Search

Levels of Influence Affecting Focus Group Participants. (PPTX 93 kb)

Analysis of Focus Group Emotional Truths, Corresponding TDF Category and Examples of Related STAR MAMA Narratives. (DOCX 32 kb)

Viral Nervous Necrosis (VNN) is a globally distributed disease that affects a large number of finfish species, causing significant economic losses on affected farms. The causative agent is a small single stranded RNA virus called Nervous Necrosis Virus (NNV) from the genus Betanodavirus. NNV is neurotropic; clinical signs involve abnormal behaviour and high mortality associated with histopathological findings of vacuolating necrosis in the central nervous system and retina. In Australia, NNV has been isolated from Australian bass (Macquaria Novemaculeata) and barramundi (Lates calcarifer) populations recurrently for the past 10 and 25 years, respectively. However, the prognosis of NNV infection is highly variable. Although NNV became notorious for mass mortalities in marine fish hatcheries, it is often detected in apparently healthy individuals in the absence of clinical signs or histopathological lesions. Current knowledge on NNV epidemiology and pathogenesis is fragmentary. It is still unclear how the virus is transmitted between hosts and why some individuals are susceptible to VNN while others are not. The aim of this work was to study the epidemiology and pathogenesis of NNV in Australian native species with a focus on transmission and disease determinants to provide a basis for the development of prevention and control strategies. In Chapter 3, a partially retrospective study was conducted on the occurrence of NNV at the Darwin Aquaculture Centre (DAC), a barramundi hatchery. Observations on NNV detection frequency and distribution provided clues to the possible transmission pathways of the virus, including the potential role of broodstock as reservoirs, and the age-dependency of the disease. To assess the NNV exposure distribution among populations of adult fish, an indirect antibody detection ELISA was developed (Chapter 4). The assay was optimized and compared with a competitive ELISA format to provide the best discriminatory power between sera from immunized and non-immunized populations. After defining the best antibody detection protocol (the indirect ELISA), the diagnostic accuracy of the assay was assessed in naturally exposed subjects using a Bayesian approach in the absence of a gold standard (Chapter 5). After validation of the ELISA, a single point and repeated cross sectional analysis of NNV seroprevalence was conducted on native Australian adult fish populations (barramundi, Australian bass and groupers Epinephelus sp.) (Chapter 6). Survey results discredited the role of broodstock as NNV reservoirs based on the lack of correspondence between NNV seroprevalence and the occurrence of NNV outbreaks at the hatchery level. Results also suggested that the exposure of adult fish to NNV antigens must be progressive as seroconversion was often observed and the seroprevalence tended to be higher in older fish populations. From this and previous accumulated epidemiological evidence, horizontal transmission of NNV was considered most likely. An environmental reservoir outside the hatcheries has yet to be investigated. In Chapter 7, the factors influencing the pathogenesis of NNV in barramundi were explored. Juveniles of different ages were challenged by immersion to analyse the influence of the age of the host on VNN disease expression. Additionally, to test the influence of the virus isolate, juveniles were challenged with two inoculums obtained from NNV outbreaks in barramundi populations with different disease presentation (clinical and subclinical). Results showed that fish from all the age groups tested (range 20 to 63 days post hatch) were susceptible to NNV infection. However, the survival of the fish following NNV challenge was highly influenced by the age of the host. Juveniles of 5 weeks of age and older showed no clinical signs and their survival odds were the same as the non-challenged controls, whereas younger fish developed clinical disease. No significant effect on disease severity was noted between different NNV isolates. In Chapter 8, the factors influencing the pathogenesis of NNV in Australian bass were explored. In addition to the age of the host and the isolate factor, the influence of the dose of the virus and the water temperature on VNN expression was examined. As with barramundi, the disease expression in Australian bass was age dependent. The severity of the disease was affected by the water temperature in younger fish but it did not affect the outcome in fish above 5 weeks of age. The dose of the virus influenced the incidence of infection but not the severity of the disease expression. Again, no significant effect on disease severity was noted between the two isolates tested. From the experimental challenge of barramundi and Australian bass, further observations on NNV pathogenesis were provided: incubation period, minimum infectious dose, tissue distribution, shedding and humoral immune response. The results from this study narrow the knowledge gap on NNV transmission mechanisms and provide important insights into the virus pathogenesis in barramundi and Australian bass. The virus is most likely being transmitted horizontally and VNN disease expression as distinct from infection with NNV is highly age dependent. From this evidence, recommendations are made on the direction of efforts to control VNN at the farm level.

