340 research outputs found
Electrochemical Behavior of Magnesium and its Alloys in non-Aqueous Solutions
Magnesium and its alloys are widely used in creation of chemical sources of current, because possesses a number of characteristics: highly negative standart potential, low equivalent weight, high melting point, low cost, relative abundance, ease of handling, machining, and disposal, and low toxicity of most its compounds. Therefore study of magnesium behavior and isolation is actually and perspective. However results of researches in this area are separated and have no a general direction. In this connection, the given article supposes by the purpose to generalize last achievements, available in the modern literature in electrochemistry of magnesium and its alloys in non-aqueous media
The Impact of a SixâYear Climate Anomaly on the âSpanish Fluâ Pandemic and WWI
The H1N1 âSpanish influenzaâ pandemic of 1918â1919 caused the highest known number of deaths recorded for a single pandemic in human history. Several theories have been offered to explain the virulence and spread of the disease, but the environmental context remains underexamined. In this study, we present a new environmental record from a European, Alpine ice core, showing a significant climate anomaly that affected the continent from 1914 to 1919. Incessant torrential rain and declining temperatures increased casualties in the battlefields of World War I (WWI), setting the stage for the spread of the pandemic at the end of the conflict. Multiple independent records of temperature, precipitation, and mortality corroborate these findings
Merging of Components in Close Binaries: Type Ia Supernovae, Massive White Dwarfs, and Ap stars
The "Scenario Machine" (a computer code designed for studies of the evolution
of close binaries) was used to carry out a population synthesis for a wide
range of merging astrophysical objects: main-sequence stars with main-sequence
stars; white dwarfs with white dwarfs, neutron stars, and black holes; neutron
stars with neutron stars and black holes; and black holes with black holes.We
calculate the rates of such events, and plot the mass distributions for merging
white dwarfs and main-sequence stars. It is shown that Type Ia supernovae can
be used as standard candles only after approximately one billion years of
evolution of galaxies. In the course of this evolution, the average energy of
Type Ia supernovae should decrease by roughly 10%; the maximum and minimum
energies of Type Ia supernovae may differ by no less than by a factor of 1.5.
This circumstance should be taken into account in estimations of parameters of
acceleration of the Universe. According to theoretical estimates, the most
massive - as a rule, magnetic - white dwarfs probably originate from mergers of
white dwarfs of lower mass. At least some magnetic Ap and Bp stars may form in
mergers of low-mass main sequence stars (<1.5 mass of the Sun) with convective
envelopes.Comment: 15 pages, 4 figure
Pathomechanisms of a CLCN1 Mutation Found in a Russian Family Suffering From Becker's Myotonia
Objective: Myotonia congenita (MC) is a rare muscle disease characterized by sarcolemma over-excitability inducing skeletal muscle stiffness. It can be inherited either as an autosomal dominant (Thomsen's disease) or an autosomal recessive (Becker's disease) trait. Both types are caused by loss-of-function mutations in the CLCN1 gene, encoding for ClC-1 chloride channel. We found a ClC-1 mutation, p.G411C, identified in Russian patients who suffered from a severe form of Becker's disease. The purpose of this study was to provide a solid correlation between G411C dysfunction and clinical symptoms in the affected patient. Methods: We provide clinical and genetic information of the proband kindred. Functional studies include patch-clamp electrophysiology, biotinylation assay, western blot analysis, and confocal imaging of G411C and wild-type ClC-1 channels expressed in HEK293T cells. Results: The G411C mutation dramatically abolished chloride currents in transfected HEK cells. Biochemical experiments revealed that the majority of G411C mutant channels did not reach the plasma membrane but remained trapped in the cytoplasm. Treatment with the proteasome inhibitor MG132 reduced the degradation rate of G411C mutant channels, leading to their expression at the plasma membrane. However, despite an increase in cell surface expression, no significant chloride current was recorded in the G411C-transfected cell treated with MG132, suggesting that this mutation produces non-functional ClC-1 chloride channels. Conclusion: These results suggest that the molecular pathophysiology of G411C is linked to a reduced plasma membrane expression and biophysical dysfunction of mutant channels, likely due to a misfolding defect. Chloride current abolition confirms that the mutation is responsible for the clinical phenotype
Coherent pion production in proton-deuteron collisions
Values of the proton analysing power in the
reactions at 350-360~MeV
per nucleon were obtained by using a polarised proton beam incident on a
deuterium cluster-jet target and with a polarised deuteron beam incident on a
target cell filled with polarised hydrogen. These results have a much larger
angular coverage than existing data. First measurements are also presented of
the deuteron vector analysing power and the deuteron-proton spin correlations.
Data were also obtained on the deuteron-proton spin correlation and proton
analysing power at small angles at 600~MeV per nucleon, though the angular
coverage at this energy was much more restricted even when using a deuteron
beam. By combining the extrapolated values of the spin correlations to the
forward or backward directions with published measurements of the deuteron
tensor analysing powers, the relative phases between the two non-vanishing
amplitudes were evaluated.Comment: 5 pages, 5 figure
The Mass Function of Dark Halos in Superclusters and Voids
A modification of the Press-Schechter theory allowing for presence of a
background large-scale structure (LSS) - a supercluster or a void, is proposed.
The LSS is accounted as the statistical constraints in form of linear
functionals of the random overdensity field. The deviation of the background
density within the LSS is interpreted in a pseudo-cosmological sense. Using the
constraints formalism may help us to probe non-trivial spatial statistics of
haloes, e.g. edge and shape effects on boundaries of the superclusters and
voids. Parameters of the constraints are connected to features of the LSS: its
mean overdensity, a spatial scale and a shape, and spatial momenta of higher
orders. It is shown that presence of a non-virialized LSS can lead to an
observable deviation of the mass function. This effect is exploited to build a
procedure to recover parameters of the background perturbation from the
observationally estimated mass function.Comment: 23 pages, 6 figures; to be appeared in Astronomy Reports, 2014, Vol.
58, No. 6, pp. 386-39
Production of the 1S0 diproton in the pp -> pp pi0 reaction at 0.8 GeV
The pp -> pp pi0 differential cross section has been measured with the ANKE
spectrometer at COSY-Juelich for pion cms angles between 0 and 15.4 degrees at
a proton beam energy of 0.8 GeV. The selection of diproton pairs with an
excitation energy E_{pp} < 3 MeV ensures that the final pp system is dominantly
in the spin-singlet 1S0 state. The kinematics are therefore very similar to
those of pp -> d pi+ but with different spin and isospin transitions. The
results will thus provide a crucial extra test of pion production models in
nucleon-nucleon collisions.
The cross sections, which are over two orders of magnitude smaller than those
of pp -> d pi+, show a forward dip, even stronger than that seen at lower
energies. This behaviour is well reproduced in a theoretical model that
includes P-wave Delta-N states.Comment: 10 pages, 5 eps figures, prepared using elsart.cl
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