8,899 research outputs found
The future and safety of ambulatory surgery
Although many advances have occurred in anaesthesia within the last 50 years, the movement of surgical procedures from a hospital setting to an ambulatory environment has had a major impact on general health care. Several factors have driven this process, including advances in anaesthesia and technology, the desire by payers to reduce healthcare costs, the demonstration of patient safety and the positive experience of patients undergoing same-day surgery. The safety of ambulatory anaesthesia and surgery is well established. Greater emphasis is placed on minor side-effects, quality of life and patient satisfaction. Advances in technologies,which continue to move procedures out of the operating room and into imaging suites and the office, are driving the future of ambulatory anaesthesia and surgery. The Society for Ambulatory Anesthesia’s Clinical Outcomes Registry database was established to enhance the quality of ambulatory anaesthesia, develop benchmarks and establish best practice. The future and growth of ambulatory anaesthesia is secure with the ageing population and advances in technology.Keywords: future; safety; ambulatory surger
Radiation and String Atmosphere for Relativistic Stars
We extend the Vaidya radiating metric to include both a radiation field and a
string fluid. Assuming diffusive transport for the string fluid, we find new
analytic solutions of Einstein's field equations. Our new solutions represent
an extention of Xanthopoulos superposition.Comment: To appear in Phys. Rev. D, Rapid Communicatio
Fractal Scales in a Schwarzschild Atmosphere
Recently, Glass and Krisch have extended the Vaidya radiating metric to
include both a radiation fluid and a string fluid [1999 Class. Quantum Grav.
vol 16, 1175]. Mass diffusion in the extended Schwarzschild atmosphere was
studied. The continuous solutions of classical diffusive transport are believed
to describe the envelope of underlying fractal behavior. In this work we
examine the classical picture at scales on which fractal behavior might be
evident.Comment: to appear in Class. Quantum Gra
Features of pulsed synchronization of a systems with a tree-dimensional phase space
Features of synchronization picture in the system with the limit cycle
embedded in a three-dimensional phase space are considered. By the example of
Ressler system and Dmitriev - Kislov generator under the action of a periodic
sequence of delta - function it is shown, that synchronization picture
significantly depends on the direction of pulse action. Features of
synchronization tons appeared in these models are observed.Comment: 16 pages, 11 figure
Schwarzschild Atmospheric Processes: A Classical Path to the Quantum
We develop some classical descriptions for processes in the Schwarzschild
string atmosphere. These processes suggest relationships between macroscopic
and microscopic scales. The classical descriptions developed in this essay
highlight the fundamental quantum nature of the Schwarzschild atmospheric
processes.Comment: to appear in Gen. Rel. Gra
Killing vectors and anisotropy
We consider an action that can generate fluids with three unequal stresses
for metrics with a spacelike Killing vector. The parameters in the action are
directly related to the stress anisotropies. The field equations following from
the action are applied to an anisotropic cosmological expansion and an
extension of the Gott-Hiscock cosmic string
Coordinates and 2MASS and OGLE identifications for all stars in Arp's 1965 finding chart for Baade's Window
Aims: We seek to provide 2MASS and OGLE identifications and coordinates for
all stars in the finding chart published by Arp\,(1965). This chart covers the
low extinction area around NGC 6522, also known as Baade's window, at
coordinates (l,b)=(1.02,-3.92).
Methods: A cross correlation, using numerical techniques, was performed
between a scan of the original finding chart from Arp (1965) and 2MASS and
OGLE-II images and stellar coordinates.
