587 research outputs found
Gentle Perturbations of the Free Bose Gas I
It is demonstrated that the thermal structure of the noncritical free Bose
Gas is completely described by certain periodic generalized Gaussian stochastic
process or equivalently by certain periodic generalized Gaussian random field.
Elementary properties of this Gaussian stochastic thermal structure have been
established. Gentle perturbations of several types of the free thermal
stochastic structure are studied. In particular new models of non-Gaussian
thermal structures have been constructed and a new functional integral
representation of the corresponding euclidean-time Green functions have been
obtained rigorously.Comment: 51 pages, LaTeX fil
Cold Dark Matter in SUSY Theories. The Role of Nuclear Form Factors and the Folding with the LSP Velocity
The momentum transfer dependence of the total cross section for elastic
scattering of cold dark matter candidates, i.e. lightest supersymmetric
particle (LSP), with nuclei is examined. The presented calculations of the
event rates refer to a number of representative nuclear targets throughout the
periodic table and have been obtained in a relatively wide phenomenologically
allowed SUSY parameter space. For the coherent cross sections it is shown that,
since the momentum transfer can be quite big for large mass of the LSP and
heavy nuclei even though the energy transfer is small (), the
total cross section can in such instances be reduced by a factor of about five.
For the spin induced cross section of odd-A nuclear targets, as is the case of
studied in this work, we found that the reduction is less
pronounced, since the high multipoles tend to enhance the cross section as the
momentum transfer increases (for LSP ) and partially cancell
the momentum retardation. The effect of the Earth's revolution around the sun
on these event rates is also studied by folding with a Maxwellian LSP-velocity
distribution which is consistent with its density in the halos. We thus found
that the convoluted event rates do not appreciably change compared to those
obtained with an average velocity. The event rates increase with A and, in the
SUSY parameter space considered, they can reach values up to 140
for Pb. The modulation effect, however, was found to be small
(less than ).Comment: 23 LATEX pages, 4 Tables, 3 PostScript Figures included. Phys. Rev.
D, to be publishe
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Outcomes in patients with gunshot wounds to the brain.
Introduction:Gunshot wounds to the brain (GSWB) confer high lethality and uncertain recovery. It is unclear which patients benefit from aggressive resuscitation, and furthermore whether patients with GSWB undergoing cardiopulmonary resuscitation (CPR) have potential for survival or organ donation. Therefore, we sought to determine the rates of survival and organ donation, as well as identify factors associated with both outcomes in patients with GSWB undergoing CPR. Methods:We performed a retrospective, multicenter study at 25 US trauma centers including dates between June 1, 2011 and December 31, 2017. Patients were included if they suffered isolated GSWB and required CPR at a referring hospital, in the field, or in the trauma resuscitation room. Patients were excluded for significant torso or extremity injuries, or if pregnant. Binomial regression models were used to determine predictors of survival/organ donation. Results:825 patients met study criteria; the majority were male (87.6%) with a mean age of 36.5 years. Most (67%) underwent CPR in the field and 2.1% (n=17) survived to discharge. Of the non-survivors, 17.5% (n=141) were considered eligible donors, with a donation rate of 58.9% (n=83) in this group. Regression models found several predictors of survival. Hormone replacement was predictive of both survival and organ donation. Conclusion:We found that GSWB requiring CPR during trauma resuscitation was associated with a 2.1% survival rate and overall organ donation rate of 10.3%. Several factors appear to be favorably associated with survival, although predictions are uncertain due to the low number of survivors in this patient population. Hormone replacement was predictive of both survival and organ donation. These results are a starting point for determining appropriate treatment algorithms for this devastating clinical condition. Level of evidence:Level II
Mapping Exoplanets
The varied surfaces and atmospheres of planets make them interesting places
to live, explore, and study from afar. Unfortunately, the great distance to
exoplanets makes it impossible to resolve their disk with current or near-term
technology. It is still possible, however, to deduce spatial inhomogeneities in
exoplanets provided that different regions are visible at different
times---this can be due to rotation, orbital motion, and occultations by a
star, planet, or moon. Astronomers have so far constructed maps of thermal
emission and albedo for short period giant planets. These maps constrain
atmospheric dynamics and cloud patterns in exotic atmospheres. In the future,
exo-cartography could yield surface maps of terrestrial planets, hinting at the
