Exposure to enriched environment improves spatial learning performances and enhances cell density but not choline acetyltransferase activity in the hippocampus of ventral subicular-lesioned rats.

The authors demonstrated the efficacy of enriched housing conditions in promoting the behavioral recovery and neuronal survival following subicular lesion in rats. Chemical lesioning of the ventral subiculum impaired the spatial learning performances in rats. The lesion also induced a significant degree of neurodegeneration in the CA1 and CA3 areas of the hippocampus and entorhinal cortex. Exposure to enriched housing conditions improved the behavioral performance and partially attenuated the neurodegeneration in the hippocampus. The choline acetyl transferase (ChAT) activity in the hippocampus remained unchanged following ventral subicular lesion and also following exposure to an enriched environment. The study implicates the effectiveness of activity-dependent neuronal plasticity induced by environmental enrichment in adulthood following brain insult. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development and quality evaluation of cooked buffalo tripe rolls

Cooked buffalo tripe rolls (BTRs) were prepared from a combination of buffalo tripe (75%) and buffalo meat (25%) by using mincing (M-BTR) and blade tenderization (BT-BTR). They were stored at 4 ± 1 °C and studied for various physico-chemical, sensory and microbial qualities. Significantly (P < 0.01) higher pH, shear force value, diameter shrinkage and fat percentage were observed in M-BTR and BT-BTR than control product (100% minced buffalo meat). The product yield and drip loss percentage were significantly (P < 0.01) lower in BT-BTR, whereas drip loss percentage was significantly higher in M-BTR compared to controls and BT-BTR. No significant change was noticed in protein and moisture content between the different products. All physico-chemical parameters and sensory evaluation scores of M-BTR were comparable with control. Significant (P < 0.01) increases were noticed in pH, moisture content, thiobarbituric acid and tyrosine values with increasing storage period, whereas the extract release volume decreased significantly. All microbial counts and sensory evaluation scores were within the acceptable limits until 15 days of storage at 4 ± 1 °C in low-density polyethylene pouches stored aerobically.     

Structural Characteristics and Electrical Conductivity of Spark Plasma Sintered Ytterbia Co‐doped Scandia Stabilized Zirconia

The effect of replacing Sc₂O₃ with Yb₂O₃ on the structural and electrical properties of xYb₂O₃–(12–x)Sc₂O₃–88ZrO₂ has been investigated. Spark plasma sintering technique is employed to fabricate dense bulk samples from the nano‐sized powders. X‐ray diffraction and transmission electron microscopy performed on pellets indicate the existence of cubic and rhombohedral phases in 12ScSZ, and a single cubic phase in all the co‐doped compositions. However, Raman spectroscopic studies suggest the presence of a metastable tetragonal t″‐phase along with rhombohedral phases in 12ScSZ, whereas a single cubic phase in all the co‐doped compositions. Significant enhancement in the conductivity of grain and grain boundary is observed on replacing Sc₂O₃ with Yb₂O₃. In the intermediate temperature range, 1Yb11ScSZ exhibits the highest, while 12ScSZ shows the lowest conductivity values, which is attributed to corresponding phases present in that range. Through co‐doping with >1 mol% Yb₂O₃ leads to conductivity decrease, but the value remains higher than that of 12ScSZ. A sharp conductivity change is observed in 12ScSZ and 1Yb11ScSZ samples, which is attributed to partial phase transition as well to the formation of cation‐vacancy complexes. In this work, the beneficial effect of Yb₂O₃ co‐doping in 12ScSZ on the phase and conductivity has been highlighted.     

Multi-mode hydrogen storage in nanocontainers

Hydrogen can be stored in containers or in materials (in molecular or atomic forms). The atomic form can further exist as multiple phases. Molecular hydrogen can be adsorbed on the surface or can be present inside the material. By invoking multiple modes of hydrogen storage, we establish a paradigm shift in the philosophy of hydrogen storage. Using a novel strategy of storage of molecular hydrogen in metal (Pd) nanocontainers, we observe that 18% hydrogen is in molecular form. Interestingly, this is achieved at 25 °C and 1 atm pressure; which is in contrast to storage in MOFs and carbonaceous materials like nanotubes. Enhancement in storage capacity as compared to Pd nanocrystals of the same mass is observed (36% increase at 1 atm & 25 °C), along with fast kinetics (0.5 wt% hydrogen absorption in 5 s). A new mechanism for hydrogen storage involving the dual catalytic role of Pd is established.     

Energy Efficient Routing Technique for Wireless Sensor Networks Using Ant-Colony Optimization

Wireless sensor networks (WSN) consists of numerous number of nodes fitted with energy reserves to collect large amount of data from the environment on which it is deployed. Energy conservation has huge importance in wsn since it is virtually impossible to recharge the nodes in their remote deployment. Forwarding the collected data from nodes to the base station requires considerable amount of energy. Hence efficient routing protocols should be used in forwarding the data to the base station in order to minimize the energy consumption thereby increasing the life-time of the network. In this proposed routing protocol, we consider a hierarchical routing architecture in which nodes in the outer-level forwards data to the inner-level nodes. Here we optimized the routing path using ant-colonies where data moves along minimal congested path. Further, when ant-colony optimization is used, certain cluster-head nodes may get overloaded with data forwarding resulting in early death due to lack of energy. To overcome this anomaly, we estimated the amount of data a neighboring Cluster-head can forward based on their residual energy. We compared the energy consumption results of this proposed Routing using Ant Colony Optimization (RACO) with other existing clustering protocols and found that this system conserves more energy thereby increasing lifetime of the network.

