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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.
241

Impacto de la zona no saturada en el transporte de metales pesados y compuestos de nitrógeno (amonio, nitritos, y nitratos), en el área industrial de Bahía Blanca

Scherger, Leonardo Ezequiel 01 July 2022 (has links)
El crecimiento de las actividades industriales en el área costera del Estuario de Bahía Blanca ha provocado consecuencias negativas relacionadas con la contaminación de los recursos suelo y agua superficial y subterránea. La investigación de la zona no saturada (ZNS) del sitio comprende una herramienta fundamental en el diseño de políticas de protección de los recursos hídricos, ya que ésta conforma una barrera natural contra las sustancias potencialmente contaminantes que son transportadas hacia el acuífero freático. La presente tesis tiene como finalidad contribuir a la comprensión del transporte de sustancias potencialmente contaminantes como metales pesados y compuestos de nitrógeno (amonio, nitritos y nitratos), dentro del ámbito de la ZNS, haciendo hincapié en los procesos físicos y químicos que ocurren en dicha zona. La metodología se basó en recopilación bibliográfica y antecedentes del área de estudio y diversas tareas de campo, laboratorio y gabinete. Para los trabajos de campo se acondicionó una parcela experimental, equipada con dos juegos de tensiómetros y un pozo somero con una sonda freatimétrica de registro continuo. En la misma se relevaron datos hidrológicos, muestreo de material sedimentario, determinación de la conductividad hidráulica saturada y no saturada, y ensayos de transporte de compuestos de nitrógeno. En laboratorio, se caracterizaron los materiales recolectados mediante análisis granulométricos, mineralógicos, determinación de la humedad volumétrica, densidad aparente y porosidad y caracterización química (contenido de carbonato de calcio, carbono orgánico total, hierro total y pH). Para estudiar el transporte de sustancias se realizaron ensayos in situ con aplicación de fertilizante urea y agua amoniacal y ensayos de laboratorio en batch de cinética e isotermas de adsorción-desorción de cadmio (Cd). En gabinete, se analizaron las características hidrometeorológicas e hidrodinámicas de la ZNS y su relación con la zona saturada (ZS). Sobre la base del modelo conceptual de funcionamiento del sistema no saturado se construyó un modelo numérico y se simuló el transporte de sustancias en el medio poroso estudiado. La ZNS, en la parcela experimental, presentó un espesor variable de aproximadamente 2 m±20 cm. Aunque el balance hidrológico para el área de estudio es deficitario (serie 2010-2019), el registro piezométrico evidencia la ocurrencia del proceso de recarga durante todo el año. Las tasas de recarga se estiman en el rango del 12% al 18% de las precipitaciones, aunque pueden superar el 20% durante años lluviosos o tornarse mínimas en años secos. Los flujos hídricos verticales en la ZNS son mayormente en sentido ascendente, predominando fuerzas capilares sobre la componente gravitatoria. El flujo de agua se torna descendente luego de precipitaciones de gran cuantía. Según los datos de infiltrometria, los mesoporos y los microporos del suelo canalizan la mayor proporción de agua infiltrada. Los macroporos sólo participan en el 15,9% del flujo total de agua. La calibración de un modelo numérico (HYDRUS 2D/3D) permitió representar correctamente el comportamiento hidrodinámico de la ZNS. Se cuantificó la retención de cadmio (Cd) en tres niveles del subsuelo de la parcela experimental. La afinidad del Cd por los niveles analizados fue en el orden: franco limoso (220 cm) > franco arenoso (30 cm) > arena (150 cm). La desorción de Cd alcanzó el 52%, 76% y 5% del metal preadsorbido para los sedimentos de 30 cm, 150 cm y 220 cm, respectivamente. Los sedimentos franco limosos (220 cm) presentan mayor capacidad de retención y también los sitios de unión más fuertes. El proceso de quimisorción en este nivel podría explicarse por la interacción del metal con minerales arcillosos como montmorillonita, oxi-hidróxidos de Fe y materia orgánica. En los sedimentos superiores (30 cm), la calcita presenta un papel importancia en la retención del metal, tras reconocerse la presencia de otavita (CdCO3) luego de la exposición de los sedimentos a una solución enriquecida en Cd. Los sedimentos arenosos (150 cm) presentaron una débil unión entre el Cd y las superficies reactivas. Esto es explicado por la interacción del metal con minerales aluminosilicatos. Se aplicó un modelo numérico capaz de simular el transporte de Cd ante un evento hipotético de ingreso del metal por deposición atmosférica. En base al modelo numérico la carga metálica acumulada en los horizontes superficiales del suelo, no representarían un peligro de contaminación potencial para el suelo y agua subterránea. Las experiencias de campo de transporte de compuestos de nitrógeno (N) permitieron identificar los principales impactos producidos por el vertido de soluciones enriquecidas en N amoniacal y urea. La cantidad de soluto afectado por volatilización se encontró en el rango del 7-8% para fuente urea y del 24- 25% para N amoniacal. En la parcela donde se regó con agua amoniacal, el N amoniacal predominó sobre el nitrato. En cambio, un mayor aporte de N en forma de urea condujo a una mayor concentración de nitratos y acidificación en la capa superior del suelo, ambos indicadores del proceso de nitrificación. Se utilizó el código HYDRUS 2D/3D para simular las experiencias de transporte de compuestos de N realizadas en la parcela experimental. Para fuente urea, una vez ocurrido el proceso de hidrólisis, la mayor parte del N amoniacal en el suelo es nitrificado en nitritos, y luego se transforma en nitratos. En el caso de fuente agua amoniacal, el proceso que tiene más relevancia en el destino final del producto es la volatilización. Bajo pH alcalinos, la forma de N amoniacal predominante es el N-NH3, compuesto que es fácilmente volatilizado a la atmósfera en forma gaseosa, aunque en forma soluble (NH4OH) puede presentar gran movilidad en el suelo, debido a la minimización de los efectos de retardo y degradación del compuesto. Si existieran grandes deposiciones de N amoniacal en superficie o aún como perdidas subterráneas en el subsuelo, la peligrosidad de degradación del acuífero freático es sumamente alta. La presencia de carga hidráulica positiva