Buffalo (Bubalus bubalis) populations are spread across northern Argentina, and they share their habitat with bovines. Both species are susceptible to brucellosis, and they are under a National Plan of Control and Eradication. To characterize the Brucella spp. that infects buffaloes, the blood of 35 animals that tested positive to brucellosis by a complement fixation test was collected. DNA was obtained and analyzed by polymerase chain reaction using different molecular markers. The genera, species, and biovars of Brucella were established by analyzing specific regions of the genes omp31, eri, alkB, and omp2ab. Brucella spp. was identified in 15 of 35 tested buffaloes. The product of the omp31 gene identified the genera. The detection of two fragments of 297 bp and/or 1000 bp from the eri gene confirmed the presence of B. abortus S19 and wild-type B. abortus. The amplification of the alkB gene allowed the identification of B. abortus biovars characterized by fragments of 498 bp (bv1, bv2, or bv4). The simultaneous amplification of 498 bp (alkB) and 1000 bp (eri) products suggested the presence of B. abortus bv1, which is highly prevalent in the cattle of Argentina. Fragments of 827 bp and 857 bp were amplified from the omp2ab gene, and their sequences showed 100% identity with B. melitensis and B. abortus bv5 (GenBank). However, the 721 bp product (alkB) specific for B. melitensis could not be amplified. This is the first report indicating the presence of B. abortus bv5 in Latin America. Fil: Martinez, Diana. Universidad Nacional del Nordeste; Argentina Fil: Thompson, Carolina. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Santa Fe. Estacion Experimental Agropecuaria Rafaela; Argentina Fil: Russo, Ana Maria. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro de Investigaciones y Transferencia de Formosa; Argentina Fil: Jacobo, Roberto. Universidad Nacional del Nordeste; Argentina Fil: Torioni de Echaide, Susana. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Santa Fe. Estacion Experimental Agropecuaria Rafaela; Argentina

Introducción: En Bogotá, el sobrepeso alcanzo el 16% y la obesidad el 6% en niños y adolescentes escolares (SED, 2008). En Bogotá en el 2013, se implementó el Programa 40x40 (P40x40) en las Instituciones Educativas Distritales (I.E.D). Objetivo: Determinar el efecto de las modalidades deportivas del P40x40 sobre la composición corporal de los escolares con sobrepeso y obesidad. Diseño: Estudio controlado no aleatorizado. Un total de 1003 escolares (6 a 17 años), fueron asignados a un grupo intervención (GI) (P40X40) (n=497) y un grupo control (GC) (n=506) (clases de educación física). Se evaluó el efecto de dos meses de intervención con el P40X40, sobre las variables porcentaje de grasa corporal, índice de masa corporal e índice de masa corporal Zscore Resultados y Conclusiones: se presentaron cambios significativos en el GI para todas las variables (p=0.00), sin significancia clínica. El P40X40 requiere modificaciones en la intensidad y frecuencia para disminuir el sobrepeso y la obesidad. Abstract. Introduction: In Bogota, overweight reached 16% and 6% obesity in children and adolescent students (SED, 2008). In Bogotá in 2013, the 40x40 Program (P40x40) was implemented in the District Educational Institutions (DFI). Objective: To determine the effect of the sports P40x40 on the body composition of overweight and obese school. Design: randomized no controlled trial. A total of 1003 school children (6-17 years) were assigned to an intervention group (IG) (P40X40) (n = 497) and a control group (CG) (n = 506) . The effect of two months of intervention with P40X40 on the variables percentage body fat, body mass index and body mass index Zscore. Results and Conclusions The evaluation included significant changes to the GI for all variables (p = 0.00) without clinical significance. The P40X40 requires modifications in the intensity and frequency to decrease overweight and obesity Maestría

