59,299 research outputs found
The Great Divide: Ruralisation of Poverty in Russia
Using data from the RLMS for the period 2000-2004 we investigate poverty trends in Russia. We find that urban poverty declines at twice the rate of rural poverty so that by 2004 poverty in Russia had become a largely rural phenomenon for the first time since transition began. This finding does not stem from changing population characteristics or shares, is not dependent on the use of a particular poverty line nor is it driven by the rapid expansions that have occurred in Moscow, St. Petersburg or other urban areas. Our findings flesh out those of Ravallion et al (2007) who, in contrast to other regions, "find signs" of a ruralisation of poverty in Eastern Europe and the Former Soviet Union. We attribute some of the differential to the labour market
EGF receptor trafficking: consequences for signaling and cancer
The ligand-stimulated epidermal growth factor receptor (EGFR) has been extensively studied in the analysis of molecular mechanisms regulating endocytic traffic and the role of that traffic in signal transduction. Although such studies have largely focused on mitogenic signaling and dysregulated traffic in tumorigenesis, there is growing interest in the potential role of EGFR traffic in cell survival and the consequent response to cancer therapy. Here we review recent advances in our understanding of molecular mechanisms regulating ligand-stimulated EGFR activation, internalization, and post-endocytic sorting. The role of EGFR overexpression/mutation and new modulators of EGFR traffic in cancer and the response to cancer therapeutics are also discussed. Finally, we speculate on the relationship between EGFR traffic and cell survival
Tunable Hydrogen Storage in Magnesium - Transition Metal Compounds
Magnesium dihydride (\mgh) stores 7.7 weight % hydrogen, but it suffers
from a high thermodynamic stability and slow (de)hydrogenation kinetics.
Alloying Mg with lightweight transition metals (TM = Sc, Ti, V, Cr) aims at
improving the thermodynamic and kinetic properties. We study the structure and
stability of MgTMH compounds, -1], by first-principles
calculations at the level of density functional theory. We find that the
experimentally observed sharp decrease in hydrogenation rates for
correlates with a phase transition of MgTMH from a fluorite to
a rutile phase. The stability of these compounds decreases along the series Sc,
Ti, V, Cr. Varying the transition metal (TM) and the composition , the
formation enthalpy of MgTMH can be tuned over the substantial
range 0-2 eV/f.u. Assuming however that the alloy MgTM does not
decompose upon dehydrogenation, the enthalpy associated with reversible
hydrogenation of compounds with a high magnesium content () is close to
that of pure Mg.Comment: 8 pages, 5 figure
Super Landau-Ginzburg mirrors and algebraic cycles
We investigate the super Landau-Ginzburg mirrors of gauged linear sigma
models which, in an appropriate low energy limit, reduce to nonlinear sigma
models with Kaehler supermanifold target spaces of nonnegative super-first
Chern class.Comment: 29 pages, 5 figures, uses edited version of jheppub.sty. Dedicated to
our dear friend and coauthor Maximilian Kreuzer, who died November 26, 2010.
v3: Modifications to the Introduction, Equations (4.2), (5.2), and (6.2), and
Remark 8.2. v2: Theorem A.1 and Corollary A.1 corrected; corresponding
changes made in Section 4. Minor change in Section 2. Minor changes in
Section
Star forming regions of the southern galaxy
A catalog of southern dust cloud properties is being compiled to aid in the planning and analysis of radio spectral line surveys in the southern hemisphere. Ultimately, images of dust temperature and column density will be produced. For the interim, a list of the 60 and 100 micron fluxes was prepared for the cores and adjacent backgrounds of 65 prominent dust clouds. Dust temperatures and column densities were derived
Discrete Imaging Models for Three-Dimensional Optoacoustic Tomography using Radially Symmetric Expansion Functions
Optoacoustic tomography (OAT), also known as photoacoustic tomography, is an
emerging computed biomedical imaging modality that exploits optical contrast
and ultrasonic detection principles. Iterative image reconstruction algorithms
that are based on discrete imaging models are actively being developed for OAT
due to their ability to improve image quality by incorporating accurate models
of the imaging physics, instrument response, and measurement noise. In this
work, we investigate the use of discrete imaging models based on Kaiser-Bessel
window functions for iterative image reconstruction in OAT. A closed-form
expression for the pressure produced by a Kaiser-Bessel function is calculated,
which facilitates accurate computation of the system matrix.
Computer-simulation and experimental studies are employed to demonstrate the
potential advantages of Kaiser-Bessel function-based iterative image
reconstruction in OAT
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