372 research outputs found
Comparison of three methods for measuring psoriasis severity in clinical studies (Part 1 of 2): change during therapy in Psoriasis Area and Severity Index, Static Physician's Global Assessment and Lattice System Physician's Global Assessment
BackgroundAccurate and reliable assessment of changes in psoriasis severity is critical in clinical trials of therapies.ObjectiveTo compare Psoriasis Area and Severity Index (PASI), static Physician's Global Assessment (sPGA), and the Lattice System Physician's Global Assessment (LSâPGA) in a trial of systemic treatments for plaque psoriasis vulgaris and to assess whether they measure change in psoriasis induced by therapy.MethodsPatients were randomized to voclosporin or cyclosporine for 24 weeks (the â24âweekâtreatmentâ group, n = 366), or placebo for 12 weeks followed by voclosporin for 12 weeks (the âinitialâplaceboâ group, n = 89).ResultsAll scoring systems changed in concert and were sensitive enough to detect reductions in severity during placebo therapy as well as with active therapy (P < 0.01 for each measurement). At study onset, there were poorer correlations of sPGA with PASI (r = 0.45) and LSâPGA (r = 0.39) than between PASI and LSâPGA (r = 0.68). After therapy, all correlations were stronger, but sPGA continued to be less well correlated (with PASI, r = 0.85; with LSâPGA, r = 0.79) than LSâPGA with PASI (r = 0.90). Twoâ or threeâstep improvements in LSâPGA showed very good to excellent accuracy in corresponding to PASIâ50 and PASIâ75, respectively, and were more accurate than comparable changes in sPGA.ConclusionPASI, sPGA and LSâPGA are responsive to the varying degrees of improvement in psoriasis induced by either placebo or active therapy. While the three systems capture similar information, each has different reasons for use in a clinical trial.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111966/1/jdv13132.pd
Gravitational field around a screwed superconducting cosmic string in scalar-tensor theories
We obtain the solution that corresponds to a screwed superconducting cosmic
string (SSCS) in the framework of a general scalar-tensor theory including
torsion. We investigate the metric of the SSCS in Brans-Dicke theory with
torsion and analyze the case without torsion. We show that in the case with
torsion the space-time background presents other properties different from that
in which torsion is absent. When the spin vanish, this torsion is a
-gradient and then it propagates outside of the string. We investigate
the effect of torsion on the gravitational force and on the geodesics of a
test-particle moving around the SSCS. The accretion of matter by wakes
formation when a SSCS moves with speed is investigated. We compare our
results with those obtained for cosmic strings in the framework of
scalar-tensor theory.Comment: 22 pages, LaTeX, presented at the "XXII - Encontro Nacional de Fisica
de Particulas e Campos", Sao Lourenco, MG, Brazi
Lorentz-invariant CPT violation
A Lorentz-invariant CPT violation, which may be termed as long-distance CPT
violation in contrast to the familiar short-distance CPT violation, has been
recently proposed. This scheme is based on a non-local interaction vertex and
characterized by an infrared divergent form factor. We show that the Lorentz
covariant -product is consistently defined and the energy-momentum
conservation is preserved in perturbation theory if the path integral is
suitably defined for this non-local theory, although unitarity is generally
lost. It is illustrated that T violation is realized in the decay and formation
processes. It is also argued that the equality of masses and decay widths of
the particle and anti-particle is preserved if the non-local CPT violation is
incorporated either directly or as perturbation by starting with the
conventional CPT-even local Lagrangian. However, we also explicitly show that
the present non-local scheme can induce the splitting of particle and
anti-particle mass eigenvalues if one considers a more general class of
Lagrangians.Comment: 28 pages; note added in proof; version published in Eur. Phys. J. C
(2013) 73: 234
Gravitational field around a time-like current-carrying screwed cosmic string in scalar-tensor theories
In this paper we obtain the space-time generated by a time-like
current-carrying superconducting screwed cosmic string(TCSCS). This
gravitational field is obtained in a modified scalar-tensor theory in the sense
that torsion is taken into account. We show that this solution is comptible
with a torsion field generated by the scalar field . The analysis of
gravitational effects of a TCSCS shows up that the torsion effects that appear
in the physical frame of Jordan-Fierz can be described in a geometric form
given by contorsion term plus a symmetric part which contains the scalar
gradient. As an important application of this solution, we consider the linear
perturbation method developed by Zel'dovich, investigate the accretion of cold
dark matter due to the formation of wakes when a TCSCS moves with speed and
discuss the role played by torsion. Our results are compared with those
obtained for cosmic strings in the framework of scalar-tensor theories without
taking torsion into account.Comment: 21 pages, no figures, Revised Version, presented at the "XXIV-
Encontro Nacional de Fisica de Particulas e Campos ", Caxambu, MG, Brazil, to
appear in Phys. Rev.
