1,724 research outputs found

    Tripartite relationships: The chemical ecology of tree-herbivore-pathogen interactions

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    The role of cytokinin receptors in plant defense response of Nicotiana attenuata

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    Phonon emission and absorption in the fractional quantum Hall effect

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    We investigate the time dependent thermal relaxation of a two-dimensional electron system in the fractional quantum Hall regime where ballistic phonons are used to heat up the system to a non-equilibrium temperature. The thermal relaxation of a 2DES at Μ=1/2\nu=1/2 can be described in terms of a broad band emission of phonons, with a temperature dependence proportional to T4T^4. In contrast, the relaxation at fractional filling Μ=2/3\nu=2/3 is characterized by phonon emission around a single energy, the magneto-roton gap. This leads to a strongly reduced energy relaxation rate compared to Μ=1/2\nu=1/2 with only a weak temperature dependence for temperatures 150 mK <T<< T < 400 mK.Comment: 4 pages, 3 figures; 14th International Conference on High Magnetic Fields in Semiconductor Physics, September 24-29, 2000, Matsue, Japa

    Full O(alpha) corrections to e+e- -> sf_i sf_j

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    We present a complete precision analysis of the sfermion pair production process e+e- -> sf_i sf_j (f = t, b, tau, nu_tau) in the Minimal Supersymmetric Standard Model. Our results extend the previously calculated weak corrections by including all one-loop corrections together with higher order QED corrections. We present the details of the analytical calculation and discuss the renormalization scheme. The numerical analysis shows the results for total cross-sections, forward-backward and left-right asymmetries. It is based on the SPS1a' point from the SPA project. The complete corrections are about 10% and have to be taken into account in a high precision analysis.Comment: 32 pages, 24 figures, RevTeX

    Microwave spectroscopy on a double quantum dot with an on-chip Josephson oscillator

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    We present measurements on microwave spectroscopy on a double quantum dot with an on-chip microwave source. The quantum dots are realized in the two-dimensional electron gas of an AlGaAs/GaAs heterostructure and are weakly coupled in series by a tunnelling barrier forming an 'ionic' molecular state. We employ a Josephson oscillator formed by a long Nb/Al-AlOx_x/Nb junction as a microwave source. We find photon-assisted tunnelling sidebands induced by the Josephson oscillator, and compare the results with those obtained using an externally operated microwave source.Comment: 6 pages, 4 figure

    Incidence of Smoking-Related Second Primary Cancers After Lung Cancer in Germany: An Analysis of Nationwide Cancer Registry Data

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    Introduction Approximately 80% of lung cancer cases in Germany are attributable to smoking. Patients with a lung cancer diagnosis may remain at increased risk of developing smoking-related second primary cancers (SPCs). Methods Anonymous data from 11 population-based cancer registries covering approximately 50% of the German population were pooled for the analysis. Included patients were diagnosed with having an index lung cancer between 2002 and 2013, aged 30 to 99 years old at diagnosis, and survived for at least 6 months. We calculated standardized incidence ratios (SIRs)—stratified by age, sex, region, and period—comparing the incidence of smoking-related and other SPCs to the general population. Results Of the 135,589 lung cancer survivors (68.2% male; mean follow-up 30.8 mo) analyzed, 5298 developed an SPC. In males, the risk was particularly high for SPCs of the larynx (SIR = 3.70, 95% confidence interval [CI]: 3.14–4.34), pharynx (3.17, 2.61–3.81), and oral cavity (2.86, 2.38–3.41). For females, SIRs were notably elevated for the esophagus (4.66, 3.15–6.66), oral cavity (3.14, 2.03–4.63), and urinary tract (2.68, 2.04–3.45). When combining all smoking-related cancer sites, SIR was 1.41 in males (95% CI: 1.36–1.47) and 1.81 in females (95% CI: 1.68–1.94). We observed that males had a 1.46-fold (95% CI: 1.37–1.56) and females a 1.33-fold (95% CI: 1.20–1.47) increased risk for smoking-related compared with other cancers. Conclusions Patients with primary lung cancer were at increased risk for developing a smoking-related SPC. Therefore, the advantages of increased patient surveillance and the benefits of smoking cessation strategies should be considered.Peer Reviewe

    Supersymmetry Tests from a Combined Analysis of Chargino and Charged Higgs Boson Pair Production at a 1 TeV Linear Collider

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    We consider the production of chargino and charged Higgs boson pairs at future linear colliders for c.m. energies in the one TeV range. Working in the MSSM under the assumption of a "moderately" light SUSY scenario, we compute the leading (double) and next-to leading (linear) supersymmetric logarithmic terms of the so-called "Sudakov expansion" at one loop. We show that a combined analysis of the slopes of the chargino and of the charged Higgs production cross sections would offer a simple possibility for determining tan⁥ÎČ\tan\beta for large (≳10\gtrsim 10) values and an allowed strip in the (M2,ÎŒM_2,\mu) plane. This could provide a strong consistency test of the considered supersymmetric model.Comment: 4 pages, 4 Encapsulated PostScript Figure

    On the two-loop sbottom corrections to the neutral Higgs boson masses in the MSSM

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    We compute the O(ab*as) two-loop corrections to the neutral Higgs boson masses in the Minimal Supersymmetric Standard Model, using the effective potential approach. Such corrections can be important in the region of parameter space corresponding to tan(beta)>>1 and sizeable mu. In spite of the formal analogy with the O(at*as) corrections, there are important differences, since the dominant effects are controlled by the sbottom-Higgs scalar couplings. We propose a convenient renormalization scheme that avoids unphysically large threshold effects associated with the bottom mass, and absorbs the bulk of the O(ab*as + ab*at) corrections into the one-loop expression. We give general explicit formulae for the O(ab*as) corrections to the neutral Higgs boson mass matrix. We also discuss the importance of the O(ab^2) corrections and derive a formula for their contribution to mh in a simple limiting case.Comment: 14 pages, 4 figures. Version to appear in Nucl. Phys.
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