448 research outputs found
Robustness and Predictivity of 4 TeV Unification
The stability of the predictions of two of the standard model parameters, and , in a TeV unification model is examined. It is concluded that varying the unification scale between TeV and TeV leaves robust all predictions within reasonable bounds. Choosing TeV gives, at lowest order, accurate predictions at . Flavor-changing effects and deviations from precision electroweak data are discussed
Environmental and workplace contamination in the semiconductor industry: implications for future health of the workforce and community.
The semiconductor industry has been an enormous worldwide growth industry. At the heart of computer and other electronic technological advances, the environment in and around these manufacturing facilities has not been scrutinized to fully detail the health effects to the workers and the community from such exposures. Hazard identification in this industry leads to the conclusion that there are many sources of potential exposure to chemicals including arsenic, solvents, photoactive polymers and other materials. As the size of the semiconductor work force expands, the potential for adverse health effects, ranging from transient irritant symptoms to reproductive effects and cancer, must be determined and control measures instituted. Risk assessments need to be effected for areas where these facilities conduct manufacturing. The predominance of women in the manufacturing areas requires evaluating the exposures to reproductive hazards and outcomes. Arsenic exposures must also be evaluated and minimized, especially for maintenance workers; evaluation for lung and skin cancers is also appropriate
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A Data Driven Approach to Profile Potential SARS-CoV-2 Drug Interactions Using TylerADE
We use a data driven approach on a cleaned adverse drug reaction database to determine the reaction severity of several covid-19 drug combinations currently under investigation. We further examine their safety for vulnerable populations such as individuals 65 years and older. Our key findings include 1. hydroxychloroquine/chloroquine are associated with increased adverse drug event severity versus other drug combinations already not recommended by NIH treatment guidelines, 2. hydroxychloroquine/azithromycin are associated with lower adverse drug event severity among older populations, 3. lopinavir/ritonavir had lower adverse reaction severity among toddlers and 4. the combination of azithromycin, hydroxychloroquine and tocilizumab is safer than its component drugs. While our approach does not consider drug efficacy, it can help prioritize clinical trials for drug combinations by focusing on those with the lowest reaction severity and thus increase potential treatment options for covid-19 patients
Duality without Supersymmetry: The Case of the SO(16)xSO(16) String
We extend strong/weak coupling duality to string theories without spacetime
supersymmetry, and focus on the case of the unique ten-dimensional,
nonsupersymmetric, tachyon-free heterotic string. We
construct a tachyon-free heterotic string model that interpolates smoothly
between this string and the ten-dimensional supersymmetric heterotic
string, and we construct a dual for this interpolating model. We find that the
perturbative massless states of our dual theories precisely match within a
certain range of the interpolation. Further evidence for this proposed duality
comes from a calculation of the one-loop cosmological constant in both
theories, as well as the presence of a soliton in the dual theory. This is
therefore the first known duality relation between nonsupersymmetric
tachyon-free string theories. Using this duality, we then investigate the
perturbative and nonperturbative stability of the string,
and present a conjecture concerning its ultimate fate.Comment: 15 pages, LaTeX, 3 figure
Reexamination of relaxation of spins due to a magnetic field gradient: Identity of the Redfield and Torrey theories
There is an extensive literature on magnetic-gradient-induced spin relaxation. Cates, Schaefer, and Happer, in a seminal publication, have solved the problem in the regime where diffusion theory (the Torrey equation) is applicable using an expansion of the density matrix in diffusion equation eigenfunctions and angular momentum tensors. McGregor has solved the problem in the same regime using a slightly more general formulation using the Redfield theory formulated in terms of the autocorrelation function of the fluctuating field seen by the spins and calculating the correlation functions using the diffusion-theory Green's function. The results of both calculations were shown to agree for a special case. In the present work, we show that the eigenfunction expansion of the Torrey equation yields the expansion of the Green's function for the diffusion equation, thus showing the identity of this approach with that of the Redfield theory. The general solution can also be obtained directly from the Torrey equation for the density matrix. Thus, the physical content of the Redfield and Torrey approaches are identical. We then introduce a more general expression for the position autocorrelation function of particles moving in a closed cell, extending the range of applicability of the theory
Topological Masses From Broken Supersymmetry
We develop a formalism for computing one-loop gravitational corrections to
the effective action of D-branes. In particular, we study bulk to brane
mediation of supersymmetry breaking in models where supersymmetry is broken at
the tree-level in the closed string sector (bulk) by Scherk-Schwarz boundary
conditions, while it is realized on a collection of D-branes in a linear or
non-linear way. We compute the gravitational corrections to the fermion masses
(gauginos or goldstino) induced from the exchange of closed strings,
which are non-vanishing for world-sheets with Euler characteristic -1 (``genus
3/2'') due to a string diagram with one handle and one hole. We show that the
corrections have a topological origin and that in general, for a small
gravitino mass, the induced mass behaves as , with
the gauge coupling. In generic orbifold compactifications however, this
leading term vanishes as a consequence of cancellations caused by discrete
symmetries, and the remainder is exponentially suppressed by a factor of
.Comment: 33 pages, 5 figures. v2 is the final Nuclear Physics B version
including an additional reference and some minor correction
Real Special Geometry
We give a coordinate-free description of real manifolds occurring in certain
four dimensional supergravity theories with antisymmetric tensor fields. The
relevance of the linear multiplets in the compactification of string and
five-brane theories is also discussed.Comment: 10 pgs (TeX with Harvmac), CERN-TH.7211/94, UCLA/94/TEP/14,
POLFIS-TH.01/9
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