2,883 research outputs found
Effect of sodium [36Cl]chlorate dose on total radioactive residues and residues of parent chlorate in swine
Sodium chlorate effectively reduces the numbers of gram-negative pathogens in gastrointestinal tracts of live animals when administered in the 24 to 72 hour period prior to slaughter
Persistence of Salmonella typhimurium in porcine gut microflora
Chlortetracycline administration, at 55 mg/l, to a continuous flow culture of mixed porcine gut bacteria enhanced the rate of clearance of a chlortetracycline resistant Salmonella Typhimurium from the culture, although the Salmonella was eventually excluded from the culture by 8 days post challenge. As expected, chlortetracycline administration, at 110mg/l, to a continuous flow culture of mixed porcine gut bacteria had little effect on the persistence of a chlortetracycline resistant strain of Salmonella typhimurium
Breakdown of Landau Fermi liquid properties in the Boson-Fermion model
We study the normal state spectral properties of the fermionic excitations in
the Boson-Fermion model. The fermionic single particle excitations show a
flattening of the dispersion as the Fermi vector is approached
from below, forshadowing a Bogoliubov spectrum of a superconducting ground
state. The width of the quasiparticle excitations near increases
monotonically as the temperature is lowered. In the fermionic distribution
function this temperature dependence is manifest in a strong modification of
in a small region below , but a nearly
independant .Comment: 10 pages, RevTeX 3.
A comparative study on the effect of subtherapeutic tylosin administration on select feral or domestic porcine gut microflora grown in continuous-flow culture
Continuous now cultures of feral (culture FC) and domesticated (culture RPCF) pig gut microflora were established in steady state. Cultures, in duplicate, were continuously infused subtherapeutic (2S lJg/ml) levels of tylosin and sampled at intervals to assess effects on total culturable anaerobes, Bacteroides spp. and Enterococcus spp. via plating on serial 10-fold dilutions to anaerobic Brucella blood agar, Bacteroides bile esculin agar, and M Enterococcus agar supplemented without or with 100 lJg tylosin/ml, the later to assess bacterial sensitivity to tylosin Concentrations of total culturable anaerobes within culture FC decreased (P \u3c 0.05), albeit slightly, following 7 days tylosin administration. Concentrations of Bacteroides and Enterococcus decreased (P \u3c 0.05) to near or below detectable levels (1.0 log10 CFU/ml) in culture FC following 7 days tylosin administration, and tylosin-insensitive colonies were recovered at low numbers (~ 2 log10 CFU/ml) and did not persist
The value of tablets as reading aids for individuals with central visual field loss:an evaluation of eccentric reading with static and scrolling text
Purpose: Technological devices such as smartphones and tablets are widely available and increasingly used as visual aids. This study evaluated the use of a novel app for tablets (MD_evReader) developed as a reading aid for individuals with a central field loss resulting from macular degeneration. The MD_evReader app scrolls text as single lines (similar to a news ticker) and is intended to enhance reading performance using the eccentric viewing technique by both reducing the demands on the eye movement system and minimising the deleterious effects of perceptual crowding. Reading performance with scrolling text was compared with reading static sentences, also presented on a tablet computer. Methods: Twenty-six people with low vision (diagnosis of macular degeneration) read static or dynamic text (scrolled from right to left), presented as a single line at high contrast on a tablet device. Reading error rates and comprehension were recorded for both text formats, and the participant’s subjective experience of reading with the app was assessed using a simple questionnaire. Results: The average reading speed for static and dynamic text was not significantly different and equal to or greater than 85 words per minute. The comprehension scores for both text formats were also similar, equal to approximately 95% correct. However, reading error rates were significantly (p=0.02) less for dynamic text than for static text. The participants’ questionnaire ratings of their reading experience with the MD_evReader were highly positive and indicated a preference for reading with this app compared with their usual method. Conclusions: Our data show that reading performance with scrolling text is at least equal to that achieved with static text and in some respects (reading error rate) is better than static text. Bespoke apps informed by an understanding of the underlying sensorimotor processes involved in a cognitive task such as reading have excellent potential as aids for people with visual impairments
