560 research outputs found
Controlled flavor violation in the MSSM from a unified flavor symmetry
We study the phenomenology of a unified supersymmetric theory with a flavor
symmetry . The model accommodates quark and lepton masses, mixing
angles and CP phases. In this model, the Dirac and Majorana mass matrices have
a unified texture zero structure in the entry that leads to the
Gatto-Sartori-Tonin relation between the Cabibbo angle and ratios of the masses
in the quark sectors, and to a natural departure from zero of the
angle in the lepton sector. We derive the flavor structures
of the trilinears and soft mass matrices, and show their general
non-universality. This causes large flavor violating effects. As a consequence,
the parameter space for this model is constrained, allowing it to be
(dis)proven by flavor violation searches in the next decade. Although the
results are model specific, we compare them to previous studies to show similar
flavour effects (and associated constraints) are expected in general in
supersymmetric flavor models, and may be used to distinguish them.Comment: 21 pages, 6 figure
Transient Propagation and Scattering of Quasi-Rayleigh Waves in Plates: Quantitative comparison between Pulsed TV-Holography Measurements and FC(Gram) elastodynamic simulations
We study the scattering of transient, high-frequency, narrow-band
quasi-Rayleigh elastic waves by through-thickness holes in aluminum plates, in
the framework of ultrasonic nondestructive testing (NDT) based on full-field
optical detection. Sequences of the instantaneous two-dimensional (2-D)
out-of-plane displacement scattering maps are measured with a self-developed
PTVH system. The corresponding simulated sequences are obtained by means of an
FC(Gram) elastodynamic solver introduced recently, which implements a full
three-dimensional (3D) vector formulation of the direct linear-elasticity
scattering problem. A detailed quantitative comparison between these
experimental and numerical sequences, which is presented here for the first
time, shows very good agreement both in the amplitude and the phase of the
acoustic field in the forward, lateral and backscattering areas. It is thus
suggested that the combination of the PTVH system and the FC(Gram)
elastodynamic solver provides an effective ultrasonic inspection tool for
plate-like structures, with a significant potential for ultrasonic NDT
applications.Comment: 46 pages, 16 figures, corresponding author Jos\'e Carlos
L\'opez-V\'azquez, [email protected]. Changes: 1st, 4th, 5th paragraphs
(intro), 3rd, 4th paragraphs (sec. 4); [59-60] cited only in appendixes; old
ref. [52] removed; misprints corrected in the uncertainty of c_L (subsec.
3.1), citation to fig. 10 (sec. 4), size of images (caption fig.15);
reference to Lam\'e constants removed in subsec. 3.
Muon and electron and lepton masses in flavor models
The stringent experimental bound on is compatible
with a simultaneous and sizable new physics contribution to the electron and
muon anomalous magnetic moments (), only if we
assume a non-trivial flavor structure of the dipole operator coefficients. We
propose a mechanism in which the realization of the correction is
manifestly related to the mass generation through a flavor symmetry. A
radiative flavon correction to the fermion mass gives a contribution to the
anomalous magnetic moment. In this framework, we introduce a chiral enhancement
from a non-trivial quartic coupling of the scalar potential.
We show that the muon and electron anomalies can be simultaneously explained in
a vast region of the parameter space with predicted vector-like mediators of
masses as large as ~TeV.Comment: 18 pages, 3 figures, 2 table
Implications of the Muon g-2 result on the flavour structure of the lepton mass matrix
The confirmation of the discrepancy with the Standard Model predictions in
the anomalous magnetic moment by the Muon g-2 experiment at Fermilab points to
a low scale of new physics. Flavour symmetries broken at low energies can
account for this discrepancy but these models are much more restricted, as they
would also generate off-diagonal entries in the dipole moment matrix.
