An automated drift correction method for in situ NaI(Tl)-detectors used in extreme environments

Gamma-ray detection systems are exposed to extreme environments during in situ measurements and the NaI(TI)-detectors in these systems are frequently subjected to significant temperature fluctuations. Several elements within these detectors are sensitive to temperature deviations, which ultimately causes a drift in gamma-ray spectra. This study aimed to determine the relationship between temperature deviation and spectrum drift and found a linear relationship over a wide range of energies. It was found that an increase in the detector temperature shifts the gamma-ray spectrum to lower channels, whereas a decrease in the detector temperature shifts the spectrum to higher channels. Using this information, a novel drift correction method based on the Gaussian distribution of the 1460 keV gamma-peak of ⁴⁰K was developed. Dividing the peak into five regions of interest (ROI), a weighted gain correction factor is calculated based on the comparative skewness of the measured data and the sensitivity of the drift. The detector gain is then adjusted by the same factor to correct the drift in gamma-spectrum. This method was first tested in a simulated in situ environment, followed by in situ measurements along a beach. As expected, the gain adjustments followed the trend in detector temperature. The corrected counts in each of the five bins also presented good results and a close fit to the Gaussian distribution.

Estimating indoor radon concentrations based on the uranium content of geological units in South Africa

Very few studies have been done on radon in South Africa, even though South Africa holds nearly a tenth of the global uranium deposits. This study aimed to map and estimate the radon risk for South Africa, and to identify potential hotspots. In this study, the uranium content of the different types of rock was determined and uranium concentrations in geological units were then projected. A uranium distribution map of South Africa was then constructed, and indoor radon concentrations were estimated and mapped based on the uranium levels of areas. Towns in areas where indoor radon measurements were conducted compared well with the estimated radon values. The maps predicted high estimated indoor radon concentrations in areas at several geological structures. Towns in these areas that have not been measured were identified. The south-western and north-eastern regions of South Africa pose the highest radon risk according to this study, and extensive radon measurements in the towns of these regions is proposed.

Medico-legal aspects regarding drunk driving: experience and competency in practice of community service doctors

Background: Drunk driving has been reported to increase the risk of road traffic accidents associated with death and severe injury. In South Africa, an increase in blood alcohol concentration of as little as 0.01 g per 100 ml above the legal limit may warrant criminal prosecution or the denial of an insurance claim for damages. However, multiple court cases have been withdrawn because of the incompetence of officials at various stages of the investigation. The scope of the mistakes range from poor scene handling to the incorrect handling of blood samples at the laboratory to eventual laboratory testing of blood samples. Using a group of community service doctors (CSDs) as a cohort study group, this study investigated the competency of medical graduates in relation to the medico-legal aspects of drunk driving.Methods: A self-administered questionnaire-based study was done with 150 CSDs. The questionnaire was administered in Afrikaans and English and was dispatched electronically via e-mail. All potential participants were contacted telephonically to obtain verbal consent. Results are displayed as percentages.Results: A response rate of 59.3% was achieved. The results obtained in this study confirm that some CSDs lack competency in handling medico-legal aspects relating to drunk driving, and are thus unable to serve the communities they have been assigned to adequately. Their lack of skills and knowledge suggests that the present undergraduate Clinical Forensic Medicine curriculum is inadequate.Conclusion: It would be beneficial to revise the curriculum for Clinical Forensic Medicine in undergraduate medical training to address the gap in knowledge and practice of various demands of forensic medicine required from new medical graduates and CSDs.

Practice of community-service doctors in the assessment and medico-legal documentation of common physical assault cases

Background: In South Africa, allegations of physical assault are managed primarily at the primary healthcare level, where they are attended to by medical officers or community service doctors (CSDs). However, reports that the knowledge and skills provided at undergraduate level are not sufficient to equip these CSDs to deal with evidence in medico-legal examinations in various settings, including in cases of patients who allege being the victims of common physical assault or assault with intent to inflict grievous bodily harm, have been documented in the literature. This study investigates the practice of CSDs in relation to the assessment and medico-legal documentation of allegations of common assault, with a view to identifying gaps in their knowledge of clinical forensic medicine. Method: The study was a cross-sectional descriptive study. A questionnaire with quantitative sections that used an adapted Likert scale was used to gather data. An electronic survey tool was employed to target 150 CSDs countrywide. Percentages are used to display results. Results: A response rate of 59.3% was achieved and results indicate that clinical forensic training in the undergraduate medical programme does not prepare CSDs sufficiently for the task of managing the medico-legal examination and documentation of allegations of assault by patients. Conclusions: The courts rely heavily on medico-legal documentation for success in criminal prosecution. Any substantial flaw in the documentation, including inadequate observations and/or notes made by a medical practitioner, may make proving guilt very difficult. This study revealed an important gap in the knowledge and practice of clinical forensic medicine by CSDs and suggests that the current curriculum should be adapted to allow adequate training of undergraduate medical students in the area of clinical forensic medicine. Appropriate undergraduate training will ensure that medico-legal documentation is completed accurately and that medical practitioners help ensure the administration of justice. (Full text of the research articles are available online at www.medpharm.tandfonline.com/ojfp) S Afr Fam Pract 2018; DOI: 10.1080/20786190.2017.1364014

