108 research outputs found

    Constraints on large extra dimensions from the MINOS experiment

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    We report new constraints on the size of large extra dimensions from data collected by the MINOS experiment between 2005 and 2012. Our analysis employs a model in which sterile neutrinos arise as Kaluza-Klein states in large extra dimensions and thus modify the neutrino oscillation probabilities due to mixing between active and sterile neutrino states. Using Fermilab\u27s Neutrinos at the Main Injector beam exposure of 10.56 x 10(20) protons on target, we combine muon neutrino charged current and neutral current data sets from the Near and Far Detectors and observe no evidence for deviations from standard three-flavor neutrino oscillations. The ratios of reconstructed energy spectra in the two detectors constrain the size of large extra dimensions to be smaller than 0.45 mu m at 90% C.L. in the limit of a vanishing lightest active neutrino mass. Stronger limits are obtained for nonvanishing masses

    Search for Sterile Neutrinos Mixing with Muon Neutrinos in MINOS

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    We report results of a search for oscillations involving a light sterile neutrino over distances of 1.04 and 735 km in a nu(mu)-dominated beam with a peak energy of 3 GeV. The data, from an exposure of 10.56 x 10(20) protons on target, are analyzed using a phenomenological model with one sterile neutrino. We constrain the mixing parameters theta(24) and Delta m(41)(2) and set limits on parameters of the four-dimensional Pontecorvo-Maki-Nakagawa-Sakata matrix, vertical bar U-mu 4 vertical bar(2) and vertical bar U-tau 4 vertical bar(2), under the assumption that mixing between nu(e) and nu(s) is negligible (vertical bar U-e4 vertical bar(2) = 0). No evidence for nu(mu) -\u3e nu(s) transitions is found and we set a world-leading limit on theta(24) for values of Delta m(41)(2) less than or similar to 1 eV(2)

    Measurement of single pi(0) production by coherent neutral-current nu Fe interactions in the MINOS Near Detector

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    Forward single pi(0) production by coherent neutral-current interactions, vA - \u3e vA pi(0), is investigated using a 2.8 x 10(20) protons-on-target exposure of the MINOS Near Detector. For single-shower topologies, the event distribution in production angle exhibits a clear excess above the estimated background at very forward angles for visible energy in the range 1-8 GeV. Cross sections are obtained for the detector medium comprised of 80% iron and 20% carbon nuclei with (A) = 48, the highest- \u3c A \u3e target used to date in the study of this coherent reaction. The total cross section for coherent neutral-current single pi(0) production initiated by the v(mu) flux of the NuMI low-energy beam with mean (mode) E-v of 4.9 GeV (3.0 GeV), is 77.6 +/- 5.0 (stat)(-) (+15.0)(16.8) (syst) x 10(-40) cm(2) pernucleus. The results are in good agreement with predictions of the Berger-Sehgal model

    The Ty1 integrase protein can exploit the classical nuclear protein import machinery for entry into the nucleus

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    Like its retroviral relatives, the long terminal repeat retrotransposon Ty1 in the yeast Saccharomyces cerevisiae must traverse a permanently intact nuclear membrane for successful transposition and replication. For retrotransposition to occur, at least a subset of Ty1 proteins, including the Ty1 integrase, must enter the nucleus. Nuclear localization of integrase is dependent upon a C-terminal nuclear targeting sequence. However, the nuclear import machinery that recognizes this nuclear targeting signal has not been defined. We investigated the mechanism by which Ty1 integrase gains access to nuclear DNA as a model for how other retroelements, including retroviruses like HIV, may utilize cellular nuclear transport machinery to import their essential nuclear proteins. We show that Ty1 retrotransposition is significantly impaired in yeast mutants that alter the classical nuclear protein import pathway, including the Ran-GTPase, and the dimeric import receptor, importin-α/β. Although Ty1 proteins are made and processed in these mutant cells, our studies reveal that an integrase reporter is not properly targeted to the nucleus in cells carrying mutations in the classical nuclear import machinery. Furthermore, we demonstrate that integrase coimmunoprecipitates with the importin-α transport receptor and directly binds to importin-α. Taken together, these data suggest Ty1 integrase can employ the classical nuclear protein transport machinery to enter the nucleus

    Search for flavor-changing nonstandard neutrino interactions using nu(e) appearance in MINOS

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    We report new constraints on flavor-changing nonstandard neutrino interactions from the MINOS long-baseline experiment using nu(e) and (nu) over bar (e) appearance candidate events from predominantly nu(mu) and (nu) over bar (mu) beams. We used a statistical selection algorithm to separate nu(e) candidates from background events, enabling an analysis of the combined MINOS neutrino and antineutrino data. We observe no deviations from standard neutrino mixing, and thus place constraints on the nonstandard interaction matter effect, vertical bar epsilon(e tau)vertical bar, and phase, (delta(CP) + delta(e tau)), using a 30-bin likelihood fit

