2,092 research outputs found
Cyclotrons as Drivers for Precision Neutrino Measurements
As we enter the age of precision measurement in neutrino physics, improved
flux sources are required. These must have a well-defined flavor content with
energies in ranges where backgrounds are low and cross section knowledge is
high. Very few sources of neutrinos can meet these requirements. However,
pion/muon and isotope decay-at-rest sources qualify. The ideal drivers for
decay-at-rest sources are cyclotron accelerators, which are compact and
relatively inexpensive. This paper describes a scheme to produce decay-at-rest
sources driven by such cyclotrons, developed within the DAEdALUS program.
Examples of the value of the high precision beams for pursuing Beyond Standard
Model interactions are reviewed. New results on a combined DAEdALUS--Hyper-K
search for CP-violation that achieve errors on the mixing matrix parameter of 4
degrees to 12 degrees are presented.Comment: This paper was invited by the journal Advances in High Energy Physics
for their upcoming special issue on "Neutrino Masses and Oscillations," which
will be published on the 100th anniversary of Pontecorvo's birt
Detection of Presumptive Pathogens in Ground Beef from Supermarket and Farmers\u27 Market Sources
This study investigates whether specific pathogens are more prevalent in retail meat sold by supermarkets compared to locally sourced markets. Ground beef samples were obtained from conventional ‘big box’ supermarkets and from local, farmers’ markets and examined for the presence of two pathogens, Escherichia coli O157,H7 and Salmonella. For the detection of E. coli O157,H7, homogenized meat samples were enriched overnight in modified EC medium with novobiocin. The enriched cultures were selected onto MacConkey agar with sorbitol, cefixime and tellurite. Presumptive positive colonies were subcultured onto tryptic soy agar with yeast extract and further tested for positive indole and motility, and negative oxidase reactions. For Salmonella detection, homogenized meat samples were incubated first in universal pre-enrichment broth, then enriched overnight in Rappaport-Vassiliadis broth, and further plated onto Salmonella selective medium. Presumptive Salmonella colonies were further incubated on triple sugar iron agar and lysine iron agar to confirm glucose fermentation, sulfide production, and lysine decarboxylase. Oxidase assays were conducted on all presumptive strains. Presumptive colonies of both E. coli and Salmonella were subjected to rapid identification assays and serological tests to confirm identity. Isolates were then tested for antibiotic sensitivity using the Kirby-Bauer assay. The presence of E. coli O157 was observed in one sample of meat sourced from a supermarket, and Salmonella was isolated from ground beef purchased from a different retail supermarket. Neither pathogen was detected from ground beef sourced from farmers’ markets. Our preliminary results demonstrate a potential difference in the prevalence of both E. coli O157 and Salmonella species based upon food source
Control and Regulation of Integrated Mitochondrial Function in Metabolic and Transport Networks
The pattern of flux and concentration control coefficients in an integrated mitochondrial energetics model is examined by applying a generalized matrix method of control analysis to calculate control coefficients, as well as response coefficients The computational model of Cortassa et al. encompasses oxidative phosphorylation, the TCA cycle, and Ca2+ dynamics. Control of ATP synthesis, TCA cycle, and ANT fluxes were found to be distributed among various mitochondrial processes. Control is shared by processes associated with ATP/ADP production and transport, as well as by Ca2+ dynamics. The calculation also analyzed the control of the concentrations of key regulatory ions and metabolites (Ca2+, NADH, ADP). The approach we have used demonstrates how properties of integrated systems may be understood through applications of computational modeling and control analysis
Reactor Simulation for Antineutrino Experiments using DRAGON and MURE
Rising interest in nuclear reactors as a source of antineutrinos for
experiments motivates validated, fast, and accessible simulations to predict
reactor fission rates. Here we present results from the DRAGON and MURE
simulation codes and compare them to other industry standards for reactor core
modeling. We use published data from the Takahama-3 reactor to evaluate the
quality of these simulations against the independently measured fuel isotopic
composition. The propagation of the uncertainty in the reactor operating
parameters to the resulting antineutrino flux predictions is also discussed.Comment: This version has increased discussion of uncertaintie
Relationship between trait anxiety and health-related factors
Growing evidence indicates that anxious individuals are more likely to engage in unhealthy lifestyle behaviors associated with coronary heart disease. We examined the relationship of Trait Anxiety (T-Anx) with lifestyle behaviors and physiological variables in a sample of 34 college undergraduates scoring in the upper/lower quartiles on T-Anx (50% women). Participants were assessed for physiological variables (BP, BMI) and behaviors including cigarette smoking, activity/exercise level, alcohol intake, and sleep. High T-Anx participants smoked significantly more cigarettes, slept significantly fewer hours, and engaged in significantly less vigorous-intensity physical activity than low T-Anx participants. No significant differences between groups were noted on BP, BMI, overall activity level, or alcohol use. These findings provide evidence that high TAnx college-age individuals engage in unhealthy behaviors
Ground state of a polydisperse electrorheological solid: Beyond the dipole approximation
The ground state of an electrorheological (ER) fluid has been studied based
on our recently proposed dipole-induced dipole (DID) model. We obtained an
analytic expression of the interaction between chains of particles which are of
the same or different dielectric constants. The effects of dielectric constants
on the structure formation in monodisperse and polydisperse electrorheological
fluids are studied in a wide range of dielectric contrasts between the
particles and the base fluid. Our results showed that the established
body-centered tetragonal ground state in monodisperse ER fluids may become
unstable due to a polydispersity in the particle dielectric constants. While
our results agree with that of the fully multipole theory, the DID model is
much simpler, which offers a basis for computer simulations in polydisperse ER
fluids.Comment: Accepted for publications by Phys. Rev.
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