The anomalous Higgs-top couplings in the MSSM
The anomalous couplings of the top quark and the Higgs boson has been studied
in an effective theory resulting in the framework of the minimal supersymmetric
extension of the standard model (MSSM) when the heavy fields are integrated
out. Constraints on the parameters of the model from the experimental data on
the ratio are derived.Comment: Latex, 26 pages + 13 ps figures, final version in PR
Supersymmetric Seesaw without Singlet Neutrinos: Neutrino Masses and Lepton-Flavour Violation
We consider the supersymmetric seesaw mechanism induced by the exchange of
heavy SU(2)_W triplet states, rather than `right-handed' neutrino singlets, to
generate neutrino masses. We show that in this scenario the neutrino flavour
structure tested at low-energy in the atmospheric and solar neutrino
experiments is directly inherited from the neutrino Yukawa couplings to the
triplets. This allows us to predict the ratio of the tau --> mu gamma (or tau
--> e gamma) and mu --> e gamma decay rates in terms of the low-energy neutrino
parameters. Moreover, once the model is embedded in a grand unified model,
quark-flavour violation can be linked to lepton-flavour violation.Comment: 26 LaTeX pages, 10 postscript figures, uses epsfig and axodraw.
Comments and references adde
CDMS, Supersymmetry and Extra Dimensions
The CDMS experiment aims to directly detect massive, cold dark matter
particles originating from the Milky Way halo. Charge and lattice excitations
are detected after a particle scatters in a Ge or Si crystal kept at ~30 mK,
allowing to separate nuclear recoils from the dominating electromagnetic
background. The operation of 12 detectors in the Soudan mine for 75 live days
in 2004 delivered no evidence for a signal, yielding stringent limits on dark
matter candidates from supersymmetry and universal extra dimensions. Thirty Ge
and Si detectors are presently installed in the Soudan cryostat, and operating
at base temperature. The run scheduled to start in 2006 is expected to yield a
one order of magnitude increase in dark matter sensitivity.Comment: To be published in the proceedings of the 7th UCLA symposium on
sources and detection of dark matter and dark energy in the universe, Marina
del Rey, Feb 22-24, 200
Resummation of the hadronic tau decay width with the modified Borel transform method
A modified Borel transform of the Adler function is used to resum the
hadronic tau decay width ratio. In contrast to the ordinary Borel transform,
the integrand of the Borel integral is renormalization--scale invariant. We use
an ansatz which explicitly accounts for the structure of the leading infrared
renormalon. Further, we use judiciously chosen conformal transformations for
the Borel variable, in order to map sufficiently away from the origin the other
ultraviolet and infrared renormalon singularities. In addition, we apply Pade
approximants for the corresponding truncated perturbation series of the
modified Borel transform, in order to further accelerate the convergence.
Comparing the results with the presently available experimental data on the tau
hadronic decay width ratio, we obtain . These predictions
virtually agree with those of our previous resummations where we used ordinary
Borel transforms instead.Comment: 32 pages, 2 eps-figures, revtex; minor changes in the formulations; a
typo in Eq.(47) corrected; version as appearing in Phys. Rev.
Calculations of binding energies and masses of heavy quarkonia using renormalon cancellation
We use various methods of Borel integration to calculate the binding ground
energies and masses of b-bbar and t-tbar quarkonia. The methods take into
account the leading infrared renormalon structure of the hard+soft part of the
binding energies E(s), and of the corresponding quark pole masses m_q, where
the contributions of these singularities in M(s) = 2 m_q + E(s) cancel.
Beforehand, we carry out the separation of the binding energy into its
hard+soft and ultrasoft parts. The resummation formalisms are applied to
expansions of m_q and E(s) in terms of quantities which do not involve
renormalon ambiguity, such as MSbar quark mass, and alpha_s. The
renormalization scales are different in calculations of m_q, E(s) and E(us).
The MSbar mass of b quark is extracted, and the binding energies of t-tbar and
the peak (resonance) energies for (t+tbar) production are obtained.Comment: 23 pages, 8 double figures, revtex4; the version to appear in
Phys.Rev.D; extended discussion between Eqs.(25) and (26); the paragraph
between Eqs.(32) and (33) is new and explains the numerical dependence of the
residue parameter on the factorization scale; several new references were
added; acknowledgments were modified; the numerical results are unchange
Characterisation of the muon beams for the Muon Ionisation Cooling Experiment
A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.2â2.3 Ïâmm-rad horizontally and 0.6â1.0 Ïâmm-rad vertically, a horizontal dispersion of 90â190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE
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