Impacto de depredadores y niveles de recursos sobre rasgos fisiológicos de Fissurella crassa (Archeogastropoda

Indexación: Web of Science; RedalycThe effects of predators on the density of prey and their resources have been widely studied; however, there is little evidence on the effects of the predators in conjunction with the availability of resources on the traits of the prey, which could affect foraging activities. In this study, the physiological state and the escape response of the intertidal herbivore Fissurella crassa were evaluated in two sites which differ in terms of the abundance of its predator Heliaster helianthus. The results suggest that the escape response of F. crassa in the site with greater predator density and lower resource availability could require a better body condition that is compensated with increments in foraging. The results highlight the need to address the physiological perspective in community ecology in order to understand the interactions within these communities.Los efectos de los depredadores sobre la densidad de presas y sus recursos ha sido ampliamente estudiado, sin embargo existe escasa evidencia sobre los efectos de los depredadores en combinación con la disponibilidad de recursos relacionados con los rasgos de las presas que pueden afectar la actividad de forrajeo. En este estudio se evaluó el estado fisiológico y la respuesta de escape del herbívoro intermareal Fissurella crassa en dos sitios con diferencias en la abundancia de su depredador Heliaster helianthus. Los resultados sugieren que la respuesta de escape de F. crassa en el sitio de mayor densidad del depredador y baja disponibilidad de recursos, podría requerir una mejor condición corporal que se compensé con un incremento en el forrajeo. Los resultados destacan la necesidad de abordar la perspectiva fisiológica en ecología de comunidades para entender mejor las interacciones dentro de estas comunidades.http://www.redalyc.org/articulo.oa?id=5784430400

Effects of the anaesthetic associations atropine-tiletamine/zolazepam and atropine-ketamine/diazepam on adult emus (Dromaius novaehollandiae)

http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0301-732X2009000200008&lang=ptEn el presente estudio se determinó el efecto de las asociaciones anestésicas atropina IM (0,05 mg/kg)-tiletamina/zolazepam EV (4 mg/kg total) y atropina IM (0,05 mg/kg-ketamina EV (5 mg/kg total)/diazepam (0,5 mg/kg) sobre la respuesta fisiológica, anestésica y bioquímica de emúes adultos. Los ejemplares (n = 7 por grupo) fueron asignados al azar a dos tratamientos anestésicos. La frecuencia cardiaca y la temperatura corporal de los emúes mostraron un incremento al inicio del tratamiento experimental (entre 5-10 min, P = 0,001). Sin embargo, la frecuencia respiratoria y pulso disminuyeron (entre 5-15 min, P = 0,003). Estos patrones fueron detectados para ambas asociaciones anestésicas. Por otra parte, la inducción anestésica y el tiempo de recuperación anestésica no fueron afectados por los tratamientos (P = 0,12 y P = 0,13 respectivamente). Los emúes tratados con tiletamina mostraron un mayor tiempo de anestesia quirúrgica, comparados con los emúes tratados con ketamina (P = 0,012). En el caso de A.S.T. y glucosa, ambas variables presentaron un incremento a las 24 h de la aplicación del tratamiento anestésico, resultando los niveles de glucosa más altos en emúes tratados con ketamina (P = 0,006 y P = 0,008 respectivamente). Finalmente, la hemoglobina, proteínas totales y ácido úrico no presentaron diferencias significativas entre tratamientos (P = 0,99, P = 0,97 y P= 0,81 respectivamente). En conclusión, los dos protocolos anestésicos resultaron seguros y eficientes para la manipulación de los animales; sin embargo, el mayor tiempo de anestesia observado en animales tratados con tiletamina podría determinar la preferencia por esta asociación anestésica.Summary: In this study, the effects of the anaesthetic associations atropine IM (0.05 mg/kg)-tiletamine/zolazepam IV (4 mg/kg total) and atropine IM (0.05 mg/kg)-ketamine IV (5 mg/kg total)/diazepam (0.5 mg/kg) on physiological, anaesthetic and biochemical responses were determined on adult emus. Animals (n = 7 per group) were randomly assigned to the two anaesthetic associations. Variables were measured at baseline, during surgical plane and during 30 min of observation. Heart rate and temperature increased at the beginning of the experimental period (between 5-10 min, P = 0.001), while respiratory frequency and pulse decreased (between 5-15 min, P = 0.003). These patterns were detected with both anaesthetic associations. Anaesthetic induction and recuperation time were not affected by treatments (P = 0.12 and P = 0.13 respectively). Emus treated with tiletamine showed a greater anaesthetic time than emus treated with ketamine (P = 0.012). Significant increases in A.S.T. and glucose were observed at 24 h post application of anaesthetic associations, resulting higher in ketamine emus (P = 0.006 and P = 0.008 respectively). Finally, there were no significant differences between anaesthetic treatments for haemoglobin, total proteins and uric acid (P = 0.99, P = 0.97 and P = 0.81 respectively). In conclusion, atropine-tiletamine/zolazepam and atropine- etamine/diazepam protocols resulted safe and efficient for animal manipulation, however the greater anaesthetic time observed in tiletamine-treated animals may determine preference for this anaesthetic combination

