523 research outputs found

    Physics practicals for distance education in an undergraduate engineering course

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    BACKGROUND : Providing engineering practicals to undergraduates by means of distance education is a significant challenge. The past 30 years have seen the rapid development of the distance education. For many years, Deakin University has offered a full Bachelor of Engineering degree programme via distance education. All first-year students study a unit in physics. This unit includes practicals. Providing practical experiences to students is distance education’s greatest challenge.PURPOSE : The purpose of this work was to develop the means for off-campus students to complete practical exercises in first-year engineering physics. The solution to the problem also had to comply with accreditation requirements set by Engineers Australia.METHOD : The long-term solution to the problem was running on-campus lab classes either on weekends or as part of the annual first-year residential school for engineering professional practice. Students work was assessed by means of standard laboratory reports. On-campus marks and off-campus lab marks have been collected and compared over the past 12 years.RESULTS : The results indicate that the off-campus lab experience is similar to the on-campus experience. Marks for the two cohorts were comparable. Those few students who completed their pracs at home faced and overcame significant challenges.CONCLUSIONS : We found that performance in their lab reports for off-campus students was similar to that of the on-campus students. Accreditation requirements has shifted the focus from developing activities that students could perform at home to offering timely and efficient on-campus lab classes for off-campus students. Future work will focus on on-campus lab classes in accordance with accreditation requirements and perhaps on-line broadcasts of prac classes for those students who cannot attend lab on-campus

    Collective Charge Fluctuations in Single-Electron Processes on Nano-Networks

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    Using numerical modeling we study emergence of structure and structure-related nonlinear conduction properties in the self-assembled nanoparticle films. Particularly, we show how different nanoparticle networks emerge within assembly processes with molecular bio-recognition binding. We then simulate the charge transport under voltage bias via single-electron tunnelings through the junctions between nanoparticles on such type of networks. We show how the regular nanoparticle array and topologically inhomogeneous nanonetworks affect the charge transport. We find long-range correlations in the time series of charge fluctuation at individual nanoparticles and of flow along the junctions within the network. These correlations explain the occurrence of a large nonlinearity in the simulated and experimentally measured current-voltage characteristics and non-Gaussian fluctuations of the current at the electrode.Comment: 10 pages, 7 figure

    CIS is a potent checkpoint in NK cell-mediated tumor immunity

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    The detection of aberrant cells by natural killer (NK) cells is controlled by the integration of signals from activating and inhibitory ligands and from cytokines such as IL-15. We identified cytokine-inducible SH2-containing protein (CIS, encoded by Cish) as a critical negative regulator of IL-15 signaling in NK cells. Cish was rapidly induced in response to IL-15, and deletion of Cish rendered NK cells hypersensitive to IL-15, as evidenced by enhanced proliferation, survival, IFN-γ production and cytotoxicity toward tumors. This was associated with increased JAK-STAT signaling in NK cells in which Cish was deleted. Correspondingly, CIS interacted with the tyrosine kinase JAK1, inhibiting its enzymatic activity and targeting JAK for proteasomal degradation. Cish -/- mice were resistant to melanoma, prostate and breast cancer metastasis in vivo, and this was intrinsic to NK cell activity. Our data uncover a potent intracellular checkpoint in NK cell-mediated tumor immunity and suggest possibilities for new cancer immunotherapies directed at blocking CIS function

    Modelling the evaporation of thin films of colloidal suspensions using Dynamical Density Functional Theory

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    Recent experiments have shown that various structures may be formed during the evaporative dewetting of thin films of colloidal suspensions. Nano-particle deposits of strongly branched `flower-like', labyrinthine and network structures are observed. They are caused by the different transport processes and the rich phase behaviour of the system. We develop a model for the system, based on a dynamical density functional theory, which reproduces these structures. The model is employed to determine the influences of the solvent evaporation and of the diffusion of the colloidal particles and of the liquid over the surface. Finally, we investigate the conditions needed for `liquid-particle' phase separation to occur and discuss its effect on the self-organised nano-structures

    Nonequilibrium dynamics of fully frustrated Ising models at T=0

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    We consider two fully frustrated Ising models: the antiferromagnetic triangular model in a field of strength, h=HTkBh=H T k_B, as well as the Villain model on the square lattice. After a quench from a disordered initial state to T=0 we study the nonequilibrium dynamics of both models by Monte Carlo simulations. In a finite system of linear size, LL, we define and measure sample dependent "first passage time", trt_r, which is the number of Monte Carlo steps until the energy is relaxed to the ground-state value. The distribution of trt_r, in particular its mean value, , is shown to obey the scaling relation, L2ln(L/L0) \sim L^2 \ln(L/L_0), for both models. Scaling of the autocorrelation function of the antiferromagnetic triangular model is shown to involve logarithmic corrections, both at H=0 and at the field-induced Kosterlitz-Thouless transition, however the autocorrelation exponent is found to be HH dependent.Comment: 7 pages, 8 figure

    The politics of the teaching of reading

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    Historically, political debates have broken out over how to teach reading in primary schools and infant classrooms. These debates and “reading wars” have often resulted from public concerns and media reportage of a fall in reading standards. They also reflect the importance placed on learning to read by parents, teachers, employers, and politicians. Public and media-driven controversies over the teaching of reading have resulted in intense public and professional debates over which specific methods and materials to use with beginning readers and with children who have reading difficulties. Recently, such debates have led to a renewed emphasis on reading proficiency and “standardized” approaches to teaching reading and engaging with literacy. The universal acceptance of the importance of learning to read has also led to vested interests in specific methods, reading programmes, and early literacy assessments amongst professional, business, commercial, and parental lobbying groups. This article traces these debates and the resulting growing support for a quantitative reductionist approach to early-reading programmes

    Please mind the gap: students’ perspectives of the transition in academic skills between A-level and degree level geography

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    This paper explores first-year undergraduates’ perceptions of the transition from studying geography at pre-university level to studying for a degree. This move is the largest step students make in their education, and the debate about it in the UK has been reignited due to the government’s planned changes to A-level geography. However, missing from most of this debate is an appreciation of the way in which geography students themselves perceive their transition to university. This paper begins to rectify this absence. Using student insights, we show that their main concern is acquiring the higher level skills required for university learning

    A life in progress: motion and emotion in the autobiography of Robert M. La Follette

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    This article is a study of a La Follette’s Autobiography, the autobiography of the leading Wisconsin progressive Robert M. La Follette, which was published serially in 1911 and, in book form, in 1913. Rather than focusing, as have other historians, on which parts of La Follette’s account are accurate and can therefore be trusted, it explains instead why and how this major autobiography was conceived and written. The article shows that the autobiography was the product of a sustained, complex, and often fraught series of collaborations among La Follette’s family, friends, and political allies, and in the process illuminates the importance of affective ties as well as political ambition and commitment in bringing the project to fruition. In the world of progressive reform, it argues, personal and political experiences were inseparable

    Height dependent molecular trapping in stacked cyclic porphyrin nanorings

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    Stacked layers of cyclic porphyrin nanorings constitute nanoscale receptacles with variable height and diameter which preferentially adsorb sublimed molecules. Using scanning tunnelling microscopy we determine the filling capacity of these nanoring traps, and the dependence of adsorbate capture on stack height and diameter
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