10 research outputs found

    Weather regimes and analogues downscaling of seasonal precipitation for the 21st century: A case study over Israel

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    Global climate models provide only partial information on local-scale phenomenon, such as precipitation, primarily due to their coarse resolution. In this study, statistical downscaling algorithms, based on both weather regimes and past analogues, are operated for 18 Israeli rain gauges with an altitude ranging between −200 and ~1,000 m above sea level (ASL). To project seasonal precipitation over Israel and its hydrologic basins, the algorithms are applied to six Coupled Model Inter-comparison Project Phase 5 (CMIP5) models for the end of the 21st century, according to the RCP4.5 and RCP8.5 scenarios. The downscaled models can capture quite well the seasonal precipitation distribution, though with underestimation in winter and overestimation in spring. All models display a significant reduction of seasonal precipitation for the 21st century according to both scenarios. The winter reductions for the end of the century and the RCP8.5 scenario are found to be ~22 and ~37% according to the weather regimes and the analogues downscaling methods, respectively. Spring reductions are found to be ~10–20% larger than winter reductions. It is shown that the projected reduction results from a decrease in the frequency of the rain-bearing systems, as well as a decrease in the average daily precipitation intensity. The areas with the largest reductions in seasonal precipitation are found over the central mountains, the Mediterranean coastal area, and the Sea of Galilee hydrologic basins, which are the main fresh-water aquifers and reservoirs of Israel. The statistical downscaling methods applied in this study can be easily transferred to other regions where long-term data sets of observed precipitation are available. This study and others may serve as a basis for priority and policy setting toward better climate adaptation with associated uncertainties related to the methods used and nonstationary of the climate system

    Surgical Antimicrobial Prophylaxis: Principles and Guidelines

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    Reproducibility of fluorescent expression from engineered biological constructs in E. coli

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    We present results of the first large-scale interlaboratory study carried out in synthetic biology, as part of the 2014 and 2015 International Genetically Engineered Machine (iGEM) competitions. Participants at 88 institutions around the world measured fluorescence from three engineered constitutive constructs in E. coli. Few participants were able to measure absolute fluorescence, so data was analyzed in terms of ratios. Precision was strongly related to fluorescent strength, ranging from 1.54-fold standard deviation for the ratio between strong promoters to 5.75-fold for the ratio between the strongest and weakest promoter, and while host strain did not affect expression ratios, choice of instrument did. This result shows that high quantitative precision and reproducibility of results is possible, while at the same time indicating areas needing improved laboratory practices.Peer reviewe

    Precision Electroweak Measurements on the Z resonance.

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    We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron–positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarised beam at SLC. The measurements include cross-sections, forward–backward asymmetries and polarised asymmetries. The mass and width of the Z boson, mZ and ΓZ, and its couplings to fermions, for example the ρ parameter and the effective electroweak mixing angle for leptons, are precisely measured: The number of light neutrino species is determined to be 2.9840±0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward–backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, , and the mass of the W boson, . These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of mt and mW, the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than at 95% confidence level

    Precision electroweak measurements on the Z resonance

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