An exploration of Grade 12 learners' use of inappropriate algorithms in calculus

Published ArticleThis study was conducted with 29 Grade 12 learners who were studying calculus. The purpose was to explore how the learners responded to questions based on the derivative and why they did so. Data was collected from the written responses of the learners to two assessments carried out over a six-month period as well as interviews with four of the learners. It was found that learners made extensive use of inappropriate formulae, drawn from other sections of the curriculum The study recommends that teachers should not focus solely on how to carry out procedures, but they should also pay attention to why certain procedures are appropriate or not

Dietary management practices for type 1 diabetes mellitus by dietitians in KwaZulu-Natal

Background: In South Africa, 5% – 15% of diabetics have type 1 diabetes mellitus (T1DM). Dietitians are an important part of the diabetes management team; however, there is a lack of published data on the dietary management practices for T1DM by dietitians. Aim: The aim of this study was to determine the dietary management practices for T1DM by dietitians in KwaZulu-Natal (KZN). Setting: This study was conducted in KZN. Methods: A cross-sectional, descriptive study was conducted using a self-administered electronic questionnaire. Results: Of the 69 dietitians who participated, 58% (n = 40) used the American Diabetes Association (ADA) guidelines to manage T1DM; just under 35% (n = 24) spent over an hour with new cases; and 87% (n = 60) used face-to-face consultations for follow-up. Dietitians used the glycaemic index, portion control using the healthy eating plate, carbohydrate counting using nutritional labels and household measures and carbohydrate awareness to manage T1DM (p < 0.05). Dietitians also used the healthy eating plate (71%; n = 49) (p < 0.05) and household measures (73.9%; n = 51) (p < 0.05) to manage T1DM. Time constraints, the literacy level of the patient, available resources and language barriers all played a role in determining the dietary management practices used (p < 0.05). Conclusion: Most dietitians in KZN used the ADA dietary guidelines to manage T1DM, which highlights the need for South African dietary guidelines for the management of T1DM. Dietitians used a variety of different dietary methods to manage T1DM in practice. This suggests that dietitians are flexible in how they manage T1DM with no one particular method being used. A variety of factors also influenced which dietary management practices were chosen

The burden of diabetes mellitus in KwaZulu-Natal’s public sector: A 5-year perspective

Background. Diabetes mellitus (DM), together with its devastating complications, has a huge impact on both the patients it affects and the global economy as a whole. The economies of developing countries are already under threat from communicable diseases. More needs to be done to stem the tide of non-communicable diseases like DM. In order for us to develop new strategies to tackle this dread disease we need to obtain and analyse as many data as possible from the geographical area where we work.Objective. To describe the burden of DM in the public sector of the province of KwaZulu-Natal (KZN), South Africa (SA).Method. Data on the number of diabetes visits, DM patients that were initiated on treatment, defaulters and DM-related amputations were accessed from the Department of Health records for the period 2010 - 2014 inclusive.Results. There was a decline in the number of patients initiated on treatment per 100 000 population from 2010 to 2014 inclusive (265.9 v. 197.5 v. 200.7 v. 133.4 v. 148.7). Defaulter rates for 2013 compared with 2014 were 3.31% v. 1.75%, respectively and amputation rates were 0.09% v. 0.05% for 2013 and 2014, respectively. There was a strong proportional relationship observed between the number of defaulters and number of diabetes-related amputations (r=0.801; p=0.000) (Pearson correlation). A notable percentage of DM patients ranging between 63% and 80% were commenced on pharmacological therapy at their local clinics rather than at hospitals in the province.Conclusion. Strategies directed towards detection and treatment of DM, together with decreasing defaulter rates and thereby decreasing diabetes-related amputations, need to be addressed urgently. The majority of patients were initiated on therapy at the clinic level. This emphasises the need to strengthen our clinics in terms of resources, staffing, and nursing and clinician education, as this is where diabetes control begins. Although this study was based solely in KZN, the second most populous province in SA, it probably reflects the current situation regarding DM in other provinces of SA as well

A symbiotic glance at ehr complexities of signature microbiomic interventions : Infusing balance

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Legal termination of pregnancy among teenagers and older women in Soweto, 1999-2001

