982 resultados para General combining ability
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IDENTIFICACIN DEL PROBLEMA DE ESTUDIO. Las sustancias orgnicas solubles en agua no biodegradables tales como ciertos herbicidas, colorantes industriales y metabolitos de frmacos de uso masivo son una de las principales fuentes de contaminacin en aguas subterrneas de zonas agrcolas y en efluentes industriales y domsticos. Las reacciones fotocatalizadas por irradiacin UV-visible y sensitizadores orgnicos e inorgnicos son uno de los mtodos ms econmicos y convenientes para la descomposicin de contaminantes en subproductos inocuos y/o biodegradables. En muchas aplicaciones es deseable un alto grado de especificidad, efectividad y velocidad de degradacin de un dado agente contaminante que se encuentra presente en una mezcla compleja de sustancias orgnicas en solucin. En particular son altamente deseables sistemas nano/micro -particulados que formen suspensiones acuosas estables debido a que estas permiten una fcil aplicacin y una eficaz accin descontaminante en grandes volmenes de fluidos. HIPTESIS Y PLANTEO DE LOS OBJETIVOS. El objetivo general de este proyecto es desarrollar sistemas nano/micro particulados formados por polmeros de impresin molecular (PIMs) y foto-sensibilizadores (FS). Un PIMs es un polmero especialmente sintetizado para que sea capaz de reconocer especficamente un analito (molcula plantilla) determinado. La actividad de unin especfica de los PIMs en conjunto con la capacidad fotocatalizadora de los sensibilizadores pueden ser usadas para lograr la fotodescomposicin especfica de molculas plantilla (en este caso un dado contaminante) en soluciones conteniendo mezclas complejas de sustancias orgnicas. MATERIALES Y MTODOS A UTILIZAR. Se utilizaran tcnicas de polimerizacin en mini-emulsin para sintetizar los sistemas nano/micro PIM-FS para buscar la degradacin de ciertos compuestos de inters. Para caracterizar eficiencias, mecanismos y especificidad de foto-degradacin en dichos sistemas se utilizan diversas tcnicas espectroscpicas (estacionarias y resueltas en el tiempo) y de cromatografa (HPLC y GC). As mismo, para medir directamente distribuciones de afinidades de unin y eficiencia de foto-degradacin se utilizaran tcnicas de fluorescencia de molcula/partcula individual. Estas determinaciones permitirn obtener resultados importantes al momento de analizar los factores que afectan la eficiencia de foto-degradacin (nano/micro escala), tales como cantidad y ubicacin de foto- sensibilizadores en las matrices polimricas y eficiencia de unin de la plantilla y los productos de degradacin al PIM. RESULTADOS ESPERADOS. Los estudios propuestos apuntan a un mejor entendimiento de procesos foto-iniciados en entornos nano/micro-particulados para aplicar dichos conocimientos al diseo de sistemas optimizados para la foto-destruccin selectiva de contaminantes acuosos de relevancia social; tales como herbicidas, residuos industriales, metabolitos de frmacos de uso masivo, etc. IMPORTANCIA DEL PROYECTO. Los sistemas nano/micro-particulados PIM-FS que se propone desarrollar en este proyecto se presentan como candidatos ideales para tratamientos especficos de efluentes industriales y domsticos en los cuales se desea lograr la degradacin selectiva de compuestos orgnicos. Los conocimientos adquiridos sern indispensables para construir una plataforma verstil de sistemas foto-catalticos especficos para la degradacin de diversos contaminantes orgnicos de inters social. En lo referente a la formacin de recursos humanos, el proyecto propuesto contribuir en forma directa a la formacin de 3 estudiantes de postgrado y 2 estudiantes de grado. En las capacidades institucionales se contribuir al acondicionamiento del Laboratorio para Microscopa ptica Avanzada (LMOA) en el Dpto. de Qumica de la UNRC y al montaje de un sistema de microscopio de fluorescencia que permitir la aplicacin de tcnicas avanzadas de espectroscopia de fluorescencia de molecula individual. Water-soluble organic molecules such as certain non-biodegradable herbicides, industrial dyes and metabolites of widespread use drugs are a major source of pollution in groundwater from agricultural areas and in industrial and domestic effluents. Photo-catalytic reactions by UV-visible irradiation and organic sensitizers are one of the most economical and convenient methods for the decomposition of pollutants into harmless byproducts. In many applications it is highly desirable a high degree of specificity, effectiveness and speed of degradation of specific pollutants present in a complex mixture. In particular nano/micro-particles systems that form stable aqueous suspensions are highly desirable because they allow for easy application and effective decontamination of large volumes of fluids. Herein we propose the development of nano/micro particles composed by molecularly imprinted polymers (MIP) and photo-sensitizers (PS). The specific binding of MIP and the photo-catalytic ability of the sensitizers are used to achieve the photo-decomposition of specific "template" molecules in complex mixtures. Mini-emulsion polymerization techniques will be used to synthesize nano/micro MIP-FS systems. Spectroscopy (steady-state and time resolved) and chromatography (GC and HPLC) will be used to characterize efficiency, mechanisms and specificity of photo-degradation in these systems. In addition single molecule/particle fluorescence spectroscopy techniques will be used to directly measure distributions of binding affinities and photo-degradation efficiency in individual particles. The proposed studies point to a more detailed understanding of the factors affecting the photo-degradation efficiency in nano/micro-particles and to apply that knowledge in the design of optimized systems for photo-selective destruction of socially relevant aqueous pollutants.
