24 research outputs found

    Investigating the influences of context on the information seeking behaviour of first-generation students

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    This paper reports on a qualitative study investigating the information seeking behaviour of first-generation students enrolled at the University of Johannesburg, South Africa, in the Humanities’ Mastering Academic and Professional Skills programme. The purpose is to determine the way in which their socio-economic situations influenced their ability to solve information problems. The target population come from low-income families with low social and cultural capacity in their home environment. A qualitative phenomenological research approach was followed. A purposive convenience sample was drawn from the target population. A total of 17 students participated in the study. Qualitative data analysis procedures were used with inductive reasoning as an open-ended approach. The data were collected using interviews with an open- and close-ended interview schedule. Both contextual (environmental) and personal experiences influence the information seeking behaviour of first-generation students. Information literacy as an intervention served as a catalyst to change the students’ information seeking behaviour. An understanding of first-generation students’ information seeking behaviour can provide insights for librarians on the way in which to meet these students’ information needs.Peer Reviewe

    A host-parasite catalogue of the haematozoa of the sub-Saharan birds

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    The prevalence of avian haematozoa in 826 species of birds representing 73 families of sub-Saharan birds as recorded in the literature or in the files of the International Reference Centre for Avian Haematozoa and the Veterinary Research Institute is presented. The most commonly occurring blood parasites were members of the genus Haemoproteus which were represented by 63 species which occurred in 19,1% of the sample. Twenty-five species of Leucocytozoon were recorded in 8,3% of the birds and represented the second most frequently encountered group of haematozoa. Species of Plasmodium, Trypanosoma, and filarioids (as microfilariae) occurred in 3,5%, 2,5% and 2,8% respectively of the birds sampled; species of Aegyptianella, Atoxoplasma, Babesia and Hepatozoon were infrequently seen. An annotated list of the birds examined for haematozoa is presented and brief descriptions of the species of Haemoproteus and Leucocytozoon in birds of the sub-Saharan zone are included.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Foundation for Research Development. Natural Sciences and Engineering Research Council of Canada.mn201

    A risk assessment of automated treatment planning and recommendations for clinical deployment

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    CITATION: Kisling, K. et al. 2019. A risk assessment of automated treatment planning and recommendations for clinical deployment. Medical Physics, 46(6): 2567-2574. doi:10.1002/mp.13552The original publication is available at https://aapm.onlinelibrary.wiley.com/journal/24734209Purpose: To assess the risk of failure of a recently developed automated treatment planning tool, the radiation planning assistant (RPA), and to determine the reduction in these risks with implementation of a quality assurance (QA) program specifically designed for the RPA. Methods: We used failure mode and effects analysis (FMEA) to assess the risk of the RPA. The steps involved in the workflow of planning a four-field box treatment of cervical cancer with the RPA were identified. Then, the potential failure modes at each step and their causes were identified and scored according to their likelihood of occurrence, severity, and likelihood of going undetected. Additionally, the impact of the components of the QA program on the detectability of the failure modes was assessed. The QA program was designed to supplement a clinic's standard QA processes and consisted of three components: (a) automatic, independent verification of the results of automated planning; (b) automatic comparison of treatment parameters to expected values; and (c) guided manual checks of the treatment plan. A risk priority number (RPN) was calculated for each potential failure mode with and without use of the QA program. Results: In the RPA automated treatment planning workflow, we identified 68 potential failure modes with 113 causes. The average RPN was 91 without the QA program and 68 with the QA program (maximum RPNs were 504 and 315, respectively). The reduction in RPN was due to an improvement in the likelihood of detecting failures, resulting in lower detectability scores. The top-ranked failure modes included incorrect identification of the marked isocenter, inappropriate beam aperture definition, incorrect entry of the prescription into the RPA plan directive, and lack of a comprehensive plan review by the physician. Conclusions: Using FMEA, we assessed the risks in the clinical deployment of an automated treatment planning workflow and showed that a specialized QA program for the RPA, which included automatic QA techniques, improved the detectability of failures, reducing this risk. However, some residual risks persisted, which were similar to those found in manual treatment planning, and human error remained a major cause of potential failures. Through the risk analysis process, we identified three key aspects of safe deployment of automated planning: (a) user training on potential failure modes; (b) comprehensive manual plan review by physicians and physicists; and (c) automated QA of the treatment plan.https://aapm.onlinelibrary.wiley.com/doi/10.1002/mp.13552Publisher’s versio

