166 research outputs found

    Exploratory Path Planning for Mobile Robots in Dynamic Environments with Ant Colony Optimization

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    In the path planning task for autonomous mobile robots, robots should be able to plan their trajectory to leave the start position and reach the goal, safely. There are several path planning approaches for mobile robots in the literature. Ant Colony Optimization algorithms have been investigated for this problem, giving promising results. In this paper, we propose the Max-Min Ant System for Dynamic Path Planning algorithm for the exploratory path planning task for autonomous mobile robots based on topological maps. A topological map is an environment representation whose focus is the main reference points of the environment and their connections. Based on this representation, the path can be composed by a sequence of state/actions pairs, which facilitates the navigability of the path, with no need to have the information of the complete map. The proposed algorithm was evaluated in static and dynamic envi- ronments, showing promising results in both of them. Experiments in dynamic environments show the adaptability of our proposal

    Exploratory Path Planning Using the Max-Min Ant System Algorithm

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    In the path planning problem for autonomous mobile robots, robots have to plan their path from the start position to the goal. In this paper, we investigate the application of the MMAS algorithm to the exploratory path planning problem, in which the robots should explore the environment at the same time they plan the path. Max-min ant system is an ant colony optimization algorithm that exploits the best solutions found. In addition, to analyze the quality of solutions obtained, we also analyze the traveled distance spent by robots in the first iteration of the algorithm. The environment is previously unknown to the robots, although it is represented by a topological map, that does not require precise information from the environment and provides a simple way to execute the navigation of the path. Thus, the paths are represented by a sequence of actions that the robots should execute to reach the goal. The navigation of the best solution found was implemented in a realistic robotic simulator. The proposed algorithm provides a very good performance in relation to a genetic algorithm and the well-known A* algorithm that deal with this problem

    Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations

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    Hutchinson–Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24-/- mouse model of HGPS. Challenge of Zmpste24-/- mice with the ß-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24-/- cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24-/- progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death.Peer ReviewedPostprint (published version

    Estratificación en bodegas catedral para la crianza de vinos generosos.

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    La zona de producción de vinos generosos conocida como Marco de Jerez cuenta con un tipo particular de bodegas, las “catedrales del vino”. Estos edificios de extraordinarias dimensiones que vivieron su apogeo durante el siglo XIX reciben su nombre por la similitud que muestran con los templos de la cristiandad. Este trabajo desvela el fenómeno de la estratificación vertical, a través de la monitorización de temperatura y humedad relativa a diferentes alturas. Los resultados del estudio demuestran que la estratificación vertical es notable en primavera y verano. En los meses más calurosos, las diferencias durante la tarde superan los 4⁰C y 15% HR en la zona de barricas, y los 15⁰C y 35% HR. considerando toda la altura de la bodega. Este comportamiento justifica las técnicas utilizadas en el sistema tradicional de crianza, situando el vino con más edad en la zona inferior. El diseño característico de las bodegas catedral hace posible estratificar el aire y proteger al vino de los incrementos de temperatura y las bajadas de humedad relativa; su comportamiento podría servir de inspiración y referencia para un diseño más eficiente de nuevas construcciones para la crianza del vino tinto.

    Comparison of the productive performance in broilers supplemented with probiotic or antibiotic

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    El estudio comparó parámetros productivos de pollos de carne suplementados con un probiótico Biomin® Poultry 5 Star (Enterococcus faecium, Pediococcus acidilactici, Bifidobacterium animalis, Lactobacillus salivarius y Lactobacillus reuteri) versus un antibiótico (Zinc Bacitracina). Se usaron 333 aves divididas en tres tratamientos de 111 animales con 3 repeticiones por tratamiento: 1, control; 2, antibiótico; y 3, probiótico. En las seis semanas de crianza no se encontró diferencia significativa entre tratamientos para peso corporal, consumo de alimento, conversión alimenticia (ICA), porcentaje de mortalidad y el índice de eficiencia productiva (IEP).The present study compared productive parameters in broilers supplemented with a probiotic Biomin® Poultry 5 Star (Enterococcus faecium, Pediococcus acidilactici, Bifidobacterium animalis, Lactobacillus salivarius y Lactobacillus reuteri) versus an antibiotic (Bacitracin). A total of 333 chicks were divided into three treatments of 111 animals with 3 repetitions for group: 1 control; 2 antibiotic; 3 probiotic. During the six weeks of the study no statistical differences were found between treatments for body weight, feed consumption, feed conversion, mortality rate, and productive efficiency index

    Skin Vaccination against Cervical Cancer Associated Human Papillomavirus with a Novel Micro-Projection Array in a Mouse Model

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    Background: Better delivery systems are needed for routinely used vaccines, to improve vaccine uptake. Many vaccines contain alum or alum based adjuvants. Here we investigate a novel dry-coated densely-packed micro-projection array skin patch (Nanopatch (TM)) as an alternate delivery system to intramuscular injection for delivering an alum adjuvanted human papillomavirus (HPV) vaccine (Gardasil (R)) commonly used as a prophylactic vaccine against cervical cancer
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