3,099 research outputs found

    RESULTS OF 1982 RODENTICIDE FIELD TESTS

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    A 2.0% zinc phosphide pellet and a 0.001% brodifacoum bait gave the lowest percentage post-treatment activity in a field test in which broadcast applications were followed shortly by rain. There was not a clear difference in performance between the single-feeding toxicants and the multiple-feeding anticoagulants in this experiment. A 0.075% cholecalciferol bait gave control comparable to some registered materials and shows promise for future development. A bait containing 0.0216% diphacinone gave significantly better control than one containing 0.005% diphacinone

    RESULTS OF 1982 RODENTICIDE FIELD TESTS

    Get PDF
    A 2.0% zinc phosphide pellet and a 0.001% brodifacoum bait gave the lowest percentage post-treatment activity in a field test in which broadcast applications were followed shortly by rain. There was not a clear difference in performance between the single-feeding toxicants and the multiple-feeding anticoagulants in this experiment. A 0.075% cholecalciferol bait gave control comparable to some registered materials and shows promise for future development. A bait containing 0.0216% diphacinone gave significantly better control than one containing 0.005% diphacinone

    Promoting deep learning through design - discussion, student activity and assessment

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    There is widespread evidence that Australia is currently facing falling student participation rates in science and mathematics subjects at secondary school and university undergraduate levels. The future implications of this science-deficit are widely acknowledged. Unfortunately, science teaching itself is also widely seen as being dull, too content-heavy, delivered to mass-audiences and assessed in ways promoting surface approaches to learning. To address these issues, and issues relating to the apparent lack of challenge for very able students in their first year at university, The University of Queensland developed the Advanced Study Program in Science (ASPinS). This initiative offers an enhanced learning experience to a select group of high-achieving students in addition to their existing undergraduate study in a Science-related degree program. ASPinS offers these students the opportunity to interact with leading research scientists, broaden their understanding of important scientific issues, experience new interactive learning opportunities, undertake research projects and obtain an authentic insight into science as a career. This presentation, however, will only focus on the unique first year course offered within the 3 year ASPinS experience – BIOL1017 “Perspectives in Science”. In this course students are encouraged to think about important current scientific issues from different perspectives – both scientific and non-scientific. Panels of expert scientists use their knowledge and experience to present real scientific issues for students to examine and discuss. These panel discussions cover a spectrum of medical, environmental and social issues, covering different viewpoints and possible solutions. Combining this effective panel model with an array of student-led activities provides an ideal environment for learning. Students are made to apply their new knowledge, discuss issues and construct thoughts, opinions and products – depending on the specifically designed activities. Relevant assessment tasks include group-writing activities and oral presentations which enable students to demonstrate their learning through authentic contexts that are carefully designed to influence the way students learn. Authentic assessment tasks enable students to see a purpose for the product (assessment) they are producing while at the same time enabling them to synthesise the various scientific ‘facts’ and issues they have been discussing. This level of assessment activity, by its nature, encourages higher-order learning. Student evaluations have consistently confirmed that the key to the success of each Module within the course lies in the breadth of speakers selected to represent the different angles associated with the topic under discussion and the related activities and assessment tasks. The findings indicate that students value the opportunity to explore the multi-disciplinary nature of science-related issues and to actually discuss the issues. The “Perspectives in Science” course is a model for the success of combining teaching and learning theory and scholarship, to a particular set of objectives, to create a highly effective learning environment and a meaningful student experience

    Quantitative Assessment of the Anatomical Footprint of the C1 Pedicle Relative to the Lateral Mass: A Guide for C1 Lateral Mass Fixation

