2,598 research outputs found

    Fast simulation of a quantum phase transition in an ion-trap realisable unitary map

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    We demonstrate a method of exploring the quantum critical point of the Ising universality class using unitary maps that have recently been demonstrated in ion trap quantum gates. We reverse the idea with which Feynman conceived quantum computing, and ask whether a realisable simulation corresponds to a physical system. We proceed to show that a specific simulation (a unitary map) is physically equivalent to a Hamiltonian that belongs to the same universality class as the transverse Ising Hamiltonian. We present experimental signatures, and numerical simulation for these in the six-qubit case.Comment: 12 pages, 6 figure

    A retrospective study of Adverse Drug Reactions in a tertiary care centre

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    Background: Adverse drug reactions (ADRs) are a major concern in present day clinical practice. They are inevitable consequences of drug therapy; as no pharmacotherapeutic agent is completely free from noxious and unintended effects. They are major contributors for morbidity, mortality and hospitalization of the patients increasing the economic burden on the society and uncertainty in clinical outcomes.Methods: This was a retrospective observational study, extending over 6 months (September 2016 to February 2017). A total of 290 cases were studied, excluding the geriatric age group. The data was collected using CDSCO ADR reporting form. A comparison of ADR between males and females was made; based on the organ system affected and the category of drug using “proportion test”.Results: The study showed the ADR incidence was equal in both sexes (≈50%). It was observed that majority ADRs were from gastro intestinal system (39%) followed by CNS (20%) and skin and soft tissue (14%). Constipation was found to be the most common of the reported ADRs (18%) followed by vomiting (9%) and diarrhoea (8%).Conclusions: ADRs are a major cause of morbidity worldwide. Several studies; including the present one, has shown GIT to be the most common system affected. Frequency of ADRs can be reduced by careful follow up and a robust hospital based pharmacovigilance setup

    Reconstructing communities in cluster trials?

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    BACKGROUND: There is growing interest in the ethics of cluster trials, but no literature on the uncertainties in defining communities in relation to the scientific notion of the cluster in collaborative biomedical research. METHODS: The views of participants in a community-based cluster randomised trial (CRT) in Mumbai, India, were solicited regarding their understanding and views on community. We conducted two focus group discussions with local residents and 20 semi-structured interviews with different respondent groups. On average, ten participants took part in each focus group, most of them women aged 18-55. We conducted semi-structured interviews with ten residents (nine women and one man) lasting approximately an hour each and seven individuals (five men and two women) identified by residents as local leaders or decision-makers. In addition, we interviewed two Municipal Corporators (locally elected government officials involved in urban planning and development) and one representative of a political party located in a slum community. RESULTS: Residents' sense of community largely matched the scientific notion of the cluster, defined by the investigators as a geographic area, but their perceived needs were not entirely met by the trial. CONCLUSION: We examined whether the possibility of a conceptual mismatch between 'clusters' and 'communities' is likely to have methodological implications for a study or to lead to potential social disharmony because of the research interventions, arguing that it is important to take social factors into account as well as statistical efficiency when choosing the size and type of clusters and designing a trial. One method of informing such a design would be to use existing forums for community engagement to explore individuals' primary sense of community or social group and, where possible, to fit clusters around them. TRIAL REGISTRATION: ISRCTN Register: ISRCTN56183183 Clinical Trials Registry of India: CTRI/2012/09/003004

    DESIGN AND DEVELOPMENT OF FLOATING PULSATILE DRUG DELIVERY OF LOSARTAN POTASSIUM

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    Objective: The objective of the present investigation was to the development of floating pulsatile drug delivery system of Losartan potassium (LP) tablets for obtaining no drug release during floating followed by pulsed, rapid drug release to achieve chronotherapeutic release. In hypertension, the risk of getting heart attacks early in the morning is high and therefore, there was need to develop drug delivery, which will release drugs at morning hours and provide efficacious therapy. LP is a short biological half-life (1.5-2.5h) and readily absorbed from the stomach and upper gastrointestinal tract. Methods: Tablet formulation was prepared by press coating of rapid release core tablets and core tablets were further top coated with a buoyant layer of HPMC K4M and sodium bicarbonate. Various grades of HPMC polymer (E5/E15/E50) were used for the pulsatile coating layer. The developed formulations were characterized for physical characteristics, floating lag time, floating time, release lag time, drug content, swelling index, in vitro dissolution studies, DSC and XRD. Results: The FTIR and DSC studies predicted that there was no chemical interaction between drug and excipients. The core tablet coated with HPMC E50 showed a high swelling index and release the drug 97.60±1.2% at 6h. Buoyant layer with 80 mg HPMC K4M and 25 mg sodium bicarbonate gave satisfactory floating lag time. Conclusion: The system showed an excellent lag phase followed by burst release in the distal small intestine, which gives site and time-specific delivery of LP acting as per chronotherapy for treatment of hypertension

    Centrifugal terms in the WKB approximation and semiclassical quantization of hydrogen

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    A systematic semiclassical expansion of the hydrogen problem about the classical Kepler problem is shown to yield remarkably accurate results. Ad hoc changes of the centrifugal term, such as the standard Langer modification where the factor l(l+1) is replaced by (l+1/2)^2, are avoided. The semiclassical energy levels are shown to be exact to first order in ℏ\hbar with all higher order contributions vanishing. The wave functions and dipole matrix elements are also discussed.Comment: 5 pages, to appear in Phys. Rev.

