24,523 research outputs found
On the rate of convergence in periodic homogenization of scalar first-order ordinary differential equations
In this paper, we study the rate of convergence in periodic homogenization of
scalar ordinary differential equations. We provide a quantitative error
estimate between the solutions of a first-order ordinary differential equation
with rapidly oscillating coefficients and the limiting homogenized solution. As
an application of our result, we obtain an error estimate for the solution of
some particular linear transport equations
Weak Isospin Violations in Charged and Neutral Higgs Couplings from SUSY Loop Corrections
Supersymmetric QCD and supersymmetric electroweak loop corrections to the
violations of weak isospin to Yukawa couplings are investigated. Specifically
it involves an analysis of the supersymmetric loop corrections to the Higgs
couplings to the third generation quarks and leptons. Here we analyze the SUSY
loop corrections to the charged Higgs couplings which are then compared with
the supersymmetric loop corrections to the neutral Higgs couplings previously
computed. It is found that the weak isospin violations can be quite
significant, i.e, as much as 40-50% or more of the total loop correction to the
Yukawa coupling. The effects of CP phases are also studied and it is found that
these effects can either enhance or suppress the weak isospin violations. We
also investigate the weak isospin violation effects on the branching ratio
and show that the effects
are sensitive to CP phases. Thus an accurate measurement of this branching
ratio along with the branching ratio of the neutral Higgs boson decays can
provide a measure of weak isospin violation along with providing a clue to the
presence of supersymmetry.Comment: 20 pages, 9 figure
Examining the cancellation mechanism of neutron EDM in a model with dilaton-dominated susy breaking
We examine the cancellation mechanism between the different contributions to
the electric dipole moment of the neutron in a model with dilaton-dominated
SUSY breaking. We find these accidental cancellations occur at few points in
parameter space. For a wide region of this space we must constrain the phase of
to be of order and have the phases of and strongly
correlated in order to have small neutron EDM. Moreover, we consider the
indirect CP violation parameter in this region where the electric
dipole moment is less than the experimental limit and find that we can generate
of order
A Note on Univalent Functions with Finitely many Coefficients
MSC 2010: 30C45The main object of this article is to introduce sufficient conditions of
univalency for a class of analytic functions with finitely many coefficients
defined by approximate functions due to Suffridge on the unit disk of the
complex plane whose image is saddle-shaped. Sandwich theorem is also
discussed
CP-odd Phase Correlations and Electric Dipole Moments
We revisit the constraints imposed by electric dipole moments (EDMs) of
nucleons and heavy atoms on new CP-violating sources within supersymmetric
theories. We point out that certain two-loop renormalization group corrections
induce significant mixing between the basis-invariant CP-odd phases. In the
framework of the constrained minimal supersymmetric standard model (CMSSM), the
CP-odd invariant related to the soft trilinear A-phase at the GUT scale,
theta_A, induces non-trivial and distinct CP-odd phases for the three gaugino
masses at the weak scale. The latter give one-loop contributions to EDMs
enhanced by tan beta, and can provide the dominant contribution to the electron
EDM induced by theta_A. We perform a detailed analysis of the EDM constraints
within the CMSSM, exhibiting the reach, in terms of sparticle spectra, which
may be obtained assuming generic phases, as well as the limits on the CP-odd
phases for some specific parameter points where detailed phenomenological
studies are available. We also illustrate how this reach will expand with
results from the next generation of experiments which are currently in
development.Comment: 31 pages, 21 eps figures; v2: additional remarks on 2-loop threshold
corrections and references added; v3: typos corrected, to appear in Phys.
Rev.
