72 research outputs found

    Centrosymmetric-noncentrosymmetric Structural Phase Transition in Quasi one-dimensional compound, (TaSe4_4)3_3I

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    (TaSe4_4)3_3I, a compound belonging to the family of quasi-one-dimensional transition-metal tetrachalcogenides, has drawn significant attention due to a recent report on possible coexistence of two antagonistic phenomena, superconductivity and magnetism below 2.5~K (Bera et. al, arXiv:2111.14525). Here, we report a structural phase transition of the trimerized phase at temperature, T ≃T~\simeq~145~K using Raman scattering, specific heat, and electrical transport measurements. The temperature-dependent single-crystal X-ray diffraction experiments establish the phase transition from a high-temperature centrosymmetric to a low-temperature non-centrosymmetric structure, belonging to the same tetragonal crystal family. The first-principle calculation finds the aforementioned inversion symmetry-breaking structural transition to be driven by the hybridization energy gain due to the off-centric movement of the Ta atoms, which wins over the elastic energy loss.Comment: 11 pages, 5 figures, Under review as a regular articl

    Thou shalt not hate: Countering Online Hate Speech

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    Hate content in social media is ever-increasing. While Facebook, Twitter, Google have attempted to take several steps to tackle the hateful content, they have mostly been unsuccessful. Counterspeech is seen as an effective way of tackling the online hate without any harm to the freedom of speech. Thus, an alternative strategy for these platforms could be to promote counterspeech as a defense against hate content. However, in order to have a successful promotion of such counterspeech, one has to have a deep understanding of its dynamics in the online world. Lack of carefully curated data largely inhibits such understanding. In this paper, we create and release the first ever dataset for counterspeech using comments from YouTube. The data contains 13,924 manually annotated comments where the labels indicate whether a comment is a counterspeech or not. This data allows us to perform a rigorous measurement study characterizing the linguistic structure of counterspeech for the first time. This analysis results in various interesting insights such as: the counterspeech comments receive much more likes as compared to the non-counterspeech comments, for certain communities majority of the non-counterspeech comments tend to be hate speech, the different types of counterspeech are not all equally effective and the language choice of users posting counterspeech is largely different from those posting non-counterspeech as revealed by a detailed psycholinguistic analysis. Finally, we build a set of machine learning models that are able to automatically detect counterspeech in YouTube videos with an F1-score of 0.71. We also build multilabel models that can detect different types of counterspeech in a comment with an F1-score of 0.60.Comment: Accepted at ICWSM 2019. 12 Pages, 5 Figures, and 7 Tables. The dataset and models are available here: https://github.com/binny-mathew/Countering_Hate_Speech_ICWSM201

    High monocytic MDSC signature predicts multi-drug resistance and cancer relapse in non-Hodgkin lymphoma patients treated with R-CHOP

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    IntroductionNon-Hodgkin Lymphoma (NHL) is a heterogeneous lymphoproliferative malignancy with B cell origin. Combinatorial treatment of rituximab, cyclophsphamide, hydroxydaunorubicin, oncovin, prednisone (R-CHOP) is the standard treatment regimen for NHL, yielding a complete remission (CR) rate of 40-50%. Unfortunately, considerable patients undergo relapse after CR or initial treatment, resulting in poor clinical implications. Patient’s response to chemotherapy varies widely from static disease to cancer recurrence and later is primarily associated with the development of multi-drug resistance (MDR). The immunosuppressive cells within the tumor microenvironment (TME) have become a crucial target for improving the therapy efficacy. However, a better understanding of their involvement is needed for distinctive response of NHL patients after receiving chemotherapy to design more effective front-line treatment algorithms based on reliable predictive biomarkers.MethodsPeripheral blood from 61 CD20+ NHL patients before and after chemotherapy was utilized for immunophenotyping by flow-cytometry at different phases of treatment. In-vivo and in-vitro doxorubicin (Dox) resistance models were developed with murine Dalton’s lymphoma and Jurkat/Raji cell-lines respectively and impact of responsible immune cells on generation of drug resistance was studied by RT-PCR, flow-cytometry and colorimetric assays. Gene silencing, ChIP and western blot were performed to explore the involved signaling pathways.ResultsWe observed a strong positive correlation between elevated level of CD33+CD11b+CD14+CD15- monocytic MDSCs (M-MDSC) and MDR in NHL relapse cohorts. We executed the role of M-MDSCs in fostering drug resistance phenomenon in doxorubicin-resistant cancer cells in both in-vitro, in-vivo models. Moreover, in-vitro supplementation of MDSCs in murine and human lymphoma culture augments early expression of MDR phenotypes than culture without MDSCs, correlated well with in-vitro drug efflux and tumor progression. We found that MDSC secreted cytokines IL-6, IL-10, IL-1β are the dominant factors elevating MDR expression in cancer cells, neutralization of MDSC secreted IL-6, IL-10, IL-1β reversed the MDR trait. Moreover, we identified MDSC secreted IL-6/IL-10/IL-1β induced STAT1/STAT3/NF-κβ signaling axis as a targeted cascade to promote early drug resistance in cancer cells.ConclusionOur data suggests that screening patients for high titre of M-MDSCs might be considered as a new potential biomarker and treatment modality in overcoming chemo-resistance in NHL patients

