637 research outputs found

    Aubry sets vs Mather sets in two degrees of freedom

    Full text link
    We study autonomous Tonelli Lagrangians on closed surfaces. We aim to clarify the relationship between the Aubry set and the Mather set, when the latter consists of periodic orbits which are not fixed points. Our main result says that in that case the Aubry set and the Mather set almost always coincide.Comment: Revised and expanded version. New proof of Lemma 2.3 (formerly Lemma 14

    Monographies on drugs, which are frequently analysed in the course of Therapeutic Drug Monitoring Monographien über Medikamente, die regelmässig im Rahmen des Therapeutic Drug Monitorings analysiert werden

    Get PDF
    In 1995 the working group "Drug Monitoring” of the Swiss Society of Clinical Chemistry (SSCC) has already published a printed version of drug monographs, which are now newly compiled and presented in a standardised manner. The aim of these monographs is to give an overview on the most important informations that are necessary in order to request a drug analysis or is helpful to interpret the results. Therefore, the targeted audience are laboratory health professionals or the receivers of the reports. There is information provided on the indication for therapeutic drug monitoring, protein binding, metabolic pathways and enzymes involved, elimination half life time and elimination routes as well as information on therapeutic or toxic concentrations. Because preanalytical considerations are of particular importance for therapeutic drug monitoring, there is also information given at which time the determination of the drug concentration is reasonable and when steady-state concentrations are reached after changing the dose. Furthermore, the stability of the drug and its metabolite(s), respectively, after blood sampling is described. For readers with a specific interest, references to important publications are given. The number of the monographs will be continuously enlarged. The updated files are presented on the homepage of the SSCC (www.sscc.ch). We hope that these monographs are helpful for you handling therapeutic drug monitoring and look forward to comments of the audienc

    On the Large Time Behavior of Solutions of Hamilton-Jacobi Equations Associated with Nonlinear Boundary Conditions

    Get PDF
    In this article, we study the large time behavior of solutions of first-order Hamilton-Jacobi Equations, set in a bounded domain with nonlinear Neumann boundary conditions, including the case of dynamical boundary conditions. We establish general convergence results for viscosity solutions of these Cauchy-Neumann problems by using two fairly different methods : the first one relies only on partial differential equations methods, which provides results even when the Hamiltonians are not convex, and the second one is an optimal control/dynamical system approach, named the "weak KAM approach" which requires the convexity of Hamiltonians and gives formulas for asymptotic solutions based on Aubry-Mather sets

    The Sensitivity of Harassment to Orbit: Mass Loss from Early-Type Dwarfs in Galaxy Clusters

    Get PDF
    We conduct a comprehensive numerical study of the orbital dependence of harassment on early-type dwarfs consisting of 168 different orbits within a realistic, Virgo-like cluster, varying in eccentricity and pericentre distance. We find harassment is only effective at stripping stars or truncating their stellar disks for orbits that enter deep into the cluster core. Comparing to the orbital distribution in cosmological simulations, we find that the majority of the orbits (more than three quarters) result in no stellar mass loss. We also study the effects on the radial profiles of the globular cluster systems of early-type dwarfs. We find these are significantly altered only if harassment is very strong. This suggests that perhaps most early-type dwarfs in clusters such as Virgo have not suffered any tidal stripping of stars or globular clusters due to harassment, as these components are safely embedded deep within their dark matter halo. We demonstrate that this result is actually consistent with an earlier study of harassment of dwarf galaxies, despite the apparent contradiction. Those few dwarf models that do suffer stellar stripping are found out to the virial radius of the cluster at redshift=0, which mixes them in with less strongly harassed galaxies. However when placed on phase-space diagrams, strongly harassed galaxies are found offset to lower velocities compared to weakly harassed galaxies. This remains true in a cosmological simulation, even when halos have a wide range of masses and concentrations. Thus phase-space diagrams may be a useful tool for determining the relative likelihood that galaxies have been strongly or weakly harassed.Comment: 17 pages, 13 figures, Accepted to MNRAS 8th September 201

    Spiral inflow feeding the nuclear starburst in M83, observed in H-alpha emission with the GHAFAS Fabry-Perot interferometer

    Full text link
    We present observations of the nearby barred starburst galaxy, M83 (NGC5236), with the new Fabry-Perot interferometer GHAFAS mounted on the 4.2 meter William Herschel Telescope on La Palma. The unprecedented high resolution observations, of 16 pc/FWHM, of the H-alpha-emitting gas cover the central two kpc of the galaxy. The velocity field displays the dominant disk rotation with signatures of gas inflow from kpc scales down to the nuclear regions. At the inner Inner Lindblad Resonance radius of the main bar and centerd at the dynamical center of the main galaxy disk, a nuclear 5.5(±0.9)×108M5.5 (\pm 0.9) \times 10^8 M_\odot rapidly rotating disk with scale length of 60±2060 \pm 20 pc has formed. The nuclear starburst is found in the vicinity as well as inside this nuclear disk, and our observations confirm that gas spirals in from the outer parts to feed the nuclear starburst, giving rise to several star formation events at different epochs, within the central 100 pc radius of M83.Comment: Accepted for publication in ApJ Letters. High-resolution version can be found at http://www.astro.su.se/~kambiz/DOC/paper-M83.pd