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    Study Design: Anatomic study. Objectives: To determine the relationship of the anatomical footprint of the C1 pedicle relative to the lateral mass (LM). Methods: Anatomic measurements were made on fresh frozen human cadaveric C1 specimens: pedicle width/height, LM width/height (minimum/maximum), LM depth, distance between LM’s medial aspect and pedicle’s medial border, distance between LM’s lateral aspect to pedicle’s lateral border, distance between pedicle’s inferior aspect and LM’s inferior border, distance between arch’s midline and pedicle’s medial border. The percentage of LM medial to the pedicle and the distance from the center of the LM to the pedicle’s medial wall were calculated. Results: A total of 42 LM were analyzed. The C1 pedicle’s lateral aspect was nearly confluent with the LM’s lateral border. Average pedicle width was 9.0 ± 1.1 mm, and average pedicle height was 5.0 ± 1.1 mm. Average LM width and depth were 17.0 ± 1.6 and 17.2 ± 1.6 mm, respectively. There was 6.9 ± 1.5 mm of bone medial to the medial C1 pedicle, which constituted 41% ± 9% of the LM’s width. The distance from C1 arch’s midline to the medial pedicle was 13.5 ± 2.0 mm. The LM’s center was 1.6 ± 1 mm lateral to the medial pedicle wall. There was on average 3.5 ± 0.6 mm of the LM inferior to the pedicle inferior border. Conclusions: The center of the lateral mass is 1.6 ± 1 mm lateral to the medial wall of the C1 pedicle and approximately 15 mm from the midline. There is 6.9 ± 1.5 mm of bone medial to the medial C1 pedicle. Thus, the medial aspect of C1 pedicle may be used as an anatomic reference for locating the center of the C1 LM for screw fixation

    The wave-vector power spectrum of the local tunnelling density of states: ripples in a d-wave sea

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    A weak scattering potential imposed on a CuO2CuO_2 layer of a cuprate superconductor modulates the local density of states N(x,ω)N(x,\omega). In recently reported experimental studies scanning-tunneling maps of N(x,ω)N(x,\omega) have been Fourier transformed to obtain a wave-vector power spectrum. Here, for the case of a weak scattering potential, we discuss the structure of this power spectrum and its relationship to the quasi-particle spectrum and the structure factor of the scattering potential. Examples of quasi-particle interferences in normal metals and ss- and d-wave superconductors are discussed.Comment: 22 pages, 21 figures; enlarged discussion of the d-wave response, to be published in Physical Review

    Persistent Currents in Multichannel Interacting Systems

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    Persistent currents of disordered multichannel mesoscopic rings of spinless interacting fermions threaded by a magnetic flux are calculated using exact diagonalizations and self-consistent Hartree-Fock methods. The validity of the Hartree-Fock approximation is controled by a direct comparison with the exact results on small 4×44\times4 clusters. For sufficiently large disorder (diffusive regime), the effect of repulsive interactions on the current distribution is to slightly decrease its width (mean square current) but to {\it increase} its mean value (mean current). This effect is stronger in the case of a long range repulsion. Our results suggest that the coupling between the chains is essential to understand the large currents observed experimentally.Comment: Revised version, uuencoded compressed file including fig

    Persistent current of two-chain Hubbard model with impurities

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    The interplay between impurities and interactions is studied in the gapless phase of two-chain Hubbard model in order to see how the screening of impurity potentials due to repulsive interactions in single-chain model will be changed by increasing the number of channels. Renormalization group calculations show that charge stiffness, and hence persistent current, of the two-chain model are less enhanced by interactions than single chain case.Comment: 4 Pages, RevTeX, No figures, Submitted to PR

    Persistent Current in the Ferromagnetic Kondo Lattice Model

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    In this paper, we study the zero temperature persistent current in a ferromagnetic Kondo lattice model in the strong coupling limit. In this model, there are spontaneous spin textures at some values of the external magnetic flux. These spin textures contribute a geometric flux, which can induce an additional spontaneous persistent current. Since this spin texture changes with the external magnetic flux, we find that there is an anomalous persistent current in some region of magnetic flux: near Phi/Phi_0=0 for an even number of electrons and Phi/Phi_0=1/2 for an odd number of electrons.Comment: 6 RevTeX pages, 10 figures include

    Permanent current from non-commutative spin algebra

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    We show that a spontaneous electric current is induced in a nano-scale conducting ring just by putting three ferromagnets. The current is a direct consequence of the non-commutativity of the spin algebra, and is proportional to the non-coplanarity (chirality) of the magnetization vectors. The spontaneous current gives a natural explanation to the chirality-driven anomalous Hall effect.Comment: 7 pages, 4 figures on separate pag
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