) of the Toconao and Talabre communities. The results show drastic differences in food consumption between the three generations of both Atacama communities, with a loss in the consumption of traditional foods by the younger generations due to the substitution of local food for foreign food in the Atacama diet of Toconao and Talabre. From this research it is concluded that economic and political factors have contributed to this rapid change in subsistence systems and, consequently, in the diet and nutrition of these indigenous communities
49

After Lithium: Reclamation Strategies for Salar de Uyuni, Bolivia

Rayle, Derek 18 June 2018 (has links)
116 pages / This project uses interview responses from local, impacted people to explore the future landscape of the Lithium Pilot Plant in Salar de Uyuni, Bolivia, as its development responds to the rise and fall of global lithium demand. As technology changes, so do the materials that support it. Recent research suggests that lithium could become obsolete in the next fifty years despite current trends towards lithium-ion based technology. Such as shift could leave mass quantities of mining remnants and would constitute the next step in a continuous history of Bolivian resource exploitation. This project explores a speculative future scenario where solutions for the gradual transition from current mining practices constructively deal with mining waste and prepare the study area for a post-mining era. Through this exploration, the project deviates from more standard approaches to mined landscape reclamation, which conceive of returning the landscape to its original state. The overarching premise is that, if a reclamation program framework is established, it could permit the territory to transition to alternative, productive uses. Based on several local interviews and my personal evaluations about the future land use and cover classes, I developed a reclamation program for the study area depicted in a 2070 scenario master plan. The proposal establishes a new economy of infrastructure tourism in the region, using agriculture, energy production and celestial movements in a new form of territorial restructuring.
50

Avaliação da resposta imunológica envolvida em transplante de células germinativas de Salmão do Atlântico (Salmo salar) em Truta arco-íris (Oncorhynchus mykiss) / Evaluation of the immune response in transplantation of germ cells from Atlantic Salmon (Salmo salar) to rainbow trout (Oncorhynchus mykiss)

Sousa, Erika Zolcsak de 23 August 2018 (has links)
Devido ao consumo predatório e ao risco inerente de extinção de várias espécies de peixes, pesquisadores têm buscado técnicas alternativas de reprodução para viabilizar tanto o cultivo como a conservação ex situ. Os transplantes xenogênicos de gônadas representam uma técnica reprodutiva inovadora e já existem resultados promissores em diversas espécies de mamíferos, aves, insetos e também de peixes. No entanto, a baixa eficiência na geração de gametas alógenos consiste em uma das limitações desta técnica. Um dos possíveis motivos seria o desencadeamento de reações de rejeição por parte do hospedeiro, comum em transplante de órgãos e tecidos humanos. Dentro deste contexto, visamos identificar e avaliar a interferência destes mecanismos durante o processo de enxerto de gônada de truta arco-íris entre linhagens diferentes e salmão do Atlântico, identificando possíveis graus de respostas imunológicas utilizando enxertos autógenos, isógenos, alógenos e xenógenos. Tais avaliações foram feitas pela análise histopatológica dos tecidos transplantados e dos locais dos implantes. Com os resultados obtidos, pudemos avaliar que a resposta imunológica em implantes de tecidos alogênicos e xenogênicos é bem evidente. Já no enxerto de células germinativas dissociadas houve apenas um discreto processo inflamatório em todas as variações dos enxertos, o que pode representar uma adaptação técnica viável e mais eficaz para a obtenção de gametas. / Due the predatory consumption and the inherent risk of extinction of various species of the fish, investigate the alternatives of reproduction to make viable the cultivation as an ex situ. Xenogeneic transplants of gonads represent an innovative reproductive technique and those that can already be found in various species of animals, birds, insects and fish. However, a low efficiency in the range of allogenic gametes is one of the limitation of this technique. A probable cause would be related to an immune response process that would lead to rejection of the transplanted tissue, as observed in organs and tissues transplantation in human. In this context, we aimed to identify and to evaluate the presence of immune rejection mechanisms during the process of gonads tissues transplantation among different rainbow trout lineages and to Atlantic salmon, observing possible response degrees according to the nature of the graft: autogenic, isogenic, allogeneic or xenogeneic transplantations. Histopathological analysis of the transplanted tissues and of the implanted sites were conducted. Results showed a clear evidence of an immune response in allogeneic and xenogeneic implants. Dissociated gonad cells grafts showed a discrete inflammatory process disregarding the graft nature, that may be an indication of a feasible and more efficient technique adaption to obtain viable gametes.

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