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Entre los factores que contribuyen a predecir el rendimiento acadmico se pueden destacar aquellos que reflejan capacidades cognitivas (inteligencia, por ejemplo), y aquellas diferencias individuales consideradas como no-cognitivas (rasgos de personalidad, por ejemplo). En los ltimos aos, tambin se considera al Conocimiento General (CG) como un criterio para el xito acadmico (ver Ackerman, 1997), ya que se ha evidenciado que el conocimiento previo ayuda en la adquisicin de nuevo conocimiento (Hambrick & Engle, 2001). Uno de los objetivos de la psicologa educacional consiste en identificar las principales variables que explican el rendimiento acadmico, como tambin proponer modelos tericos que expliquen las relaciones existentes entre estas variables. El modelo terico PPIK (Inteligencia-como-Proceso, Personalidad, Intereses e Inteligencia-como-Conocimiento) propuesto por Ackerman (1996) propone que el conocimiento y las destrezas adquiridas en un dominio en particular son el resultado de la dedicacin de recursos cognitivos que una persona realiza durante un prolongado perodo de tiempo. Este modelo propone que los rasgos de personalidad, intereses individuales/vocacionales y aspectos motivacionales estn integrados como rasgos complejos que determinan la direccin y la intensidad de la dedicacin de recursos cognitivos sobre el aprendizaje que realiza una persona (Ackerman, 2003). En nuestro medio (Crdoba, Argentina), un grupo de investigadores ha desarrollado una serie de recursos tcnicos necesarios para la evaluacin de algunos de los constructos propuesto por este modelo. Sin embargo, por el momento no contamos con una medida de Conocimiento General. Por lo tanto, en el presente proyecto se propone la construccin de un instrumento para medir Conocimiento General (CG), indispensable para poder contar con una herramienta que permita establecer parmetros sobre el nivel de conocimiento de la poblacin universitaria y para en prximos trabajos poner a prueba los postulados de la teora PPIK (Ackerman, 1996). Between the factors that contribute to predict the academic achievement, may be featured those who reflect cognitive capacities (i.g. intelligence) and those who reflect individual differences that are considered like non-cognitive (i.g. personality traits). In the last years, also the General Knowledge has been considered like a criterion for the academic successfully (see Ackerman, 1997), since it has been shown that the previous knowledge helps in the acquisition of the new knowledge (Hambrick & Engle, 2001). An interesting theoretical model that has proposed an explanation for the academic achievement, is the PPIK (intelligence like a process, interests and inteligence like knowledge) proposed by Ackerman (1996), who argues that knowledge and the acquired skills in a particular domain are the result of the dedication of cognitive resources that a person perform during a long period of time. This model proposes that personality traits, individuals interests and motivational aspects are integrated as complex traits that determine the direction and the intensity of the dedication of cognitive resources on the learning that a person make (Ackerman, 2003). In our context, (Crdoba, Argentina), a group of researcher has developed a series of necessary technical resoures for the assesment of some of the theoretical constructs proposed by this model. However, by the moment, we do not have an instrument for evaluate the General Knowledge. Therefore, this project aims the construction of an instrument to asess General Knowledge, essential to set parameters on the knowledge level of the university population and for in next works test the PPIK theory postulates.
