4,703 research outputs found
Estimating Lattice Artifacts from Flowed SU(2) Calorons
Lattice computations of the high-temperature topological susceptibility of
QCD receive lattice-spacing corrections and suffer from systematics arising
from the type and depth of gradient flow. We study the lattice spacing
corrections to semi-analytically by exploring the behavior
of discretized Harrington-Shepard calorons under the action of different forms
of gradient flow. From our study we conclude that is definitely
too small of a time extent to study the theory at temperatures of order
and we explore how the amount of gradient flow influences the
continuum extrapolation.Comment: 10 pages, 8 figures (published version
Scaling up antiretroviral therapy in Malawi-implications for managing other chronic diseases in resource-limited countries.
The national scale-up of antiretroviral therapy (ART) in Malawi is based on the public health approach, with principles and practices borrowed from the successful DOTS (directly observed treatment, short course) tuberculosis control framework. The key principles include political commitment, free care, and standardized systems for case finding, treatment, recording and reporting, and drug procurement. Scale-up of ART started in June 2004, and by December 2008, 223,437 patients were registered for treatment within a health system that is severely underresourced. The Malawi model for delivering lifelong ART can be adapted and used for managing patients with chronic noncommunicable diseases, the burden of which is already high and continues to grow in low-income and middle-income countries. This article discusses how the principles behind the successful Malawi model of ART delivery can be applied to the management of other chronic diseases in resource-limited settings and how this paradigm can be used for health systems strengthening
The Path Integral for 1+1-dimensional QCD
We derive a path integral expression for the transition amplitude in
1+1-dimensional QCD starting from canonically quantized QCD. Gauge fixing after
quantization leads to a formulation in terms of gauge invariant but curvilinear
variables. Remainders of the curved space are Jacobians, an effective
potential, and sign factors just as for the problem of a particle in a box.
Based on this result we derive a Faddeev-Popov like expression for the
transition amplitude avoiding standard infinities that are caused by
integrations over gauge equivalent configurations.Comment: 16 pages, LaTeX, 3 PostScript figures, uses epsf.st
A dynamical model for the penumbral fine structure and the Evershed effect in sunspots
Relying on the assumption that the interchange convection of magnetic flux
tubes is the physical cause for the existence of sunspot penumbrae, we propose
a model in which the dynamical evolution of a thin magnetic flux tube
reproduces the Evershed effect and the penumbral fine structure such as bright
and dark filaments and penumbral grains.
According to our model, penumbral grains are the manifestation of the
footpoints of magnetic flux tubes, along which hot subphotospheric plasma flows
upwards with a few km/s. Above the photosphere the hot plasma inside the tube
is cooled by radiative losses as it flows horizontally outwards. As long as the
flowing plasma is hotter than the surroundings, it constitutes a bright radial
filament. The flow confined to a thin elevated channel reaches the temperature
equilibrium with the surrounding atmosphere and becomes optically thin near the
outer edge of the penumbra.
Here, the tube has a height of approximately 100 km above the continuum and
the flow velocity reaches up to 14 km/s. Such a flow channel can reproduce the
observed signatures of the Evershed effect.Comment: 5 pages, 2 figures, accepted for publication in ApJ letter
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Application of molecular SERS nanosensors: where we stand and where we are headed towards?
Molecular specific and highly sensitive detection is the driving force of the surface-enhanced Raman spectroscopy (SERS) community. The technique opens the window to the undisturbed monitoring of cellular processes in situ or to the quantification of small molecular species that do not deliver Raman signals. The smart design of molecular SERS nanosensors makes it possible to indirectly but specifically detect, e.g. reactive oxygen species, carbon monoxide or potentially toxic metal ions. Detection schemes evolved over the years from simple metallic colloidal nanoparticles functionalized with sensing molecules that show uncontrolled aggregation to complex nanostructures with magnetic properties making the analysis of complex environmental samples possible. The present article gives the readership an overview of the present research advancements in the field of molecular SERS sensors, highlighting future trends. © 2020, The Author(s)
More evidence of localization in the low-lying Dirac spectrum
We have extended our computation of the inverse participation ratio of
low-lying (asqtad) Dirac eigenvectors in quenched SU(3). The scaling dimension
of the confining manifold is clearer and very near 3. We have also computed the
2-point correlator which further characterizes the localization.Comment: presented at Lattice2005(Topology and Confinement), Dublin, July
25-30, 2005, 6 pages, 3 figures, to appear in Proceedings of Scienc
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