Neutrino masses and mixing in A4 models with three Higgs doublets

We study neutrino masses and mixing in the context of flavor models with A4 symmetry, three scalar doublets in the triplet representation, and three lepton families. We show that there is no representation assignment that yields a dimension-five mass operator consistent with experiment. We then consider a type-I seesaw with three heavy right-handed neutrinos, explaining in detail why it fails, and showing with a numerical example that agreement with the present neutrino oscillation data can be recovered with the inclusion of dimension-three heavy neutrino mass terms that break softly the A4 symmetry.Comment: 10 pages, RevTex, 3 figures. v2: much expanded section on softly broken A4; refs adde

Physical constraints on interacting dark energy models

Physical limits on the equation-of-state (EoS) parameter of a dark energy component non-minimally coupled with the dark matter field are examined in light of the second law of thermodynamics and the positiveness of entropy. Such constraints are combined with observational data sets of type Ia supernovae, baryon acoustic oscillations and the angular acoustic scale of the cosmic microwave background to impose restrictions on the behaviour of the dark matter/dark energy interaction. Considering two EoS parameterisations of the type $w = w_0 + w_a\zeta(z)$, we derive a general expression for the evolution of the dark energy density and show that the combination of thermodynamic limits and observational data provide tight bounds on the $w_0 - w_a$ parameter space.Comment: 7 pages, 4 figures. Accepted for publication in European Physical Journal

Grasping bulky objects with two anthropomorphic hands

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThis paper presents an algorithm to compute precision grasps for bulky objects using two anthropomorphic hands. We use objects modeled as point clouds obtained from a sensor camera or from a CAD model. We then process the point clouds dividing them into two set of slices where we look for sets of triplets of points. Each triplet must accomplish some physical conditions based on the structure of the hands. Then, the triplets of points from each set of slices are evaluated to find a combination that satisfies the force closure condition (FC). Once one valid couple of triplets have been found the inverse kinematics of the system is computed in order to know if the corresponding points are reachable by the hands, if so, motion planning and a collision check are performed to asses if the final grasp configuration of the system is suitable. The paper inclu des some application examples of the proposed approachAccepted versio

Parent Stars of Extrasolar Planets. X. Lithium Abundances and vsini Revisited

We determine Li abundances and vsini values from new spectra of 53 stars with Doppler-detected planets not included in our previous papers in this series. We also examine two sets of stars without detected planets, which together serve as our comparison sample. Using the method of comparison of Li abundances and vsini values between two sets of stars we introduced in Gonzalez (2008), we confirm that these two quantities are smaller among stars with planets compared to stars without detected planets near the solar temperature. The transition from low to high Li abundance among SWPs occurs near 5850 K, a revision of about 50 K from our previous determination. The transition from low to high vsini occurs near 6000 K, but this temperature is not as well constrained.Comment: accepted for publication in MNRAS; 14 pages, 13 figures, 3 table

Astrophysical and Cosmological Information from Large-scale sub-mm Surveys of Extragalactic Sources

We present a quantitative analysis of the astrophysical and cosmological information that can be extracted from the many important wide-area, shallow surveys that will be carried out in the next few years. Our calculations combine the predictions of the physical model by Granato et al. (2004) for the formation and evolution of spheroidal galaxies with up-to-date phenomenological models for the evolution of starburst and normal late-type galaxies and of radio sources. We compute the expected number counts and the redshift distributions of these source populations separately and then focus on proto-spheroidal galaxies. For the latter objects we predict the counts and redshift distributions of strongly lensed sources at 250, 350, 500, and 850 micron, the angular correlation function of sources detected in the surveys considered, the angular power spectra due to clustering of sources below the detection limit in Herschel and Planck surveys. An optimal survey for selecting strongly lensed proto-spheroidal galaxies is described, and it is shown how they can be easily distinguished from the other source populations. We also discuss the detectability of the imprints of the 1-halo and 2-halo regimes on angular correlation functions and clustering power spectra, as well as the constraints on cosmological parameters that can be obtained from the determinations of these quantities. The novel data relevant to derive the first sub-millimeter estimates of the local luminosity functions of starburst and late-type galaxies, and the constraints on the properties of rare source populations, such as blazars, are also briefly described.Comment: 16 pages, 10 figures. Accepted for publication on MNRA

