1,970 research outputs found

    The Earth Mantle-Core Effect in Matter-Induced Asymmetries for Atmospheric Neutrino Oscillations

    Get PDF
    Earth medium effects in the three-neutrino oscillations of atmospheric neutrinos are observable under appropriate conditions. This paper generalizes the study of the medium effects and the possibility of their observation in the atmospheric neutrino oscillations from the case of neutrinos traversing only the Earth mantle, where the density is essentially constant, to the case of atmospheric neutrinos crossing also the Earth core. In the latter case new resonance-like effects become apparent. We calculate the CPT-odd asymmetry for the survival probability of muon neutrinos and the observable muon-charge asymmetry, taking into account the different atmospheric neutrino fluxes, and show the dependence of these asymmetries on the sign of Δm312\Delta m^{2}_{3 1} and on the magnitude of the mixing angle θ13\theta_{13}. A magnetized detector with a sufficiently good neutrino momentum resolution is required for the observation of the muon-charge asymmetry generated by the Earth mantle-core effect.Comment: 14 pages, 5 figure

    Are small neutrino masses unveiling the missing mass problem of the Universe?

    Get PDF
    We present a scenario in which a remarkably simple relation linking dark matter properties and neutrino masses naturally emerges. This framework points towards a low energy theory where the neutrino mass originates from the existence of a light scalar dark matter particle in the MeV mass range. A very surprising aspect of this scenario is that the required MeV dark matter is one of the favoured candidates to explain the mysterious emission of 511 keV photons in the centre of our galaxy. A possible interpretation of these findings is that dark matter is the stepping stone of a theory beyond the standard model instead of being an embarrassing relic whose energy density must be accounted for in any successful model building.Comment: 4pages, 2 figures. Two paragraphs have been added. One for the complex case; the other one for the UV completio

    Growth, mortality and recruitment of commercially important fishes and penaeid shrimps in Indonesian waters

    Get PDF
    Population dynamics, Stock assessment, Commercial species, Shrimp fisheries, Arafura Sea, Indonesia, Penaeus merguiensis

    On the Atmospheric Neutrino Oscillations, theta13 and Neutrino Mass Hierarchy

    Full text link
    We give predictions for the up-down asymmetry in the Nadir angle dependence of the ratio Nmu/Ne of the rates of the mu-like and e-like multi-GeV events measured in water-Cerenkov detectors (Super-Kamiokande, etc.) in the case of 3-neutrino oscillations of the atmospheric nu_e (antinu_e) and nu_mu (antinu_mu), driven by one neutrino mass squared difference, |Delta m^2_{atm}| = |Delta m^2_{31}| ~ (2.0 - 3.0) 10^{-3} eV^2 >> Delta m^2_{21} = Delta m^2_{sol}. This ratio is particularly sensitive to the Earth matter effects in the atmospheric neutrino oscillations, and thus to the values of sin^2(theta13) and sin^2(theta23), theta13 and theta23 being the neutrino mixing angle limited by the CHOOZ and Palo Verde experiments and that responsible for the dominant atmospheric nu_mu -> nu_tau (antinu_mu -> antinu_tau) oscillations, respectively. It is also sensitive to the type of neutrino mass spectrum which can be with normal (Delta m^2_{atm} > 0) or with inverted (Delta m^2_{atm} < 0) hierarchy.Comment: 8 pages, 1 figure. Talk given at NOON2004, February 11 - 15, 2004, Tokyo, Japa

    Population kinetics during simultaneous infection of insect cells with two different recombinant baculoviruses for the production of rotavirus-like particles

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The simultaneous production of various recombinant proteins in every cell of a culture is often needed for the production of virus-like particles (VLP) or vectors for gene therapy. A common approach for such a purpose is the coinfection of insect cell cultures with different recombinant baculoviruses, each containing one or more recombinant genes. However, scarce information exists regarding kinetics during multiple infections, and to our knowledge, no studies are available on the behavior of the different populations that arise during coinfections. Such information is useful for designing infection strategies that maximize VLP or vector yield. In this work, kinetics of cell populations expressing rotavirus GFPVP2 (infected with bacGFPVP2), VP6 (infected with bacVP6), or both proteins simultaneously (coinfected with both baculoviruses) were followed by flow cytometry.</p> <p>Results</p> <p>In single infections, the population infected with any of the recombinant baculoviruses followed the Poisson distribution, as the population expressing a recombinant protein exhibited a hyperbolic-type function with respect to the multiplicity of infection (MOI) up to 5 pfu/cell. In coinfections, the population fraction expressing each recombinant protein could not be anticipated from results of single infections, as in some cases interference and synergistic effects were found. Only cultures with a total MOI below 5 pfu/cell followed the Poisson distribution. For cultures with a MOI of bacGFPVP2 above that of bacVP6 (overall MOI above 5 pfu/cell), the total population expressing one or both recombinant proteins was as low as 50% below that predicted by Poisson. In contrast, the population fraction expressing VP6 increased in coinfections, compared to that in single infections. The largest population fraction simultaneously expressing both recombinant proteins was 58%, and corresponded to cultures infected at a MOI of 5 and 1 pfu/cell of bacGFPVP2 and bacVP6, respectively.</p> <p>Conclusion</p> <p>The infection conditions that maximize the cell population simultaneously expressing two recombinant proteins were determined. Such conditions could not have been anticipated from population kinetics in individual infections. This information should be taken into account for improved simultaneous production of various recombinant proteins in any work dealing with coinfections.</p

