5,337 research outputs found
Recommended from our members
Magnetotail energy dissipation during an auroral substorm.
Violent releases of space plasma energy from the Earth's magnetotail during substorms produce strong electric currents and bright aurora. But what modulates these currents and aurora and controls dissipation of the energy released in the ionosphere? Using data from the THEMIS fleet of satellites and ground-based imagers and magnetometers, we show that plasma energy dissipation is controlled by field-aligned currents (FACs) produced and modulated during magnetotail topology change and oscillatory braking of fast plasma jets at 10-14 Earth radii in the nightside magnetosphere. FACs appear in regions where plasma sheet pressure and flux tube volume gradients are non-collinear. Faster tailward expansion of magnetotail dipolarization and subsequent slower inner plasma sheet restretching during substorm expansion and recovery phases cause faster poleward then slower equatorward movement of the substorm aurora. Anharmonic radial plasma oscillations build up displaced current filaments and are responsible for discrete longitudinal auroral arcs that move equatorward at a velocity of about 1km/s. This observed auroral activity appears sufficient to dissipate the released energy
The present rate of Supernovae
We present and discuss the most recent determination of the rate of
Supernovae in the local Universe. A comparison with other results shows a
general agreement on the gross values but still significant differences on the
values of the rates of various SN rates in different kinds of galaxies. The
rate of SNe, used as a probe of Star Formation, confirms the young progenitor
scenario for SNII+Ib/c. The increasing diversity of SNe reflects also in the SN
yields which may affect the chemical evolution of the Galaxy but, because of
the limited statistics, we cannot estimate the contributions of the new
subtypes yet. It is also expected that in a few years observational
determinations of the SN rates at various look-back times will be available.Comment: 9 pages, Latex, 1 figure, To appear in the proceedings of the
conference "The Chemical Evolution of The Milky Way: Stars versus Clusters",
eds. F. Matteucci and F. Giovannelli, Vulcano, Italy, September 20-24 199
Influence of donor-recipient strain combinations on immunologic responses after allogeneic rat small bowel transplantation
N-acetyltaurine and Acetylcarnitine Production for the Mitochondrial Acetyl-CoA Regulation in Skeletal Muscles during Endurance Exercises
During endurance exercises, a large amount of mitochondrial acetyl-CoA is produced in skeletal muscles from lipids, and the excess acetyl-CoA suppresses the metabolic flux from glycolysis to the TCA cycle. This study evaluated the hypothesis that taurine and carnitine act as a buffer of the acetyl moiety of mitochondrial acetyl-CoA derived from the short- and long-chain fatty acids of skeletal muscles during endurance exercises. In human subjects, the serum concentrations of acetylated forms of taurine (NAT) and carnitine (ACT), which are the metabolites of acetyl-CoA buffering, significantly increased after a full marathon. In the culture medium of primary human skeletal muscle cells, NAT and ACT concentrations significantly increased when they were cultured with taurine and acetate or with carnitine and palmitic acid, respectively. The increase in the mitochondrial acetyl-CoA/free CoA ratio induced by acetate and palmitic acid was suppressed by taurine and carnitine, respectively. Elevations of NAT and ACT in the blood of humans during endurance exercises might serve the buffering of the acetyl-moiety in mitochondria by taurine and carnitine, respectively. The results suggest that blood levels of NAT and ACT indicate energy production status from fatty acids in the skeletal muscles of humans undergoing endurance exercise
Nitrogen doping of TiO2 photocatalyst forms a second eg state in the Oxygen (1s) NEXAFS pre-edge
Close inspection of the pre-edge in oxygen near-edge x-ray absorption fine
structure spectra of single step, gas phase synthesized titanium oxynitride
photocatalysts with 20 nm particle size reveals an additional eg resonance in
the VB that went unnoticed in previous TiO2 anion doping studies. The relative
spectral weight of this Ti(3d)-O(2p) hybridized state with respect to and
located between the readily established t2g and eg resonances scales
qualitatively with the photocatalytic decomposition power, suggesting that this
extra resonance bears co-responsibility for the photocatalytic performance of
titanium oxynitrides at visible light wavelengths
Glimpsing Colour in a World of Black and White
The past 40 years have taught us that nucleons are built of constituents that
carry colour charges with interactions governed by Quantum Chromodynamics
(QCD). How experiments (past, present and future) at Jefferson Lab probe
colourless nuclei to map out these internal colour degrees of freedom is
presented. When combined with theoretical calculations, these will paint a
picture of how the confinement of quarks and gluons, and the structure of the
QCD vacuum, determine the properties of all (light) strongly interacting
states.Comment: 8 pages, 9 figures. Invited talk at the Rutherford Centennial
Conference on Nuclear Physics, University of Manchester, 8-12 August 2011. To
appear in the Proceeding
Magnetic effects in a holographic Fermi-like liquid
We explore the magnetic properties of the Fermi-like liquid represented by
the D3-D7' system. The system exhibits interesting magnetic properties such as
ferromagnetism and an anomalous Hall effect, which are due to the Chern-Simons
term in the effective gravitational action. We investigate the spectrum of
quasi-normal modes in the presence of a magnetic field and show that the
magnetic field mitigates the instability towards a striped phase. In addition,
we find a critical magnetic field above which the zero sound mode becomes
massive.Comment: 18 pages, 15 figure
Physicians' communication skills with patients and legal liability in decided medical malpractice litigation cases in Japan
<p>Abstract</p> <p>Background</p> <p>In medical malpractice litigations in recent years in Japan, it is notable that the growing number of medical litigation cases includes the issue of a doctor's explanation to the patient as a pivotal point. The objective of this study was to identify factors of physicians' communication skills with patients, as related to their legal liability, and differences in doctors' communication skills with patients by the type of medical facility.</p> <p>Methods</p> <p>Decisions of medical malpractice litigation cases between 1988 and 2005 in Japan, the pivotal issue of which was a physician's explanation, were analyzed in the study. The content of each decision was summarized using the study variables (information about the patient, doctor, manner of the doctor's explanation, and subsequent litigation), and a database comprising the content of each decision (<it>N </it>= 100) was constructed. In order to evaluate an association between doctors' communication skills with patients and the outcome of the litigation, the analysis was performed based on the outcome of litigation or the type of medical facility.</p> <p>Results</p> <p>The ratio of acknowledged physician liability by court decision was lower in cases in which the doctor's explanation occurred before treatment or surgery (<it>p </it>= 0.013). The ratio of acknowledged physician liability by court decision was higher in cases of elective or non-urgent treatment (<it>p </it>= 0.046). The ratio of acknowledged physician liability by court decision was higher in clinics than in hospital groups (<it>p </it>= 0.036).</p> <p>Conclusion</p> <p>These findings are beneficial for the prevention of medical disputes and improvement of patient-physician communication.</p
Hydrodynamics from charged black branes
We extend the recent work on fluid-gravity correspondence to charged
black-branes by determining the metric duals to arbitrary charged fluid
configuration up to second order in the boundary derivative expansion. We also
derive the energy-momentum tensor and the charge current for these
configurations up to second order in the boundary derivative expansion. We find
a new term in the charge current when there is a bulk Chern-Simons interaction
thus resolving an earlier discrepancy between thermodynamics of charged
rotating black holes and boundary hydrodynamics. We have also confirmed that
all our expressions are covariant under boundary Weyl-transformations as
expected.Comment: 0+ 31 Pages; v2: 0+33 pages, typos corrected and new sections (in
appendix) added; v3:published versio
- …