Photon and Pomeron -- induced production of Dijets in pppp, pApA and AAAA collisions

In this paper we present a detailed comparison of the dijet production by photon -- photon, photon -- pomeron and pomeron -- pomeron interactions in $pp$, $pA$ and ${\rm AA}$ collisions at the LHC energy. The transverse momentum, pseudo -- rapidity and angular dependencies of the cross sections are calculated at LHC energy using the Forward Physics Monte Carlo (FPMC), which allows to obtain realistic predictions for the dijet production with two leading intact hadrons. We obtain that \gamma \pom channel is dominant at forward rapidities in $pp$ collisions and in the full kinematical range in the nuclear collisions of heavy nuclei. Our results indicate that the analysis of dijet production at the LHC can be useful to test the Resolved Pomeron model as well as to constrain the magnitude of the absorption effects.Comment: 11 pages, 6 figures, 1 table. Improved and enlarged version published in European Physical Journal

Direct calorimetric measurements of isothermal entropy change on single crystal W-type hexaferrites at the spin reorientation transition

We report on the magnetic field induced isothermal entropy change, \Delta s(Ha, T), of W-type ferrite with CoZn substitution. Entropy measurements are performed by direct calorimetry. Single crystals of the composition BaCo$_0.62$Zn$_1.38$Fe$_16$O$_27$, prepared by the flux method, are measured at different fixed temperatures under an applied field perpendicular and parallel to the c axis. At 296 K one deduces a value of K$_1$ = 8.7 \times 10^{4} J m$^-3$ for the first anisotropy constant, which is in good agreement with the literature. The spin reorientation transition temperature is estimated to take place between 200 and 220 K

Longitudinal spin Seebeck coefficient: heat flux vs. temperature difference method

The determination of the longitudinal spin Seebeck effect (LSSE) coefficient is currently plagued by a large uncertainty due to the poor reproducibility of the experimental conditions used in its measurement. In this work we present a detailed analysis of two different methods used for the determination of the LSSE coefficient. We have performed LSSE experiments in different laboratories, by using different setups and employing both the temperature difference method and the heat flux method. We found that the lack of reproducibility can be mainly attributed to the thermal contact resistance between the sample and the thermal baths which generate the temperature gradient. Due to the variation of the thermal resistance, we found that the scaling of the LSSE voltage to the heat flux through the sample rather than to the temperature difference across the sample greatly reduces the uncertainty. The characteristics of a single YIG/Pt LSSE device obtained with two different setups was $(1.143\pm0.007)\cdot 10^{-7}$ Vm/W and $(1.101\pm0.015)\cdot 10^{-7}$ Vm/W with the heat flux method and $(2.313\pm0.017)\cdot 10^{-7}$ V/K and $(4.956\pm0.005)\cdot 10^{-7}$ V/K with the temperature difference method. This shows that systematic errors can be considerably reduced with the heat flux method.Comment: PDFLaTeX, 10 pages, 6 figure

Grapevine virus diseases: economic impact and current advances in viral prospection and management.

