380 research outputs found

    Beitrag einer termingerecht durchgefĂŒhrten Kainit-DĂŒngung zur Beikrautregulierung in Winterweizen

    Get PDF
    Due to etching effects on broad leafed weeds, fine ground kainite was used for weed control before synthetic herbicides have become common practice in conventional farming. According to the organic standards kainite can be used as potassium fertiliser. The present study investigates optimal growing stages for application in organic winter wheat and the range of effectiveness. Kainite was applied at a rate of 800 kg per hectare alternatively at EC 29 and EC 30 under the conditions of morning dew on days with high sunshine duration. At both growing stages kainite application reduced the population of hairy vetch, chamomile, cornflower, field pansy, winter rape, common chickweed and persian speedwell. Application at early growing stages led to a higher weed reduction

    Classification of one-dimensional quasilattices into mutual local-derivability classes

    Full text link
    One-dimensional quasilattices are classified into mutual local-derivability (MLD) classes on the basis of geometrical and number-theoretical considerations. Most quasilattices are ternary, and there exist an infinite number of MLD classes. Every MLD class has a finite number of quasilattices with inflation symmetries. We can choose one of them as the representative of the MLD class, and other members are given as decorations of the representative. Several MLD classes of particular importance are listed. The symmetry-preserving decorations rules are investigated extensively.Comment: 42 pages, latex, 5 eps figures, Published in JPS

    Barriers and Facilitators of Safe Communication in Obstetrics: Results from Qualitative Interviews with Physicians, Midwives and Nurses.

    Get PDF
    Patient safety is an important objective in health care. Preventable adverse events (pAEs) as the counterpart to patient safety are harmful incidents that fell behind health care standards and have led to temporary or permanent harm or death. As safe communication and mutual understanding are of crucial importance for providing a high quality of care under everyday conditions, we aimed to identify barriers and facilitators that impact safe communication in obstetrics from the subjective perspective of health care workers. A qualitative study with 20 semi-structured interviews at two university hospitals in Germany was conducted to explore everyday perceptions from a subjective perspective (subjective theories). Physicians, midwives, and nurses in a wide span of professional experience and positions were enrolled. We identified a structural area of conflict at the professional interface between midwives and physicians. Mandatory interprofessional meetings, acceptance of subjective mistakes, mutual understanding, and debriefings of conflict situations are reported to improve collaboration. Additionally, emergency trainings, trainings in precise communication, and handovers are proposed to reduce risks for pAEs. Furthermore, the participants reported time-constraints and understaffing as a huge burden that hinders safe communication. Concluding, safety culture and organizational management are closely entwined and strategies should address various levels of which communication trainings are promising

    Means of confusion: how pixel noise affects shear estimates for weak gravitational lensing

    Get PDF
    Weak-lensing shear estimates show a troublesome dependence on the apparent brightness of the galaxies used to measure the ellipticity: In several studies, the amplitude of the inferred shear falls sharply with decreasing source significance. This dependence limits the overall ability of upcoming large weak-lensing surveys to constrain cosmological parameters. We seek to provide a concise overview of the impact of pixel noise on weak-lensing measurements, covering the entire path from noisy images to shear estimates. We show that there are at least three distinct layers, where pixel noise not only obscures but biases the outcome of the measurements: 1) the propagation of pixel noise to the non-linear observable ellipticity; 2) the response of the shape-measurement methods to limited amount of information extractable from noisy images; and 3) the reaction of shear estimation statistics to the presence of noise and outliers in the measured ellipticities. We identify and discuss several fundamental problems and show that each of them is able to introduce biases in the range of a few tenths to a few percent for galaxies with typical significance levels. Furthermore, all of these biases do not only depend on the brightness of galaxies but also on their ellipticity, with more elliptical galaxies often being harder to measure correctly. We also discuss existing possibilities to mitigate and novel ideas to avoid the biases induced by pixel noise. We present a new shear estimator that shows a more robust performance for noisy ellipticity samples. Finally, we release the open-source python code to predict and efficiently sample from the noisy ellipticity distribution and the shear estimators used in this work at https://github.com/pmelchior/epsnoiseComment: integrated the origin of the moment correlation (thanks to Alan Heavens). source code at https://github.com/pmelchior/epsnois

    Nonequilibrium coupled Brownian phase oscillators

    Full text link
    A model of globally coupled phase oscillators under equilibrium (driven by Gaussian white noise) and nonequilibrium (driven by symmetric dichotomic fluctuations) is studied. For the equilibrium system, the mean-field state equation takes a simple form and the stability of its solution is examined in the full space of order parameters. For the nonequilbrium system, various asymptotic regimes are obtained in a closed analytical form. In a general case, the corresponding master equations are solved numerically. Moreover, the Monte-Carlo simulations of the coupled set of Langevin equations of motion is performed. The phase diagram of the nonequilibrium system is presented. For the long time limit, we have found four regimes. Three of them can be obtained from the mean-field theory. One of them, the oscillating regime, cannot be predicted by the mean-field method and has been detected in the Monte-Carlo numerical experiments.Comment: 9 pages 8 figure

    Hybrid administrative interfaces : authority delegation and reversion in strategic alliances

    Get PDF
    Steering committees are pivotal for governing complex collaborations by consensus to facilitate coordination and knowledge sharing. Although consensus-based governance promotes mutuality, it can also cause deadlocks, stalling expeditious decision making. We examine the conditions under which alliance partners delegate decision-making authority to steering committees as well as the conditions under which authority over discordant matters can be relocated to one of the alliance partners. We argue that joint coordination concerns increase the likelihood of authority delegation, whereas the higher costs and stakes associated with decision stalemates provide grounds for authority reversion. Empirical analyses of strategic alliances in the biopharmaceutical industry support our arguments. Our paper demonstrates the versatility of contractually defined administrative interfaces in alliance governance, allowing partners to coordinate bilaterally and adapt hierarchically as and when required

    Disorder Effects in Superconducting Multiple Loop Quantum Interferometers

    Full text link
    A theoretical study is presented on a number N of resistively shunted Josephson junctions connected in parallel as a disordered 1D array by superconducting wiring in such a manner that there are N-1 individual SQUID loops with arbitrary shape formed.Comment: 4 pages, 2 figure
    • 

    corecore