33,260 research outputs found

    Production of nuclei and antinuclei in pp and Pb-Pb collisions with ALICE at the LHC

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    We present first results on the production of nuclei and antinuclei such as (anti)deuterons, (anti)tritons, (anti)3He and (anti)4He in pp collisions at \s = 7 TeV and Pb-Pb collisions at \sNN = 2.76 TeV. These particles are identified using their energy loss (dE/dx) information in the Time Projection Chamber of the ALICE experiment. The Inner Tracking System gives a precise determination of the event vertex, by which primary and secondary particles are separated. The high statistics of over 360 million events for pp and 16 million events for Pb-Pb collisions give a significant number of light nuclei and antinuclei (Pb-Pb collisions: \sim30,000 anti-deuterons(dˉ\bar{d}) and \sim4 anti-alpha(4Heˉ\bar{^4He})). The predictions of various particle ratios from the THERMUS model is also discussed.Comment: 4 pages, 5 figures, parallel talk at Quark Matter 2011, May 23rd-28th 2011, Annecy, Franc

    The Crystallography of Strange Quark Matter

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    Cold three-flavor quark matter at large (but not asymptotically large) densities may exist as a crystalline color superconductor. We explore this possibility by calculating the gap parameter Delta and free energy Omega(Delta) for possible crystal structures within a Ginzburg-Landau approximation, evaluating Omega(Delta) to order Delta^6. We develop a qualitative understanding of what makes a crystal structure stable, and find two structures with particularly large values of Delta and the condensation energy, within a factor of two of those for the CFL phase known to characterize QCD at asymptotically large densities. The robustness of these phases results in their being favored over wide ranges of density and though it also implies that the Ginzburg-Landau approximation is not quantitatively reliable, previous work suggests that it can be trusted for qualitative comparisons between crystal structures. We close with a look ahead at the calculations that remain to be done in order to make contact with observed pulsar glitches and neutron star cooling.Comment: 6 pages, 3 figures. Contribution to the proceedings of Strangeness in Quark Matter 2006, UCLA. Talk given by Rishi Sharm

    Generalized q-Deformed Symplectic sp(4) Algebra for Multi-shell Applications

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    A multi-shell generalization of a fermion representation of the q-deformed compact symplectic sp_q(4) algebra is introduced. An analytic form for the action of two or more generators of the Sp_q(4) symmetry on the basis states is determined and the result used to derive formulae for the overlap between number preserving states as well as for matrix elements of a model Hamiltonian. A second-order operator in the generators of Sp_q(4) is identified that is diagonal in the basis set and that reduces to the Casimir invariant of the sp(4) algebra in the non-deformed limit of the theory. The results can be used in nuclear structure applications to calculate beta-decay transition probabilities and to provide for a description of pairing and higher-order interactions in systems with nucleons occupying more than a single-j orbital.Comment: 10 page

    Large magnetocrystalline anisotropy in tetragonally distorted Heuslers: a systematic study

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    With a view to the design of hard magnets without rare earths we explore the possibility of large magnetocrystalline anisotropy energies in Heusler compounds that are unstable with respect to a tetragonal distortion. We consider the Heusler compounds Fe2_2YZ with Y = (Ni, Co, Pt), and Co2_2YZ with Y = (Ni, Fe, Pt) where, in both cases, Z = (Al, Ga, Ge, In, Sn). We find that for the Co2_2NiZ, Co2_2PtZ, and Fe2_2PtZ families the cubic phase is always, at T=0T=0, unstable with respect to a tetragonal distortion, while, in contrast, for the Fe2_2NiZ and Fe2_2CoZ families this is the case for only 2 compounds -- Fe2_2CoGe and Fe2_2CoSn. For all compounds in which a tetragonal distortion occurs we calculate the MAE finding remarkably large values for the Pt containing Heuslers, but also large values for a number of the other compounds (e.g. Co2_2NiGa has an MAE of -2.11~MJ/m3^3). The tendency to a tetragonal distortion we find to be strongly correlated with a high density of states at the Fermi level in the cubic phase. As a corollary to this fact we observe that upon doping compounds for which the cubic structure is stable such that the Fermi level enters a region of high DOS, a tetragonal distortion is induced and a correspondingly large value of the MAE is then observed.Comment: 8 pages, 5 figure

    Raising concerns in the current NHS climate: a qualitative study exploring junior doctors’ attitudes to training and teaching