    Factors associated with stigma and manifestations experienced by Indian health care workers involved in COVID-19 management in India: A qualitative study

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    Healthcare personnel who deal with COVID-19 experience stigma. There is a lack of national-level representative qualitative data to study COVID-19-related stigma among healthcare workers in India. The present study explores factors associated with stigma and manifestations experienced by Indian healthcare workers involved in COVID-19 management. We conducted in-depth interviews across 10 centres in India, which were analysed using NVivo software version 12. Thematic and sentiment analysis was performed to gain deep insights into the complex phenomenon by categorising the qualitative data into meaningful and related categories. Healthcare workers (HCW) usually addressed the stigma they encountered when doing their COVID duties under the superordinate theme of stigma. Among them, 77.42% said they had been stigmatised in some way. Analyses revealed seven interrelated themes surrounding stigma among healthcare workers. It can be seen that the majority of the stigma and coping sentiments fall into the mixed category, followed by the negative sentiment category. This study contributes to our understanding of stigma and discrimination in low- and middle-income settings. Our data show that the emergence of fear of the virus has quickly turned into a stigma against healthcare workers

    Precision measurements of A1N in the deep inelastic regime

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    We have performed precision measurements of the double-spin virtual-photon asymmetry A1A1 on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized 3He target. Our data cover a wide kinematic range 0.277≤x≤0.5480.277≤x≤0.548 at an average Q2Q2 value of 3.078 (GeV/c)2, doubling the available high-precision neutron data in this x range. We have combined our results with world data on proton targets to make a leading-order extraction of the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with a previous observation of anA1n zero crossing near x=0.5x=0.5. We find no evidence of a transition to a positive slope in(Δd+Δd¯)/(d+d¯) up to x=0.548x=0.548

    Facilitators and barriers to the uptake of COVID-19 vaccine precaution dose among adult population: qualitative analysis across six different states of India

