Asymmetries in t tbar production: LHC versus Tevatron

The measurement of a charge asymmetry in t tbar production at LHC constitutes more than an independent confirmation of the forward-backward asymmetry found at Tevatron. Indeed, both measurements together can be used to identify the source of the asymmetry. This is demonstrated for the case of new Z', W' vector bosons and colour-sextet and triplet scalars, exchanged in t, u channels respectively, and a very heavy axigluon in the s channel.Comment: LaTeX 5 pages. Updated with discussion on implications of summer results. Final version to appear in PR

Intersection between class and gender and its effect on the quality of employment in Chile

Indexación: Web of Science; Scopus.En este artículo se analiza el efecto de la intersección entre clase y género sobre la calidad del empleo en Chile. La medida de posición de clase utilizada está basada en la propuesta de Erik O. Wright y la calidad del empleo en una medida multidimensional, que incluye un índice de condiciones objetivas de empleo y dos índices de condiciones subjetivas (motivación en el trabajo y percepción del control sobre el proceso de trabajo). Los resultados demuestran que la clase y el género determinan diferencias significativas en la calidad objetiva y subjetiva del empleo. Sin embargo, los datos también indican que el género (particularmente, el hecho de ser mujer) no actúa necesariamente como “amplificador” de las desigualdades de clase observadas en el mercado laboral. A partir de esto, al final del artículo se plantean algunas reflexiones sobre cómo opera la intersección entre clase y género en el mercado laboral chileno.This study explores the impact of the intersection between class and gender on the quality of employment in Chile. The method used to measure social class position is based on the work of Erik O. Wright, while, for the quality of employment, a multidimensional measurement was used, including one index for objective working conditions and two indices for subjective ones (motivation on the job and the perception of control over work processes). The results demonstrate that class and gender give rise to signifcant differences in objective and subjective job quality. However, the data also indicate that gender (more specifcally, the fact of being female) does not necessarily amplify the class-based inequalities observed in the labour market. Drawing on these fndings, a number of thoughts about how the class/gender intersection operates in the Chilean labour market are shared in the fnal section of this studyhttp://hdl.handle.net/11362/4079

Ética y política en la filosofía política: clasica, medieval, renacentista y moderna

Ética y política son conceptos oídos normalmente por cualquiera, sin embargo, pocas veces son asociados sino es para reprochar, respectivamente, su falta de una a la otra. En general en ciencia política se suelen separar, aludiendo que cada una tiene menesteres que resolver. A pesar de que el tema ha dado mucho de qué hablar, no todo está dicho, es decir, subsisten muchas interrogantes aún pendientes de resolver, así como muchos temas sobre los cuales discurrir; de tal suerte esta situación incita e invita a querer conocer más entorno a la relación entre ética y política, con el objetivo de comprender qué correspondencia tienen en realidad. El por qué de la investigación está asociado a las vivencias comunes, ellas generan creencias, creencias que se transforman en prejuicios de cómo se configura la realidad, dando por sentado, en especificó, que la ética y la política no se relacionan profundamente. Puesto así, la finalidad de este estudio es analizar y valorar la injerencia de la ética en la política en sentido ontológico, epistemológico y axiológico. Saber qué ideas hay de ética y de política es por tanto imprescindible para la investigación, sin embargo, tal pretensión no es nada pequeña y requiere la generación de marco teórico consistente que sirva como basamento de la investigación; en este sentido, la orientación adoptada hace eco de lo planteado por Giovanni Sartori: ―una ciencia en sus primeros pasos, debe volver a los comienzos de la ciencia que adoptó como modelo‖ (Sartori, 2011, p. 9). Por tanto, partiendo de la creencia sustentada de que la política y la ética debían estar separadas

Asymmetries in top quark pair production at hadron colliders

We review the asymmetries in top quark pair production at the Tevatron and the LHC. We summarize the experimental measurements and the interpretations of a possible excess in terms of new physics. We also review other top quark properties-emphasizing effects related to the $t \bar t$ asymmetries-as well as other collider signals.Comment: RevTeX 40 pages. Final version to be published in Reviews of Modern Physics, with several addition

Computational Protein Design and Molecular Dynamics Simulations: A Study of Membrane Proteins, Small Peptides and Molecular Systems