El tema central de esta tesis doctoral ha sido el crecimiento cristalino de nano y microestructuras de ZnO mediantes los métodos PVD y MOCVD. De manera general, mediante los diversos estudios realizados, hemos profundizado en el proceso de crecimiento de las nano y microestructuras de ZnO obtenidas con el método PVD en ausencia de catalizador dentro de un rango de temperaturas relativamente bajo (300-500 ºC). Los estudios realizados nos permitieron obtener la síntesis de una amplia gama de estructuras de ZnO con diferentes morfologías, como por ejemplo: poliedros aislados, agujas, hilos y capas rugosas. Adicionalmente, estos estudios nos han permitido mostrar que las características morfológicas de estas estructuras están principalmente gobernadas por el nivel de supersaturación de las especies en fase gaseosa a lo largo de la zona de cristalización con respecto al tiempo de crecimiento. De manera particular, hemos podido concluir que nuestras estructuras en forma de agujas o hilos evolucionan, en condiciones de baja supersaturación, a partir de la faceta piramidal o basal de un nanopoliedro sintetizado durante las primeras etapas de crecimiento, mientras que en condiciones de alta supersaturación se favorece la formación de capas rugosas conformadas por estructuras en forma de poliedros que tienden a coalescer debido al reforzamiento del crecimiento lateral que experimentan bajo condiciones de alta supersaturación. Adicionalmente, las medias ópticas realizadas en estructuras individuales, permitieron concluir que, debido al proceso de descomposición de la fuente de material, las estructuras que son sintetizadas durante las primeras etapas de crecimiento, crecen en condiciones de deficiencia de oxígeno y por ende tiende a incorporar una mayor densidad de defectos intrínsecos como vacantes de oxigeno (VO), mientras que las estructuras que se desarrollan en etapas posteriores, crecen con mayor riqueza de oxígeno de tal manera que se reduce significativamente la incorporación de este tipo de defectos. Por otra parte, a lo largo de esta tesis también hemos profundizado en la correlación entre los parámetros de crecimiento de MOCVD y las características morfológicas, estructurales y ópticas de las nanocolumnas de ZnO. Los estudios mostraron que mediante la variación de la riqueza de oxígeno en el proceso de crecimiento es posible inducir diferentes transiciones morfológicas en las nanocolumnas de ZnO: nanocolumnas–nanotubos-capas rugosas. Este tipo de transiciones han sido explicadas como una consecuencia de la reducción de la longitud de difusión que sufren los adátomos de zinc en algunos planos cristalinos cuando se incrementa la riqueza de oxígeno en el proceso de crecimiento. Los diferentes estudios llevados a cabo adicionalmente nos han permitido mostrar la existencia de una correlación entre el nivel de supersaturación y el ordenamiento vertical de las nanocolumnas. A partir de los resultados hemos concluido que esto se debe al reforzamiento del crecimiento lateral que experimenta el material bajo condiciones de alta supersaturación, el cual favorece, durante las primeras etapas de crecimiento, la formación de complejos estructurales pirámides-hilos bien definidos y verticalmente alineados. Esto a su vez facilita el buen ordenamiento vertical de las nanocolumnas de ZnO que se desarrollan posteriormente a partir estos complejos estructurales bajo condiciones de alta supersaturación. Los estudios que hemos realizado acerca de la influencia del tratamiento térmico del sustrato y el uso de una capa buffer de ZnO sobre las propiedades de las nanocolumnas de ZnO sintetizadas por MOCVD han mostrado que el uso combinado de sustratos recocidos de zafiro y una capa buffer de ZnO, crecida también por MOCVD, permite mejorar sustancialmente la calidad cristalina de las nanocolumnas de ZnO. Adicionalmente, mediante la aplicación del método de Williamson-Hall a nuestras nanoestructuras, se demostró que es posible diferenciar entre las características estructurales de la capa y las nanocolumnas dentro una misma muestra. Por su parte, la caracterización, mediante las espectroscopias Raman y CL, de los diferentes conjuntos de muestras sintetizadas por MOCVD, nos permitió establecer que las condiciones de crecimiento ricas en zinc favorecen la formación de defectos complejos relacionados con intersticiales de zinc (ZnI) en las nanocolumnas de ZnO. Este tipo de defectos demostraron comportarse como centros de recombinación no radiativos reduciendo sustancialmente la eficiencia luminiscente de nuestras estructuras. Adicionalmente, se logró determinar que este tipo de defectos tienden a incorporarse principalmente en la punta de las nanocolumnas, lo cual parece estar relacionado con el reforzamiento del crecimiento lateral que sufren estas estructuras bajo condiciones ricas en zinc. Por otra parte, demostramos que la presencia de una capa buffer induce un cambio en el modo de crecimiento de las nanocolumnas de ZnO, lo cual parece favorecer la no formación de defectos relacionados a ZnI y por ende mejora las propiedades luminiscentes de estas estructuras. The aim of this doctoral thesis has been to contribute to a better understanding of the correlation between method and parameters of the growth process and the morphological, structural, and optical properties of ZnO nanostructures. In order to carry it out, we have selected two different growth methods: a low-cost method such as physical vapor deposition (PVD) and a method with industrial character like metal organic chemical vapour deposition (MOCVD). In each experimental system, we have done different systematic studies on the influence of growth parameters. From these studies we have obtained relevant results which are shown in the following paragraphs. Regarding the growth by means of PVD, ZnO nano and microstructures with different shapes as polyhedrons, needles, wires and tripods, were obtained