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https://www.readbyqxmd.com/read/27915152/goal-equivalent-manifold-analysis-of-task-performance-in-non-specific-lbp-and-healthy-subjects-during-repetitive-trunk-movement-effect-of-load-velocity-symmetry
#1
Mahshid Chehrehrazi, Mohammad Ali Sanjari, Hamid Reza Mokhtarinia, Ali Ashraf Jamshidi, Nader Maroufi, Mohamad Parnianpour
Motor abundance allows reliability of motor performance despite its variability. The nature of this variability provides important information on the flexibility of control strategies. This feature of control may be affected by low back pain (LPB) and trunk flexion/extension conditions. Goal equivalent manifold (GEM) analysis was used to quantify the ability to exploit motor abundance during repeated trunk flexion/extension in healthy individuals and people with chronic non-specific LBP (CNSLBP). Kinematic data were collected from 22 healthy volunteers and 22 CNSLBP patients during metronomically timed, repeated trunk flexion/extension in three conditions of symmetry, velocity, and loading; each at two levels...
December 1, 2016: Human Movement Science
https://www.readbyqxmd.com/read/27914376/mode-converted-ultrasonic-scattering-in-polycrystals-with-elongated-grains
#2
Andrea P Arguelles, Christopher M Kube, Ping Hu, Joseph A Turner
Elastic wave scattering is used to study polycrystalline media for a wide range of applications. Received signals, which include scattering from the randomly oriented grains comprising the polycrystal, contain information from which useful microstructural parameters may often be inferred. Recently, a mode-converted diffuse ultrasonic scattering model was developed for evaluating the scattered response of a transverse wave from an incident longitudinal wave in a polycrystalline medium containing equiaxed single-phase grains with cubic elastic symmetry...
September 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27913377/optimization-and-assessment-of-three-different-high-performance-liquid-chromatographic-systems-for-the-combinative-fingerprint-analysis-and-multi-ingredients-quantification-of-sangju-ganmao-tablet
#3
Meng-Zhe Guo, Jie Han, Dan-Dan He, Jia-Hui Zou, Zheng Li, Yan Du, Dao-Quan Tang
Chromatographic separation is still a critical subject for the quality control of traditional Chinese medicine. In this study, three different high performance liquid chromatographic (HPLC) systems employing commercially available columns packed with 1.8, 3.5 and 5.0 μm particles were respectively developed and optimized for the combinative fingerprint analysis and multi-ingredients quantification of Sangju Ganmao tablet (SGT). Chromatographic parameters including the repeatability of retention time and peak area, symmetry factor, resolution, number of theoretical plates and peak capacity were used to assess the chromatographic performance of different HPLC systems...
December 1, 2016: Journal of Chromatographic Science
https://www.readbyqxmd.com/read/27912180/radicals-formed-from-proton-loss-of-carotenoid-radical-cations-a-special-form-of-carotenoid-neutral-radical-occurring-in-photoprotection
#4
A Ligia Focsan, Lowell D Kispert
In an organized assembly in Arabidopsis thaliana plant, proton loss from the radical cation of zeaxanthin (Zea(+)) was found to occur under intense illumination, a possible component in photoprotection. A stable neutral radical is formed because of the favorable proton loss at C4(4') position(s) of the terminal ends of Zea(+) that extends the unpaired spin density distribution (notation Zea(4) or Zea(4') by symmetry). Proton loss from the radical cation of β-carotene (β-car(+)) to available proton acceptors was also detected in a PSII sample upon irradiation...
November 19, 2016: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/27912103/gait-symmetry-in-individuals-with-and-without-developmental-coordination-disorder
#5
K Wilmut, J Gentle, A L Barnett
BACKGROUND: Symmetry between the left and right side of the body during locomotion is key in a coordinated gait cycle and is also thought to be important in terms of efficiency. Although previous studies have identified aspects of the gait cycle which are atypical in children and adults with Developmental Coordination Disorder (DCD), studies have not considered whether this could be explained by asymmetrical gait. METHOD AND PROCEDURE: The current study included 62 participants with and 62 without DCD (aged 7-34 years)...
November 29, 2016: Research in Developmental Disabilities
https://www.readbyqxmd.com/read/27911882/a-unified-perspective-of-complex-band-structure-interpretations-formulations-and-applications
#6
Matthew G Reuter
Complex band structure generalizes conventional band structure by also considering wavevectors with complex components. In this way, complex band structure describes both the bulk-propagating states from conventional band structure and the evanescent states that grow or decay from one unit cell to the next. Even though these latter states are excluded by translational symmetry, they become important when translational symmetry is broken via, for example, a surface or impurity. Many studies over the last 80 years have directly or indirectly developed complex band structure for an impressive range of applications, but very few discuss its fundamentals or compare its various results...
