17,192 research outputs found
Treatment Decision-Making in Catastrophic Illness
It is well established that the social and economic environment of medical care distinguishes its provision from that of other goods and services. While scholars have studied the influences of this idiosyncratic environment, there is relatively little empirical knowledge about how it affects decision-making in specific medical contexts. Through general conceptual discussion and consideration of a case study of leukemia chemo-therapy, this paper examines the medical decision-making process in one specific context: the response of physicians to the availability of an innovative treatment for a catastrophic illness. The manner in which the medical profession deals with serious illness is relevant to concerns as diverse as the promotion of economic efficiency and the preservation of human dignity.
Linear hydrodynamics and viscoelasticity of nematic elastomers
We develop a continuum theory of linear viscoelastic response in oriented
monodomain nematic elastomers. The expression for dissipation function is
analogous to the Leslie-Ericksen version of anisotropic nematic viscosity; we
propose the relations between the anisotropic rubber moduli and new viscous
coefficients. A new dimensionless number is introduced, which describes the
relative magnitude of viscous and rubber-elastic torques. In an elastic medium
with an independently mobile internal degree of freedom, the nematic director
with its own relaxation dynamics, the model shows a dramatic decrease in the
dynamic modulus in certain deformation geometries. The degree to which the
storage modulus does not altogether drop to zero is shown to be both dependent
on frequency and to be proportional to the semi-softness, the non-ideality of a
nematic network. We consider the most interesting geometry for the
implementation of the theory, calculating the dynamic response to an imposed
simple shear and making predictions for effective moduli and (exceptionally
high) loss factors.Comment: Latex 2e or PDFlatex (4 EPS or JPG figures) - to appear in
Euro.Phys.J.
Doubly-Fluctuating BPS Solutions in Six Dimensions
We analyze the BPS solutions of minimal supergravity coupled to an
anti-self-dual tensor multiplet in six dimensions and find solutions that
fluctuate non-trivially as a function of two variables. We consider families of
solutions coming from KKM monopoles fibered over Gibbons-Hawking metrics or,
equivalently, non-trivial T^2 fibrations over an R3 base. We find smooth
microstate geometries that depend upon many functions of one variable, but each
such function depends upon a different direction inside the T^2 so that the
complete solution depends non-trivially upon the whole T^2 . We comment on the
implications of our results for the construction of a general superstratum.Comment: 24 page
Four new Aphodius Illiger from pocket gopher burrows in Arizona, Utah, Kansas and Nebraska (Coleoptera: Scarabaeidae: Aphodiinae)
We describe four new species of winter-active Aphodius (sensu lato) from pocket gopher burrows in Arizona, Utah, Kansas, and Nebraska: A. cacabatus, A. paulseni, A. skillmani, and A. utopensis. Diagnostic characters of all four species are illustrated
Molecular films associated with LDEF
The molecular films deposited on the surface of the Long Duration Exposure Facility (LDEF) originated from the paints and room-temperature-vulcanized (RTV) silicone materials intentionally used on the satellite and not from residual contaminants. The high silicone content of most of the films and the uniformity of the films indicates a homogenization process in the molecular deposition and suggests a chemically most favored composition for the final film. The deposition on interior surfaces and vents indicated multiple bounce trajectories or repeated deposition-reemission cycles. Exterior surface deposits indicated a significant return flux. Ultraviolet light exposure was required to fix the deposited film as is indicated by the distribution of the films on interior surfaces and the thickness of films at the vent locations. Thermal conditions at the time of exposure to ultraviolet light seems to be an important factor in the thickness of the deposit. Sunrise facing (ram direction) surfaces always had the thicker film. These were the coldest surfaces at the time of their exposure to ultraviolet light. The films have a layered structure suggesting cyclic deposition. As many as 34 distinct layers were seen in the films. The cyclic nature of the deposition and the chemical uniformity of the film one layer to the next suggest an early deposition of the films though there is evidence for the deposition of molecular films throughout the nearly six year exposure of the satellite. A final 'spray' of an organic material associated with water soluble salts occurred very late in the mission. This may have been the result of one of the shuttle dump activities
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