An Analysis of Specialist Surgeons and their Practices

A purposive sample of South African doctors provided data for the analysis of revenues, costs and earnings associated with specialist surgical medicine. Empirical analysis of the data, based on both nonparametric and parametric regression, finds that practice revenues increase by, on average, between R690 and R1050 per new patient, while costs increase by between R690 and 750 per patient. The total number of surgeries performed is not a consistently significant predictor of revenues, although it is a consistently cubic determinant of costs. In terms of total earnings, the total number of patients tends to decrease earnings, while the number of new patients increases earnings. Due to the low response rate in the survey, there is a a need to conduct further research into this topic, to provide better information to both specialists and the South African Department of Health, which sets pay packages for public sector health workers.

Stochastic frontier analysis of specialist surgeon clinics

Stochastic frontier analysis was used to estimate the technical efficiency of specialist surgeon practices based in Gauteng Province, South Africa. The analysis was conducted for both single and multiple output production functions, while efficiency was allowed to depend upon surgeon and practice characteristics.Multiple output models, due to an increase in the number of observations, can be more precisely estimated and, as there are multiple observations per surgeon, can be estimated with fixed effects. The results of the analyses suggest that efficiency averages around 50% for this sample and is convex in years of surgical experience. The benefit of multiple output analysis – improved precision – obtains, while surgeon-level fixed effects alleviate some concerns related to unobserved heterogeneity.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1813-698

An analysis of specialist surgeons and their practices

A purposive sample of South African specialist doctors provided data for an empirical analysis of revenues, costs and earnings associated with specialist surgical medicine. The empirical analysis includes both parametric and nonparametric regression. Parametric estimates of revenues per new patient range between R689 to R818, while cost per new patient estimates range between R694 and R749; average surgeon income per new patient falls within a similar range. Furthermore, costs per surgery follow a cubic specification, implying increasing marginal costs at the practice level. Returns to experience are estimated to be quadratic, although imprecisely so, given limited observations. Due to the low response rate in the survey, there is a need to conduct further research into this topic, to provide better information to both specialists and the South African Department of Health, which sets pay packages for public sector health workers.http://www.sajems.org/index.php/sajem

An analysis of specialist surgeons and their practices

A purposive sample of South African specialist doctors provided data for an empirical analysis of revenues, costs and earnings associated with specialist surgical medicine. The empirical analysis includes both parametric and nonparametric regression. Parametric estimates of revenues per new patient range between R689 to R818, while cost per new patient estimates range between R694 and R749; average surgeon income per new patient falls within a similar range. Furthermore, costs per surgery follow a cubic specification, implying increasing marginal costs at the practice level. Returns to experience are estimated to be quadratic, although imprecisely so, given limited observations. Due to the low response rate in the survey, there is a need to conduct further research into this topic, to provide better information to both specialists and the South African Department of Health, which sets pay packages for public sector health workers.http://www.sajems.org/index.php/sajem

Chromosomal radiosensitivity of lymphocytes in South African breast cancer patients of different ethnicity: An indirect measure of cancer susceptibility

Background. Breast cancer is the leading cancer among South African (SA) women. SA has citizens from diverse ethnic groups, and the lifetime risk of breast cancer differs according to ethnicity. Candidate genes for increased breast cancer risk are those involved in DNA damage repair pathways, and mutations in these genes are characterised by increased chromosomal radiosensitivity. Several European studies have shown that breast cancer patients are more sensitive to ionising radiation than healthy individuals.Objectives. To investigate the in vitro chromosomal radiosensitivity of SA women with breast cancer and the possible influence of ethnicity and clinical parameters on chromosomal radiosensitivity.Methods. Chromosomal radiosensitivity was analysed with the micronucleus assay using lymphocytes of breast cancer patients and healthy individuals of different ethnic groups. Lymphocytes were irradiated in vitro with 2 Gy or 4 Gy, and micronuclei (MN) were scored 70 hours after irradiation. These MN frequencies were correlated with the ethnicity and clinical parameters of the breast cancer patients.Results. MN values were higher in breast cancer patients than in healthy controls. This was noted for black and white breast cancer patients at the different radiation doses. No correlations could be demonstrated between MN values and clinical parameters of the breast cancer, except that MN values were significantly higher in oestrogen receptor (ER)-positive breast cancers.Conclusion. SA breast cancer patients have elevated chromosomal radiosensitivity compared with healthy controls. ER positivity also influences chromosomal radiosensitivity

African leafy vegetables in South Africa

In this article the term ‘African leafy vegetables’ was adopted to refer to the collective of plant species which are used as leafy vegetables and which are referred to as morogo or imifino by African people in South Africa. Function is central in this indigenous concept, which is subject to spatial and temporal variability in terms of plant species that are included as a result of diversity in ecology, culinary repertoire and change over time. As a result, the concept embraces indigenous, indigenised and recently introduced leafy vegetable species but this article is concerned mainly with the indigenous and indigenisedspecies. In South Africa, the collection of these two types of leafy vegetables from the wild, or from cultivated fields where some of them grow as weeds, has a long history that has been intimately linked to women and their traditional livelihood tasks. Among poor people in remote rural areas the use of these types of leafy vegetables is still common but nationwide there is evidence of decline, particularly in urban areas. Cultivation of indigenous or indigenised leafy vegetables is restricted to a narrow group of primarily indigenised species in South Africa. Seven groups of indigenous or indigenised African leafyvegetables that are important in South Africa were given special attention and their local nomenclature, ecology, use and cultivation are discussed

