256 research outputs found
Clinical and functional impairment after nonoperative treatment of distal biceps ruptures
© 2018 Journal of Shoulder and Elbow Surgery Board of Trustees Background: Clinical and functional impairment after nonoperative treatment of distal biceps ruptures is not well understood. The goal of this study was to measure patients’ perceived disability, kinematic adjustment, and forearm supination power after nonoperative treatment of distal biceps ruptures. Methods: Fourteen individuals after nonoperative treatment of distal biceps ruptures were matched to a control group of 18 uninjured volunteers. Both groups prospectively completed the Disabilities of the Arm, Shoulder and Hand (DASH), Single Assessment Numerical Evaluation (SANE), and Biceps Disability Questionnaire. Both performed a new timed isotonic supination test that was designed to simulate activities of daily life. The isotonic torque dynamometer measures the supination arc, center of supination arc, torque, angular velocity, and power. Motion analysis quantifies forearm and shoulder contributions to the arc of supination. Results: The nonoperative treated group\u27s DASH (23.2 ± 10.3) and SANE (59.6 ± 16.2) scores demonstrated a clinical meaningful impairment. The control group showed no significant differences in kinematic values between dominant and nondominant arms (P =.854). The nonoperative biceps ruptured arms, compared with their uninjured arms, changed supination motion by decreasing the supination arc (P ≤.036), shifting the center of supination arc to a more pronated position (P ≤.030), and increasing the shoulder contribution to rotation (P ≤.001); despite this adaptation, their average corrected power of supination decreased by 47% (P =.001). Conclusion: Patients should understand that nonoperative treatment for distal biceps ruptures will result in varying degrees of functional loss as measured by the DASH, SANE, and Biceps Disability Questionnaire, change their supination kinematics during repetitive tasks, and that they will lose 47% of their supination power
A Survey of CN and CH Variations in Galactic Globular Clusters from SDSS Spectroscopy
We present a homogeneous survey of the CN and CH bandstrengths in eight
Galactic globular clusters observed during the course of the Sloan Extension
for Galactic Understanding and Exploration (SEGUE) sub-survey of the SDSS. We
confirm the existence of a bimodal CN distribution among RGB stars in all of
the clusters with metallicity greater than [Fe/H] = -1.7; the lowest
metallicity cluster with an observed CN bimodality is M53, with [Fe/H] ~ -2.1.
There is also some evidence for individual CN groups on the subgiant branches
of M92, M2, and M13, and on the red giant branches of M92 and NGC 5053.
Finally, we quantify the correlation between overall cluster metallicity and
the slope of the CN bandstrength-luminosity plot as a means of further
demonstrating the level of CN-enrichment in cluster giants. Our results agree
well with previous studies reported in the literature.Comment: AJ submitted; 80 pages, 22 figure
Examination of Triacylglycerol Biosynthetic Pathways via De Novo Transcriptomic and Proteomic Analyses in an Unsequenced Microalga
Biofuels derived from algal lipids represent an opportunity to dramatically impact the global energy demand for transportation fuels. Systems biology analyses of oleaginous algae could greatly accelerate the commercialization of algal-derived biofuels by elucidating the key components involved in lipid productivity and leading to the initiation of hypothesis-driven strain-improvement strategies. However, higher-level systems biology analyses, such as transcriptomics and proteomics, are highly dependent upon available genomic sequence data, and the lack of these data has hindered the pursuit of such analyses for many oleaginous microalgae. In order to examine the triacylglycerol biosynthetic pathway in the unsequenced oleaginous microalga, Chlorella vulgaris, we have established a strategy with which to bypass the necessity for genomic sequence information by using the transcriptome as a guide. Our results indicate an upregulation of both fatty acid and triacylglycerol biosynthetic machinery under oil-accumulating conditions, and demonstrate the utility of a de novo assembled transcriptome as a search model for proteomic analysis of an unsequenced microalga
Superexchange in the quarter- filled two- leg ladder system NaV2O5
A theory of superexchange in the mixed valent layer compound NaV2O5 is
presented which provides a consistent description of exchange both in the
disordered and charge ordered state. Starting from results of band structure
calculations for NaV2O5 first an underlying electronic model for a ladder unit
in the Trellis lattice is formulated. By using the molecular orbital
representation for intra-rung electronic states a second-order perturbation
procedure is developed and an effective spin-chain model for a ladder is
derived. Variation of the resulting superexchange integral J is examined
numerically as the ladder system evolves from a charge disordered to the
extreme ('zig-zag') charge ordered state. It is found that the effective intra-
ladder superexchange is always antiferromagnetic.Comment: 18 pages Revtex, 7 Postscript figure
Building the Galactic halo from globular clusters: evidence from chemically unusual red giants
We present a spectroscopic search for halo field stars that originally formed
in globular clusters. Using moderate-resolution SDSS-III/SEGUE-2 spectra of 561
