2,103 research outputs found
Non-enteric adenovirus among children with gastroenteritis in Warri, Southern Nigeria
No Abstract
Infrared behaviour of massless QED in space-time dimensions 2 < d < 4
We show that the logarithmic infrared divergences in electron self-energy and
vertex function of massless QED in 2+1 dimensions can be removed at all orders
of 1/N by an appropriate choice of a non-local gauge. Thus the infrared
behaviour given by the leading order in 1/N is not modified by higher order
corrections. Our analysis gives a computational scheme for the Amati-Testa
model, resulting in a non-trivial conformal invariant field theory for all
space-time dimensions 2 < d < 4.Comment: 12 pages, uses axodraw.sty; added comments at the end, and one
reference; to appear in Phys. Lett.
Interchannel coupling effects in the spin polarization of energetic photoelectrons
Effects of the interchannel coupling on the spin polarization of energetic
photoelectrons emitted from atomic Ne valence subshells are examined. Like
previously obtained results for cross sections and angular distributions, the
photoelectron spin polarization parameters too are found considerably
influenced by the coupling. The result completes a series of studies to finally
conclude that the independent particle description is inadequate for the {\em
entire} range of photoionization dynamics over the {\em full} spectral energy
domainComment: 7 pages, 5 figures, accepted in Phys. Rev.
Third-order relativistic many-body calculations of energies and lifetimes of levels along the silver isoelectronic sequence
Energies of 5l_j (l= s, p, d, f, g) and 4f_j states in neutral Ag and Ag-like
ions with nuclear charges Z = 48 - 100 are calculated using relativistic
many-body perturbation theory. Reduced matrix elements, oscillator strengths,
transition rates and lifetimes are calculated for the 17 possible 5l_j-5l'_{j'}
and 4f_j-5l_{j'} electric-dipole transitions. Third-order corrections to
energies and dipole matrix elements are included for neutral Ag and for ions
with Z60. Comparisons are made
with available experimental data for transition energies and lifetimes.
Correlation energies and transition rates are shown graphically as functions of
nuclear charge Z for selected cases. These calculations provide a theoretical
benchmark for comparison with experiment and theory.Comment: 8 page
Mitigation of electroencephalographic and cardiovascular responses to castration in Bos indicus bulls following the administration of either lidocaine or meloxicam
Objective
To investigate the mitigating effects of administration of local or systemic meloxicam on the electroencephalographic (EEG) and cardiovascular responses during surgical castration of Bos indicus bull calves.
Study design
Prospective, randomized, experimental study.
Animals
Thirty-six 6â8 month-old Bos indicus bull calves, with a mean ± standard deviation weight of 237 ± 19 kg.
Methods
Animals were randomly allocated to three groups of 12 (group L, 260 mg of 2% lidocaine subcutaneously and intratesticularly 5 minutes prior to castration; group M, 0.5 mg kgâ1 of meloxicam subcutaneously 30 minutes prior to castration; group C, no pre-operative analgesia administered). Anaesthesia was induced and maintained with halothane (0.9â1.1%) in oxygen. Electroencephalogram, heart rate (HR) and mean blood pressure (MAP) were recorded for 300 seconds prior to (baseline, B) and from the start of surgery (first testicle incision, T1). HR and MAP were compared at 10 second intervals for 90 seconds from the start of T1. Median frequency (F50), spectral edge frequency (F95) and total power of the EEG (Ptot) were analysed using area under the curve comparing T1 to B.
Results
All EEG variables were significantly different between B and T1 (p †0.0001). No differences in F50 were found between groups during T1 (p = 0.6491). F95 and Ptot were significantly different between group L and groups C and M during T1 (p = 0.0005 and 0.0163, respectively). There were transient significant changes in HR and MAP in groups L and M compared to group C during the 20â50 second periods.
Conclusions
The EEG changes indicate nociceptive responses in all three groups during surgical castration, greater in group L compared to groups C and M. Both analgesics attenuated the peracute cardiovascular response. Lidocaine and meloxicam administered prior to castration attenuated these responses in Bos indicus bull calves.
Clinical relevance
These findings provide support for the pre-operative administration of lidocaine and potentially meloxicam for castration in Bos indicus bull calves
Etched distributed Bragg reflectors as three-dimensional photonic crystals: photonic bands and density of states
The photonic band dispersion and density of states (DOS) are calculated for
the three-dimensional (3D) hexagonal structure corresponding to a distributed
Bragg reflector patterned with a 2D triangular lattice of circular holes.
Results for the Si/SiO and GaAs/AlGaAs systems determine the optimal
parameters for which a gap in the 2D plane occurs and overlaps the 1D gap of
the multilayer. The DOS is considerably reduced in correspondence with the
overlap of 2D and 1D gaps. Also, the local density of states (i.e., the DOS
weighted with the squared electric field at a given point) has strong
variations depending on the position. Both results imply substantial changes of
spontaneous emission rates and patterns for a local emitter embedded in the
structure and make this system attractive for the fabrication of a 3D photonic
crystal with controlled radiative properties.Comment: 8 pages, 5 figures; to appear in Phys. Rev.
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
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