     

Temporal stability of oxygen-ion conductivity in 1Nb2O5-10Sc2O3-89ZrO2

A slight Nb₂O₅ co-doping in 11Sc₂O₃-89ZrO₂ was earlier reported to stabilize the high-symmetry cubic phase completely and enhances the conductivity significantly. The present work looked at the temporal stability of conductivity in 1Nb₂O₅-10Sc₂O₃-89ZrO₂ (1Nb10ScSZ) for the electrolyte application in solid oxide fuel cells. In-situ conductivity measurement was done using impedance spectroscopy at 650 °C in the air for 2000 h. A substantial conductivity loss (29%) was observed in the first 1000 h. Following which, conductivity remained relatively stable for the next 1000 h. Impedance analysis showed that the main contribution to the conductivity degradation was from grain conductivity. Phase analysis performed using XRD, TEM and Raman spectroscopy revealed that both the unaged and aged 1Nb10ScSZ samples consisted of metastable t″-phase. However, the extent of tetragonality was found to increase after ageing. The formation of low-symmetry phase was suggested to be the reason for the grain conductivity loss in 1Nb10ScSZ.     

Visual Enhancement of Underwater Images Using Transmission Estimation and Multi-Scale Fusion

The demand for the exploration of ocean resources is increasing exponentially. Underwater image data plays a significant role in many research areas. Despite this, the visual quality of underwater images is degraded because of two main factors namely, backscattering and attenuation. Therefore, visual enhancement has become an essential process to recover the required data from the images. Many algorithms had been proposed in a decade for improving the quality of images. This paper aims to propose a single image enhancement technique without the use of any external datasets. For that, the degraded images are subjected to two main processes namely, color correction and image fusion. Initially, veiling light and transmission light is estimated to find the color required for correction. Veiling light refers to unwanted light, whereas transmission light refers to the required light for color correction. These estimated outputs are applied in the scene recovery equation. The image obtained from color correction is subjected to a fusion process where the image is categorized into two versions and applied to white balance and contrast enhancement techniques. The resultants are divided into three weight maps namely, luminance, saliency, chromaticity and fused using the Laplacian pyramid. The results obtained are graphically compared with their input data using RGB Histogram plot. Finally, image quality is measured and tabulated using underwater image quality measures.     

Tensile fracture and thermal conductivity characterization of toughened epoxy/CNT nanocomposites

Rubber toughened epoxy/CNT nanocomposites were manufactured at different weight percents between 0 and 1% of multiwall carbon nanotube (MWNT) using a high intensity ultrasonic liquid processor with a titanium probe. Mechanical properties of manufactured dog bone samples were measured in tension and the results indicated a maximum of 23% increase in the elastic modulus at 0.6% by weight of MWNT. However, the fracture strength showed a maximum decrease of about 11% as a function of increasing MWNT loading. Scanning Electron Microscopy (SEM) images from the neat samples revealed a distinct circular pit at the top left edge of the specimen with an overall tearing deformation causing the fracture paths. Comparatively, all nanocomposite samples on an average seemed to show a prominent brittle fracture with little or no evidence of circular pit formation. The amount of tearing deformation seemed to be enhanced in the nanocomposite specimens as compare to the neat ones. Finally, Transmission Electron Microscopy images indicated that different states of dispersion exist in all of the nanocomposite samples. The data showed that agglomeration of nanotubes increases as a function of weight percent. In addition to mechanical property characterization, thermal conductivity of all the samples was determined as a function of temperature between 30 °C and 100 °C using the 3ω method. The tested samples showed an almost 16% increase in thermal conductivity. The minimal enhancement in thermal conductivity has been analyzed from the standpoint of the Effective Medium Theory. Interfacial thermal resistances exhibit no order of magnitude changes explaining the conductivity results.     

Transplantation of hippocampal cell lines restore spatial learning in rats with ventral subicular lesions.

We have demonstrated in our previous studies that ventral subicular lesion induces neurodegeneration of the hippocampus and produces cognitive impairment in rats. In the present study, the efficacy of transplanted green fluorescent protein (GFP)-labeled hippocampal cell line (H3-GFP) cells in establishing functional recovery in ventral subicular lesioned rats has been evaluated. The survival of H3-GFP transplants and their ability to express trophic factors in vivo were also investigated. Adult male Wistar rats were subjected to selective lesioning of ventral subiculum and were transplanted with H3-GFP cells into the cornu ammonis 1 (CA1) hippocampus. The transplants settled mainly in the dentate gyrus and expressed neurotrophic factors, brain-derived neurotrophic factor (BDNF), and basic fibroblast growth factor (bFGF). The ventral subicular lesioned (VSL) rats with H3-GFP transplants showed enhanced expression of BDNF in the hippocampus and performed well in eight-arm radial maze and Morris water maze tasks. The VSL rats without hippocampal transplants continued to show cognitive impairment in task learning. The present study demonstrated the H3-GFP transplants mediated recovery of cognitive functions in VSL rats. Our study supports the notion of graft meditated host regeneration and functional recovery through trophic support, although these mechanisms require further investigation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)