2,648 research outputs found
Cosmological energy in a thermo-horizon and the first law
We consider a cosmological horizon, named thermo-horizon, to which are
associated a temperature and an entropy of Bekenstein-Hawking and which obeys
the first law for an energy flow calculated through the corresponding limit
surface. We point out a contradiction between the first law and the definition
of the total energy contained inside the horizon. This contradiction is removed
when the first law is replaced by a Gibbs' equation for a vacuum-like component
associated to the event horizon
Bluefish: A Relational Framework for Graphic Representations
Complex graphic representations -- such as annotated visualizations,
molecular structure diagrams, or Euclidean geometry -- convey information
through overlapping perceptual relations. To author such representations, users
are forced to use rigid, purpose-built tools with limited flexibility and
expressiveness. User interface (UI) frameworks provide only limited relief as
their tree-based models are a poor fit for expressing overlaps. We present
Bluefish, a diagramming framework that extends UI architectures to support
overlapping perceptual relations. Bluefish graphics are instantiated as
relational scenegraphs: hierarchical data structures augmented with adjacency
relations. Authors specify these relations with scoped references to components
found elsewhere in the scenegraph. For layout, Bluefish lazily materializes
necessary coordinate transformations. We demonstrate that Bluefish enables
authoring graphic representations across a diverse range of domains while
preserving the compositional and abstractional affordances of traditional UI
frameworks. Moreover, we show how relational scenegraphs capture previously
latent semantics that can later be retargeted (e.g., for screen reader
accessibility).Comment: 27 pages, 14 figure
Schwarzschild black hole and the generalized second law in phantom-dominated universe
We study the conditions required for validity of the generalized second law
in phantom dominated universe in the presence of Schwarzschild black hole. Our
study is independent of the origin of the phantom like behavior of the
considered universe. We also discuss the generalized second law in the
neighborhood of transition (from quintessence to phantom regime) time. We show
that even for a constant equation of state parameter the generalized second law
may be satisfied provided the temperature is not taken as de Sitter
temperature. It is shown that in models with (only) a transition from
quintessence to phantom regime the generalized second law does not hold in the
transition epoch.Comment: 10 pages, references added, typos corrected, accepted for publication
in Physics Letters
Enrichment in conservative amino acid changes among fixed and standing missense variations in slowly evolving proteins
The process of molecular evolution has many elements that are not yet fully understood. Evolutionary rates are known to vary among protein coding and noncoding DNAs, and most of the observed changes in amino acid or nucleotide sequences are assumed to be non-adaptive by the neutral theory of molecular evolution. However, it remains unclear whether fixed and standing missense changes in slowly evolving proteins are more or less neutral compared to those in fast evolving genes. Here, based on the evolutionary rates as inferred from identity scores between orthologs in human and Rhesus Macaques (Macaca mulatta), we found that the fraction of conservative substitutions between species was significantly higher in their slowly evolving proteins. Similar results were obtained by using four different methods of scoring conservative substitutions, including three that remove the impact of substitution probability, where conservative changes require fewer mutations. We also examined the single nucleotide polymorphisms (SNPs) by using the 1000 Genomes Project data and found that missense SNPs in slowly evolving proteins also had a higher fraction of conservative changes, especially for common SNPs, consistent with more non-conservative substitutions and hence stronger natural selection for SNPs, particularly rare ones, in fast evolving proteins. These results suggest that fixed and standing missense variants in slowly evolving proteins are more likely to be neutral
Superfluidity vs Bose-Einstein condensation in a Bose gas with disorder
We investigate the phenomenon of Bose-Einstein condensation and superfluidity
in a Bose gas at zero temperature with disorder. By using the Diffusion
Monte-Carlo method we calculate the superfluid and the condensate fraction of
the system as a function of density and strength of disorder. In the regime of
weak disorder we find agreement with the analytical results obtained within the
Bogoliubov model. For strong disorder the system enters an unusual regime where
the superfluid fraction is smaller than the condensate fraction.Comment: 4 pages, 4 Postscript figure
Precision Monte Carlo Test of the Hartree-Fock Approximation for a trapped Bose Gas
We compare the semiclassical Hartree-Fock approximation for a trapped Bose
gas to a direct Path Integral Quantum Monte Carlo simulation. The chosen
parameters correspond to current Rb experiments. We observe corrections to the
mean-field density profile. The Path Integral calculation reveals an increase
of the number of condensed particles, which is of the same order as a
previously computed result for a homogeneous system. We discuss the
experimental observability of the effect and propose a method to analyze data
of in-situ experiments.Comment: 4 pages, 3 figures, revte
The sputum microbiome and clinical outcomes in patients with bronchiectasis:a prospective observational study
Pulmonary metastatic colonisation and granulomas in NOX2-deficient mice
Metastasis is the leading cause of death in cancer patients, and successful colonisation of a secondary organ by circulating tumour cells (CTCs) is the rate‐limiting step of this process. We used tail‐vein injection of B16‐F10 melanoma cells into mice to mimic the presence of CTCs and to allow for the assessment of host (microenvironmental) factors that regulate pulmonary metastatic colonisation. We found that mice deficient for the individual subunits of the NADPH oxidase of myeloid cells, NOX2 (encoded by Cyba, Cybb, Ncf1, Ncf2, and Ncf4), all showed decreased pulmonary metastatic colonisation. To understand the role of NOX2 in controlling tumour cell survival in the pulmonary microenvironment, we focused on Cyba‐deficient (Cybatm1a) mice, which showed the most significant decrease in metastatic colonisation. Interestingly, histological assessment of pulmonary metastatic colonisation was not possible in Cybatm1a mice, owing to the presence of large granulomas composed of galectin‐3 (Mac‐2)‐positive macrophages and eosinophilic deposits; granulomas of variable penetrance and severity were also found in Cybatm1a mice that were not injected with melanoma cells, and these contributed to their decreased survival. The decreased pulmonary metastatic colonisation of Cybatm1a mice was not due to any overt defects in vascular permeability, and bone marrow chimaeras confirmed a role for the haematological system in the reduced metastatic colonisation phenotype. Examination of the lymphocyte populations, which are known key regulators of metastatic colonisation, revealed an enhanced proportion of activated T and natural killer cells in the lungs of Cybatm1a mice, relative to controls. The reduced metastatic colonisation, presence of granulomas and altered immune cell populations observed in Cybatm1a lungs were mirrored in Ncf2‐deficient (Ncf2tm1a) mice. Thus, we show that NOX2 deficiency results in both granulomas and the accumulation of antitumoural immune cells in the lungs that probably mediate the decreased pulmonary metastatic colonisation. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland
Quantum Phase Diagram for Homogeneous Bose-Einstein Condensate
We calculate the quantum phase transition for a homogeneous Bose gas in the
plane of s-wave scattering length a_s and temperature T. This is done by
improving a one-loop result near the interaction-free Bose-Einstein critical
temperature T_c^{(0)} with the help of recent high-loop results on the shift of
the critical temperature due to a weak atomic repulsion using variational
perturbation theory. The quantum phase diagram shows a nose above T_c^{(0)}, so
that we predict the existence of a reentrant transition above T_c^{(0)}, where
an increasing repulsion leads to the formation of a condensate.Comment: Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of
paper (including all PS fonts) at
http://www.physik.fu-berlin.de/~kleinert/34
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