8,694 research outputs found

    Macroscopic fluctuations theory of aerogel dynamics

    Full text link
    We consider the thermodynamic potential describing the macroscopic fluctuation of the current and local energy of a general class of Hamiltonian models including aerogels. We argue that this potential is neither analytic nor strictly convex, a property that should be expected in general but missing from models studied in the literature. This opens the possibility of describing in terms of a thermodynamic potential non-equilibrium phase transitions in a concrete physical context. This special behaviour of the thermodynamic potential is caused by the fact that the energy current is carried by particles which may have arbitrary low speed with sufficiently large probability.Comment: final versio

    Numerical Implementation of lepton-nucleus interactions and its effect on neutrino oscillation analysis

    Full text link
    We discuss the implementation of the nuclear model based on realistic nuclear spectral functions in the GENIE neutrino interaction generator. Besides improving on the Fermi gas description of the nuclear ground state, our scheme involves a new prescription for Q2Q^2 selection, meant to efficiently enforce energy momentum conservation. The results of our simulations, validated through comparison to electron scattering data, have been obtained for a variety of target nuclei, ranging from carbon to argon, and cover the kinematical region in which quasi elastic scattering is the dominant reaction mechanism. We also analyse the influence of the adopted nuclear model on the determination of neutrino oscillation parameters.Comment: 19 pages, 35 figures, version accepted by Phys. Rev.

    Discontinuous Euler instability in nanoelectromechanical systems

    Full text link
    We investigate nanoelectromechanical systems near mechanical instabilities. We show that quite generally, the interaction between the electronic and the vibronic degrees of freedom can be accounted for essentially exactly when the instability is continuous. We apply our general framework to the Euler buckling instability and find that the interaction between electronic and vibronic degrees of freedom qualitatively affects the mechanical instability, turning it into a discontinuous one in close analogy with tricritical points in the Landau theory of phase transitions.Comment: 4+ pages, 3 figures, published versio

    Efeito do glyphosate sobre parâmetros fisiológicos de Conyza sumatrensis.

    Get PDF
    Editores técnicos: Joseani Mesquita Antunes, Ana Lídia Variani Bonato, Márcia Barrocas Moreira Pimentel

    NMR and ÎĽ+\mu^{+}SR detection of unconventional spin dynamics in Er(trensal) and Dy(trensal) molecular magnets

    Get PDF
    Measurements of proton Nuclear Magnetic Resonance (1H NMR) spectra and relaxation and of Muon Spin Relaxation (μ+\mu^{+}SR) have been performed as a function of temperature and external magnetic field on two isostructural lanthanide complexes, Er(trensal) and Dy(trensal) featuring crystallographically imposed trigonal symmetry. Both the nuclear 1/T1 and muon λ\lambda longitudinal relaxation rates, LRR, exhibit a peak for temperatures T lower than 30K, associated to the slowing down of the spin dynamics, and the width of the NMR absorption spectra starts to increase significantly at T ca. 50K, a temperature sizably higher than the one of the LRR peaks. The LRR peaks have a field and temperature dependence different from those previously reported for all Molecular Nanomagnets. They do not follow the Bloembergen-Purcell-Pound scaling of the amplitude and position in temperature and field and thus cannot be explained in terms of a single dominating correlation time τ\tauc determined by the spin slowing down at low temperature. Further, for T lower than 50K the spectral width does not follow the temperature behavior of the magnetic susceptibility chi. We suggest, using simple qualitative considerations, that the observed behavior is due to a combination of two different relaxation processes characterized by the correlation times τ\tauLT and τ\tauHT, dominating for T lower than 30K and T higher than 50K, respectively. Finally, the observed flattening of LRR for T lower than 5K is suggested to have a quantum origin

    single nucleotide polymorphism discovery in the avian tapasin gene

    Get PDF
    Abstract Tapasin is a transmembrane glycoprotein located in the endoplasmic reticulum. Its function is to assist the assembly of major histocompatibility complex class I molecules. The chicken Tapasin gene includes 8 exons and is localized inside the major histocompatibility complex between the 2 class IIβ genes. The aim of the current study was the estimation of single nucleotide polymorphism frequency within the avian Tapasin gene. The Tapasin gene sequence from exon 5 to exon 6 was amplified for the chicken, turkey, and pheasant, and sequences of different lengths were obtained. The sequence analysis based on PolyBayes identified 25 putative single nucleotide polymorphism sites when the 3 species were compared. The coding sequences were further translated and analyzed to identify amino acid substitutions. The results indicated that polymorphisms within this region of the gene was mainly observed in the heterozygous state. The level of conservation of the Tapasin gene sequence among species is likely to be related to the functional importance of the gene

    Estádio de desenvolvimento e superfície foliar reduzem a eficiência de chlorimuron-ethyl e glyphosate em Conyza sumatrensis.

    Get PDF
    Editores técnicos: Joseani Mesquita Antunes, Ana Lídia Variani Bonato, Márcia Barrocas Moreira Pimentel

    Parametric amplification of magnetoplasmons in semiconductor quantum dots

    Full text link
    We show that the magnetoplasmon collective modes in quasi-two-dimensional semiconductor quantum dots can be parametrically amplified by periodically modulating the magnetic field perpendicular to the nanostructure. The two magnetoplasmon modes are excited and amplified simultaneously, leading to an exponential growth of the number of bosonic excitations in the system. We further demonstrate that damping mechanisms as well as anharmonicities in the confinement of the quantum dot lead to a saturation of the parametric amplification. This work constitutes a first step towards parametric amplification of collective modes in many-body fermionic systems beyond one dimension.Comment: 12 pages, 5 figures; published versio

    Overview of the benefitsand potential issues of the nonavalent HPV vaccine

    Get PDF
    HPV-related diseases affect anogenital and oropharyngeal regions, heavily affecting the psychosexual dimension of both male and female individuals. HPV vaccination programs based on a bivalent or quadrivalent vaccine have opened broad perspectives for primary prevention. A nonavalent HPV vaccine (9vHPV), covering nine genotypes (HPV6, HPV11, HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, and HPV58), might provide further improvement in terms of direct protection. In the present report, efficacy and safety data from 9vHPV vaccine development programs are examined. Efficacy data come from a pivotal trial, which was conducted among women aged 16–26 years randomly assigned to receive either the 9vHPV or the quadrivalent HPV (4vHPV) vaccine. The 9vHPV vaccine was shown to have potential benefits as compared with 4vHPV, increasing the overall estimated rate of prevention to 90% for cervical cancer and up to 80% for precancerous cervical lesions. For all other HPV-related pre-invasive and invasive lesions, 9vHPV showed potentially greater disease reduction, depending on the anatomic region examined. Thus, the 9vHPV vaccine shows clinical potential for the prevention of HPV-related diseases in both sexes. Future adoption of 9vHPV will depend on factors including market price, cost-effectiveness data, use of a two-dose schedule, and safety and efficacy monitoring in real-life programs

    Suscetibilidade diferencial de biĂłtipos de Conyza sumatrensis ao herbicida chlorimuron-ethyl.

    Get PDF
    Editores técnicos: Joseani Mesquita Antunes, Ana Lídia Variani Bonato, Márcia Barrocas Moreira Pimentel
    • …
    corecore