Performance on Well and Ill-Structured Problems in University Physics: The role of Instruction in Cooperative Learning

In this study, I explore the learning opportunities that emerge from ill-structured activities in a university physics course and how collaboration enables performance under different teaching conditions. The study was conducted over two months on three sections of an introductory physics course in a University in Northern Chile. Each section utilized a different variety of teaching strategies and combinations of problems (well and ill-structured) for assessing content on the day of data collection, students were asked to work in groups and ill-structured activity in physics. I gathered audio of students' discussion in four groups for a total of 26 participants, and I collected the generated problems from the whole sample. From the audio, I explored the emergent processes students engaged while solving the problems. Student generated activities were coded to investigate combinations of concepts and problem characteristics, which were later combined into a measure of problem elaboration. Later, I explored students’ social networks to determine how different instructional strategies led to different social configurations and their differences in academic performance. For this, I collected data on students' performance on a physics test designed with well-structured problems and problem elaboration, and I asked students to respond to an on-line peer-nomination survey related to their social interactions engaged for information seeking to solve problems. I tested the effect of different network structures over academic performance on both types of activities by setting statistical linear models. Generating problems is an opportunity for students to propose ideas and make decisions regarding the content and the contextual details to introduce into their problems, as well as to engage in problem solving strategies. The combination of concepts and attributes for problem elaboration showed students' familiarity with particular portions of the content and characteristics, with differences across sections. Finally, students who actively sought out information from multiple peers were less likely to achieve good performance on well-structured problems, whereas for ill-structured problems, this effect depended on the features of the learning environment enacted in each section. These results suggest that teaching and instructional strategies have a key role in the way cooperation lead to good performance

Oscillation energy based sensitivity analysis and control for multi-mode oscillation systems

This paper describes a novel approach to analyze and control systems with multi-mode oscillation problems. Traditional single dominant mode analysis fails to provide effective control actions when several modes have similar low damping ratios. This work addresses this problem by considering all modes in the formulation of the system kinetic oscillation energy. The integral of energy over time defines the total action as a measure of dynamic performance, and its sensitivity allows comparing the performance of different actuators/locations in the system to select the most effective one to damp the oscillation energy. Time domain simulations in the IEEE 9-bus system and IEEE 39-bus system verify the findings obtained by the oscillation energy based analysis. Applications of the proposed method in control and system planning are discussed.Comment: Conference paper, IEEE PESGM 201

Path planning for reconfigurable rovers in planetary exploration

This paper introduces a path planning algorithm that takes into consideration different locomotion modes in a wheeled reconfigurable rover. Such algorithm, based on Fast Marching, calculates the optimal path in terms of power consumption between two positions, providing the most appropriate locomotion mode to be used at each position. Finally, the path planning algorithm is validated on a virtual Martian scene created within the V-REP simulation platform, where a virtual model of a planetary rover prototype is controlled by the same software that is used on the real one. Results of this contribution also demonstrate how the use of two locomotion modes, wheel-walking and normal-driving, can reduce the power consumption for a particular area.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Sistema Integrado de Gestión (calidad, medio ambiente y PRL) en una empresa de gestión integral del agua

Resumen de las prácticas realizadas en una empresa de gestión integral del agua, dentro del departamento de calidad y medio ambiente, donde se han desarrollado labores de estudio del sistema de gestión integral de calidad y medio ambiente, donde se iba a implantar el sistema OSHAS 18001, se han elaborado fichas de procedimiento para los diferentes sectores de la empresa y manuales de formación en PRL, para trabajadores de los diferentes servicios, además se adjunta uno de los manuales realizados, el manual para personal de limpiezas industriales.Departamento de Ingeniería Química y Tecnología del Medio AmbienteMáster en Gestión y Tecnología Ambienta