15,485 research outputs found
Supersymmetric features of the Maxwell fish-eye lens
We provide a supersymmetric analysis of the Maxwell fisheye (MF) wave problem
at zero energy. Working in the so-called sector, we obtain the
corresponding superpartner (fermionic) MF effective potential within Witten's
one-dimensional (radial) supersymmetric procedure.Comment: 5 pages in Latex, one figure not included has been published as Fig.
2 in Phys. Lett. A 208 (1995) 33-3
Parvovirus B19 infection in pediatric transplant patients
Evidence of recent parvovirus virus infection (as determined by the presence of a positive IgM antibody titer) without other identified causes of anemia was found in 5 of 26 pediatric solid-organ transplant recipients evaluated for moderate-to-severe anemia between June 1990 and July 1991. Anemia tended to be chronic (median duration of anemia at the time of diagnosis was 12 weeks) and was associated with normal red blood cell indices in the absence of reticulocytes. The median age of the children at the time of presentation with anemia due to parvovirus was 1.8 years at a median time of 8 months after transplantation. Four of the 5 children were treated with i.v. immunoglobulin because of persistance of anemia requiring blood transfusions. A response characterized by an increase in reticulocyte count and normalization of hemoglobin was seen in each of these patients 2-4 weeks after treatment. The remaining patient experienced a spontaneous recovery from her anemia. Parvovirus infection should be included in the differential diagnosis of solid-organ transplant recipients presenting with severe anemia associated with low or absent reticulocytes
La inclusión de niños/as en situación de discapacidad a través del arte
Esta tesina busca concebir el Arte como una herramienta de inclusión que permite eliminar barreras y hacer efectivo el Derecho a la cultura, a la libre expresión y fomenta la participación de lxs niñxs en situación de discapacidad.
Este proyecto se divide en nueve capítulos que se relacionan entre sí, con el objeto de fortalecer y empoderar nuestra postura, articulando el arte con la concepción de discapacidad desde el paradigma de la Autonomía Personal, las Políticas Públicas y Sociales, y la intervención profesional.Fil: Reyes, Ivana. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y Sociales.Fil: Totera, Ana M. B.. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y Sociales
Spatial dispersion in Casimir forces: A brief review
We present the basic principles of non-local optics in connection with the
calculation of the Casimir force between half-spaces and thin films.
At currently accessible distances , non-local corrections amount to about
half a percent, but they increase roughly as 1/L at smaller separations. Self
consistent models lead to corrections with the opposite sign as models with
abrupt surfaces.Comment: Proceedings of QFEXT05, Barcelona, Sept. 5-9, 200
A Knowledge Gradient Policy for Sequencing Experiments to Identify the Structure of RNA Molecules Using a Sparse Additive Belief Model
We present a sparse knowledge gradient (SpKG) algorithm for adaptively
selecting the targeted regions within a large RNA molecule to identify which
regions are most amenable to interactions with other molecules. Experimentally,
such regions can be inferred from fluorescence measurements obtained by binding
a complementary probe with fluorescence markers to the targeted regions. We use
a biophysical model which shows that the fluorescence ratio under the log scale
has a sparse linear relationship with the coefficients describing the
accessibility of each nucleotide, since not all sites are accessible (due to
the folding of the molecule). The SpKG algorithm uniquely combines the Bayesian
ranking and selection problem with the frequentist regularized
regression approach Lasso. We use this algorithm to identify the sparsity
pattern of the linear model as well as sequentially decide the best regions to
test before experimental budget is exhausted. Besides, we also develop two
other new algorithms: batch SpKG algorithm, which generates more suggestions
sequentially to run parallel experiments; and batch SpKG with a procedure which
we call length mutagenesis. It dynamically adds in new alternatives, in the
form of types of probes, are created by inserting, deleting or mutating
nucleotides within existing probes. In simulation, we demonstrate these
algorithms on the Group I intron (a mid-size RNA molecule), showing that they
efficiently learn the correct sparsity pattern, identify the most accessible
region, and outperform several other policies
Fermion Condensate and Vacuum Current Density Induced by Homogeneous and Inhomogeneous Magnetic Fields in (2+1)-Dimensions
We calculate the condensate and the vacuum current density induced by
external static magnetic fields in (2+1)-dimensions. At the perturbative level,
we consider an exponentially decaying magnetic field along one cartesian
coordinate. Non-perturbatively, we obtain the fermion propagator in the
presence of a uniform magnetic field by solving the Schwinger-Dyson equation in
the rainbow-ladder approximation. In the large flux limit, we observe that both
these quantities, either perturbative (inhomogeneous) and non-perturbative
(homogeneous), are proportional to the external field, in agreement with early
expectations.Comment: 8 pages, 2 figures. Accepted for publication in Phys. Rev.
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