Subash Dhakal

Ammonia and its amine-containing derivatives are widely found in natural decomposition byproducts. Here, we conducted biased chemoreceptor screening to investigate the mechanisms by which different concentrations of ammonium salt, urea, and putrescine in rotten fruits affect feeding and oviposition behavior. We identified three ionotropic receptors, including the two broadly required IR25a and IR76b receptors, as well as the narrowly tuned IR51b receptor. These three IRs were fundamental in eliciting avoidance against nitrogenous waste products, which is mediated by bitter-sensing gustatory receptor neurons (GRNs). The aversion of nitrogenous wastes was evaluated by the cellular requirement by expressing Kir2.1 and behavioral recoveries of the mutants in bitter-sensing GRNs. Furthermore, by conducting electrophysiology assays, we confirmed that ammonia compounds are aversive in taste as they directly activated bitter-sensing GRNs. Therefore, our findings provide insights into the ec...

Stone quarries and stone crushing are a global phenomenon and have been a cause of concern everywhere. Stone quarrying around Ahmednagar city which lies in between 19 02' 50'' N to 19 07' 44'' N latitude and 74 35' 16'' E to 74 48' 00'' E longitude, has seen tremendous growth in the last decade. The quarrying activities have grown because of the growing urbanization, enormous demand for housing and abundant availability of rocky hills in the surroundings. It has enormous impact on the environment, people and ecology. For the present study, three areas around Ahmednagar city were selected and a total of 33 quarries were distributed in these areas. All the sites were visited and the people were interviewed. Traffic flow survey was conducted to find out the frequency of quarrying vehicles plying back and forth from the quarrying sites. It was found that the growth of quarrying activity has put enormous pressure on the rare vegetal cover i...

River bed and floodplain sediments are a direct reflection of river channel processes. This paper examines sediment transfer processes at river junctions, using as a case study the River Kas, a tributary of the River Mula, Godavari basin, Maharashtra, India. The study uses four cross-sections, two from upstream tributaries, one in the main confluence zone, and one downstream. Sediment samples are collected from each cross-section and adjacent banks. To understand the tributary impact on the main channel, variations in sand, silt and clay percentages and variations in the shape of sediment particles were recorded. Data suggest that the percentage of silt and clay increased away from the active channel towards banks along a cross-section, except for the mid-channel bar and the downstream segment of the confluence. The `a axis' and `c axis' lengths of particles increased for the samples on the confluence compared to upstream and downstream samples. Sediment characteristics betw...