3,658 research outputs found
Lattice three-gluon vertex in extended kinematics: planar degeneracy
We present novel results for the three-gluon vertex, obtained from an
extensive quenched lattice simulation in the Landau gauge. The simulation
evaluates the transversely projected vertex, spanned on a special tensorial
basis, whose form factors are naturally parametrized in terms of individually
Bose-symmetric variables. Quite interestingly, when evaluated in these
kinematics, the corresponding form factors depend almost exclusively on a
single kinematic variable, formed by the sum of the squares of the three
incoming four-momenta, , , and . Thus, all configurations lying on a
given plane in the coordinate system share, to a high degree
of accuracy, the same form factors, a property that we denominate \emph{planar
degeneracy}. We have confirmed the validity of this property through an
exhaustive study of the set of configurations satisfying the condition , within the range . Moreover, a preliminary exploration
reveals that the planar degeneracy persist in the case of more arbitrary
configurations. This drastic simplification allows for a remarkably compact
description of the main bulk of the data, which is particularly suitable for
future numerical applications. A semi-perturbative analysis reproduces the
lattice findings rather accurately, once the inclusion of a gluon mass has
cured all spurious divergences.Comment: 8 pages, 7 figure
La dimensión política e institucional del Trabajo Social Comunitario en el ámbito local
El presente artículo quiere profundizar en el conocimiento de la acción política en la intervención profesional de los trabajadores sociales en el ámbito local. Para ello, se presentan las respuestas de una investigación empírica en la que se recogió la información relativa a los problemas en la organización de las políticas sociales en los municipios de más de cien mil habitantes de la Comunidad de Madrid (España), y la visión de los representantes políticos de las áreas de Bienestar Social de la Comunidad de Madrid en relación a la importancia del Trabajo Social Comunitario en el ámbito local. Las conclusiones muestran la complementariedad de las dimensiones técnicas y políticas en lo relativo a la implementación de las políticas sociales inclusivas.info:eu-repo/semantics/publishedVersio
Markers linked to the bc-3 gene conditioning resistance to bean common mosaic potyviruses in common bean
Necrotic strains of bean common mosaic potyviruses are becoming increasingly problematic in bean growing areas
of Africa and Europe. Pyramiding epistatic resistance genes provides the most effective long-term strategy for
disease control against all known strains of the virus. Indirect selection using tightly linked markers should facilitate
the breeding of desired epistatic resistance gene combinations. In common bean, the most effective strategy for
broad spectrum control of the bean common mosaic potyviruses is to combine I and bc-3 genes. We describe the
use of near-isogenic lines and segregating populations from different gene pools combined with bulked segregant
analysis to identify markers tightly linked with the recessive bc-3 gene that conditions resistance to all strains of
bean common mosaic necrosis virus. We identified a RAPD marker, OG6595, linked at 3.7 cM from the bc-3, and
the marker was used to confirm the location of bc-3 gene on bean linkage group B6. A codominant AFLP marker,
EACAMCGG-169/172was identified and linked at 3.5 cM from the bc-3 and the AFLP and OG6595 markers flanked the
bc-3 gene. The AFLP marker was converted to the STS marker SEACAMCGG-134/137 which showed co-segregation
with the original AFLP marker. The 134 bp fragment associated with resistance was linked with the bc-3 gene
present in a diverse group of bean genotypes except in two kidney bean lines. The OG6595 marker mapped on B6
supported independence of bc-3 from the I gene located on B2, which provides the opportunity to readily combine
both genes in a single bean cultivar for broad spectrum resistance to bean common mosaic potyviruses
Wave Attenuation by Spartina Saltmarshes in the Chesapeake Bay Under Storm Surge Conditions
This material is based upon work supported by the National Fish and Wildlife Foundation and the U.S. Department of the Interior under grant 43932.This material is also based upon work supported by the National Science Foundation under grant SES‐1331399.This research was also supported in part by the Thomas F. and Kate Miller Jeffress Memorial Trust, Bank of America, Trustee. M. Maza, J.L. Lara, and I.J. Losada are indebted to the Spanish Ministry of Economy and Competitiveness for the funding provided in the RETOS INVESTIGACION 2014 (grant BIA2014‐59718‐R) grant program
Lattice three-gluon vertex in extended kinematics: Planar degeneracy
