3,816 research outputs found
Chromogranin A in neurons of the rat cerebellum and spinal cord: quantification and sites of expression
Chromogranin A (CGA) is an abundant protein of dense-cored secretory vesicles in endocrine and neuronal cells. The present study, for the first time, compares CGA of neurons of the central nervous system with the CGA of adrenal origin. By S1 nucleus protection assay, we found that the 3' part of the CGA mRNA between exons 5-8 of the cerebellum and the spinal cord of the rat is homologous to that of the adrenal. In situ hybridization histochemistry revealed that CGA mRNA in the cerebellar cortex is present in cell bodies of Purkinje cells and in neurons of the deep cerebellar nuclei. The perikarya of these cells also exhibit CGA-like immunoreactivity. CGA mRNA and CGA-like immunoreactivity are also present in the motoneurons of the ventral, lateral, and dorsal horns of the rat spinal cord. The amounts of CGA, as determined by radioimmunoassay in cerebellum and spinal cord, were about one tenth of the amounts detected in the adrenal, adenohypophysis, or the olfactory bulb. The sites of CGA expression suggest that CGA may be involved in signal transduction in the motor system
Incomplete beta-function expansions of the solutions to the confluent Heun equation
Several expansions of the solutions to the confluent Heun equation in terms
of incomplete Beta functions are constructed. A new type of expansion involving
certain combinations of the incomplete Beta functions as expansion functions is
introduced. The necessary and sufficient conditions when the derived expansions
are terminated, thus generating closed-form solutions, are discussed. It is
shown that termination of a Beta-function series solution always leads to a
solution that is necessarily an elementary function
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Translational Retinal Research and Therapies.
The following review summarizes the state of the art in representative aspects of gene therapy/translational medicine and evolves from a symposium held at the School of Veterinary Medicine, University of Pennsylvania on November 16, 2017 honoring Dr. Gustavo Aguirre, recipient of ARVO's 2017 Proctor Medal. Focusing on the retina, speakers highlighted current work on moving therapies for inherited retinal degenerative diseases from the laboratory bench to the clinic
Leydig cells express neural cell adhesion molecules in vivo and in vitro
The neural cell adhesion molecule (NCAM) polypeptides are expressed by numerous tissues during embryonic development, where they are involved in cell-cell interactions. In the adult, NCAM expression is confined to a few cell types, including neurons and peptide-hormone-producing cells. Here we demonstrate that the Leydig cells of the adult rat, mouse, and hamster testes express NCAM as well. Western blotting showed that an NCAM of approximately 120 kDa was present in the adult testes of all three species investigated. This form was also found in freshly isolated mouse Leydig cells and in Leydig cells after 2 days in culture. After 4 days in culture, mouse Leydig cells expressed additional NCAM isoforms of approximately 140 and 180 kDa, indicating changes in alternative splicing of NCAM primary transcripts. Also, NCAM mRNA of all isoforms, as detected by S1-nuclease protection assays, increased with time in culture. The expression of the cell adhesion molecule NCAM by adult Leydig cells may explain the aggregation of Leydig cells in clusters in rodent testes, which could be a prerequisite for functional coordination of groups of Leydig cells. Furthermore, the presence of this neural and endocrine marker may indicate a closer relationship between Leydig cells and neural and peptide-hormone-producing cells than is considered to exist at the present time
Magnetic scattering of Dirac fermions in topological insulators and graphene
We study quantum transport and scattering of massless Dirac fermions by
spatially localized static magnetic fields. The employed model describes in a
unified manner the effects of orbital magnetic fields, Zeeman and exchange
fields in topological insulators, and the pseudo-magnetic fields caused by
strain or defects in monolayer graphene. The general scattering theory is
formulated, and for radially symmetric fields, the scattering amplitude and the
total and transport cross sections are expressed in terms of phase shifts. As
applications, we study ring-shaped magnetic fields (including the Aharanov-Bohm
geometry) and scattering by magnetic dipoles.Comment: 11 pages, 4 figure
Mirror Inversion of Quantum States in Linear Registers
Transfer of data in linear quantum registers can be significantly simplified
with pre-engineered but not dynamically controlled inter-qubit couplings. We
show how to implement a mirror inversion of the state of the register in each
excitation subspace with respect to the centre of the register. Our
construction is especially appealing as it requires no dynamical control over
individual inter-qubit interactions. If, however, individual control of the
interactions is available then the mirror inversion operation can be performed
on any substring of qubits in the register. In this case a sequence of mirror
inversions can generate any permutation of a quantum state of the involved
qubits.Comment: 4 page
Small-sample corrections for score tests in Birnbaum-Saunders regressions
In this paper we deal with the issue of performing accurate small-sample
inference in the Birnbaum-Saunders regression model, which can be useful for
modeling lifetime or reliability data. We derive a Bartlett-type correction for
the score test and numerically compare the corrected test with the usual score
test, the likelihood ratio test and its Bartlett-corrected version. Our
simulation results suggest that the corrected test we propose is more reliable
than the other tests.Comment: To appear in the Communications in Statistics - Theory and Methods,
http://www.informaworld.com/smpp/title~content=t71359723
Optimal quantum circuits for general phase estimation
We address the problem of estimating the phase phi given N copies of the
phase rotation gate u(phi). We consider, for the first time, the optimization
of the general case where the circuit consists of an arbitrary input state,
followed by any arrangement of the N phase rotations interspersed with
arbitrary quantum operations, and ending with a POVM. Using the polynomial
method, we show that, in all cases where the measure of quality of the estimate
phi' for phi depends only on the difference phi'-phi, the optimal scheme has a
very simple fixed form. This implies that an optimal general phase estimation
procedure can be found by just optimizing the amplitudes of the initial state.Comment: 4 pages, 3 figure
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