Landslide Hazard and Risk Mapping Using the Weighted Linear Combination Model Applied to the Tevankarai Stream Watershed,Kodaikkanal, India

Natural hazards like landslides, earthquakes, and floods are a major deterrent to the development of mountain regions of the world. Recently, there has been a rise in the number of landslides in Western Ghats, India. Several factors cause landslides and they depend on the local geo-environmental set-up of the region. This study attempts to map the spatial distribution of landslide hazard and analyze the risk for a typical hill town, Kodaikkanal in the Western Ghats, India, facing rapid urbanization and infra-structure growth, using a weighted linear combination model in a geographic information system platform. Landslides in the region are triggered by rainfall and it is fairly uniform throughout the area. Hence, the susceptibility map is used as the hazard map. Validation of the weighted linear combination model using landslide hazard index shows that landslide density increases with the hazard class. The risk assessment matrix (RAM) is used to evaluate risk based on the land use and landslide hazard category. The land use map is reclassified by assigning damage potential for each land use feature. The risk map is classified into low, moderate, and high risk categories. Suitable control measures are suggested for various risk categories.     

Enhanced glutamate,IP3 and cAMP activity in the cerebral cortex of Unilateral 6-hydroxydopamine induced Parkinson's rats: Effect of 5-HT,GABA and bone marrow cell supplementation

Parkinson's disease is characterized by progressive cell death in the substantia nigra pars compacta, which leads to dopamine depletion in the striatum and indirectly to cortical dysfunction. Increased glutamatergic transmission in the basal ganglia is implicated in the pathophysiology of Parkinson's disease and glutamate receptor mediated excitotoxicity has been suggested to be one of the possible causes of the neuronal degeneration. In the present study, the effects of serotonin, gamma-aminobutyric acid and bone marrow cells infused intranigrally to substantia nigra individually and in combination on unilateral 6-hydroxydopamine induced Parkinson's rat model was analyzed. Scatchard analysis of total glutamate and NMDA receptor binding parameters showed a significant increase in B_max (P < 0.001) in the cerebral cortex of 6-hydroxydopamine infused rat compared to control. Real Time PCR amplification of NMDA2B, mGluR5, bax, and ubiquitin carboxy-terminal hydrolase were up regulated in cerebral cortex of 6-hydroxydopamine infused rats compared to control. Gene expression studies of GLAST, ά-Synuclien and Cyclic AMP response element-binding protein showed a significant (P < 0.001) down regulation in 6-OHDA infused rats compared to control. Behavioural studies were carried out to confirm the biochemical and molecular studies. Serotonin and GABA along with bone marrow cells in combination showed reversal of glutamate receptors and behaviour abnormality shown in the Parkinson's rat model. The therapeutic significance in Parkinson's disease is of prominence.