Hemodynamic and inotropic effects of endothelin-1 in vivo

Endothelin-1 (ET-1) is known to have strong vasoactive properties. Contradictory results have been reported with regard to its inotropic effects. This study examined the dose-dependent (500, 1000, 2500, 5000 and 10,000 ng ET-1/kg vs. NaCl controls) hemodynamic and inotropic effects of ET-1 in 53 open-chest rats during and after a 7-min infusion. Besides measurements in the intact circulation the myocardial function was examined by isovolumic registrations independent of peripheral vascular effects. A transient ET-1 induced (500, 1000, 2500, 5000 ng ET-1/kg) decrease of the left ventricular systolic pressure (LVSP) and the mean aortic pressure (AoPmean) was followed by a dose-related rise of these pressures (LVSP: -1%, -1%, +8%, +16% vs. preinfusion values; AoPmean: -11%, +9%, +39%, +52%). Heart rate (HR) was not influenced by ET-1. Due to the dose-dependent decrease of the stroke volume (SV) the cardiac output (CO) was reduced (CO: -8%, -23%, -40%, -50%). After an initial vasodilatation ET-1 elevates the total peripheral resistance (TPR: -1%, +49%, +139%, +215%) dose-dependently. 10,000 ng ET-1/kg was a lethal dose resulting in cardiac failure within minutes (low output). Since the maximum of the isovolumic LVSP (peak LVSP) and the corresponding dP/dtmax (peak dP/dtmax) were unchanged under ET-1, the isovolumic measurements do not indicate a positive inotropic effect of ET-1 in vivo in contrast to published results of in vitro experiments. It may be possible that a direct positive inotropic effect of ET-1 observed in in vitro studies is counterbalanced in vivo by an indirect negative inotropic effect due to the coronary-constrictive effect of ET-1

Hysteresis effects in rotating Bose-Einstein condensates

We study the formation of vortices in a dilute Bose-Einstein condensate confined in a rotating anisotropic trap. We find that the number of vortices and angular momentum attained by the condensate depends upon the rotation history of the trap and on the number of vortices present in the condensate initially. A simplified model based on hydrodynamic equations is developed, and used to explain this effect in terms of a shift in the resonance frequency of the quadrupole mode of the condensate in the presence of a vortex lattice. Differences between the spin-up and spin-down response of the condensate are found, demonstrating hysteresis phenomena in this system.Comment: 16 pages, 7 figures; revised after referees' report

Color-Octet Contributions to J/ψJ/\psi Photoproduction

We have calculated the leading color-octet contributions to the production of $J/\psi$ particles in photon-proton collisions. Using the values for the color-octet matrix elements extracted from fits to prompt $J/\psi$ data at the Tevatron, we demonstrate that distinctive color-octet signatures should be visible in $J/\psi$ photoproduction. However, these predictions appear at variance with recent experimental data obtained at HERA, indicating that the phenomenological importance of the color-octet contributions is smaller than expected from theoretical considerations and suggested by the Tevatron fits.Comment: 10 pages, LaTeX, epsfig, 4 figure

Magnetotransport of lanthanum doped RuSr2GdCu2O8 - the role of gadolinium

Strongly underdoped RuSr_1.9La_0.1GdCu_2O_8 has been comprehensively studied by dc magnetization, microwave measurements, magnetoresistivity and Hall resistivity in fields up to 9 T and temperatures down to 1.75 K. Electron doping by La reduces the hole concentration in the CuO2 planes and completely suppresses superconductivity. Microwave absorption, dc resistivity and ordinary Hall effect data indicate that the carrier concentration is reduced and a semiconductor-like temperature dependence is observed. Two magnetic ordering transitions are observed. The ruthenium sublattice orders antiferromagnetically at 155 K for low applied magnetic field and the gadolinium sublattice antiferromagnetically orders at 2.8 K. The magnetoresistivity exhibits a complicated temperature dependence due to the combination of the two magnetic orderings and spin fluctuations. It is shown that the ruthenium magnetism influences the conductivity in the RuO2 layers while the gadolinium magnetism influences the conductivity in the CuO2 layers. The magnetoresistivity is isotropic above 4 K, but it becomes anisotropic when gadolinium orders antiferromagnetically.Comment: 7 pages, 9 figures, submitted to European Physical Journal

TMDlib and TMDplotter: library and plotting tools for transverse-momentum-dependent parton distributions

Transverse-momentum-dependent distributions (TMDs) are central in high-energy physics from both theoretical and phenomenological points of view. In this manual we introduce the library, TMDlib, of fits and parameterisations for transverse-momentum-dependent parton distribution functions (TMD PDFs) and fragmentation functions (TMD FFs) together with an online plotting tool, TMDplotter. We provide a description of the program components and of the different physical frameworks the user can access via the available parameterisations.Comment: version 2, referring to TMDlib 1.0.2 - comments and references adde