aumenta en gran medida la generación de lixiviados, como así también influencia las especies de N que alcanzarían el agua subterránea. La identificación y cuantificación de los procesos fuente-sumidero que sufren tanto los metales pesados como los compuestos de nitrógeno, resultan fundamentales en la definición de los lineamientos básicos para la ejecución de medidas de protección o remediación adaptadas al suelo y agua subterránea del área de estudio. / The expansion of industrial activities in the coastal area of the Bahía Blanca Estuary has provoked a series of negative consequences related to the contamination of soil and surface and groundwater. The investigation of unsaturated zone (UZ) at this site is a fundamental tool for the design of protection policies for water resources. The UZ is a natural barrier, against potentially polluting substances that are transported to the phreatic aquifer. The aim of this thesis is to contribute to the understanding of potentially polluting substances such as heavy metals and, nitrogen compounds (ammonium, nitrites, and nitrates) transport in the UZ, with emphasis on the physical and chemical processes that occurs in this media. The methodology was based on bibliographic compilation of background antecedents and diverse field, laboratory, and cabinet tasks. For field work, an experimental plot was equipped with two sets of tensiometers, and a shallow well with a continuous phreatimetric recorder. The main field tasks consisted of hydrological data collection, sedimentary material sampling, determination of saturated and unsaturated hydraulic conductivity, and nitrogen compounds transport essays. In laboratory, the sample sediments were characterized by granulometric and mineralogical analyses, determination of volumetric soil moisture, bulk density and porosity, and chemical properties (calcium carbonate, total organic carbon, total iron, and pH). Solute transport was study be means of field tests by application of urea fertilizer and ammonia solutions in experimental plots and laboratory kinetics and isothermal batch tests for cadmium (Cd) adsorption-desorption studies. In cabinet, the hydrometeorological and hydrodynamic characteristics of the UZ were analyzed and its relationship with the saturated zone (SZ). Based on the conceptual model of the unsaturated porous media, a numerical model was built, and the transport of solutes was simulated. The UZ in the experimental plot presented a variable thickness of approximately 2 m±20 cm. Although the hydrological balance for the study area is deficient (2010-2019 series), the piezometric record evidenced the occurrence of recharge throughout the year. Recharge rates were estimated in the range of 12% to 18% of precipitation, although it can exceed 20% during rainy years or become minimal in dry years. Vertical water flows in the UZ were mostly upward, with capillary forces predominating over the gravitational component. Water flow becomes downward only after heavy precipitations. According to infiltrometer essays, soil mesopores and micropores channeled the greatest proportion of water flux. Macropores only participate in 15.9% of total water flux. The calibration of a numerical model (HYDRUS 2D/3D) allowed to correctly represent the hydrodynamic behavior of the UZ. Cadmium (Cd) retention was analyzed in three subsoil layers of the experimental plot. The affinity of Cd for the analyzed sediments was in the order: silt loam (220 cm) > sandy loam (30 cm) > sand (150 cm). Cd desorption reached 52%, 76% and 5% of the pre-adsorbed metal for the 30 cm, 150 cm, and 220 cm depths, respectively. This result confirmed the quality of silt loam for Cd retention, being the layer with the highest retention capacity and the one with the strongest binding sites. Chemisorption process at this layer could be explained by the interaction of cadmium with clay minerals such as montmorillonite, Fe oxy-hydroxides and organic matter. For the upper layer (30 cm), calcite plays an important role in the retention of Cd, as the presence of otavite (CdCO3) was recognized after the exposure of sediments to a Cd enriched solution. The sandy sediments (150 cm) presented the weakest binding between Cd and reactive soil surfaces. This is explained by the interaction of the metal with aluminosilicate minerals. A numerical model was applied to simulate the transport of Cd in the UZ for a hypothetical event of metal input by atmospheric deposition. Based on simulations, the metallic load accumulated in the surface soil would not represent a potential contamination risk for soil and groundwater. Field experiments of nitrogen (N) transport in the UZ were carried out to identify the main effects produced in the soil by discharge of enriched solutions of ammoniacal N and urea fertilizer. The amount of solute affected by volatilization was found to be in the range of 7-8% for urea and 24-25% for ammoniacal N sources. For the ammoniacal N source, ammoniacal N predominated over nitrate. Otherwise, a higher N input in the form of urea led to higher nitrate concentration and acidification in the topsoil, both indicators of nitrification process. The HYDRUS 2D/3D software was used to simulate the transport of N compound in the experimental plot based on field experiments. For urea source, once hydrolysis process has occurred, most of the ammoniacal N is nitrified into nitrites, and then transformed into nitrates. In the case of ammoniacal N source, the process that has more relevance in the fate of the product is volatilization. Under alkaline conditions, the predominant form of ammoniacal N is N-NH3, a compound that is easily volatilized to the atmosphere in gaseous form, although in soluble form (NH4OH) it can be highly mobile in the soil, due to the minimization of retardation and degradation processes. If high amounts of ammoniacal N are discharge on the soil surface or as underground leakages, the risk of degradation of the phreatic aquifer is extremely high. The presence of positive hydraulic load greatly increases leachate generation, as well as influence the type of N species that reach groundwater. The identification and quantification of processes that both heavy metals and nitrogen compounds undergo in the UZ are fundamental for defining the basic guidelines for the implementation of protection or remediation actions adapted to soil and groundwater conditions in the study area
242

