Probing the Fermi surface and magnetotransport properties in MoAs2_{2}

Transition metal dipnictides (TMDs) have recently been identified as possible candidates to host topology protected electronic band structure. These materials belong to an isostructural family and show several exotic transport properties. Especially, the large values of magnetoresistance (MR) and carrier mobility have drawn significant attention from the perspective of technological applications. In this report, we have investigated the magnetotransport and Fermi surface properties of single crystalline MoAs$_{2}$, another member of this group of compounds. Field induced resistivity plateau and a large MR have been observed, which are comparable to several topological systems. Interestingly, in contrast to other isostructural materials, the carrier density in MoAs$_{2}$ is quite high and shows single-band dominated transport. The Fermi pockets, which have been identified from the quantum oscillation, are largest among the members of this group and have significant anisotropy with crystallographic direction. Our first-principles calculations reveal a substantial difference between the band structures of MoAs$_{2}$ and other TMDs. The calculated Fermi surface consists of one electron pocket and another 'open-orbit' hole pocket, which has not been observed in TMDs so far.Comment: 8 pages, 9 figure

Characterization of the restriction enzyme-like endonuclease encoded by the Entamoeba histolytica non-long terminal repeat retrotransposon EhLINE1

The genome of the human pathogen Entamoeba histolytica, a primitive protist, contains non-long terminal repeat retrotransposable elements called EhLINEs. These encode reverse transcriptase and endonuclease required for retrotransposition. The endonuclease shows sequence similarity with bacterial restriction endonucleases. Here we report the salient enzymatic features of one such endonuclease. The kinetics of an EhLINE1-encoded endonuclease catalyzed reaction, determined under steady-state and single-turnover conditions, revealed a significant burst phase followed by a slower steady-state phase, indicating that release of product could be the slower step in this reaction. For circular supercoiled DNA the km was 2.6 × 10-8 m and the kcat was 1.6 × 10-2 sec-1. For linear E. histolytica DNA substrate the Km and kcat values were 1.3 × 10-8 m and 2.2 × 10-4 sec-1 respectively. Single-turnover reaction kinetics suggested a noncooperative mode of hydrolysis. The enzyme behaved as a monomer. While Mg2+ was required for activity, 60% activity was seen with Mn2+ and none with other divalent metal ions. Substitution of PDX12-14D (a metal-binding motif) with PAX12-14D caused local conformational change in the protein tertiary structure, which could contribute to reduced enzyme activity in the mutated protein. The protein underwent conformational change upon the addition of DNA, which is consistent with the known behavior of restriction endonucleases. The similarities with bacterial restriction endonucleases suggest that the EhLINE1-encoded endonuclease was possibly acquired from bacteria through horizontal gene transfer. The loss of strict sequence specificity for nicking may have been subsequently selected to facilitate spread of the retrotransposon to intergenic regions of the E. histolytica genome

Large intramuscular plexiform neurofibroma of thigh: a multidisciplinary team approach

Large plexiform neurofibroma of lower extremity involving the muscle is a rare entity. In this article we present the case of plexiform neurofibroma of right thigh involving the muscular plane and entrapment of the sciatic nerve. A 28 year lady presented with a plexiform neurofibroma of right thigh of size 60 cm×30 cm×25 cm with a positive family history of neurofibromatosis type 1. MRI was done for the assessment of the tumour and the adjacent structure involvement. The neurofibroma was removed with a multidisciplinary team approach with an intensive peri operative management. The pathological diagnosis was plexiform neurofibroma with diffuse neurofibroma. We have reported a rare case of large plexiform neurofibroma of lower extremity with muscle involvement and nerve entrapment

Rock Mechanics challenges of depillaring at deep cover

Underground coal mining at deeper cover encounters difficult underground environment due to increase in gas content and rise in temperature transition of a mining practice from shallow to high depth cover encounters a big change in the rock mass characteristics and the stress condition becomes more complex. At higher depth of cover, the excavation starts encountering stress control regime rather than structural control behavior of the rock mass. Mechanisation and automation of underground mining activities is a solution to improve the performance of deeper mines but the approach should match with the rock mass and stress conditions of the site. Since inception, CIMFR (formerly, CMRI) is continuously working to understand behavior of the rock mass through laboratory testing, field investigations and study on simulated models. Obtained experiences during these investigations are observed to be of strategic importance during application of a modern technology to improve practical mining conditions. This paper reviews rock mechanics aspects of different mechanized pillar extraction approaches during mining of a deep seated coal seam and, also attempts to present an appraisal of some of the recent technical developments to overcome the challenges of a deep underground coal mining

Exploitation of mica deposits at Nellore mica belt, Andhra Pradesh, India

India is the leading producer of sheet mica and a major part of this is exported. Nellore mica belt is the largest mica-producing area covering part of Nellore district in Andhra Pradesh, India. As most of the mines are old and privately operated, they are developed and operated purely based on local experiences. In this article, we highlight the problems associated with the present mica-mining practices in the Nellore mica belt, and scientific approaches that have been adopted for fixing different parameters associated with mica extraction. Based on detailed field study, geo-mechanical data and tested rock properties, extensive numerical modelling is done to suggest the best possible method of mining for safe and sustainable mica extraction from the area

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.