Large evolution of the bilinear Higgs coupling parameter in SUSY models and reduction of phase sensitivity
The phases in a generic low-energy supersymmetric model are severely
constrained by the experimental upper bounds on the electric dipole moments of
the electron and the neutron. Coupled with the requirement of radiative
electroweak symmetry breaking, this results in a large degree of fine tuning of
the phase parameters at the unification scale. In supergravity type models,
this corresponds to very highly tuned values for the phases of the bilinear
Higgs coupling parameter and the universal trilinear coupling . We
identify a cancellation/enhancement mechanism associated with the
renormalization group evolution of , which, in turn, reduces such
fine-tuning quite appreciably without taking recourse to very large masses for
the supersymmetric partners. We find a significant amount of reduction of this
fine-tuning in nonuniversal gaugino mass models that do not introduce any new
phases.Comment: Version to appear in Phys.Rev.D. Insignificant changes like a few
typos corrected. 26 pages, 7 figures, LaTe
Future Community-Based Ecotourism (CBET) development
Ecotourism is an alternative form of tourism and is usually confused with natural and cultural tourism.CBET is fast becoming a popular biodiversity conservation tool that develops and benefits the local community. Based on the context of conservation theory and practice, Community-Based Ecotourism (CBET) is a form of community-based natural resource management. However, a sustainable CBET development through Community Capacity Building (CCB)programs is not something that it easily achievable. Local community’s capacity varies from one culture to another. It takes a high level of community participation, in order for it to come to a level where the community members themselves are motivated to participate and contribute to the development of the program. This fully qualitative research involved 15 respondents from the community of Kg. Selai, Bekok in Johor, Malaysia. The result show there are five factors that sustained the ecotourism development based for Orang Asli Community in Kg. Selai, namely, existing CBET development, past CBET development, local community participation in planning stage of tourism, local participation in implementation stage of tourism and participation in nature conservation
Solving modal equations of motion with initial conditions using MSC/NASTRAN DMAP. Part 1: Implementing exact mode superposition
Within the MSC/NASTRAN DMAP (Direct Matrix Abstraction Program) module TRD1, solving physical (coupled) or modal (uncoupled) transient equations of motion is performed using the Newmark-Beta or mode superposition algorithms, respectively. For equations of motion with initial conditions, only the Newmark-Beta integration routine has been available in MSC/NASTRAN solution sequences for solving physical systems and in custom DMAP sequences or alters for solving modal systems. In some cases, one difficulty with using the Newmark-Beta method is that the process of selecting suitable integration time steps for obtaining acceptable results is lengthy. In addition, when very small step sizes are required, a large amount of time can be spent integrating the equations of motion. For certain aerospace applications, a significant time savings can be realized when the equations of motion are solved using an exact integration routine instead of the Newmark-Beta numerical algorithm. In order to solve modal equations of motion with initial conditions and take advantage of efficiencies gained when using uncoupled solution algorithms (like that within TRD1), an exact mode superposition method using MSC/NASTRAN DMAP has been developed and successfully implemented as an enhancement to an existing coupled loads methodology at the NASA Lewis Research Center
Electron and Neutron Electric Dipole Moments in the Focus Point Scenario of SUGRA Model
We estimate the electron and neutron electric dipole moments in the focus
point scenario of the minimal SUGRA model corresponding to large sfermion
masses and moderate to large . There is a viable region of moderate
fine-tuning in the parameter space, around , where the
experimental limits on these electric dipole moments can be satisfied without
assuming unnaturally small phase angles. But the fine-tuning constraints become
more severe for .Comment: 16 pages, LaTeX, 4 postscript figures. Very minor changes made in
only a few sentences for clarification. Final version to appear in Phys. Rev.
PD-L1 testing for lung cancer in the UK: recognizing the challenges for implementation.
A new approach to the management of non-small-cell lung cancer (NSCLC) has recently emerged that works by manipulating the immune checkpoint controlled by programmed death receptor 1 (PD-1) and its ligand programmed death ligand 1 (PD-L1). Several drugs targeting PD-1 (pembrolizumab and nivolumab) or PD-L1 (atezolizumab, durvalumab, and avelumab) have been approved or are in the late stages of development. Inevitably, the introduction of these drugs will put pressure on healthcare systems, and there is a need to stratify patients to identify those who are most likely to benefit from such treatment. There is evidence that responsiveness to PD-1 inhibitors may be predicted by expression of PD-L1 on neoplastic cells. Hence, there is considerable interest in using PD-L1 immunohistochemical staining to guide the use of PD-1-targeted treatments in patients with NSCLC. This article reviews the current knowledge about PD-L1 testing, and identifies current research requirements. Key factors to consider include the source and timing of sample collection, pre-analytical steps (sample tracking, fixation, tissue processing, sectioning, and tissue prioritization), analytical decisions (choice of biomarker assay/kit and automated staining platform, with verification of standardized assays or validation of laboratory-devised techniques, internal and external quality assurance, and audit), and reporting and interpretation of the results. This review addresses the need for integration of PD-L1 immunohistochemistry with other tests as part of locally agreed pathways and protocols. There remain areas of uncertainty, and guidance should be updated regularly as new information becomes available
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