December 2, 2016: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/27911565/radiative-screening-of-fifth-forces
#7
Clare Burrage, Edmund J Copeland, Peter Millington
We describe a symmetron model in which the screening of fifth forces arises at the one-loop level through the Coleman-Weinberg mechanism of spontaneous symmetry breaking. We show that such a theory can avoid current constraints on the existence of fifth forces but still has the potential to give rise to observable deviations from general relativity, which could be seen in cold atom experiments.
November 18, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/27911547/parametric-symmetry-breaking-in-a-nonlinear-resonator
#8
Anina Leuch, Luca Papariello, Oded Zilberberg, Christian L Degen, R Chitra, Alexander Eichler
Much of the physical world around us can be described in terms of harmonic oscillators in thermodynamic equilibrium. At the same time, the far-from-equilibrium behavior of oscillators is important in many aspects of modern physics. Here, we investigate a resonating system subject to a fundamental interplay between intrinsic nonlinearities and a combination of several driving forces. We have constructed a controllable and robust realization of such a system using a macroscopic doubly clamped string. We experimentally observe a hitherto unseen double hysteresis in both the amplitude and the phase of the resonator's response function and present a theoretical model that is in excellent agreement with the experiment...
November 18, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/27911532/spin-nernst-effect-of-magnons-in-collinear-antiferromagnets
#9
Ran Cheng, Satoshi Okamoto, Di Xiao
In a collinear antiferromagnet with easy-axis anisotropy, symmetry guarantees that the spin wave modes are doubly degenerate. The two modes carry opposite spin angular momentum and exhibit opposite chirality. Using a honeycomb antiferromagnet in the presence of the Dzyaloshinskii-Moriya interaction, we show that a longitudinal temperature gradient can drive the two modes to opposite transverse directions, realizing a spin Nernst effect of magnons with vanishing thermal Hall current. We find that magnons around the Γ point and the K point contribute oppositely to the transverse spin transport, and their competition leads to a sign change of the spin Nernst coefficient at finite temperature...
November 18, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/27911531/magnon-spin-nernst-effect-in-antiferromagnets
#10
Vladimir A Zyuzin, Alexey A Kovalev
We predict that a temperature gradient can induce a magnon-mediated spin Hall response in an antiferromagnet with nontrivial magnon Berry curvature. We develop a linear response theory which gives a general condition for a Hall current to be well defined, even when the thermal Hall response is forbidden by symmetry. We apply our theory to a honeycomb lattice antiferromagnet and discuss a role of magnon edge states in a finite geometry.
November 18, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/27911515/superconductivity-in-fese-thin-films-driven-by-the-interplay-between-nematic-fluctuations-and-spin-orbit-coupling
#11
Jian Kang, Rafael M Fernandes
The origin of the high-temperature superconducting state observed in FeSe thin films, whose phase diagram displays no sign of magnetic order, remains a hotly debated topic. Here we investigate whether fluctuations arising due to the proximity to a nematic phase, which is observed in the phase diagram of this material, can promote superconductivity. We find that nematic fluctuations alone promote a highly degenerate pairing state, in which both s-wave and d-wave symmetries are equally favored, and T_{c} is consequently suppressed...
November 18, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/27910969/the-intramolecular-h-bonding-effect-on-the-growth-and-stability-of-schiff-base-surface-covalent-organic-frameworks
#12
Yi-Ping Mo, Xuan-He Liu, Bing Sun, Hui-Juan Yan, Dong Wang, Li-Jun Wan
The introduction of intramolecular H-bonding by adding -OH functionalities adjacent to the Schiff base centers is considered to be a useful strategy to enhance the stability and crystallinity of bulk covalent organic frameworks (COFs). However, the influence of intramolecular H-bonding on the synthesis of surface COFs (SCOFs) have been barely explored. Herein, SCOFs based on the Schiff-base reaction between 1,3,5-tris(4-aminophenyl)benzene (TAPB) and terephthalaldehydes with symmetry or asymmetrically substituted hydroxyl functional groups are designed...
December 2, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27910841/incommensurate-density-modulation-in-a-na-rich-plagioclase-feldspar-z-contrast-imaging-and-single-crystal-x-ray-diffraction-study
#13
Huifang Xu, Shiyun Jin, Bruce C Noll
Plagioclase feldspars are the most abundant mineral in the Earth's crust. Intermediate plagioclase feldspars commonly display incommensurately modulated or aperiodic structures. Z-contrast images show both Ca-Na ordering and density modulation. The local structure of lamellae domains has I1-like symmetry. The neighboring lamellae domains are in an inversion twinning relationship. With a state-of-the-art X-ray diffraction unit, second-order satellite reflections (f-reflections) are observed for the first time in andesine (An45), a Na-rich e-plagioclase...
