976 research outputs found
Neonatal oxytocin administration and weaning onto a gruel based diet reduce weight loss at weaning and enhance gastric leptin expression
Administering oxytocin to neonatal rats has positive long-term effects on growth and development (Uvnas-Moberg and Petersson, 2005). These effects include a reduction in the stress response to weaning, increased post-weaning feed intake and alterations in the expression of gastrointestinal (GI) hormones regulating feed intake (Uvnas-Moberg et al., 1998; Sohlstrom et al., 1999). Two GI hormones of importance in regulating feed intake are ghrelin and leptin, which have antagonistic actions. Ghrelin expression is increased in response to fasting and leptin expression increases rapidly in response to feed intake. Since weaning the piglet is associated with stress and growth restriction, this study examined whether oxytocin given to young pigs could reduce the extent of the post-weaning growth check, along with any associated changes in ghrelin and leptin expression
Fluctuation properties of the TASEP with periodic initial configuration
We consider the joint distributions of particle positions for the continuous
time totally asymmetric simple exclusion process (TASEP). They are expressed as
Fredholm determinants with a kernel defining a signed determinantal point
process. We then consider certain periodic initial conditions and determine the
kernel in the scaling limit. This result has been announced first in a letter
by one of us and here we provide a self-contained derivation. Connections to
last passage directed percolation and random matrices are also briefly
discussed.Comment: 33 pages, 4 figure, LaTeX; We added several references to the general
framework and techniques use
On the effective potential in higher-derivative superfield theories
We study the one-loop quantum corrections for higher-derivative superfield
theories, generalizing the approach for calculating the superfield effective
potential. In particular, we calculate the effective potential for two versions
of higher-derivative chiral superfield models. We point out that the
equivalence of the higher-derivative theory for the chiral superfield and the
one without higher derivatives but with an extended number of chiral
superfields occurs only when the mass term is contained in the general
Lagrangian. The presence of divergences can be taken as an indication of this
equivalence.Comment: 14 page
Neonatal oxytocin administration and supplemental milk ameliorate the weaning transition and alter hormonal expression in the gastrointestinal tract in pigs
The aim of this study was to investigate the influences of milk supplementation during lactation, over 1wk after weaning, and oxytocin administration for the first 14d of life on the pigs' response to weaning. Pigs from 20 litters were allocated to each of these 3 treatments in a randomized factorial design. Oxytocin was administered subcutaneously daily from 0 to 14d of age at a rate of 10 I.U. per kg. The milk supplement consisted of a mixture of 25% skim milk powder offered either during lactation between 10 and 20d of age or for the first week after weaning as a transitional dietalong with dry pellets. Pigs were weaned at 21d of age. Growth rate was measured from birth to slaughter at 140d of age and feed intake of supplemental milk or feed from 10 to 56d of age. Organ weights (heart, liver, stomach, and kidneys) and the gene expression of ghrelin, leptin, and glucagon-like peptides (glucagon-like peptide-1 and glucagon-like peptide-2) were measured in the stomach, ileum, and duodenum at 10, 21, and 28d of age. Milk supplementation after weaning resulted in immediate feed intake and partially alleviated the depression in growth rate over the first 7d postweaning (P 0.1). However, effects were only transient and disappeared once the milk liquid diet was removed. Neonatal oxytocin administration reduced weight loss over the first 2d after weaning (P = 0.03), without affecting feed intake (P > 0.1), hence possibly reducing weaning stress. Seven days after weaning, oxytocin-treated pigs had greater stomach ghrelin and leptin expression (both P = 0.02), and pigs supplemented with milk after weaning had greater stomach leptin and glucagon-like peptide-2 expression (P = 0.02 and P = 0.05, respectively). Hence, neonatal oxytocin administration or postweaning milk supplementation are both effective means of enhancing gastric leptin expression and reducing weight loss at weaning, likely improving gut health during this critical period
Real-space local polynomial basis for solid-state electronic-structure calculations: A finite-element approach
We present an approach to solid-state electronic-structure calculations based
on the finite-element method. In this method, the basis functions are strictly
local, piecewise polynomials. Because the basis is composed of polynomials, the
method is completely general and its convergence can be controlled
systematically. Because the basis functions are strictly local in real space,
the method allows for variable resolution in real space; produces sparse,
structured matrices, enabling the effective use of iterative solution methods;
and is well suited to parallel implementation. The method thus combines the
significant advantages of both real-space-grid and basis-oriented approaches
and so promises to be particularly well suited for large, accurate ab initio
calculations. We develop the theory of our approach in detail, discuss
advantages and disadvantages, and report initial results, including the first
fully three-dimensional electronic band structures calculated by the method.Comment: replacement: single spaced, included figures, added journal referenc
A diffusive system driven by a battery or by a smoothly varying field
We consider the steady state of a one dimensional diffusive system, such as
the symmetric simple exclusion process (SSEP) on a ring, driven by a battery at
the origin or by a smoothly varying field along the ring. The battery appears
as the limiting case of a smoothly varying field, when the field becomes a
delta function at the origin. We find that in the scaling limit, the long range
pair correlation functions of the system driven by a battery turn out to be
very different from the ones known in the steady state of the SSEP maintained
out of equilibrium by contact with two reservoirs, even when the steady state
density profiles are identical in both models
Thickness Estimation of Epitaxial Graphene on SiC using Attenuation of Substrate Raman Intensity
A simple, non-invasive method using Raman spectroscopy for the estimation of
the thickness of graphene layers grown epitaxially on silicon carbide (SiC) is
presented, enabling simultaneous determination of thickness, grain size and
disorder using the spectra. The attenuation of the substrate Raman signal due
to the graphene overlayer is found to be dependent on the graphene film
thickness deduced from X-ray photoelectron spectroscopy and transmission
electron microscopy of the surfaces. We explain this dependence using an
absorbing overlayer model. This method can be used for mapping graphene
thickness over a region and is capable of estimating thickness of multilayer
graphene films beyond that possible by XPS and Auger electron spectroscopy
(AES).Comment: 14 pages, 9 figure
Tunneling and Metastability of continuous time Markov chains
We propose a new definition of metastability of Markov processes on countable
state spaces. We obtain sufficient conditions for a sequence of processes to be
metastable. In the reversible case these conditions are expressed in terms of
the capacity and of the stationary measure of the metastable states
Equivalence between supersymmetric self-dual and Maxwell-Chern-Simons models coupled to a matter spinor superfield
We study the duality of the supersymmetric self-dual and Maxwell-Chern-Simons
theories coupled to a fermionic matter superfield, using a master action. This
approach evades the difficulties inherent to the quartic couplings that appear
when matter is represented by a scalar superfield. The price is that the
spinorial matter superfield represents a unusual supersymmetric multiplet,
whose main physical properties we also discuss.Comment: v2, 16 pages, elsarticle.cls, accepted for publication in PL
Fluxoid dynamics in superconducting thin film rings
We have measured the dynamics of individual magnetic fluxoids entering and
leaving photolithographically patterned thin film rings of the underdoped
high-temperature superconductor BiSrCaCuO, using a
variable sample temperature scanning SQUID microscope. These results can be
qualitatively described using a model in which the fluxoid number changes by
thermally activated nucleation of a Pearl vortex in, and transport of the Pearl
vortex across, the ring wall.Comment: 9 pages, 10 figures, fixed typo
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