    Extruded cellulose/ionic liquid carbon scaffolds

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    Monolithic carbon scaffolds were obtained by pyrolysis of regenerated cellulose. First, microcrystalline cellulose was compounded, at a 1:1 mass ratio, with 1-ethyl-3-methylimidazolium acetate, choline chloride or a mixture of the two ionic liquids. Test bars were extrusion-molded and the ionic liquid removed by leaching with water. The porous cellulose bars were carbonized at 800 °C in a nitrogen atmosphere. The Raman ID/IG peak intensity ratios ranged from 0.74 to unity confirming the formation of amorphous carbon. Scanning electron microscopy revealed a highly porous structure consisting of both micro- and nanopores.https://aip.scitation.org/journal/apcpm2021Chemical Engineerin

    Guided reflection as a tool to deal with the theory– practice gap in critical care nursing students

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    Critical care nursing students experience inconsistencies between the theoretical content they have learnt and what is expected from them in practice, which retards the learning process. This has been described as the theory–practice gap. There seems to be no single solution to address the integration of theory and practice. In an attempt to bridge this gap, a study was done to establish the influence of guided reflection on critical care nursing students in dealing with their theoretical and practical experiences. A qualitative, explorative, descriptive and contextual design was followed. An instrument for guided reflection was designed which was used during semi-structured interviews during the data collection process. Field notes and narrative descriptions were also used as means to collect data. Themes that emerged from the data included a description of incidents experienced, critical analysis of knowledge, critical analysis of feelings and changed perspective experienced. Theory–practice integration occurred to an extent in some of the categories; conversely, the inability to apply theory to practice evoked responses such as feelings of guilt and incompetence. Guided reflection appeared to have assisted the participants in clarifying theoretical and practical experiences, and in reaching a changed perspective by understanding the link between theory and practice. Guided reflection ought to be incorporated in the education of nurses from their basic training in theory and practice so that student nurses will be aware of their own competencies in order to provide optimal patient care. Opsomming Kritiekesorgverpleegstudente ervaar teenstrydighede ten opsigte van dit wat hul geleer word en wat van hul in die praktyk verwag word wat weer die leerproses vertraag. Dit word as die teorie–praktykgaping beskryf. Daar blyk geen enkelvoudige oplossing te wees vir die integrasie van teorie en praktyk nie. In ’n poging om die gaping te oorbrug, is ’n studie oor die invloed van begeleide refleksie op kritiekesorgverpleegkundige studente se teoretiese en praktiese ervaringe gedoen. ’n Kwalitatiewe, verkennende, beskrywende en kontekstuele navorsingsontwerp is gevolg. ‘n Instrument vir begeleide refleksie is ontwerp wat gebruik is tydens semi-gestruktureerde onderhoude in die data-insamelingsproses. Veldnotas en narratiewe beskrywings was ook middele ten einde data in te samel. Tema’s wat uit die data na vore gekom het was ‘n beskrywing van ervaringe, kritiese analise van data, kritiese analise van gevoelens en ‘n veranderde perspektief met betrekking tot ervaringe. Teorie–praktyk integrasie het tot ‘n mate in sommige kategorieë plaasgevind het. Daarinteen het die onvermoë om die teorie in die praktyk toe te pas response tot gevolg gehad, soos skuldgevoelens en gevoelens van onbevoegdheid. Dit wil voorkom asof begeleide refleksie die deelnemers gehelp het om duidelikheid en ’n veranderde perspektief ten opsigte van hul teoretiese en praktiese ervaringe te verkry. Begeleide refleksie behoort reeds vanaf basiese opleiding in verpleegkundiges se teoretiese en praktiese opleiding geïnkorporeer te word sodat verpleegkundiges bewus sal wees van hulle eie vaardighede om sodoende optimale pasiëntsorg te kan lewer