Results: We provide coordinates for all stars in Arp's finding chart and
2MASS and OGLE identifications wherever possible. Two identifications in
quadrant II do not appear in the original finding chart.Comment: 30 pages, accepted by A&A as a Research Not
The Metallicity and Reddening of Stars in the Inner Galactic Bulge
We present a preliminary analysis of K, J-K color magnitude diagrams (CMDs)
for 7 different positions on or close to the minor axis of the Milky Way at
Galactic latitudes between +0.1^\circ and -2.8^\circ. From the slopes of the
(linear) giant branches in these CMDs we derive a dependence of on
latitude for b between -0.8^\circ and -2.8^\circ of -0.085 \pm 0.033
dex/degree. When combined with the data from Tiede et al. we find for
-0.8^\circ \leq b \leq -10.3^\circ the slope in is -0.064 \pm 0.012
dex/degree. An extrapolation to the Galactic Center predicts [Fe/H] = +0.034
\pm 0.053 dex. We also derive average values for the extinction in the K band
(A_K) of between 2.15 and 0.27 for the inner bulge fields corresponding to
average values of E(J-K) of between 3.46 and 0.44. There is a well defined
linear relation between the average extinction for a field and the star-to-star
scatter in the extinction for the stars within each field. This result suggests
that the typical apparent angular scale size for an absorbing cloud is small
compared with the field size (90\arcsec on a side). Finally, from an
examination of the luminosity function of bright giants in each field we
conclude that the young component of the stellar population observed near the
Galactic center declines in density much more quickly than the overall bulge
population and is undetectable beyond 1^\circ from the Galactic center.Comment: accepted for publication in Astron. Jour. Compressed file contains
the text, 9 figures, and 6 tables prepared with AAS Latex macros v. 4.
Recent star formation in the inner Galactic Bulge seen by ISOGAL. I - Classification of bright mid-IR sources in a test field
Context: The stellar populations in the central region of the Galaxy are
poorly known because of the high visual extinction and very great source
density in this direction.
Aims: To use recent infrared surveys for studying the dusty stellar objects
in this region.
Methods: We analyse the content of a 20x20 arcmin^2 field centred at
(l,b)=(-0.27,-0.06) observed at 7 and 15 microns as part of the ISOGAL survey.
These ISO observations are more than an order of magnitude better in
sensitivity and spatial resolution than the IRAS observations. The sources are
cross-associated with other catalogues to identify various types of objects. We
then derive criteria to distinguish young objects from post-main sequence
stars.
Results: We find that a sample of about 50 young stellar objects and
ultra-compact HII regions emerges, out of a population of evolved AGB stars. We
demonstrate that the sources colours and spatial extents, as they appear in the
ISOGAL catalogue, possibly complemented with MSX photometry at 21 microns, can
be used to determine whether the ISOGAL sources brighter than 300 mJy at 15
microns (or [15] < 4.5 mag) are young objects or late-type evolved stars.Comment: 15 pages, 12 figures. Accepted for publication in Astronomy and
Astrophysic
Relieving the frustration through Mn3+ substitution in Holmium Gallium Garnet
We present a study on the impact of Mn3+ substitution in the geometrically frustrated Ising garnet Ho3Ga5O12 using bulk magnetic measurements and low temperature powder neutron diffraction. We find that the transition temperature, TN = 5.8 K, for Ho3MnGa4O12 is raised by almost 20 when compared to Ho3Ga5O12. Powder neutron diffraction on Ho3MnxGa5-xO12 (x = 0.5, 1) below TN shows the formation of a long range ordered ordered state with k = (0,0,0). Ho3+ spins are aligned antiferromagnetically along the six crystallographic axes with no resultant moment while the Mn3+ spins are oriented along the body diagonals, such that there is a net moment along [111]. The magnetic structure can be visualised as ten-membered rings of corner-sharing triangles of Ho3+ spins with the Mn3+ spins ferromagnetically coupled to each individual Ho3+ spin in the triangle. Substitution of Mn3+ completely relieves the magnetic frustration with f = CW/TN ~ 1.1 for Ho3MnGa4O12.We acknowledge funding support from the Winton Programme for the Physics of Sustainability. Magnetic measurements were carried out using the Advanced Materials Characterisation Suite, funded by EPSRC Strategic Equipment Grant EP1M00052411
- …