1,853 research outputs found

    State of the art of financial research in Mexico

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    El objetivo de esta investigación consiste en presentar el estado que guarda la investigación en el área financiera, a partir de los trabajos académicos presentados en los tres principales foros que agrupan a una gran parte del sector académico en Ciencias Administrativas en México: Academia de Ciencias Administrativas, Foro de Investigación UNAM-FCA y Congreso de Análisis Organizacional UAM, por un período de 5 años 2003 a 2007. Los hallazgos permiten determinar que ha sido incipiente el alcance de la investigación financiera que se ha desarrollado en México en comparación con los países de Europa y Estados Unidos, el desafío para los investigadores en México es el desarrollo de temáticas como: Finanzas personales, Finanzas del comportamiento e innovación financiera, ya que han sido temas poco estudiados y contextualizados en nuestro medio.The objective of this research is to present the state of research in the financial area, from the scholarly papers presented at the three main forums which bring together much of the academic sector in Mexico Administrative Sciences: Academy of Administrative Sciences , Research Forum FCA-UNAM and UAM Congress Organizational Analysis, for a period of 5 years 2003 to 2007. The findings help determine which was the extent of incipient financial investigation that has developed in Mexico in comparison with the countries of Europe and the United States, the challenge for researchers in Mexico is the development of themes such as: Personal Finance, Finance behavior and financial innovation, as they have been little studied and contextualized issues in our environment

    Enhanced graphene nonlinear response through geometrical plasmon focusing

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    We propose a simple approach to couple light into graphene plasmons and focus these excitations at focal spots of a size determined by the plasmon wavelength, thus producing high optical field enhancement that boosts the nonlinear response of the material. More precisely, we consider a graphene structure in which incident light is coupled to its plasmons at the carbon edges and subsequently focused on a spot of size comparable to the plasmon wavelength. We observe large confinement of graphene plasmons, materializing in small, intense focal spots, in which the extraordinary nonlinear response of this material leads to relatively intense harmonic generation. This result shows the potential of plasmon focusing in suitably edged graphene structures to produce large field confinement and nonlinear response without involving elaborated nanostructuring.Peer ReviewedPostprint (published version

    Effect of being the organizer of a Handball Worl Championship in team perfomance

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    Cuando un equipo actúa como local parece tener cierta ventaja. Este hecho se denomina home advantage (HA) y ha sido muy estudiado en competiciones de liga, pero poco en competiciones de sede única. Se analizaron 4.340 partidos disputados en todos los Campeonatos del Mundo de balonmano disputados hasta 2011. Las variables registradas fueron: partidos ganados, empatados, perdidos, número goles marcados y recibidos y sexo de los competidores. La HA en los Campeonatos del Mundo de balonmano es de 67,9±0,23 para la categoría masculina y de 71,2±0,27 para la femenina. Existe una asociación entre la HA, los puntos obtenidos y la clasificación final del equipo.When a team plays at home seems to get some advantage. This effect is called home advantage (HA) and has been widely studied in league competitions, but little in competitions in a single venue. 4.340 games played in all Handballl World Championships since 1936 to 2011 were analyzed. The variables registered were games won, games drawn, games lost, the number of goals scored and goals against and the gender of the competitors. The HA (mean±sd) in the World Handball Championships is 67.9±0.23, for the male category and 71.2±0.27 for the female. A significant association exists between HA, the points obtained in a competition and the final classification of a team

    Strong plasmon-phonon splitting and hybridization in 2D materials revealed through a self-energy approach

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    We reveal new aspects of the interaction between plasmons and phonons in 2D materials that go beyond a mere shift and increase in plasmon width due to coupling to either intrinsic vibrational modes of the material or phonons in a supporting substrate. More precisely, we predict strong plasmon splitting due to this coupling, resulting in a characteristic avoided crossing scheme. We base our results on a computationally efficient approach consisting in including many-body interactions through the electron self-energy. We specify this formalism for a description of plasmons based upon a tight-binding electron Hamiltonian combined with the random-phase approximation. This approach is accurate provided vertex corrections can be neglected, as is is the case in conventional plasmon-supporting metals and Dirac-fermion systems. We illustrate our method by evaluating plasmonic spectra of doped graphene nanotriangles with varied size, where we predict remarkable peak splittings and other radical modifications in the spectra due to plasmons interactions with intrinsic optical phonons. Our method is equally applicable to other 2D materials and provides a simple approach for investigating coupling of plasmons to phonons, excitons, and other excitations in hybrid thin nanostructures

    Beta interferon restricts the inflammatory potential of CD4+ cells through the boost of the Th2 phenotype, the inhibition of Th17 response and the prevalence of naturally occurring T regulatory cells

