33,260 research outputs found
Production of nuclei and antinuclei in pp and Pb-Pb collisions with ALICE at the LHC
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() and \sim4
anti-alpha()). 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
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
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
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 FeYZ with Y = (Ni, Co, Pt), and CoYZ
with Y = (Ni, Fe, Pt) where, in both cases, Z = (Al, Ga, Ge, In, Sn). We find
that for the CoNiZ, CoPtZ, and FePtZ families the cubic phase is
always, at , unstable with respect to a tetragonal distortion, while, in
contrast, for the FeNiZ and FeCoZ families this is the case for only 2
compounds -- FeCoGe and FeCoSn. 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. CoNiGa has an MAE of -2.11~MJ/m). 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
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
High-soft to low-hard state transition in black hole X-ray binaries with GRMHD simulations
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 soft-intermediate state hard-intermediate
state hard state 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
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.
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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