    LEDGF/p75-Independent HIV-1 Replication Demonstrates a Role for HRP-2 and Remains Sensitive to Inhibition by LEDGINs

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    Lens epithelium–derived growth factor (LEDGF/p75) is a cellular cofactor of HIV-1 integrase (IN) that interacts with IN through its IN binding domain (IBD) and tethers the viral pre-integration complex to the host cell chromatin. Here we report the generation of a human somatic LEDGF/p75 knockout cell line that allows the study of spreading HIV-1 infection in the absence of LEDGF/p75. By homologous recombination the exons encoding the LEDGF/p75 IBD (exons 11 to 14) were knocked out. In the absence of LEDGF/p75 replication of laboratory HIV-1 strains was severely delayed while clinical HIV-1 isolates were replication-defective. The residual replication was predominantly mediated by the Hepatoma-derived growth factor related protein 2 (HRP-2), the only cellular protein besides LEDGF/p75 that contains an IBD. Importantly, the recently described IN-LEDGF/p75 inhibitors (LEDGINs) remained active even in the absence of LEDGF/p75 by blocking the interaction with the IBD of HRP-2. These results further support the potential of LEDGINs as allosteric integrase inhibitors

    Hydroponic technologies

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    This open access book, written by world experts in aquaponics and related technologies, provides the authoritative and comprehensive overview of the key aquaculture and hydroponic and other integrated systems, socio-economic and environmental aspects. Aquaponic systems, which combine aquaculture and vegetable food production offer alternative technology solutions for a world that is increasingly under stress through population growth, urbanisation, water shortages, land and soil degradation, environmental pollution, world hunger and climate change.Hydroponics is a method to grow crops without soil, and as such, these systems are added to aquaculture components to create aquaponics systems. Thus, together with the recirculating aquaculture system (RAS), hydroponic production forms a key part of the aqua-agricultural system of aquaponics. Many different existing hydroponic technologies can be applied when designing aquaponics systems. This depends on the environmental and financial circumstances, the type of crop that is cultivated and the available space. This chapter provides an overview of different hydroponic types, including substrates, nutrients and nutrient solutions, and disinfection methods of the recirculating nutrient solutions

    Peptides derived from the HIV-1 integrase promote HIV-1 infection and multi-integration of viral cDNA in LEDGF/p75-knockdown cells

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    <p>Abstract</p> <p>Background</p> <p>The presence of the cellular Lens Epithelium Derived Growth Factor p75 (LEDGF/p75) protein is essential for integration of the Human immunodeficiency virus type 1 (HIV-1) cDNA and for efficient virus production. In the absence of LEDGF/p75 very little integration and virus production can be detected, as was demonstrated using LEDGF/p75-knokdown cells.</p> <p>Results</p> <p>Here we show that the failure to infect LEDGF/p75-knockdown cells has another reason aside from the lack of LEDGF/p75. It is also due to inhibition of the viral integrase (IN) enzymatic activity by an early expressed viral Rev protein. The formation of an inhibitory Rev-IN complex in virus-infected cells can be disrupted by the addition of three IN-derived, cell-permeable peptides, designated INr (IN derived-Rev interacting peptides) and INS (IN derived-integrase stimulatory peptide). The results of the present work confirm previous results showing that HIV-1 fails to infect LEDGF/p75-knockdown cells. However, in the presence of INrs and INS peptides, relatively high levels of viral cDNA integration as well as productive virus infection were obtained following infection by a wild type (WT) HIV-1 of LEDGF/p75-knockdown cells.</p> <p>Conclusions</p> <p>It appears that the lack of integration observed in HIV-1 infected LEDGF/p75-knockdown cells is due mainly to the inhibitory effect of Rev following the formation of a Rev-IN complex. Disruption of this inhibitory complex leads to productive infection in those cells.</p

    Measurement of single π0 production by coherent neutral-current ν Fe interactions in the MINOS Near Detector

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    Forward single π0 production by coherent neutral-current interactions, νA→νAπ0, is investigated using a 2.8×1020 protons-on-target exposure of the MINOS Near Detector. For single-shower topologies, the event distribution in production angle exhibits a clear excess above the estimated background at very forward angles for visible energy in the range 1-8 GeV. Cross sections are obtained for the detector medium comprised of 80% iron and 20% carbon nuclei with =48, the highest- target used to date in the study of this coherent reaction. The total cross section for coherent neutral-current single π0 production initiated by the νμ flux of the NuMI low-energy beam with mean (mode) Eν of 4.9 GeV (3.0 GeV), is 77.6±5.0(stat)-16.8+15.0(syst)×10-40 cm2 pernucleus. The results are in good agreement with predictions of the Berger-Sehgal model
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