A Rapid and Efficient Method for Purifying High Quality Total RNA from Peaches (Prunus persica) for Functional Genomics Analyses

http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000100010&lng=es&nrm=isoPrunus persica has been proposed as a genomic model for deciduous trees and the Rosaceae family. Optimized protocols for RNA isolation are necessary to further advance studies in this model species such that functional genomics analyses may be performed. Here we present an optimized protocol to rapidly and efficiently purify high quality total RNA from peach fruits (Prunus persica). Isolating high-quality RNA from fruit tissue is often difficult due to large quantities of polysaccharides and polyphenolic compounds that accumulate in this tissue and co-purify with the RNA. Here we demonstrate that a modified version of the method used to isolate RNA from pine trees and the woody plant Cinnamomun tenuipilum is ideal for isolating high quality RNA from the fruits of Prunus persica. This RNA may be used for many functional genomic based experiments such as RT-PCR and the construction of large-insert cDNA libraries

Does insecure attachment lead to (mis)wired brains? Emotion, cognition, and attachment: an outlook through psychophysiological pathways

2346, 2360, 2560The evolutionary-based attachment theory (Bowlby, 1969, 1973, 1980) asserts that approach/attachment or avoidance/withdrawal tendencies may reflect distinct regulation strategies underlying individual differences in attachment styles. The influence of the internal working models of attachment on emotion and cognition, and more recently, on its psychophysiological underpinnings has been a central focus of research. Despite the endeavours at clarifying this modulatory influence in behaviour, inconsistent results have prevented definite answers. Aiming at contributing to the current knowledge in the filed, and embedded in a psychophysiological framework, the present thesis brings together findings of empirical studies focusing on the regulation abilities in attentional bias towards emotion information. Following an integrative approach, these studies coupled behavioural responses with measures of skin conductance, heart rate, and eye movements. Findings of these studies converge to show distinctive features between regulation strategies deployed by insecure attached individuals when processing threat-related information on visual attention tasks, as measured by behavioural (Study I), sympathetic (Study II), and eye movement (Study III) responses. Taken together these findings point up the evolutionary value of the attachment behavioural system, providing support for fundamental distinctions between insecure attachment styles, both at a behavioural and physiological level. Considering recent advances emerging in the filed, results are discussed within in a comprehensive and all-encompassing approach.Fundamentada num cenário evolucionista, a teoria da vinculação (Bowlby, 1969, 1973, 1980) considera que comportamentos de aproximação/evitamento reflectem estratégias de regulação subjacentes a diferenças individuais nos estilos de vinculação. Neste âmbito, a natureza dos modelos internos dinâmicos têm sido um foco central na investigação, tendo sido dada particular atenção à sua influência nos processos emocionais e cognitivos e, mais recentemente, às suas bases psicofisiológicas. Contudo, apesar de vários estudos terem examinado estas questões, a ausência de dados consistentes acerca dos mecanismos que poderão contribuir para esta influência estão ainda por conhecer de modo consistente. Visando contribuir para o conhecimento neste campo, a presente tese reúne um conjunto de estudos empíricos que, numa perspectiva psicofisiológica, focam a acção das estratégias de regulação associadas aos estilos de vinculação insegura – ansiosa e evitante –, nos enviesamentos atencionais no processamento de informação emocional. Numa abordagem integrativa, estes estudos combinam respostas comportamentais com medidas fisiológicas: condutância da pele; frequência cardíaca; e movimentos oculares. Utilizando tarefas de atenção visual, os resultados destes estudos apoiam a hipótese de que os estilos de vinculação insegura estão relacionados com estratégias de regulação específicas no processamento de estímulos potencialmente ameaçadores, avaliadas através de respostas comportamentais (Estudo I), do sistema nervoso simpático (Estudo II), e dos movimentos oculares (Estudo III). Globalmente, os resultados corroboraram o valor evolutivo do sistema comportamental de vinculação, dando suporte para diferenças entre os estilos de vinculação insegura, tanto a nível comportamental como fisiológico. Considerando progressos científicos emergentes, os resultados são discutidos numa abordagem compreensiva e abrangente