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    BACKGROUND: High profile cases continue to demonstrate failures to raise concerns with detrimental effects on patient safety. This research sought to establish what educational support junior doctors needed to effectively raise clinical and professional concerns. // STUDY DESIGN: A qualitative study with 16 participants taking part in three focus groups. The transcripts were thematically analysed. // RESULTS: All the data could be coded into four themes: past experiences of teaching; suggested teaching; reporting mechanisms and educational challenges. Most participants were dissatisfied with the teaching they had received on raising concerns. Current systems were thought to be good for raising patient safety issues but not for concerns about professional behaviour of healthcare staff. // CONCLUSIONS: There is a need for improved education to tackle the way this is taught in postgraduate curricula. Frequent rotations and a lack of meaningful relationships left junior doctors feeling less invested in improving organisational culture. Junior doctors are apprehensive about raising concerns because of personal risk to their career trajectory

    Aspects of Urological Tissue Engineering

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    Editorial

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    High-soft to low-hard state transition in black hole X-ray binaries with GRMHD simulations

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    To understand the decaying phase of outbursts in the black hole (BH) X-ray binaries (BH-XRBs), we performed very long general relativistic magneto-hydrodynamic (GRMHD) simulations of a geometrically thin accretion disk around a Kerr BH with slowly rotating matter injected from outside. We thoroughly studied the flow properties, dynamical behavior of the accretion rate, magnetic flux rate, and jet properties during the temporal evolution. Due to the interaction between the thin disk and injected matter, the accretion flow near the BH goes through different phases. The sequence of phases is: soft state →\rightarrow soft-intermediate state →\rightarrow hard-intermediate state →\rightarrow hard state →\rightarrow quiescent state. For the accretion rate (and hence the luminosity) to decrease (as observed) in our model, the mass injection should not decay slower than angular momentum injection. We also observed quasi-periodic oscillations (QPOs) in the accretion flow. Throughout the evolution, we observed low-frequency QPOs (~10Hz) and high-frequency QPOs (\sim 200Hz). Our simple unified accretion flow model for state transitions is able to describe outbursts in BH-XRBs.Comment: 13 pages, 11 figures, Accepted for publication on Ap

    Expression of genes related to Na<sup>+</sup> exclusion and proline accumulation in tolerant and susceptible wheat genotypes under salt stress

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    In the present investigation, expression of genes related to Na+ exclusion such as salt overly sensitive (TaSOS1) and Na+/H+ antiporter (TaNHX1) and proline accumulation such as pyrroline-5-carboxylate reductase (P5CR) and glutamate synthase (GOGAT) was studied in seedlings of Kharchia 65 (Kh 65, salt tolerant) and HD 2009 (sensitive) under salt stress (ECe, 12 dSm–1) and controlled conditions. As compared to HD 2009, Kh 65 showed significantly lower accumulation of Na+ (p + exclusion in root and compartmentation in leaf and increased proline concentration are associated with tolerance to salinity stress in wheat. The information will be useful for improving wheat genotypes for salt tolerance

    Time trends in the incidence of clinically diagnosed type 2 diabetes and pre-diabetes in the UK 2009-2018: a retrospective cohort study.

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    INTRODUCTION: To describe recent trends in the incidence of clinically diagnosed type 2 diabetes and pre-diabetes in people seen in UK general practice. RESEARCH DESIGN AND METHODS: A retrospective cohort study using IQVIA Medical Research Data looking at people newly diagnosed with type 2 diabetes and pre-diabetes through primary care registers in the UK between 1 January 2009 and 31 December 2018. RESULTS: A cohort of 426 717 people were clinically diagnosed with type 2 diabetes and 418 656 people met the criteria for a diagnosis of pre-diabetes in that time period. The incidence of clinically diagnosed type 2 diabetes per 1000 person years at risk (PYAR) in men decreased from a peak of 5.06 per 1000 PYAR (95% CI 4.97 to 5.15) in 2013 to 3.56 per 1000 PYAR (95% CI 3.46 to 3.66) by 2018. For women, the incidence of clinically diagnosed type 2 diabetes per 1000 PYAR decreased from 4.45 (95% CI 4.37 to 4.54) in 2013 to 2.85 (2.76 to 2.93) in 2018. The incidence rate of pre-diabetes tripled by the end of the same study period in men and women. CONCLUSIONS: Between 2009 and 2018, the incidence rate of new clinical diagnoses of type 2 diabetes recorded in a UK primary care database decreased by a third from its peak in 2013-2014, while the incidence of pre-diabetes has tripled. The implications of this on timely treatment, complication rates and mortality need further longer term exploration
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