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Mechanosensitive ion channels are expressed in the central nervous system of the medicinal leech. The plasma membranes of neurons whose primary function is not sensory contain stretch-activated cation channels in relatively high density. Different stimuli, associated with membrane deformation, such as perfusion with hypotonic solutions or pressure pulses applied to the patch pipette, increase the channel's open probability. These cation channels contribute to macroscopic elevations of intracellular free calcium concentration produced by cell mechanical stimulation. Leech cation channels exhibit two activity modes differing both in kinetics and in conductance. In regenerating neurons one of these modes, characterized by long mean channel open time and high mechanosusceptibility, is preferentially expressed. Gentamicin, a voltage-dependent blocker of these channels, affects the neurite growth in culture. A possible role of mechanosensitive cation channels in the processes of neurite growth is discussed.

This study deals with the creation of a model to define the best allocation within the area of new projects for road infrastructures, and to evaluate the effectiveness of a road which is part of a wide-ranging project currently under construction, known as the Marches-Umbria Quadrilateral Project. The aim of the work is to develop a speedy, versatile instrument which will be able not only to calculate but also to interpret and correlate the various environmental, social, economic, technical and operational aspects of the construction of road works. Special attention is paid to the dynamics of the use and consumption of the natural habitats and the problems linked to the phenomena of ecological fragmentation caused by the road network and by settlements. The methodology which has been developed includes the collection and implementation within a dedicated territorial informative system of a wide range of information capable of defining the special characteristics of the area under study, which will then be interpreted and summarised by means of the application of a series of specific indicators. The defined indicators are subsequently integrated by applying techniques of multi-criterial analysis to define an index of concise evaluation capable of assessing and supporting the sensitivity of the territory to the integration of new road infrastructures. In order to validate the methodology, the proposed indices were applied to a study area in which a road infrastructure of considerable importance is currently being built to link central Italy from one side of the country to the other. El trabajo contempla la creación de un modelo para definir la mejor localización en el territorio de nuevos proyectos de infraestructuras viarias y su convalidación en una carretera que forma parte de un proyecto de gran envergadura denominado Cuadrilátero Marcas-Umbría, en vías de realización. El objetivo del trabajo consiste en la puesta a punto de una herramienta ágil y versátil, capaz de sopesar, interpretándolos de forma correlacionada, los distintos aspectos de carácter medioambiental, socioeconómico, técnico y operativo, ligados a la construcción de una obra viaria. Se ha prestado especial atención a las dinámicas de uso y consumo de los hábitats naturales y a las problemáticas vinculadas a los fenómenos de fragmentación ecológica provocados por la red viaria y los asentamientos. La metodología que se ha puesto a punto prevé la recogida y la implementación, dentro de un sistema de información territorial dedicado, de un amplio abanico de datos capaces de definir las características peculiares del ámbito que es objeto del estudio, posteriormente interpretados y reconducidos a síntesis mediante la aplicación de una serie de indicadores específicos. Los indicadores definidos se incorporan posteriormente mediante la aplicación de técnicas de análisis multicriterio para definir un índice de evaluación sintético capaz de estimar de forma correlacionada la sensibilidad del territorio ante la introducción de nuevas infraestructuras viarias. Para convalidar la metodología, los índices propuestos se han aplicado a un área de estudio donde se está construyendo una infraestructura viaria de importancia considerable para las conexiones transversales de Italia central.