Studium proteinů spermií různých savčích druhů / Study of sperm proteins in different mammalian species

Pohlová, Alžběta January 2016 (has links)
Reproduction is an essential feature of all animals and a fundamental step to produce new generations. Study of sperm proteins is crucial for understanding of the sperm-egg recognition. We searched out sperm surface proteins involving in the zona pellucida (ZP) binding and studied whether these proteins are preserved throughout mammalian species. Indirect immunofluorescent technique was used to test a panel of monoclonal antibodies prepared against boar sperm surface proteins on spermatozoa of bull and mice. We found a cross-reactivity of some antibodies against boar sperm with bull ejaculated and mouse epididymal spermatozoa. Further, we isolated sperm proteins from different mammalian species, such as pig, bull, dog, cat, mouse and human. Proteins were separated by SDS- electrophoresis and protein/glycoprotein profiles from epididymal, ejaculated and in vitro capacitated sperm were compared. The interaction of sperm with ZP was studied on electrophoretically-separated sperm surface proteins from pig and bull with biotin-labeled ZP glycoproteins. Antibodies, which reacted with boar sperm surface proteins with ZP- binding activity, therefore could be potential egg-binding receptors, were used for monitoring of the sperm protein origin in reproductive fluids and tissues. (In Czech) Keywords: sperm...
243

