Proyectos

Compelling evidence shows that adverse intrauterine conditions increase the risk to develop cardiometabolic diseases in the adulthood. This concept has been called ‘Developmental Origins of Health and Disease’ (DOHaD) and relies on the activation of mechanisms sensing and signaling a diversity of stimuli during early development that later lead to higher risk of disease. The mechanisms that have been broadly suggested to be involved in these processes are epigenetic modifications in key gene promoters that could ‘record’ normal and abnormal perinatal stimuli. Intrauterine oxidative stress is a common feature in conditions with altered fetal growth (i.e. intrauterine growth restriction –IUGR-, or macrosomia). Several cellular processes require the participation of pro-oxidant molecules which are normally neutralized by antioxidant defenses. However, under determined conditions the pro-oxidants overcome these defenses inducing oxidative stress. The latter is an important stimulus that regulates vascular function and cardiovascular physiology, playing a key role in the development of cardiovascular diseases, regulating negatively the bioavailability of the main vasodilator nitric oxide (NO). In addition, the vascular system presents a high phenotypic plasticity during life, which is modulated and restricted by epigenetic mechanisms (including DNA methylation, histone post-translational modifications and micro RNAs). Interestingly, cultured placental endothelium derived from complicated pregnancies presents persistent abnormal phenotypes, characterized by altered expression of proteins involved in NO-dependent vasodilation (i.e. eNOS and arginase), suggesting an early onset of endothelial dysfunction. Preliminary data from in vitro experiments, show that this altered expression of eNOS in IUGR placenta-derived endothelial cells is accompanied by epigenetic alterations in the promoter of its gene. Moreover, these cells can be reprogrammed to a “normal type”, interfering with the molecular machinery that preserves the DNA methylation pattern. However, there are no studies addressing the role of the pro-oxidant status associated to IUGR on the epigenetic programming of placental vascular dysfunction, and whether these epigenetic changes reflect those present in other fetal vascular beds or in the adult cardiovascular system. Therefore, we hypothesized that the in utero oxidative stress, that characterizes IUGR, induces an epigenetic programming of the endothelial function, which is linked to abnormal umbilical and fetal vascular reactivity and higher risk of adult cardiovascular disease. These epigenetic changes lead to an altered expression of endothelial function-related proteins and to their response to superimposed oxidative stress in umbilical and systemic arteries in the fetus and adult guinea pig. If true, the development of IUGR in the presence of antioxidant treatment should prevent the vascular impairment in the fetus and the adult guinea pig. This hypothesis will be tested in an IUGR guinea pig model according to the following general aims (GA): GA-1. To determine whether the IUGR-associated oxidative stress induces endothelial dysfunction in umbilical and systemic arteries, altering the basal expression of proteins implicated in the NO-dependent vasodilation (NO-DV) pathway and their response to oxidative stress; GA-2. To determine in umbilical artery (UAEC) and aortic (AEC) endothelial cells whether endothelial dysfunction induced by fetal oxidative stress associates with epigenetic changes in the promoter of genes implicated in the NO-DV pathway, altering their response to oxidative stress in vitro; GA-3. To determine in adult life whether the IUGR-associated oxidative stress results in increased markers of endothelial dysfunction, oxidative stress and cardiovascular disease. GA-4. To determine in AEC of adults born with IUGR whether endothelial dysfunction induced by fetal oxidative stress is associated with epigenetic changes in the promoter of genes implicated in the NO-DV pathway and their response to oxidative stress in vitro, correlating them with those found at term of gestation. IUGR will be induced by uterine artery ligation in a pregnant sow, and the role of oxidative stress in the vascular programming will be analyzed treating IUGR pregnancies with the antioxidant N-acetylcysteine. The acute effect of pro- and anti-oxidants on vascular reactivity and NO-dependent vasodilation will be determined by wire-myography in IUGR near-term fetuses and adults guinea pig arteries. Further, the presence of proteins related with NO-dependent vasodilation (eNOS, arginase, HO-1, NQO1 and DHFR) in these vessels will be determined by immunohistochemistry. Endothelial epigenetic programming will be analyzed in primary cell cultures from UAEC and AEC in near-term fetuses and AEC in adult guinea pigs. Our expected outcome is to demonstrate that oxidative stress is one of the main sources of the IUGR-induced dysfunction in fetal and adult vascular beds. Further, we expect that the NAC treatment should be able to prevent partially or totally the programmed vascular impairment. This project is not only relevant to uncover the developmental mechanisms that determine short- and long-term vascular dysfunction, but also to propose eventual treatments in complicated pregnancies, that unfortunately present a very high rate in humans.

