560 research outputs found
Treatment regimens and outcomes in severe and moderate haemophilia A in the UK: The THUNDER study
Introduction: The THUNDER study provides an analysis of treatment patterns and outcomes in UK patients with severe or moderate haemophilia A (SHA/MHA) in 2015.
Methods: Patients with SHA or MHA registered with the UK National Haemophilia Database (NHD) were segregated by severity, inhibitor status and age. Haemophilia joint health score (HJHS) was derived from NHD records and treatment regimen and annualized bleed/jointâbleed rate (ABR/AJBR) from Haemtrack (HT) in HTâcompliant patients.
Results: We report 1810 patients with SHA and 864 with MHA. Prophylaxis was used in 94.9% (n = 130/137) of HTâcompliant children <12 years with SHA, falling to 74.1% (n = 123/166) aged â„40 years. Median ABR increased with age (1.0, IQR 0.0â5.0, <12 years; 3.0 IQR, 1.0â8.0, â„40 years). Inhibitors were present in 159 (8.8%) SHA and 34 (3.9%) MHA. Median ABR increased from 2.0 (<12 years) to 21.(â„40 years) in SHA inhibitor patients using prophylaxis. Prophylaxis was used by 68.8% of HTâcompliant MHA patients (n = 106) (median FVIII baseline 0.01 IU/mL) associated with a median (IQR) ABR of 3.0 (1.0â7.0). Median HJHS (n = 453) increased with age in SHA and MHA. Median (IQR) HJHS was higher in SHA inhibitor (17.0, 0.0â64.5) than nonâ or past inhibitor patients (7.0, 0.0â23.0).
Conclusions: Increasing ABR with age persists despite current prophylaxis regimens.SHA and MHA had similar ABR/AJBR and HJHS, leading to a suspicion that a subgroup of MHA may be relatively undertreated. More intensive prophylaxis may improve outcomes, but this requires further study
Personalised service? Changing the role of the government librarian
Investigates the feasibility of personalised information service in a government department. A qualitative methodology explored stakeholder opinions on the remit, marketing, resourcing and measurement of the service. A questionnaire and interviews gathered experiences of personalised provision across the government sector. Potential users were similarly surveyed to discuss how the service could meet their needs. Data were analysed using coding techniques to identify emerging theory. Lessons learned from government librarians centred on clarifying requirements, balancing workloads and selective marketing. The user survey showed low usage and awareness of existing specialist services, but high levels of need and interest in services repackaged as a tailored offering. Fieldwork confirmed findings from the literature on the scope for adding value through information management advice, information skills training and substantive research assistance and the need to understand business processes and develop effective partnerships. Concluding recommendations focus on service definition, strategic marketing, resource utilisation and performance measurement
Aspects of Two-Photon Physics at Linear e+e- Colliders
We discuss various reactions at future e+e- and gamma-gamma colliders
involving real (beamstrahlung or backscattered laser) or quasi--real
(bremsstrahlung) photons in the initial state and hadrons in the final state.
The production of two central jets with large pT is described in some detail;
we give distributions for the rapidity and pT of the jets as well as the
di--jet invariant mass, and discuss the relative importance of various initial
state configurations and the uncertainties in our predictions. We also present
results for `mono--jet' production where one jet goes down a beam pipe, for the
production of charm, bottom and top quarks, and for single production of W and
Z bosons. Where appropriate, the two--photon processes are compared with
annihilation reactions leading to similar final states. We also argue that the
behaviour of the total inelastic gamma-gamma cross section at high energies
will probably have little impact on the severity of background problems caused
by soft and semi--hard (`minijet') two--photon reactions. We find very large
differences in cross sections for all two--photon processes between existing
designs for future e+e- colliders, due to the different beamstrahlung spectra;
in particular, both designs with >1 events per bunch crossing exist.Comment: 51 pages, 13 figures(not included
A Phenomenological Analysis of Heavy Hadron Lifetimes
A phenomenological analysis of lifetimes of bottom and charmed hadrons within
the framework of the heavy quark expansion is performed. The baryon matrix
element is evaluated using the bag model and the nonrelativistic quark model.
We find that bottom-baryon lifetimes follow the pattern
.
However, neither the lifetime ratio nor the
absolute decay rates of the baryon and mesons can be explained.
