104 research outputs found

    Quantum realizations of Hilbert-Palatini second-class constraints

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    In a classical theory of gravity, the Barbero-Immirzi parameter (η\eta) appears as a topological coupling constant through the Lagrangian density containing the Hilbert-Palatini term and the Nieh-Yan invariant. In a quantum framework, the topological interpretation of η\eta can be captured through a rescaling of the wavefunctional representing the Hilbert-Palatini theory, as in the case of the QCD vacuum angle. However, such a rescaling cannot be realized for pure gravity within the standard (Dirac) quantization procedure where the second-class constraints of Hilbert-Palatini theory are eliminated beforehand. Here we present a different treatment of the Hilbert-Palatini second-class constraints in order to set up a general rescaling procedure (a) for gravity with or without matter and (b) for any choice of gauge (e.g. time gauge). The analysis is developed using the Gupta-Bleuler and the coherent state quantization methods.Comment: Published versio

    Use of Matrix-Pencil Method for Efficient Islanding Detection in Static DG and a Parallel Comparison With DWT Method

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    Islanding or nonislanding events in grid-connected distributed generation bring along a typical distinguishable transient signature in its frequency profile. This demarcation leads to the development of a new islanding protection approach, which is based on the estimation of frequency waveform parameter (transient\u27s frequency) by Matrix pencil (MP) method. To demonstrate the efficacy of the proposed MP method, four critical scenarios are considered in this paper for covering all possible disturbance events. These events are also compared along with a discrete wavelet transform (DWT) based islanding detection method in simulations as well as in RT-LAB-based real-time environment. It is noteworthy to mention that the proposed MP method has been found to have a positive edge over the DWT-based method in terms of robustness and chances of misidentification

    Trend of Entamoeba histolytica infestation in Kolkata

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    Background: Entamoeba histolytica infection is found almost all over the world and is highly endemic and a major cause of parasitic diarrhoea particularly in the developing countries. Methods: A systemic surveillance was set up at the Infectious Disease hospital, Kolkata, India between November 2007 and October 2009 for understanding the trend of E. histolytica infection in Kolkata. Fecal samples were collected from diarrhoeal patients attending the hospital, under the surveillance system and processed for detection of E. histolytica. Results: During the last two years about 2500 diarrhoeal samples were collected and screened for E. histolytica. About 3.6% were positive for E. histolytica. As compared to the earlier years, E. histolytica infection was observed to be less amongst patients screened during the last two years. No seasonality was observed in Kolkata although in the neighboring tropical country Bangladesh, a typical seasonality of E. histolytica infection was noticed. Conclusion: The study indicates that the detection rate of E. histolytica infection amongst diarrhoeal patients in Kolkata is decreasing during the last two years than that of Bangladesh

    Examining the Experience of Teen-to-Teen Crisis Line Work for Adolescent Volunteers: A Pilot Study

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    Suicidal thoughts and behaviors are high and increasing among youth. Crisis lines are one of the oldest downstream approaches for suicide prevention, which have demonstrated effectiveness for adults and preliminary effectiveness for youth. Teen-to-teen (t2t) crisis lines are a unique resource where adolescent volunteers help their similarly aged peers (through texts, chats, calls, and emails). However, no research to date has examined the impacts of t2t crisis line volunteering on the youth. The goal of this pilot study is to begin to evaluate the experience of t2t crisis lines for the youth volunteers. Adolescent (n=20, ages 15-20) volunteers were recruited from two of the largest crisis lines in the U.S. – Teen Line and YouthLine. Enrolled volunteers were administered surveys assessing positive/helpful experiences, negative/unhelpful experiences, and motivations for joining the t2t crisis line. Volunteers were assessed up to five times over the course of one year; once at baseline and then every three months for up to one year (baseline, 3-month follow-up, 6-month follow-up, 9-month follow-up, 12-month/1-year follow-up). Direct content analysis was used to examine the experiences and motivations of volunteering on the crisis line. Preliminary results indicate that all volunteers reported some positive aspects of the t2t line experience, and many reported some negative aspects as well.https://digitalcommons.odu.edu/gradposters2023_sciences/1011/thumbnail.jp

    Seed yield increase in Niger crop in to relation to honeybee and other pollinators

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    Niger (Guizotia abyssinica Cass) is an important minor oilseed crop of hilly and tribal regions and it is used for oil as well as for various other purposes only by the tribal people. Therefore, a systematic study was arranged to document about the increase in the seed yield of niger crop in relation to honeybees (Aphis mellifera), as a pollinator in niger crop with paired plot technique at the Niger Research Station (NRS) at Navsari Agricultural University (NAU) and at farmer’s field, Vanarasi, Navsari, Gujarat (India) and also studied its relation in terms of cost benefit ratio (CB). The trial was conducted at Niger Research Station (NRS), Vanarasi for 3 years (2013- 14, 2014-15 and 2015-16) and also at farmer's field to ascertain the role and involvement of honey bees (Aphis mellifera) in swelling the seed yield of niger crop (due to pollination) and its effect on income due to increase in the niger seed yield. Significant differences were observed for number of capitula/plant, number of seeds/capitula, 1000 seed weight and seed yield in both the location for the consecutive 3 years. However, the seed yield and gross returns were considerably higher in first location of T1 Natural plot/ open pollinated with beehive (Aphis mellifera) in all the 3 years data with the maximum seed yield with the gross return was obtained in this treatment

    Discovery and Optimisation of a Compound Series active against Trypanosoma cruzi, the causative agent of Chagas’ Disease

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    Chagas disease is caused by the protozoan parasite; Trypanosoma cruzi; . It is endemic in South and Central America and recently has been found in other parts of the world, due to migration of chronically infected patients. The current treatment for Chagas disease is not satisfactory, and there is a need for new treatments. In this work, we describe the optimization of a hit compound resulting from the phenotypic screen of a library of compounds against; T. cruzi; . The compound series was optimized to the level where it had satisfactory pharmacokinetics to allow an efficacy study in a mouse model of Chagas disease. We were able to demonstrate efficacy in this model, although further work is required to improve the potency and selectivity of this series

    Back-reaction of Non-supersymmetric Probes: Phase Transition and Stability

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    We consider back-reaction by non-supersymmetric D7/anti-D7 probe branes in the Kuperstein-Sonnenschein model at finite temperature. Using the smearing technique, we obtain an analytical solution for the back-reacted background to leading order in N_f/N_c. This back-reaction explicitly breaks the conformal invariance and introduces a dimension 6 operator in the dual field theory which is an irrelevant deformation of the original conformal field theory. We further probe this back-reacted background by introducing an additional set of probe brane/anti-brane. This additional probe sector undergoes a chiral phase transition at finite temperature, which is absent when the back-reaction vanishes. We investigate the corresponding phase diagram and the thermodynamics associated with this phase transition. We also argue that additional probes do not suffer from any instability caused by the back-reaction, which suggests that this system is stable beyond the probe limit.Comment: 56 pages, 8 figures. References updated, improved discussion on dimension eight operato

    Finite-temperature quantum effects on confined charges

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    A quantum system of N Coulomb charges confined within a harmonic trap is considered over a wide range of densities and temperatures. A recently described construction of an equivalent classical system is applied in order to exploit the rather complete classical description of harmonic confinement via liquid-state theory. Here, the effects of quantum mechanics on that representation are described with attention focused on the origin and nature of shell structure. The analysis extends from the classical strong Coulomb coupling conditions of dusty plasmas to the opposite limit of low temperatures and large densities characteristic of warm, dense matter.close0
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