2,893 research outputs found

    HIV-associated opportunistic fungal infections: a guide to using the clinical microbiology laboratory

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    This review aims to provide a guide for clinicians to using the clinical microbiology laboratory for management of common HIV-associated opportunistic fungal infections, e.g. mucosal candidiasis, cryptococcosis, Pneumocystis jirovecii pneumonia (PCP), histoplasmosis, etc. Laboratory tests provide valuable guidance at various stages of management of HIV-infected patients with fungal infections: (i ) establishing a diagnosis, (ii) guiding appropriate antifungal therapy in selected circumstances, (iii) providing laboratory prognostic markers, (iv) monitoring response to therapy; and (v ) detecting relapses. However, the laboratory is not always able to provide reliable answers to clinically relevant questions, and these limitations must be considered in the interpretation of test results. Southern African Journal of HIV Medicine Vol. 8 (3) 2007: pp. 18-2

    A clash of rights in the legal and spatial planning contexts: The case of the Philippi Horticultural Area

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    The Philippi Horticultural Area (PHA) is often referred to as Cape Town’s ‘food basket’, providing over one-third of Cape Town’s fresh vegetable produce. Located in the heart of the Cape Flats District, the PHA is surrounded by some of the poorest and most densely populated suburbs in the Cape Town metropolitan region. The agricultural area has come under increasing development pressure in recent years, caught in the midst of the ongoing battle between urban development and housing delivery, on the one hand, and the protection of agricultural activity, on the other. This article evaluates the arguments for and against the development of portions of the PHA against secs. 24-27 of the Constitution of the Republic of South Africa, 1996 relating to rights associated with the environment; property; housing; healthcare, food, water, and social security. The article seeks to determine whether a balancing of these rights can be achieved within the PHA, and whether portions of the PHA can be developed in a manner that protects and enhances the cultural and environmental integrity of the area, while also allowing urban development to accommodate new and existing communities. We argue that issues related to food security, environmental well-being, and access to land and development are inextricably linked and cannot be dealt with in isolation. Instead, a more holistic approach is needed, which takes a balanced view of these issues and embraces the spirit of the Bill of Rights (as contained in Chapter 2 of the Constitution) in an all-encompassing manner. Given that the PHA faces enormous challenges such as rampant crime, illegal occupation of land, and so on, we take the position that a balancing of rights is not only the most appropriate strategy for the PHA from a legal point of view, but also crucial to its very survival. We, therefore, argue that a symbiotic relationship must be cultivated between urban and agricultural land uses, through appropriate urban development articulated in a spatial framework that provides clarity as to how urban development can assist in protecting productive agricultural activity. In this way, the role of the PHA as Cape Town’s ‘food basket’ can be better conserved for current and future generations

    Local Rheology Relation with Variable Yield Stress Ratio across Dry, Wet, Dense, and Dilute Granular Flows

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    Dry, wet, dense, and dilute granular flows have been previously considered fundamentally different and thus described by distinct, and in many cases incompatible, rheologies. We carry out extensive simulations of granular flows, including wet and dry conditions, various geometries and driving mechanisms (boundary driven, fluid driven, and gravity driven), many of which are not captured by standard rheology models. For all simulated conditions, except for fluid-driven and gravity-driven flows close to the flow threshold, we find that the Mohr-Coulomb friction coefficient μ\mu scales with the square root of the local P\'eclet number Pe\mathrm{Pe} provided that the particle diameter exceeds the particle mean free path. With decreasing Pe\mathrm{Pe} and granular temperature gradient MM, this general scaling breaks down, leading to a yield condition with a variable yield stress ratio characterized by MM

    Integrating critical cross-field outcomes in an anatomy course at a university of technology: A reflective perspective

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    Background. Recent trends in higher education have become particularly directed towards incorporating elements of general education in professionspecific training. Consequently, the inclusion of critical cross-field outcomes (CCFOs) – a set of generic outcomes gazetted by the South African Qualification Authority – in curricula, is directed towards stimulating a critical social conscience among students. This embraces the concept of education, more than simply certification, in embedding underlying principles that foster lifelong learning, critical thinking and social responsibility, and provides an opportune platform to examine our teaching strategies in the context of reflective practice.Objectives. This article demonstrates an application of the theory of reflective practice in the modification of teaching strategies and the integration of the CCFOs in a human anatomy course at a university of technology.Methods. We present the different teaching strategies that were applied, and highlight the CCFOs embodied in each approach.Results. In so doing, we demonstrate how the integration of underpinning general education principles and discipline-specific core competencies can be easily attained through simple modifications of conventional teaching practices.Conclusion. The teaching methods highlighted attempt to encourage and ensure that students evaluate, understand and apply their knowledge in an integrated and shared manner, as embraced by the CCFOs