Background. Legal termination of pregnancy (TOP) was introduced in South Africa in 1996. No data are available to relate the numbers of TOPs to the total number of pregnancies in specific health regions. The level of use of TOPs by women of different age groups is not known.Objective. To determine the proportion of pregnancies that end in TOP, with special reference to maternal age, and to measure trends in use from 1999 to 2001.Setting. Greater Soweto, Orange Farm and Lenasia, a densely populated urban health region served by Chris Hani Baragwanath Hospital and comprehensive primary care reproductive health services.Methods. Two cross-sectional studies performed in 1999 and 2001, counting all pregnancies managed in state-run health services, including legal terminations, spontaneous miscarriages, ectopic pregnancies and deliveries. Results. There were 5412 pregnancies in the study period (9 weeks) in 1999, and 5316 in the study period (8 weeks) in 2001. The TOP rates decreased from 16.1% to 13.6% (P = 0.20). The TOP rates for teenagers decreased from 22.3% to 16.3% (P = 0.006), but were higher than those for older women (15.2% in 1999 and 13.2% in 2001, P = 0.006 and 0.028 respectively). TOP rates for teenagers 13- 16 years decreased from 28.0% to 23.0% (P = 0.44), and rates for older teenagers declined from 21.0% to 14.9% (P = 0.008). In 2001, 16.2% of women aged 35 and above underwent TOP, compared with 12.7% of women aged 20 - 34 years (P =0.014).Conclusion. Use of TOP services was highest in women at the extremes of reproductive age. There was a significant decline in TOP rates among older teenagers between 1999 and 2001. These data, from a comprehensive urban reproductive health service, provide a benchmark for comparison elsewhere and in the future

Ploidy and genome composition of Musa germplasm at the International Institute of Tropical Agriculture (IITA)

Musa spp (bananas and plantains) constitute a hybrid-polyploid complex and are classified according to different genome compositions such as AA, BB, AB, AAA, AAB, ABB, AAAA, ABBB, AAAB and AABB. Knowledge of ploidy and exact genome compositions of the parental material is essential forMusa breeding. This study determined the ploidy levels and genome composition of the Musa germplasm collection, constituting over 300 accessions, at the International Institute of Tropical Agriculture in Nigeria and Uganda. Flow cytometric analysis of nuclear DNA content was used toestimate ploidy levels, while genome composition was ascertained with RAPD markers that are specific for the A and B genomes of Musa. It was determined that at least 8% of the plants in the germplasmcollection were miss-classified in terms of ploidy and/or genome composition. The cultivars 'Pisang awak', 'Foulah 4' and 'Nzizi', previously classified as triploids, were found to be tetraploids by flowcytometry and conventional root tip chromosome counts. Similarly, cultivars that were previously classified as diploids including ‘Too’, and ‘Toowoolee’ were found to be triploids in our analysis. Ploidy and genome classification in Musa was generally determined from morphological characteristics. While our study showed that such a system is not always reliable, it was interesting to find that none of the plantains in the germplasm collection were miss-classified with regards to both ploidy and genome composition

Incisional Hernia: Experience in a single surgical unit

Background: Incisional hernias are a common problem in general surgery and they have a varied aetiology. The aim of this study was to document a single unit experience with the management of incisional hernias at King Edward VIII Hospital, Durban, South Arica.Patients and Methods: This was a prospective audit of incisional hernias in a single surgical unit from January 2001 to May 2004. All patients underwent open repair. Clinical data and intra-operative findings were documented.Results: A total number of 77 patients were seen of which 70 were female. Fifty three (68.8%) and 24 (31.2%) of patients underwent elective and emergency surgery respectively. A total of 56 patients had previously undergone gynaecological surgery compared to 21 who had undergone general surgery. There was a documented history of previous sepsis in 4 (7%) of patients. There was 1 sheath defect in 36 patients, 2 defects in 9 patients, 3 defects in 10 patients, 4 or more defects in 9 cases. In 55 patients the original suture could not be identified. Gangrenous bowel was present in 3 patients. Only 3 (3.9%) of the patients had a mesh repair. The rest (96.1%) underwent tissue repair. Morbidity rate was 17% and there were no deaths. Five patients needed management in the ICU. Hospital stay was 8 + 11 yearsConclusion: Most incisional hernias followed gynaecological surgery. There was no evidence of a nonabsorbable suture having been used at the original operation in over half of the patients. We recommend that meticulous technique is essential in closing the abdominal incision

Small signal stability analysis of a four-machine system with placement of multi-terminal high voltage direct current link

Inter-area oscillation caused by weak interconnected lines or low generator inertia is a critical problem facing power systems. This study investigated the performance analysis of a multi-terminal high voltage direct current (MTDC) on the damping of inter-area oscillations of a modified two-area four-machine network. Two case studies were considered, utilising scenario 1: a double alternating current (AC) circuit in linking Bus_10 and Bus_11; and scenario 2: a three-terminal line commutated converter high voltage direct current system in linking Bus_6 and Bus_11 into Bus_9. It was found that scenario 2 utilising MTDC link with a robust controller provided quick support in minimising the network oscillations following a fault on the system. The MTDC converter controllers’ setup offered sufficient support for the inertia of the AC system, thus providing efficient damping of the inter-area oscillation of the system