A comparison of water quality and macroinvertebrate community structure in endorheic depression wetlands and a salt pan in the Gauteng province, South Africa.

Depression wetlands (colloquially referred to in South Africa (SA) as pans) are found worldwide and primarily occur in arid regions including North and South America, southern and central Africa and southern and western Australia. Surface water resources in SA, and specifically in Gauteng, are under pressure from urbanisation, poor agricultural practices and untreated mining and industrial effluent. Research of these wetlands will benefit the development of health assessment tools for these unique aquatic resources. The aim of this project was to determine the water quality and macroinvertebrate community structure for each perennial pan during consecutive dry and wet seasons and to establish a possible comparison between these pans that can be used as a baseline for future research on pans. The sampled pans in Gauteng presented higher TDS, Cl and Mg results compared to other South African studies, and similar SO4 results to pans in the Mpumalanga province. Ammonia, Al and Zn results of all pans through all sampling events exceed the Target Water Quality Range (TWQR) for aquatic ecosystems of the Water Quality Guidelines (WQG) from the Department of Water and Sanitation (DWS). The water quality from selected systems is suitable for livestock watering based on the DWS TWQR. Macroinvertebrate species of all sampled pans were mostly low water quality tolerant species with a predator dominant community structure. Seasonal variation of species was evident. Macroinvertebrate families found in the wet season include Hydrophilidae, Aeshnidae, Pleiidae, Ephemeroptera, Belostomatidae and Notonectidae. Families found in the dry season include Planaridae, Dysticidae, Hirudinidae and Daphnidae. Graphical representation of ordination analyses with Canoco version 5 (Ter Braak and Smilauer 2012) indicated that TDS, temperature, pH, sulphates and hardness are strong drivers of the existing macroinvertebrate community in most of the pans.

Supportive periodontal treatment: Pocket depth changes and tooth loss.

AIM: The purpose of this retrospective study was to determine the results of 10 years of supportive periodontal treatment(SPT) following active periodontal therapy(APT). Probing pocket depth(PPD), bleeding on probing(BOP), tooth loss(TL)and the effects of two patient-related factors, smoking and gender were evaluated. METHODS: This retrospective study examined patients who underwent APT and SPT for adult periodontitis. Analyses were conducted using site-, tooth- and patient-level information. Mean values were calculated, and parametric and nonparametric analyses were conducted as appropriate to assess the results of APT and SPT. RESULTS: There was a significant improvement in BOP and PPD after APT. After 10 years, 9.3% of the patients adhered to the SPT protocol. The improvement in BOP and PPD was maintained, with no additional improvement in the clinical parameters at the 10-year follow-up. Furthermore, differences between non-smokers and smokers were found. After the 10-year follow-up, smokers had a significantly higher percentage of sites with a PPD of 4 mm or higher; the mean PPD was also significantly higher in smokers. A significant difference was also found between males and females during SPT for the percentage of sites with BOP and the percentage of sites with a PPD≥6 mm. A minority of patients(18.5%) did not lose teeth, and it was found that molars are the teeth most likely to be lost. The mean number of teeth lost was 2.6 during 10-year follow-up. CONCLUSION: This study indicates that with regard to bleeding on probing and probing pocket depth, patients receiving supportive periodontal treatment maintain their periodontal condition. However, in this group of adherent maintenance patients, tooth loss was most prevalent for molar teeth.

Computer-assisted image analysis to quantify daily growth rates of broiler chickens.

1. The objective was to investigate the possibility of detecting daily body weight changes of broiler chickens with computer-assisted image analysis. 2. The experiment included 50 broiler chickens reared under commercial conditions. Ten out of 50 chickens were randomly selected and video recorded (upper view) 18 times during the 42-d growing period. The number of surface and periphery pixels from the images was used to derive a relationship between body dimension and live weight. 3. The relative error in weight estimation, expressed in terms of the standard deviation of the residuals from image surface data was 10%, while it was found to be 15% for the image periphery data. 4. Image-processing systems could be developed to assist the farmer in making important management and marketing decisions.

The electronic patient record in general practice--a South-African perspective.

A research project was undertaken to design an electronic medical record system which will cater for the specific needs of South African general practitioners and their unique requirements. The project was launched by sending out a questionnaire to general practitioners in the Free State, trying to determine their specific requirements and to gain insight into their attitudes and opinions regarding the use of computers, especially the computer-based patient record, in a general practice setting. The results indicated that there was a need to replace the current manual patient record with an electronic version, and that the attitudes of the general practitioners in South Africa were generally favourable regarding implementing and using such a system. Given these results, we can proceed to design a computer-based patient record system, specifically addressing the needs and requirements of the South African general practitioner.