176,843 research outputs found

    The Indians\u27 Friends

    Full text link

    Structural Antennas for 3cm Radar Onboard Multi-Rotor UAV

    Get PDF
    A series of 3cm amateur band radar antennas suitable for installation on a cinematic grade multi-rotor UAV were considered. A wideband open waveguide mouth antenna was developed that can be made from the existing arms of a multi-rotor UAV without any increase in weight for side-looking wall detection ranging radar. For downward looking radio altimeter, cutting slots in the arms to form slotted waveguide antennas was shown in simulation to be possible both in terms of covering the entire 3cm band from 10 to 10.5GHz and without overly weakening the arms as structural members

    Study of Multi-muon Events from EAS with the L3 Detector at Shallow Depth Underground

    Get PDF
    We present first preliminary data from the L3+Cosmics experiment and results from Monte Carlo simulations of multi-muon events as observed 30 m underground.Comment: 3 pages, 2 figures; presented at the 6th International Workshop on Topics in Astroparticle and Underground Physics, TAUP99, September 6-10, 1999, Paris, Franc

    Expressive Stream Reasoning with Laser

    Full text link
    An increasing number of use cases require a timely extraction of non-trivial knowledge from semantically annotated data streams, especially on the Web and for the Internet of Things (IoT). Often, this extraction requires expressive reasoning, which is challenging to compute on large streams. We propose Laser, a new reasoner that supports a pragmatic, non-trivial fragment of the logic LARS which extends Answer Set Programming (ASP) for streams. At its core, Laser implements a novel evaluation procedure which annotates formulae to avoid the re-computation of duplicates at multiple time points. This procedure, combined with a judicious implementation of the LARS operators, is responsible for significantly better runtimes than the ones of other state-of-the-art systems like C-SPARQL and CQELS, or an implementation of LARS which runs on the ASP solver Clingo. This enables the application of expressive logic-based reasoning to large streams and opens the door to a wider range of stream reasoning use cases.Comment: 19 pages, 5 figures. Extended version of accepted paper at ISWC 201

    A Case of Hyperkalemia Versus Pseudohyperkalemia in Chronic Lymphocytic Leukemia

    Get PDF
    Introduction: Both hyperkalemia and pseudohyperkalemia occur in the emergency department. True hyperkalemia necessitates emergent treatment while pseudohyperkalemia requires recognition to prevent inappropriate treatment. It is imperative that the emergency physician (EP) have an understanding of the causes and clinical presentations of both phenomena.Case Report: We present a case of an 88-year-old male with chronic lymphocytic leukemia (CLL) and suspected blast crisis who was found to have elevated serum potassium levels without other manifestations of hyperkalemia and eventually was determined to have pseudohyperkalemia due to white cell fragility.Discussion: Differentiation of hyperkalemia and pseudohyperkalemia is a critical skill for the EP. We discuss multiple causes of hyperkalemia and pseudohyperkalemia in an effort to broaden the knowledge base.Conclusion: We present a case of CLL as an unusual cause of pseudohyperkalemia and review common causes of pseudohyperkalemia

    Probing the elastic limit of DNA bending

    Full text link
    Many structures inside the cell such as nucleosomes and protein-mediated DNA loops contain sharply bent double-stranded (ds) DNA. Therefore, the energetics of strong dsDNA bending constitutes an essential part of cellular thermodynamics. Although the thermomechanical behavior of long dsDNA is well described by the worm-like chain (WLC) model, the length limit of such elastic behavior remains controversial. To investigate the energetics of strong dsDNA bending, we measured the opening rate of small dsDNA loops with contour lengths of 40-200 bp using Fluorescence Resonance Energy Transfer (FRET). From the measured relationship of loop stability to loop size, we observed a transition between two separate bending regimes at a critical loop size below 100 bp. Above this loop size, the loop lifetime decreased with decreasing loop size in a manner consistent with an elastic bending stress. Below the critical loop size, however, the loop lifetime became less sensitive to loop size, indicative of softening of the double helix. The critical loop size was measured to be ~60 bp with sodium only and ~100 bp with 5 mM magnesium, which suggests that magnesium facilitates the softening transition. We show that our results are in quantitative agreement with the kinkable worm-like chain model. Furthermore, the model parameters constrained by our data can reproduce previously measured J factors between 50 and 200 bp. Our work provides powerful means to study dsDNA bending in the strong bending regime
    corecore