    Teaching and learning considerations during the COVID 19 pandemic: Supporting multimodal student learning preferences

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    Background. The advent of COVID‑19 and the subsequent national lockdown has catapulted higher education institutions into emergency remote teaching (ERT). A principal challenge in this shift is the ability to stimulate student interest towards engagement with, and retention of, course content. The creation of teaching and learning (T&L) resources and activities using a combination of the visual, aural, read/write and kinaesthetic (VARK) modes is fundamental in ensuring student engagement. Objectives. To determine the learning style profiles of undergraduate students and to explore how student learning profiles may be incorporated in T&L approaches during ERT. Methods. This descriptive study profiles the learning preferences of undergraduate students in a health science faculty using the VARK questionnaire. The study further outlines modifications in T&L implemented to support the varied learning preferences during the COVID‑19 ERT response. Results. Our findings demonstrate that the majority of our students have a multimodal learning preference, with the kinaesthetic modality being the most preferred. Voice-over PowerPoint presentations with transitioning images, and audio files, supported the visual and aural learners through asynchronous engagement. Additionally, online discussion forums and applied projects (such as theme park designs) enhanced asynchronous learning by stimulating the visual, read/write and kinaesthetic preferences, respectively. Microsoft Team sessions with PowerPoint presentations supported visual and aural learning preferences through synchronous engagement. Conclusions. Rethinking traditional T&L approaches towards supporting the diverse student learning preferences is critical in student-centred T&L amidst the many challenges that ERT has precipitated. Academics need to be dynamic in their T&L approaches and intuitive in their awareness of how subject content may be modified/enhanced in the ERT environment

    Blaze-DEMGPU: Modular high performance DEM framework for the GPU architecture

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    AbstractBlaze-DEMGPU is a modular GPU based discrete element method (DEM) framework that supports polyhedral shaped particles. The high level performance is attributed to the light weight and Single Instruction Multiple Data (SIMD) that the GPU architecture offers. Blaze-DEMGPU offers suitable algorithms to conduct DEM simulations on the GPU and these algorithms can be extended and modified. Since a large number of scientific simulations are particle based, many of the algorithms and strategies for GPU implementation present in Blaze-DEMGPU can be applied to other fields. Blaze-DEMGPU will make it easier for new researchers to use high performance GPU computing as well as stimulate wider GPU research efforts by the DEM community

    Mainstreaming Underutilized Indigenous and Traditional Crops into Food Systems: A South African Perspective

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    Business as usual or transformative change? While the global agro-industrial food system is credited with increasing food production, availability and accessibility, it is also credited with giving birth to ‘new’ challenges such as malnutrition, biodiversity loss, and environmental degradation. We reviewed the potential of underutilized indigenous and traditional crops to bring about a transformative change to South Africa’s food system. South Africa has a dichotomous food system, characterized by a distinct, dominant agro-industrial, and, alternative, informal food system. This dichotomous food system has inadvertently undermined the development of smallholder producers. While the dominant agro-industrial food system has led to improvements in food supply, it has also resulted in significant trade-offs with agro-biodiversity, dietary diversity, environmental sustainability, and socio-economic stability, especially amongst the rural poor. This challenges South Africa’s ability to deliver on sustainable and healthy food systems under environmental change. The review proposes a transdisciplinary approach to mainstreaming underutilized indigenous and traditional crops into the food system, which offers real opportunities for developing a sustainable and healthy food system, while, at the same time, achieving societal goals such as employment creation, wellbeing, and environmental sustainability. This process can be initiated by researchers translating existing evidence for informing policy-makers. Similarly, policy-makers need to acknowledge the divergence in the existing policies, and bring about policy convergence in pursuit of a food system which includes smallholder famers, and where underutilized indigenous and traditional crops are mainstreamed into the South African food system

    Collapsing sphere on the brane radiates

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    We study the analogue of the Oppenheimer-Snyder model of a collapsing sphere of homogeneous dust on the Randall-Sundrum type brane. We show that the collapsing sphere has the Vaidya radiation envelope which is followed by the brane analogue of the Schwarzschild solution described by the Reissner-Nordstrom metric. The collapsing solution is matched to the brane generalized Vaidya solution and which in turn is matched to the Reissner-Nordstrom metric. The mediation by the Vaidya radiation zone is the new feature introduced by the brane. Since the radiating mediation is essential, we are led to the remarkable conclusion that a collapsing sphere on the brane does indeed, in contrast to general relativity, radiate null radiation.Comment: Minor changes, main results remain unchanged, to appear in Phys. Lett.