    A novel cost-effective choline chloride/ionic liquid solvent for all-cellulose composite production

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    The potential of a blended cellulose solvent, consisting of a 1:1 mass ratio of choline chloride with the ionic liquid 1-ethyl-3-methylimadazolium acetate, was evaluated by using a film-casting technique. When comparing films produced with the neat ionic liquid to casting products from the mixed solvent, mechanical properties could largely be retained, while transparency was somewhat impaired. This is attributed to a fibrous microstructure and a higher degree of crystallinity caused by incomplete dissolution of the initial cellulose fibres. The presence of these residual fibres significantly reduced shrinkage during the film formation process. Functional group analyses, together with information on their crystallographic structure, proved that these film-like products should be classified as all-cellulose composites (ACCs). Statistical analyses of tensile properties justify further research on the mixed solvent system for cellulose processing.PAMSA and the Department of Science and Innovation.https://link.springer.com/journal/105702023-10-31hj2023Chemical Engineerin

    Dextrin nanocomposites as matrices for solid dosage forms

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    Safe application of water-insoluble acaricides requires fast release from solid dosage systems into aquatic environments. Dextrin is a water-soluble form of partially hydrolyzed starch, which may be used as matrix material for these systems if retrogradation can be inhibited by the inclusion of nanofillers. Several glycerol-plasticized thermoplastic dextrin-based nanocomposites were prepared with a twin-screw extrusion-compounding process. The nanofillers included a layered double hydroxide (LDH), cellulose nanofibers (CNF), and stearic acid. The time-dependent retrogradation of the compounds was monitored by X-ray diffraction (XRD) and dynamic mechanical thermal analysis (DMA). XRD showed that composite samples that included stearic acid in the formulation led to the formation of an amylose-lipid complex and a stable crystallinity during aging. The most promising nanocomposite included both stearic acid and CNF. It was selected as the carrier material for the water-insoluble acaricide Amitraz. Fast release rates were observed for composites containing 5, 10, and 20% (w/w) of the pesticide. A significant reduction in the particle size of the released Amitraz powder was observed, which is ascribed to the high-temperature compounding procedure.PAMSA and the Department of Science and Innovationhttps://pubs.acs.org/journal/aamickhj2021Chemical EngineeringConsumer ScienceFood Scienc

    Automated treatment planning of postmastectomy radiotherapy

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    CITATION: Kisling, K., et al. 2019. Automated treatment planning of postmastectomy radiotherapy. Medical physics, 46(9), 3767–3775. https://doi.org/10.1002/mp.13586The original publication is available at https://aapm.onlinelibrary.wiley.com/journal/24734209Purpose: Breast cancer is the most common cancer in women globally and radiation therapy is a cornerstone of its treatment. However, there is an enormous shortage of radiotherapy staff, especially in low- and middle-income countries. This shortage could be ameliorated through increased automation in the radiation treatment planning process, which may reduce the workload on radiotherapy staff and improve efficiency in preparing radiotherapy treatments for patients. To this end, we sought to create an automated treatment planning tool for postmastectomy radiotherapy (PMRT). Methods: Algorithms to automate every step of PMRT planning were developed and integrated into a commercial treatment planning system. The only required inputs for automated PMRT planning are a planning computed tomography scan, a plan directive, and selection of the inferior border of the tangential fields. With no other human input, the planning tool automatically creates a treatment plan and presents it for review. The major automated steps are (a) segmentation of relevant structures (targets, normal tissues, and other planning structures), (b) setup of the beams (tangential fields matched with a supraclavicular field), and (c) optimization of the dose distribution by using a mix of high- and low-energy photon beams and field-in-field modulation for the tangential fields. This automated PMRT planning tool was tested with ten computed tomography scans of patients with breast cancer who had received irradiation of the left chest wall. These plans were assessed quantitatively using their dose distributions and were reviewed by two physicians who rated them on a three-tiered scale: use as is, minor changes, or major changes. The accuracy of the automated segmentation of the heart and ipsilateral lung was also assessed. Finally, a plan quality verification tool was tested to alert the user to any possible deviations in the quality of the automatically created treatment plans. Results: The automatically created PMRT plans met the acceptable dose objectives, including target coverage, maximum plan dose, and dose to organs at risk, for all but one patient for whom the heart objectives were exceeded. Physicians accepted 50% of the treatment plans as is and required only minor changes for the remaining 50%, which included the one patient whose plan had a high heart dose. Furthermore, the automatically segmented contours of the heart and ipsilateral lung agreed well with manually edited contours. Finally, the automated plan quality verification tool detected 92% of the changes requested by physicians in this review. Conclusions: We developed a new tool for automatically planning PMRT for breast cancer, including irradiation of the chest wall and ipsilateral lymph nodes (supraclavicular and level III axillary). In this initial testing, we found that the plans created by this tool are clinically viable, and the tool can alert the user to possible deviations in plan quality. The next step is to subject this tool to prospective testing, in which automatically planned treatments will be compared with manually planned treatments.https://aapm.onlinelibrary.wiley.com/doi/10.1002/mp.13586Publisher’s versio