Negócios e participação política: fazendeiros da Zona da Mata de Minas Gerais (1821-1841) / Business and political participation: the lanlords of Zona da Mata de Minas Gerais (1821-1841)

Rezende, Irene Nogueira de 24 June 2008 (has links)
Este trabalho tem como objetivo demonstrar que os proprietários da parte norte da Zona da Mata mineira também tiveram sua participação na construção do Estado nacional. A partir de um conjunto documental formado por inventários, testamentos, listas de eleitores, jornais de época e listas nominativas estudamos as bases econômicas e materiais de um grupo de fazendeiros nos meados do século XIX, avaliando concomitantemente sua participação política na configuração dos poderes provinciais e no âmbito mais amplo do Estado monárquico. O espaço geográfico escolhido foi uma parcela da zona da Mata norte, mais precisamente, a região que inclui as cidades de Barra Longa, Viçosa e Ponte Nova. O recorte temporal foi estabelecido entre 1821 e 1841. / This work tries to demonstrate that the landlords from the north side of the \"Zona da Mata Mineira\" had their share in the construction of the Brazilian National State. Their economic and political powers as well as their participation on politics are analyzed through data obtained from inventories, wills, lists of voters and census lists. The context is the region of Barra Longa, Viçosa and Ponte Nova in the period from 1821 to 1841.
244

Agudeza visual baja según residir en una ciudad rural del norte del Perú: estudio de casos y controles

Vilela Estrada, Martín A., Araujo Chumacero, Mary M., Solano Zapata, Fiorela E., Dávila Adrianzén, Aarón, Mejia, Christian R. 06 1900 (has links)
Introduction In Peru, there are few studies which show that they might be a difference between school children in rural areas and the ones from non-rural areas, this is necessary because it has been shown that the place of residence is an influential exogenous factor in the development of low visual acuity. Likewise, the influence of environment on the development of visual errors and low visual acuity has been demonstrated. Methodology Case-control study between child population of an urban and a rural area (Piura and Joras); prior informed consent of their parents. The primary variable was the visual acuity, qualified with the principles of Snellen (sensitivity 85%, specificity 96%) 20/0 was considered as optimal and normal visual acuity was considered to 20/25. Values below were low visual acuity. Results 1,094 were surveyed. 50.0% (488) were female, and the median age was 9 years (interquartile range: 7-10 years). 22.6% (221) of the children had low visual acuity. In bivariate analysis, the age of children (p = .001), the degree coursing (p <.001) and city of residence (p = .005) were associated with low visual acuity of children. The multivariate analysis found that non-rural children had 1.55 (95% CI: 1.14 to 2.11, p-value = .005) more chances of having low visual acuity, adjusted for sex, age and degree academic growth of children. Conclusions It is concluded that children living non-rural residences have more low visual acuity in the northern Peru. / Revisión por pares
245

Negócios e participação política: fazendeiros da Zona da Mata de Minas Gerais (1821-1841) / Business and political participation: the lanlords of Zona da Mata de Minas Gerais (1821-1841)

Irene Nogueira de Rezende 24 June 2008 (has links)
Este trabalho tem como objetivo demonstrar que os proprietários da parte norte da Zona da Mata mineira também tiveram sua participação na construção do Estado nacional. A partir de um conjunto documental formado por inventários, testamentos, listas de eleitores, jornais de época e listas nominativas estudamos as bases econômicas e materiais de um grupo de fazendeiros nos meados do século XIX, avaliando concomitantemente sua participação política na configuração dos poderes provinciais e no âmbito mais amplo do Estado monárquico. O espaço geográfico escolhido foi uma parcela da zona da Mata norte, mais precisamente, a região que inclui as cidades de Barra Longa, Viçosa e Ponte Nova. O recorte temporal foi estabelecido entre 1821 e 1841. / This work tries to demonstrate that the landlords from the north side of the \"Zona da Mata Mineira\" had their share in the construction of the Brazilian National State. Their economic and political powers as well as their participation on politics are analyzed through data obtained from inventories, wills, lists of voters and census lists. The context is the region of Barra Longa, Viçosa and Ponte Nova in the period from 1821 to 1841.
246