in the 300-500 ºC temperature range by using a well selected value of the carrier gas flow. The systematic studies carried out about the influence of growth time and temperature gradient, have allowed to correlate the morphology characteristics of ZnO structures with the level of the gas-phase supersaturation along the crystallization zone. The results have shown that: (i) under low supersaturation conditions, the anisotropic growth is more favorable. The structures in form of needles and wires tend to develop from the basal o pyramidal facets of a nanopolyhedron synthetized during the early growth stages; (ii) under high supersaturation conditions, rough layers conformed by coalesced polyhedrons tend to be formed. This can be explained by the enhanced lateral growth of the polyhedrons under high supersaturation conditions. Moreover, we have investigated the influence of the nature of the substrate on the nanostructures growth processes. This study indicated that, under our experimental conditions, the growth of nanostructures is free enough to not be significantly affected by the type of substrate. Otherwise, optical measurements made on the samples and on the individual structures by means of Raman and cathodoluminescence spectroscopy showed that the morphology evolution of the structures regarding the growth time have a significant influence on the luminescent properties of these structures. The results showed that the luminescence of the structures synthetized during the early growth stages (polyhedrons) is principally governed by the deep level emission centered in the green spectral range. Meanwhile, the luminescence of the structures grown at the subsequent growth stages is dominated by the near band edge emission. These results evidenced that the richness of oxygen chemical species varies during the growth time, which can be related with the role of carbon in the evaporation process of ZnO. This can promote the incorporation of defects related with the lack of oxygen, such as oxygen vacancy which is commonly associated with green emission in ZnO. Moreover with regard to the growth by MOCVD, by carrying out a systematic study, we have focused on the influence of the oxygen/zinc partial pressure ratio (VI/II ratio) and precursor flow-rate on the morphological and structural properties of ZnO. Zinc and oxygen flow-rates were individually controlled and varied in order to analyze a wide range of VI/II ratio (80 to 510), i.e. attempting to modulate oxygen-rich conditions by changing either oxygen or zinc partial pressure. Growth rate effects have been also investigated by simultaneously increasing the precursor flows at constant VI/II ratio. In addition, we have deepened on the influence of annealing sapphire substrates and ZnO buffer layer on ZnO nanorods growth. The systematical studies regarding the VI/II ratio influence showed that under O-rich conditions, increasing VI/II ratio induces a morphological transition from nanorods towards nanotubes and, further, rough layers. This influence of VI/II ratio on the surface smoothening agrees with the commonly admitted fact that, when using MOCVD, high VI/II ratio conditions favor the growth of 2D layers, while low VI/II ratios lead to the growth of ZnO nanowires. The morphology transition observed in our samples can be understood by the reduction of the diffusion length of Zn adatoms on the growing surface as the oxygen richness increases. By studying the effect of the zinc precursor flow, which controls the growth rate, it has been shown that the precursor’s supersaturation has a significant influence on the vertical alignment of the nanorods, as well as on the aspect ratio. High supersaturation conditions enhance lateral growth in detriment of the c-axis growth and high aspect ratio. The formation of well-defined pyramids and/or nucleation islands at the base of vertical nanorods is also favored. Thus it can be inferred that the enhanced lateral growth could be at the origin of the enhanced vertical alignment. Otherwise, structural measurements showed that a combined use of an annealed substrate and a ZnO buffer layer can improve substantially the crystal quality, vertical alignment and aspect ratio (length/width) of ZnO nanorods. The rocking curves measurements made on these nanorods arrays allowed a FWHM as low as 288 arc sec. The tilt and twist obtained from our nanorods arrays have also demonstrated that, by using annealed substrate and a ZnO buffer layer, the density of edge and screw defects can be significantly reduced. In addition, by applying the Williamson-Hall method in our samples, we have showed the possibility to separate the structural properties of the nanorods from those of the layer on which they grown. Finally, the analysis of the micro-Raman and CL mesurements has allowed to conclude that the nonradiative recombination centers (NRRCs), which substantially affect the light emission in the visible spectral range of our nanorods, can be ascribed to ZnI-related defects. Indeed, it has been shown that high Zn supersaturation reduces the luminescence efficiency. The characterization of individual nanorods, grown on bare sapphire substrates, has allowed to focus on the spatial location of these defects that seems to be principally located at the nanorod tips. The Raman and CL measurements of individual nanorods permitted to detect inhomogeneities, showing that the excess ZnI defects accumulate in a region extending few micrometers below the tip. Moreover, we have observed that the use of a ZnO buffer layer instead of a bare sapphire substrate during the synthesis process could substantially modify the growth mode of ZnO nanorods. This is explained by the reduction of the formation of ZnI-related defects and hence the concentration of NRRCs associated with these defects, and finally these results in a substantial improvement of the optical quality of ZnO nanorods.

