27,887 research outputs found

    Scholarly collaboration across time zones

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    The barriers to global collaboration of yesteryear were, for example, country boundaries and time zones. Today however, in a world where communication is thriving on new technologies, these barriers have been overcome, not only by the technology itself, but also by the collaborators in a desire (and need) to extend knowledge, seize opportunities and build partnerships. This chapter reports on one such collaboration: a case study where the focus is the writing of a scholarly article between authors from Australia, England and South Africa. The challenges of different time zones, academic calendars, and managing the collaboration are outlined in this chapter. Findings from the case study suggests that the key elements of success are related to the individuals and project management techniques, and not the technology per se. The constructivist learning theory as well as the e-Moderation model are supported by this work and thus extend their application to the academic writing process

    Information technology team projects in higher education: an international viewpoint

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    It is common to find final or near final year undergraduate Information Technology students undertaking a substantial development project; a project where the students have the opportunity to be fully involved in the analysis, design, and development of an information technology service or product. This involvement has been catalyzed and prepared for during their previous studies where the students have been told and shown how to develop similar systems. It is the belief that only through this ‘real’ project do they get the chance to experience something similar to what is expected of them when they embark on their chosen profession; that is, as an information technology professional. The high value of ‘near real life’ educational experience is recognized by many universities across the globe. The aim of this paper is to present examples from three countries - Australia, United Kingdom and South Africa, of the delivery of these team, capstone or industrial experience projects; their curricula and management processes. Academics from institutions in each of the countries share experiences, challenges and pitfalls encountered during the delivery of these information technology projects within their institutions. An overview of each institution’s strategies is provided and highlights specific issues such as the selection of projects, allocation of teams to projects, legal requirements, assessment methods, challenges and benefits. The pedagogies presented here are not exhaustive; however, the three institutions do have in common the implementation of a combination of constructivism with a community of practice approach in delivering the project unit. The three universities recognize the need for industrial experience and learning of applied skills, and therefore make these projects a compulsory part of the curriculum. The projects tend to be real life business problems which are solved over a period of two semesters, and in the case of Cape Town it could be two consecutive years of two semesters each. These projects tend to involve practical development (for example databases and web sites). The process of project-to-team allocation is generally similar in all cases. Despite their differences, team work related problems are quite similar in all three cases presented, and seem to appear as a result of team work complexity, and the number of stakeholders involved. The intention of this paper is not to propose solutions to these problems (as these would be context dependent), but to draw the attention to the main problem categories for similar schemes, these are; • project selection, • management of students, • management of academic staff, • student team motivation, • equality and diversity, • passengers, and • assessment. Furthermore, it is not the intention of the authors to portray one approach as better than another, however, the approaches are representative of how team projects are being delivered across the globe, and in particular, in the contributing institutions. It is hoped that the assimilation and dissemination of information regarding the various approaches presented will nurture further discussion, and open communication across the globe with the view to enhancing the teaching and learning experience of such projects

    Aerosol studies in mid-latitude coastal environments in Australia

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    The results of the evaluation of several inversion procedures that were used to select one which provides the most accurate atmospheric extinction profiles for small aerosol extinction coefficients (that often predominate in the maritime airmass) are presented. Height profiles of atmospheric extinction calculated by a two component atmospheric solution to the LIDAR equation will be compared with corresponding in-situ extinction profiles based on the size distribution profiles obtained in Western Australia. Values of the aerosol backscatter to extinction ratio obtained from multi-angle LIDAR measurements will be used in this solution

    Compression of Martian atmosphere for production of oxygen

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    The compression of CO2 from the Martian atmosphere for production of O2 via an electrochemical cell is addressed. Design specifications call for an oxygen production rate of 10 kg per day and for compression of 50 times that mass of CO2. Those specifications require a compression rate of over 770 cfm at standard Martian temperature and pressure (SMTP). Much of the CO2 being compressed represents waste, unless it can be recycled. Recycling can reduce the volume of gas that must be compressed to 40 cfm at SMTP. That volume reduction represents significant mass savings in the compressor, heating equipment, filters, and energy source. Successful recycle of the gas requires separation of CO (produced in the electrochemical cell) from CO2, N2, and Ar found in the Martian atmosphere. That aspect was the focus of this work

