100,259 research outputs found
Novel translational approaches to the search for precision therapies for acute respiratory distress syndrome.
In the 50 years since acute respiratory distress syndrome (ARDS) was first described, substantial progress has been made in identifying the risk factors for and the pathogenic contributors to the syndrome and in characterising the protein expression patterns in plasma and bronchoalveolar lavage fluid from patients with ARDS. Despite this effort, however, pharmacological options for ARDS remain scarce. Frequently cited reasons for this absence of specific drug therapies include the heterogeneity of patients with ARDS, the potential for a differential response to drugs, and the possibility that the wrong targets have been studied. Advances in applied biomolecular technology and bioinformatics have enabled breakthroughs for other complex traits, such as cardiovascular disease or asthma, particularly when a precision medicine paradigm, wherein a biomarker or gene expression pattern indicates a patient's likelihood of responding to a treatment, has been pursued. In this Review, we consider the biological and analytical techniques that could facilitate a precision medicine approach for ARDS
Diffusion in the chromosphere and the composition of the solar corona and energetic particles
Composition observations, in the solar photosphere, and in the upper transition region (TR) and corona imply a change of composition of the solar atmosphere somewhere between the photosphere and the upper TR. Heavy elements with first ionization potential (FIP) 9 eV (high-FIP element) are approx. 4 times less abundant in the TR and corona than in the photosphere, as compared to both hydrogen and heavy elements with lower low-FIP elements. A separation is suggested between neutral and ionized elements in a region where the high-FIP elements are mostly neutral, and the low-FIP elements ionized. This occurs in the chromosphere at altitudes above 600 km and below 2000 km above Photosphere. Whether the diffusion processes can explain the observed change in composition is investigated
Rotational properties of two-component Bose gases in the lowest Landau level
We study the rotational (yrast) spectra of dilute two-component atomic Bose
gases in the low angular momentum regime, assuming equal interspecies and
intraspecies interaction. Our analysis employs the composite fermion (CF)
approach including a pseudospin degree of freedom. While the CF approach is not
{\it a priori} expected to work well in this angular momentum regime, we show
that composite fermion diagonalization gives remarkably accurate approximations
to low energy states in the spectra. For angular momenta (where
and denote the numbers of particles of the two species, and ), we
find that the CF states span the full Hilbert space and provide a convenient
set of basis states which, by construction, are eigenstates of the symmetries
of the Hamiltonian. Within this CF basis, we identify a subset of the basis
states with the lowest -level kinetic energy. Diagonalization within
this significally smaller subspace constitutes a major computational
simplification and provides very close approximations to ground states and a
number of low-lying states within each pseudospin and angular momentum channel
Structure and function of natural sulphide-oxidizing microbial mats under dynamic input of light and chemical energy
We studied the interaction between phototrophic and chemolithoautotrophic sulphide-oxidizing microorganisms in natural microbial mats forming in sulphidic streams. The structure of these mats varied between two end-members: one characterized by a layer dominated by large sulphur-oxidizing bacteria (SOB; mostly Beggiatoa-like) on top of a cyanobacterial layer (B/C mats) and the other with an inverted structure (C/B mats). C/B mats formed where the availability of oxygen from the water column was limited (<5 mu M). Aerobic chemolithotrophic activity of the SOB depended entirely on oxygen produced locally by cyanobacteria during high light conditions. In contrast, B/C mats formed at locations where oxygen in the water column was comparatively abundant (445 mu M) and continuously present. Here SOB were independent of the photosynthetic activity of cyanobacteria and outcompeted the cyanobacteria in the uppermost layer of the mat where energy sources for both functional groups were concentrated. Outcompetition of photosynthetic microbes in the presence of light was facilitated by the decoupling of aerobic chemolithotrophy and oxygenic phototrophy. Remarkably, the B/C mats conserved much less energy than the C/B mats, although similar amounts of light and chemical energy were available. Thus ecosystems do not necessarily develop towards optimal energy usage. Our data suggest that, when two independent sources of energy are available, the structure and activity of microbial communities is primarily determined by the continuous rather than the intermittent energy source, even if the time-integrated energy flux of the intermittent energy source is greater
Spontaneous Spin Polarization in Quantum Wires
A number of recent experiments report spin polarization in quantum wires in
the absence of magnetic fields. These observations are in apparent
contradiction with the Lieb-Mattis theorem, which forbids spontaneous spin
polarization in one dimension. We show that sufficiently strong interactions
between electrons induce deviations from the strictly one-dimensional geometry
and indeed give rise to a ferromagnetic ground state in a certain range of
electron densities.Comment: 4 pages, 4 figure
Three-dimensional fast electron transport for ignition-scale inertial fusion capsules
Three-dimensional hybrid PIC simulations are presented to study electron
energy transport and deposition in a full-scale fast ignition configuration.
Multi-prong core heating close to ignition is found when a few GA, few PW beam
is injected. Resistive beam filamentation in the corona seeds the 3D current
pattern that penetrates the core. Ohmic heating is important in the low-density
corona, while classical Coulomb deposition heats the core. Here highest energy
densities (few Tbar at 10 keV) are observed at densities above 200 g/cc. Energy
coupling to the core ranges from 20 to 30%; it is enhanced by beam collimation
and decreases when raising the beam particle energy from 1.5 to 5.5 MeV.Comment: 5 pages, 5 figure
Scanning-electron-microscopy observations and mechanical characteristics of ion-beam-sputtered surgical implant alloys
An electron bombardment ion thruster was used as an ion source to sputter the surfaces of orthopedic prosthetic metals. Scanning electron microscopy photomicrographs were made of each ion beam textured surface. The effect of ion texturing an implant surface on its bond to bone cement was investigated. A Co-Cr-W alloy and surgical stainless steel were used as representative hard tissue implant materials to determine effects of ion texturing on bulk mechanical properties. Work was done to determine the effect of substrate temperature on the development of an ion textured surface microstructure. Results indicate that the ultimate strength of the bulk materials is unchanged by ion texturing and that the microstructure will develop more rapidly if the substrate is heated prior to ion texturing
Public Release of 2dF data from the Fornax Cluster Spectroscopic Survey
Thanks to the 2dF spectrograph on the Anglo-Australian Telescope, we have
recently completed the first stage of a complete spectroscopic survey more than
one order of magnitude larger than any previous study, measuring 7000 spectra
in a 6 sq.deg. area as part of our study of the Fornax Cluster. In this article
we describe the public release of 3600 spectra from our first field. We hope
that this public release will encourage colleagues making surveys for rare
objects to choose these fields, as much of the follow-up spectroscopy that
might be required is available from our data.Comment: To appear in the AAO Newsletter. Data online at
http://astro.ph.unimelb.edu.au/data
- …