December 1, 2016: Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials
https://www.readbyqxmd.com/read/27910836/neutron-and-high-pressure-x-ray-diffraction-study-of-hydrogen-bonded-ferroelectric-rubidium-hydrogen-sulfate
#14
Jack Binns, Garry J McIntyre, Simon Parsons
The pressure- and temperature-dependent phase transitions in the ferroelectric material rubidium hydrogen sulfate (RbHSO4) are investigated by a combination of neutron Laue diffraction and high-pressure X-ray diffraction. The observation of disordered O-atom positions in the hydrogen sulfate anions is in agreement with previous spectroscopic measurements in the literature. Contrary to the mechanism observed in other hydrogen-bonded ferroelectric materials, H-atom positions are well defined and ordered in the paraelectric phase...
December 1, 2016: Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials
https://www.readbyqxmd.com/read/27910831/high-z-structures-of-organic-molecules-their-diversity-and-organizing-principles
#15
Carolyn Pratt Brock
A list has been compiled of 284 well determined organic structures having more than four crystallographically independent molecules or formula units (i.e. Z' > 4). Another 22 structures were rejected because the space group or unit cell was probably misassigned; the rate for that type of error is then only 7%. The space-group frequencies are unusual; half the structures are in Sohncke groups, partly because the fraction of enantiopure structures of resolvable enantiomers is higher than for lower Z' structures...
December 1, 2016: Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials
https://www.readbyqxmd.com/read/27910671/a-high-speed-compact-microwave-interferometer-for-density-fluctuation-measurements-in-sino-united-spherical-tokamak
#16
H Zhong, Y Tan, Y Q Liu, H Q Xie, Z Gao
A single-channel 3 mm interferometer has been developed for plasma density diagnostics in the Sino-UNIted Spherical Tokamak (SUNIST). The extremely compact microwave interferometer utilizes one corrugated feed horn antenna for both emitting and receiving the microwave. The beam path lies on the equatorial plane so the system would not suffer from beam path deflection problems due to the symmetry of the cross section. A focusing lens group and an oblique vacuum window are carefully designed to boost the signal to noise ratio, which allows this system to show good performance even with the small-diameter central column itself as a reflector, without a concave mirror...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910619/a-compact-five-port-waveguide-structure-and-its-application-as-a-three-way-power-divider
#17
Letian Guo, Jiawei Li, Tao Ba, Wenhua Huang, Hao Shao
A compact five-port waveguide structure consisting of three rectangular ports, one coaxial port, and one circular waveguide port is proposed. The three rectangular waveguides are uniformly distributed in space at angles of 120°, and the coaxial and circular waveguides are located at the top and bottom, respectively, of the rectangular waveguides. The ideal scattering matrix is derived from the symmetry properties of the structure. If the circular and coaxial ports are matched, then the entire five-port waveguide structure is automatically matched...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910552/versatile-wetting-measurement-of-microplate-wells
#18
Enoch Ming Wei Ng, Brandon Huey-Ping Cheong, Yang Yu, Oi Wah Liew, Tuck Wah Ng
A method to measure the contact angle, which is indicative of wetting, using small liquid volumes dispensed directly on microplate wells is described and demonstrated. Experiments with enhanced green protein samples of volumes 4.4-6 μl showed no measured variance in the contact angle. Experiments with phosphate buffer solution with varied concentrations of a non-ionic detergent (Tween 20) dissolved, however, revealed smaller contact angles with increased detergent concentration. It is experimentally shown that drops can be located up to 7° from the lowest position of the well without affecting the accuracy of contact angle measurements...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910498/using-visar-to-assess-the-m-band-isotropy-in-hohlraums
#19
N E Lanier, J L Kline, J Morton
In laser based radiation flow experiments, drive variability can often overwhelm the physics sensitivity that one seeks to quantify. Hohlraums can help by providing a more symmetrized, Planckian-like source. However, at higher temperatures, the hohlraum's actual emission can deviate significantly from a truly blackbody, Lambertian source. At the National Ignition Facility (NIF), Dante provides the best quantification of hohlraum output. Unfortunately, limited diagnostic access coupled with NIF's natural symmetry does not allow for Dante measurements at more than two angles...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910429/automated-analysis-of-hot-spot-x-ray-images-at-the-national-ignition-facility
#20
S F Khan, N Izumi, S Glenn, R Tommasini, L R Benedetti, T Ma, A Pak, G A Kyrala, P Springer, D K Bradley, R P J Town
At the National Ignition Facility, the symmetry of the hot spot of imploding capsules is diagnosed by imaging the emitted x-rays using gated cameras and image plates. The symmetry of an implosion is an important factor in the yield generated from the resulting fusion process. The x-ray images are analyzed by decomposing the image intensity contours into Fourier and Legendre modes. This paper focuses on the additional protocols for the time-integrated shape analysis from image plates. For implosions with temperatures above ∼4 keV, the hard x-ray background can be utilized to infer the temperature of the hot spot...
November 2016: Review of Scientific Instruments
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