Minimal knotted polygons in cubic lattices

An implementation of BFACF-style algorithms on knotted polygons in the simple cubic, face centered cubic and body centered cubic lattice is used to estimate the statistics and writhe of minimal length knotted polygons in each of the lattices. Data are collected and analysed on minimal length knotted polygons, their entropy, and their lattice curvature and writhe

The Compressibility of Minimal Lattice Knots

The (isothermic) compressibility of lattice knots can be examined as a model of the effects of topology and geometry on the compressibility of ring polymers. In this paper, the compressibility of minimal length lattice knots in the simple cubic, face centered cubic and body centered cubic lattices are determined. Our results show that the compressibility is generally not monotonic, but in some cases increases with pressure. Differences of the compressibility for different knot types show that topology is a factor determining the compressibility of a lattice knot, and differences between the three lattices show that compressibility is also a function of geometry.Comment: Submitted to J. Stat. Mec

“A hundred times we learned from one another” Collaborative learning in an academic writing workshop

Using Design Research as methodology and research design type, this article reports on a research proposal writing workshop conducted with Education postgraduate students, with the aim of ascertaining the roles that conversation, collaboration and feedback play in constructing meaning and supporting writing. It was found that through conversation, as part of a general discourse within a community that students whose first language may differ from that of others, but for whom the language of learning is English, are able to share with tutors and other students, and to negotiate meaning. The construction of knowledge is consequently dependent on conversation between students, their peers and the tutors within a collaborative community, such as a writing centre, in which feedback on writing is offered and received in order to support student writing.Key words: academic writing; academic writing support; collaborative learning; feedback tutoring; writing centre

Manufacturing challenges for custom made solar vehicles in South Africa

Solar challenges are designed to test the reliability and efficiency of solar powered vehicles in endurance races. In the past these manufactured vehicles were technology drivers and led to advances in electric motors and solar cell efficiency. The speed in relation to power consumption is one of the main design considerations, with the only energy source being solar power. In the design and manufacturing of these vehicles a number of requirements need to be met in order to pass the safety standards. The Sasol Solar Challenge (SSC) created an opportunity for South African universities to design and manufacture custom made solar powered vehicles. This paper explores and discusses the challenges for manufacturing solar vehicles in South Africa. Key elements like the communication gap between design and manufacturing, the cost of lightweight solar encapsulation, the shortage of local suppliers and expertise in composite manufacturing are evaluated. These insights can be used as foundation for strategic decisions by future stakeholders

Acute mental health care according to recent mental health legislation Part II. Activity-based costing

Objective: This is the second of three reports on the follow-up review of mental health care at Helen Joseph Hospital (HJH). Objectives for the review were to provide realistic estimates of cost for unit activities and to establish a quality assurance cycle that may facilitate cost centre management. Method: The study described and used activity-based costing (ABC) as an approach to analyse the recurrent cost of acute in-patient care for the financial year 2007-08. Fixed (e.g. goods and services, staff salaries) and variable recurrent costs (including laboratory’, ‘pharmacy’) were calculated. Cost per day, per user and per diagnostic group was calculated. Results: While the unit accounted for 4.6% of the hospital’s total clinical activity (patient days), the cost of R8.12 million incurred represented only 2.4% of the total hospital expenditure (R341.36 million). Fixed costs constituted 90% of the total cost. For the total number of 520 users that stayed on average 15.4 days, the average cost was R1,023.00 per day and R15748.00 per user. Users with schizophrenia accounted for the most (35%) of the cost, while the care of users with dementia was the most expensive (R23,360.68 per user). Costing of the application of World Health Organization norms for acute care staffing for the unit, projected an average increase of 103% in recurrent costs (R5.1 million), with the bulk (a 267% increase) for nursing. Conclusion: In the absence of other guidelines, aligning clinical activity with the proportion of the hospital’s total budget may be an approach to determine what amount should be afforded to acute mental health in-patient care activities in a general regional hospital such as HJH. Despite the potential benefits of ABC, its continued application will require time, infrastructure and staff investment to establish the capacity to maintain routine annual cost analyses for different cost centres.Key words: Cost analysis; Activity-based costing; Acute mental health care; Recurrent cost; Fixed and variable cost; Cost centre management; Hospital expenditur

