Browsing by Author "Van der Merwe, M."

Now showing 1 - 3 of 3
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    Application of European standards for health and quality control of game meat on game ranches in South Africa
    (AOSIS, 2011) Van der Merwe, M.; Jooste, P. J.; Hoffman, L. C.
    The health and quality compliance of game carcasses (n = 295) intended for the South African export market and aspiring to comply with the strict hygiene requirements of the European Union were compared with game carcasses (n = 330) available for the local market and currently not subjected to meat safety legislation. Samples were collected in similar seasons and geographical areas in South Africa from 2006 to 2009. Aerobic plate counts (APC) of the heart blood verified that both groups possessed similar ante mortem bacterial status. For health compliance APC, tests for Escherichia coli, Salmonella spp. and Staphylococcus aureus were performed on the carcasses. Surfaces of the local carcasses were swabbed using the European Enviro-biotrace sponge technique at 3 and 72 h post mortem. Unskinned but eviscerated export carcasses in the abattoir were skinned and sampled by incision using a cork borer 72h post mortem. Temperature andpHreadings were recorded at 3 and 72 h post mortem from the longissimus dorsi muscle and the readings at 3 h differed (P = 0.035). Temperatures at 72 h were lower for export than local carcasses (P < 0.001) because of earlier introduction and maintenance of the cold chain. The pH readings also differed between groups at 3 and 72 h (P<0.001). APC results for the local group exceeded the maximum permissible count (<105). S. aureus results showed differences (P <0.001), with readings from the local group being higher. The same tendency was exhibited for E. coli (P = 0.008). Imposition of hygiene guidelines for game ranchers producing meat for the local market is therefore recommended.
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    Evaluation of nutrition care to adult patients on HAART attending primary healthcare facilities in Mpumalanga
    (MedPharm Publications, 2019-03-06) Schiever, J. F.; Visser, Janicke; Van der Merwe, M.; Nel, D. G.
    Objectives: This study aimed to evaluate nutrition care and nursing professional knowledge received by adults on highly active antiretroviral therapy attending primary health care (PHC) facilities Design: Cross-sectional, descriptive study. Subjects and setting: The study was conducted on 263 adults and 75 nursing professionals, recruited from 19 facilities in the Mbombela sub-district, Mpumalanga. Outcome measures: Interviewer-administered questionnaires were completed for each patient. Nursing professionals completed a self-administered questionnaire. Assessment tools were completed for each facility. Results: Some 41% of patients were either overweight or obese, and most females (n = 87; 51.8%) had a BMI ≥ 25 kg/m2. Based on waist circumference, 52.7% (n = 88) of females and 8.4% (n = 8) of males showed increased risk of cardiovascular disease. Although nurses were aware of a nutrition supplementation programme, knowledge of national nutrition guidelines was inadequate. Clinical judgement, rather than eligibility criteria, was used to identify suitable patients, with 13.3% (n = 35) receiving supplementation whereas only 4.9% (n = 13) qualified. Facilities generally had sufficient equipment and fair storage conditions, but stock shortages of nutrition supplements were problematic. Conclusions: Whilst certain positive findings emerged, nutrition care could be improved, largely through adequate training and support to professional nurses. Training should focus on correct execution of assessment measurements and appropriate nutritional counselling, emphasising balanced eating, food security and prevention of over-nutrition. Nurses should be familiarised with national nutrition guidelines and have access to a constant nutrition supplementation supply. Improved monitoring and evaluation of nutrition care to adults on treatment at PHC facilities is needed.
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    The evolutionary spatial prisoner's dilemma on a cycle
    (Operations Research Society of South Africa (ORSSA), 2013) Burger, A. P.; Van der Merwe, M.; Van Vuuren, J. H.
    In this paper we consider the Evolutionary Spatial Prisoner's Dilemma (ESPD) in which players are modelled by the vertices of a cycle representing a spatial or organisational structure amongst the players. During each round of the ESPD every pair of adjacent players in the cycle play a classical prisoner's dilemma against each other, and they update their strategies from one round to the next based on the perceived success achieved by the strategies of neighbouring players during the previous round. In this way players are able to adapt and learn from each other's strategies as the game progresses without being able to rationalise good strategies. We characterise all steady states of the game as well as the structures of those initial states that lead to the emergence of persistent substates of cooperation over time. We finally determine analytically (i.e. without using simulation) the probability that the game's states will evolve from a randomly generated initial state towards a steady state which accommodates some form of persistent cooperation. More specifically, we show that there exists a range of game parameter values for which the likelihood of the emergence of persistent cooperation increases to almost certainty as the length of the cycle increases.