Como investigador de postdoctorado: - Realizar investigación sobre problemas asociados a la integración de plantas fotovoltaicas de gran tamaño a redes eléctricas. - Desarrollar plan personal de investigación y apoyar el logro de los objetivos de investigación del grupo. - Apoyar la investigación de estudiantes de pre y posgrado. - Apoyar en la escritura de proyectos de investigación y organización de eventos técnicos y de difusión. - Organizar reuniones del grupo de investigación. - Organizar seminario anual con expositores nacionales e internacionales. - Apoyar el reporte de las actividades y logros del grupo al equipo de gestión del centro. Como investigador adjunto: - Realizar investigación sobre problemas asociados a la integración de plantas fotovoltaicas de gran tamaño a redes eléctricas.

La investigación, de tipo cualitativo y corte etnográfico, fue desarrollada en cuatro estructuras diferentes de atención y educación a la primera infancia en Francia que reciben a niños entre 2 y 3 años: una “pequeña sección” de una "école maternelle"; una "clase passerelle" inserta también en una "école maternelle"; un "jardin maternel"; y una sala cuna o "crèche". Combinando diversas técnicas – fundamentalmente observación y filmación de niños y niñas, entrevistas en profundidad individuales y colectivas tanto con padres como con profesionales, utilizando como soporte parte del material audiovisual recopilado, y un trabajo experimental para recabar el punto de vista infantil – se indagó en las principales modalidades de participación e interacción desarrolladas por los niños y niñas, así como en las prácticas profesionales de socialización por parte del equipo pedagógico de cada estructura.

Concordia University/Geo Data Solutions Inc., R&D Dep. . Diseñar, simular y especificar partes para la implementación de un prototipo convertidor puente H semi-controlado de alta corriente. . Diseñar e implementar el sistema de control y adquisición de datos basado en plataforma Lab-View/CompactRIO.

El objetivo del trabajo fue evaluar diferentes formas de aplicación de microorganismos eficientes (ME) en diferentes cultivos y sobre el suelo, tanto en clima tropical (Cuba), como en clima frío (Canadá). Se llevaron a cabo diversos experimentos en los que se concluyó que el empleo de ME en aplicaciones foliares correspondientes a 50, 100, 150 y 200 ml/L mejora el crecimiento y consecuentemente la producción de las plantas, siendo ese efecto más significativo en la dosis de 100 ml/L en cultivos como el tomate, zanahorias, pepino y arroz. En los parámetros del suelo, contribuyen con la degradación de la materia orgánica y con el proceso de mineralización de los compuestos orgánicos.

Concordia University/Geo Data Solutions Inc., R&D Dep. . Diseñar, simular y especificar partes para la implementación de un prototipo convertidor puente H semi-controlado de alta corriente. . Diseñar e implementar el sistema de control y adquisición de datos basado en plataforma Lab-View/CompactRIO.

In the previous project the research focus was on the sensing principle and the development of prototype modules for a tactile proximity sensor (TPS). In the current project the focus is on the methods and algorithms with which the events in the near proximity of the robots can be modelled by means of these sensors. Collectively, the TPS on the robot surface and gripper constitute a smart skin. The application scenarios here are the Active Exploration of the Environment, Grasping and the Safe Human-Robot-Interaction. The methods to be developed will improve significantly on the quality of state of the art methods and expand the horizon of possible solutions for these problems. The capacitive measuring principle and the spatial resolution in both, the tactile and proximity modalities, enable an area-wide and distance based coverage of the robot surroundings. It is the first time that algorithms for Exploration, Grasping and Safe-Human-Robot-Interaction are presented that rely simultaneously on both tactile and proximity sensing with spatial resolution. The goal of the Exploration is to research which methods and strategies enable the robot to acquire a contact- and proximity-based world-model by means of TPS. The quality of state of the art solutions for grasping should be improved significantly. For the Safe-Human-Robot-Interaction algorithms should be developed that adapt the robots path and velocity according to the current situation as determined by the TPS. Also, new algorithms should make a TPS-based Interaction possible with the goal of robot controlling and programming by the human through tactile and proximity input. Finally, according to the context of the task and situation at hand (Exploration, Manipulation and Interaction) the robot should show an appropriate behaviour which is given by a behavioural strategy that will also be developed. The starting point in the project is the TPS-modules which were successfully developed in the previous project. At the beginning, research will be focused on the algorithms for signal processing that extract robust features from TPS for higher level tasks. This step is followed by the integration of TPS into a robot system realizing the smart skin. Building on these steps the methods for Exploration, Manipulation and Safe-Human-Interaction are developed. Finally, the results of the project will be shown and evaluated in a combined demonstration scenario that includes a robot endowed with TPS.