1,358 research outputs found
A Brazilian glycoprotein E-negative bovine herpesvirus type 1.2a (BHV-1.2a) mutant is attenuated for cattle and induces protection against wild-type virus challenge
The authors previously reported the construction of a glycoprotein E-deleted (gE-) mutant of bovine herpesvirus type 1.2a (BHV-1.2a). This mutant, 265gE-, was designed as a vaccinal strain for differential vaccines, allowing the distinction between vaccinated and naturally infected cattle. In order to determine the safety and efficacy of this candidate vaccine virus, a group of calves was inoculated with 265gE-. The virus was detected in secretions of inoculated calves to lower titres and for a shorter period than the parental virus inoculated in control calves. Twenty one days after inoculation, the calves were challenged with the wild type parental virus. Only mild signs of infection were detected on vaccinated calves, whereas non-vaccinated controls displayed intense rhinotracheitis and shed virus for longer and to higher titres than vaccinated calves. Six months after vaccination, both vaccinated and control groups were subjected to reactivation of potentially latent virus. The mutant 265gE- could not be reactivated from vaccinated calves. The clinical signs observed, following the reactivation of the parental virus, were again much milder on vaccinated than on non-vaccinated calves. Moreover, parental virus shedding was considerably reduced on vaccinated calves at reactivation. In view of its attenuation, immunogenicity and protective effect upon challenge and reactivation with a virulent BHV-1, the mutant 265gE- was shown to be suitable for use as a BHV-1 differential vaccine viru
Peroxidase activity and total phenol content in citrus cuttings treated with different copper sources
Abstract The proper citrus cutting choice is considered of basic importance for a healthy and productive citriculture. Substrates composed of organic materials are widely used for the production of citrus seedlings but this can lead to plant copper deficiency, mainly caused by substrate high chelating properties. Copper is an essential heavy metal and is involved in many different plant physiological processes. This experiment was carried out in order to evaluate the behavior of 'Rangpur lime' lemon rootstock ( Citrus limonia Osbeck) grafted with cv. 'Valencia' ( Citrus sinensis L. Osbeck), when treated with different copper formulations, as cupric oxychloride (50% Cu — Novartis Biociencias™), cuprous oxide (32.8% Cu — Yara Vita™), chelated copper (5% Cu — Stoller™) and copper sulphate (25% Cu — Microsal™) analyzing the activity of peroxidase (POD) and the total content of phenols. The different copper formulations did not show significant differences about plant height, diameter, leaf and root dry weight. The comparison among copper treatments shows that cuprous oxide promoted the antioxidant system (POD activity and phenolic content) while chelated copper was not effective
The pion's electromagnetic form factor at small momentum transfer in full lattice QCD
We compute the electromagnetic form factor of a "pion" with mass m_pi=330MeV
at low values of Q^2\equiv -q^2, where q is the momentum transfer. The
computations are performed in a lattice simulation using an ensemble of the
RBC/UKQCD collaboration's gauge configurations with Domain Wall Fermions and
the Iwasaki gauge action with an inverse lattice spacing of 1.73(3)GeV. In
order to be able to reach low momentum transfers we use partially twisted
boundary conditions using the techniques we have developed and tested earlier.
For the pion of mass 330MeV we find a charge radius given by
_{330MeV}=0.354(31)fm^2 which, using NLO SU(2) chiral perturbation
theory, extrapolates to a value of =0.418(31)fm^2 for a physical pion,
in agreement with the experimentally determined result. We confirm that there
is a significant reduction in computational cost when using propagators
computed from a single time-slice stochastic source compared to using those
with a point source; for m_pi=330MeV and volume (2.74fm)^3 we find the
reduction is approximately a factor of 12.Comment: 20 pages, 3 figure
Spin Glass Behavior in RuSr2Gd1.5Ce0.5Cu2O10
The dynamics of the magnetic properties of polycrystalline
RuSr2Gd1.5Ce0.5Cu2O10 (Ru-1222) have been studied by ac susceptibility and dc
magnetization measurements, including relaxation and ageing studies. Ru-1222 is
a reported magneto-superconductor with Ru spins magnetic ordering at
temperatures near 100 K and superconductivity in Cu-O2 planes below Tc ~ 40 K.