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La infeccin de mamferos con el T. cruzi resulta en diferentes alteraciones inmunolgicas que permiten la persistencia crnica del parsito y destruccin inflamatoria progresiva del tejido cardiaco, nervioso y heptico. Los mecanismos responsables de la patologa de la enfermedad de Chagas han sido materia de intensa investigacin habindose propuesto que el dao producido en esta enfermedad puede ser consecuencia de la respuesta inflamatoria del individuo infectado y/o de una accin directa del parsito sobre los tejidos del hospedador. El propsito del presente proyecto es estudiar comparativamente, en dos cepas de ratones con diferente susceptibilidad a la infeccin y desarrollo de patologa, la participacin y los mecanismos efectores de las clulas supresoras mieloides (CSM) y las celulas T regulatorias inducidas por la infeccin experimental con Trypanosoma cruzi en el control de la infeccin con este protozoario y en el desarrollo de la patologa heptica siendo los objetivos especificos desarrolar: - Investigar la generacin y/o reclutamiento de clulas de CSM en bazo e hgado de ratones infectados con Trypanosoma cruzi y su contribucin a la desigual susceptibilidad a la infeccin y respuesta inmune desarrollada en las cepas de ratones BALB/c y C57BL/6; - Investigar la capacidad de las CSM inducidas por la infeccin con T. cruzi en bazo e hgado de ratones de ambas cepas para suprimir la respuesta de clulas T in vitro e indagar sobre los mecanismos de supresin utilizados; - Investigar la generacin y/o reclutamiento de clulas Treg durante la infeccin experimental con Trypanosoma cruzi, su participacin en la desigual susceptibilidad a la infeccin y respuesta inmune desarrollada en ambas cepas de ratones y los mecanismos de supresin utilizados. - Analizar en tejido heptico o leucocitos infiltrantes la presencia de COX2, PGE2, MMP2 y 9, IL1b, IL6, IDO, IL10 y GM-CSF capaces de inducir la expansin de las CSM; - Dilucidar si la administracin del ligando para TLR2 (Pam3CyS) previo a la infeccin de ratones C57BL/6 (en los cuales se detecta un menor nmero de CSM) es capaz de modular la respuesta inflamatoria y el dao heptico a travs de la induccin de CSM y/o T reg en hgado y bazo. La comprension de los eventos celulares y moleculares que regulan la produccin de citoquinas pro- y anti-inflamatorias y otros mediadores, as como el papel de los receptores de la inmunidad innata durante la infeccin con T. cruzi contribuir a responder interrogantes que son claves para el diseo de nuevas estrategias de intervencin inmune tendientes a preservar los mecanismos de defensa del husped. Two nonexclusive mechanisms have been proposed to explain the Chagass disease pathology: 1) The pathology of the disease seems to be consequence of the inflammatory response triggered for the parasite; or 2) The damage is produced by the parasite direct effect. Recently, we reported that TLR2, TLR4 and TLR9 (innate immune response receptors) are differentially modulated in injured livers from BALB/c (lesser liver pathology) and C57BL/6 (elevated liver pathology) mice during Trypanosoma cruzi infection. The aim of our proposal is the study of role of Myeloid-Derived Suppressor Cells (MDSC) and regulatory T cells in the control of T. cruzi infection and the infection-associated pathology. Our specific aims are: -To study the induction or recruitment of MDSC in splenn and liver of BALB/c and C57BL/6 mice and their relationship with the differential susceptibility and immune response observed in these both mice strains; - To determine the ability and the mechanisms used by the T. cruzi-induced MDSC to suppress the T cell proliferative response; -To study the induction or recruitment of Treg in liver of BALB/c and C57BL/6 mice and their relationship with the differential susceptibility and immune response observed in these both mice strains; -To analize in liver tissue or tissue infiltrating lymphocytes the activation of COX2, PGE2, MMP2 y 9, IL1b, IL6, IDO, IL10 y GM-CSF known to promote the development of MDSC; -To determine whether the treatment with Pam3CyS (TLR2 ligand) is able to modulate the liver inflammatory respose and damage througth the induction of MDSC or Treg.
Catalogue of Australian mammals, with introductory notes on general mammalogy, by J. Douglas Ogilby.