The needs and preferences of general practitioners regarding their CPD learning: a Free State perspective

Background: The Health Professions Council of South Africa (HPCSA) requires all registered Health Practitioners in South Africa to complete accredited learning opportunities, and provide proof thereof. CPD is the chosen model, which focuses on holistic development of the professional. The UFS Department of Family Medicine presents refresher courses for general practitioners, covering all relevant fields of interest.Aim: The aim of this study was to find reasons and possible solutions for the perceived lack of interest in refresher courses by determining general practitioners’ needs and preferences for CPD training.Methodology: A cross-sectional study design was chosen, whereby a systematic sample of 300 general practitioners registered with the HPCSA as doctors in the Free State were asked to complete a questionnaire. Needs and preferences regarding learning opportunities and factors influencing usage of these learning opportunities were assessed.Results: The responses from 60 participants revealed that general practitioners still prefer the lecture form of presentations in large or small groups. Topics that ranked highly were Infective Diseases, Cardiology and Respiratory Diseases. Respondents indicated that general practitioners prefer not to leave their practices unattended for an extended period of time.Conclusion: Free State general practitioners still prefer the traditional lecture-room style of learning. Their declared learning needs are in line with the regular ailments they encounter within their practices. Strategies to accommodate those who find it difficult to attend, due to time and distance concerns, should be considered.

'Going rural': driving change through a rural medical education innovation

INTRODUCTION

Medical education across the globe is in a state of flux influenced by a number of drivers for change. In response, institutions are seeking to re-align their curricula to address the prevailing imperatives. Against this backdrop, the training of practitioners for practice in rural communities was identified as an educational priority, and led to the establishment of a rural clinical school (RCS) within a Faculty of Medicine and Health Sciences in South Africa in 2011. This article describes the students' experiences in the first year that this innovative educational model was implemented and explores the extent to which it influenced their thinking and practice.

METHODS

A qualitative, formative evaluation study of the first year of implementation was undertaken. Data was generated from in-depth interviews. This article focuses on individual interviews conducted with the eight students at the RCS, which explored their experiences during a year-long clerkship. Transcripts of interviews were thematically analysed.

RESULTS

Four themes emerged from the analysis: a learning experience that differed from what was experienced at the tertiary training hospital, an enabling clinical environment in the district and regional hospital, the positive role played by the specialists, and the influence of the community immersion. Underlying all of the responses was the building of relationships over time both with supervisors and with patients. Evident from the responses was that students' confidence in their clinical skills and decision-making abilities was heightened while their approaches to their own learning were enhanced.

CONCLUSIONS

To respond to the call for educational reform and a heightened awareness of social realities, innovative approaches to the training of medical students, such as those adopted at the RCS, are indicated. It is argued that the learning facilitated by these rural medical education models has the potential to offer learning experiences that can lead to transformation through a change in practice and attitude among the students, and ultimately also enable curricular renewal at the institutional core.

'I felt colonised': emerging clinical teachers on a new rural teaching platform

INTRODUCTION

Studies that investigate the impact of long-term rural exposure for undergraduate medical students often focus largely on students' experiences and perspectives. Research focusing on the physician experience in clinical exposures appears to be limited. When the Ukwanda Rural Clinical School (RCS) at the Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa was implemented in 2011, the clinical specialists working at the rural hospitals were expected to take on the additional task of teaching the students in the year-long rotation. The specialists were prepared for the task through a series of workshops. The objective of this study was to explore what the implementation of the RCS meant for the practice of these physicians and to what extent the shift from full-time practising clinician to clinical teacher required them to adapt and change.

