3,377 research outputs found

    TEACHING MICRO-COMPUTER SKILLS TO MANAGEMENT STUDENTS: ACADEMIC ACHIEVEMENT, GENDER, STUDENT EFFORT ON HOMEWORK, AND LEARNING PERFORMANCE

    Get PDF
    This paper examines the relationship between previous computer exposure, past academic achievement, time spent on homework, and performance in a course teaching computer literacy by means of an exploratory study using undergraduate management students. The results show that mate students with low past academic performance can gain most from previous computer exposure. Furthermore, female students are benefit more from an extra effort into the microcomputer course than having previously attended a course teaching traditional computer literacy. Females appear more effective in transferring time spent using the equipment into better performance than their male peers are, thereby closing the performance gap to their higher achieving peers of the same sex faster than do males do. The implications of the results for training and future research are discussed

    Calculating the Jet Quenching Parameter from AdS/CFT

    Get PDF
    Models of medium-induced radiative parton energy loss account for the strong suppression of high-pT hadron spectra in sNN=200\sqrt{s_{NN}}=200 GeV Au-Au collisions at RHIC in terms of a single "jet quenching parameter'' q^\hat q. The available suite of jet quenching measurements make q^\hat q one of the experimentally best constrained properties of the hot fluid produced in RHIC collisions. We observe that q^\hat q can be given a model-independent, nonperturbative, quantum field theoretic definition in terms of the short-distance behavior of a particular light-like Wilson loop. We then use the AdS/CFT correspondence to obtain a strong-coupling calculation of q^\hat q in hot N=4 supersymmetric QCD, finding q^SYM=26.69αSYMNcT3\hat{q}_{SYM} = 26.69 \sqrt{\alpha_{SYM} N_c} T^3 in the limit in which both NcN_c and 4παSYMNc4\pi\alpha_{SYM} N_c are large. We thus learn that at strong coupling q^\hat q is not proportional to the entropy density ss, or to some "number density of scatterers'' since, unlike the number of degrees of freedom, q^\hat q does not grow like Nc2N_c^2.Comment: Version accepted for publication in Phys. Rev. Lett.; factor of Sqrt[2] error corrected, improving agreement between q^\hat q in N=4 SYM and that extracted from RHIC dat

    Effect of spin-orbit coupling on zero-conductance resonances in asymmetrically coupled one-dimensional rings

    Full text link
    The influence of Rashba spin-orbit coupling on zero conductance resonances appearing in one dimensional ring asymmetrically coupled to two leads is investigated. For this purpose, the transmission function of the corresponding one-electron scattering problem is derived analytically and analyzed in the complex energy plane with focus on the zero-pole structure characteristic of transmission (anti)resonances. The lifting of real conductance zeros due to spin-orbit coupling in the asymmetric Aharonov-Casher (AC) ring is related to the breaking of spin reversal symmetry in analogy to the time-reversal symmetry breaking in the asymmetric Aharonov-Bohm (AB) ring.Comment: 10 pages, 11 figure

    Granulocyte Neutral Proteases and Pseudomonas Elastase as Possible Causes of Airway Damage in Patients with Cystic Fibrosis

    Get PDF
    We studied the possible role of granulocyte neutral proteases as mediators of airway destruction in patients with cystic fibrosis (CF) who were infected with Pseudomonas aeruginosa. We measured the enzymatic activities of bronchial secretions on purified radioactively labeled complement component three (C3), elastin, and a granulocyte elastase-specific substrate. Bronchial secretions from 18 patients with CF who were infected with P aeruginosa had a significantly higher mean value for C3 cleaving, elastolytic, and granulocyte elastase-like activity than did two control groups. High enzymatic activities were observed in patients with CF who have advanced bronchial disease (that had been determined by a clinical scoring system). Kinetics of proteolysis of radioactively labeled C3 and inhibition profiles of the activities of the three enzymatic activities studied suggest that they are mainly derived from granulocytes. In addition, 20 of 31 strains of P aeruginosa isolated from patients with CF inactivated purified α1-antiprotease in vitro. We postulate that granulocyte neutral proteases and P aeruginosa may act synergistically in the airways of patients with CF and may contribute to the destruction of elastin and inactivation of C

