7,747 research outputs found

    Non-standard neutrinos interactions in a 331 model with minimum Higgs sector

    Get PDF
    We present a detailed analysis of a class of extensions to the SM Gauge chiral symmetry SU(3)CĂ—SU(3)LĂ—U(1)XSU(3)_{C}\times SU(3)_{L}\times U(1)_{X} (331 model), where the neutrino electroweak interaction with matter via charged and neutral current is modified through new gauge bosons of the model. We found the connections between the non-standard contributions on 331 model with non-standard interactions. Through limits of such interactions in cross section experiments we constrained the parameters of the model, obtaining that the new energy scale of this theory should obey V>1.3V>1.3 TeV and the new bosons of the model must have masses greater than 610 GeV.Comment: 17 Pages, latex, 1 Table

    Acceptance of fluorescence detectors and its implication in energy spectrum inference at the highest energies

    Full text link
    Along the years HiRes and AGASA experiments have explored the fluorescence and the ground array experimental techniques to measure extensive air showers, being both essential to investigate the ultra-high energy cosmic rays. However, such Collaborations have published contradictory energy spectra for energies above the GZK cut-off. In this article, we investigate the acceptance of fluorescence telescopes to different primary particles at the highest energies. Using CORSIKA and CONEX shower simulations without and with the new pre-showering scheme, which allows photons to interact in the Earth magnetic field, we estimate the aperture of the HiRes-I telescope for gammas, iron nuclei and protons primaries as a function of the number of simulated events and primary energy. We also investigate the possibility that systematic differences in shower development for hadrons and gammas could mask or distort vital features of the cosmic ray energy spectrum at energies above the photo-pion production threshold. The impact of these effects on the true acceptance of a fluorescence detector is analyzed in the context of top-down production models

    MĂ©todo laboratorial para inferĂŞncia da qualidade de bananas (amadurecimento e injĂşrias) com visĂŁo computacional.

    Get PDF
    bitstream/CNPDIA-2009-09/11164/1/CT83_2007.pd

    Tissue-Specific Transcriptomes Reveal Gene Expression Trajectories in Two Maturing Skin Epithelial Layers in Zebrafish Embryos.

    Get PDF
    Epithelial cells are the building blocks of many organs, including skin. The vertebrate skin initially consists of two epithelial layers, the outer periderm and inner basal cell layers, which have distinct properties, functions, and fates. The embryonic periderm ultimately disappears during development, whereas basal cells proliferate to form the mature, stratified epidermis. Although much is known about mechanisms of homeostasis in mature skin, relatively little is known about the two cell types in pre-stratification skin. To define the similarities and distinctions between periderm and basal skin epithelial cells, we purified them from zebrafish at early development stages and deeply profiled their gene expression. These analyses identified groups of genes whose tissue enrichment changed at each stage, defining gene flow dynamics of maturing vertebrate epithelia. At each of 52 and 72 hr post-fertilization (hpf), more than 60% of genes enriched in skin cells were similarly expressed in both layers, indicating that they were common epithelial genes, but many others were enriched in one layer or the other. Both expected and novel genes were enriched in periderm and basal cell layers. Genes encoding extracellular matrix, junctional, cytoskeletal, and signaling proteins were prominent among those distinguishing the two epithelial cell types. In situ hybridization and BAC transgenes confirmed our expression data and provided new tools to study zebrafish skin. Collectively, these data provide a resource for studying common and distinguishing features of maturing epithelia

    Mentoring in pre-service teaching: from reflection on practice to a didactic proposal

    Get PDF
    This article offers a review of different methodologies to mentor pre-service teachers’ pedagogical experience in EFL contexts in Colombia and their pedagogical implications when training future teachers. It also gives an overview of models presented for the purpose of mentoring. Finally, it proposes a model to guide the mentoring of pre-service teachers’ pedagogical experiences at schools in Bogotá considering the implications of talking about the mentoring in the teaching practicum and the roles of the participants. This model is a selection of mentoring strategies that can be extended to other contexts with similar characteristics

