883 research outputs found
Spatial structure of an incompressible Quantum Hall strip
The incompressible Quantum Hall strip is sensitive to charging of localized
states in the cyclotron gap. We study the effect of localized states by a
density functional approach and find electron density and the strip width as a
function of the density of states in the gap. Another important effect is
electron exchange. By using a model density functional which accounts for
negative compressibility of the QH state, we find electron density around the
strip. At large exchange, the density profile becomes nonmonotonic, indicating
formation of a 1D Wigner crystal at the strip edge. Both effects, localized
states and exchange, lead to a substantial increase of the strip width.Comment: 6 LaTeX pages, 2 postscript figures, to be published in EP2DS
proceeding
Quark and Nucleon Self-Energy in Dense Matter
In a recent work we introduced a nonlocal version of the
Nambu--Jona-Lasinio(NJL) model that was designed to generate a quark
self-energy in Euclidean space that was similar to that obtained in lattice
simulations of QCD. In the present work we carry out related calculations in
Minkowski space, so that we can study the effects of the significant vector and
axial-vector interactions that appear in extended NJL models and which play an
important role in the study of the , and mesons. We study
the modification of the quark self-energy in the presence of matter and find
that our model reproduces the behavior of the quark condensate predicted by the
model-independent relation , where is the
pion-nucleon sigma term and is the density of nuclear matter. (Since
we do not include a model of confinement, our study is restricted to the
analysis of quark matter. We provide some discussion of the modification of the
above formula for quark matter.) The inclusion of a quark current mass leads to
a second-order phase transition for the restoration of chiral symmetry. That
restoration is about 80% at twice nuclear matter density for the model
considered in this work. We also find that the part of the quark self-energy
that is explicitly dependent upon density has a strong negative Lorentz-scalar
term and a strong positive Lorentz-vector term, which is analogous to the
self-energy found for the nucleon in nuclear matter when one makes use of the
Dirac equation for the nucleon. In this work we calculate the nucleon self
-energy in nuclear matter using our model of the quark self-energy and obtain
satisfactory results.Comment: 19 pages, 8 figures, 2 tables, revte
The EBV-encoded latent membrane proteins, LMP2A and LMP2B, limit the actions of interferon by targeting interferon receptors for degradation
Although frequently expressed in Epstein–Barr virus (EBV)-positive malignancies, the role that latent membrane protein 2A and 2B (LMP2A and LMP2B) have in the oncogenic process remains obscure. Here we show a novel function for these proteins in epithelial cells, namely, their ability to modulate signalling from type I/II interferon receptors (IFNRs). We show that LMP2A- and LMP2B-expressing epithelial cells show decreased responsiveness to interferon (IFN)α and IFNγ, as assessed by STAT1 phosphorylation, ISGF3 and GAF-mediated binding to IFN-stimulated response element and IFNγ-activated factor sequence elements and luciferase reporter activation. Transcriptional profiling highlighted the extent of this modulation, with both viral proteins impacting ‘globally’ on IFN-stimulated gene expression. Although not affecting the levels of cell-surface IFNRs, LMP2A and LMP2B accelerated the turnover of IFNRs through processes requiring endosome acidification. This function may form part of EBV's strategy to limit anti-viral responses and define a novel function for LMP2A and LMP2B in modulating signalling from receptors that participate in innate immune responses
Is Schr\"{o}dinger's Conjecture for the Hydrogen Atom Coherent States Attainable
We construct the most general SO(4,2) hydrogen atom coherent states which are
the counterpart of Schr\"{o}dinger's harmonic oscillator coherent states. We
show that these states cannot be localized and cannot follow the classical
orbits. Thus, Schr\"{o}dinger's conjecture for the hydrogen atom coherent
states is unattainable.Comment: 10 pages, report
The EBV-encoded oncoprotein, LMP1, induces an epithelial-to-mesenchymal transition (EMT) via Its CTAR1 domain through integrin-mediated ERK-MAPK signalling
The Epstein⁻Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) oncogene can induce profound effects on epithelial growth and differentiation including many of the features of the epithelial-to-mesenchymal transition (EMT). To better characterise these effects, we used the well-defined Madin Darby Canine Kidney (MDCK) epithelial cell model and found that LMP1 expression in these cells induces EMT as defined by characteristic morphological changes accompanied by loss of E-cadherin, desmosomal cadherin and tight junction protein expression. The induction of the EMT phenotype required a functional CTAR1 domain of LMP1 and studies using pharmacological inhibitors revealed contributions from signalling pathways commonly induced by integrin⁻ligand interactions: extracellular signal-regulated kinases/mitogen-activated protein kinases (ERK-MAPK), PI3-Kinase and tyrosine kinases, but not transforming growth factor beta (TGFβ). More detailed analysis implicated the CTAR1-mediated induction of Slug and Twist in LMP1-induced EMT. A key role for β1 integrin signalling in LMP1-mediated ERK-MAPK and focal adhesion kianse (FAK) phosphorylation was observed, and β1 integrin activation was found to enhance LMP1-induced cell viability and survival. These findings support an important role for LMP1 in disease pathogenesis through transcriptional reprogramming that enhances tumour cell survival and leads to a more invasive, metastatic phenotype
Path integral solution for an angle-dependent anharmonic oscillator
We have given a straightforward method to solve the problem of noncentral
anharmonic oscillator in three dimensions. The relative propagator is presented
by means of path integrals in spherical coordinates. By making an adequate
change of time we were able to separate the angular motion from the radial one.
