193 research outputs found
Evolutionary Approaches to Optimization Problems in Chimera Topologies
Chimera graphs define the topology of one of the first commercially available
quantum computers. A variety of optimization problems have been mapped to this
topology to evaluate the behavior of quantum enhanced optimization heuristics
in relation to other optimizers, being able to efficiently solve problems
classically to use them as benchmarks for quantum machines. In this paper we
investigate for the first time the use of Evolutionary Algorithms (EAs) on
Ising spin glass instances defined on the Chimera topology. Three genetic
algorithms (GAs) and three estimation of distribution algorithms (EDAs) are
evaluated over hard instances of the Ising spin glass constructed from
Sidon sets. We focus on determining whether the information about the topology
of the graph can be used to improve the results of EAs and on identifying the
characteristics of the Ising instances that influence the success rate of GAs
and EDAs.Comment: 8 pages, 5 figures, 3 table
Diagnosis And Antimicrobial Treatment Of Bacterial Of Neisseria Gonorrhea Infections: Update Review Article
Sexually transmitted infections (STIs) are caused by a wide spectrum of bacteria, viruses and parasites. These agents can be easily transmitted during any direct genital or oral sexual contact. Recently, World Health Organization (WHO), reported that more than 1 million STIs are acquired every day worldwide, Each year, there are an estimated 357 million new infections with 1 of 4 STIs: chlamydia, gonorrhoea, syphilis and trichomoniasis. There are few studies and official reports published on the prevalence of STIs in most Arab countries. However, few new recent studies showed increased prevalence of certain STIs in some Arab countries
Assessment of SNAP Utilization and Accessibility in Vermont
Food insecurity exemplifies one of the many public health crises that the COVID19 pandemic both exposed and amplified. In 2019 an estimated 10.5% of households (13.7 million households) were food insecure as determined by the US Department of Agriculture (USDA) including 5.3 million children. In 2020 this number increased to 15.6% of households, including 17.0 million children as projected by Feeding America. Food insecurity in children, especially in infancy, is associated with the development of obesity and hyperlipidemia, highlighting the necessity of federal and state food assistance programs.
We believe that increased funding for SNAP incentive programs and wireless EBT devices for Farmers will result in a longitudinal and sustainable increase in produce consumption among low income individuals in VT. We hypothesize such changes will ultimately result in improved health outcomes and decreased burden on Vermont Medicaid systems.https://scholarworks.uvm.edu/comphp_gallery/1306/thumbnail.jp
Bayesian Parameter Estimation for Latent Markov Random Fields and Social Networks
Undirected graphical models are widely used in statistics, physics and
machine vision. However Bayesian parameter estimation for undirected models is
extremely challenging, since evaluation of the posterior typically involves the
calculation of an intractable normalising constant. This problem has received
much attention, but very little of this has focussed on the important practical
case where the data consists of noisy or incomplete observations of the
underlying hidden structure. This paper specifically addresses this problem,
comparing two alternative methodologies. In the first of these approaches
particle Markov chain Monte Carlo (Andrieu et al., 2010) is used to efficiently
explore the parameter space, combined with the exchange algorithm (Murray et
al., 2006) for avoiding the calculation of the intractable normalising constant
(a proof showing that this combination targets the correct distribution in
found in a supplementary appendix online). This approach is compared with
approximate Bayesian computation (Pritchard et al., 1999). Applications to
estimating the parameters of Ising models and exponential random graphs from
noisy data are presented. Each algorithm used in the paper targets an
approximation to the true posterior due to the use of MCMC to simulate from the
latent graphical model, in lieu of being able to do this exactly in general.
