10,031 research outputs found
Longitudinal variations, the opposition effect and monochromatic albedos for Mars
Magnitude at zero phase, phase coefficient, and monochromatic albedo computed for Mars as function of wavelengt
Impact of the annealing temperature on Pt/g-C3N4 structure, activity and selectivity between photodegradation and water splitting
Acknowledgements: The authors would like to thank SABIC as well as EPSRC platform grant [EP/K015540/1] for financial support and the Royal Society of Chemistry for a Wolfson Merit Award. In order to protect intellectual property the data underpinning this publication are not made publicly available. All enquiries about the data should be addressed to [email protected] reviewedPostprin
Highly active iridium(I) complexes for the selective hydrogenation of carbon-carbon multiple bonds
New iridium(I) complexes, bearing a bulky NHC/phosphine ligand combination, have been established as extremely efficient hydrogenation catalysts that can be used at low catalyst loadings, and are compatible with functional groups which are often sensitive to more routinely employed hydrogenation methods
Mortality associated with avian reovirus infection in a free-living magpie (Pica pica) in Great Britain
Avian reoviruses (ARVs) cause a range of disease presentations in domestic, captive and free-living bird species. ARVs have been reported as a cause of significant disease and mortality in free-living corvid species in North America and continental Europe. Until this report, there have been no confirmed cases of ARV-associated disease in British wild birds
Projected free energies for polydisperse phase equilibria
A `polydisperse' system has an infinite number of conserved densities. We
give a rational procedure for projecting its infinite-dimensional free energy
surface onto a subspace comprising a finite number of linear combinations of
densities (`moments'), in which the phase behavior is then found as usual. If
the excess free energy of the system depends only on the moments used, exact
cloud, shadow and spinodal curves result; two- and multi-phase regions are
approximate, but refinable indefinitely by adding extra moments. The approach
is computationally robust and gives new geometrical insights into the
thermodynamics of polydispersity.Comment: 4 pages, REVTeX, uses multicol.sty and epsf.sty, 1 postscript figure
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The microbiome in patients with atopic dermatitis.
As an interface with the environment, the skin is a complex ecosystem colonized by many microorganisms that coexist in an established balance. The cutaneous microbiome inhibits colonization with pathogens, such as Staphylococcus aureus, and is a crucial component for function of the epidermal barrier. Moreover, crosstalk between commensals and the immune system is now recognized because microorganisms can modulate both innate and adaptive immune responses. Host-commensal interactions also have an effect on the developing immune system in infants and, subsequently, the occurrence of diseases, such as asthma and atopic dermatitis (AD). Later in life, the cutaneous microbiome contributes to the development and course of skin disease. Accordingly, in patients with AD, a decrease in microbiome diversity correlates with disease severity and increased colonization with pathogenic bacteria, such as S aureus. Early clinical studies suggest that topical application of commensal organisms (eg, Staphylococcus hominis or Roseomonas mucosa) reduces AD severity, which supports an important role for commensals in decreasing S aureus colonization in patients with AD. Advancing knowledge of the cutaneous microbiome and its function in modulating the course of skin disorders, such as AD, might result in novel therapeutic strategies
Low voltage control of ferromagnetism in a semiconductor p-n junction
The concept of low-voltage depletion and accumulation of electron charge in
semiconductors, utilized in field-effect transistors (FETs), is one of the
cornerstones of current information processing technologies. Spintronics which
is based on manipulating the collective state of electron spins in a
ferromagnet provides complementary technologies for reading magnetic bits or
for the solid-state memories. The integration of these two distinct areas of
microelectronics in one physical element, with a potentially major impact on
the power consumption and scalability of future devices, requires to find
efficient means for controlling magnetization electrically. Current induced
magnetization switching phenomena represent a promising step towards this goal,
however, they relay on relatively large current densities. The direct approach
of controlling the magnetization by low-voltage charge depletion effects is
seemingly unfeasible as the two worlds of semiconductors and metal ferromagnets
are separated by many orders of magnitude in their typical carrier
concentrations. Here we demonstrate that this concept is viable by reporting
persistent magnetization switchings induced by short electrical pulses of a few
volts in an all-semiconductor, ferromagnetic p-n junction.Comment: 11 pages, 4 figure
Isolating Triggered Star Formation
Galaxy pairs provide a potentially powerful means of studying triggered star
formation from galaxy interactions. We use a large cosmological N-body
simulation coupled with a well-tested semi-analytic substructure model to
demonstrate that the majority of galaxies in close pairs reside within cluster
or group-size halos and therefore represent a biased population, poorly suited
for direct comparison to ``field'' galaxies. Thus, the frequent observation
that some types of galaxies in pairs have redder colors than ``field'' galaxies
is primarily a selection effect. We select galaxy pairs that are isolated in
their dark matter halos with respect to other massive subhalos (N=2 halos) and
a control sample of isolated galaxies (N=1 halos) for comparison. We then apply
these selection criteria to a volume-limited subset of the 2dF Galaxy Redshift
Survey with M_Bj <= -19 and obtain the first clean measure of the typical
fraction of galaxies affected by triggered star formation and the average
elevation in the star formation rate. We find that 24% (30.5%) of these L^\star
and sub-L^{\star} galaxies in isolated 50 (30) kpc/h pairs exhibit star
formation that is boosted by a factor of >~ 5 above their average past value,
while only 10% of isolated galaxies in the control sample show this level of
enhancement. Thus, 14% (20 %) of the galaxies in these close pairs show clear
triggered star formation. The isolation criteria we develop provide a means to
constrain star formation and feedback prescriptions in hydrodynamic simulations
and a very general method of understanding the importance of triggered star
formation in a cosmological context. (Abridged.)Comment: 12 pages, 10 figures, emulateapj format, accepted by Ap
Multi-level study of C3H2: The first interstellar hydrocarbon ring
Cyclic species in the interstellar medium have been searched for almost since the first detection of interstellar polyatomic molecules. Eleven different C3H2 rotational transitions were detected; 9 of which were studied in TMC-1, a nearby dark dust cloud, are shown. The 1 sub 10 yields 1 sub 01 and 2 sub 20 yields 2 sub 11 transitions were observed with the 43 m NRAO telescope, while the remaining transitions were detected with the 14 m antenna of the Five College Radio Observatory (FCRAO). The lines detected in TMC-1 have energies above the ground state ranging from 0.9 to 17.1 K and consist of both ortho and para species. Limited maps were made along the ridge for several of the transitions. The HC3N J = 2 yields 1 transition were mapped simultaneously with the C3H2 1 sub 10 yields 1 sub 01 line and therefore can compare the distribution of this ring with a carbon chain in TMC-1. C3H2 is distributed along a narrow ridge with a SE - NW extension which is slightly more extended than the HC2N J = 2 yields 1. Gaussian fits gives a FWHP extension of 8'5 for C3H2 while HC3N has a FWHP of 7'. The data show variations of the two velocity components along the ridge as a function of transition. Most of the transitions show a peak at the position of strongest HC3N emission while the 2 sub 21 yields 2 sub 10 transition shows a peak at the NH3 position
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