Influência de sistemas meteorológicos de grande escala sobre a distribuição de raios na Amazônia Oriental, com aplicação no setor elétrico

SANTOS, Alex de Assis Santos dos January 2010 (has links)
Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2015-08-10T17:05:33Z No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_InfluenciaSistemasMeteorologicos.pdf: 2592577 bytes, checksum: b8aa11439bcd02781bf7d7a0d5acf2c8 (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2015-08-17T12:32:55Z (GMT) No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_InfluenciaSistemasMeteorologicos.pdf: 2592577 bytes, checksum: b8aa11439bcd02781bf7d7a0d5acf2c8 (MD5) / Made available in DSpace on 2015-08-17T12:32:55Z (GMT). No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_InfluenciaSistemasMeteorologicos.pdf: 2592577 bytes, checksum: b8aa11439bcd02781bf7d7a0d5acf2c8 (MD5) Previous issue date: 2010 / REDE CELPA - Centrais Elétricas do Pará / Foi feito um estudo da associação entre a densidade de ocorrência de raios com condições meteorológicas no leste da região Amazônica entre os anos de 2006 a 2008. A região estudada foi limitada por uma grade geográfica entre as latitudes 0º a -10º e longitudes -53º a -43º. Foram desenvolvidos métodos computacionais de processamento estatístico e geração de mapas de ocorrências de raios para diferentes intervalos de tempo. Esses métodos foram aplicados para determinar os pontos de altas ocorrências de raios ao longo de linhas de transmissão de energia elétrica, a fim de oferecer subsídios para a proteção e operação dos sistemas elétricos da região. Foram utilizados dados da rede de detecção de raios do SIPAM para redimensionar a detecção do sistema de alcance intercontinental STARNET, e subsequentemente, foram obtidos mapas de densidade de raios mais uniformes e realistas. Esses mapas foram interpretados em períodos semanais e sazonais, considerando as observações simultâneas de chuva, vento, radiação de onda longa e a presença de sistemas meteorológicos de grande escala. Zona de Convergência Intertropical e Zona de Convergência do Atlântico Sul (ZCIT, ZCAS) definidos pela convergência de ventos e anomalias negativas de Radiação de Ondas Longas ( ROL). Os resultados mostraram boa correspondência entre as áreas de convecção e a intensa ocorrência de raios. Nas regiões de mais alta atividade elétrica atmosférica, foi observada ocorrência de convergência dos ventos e anomalias negativas de ROL, para situações de presença de ZCAS e ZCIT sobre a região. A atividade de raios também coincidiu, com algumas exceções, com áreas de maior precipitação em períodos semanais. Foi observado também que, durante um trimestre seco, os segmentos de linhas de transmissão de Mojú-Tailândia e Jacundá-Marabá apresentaram maior incidência de raios. O pico da densidade de raios chegou a 18 raios/km2/trimestre em alguns locais. Durante o trimestre chuvoso, a densidade geral de raios foi 86% maior e apresentou distribuição espacial mais uniforme quando comparada com um trimestre seco. Este estudo mostrou não somente como as características meteorológicas influenciaram na distribuição e quantidade raios, mas também que a elevada atividade de descargas elétricas na região deve ser uma preocupação importante para os sistemas de distribuição de energia elétrica e outras atividades humanas na Amazônia Oriental. / A study was made of the relationship between lightning occurrence density distribution and their associated meteorological conditions over an area in eastern Amazon region. In order to do that, special programs were developed to statistically process lightning data, as well as, to generate lightning occurrence density maps on a geographical grid, for different time intervals. Using these methods an application analysis was performed to determine “spots” of high lightning frequency of occurrences along electric power transmission lines, in order to offer subsidies for the protection and operation of these electric systems in the region. Lightning data from the Amazonian Protection System (SIPAM) lightning detection network were used to upgrade the detection efficiency of the intercontinental STARNET system, and obtain more uniform and realistic lightning density maps over the limits of 0º to -10º of latitude and -53º to -43º of longitude. These maps were interpreted at weekly and seasonal periods, considering the simultaneous observations of rainfall, wind, long wave radiation (LWR) and the presence of large scale, the Intertropical Convergence Zone and South Atlantic Convergence Zone (ITCZ, SACZ) meteorological systems, acting over the area of study. The results showed good correlation among the areas of intense convection, determined by the convergence of winds and negative LWR anomalies and high lightning activity both for ITCZ and SACZ configuration over the area. Lightning activity also coincided, with a few exceptions, with the areas of higher weekly precipitation. It was observed also that during a dry trimester the transmission lines segment of Mojú-Tailândia and Jacundá-Marabá presented significantly higher incidence of lightning over them. During a rainy quarter the lightning density of currences was, overall, 86% higher and more evenly distributed than during the equivalent drier period, over the area considered. Density maxima of lightning occurrences reached values of 18 events/km2/trimester, at some spot areas. This study showed not only the meteorological characteristics of some lightning producing systems but also the elevated regional lightning activity, which should be an important concern to the electric power distribution systems and other human activities in eastern Amazonia.
247

