Lobbies contra Agrarwende

Eine Agrarwende benötigt modifizierte politisch-rechtliche Rahmenbedingungen und ein offenes Beratungssystem, das sie flankiert und unterstützt. Eine aktu­elle Studie der Lobbyverflechtungen in Deutschland zeigt, dass es vor allem an Letzterem noch hapert

The quest for the Cabibbo Kobayashi Maskawa Matrix

A piece of the Standard Model presently undergoing intense experimental scrutiny is the Cabibbo Kobayashi Maskawa matrix. Several different measurements are planned to enrich the spectrum of experimental constraints and thus provide one of the most stringent tests of Standard Model validity. The success of this program is closely related to theoretical progress in evaluating QCD matrix elements in a non-perturbative regime, as we need to extract fundamental quark properties from observations on decays involving hadrons. This interplay between experimental and theoretical progress will be illustrated in the context of the present knowledge of the magnitudes of the quark mixing parameters $| V_{cb}|$ and $| V_{ub}|$.Comment: 10 pages, 1 figure, contributed paper to BEAUTY 200

Three-Dimensional Light Bullets in Arrays of Waveguides

We report the first experimental observation of 3D-LBs, excited by femtosecond pulses in a system featuring quasi-instantaneous cubic nonlinearity and a periodic, transversally-modulated refractive index. Stringent evidence of the excitation of LBs is based on time-gated images and spectra which perfectly match our numerical simulations. Furthermore, we reveal a novel evolution mechanism forcing the LBs to follow varying dispersion/diffraction conditions, until they leave their existence range and decay.Comment: 4 pages, 5 figures - Published by the American Physical Societ

Intra-cavity measurement concept of dispersion properties with a tunable fiber-integrated laser

The dispersion properties of fibers depict a key characteristic to model the propagation of ultra-short pulses in waveguides. In the following, a new method is presented to directly measure the dispersion properties of fibers and optical components in the time domain. The analysis is based on pulse shape variations along the tuning range of a theta cavity fiber laser (TCFL) depending on the adjusted repetition rate. The automated measurement procedure, evaluating pulse symmetry, achieves a temporal sensitivity below 5 ps surpassing the resolution of the acquisition electronics. Exemplarily, two samples of Nufern PM980-XP fiber are investigated with an Yb-doped tunable TCFL retrieving the mean dispersion parameter D? by comparative measurements. The obtained results are compared to a reference method based on spectral interferometry. With deviations in D? between either approach of 0.3% and 1.3%, respectively, the results agree well within the measurement errors of the TCFL, verifying the presented concept. Due to the pulse formation process extending over multiple round trips, this approach achieves an enhanced sensitivity compared to competing direct temporal methods. Together with an alignment free operation, the fiber-integrated TCFL depicts a simple and robust concept showing potential in specific measurement scenarios such as in quality management. © 2019 Astro Ltd

Third-generation leptoquark decays and collider searches

Collider searches for first-, second-, and third-generation scalar (S) or vector (V) leptoquarks (LQs) focus on the quark-lepton decay modes S,V -> q l. For SU(2)-doublet and -triplet leptoquarks with a sufficiently large splitting between the components, decays involving real W-boson emission (such as S_2^{(+5/3)} -> S_2^{(+2/3)} W^{+} and others) become possible and can change the patterns of leptoquark decays. For third-generation leptoquarks, where these mass splittings might be large, such modes could dominate certain leptoquark decays as they are (if kinematically allowed) guaranteed to be of order g^2 where g is the electroweak coupling. We calculate the decay rates for all such processes involving SU(2)-doublet and triplet, scalar and vector leptoquarks. Standard limits on mass splittings from precision electroweak measurements imply that only such decays involving SU(2)-doublet scalar LQs are likely kinematically possible.Comment: 13 pages, LaTeX, 2 separate postscript figure

CLEO Contributions to Tau Physics

We review many of the contributions of the CLEO experiment to tau physics. Topics discussed are: branching fractions for major decay modes and tests of lepton universality; rare decays; forbidden decays; Michel parameters and spin physics; hadronic sub-structure and resonance parameters; the tau mass, tau lifetime, and tau neutrino mass; searches for CP violation in tau decay; tau pair production, dipole moments, and CP violating EDM; and tau physics at CLEO-III and at CLEO-c.Comment: Invited talk at the Seventh International Workshop on Tau Lepton Physics (TAU02), Santa Cruz, Ca, USA, Sept 2002, 14 pages, LaTeX, 21 eps figure

Interfaces with a single growth inhomogeneity and anchored boundaries

The dynamics of a one dimensional growth model involving attachment and detachment of particles is studied in the presence of a localized growth inhomogeneity along with anchored boundary conditions. At large times, the latter enforce an equilibrium stationary regime which allows for an exact calculation of roughening exponents. The stochastic evolution is related to a spin Hamiltonian whose spectrum gap embodies the dynamic scaling exponent of late stages. For vanishing gaps the interface can exhibit a slow morphological transition followed by a change of scaling regimes which are studied numerically. Instead, a faceting dynamics arises for gapful situations.Comment: REVTeX, 11 pages, 9 Postscript figure

Mirabegron-induced brown fat activation does not exacerbate atherosclerosis in mice with a functional hepatic ApoE-LDLR pathway

Activation of brown adipose tissue (BAT) with the β3-adrenergic receptor agonist CL316,243 protects mice from atherosclerosis development, and the presence of metabolically active BAT is associated with cardiometabolic health in humans. In contrast, exposure to cold or treatment with the clinically used β3-adrenergic receptor agonist mirabegron to activate BAT exacerbates atherosclerosis in apolipoprotein E (ApoE)- and low-density lipoprotein receptor (LDLR)-deficient mice, both lacking a functional ApoE-LDLR pathway crucial for lipoprotein remnant clearance. We, therefore, investigated the effects of mirabegron treatment on dyslipidemia and atherosclerosis development in APOE*3-Leiden.CETP mice, a humanized lipoprotein metabolism model with a functional ApoE-LDLR clearance pathway. Mirabegron activated BAT and induced white adipose tissue (WAT) browning, accompanied by selectively increased fat oxidation and attenuated fat mass gain. Mirabegron increased the uptake of fatty acids derived from triglyceride (TG)-rich lipoproteins by BAT and WAT, which was coupled to increased hepatic uptake of the generated cholesterol-enriched core remnants. Mirabegron also promoted hepatic very low-density lipoprotein (VLDL) production, likely due to an increased flux of fatty acids from WAT to the liver, and resulted in transient elevation in plasma TG levels followed by a substantial decrease in plasma TGs. These effects led to a trend toward lower plasma cholesterol levels and reduced atherosclerosis. We conclude that BAT activation by mirabegron leads to substantial metabolic benefits in APOE*3-Leiden.CETP mice, and mirabegron treatment is certainly not atherogenic. These data underscore the importance of the choice of experimental models when investigating the effect of BAT activation on lipoprotein metabolism and atherosclerosis.</p