    Plasma polyunsaturated fatty acids and liver enzymes in HIV-infected subjects: the prospective urban and rural epidemiology (PURE) study

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    Background: Omega-6 (n–6) polyunsaturated fatty acid (PUFA) intake was previously reported to be adversely related to liver function in HIV-infected subjects, when compared with HIV-uninfected subjects, in a black population in South Africa. It was speculated that the use of heavily oxidized vegetable fats (abused fats) could have been responsible. Objectives: The objectives were to investigate the relation between plasma total PUFA concentrations (a marker of PUFA intake) and liver enzymes in HIV-infected asymptomatic compared with HIVuninfected black South Africans and to investigate the reuse of oil and the use of abused oils. Design: This was a case-control study nested in an epidemiologic study in 305 HIV-infected cases and 301 HIV-uninfected matched controls (matched according to location, sex, and age), as part of the PURE (Prospective Urban and Rural Epidemiology) Study, a prospective cohort study that includes a representative sample of 2000 apparently healthy black volunteers, aged between 36 and 60 y, from the North West Province of South Africa. Results: Plasma total omega-6 PUFA concentrations were negatively (P , 0.05) associated with liver enzymes (c-glutamyl transpeptidase, alanine aminotransferase, aspartate aminotranferase, and alkaline phosphatase) in both HIV-infected and HIV-uninfected subjects (r values ranged from 20.22 to 20.56). Almost all subjects (99%) reported that they did not buy oil that had been used before. Oil was only used a mean (6SD) of 2.23 6 0.85 times for deep frying before being discarded. Conclusions: The adverse relations between omega-6 PUFA intake and liver enzymes that were previously shown could not be confirmed in this study. In contrast, plasma omega-6 PUFA concentration was inversely related to liver enzymes in both HIV-infected and HIV-uninfected subjects. Subjects in this study did not use abused fats, which could partly explain these finding

    Addressing the Global Expertise Gap in Radiation Oncology: The Radiation Planning Assistant

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    PURPOSEAutomation, including the use of artificial intelligence, has been identified as a possible opportunity to help reduce the gap in access and quality for radiotherapy and other aspects of cancer care. The Radiation Planning Assistant (RPA) project was conceived in 2015 (and funded in 2016) to use automated contouring and treatment planning algorithms to support the efforts of oncologists in low- and middle-income countries, allowing them to scale their efforts and treat more patients safely and efficiently (to increase access).DESIGNIn this review, we discuss the development of the RPA, with a particular focus on clinical acceptability and safety/risk across jurisdictions as these are important indicators for the successful future deployment of the RPA to increase radiotherapy availability and ameliorate global disparities in access to radiation oncology.RESULTSRPA tools will be offered through a webpage, where users can upload computed tomography data sets and download automatically generated contours and treatment plans. All interfaces have been designed to maximize ease of use and minimize risk. The current version of the RPA includes automated contouring and planning for head and neck cancer, cervical cancer, breast cancer, and metastases to the brain.CONCLUSIONThe RPA has been designed to bring high-quality treatment planning to more patients across the world, and it may encourage greater investment in treatment devices and other aspects of cancer treatment
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