Molecular evolution of the carboxy terminal, the putative sperm-ZP binding site, of the zona pellucida 3 glycoprotein in old world murine rodents.

Swann, Christine A. January 2007 (has links)
In mammals, before fertilisation can occur, sperm have to bind to, and penetrate, the extracellular coat of the oocyte, the zona pellucida (ZP). In the laboratory mouse, which has been used as a model system for fertilization studies, sperm-ZP binding has been found to be mediated by a region near the carboxy terminal, encoded by exon 7 of the Zp3 gene. This region shows considerable interspecific sequence diversity in North American cricetid rodents, with some evidence of adaptive evolution, suggesting that this may contribute to species specific sperm-ZP binding. However, by contrast, in a preliminary study of three species of Australian murine rodents an identical protein sequence of the region encoded by exon 7 of Zp3 was found to be present. The aim of this present study was to determine the pattern of sequence diversity of this region in the most speciose subfamily of mammals, the murine rodents, and to obtain insight into the selective pressures involved in its evolution. For this, DNA was extracted from murine rodents of Africa, Eurasia, South-east Asia, New Guinea and Australia. The nucleotide and predicted amino acid sequence of exons 6 and 7 of Zp3 in 96 murine species from 14 divisions, as recently defined by Musser and Carleton (2005), was determined and compared. Generally, it was found that closely related species shared a highly similar ZP3 sequence. Maximum likelihood analyses of codon substitution models using representatives from 14 murine divisions, suggested that positive selection had occurred within only a few lineages at several different codon sites adjacent to, or within, the putative combining-site for sperm of ZP3. Positive selection was not evident when the analysis was restricted to the Australian taxa which showed low levels of both intra- and inter-generic sequence divergence. There was no good evidence that this region contributes to species specificity of sperm-ZP binding in these species. These findings thus suggest that the selective forces acting on the Zp3 exon 7 region during the evolution of the murine rodents have varied possibly due to a range of selective pressures not necessarily restricted to the prevention of hybridization. It seems unlikely, therefore, that the amino acid sequence of the exon 7 coding region contributes to species specificity of sperm-ZP binding within most of the lineages from this most speciose subfamily of eutherian mammals. / http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1294654 / Thesis(Ph.D.)-- School of Medical Sciences, 2007
248

Función del sistema plasminógeno-plasmina en la fecundación de ovocitos bovinos y porcinos