We present novel results for the three-gluon vertex, obtained from an extensive quenched lattice simulation in the Landau gauge. The simulation evaluates the transversely projected vertex, spanned on a special tensorial basis, whose form factors are naturally parametrized in terms of individually Bose-symmetric variables. Quite interestingly, when evaluated in these kinematics, the corresponding form factors depend almost exclusively on a single kinematic variable, formed by the sum of the squares of the three incoming four-momenta, q, r, and p. Thus, all configurations lying on a given plane in the coordinate system (q2,r2,p2) share, to a high degree of accuracy, the same form factors, a property that we denominate planar degeneracy. We have confirmed the validity of this property through an exhaustive study of the set of configurations satisfying the condition q2=r2, within the range [0,5GeV]. This drastic simplification allows for a remarkably compact description of the main bulk of the data, which is particularly suitable for future numerical applications. A semi-perturbative analysis reproduces the lattice findings rather accurately, once the inclusion of a gluon mass has cured all spurious divergences.The authors thank A. C. Aguilar, G. Eichmann and C. D. Roberts for useful discussions. M.N.F. acknowledges financial support from the FAPESP projects 2017/05685-2 and 2020/12795-1, respectively. J.P. is supported by the Spanish MICINN grant PID2020-113334GB-I00 and the regional Prometeo/2019/087 from the Generalitat Va-lenciana; while F.D.S. and J.R.Q. are by the Spanish MICINN grant PID2019-107844GB-C22 and the regional Andalusian P18-FR-5057. All calculations have been performed at the UPO computing center, C3UPO
Exploiting the potential of bioactive molecules extracted by ultrasounds from avocado peelsfood and nutraceutical applications
Natural bioactive compounds from food waste have fomented interest in food and pharmaceutical industries for the past decade. In this work, it purposed the recovery of bioactive avocado peel extract using an environmentally friendly technique: the ultrasound assisted extraction. The response surface methodology was applied in order to optimize the conditions of the extraction, ethanol-water mixtures and time. The optimized extracts (ethanol 38.46%, 44.06 min, and 50 °C) were chemically characterized by HPLC-ESI-MS and FTIR. Its antioxidant ability, as well as, its effect on cell metabolic activity of normal (L929) and cancer (Caco-2, A549 and HeLa) cell lines were assessed. Aqueous ethanol extracts presented a high content in bioactive compounds with high antioxidant potential. The most representative class of the phenolic compounds found in the avocado peel extract were phenolic acids, such as hydroxybenzoic and hydroxycinnamic acids. Another important chemical group detected were the flavonoids, such as flavanols, flavanonols, flavones, flavanones and chalcone, phenylethanoids and lignans. In terms of its influence on the metabolic activity of normal and cancer cell lines, the extract does not significantly affect normal cells. On the other hand, it can negatively affect cancer cells, particularly HeLa cells. These results clearly demonstrated that ultrasound is a sustainable extraction technique, resulting in extracts with low toxicity in normal cells and with potential application in food, pharmaceutical or nutraceutical sectors.The authors acknowledge the financial support received from “Xunta de Galicia” (GRC
ED431C 2017/62-GRC, and Project ED431F 2020/03). These projects are partially funded by the
FEDER Program of the European Union (“Unha maneira de facer Europa”). This research was also
funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the
strategic funding of UIDB/04469/2020 unit. Beatriz Gullón would like to express her gratitude
to the Spanish Ministry of Economy and Competitiveness for her postdoctoral grant (Reference
RYC2018-026177-I).info:eu-repo/semantics/publishedVersio
Rotation-disk connection for very low mass and substellar objects in the Orion Nebula Cluster
Angular momentum loss requires magnetic interaction between the forming star
and both the circumstellar disk and the magnetically driven outflows. In order
to test these predictions many authors have investigated a rotation-disk
connection in pre-main sequence objects with masses larger than about 0.4Msun.
For brown dwarfs this connection was not investigated as yet because there are
very few samples available. We aim to extend this investigation well down into
the substellar regime for our large sample of BDs in the Orion Nebula Cluster,
for which we have recently measured rotational periods. In order to investigate
a rotation-disk correlation, we derived near-infrared (NIR) excesses for a
sample of 732 periodic variables in the Orion Nebula Cluster with masses
ranging between 1.5-0.02 Msun and whose IJHK colors are available.
Circumstellar NIR excesses were derived from the Delta[I-K] index. We performed
our analysis in three mass bins.We found a rotation-disk correlation in the
high and intermediate mass regime, in which objects with NIR excess tend to
rotate slower than objects without NIR excess. Interestingly, we found no
correlation in the substellar regime. A tight correlation between the
peak-to-peak (ptp) amplitude of the rotational modulation and the NIR excess
was found however for all objects with available ptp values. We discuss
possible scenarios which may explain the lack of rotation-disk connection in
the substellar mass regime. One possible reason could be the strong dependence
of the mass accretion rate on stellar mass in the investigated mass range.Comment: 12 pages, 7 figures, accepted for publication "Astronomy and
Astrophysics
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