| 1. |
- Schael, S., et al.
(författare)
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Electroweak measurements in electron positron collisions at W-boson-pair energies at LEP
- 2013
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 532:4, s. 119-244
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Forskningsöversikt (refereegranskat)abstract
- Electroweak measurements performed with data taken at the electron positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3 fb(-1) collected by the four LEP experiments ALEPH, DELPHI, 13 and OPAL, at centre-of-mass energies ranging from 130 GeV to 209 GeV. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose Einstein correlations between the two W decay systems arising in WW production, are searched for and upper limits on the strength of possible effects are obtained. The data are used to determine fundamental properties of the W boson and the electroweak theory. Among others, the mass and width of the W boson, m(w) and Gamma(w), the branching fraction of W decays to hadrons, B(W -> had), and the trilinear gauge-boson self-couplings g(1)(Z), K-gamma and lambda(gamma), are determined to be: m(w) = 80.376 +/- 0.033 GeV Gamma(w) = 2.195 +/- 0.083 GeV B(W -> had) = 67.41 +/- 0.27% g(1)(Z) = 0.984(-0.020)(+0.018) K-gamma - 0.982 +/- 0.042 lambda(gamma) = 0.022 +/- 0.019. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- 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 SLID 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, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. 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, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), 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 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 5. |
- Holdaas, Hallvard, et al.
(författare)
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Conversion of Long-Term Kidney Transplant Recipients From Calcineurin Inhibitor Therapy to Everolimus : A Randomized, Multicenter, 24-Month Study
- 2011
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Ingår i: Transplantation. - 0041-1337 .- 1534-6080. ; 92:4, s. 410-418
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Tidskriftsartikel (refereegranskat)abstract
- Background. Benefits of conversion from calcineurin inhibitor (CNI) to mammalian target of rapamycin inhibitor-based immunosuppression in long-term kidney transplant patients remain uncertain. Methods. ASCERTAIN was a 24-month, open-label, multicenter study. Kidney transplant patients more than 6 months posttransplant receiving CNI (baseline glomerular filtration rate [GFR] 30-70 mL/min/1.73 m(2)) were randomized to everolimus with CNI elimination (n = 127) or CNI minimization (n = 144), or continued CNI unchanged (controls, n = 123) to assess the effect on measured GFR at month 24 after randomization. Results. Renal function was stable in all groups to month 24. Mean measured GFR at month 24, the primary endpoint, was 48.0 +/- 22.0 mL/min/1.73 m(2), 46.6 +/- 21.1 mL/min/1.73 m(2), and 46.0 +/- 20.4 mL/min/1.73 m(2) in the CNI elimination, CNI minimization, and control groups, respectively. Differences between CNI elimination (1.12 mL/min/1.73 m(2), 95% confidence interval [CI] -3.51 to 5.76, P=0.63) and CNI minimization (0.59 mL/min/1.73 m(2), 95% CI -3.88 to 5.07, P=0.79) versus controls at month 24 were nonsignificant that is, the primary endpoint was not met. No efficacy endpoint differed significantly between groups. Post hoc analyses showed that patients with baseline creatinine clearance (CrCl) more than 50 mL/min had a significantly greater increase in measured GFR after CNI elimination versus controls (difference 11.4 mL/min/1.73 m(2), 95% CI 2.1 to 20.8 mL/min/1.73 m(2), P=0.017). Adverse events resulted in discontinuation in 36 (28.3%) CNI elimination patients, 24 (16.7%) CNI minimization patients, and 5 (4.1%) controls (P<0.001 vs. CNI elimination; P=0.020 vs. CNI minimization). Conclusion. Conversion to everolimus with CNI elimination or minimization a mean of 5.6 years after kidney transplantation had no overall renal benefit and was associated with more frequent adverse events and discontinuations. Patients with CrCl more than 50 mL/min may benefit from a change in therapy more than 6 months after renal transplantation.
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| 6. |
- Kaltenbaek, Rainer, et al.
(författare)
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Macroscopic Quantum Resonators (MAQRO) : 2015 update
- 2016
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Ingår i: EPJ Quantum Technology. - : Springer Berlin/Heidelberg. - 2196-0763. ; 3:1
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Forskningsöversikt (refereegranskat)abstract
- Do the laws of quantum physics still hold for macroscopic objects - this is at the heart of Schrodinger's cat paradox - or do gravitation or yet unknown effects set a limit for massive particles? What is the fundamental relation between quantum physics and gravity? Ground-based experiments addressing these questions may soon face limitations due to limited free-fall times and the quality of vacuum and microgravity. The proposed mission Macroscopic Quantum Resonators (MAQRO) may overcome these limitations and allow addressing such fundamental questions. MAQRO harnesses recent developments in quantum optomechanics, high-mass matter-wave interferometry as well as state-of-the-art space technology to push macroscopic quantum experiments towards their ultimate performance limits and to open new horizons for applying quantum technology in space. The main scientific goal is to probe the vastly unexplored 'quantum-classical' transition for increasingly massive objects, testing the predictions of quantum theory for objects in a size and mass regime unachievable in ground-based experiments. The hardware will largely be based on available space technology. Here, we present the MAQRO proposal submitted in response to the 4th Cosmic Vision call for a medium-sized mission (M4) in 2014 of the European Space Agency (ESA) with a possible launch in 2025, and we review the progress with respect to the original MAQRO proposal for the 3rd Cosmic Vision call for a medium-sized mission (M3) in 2010. In particular, the updated proposal overcomes several critical issues of the original proposal by relying on established experimental techniques from high-mass matter-wave interferometry and by introducing novel ideas for particle loading and manipulation. Moreover, the mission design was improved to better fulfill the stringent environmental requirements for macroscopic quantum experiments.
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| 7. |
- Osterman, Julia, et al.
(författare)
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Mason bees and honey bees synergistically enhance fruit set in sweet cherry orchards
- 2023
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Ingår i: Ecology and Evolution. - 2045-7758. ; 13:7
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Tidskriftsartikel (refereegranskat)abstract
- Mason bees (Osmia spp.) are efficient fruit tree pollinators that can be encouraged to occupy and breed in artificial nesting material. In sweet cherry orchards, they are occasionally used as an alternative managed pollinator as a replacement for or in addition to honey bees (Apis mellifera). Yet, the lack of practical guidelines on management practices, for example optimal stocking rates, for both mason bee nesting material and honey bees might compromise pollination service provision. In this study, we assessed the relationship between stocking rates (honey bee hives and mason bee nesting material) and the abundance of honey bees and mason bees in 17 sweet cherry (Prunus avium) orchards in Central Germany. We furthermore performed a pollination experiment to explore the interactive effect of mason bees and honey bees on sweet cherry fruit set. In the orchards, both honey bee and mason bee abundance increased with increasing stocking rates of hives or nesting material, respectively. Honey bee abundance increased linearly with stocking rates. In contrast, mason bee abundance asymptoted at 2-3 nesting boxes per ha, beyond which more boxes resulted in little increase in visitation rate. Our pollination experiment demonstrated that orchards were pollen limited, with only 28% of insect-pollinated flowers setting fruit versus 39% of optimally hand-pollinated flowers. Honey bees and mason bees enhanced sweet cherry fruit set, but only when both were present and not when either was present alone in an orchard. Our findings demonstrate that offering nesting material for mason bees and employing honey bee hives can enhance bee abundance in sweet cherry orchards. By increasing honey bee abundance in combination with enhanced mason bee abundance, farmers can substantially boost fruit set and potentially sweet cherry yield. To enhance pollination services, farmers should consider the benefits of increasing pollinator biodiversity as an immediate benefit to improve crop yields.
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