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This thesis details the findings of a study relating the transfer of 238U, 228Ra (232Th), 226Ra, and 137Cs from soil to vegetation in an Atlantic blanket bog, upland blanket bog and semi-natural grassland situated along the north-west coast of Ireland. The results of this study provide information on the uptake of these radionuclides by the indigenous vegetation found present in these ecosystems. The ecosystems chosen are internationally recognizable ecosystems and provide a wide variety of vegetation species and contrasting soil physiochemical properties which allow the influence of these parameters on radionuclide uptake to be assessed. The levels of radionuclides in the soil and vegetation were measured using gamma spectrometry, alpha spectrometry and ICP-MS. The nutrient status of the vegetation and soil physiochemical properties were measured using atomic absorption, flame photometry and other analytical techniques. The results of the study indicate that the uptake of 238U and 228Ra (232Th) by vegetation from all three ecosystems was negligible as the levels in all vegetation was below the limits of detection for the methods used in this study. These results appear to indicate that the vegetation studied do not possess the ability to accumulate significant levels of these radionuclides however this assumption cannot be upheld in the case of the Atlantic blanket bog as the levels in the soil of this ecosystem were too low for detection. Similar results were obtained for 226Ra uptake in both the Atlantic blanket bog and grassland for all vegetation with the exception of H. lanatus from the grassland ecosystem. Radium-226 uptake in upland blanket bog was higher and was detectable in the majority of vegetation indigenous to this ecosystem. Transfer factor values ranged from 0.07 to 2.35 and the TF values for E. tetralix were significantly higher than all other vegetation studied. This species of heather demonstrated the ability to accumulate 226Ra to a greater extent than all other vegetation. The uptake of 226Ra by upland blanket bog vegetation appears to be significantly influenced by a range of soil physiochemical properties. The nutrient status of the vegetation, in particular the calcium content in the vegetation appears to have a negative impact on the uptake of this radionuclide. Potassium-40 was detectable in all vegetation present in the three ecosystems and the levels in the grassland soil were significantly higher than the levels in both bogland soils. Transfer factor values for Atlantic blanket bog vegetation ranged from 0.9 to 13 .8 and were significantly higher in E. vaginatum in comparison to C. vulgaris. Potassium-40 TF values for upland blanket bog vegetation on average ranged from 1.4 for C. vulgaris (stems) to 5.2 for E. vaginatum and were statistically similar for all species of vegetation. Transfer factor values for grassland vegetation ranged from 0.7 to 3.8 and were also statistically similar for all species of vegetation indicating that the transfer of 40K to vegetation within the upland bog and grassland ecosystem is not dependent on plant species. Comparisons of 40K TF values for all three ecosystems indicate that the uptake in E. vaginatum from the Atlantic blanket bog was statistically higher than all other vegetation studied. This appears to indicate that E. vaginatum has the ability to accumulate 40K, however, this species of vegetation was also present in the upland blanket and did not demonstrate the same behaviour. The uptake of 40K by vegetation from all three ecosystems was significantly affected by a range of soil physiochemical properties and in some cases the results were contradictory in nature possibly indicating that the affect of these parameters on 40K uptake is species dependent. The most obvious trend in the data was the influence of soil CEC and magnesium levels in vegetation on 40K TF values. A positive correlation was apparent between the CEC of the soil and 40K uptake in vegetation from both the Atlantic blanket bog and grassland ecosystem. A similar trend was apparent between magnesium levels in vegetation and 40K TF values for the upland blanket bog and grassland vegetation. Caesium-13 7 levels were found to be significantly higher in the two bogland soils in comparison to the grassland soil and levels of 137Cs decreased with increasing soil depth. Transfer factor values for Atlantic blanket bog vegetation ranged from 1.9 to 9.6 and TF values were significantly higher in the leaves o f C. vulgaris in comparison to all other vegetation from this ecosystem. Caesium-13 7 TF values for the upland blanket bog vegetation on average ranged from 0.29 for E. tetralix to 1.6 for C. vulgaris. Uptake by the leaves of C. vulgaris was significantly higher than all other vegetation present thereby supporting the trend found within the Atlantic blanket bog vegetation. These results appear to indicate that the leaves of C. vulgaris have the ability to accumulate significant quantities of 137Cs and also that the uptake of 137Cs by this vegetation is dependent on plant compartment as the stems of this vegetation contained significantly lower levels than the leaves in both ecosystems. The uptake of 137Cs by grassland vegetation was very low and was only detectable in a fraction of the vegetation sampled. Caesium-137 TF values for grassland vegetation were in general lower than 0.02. The impact of soil physiochemical properties and nutrient status of vegetation on 137Cs uptake by vegetation appears to be complex and in some cases contradictory. The most apparent trend in the data was the positive influence of vegetation nutrients on 137Cs uptake in particular the magnesium levels present in the vegetation and to a lesser extent the calcium levels present. The results in general indicate that the uptake of 226Ra, 40K and 137Cs by the chosen vegetation is varied and complex and is significantly dependent on the species of vegetation, soil radionuclide concentration, soil physiochemical properties and the nutrient status of the vegetation.
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Third Edition
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5
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First Edition
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v.6:pt.1 (1806)
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v.6:pt.2 (1806)
