2,822 research outputs found
Self-organising management of Grid environments
This paper presents basic concepts, architectural principles and algorithms for efficient resource and security management in cluster computing environments and the Grid. The work presented in this paper is funded by BTExacT and the EPSRC project SO-GRM (GR/S21939)
A Simple Passive Scalar Advection-Diffusion Model
This paper presents a simple, one-dimensional model of a randomly advected
passive scalar. The model exhibits anomalous inertial range scaling for the
structure functions constructed from scalar differences. The model provides a
simple computational test for recent ideas regarding closure and scaling for
randomly advected passive scalars. Results suggest that high order structure
function scaling depends on the largest velocity eddy size, and hence scaling
exponents may be geometry-dependent and non-universal.Comment: 30 pages, 11 figure
Local spin density in two-dimensional electron gas with hexagonal boundary
The intrinsic spin-Hall effect in hexagon-shaped samples is investigated. To
take into account the spin-orbit couplings and to fit the hexagon edges, we
derive the triangular version of the tight-binding model for the linear Rashba
[Sov. Phys. Solid State 2, 1109 (1960)] and Dresselhaus [Phys. Rev. 100, 580
(1955)] [001] Hamiltonians, which allow direct application of the
Landauer-Keldysh non-equilibrium Green function formalism to calculating the
local spin density within the hexagonal sample. Focusing on the out-of-plane
component of spin, we obtain the geometry-dependent spin-Hall accumulation
patterns, which are sensitive to not only the sample size, the spin-orbit
coupling strength, the bias strength, but also the lead configurations.
Contrary to the rectangular samples, the accumulation pattern can be very
different in our hexagonal samples. Our present work provides a fundamental
description of the geometry effect on the intrinsic spin-Hall effect, taking
the hexagon as the specific case. Moreover, broken spin-Hall symmetry due to
the coexistence of the Rashba and Dresselhaus couplings is also discussed. Upon
exchanging the two coupling strengths, the accumulation pattern is reversed,
confirming the earlier predicted sign change in spin-Hall conductivity.Comment: 7 pages, 4 figure
Spin precession due to spin-orbit coupling in a two-dimensional electron gas with spin injection via ideal quantum point contact
We present the analytical result of the expectation value of spin resulting
from an injected spin polarized electron into a semi-infinitely extended 2DEG
plane with [001] growth geometry via ideal quantum point contact. Both the
Rashba and Dresselhaus spin-orbit couplings are taken into account. A pictorial
interpretation of the spin precession along certain transport directions is
given. The spin precession due to the Rashba term is found to be especially
interesting since it behaves simply like a windshield wiper which is very
different from the ordinary precession while that due to the Dresselhaus term
is shown to be crystallographic-direction-dependent. Some crystallographic
directions with interesting and handleable behavior of spin precession are
found and may imply certain applicability in spintronic devices.Comment: 5 pages, 2 figures, submitted to Phys. Rev.
Benign intermuscular lipoma in a bitch
A case of intermuscular lipoma located between the external abdominal oblique and internal abdominal oblique muscles in a fourteen- year -old dog is described. Presenting signs, radiographic findings, surgical treatments and the follow-up treatment are discussed
Activation of a prophage‐encoded tyrosine kinase by a heterologous infecting phage results in a self‐inflicted abortive infection
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87011/1/j.1365-2958.2011.07847.x.pd
Fucosyltransferase 1 and 2 play pivotal roles in breast cancer cells.
FUT1 and FUT2 encode alpha 1, 2-fucosyltransferases which catalyze the addition of alpha 1, 2-linked fucose to glycans. Glycan products of FUT1 and FUT2, such as Globo H and Lewis Y, are highly expressed on malignant tissues, including breast cancer. Herein, we investigated the roles of FUT1 and FUT2 in breast cancer. Silencing of FUT1 or FUT2 by shRNAs inhibited cell proliferation in vitro and tumorigenicity in mice. This was associated with diminished properties of cancer stem cell (CSC), including mammosphere formation and CSC marker both in vitro and in xenografts. Silencing of FUT2, but not FUT1, significantly changed the cuboidal morphology to dense clusters of small and round cells with reduced adhesion to polystyrene and extracellular matrix, including laminin, fibronectin and collagen. Silencing of FUT1 or FUT2 suppressed cell migration in wound healing assay, whereas FUT1 and FUT2 overexpression increased cell migration and invasion in vitro and metastasis of breast cancer in vivo. A decrease in mesenchymal like markers such as fibronectin, vimentin, and twist, along with increased epithelial like marker, E-cadherin, was observed upon FUT1/2 knockdown, while the opposite was noted by overexpression of FUT1 or FUT2. As expected, FUT1 or FUT2 knockdown reduced Globo H, whereas FUT1 or FUT2 overexpression showed contrary effects. Exogenous addition of Globo H-ceramide reversed the suppression of cell migration by FUT1 knockdown but not the inhibition of cell adhesion by FUT2 silencing, suggesting that at least part of the effects of FUT1/2 knockdown were mediated by Globo H. Our results imply that FUT1 and FUT2 play important roles in regulating growth, adhesion, migration and CSC properties of breast cancer, and may serve as therapeutic targets for breast cancer
Presentation and Outcomes After Medical and Surgical Treatment Versus Medical Treatment Alone of Spontaneous Infectious Spondylodiscitis: A Systematic Literature Review and Meta-Analysis.
Study Design: Systematic literature review.
Objectives: The aims of this study were to (1) describe the clinical features, disabilities, and incidence of neurologic deficits of pyogenic spondylodiscitis prior to treatment and (2) compare the functional outcomes between patients who underwent medical treatment alone or in combination with surgery for pyogenic spondylodiscitis.
Methods: A systematic literature review was performed using PubMed according to PRISMA guidelines. No year restriction was put in place. Statistical analysis of pooled data, when documented in the original report (ie, number of patients with desired variable and number of patients evaluated), was conducted to determine the most common presenting symptoms, incidence of pre- and postoperative neurologic deficits, associated comorbidities, infectious pathogens, approach for surgery when performed, and duration of hospitalization. Outcomes data, including return to work status, resolution of back pain, and functional recovery were also pooled among all studies and surgery-specific studies alone. Meta-analysis of studies with subgroup analysis of pain-free outcome in surgical and medical patients was performed.
Results: Fifty of 1286 studies were included, comprising 4173 patients undergoing either medical treatment alone or in combination with surgery. Back pain was the most common presenting symptom, reported in 91% of patients. Neurologic deficit was noted in 31% of patients.
Conclusion: Medical management remains first-line treatment of infectious pyogenic spondylodiscitis. Surgery may be indicated for progressive pain, persistent infection on imaging, deformity or neurologic deficits. If surgery is required, reported literature shows potential for significant pain reduction, improved neurologic function and a high number of patients returning to a normal functional/work status
Strong Universality in Forced and Decaying Turbulence
The weak version of universality in turbulence refers to the independence of
the scaling exponents of the th order strcuture functions from the
statistics of the forcing. The strong version includes universality of the
coefficients of the structure functions in the isotropic sector, once
normalized by the mean energy flux. We demonstrate that shell models of
turbulence exhibit strong universality for both forced and decaying turbulence.
The exponents {\em and} the normalized coefficients are time independent in
decaying turbulence, forcing independent in forced turbulence, and equal for
decaying and forced turbulence. We conjecture that this is also the case for
Navier-Stokes turbulence.Comment: RevTex 4, 10 pages, 5 Figures (included), 1 Table; PRE, submitte
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