150 research outputs found
PCV29 Rates Of Acute Coronary Events And All Cause Mortality In Patients With Stable Coronary Artery Disease (Cad) After Myocardial Infarction And Additional Cardiovascular Risk Factors
Magnetar outbursts: an observational review
Transient outbursts from magnetars have shown to be a key property of their
emission, and one of the main way to discover new sources of this class. From
the discovery of the first transient event around 2003, we now count about a
dozen of outbursts, which increased the number of these strongly magnetic
neutron stars by a third in six years. Magnetar outbursts might involve their
multi-band emission resulting in an increased activity from radio to hard
X-ray, usually with a soft X-ray flux increasing by a factor of 10-1000 with
respect to the quiescent level. A connected X-ray spectral evolution is also
often observed, with a spectral softening during the outburst decay. The flux
decay times vary a lot from source to source, ranging from a few weeks to
several years, as also the decay law which can be exponential-like, a power-law
or even multiple power-laws can be required to model the flux decrease. We
review here on the latest observational results on the multi-band emission of
magnetars, and summarize one by one all the transient events which could be
studied to date from these sources.Comment: 34 pages, 6 figures. Chapter of the Springer Book ASSP 7395
"High-energy emission from pulsars and their systems", proceeding of the Sant
Cugat Forum on Astrophysics (12-16 April 2010). Review updated to January
201
Growth of (110) Diamond using pure Dicarbon
We use a density-functional based tight-binding method to study diamond
growth steps by depositing dicarbon species onto a hydrogen-free diamond (110)
surface. Subsequent C_2 molecules are deposited on an initially clean surface,
in the vicinity of a growing adsorbate cluster, and finally, near vacancies
just before completion of a full new monolayer. The preferred growth stages
arise from C_2n clusters in near ideal lattice positions forming zigzag chains
running along the [-110] direction parallel to the surface. The adsorption
energies are consistently exothermic by 8--10 eV per C_2, depending on the size
of the cluster. The deposition barriers for these processes are in the range of
0.0--0.6 eV. For deposition sites above C_2n clusters the adsorption energies
are smaller by 3 eV, but diffusion to more stable positions is feasible. We
also perform simulations of the diffusion of C_2 molecules on the surface in
the vicinity of existing adsorbate clusters using an augmented Lagrangian
penalty method. We find migration barriers in excess of 3 eV on the clean
surface, and 0.6--1.0 eV on top of graphene-like adsorbates. The barrier
heights and pathways indicate that the growth from gaseous dicarbons proceeds
either by direct adsorption onto clean sites or after migration on top of the
existing C_2n chains.Comment: 8 Pages, 7 figure
AltitudeOmics: The Integrative Physiology of Human Acclimatization to Hypobaric Hypoxia and Its Retention upon Reascent.
An understanding of human responses to hypoxia is important for the health of millions of people worldwide who visit, live, or work in the hypoxic environment encountered at high altitudes. In spite of dozens of studies over the last 100 years, the basic mechanisms controlling acclimatization to hypoxia remain largely unknown. The AltitudeOmics project aimed to bridge this gap. Our goals were 1) to describe a phenotype for successful acclimatization and assess its retention and 2) use these findings as a foundation for companion mechanistic studies. Our approach was to characterize acclimatization by measuring changes in arterial oxygenation and hemoglobin concentration [Hb], acute mountain sickness (AMS), cognitive function, and exercise performance in 21 subjects as they acclimatized to 5260 m over 16 days. We then focused on the retention of acclimatization by having subjects reascend to 5260 m after either 7 (n = 14) or 21 (n = 7) days at 1525 m. At 16 days at 5260 m we observed: 1) increases in arterial oxygenation and [Hb] (compared to acute hypoxia: PaO2 rose 9±4 mmHg to 45±4 while PaCO2 dropped a further 6±3 mmHg to 21±3, and [Hb] rose 1.8±0.7 g/dL to 16±2 g/dL; 2) no AMS; 3) improved cognitive function; and 4) improved exercise performance by 8±8% (all changes p<0.01). Upon reascent, we observed retention of arterial oxygenation but not [Hb], protection from AMS, retention of exercise performance, less retention of cognitive function; and noted that some of these effects lasted for 21 days. Taken together, these findings reveal new information about retention of acclimatization, and can be used as a physiological foundation to explore the molecular mechanisms of acclimatization and its retention
A fish otolith assemblage from the Late Miocene (Pannonian) deposits of Lake Pannon (Doba, NW Hungary)
Stability of multi-component epilayers and nanopattern formation
A uniform multi-component epilayer may lose stability under the combined action of spinodal decomposition and epilayer–substrate interaction, separating into multiple phases. The phases may further self-organize into regular patterns. This paper investigates the compositional stability of a ternary epliayer and the subsequent emergence of nanoscale patterns. Multiple energetic forces and kinetic processes involving phase separation, phase coarsening and phase refining are incorporated into a continuous phase field model. Linear stability analysis is performed by perturbing a uniform concentration field into a sinusoidal field with small amplitude and arbitrary wavelength. The analysis shows that the epilayer–substrate interaction counteracts the coarsening effect of phase boundary energy and may lead to the formation of steady nanoscale patterns. Detailed analysis also reveals the interaction of multi-phases and its effect on the stability condition. Numerical simulation of evolving concentration field is discussed at the end of the paper. The simulations show that the pattern formation process of multi-component epilayers involves remarkably rich dynamics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43296/1/11051_2004_Article_3304.pd
Gendering the careers of young professionals: some early findings from a longitudinal study. in Organizing/theorizing: developments in organization theory and practice
Wonders whether companies actually have employees best interests at heart across physical, mental and spiritual spheres. Posits that most organizations ignore their workforce – not even, in many cases, describing workers as assets! Describes many studies to back up this claim in theis work based on the 2002 Employment Research Unit Annual Conference, in Cardiff, Wales
Analysis of health care costs containing a large proportion of $0 data using traditional and zero-inflated gamma regression models
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