Molecular design and modeling can provide stringent assessment of our understanding of the structure and function of proteins. Due to the subtleness of the interactions that largely stabilize proteins, computational methods have been particularly valuable in establishing practical, formal and physically grounded protocols to study the structure and function of these biomolecules. Especifically, computational protein design seeks to identify sequences that fold into a desired structure and have specific structural and functional properties using computational methodologies. Among current techniques, an entropy-based formalism that efficiently determines the number and composition of sequences satisfying a predefined set of constraints seems particularly promising and powerful. Complementary to this methodology are the well-established molecular dynamics simulation techniques that have been extensively used to study structure, function and dynamics of biologically relevant systems. Herein different studies of systems using computational techniques to address particular molecular problems are described. Efforts to redesign membrane proteins to generate water-soluble variants were applied to a widely studied pentameric ligand-gated ion channel, the nicotinic acetylchoilne receptor (nAChR). NMR structures and binding studies demostrated the robustness and applicability of the computational design approach. Toward the creation of water-soluble variants of a G protein–coupled receptor (GPCR), comparative modeling and docking calculations were used to investigate the structure of the human μ opioid receptor and presented in light of previous mutagenesis studies of structure and agonist-induced activation. Candidate peptides for possible therapeutic agents were computationally analyzed. Peptide design, loop modeling and MD simulations were applied to investigate the stromal cell-derived factor-1&a; (SDF-1&a;). SDF-1&a; displays promising therapeutic benefits to treat blood-supply related heart disease and elicit growth of microvasculature. Simplified analogs of SDF-1&a; exhibit enhanced therapeutic properties in cell-based assays. MD simulations provide insights about the molecular features of this enhancement. One simplified peptide offers a potentially clinically translatable neovasculogenic therapy. Lastly, MD simulations were utilized to analyze a molecule with hindered internal rotors, a tribenzylamine hemicryptophane. The molecule was characterized by different experimental and computational techniques. The structural and dynamic features of the hemicryptophane molecule make it an attractive starting point for controlling internal rotation of aromatic rings within molecular systems

Lessons from Chile: protesting the state of education

On the second day of industrial action, as staff and students from UK universities participate in record numbers, Daniela Perez Aguilar and Cristóbal Villalobos Dintrans shed light on the Chilean approach to resistance drawing important comparisons between the participants and strategies for protest in the two countries

Brazilian foreign policy in health during Ddilma Rrousseff's administration (2011-2014)

Abstract This article analyses changes and continuities in Brazilian international actions in the field of public health, aiming at understanding how the Brazilian foreign policy in health during President Dilma Rousseff's first term (2011-2014) was developed. Available data from President Luiz Inácio Lula da Silva (2003-2010) years and Dilma's first term were used for comparative purposes. Emphasis was given on South-South cooperation projects, more specifically the Union of South American Countries (USAN, Unión de Naciones Suramericanas - Unasur) and to the Community of Portuguese-speaking Countries (CPLP). Brazilian behavior in international fora, such as the World Health Organization, was analyzed as well, with the purpose of understanding how such behavior evolved. In addition, domestic issues were considered. In this case, the coordination among different actors of the Brazilian Executive Power received due attention. Findings suggest that there has been downfall and even decline in the Government's foreign health policy

Sexual pheromone modulates the frequency of cytosolic Ca2+ bursts in Saccharomyces cerevisiae

Transient and highly regulated elevations of cytosolic Ca2+ control a variety of cellular processes. Bulk measurements using radioactive Ca2+ and the luminescent sensor aequorin have shown that in response to pheromone, budding yeast cells experience a rise of cytosolic Ca2+ that is mediated by two import systems composed by the Mid1-Cch1-Ecm7 protein complex, and the Fig 1 protein. Although this response has been largely studied, there is no report on Ca2+ dynamics at the single cell level. Here, using protein calcium indicators we show that both vegetative and pheromone-treated yeast cells exhibit discrete and asynchronous Ca2+ bursts. Most bursts reach maximal amplitude in 1-10 secs, span between 7 and 30 secs and decay fitting a single exponential model. In vegetative cells bursts are scarce but preferentially occur when cells are transitioning G1 and S phase. Upon pheromone presence Ca2+ burst occurrence increases dramatically, persisting during cell growth polarization. Pheromone concentration modulates burst frequency in a mechanism that depends on Mid1, Fig 1 and a third, still unidentified, import system. We also show that the calcineurin-responsive transcription factor Crz1 experiences nuclear localization bursts during the pheromone response.Fil: Carbo, Natalia. Instituto Pasteur de Montevideo; UruguayFil: Tarkowski, Nahuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Perez Ipiña, Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Ponce Dawson, Silvina Martha. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Aguilar, Pablo Sebastián. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin