3,849 research outputs found
Hermite-Hadamard, Hermite-Hadamard-Fejer, Dragomir-Agarwal and Pachpatte Type Inequalities for Convex Functions via Fractional Integrals
The aim of this paper is to establish Hermite-Hadamard,
Hermite-Hadamard-Fej\'er, Dragomir-Agarwal and Pachpatte type inequalities for
new fractional integral operators with exponential kernel. These results allow
us to obtain a new class of functional inequalities which generalizes known
inequalities involving convex functions. Furthermore, the obtained results may
act as a useful source of inspiration for future research in convex analysis
and related optimization fields.Comment: 14 pages, to appear in Journal of Computational and Applied
Mathematic
GRID PRICING FOR FED CATTLE: AN EMPIRICAL ANALYSIS
Weekly grid premium and discount price date for fed cattle have been collected over a 3-year period. The grid price data are combined with carcass data (2590 South Dakota slaughter steers) to investigate the variability in the average weekly carcass premium is affected by changes in packer-determined grid premiums and discounts on a weekly basis. The three-stage recursive model is then estimated using an autoregressive procedure. The results of the empirical analysis indicated that among all grid premiums and discounts, it is the choice-select discount that plays the dominant role in determining weekly changes in the average weekly carcass premium (discount).slaughter cattle, grid pricing, average pricing, value-based-marketing, Marketing,
Synthesis and characterization of silver nanoarticles from extract of Eucalyptus citriodora
The primary motivation for the study to develop simple eco-friendly green synthesis of silver nanoparticles using leaf extract of Eucalyptus citriodora as reducing and capping agent. The green synthesis process was quite fast and silver nanoparticles were formed within 0.5 h. The synthesis of the particles was observed by UV-visible spectroscopy by noting increase in absorbance. Characterization of the particles was carried out by X-ray diffraction, FTIR and electron microscopy. The developed nanoparticles demonstrated that E. citriodora is good source of reducing agents. UV-visible absorption spectra of the reaction medium containing silver nanoparticles showed maximum absorbance at 460 nm. FTIR analysis confirmed reduction of Ag+ to Ag0 atom in silver nanoparticles. The XRD pattern revealed the crystalline structure of silver nanoparticles. The SEM analysis showed the size and shape of the nanoparticles. The method being green, fast, easy and cost effective can be recommended for large scale production of AgNPs for their use in food, medicine and materials
Constructing the fermion-boson vertex in QED3
We derive perturbative constraints on the transverse part of the
fermion-boson vertex in massive QED3 through its one loop evaluation in an
arbitrary covariant gauge. Written in a particular form, these constraints
naturally lead us to the first non-perturbative construction of the vertex,
which is in complete agreement with its one loop expansion in all momentum
regimes. Without affecting its one-loop perturbative properties, we also
construct an effective vertex in such a way that the unknown functions defining
it have no dependence on the angle between the incoming and outgoing fermion
momenta. Such a vertex should be useful for the numerical study of dynamical
chiral symmetry breaking, leading to more reliable results.Comment: 13 pages, 2 figure
A shared latent space matrix factorisation method for recommending new trial evidence for systematic review updates
Clinical trial registries can be used to monitor the production of trial
evidence and signal when systematic reviews become out of date. However, this
use has been limited to date due to the extensive manual review required to
search for and screen relevant trial registrations. Our aim was to evaluate a
new method that could partially automate the identification of trial
registrations that may be relevant for systematic review updates. We identified
179 systematic reviews of drug interventions for type 2 diabetes, which
included 537 clinical trials that had registrations in ClinicalTrials.gov. We
tested a matrix factorisation approach that uses a shared latent space to learn
how to rank relevant trial registrations for each systematic review, comparing
the performance to document similarity to rank relevant trial registrations.