African leafy vegetables in South Africa

In this article the term ‘African leafy vegetables’ was adopted to refer to the collective of plant species which are used as leafy vegetables and which are referred to as morogo or imifino by African people in South Africa. Function is central in this indigenous concept, which is subject to spatial and temporal variability in terms of plant species that are included as a result of diversity in ecology, culinary repertoire and change over time. As a result, the concept embraces indigenous, indigenised and recently introduced leafy vegetable species but this article is concerned mainly with the indigenous and indigenised species. In South Africa, the collection of these two types of leafy vegetables from the wild, or from cultivated fields where some of them grow as weeds, has a long history that has been intimately linked to women and their traditional livelihood tasks. Among poor people in remote rural areas the use of these types of leafy vegetables is still common but nationwide there is evidence of decline, particularly in urban areas. Cultivation of indigenous or indigenised leafy vegetables is restricted to a narrow group of primarily indigenised species in South Africa. Seven groups of indigenous or indigenised African leafy vegetables that are important in South Africa were given special attention and their local nomenclature, ecology, use and cultivation are discussed.Keywords: African leafy vegetables, morogo, imifino, history, ecology, gender, collection, cultivation, use, processing, storag

First steps towards a fast-neutron therapy planning program

<p>Abstract</p> <p>Background</p> <p>The Monte Carlo code GEANT4 was used to implement first steps towards a treatment planning program for fast-neutron therapy at the FRM II research reactor in Garching, Germany. Depth dose curves were calculated inside a water phantom using measured primary neutron and simulated primary photon spectra and compared with depth dose curves measured earlier. The calculations were performed with GEANT4 in two different ways, simulating a simple box geometry and splitting this box into millions of small voxels (this was done to validate the voxelisation procedure that was also used to voxelise the human body).</p> <p>Results</p> <p>In both cases, the dose distributions were very similar to those measured in the water phantom, up to a depth of 30 cm. In order to model the situation of patients treated at the FRM II MEDAPP therapy beamline for salivary gland tumors, a human voxel phantom was implemented in GEANT4 and irradiated with the implemented MEDAPP neutron and photon spectra. The 3D dose distribution calculated inside the head of the phantom was similar to the depth dose curves in the water phantom, with some differences that are explained by differences in elementary composition. The lateral dose distribution was studied at various depths. The calculated cumulative dose volume histograms for the voxel phantom show the exposure of organs at risk surrounding the tumor.</p> <p>Conclusions</p> <p>In order to minimize the dose to healthy tissue, a conformal treatment is necessary. This can only be accomplished with the help of an advanced treatment planning system like the one developed here. Although all calculations were done for absorbed dose only, any biological dose weighting can be implemented easily, to take into account the increased radiobiological effectiveness of neutrons compared to photons.</p

Efficacy of tissue brushing as measured by the prosthodontic tissue index

This study was conducted to determine the efficacy of brushing the oral mucosa supporting complete dentures with a soft brush to see if this treatment would reduce inflammation. The oral mucosa health status of 60 patients was monitored for 120 days using the PTI to measure inflammation. For comparison the patients were divided into two groups, and every effort was made to balance the groups for those variables that may effect inflammation. The patients were also compared with themselves. The experiment consisted of three phases; Phase 1 established baseline data, and Phases 2 and 3 were information-gathering sessions. Each patient received brushing instructions at the start of the brushing test period and additional brushing instruction during a reinforcement session after 30 days. Tissue brushing did reduce the inflammation index of the oral mucosa examined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74782/1/j.1754-4505.1984.tb00150.x.pd

Familiarity bias and physiological responses in contagious yawning by dogs support link to empathy

In humans, the susceptibility to yawn contagion has been theoretically and empirically related to our capacity for empathy. Because of its relevance to evolutionary biology, this phenomenon has been the focus of recent investigations in nonhuman species. In line with the empathic hypothesis, contagious yawning has been shown to correlate with the level of social attachment in several primate species. Domestic dogs (Canis familiaris) have also shown the ability to yawn contagiously. To date, however, the social modulation of dog contagious yawning has received contradictory support and alternative explanations (i.e., yawn as a mild distress response) could explain positive evidence. The present study aims to replicate contagious yawning in dogs and to discriminate between the two possible mediating mechanisms (i.e., empathic vs. distress related response). Twenty-five dogs observed familiar (dog’s owner) and unfamiliar human models (experimenter) acting out a yawn or control mouth movements. Concurrent physiological measures (heart rate) were additionally monitored for twenty-one of the subjects. The occurrence of yawn contagion was significantly higher during the yawning condition than during the control mouth movements. Furthermore, the dogs yawned more frequently when watching the familiar model than the unfamiliar one demonstrating that the contagiousness of yawning in dogs correlated with the level of emotional proximity. Moreover, subjects’ heart rate did not differ among conditions suggesting that the phenomenon of contagious yawning in dogs is unrelated to stressful events. Our findings are consistent with the view that contagious yawning is modulated by affective components of the behavior and may indicate that rudimentary forms of empathy could be present in domesticated dogs