Estudio de la modificacion genica en conifera como respuesta a la perdida de verticalidad

75 p.En el presente trabajo se estudió la expresión diferencial de genes de xilema de plántulas de Pinus radiata expuestas a una inclinación de 45°. Al extraer el RNA y analizar los ranscritos, se busca determinar el mecanismo molecular implicado en la respuesta a la pérdida de verticalidad de fuste durante el crecimiento. Se evaluó el comportamiento de 69 plantas sometidas al tratamiento, comparándose contra 25 plantas controles con crecimiento normal. Se colectaron muestras a partir de tallo superior, tallo inferior, hoja y raíz, durante tres tiempos diferentes (2:30 horas, 10 horas y 24 horas), se transportaron en nitrógeno líquido y se almacenaron a -80°C hasta su posterior procesamiento. Se extrajo el RNA por el método de CTAB, posteriormente se sometió a tratamiento con DNAsa para sintetizar a partir del RNA cDNA, el cual se procesó por SSH para generar bibliotecas de ESTs. La clonación y la caracterización de los genes expresados se realizó mediante Hibridación Sustractiva. Se secuenciaron 31 fragmentos diferenciales dentro de los cuales se identificaron genes estructurales de pared celular, trasporte, metabolismo y otros. Así mismo se realizó una hibridación de RNA total en membrana con los distintos fragmentos secuenciados por SSH, observándose solamente una hibridación positiva con el clon 8, el cual representa el gen que codifica a la enzima adenosil metionina sintetasa relacionada con el proceso de biosíntesis de las poliaminas e involucradas en la multiplicación y en el crecimiento celular en el pino, observándose una expresión no tejido específica de esta secuencia. Las demás hibridaciones no entregaron resultados positivos por lo cual se seguirá el estudio, con el uso de técnicas más sensibles como PCR en tiempo real

Effects of fish movement and environmental variability in the design and success of a marine protected area

Marine Protected Areas (MPA) are broadly used to protect marine ecosystems, restore biomass, and increasingly as tools in fisheries management for benthic stocks. Nevertheless, MPAs are seldom used to target pelagic species due the challenges of designing an effective MPA in a highly dynamic environment. It is believed that highly mobile organisms will get few benefits, since they leave the protected area too frequently. One possible solution is to compensate for such movement with larger MPAs. Nevertheless, uncertainty about the benefits in the face of vagaries about fish movement make it unlikely that such efforts would be successfully pursued.Although it is a generally accepted that MPAs provide multiple benefits if well designed, empirical demonstrations of benefits from MPA are hard to obtain. They require long term evaluations, and as a consequence, comparisons between alternative MPA designs are almost nonexistent. Simulation models provide an alternative to empirical approaches that allow tests of designs and forecasts of potential outcomes. To date, most of the simulation models of MPAs have been developed for benthic systems, where simplified assumptions about fish and fisherman movement are reasonable. Fortunately, with the advent of more realistic fish movement models, new approaches are now possible that can combine complex individual-based models of movement, population dynamics and virtual MPA systems. The use of these new complex simulation models can guide the optimization of MPA design to increase both stock sizes and fisheries yields.The goal of the research presented in this dissertation is to study the potential of a large MPA to protect a pelagic stock and determine how fish movement characteristics and complex environmental dynamics influence the optimal design criteria for a successful pelagic MPA. The findings are timely given increasing interest in developing large no fishing zones to protect overfished pelagic stocks, especially for those taxa whose distribution spans more than one exclusive economic zone or resides in international waters. For this purpose I implemented a simulation model that incorporates detailed fish movement and their responses to complex environmental forcing to study the effect of fish movement on the efficacy of MPAs of different size and location.In Chapter 1, I examined the effects of movement assumptions on the effectiveness of different MPA sizes on fish stocks and fisheries yields. I compared the results to prior modelling studies of MPA design that assumed simple random movement. I explored four movement assumptions with increasing behavioural complexity: a) random, diffusive movement, b) aggregations, c) aggregations that respond to environmental forcing (sea surface temperature), and d) aggregations that respond to environmental forcing and are transported by currents. I found that MPAs can protect pelagic stocks and increase fisheries yields. The optimal MPA size to maximize fisheries benefits increased with fish movement complexity from an area of ~10% when diffusive movement was assumed to ~30% when the movement included aggregations, responses to the sea surface temperature (SST) and transport by currents.In Chapter 2, I studied the effect of spatial environmental variability in the design of the MPA. For this purpose, I specifically explored the same four movement assumptions with increasing behavioural complexity: a) random, diffusive movement, b) aggregations, c) aggregations that respond to environmental forcing (sea surface temperature), and d) aggregations that respond to environmental forcing and are transported by currents, to compare the outcomes from several MPA designs in terms of placement and size. The goal was to analyse how complexities of fish movement and environmental dynamics theoretically affect the predicted outcomes from different MPA designs. In this chapter I found that increasing the size of an MPA reduces the risk of selecting poor or suboptimal placements and protects a larger fraction of the stock while maintaining similar fisheries yields. Simplified movement assumptions (e.g. diffusive movement) underestimated the relative importance of MPA placement and overestimated both the expected stock size and the mean time to recovery. These findings highlight the value of understanding fish movement dynamics and their responses to environmental forcing, providing further evidence that MPAs have the potential to protect, rebuild and manage pelagic stocks.In Chapter 3, I included the effects of temporal variability in environmental forcing. I used the MPA model to simulate a complex pelagic environment with a spatially and temporally heterogeneous sea surface temperature that drove the organism’s movement dynamics. The goal was to include the effects of a highly variable environment on MPA design and successfully increase stock size and fisheries yields. The results suggested that when temporal environmental variability occurs, the expected fisheries benefits are significantly reduced relative to simulations with constant environments. The reduced fishery benefits occur even when the stock density levels were similar, suggesting that in highly variable pelagic environments MPAs may require more of a tradeoff between protect the stocks and increasing fisheries yields.The results of this research suggest that MPAs can effectively be used to protect and rebuild pelagic stocks, and have the potential to increase fisheries yields. Nevertheless, to effectively design MPAs with conservation and management goals, it is necessary to understand the organism’s movement dynamics and how they respond to environmental forcing. Models like the one used in this dissertation have the potential to inform future management decisions and help to design future pelagic MPAs that produce multiple benefits in a variety of environmental settings