The exact nature of Ru spins magnetic ordering is still debated and no
conclusion has been reached yet. In this work, a frequency-dependent cusp was
observed in ac susceptibility vs. T measurements, which is interpreted as a
spin glass transition. The change in the cusp position with frequency follows
the Vogel-Fulcher law, which is commonly accepted to describe a spin glass with
magnetically interacting clusters. Such interpretation is supported by
themoremanaent magnetization (TRM) measurements at T = 60 K. TRM relaxations
are well described by a stretched exponential relation, and present significant
ageing effects.Comment: 4 pages, 6 figures, submitted to Phys. Rev.
On the thickness of a mildly relativistic collisional shock wave
We consider an imperfect relativistic fluid which develops a shock wave and
discuss its structure and thickness, taking into account the effects of
viscosity and heat conduction in the form of sound absorption. The junction
conditions and the non linear equations describing the evolution of the shock
are derived with the corresponding Newtonian limit discussed in detail. As
happens in the non relativistic regime, the thickness is inversely proportional
to the discontinuity in the pressure, but new terms of purely relativistic
origin are present. Particularizing for a polytropic gas, it is found that the
pure viscous relativistic shock is thicker than its nonrelativistic
counterpart, while the opposite holds for pure heat conduction.Comment: 11 pages, no figures, title changed, improved introduction and
discussion. New author adde
A Influência De Crenças E Tabus Alimentares Na Amamentação
Cultural factors, such as food taboos, negatively influence the promotion of breastfeeding, resulting in early weaning. The aim of this study was to investigate differences in eating habits of a group of mothers in relation to breastfeeding. Cross-sectional study consisting of mothers of children under two years old enrolled in the Child Care Program of two Basic Health Units of Guarapuava-PR. One located in the peripheral region (US 1) and the other in the central area (US 2) to detect differences in eating habits of this population. The study included 96 mothers with mean age 25,11 years, of which 86.5% said they believed that some food would undermine breastfeeding. The main foods to be avoided, according to the mothers, were acidic foods, alcohol, chocolate and soft drinks. Mothers of units 1 and 2 have made mention consumption of foods derived from corn, and only two mentioned in the U.S. 2 beer consumption as food lactogenic black. No differences were found between the health U.S. 1 and U.S. 2. In relation to dietary restrictions were not found relevant data related to the taboos of the interviewees. Highlights the importance of orientation to promote breastfeeding and encourage mothers to solve any doubts, avoiding early weaning and continued breastfeeding until two years of age or older child.40222122
Algorithms for outerplanar graph roots and graph roots of pathwidth at most 2.
Deciding whether a given graph has a square root is a classical problem that has been studied extensively both from graph theoretic and from algorithmic perspectives. The problem is NP-complete in general, and consequently substantial effort has been dedicated to deciding whether a given graph has a square root that belongs to a particular graph class. There are both polynomial-time solvable and NP-complete cases, depending on the graph class. We contribute with new results in this direction. Given an arbitrary input graph G, we give polynomial-time algorithms to decide whether G has an outerplanar square root, and whether G has a square root that is of pathwidth at most 2
Self-consistent field theory of polarized BEC: dispersion of collective excitation
We suggest the construction of a set of the quantum hydrodynamics equations
for the Bose-Einstein condensate (BEC), where atoms have the electric dipole
moment. The contribution of the dipole-dipole interactions (DDI) to the Euler
equation is obtained. Quantum equations for the evolution of medium
polarization are derived. Developing mathematical method allows to study effect
of interactions on the evolution of polarization. The developing method can be
applied to various physical systems in which dynamics is affected by the DDI.
Derivation of Gross-Pitaevskii equation for polarized particles from the
quantum hydrodynamics is described. We showed that the Gross-Pitaevskii
equation appears at condition when all dipoles have the same direction which
does not change in time. Comparison of the equation of the electric dipole
evolution with the equation of the magnetization evolution is described.
Dispersion of the collective excitations in the dipolar BEC, either affected or
not affected by the uniform external electric field, is considered using our
method. We show that the evolution of polarization in the BEC leads to the
formation of a novel type of the collective excitations. Detailed description
of the dispersion of collective excitations is presented. We also consider the
process of wave generation in the polarized BEC by means of a monoenergetic
beam of neutral polarized particles. We compute the possibilities of the
generation of Bogoliubov and polarization modes by the dipole beam.Comment: 16 pages, 15 figures. arXiv admin note: substantial text overlap with
arXiv:1106.082
Reproductive biology of Artibeus fimbriatus Gray 1838 (Chiroptera) at the southern limit of its geographic range
Avaliação de atividade inflamatória na osteomielite crônica. Contribuição da cintilografia com anticorpos policlonais
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