    Bulk photonic metamaterial with hyperbolic dispersion

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    In this work, we demonstrate a self-standing bulk three-dimensional metamaterial based on the network of silver nanowires in an alumina membrane. This constitutes an anisotropic effective medium with hyperbolic dispersion, which can be used in sub-diffraction imaging or optical cloaks. Highly anisotropic dielectric constants of the material range from positive to negative, and the transmitted laser beam shifts both toward the normal to the surface, as in regular dielectrics, and off the normal, as in anisotropic dielectrics with the refraction index smaller than one. The designed photonic metamaterial is the thickest reported in the literature, both in terms of its physical size 1cm x 1cm x 51 mm, and the number of vacuum wavelengths, N=61 at l=0.84 mm.Comment: 6 pages, 4 figur

    GUCY2C maintains intestinal LGR5+ stem cells by opposing ER stress

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    Long-lived multipotent stem cells (ISCs) at the base of intestinal crypts adjust their phenotypes to accommodate normal maintenance and post-injury regeneration of the epithelium. Their long life, lineage plasticity, and proliferative potential underlie the necessity for tight homeostatic regulation of the ISC compartment. In that context, the guanylate cyclase C (GUCY2C) receptor and its paracrine ligands regulate intestinal epithelial homeostasis, including proliferation, lineage commitment, and DNA damage repair. However, a role for this axis in maintaining ISCs remains unknown. Transgenic mice enabling analysis of ISCs (Lgr5-GFP) in the context of GUCY2C elimination (Gucy2c-/-) were combined with immunodetection techniques and pharmacological treatments to define the role of the GUCY2C signaling axis in supporting ISCs. ISCs were reduced in Gucy2c-/- mice, associated with loss of active Lgr5+ cells but a reciprocal increase in reserve Bmi1+ cells. GUCY2C was expressed in crypt base Lgr5+ cells in which it mediates canonical cyclic (c) GMPdependent signaling. Endoplasmic reticulum (ER) stress, typically absent from ISCs, was elevated throughout the crypt base in Gucy2c-/- mice. The chemical chaperone tauroursodeoxycholic acid resolved this ER stress and restored the balance of ISCs, an effect mimicked by the GUCY2C effector 8Br-cGMP. Reduced ISCs in Gucy2c-/-mice was associated with greater epithelial injury and impaired regeneration following sub-lethal doses of irradiation. These observations suggest that GUCY2C provides homeostatic signals that modulate ER stress and cell vulnerability as part of the machinery contributing to the integrity of ISCs. Š Kraft et al

    An Attempt to Reproduce the Schwarz‐Hora Effect

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    Several attempts were made to observe the modulation of an electron beam by a laser (the Schwarz‐Hora effect). These were not successful and possible reasons are reported

    Isospin fractionation and isoscaling in dynamical nuclear collisions

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    Isoscaling is found to hold for fragment yields in the antisymmetrized molecular dynamics (AMD) simulations for collisions of calcium isotopes at 35 MeV/nucleon. This suggests the applicability of statistical considerations to the dynamical fragment emission. The observed linear relationship between the isoscaling parameters and the isospin asymmetry of fragments supports the above suggestion. The slope of this linear function yields information about the symmetry energy in low density region where multifragmentation occurs.Comment: 11 pages, 6 figure

    Thermoreflectance investigation of the antiferromagnetic and paramagnetic phases of Cr

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    Thermoreflectance measurements have been performed on Cr single crystals at several temperatures above and below the NĂŠel temperature. We observe dramatic changes induced by the magnetic phase transition. In contrast, static optical data fail to show appreciable differences in the (0.5-5.0)-eV photon-energy range. Magnetic ordering gives rise to the disappearance of transitions involving specific regions of the Fermi surface. New critical-point absorptions appear at the boundaries of the new Brillouin zone in antiferromagnetic Cr. Most of the observed experimental features have been identified by comparison with recent band-structure calculations

    A Self-Exciting Controller for High-Speed Vertical Running

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    Traditional legged runners and climbers have relied heavily on gait generators in the form of internal clocks or reference trajectories. In contrast, here we present physical experiments with a fast, dynamical, vertical wall climbing robot accompanying a stability proof for the controller that generates it without any need for an additional internal clock or reference signal. Specifically, we show that this “self-exciting” controller does indeed generate an “almost” globally asymptotically stable limit cycle: the attractor basin is as large as topologically possible and includes all the state space excluding a set with empty interior. We offer an empirical comparison of the resulting climbing behavior to that achieved by a more conventional clock-generated gait trajectory tracker. The new, self-exciting gait generator exhibits a marked improvement in vertical climbing speed, in fact setting a new benchmark in dynamic climbing by achieving a vertical speed of 1.5 body lengths per second. For more information: Kod*La
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