    Transcriptional and metabolic response of CHO cells to different carbon dioxide concentrations

    Get PDF
    Please click Additional Files below to see the full abstract

    Overexpression of the mitochondrial pyruvate carrier increases CHO cell and recombinant protein productivity and reduces lactate production

    Get PDF
    The metabolism of CHO cells is characterized by a low efficiency of glucose metabolism, resulting in lactate production. We hypothesized that the cause of such low efficiency is a slow transportation of pyruvate into the mitochondria. The mitochondrial pyruvate carrier (mpc), responsible of introducing pyruvate into the mitochondria, is formed of two subunits, mpc1 and mpc2. We constructed stable CHO cell lines overexpressing both genes in order to facilitate the entry of pyruvate into the mitochondria and its incorporation into oxidative pathways. Overexpression of both genes was verified by qPCR and Western Blot, showing a significant increase compared to the basal level on the control cells. Kinetic evaluation of the CHO-mpc cells showed a 50% reduction of the lactate concentration respect to the control. Cell growth rate and maximum concentration were also increased, and an increase of 40% on the production of recombinant secreted placental alkaline phosphatase was observed. We show that transport of pyruvate into the mitochondria limits the efficiency of oxidation of glucose, which can be overcome by a cell engineering approach. Financial support by UNAM-DGAPA-PAPIIT IT-200315 and SEP-CONACyT Ciencia Básica 255445

    Neutrino decay as a possible interpretation to the MiniBooNE observation with unparticle scenario

    Full text link
    In a new measurement on neutrino oscillation νμ→νe\nu_{\mu}\to\nu_e, the MiniBooNE Collaboration observes an excess of electron-like events at low energy and the phenomenon may demand an explanation which obviously is beyond the oscillation picuture. We propose that heavier neutrino ν2\nu_2 decaying into a lighter one ν1\nu_1 via the transition process νμ→νe+X\nu_{\mu}\to \nu_e+X where XX denotes any light products, could be a natural mechanism. The theoretical model we employ here is the unparticle scenario established by Georgi. We have studied two particular modes \nu_\mu\to \nu_e+\Un and νμ→νe+νˉe+νe\nu_\mu\to \nu_e+\bar\nu_e+\nu_e. Unfortunately, the number coming out from the computation is too small to explain the observation. Moreover, our results are consistent with the cosmology constraint on the neutrino lifetime and the theoretical estimation made by other groups, therefore we can conclude that even though neutrino decay seems plausible in this case, it indeed cannot be the source of the peak at lower energy observed by the MiniBooNE collaboration and there should be other mechanisms responsible for the phenomenon.Comment: 14 pages, conclusions are changed; published version for EPJ

    Distinct regulation of tonsillar immune response in virus infection

    Get PDF
    Cataloged from PDF version of article.Background: The relationships between tonsillar immune responses, and viral infection and allergy are incompletely known. Objective To study intratonsillar/nasopharyngeal virus detections and in vivo expressions of T-cell- and innate immune response-specific cytokines, transcription factors, and type I/II/III interferons in human tonsils. Methods: Palatine tonsil samples were obtained from 143 elective tonsillectomy patients. Adenovirus, bocavirus-1, coronavirus, enteroviruses, influenza virus, metapneumovirus, parainfluenza virus, rhinovirus, and respiratory syncytial virus were detected using PCR. The mRNA expression levels of IFN-α, IFN-β, IFN-γ, IL-10, IL-13, IL-17, IL-28, IL-29, IL-37, TGF-β, FOXP3, GATA3, RORC2, and Tbet were directly analyzed by quantitative RT-PCR. Results Fifty percentage of subjects reported allergy, 59% had ≥1 nasopharyngeal viruses, and 24% had ≥1 intratonsillar viruses. Tonsillar virus detection showed a strong negative association with age; especially rhinovirus or parainfluenza virus detection showed positive association with IFN-γ and Tbet expressions. IL-37 expression was positively associated with atopic dermatitis, whereas IFN-α, IL-13, IL-28, and Tbet expressions were negatively associated with allergic diseases. Network analyses demonstrated strongly polarized clusters of immune regulatory (IL-10, IL-17, TGF-β, FOXP3, GATA3, RORC2, Tbet) and antiviral (IFN-α, IFN-β, IL-28, IL-29) genes. These two clusters became more distinctive in the presence of viral infection or allergy. A negative correlation between antiviral cytokines and IL-10, IL-17, IL-37, FOXP3, and RORC2 was observed only in the presence of viruses, and interestingly, IL-13 strongly correlated with antiviral cytokines. Conclusions: Tonsillar cytokine expression is closely related to existing viral infections, age, and allergic illnesses and shows distinct clusters between antiviral and immune regulatory genes. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
    • …
    corecore