Altered NR2A/NR2B ratio in hippocampus of spatial learning-impaired aged rats

The activation of the N-methyl-D-aspartate receptor (NMDAR) is critical for the induction of synaptic plasticity in the hippocampus. Aging can alter glutamatergic synaptic transmission in the hippocampus, and cognitive impairments in aged animals are accompanied by reduced NMDARmediated plasticity at Schaffer collateral—CA1 synapses. However, the specific contribution of NMDAR subunits to NMDAR-mediated synaptic responses in aged tissue has not yet been fully understood. The main purpose of present study was to examine whether there is an impact of aging on NMDAR subunit expression and whether synaptic plasticity may depend on NMDAR subunit composition in the aged hippocampus

Altered NR2A/NR2B ratio in hippocampus of spatial learning-impaired aged rats

The activation of the N-methyl-D-aspartate receptor (NMDAR) is critical for the induction of synaptic plasticity in the hippocampus. Aging can alter glutamatergic synaptic transmission in the hippocampus, and cognitive impairments in aged animals are accompanied by reduced NMDARmediated plasticity at Schaffer collateral—CA1 synapses. However, the specific contribution of NMDAR subunits to NMDAR-mediated synaptic responses in aged tissue has not yet been fully understood. The main purpose of present study was to examine whether there is an impact of aging on NMDAR subunit expression and whether synaptic plasticity may depend on NMDAR subunit composition in the aged hippocampus

High Resolution Observations of Drop Size Distribution for GPM Ground Validation

During the Mid-latitude Continental Convective Cloud Experiment (MC3E), NASA's GPM GV Disdrometer and Radar Observations of Precipitation (DROP) Facility deployed an array of disdrometers and rain gauges in northern Oklahoma to sample, with high resolution, the drop size distribution for use in development of precipitation retrieval algorithms for the GPM core satellites. The DROP Facility instruments deployed during MC3E consisted of 16 autonomous Parsivel units, 5 two-dimensional video disdrometers (2dvds), a vertically pointing K band radar, and 32 tipping bucket rain gauges. There were several rainfall events during MC3E in which rain drops exceeding 6 mm in diameter were recorded. The disdrometer array revealed large rain drops with diameters exceeding 6 mm and 8 mm during two separate stratiform and convective rainfall events, respectively. The NPOL radar, which was scanning in high resolution RHI mode (every 40 sec) over the disdrometer array during the stratiform event, indicated a 1 km thick bright band with a differential reflectivity column of 2-3 dB extending below the melting layer to the surface where the large drops were recorded by the 2dvds. These large drops are important for GPM since they can have a great impact upon satellite precipitation retrieval, especially near the ground and below heavy convective rainfall cores where satellites have had problems depicting the rainfall

High-concentration compact agar gels from hydrothermal synthesis

3 páginas, 2 figuras, 1 tabla.-- et al.A simple hydrothermal method has been used to prepare for the first time high-concentration, microstructurally compact agar hydrogels (3–30 g agar per 100 ml H2O). These gels reach concentrations unachievable by conventional methods and overcome problems normally associated to them. They feature superior homogeneity, modified and controllable porosity, increased densities and higher strength, thus widening possible applications of this widely used biocompatible polysaccharide.Partial funding from the Spanish Ministry of Science and Innovation (MICINN) (CTQ2008-06779-C02-01).Peer reviewe

WRF Simulations of the 20-22 January 2007 Snow Events over Eastern Canada: Comparison with In-Situ and Satellite Observations

One of the grand challenges of the Global Precipitation Measurement (GPM) mission is to improve cold season precipitation measurements in middle and high latitudes through the use of high-frequency passive microwave radiometry. For this, the Weather Research and Forecasting (WRF) model with the Goddard microphysics scheme is coupled with a satellite data simulation unit (WRF-SDSU) that has been developed to facilitate over-land snowfall retrieval algorithms by providing a virtual cloud library and microwave brightness temperature (Tb) measurements consistent with the GPM Microwave Imager (GMI). This study tested the Goddard cloud microphysics scheme in WRF for two snowstorm events, a lake effect and a synoptic event, that occurred between 20 and 22 January 2007 over the Canadian CloudSAT/CALIPSO Validation Project (C3VP) site in Ontario, Canada. The 24h-accumulated snowfall predicted by the WRF model with the Goddard microphysics was comparable to the observed accumulated snowfall by the ground-based radar for both events. The model correctly predicted the onset and ending of both snow events at the CARE site. WRF simulations capture the basic cloud properties as seen by the ground-based radar and satellite (i.e., CloudSAT, AMSU-B) observations as well as the observed cloud streak organization in the lake event. This latter result reveals that WRF was able to capture the cloud macro-structure reasonably well

Catalytic Oxidation Of Methanol And Ethanol Via Nafion Supported Platinum/Gold Nanoparticles

Polymer electrolyte membrane fuels cells (PEMFC) have recently shown promise as an alternative energy source. PEMFCs were originally conceived for use with hydrogen, however fuels such as methanol and ethanol are gaining attention due to their stability at room temperature, making these fuels safer and easier to store. Studies have shown utilizing various nanoparticles, such as ceria and gold/platinum, at the surface of the electrode significantly increase the catalytic ability of the electorde to oxidize alcohols. Until recently, these nanoparticles have been allocated to the surface via electro-deposition, which is a difficult method to implement in industry. In this study, methods characterizing these nanoparticles were pursued as well as alternative methods of depositing these nanoparticles using nafion. These nafion supported electrodes have shown comparable catalytic capability as well as demonstrating an easier and more practical way of utilizing nanoparticles for alcohol oxidation

Anticardiolipin antibodies in Behcet's disease: a reassessment

Objective. To assess the frequency and clinical relevance of anticardiolipin antibodies (aCL) in Behcet's disease (BD)

Replacement of Natural Sand with Expanded Vermiculite in Fly Ash-Based Geopolymer Mortars

Increasing the thermal insulation of building components to reduce the thermal energy loss of buildings has received significant attention. Owing to its porous structure, using expanded vermiculite as an alternative to natural river sand in the development of building materials would result in improvement of the thermal performance of buildings. This study investigates the properties of fly ash (FA)-based geopolymer mortars prepared with expanded vermiculite. The main aim of this study was to produce geopolymer mortar with lower thermal conductivity than conventional mortar for thermal insulation applications in buildings. A total of twelve batches of geopolymers were prepared for evaluating their different properties. The obtained results show that, at a given FA and expanded vermiculite content, the geopolymers prepared with a 10 molar NaOH solution exhibited a higher flowability, water absorption and porosity, as well as a lower dry unit weight, compressive strength, ultrasound pulse velocity and thermal conductivity compared with those prepared with a 15 molar NaOH solution. As is also shown, the geopolymers containing expanded vermiculite (15%) developed a lower flowability (~6%), dry unit weight (~6%), compressive strength (~7%), ultrasound pulse velocity (~6%) and thermal conductivity (~18%), as well as a higher apparent porosity (~6%) and water absorption (~9%) compared with those without expanded vermiculite at a given FA content and NaOH concentration. The findings of this study suggest that incorporating expanded vermiculite in FA-based geopolymer mortar can provide eco-friendly and lightweight building composites with improved sound and thermal insulation properties, contributing toward the reduction of the environmental effects of waste materials and conservation of natural sand