    Chaos in the Einstein-Yang-Mills Equations

    Full text link
    Yang-Mills color fields evolve chaotically in an anisotropically expanding universe. The chaotic behaviour differs from that found in anisotropic Mixmaster universes. The universe isotropizes at late times, approaching the mean expansion rate of a radiation-dominated universe. However, small chaotic oscillations of the shear and color stresses continue indefinitely. An invariant, coordinate-independent characterisation of the chaos is provided by means of fractal basin boundaries.Comment: 3 pages LaTeX + 3 pages of figure

    A Magellan-IMACS-IFU Search for Dynamical Drivers of Nuclear Activity. I. Reduction Pipeline and Galaxy Catalog

    Full text link
    Using the Inamori Magellan Areal Camera and Spectrograph (IMACS) integral-field unit (IFU) on the 6.5m Magellan telescope, we have designed the first statistically significant investigation of the two-dimensional distribution and kinematics of ionized gas and stars in the central kiloparsec regions of a well-matched sample of Seyfert and inactive control galaxies selected from the Sloan Digital Sky Survey. The goals of the project are to use the fine spatial sampling (0.2 arcsec/pixel) and large wavelength coverage (4000-7000A) of the IMACS-IFU to search for dynamical triggers of nuclear activity in the central region where active galactic nucleus (AGN) activity and dynamical timescales become comparable, to identify and assess the impact of AGN-driven outflows on the host galaxy and to provide a definitive sample of local galaxy kinematics for comparison with future three-dimensional kinematic studies of high-redshift systems. In this paper, we provide the first detailed description of the procedure to reduce and calibrate data from the IMACS-IFU in `long mode' to obtain two-dimensional maps of the distribution and kinematics of ionized gas and stars. The sample selection criteria are presented, observing strategy described and resulting maps of the sample galaxies presented along with a description of the observed properties of each galaxy and the overall observed properties of the sample.Comment: 62 pages. 41 figures. 5 tables. Accepted for publication in ApJS. High-resolution version available at: http://www.astro.ljmu.ac.uk/~pbw/IMACS-IFU/IMACS-1-highRes.pd

    Improving Employment and Income through Development of Egypt’s Aquaculture Sector (IEIDEAS) project

    Get PDF
    The Swiss Agency for Development and Cooperation (SDC)-funded Improving Employment and Income through Development of Egypt’s Aquaculture Sector (IEIDEAS) project was implemented by WorldFish in partnership with CARE Egypt and the Egyptian Ministry of Agriculture and Land Reclamation from 2011 to 2014 and later extended to November 2015. The project focused on four governorates with significant aquaculture production (Kafr El Sheikh, Behera, Sharkia and Fayoum) and one governorate (El Mineya), where aquaculture was a new activity. The project was based on a value chain analysis conducted by WorldFish in September 2011 that identified the aquaculture value chain as a significant employer, particularly in rural areas. The analysis suggested that there was scope to increase employment of youth and women in the aquaculture sector The main objective was to increase aquaculture production by 10% and create 10,000 jobs. Other objectives included improving profitability for existing producers, securing employment for women fish retailers, expanding aquaculture in El Mineya and improving the policy environment for aquaculture

    Physical Condition of Molecular Gas at the Centre of NGC 1097

    Full text link
    We have used the Xco conversion factor, Local Thermal Equilibrium and Large Velocity Gradient approximation to parametrize the cold and warm phase of the interstellar medium from five different low transitions of CO in the central 21"(kpc) of NGC 1097. We have applied a one-component model and derived a typical kinetic temperature of ~33K, and its molecular Hydrogen density and a CO column density. A two-component model results in 85% cold-to-total gas fraction with a 90K warm counterpart. Furthermore, we "resolve" the spatially unresolved single dish observations by selecting velocity channels that in an interferometric velocity map correspond to specific regions. We have selected five such regions and found that the physical properties in these regions are comparable to those derived from the full line profile. This implies that the central kpc of NGC 1097 is rather homogeneous in nature, and, although the regions are not uniquely located within the ring, the star formation along the ring is homogeneously distributed (in agreement with recent Herschel observations). We have further revised the mass inflow rate onto the Supermassive Black Hole in this prototype LINER/Sy1 galaxy and found that, accounting for the total interstellar medium and applying a careful contribution of the disc thickness and corresponding stability criterion, increases the previous estimations by a factor 10. Finally we have calculated the Xco for the centre of NGC 1097 using an independent estimation of the surface density to the CO emission, and obtained Xco=(2.8+-0.5)x10^20 cm^-2(K km s^-1)^-1 at radius 10.5" and Xco=(5.0+-0.5)x10^20 cm^-2(K km s^-1)^-1 at 7.5". With the approach and analysis described, we have demonstrated that important physical properties can be derived to a resolution beyond the single dish resolution element, however, caution is necessary for interpreting the results.(Abriged)Comment: 10 pages, 6 figures, 4 tables, Accepted for publication in MNRA
    corecore