Metal-insulator crossover in the Boson-Fermion model in infinite dimensions
The Boson-Fermion model, describing a mixture of tightly bound electron pairs
and quasi-free electrons hybridized with each other via a charge exchange term,
is studied in the limit of infinite dimensions, using the Non-Crossing
Approximation within the Dynamical Mean Field Theory. It is shown that a
metal-insulator crossover, driven by strong pair fluctuations, takes place as
the temperature is lowered. It manifests itself in the opening of a pseudogap
in the electron density of states, accompanied by a corresponding effect in the
optical and dc conductivity.Comment: 4 pages, 3 figures, to be published in Phys. Rev. Let
Influence of light exposure on horizontal transmission of Salmonella typhimurium in weaned pigs
The objective of the following experiment was to examine the effect of light exposure on horizontal transmission of Salmonella typhimurium in weaned pigs. Twenty crossbred pigs (average BW = 15 kg) were housed in isolation rooms (10 pigs/room) and randomly assigned to one of two lighting regimes. Low (8 h light, 16 h dark) or High (16 h light, 8 h dark). Pigs were adjusted to their respective lighting treatments for six days and on the seventh day, two randomly selected pigs/room orally inoculated with 5 ml of tryptic soy broth containing 18 x 108 cfu Salmonella typhimurium/ml. Rectal swabs were collected from each pig daily over the next eight days for direct plating and plating following 24-h enrichment. On day nine, following inoculation of the seeder pigs, all pigs were euthanized and necropsied. Luminal contents were collected from the ileum, colon, cecum and rectum (quantification and qualification of inoculated strain) and tissue samples collected from the above gut segments as well as the tonsils, ileo-cecal lymph nodes, spleen and liver (qualification only)
Identifying Priority Areas for Chronic Wasting Disease Surveillance in Montana
Chronic Wasting Disease is a fatal prion disease affecting ungulate species throughout North America. As of 2013, no CWD positive deer have been found in the state of Montana, however, several surrounding states and provinces have identified multiple cases of the disease. We used information on mule deer habitat selection, abundance, and locations of CWD cases in surrounding states to identify priority areas in Montana for CWD surveillance. The habitat selection models were based on over 10000 VHF and GPS locations collected from mule deer from 1975-2011, and predicted resource selection function (RSF) values for winter and summer in 5 of the 7 wildlife management regions in the state of Montana. We estimated mule deer density using the aerial survey counts weighted by the value of the RSF for each pixel. High priority areas were those that contained the highest densities of mule deer and were closest to locations with CWD positive deer. This information can be used to inform Montana’s CWD surveillance program for mule deer. We concluded that based on mule deer distribution and movement patterns several mule deer herds in Montana were at risk of coming into contact with deer from known infected herds
Siegert pseudostates: completeness and time evolution
Within the theory of Siegert pseudostates, it is possible to accurately
calculate bound states and resonances. The energy continuum is replaced by a
discrete set of states. Many questions of interest in scattering theory can be
addressed within the framework of this formalism, thereby avoiding the need to
treat the energy continuum. For practical calculations it is important to know
whether a certain subset of Siegert pseudostates comprises a basis. This is a
nontrivial issue, because of the unusual orthogonality and overcompleteness
properties of Siegert pseudostates. Using analytical and numerical arguments,
it is shown that the subset of bound states and outgoing Siegert pseudostates
forms a basis. Time evolution in the context of Siegert pseudostates is also
investigated. From the Mittag-Leffler expansion of the outgoing-wave Green's
function, the time-dependent expansion of a wave packet in terms of Siegert
pseudostates is derived. In this expression, all Siegert pseudostates--bound,
antibound, outgoing, and incoming--are employed. Each of these evolves in time
in a nonexponential fashion. Numerical tests underline the accuracy of the
method
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