La escuela municipal en Chile. La educación como un bien público. Percepción de actores claves de la educación municipal de la comuna de Curicó

163 p.La investigación que se presenta a continuación, tiene relación con investigar las características que presenta de la escuela municipal del chile actual y su relación con la educación como bien público, desde la mirada de algunos actores claves que están involucrados con las escuelas municipales de la comuna de Curicó. y lleva como título “La escuela municipal en Chile. La educación como un bien público. Percepción de actores claves de la educación municipal de la comuna de Curicó”. El método de investigación se llevó a cabo haciendo una revisión bibliográfica del tema desde el punto de vista de la política y gestión educacional, a través de las siguientes interrogantes ¿En qué consiste el sistema de municipalización aplicado a la educación chilena desde la década de los 80 a la época actual?, ¿Cuáles son las características de una educación democrática? , ¿Que significa que la educación sea un bien público? ¿Se observa el cumplimiento de los cánones de la educación como un bien público, propia de una educación democrática, en el estudio de algunas escuelas municipales de la comuna de Curicó? , la segunda parte, se realiza un trabajo de campo, que consiste en recopilar la información a través de la utilización de un cuestionario abierto dirigido a los diversos actores que están involucrados en la educación municipal de la comuna de Curicó. Una vez terminado el análisis de los datos se concluye que la educación municipal no preserva el valor de la educación como bien público, porque la confianza de los usuarios en los estos establecimientos se ha perdido, los estudiantes que asisten a esta escuela lo hacen porque no tienen opción de estar en los otros establecimientos particulares pagados o particulares subvencionados. Por lo tanto el concepto de igualdad no es efectiva, porque no existe igualdad para ellos, lo que hace el Estado es tratar de que esta desigualdad sea menor, pero no la elimina, además no es el responsable directo de este tipo de educación, ya que entrega este compromiso a la municipalidad, y depende de ella que este sea efectivo

Association between biomarkers of iron status and cardiometabolic risk in Spanish children aged 9-10 years. The ELOIN study