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    Beta-interferon (IFN-beta) is a valuable therapy for multiple sclerosis (MS) which is also effective in the animal model of experimental autoimmune encephalomyelitis (EAE). However, the accurate mechanisms to explain its anti-inflammatory activity in the disease are not fully revealed. Available data support that T lymphocytes are among the main cell targets of IFN-beta. We have found that in vitro anti-CD3 stimulation of uncommitted murine naïve T cells under IFN-beta treatment results in skewing the T cell differentiation process towards the T2 phenotype, in a prevention from apoptosis of naturally occurring CD4+ T regulatory cells (nTreg) in correlation with an increase in Bcl-XL expression, and in a decrease of IL-17 expression. Elimination of nTreg from the primary culture of naïve CD4+ cells abolished the down-regulation of IL-17 driven by IFN-beta, what suggests the interaction between Th17 and nTreg subsets. Experiments in EAE induced in SJL mice, showed in vivo evidence for the accumulation of spleen CD4+CD25+GITR+Foxp3+ cells after IFN-beta treatment. On the other hand, treated animals showed a striking decrease of IL-17 expression by peripheral CD4+ cells (Th17) and MBP-specific spinal cord cells. Both the in vivo and in vitro results point out new targets through which IFN-beta could exert its therapeutic action.This work was supported by grants from Plan Nacional de Investigación Científica y Tecnológica (SAF2003-00189), Instituto de Salud Carlos III (FIS-PI061012) and MM Foundation (MPY-1156/07). BB was supported by a grant from Instituto de Salud Carlos III, and FMMS was supported by a grant from MM Foundation.S

    Associations between the duration of active commuting to school and academic achievement in rural Chilean adolescents

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    Background: Habitual active commuting to school may be positively associated with academic achievement. The aim of this study was to examine the relationship between duration of walking or otherwise actively commuting to school and academic achievement. Methods: This cross-sectional study included 389 adolescents from seven rural schools (12-13 years). Mode and duration of active commuting to school (use of active means such as walking or biking to and from school) and screen time were self-reported. Academic achievement was determined by the outcome in basic grades (language and mathematics). Results: Active commuting to school was not associated with higher scores in any grades after adjustment for potential confounders. No evidence was found of interactions between gender and academic achievement, but there was interaction with duration of walking (<30 min, 30-60 min, and >60 min). Adjusted binary logistic regression analysis suggested that adolescents who spent between 30 and 60 min actively commuting were more likely to obtain high academic achievement (language and mathematics). Conclusions: Thirty to 60 min of ACS may have a positive influence on academic achievement in adolescents, so, it is necessary to make recommendations for the children to walk from and/or to school. This could help society to recognize the relevance of physical activity to health as well as to academic performance. © The Author(s). 2017

    Smith-Purcell radiation emission in aperiodic arrays

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    We study the Smith-Purcell light emission produced by electrons moving parallel to linear aperiodic particle arrays. This constitutes a generalization of this type of phenomenon from periodic to aperiodic structures. As in the periodic case, the emission is found to exhibit intense features in its angular and frequency distributions, associated with the condition of constructive interference between the contributions arising from different particles in the array. This condition can also be expressed in terms of momentum conservation involving reciprocal wave-vector transfers from the array. We consider two examples of quasiperiodic and hyperuniform aperiodic arrays that allow us to illustrate this idea. Our study provides insight into the interaction of fast electrons with aperiodic arrays characterized by strong features in reciprocal space, which dominate the electron-array coupling.Postprint (published version

    Measuring home advantage in Spanish Football (1928-2011)

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    Pollard (1986) estableció el procedimiento para analizar la ventaja de jugar en casa, efecto que en términos anglosajones se denomina “home advantage” (HA). La HA ha sido estudiada en multitud de deportes, tanto individuales como de equipo, determinando su existencia y sus posibles causas. Este artículo analiza la HA de la primera división de fútbol español a lo largo de su historia (desde 1928 hasta el 2011). La muestra es de 80 temporadas y 22.015 partidos jugados en las competiciones de liga de máxima categoría española. La HA es de 70,8±0,14 en las máximas categorías del fútbol español en la época en la que el valor de la victoria era de dos puntos (1928-1995) y de 56,7±0,14 cuando se otorgan tres puntos por la victoria (1995-2011Pollard (1986) established the procedure for analyzing the home advantage (HA). The HA has been studied in many different sports, both individual and team sports, determining its existence and its possible causes. This article analyzes the HA of the first division of Spanish football across the history (from 1928 until 2011). The sample is of 80 seasons and 22015 games of the highest level in Spain. The HA (mean±sd) is of 70.8±0.14 in the highest category in Spanish football during the period when a victory was worth two points (1928-1995) and 56.7±0.14 when three points were awarded for a victory (1995-2011

    Characterization of wheat/Aegilops ventricosa introgression and addition lines corresponding to the Mv genome.

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    Stable wheat-Aegilops introgression lines with 42 chromosomes (H-93), derived by repeated selfing from a cross (Triticum turgidum x Aegilops ventricosa) x T. aestivum, have been characterized using the following DNA probes and isozyme markers: (1) single or low-copy DNA fragments from Ae. ventricosa; (2) known cDNA probes corresponding to 1-thionin, monomeric -amylase inhibitor, the CM3 subunit of tetrameric -amylase inhibitor, and sucrose synthase from wheat; (3) anonymous cDNA probes from wheat that have been mapped by Sharp et al. (1989); (4) isozyme markers corresponding to aconitase, shikimate dehydrogenase, adenylate kinase, and endopeptidase. Meiotic metaphases of appropriate hybrids involving selected H-93 lines have been investigated by the Giemsa C-banding technique. The substitution of whole chromosomes [(5A) 5Mv; (4D) 4Mv; (5D) 5Mv; (7D) 7Mv] and chromosomal segments (1Mv; 3Mv; 5Mv; 7Mv) from the Mv genome of Aegilops ventricosa has been demonstrated. The distribution of selected markers among putative wheat-Ae. ventricosa addition lines has also been investigated. The 7Mv addition has been characterized for the first time, while the identity of the previously reported 5Mv and 6Mv additions has been confirmed
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