51,467 research outputs found
A formal theory of cubical complexes Formal report, 1 Sep. 1968 - 30 Apr. 1969
Algorithm for computation of test failures in cyclic circuit
A Program for the Collection, Storage, and Analysis of Baseline Environmental Data for Cook Inlet, Alaska
The scope of this report is to provide a general, yet comprehensive,
description of the Cook Inlet System which will serve as a
basis for understanding the interrelated natural and man-made factors
governing its future; to present a program of field research studies
for the estuarine environment that will describe the existing state of
the Inlet with respect to the water quality and biota; to provide a
framework whereby the program of studies can be evaluated and redirected
in light of the preliminary results; and, to provide a method of storing
and analyzing the data from the investigations so that it can be made
available to interested parties in the most efficient manner possible.This report was prepared by the Institute of Water Resources of the
University of Alaska for the Alaska Water Laboratory, Federal Water
Pollution Control Administration under Contract No. 14-12-449
Suggestions for Improved Benchmark Scenarios for Higgs-Boson Searches at LEP2
We suggest new benchmark scenarios for the Higgs-boson search at LEP2.
Keeping m_t and M_SUSY fixed, we improve on the definition of the maximal
mixing benchmark scenario defining precisely the values of all MSSM parameters
such that the new m_h^max benchmark scenario yields the parameters which
maximize the value of m_h for a given tan(beta). The corresponding scenario
with vanishing mixing in the scalar top sector is also considered. We propose a
further benchmark scenario with a relatively large value of |mu|, a moderate
value of M_SUSY, and moderate mixing parameters in the scalar top sector. While
the latter scenario yields m_h values that in principle allow to access the
complete M_A-tan(beta)-plane at LEP2, on the other hand it contains parameter
regions where the Higgs-boson detection can be difficult, because of a
suppression of the branching ratio of its decay into bottom quarks.Comment: 9 pages, no figures, Contribution to the Workshop on ``New
Theoretical Developments for Higgs Physics at LEP2'', CERN, October 199
Defect free global minima in Thomson's problem of charges on a sphere
Given unit points charges on the surface of a unit conducting sphere,
what configuration of charges minimizes the Coulombic energy ? Due to an exponential rise in good local minima, finding global
minima for this problem, or even approaches to do so has proven extremely
difficult. For \hbox{} recent theoretical work based on
elasticity theory, and subsequent numerical work has shown, that for --1000 adding dislocation defects to a symmetric icosadeltahedral lattice
lowers the energy. Here we show that in fact this approach holds for all ,
and we give a complete or near complete catalogue of defect free global minima.Comment: Revisions in Tables and Reference
Chandra observations of the HII complex G5.89-0.39 and TeV gamma-ray source HESSJ1800-240B
We present the results of our investigation, using a Chandra X-ray
observation, into the stellar population of the massive star formation region
G5.89-0.39, and its potential connection to the coincident TeV gamma-ray source
HESSJ1800-240B. G5.89-0.39 comprises two separate HII regions G5.89-0.39A and
G5.89-0.39B (an ultra-compact HII region). We identified 159 individual X-ray
point sources in our observation using the source detection algorithm
\texttt{wavdetect}. 35 X-ray sources are associated with the HII complex
G5.89-0.39. The 35 X-ray sources represent an average unabsorbed luminosity
(0.3-10\,keV) of \,erg/s, typical of B7-B5 type stars. The
potential ionising source of G5.89-0.39B known as Feldt's star is possibly
identified in our observation with an unabsorbed X-ray luminosity suggestive of
a B7-B5 star. The stacked energy spectra of these sources is well-fitted with a
single thermal plasma APEC model with kT5\,keV, and column density
N\,cm (A). The residual
(source-subtracted) X-ray emission towards G5.89-0.39A and B is about 30\% and
25\% larger than their respective stacked source luminosities. Assuming this
residual emission is from unresolved stellar sources, the total
B-type-equivalent stellar content in G5.89-0.39A and B would be 75 stars,
consistent with an earlier estimate of the total stellar mass of hot stars in
G5.89-0.39. We have also looked at the variability of the 35 X-ray sources in
G5.89-0.39. Ten of these sources are flagged as being variable. Further studies
are needed to determine the exact causes of the variability, however the
variability could point towards pre-main sequence stars. Such a stellar
population could provide sufficient kinetic energy to account for a part of the
GeV to TeV gamma-ray emission in the source HESSJ1800-240B.Comment: 34 pages, 9 figure
Gene transfer into hepatocytes using asialoglycoprotein receptor mediated endocytosis of DNA complexed with an artificial tetra-antennary galactose ligand
