1,190 research outputs found

    Comparing e-Learning Tools’ Success: The Case of Instructor–Student Interactive vs. Self-paced Tools

    Get PDF
    E-learning tools have profoundly transformed modern pedagogical approaches. Vendors provide different types of systems, such as self-paced (SP) and instructor–student interactive (ISI) e-learning tools. Although both types of tools represent promising solutions to facilitate the learning process, it is important to theoretically identify a framework to evaluate the success of these tools and assess whether one type of tool is more effective than another. Toward this end, we (1) propose a model to evaluate e-learning tools’ success by extending and contextualizing Seddon’s information systems (IS) success model for the e-learning environment and (2) formulate four hypotheses to predict the differences in the success factors between SP and ISI tools. We test the model and hypotheses using data from 783 students across seven higher education institutions in Hong Kong. The results support the proposed e-learning tool success model and three of the four hypotheses. ISI tools outperform SP tools in terms of system quality, perceived usefulness, satisfaction, and learning outcome

    Host List of Plants Susceptible to Tomato Spotted Wilt Virus (TSWV)

    Get PDF
    Tomato spotted wilt virus (TSWV)-infected plant hosts in vegetable-growing regions play an important role in the epidemiology of the disease. Susceptible hosts are commonly found growing along field borders and among crops of Hawaii's major vegetable-growing regions. Elimination of these TSWV reservoirs should be helpful in reducing disease losses. This paper presents an up-to-date listing of TSWV-susceptible plant species

    Toward biomaterial-based implantable photonic devices

    Get PDF
    Optical technologies are essential for the rapid and efficient delivery of health care to patients. Efforts have begun to implement these technologies in miniature devices that are implantable in patients for continuous or chronic uses. In this review, we discuss guidelines for biomaterials suitable for use in vivo. Basic optical functions such as focusing, reflection, and diffraction have been realized with biopolymers. Biocompatible optical fibers can deliver sensing or therapeutic-inducing light into tissues and enable optical communications with implanted photonic devices. Wirelessly powered, light-emitting diodes (LEDs) and miniature lasers made of biocompatible materials may offer new approaches in optical sensing and therapy. Advances in biotechnologies, such as optogenetics, enable more sophisticated photonic devices with a high level of integration with neurological or physiological circuits. With further innovations and translational development, implantable photonic devices offer a pathway to improve health monitoring, diagnostics, and light-activated therapies. Keywords: biomaterials; biocompatible; biodegradable; optics; photonicsUnited States. Department of Defense (Award FA9550-13-1-0068)National Institutes of Health (U.S.) (Award P41-EB015903)National Institutes of Health (U.S.) (Award R01-CA192878)National Science Foundation (U.S.) (Award CBET-1264356)National Science Foundation (U.S.) (Award ECCS-1505569

    High-resolution Ce 3d-edge resonant photoemission study of CeNi_2

    Full text link
    Resonant photoemission (RPES) at the Ce 3d -> 4f threshold has been performed for alpha-like compound CeNi_2 with extremely high energy resolution (full width at half maximum < 0.2 eV) to obtain bulk-sensitive 4f spectral weight. The on-resonance spectrum shows a sharp resolution-limited peak near the Fermi energy which can be assigned to the tail of the Kondo resonance. However, the spin-orbit side band around 0.3 eV binding energy corresponding to the f_{7/2} peak is washed out, in contrast to the RPES spectrum at the Ce 3d -> 4f RPES threshold. This is interpreted as due to the different surface sensitivity, and the bulk-sensitive Ce 3d -> 4f RPES spectra are found to be consistent with other electron spectroscopy and low energy properties for alpha-like Ce-transition metal compounds, thus resolves controversy on the interpretation of Ce compound photoemission. The 4f spectral weight over the whole valence band can also be fitted fairly well with the Gunnarsson-Schoenhammer calculation of the single impurity Anderson model, although the detailed features show some dependence on the hybridization band shape and (possibly) Ce 5d emissions.Comment: 4 pages, 3 figur

    Non--decoupling, triviality and the ρ\rho parameter

    Full text link
    The dependence of the ρ\rho parameter on the mass of the Higgs scalar and the top quark is computed non--perturbatively using the 1/NF1/N_F expansion in the standard model. We find an explicit expression for the ρ\rho parameter that requires the presence of a physical cutoff. This should come as no surprise since the theory is presumably trivial. By taking this cutoff into account, we find that the ρ\rho parameter can take values only within a limited range and has finite ambiguities that are suppressed by inverse powers of the cutoff scale, the so called ``scaling--violations". We find that large deviations from the perturbative results are possible, but only when the cutoff effects are also large.Comment: 16pp, Figures NOT included, harvmac, minor modifications incl. wording, refs., UCLA/92/TEP/23,OHSTPY-HEP-T-92-00