The supplementary appendix also describes the nature of the resulting
approximation.Comment: 26 pages, 2 figures, accepted in Journal of Computational and
Graphical Statistics (http://www.amstat.org/publications/jcgs.cfm
Topical curcumin nanocarriers are neuroprotective in eye disease
Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5dione) is a polyphenol extracted from turmeric that has long been advocated for the treatment of a variety of conditions including neurodegenerative and inflammatory disorders. Despite this promise, the clinical use of curcumin has been limited by the poor solubility and low bioavailability of this molecule. In this article, we describe a novel nanocarrier formulation comprising Pluronic-F127 stabilised D-α-Tocopherol polyethene glycol 1000 succinate nanoparticles, which were used to successfully solubilize high concentrations (4.3 mg/mL) of curcumin. Characterisation with x-ray diffraction and in vitro release assays localise curcumin to the nanocarrier interior, with each particle measuring <20 nm diameter. Curcumin-loaded nanocarriers (CN) were found to significantly protect against cobalt chloride induced hypoxia and glutamate induced toxicity in vitro, with CN treatment significantly increasing R28 cell viability. Using established glaucoma-related in vivo models of ocular hypertension (OHT) and partial optic nerve transection (pONT), topical application of CN twice-daily for three weeks significantly reduced retinal ganglion cell loss compared to controls. Collectively, these results suggest that our novel topical CN formulation has potential as an effective neuroprotective therapy in glaucoma and other eye diseases with neuronal pathology
Basin-scale gyres and mesoscale eddies in large lakes: a novel procedure for their detection and characterization, assessed in Lake Geneva
In large lakes subject to the Coriolis force, basin-scale
gyres and mesoscale eddies, i.e. rotating coherent water masses, play a key
role in spreading biochemical materials and energy throughout the lake. In
order to assess the spatial and temporal extent of gyres and eddies, their
dynamics and vertical structure, as well as to validate their prediction in
numerical simulation results, detailed transect field observations are
needed. However, at present it is difficult to forecast when and where such
transect field observations should be taken. To overcome this problem, a
novel procedure combining 3D numerical simulations, statistical analyses,
and remote sensing data was developed that permits determination of the
spatial and temporal patterns of basin-scale gyres during different seasons.
The proposed gyre identification procedure consists of four steps: (i)Â data
pre-processing, (ii)Â extracting dominant patterns using empirical orthogonal
function (EOF) analysis of Okubo–Weiss parameter fields, (iii) defining the
3D structure of the gyre, and (iv)Â finding the correlation between the
dominant gyre pattern and environmental forcing. The efficiency and
robustness of the proposed procedure was validated in Lake Geneva. For the
first time in a lake, detailed field evidence of the existence of
basin-scale gyres and (sub)mesoscale eddies was provided by data collected
along transects whose locations were predetermined by the proposed
procedure. The close correspondence between field observations and detailed
numerical results further confirmed the validity of the model for capturing
large-scale current circulations as well as (sub)mesoscale eddies. The
results also indicated that the horizontal gyre motion is mainly determined
by wind stress, whereas the vertical current structure, which is influenced
by the gyre flow field, primarily depends on thermocline depth and strength.
The procedure can be applied to other large lakes and can be extended to the
interaction of biological–chemical–physical processes.</p
Novel Polyepoxysuccinic Acid-Grafted Polyacrylamide as a Green Corrosion Inhibitor for Carbon Steel in Acidic Solution.
Utilizing green corrosion inhibitors has been classified among the most efficient and economical mitigation practices against metallic degradation and failure. This study aims to integrate the features of green and complementary properties of polyepoxysuccinic acid (PESA) and polyacrylamide (PAM) for steel corrosion inhibition. A novel PESA-grafted-PAM (PESAPAM) has been first-ever synthesized in this research study and deployed as a corrosion inhibitor for C-steel in 1.0 M HCl solution. Eco-toxicity prediction confirmed the environmentally friendly properties acquired by the synthesized inhibitor. Electrochemical, kinetics, and surface microscopic studies were carried out to gain a holistic view of C-steel corrosion behavior with the PESAPAM. Furthermore, the performance of PESAPAM was compared with that of the pure PESA under the same testing conditions. Results revealed predominant inhibitive properties of PESAPAM with an inhibition efficiency (IE) reaching 90% at 500 mg·L at 25 °C. Grafting PAM onto the PESA chain showed an overall performance improvement of 109% from IE% of 43 to 90%. Electrochemical measurements revealed a charge transfer-controlled corrosion mechanism and the formation of a thick double layer on the steel surface. The potentiodynamic study classified PESAPAM as a mixed-type inhibitor. Furthermore, the investigation of C-steel corrosion kinetics with the presence of PESAPAM predicted an activation energy of 85 kJ·mol, correlated with a physical adsorption behavior. Finally, performed scanning electron microscopy and energy-dispersive X-ray analyses confirmed the adsorption of PESA and PESAPAM, with superior coverage of PESAPAM onto the steel surface.This work was made possible by the support of the Undergraduate Research Experience Program (UREP) from Qatar National Research Fund (QNRF), grant #UREP28-104-2-036. R.J. would like to acknowledge the support of Qatar University project, grant #QUCP-CENG-2021-03. The findings achieved herein are solely the responsibility of the authors. Central Laboratories Unit at Qatar University are acknowledged for providing facilities to perform SEM/EDX analyses. Qatar National Library (QNL) is acknowledged for providing open access funding
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