The two approaches were tested on a holdout set of the newest trials from the
set of type 2 diabetes systematic reviews and an unseen set of 141 clinical
trial registrations from 17 updated systematic reviews published in the
Cochrane Database of Systematic Reviews. The matrix factorisation approach
outperformed the document similarity approach with a median rank of 59 and
recall@100 of 60.9%, compared to a median rank of 138 and recall@100 of 42.8%
in the document similarity baseline. In the second set of systematic reviews
and their updates, the highest performing approach used document similarity and
gave a median rank of 67 (recall@100 of 62.9%). The proposed method was useful
for ranking trial registrations to reduce the manual workload associated with
finding relevant trials for systematic review updates. The results suggest that
the approach could be used as part of a semi-automated pipeline for monitoring
potentially new evidence for inclusion in a review update.Comment: Journal of Biomedical Informatics Vol. 79, March 2018, p. 32-4
A fresh look at the (non-)Abelian Landau-Khalatnikov-Fradkin transformations
The Landau-Khalatnikov-Fradkin transformations (LKFTs) allow to interpolate
-point functions between different gauges. We first offer an alternative
derivation of these LKFTs for the gauge and fermions field in the Abelian (QED)
case when working in the class of linear covariant gauges. Our derivation is
based on the introduction of a gauge invariant transversal gauge field, which
allows a natural generalization to the non-Abelian (QCD) case of the LKFTs. To
our knowledge, within this rigorous formalism, this is the first construction
of the LKFTs beyond QED. The renormalizability of our setup is guaranteed to
all orders. We also offer a direct path integral derivation in the non-Abelian
case, finding full consistency.Comment: 16 page
Landau-Khalatnikov-Fradkin Transformations and the Fermion Propagator in Quantum Electrodynamics
We study the gauge covariance of the massive fermion propagator in three as
well as four dimensional Quantum Electrodynamics (QED). Starting from its value
at the lowest order in perturbation theory, we evaluate a non-perturbative
expression for it by means of its Landau-Khalatnikov-Fradkin (LKF)
transformation. We compare the perturbative expansion of our findings with the
known one loop results and observe perfect agreement upto a gauge parameter
independent term, a difference permitted by the structure of the LKF
transformations.Comment: 9 pages, no figures, uses revte
Gauge Dependence of Mass and Condensate in Chirally Asymmetric Phase of Quenched QED3
We study three dimensional quenched Quantum Electrodynamics in the bare
vertex approximation. We investigate the gauge dependence of the dynamically
generated Euclidean mass of the fermion and the chiral condensate for a wide
range of values of the covariant gauge parameter . We find that (i) away
from , gauge dependence of the said quantities is considerably reduced
without resorting to sophisticated vertex {\em ansatze}, (ii) wavefunction
renormalization plays an important role in restoring gauge invariance and (iii)
the Ward-Green-Takahashi identity seems to increase the gauge dependence when
used in conjunction with some simplifying assumptions. In the Landau gauge, we
also verify that our results are in agreement with those based upon dimensional
regularization scheme within the numerical accuracy available.Comment: 14 pages, 11 figures, uses revte
Infrared behaviour of massless QED in space-time dimensions 2 < d < 4
We show that the logarithmic infrared divergences in electron self-energy and
vertex function of massless QED in 2+1 dimensions can be removed at all orders
of 1/N by an appropriate choice of a non-local gauge. Thus the infrared
behaviour given by the leading order in 1/N is not modified by higher order
corrections. Our analysis gives a computational scheme for the Amati-Testa
model, resulting in a non-trivial conformal invariant field theory for all
space-time dimensions 2 < d < 4.Comment: 12 pages, uses axodraw.sty; added comments at the end, and one
reference; to appear in Phys. Lett.
Coil-Assisted Retrograde Transvenous Obliteration (CARTO) for the Treatment of Portal Hypertensive Variceal Bleeding: Preliminary Results.
ObjectivesTo describe the technical feasibility, safety, and clinical outcomes of coil-assisted retrograde transvenous obliteration (CARTO) in treating portal hypertensive non-esophageal variceal hemorrhage.MethodsFrom October 2012 to December 2013, 20 patients who received CARTO for the treatment of portal hypertensive non-esophageal variceal bleeding were retrospectively evaluated. All 20 patients had at least 6-month follow-up. All patients had detachable coils placed to occlude the efferent shunt and retrograde gelfoam embolization to achieve complete thrombosis/obliteration of varices. Technical success, clinical success, rebleeding, and complications were evaluated at follow-up.ResultsA 100% technical success rate (defined as achieving complete occlusion of efferent shunt with complete thrombosis/obliteration of bleeding varices and/or stopping variceal bleeding) was demonstrated in all 20 patients. Clinical success rate (defined as no variceal rebleeding) was 100%. Follow-up computed tomography after CARTO demonstrated decrease in size with complete thrombosis and disappearance of the varices in all 20 patients. Thirteen out of the 20 had endoscopic confirmation of resolution of varices. Minor post-CARTO complications, including worsening of esophageal varices (not bleeding) and worsening of ascites/hydrothorax, were noted in 5 patients (25%). One patient passed away at 24 days after the CARTO due to systemic and portal venous thrombosis and multi-organ failure. Otherwise, no major complication was noted. No variceal rebleeding was noted in all 20 patients during mean follow-up of 384±154 days.ConclusionsCARTO appears to be a technically feasible and safe alternative to traditional balloon-occluded retrograde transvenous obliteration or transjugular intrahepatic portosystemic shunt, with excellent clinical outcomes in treating portal hypertensive non-esophageal variceal bleeding
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