Therefore, if we assume that the observed discrepancy in the muon is
explained by the contributions of a low-energy flavor symmetry, lepton flavour
violating processes can constrain the structure of the lepton mass matrices and
therefore the flavour symmetries themselves predicting these structures. We
apply these ideas to several discrete flavour symmetries popular in the
leptonic sector, such as , , and .Comment: 21 pages; v3: comments added, typos corrected, version accepted for
publication in EPJ
Numerical modeling and measurement by pulsed television holography of ultrasonic displacement maps in plates with through-thickness defects
We present a novel numerical modeling of ultrasonic Lamb and Rayleigh wave propagation and scattering by through-thickness defects like holes and slots in homogeneous plates, and its experimental verification in both near and far field by a self-developed pulsed TV holography system. In contrast to rigorous vectorial formulation of elasticity theory, our model is based on the 2-D scalar wave equation over the plate surface, with specific boundary conditions in the defects and plate edges. The experimental data include complex amplitude maps of the out-of-plane displacements of the plate surface, obtained by a two-step spatiotemporal Fourier transform method. We find a fair match between the numerical and experimental results, which allows for quantitative characterization of the defects
Bioinformatic identification of cassava miRNAs differentially expressed in response to infection by Xanthomonas axonopodis pv. manihotis
Uso De Un Polímero Hidrófilo A Base De Poliacrilamida Para Mejorar La Eficiencia En El Uso Del Agua
As an alternative in search of new options to reduce overexploitation of groundwater that allow us to increase agricultural profitability in water scarce areas, the behavior of a commercial hydrophilic polymer based in polyacrylamide (PAM) Lluvia solida®, was analyzed by evaluating the polymer hydration capacity. The tests that we used showed that this polymer is capable of absorbing its own weight in 268 times when using distilled water. When salts are dissolved in the water, the polymer reduces its water absorbing capacity, the hydration capacity being lower as the salt content increases, with a water absorption reduction up to 116 times its weight. The polymer hydration capacity also decreases significantly when a complete nutritive solution is used, reducing water absorption up to 55 times its weight; in the presence of divalent (Ca2+ and Mg2+) and monovalent (K+ and NH4 +) cations the polymer hydration capacity reduces proportionally to the cation concentration as an exponential function. Urea did not have any effect in the polymer hydration, thus this fertilizer may be used along with the polymer. The use of this hydrophilic polymer is a tool that improves the water use efficiency but the effect depends on water quality, being reduced by the presence of salts in water
La cuenca del Salado: uso y posibilidades de sus recursos pesqueros.
The fishing resources of the Salado Basin are extraordinary important in the context of the inland waters of Argentina. However, the diversity of landscapes in the basin and the lack of continuity in the regional planning , have made difficult a proper management of the fishing resources. This paper has a general overview of the main aspects related to the fishing fauna of the region, with a natural point of view of the processes and mechanisms of the management. A description of the fishes basin community and the identification of the species with commercial and game interests is included . We describe the different fishing gears used in the province for game, commercial and scientific fishing. We review the criteria of diagnosis of the silver side population as a main resource of fishing interest and under this point of view we propose new outlooks to promote a proper management of the resources and its sustainable use.
We identify the different kinds of fisheries that are common in the basin and we make a survey of the related socioeconomic aspects. Moreover, we analyze the development of a new institutional and regulatory frame in order to optimize the management of the fishing resources. Finally, we define criteria for ordering and conserving such resources and identify conflict points and requirements for its sustainable use in the context of new
proposals for the public policies
Neuroimaging analyses from a randomized, controlled study to evaluate plasma exchange with albumin replacement in mild-to-moderate Alzheimer’s disease: additional results from the AMBAR study
Albumin; Intravenous immunoglobulin; PlasmapheresisAlbúmina; Inmunoglobulina intravenosa; PlasmaféresisAlbúmina; Immunoglobulina intravenosa; PlasmafèresiPurpose
This study was designed to detect structural and functional brain changes in Alzheimer’s disease (AD) patients treated with therapeutic plasma exchange (PE) with albumin replacement, as part of the recent AMBAR phase 2b/3 clinical trial.
Methods
Mild-to-moderate AD patients were randomized into four arms: three arms receiving PE with albumin (one with low-dose albumin, and two with low/high doses of albumin alternated with IVIG), and a placebo (sham PE) arm. All arms underwent 6 weeks of weekly conventional PE followed by 12 months of monthly low-volume PE. Magnetic resonance imaging (MRI) volumetric analyses and regional and statistical parametric mapping (SPM) analysis on 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) were performed.
Results
MRI analyses (n = 198 patients) of selected subcortical structures showed fewer volume changes from baseline to final visit in the high albumin + IVIG treatment group (p < 0.05 in 3 structures vs. 4 to 9 in other groups). The high albumin + IVIG group showed no statistically significant reduction of right hippocampus. SPM 18FDG-PET analyses (n = 213 patients) showed a worsening of metabolic activity in the specific areas affected in AD (posterior cingulate, precuneus, and parieto-temporal regions). The high-albumin + IVIG treatment group showed the greatest metabolic stability over the course of the study, i.e., the smallest percent decline in metabolism (MaskAD), and least progression of defect compared to placebo.
Conclusions
PE with albumin replacement was associated with fewer deleterious changes in subcortical structures and less metabolic decline compared to the typical of the progression of AD. This effect was more marked in the group treated with high albumin + IVIG.The AMBAR study is sponsored by Grifols, a manufacturer of therapeutic human serum albumin and intravenous immune globulin. GC-B, IR, JC-C, DP, MBo, and OLL received direct or indirect funding from Grifols to carry out the study and the preparation of the manuscript
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