Suchergebnisse

ABSTRACT: Implementation of an ecological analysis in the framework of water management in three aquatic ecosystems in Colombia. Introduction: Research and diagnosis of water sources is on academic and governmental interest, for this reason, the exploration of numerical instruments applied to watershed management offers the possibility to identify where and what variables are useful in monitoring and rehabilitation programs of aquatic ecosystems. The territories environmental planning and management, which includes water quality, is conventionally analyzed by physico-chemical and hydrobiological indices, in 2014 through the water management guide, included the assessment of the ecological quality index (EQI); this index generates a comprehensive approach through a numerical system of correlations that diagnoses, classifies and detects the affections in a reach of a water system. Objective: This research aims to demonstrate that the index allows to assess the quality of aquatic ecosystems affected by different environmental situations. Methods: In order to analyze the application of this tool, we analyzed three scenarios located in different biogeographical regions of Colombia and as an indicator hydrobiological group we used peripheral and phytoplankton algae. The ecosystems were monitored between 2007 and 2015 and correspond to a flood plain, a high mountain Andean river and a group of ravines in a tropical humid forest. Results: Among the general results, the matrices of response variables determined canonical correlations with (p<0.005) and a model of weighted averages allowed to estimate the optimum and the tolerance of each taxa for the ecological classification of the sites; variables related to ion concentration, acidity damping, temperature and hydraulics, influenced the models that explained the distribution of abundances of the studied biological groups. Conclusions: The application of the index makes it possible to identify variables, organisms and numerical systems that allows to classify ecological status in a system, useful results in the diagnosis and monitoring of aquatic ecosystems studied and that can be implemented with other scenarios. ; Introducción: La investigación y el diagnóstico de fuentes hídricas es de interés académico y gubernamental, por esta razón, la exploración de instrumentos numéricos aplicados al ordenamiento de cuencas brinda la posibilidad de identificar dónde y qué variables son útiles en programas de monitoreo y rehabilitación en ecosistemas acuáticos. La planificación ambiental de los territorios y su ordenación, lo cual incluye la calidad del agua, es convencionalmente analizada por índices fisicoquímicos e hidrobiológicos, incluyó en el año 2014 a través de la guía de ordenamiento hídrico, la evaluación del índice de calidad ecológica (ICE); este índice genera un enfoque integral por medio de un sistema numérico de correlaciones que diagnostica, clasifica y detecta las afectaciones en el tramo de un sistema hídrico. Objetivo: Esa investigación pretende demostrar que el índice permite evaluar la calidad de ecosistemas acuáticos afectados por diferentes situaciones ambientales. Métodos: Con el fin de analizar la aplicación de esta herramienta, se analizaron tres escenarios ubicados en diferentes regiones biogeográficas de Colombia y como grupo hidrobiológico indicador se utilizaron las algas perifíticas y fitoplanctónicas. Los ecosistemas fueron monitoreados entre los años 2007 y 2015 y corresponden a una planicie de inundación, un río andino de alta montaña y un grupo de quebradas en un bosque húmedo tropical. Resultados: Entre los resultados generales, las matrices de variables respuesta determinaron correlaciones canónicas con (p<0,005) y un modelo de promedios ponderados permitió estimar el óptimo y la tolerancia de cada taxon para la clasificación ecológica de los sitios; variables relacionadas con la concentración de iones, la amortiguación de la acidez, la temperatura y la hidráulica, incidieron en los modelos que explicaban la distribución de las abundancias de los grupos biológicos estudiados. Conclusiones: La aplicación del índice permite identificar variables, organismos y ordenamientos numéricos que posibilitan clasificar el estado ecológico en un sistema, resultados útiles en el diagnóstico y seguimiento de los ecosistemas acuáticos estudiados y que pueden ser implementados con otros escenarios.

This work presents a photodissociation study of the diamondoid adamantane using extreme ultraviolet femtosecond pulses. The fragmentation dynamics of the dication is unraveled by the use of advanced ion and electron spectroscopy giving access to the dissociation channels as well as their energetics. To get insight into the fragmentation dynamics, we use a theoretical approach combining potential energy surface determination, statistical fragmentation methods and molecular dynamics simulations. We demonstrate that the dissociation dynamics of adamantane dications takes place in a two-step process: barrierless cage opening followed by Coulomb repulsion-driven fragmentation ; This research was supported by the Swedish Research Council, the Swedish Foundation for Strategic Research and the Crafoord Foundation. This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant Agreement No. 641789 MEDEA and under grant agreement no 654148 Laserlab-Europe. The research was conducted in the framework of the International Associated Laboratory (LIA) Fragmentation DYNAmics of complex MOlecular systems - DYNAMO, funded by the Centre National de la Recherche Scientifique (CNRS). The authors acknowledge the generous allocation of computer time at the Centro de Computación Científica at the Universidad Autónoma de Madrid (CCC-UAM). This work was partially supported by the project CTQ2016-76061-P of the Spanish Ministerio de Economía y Competitividad (MINECO). Financial support from the MINECO through the "María de Maeztu" Program for Units of Excellence in R&D (MDM-2014-0377) is also acknowledged