6,837 research outputs found

    Inclusive hadron and photon production at LHC in dipole momentum space

    Get PDF
    Using a momentum space model for the dipole scattering amplitude we present an analysis of the saturation effects at LHC energies, describing the data on proton-proton and proton-lead collisions. The model is based on the asymptotic solutions of the Balitsky-Kovchegov equation, being ideal in the saturation domain where the target wave function has a high occupation number. We also make predictions for the nuclear modification ratios on charged hadron and prompt photon production in the forward region, where the high parton density effects are important.Comment: New section added and typos corrected. To be published in PR

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

    Full text link
    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 BaCo0.62_0.62Zn1.38_1.38Fe16_16O27_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 K1_1 = 8.7 \times 10^{4} J m−3^-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

    Effect of Hyperbaric Storage at Room Temperature on the Activity of Polyphenoloxidase in Model Systems and Fresh Apple Juice

    Get PDF
    The effect of hyperbaric storage (HS) on polyphenoloxidase activity (PPO) was studied in model solutions and apple juice. Model solutions containing increasing amounts of mushroom (Agaricus bisporus) PPO (up to 26 U) were stored at room temperature at pressure up to 200 MPa. During HS, samples were assessed for residual PPO activity. The enzyme was completely inactivated according to a first-order kinetic model that was used to calculate PPO decimal reduction time (Dp) and pressure sensitivity (zp = 140.8 MPa) in diluted model solutions (2 U PPO). The increase in enzyme concentration (6–26 U) nullified the effect of HS, probably due to protein structure stabilization by self-crowding. The application of HS at 100 and 200 MPa to apple juice promoted a decrease in total bacteria, lactic acid bacteria, yeasts, and molds. These changes occurred in concomitance with the inactivation of PPO (zp = 227.3 MPa). At 200 MPa, PPO inactivation followed a biphasic first-order kinetic, suggesting the presence of PPO isozymes with different pressure sensitivity. The inactivation of PPO was observed to occur more rapidly with increasing storage pressure and led to the maintenance of the original bright juice color. This study proves the capability of HS to control enzyme-related quality decay in fruit juices and, potentially, in many other food matrices suffering enzymatic alteration

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

    Get PDF
    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.) Ă© propagada vegetativamente e considerada uma das principais culturas frutĂ­feras por sua importĂąncia socioeconĂŽmica mundial. Ela Ă© suscetĂ­vel a vĂĄrios 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 intercĂąmbio de material propagativo entre paĂ­ses contribuem para a disseminação destes patĂłgenos, favorecendo a emergĂȘncia de doenças complexas. Seu ciclo de vida perene acelera ainda mais a mistura e a introdução de vĂĄrios agentes virais em uma mesma planta. Atualmente, aproximadamente 65 vĂ­rus pertencentes a diferentes famĂ­lias foram reportados infectando videiras, embora nem todos causem doenças economicamente relevantes. As viroses do enrolamento da folha, complexo do lenho rugoso, degenerescĂȘncia e mancha-das-nervuras da videira sĂŁo as quatro principais desordens que tĂȘm importĂąncia econĂŽmica mundial. AlĂ©m disso, novas espĂ©cies e estirpes virais foram identificadas e associadas a limitaçÔes economicamente importantes para a produção de uvas. Em vinhedos brasileiros, dezoito espĂ©cies virais, trĂȘs viroides e duas doenças semelhantes a viroses jĂĄ tiveram sua ocorrĂȘncia reportada e foram molecularmente caracterizados. Aqui, nĂłs revisamos o conhecimento atual dessas viroses, os recentes avanços na diagnose e prospecção viral, e fornecemos recomentaçÔes sobre o manejo das viroses da videira. Termos para indexação: Propagação vegetativa, vĂ­rus de plantas, redução da produtividade e produção, qualidade das bagas, sequenciamento de nova geração

    Changes in microbial, chemical, physical and techno-functional properties of liquid egg yolk during hyperbaric storage

    Get PDF
    The effects of hyperbaric storage (HS) at 200 MPa on the microbial, chemical, physical and techno-functional properties of liquid egg yolk were investigated and compared to refrigeration. Inoculated Salmonella enterica (3.35 ± 0.12 logCFU g−1) and Staphylococcus aureus (2.78 ± 0.19 logCFU g−1) resulted below the detection limit after 24 and 48 h HS, respectively. Liquid egg yolk oxidative status remained unaffected for up to 28 days under pressure, probably due to the presence of egg yolk antioxidants. The decrease in egg yolk denaturation enthalpy and the increase in aromatic amino acid exposure indicated that egg yolk proteins unfolded according to structural changes other than those observed during refrigeration. Liquid egg yolk viscosity progressively increased during HS, eventually leading to gelling. Protein modification did not affect liquid egg yolk foaming and emulsifying properties but impaired its solubility and thermally-induced gelling. HS could be used for microbial decontamination of liquid egg yolk while maintaining oxidative stability and the typical capacity to stabilize foams and emulsions

    Exploring the effects of hyperbaric storage on the optical, structural, mechanical and diffusional properties of food packaging materials

    Get PDF
    The effect of hyperbaric storage (HS) on food packaging materials was evaluated. PA/PE, PP/EVOH/PE, PET and PLA pouches filled with hydroethanolic simulant (D1) were stored at 0.1 and 200 MPa for up to 35 days and analyzed for optical, structural, mechanical and diffusional properties. HS weakened PLA seals, which easily failed after 7 days releasing the simulant. Both PET and PLA films swelled during HS, reducing PET physical ageing and PLA crystallinity. These structural effects caused PET and PLA mechanical properties to vary during HS, and a slight WVTR increase in PLA. Optical, structural and mechanical properties of multi-material films did not change upon HS. Nevertheless, both PA/PE and PP/EVOH/PE released critical amounts of adhesives after 7 and 35 days under pressure, respectively. Results indicate the critical role of the packaging material of foods intended for HS, and the need for its careful selection in future studies on the topic

    Inclusive gauge boson production in the color dipole formalism

    Full text link
    The inclusive production of the gauge bosons W±W^{\pm} and Z0Z^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

    Genomic stability in Arabidopsis thaliana transgenic plants obtained by floral dip

    Get PDF
    . The occurrence of DNA modification is an undesired phenomenon accompanying plant cell transformation. The event has been correlated with the stress imposed by the presently utilised transformation procedures, all depending on plant differentiation from in vitro cell culture, but other causes have not been excluded. In this work, transgenic Arabidopsis thaliana plants have been produced by an approach that does not require cell dedifferentiation, being based on in planta Agrobacterium-mediated gene transfer by flower infiltration, which is followed by recovery and selection of transgenic progeny. Genomic DNA changes in transgenic and control plants have been investigated by AFLP and RAMP analysis. Results show no statistically relevant genomic modifications in transgenic plants, as compared with control untreated plants. Variations were observed in callus-derived A. thaliana plants, thus supporting the conclusion that somaclonal variation is essentially correlated with the stress imposed by the in vitro cell culture, rather than with the integration of a foreign gene
    • 

    corecore