One way of solving both difficulties is to allow the presence of linear
corrections by scaling the inclusive nonleptonic width with the fifth power of
the hadron mass rather than the heavy quark mass . The hierarchy
of bottom baryon lifetimes is dramatically modified to
: The
longest-lived among bottom baryons in the OPE prescription now
becomes shortest-lived. The replacement of by in nonleptonic
widths is natural and justified in the PQCD-based factorization approach
formulated in terms of hadron-level kinematics. For inclusive charmed baryon
decays, we argue that since the heavy quark expansion does not converge, local
duality cannot be tested in this case. We show that while the ansatz of
substituting the heavy quark mass by the hadron mass provides a much better
description of the charmed-baryon lifetime {\it ratios}, it appears unnatural
and unpredictive for describing the {\it absolute} inclusive decay rates of
charmed baryons, contrary to the bottom case.Comment: 35 pages, to appear in Phys. Rev. The CDF result on the lifetime
ratio of Lambda_b and B_d is discusse
Possible origins of macroscopic left-right asymmetry in organisms
I consider the microscopic mechanisms by which a particular left-right (L/R)
asymmetry is generated at the organism level from the microscopic handedness of
cytoskeletal molecules. In light of a fundamental symmetry principle, the
typical pattern-formation mechanisms of diffusion plus regulation cannot
implement the "right-hand rule"; at the microscopic level, the cell's
cytoskeleton of chiral filaments seems always to be involved, usually in
collective states driven by polymerization forces or molecular motors. It seems
particularly easy for handedness to emerge in a shear or rotation in the
background of an effectively two-dimensional system, such as the cell membrane
or a layer of cells, as this requires no pre-existing axis apart from the layer
normal. I detail a scenario involving actin/myosin layers in snails and in C.
elegans, and also one about the microtubule layer in plant cells. I also survey
the other examples that I am aware of, such as the emergence of handedness such
as the emergence of handedness in neurons, in eukaryote cell motility, and in
non-flagellated bacteria.Comment: 42 pages, 6 figures, resubmitted to J. Stat. Phys. special issue.
Major rewrite, rearranged sections/subsections, new Fig 3 + 6, new physics in
Sec 2.4 and 3.4.1, added Sec 5 and subsections of Sec
Quantum magnetism in two dimensions: From semi-classical N\'eel order to magnetic disorder
This is a review of ground-state features of the s=1/2 Heisenberg
antiferromagnet on two-dimensional lattices. A central issue is the interplay
of lattice topology (e.g. coordination number, non-equivalent nearest-neighbor
bonds, geometric frustration) and quantum fluctuations and their impact on
possible long-range order. This article presents a unified summary of all 11
two-dimensional uniform Archimedean lattices which include e.g. the square,
triangular and kagome lattice. We find that the ground state of the spin-1/2
Heisenberg antiferromagnet is likely to be semi-classically ordered in most
cases. However, the interplay of geometric frustration and quantum fluctuations
gives rise to a quantum paramagnetic ground state without semi-classical
long-range order on two lattices which are precisely those among the 11 uniform
Archimedean lattices with a highly degenerate ground state in the classical
limit. The first one is the famous kagome lattice where many low-lying singlet
excitations are known to arise in the spin gap. The second lattice is called
star lattice and has a clear gap to all excitations.
Modification of certain bonds leads to quantum phase transitions which are
also discussed briefly. Furthermore, we discuss the magnetization process of
the Heisenberg antiferromagnet on the 11 Archimedean lattices, focusing on
anomalies like plateaus and a magnetization jump just below the saturation
field. As an illustration we discuss the two-dimensional Shastry-Sutherland
model which is used to describe SrCu2(BO3)2.Comment: This is now the complete 72-page preprint version of the 2004 review
article. This version corrects two further typographic errors (three total
with respect to the published version), see page 2 for detail
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Measurement of the top pair production cross section in 8 TeV proton-proton collisions using kinematic information in the lepton plus jets final state with ATLAS
A measurement is presented of the inclusive production
cross-section in collisions at a center-of-mass energy of TeV
using data collected by the ATLAS detector at the CERN Large Hadron Collider.
The measurement was performed in the lepton+jets final state using a data set
corresponding to an integrated luminosity of 20.3 fb. The cross-section
was obtained using a likelihood discriminant fit and -jet identification was
used to improve the signal-to-background ratio. The inclusive
production cross-section was measured to be
pb assuming a top-quark mass of 172.5 GeV, in good agreement with the
theoretical prediction of pb. The production cross-section in the fiducial region
determined by the detector acceptance is also reported.Comment: Published version, 19 pages plus author list (35 pages total), 3
figures, 2 tables, all figures including auxiliary figures are available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2013-06
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