11,375 research outputs found
Dilemma and Quantum Battle of Sexes
We analysed quantum version of the game battle of sexes using a general
initial quantum state. For a particular choice of initial entangled quantum
state it is shown that the classical dilemma of the battle of sexes can be
resolved and a unique solution of the game can be obtained.Comment: Revised, Latex, 9 pages, no figure, corresponding author's email:
[email protected]
Relative entropy in 2d Quantum Field Theory, finite-size corrections and irreversibility of the Renormalization Group
The relative entropy in two-dimensional Field Theory is studied for its
application as an irreversible quantity under the Renormalization Group,
relying on a general monotonicity theorem for that quantity previously
established. In the cylinder geometry, interpreted as finite-temperature field
theory, one can define from the relative entropy a monotonic quantity similar
to Zamolodchikov's c function. On the other hand, the one-dimensional quantum
thermodynamic entropy also leads to a monotonic quantity, with different
properties. The relation of thermodynamic quantities with the complex
components of the stress tensor is also established and hence the entropic c
theorems are proposed as analogues of Zamolodchikov's c theorem for the
cylinder geometry.Comment: 5 pages, Latex file, revtex, reorganized to best show the generality
of the results, version to appear in Phys. Rev. Let
Random Fixed Point of Three-Dimensional Random-Bond Ising Models
The fixed-point structure of three-dimensional bond-disordered Ising models
is investigated using the numerical domain-wall renormalization-group method.
It is found that, in the +/-J Ising model, there exists a non-trivial fixed
point along the phase boundary between the paramagnetic and ferromagnetic
phases. The fixed-point Hamiltonian of the +/-J model numerically coincides
with that of the unfrustrated random Ising models, strongly suggesting that
both belong to the same universality class. Another fixed point corresponding
to the multicritical point is also found in the +/-J model. Critical properties
associated with the fixed point are qualitatively consistent with theoretical
predictions.Comment: 4 pages, 5 figures, to be published in Journal of the Physical
Society of Japa
Quantum String Dynamics in the conformal invariant SL(2,R) WZWN Background: Anti-de Sitter Space with Torsion
We consider classical and quantum strings in the conformally invariant
background corresponding to the SL(2,R) WZWN model. This background is locally
anti-de Sitter spacetime with non-vanishing torsion. Conformal invariance is
expressed as the torsion being parallelized. The precise effect of the
conformal invariance on the dynamics of both circular and generic classical
strings is extracted. In particular, the conformal invariance gives rise to a
repulsive interaction of the string with the background which precisely cancels
the dominant attractive term arising from gravity. We perform both
semi-classical and canonical string-quantization, in order to see the effect of
the conformal invariance of the background on the string mass spectrum. Both
approaches yield that the high-mass states are governed by m sim HN (N,`large
integer'), where m is the string mass and H is the Hubble constant. It follows
that the level spacing grows proportionally to N: d(m^2 alpha')/dN sim N, while
the entropy goes like: S sim sqrt{m}. Moreover, it follows that there is no
Hagedorn temperature,so that the partition function is well defined at any
positive temperature. All results are compared with the analogue results in
Anti- de Sitter spacetime, which is a non conformal invariant background.
Conformal invariance simplifies the mathematics of the problem but the physics
remains mainly unchanged. Differences between conformal and non-conformal
backgrounds only appear in the intermediate region of the string spectrum, but
these differences are minor. For low and high masses, the string mass spectra
in conformal and non-conformal backgrounds are identical. Interestingly enough,
conformal invariance fixes the value of the spacetime curvature to be -69/(26
alpha').Comment: Latex file, 23 pages, no figure
Switching to second-line antiretroviral therapy in resource-limited settings: comparison of programmes with and without viral load monitoring.
In high-income countries, viral load is routinely measured to detect failure of antiretroviral therapy (ART) and guide switching to second-line ART. Viral load monitoring is not generally available in resource-limited settings. We examined switching from nonnucleoside reverse transcriptase inhibitor (NNRTI)-based first-line regimens to protease inhibitor-based regimens in Africa, South America and Asia
Modular Invariance of Finite Size Corrections and a Vortex Critical Phase
We analyze a continuous spin Gaussian model on a toroidal triangular lattice
with periods and where the spins carry a representation of the
fundamental group of the torus labeled by phases and . We find the
{\it exact finite size and lattice corrections}, to the partition function ,
for arbitrary mass and phases . Summing over phases gives
the corresponding result for the Ising model. The limits and
do not commute. With the model exhibits a {\it vortex
critical phase} when at least one of the is non-zero. In the continuum or
scaling limit, for arbitrary , the finite size corrections to are
{\it modular invariant} and for the critical phase are given by elliptic theta
functions. In the cylinder limit the ``cylinder charge''
is a non-monotonic function of that ranges from
for to zero for .Comment: 12 pages of Plain TeX with two postscript figure insertions called
torusfg1.ps and torusfg2.ps which can be obtained upon request from
[email protected]
Verapamil-Sensitive Transport of Quinacrine and Methylene Blue via the Plasmodium falciparum Chloroquine Resistance Transporter Reduces the Parasite's Susceptibility to these Tricyclic Drugs.