    Resumming the color-octet contribution to e+ e- -> J/psi + X

    Full text link
    Recent observations of the spectrum of J/psi produced in e+ e- collisions at the Upsilon(4S) resonance are in conflict with fixed-order calculations using the Non-Relativistic QCD (NRQCD) effective field theory. One problem is that leading order color-octet mechanisms predict an enhancement of the cross section for J/psi with maximal energy that is not observed in the data. However, in this region of phase space large perturbative corrections (Sudakov logarithms) as well as enhanced nonperturbative effects are important. In this paper we use the newly developed Soft-Collinear Effective Theory (SCET) to systematically include these effects. We find that these corrections significantly broaden the color-octet contribution to the J/psi spectrum. Our calculation employs a one-stage renormalization group evolution rather than the two-stage evolution used in previous SCET calculations. We give a simple argument for why the two methods yield identical results to lowest order in the SCET power counting.Comment: 27 pages, 7 figure

    Investigation of the reactivity of AlCl3 and CoCl2 toward molten alkali-metal nitrates in order to synthesize CoAl2O4

    Get PDF
    Cobalt aluminate CoAl2O4 powder, constituted of nano-sized crystallites, is prepared, involving the reactivity of AlCl3 and CoCl2 with molten alkali-metal nitrates. The reaction at 450 °C for 2 h leads to a mixture of spinel oxide Co3O4 and amorphous γ-Al2O3. It is transformed into the spinel oxide CoAl2O4 by heating at 1000 °C. The powders are mainly characterized by XRD, FTIR, ICP, electron microscopy and diffraction, X-EDS and diffuse reflection. Their properties are compared to those of powders obtained by solid state reactions of a mechanical mixture of chlorides or oxides submitted to the same thermal treatment

    The Relationship Between Plasma Flow Doppler Velocities and Magnetic Field Parameters During the Emergence of Active Regions at the Solar Photospheric Level

    Full text link
    A statistical study has been carried out of the relationship between plasma flow Doppler velocities and magnetic field parameters during the emergence of active regions at the solar photospheric level with data acquired by the Michelson Doppler Imager (MDI) onboard the Solar and Heliospheric Observatory (SOHO). We have investigated 224 emerging active regions with different spatial scales and positions on the solar disc. The following relationships for the first hours of the emergence of active regions have been analysed: i) of peak negative Doppler velocities with the position of the emerging active regions on the solar disc; ii) of peak plasma upflow and downflow Doppler velocities with the magnetic flux growth rate and magnetic field strength for the active regions emerging near the solar disc centre (the vertical component of plasma flows); iii) of peak positive and negative Doppler velocities with the magnetic flux growth rate and magnetic field strength for the active regions emerging near the limb (the horizontal component of plasma flows); iv) of the magnetic flux growth rate with the density of emerging magnetic flux; v) of the Doppler velocities and magnetic field parameters for the first hours of the appearance of active regions with the total unsigned magnetic flux at the maximum of their development.Comment: 14 pages, 8 figures. The results of article were presented at the ESPM-13 (12-16 September 2011, Rhodes, Greece, Abstract Book p. 102-103, P.4.13, http://astro.academyofathens.gr/espm13/documents/ESPM13_abstract_programme_book.pdf

    Palm kernel expellers as an alternative ingredient in growing pig diets

    Get PDF
    This study evaluated the effects of palm kernel expellers in growing diets on growth performance, nutrient digestibility, and carcass and meat quality characteristics of growing-finishing pigs. A total of 88 growing pigs were randomly assigned to two dietary treatment groups. The control diet (CON) was a typical growing or finishing diet based on corn-soybean meal, and the treatment diet (PKE) was formulated by replacing CON with 20% palm kernel expellers. The PKE-CON group was fed the PKE diet during the growing period (six weeks) and the CON diet during the finishing period (12 weeks). The CON-CON group was fed the CON diets during both growing and finishing periods. The PKE-CON group showed significantly depressed growth performance and lower nutrient digestibility than the CON-CON group during the growing period. However, after feeding the typical finisher diets during the finishing period, the PKE-CON group showed no difference in growth performance in comparison with the CON-CON group during both the finishing and overall experimental periods. In addition, carcass and meat quality characteristics were not significantly different between the PKE-CON and the CON-CON groups. The results of this study imply that palm kernel expellers can be an alternative ingredient in the growing diets of growing-finishing pigs if the combined feeding strategy (PKE for the growing period and CON for the finishing period) is used.Keywords: Feed alternatives, growing pig diet, growth performance, meat quality traits, palm kernel expelle
    • 

    corecore