The relative propagator is then exactly calculated. The energy spectrum and the
corresponding wave functions are obtained.Comment: Corrected typos and mistakes, To appear in Communications in
Theoretical Physic
Efficacy and safety of ixekizumab through 52 weeks in two phase 3, randomised, controlled clinical trials in patients with active radiographic axial spondyloarthritis (COAST-V and COAST-W).
OBJECTIVES: To investigate the efficacy and safety of ixekizumab for up to 52 weeks in two phase 3 studies of patients with active radiographic axial spondyloarthritis (r-axSpA) who were biological disease-modifying antirheumatic drug (bDMARD)-naive (COAST-V) or tumour necrosis factor inhibitor (TNFi)-experienced (COAST-W). METHODS: Adults with active r-axSpA were randomised 1:1:1:1 (n=341) to 80 mg ixekizumab every 2 (IXE Q2W) or 4 weeks (IXE Q4W), placebo (PBO) or 40 mg adalimumab Q2W (ADA) in COAST-V and 1:1:1 (n=316) to IXE Q2W, IXE Q4W or PBO in COAST-W. At week 16, patients receiving ixekizumab continued their assigned treatment; patients receiving PBO or ADA were rerandomised 1:1 to IXE Q2W or IXE Q4W (PBO/IXE, ADA/IXE) through week 52. RESULTS: In COAST-V, Assessment of SpondyloArthritis international Society 40 (ASAS40) responses rates (intent-to-treat population, non-responder imputation) at weeks 16 and 52 were 48% and 53% (IXE Q4W); 52% and 51% (IXE Q2W); 36% and 51% (ADA/IXE); 19% and 47% (PBO/IXE). Corresponding ASAS40 response rates in COAST-W were 25% and 34% (IXE Q4W); 31% and 31% (IXE Q2W); 14% and 39% (PBO/IXE). Both ixekizumab regimens sustained improvements in disease activity, physical function, objective markers of inflammation, QoL, health status and overall function up to 52 weeks. Safety through 52 weeks of ixekizumab was consistent with safety through 16 weeks. CONCLUSION: The significant efficacy demonstrated with ixekizumab at week 16 was sustained for up to 52 weeks in bDMARD-naive and TNFi-experienced patients. bDMARD-naive patients initially treated with ADA demonstrated further numerical improvements after switching to ixekizumab. Safety findings were consistent with the known safety profile of ixekizumab. TRIAL REGISTRATION NUMBER: NCT02696785/NCT02696798
A geometric approach to time evolution operators of Lie quantum systems
Lie systems in Quantum Mechanics are studied from a geometric point of view.
In particular, we develop methods to obtain time evolution operators of
time-dependent Schrodinger equations of Lie type and we show how these methods
explain certain ad hoc methods used in previous papers in order to obtain exact
solutions. Finally, several instances of time-dependent quadratic Hamiltonian
are solved.Comment: Accepted for publication in the International Journal of Theoretical
Physic
Direct Measurements of the Branching Fractions for and and Determinations of the Form Factors and
The absolute branching fractions for the decays and
are determined using singly
tagged sample from the data collected around 3.773 GeV with the
BES-II detector at the BEPC. In the system recoiling against the singly tagged
meson, events for and events for decays are observed. Those yield
the absolute branching fractions to be and . The
vector form factors are determined to be
and . The ratio of the two form
factors is measured to be .Comment: 6 pages, 5 figure
The pole in
Using a sample of 58 million events recorded in the BESII detector,
the decay is studied. There are conspicuous
and signals. At low mass, a large
broad peak due to the is observed, and its pole position is determined
to be - MeV from the mean of six analyses.
The errors are dominated by the systematic errors.Comment: 15 pages, 6 figures, submitted to PL
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