988 resultados para Cyanex 923
Resumo:
Purpose. Mice rendered hypoglycemic by a null mutation in the glucagon receptor gene Gcgr display late-onset retinal degeneration and loss of retinal sensitivity. Acute hyperglycemia induced by dextrose ingestion does not restore their retinal function, which is consistent with irreversible loss of vision. The goal of this study was to establish whether long-term administration of high dietary glucose rescues retinal function and circuit connectivity in aged Gcgr−/− mice. Methods. Gcgr−/− mice were administered a carbohydrate-rich diet starting at 12 months of age. After 1 month of treatment, retinal function and structure were evaluated using electroretinographic (ERG) recordings and immunohistochemistry. Results. Treatment with a carbohydrate-rich diet raised blood glucose levels and improved retinal function in Gcgr−/− mice. Blood glucose increased from moderate hypoglycemia to euglycemic levels, whereas ERG b-wave sensitivity improved approximately 10-fold. Because the b-wave reflects the electrical activity of second-order cells, we examined for changes in rod-to-bipolar cell synapses. Gcgr−/− retinas have 20% fewer synaptic pairings than Gcgr+/− retinas. Remarkably, most of the lost synapses were located farthest from the bipolar cell body, near the distal boundary of the outer plexiform layer (OPL), suggesting that apical synapses are most vulnerable to chronic hypoglycemia. Although treatment with the carbohydrate-rich diet restored retinal function, it did not restore these synaptic contacts. Conclusions. Prolonged exposure to diet-induced euglycemia improves retinal function but does not reestablish synaptic contacts lost by chronic hypoglycemia. These results suggest that retinal neurons have a homeostatic mechanism that integrates energetic status over prolonged periods of time and allows them to recover functionality despite synaptic loss.
Resumo:
Existen dos mitos fuertemente arraigados en un amplio sector de la sociedad española, convencido, por una parte, que la edad de setenta años constituye una patente de corso para delinquir sin que la consecuencia jurídica asociada entrañe el ingreso en prisión y, por otra, que quien se halla cumpliendo condena en un establecimiento penitenciario y alcanza dicha edad obtiene, de manera automática, la libertad condicional. Sin embargo, no solo ambas creencias han carecido, desde siempre, de escarpia normativa que las sustentase, sino que la realidad penitenciaria ha evidenciado, desde antiguo, la presencia de ancianos en sus centros.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Nieuwe Platte Grond Vande Stad Rotterdam geleege aand Rivierea de Maase en de Rotte = Plan nouveau de la ville de Rotterdam située sur les Rivieres de la Meuse et de la Rotte, Henry de Leth, a l'enseigne du Pêcheur. It was published by J. Covens & Zoon in 1768. Scale [ca.1:3,923]. Covers Rotterdam, Netherlands. Map in Dutch and French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'RD_New (Rijksdriehoekstelsel), GCS Amersfoort' coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, built-up areas and selected buildings, fortification, ground cover, docks, wharves, canals, windmills, and more. Includes index. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.
Resumo:
Solar heating of potable water has traditionally been accomplished through the use of solar thermal (ST) collectors. With the recent increases in availability and lower cost of photovoltaic (PV) panels, the potential of coupling PV solar arrays to electrically heated domestic hot water (DHW) tanks has been considered. Additionally, innovations in the SDHW industry have led to the creation of photovoltaic/thermal (PV/T) collectors, which heat water using both electrical and thermal energy. The current work compared the performance and cost-effectiveness of a traditional solar thermal (ST) DHW system to PV-solar-electric DHW systems and a PV/T DHW system. To accomplish this, a detailed TRNSYS model of the solar hot water systems was created and annual simulations were performed for 250 L/day and 325 L/day loads in Toronto, Vancouver, Montreal, Halifax, and Calgary. It was shown that when considering thermal performance, PV-DHW systems were not competitive when compared to ST-DHW and PVT-DHW systems. As an example, for Toronto the simulated annual solar fractions of PV-DHW systems were approximately 30%, while the ST-DHW and PVT-DHW systems achieved 65% and 71% respectively. With current manufacturing and system costs, the PV-DHW system was the most cost-effective system for domestic purposes. The capital cost of the PV-DHW systems were approximately $1,923-$2,178 depending on the system configuration, and the ST-DHW and PVT system were estimated to have a capital cost of $2,288 and $2,373 respectively. Although the capital cost of the PVT-DHW system was higher than the other systems, a Present Worth analysis for a 20-year period showed that for a 250 L/day load in Toronto the Present Worth of the PV/T system was approximately $4,597, with PV-DHW systems costing approximately $7,683-$7,816 and the ST-DHW system costing $5,238.
Resumo:
O processo de reforma da lei de direitos autorais brasileira (Lei 9.610/98) teve início em 2007, durante a gestão de Gilberto Gil no Ministério da Cultura, a partir do Fórum Nacional de Direito Autoral, do debate público e da consulta online do anteprojeto de modernização da lei. Desde então, o país presenciou movimentos de avanço e estagnação da reforma, esperando-se que com a nomeação de Juca Ferreira para o Ministério da Cultura em 2015, a reforma da lei entre novamente em pauta. Contudo, existem diversos desafios nesse percurso que serão brevemente analisados neste artigo.
Resumo:
The work in this sub-project of ESOP focuses on the advective and convective transforma-tion of water masses in the Greenland Sea and its neighbouring areas. It includes observational work on the sub-mesoscale and analysis of hydrographic data up to the gyre-scale. Observations of active convective plumes were made with a towed chain equipped with up to 80 CTD sensors, giving a horizontal and vertical resolution of the hydrographic fields of a few metres. The observed scales of the penetrative convective plumes compare well with those given by theory. On the mesoscale the structure of homogeneous eddies formed as a result of deep convection was observed and the associated mixing and renewal of the intermediate layers quantified. The relative importance and efficiency of thermal and haline penetrative convection in relation to the surface boundary conditions (heat and salt fluxes and ice cover) and the ambient stratification are studied using the multi year time series of hydro-graphic data in the central Greenland Sea. The modification of the water column of the Greenland Sea gyre through advection from and mixing with water at its rim is assessed on longer time scales. The relative contributions are quantified using modern water mass analysis methods based on inverse techniques. Likewise the convective renewal and the spreading of the Arctic Intermediate Water from its formation area is quantified. The aim is to budget the heat and salt content of the water column, in particular of the low salinity surface layer, and to relate its seasonal and interannual variability to the lateral fluxes and the fluxes at the air-sea-ice interface. This will allow to estimate residence times for the different layers of the Greenland Sea gyre, a quantity important for the description of the Polar Ocean carbon cycle.