The relationship between iron metabolism and cardiometabolic risk factors has been scarcely studied in children, and the results are controversial. The objective of this study was to evaluate the association between iron parameters and lipid, glycemic and blood pressure alterations in the pediatric population. This was a cross-sectional study of 1954 children between 9 and 10 years of age in Madrid (Spain), participants in a longitudinal study of childhood obesity. Iron metabolism parameters, i.e., serum iron (Is), ferritin (Fs), transferrin (Tf) and transferrin saturation (STf) and lipid, glycemic and blood pressure profiles were evaluated. Odds ratios (ORs) were estimated using logistic regression models adjusted for sociodemographic characteristics, diet, physical activity, C-reactive protein and body mass index. Compared with the participants in the low Is and STf tertiles, those in the upper tertiles had a lower risk of low HDL-Chol (OR: 0.34; 95%CI: 0.17; 0.67) and OR: 0.44 (95%CI: 0.23; 0.84), respectively, and children in the upper Fs tertile had an OR of 2.07 (95%CI: 1.16; 3.68) for low HDL-Chol. Children in the highest Is and STf tertiles had a lower risk of prediabetes [OR: 0.63 (95%CI: 0.41; 0.97) and OR: 0.53 (95%CI: 0.34; 0.82)] and insulin resistance (IR) (OR: 0.37; 95%CI: 0.22; 0.64), and those in the upper Tf tertile had a higher risk of IR (OR: 1.90; 95%CI: 1.16; 3.12). An increased risk of hypertension was found only in children in the upper Fs tertile (OR: 1.46; 95%CI: 1.01; 2.13). Conclusions: Biomarkers of iron metabolism are associated with cardiometabolic alterations in the pediatric population, with a variable direction and magnitude depending on the indicators used. What is known: • Iron metabolism is related to important cardiometabolic alterations such as metabolic syndrome and its components. • Association between biomarkers of iron status and cardiometabolic risk have been less explored in children. What is new: • Biomarkers of iron metabolism are associated with cardiometabolic alterations in the pediatric population. • Iron parameters in the pediatric population could be of great help to detect and prevent cardiometabolic abnormalities early.The ELOIN study was funded by the General Directorate of Public Health of the Ministry of Health of the Community of Madrid. The authors have not received financial support for the research, authorship or publication of this article. This project received a grant for the translation and publication of this paper from the Foundation for Biosanitary Research and Innovation in Primary Care (FIIBAP).S

The Role of the Rodent Insula in Anxiety

The human insula has been consistently reported to be overactivated in all anxiety disorders, activation which has been suggested to be proportional to the level of anxiety and shown to decrease with effective anxiolytic treatment. Nonetheless, studies evaluating the direct role of the insula in anxiety are lacking. Here, we set out to investigate the role of the rodent insula in anxiety by either inactivating different insular regions via microinjections of glutamatergic AMPA receptor antagonist CNQX or activating them by microinjection of GABA receptor antagonist bicuculline in rats, before measuring anxiety-like behavior using the elevated plus maze. Inactivation of caudal and medial insular regions induced anxiogenic effects, while their activation induced anxiolytic effects. In contrast, inactivation of more rostral areas induced anxiolytic effects and their activation, anxiogenic effects. These results suggest that the insula in the rat has a role in the modulation of anxiety-like behavior in rats, showing regional differences; rostral regions have an anxiogenic role, while medial and caudal regions have an anxiolytic role, with a transition area around bregma +0.5. The present study suggests that the insula has a direct role in anxiety

The importance of Antarctic krill in biogeochemical cycles

Antarctic krill (Euphausia superba) are swarming, oceanic crustaceans, up to two inches long, and best known as prey for whales and penguins – but they have another important role. With their large size, high biomass and daily vertical migrations they transport and transform essential nutrients, stimulate primary productivity and influence the carbon sink. Antarctic krill are also fished by the Southern Ocean’s largest fishery. Yet how krill fishing impacts nutrient fertilisation and the carbon sink in the Southern Ocean is poorly understood. Our synthesis shows fishery management should consider the influential biogeochemical role of both adult and larval Antarctic krill

Espacios dentro de espacios: de la caja a la disolución del límite

Màster universitari en Estudis Avançats en Arquitectura: Projecte. Procés i ProgramacióConstantemente nos encontramos delimitados por espacios que nos contienen. Empezando desde lo general o macro como es la ciudad hasta llegar a una escala más humana: las edi caciones. La búsqueda de ciertos factores ligados al confort y necesidades del usuario nos lleva a atravesar capas que nos sumergen en mundos contenidos que dependen directamente de su contenedor, brindando una serie de ventajas, posibilidades y características en cada caso en particular. Sabemos que la percepción, la interpretación y el resultado de un espacio dependen de ciertas variables como: el manejo de factores climáticos, las necesidades de cada usuario, la época en la que fue concebido el espacio, y algunos más, pero la concepción de un espacio depende sobre todo de su límite. El interés por el término no solo hace pausa en aquel concepto de elemento rígido y ciego que separa dos partes, sino también en aquel que se presenta como elemento exible, poroso, que permite el traspaso de un mundo a otro. “El límite como caja”, “El límite permeable” y “El límite diluido” son tres ejes transversales bajo los cuales el presente estudio organiza su desarrollo. ¿Qué pasa cuando estos elementos se plantean en su máxima o mínima expresión? como se comporta el espacio? Este análisis de espacios contenidos busca exponer paralelamente casos con propiedades distintas entre ellos para así llegar a un entendimiento de las diferentes posibilidades que tienen los espacios a partir de un protagonista fundamental: su límite