Rotenone induces degeneration of photoreceptors and impairs the dopaminergic system in the rat retina

Rotenone is a widely used pesticide and a potent inhibitor of mitochondrial complex I (NADH-quinone reductase) that elicits the degeneration of dopaminergic neurons and thereby the appearance of a parkinsonian syndrome. Here we have addressed the alterations induced by rotenone at the functional, morphological and molecular levels in the retina, including those involving both dopaminergic and non-dopaminergic retinal neurons. Rotenone-treated rats showed abnormalities in equilibrium, postural instability and involuntary movements. In their outer retina we observed a loss of photoreceptors, and a reduced synaptic connectivity between those remaining and their postsynaptic neurons. A dramatic loss of mitochondria was observed in the inner segments, as well as in the axon terminals of photoreceptors. In the inner retina we observed a decrease in the expression of dopaminergic cell molecular markers, including loss of tyrosine hydroxylase immunoreactivity, associated with a reduction of the dopaminergic plexus and cell bodies. An increase in immunoreactivity of AII amacrine cells for parvalbumin, a Ca2+-scavenging protein, was also detected. These abnormalities were accompanied by a decrease in the amplitude of scotopic and photopic a- and b-waves and an increase in the b-wave implicit time, as well as by a lower amplitude and greater latency in oscillatory potentials. These results indicate that rotenone induces loss of vision by promoting photoreceptor cell death and impairment of the dopaminergic retinal system.

El arquitecto Francisco Fernández Molina (1899-1929)

En el período de máximo esplendor de la arquitectura urbana de la ciudad de Albacete, primer tercio del siglo XX, destaca y sorprende la figura del arquitecto Francisco Fernández Molina por dos razones: primera, porque sus numerosos proyectos se concentran entre los años 1924 y 1929 y, segunda, porque todos ellos presentan un especial esmero puesto tanto en la composición como en los detalles, a pesar de tratarse, en la mayoría de los casos, de encargos modestos, entendiendo por tales tanto su entidad (viviendas particulares) como su emplazamiento (periférico) en el casco urbano. El presente trabajo recopila los datos biográficos disponibles de su autor a la vez que selecciona y analiza en profundidad una muestra representativa de sus obras con el objetivo de conocer y dar a conocer a este arquitecto albaceteño al cual el municipio dedicó una de sus calles. Para la consecución de este objetivo, se ha vaciado los archivos municipal y provincial, se ha rastreado la ciudad en busca de las posibles obras en pie, se ha seleccionado los proyectos, reproducido su documentación y dado buena cuenta de sus características y cualidades. Se pretende que el estudio de la vida y obra del arquitecto Francisco Fernández Molina sirva para valorar la figura de este insigne profesional y, con ella, recuperar parte de nuestra memoria que, maltrecha por las demoliciones indiscriminadas que ha sufrido el patrimonio arquitectónico de Albacete, ha de nutrirse de esas actas de su pasado llamadas proyectos.

Tasas de deformación GPS en la cuenca del Bajo Segura (Cordillera Bética oriental)

En este trabajo hemos cuantificado las tasas de deformación actual de la cuenca del Bajo Segura (NE del corredor de cizalla de la Bética oriental), a partir del análisis de una red GPS con 11 vértices geodésicos. Se han analizado los datos de cuatro campañas GPS entre junio de 1999 y enero de 2013, que han sido procesados con la versión 6.2 del software GIPSY-OASIS. Este software utiliza la técnica de posicionamiento puntual de precisión conocido por las siglas PPP. Se observa un acortamiento ~N-S en toda la cuenca de mayor magnitud en el sur, en la zona de falla del Bajo Segura, con valores que varían de oeste a este entre 0,73 y 0,24 mm/año. En el borde septentrional de la cuenca, en la zona de falla de Crevillente, los valores de acortamiento N-S son menores. Sin embargo, en esta falla se ha observado un movimiento lateral sinistrorso que, en la componente E-O, varía entre 0,44 y 0,75 mm/año.

Fortification and Frontier: The Project Drawn up by Juan Martín Zermeño for Puebla de Sanabria in 1766

Following the death of engineer General Jorge Próspero de Verboom in 1744 and after a few years of transition in the management of Spanish fortifications, Juan Martín Zermeño took on the role, initially with a temporary mandate, but then definitively during a second period that ran from 1766 until his death in 1772. He began this second period with a certain amount of concern because of what had taken place during the last period of conflict. The Seven Years War (1756–1763) which had brought Spain into conflict with Portugal and England in the Caribbean had also lead to conflict episodes along the Spanish–Portuguese border. Zermeño’s efforts as a planner and general engineer gave priority to the northern part of the Spanish–Portuguese border. After studying the territory and the existing fortifications on both sides of the border, Zermeño drew up three important projects in 1766. The outposts that needed to be reinforced were located, from north to south, at Puebla de Sanabria, Zamora and Ciudad Rodrigo, which is where he is believed to have come from. This latter township already had a modern installation built immediately after the war of the Spanish Succession and reinforced with the Fort of La Concepción. However, Zamora and Puebla de Sanabria had some obsolete fortifications that needed modernising. Since the middle of the 15th century Puebla de Sanabria had had a modern castle with rounded turrets, that of the counts of benavente. During the 16th and 17th centuries it had also been equipped with a walled enclosure with small bastions. During the war of the Spanish Succession the Portuguese had enlarged the enclosure and had erected a tentative offshoot to the west. In order to draw up the ambitious Puebla de Sanabria project Zermeño had the aid of some previous reports and projects, such as those by the count of robelin in 1722, the one by Antonio de Gaver in 1752, and Pedro Moreau’s report dated June 1755. This study includes a technical analysis of Zermeño’s project and its strategic position within the system of fortifications along the Spanish–Portuguese border.