12,786 research outputs found
The (strong) Liouville property for a class of non-local operators
We prove a necessary and sufficient condition for the Liouville and strong
Liouville properties of the infinitesimal generator of a L\'evy process and
subordinate L\'evy processes. Combining our criterion with the necessary and
sufficient condition obtained by Alibaud et al., we obtain a characterization
of (orthogonal subgroup of) the set of zeros of the characteristic exponent of
the L\'evy process.Comment: arXiv admin note: text overlap with arXiv:1909.0123
Harmonic coordinate method for simulating generic singularities
This paper presents both a numerical method for general relativity and an
application of that method. The method involves the use of harmonic coordinates
in a 3+1 code to evolve the Einstein equations with scalar field matter. In
such coordinates, the terms in Einstein's equations with the highest number of
derivatives take a form similar to that of the wave equation. The application
is an exploration of the generic approach to the singularity for this type of
matter. The preliminary results indicate that the dynamics as one approaches
the singularity is locally the dynamics of the Kasner spacetimes.Comment: 5 pages, 4 figures, Revtex, discussion expanded, references adde
Cloning the \u3cem\u3ebchZ\u3c/em\u3e Gene from \u3cem\u3eChloroflexus Aurantiacus\u3c/em\u3e
The GeoClaw software for depth-averaged flows with adaptive refinement
Many geophysical flow or wave propagation problems can be modeled with
two-dimensional depth-averaged equations, of which the shallow water equations
are the simplest example. We describe the GeoClaw software that has been
designed to solve problems of this nature, consisting of open source Fortran
programs together with Python tools for the user interface and flow
visualization. This software uses high-resolution shock-capturing finite volume
methods on logically rectangular grids, including latitude--longitude grids on
the sphere. Dry states are handled automatically to model inundation. The code
incorporates adaptive mesh refinement to allow the efficient solution of
large-scale geophysical problems. Examples are given illustrating its use for
modeling tsunamis, dam break problems, and storm surge. Documentation and
download information is available at www.clawpack.org/geoclawComment: 18 pages, 11 figures, Animations and source code for some examples at
http://www.clawpack.org/links/awr10 Significantly modified from original
posting to incorporate suggestions of referee
Increased Yield of ttbb at Hadron Colliders in Low-Energy Supersymmetry
Light bottom squarks and gluinos have been invoked to explain the b quark
pair production excess at the Tevatron. We investigate the associated
production of ttbb at hadron colliders in this scenario, and find that the
rates for this process are enhanced over the Standard Model prediction. If
light gluinos exist, it may be possible to detect them at the Tevatron, and
they could easily be observed at the LHC.Comment: 5p, references added, version accepted to PR
An extension of the Liouville theorem for Fourier multipliers to sub-exponentially growing solutions
We study the equation m(D)ƒ=0 in a large class of sub-exponentially growing functions. Under appropriate restrictions on m ∈ C(Rn), we show that every such solution can be analytically continued to a sub-exponentially growing entire function on Cn if and only if m(ξ)≠0 for ξ≠0
HIFiRE-5 Flight Vehicle Design
The Hypersonic International Flight Research Experimentation (HIFiRE) program is a hypersonic flight test program executed by the Air Force Research Laboratories (AFRL) and Australian Defence Science and Technology Organization (DSTO). HIFiRE flight 5 is devoted to measuring transition on a three-dimensional body. This paper summarizes payload configuration, trajectory, vehicle stability limits and roughness tolerances. Results show that the proposed configuration is suitable for testing transition on a three-dimensional body. Transition is predicted to occur within the test window, and a design has been developed that will allow the vehicle to be manufactured within prescribed roughness tolerance
Update on Transanal NOTES for Rectal Cancer: Transitioning to Human Trials
The feasibility of natural orifice translumenal endoscopic surgery (NOTES) resection for rectal cancer has been demonstrated in both survival swine and fresh human cadaveric models. In preparation for transitioning to human application, our group has performed transanal NOTES rectal resection in a large series of human cadavers. This experience both solidified the feasibility of resection and allowed optimization of technique prior to clinical application. Improvement in specimen length and operative time was demonstrated with increased experience and newer platforms. This extensive laboratory experience has paved the way for successful clinical translation resulting in an ongoing clinical trial. To date, based on published reports, 4 human subjects have undergone successful hybrid transanal NOTES resection of rectal cancer. While promising, instrument limitations continue to hinder a pure transanal approach. Careful patient selection and continued development of new endoscopic and flexible-tip instruments are imperative prior to pure NOTES clinical application
The 30-bp Deletion Variant of Epstein-Barr Virus-Encoded Latent Membrane Protein-1 Prevails in Acute Infectious Mononucleosis
To assess the frequency of malignancy-associated 30-bp deletion variants of the latent membrane protein 1 (LMP-1) in benign conditions, a comparative sequence analysis was done using samples from 20 American children with acute infectious mononucleosis and 16 Swiss children with chronic tonsillar hyperplasia. The 30-bp deletion variant (LMP-1-del) was present in 66% of patients (12/20 with infectious mononucleosis and 12/16 with tonsillar hyperplasia). Two additional patients had a 3-bp deletion and an inframe insertion of 18 nucleotides, respectively. All but 1 isolate had numerous nonsilent point mutations. These data identify a hypervariable region within the Cterminus of LMP-1, in a domain required for maximal stimulation of NF-κB activity. These data demonstrate that LMP-1-del variants are frequent in acute infectious mononucleosis and tonsillar hyperplasia and identical to those observed in Epstein-Barr virus-associated AIDS-related lymphom
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