6,841,511 research outputs found

    The Willowbrook Experiments

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    Susceptibility of Myzus persicae, Brevicoryne brassicae and Nasonovia ribisnigri to fungal biopesticides in laboratory and field experiments

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    The aim of this study was to evaluate the potential of entomopathogenic fungi (EPF) for the control of aphid pests of field vegetable crops. Four biopesticides based on the EPF Beauveria bassiana (Botanigard ES and Naturalis L), Cordyceps fumosorosea s.l. (Preferal WG), and Akanthomyces dipterigenus (Vertalec) were evaluated in a laboratory bioassay against peach-potato aphid Myzus persicae, cabbage aphid Brevicoryne brassicae, and currant-lettuce aphid Nasonovia ribisnigri. There was significant variation in the spore dose provided by the products, with Botanigard ES producing the highest dose (639 viable spores per mm2). Botanigard ES also caused more mortality than the other products. Combining Vertalec with the vegetable oil-based adjuvant Addit had an additive effect on the mortality of B. brassicae. All fungal products reduced the number of progeny produced by M. persicae but there was no effect with B. brassicae or N. ribisnigri. When aphid nymphs were treated with Botanigard ES and Preferal WG, both products reduced population development, with up to 86% reduction occurring for Botanigard ES against M. persicae. In a field experiment, Botanigard ES sprayed twice, at seven-day intervals, against B. brassicae on cabbage plants, reduced aphid numbers by 73%. In a second field experiment with B. brassicae, M. persicae, and N. ribisnigri, Botanigard ES reduced populations of B. brassicae and N. ribisnigri but there was no significant effect on M. persicae

    Reactor antineutrino experiments

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    Neutrinos are elementary particles in the standard model of particle physics. There are 3 flavors of neutrinos that oscillate among themselves. Their oscillation can be described by a 3×\times3 unitary matrix, containing three mixing angles θ12\theta_{12}, θ23\theta_{23}, θ13\theta_{13}, and one CP phase. Both θ12\theta_{12} and θ23\theta_{23} are known from previous experiments. θ13\theta_{13} was unknown just two years ago. The Daya Bay experiment gave the first definitive non-zero value in 2012. An improved measurement of the oscillation amplitude sin22(θ13)\sin^{2}2(\theta_{13}) = 0.0900.009+0.0080.090^{+0.008}_{-0.009} and the first direct measurement of the νˉe\bar\nu_{e} mass-squared difference \midΔmee2\Delta m^2_{ee}\mid = (2.590.20+0.19)×103eV2(2.59^{+0.19}_{-0.20})\times10^{-3} \rm eV^{2} were obtained recently. The large value of θ13\theta_{13} boosts the next generation of reactor antineutrino experiments designed to determine the neutrino mass hierarchy, such as JUNO and RENO-50

    CMB Polarization Experiments

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    We discuss the analysis of polarization experiments with particular emphasis on those that measure the Stokes parameters on a ring on the sky. We discuss the ability of these experiments to separate the EE and BB contributions to the polarization signal. The experiment being developed at Wisconsin university is studied in detail, it will be sensitive to both Stokes parameters and will concentrate on large scale polarization, scanning a 47o47^o degree ring. We will also consider another example, an experiment that measures one of the Stokes parameters in a 1o1^o ring. We find that the small ring experiment will be able to detect cosmological polarization for some models consistent with the current temperature anisotropy data, for reasonable integration times. In most cosmological models large scale polarization is too small to be detected by the Wisconsin experiment, but because both QQ and UU are measured, separate constraints can be set on EE and BB polarization.Comment: 27 pages with 12 included figure

    Hadron Production Experiments

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    Precise prediction of the neutrino flux is a key ingredient to achieving the physics goals of accelerator-based neutrino experiments. In modern accelerator-based neutrino experiments, neutrino beams are created by colliding protons with a nuclear target. Secondary hadrons are produced in these collisions, and their decays contribute to the neutrino flux. The hadron production is the leading systematic uncertainty source on the neutrino flux prediction; therefore its precise measurement is desirable. In these proceedings, review of recent hadron production measurements and the latest results from the NA61/SPS Heavy Ion and Neutrino Experiment (NA61/SHINE) are presented. In addition, plans of NA61/SHINE hadron production measurements for the next generation neutrino experiments and NA61/SHINE physics program extension beyond 2020 are discussed.Comment: Talk presented at NuPhys2016 (London, 12-14 December 2016). 8 pages, LaTeX, 10 figure

    Experiments On Humans

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    From Models to Experiments

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    In this paper we discuss James Buchanan’s contribution in the narrow domain of understanding committee voting under majority rule. We then go on to discuss Charles Plott’s seminal experimental work on the topic that sparked a wave of public choice experimental work. However, given Plott’s claims that Buchanan influenced him significantly, it is puzzling that his work with Morris Fiorina explores a question outside of those which Buchanan and Tullock found interesting. We suggest several ways to resolve this tension. Our chapter concludes by discussing a lacuna in the experimental public choice literature in which Buchanan was particularly interested—logrolling, or vote trading
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