1,306 research outputs found

    Effects of different plant leaf extracts on postharvest life and quality of mango

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    An experiment was carried out to investigate the efficacy of plant leaf extracts on elongation of shelf life and maintenance of quality of harvested mangoes. Freshly harvested mature green mangoes cv. 'Calcuttia maldah' of uniform size and weight were dipped in 50% concentration of different plant leaf extracts and stored in ambient condition (32±2ºC and 65±5 % RH). The treatments were leaf extracts from five different plants viz. neem (Azadirachta indica), Chinaberry (Melia azadirach), lantana (Lantana camara), ashok (Polyalthea longifolia) and cinnamomum (Cinnamomum zeylanicum) while control was the other treatment. In addition, carbendazim (fungicide) was also kept as a benchmark treatment. Each treatment composed of 5 mangoes and replicated thrice. For each replication destructive sample was also kept. The treatment with neem leaf extract gave the most promising result as there was minimum physiological weight loss, maximum ascorbic acid content, maximum acidity and minimum pH. Similarly, shelf life, total soluble solids, freshness and firmness were highest in neem leaf extract treated fruits next to the carbendazim treated fruits. Control was the most ineffective of all the treatment regarding all the parameters

    Vegetation composition and soil nutrients status from polyculture to monoculture

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    The study was conducted on status of nutrients in three major types of forests namely, broad-leaved, mixed pine and pine forests in Meghalaya, considering altitude and seasonality as variables. The findings revealed that the change in micro-environmental conditions as influenced by attitude and seasonality has marked effect on status and release of nutrients in the soil of representative forest stands at markedly difference. The ambient and soil temperature was sharply greater at high altitude (Upper Shillong) and values were decreased from broad-leaved to pine forests. The soil temperature was lower than air temperature in all cases. The soil temperature at low altitude (Umroi) during postmonsoon season was higher than pre-monsoon season; however, on the contrary, it was higher during pre-monsoon season in other cases. The light interception decreased from broad-leaved to pine forests, and greater values were recorded at high altitude. The light interception and temperature played a key role in determining relative humidity, and as a result more relative humidity was recorded at high altitude and the values were decreased from broad-leaved to pine forests. The litter thickness and litter accumulation on forest floor at high altitude was about two fold greater than representative forest at low altitude. The values were higher during post-monsoon season, except that more litter thickness was noticed during pre-monsoon season at high altitude; this could be linked with high litter production and low rate of litter decomposition. Soil moisture content was always higher in top-soil, and post-monsoon season showed greater values. Soil pH ranged from 4.6 to 5.8 in top-soil, and from 4.8 to 6.3 in sub-soil. High rate of litter decomposition leads to greater soil pH in top-soil during postmonsoon season. The organic carbon, total nitrogen and available phosphorus contents were more in top-soil, with exception that the phosphorus content was generally higher in sub-soil during postmonsoon season. The values for soil moisture, organic carbon, nitrogen, and phosphorus were markedly higher at high altitude with respect to forest types and seasonality. Normally, the nutrient poor soil has high C:N ratio, and on account of this fertility of soil decreased from polyculture to monoculture. The finding reveal that the C:N ratio was increased from broad-leaved to pine forests, and more values were observed in sub-soil.Key words: Altitude, monoculture, nutrient release, polyculture, seasonality, top-soil and sub-soil, vegetation

    Practical computational toolkits for dendrimers and dendrons structure design

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    Dendrimers and dendrons offer an excellent platform for developing novel drug delivery systems and medicines. The rational design and further development of these repetitively branched systems are restricted by difficulties in scalable synthesis and structural determination, which can be overcome by judicious use of molecular modelling and molecular simulations. A major difficulty to utilise in silico studies to design dendrimers lies in the laborious generation of their structures. Current modelling tools utilise automated assembly of simpler dendrimers or the inefficient manual assembly of monomer precursors to generate more complicated dendrimer structures. Herein we describe two novel graphical user interface (GUI) toolkits written in Python that provide an improved degree of automation for rapid assembly of dendrimers and generation of their 2D and 3D structures. Our first toolkit uses the RDkit library, SMILES nomenclature of monomers and SMARTS reaction nomenclature to generate SMILES and mol files of dendrimers without 3D coordinates. These files are used for simple graphical representations and storing their structures in databases. The second toolkit assembles complex topology dendrimers from monomers to construct 3D dendrimer structures to be used as starting points for simulation using existing and widely available software and force fields. Both tools were validated for ease-of-use to prototype dendrimer structure and the second toolkit was especially relevant for dendrimers of high complexity and size.Peer reviewe