    Instabilities in the Nuclear Energy Density Functional

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    In the field of Energy Density Functionals (EDF) used in nuclear structure and dynamics, one of the unsolved issues is the stability of the functional. Numerical issues aside, some EDFs are unstable with respect to particular perturbations of the nuclear ground-state density. The aim of this contribution is to raise questions about the origin and nature of these instabilities, the techniques used to diagnose and prevent them, and the domain of density functions in which one should expect a nuclear EDF to be stable.Comment: Special issue "Open Problems in Nuclear Structure Theory" of Jour.Phys.G - accepted. 7 pages, 2 figure

    Phonon amplification using evaporation and adsorption of helium

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    We report the results of experiments designed to investigate the feasibility of amplifying a phonon signal using the evaporation of helium from a superfluid film and its subsequent readsorption onto a helium-free surface. We envision a multistage amplifier in which helium is evaporated from a wafer with a helium film only on one side and then adsorbed onto the film-free surface of a similar wafer. The phonons created by the adsorption reach the film on the opposite side of the wafer and potentially desorb more helium than was evaporated by the first wafer. The amplification would come from the high ratio of the binding energy of a helium atom to a film-free surface relative to the binding energy to the liquid. A number of experiments are reported that investigate the efficiencies of the individual steps of the process. The gain per stage is found to be about 3 for high-energy densities in which multiphonon processes are possible. At low-energy densities, the energy deposited into a film-free wafer is found to be less than the original input energy, with the ratio of output to input energy 0.2. Since in applications requiring amplification the phonon density produced by the adsorption of helium on a wafer will be low, the configuration we have studied—phonons produced in silicon coated with a saturated He4 film—will not result in amplification. However, other configurations might improve the efficiency enough to make an amplifier possible

    A genome-wide association study for genetic susceptibility to Mycobacterium bovis infection in dairy cattle identifies a susceptibility QTL on chromosome 23

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    Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Bovine tuberculosis (bTB) infection in cattle is a significant economic concern in many countries, with annual costs to the UK and Irish governments of approximately €190 million and €63 million, respectively, for bTB control. The existence of host additive and non-additive genetic components to bTB susceptibility has been established. METHODS: Two approaches i.e. single-SNP (single nucleotide polymorphism) regression and a Bayesian method were applied to genome-wide association studies (GWAS) using high-density SNP genotypes (n = 597,144 SNPs) from 841 dairy artificial insemination (AI) sires. Deregressed estimated breeding values for bTB susceptibility were used as the quantitative dependent variable. Network analysis was performed using the quantitative trait loci (QTL) that were identified as significant in the single-SNP regression and Bayesian analyses separately. In addition, an identity-by-descent analysis was performed on a subset of the most prolific sires in the dataset that showed contrasting prevalences of bTB infection in daughters. RESULTS: A significant QTL region was identified on BTA23 (P value >1 × 10(-5), Bayes factor >10) across all analyses. Sires with the minor allele (minor allele frequency = 0.136) for this QTL on BTA23 had estimated breeding values that conferred a greater susceptibility to bTB infection than those that were homozygous for the major allele. Imputation of the regions that flank this QTL on BTA23 to full sequence indicated that the most significant associations were located within introns of the FKBP5 gene. CONCLUSIONS: A genomic region on BTA23 that is strongly associated with host susceptibility to bTB infection was identified. This region contained FKBP5, a gene involved in the TNFα/NFÎș-B signalling pathway, which is a major biological pathway associated with immune response. Although there is no study that validates this region in the literature, our approach represents one of the most powerful studies for the analysis of bTB susceptibility to date

    Dark matter-baryons separation at the lowest mass scale: the Bullet Group

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    We report on the X-ray observation of a strong lensing selected group, SL2S J08544-0121, with a total mass of 2.4±0.6×10142.4 \pm 0.6 \times 10^{14} M⊙\rm{M_\odot} which revealed a separation of 124±20124\pm20 kpc between the X-ray emitting collisional gas and the collisionless galaxies and dark matter (DM), traced by strong lensing. This source allows to put an order of magnitude estimate to the upper limit to the interaction cross section of DM of 10 cm2^2 g−1^{-1}. It is the lowest mass object found to date showing a DM-baryons separation and it reveals that the detection of bullet-like objects is not rare and confined to mergers of massive objects opening the possibility of a statistical detection of DM-baryons separation with future surveys.Comment: 5 pages, 3 figures. Accepted for publication in MNRAS Letters. Typos correcte
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