Teaching and learning English as a Home Language in a predominantly non-native English classroom: A study from KwaZulu-Natal1

This study focuses on a secondary school in an Indian-African suburb of Merewent in KwaZulu-Natal, an example of a suburban school where English as a Home Language (EHL) is taught to a majority of non-native English learners from township schools. The EHL classrooms were investigated for ‘communicativeness’ and then compared to English as a Second Language (ESL) classrooms. It might be expected that EHL classrooms would exhibit an affinity with ESL classrooms. However, although non-native EHL has many aspects in common with ESL, there were significant differences between the two. The most important difference from the standpoint of Communicative Language Teaching (CLT) was in the learning content selection, with the EHL settings using more literary works, and so focusing less on the direct teaching of grammatical forms. However, a disturbing pattern was the inability of the learners in both sets of settings to take full advantage of CLT, which suggested that the learners might not be at the appropriate level of language development.Keywords: English as Home Language (EHL), non-native English learners, township schools, English as a Second Language (ESL), Communicative Language Teaching (CLT), language developmen

Estimating Linkages between Redfish and Cold Water Coral on the Norwegian Coast

The importance of essential fish habitat in supporting commercial fisheries has received increasing attention in recent years. Bottom trawling is known to cause particularly destructive damage to habitat that is effectively non-renewable, such as cold water corals. This paper applies the production function approach to estimate the link between cold water corals and redfish in Norway. Both the carrying capacity and growth rate of redfish are found to be functions of cold water coral habitat and thus cold water corals can be considered an essential fish habitat. The paper also estimates a facultative relationship between cold water coral and redfish stocks. The essential habitat model shows the best fit to the data. Comparative statics of an essential habitat indicate an approximate annual loss in harvest of between 11 and 29% within the bounds of coral decline estimated by scientists. In terms of policy, our results indicate that essential fish habitat protection should be considered when managing commercially important species.Cold water coral, redfish, production function, habitat-fishery linkages, essential fish habitat, International Development, Research Methods/ Statistical Methods, Q22,

Blended teaching and learning: Exploring the concept, barriers to implementation and designing of learning resources

With the advent of the coronavirus disease 2019 (COVID-19), several institutions worldwide have adopted the blended mode of teaching and learning. However, literature on this concept in South Africa and on the African continent is scarce. This scoping review explores the concept of blended approach to training and how to design resources for the blended teaching and learning approach. In addition, the review investigates barriers to the implementation of blended learning. The findings of this study demonstrate that the understanding of the concept of blended teaching and learning is not homogenous and is often left to individual academics to decide on the approach. The review identified several hurdles that need to be addressed for successful implementation of blended teaching and learning, however these are not specific to South African institutions. Available literature on studies done elsewhere and in South African, suggest that some of the identified barriers to adoption of blended teaching and learning are real, while others are perceived or imagined. Lastly, the authors observed that there are several approaches to designing learning resources for the blended mode of teaching and learning. The choice of approach is dependent on the intended purpose for which the specific design is adopted. There is a need for studies that specifically investigate blended learning in Universities in South Africa and on the continent to help identify barriers to adopting blended teaching and learning among institutions that are specific to the South African and African context. Institutions adopting the blended teaching and learning mode of delivery, need to be unambiguous in their philosophy of blending teaching and learning and not leave it to the implementing academics. Policymakers can use the information generated in this review to recommend minimum requirements for a blended delivery mode in public institutions of higher learning

Learning Area Methodology: Arts and Culture B

Exam paper for seond semester Learning Area Methodology: Arts and Culture

Learning Area Methodology: Arts and Culture B

Exam paper for second semester (Supplementary) Learning Area Methodology: Arts and Culture