red giants with typical halo metallicities (-1.8 < [Fe/H] < -1.0), we identify
16 stars, 3% of the sample, with CN and CH bandstrength behavior indicating
depleted carbon and enhanced nitrogen abundances relative to the rest of the
data set. Since globular clusters are the only environment known in which stars
form with this pattern of atypical light-element abundances, we claim that
these stars are second-generation globular cluster stars that have been lost to
the halo field via normal cluster mass-loss processes. Extrapolating from
theoretical models of two-generation globular cluster formation, this result
suggests that globular clusters contributed significant numbers of stars to the
construction of the Galactic halo: we calculate that a minimum of 17% of the
present-day mass of the stellar halo was originally formed in globular
clusters. The ratio of CN-strong to CN-normal stars drops with Galactocentric
distance, suggesting that the inner-halo population may be the primary
repository of these stars.Comment: 9 pages including 8 figures, A&A accepte
Entanglement and Tensor Product Decomposition for Two Fermions
The problem of the choice of tensor product decomposition in a system of two
fermions with the help of Bogoliubov transformations of creation and
annihilation operators is discussed. The set of physical states of the
composite system is restricted by the superselection rule forbidding the
superposition of fermions and bosons. It is shown that the Wootters concurrence
is not proper entanglement measure in this case. The explicit formula for the
entanglement of formation is found and its dependence on tensor product
decompositions of the Hilbert space is discussed. It is shown that the set of
separable states is narrower than in two-qubit case. Moreover, there exist
states which are separable with respect to all tensor product decompositions of
the Hilbert space.Comment: 8pp, published versio
Exact diagonalisation study of charge order in the quarter-filled two-leg ladder system NaV2O5
The charge ordering transition in the layer compound NaV2O5 is studied by
means of exact diagonalization methods for finite systems. The 2-leg ladders of
the V-Trellis lattice are associated with one spin variable of the vanadium
3d-electron in the rung and a pseudospin variable that describes its positional
degree of freedom. The charge ordering (CO) due to intersite Coulomb
interactions is described by an effective Ising-like Hamiltonian for the
pseudo-spins that are coupled to the spin fluctuations along the ladder. We
employ a Lanczos algortihm on 2D lattice to compute charge (pseudo-spin) and
spin-correlation functions and the energies of the low lying excited states. A
CO-phase diagram is constructed and the effect of intra-ladder exchange on the
CO transition is studied. It is shown that a phase with no-longe range order
(no-LRO) exists between the in-line and zig-zag ordered structures. We provide
a finite-size scaling analysis for the spin excitation gap and also discuss the
type of excitations. In addition we studied the effect of bond-alternation of
spin exchange and derived a scaling form for the spin gap in terms of the
dimerization parameter.Comment: 9 pages with 9 EPS figures and 1 table, To be appeared in Phys. Rev.
B (2001
Infrared optical properties of the spin-1/2 quantum magnet
We report results on the electrodynamic response of , a
low-dimensional spin-1/2 quantum magnet that shows a spin gap formation for
T= 67 . The Fano-like shape of a few selected infrared active
phonons suggests an interaction between lattice vibrations and a continuum of
low frequency (spin) excitations. The temperature dependence of the phonon mode
parameters extends over a broad temperature range well above ,
indicating the presence of an extended fluctuation regime. In the temperature
interval between 200 and there is a progressive dimensionality
crossover (from two to one), as well as a spectral weight shift from low
towards high frequencies. This allows us to identify a characteristic energy
scale of about 430 , ascribed to a pseudo spin-gap
Zigzag Charge Ordering in alpha'-NaV2O5
23Na NMR spectrum measurements in alpha'-NaV2O5 with a single- crystalline
sample are reported. In the charge-ordered phase, the number of inequivalent Na
sites observed is more than that expected from the low-temperature structures
of space group Fmm2 reported so far. This disagreement indicates that the real
structure including both atomic displacement and charge disproportionation is
of lower symmetry. It is suggested that zigzag ordering is the most probable.
The temperature variation of the NMR spectra near the transition temperature is
incompatible with that of second-order transitions. It is thus concluded that
the charge ordering transition is first-order.Comment: 4 pages, 5 eps figures, submitted to J. Phys. Soc. Jp
X-ray anomalous scattering investigations on the charge order in -NaVO
Anomalous x-ray diffraction studies show that the charge ordering in
-NaVO is of zig-zag type in all vanadium ladders. We
have found that there are two models of the stacking of layers along
\emph{c-}direction, each of them consisting of 2 degenerated patterns, and that
the experimental data is well reproduced if the 2 patterns appears
simultaneously. We believe that the low temperature structure contains stacking
faults separating regions corresponding to the four possible patterns.Comment: Submitted to Phys. Rev. Lett., 4 pages, 4 eps figures inserted in the
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