El interés por recopilar las experiencias desarrolladas al interior de procesos sociales con poblaciones que han contado con poco acompañamiento toma una vital importancia dentro del desarrollo de la praxis del Trabajo Social con el fin de visibilizar los aportes realizados a las dinámicas sociales. Los procesos con comunidades fomentan las prácticas educativas populares que permiten el avance de la participación activa, posibilitando el empoderamiento de las comunidades para que así ellas mismas transformen su realidad. La presente sistematización de experiencias da a conocer el proceso de acompañamiento en el fortalecimiento del proyecto de vida con mujeres-madres, integrantes de dos hogares comunitarios de Familia, Mujer e Infancia (FAMI), con el proceso se lograron evidenciar, las transformaciones que ha tenido el significado de “ser mujer” en la sociedad, viéndose ello reflejado en el cambio del proyecto de vida, que antes se basaba en el “ser para los otros”, y luego se repensó desde el “ser para sí mismas” , todo ello, se construyo y evidencio dentro de una dinámica colectiva y participativa desarrollada con la comunidad.

Preclinical studies demonstrate that glutamate homeostasis in the striatum is disrupted following cocaine exposure, including a decrease in metabotropic glutamate receptor type 5 (mGluR5) expression and reduced glutamate turnover. The goal of this study was to use imaging of the human brain to investigate alterations in the glutamate signaling in cocaine addiction.Positron emission tomography imaging with the radiotracer [(11)C]ABP688 was used to measure mGluR5 binding and magnetic resonance spectroscopy was used to measure glutamate-glutamine levels in the striatum of cocaine-addicted participants (n = 15) compared with healthy control subjects (n = 15). Following the scans, the cocaine-addicted volunteers performed cocaine self-administration sessions to investigate the correlation between cocaine-seeking behavior and mGluR5 receptor binding.The results of the study showed that cocaine addiction was associated with a 20% to 22% reduction in [(11)C]ABP688 binding in the striatum. A secondary analysis of cortical and subcortical regions other than the striatum showed a similar reduction in [(11)C]ABP688 binding, suggesting that the decrease was widespread. No between-group differences were seen in the magnetic resonance spectroscopy measures of glutamate-glutamine in the left striatum. In addition, no correlation was seen between [(11)C]ABP688 binding in the striatum and the choice to self-administer cocaine.Overall, these results show that long-term cocaine use is associated with a decrease in mGluR5 availability compared with matched healthy control subjects and suggests that this receptor may serve as a viable target for treatment development for this disorder.

