1,377 research outputs found
Field Application of a Monoclonal Antibody Panel to Differentiate Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Isolates
Porcine reproductive and respiratory syndrome (PRRS) is recognized as the most economically devastating disease of swine throughout the world. Nucleotide sequencing and serological studies have deomnstrated sustantial antigenic variation amoung PRRS virus (PRRSV) isolates (Murtaugh, et al., 1995; Nelson, et al., 1993, 1996). Recently, European-like PRRSV isolates have been identified in the US (Rossow, et al. 2000) and other new, highly virulent PRRSV isolates have appeared and affect sows at all stages of gestation causing mortality of adult pigs as well as young pigs (Epperson et al., 1997). Therefore, it is even more important to control the spread of these new strains. Clinical signs vary between herds, indicating that viruses may differ in pathogenicity. Furthermore, effective use of vaccines and management approaches to control PRRS has not always been successful
Hypercontractivity on the -Araki-Woods algebras
Extending a work of Carlen and Lieb, Biane has obtained the optimal
hypercontractivity of the -Ornstein-Uhlenbeck semigroup on the
-deformation of the free group algebra. In this note, we look for an
extension of this result to the type III situation, that is for the
-Araki-Woods algebras. We show that hypercontractivity from to
can occur if and only if the generator of the deformation is bounded.Comment: 17 page
Optimal Hypercontractivity for Fermi Fields and Related Non-Commutative Integration
Optimal hypercontractivity bounds for the fermion oscillator semigroup are
obtained. These are the fermion analogs of the optimal hypercontractivity
bounds for the boson oscillator semigroup obtained by Nelson. In the process,
several results of independent interest in the theory of non-commutative
integration are established. {}.Comment: 18 p., princeton/ecel/7-12-9
Quantum measurement in a family of hidden-variable theories
The measurement process for hidden-configuration formulations of quantum
mechanics is analysed. It is shown how a satisfactory description of quantum
measurement can be given in this framework. The unified treatment of
hidden-configuration theories, including Bohmian mechanics and Nelson's
stochastic mechanics, helps in understanding the true reasons why the problem
of quantum measurement can succesfully be solved within such theories.Comment: 16 pages, LaTeX; all special macros are included in the file; a
figure is there, but it is processed by LaTe
Vortex Lattice Melting into Disentangled Liquid Followed by the 3D-2D Decoupling Transition in YBa_2Cu_4O_8 Single Crystals
A sharp resistance drop associated with vortex lattice melting was observed
in high quality YBa_2Cu_4O_8 single crystals. The melting line is well
described well by the anisotropic GL theory. Two thermally activated flux flow
regions, which were separated by a crossover line B_cr=1406.5(1-T/T_c)/T
(T_c=79.0 K, B_cr in T), were observed in the vortex liquid phase. Activation
energy for each region was obtained and the corresponding dissipation mechanism
was discussed. Our results suggest that the vortex lattice in YBa_2Cu_4O_8
single crystal melts into disentangled liquid, which then undergoes a 3D-2D
decoupling transition.Comment: 5 pages, 4 eps figures, RevTex (Latex2.09
On the Global Existence of Bohmian Mechanics
We show that the particle motion in Bohmian mechanics, given by the solution
of an ordinary differential equation, exists globally: For a large class of
potentials the singularities of the velocity field and infinity will not be
reached in finite time for typical initial values. A substantial part of the
analysis is based on the probabilistic significance of the quantum flux. We
elucidate the connection between the conditions necessary for global existence
and the self-adjointness of the Schr\"odinger Hamiltonian.Comment: 35 pages, LaTe
Incidence and progression of hand osteoarthritis in a large community-based cohort: the Johnston County Osteoarthritis Project
