355 research outputs found
Combined CI+MBPT calculations of energy levels and transition amplitudes in Be, Mg, Ca, and Sr
Configuration interaction (CI) calculations in atoms with two valence
electrons, carried out in the V(N-2) Hartree-Fock potential of the core, are
corrected for core-valence interactions using many-body perturbation theory
(MBPT). Two variants of the mixed CI+MBPT theory are described and applied to
obtain energy levels and transition amplitudes for Be, Mg, Ca, and Sr
Comparison of two pancreatic enzyme products for exocrine insufficiency in patients with cystic fibrosis
Background: Zenpep (APT-1008) is a pancreatic enzyme product for the treatment of exocrine pancreatic insufficiency (EPI) associated with cystic
fibrosis (CF).
Methods: Zenpep and Kreon, both containing 25,000 lipase units, were compared in a randomised, double-blind, crossover, non-inferiority study
for CF-associated EPI in patients aged â„12 years. Patients on a standardised diet and stabilised treatment were randomised to two treatment
sequences: Zenpep/Kreon or Kreon/Zenpep. The primary efficacy endpoint was the coefficient of fat absorption over 72 h (CFA-72 h).
Results: 96 patients (mean age 19.2 years, 60.4% males) were randomised with 83 completers of both sequences comprising the efficacy
population. Zenpep demonstrated non-inferiority and equivalence to Kreon in fat absorption (LS mean CFA-72 h: Zenpep, 84.1% [SE 1.1] vs.
Kreon, 85.3% [SE 1.1]; p = 0.297). Safety and tolerability were similar.
Conclusions: Zenpep is comparable with Kreon in efficacy and safety for the treatment of adolescents and adults with CF-associated EPI.
NCT0164139
Patient use of blood pressure self-screening facilities in general practice waiting rooms: a qualitative study in the UK
Background Blood pressure (BP) self-screening, whereby members of the public have access to BP monitoring equipment outside of healthcare consultations, may increase the detection and treatment of hypertension. Currently in the UK such opportunities are largely confined to GP waiting rooms.Aim To investigate the reasons why people do or do not use BP self-screening facilities.Design and setting A cross-sectional, qualitative study in Oxfordshire, UK.Method Semi-structured interviews with members of the general public recruited using posters in GP surgeries and community locations were recorded, transcribed, and coded thematically.Results Of the 30 interviewees, 20% were hypertensive and almost half had self-screened. Those with no history of elevated readings had limited concern over their BP: self-screening filled the time waiting for their appointment or was done to help their doctor. Patients with hypertension self-screened to avoid the feelings they associated with âwhite coat syndromeâ and to introduce more control into the measurement process. Barriers to self-screening included a lack of awareness, uncertainty about technique, and worries over measuring BP in a public place. An unanticipated finding was that several interviewees preferred monitoring their BP in the waiting room than at home.Conclusion BP self-screening appeared acceptable to service users. Further promotion and education could increase awareness among non-users of the need for BP screening, the existence of self-screening facilities, and its ease of use. Waiting room monitors could provide an alternative for patients with hypertension who are unwilling or unable to monitor at home
Warp propagation in astrophysical discs
Astrophysical discs are often warped, that is, their orbital planes change
with radius. This occurs whenever there is a non-axisymmetric force acting on
the disc, for example the Lense-Thirring precession induced by a misaligned
spinning black hole, or the gravitational pull of a misaligned companion. Such
misalignments appear to be generic in astrophysics. The wide range of systems
that can harbour warped discs - protostars, X-ray binaries, tidal disruption
events, quasars and others - allows for a rich variety in the disc's response.
Here we review the basic physics of warped discs and its implications.Comment: To be published in Astrophysical Black Holes by Haardt et al.,
Lecture Notes in Physics, Springer 2015. 19 pages, 2 figure
Chiral perturbation theory calculation for pn -> dpipi at threshold
We investigate the reaction pn -> dpipi in the framework of Chiral
Perturbation Theory. For the first time a complete calculation of the leading
order contributions is presented. We identify various diagrams that are of
equal importance as compared to those recognized in earlier works. The diagrams
at leading order behave as expected by the power counting. Also for the first
time the nucleon-nucleon interaction in the initial, intermediate and final
state is included consistently and found to be very important. This study
provides a theoretical basis for a controlled evaluation of the non-resonant
contributions in two-pion production reactions in nucleon-nucleon collisions.Comment: 24 pages, 3 figures, 3 table
Deep exclusive electroproduction off the proton at CLAS
The exclusive electroproduction of above the resonance region was
studied using the Large Acceptance Spectrometer () at
Jefferson Laboratory by scattering a 6 GeV continuous electron beam off a
hydrogen target. The large acceptance and good resolution of ,
together with the high luminosity, allowed us to measure the cross section for
the process in 140 (, , ) bins:
, 1.6 GeV GeV and 0.1 GeV
GeV. For most bins, the statistical accuracy is on the order of a few
percent. Differential cross sections are compared to two theoretical models,
based either on hadronic (Regge phenomenology) or on partonic (handbag diagram)
degrees of freedom. Both can describe the gross features of the data reasonably
well, but differ strongly in their ingredients. If the handbag approach can be
validated in this kinematical region, our data contain the interesting
potential to experimentally access transversity Generalized Parton
Distributions.Comment: 18pages, 21figures,2table
Mesophyll porosity is modulated by the presence of functional stomata
The formation of stomata and leaf mesophyll airspace must be coordinated to establish an efficient and robust network that facilitates gas exchange for photosynthesis, however the mechanism by which this coordinated development occurs remains unclear. Here, we combine microCT and gas exchange analyses with measures of stomatal size and patterning in a range of wild, domesticated and transgenic lines of wheat and Arabidopsis to show that mesophyll airspace formation is linked to stomatal function in both monocots and eudicots. Our results support the hypothesis that gas flux via stomatal pores influences the degree and spatial patterning of mesophyll airspace formation, and indicate that this relationship has been selected for during the evolution of modern wheat. We propose that the coordination of stomata and mesophyll airspace pattern underpins water use efficiency in crops, providing a target for future improvement
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
Parsimony and Maximum Likelihood phylogenetic analyses of morphology do not generally integrate uncertainty in inferring evolutionary history:A response to Brown et al.
Our recent study evaluated the performance of parsimony and probabilistic
models of phylogenetic inference based on categorical data [1]. We found that a
Bayesian implementation of a probabilistic Markov model produced more accurate
results than either of the competing parsimony approaches (the main method currently employed), and the maximum-likelihood implementation of the same
model. This occurs principally because the results of Bayesian analyses are less
resolved (less precise) as a measure of topological uncertainty is intrinsically recovered in this MCMC-based approach and can be used to construct a majority-rule
consensus tree that reflects this. Of the three main methods, maximum likelihood
performed theworst of all as a single exclusively bifurcating tree is estimated in this
framework which does not integrate an intrinsic measure of support.N
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