We have constructed an artificial ligand for the hepatocyte-specific asialoglycoprotein receptor for the purpose of generating a synthetic delivery system for DNA. This ligand has a tetra-antennary structure, containing four terminal galactose residues on a branched carrier peptide. The carbohydrate residues of this glycopeptide were introduced by reductive coupling of lactose to the alpha- and epsilon-amino groups of the two N-terminal lysines on the carrier peptide. The C-terminus of the peptide, containing a cysteine separated from the branched N-terminus by a 10 amino acid spacer sequence, was used for conjugation to 3-(2-pyridyldithio)propionate-modified polylysine via disulfide bond formation. Complexes containing plasmid DNA bound to these galactose-polylysine conjugates have been used for asialoglycoprotein receptor-mediated transfer of a luciferase gene into human (HepG2) and murine (BNL CL.2) hepatocyte cell lines. Gene transfer was strongly promoted when amphipathic peptides with pH-controlled membrane-disruption activity, derived from the N-terminal sequence of influenza virus hemagglutinin HA-2, were also present in these DNA complexes. Thus, we have essentially borrowed the small functional domains of two large proteins, asialoglycoprotein and hemagglutinin, and assembled them into a supramolecular complex to generate an efficient gene-transfer system
Exact results for Casimir interactions between dielectric bodies: The weak-coupling or van der Waals Limit
In earlier papers we have applied multiple scattering techniques to calculate
Casimir forces due to scalar fields between different bodies described by delta
function potentials. When the coupling to the potentials became weak,
closed-form results were obtained. We simplify this weak-coupling technique and
apply it to the case of tenuous dielectric bodies, in which case the method
involves the summation of van der Waals (Casimir-Polder) interactions. Once
again exact results for finite bodies can be obtained. We present closed
formulas describing the interaction between spheres and between cylinders, and
between an infinite plate and a retangular slab of finite size. For such a
slab, we consider the torque acting on it, and find non-trivial equilibrium
points can occur.Comment: 4 pages, 3 figure
SUSY-Breaking Parameters from RG Invariants at the LHC
We study Renormalization Group invariant (RGI) quantities in the Minimal
Supersymmetric Standard Model and show that they are a powerful and simple
instrument for testing high scale models of supersymmetry (SUSY)-breaking. For
illustration, we analyze the frameworks of minimal and general gauge mediated
(MGM and GGM) SUSY-breaking, with additional arbitrary soft Higgs mass
parameters at the messenger scale. We show that if a gaugino and two first
generation sfermion soft masses are determined at the LHC, the RGIs lead to MGM
sum rules that yield accurate predictions for the other gaugino and first
generation soft masses. RGIs can also be used to reconstruct the fundamental
MGM parameters (including the messenger scale), calculate the hypercharge
D-term, and find relationships among the third generation and Higgs soft
masses. We then study the extent to which measurements of the full first
generation spectrum at the LHC may distinguish different SUSY-breaking
scenarios. In the case of MGM, although most deviations violate the sum rules
by more than estimated experimental errors, we find a 1-parameter family of GGM
models that satisfy the constraints and produce the same first generation
spectrum. The GGM-MGM degeneracy is lifted by differences in the third
generation masses and the messenger scales.Comment: (v1) 30 pages; (v2) mislabeling in figs 2 and 3 corrected, version
accepted for publication in Phys. Rev.
Implications of sterile neutrinos for medium/long-baseline neutrino experiments and the determination of
We revisit some of the recent neutrino observations and anomalies in the
context of sterile neutrinos. Based on a general parametrization motivated in
the presence of sterile neutrinos, the consistency of the MINOS disappearance
data with additional sterile neutrinos is discussed. We also explore the
implications of sterile neutrinos for the measurement of in this
case. Regarding the determination of , we observe that the existence
of sterile neutrinos may induce a significant modification of the
angle in neutrino appearance experiments like T2K and MINOS, over and above the
ambiguities and degeneracies that are already present in 3-neutrino parameter
extractions. The modification is less significant in reactor neutrino
experiments like Double-CHOOZ, Daya Bay and RENO and therefore the extracted
value when sterile neutrinos are present is close to the one that
would be obtained in the 3-neutrino case. We also conclude that the results
from T2K imply a 90% C.L. lower-bound on , in the "" neutrino
case, which is still within the sensitivity of future reactor neutrino
experiments like Daya Bay, and consistent with the one- range of
recently reported by the Double-CHOOZ experiment. Finally,
we argue that for the recently determined best-fit parameters, the results in
the "" scenario would be very close to the medium/long baseline results
obtained in the "" case analyzed in this work.Comment: 25 pages, 9 figures, revtex4-1. Typos corrected, published versio
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