1,510 research outputs found
A growth chamber study on the effects of metribuzin on the rhizobium-lentil symbiosis
Non-Peer Reviewe
Ostracoda (Myodocopina) of the Hawaiian Islands.
v. ill. 23 cm.QuarterlyOstracoda (Myodocopina) from four of the Hawaiian Islands (Kaua‘i, Moloka‘i, Maui, and Hawai‘i) are identified, and a new species, Pterocypridina colesi Kornicker & Harrison-Nelson, that was present on all the Islands is described and illustrated, including all five instars and the adult male and female. The genus was not previously known from the area, and its ontogeny had not been described. The number of species collected on the Islands varied from two on Moloka‘i to six on Kaua‘i
A new lower bound approach for single-machine multicriteria scheduling
The concept of maximum potential improvement has played an important role in computing lower bounds for single-machine scheduling problems with composite objective functions that are linear in the job completion times. We introduce a new method for lower bound computation; objective splitting. We show that it dominates the maximum potential improvement method in terms of speed and quality
Electrooxidation and determination of dopamine using a Nafion®-cobalt hexacyanoferrate film modified electrode
The electrocatalysis of dopamine has been studied using a cobalt
hexacyanoferrate film (CoHCFe)-modified glassy carbon electrode. Using a rotating disk
CoHCFe-modified electrode, the reaction rate constant for dopamine was found to be 3.5 ×
105 cm3 mol-1 s-1 at a concentration of 5.0 × 10-5 mol L-1. When a Nafion® film is applied to
the CoHCFe-modified electrode surface a high selectivity for the determination of
dopamine over ascorbic acid was obtained. The analytical curve for dopamine presented
linear dependence over the concentration range from 1.2 × 10-5 to 5.0 × 10-4 mol L-1 with a
slope of 23.5 mA mol-1 L and a linear correlation coefficient of 0.999. The detection limit
of this method was 8.9 × 10-6 mol L-1 and the relative standard deviation for five
measurements of 2.5 × 10-4 mol L-1 dopamine was 0.58%
The association between dry needling-induced twitch response and change in pain and muscle function in patients with low back pain: a quasi-experimental study
Objective
To investigate the relationship between dry needling-induced twitch response and change in pain, disability, nociceptive sensitivity, and lumbar multifidus muscle function, in patients with low back pain (LBP).
Design
Quasi-experimental study.
Setting
Department of Defense Academic Institution.
Participants
Sixty-six patients with mechanical LBP (38 men, 28 women, age: 41.3 [9.2] years).
Interventions
Dry needling treatment to the lumbar multifidus muscles between L3 and L5 bilaterally.
Main outcome measures
Examination procedures included numeric pain rating, the Modified Oswestry Disability Index, pressure algometry, and real-time ultrasound imaging assessment of lumbar multifidus muscle function before and after dry needling treatment. Pain pressure threshold (PPT) was used to measure nocioceptive sensitivity. The percent change in muscle thickness from rest to contraction was calculated to represent muscle function. Participants were dichotomized and compared based on whether or not they experienced at least one twitch response on the most painful side and spinal level during dry needling.
Results
Participants experiencing local twitch response during dry needling exhibited greater immediate improvement in lumbar multifidus muscle function than participants who did not experience a twitch (thickness change with twitch: 12.4 [6]%, thickness change without twitch: 5.7 [11]%, mean difference adjusted for baseline value, 95%CI: 4.4 [1 to 8]%). However, this difference was not present after 1-week, and there were no between-groups differences in disability, pain intensity, or nociceptive sensitivity.
Conclusions
The twitch response during dry needling might be clinically relevant, but should not be considered necessary for successful treatment
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
Two-sided hypergenic functions
In this paper we present an analogous of the class of two-sided axial monogenic functions to the case of axial hypermonogenic functions. In order to do that we will solve a Vekua-type system in terms of Bessel functions
Lattice swelling and modulus change in a helium-implanted tungsten alloy: X-ray micro-diffraction, surface acoustic wave measurements, and multiscale modelling
Using X-ray micro-diffraction and surface acoustic wave spectroscopy, we measure lattice swelling and elastic modulus changes in a W-1% Re alloy after implantation with 3110 appm of helium. An observed lattice expansion of a fraction of a per cent gives rise to an order of magnitude larger reduction in the surface acoustic wave velocity. A multiscale model, combining elasticity and density functional theory, is applied to the interpretation of observations. The measured lattice swelling is consistent with the relaxation volume of self-interstitial and helium-filled vacancy defects that dominate the helium-implanted material microstructure. Larger scale atomistic simulations using an empirical potential confirm the findings of the elasticity and density functional theory model for swelling. The reduction of surface acoustic wave velocity predicted by density functional theory calculations agrees remarkably well with experimental observations.National Science Foundation (U.S.) (CHE-1111557
Vector Bosons in the Randall-Sundrum 2 and Lykken-Randall models and unparticles
Unparticle behavior is shown to be realized in the Randall-Sundrum 2 (RS 2)
and the Lykken-Randall (LR) brane scenarios when brane-localized Standard Model
currents are coupled to a massive vector field living in the five-dimensional
warped background of the RS 2 model. By the AdS/CFT dictionary these
backgrounds exhibit certain properties of the unparticle CFT at large N_c and
strong 't Hooft coupling. Within the RS 2 model we also examine and contrast in
detail the scalar and vector position-space correlators at intermediate and
large distances. Unitarity of brane-to-brane scattering amplitudes is seen to
imply a necessary and sufficient condition on the positivity of the bulk mass,
which leads to the well-known unitarity bound on vector operators in a CFT.Comment: 60 pages, 8 figure
Effects of columnar disorder on flux-lattice melting in high-temperature superconductors
The effect of columnar pins on the flux-lines melting transition in
high-temperature superconductors is studied using Path Integral Monte Carlo
simulations. We highlight the similarities and differences in the effects of
columnar disorder on the melting transition in YBaCuO
(YBCO) and the highly anisotropic BiSrCaCuO (BSCCO) at
magnetic fields such that the mean separation between flux-lines is smaller
than the penetration length. For pure systems, a first order transition from a
flux-line solid to a liquid phase is seen as the temperature is increased. When
adding columnar defects to the system, the transition temperature is not
affected in both materials as long as the strength of an individual columnar
defect (expressed as a flux-line defect interaction) is less than a certain
threshold for a given density of randomly distributed columnar pins. This
threshold strength is lower for YBCO than for BSCCO. For higher strengths the
transition line is shifted for both materials towards higher temperatures, and
the sharp jump in energy, characteristic of a first order transition, gives way
to a smoother and gradual rise of the energy, characteristic of a second order
transition. Also, when columnar defects are present, the vortex solid phase is
replaced by a pinned Bose glass phase and this is manifested by a marked
decrease in translational order and orientational order as measured by the
appropriate structure factors. For BSCCO, we report an unusual rise of the
translational order and the hexatic order just before the melting transition.
No such rise is observed in YBCO.Comment: 32 pages, 13 figures, revte
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