Grapevine (Vitis spp.) is a major vegetative propagated fruit crop with high socioeconomic importance worldwide. It is susceptible to several graft-transmitted agents that cause several diseases and substantial crop losses, reducing fruit quality and plant vigor, and shorten the longevity of vines. ] The vegetative propagation and frequent exchanges of propagative material among countries contribute to spread these pathogens, favoring the emergence of complex diseases. Its perennial life cycle further accelerates the mixing and introduction of several viral agents into a single plant. Currently, approximately 65 viruses belonging to different families have been reported infecting grapevines, but not all cause economically relevant diseases. The grapevine leafroll, rugose wood complex, leaf degeneration and fleck diseases are the four main disorders having worldwide economic importance. In addition, new viral species and strains have been identified and associated with economically important constraints to grape production. In Brazilian vineyards, eighteen viruses, three viroids and two virus-like diseases had already their occurrence reported and were molecularly characterized. Here, we review the current knowledge of these viruses, report advances in their diagnosis and prospection of new species, and give indications about the management of the associated grapevine diseases. Index terms: Vegetative propagation, plant viruses, crop losses, berry quality, next-generation sequencing. VIROSES EM VIDEIRAS: IMPACTO ECONÔMICO E RECENTES AVANÇOS NA PROSPECÇÃO DE VÍRUS E MANEJO DAS DOENÇAS DE ORIGEM VIRAL A videira (Vitis spp.) é propagada vegetativamente e considerada uma das principais culturas frutíferas por sua importância socioeconômica mundial. Ela é suscetível a vários agentes transmitidos por meio da enxertia, os quais causam diversas doenças e significativas perdas na produtividade e produção, redução na qualidade dos frutos, no vigor da planta e na longevidade dos vinhedos. A propagação vegetativa e o frequente intercâmbio de material propagativo entre países contribuem para a disseminação destes patógenos, favorecendo a emergência de doenças complexas. Seu ciclo de vida perene acelera ainda mais a mistura e a introdução de vários agentes virais em uma mesma planta. Atualmente, aproximadamente 65 vírus pertencentes a diferentes famílias foram reportados infectando videiras, embora nem todos causem doenças economicamente relevantes. As viroses do enrolamento da folha, complexo do lenho rugoso, degenerescência e mancha-das-nervuras da videira são as quatro principais desordens que têm importância econômica mundial. Além disso, novas espécies e estirpes virais foram identificadas e associadas a limitações economicamente importantes para a produção de uvas. Em vinhedos brasileiros, dezoito espécies virais, três viroides e duas doenças semelhantes a viroses já tiveram sua ocorrência reportada e foram molecularmente caracterizados. Aqui, nós revisamos o conhecimento atual dessas viroses, os recentes avanços na diagnose e prospecção viral, e fornecemos recomentações sobre o manejo das viroses da videira. Termos para indexação: Propagação vegetativa, vírus de plantas, redução da produtividade e produção, qualidade das bagas, sequenciamento de nova geração

Inclusive gauge boson production in the color dipole formalism

The inclusive production of the gauge bosons $W^{\pm}$ and $Z^0$ is studied within the color dipole formalism. Gluon saturation effects associated to non-linear corrections to the QCD dynamics, which are expected to contribute at high energies, are naturally included in such formalism. We estimate the contribution of these effects at LHC energies and compare our results with the next-to-next-to-leading order collinear predictions. A comparison with the current experimental data is performed and predictions for higher energies are presented.Comment: 12 pages, 6 figures, 2 tables. Version to be published in Physical Review

Noise Measurement of Interacting Ferromagnetic Particles with High Resolution Hall Microprobes

We present our first experimental determination of the magnetic noise of a superspinglass made of < 1 pico-liter frozen ferrofluid. The measurements were performed with a local magnetic field sensor based on Hall microprobes operated with the spinning current technique. The results obtained, though preliminary, qualitatively agree with the theoretical predictions of Fluctuation-Dissipation theorem (FDT) violation [1].Comment: 4pages, 2 figure

Produção de antissoro policlonal utilizando a proteína capsidial recombinante do Rupestris stem pitting-associated virus.

O Rupestris stem pitting-associated virus (RSPaV) é o agente causal das caneluras do lenho da videira. Este trabalho teve como objetivo produzir antissoro policlonal a partir da proteína capsidial (CP) recombinante do RSPaV e avaliar a sua especificidade e sensibilidade. O gene da CP do RSPaV, com 780pb, foi previamente caracterizado. Esse gene foi subclonado no sítio de restrição EcoRI, no vetor de expressão pRSET-B e o plasmídeo recombinante foi utilizado para induzir a expressão da CP em Escherichia coli. A CP, ligada a uma cauda de seis histidinas, foi purificada por meio de cromatografia de afinidade em coluna de Ni-NTA a partir do extrato de proteínas totais extraídas de E. coli. A identidade da proteína purificada foi confirmada em SDS-PAGE e Western blot, utilizando-se anticorpos comerciais contra a cauda de seis histidinas. A CP recombinante expressada in vitro apresentou massa molecular de cerca de 31kDa. A proteína purificada foi quantificada e 2,55mg foram utilizados para a imunização de um coelho. O antissoro policlonal obtido reagiu com diferentes isolados deste vírus, extraídos de videiras em ELISA indireto.Nota técnica

Domain-wall motion in random potential and hysteresis modeling

Two different approaches to hysteresis modeling are compared using a common ground based on energy relations, defined in terms of dissipated and stored energy. Using the Preisach model and assuming that magnetization is mainly due to domain-wall motion, one can derive the expression of magnetization along a major loop typical of the Jiles–Atherton model and then extend its validity to cases where mean-field effects and reversible contributions are present