64 research outputs found

    The role of the tutorial system in enabling students’ academic success

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    Abstract: A worrying trend in South Africa has been the high attrition rate for first-time university students. At the University of Johannesburg (UJ), one intervention used to address this low throughput rate is the tutorial system. While it is important to broaden formal access to universities, it is also crucial to provide first-year students with access to the epistemologies of their discipline to ensure their academic success. This can potentially be enabled through the tutorial system. While tutorials are growing in size due to increased numbers, the tutorial still has a role to play in giving students the opportunity to engage with each other and their tutor in a smaller group than that of the lecture. For the tutorial system to enable students’ academic success, however, tutors need to support their students not only in their acquisition of the target epistemologies, but also to take cognisance of their students’ ontological needs

    Physically Similar Systems - A History of the Concept

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    PreprintThe concept of similar systems arose in physics, and appears to have originated with Newton in the seventeenth century. This chapter provides a critical history of the concept of physically similar systems, the twentieth century concept into which it developed. The concept was used in the nineteenth century in various fields of engineering (Froude, Bertrand, Reech), theoretical physics (van der Waals, Onnes, Lorentz, Maxwell, Boltzmann) and theoretical and experimental hydrodynamics (Stokes, Helmholtz, Reynolds, Prandtl, Rayleigh). In 1914, it was articulated in terms of ideas developed in the eighteenth century and used in nineteenth century mathematics and mechanics: equations, functions and dimensional analysis. The terminology physically similar systems was proposed for this new characterization of similar systems by the physicist Edgar Buckingham. Related work by Vaschy, Bertrand, and Riabouchinsky had appeared by then. The concept is very powerful in studying physical phenomena both theoretically and experimentally. As it is not currently part of the core curricula of STEM disciplines or philosophy of science, it is not as well known as it ought to be

    Effect of a 2-week interruption in methotrexate treatment on COVID-19 vaccine response in people with immune-mediated inflammatory diseases (VROOM study): a randomised, open label, superiority trial

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    Background: Methotrexate is the first-line treatment for immune-mediated inflammatory diseases and reduces vaccine-induced immunity. We evaluated if a 2-week interruption of methotrexate treatment immediately after COVID-19 booster vaccination improved antibody response against the S1 receptor binding domain (S1-RBD) of the SARS-CoV-2 spike protein and live SARS-CoV-2 neutralisation compared with uninterrupted treatment in patients with immune-mediated inflammatory diseases. Method: We did a multicentre, open-label, parallel-group, randomised, superiority trial in secondary-care rheumatology and dermatology clinics in 26 hospitals in the UK. Adults (aged ≥18 years) with immune-mediated inflammatory diseases taking methotrexate (≤25 mg per week) for at least 3 months, who had received two primary vaccine doses from the UK COVID-19 vaccination programme were eligible. Participants were randomly assigned (1:1) using a centralised validated computer program, to temporarily suspend methotrexate treatment for 2 weeks immediately after COVID-19 booster vaccination or continue treatment as usual. The primary outcome was S1-RBD antibody titres 4 weeks after COVID-19 booster vaccination and was assessed masked to group assignment. All randomly assigned patients were included in primary and safety analyses. This trial is registered with ISRCTN, ISRCTN11442263; following a pre-planned interim analysis, recruitment was stopped early. Finding: Between Sept 30, 2021, and March 7, 2022, we screened 685 individuals, of whom 383 were randomly assigned: to either suspend methotrexate (n=191; mean age 58·8 years [SD 12·5], 118 [62%] women and 73 [38%] men) or to continue methotrexate (n=192; mean age 59·3 years [11·9], 117 [61%] women and 75 [39%] men). At 4 weeks, the geometric mean S1-RBD antibody titre was 25 413 U/mL (95% CI 22 227–29 056) in the suspend methotrexate group and 12 326 U/mL (10 538–14 418) in the continue methotrexate group with a geometric mean ratio (GMR) of 2·08 (95% CI 1·59–2·70; p<0·0001). No intervention-related serious adverse events occurred. Interpretation: 2-week interruption of methotrexate treatment in people with immune-mediated inflammatory diseases enhanced antibody responses after COVID-19 booster vaccination that were sustained at 12 weeks and 26 weeks. There was a temporary increase in inflammatory disease flares, mostly self-managed. The choice to suspend methotrexate should be individualised based on disease status and vulnerability to severe outcomes from COVID-19. Funding: National Institute for Health and Care Research

    Quasi-hybrid airships

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    The dynamic lift required for operating even a conventionally shaped non­ rigid airship with a weight in excess of the static buoyancy may be obtained by operating in a quasi-hybrid mode wherein the deflected longitudinal control sources are used to obtain dynamic lift at near-zero angles of attack of the airship envelope, This results in a sig­nificant reduction in the drag of the airship and, as a result, a decrease in the power required to fly at a given airspeed

    Airship lift - static, dynamic and powered static

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    The basic principles of airship aerostatics and aerodynamics as they apply to powered Lighter Than Air vehicles are summarized. The development of static lift is discussed, as is the effect of the variation of atmospheric parameters on the lift of an aerostat. In addition, the use of dynamics and powered statics as a lift adjunct is reviewed

    Refractory anaemia with preleukaemic polyclonal haemopoiesis and the emergence of monoclonal erythropoiesis on disease progression

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    We describe a young woman with a myelodysplastic syndrome (MDS) of the type refractory anaemia (RA) which remained stable for 11 years and then underwent rapid progression manifested by bone marrow failure with the emergence of a complex clonal cytogenetic abnormality. Peripheral blood granulocytes. mononuclear cells and bone marrow erythro-blasts were all polyclonal by X-inactivation analysis detected by the probe M27B during the preleukaemic phase. On disease progression, bone marrow erythroblasts developed an extremely skewed monoclonal pattern of X-inactivation. In some cases of MDS, therefore, polyclonal haemopoiesis can be detected for a considerable time during the preleukaemic phase and we report the demonstration of bone marrow erythroblasts changing from a polyclonal to a monoclonal pattern on disease progression

    An apparatus for automated cross flow solute permeation characterization of membranes

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    An apparatus is described for the automated characterization of ultrafiltration membranes using solute permeation in cross flow mode. The automated characterization approach described in this work lends itself well for the purpose of increased productivity and reducing operator fatigue/error. The operational, control, and data acquisition aspects of an automated membrane cross flow test unit, which are accomplished using LabVIEW 5.0TM are described. The interpretation of the flux and separation data is independent of the apparatus and depends on the filtration regime and various theoretical models available. The apparatus can be used for reverse osmosis, nanofiltration, or ultrafiltration experiments, with appropriate selection of test cells and pumps.NRC publication: Ye

    English 1D

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    Exam paper for second semester 201
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