392 research outputs found
Evaluation of Reticuloruminal Temperature for the Prediction of Clinical Mastitis in Dairy Cows Challenged with \u3cem\u3eStreptococcus uberis\u3c/em\u3e
Automated monitoring devices have become increasingly utilized in the dairy industry, especially for monitoring or predicting disease status. While multiple automated monitoring devices have been developed for the prediction of clinical mastitis (CM), limitations in performance or applicability remain. The aims of this study were to (1) detect variations in reticuloruminal temperature (RRT) relative to an experimental intramammary challenge with Streptococcus uberis and (2) evaluate alerts generated automatically based on variation in RRT to predict initial signs of CM in the challenged cows based on severity of clinical signs and the concentration of bacteria (cfu/mL) in the infected quarter separately. Clinically healthy Holstein cows without a history of CM in the 60 d before the experiment (n = 37, parity 1 to 5, ≥120 d in milk) were included if they were microbiologically negative and had a somatic cell count under 200,000 cells/mL based on screening of quarter milk samples 1 wk before challenge. Each cow received an intra-reticuloruminal automated monitoring device before the trial and was challenged with 2,000 cfu of Strep. uberis 0140J in 1 rear quarter. Based on interrupted time series analysis, intramammary challenge with Strep. uberis increased RRT by 0.54°C [95% confidence interval (CI): 0.41, 0.66] at 24 h after the challenge, which remained elevated until the end of the study. Alerts based on RRT correctly classified 78.3% (95% CI: 65.8, 87.9) of first occurrences of CM at least 24 h in advance, with a sensitivity of 70.0% (95% CI: 50.6, 85.3) and a specificity of 86.7% (95% CI: 69.3, 96.2). The accuracy of CM for a given severity score was 90.9% (95% CI: 70.8, 98.9) for mild cases, 85.2% (95% CI: 72.9, 93.4) for moderate cases, and 92.9% (95% CI: 66.1, 99.8) for severe cases. Test characteristics of the RRT alerts to predict initial signs of CM improved substantially after bacterial count in the challenged quarter reached 5.0 log10 cfu/mL, reaching a sensitivity of 73.5% (95% CI: 55.6, 87.1) and a specificity of 87.5% (95% CI: 71.0, 96.5). Overall, the results of this study indicated that RRT was affected by the intramammary challenge with Strep. uberis and the RRT-generated alerts had similar accuracy as reported for other sensors and algorithms. Further research that includes natural infections with other pathogens as well as different variations in RRT to determine CM status is warranted
Combination treatment with zidovudine, didanosine, and nevirapine in infants with human immunodeficiency virus type 1 infection
BACKGROUND: In infants and children with maternally acquired human immunodeficiency virus type 1 (HIV-1) infection, treatment with a single antiretroviral agent has limited efficacy. We evaluated the safety and efficacy of a three-drug regimen in a small group of maternally infected infants. METHODS: Zidovudine, didanosine, and nevirapine were administered in combination orally to eight infants 2 to 16 months of age. The efficacy of antiretroviral treatment was evaluated by serial measurements of plasma HIV-1 RNA, quantitative plasma cultures, and quantitative cultures of peripheral-blood mononuclear cells. RESULTS: The three-drug regimen was well tolerated, without clinically important adverse events. Within four weeks, there were reductions in plasma levels of HIV-1 RNA of at least 96 percent (1.5 log) in seven of the eight study patients. Over the 6-month study period, replication of HIV-1 was controlled in two infants who began therapy at 2 1/2 months of age. Plasma RNA levels were reduced by 0.5 to 1.5 log in five of the other six infants. CONCLUSIONS: Although further observations are needed, it appears that in infants with maternally acquired HIV-1 infection, combined treatment with zidovudine, didanosine, and nevirapine is well tolerated and has sustained efficacy against HIV-1
Renormalization group in the infinite-dimensional turbulence: third-order results
The field theoretic renormalization group is applied to the stochastic
Navier-Stokes equation with the stirring force correlator of the form
k^(4-d-2\epsilon) in the d-dimensional space, in connection with the problem of
construction of the 1/d expansion for the fully developed fluid turbulence
beyond the scope of the standard epsilon expansion. It is shown that in the
large-d limit the number of the Feynman diagrams for the Green function (linear
response function) decreases drastically, and the technique of their analytical
calculation is developed. The main ingredients of the renormalization group
approach -- the renormalization constant, beta function and the ultraviolet
correction exponent omega, are calculated to order epsilon^3 (three-loop
approximation). The two-point velocity-velocity correlation function, the
Kolmogorov constant C_K in the spectrum of turbulent energy and the
inertial-range skewness factor S are calculated in the large-d limit to third
order of the epsilon expansion. Surprisingly enough, our results for C_K are in
a reasonable agreement with the existing experimental estimates.Comment: 30 pages with EPS figure
Lattice dynamical analogies and differences between SrTiO3 and EuTiO3 revealed by phonon-dispersion relations and double-well potentials
A comparative analysis of the structural phase transitions of EuTiO3 and
SrTiO3 (at TS = 282 and 105 K, respectively) is made on the basis of
phonon-dispersion and density functional calculations. The phase transition of
