1,996 research outputs found
Renormalization group evolution of the CKM matrix
We present here the most important ideas, equations and solutions for the
running of all the quark Yukawa couplings and all the elements of the
Cabibbo-Kobayashi-Maskawa matrix, in the approximation of one loop, and up to
order , where is the sine of the Cabibbo
angle. Our purpose is to determine what the evolution of these parameters may
indicate for the physics of the standard model (SM), the minimal supersymmetric
standard model (MSSM) and for the Double Higgs Model (DHM).Comment: Talk given in the X Mexican School of Particles and Fields, Playa del
Carmen, Mexico, 2002. 6 pages, LaTeX, needs aipproc.cls styl
Renormalization Group Equations for the CKM matrix
We derive the one loop renormalization group equations for the
Cabibbo-Kobayashi-Maskawa matrix for the Standard Model, its two Higgs
extension and the minimal supersymmetric extension in a novel way. The derived
equations depend only on a subset of the model parameters of the
renormalization group equations for the quark Yukawa couplings so the CKM
matrix evolution cannot fully test the renormalization group evolution of the
quark Yukawa couplings. From the derived equations we obtain the invariant of
the renormalization group evolution for three models which is the angle
of the unitarity triangle. For the special case of the Standard Model
and its extensions with we demonstrate that also the shape
of the unitarity triangle and the Buras-Wolfenstein parameters
and
are conserved. The invariance of the angles of the unitarity triangle means
that it is not possible to find a model in which the CKM matrix might have a
simple, special form at asymptotic energies.Comment: 9 page
Energy dependence of the quark masses and mixings
The one loop Renormalization Group Equations for the Yukawa couplings of
quarks are solved. From the solution we find the explicit energy dependence on
of the evolution of the {\em down} quark masses from
the grand unification scale down to the top quark mass . These results
together with the earlier published evolution of the {\em up} quark masses
completes the pattern of the evolution of the quark masses. We also find the
energy dependence of the absolute values of the Cabibbo-Kobayashi-Maskawa (CKM)
matrix . The interesting property of the evolution of the CKM matrix
and the ratios of the quark masses: and is that
they all depend on through only one function of energy .Comment: Talk presented at the IX Mexican School on Particles and Fields,
August 9-19, Metepec, Pue., Mexico. To be published in the AIP Conference
Proceedings. 5 pages and 1 eps figure included in the tex
Sperm mobility: mechanisms of fertilizing efficiency, genetic variation and phenotypic relationship with male status in the domestic fowl, Gallus gallus domesticus
When females are sexually promiscuous, sexual selection continues after insemination through sperm
competition and cryptic female choice, and male traits conveying an advantage in competitive fertilization
are selected for. Although individual male and ejaculate traits are known to influence paternity in a competitive
scenario, multiple mechanisms co-occur and interact to determine paternity. The way in which
different traits interact with each other and the mechanisms through which their heritability is maintained
despite selection remain unresolved. In the promiscuous fowl, paternity is determined by the number of
sperm inseminated into a female, which is mediated by male social dominance, and by the quality of the
sperm inseminated, measured as sperm mobility. Here we show that: (i) the number of sperm inseminated
determines how many sperm reach the female sperm-storage sites, and that sperm mobility mediates the
fertilizing efficiency of inseminated sperm, mainly by determining the rate at which sperm are released
from the female storage sites, (ii) like social status, sperm mobility is heritable, and (iii) subdominant
males are significantly more likely to have higher sperm mobility than dominant males. This study indicates
that although the functions of social status and sperm mobility are highly interdependent, the lack of
phenotypic integration of these traits may maintain the variability of male fitness and heritability of fertilizing
efficiency
Circulating anti-galectin-1 antibodies are associated with the severity of ocular disease in autoimmune and infectious uveitis
Galectin (Gal)-1, an endogenous lectin found at sites of immune privilege, plays a critical role in the regulation of the immune response. Therapeutic administration of Gal-1 or its genetic delivery suppresses chronic inflammation in experimental models of autoimmunity. The purpose of this work was to investigate the occurrence of circulating anti-Gal-1 antibodies in patients with autoimmune and infectious uveitis as potential determinant factors of disease progression.Fil: Romero, Marta D.. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Fundación Ver; Argentina. Laboratorio Inmunopatología Investigación y Docencia LIIDO; ArgentinaFil: Muiño, Juan Carlos. Universidad Nacional de Córdoba; Argentina. Fundación Ver; ArgentinaFil: Bianco, German Ariel. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Ferrero, Mercedes. Laboratorio Inmunopatología Investigación y Docencia LIIDO; Argentina. Fundación Ver; ArgentinaFil: Juarez, Claudio P.. Fundación Ver; ArgentinaFil: Luna, José Domingo. Fundación Ver; ArgentinaFil: Rabinovich, Gabriel A.. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin
Design during COVID-19: Agents and allies in the role of designer, digital fabrication and distributed production
During COVID-19 global emergency, designers proposed solutions at different scales, as quick responses to demands from different agents. In the same way, we critically analyzed the emergence of allies, protocols and tools, which allowed the optimization of fabrication, from traditional manufacturing into distributed co-production. The analyzed local networks produced global co-design experiences, with involvement of FabLabs and users from different disciplines. Through case studies and the evaluation of surveys and testimonials from users and makers, we analyze the global panorama, to finally explore the specific situation in Latin America. This establishes a relationship between medical demand and digital fabrication, which allows evidence of positive and negative situations to be consider as new, significant aspects for the design in the future. The leading role acquired by the ecosystem surrounding digital fabrication during the pandemic, could enhance its processes in the search for greater positioning, changing society from within the different communities
Motility of small nematodes in disordered wet granular media
The motility of the worm nematode \textit{Caenorhabditis elegans} is
investigated in shallow, wet granular media as a function of particle size
dispersity and area density (). Surprisingly, we find that the nematode's
propulsion speed is enhanced by the presence of particles in a fluid and is
nearly independent of area density. The undulation speed, often used to
differentiate locomotion gaits, is significantly affected by the bulk material
properties of wet mono- and polydisperse granular media for .
This difference is characterized by a change in the nematode's waveform from
swimming to crawling in dense polydisperse media \textit{only}. This change
highlights the organism's adaptability to subtle differences in local structure
and response between monodisperse and polydisperse media
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