228 research outputs found

    Nigrosine staining of wheat endosperm proteolipid patterns on starch gels

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    We have previously characterized a group of proteolipids from wheat endosperm, designated CM proteins, which are soluble in chloroformmethanol (2:1, v/v) and have a molecular weight lower than 25,000 daltons (1-3). These have been also studied by Redman and Ewart (4). The CM proteins are suitably fractionated into several components by starch gel electrophoresis at pH 3.2 (1). A sensitive staining procedure was required in connection with genetic studies of these proteins because phenotypes had to be ascertained in small endosperm fractions dissected without impairing normal germination and plant development. We report here on Nigrosine staining conditions for CM proteins under which high sensitivity and selectivity are achieve

    Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk

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    BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat

    On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

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    A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

    Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

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    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

    Volume I. Introduction to DUNE

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    The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE\u27s physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology

    Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

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    A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

    Highly-parallelized simulation of a pixelated LArTPC on a GPU

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    The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

    Deep Underground Neutrino Experiment (DUNE), far detector technical design report, volume III: DUNE far detector technical coordination

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    The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume III of this TDR describes how the activities required to design, construct, fabricate, install, and commission the DUNE far detector modules are organized and managed. This volume details the organizational structures that will carry out and/or oversee the planned far detector activities safely, successfully, on time, and on budget. It presents overviews of the facilities, supporting infrastructure, and detectors for context, and it outlines the project-related functions and methodologies used by the DUNE technical coordination organization, focusing on the areas of integration engineering, technical reviews, quality assurance and control, and safety oversight. Because of its more advanced stage of development, functional examples presented in this volume focus primarily on the single-phase (SP) detector module

    Overview of the JET results in support to ITER

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    An overview of the geochemical and isotopic characteristics of the eastern australian cainozoic volcanic provinces

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    A broad zone of intra-plate volcanism occurs for some 3000 km along eastern Australia. Mafic lavas dominate, and include the following types (with frequency % occurrence, based on 1757 analyses): Leucitites (21), melilitites, nephelinites, and analcimites (5-4), basanites (12-7), alkali basalts (7-0), ne- hawaiites and hawaiites (44-4), transitional basalts and Ol-tholeiites (17-4), and Q-tholeiites (11-0). These lavas are erupted through a wide variety of crustal-tectonic environments, from Proterozoic to Mesozoic. Marked differences in chemistry exist between the lavas erupted from central volcano provinces (in which most ‘evolved’ lava types occur) and lava-field provinces, the former exhibiting greater isotopic variability and evidence for more extensive crystal fractionation (AFC). More evolved lava types include mugearites, benmoreites, icelandites, peralkaline and non-peralkaline trachytes and phonolites, comendites, low-silica and high-silica rhyolites. Marked regional differences exist with respect to distribution of various lava types; northern Queensland and Tasmania, for example, apparently have very few strongly evolved lavas, the latter region also containing a disproportionately high percentage of nephelinites. Trace element geochemistry of the mafic lavas is very variable, but typically continental; the lavas are enriched in incompatible elements, but enrichment varies greatly, being extreme in the leucitites, melilitites, and nephelinites, and slight (relative to MORB) in certain Q-tholeiites. It is shown that the patterns of the more extreme incompatible element enrichments are consistent with recent work on extraction of small melt fractions. Nevertheless, marked source inhomogeneities are indicated by the data, believed to be lithospheric; arc-modified lithosphere is suggested as a source for at least some lava field tholeiites. It is clear, however, that the majority of lavas have been modified by some degree of low-medium pressure crystal fractionation processes (olivine ±augite ± plagioclase ± Fe-Ti oxides). The critical role of fractional crystallization is even more apparent in the chemistry of the intermediate and silicic lavas, which exhibit dual patterns of progressive and ultimately extreme element enrichment (e.g., Pb, Th) and depletion (e.g., Mg, V, Ni, Cr, Sr, Ba, Eu). These patterns are readily modelled by Rayleigh fractionation, but require elevated K values, appropriate to silicic magmas; continually varying Ks are also indicated by some data sets. The mafic lavas exhibit a wide, but continuous variation of isotopic compositions, there being marked regional differences, but with the leucitite exception, no particular compositional ranges characterize particular compositional types. Correlations are observed between Sr, Nd, and to a less extent Pb isotopic compositions with, for example, Bh/Th, Ba/Nb, and mg-ratios. Much of the observed geochemical-isotope data, excepting the most undersaturated lavas, can be modelled in terms of AFC processes, utilizing upper and lower crustal models. The isotopic data of the alkaline Tasmanian lavas are distinctive and are interpreted as asthenospheric; these compositions, and those of rare magnesian alkaline lavas from elsewhere in the region, suggest a mixed mantle source containing a component approaching the ‘St. Helena-type’. The leucitites have a marked DUPAL isotopic signature, and it is noted that these occur above an interpreted Proterozoic rift system, suggesting a lithospheric source. Isotopic and geochemical data for the trachytes and low-silica rhyolites are consistent with AFC processes, with variable assimilation, modelled in terms of upper crustal components. The high-silica rhyolites are isotopically distinctive, and are interpreted as local upper crustal melts, but modified by subsequent crystal-liquid fractionation
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