EuTiO3 is predicted to arise from the softening of a transverse acoustic
zone-boundary mode caused by the rotations of the TiO6 octahedra, as also found
for the phase transition of SrTiO3. While the temperature dependence of the
soft mode is similar in both compounds, their elastic properties differ
drastically due to a large difference in the double-well potentials associated
with the soft zone boundary-acoustic mode.Comment: 16 pages, 6 figure
Drug Discovery, Development and Deployment: A Report from the 28th Joint Conference of the U.S.-Japan Parasitic Diseases Panels, Baltimore, Maryland, July 1993
The 28th Joint Conference of the Parasitic Diseases Panels of the U.S.-Japan Cooperative Medical Sciences Program held in Baltimore, Maryland focused on current research within both countries on antiparasitic chemotherapy. This meeting report summarizes presentations of work in progress on antiparasitic drugs currently in use and drugs under development or in clinical trials, as well as reports on potentially unique parasite characteristics that may provide targets for development of future therapeutics
Randomized Dose-Ranging Controlled Trial of AQ-13, a Candidate Antimalarial, and Chloroquine in Healthy Volunteers
OBJECTIVES: To determine: (1) the pharmacokinetics and safety of an investigational aminoquinoline active against multidrug–resistant malaria parasites (AQ-13), including its effects on the QT interval, and (2) whether it has pharmacokinetic and safety profiles similar to chloroquine (CQ) in humans. DESIGN: Phase I double-blind, randomized controlled trials to compare AQ-13 and CQ in healthy volunteers. Randomizations were performed at each step after completion of the previous dose. SETTING: Tulane–Louisiana State University–Charity Hospital General Clinical Research Center in New Orleans. PARTICIPANTS: 126 healthy adults 21–45 years of age. INTERVENTIONS: 10, 100, 300, 600, and 1,500 mg oral doses of CQ base in comparison with equivalent doses of AQ-13. OUTCOME MEASURES: Clinical and laboratory adverse events (AEs), pharmacokinetic parameters, and QT prolongation. RESULTS: No hematologic, hepatic, renal, or other organ toxicity was observed with AQ-13 or CQ at any dose tested. Headache, lightheadedness/dizziness, and gastrointestinal (GI) tract–related symptoms were the most common AEs. Although symptoms were more frequent with AQ-13, the numbers of volunteers who experienced symptoms with AQ-13 and CQ were similar (for AQ-13 and CQ, respectively: headache, 17/63 and 10/63, p = 0.2; lightheadedness/dizziness, 11/63 and 8/63, p = 0.6; GI symptoms, 14/63 and 13/63; p = 0.9). Both AQ-13 and CQ exhibited linear pharmacokinetics. However, AQ-13 was cleared more rapidly than CQ (respectively, median oral clearance 14.0–14.7 l/h versus 9.5–11.3 l/h; p ≤ 0.03). QTc prolongation was greater with CQ than AQ-13 (CQ: mean increase of 28 ms; 95% confidence interval [CI], 18 to 38 ms, versus AQ-13: mean increase of 10 ms; 95% CI, 2 to 17 ms; p = 0.01). There were no arrhythmias or other cardiac AEs with either AQ-13 or CQ. CONCLUSIONS: These studies revealed minimal differences in toxicity between AQ-13 and CQ, and similar linear pharmacokinetics
Unconventional nodal superconductivity in miassite RhS
Unconventional superconductivity has long been believed to arise from a
lab-grown correlated electronic system. Here we report compelling evidence of
unconventional nodal superconductivity in a mineral superconductor \rhs. We
investigated the temperature-dependent London penetration depth
and disorder evolution of the critical temperature and
upper critical field in synthetic miassite \rhs. We found a
power-law behavior of with at low
temperatures below ( = 5.4 K), which is consistent with the
presence of lines of the node in the superconducting gap of \rhs. The nodal
character of the superconducting state in \rhs~was supported by the observed
pairbreaking effect in and in samples with the controlled
disorder that was introduced by low-temperature electron irradiation. We
propose a nodal sign-changing superconducting gap in the irreducible
representation, which preserves the cubic symmetry of the crystal and is in
excellent agreement with the superfluid density,
Doppler spectra of airborne sound backscattered by the free surface of a shallow turbulent water flow
Measurements of the Doppler spectra of airborne ultrasound backscattered by the rough dynamic surface of a shallow turbulent flow are presented in this paper. The interpretation of the observed acoustic signal behavior is provided by means of a Monte Carlo simulation based on the Kirchhoff approximation and on a linear random-phase model of the water surface elevation. Results suggest that the main scattering mechanism is from capillary waves with small amplitude. Waves that travel at the same velocity of the flow, as well as dispersive waves that travel at a range of velocities, are detected, studied and used in the acoustic Doppler analysis. The dispersive surface waves are not observed when the flow velocity is slow compared to their characteristic velocity. Relatively wide peaks in the experimental spectra also suggest the existence of nonlinear modulations of the short capillary waves, or their propagation in a wide range of directions. The variability of the Doppler spectra with the conditions of the flow can affect the accuracy of the flow velocity estimations based on backscattering Doppler. A set of different methods to estimate this velocity accurately and remotely at different ranges of flow conditions is suggested
- …