Grullón Yunén, Luis Alberto 13 December 2010 (has links)
El objetivo de este trabajo consistió en describir el papel del sistema plasminógeno/plasmina (PLG/PLA) en la fecundación bovina y porcina. Mediante fecundación in vitro, demostramos que la presencia de PLG ó PLA en el medio de coincubación de los gametos disminuía la penetración de los espermatozoides en los ovocitos y su unión a la zona pelúcida (ZP). Esta disminución no se debía a alteraciones de la funcionalidad espermática ni a cambios en la resistencia de la ZP a la proteolisis, sino a que la PLA provocaba la liberación de los espermatozoides adheridos a la ZP. Mediante inmunofluorescencia indirecta detectamos la presencia de PLG y sus activadores en la ZP y en el oolema de los ovocitos antes de la fecundación. Tras la fecundación, dicha presencia disminuyó o desapareció por completo, por lo que proponemos que el sistema PLG/PLA se activa durante la interacción espermatozoide-ovocito y contribuye a regular la polispermia. / The aim of this study was to describe the role of the plasminogen/plasmin system (PLG/PLA) in bovine and porcine fertilization. Through in vitro fertilization, we demonstrated that the presence of PLG or PLA in the incubation medium of gametes decreased penetration of oocytes and sperm binding to the zona pellucida (ZP). This decrease was not due to alterations in sperm function or changes in the ZP resistance to proteolysis, but the PLA caused the release of sperm previously bound to the ZP. By indirect immunofluorescence we detected the presence of PLG and its activators in the ZP and oolema of the oocytes before fertilization. After fertilization, this presence diminished or disappeared completely, so we propose that the PLG/PLA system is activated during sperm-oocyte interaction and contributes to the regulation of polyspermy.
249

Stereotactic functional procedures in the treatment of essential tremor

Sandvik, Ulrika January 2011 (has links)
Background: Essential tremor (ET) is the most common movement disorder. In cases resistant to pharmacological treatment, functional stereotactic neurosurgery can be an alternative. Lesional surgery has largely been replaced by deep brain stimulation (DBS). The current target of choice is the ventrolateral thalamus (Vim). Vim DBS has generally shown good results, but in some cases it is associated with a suboptimal effect as well as side effects. DBS in the posterior subthalamic area/caudal zona incerta (PSA/cZi) has recently shown promising effects. Recently the role of lesional therapy in selected cases has been discussed. Aim: The aim is to evaluate stereotactic functional procedures in the treatment of ET, with special emphasis on PSA DBS. Further the effects of DBS in the PSA are evaluated. The optimal target is also assessed by evaluating the effect of Vim and PSA DBS in relation to the position of the electrode. An attempt to identify patient-specific factors of prognostic importance for the outcome after DBS will be made. The quality of life (QoL) of patients treated with PSA DBS for ET will be assessed. Finally, the aim is also to analyze retrospectively the long-term outcome of lesional procedures (thalamotomies). Method: The thesis consists of five studies. The optimal electrode location is evaluated in a study analyzing the location of the electrode contact yielding the best effect in Vim DBS and PSA DBS groups. The efficacy of PSA DBS in 21 patients is evaluated in a prospective study. The correlation between outcome, age, tremor grade and gender is established in a prospective study consisting of 68 patients. Finally, the degree of improvement in QoL is determined in 16 patients operated on in the PSA. The very long-term effect of lesional surgery has been investigated in a retrospective study of nine patients who have undergone thalamotomy. Results: In the study of PSA DBS the total score on the Essential Tremor Rating Scale (ETRS) was reduced by 60% compared to the baseline value. Tremor of the arm was improved by 95%. The study evaluating the optimal contact location showed that the best effect was in the PSA in 54% and in the Vim in 12%. The efficacy of DBS was not related to age, gender, or the severity of tremor with regard to the percentage reduction of tremor on stimulation. In patients with a more severe tremor at baseline, a higher degree of residual tremor on stimulation was seen. With regard to QoL, the activities of daily living (ADL) according to the ETRS score were significantly improved, as well as according to the ADL and psychosocial subscores on the Questionnaire for Essential Tremor (QUEST) scale. No significant changes were found on the generic Short Form (SF-36) QoL scale. Thalamotomy had some positive effects, but also a significant amount of side effects that might be attributed to the surgery. Conclusions: The effect of PSA DBS was very satisfying and compares well with the results from Vim DBS. When both Vim and PSA DBS are considered, the optimal target seems to be located in the PSA. PSA DBS shows good results in improving ADL, but the results have been difficult to demonstrate on QoL scales. The efficacy of DBS could not be shown to be associated with gender or age. Nor was it associated with the severity of tremor regarding the percentage of tremor reduction on stimulation. The preoperative severity of tremor was the most important factor regarding outcome following DBS. With regard to thalamotomies, some possible remaining benefit of the surgery could be seen along with some severe side effects.
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Uma análise da implantação da integração lavoura pecuária e floresta (ILPF) na Microrregião de Viçosa, Minas Gerais / An analysis of the implementation of integrated cattle farming forest (IAFP) in Viçosa Microregion of Minas Gerais

