268 research outputs found
Lattice-Boltzmann Method for Geophysical Plastic Flows
We explore possible applications of the Lattice-Boltzmann Method for the
simulation of geophysical flows. This fluid solver, while successful in other
fields, is still rarely used for geotechnical applications. We show how the
standard method can be modified to represent free-surface realization of
mudflows, debris flows, and in general any plastic flow, through the
implementation of a Bingham constitutive model. The chapter is completed by an
example of a full-scale simulation of a plastic fluid flowing down an inclined
channel and depositing on a flat surface. An application is given, where the
fluid interacts with a vertical obstacle in the channel.Comment: in W. Wu, R.I. Borja (Edts.) Recent advances in modelling landslides
and debris flow, Springer Series in Geomechanics and Geoengineering (2014),
ISBN 978-3-319-11052-3, pp. 131-14
The nucleon's strange electromagnetic and scalar matrix elements
Quenched lattice QCD simulations and quenched chiral perturbation theory are
used together for this study of strangeness in the nucleon. Dependences of the
matrix elements on strange quark mass, valence quark mass and momentum transfer
are discussed in both the lattice and chiral frameworks. The combined results
of this study are in good agreement with existing experimental data and
predictions are made for upcoming experiments. Possible future refinements of
the theoretical method are suggested.Comment: 24 pages, 9 figure
A novel way of constraining WIMPs annihilations in the Sun: MeV neutrinos
Annihilation of dark matter particles accumulated in the Sun would produce a
flux of high-energy neutrinos whose prospects of detection in neutrino
telescopes and detectors have been extensively discussed in the literature.
However, for annihilations into Standard Model particles, there would also be a
flux of neutrinos in the MeV range from the decays at rest of muons and
positively charged pions. These low-energy neutrinos have never been considered
before and they open the possibility to also constrain dark matter annihilation
in the Sun into e+e-, mu+mu- or light quarks. Here we perform a detailed
analysis using the recent Super-Kamiokande data in the few tens of MeV range to
set limits on the WIMP-nucleon scattering cross section for different
annihilation channels and computing the evaporation rate of WIMPs from the Sun
for all values of the scattering cross section in a consistent way.Comment: 26 pages, 7 figures. Substantial additions with further explanations.
Two significant improvements: in the calculation of the evaporation and
capture rates; and in the analysis of the SK data. Minor changes in the
conclusions. It matches published versio
FUV and X-ray absorption in the Warm-Hot Intergalactic Medium
The Warm-Hot Intergalactic Medium (WHIM) arises from shock-heated gas
collapsing in large-scale filaments and probably harbours a substantial
fraction of the baryons in the local Universe. Absorption-line measurements in
the ultraviolet (UV) and in the X-ray band currently represent the best method
to study the WHIM at low redshifts. We here describe the physical properties of
the WHIM and the concepts behind WHIM absorption line measurements of H I and
high ions such as O VI, O VII, and O VIII in the far-ultraviolet and X-ray
band. We review results of recent WHIM absorption line studies carried out with
UV and X-ray satellites such as FUSE, HST, Chandra, and XMM-Newton and discuss
their implications for our knowledge of the WHIM.Comment: 26 pages, 9 figures, accepted for publication in Space Science
Reviews, special issue "Clusters of galaxies: beyond the thermal view",
Editor J.S. Kaastra, Chapter 3; work done by an international team at the
International Space Science Institute (ISSI), Bern, organised by J.S.
Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke
CP violation in in the model III 2HDM
We have calculated the Wilson coefficients (i=1,2) in the
renormalization scheme in the model III 2HDM. Using the obtained
Wilson coefficients, we have analyzed the CP violation in decays (q=d,s) in the model. The CP asymmetry, , depends on the
parameters of models and in can be as large as 40% and
35% for and respectively. It can reach 4% for decays.
Because in SM CP violation is smaller than or equal to O() which is
unobservably small, an observation of CP asymmetry in the decays would unambiguously signal the existence of new physics.Comment: revtex4, 16 pages, 7 figure
Abundances of the elements in the solar system
A review of the abundances and condensation temperatures of the elements and
their nuclides in the solar nebula and in chondritic meteorites. Abundances of
the elements in some neighboring stars are also discussed.Comment: 42 pages, 11 tables, 8 figures, chapter, In Landolt- B\"ornstein, New
Series, Vol. VI/4B, Chap. 4.4, J.E. Tr\"umper (ed.), Berlin, Heidelberg, New
York: Springer-Verlag, p. 560-63
Proteogenomic analysis of human colon cancer reveals new therapeutic opportunities
We performed the first proteogenomic study on a prospectively collected colon cancer cohort. Comparative proteomic and phosphoproteomic analysis of paired tumor and normal adjacent tissues produced a catalog of colon cancer-associated proteins and phosphosites, including known and putative new biomarkers, drug targets, and cancer/testis antigens. Proteogenomic integration not only prioritized genomically inferred targets, such as copy-number drivers and mutation-derived neoantigens, but also yielded novel findings. Phosphoproteomics data associated Rb phosphorylation with increased proliferation and decreased apoptosis in colon cancer, which explains why this classical tumor suppressor is amplified in colon tumors and suggests a rationale for targeting Rb phosphorylation in colon cancer. Proteomics identified an association between decreased CD8 T cell infiltration and increased glycolysis in microsatellite instability-high (MSI-H) tumors, suggesting glycolysis as a potential target to overcome the resistance of MSI-H tumors to immune checkpoint blockade. Proteogenomics presents new avenues for biological discoveries and therapeutic development
Embryonic dormancy in seeds of Bactris gasipaes Kunth (peach-palm)
Bactris gasipaes is a domesticated palm whose fruits are of great importance for the Amazonian people and whose heart of palm is also receiving economic interest in other brazilian and Latin America regions. The aim of this study was verify embryonic dormancy and its correlation with first cataphyll emergence in B. gasipaes seeds collected from four plants at Manaus city and four others at Coari city, both in the Amazonas state, Brazil. After extraction and cleaning, some of the seeds (4 replications of 25 per plant) were sown in a seedbed with a sawdust and sand mixture as substrate, and embryos (4 replications of 10 per plant), after extraction, were inoculated into half strength Murashige and Skoog cultures. Were used 100 seeds and 40 embryo per treatment. Whole seed and embryo germination varied between the different source plants and locations, with the greatest difference observed for the emergence of first cataphyll from seeds in the seedbed. For the most part of variables, results of seed and embryo were positively associated, namely, as one went up the other also, and vice versa. These results suggesting that, at least in part, seed dormancy in Bactris gasipaes is associated with embryonic dormancy. © 2017, Associacao Brasileira de Tecnologia de Sementes. All rights reserved
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