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    IntroductionIndia launched the COVID-19 vaccination drive on 16th January 2021 by vaccinating the adult population above 18 years of age. This was followed by the introduction of an additional precaution dose. As on 18th October 2022, 1,02,66,96,808 (1.02 Billion) first dose and 94, 95, 39,516 (949 Million) second doses of COVID-19 vaccine were administered. However, when compared to the uptake of the primary doses, the precaution dose uptake lagged behind with only 21,75, 12,721 (217 million) doses administered. Even though, the uptake of the primary doses remained optimal, irrespective of different interventions by the Government of India, the uptake of the precaution dose remained poor. In this context, the Ministry of Health & Family Welfare wanted to understand the facilitators and Barriers for precaution dose uptake among adults so that future immunization campaigns could address these issues.MethodsAn exploratory qualitative study was conducted to assess the facilitators and barriers for COVID-19 precaution dose uptake at community level across 6 different states in India. From each of the states, two districts with the highest and lowest rates of COVID-19 vaccine precaution dose uptake were selected. In each of these districts, 2 block Primary Healthcare Centres (PHCs), one with high and one with low uptake were identified. Within these block PHCs, a PHC field area with high and low precaution dose uptakes was identified. From the identified sites a minimum of four IDIs, four FGDs were conducted among the community members. KIIs of the State Immunization Officers, District Immunisation Officers, PHC Medical Officers, healthcare workers like Accredited Social Health Activist/Auxiliary Nurse Midwife were also conducted. The data was audio recorded and it was transcribed, translated and analysed using framework approach.ResultsIt was observed that rise in COVID-19 cases prompted the community to take the precaution dose, this along with the cost of hospitalization and the number of productive days being lost as a result of being infected resulted in vaccine uptake. The fear of non-availability of COVID-19 vaccines latter on also prompted people for vaccine uptake. While the barriers were, poor accessibility to vaccination centers, long hours of travel, poor road connectivity and lack of transportation facilities. However, the most prominent barriers observed across all study sites was that a sense of pandemic fatigue and complacency had developed both among the providers as well as the beneficiaries. Other barriers include differences in vaccination schedules and longer duration between the primary doses of some vaccines. Media was identified to be both a barrier and facilitator for Covid-19 Precaution dose uptake. Even though media played an important role in disseminating information in the beginning of the campaign, it was soon followed by the circulation of both misinformation and disinformation.DiscussionThe study identified that dissemination of accurate information and community involvement at each stage of planning and implementation are crucial for the success of any campaign. Efforts should be constantly made to address and re-invent strategies that will be most suitable for the needs of the community. Therefore, in order to ensure successful vaccination campaigns, it is crucial that along with political will it is also important to have a decentralized approach with inter-sectoral coordination with different stakeholders such as healthcare workers, community members and the different departments such as the local self-governments, education department, law & order department etc. These lessons learnt from COVID-19 vaccination campaigns must not be forgotten and must be applied in future vaccination campaigns and while framing public health policies

    Probing the Repulsive Core of the Nucleon-Nucleon Interaction via the 4He(e,e'pN) Triple-Coincidence Reaction

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    We studied simultaneously the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn) reactions at Q^2=2 [GeV/c]2 and x_B>1, for a (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum in a region where the nucleon-nucleon force is expected to change from predominantly tensor to repulsive. Neutron-proton pairs dominate the high-momentum tail of the nucleon momentum distributions, but their abundance is reduced as the nucleon momentum increases beyond ~500 MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum in the range we studied. Our data are compared with ab-initio calculations of two-nucleon momentum distributions in 4He.Comment: 6 pages, 2 figure

    Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction 3He↑(e,e′)X^{3}\mathrm{He}^{\uparrow}(e,e')X

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    We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction 3^3He↑(e,e′)X^{\uparrow}\left(e,e' \right)X on a polarized 3^3He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be non-zero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.7<W<2.91.7 < W < 2.9 GeV, 1.0<Q2<4.01.0<Q^2<4.0 GeV2^2 and 0.16<x<0.650.16<x<0.65. Neutron asymmetries were extracted using the effective nucleon polarization and measured proton-to-3^3He cross section ratios. The measured neutron asymmetries are negative with an average value of (−1.09±0.38)×10−2(-1.09 \pm 0.38) \times10^{-2} for invariant mass W>2W>2 GeV, which is non-zero at the 2.89σ2.89\sigma level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.Comment: This is the final edited version as published in PR

    Sol-gel processed Al2O3 thick film template as sensitive capacitive trace moisture sensor

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    Sol-gel processed Al2O3 thick film template has been tested for the first time to fabricate a trace moisture sensor. The device consists of a thick film nano porous &gamma;-Al2O3 film, electrodes coated by silver palladium (AgPd) conductive past on both sides of the film forming a parallel plate capacitor. A high change in capacitance was observed with increasing ppmV moisture level from 0 to 100 ppmV The results show that sol-gel processed monoliths are promising materials for capacitive type trace moisture sensor. &COPY; 2004 Elsevier B.V. All rights reserved
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