Martins, Mauro Cesar 06 November 2012 (has links)
Made available in DSpace on 2015-03-26T13:33:50Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2927678 bytes, checksum: 2b604170cbf708f71cd2307b1cbc5a74 (MD5) Previous issue date: 2012-11-06 / A series of discussions on modernization in the field have been fought seeks to reflect on the models of rural development aimed at the mechanisms that allow for sustainability of interventions in agriculture. Amid these issues various policies and programs have been orchestrated in pursuit of more sustainable agricultural practices. In this sense in the Zona da Mata region mineira since 2005 Emater-MG and researchers from the Federal University of Viçosa (UFV), is developing on farms in the region new forms of agricultural production as defined by these technicians models that seek to value of production less harmful to the environment. Among these strategies is possible to mention the Integrated Cattle Farming Forest (IAFP), which consists of a system that seeks switch to agriculture and forest grazing in the same area. Thus, the research aimed to analyze the implementation of the IAFP in municipalities of the region of Viçosa, located in the Zona da Mata of Minas Gerais. With this, we adopted a methodology that allowed the use of some criteria for the choice of farmers and technicians to be interviewed, the data presented here are the result of field research conducted in some municipalities of the region of Viçosa, in the first half of 2012. Therefore, what we can see in this dissertation, among many conclusions, embraced on empirical data, scientific and conceptual is that the process of diffusion of innovative extension tied to technology transfer is insufficient to account for a complex reality that is the rural universe. Although the strategy deployed IAFP is under a process of transition from conventional agriculture production to a system that seeks to favor the most sustainable, even if far from desired. Nevertheless, it is possible to discuss what should be done, ie the improvement of processes instilled in implementing the above strategy, so that all content anharmonic and anti inclusive may give rise inclusive environmental strategies that ensure a more sustainable agriculture. / Uma série de discussões sobre a modernização no campo já foi travada buscando refletir sobre os modelos de desenvolvimento voltados para o rural e que permitissem mecanismos de intervenções para a sustentabilidade da agricultura. No bojo dessas questões, diversas políticas e programas vêm sendo orquestrados na busca por práticas agrícolas mais sustentáveis. Nesse sentido, na Zona da Mata mineira, desde 2005, a Emater-MG e os pesquisadores da Universidade Federal de Viçosa (UFV) vêm desenvolvendo, em propriedades rurais da região, novas formas de produção agrícola definidas por esses técnicos, que buscam valorizar modelos de produção menos agressivos ao ambiente. Entre essas estratégias, é possível citar a Integração Lavoura Pecuária Floresta (ILPF), que consiste em um sistema que busca alternar pastagem com agricultura e floresta em uma mesma área. Dessa forma, a pesquisa teve como objetivo analisar a implantação da ILPF nos municípios da microrregião de Viçosa, localizada na Zona da Mata do Estado de Minas Gerais. Para isso, adotouse uma metodologia que permitiu o uso de alguns critérios para a escolha dos agricultores e técnicos a serem entrevistados, cujos dados apresentados neste trabalho são frutos de pesquisa de campo realizada em alguns municípios da Microrregião de Viçosa, no primeiro semestre de 2012. Para tanto, o que se pôde observar nesta dissertação, entre inúmeras conclusões, abarcadas em dados empíricos, científicos e conceituais, é que o processo de difusão inovadora da extensão rural atrelado à transferência de tecnologia é insuficiente para dar conta de uma realidade complexa que é o universo rural. Embora a estratégia da ILPF implantada se encontre sob um processo de transição do sistema de agricultura convencional de produção para um sistema que procura privilegiar aspectos mais sustentáveis, estando ainda muito distante do desejado. Apesar disso, é possível discorrer sobre o que deve ser feito, ou seja, o aprimoramento dos processos incutidos na implantação da supracitada estratégia, de forma que todo o conteúdo anarmônico e anti-inclusivo possa dar lugar às estratégias inclusivas socioambientais que garantam uma agricultura mais sustentável.

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