BACKGROUND: It is becoming increasingly apparent that certain mutations in the Plasmodium falciparum chloroquine resistance transporter (PfCRT) alter the parasite's susceptibility to diverse compounds. Here we investigated the interaction of PfCRT with 3 tricyclic compounds that have been used to treat malaria (quinacrine [QC] and methylene blue [MB]) or to study P. falciparum (acridine orange [AO]). METHODS: We measured the antiplasmodial activities of QC, MB, and AO against chloroquine-resistant and chloroquine-sensitive P. falciparum and determined whether QC and AO affect the accumulation and activity of chloroquine in these parasites. We also assessed the ability of mutant (PfCRT(Dd2)) and wild-type (PfCRT(D10)) variants of the protein to transport QC, MB, and AO when expressed at the surface of Xenopus laevis oocytes. RESULTS: Chloroquine resistance-conferring isoforms of PfCRT reduced the susceptibility of the parasite to QC, MB, and AO. In chloroquine-resistant (but not chloroquine-sensitive) parasites, AO and QC increased the parasite's accumulation of, and susceptibility to, chloroquine. All 3 compounds were shown to bind to PfCRT(Dd2), and the transport of QC and MB via this protein was saturable and inhibited by the chloroquine resistance-reverser verapamil. CONCLUSIONS: Our findings reveal that the PfCRT(Dd2)-mediated transport of tricyclic antimalarials reduces the parasite's susceptibility to these drugs
On Random Bubble Lattices
We study random bubble lattices which can be produced by processes such as
first order phase transitions, and derive characteristics that are important
for understanding the percolation of distinct varieties of bubbles. The results
are relevant to the formation of topological defects as they show that infinite
domain walls and strings will be produced during appropriate first order
transitions, and that the most suitable regular lattice to study defect
formation in three dimensions is a face centered cubic lattice. Another
application of our work is to the distribution of voids in the large-scale
structure of the universe. We argue that the present universe is more akin to a
system undergoing a first-order phase transition than to one that is
crystallizing, as is implicit in the Voronoi foam description. Based on the
picture of a bubbly universe, we predict a mean coordination number for the
voids of 13.4. The mean coordination number may also be used as a tool to
distinguish between different scenarios for structure formation.Comment: several modifications including new abstract, comparison with froth
models, asymptotics of coordination number distribution, further discussion
of biased defects, and relevance to large-scale structur
Ear and hearing care programs for First Nations children: a scoping review
Background: Ear and hearing care programs are critical to early detection and management of otitis media (or middle ear disease). Otitis media and associated hearing loss disproportionately impacts First Nations children. This affects speech and language development, social and cognitive development and, in turn, education and life outcomes. This scoping review aimed to better understand how ear and hearing care programs for First Nations children in high-income colonial-settler countries aimed to reduce the burden of otitis media and increase equitable access to care. Specifically, the review aimed to chart program strategies, map the focus of each program against 4 parts of a care pathway (prevention, detection, diagnosis/management, rehabilitation), and to identify the factors that indicated the longer-term sustainability and success of programs. Method: A database search was conducted in March 2021 using Medline, Embase, Global Health, APA PsycInfo, CINAHL, Web of Science Core Collection, Scopus, and Academic Search Premier. Programs were eligible or inclusion if they had either been developed or run at any time between January 2010 to March 2021. Search terms encompassed terms such as First Nations children, ear and hearing care, and health programs, initiatives, campaigns, and services. Results: Twenty-seven articles met the criteria to be included in the review and described a total of twenty-one ear and hearing care programs. Programs employed strategies to: (i) connect patients to specialist services, (ii) improve cultural safety of services, and (iii) increase access to ear and hearing care services. However, program evaluation measures were limited to outputs or the evaluation of service-level outcome, rather than patient-based outcomes. Factors which contributed to program sustainability included funding and community involvement although these were limited in many cases. Conclusion: The result of this study highlighted that programs primarily operate at two points along the care pathway—detection and diagnosis/management, presumably where the greatest need lies. Targeted strategies were used to address these, some which were limited in their approach. The success of many programs are evaluated as outputs, and many programs rely on funding sources which can potentially limit longer-term sustainability. Finally, the involvement of First Nations people and communities typically only occurred during implementation rather than across the development of the program. Future programs should be embedded within a connected system of care and tied to existing policies and funding streams to ensure long term viability. Programs should be governed and evaluated by First Nations communities to further ensure programs are sustainable and are designed to meet community needs
Gauged Yukawa Matrix Models and 2-Dimensional Lattice Theories
We argue that chiral symmetry breaking in three dimensional QCD can be
identified with N\'eel order in 2-dimensional quantum antiferromagnets. When
operators which drive the chiral transition are added to these theories, we
postulate that the resulting quantum critical behavior is in the universality
class of gauged Yukawa matrix models. As a consequence, the chiral transition
is typically of first order, although for a limited class of parameters it can
be second order with computable critical exponents.Comment: LaTeX, 11 page
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