Los obispos se constituyeron como uno de los grupos de promotores más importantes del panorama artístico bajomedieval castellano. El objetivo de este estudio es ofrecer una visión de conjunto sobre la promoción artística de tres importantes prelados de la sede toledana: Gil de Albornoz, Pedro Tenorio y Sancho de Rojas. Para ello, se ofrece una visión actualizada del conocimiento de los encargos de cada prelado en la que se ha tratado de resaltar las aportaciones más relevantes, además de destacar los aspectos que merecen un estudio específico.

Este trabajo analiza las técnicas narrativas de los "cómics" aplicadas en la adaptación de la novela "Los vagabundos del Dharma" de Jack Kerouac. Se trata de un trabajo de investigación basado en los estudios de los teóricos Will Eisner y Scott McCloud y de la estudiosa de la adaptación Linda Hutcheon. En la inverstigación se exploran las posibilidades de los "cómics" como medio de expressión gráfica y las características de las adaptaciones de algunas obras clásicas de la literatura para establecer las ventajas y desventajas de la adaptación de novela a novela gráfica., Este trabalho analisa as técnicas narrativas das histórias em quadrinhos aplicadas na adaptação do romance Os vagabundos iluminados de Jack Kerouac. Trata-se de um trabalho de investigação baseado nos estudos dos teóricos e quadrinhistas Wil Eisner e Scott McCloud e da estudosa da adaptação Linda Hutcheon. Na pesquisa exploram-se as possibilidades das histórias em quadrinhos como meio de expressão gráfica e as características na adaptação de algumas obras clássicas da literatura para estabelecer as vantagens e desvantagens da adaptação de romances em HQ.

La elaboración de películas y recubrimientos con materiales naturales y biodegradables, disminuyen los daños ambientales comparados con los ocasionados por materiales comunes de plásticos sintéticos. Las formulaciones con biopolímeros como celulosa, gomas, almidones o proteínas; permiten conservar la calidad de las frutas y los vegetales frescos. La determinación de las propiedades que tiene la superficie de la piel de la fruta y la solución de recubrimiento, permiten predecir la eficiencia del proceso. El estudio del fenómeno de humectabilidad, considerando el trabajo de expansión, cohesión, adhesión y medición del ángulo de contacto, logra optimizar la formulación de recubrimiento en cuanto a concentraciones de biopolímeros, plastificantes, surfactantes, antioxidantes, etc. Este trabajo es una revisión de las ecuaciones que permiten determinar las propiedades superficiales de las frutas, considerando el cálculo de las interacciones polares, dispersivas y la determinación del ángulo de contacto. Environmental conservation concerns have led to research and development regarding biodegradable materials from biopolymers, leading to new formulations for edible films and coatings for preserving the quality of fresh fruit and vegetables. Determining fruit skin surface properties for a given coating solution has led to predicting coating efficiency. Wetting was studied by considering spreading, adhesion and cohesion and measuring the contact angle, thus optimising the coating formulation in terms of biopolymer, plasticiser, surfactant, antimicrobial and antioxidant concentration. This work reviews the equations for determining fruit surface properties by using polar and dispersive interaction calculations and by determining the contact angle.