    Simulations of extensional flow in microrheometric devices

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    We present a detailed numerical study of the flow of a Newtonian fluid through microrheometric devices featuring a sudden contraction–expansion. This flow configuration is typically used to generate extensional deformations and high strain rates. The excess pressure drop resulting from the converging and diverging flow is an important dynamic measure to quantify if the device is intended to be used as a microfluidic extensional rheometer. To explore this idea, we examine the effect of the contraction length, aspect ratio and Reynolds number on the flow kinematics and resulting pressure field. Analysis of the computed velocity and pressure fields show that, for typical experimental conditions used in microfluidic devices, the steady flow is highly three-dimensional with open spiraling vortical structures in the stagnant corner regions. The numerical simulations of the local kinematics and global pressure drop are in good agreement with experimental results. The device aspect ratio is shown to have a strong impact on the flow and consequently on the excess pressure drop, which is quantified in terms of the dimensionless Couette and Bagley correction factors. We suggest an approach for calculating the Bagley correction which may be especially appropriate for planar microchannels

    Effect of Crop Establishment Methods on Crop Yield, Weed Dynamics, Profitability and Nutrient Uptake Under Rice-Wheat Cropping System of Indo-Gangetic Plains of Eastern India

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    The rice–wheat cropping system covering 13.5 million ha in the Indo-Gangetic Plains in South-Asia is vital for food security. Water, energy and labour scarcity, increasing cost of production, diminishing farm profit and the changing climate are major challenges faced by the farmers under intensive tillage based conventional practices. In a field study, we evaluated productivity, weed dynamics, nutrient uptake and economical profitability of four wheat establishment methods during two years. The wheat establishment methods included zero-till wheat (ZTW), happy seeder planted wheat (HSW), bed planted wheat (BPW) and conventional till wheat (CTW). The treatments were completely randomized and replicated five times. Wheat grain yield under HSW was 3.4% and 4.1% higher than BPW, 8.3% and 11.0% higher than ZTW and 20.8% and 24.5% higher than CTW in 2012-13 and 2013-14, respectively. Nutrient (N, P and K) uptake in wheat grain was also higher in HSW than in the other treatments. Weed density and biomass was the lowest under HSW followed by BPT, and the highest in CTW. The weed pressure was reduced in the second growing season compared to the first. Net profit and benefit cost ratio was highest under HSW and the lowest under CTW. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Apoptosis-like cell death in Leishmania donovani treated with KalsomeTM10, a new liposomal amphotericin B

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    The present study aimed to elucidate the cell death mechanism in Leishmania donovani upon treatment with KalsomeTM10, a new liposomal amphotericin B. Methodology/Principal findings We studied morphological alterations in promastigotes through phase contrast and scanning electron microscopy. Phosphatidylserine (PS) exposure, loss of mitochondrial membrane potential and disruption of mitochondrial integrity was determined by flow cytometry using annexinV-FITC, JC-1 and mitotraker, respectively. For analysing oxidative stress, generation of H2O2 (bioluminescence kit) and mitochondrial superoxide O2 − (mitosox) were measured. DNA fragmentation was evaluated using terminal deoxyribonucleotidyl transferase mediated dUTP nick-end labelling (TUNEL) and DNA laddering assay. We found that KalsomeTM10 is more effective then Ambisome against the promastigote as well as intracellular amastigote forms. The mechanistic study showed that KalsomeTM10 induced several morphological alterations in promastigotes typical of apoptosis. KalsomeTM10 treatment showed a dose- and time-dependent exposure of PS in promastigotes. Further,study on mitochondrial pathway revealed loss of mitochondrial membrane potential as well as disruption in mitochondrial integrity with depletion of intracellular pool of ATP. KalsomeTM10 treated promastigotes showed increased ROS production, diminished GSH levels and increased caspase-like activity. DNA fragmentation and cell cycle arrest was observed in KalsomeTM10 treated promastigotes. Apoptotic DNA fragmentation was also observed in KalsomeTM10 treated intracellular amastigotes. KalsomeTM10 induced generation of ROS and nitric oxide leads to the killing of the intracellular parasites. Moreover, endocytosis is indispensable for KalsomeTM10 mediated anti-leishmanial effect in host macrophag

    Monolithic InAs QDs based Active-Passive Integration for Photonic Integrated Circuits

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    We demonstrated 20 nm relative blue shifted III-V passive waveguides monolithically integrated with InAs QDs active laser diode emitting at 1290 nm through selective area proton implantation and post-annealing method. This work is promising for low-loss monolithic Photonic Integrated Circuits
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