Engineering students' actions in a mathematical modelling task: Mediating mathematical understanding in a computer algebra system

Many engineering subjects rely on the interpretation of symbolic, numeric and graphic representations. Engineering students have challenges pertaining to their mathematical understanding of their actions with a computer algebra system (CAS). We investigated how a mathematical modelling task could mediate varied levels of mathematical understanding. When engineering students are exposed to a CAS environment, they habitually engage in programming activities without considering the computerised outputs. The purpose of this paper was to ascertain South African engineering students’ actions that can mediate broader levels of mathematical understanding in a CAS by utilising the Pirie- Kieren model of growth in mathematical understanding. Thirteen participants agreed to engage collaboratively in a mathematical modelling task. The task was analysed by means of content analysis following a deductive research approach. The findings disclosed that engineering students interdepend on paper-and-pen, computerised and reflective actions in their growth of mathematical understanding. Engineering students can be assisted in mediated and folding-back actions in order to fluctuate back and forth on their way to a more sound mathematical understanding. Explicit planning and sequence of subtasks can support engineering students to merge new levels of mathematics understanding with past comprehensions. Thoroughly planned modelling tasks can mediate novel levels of mathematical understanding when engineering students learn with a CAS

Part 1: Medico-legal documentation South African Police Services forms, Department of Justice forms and patient information

Medical practitioners share the responsibility of action against crime by supporting the justice system. The best way for a medical practitioner to achieve this is by proper examination of victims and/or perpetrators, and completing the legal documents meticulously. This can be a frightening experience without proper formal training. Paper 1 addresses the role and responsibility of the medical practitioner and issues around consent, general information on the completion of the J88, as well as the perceived gold standard of medical information relayed to the courts. Medico-legal documentation is more than the compilation of a medico-legal report. The clinical notes are part and parcel of the documentation to protect  practitioners against negligence and malpractice investigations. Valid medico-legal consent differs from medical consent. Knowledge of legislation pertaining to child pornography and the practical and ethical aspects of photography is also necessary. Inappropriate completion of medico-legal documentation may necessitate the practitioner having to explain the documentation to make it understandable to the court

Part 3: Medico-legal documentation Practical completion of pages 2 and 3 of the J88 form

This is Part 3 of a three-part series on medico-legal documentation. Part 1 addressed the knowledge and skills necessary to complete a legal J88 document. Part 2 provided practical guidance on completion of the J88 form in the case of assault. This article will focus on pages 2 and 3 of the J88 document, which deals with the alleged sexual offences of both adults and children. The assumption may exist that the J88 is the only significant document with respect to medical findings in alleged rape and child sexual abuse cases, and that the court needs this information to make a decision on the medical aspects of a case. However, the court needs the information to be interpreted by a medical practitioner, who must indicate the significance of the findings, determine who should supply relevant additional information, and then place the entire picture in context. This article attempts to highlight the value of the relevant aspects, while raising awareness of an unscientific interpretation of clinical examination.Keywords: medico-legal documentation, J88 form, sexual offences, pages 2 and 3 of J88 for

Part 2: Medico-legal documentation Practical completion of pages 1 and 4 of the J88 form

This is Part 2 of a three-part series on medico-legal documentation. Part 1 addressed the knowledge and skills necessary to complete a legal J88 document. The aim of Part 2 is to give practical guidance on completion of the J88 form in the case of assault. Part 3 will address the sexual assault section of the J88 form. As a legal document, the J88 form must be completed accurately with regard to demographic information, including the time and date of examination, to assist with interpretation of the findings. The full names of the person examined appear on the SAPS 308 form, and must be confirmed by the patient and an identification document, if available. The name of the healthcare provider must be identifiable and contact details must be stated to assist with tracing, if necessary. A complete history is important because a differential diagnosis needs be considered, and the clinical findings must be consistent with the description of the incident in terms of time, mechanism of the injury and the place at which the incident took place, as these all add to the probability that the incident occurred as disclosed. The health worker has a dual responsibility with regard to both the health and medico-legal aspects pertaining to the patient and must record these in the clinical notes. Only medico-legal aspects are recorded on the J88 form. A top-to-toe, back-to-front examination must be performed methodically, since the person may be unaware of certain injuries. The healthcare worker must write a conclusion in the space provided. Support of the history with the clinical picture is the basis for the conclusion

On the spin modulated circular polarization from the intermediate polars NY Lup and IGRJ1509-6649

We report on high time resolution, high signal/noise, photo-polarimetry of the intermediate polars NY Lup and IGRJ1509-6649. Our observations confirm the detection and colour dependence of circular polarization from NY Lup and additionally show a clear white dwarf, spin modulated signal. From our new high signal/noise photometry we have unambiguously detected wavelength dependent spin and beat periods and harmonics thereof. IGRJ1509-6649 is discovered to also have a particularly strong spin modulated circularly polarized signal. It appears double peaked through the I filter and single peaked through the B filter, consistent with cyclotron emission from a white dwarf with a relatively strong magnetic field. We discuss the implied accretion geometries in these two systems and any bearing this may have on the possible relationship with the connection between polars and soft X-ray-emitting IPs. The relatively strong magnetic fields is also suggestive of them being polar progenitors.Comment: 8 pages, 6 figures and 1 table. Accepted for publication in MNRA

The influence of a Mediterranean Diet with and without Red Wine on the Haemostatic and Inflammatory Parameters of Subjects with the Metabolic Syndrome

This 8 week study examined whether a Mediterranean diet supplemented with red wine, had an acute impact onsubjects diagnosed with the metabolic syndrome. Twelve non-smoking subjects with diagnostic criteria of themetabolic syndrome on minimal medication, consumed a Mediterranean-like diet for 4 weeks respectively withoutand with red wine. The amount of red wine consumed was 250 ml (26 grams of alcohol) per day for male and 180ml (19 grams) per day for female participants. A nutrigenetic profile for cardiovascular risk factors was performedon each participant. Fasting blood specimens were taken at baseline, after the diet and after the diet with wineinterventions for platelet function, procoagulants FVII and FVIII, von Willebrand’s factor, fibrinogen, tissueplasminogen activator, plasminogen activator inhibitor-1, highly sensitive C-reactive protein and oxygen radicalabsorbance capacity (ORAC). After both periods of diet without wine and with wine, ORAC increased significantlycompared to baseline levels. Except for platelet H2O2 fluxes and FVII concentration, none of the haemostatic orinflammatory parameters changed significantly after the intervention periods compared with baseline levels.Genetic risk factors for cardiovascular disease were identified in all study participants and the potential genotypiceffects relevant to this study were generally in agreement with expected phenotypic response following the dietaryintervention. Our conclusions are that the period of intervention was too short for substantial changes inhaemostatic or in inflammatory parameters in subjects who already manifest some changes in their cardiovascularsystem and who showed diverse genetic profiles underlying increased cardiovascular risk

Environmental factors influencing the distribution of Opuntia stricta, an invasive alien plant in the Kruger National Park, South Africa

Opuntia stricta (Cactaceae), an alien weed, has invaded an area of more than 35 000 ha in the Skukuza region of the Kruger National Park [KNP]. The distribution of the plant and features of the environment were used to identify biotic and abiotic factors which may be affecting the distribution and density of the plant. A Canonical Community Analysis revealed that none of the environmental factors that were monitored influenced the distribution or abundance of O. stricta in KNP. There were no apparent natural barriers that might limit the occurrence of O. stricta within the KNP. The study provides insight into the relationship between the invader and host environment, showing that there is a high probability that, unless there is appropriate intervention, O. stricta will eventually colonise the entire KNP