    The Zero-Removing Property and Lagrange-Type Interpolation Series

    Get PDF
    The classical Kramer sampling theorem, which provides a method for obtaining orthogonal sampling formulas, can be formulated in a more general nonorthogonal setting. In this setting, a challenging problem is to characterize the situations when the obtained nonorthogonal sampling formulas can be expressed as Lagrange-type interpolation series. In this article a necessary and sufficient condition is given in terms of the zero removing property. Roughly speaking, this property concerns the stability of the sampled functions on removing a finite number of their zeros

    Formative research: challenges and tendencies

    Get PDF
    21st century teachers are not only required to develop top teaching skills, but also strong research ones that allow them to expand their understanding of teaching-learning phenomena and improve their school practices. This relatively recent trend has also impacted the Language Teaching field, making language programs in universities to develop different approaches to Formative Research for their student-teachers. This paper aims to contrast how two different universities (a private and a state one) understand and carry out formative research processes. The analysis attempts to specifically describe how two Bachelors of Arts in Education of teachers in Foreign Languages programs have dealt with formative research revealing goals and difficulties when initiating student-teachers in research

    Using plant-based preparations to protect common bean against halo blight disease: the potential of nettle to trigger the immune system

    Get PDF
    Halo blight disease of beans (Phaseolus vulgaris L.), caused by the bacterium Pseudomonas syringae pv. phaseolicola (Pph), is responsible for severe losses in crop production worldwide. As the current agronomic techniques used are not effective, it is necessary to search for new ones which may prevent disease in common bean. In this study, we challenged four plant-based preparations (PBPs), with no other agronomic uses, as they come from industrial waste (grapevine pomace (R-G) and hop residue (R-H)) or wild plants (Urtica dioica (U) and Equisetum sp. (E)), to be used as immune defense elicitors against Pph in common bean. After studying their inhibitory effect against Pph growth by bioassays, the two most effective PBPs (R-G and U) were applied in common bean plants. By measuring the total H2O2, lipid peroxidation, and antioxidant enzymatic activities, as well as the expression of six defense-related genes-PR1, WRKY33, MAPKK, RIN4, and PAL1-, it was observed that U-PBP application involved a signaling redox process and the overexpression of all genes, mostly PR1. First infection trials in vitro suggested that the application of U-PBP involved protection against Pph. The elicitation of bean defense with U-PBP involved a decrease in some yield parameters, but without affecting the final production. All these findings suggest a future use of U-PBP to diminish halo blight disease

    General Non-equilibrium Theory of Colloid Dynamics

    Full text link
    A non-equilibrium extension of Onsager's canonical theory of thermal fluctuations is employed to derive a self-consistent theory for the description of the statistical properties of the instantaneous local concentration profile n(r,t) of a colloidal liquid in terms of the coupled time evolution equations of its mean value n(r,t) and of the covariance {\sigma}(r,r';t) \equiv of its fluctuations {\delta}n(r, t) = n(r, t) - n(r, t). These two coarse-grained equations involve a local mobility function b(r, t) which, in its turn, is written in terms of the memory function of the two-time correlation function C(r, r' ; t, t') \equiv <{\delta}n(r, t){\delta}n(r',t')>. For given effective interactions between colloidal particles and applied external fields, the resulting self-consistent theory is aimed at describing the evolution of a strongly correlated colloidal liquid from an initial state with arbitrary mean and covariance n^0(r) and {\sigma}^0(r,r') towards its equilibrium state characterized by the equilibrium local concentration profile n^(eq)(r) and equilibrium covariance {\sigma}^(eq)(r,r'). This theory also provides a general theoretical framework to describe irreversible processes associated with dynamic arrest transitions, such as aging, and the effects of spatial heterogeneities
    • …
    corecore