geophysical and geochemical processes that shape them.Comment: Updated chapter for Handbook of Exoplanets, eds. Deeg & Belmonte. 17
pages, including 6 figures and 4 pages of reference
Prevalence and influence of cys407* Grm2 mutation in Hannover-derived Wistar rats:mGlu2 receptor loss links to alcohol intake, risk taking and emotional behaviour
AbstractModulation of metabotropic glutamate 2 (mGlu2) receptor function has huge potential for treating psychiatric and neurological diseases. Development of drugs acting on mGlu2 receptors depends on the development and use of translatable animal models of disease. We report here a stop codon mutation at cysteine 407 in Grm2 (cys407*) that is common in some Wistar rats. Therefore, researchers in this field need to be aware of strains with this mutation. Our genotypic survey found widespread prevalence of the mutation in commercial Wistar strains, particularly those known as Han Wistar. Such Han Wistar rats are ideal for research into the separate roles of mGlu2 and mGlu3 receptors in CNS function. Previous investigations, unknowingly using such mGlu2 receptor-lacking rats, provide insights into the role of mGlu2 receptors in behaviour. The Grm2 mutant rats, which dominate some selectively bred lines, display characteristics of altered emotionality, impulsivity and risk-related behaviours and increased voluntary alcohol intake compared with their mGlu2 receptor-competent counterparts. In addition, the data further emphasize the potential therapeutic role of mGlu2 receptors in psychiatric and neurological disease, and indicate novel methods of studying the role of mGlu2 and mGlu3 receptors
A Mechanistic Paradigm for Broad-Spectrum Antivirals that Target Virus-Cell Fusion
10.1371/journal.ppat.1003297PLoS Pathogens94
Quantum state preparation and macroscopic entanglement in gravitational-wave detectors
Long-baseline laser-interferometer gravitational-wave detectors are operating
at a factor of 10 (in amplitude) above the standard quantum limit (SQL) within
a broad frequency band. Such a low classical noise budget has already allowed
the creation of a controlled 2.7 kg macroscopic oscillator with an effective
eigenfrequency of 150 Hz and an occupation number of 200. This result, along
with the prospect for further improvements, heralds the new possibility of
experimentally probing macroscopic quantum mechanics (MQM) - quantum mechanical
behavior of objects in the realm of everyday experience - using
gravitational-wave detectors. In this paper, we provide the mathematical
foundation for the first step of a MQM experiment: the preparation of a
macroscopic test mass into a nearly minimum-Heisenberg-limited Gaussian quantum
state, which is possible if the interferometer's classical noise beats the SQL
in a broad frequency band. Our formalism, based on Wiener filtering, allows a
straightforward conversion from the classical noise budget of a laser
interferometer, in terms of noise spectra, into the strategy for quantum state
preparation, and the quality of the prepared state. Using this formalism, we
consider how Gaussian entanglement can be built among two macroscopic test
masses, and the performance of the planned Advanced LIGO interferometers in
quantum-state preparation
Searching for a Stochastic Background of Gravitational Waves with LIGO
The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed
the fourth science run, S4, with significantly improved interferometer
sensitivities with respect to previous runs. Using data acquired during this
science run, we place a limit on the amplitude of a stochastic background of
gravitational waves. For a frequency independent spectrum, the new limit is
. This is currently the most sensitive
result in the frequency range 51-150 Hz, with a factor of 13 improvement over
the previous LIGO result. We discuss complementarity of the new result with
other constraints on a stochastic background of gravitational waves, and we
investigate implications of the new result for different models of this
background.Comment: 37 pages, 16 figure
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
SEARCHING FOR COLD DARK MATTER
The differential cross-section for the elastic scattering of the lightest
supersymmetric particle (LSP) with nuclear targets is calculated in the context
of currently fashionable supersymmetric theories (SUSY). An effective four
fermion interaction is constructed by considering i) exchange ii)s-quark
exchange and iii) Higgs exchange. It is expressed in terms of the form factors
(isoscalar) and and (isovector)
which contain all the information of the underlining theory. Numerical values
were obtained using representative input parameters in the constrained
parameter space of SUSY phenomenology. Both the coherent and for odd-A nuclei
the incoherent (spin) nuclear matrix elements were evaluated for nuclei of
experimental interest. The spin matrix elements tend to dominate for
odd nuclei but the coherent matrix elements become more important in all
other cases. For the coherent part the Higgs contribution competes with the Z-
and s-quark contributions. Cross-sections as high as have been
obtained.Comment: Latex file, 25 pages , 2 figures (available by fax
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