Objective: To describe the incidence and progression of radiographic and symptomatic hand osteoarthritis (rHOA and sxHOA) in a large community-based cohort. Design: Data were from the Johnston County OA Project (1999–2015, 12 ± 1.2 years follow-up, age 45+). Participants had bilateral hand radiographs each visit, read for Kellgren–Lawrence grade (KLG) at 30 joints. We defined rHOA as KLG ≥2 in ≥1 joint. SxHOA was defined in a hand/joint with rHOA and self-reported symptoms or tenderness on exam. Incidence was assessed in those without, while progression was assessed in those with, baseline rHOA. Proportions or medians are reported; differences by sex and race were assessed using models appropriate for dichotomous or continuous definitions, additionally adjusted for age, education, body mass index (BMI), and weight change. Results: Of 800 participants (68% women, 32% African American, mean age 60 years), 327 had baseline rHOA and were older, more often white and female, than those without rHOA (n = 473). The incidence of HOA was high, for rHOA (60%) and for sxHOA (13%). Women were more likely than men to have incident HOA, particularly for distal interphalangeal joint radiographic osteoarthritis (DIP rOA) (adjusted odds ratios (aOR) 1.60 95% confidence intervals (95% CI) [1.03, 2.49]) and sxHOA (aOR 2.98 [1.50, 5.91]). Progressive HOA was more similar by sex, although thumb base rOA progressed more frequently in women than in men (aOR 2.56 [1.44, 4.55]). Particularly HOA incidence, but also progression, was more frequent among whites compared with African Americans. Conclusion: This study provides much needed information about the natural history of HOA, a common and frequently debilitating condition, in the general population
Hsp70 in mitochondrial biogenesis
The family of hsp70 (70 kilodalton heat shock protein) molecular chaperones plays an essential and diverse role in cellular physiology, Hsp70 proteins appear to elicit their effects by interacting with polypeptides that present domains which exhibit non-native conformations at distinct stages during their life in the cell. In this paper we review work pertaining to the functions of hsp70 proteins in chaperoning mitochondrial protein biogenesis. Hsp70 proteins function in protein synthesis, protein translocation across mitochondrial membranes, protein folding and finally the delivery of misfolded proteins to proteolytic enzymes in the mitochondrial matrix
Clinical perspectives on sampling and processing approaches for the management of infection in diabetic foot ulceration: A qualitative study
Diabetic foot ulcers (DFUs) often become infected and are treated with antimicrobials, with samples collected to inform care. Swab samples are easier than tissue sampling but report fewer organisms. Compared with culture and sensitivity (C&S) methods, molecular microbiology identifies more organisms. Clinician perspectives on sampling and processing are unknown. We explored clinician perspectives on DFU sampling—tissue samples/wound swabs—and on processing techniques, culture and sensitivity or molecular techniques. The latter provides information on organisms which have not survived transport to the laboratory for culture. We solicited feedback on molecular microbiology reports. Qualitative study using semi-structured interview, with analysis using a Framework approach. CODIFI2 clinicians from UK DFU clinics. Seven consultants agreed to take part. They reported, overall, a preference for tissue samples over swabbing. Clinicians were not confident replacing C&S with molecular microbiology as the approach to reporting was unfamiliar. The study was small and did not recruit any podiatrists or nurses, who may have discipline-specific attitudes or perspectives on DFU care. Both sampling approaches appear to be used by clinicians. Molecular microbiology reports would not be, at present, suitable for replacement of traditional culture and sensitivity
Critical Dynamics of Magnets
We review our current understanding of the critical dynamics of magnets above
and below the transition temperature with focus on the effects due to the
dipole--dipole interaction present in all real magnets. Significant progress in
our understanding of real ferromagnets in the vicinity of the critical point
has been made in the last decade through improved experimental techniques and
theoretical advances in taking into account realistic spin-spin interactions.
We start our review with a discussion of the theoretical results for the
critical dynamics based on recent renormalization group, mode coupling and spin
wave theories. A detailed comparison is made of the theory with experimental
results obtained by different measuring techniques, such as neutron scattering,
hyperfine interaction, muon--spin--resonance, electron--spin--resonance, and
magnetic relaxation, in various materials. Furthermore we discuss the effects
of dipolar interaction on the critical dynamics of three--dimensional isotropic
antiferromagnets and uniaxial ferromagnets. Special attention is also paid to a
discussion of the consequences of dipolar anisotropies on the existence of
magnetic order and the spin--wave spectrum in two--dimensional ferromagnets and
antiferromagnets. We close our review with a formulation of critical dynamics
in terms of nonlinear Langevin equations.Comment: Review article (154 pages, figures included
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