15,898 research outputs found
Refeeding Syndrome: A Literature Review
Refeeding syndrome (RFS) describes the biochemical changes, clinical manifestations, and complications that can occur as a consequence of feeding a malnourished catabolic individual. RFS has been recognised in the literature for over fifty years and can result in serious harm and death. Crude estimates of incidence, morbidity, and mortality are available for specific populations. RFS can occur in any individual but more commonly occurs in at-risk populations. Increased awareness amongst healthcare professionals is likely to reduce morbidity and mortality. This review examines the physiology of RFS and describes the clinical manifestations. A management strategy is described. The importance of a multidisciplinary approach is emphasized
Colliding Axion-Dilaton Plane Waves from Black Holes
The colliding plane wave metric discovered by Ferrari and Iba\~{n}ez to be
locally isometric to the interior of a Schwarzschild black hole is extended to
the case of general axion-dilaton black holes. Because the transformation maps
either black hole horizon to the focal plane of the colliding waves, this
entire class of colliding plane wave spacetimes only suffers from the formation
of spacetime singularities in the limits where the inner horizon itself is
singular, which occur in the Schwarzschild and dilaton black hole limits. The
supersymmetric limit corresponding to the extreme axion-dilaton black hole
yields the Bertotti-Robinson metric with the axion and dilaton fields flowing
to fixed constant values. The maximal analytic extension of this metric across
the Cauchy horizon yields a spacetime in which two sandwich waves in a
cylindrical universe collide to produce a semi-infinite chain of
Reissner-Nordstrom-like wormholes. The focussing of particle and string
geodesics in this spacetime is explored.Comment: 19 pages, 6 figure
Effect of different levels of alpha tocopherol on performance traits, serum antioxidant enzymes, and trace elements in Japanese quail ( Coturnix coturnix japonica ) under low ambient temperature
The Near-Linear Regime of Gravitational Waves in Numerical Relativity
We report on a systematic study of the dynamics of gravitational waves in
full 3D numerical relativity. We find that there exists an interesting regime
in the parameter space of the wave configurations: a near-linear regime in
which the amplitude of the wave is low enough that one expects the geometric
deviation from flat spacetime to be negligible, but nevertheless where
nonlinearities can excite unstable modes of the Einstein evolution equations
causing the metric functions to evolve out of control. The implications of this
for numerical relativity are discussed.Comment: 10 pages, 2 postscript figures, revised tex
Soliton response to transient trap variations
The response of bright and dark solitons to rapid variations in an expulsive
longitudinal trap is investigated. We concentrate on the effect of transient
changes in the trap frequency in the form of temporal delta kicks and the
hyperbolic cotangent functions. Exact expressions are obtained for the soliton
profiles. This is accomplished using the fact that a suitable linear
Schrodinger stationary state solution in time can be effectively combined with
the solutions of non-linear Schrodinger equation, for obtaining solutions of
the Gross-Pitaevskii equation with time dependent scattering length in a
harmonic trap. Interestingly, there is rapid pulse amplification in certain
scenarios
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COBRA-WC pretest predictions and post-test analysis of the FOTA temperature distribution during FFTF natural-circulation transients
The natural circulation tests of the Fast Flux Test Facility (FFTF) demonstrated a safe and stable transition from forced convection to natural convection and showed that natural convection may adequately remove decay heat from the reactor core. The COBRA-WC computer code was developed by the Pacific Northwest laboratory (PNL) to account for buoyancy-induced coolant flow redistribution and interassembly heat transfer, effects that become important in mitigating temperature gradients and reducing reactor core temperatures when coolant flow rate in the core is low. This report presents work sponsored by the US Department of Energy (DOE) with the objective of checking the validity of COBRA-WC during the first 220 seconds (sec) of the FFTF natural-circulation (plant-startup) tests using recorded data from two instrumented Fuel Open Test Assemblies (FOTAs). Comparison of COBRA-WC predictions of the FOTA data is a part of the final confirmation of the COBRA-WC methodology for core natural-convection analysis
Nucleon matrix elements and baryon masses in the Dirac orbital model
Using the expansion of the baryon wave function in a series of products of
single quark bispinors (Dirac orbitals), the nonsinglet axial and tensor
charges of a nucleon are calculated. The leading term yields in
good agreement with experiment. Calculation is essentially parameter-free and
depends only on the strong coupling constant value . The importance
of lower Dirac bispinor component, yielding 18% to the wave function
normalization is stressed. As a check, the baryon decuplet masses in the
formalism of this model are also computed using standard values of the string
tension and the strange quark mass ; the results being in a good
agreement with experiment.Comment: 8 pages, 2 tables; LaTeX2
Weakly Z symmetric manifolds
We introduce a new kind of Riemannian manifold that includes weakly-, pseudo-
and pseudo projective- Ricci symmetric manifolds. The manifold is defined
through a generalization of the so called Z tensor; it is named "weakly Z
symmetric" and denoted by (WZS)_n. If the Z tensor is singular we give
conditions for the existence of a proper concircular vector. For non singular Z
tensor, we study the closedness property of the associated covectors and give
sufficient conditions for the existence of a proper concircular vector in the
conformally harmonic case, and the general form of the Ricci tensor. For
conformally flat (WZS)_n manifolds, we derive the local form of the metric
tensor.Comment: 13 page
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