    Advanced magneto-optical microscopy: Imaging from picoseconds to centimeters - imaging spin waves and temperature distributions (invited)

    Get PDF
    © 2016 Author(s).Recent developments in the observation of magnetic domains and domain walls by wide-field optical microscopy based on the magneto-optical Kerr, Faraday, Voigt, and Gradient effect are reviewed. Emphasis is given to the existence of higher order magneto-optical effects for advanced magnetic imaging. Fundamental concepts and advances in methodology are discussed that allow for imaging of magnetic domains on various length and time scales. Time-resolved imaging of electric field induced domain wall rotation is shown. Visualization of magnetization dynamics down to picosecond temporal resolution for the imaging of spin-waves and magneto-optical multi-effect domain imaging techniques for obtaining vectorial information are demonstrated. Beyond conventional domain imaging, the use of a magneto-optical indicator technique for local temperature sensing is shown

    Measurement of I-129 in environmental samples by ICP-CRI-QMS: possibilities and limitations

    Get PDF
    129I is preconcentrated from environmental samples and its accessibility is addressed for inductively coupled plasma quadrupole mass spectrometer with collision/reaction interface (ICP-CRI-QMS). By applying oxygen as CRI gas through skimmer cone, the signal of the interfering 129Xe from the impurity of plasma gas can be eliminated while the formation of 127I1H1H+ can be partially removed. The improved ICP-QMS can be employed for investigation of 129I in environmental samples with a 129I/127I ratio down to 10-7. The detection capability was demonstrated by measuring 129I in seaweed samples collected around the nuclear fuel reprocessing plant at La Hague. The abundant 127I in the sample matrix causes a serious problem and degrades the detection capability of the instrument when the concentration of 127I is larger than 105ng/g. Even combined with a sufficient pre-concentration procedure, ICP-QMS is not considered as a suitable technique for the analysis of 129I in uncontaminated environmental samples with 129I/127I ratio of less than 10-7. Results are presented for seaweed samples collected around La Hague. In addition, time dependant I concentrations and ratios are given for colloids and water sampled from Lake Thu

    Point-of-care testing in the cardiovascular operating theatre

    Get PDF
    Point-of-care testing (POCT) remains under scrutiny by healthcare professionals because of its ill-tried, young history. POCT methods are being developed by a few major equipment companies based on rapid progress in informatics and nanotechnology. Issues as POCT quality control, comparability with standard laboratory procedures, standardisation, traceability and round robin testing are being left to hospitals. As a result, the clinical and operational benefits of POCT were first evident for patients on the operating table. For the management of cardiovascular surgery patients, POCT technology is an indispensable aid. Improvement of the technology has meant that clinical laboratory pathologists now recognise the need for POCT beyond their high-throughput areas. Clin Chem Lab Med 2006;44:1060-

    Fractionation of magnetic microspheres in a microfluidic spiral: interplay between magnetic and hydrodynamic forces

    Get PDF
    Magnetic forces and curvature-induced hydrodynamic drag have both been studied and employed in continuous microfluidic particle separation and enrichment schemes. Here we combine the two. We investigate consequences of applying an outwardly directed magnetic force to a dilute suspension of magnetic microspheres circulating in a spiral microfluidic channel. This force is realized with an array of permanent magnets arranged to produce a magnetic field with octupolar symmetry about the spiral axis. At low flow rates particles cluster around an apparent streamline of the flow near the outer wall of the turn. At high flow rates this equilibrium is disrupted by the induced secondary (Dean) flow and a new equilibrium is established near the inner wall of the turn. A model incorporating key forces involved in establishing these equilibria is described, and is used to extract quantitative information about the magnitude of local Dean drag forces from experimental data. Steady-state fractionation of suspensions by particle size under the combined influence of magnetic and hydrodynamic forces is demonstrated. Extensions of this work could lead to new continuous microscale particle sorting and enrichment processes with improved fidelity and specificity

    A robust digital method for film contrast correction in subtraction radiography

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66366/1/j.1600-0765.1986.tb01484.x.pd
    • 

    corecore