METHODS

This was a qualitative study. Semi-structured interviews were conducted with lead clinical specialists who were responsible for teaching medical students in the year-long RCS rotation. Following an interpretive approach, thematic content analysis was performed to obtain a clearer understanding of how these clinicians had experienced their first year as clinical teachers in the RCS.

RESULTS

Four overarching themes were identified from the interviews with the clinicians: attitudes towards the implementation of the new medical education model, uncertainty and insecurity as a teacher, emergence of the clinician teacher, and a sense of responsibility for training a future colleague. These depict in part, the journey from clinician to clinician teacher travelled during the first year of implementation.

CONCLUSIONS

Embracing the role of clinical teacher enabled the development of constructive relationships between clinicians and their students with a mutual sense of responsibility for learning, patient care and improvement in clinical practice. Understanding this journey ought to influence the thinking of those considering faculty development initiatives for novice clinical teachers.

Developing an educational research framework for evaluating rural training of health professionals: a case for innovation

BACKGROUND

World-wide, rural clinical training of undergraduate medical students is looking to transform learning experiences, calling for the adoption of innovative approaches that create spaces for curriculum renewal and new ways of thinking. In order for these teaching models to gain acceptance and credibility among the relevant academic communities, it is critical that they be studied and evaluated.

AIM

This article describes an innovative rural education intervention and a concomitant, intentional process that was adopted to establish a research framework within which the intervention will be evaluated.

METHODS

Key role-players participated in a one-day workshop aimed at developing the framework. A collaborative, structured process that moved through three phases of deliberation and reflection was followed.

RESULTS

The documentation and raw data generated during the workshop was used to generate the framework that will serve as a blueprint for ensuring the study and evaluation of the educational innovation.

CONCLUSION

Establishing an educational research framework, by adopting a consultative and collaborative process, provides a vehicle for encouraging a culture of critical accountability that seeks to discern evidence of good practice in the training of health care workers in a rural context.

Clinical rotation in pathology: description of a case based approach

BACKGROUND

The implementation of a system based, integrated curriculum at the Faculty of Health Sciences of Stellenbosch University, Western Cape, South Africa, resulted in less contact time for the pathology disciplines during theoretical modules, while a weekly rotation in pathology was introduced during clinical training in the fourth and fifth years.

OBJECTIVE

To describe a problem based approach for this rotation.

METHODS

Students are presented with a clinical "paper" case daily, integrating as many of the pathology disciplines as possible to demonstrate the interdependence of the various disciplines. They receive chemical pathology tutorials, visit the various laboratories, and receive practical training in fine needle aspiration biopsy. On the final day, the case studies are assessed and discussed.

RESULTS

Most students appreciated all activities. This rotation enhanced student interactivity and autonomy and guaranteed immediate feedback. On evaluation of the rotation it was found that the students enjoyed the rotation, learnt something new, and realised the value of group work.

CONCLUSIONS

This innovation integrates pathology with clinical practice and illustrates the use of laboratory medicine in the management of common diseases seen in this country. Students appreciate learning practical skills and having to request special investigations under a pathologist's supervision changes their approach to pathology requests. Familiarity with the pathology environment empowers the student to use pathology with greater ease. A bank of case studies that can be expanded to include all medical disciplines will facilitate the application of a problem based approach and enhance communication between the basic science disciplines and the clinical and pathology disciplines.

Diagnostic tools in tuberculous pleurisy: a direct comparative study

Thoracoscopy is the most accurate yet most expensive tool for establishing the diagnosis of tuberculous (TB) pleurisy. However, most high TB-incidence regions have limited financial resources, lack the infrastructure needed for routine thoracoscopy and require an alternative, cost-effective diagnostic approach for pleural effusions. Altogether, 51 patients with undiagnosed exudative pleural effusions were recruited for a prospective, direct comparison between bronchial wash, pleural fluid microbiology and biochemistry (adenosine deaminase (ADA) and cell count), closed needle biopsy, and medical thoracoscopy. The final diagnosis was TB in 42 patients (82%), malignancy in five (10%) and idiopathic in four patients (8%). Sensitivity of histology, culture and combined histology/culture was 66, 48 and 79%, respectively for closed needle biopsy and 100, 76 and 100%, respectively for thoracoscopy. Both were 100% specific. Pleural fluid ADA of > or = 50 U x L(-1) was 95% sensitive and 89% specific. Combined ADA, lymphocyte/neutrophil ratio > or = 0.75 plus closed needle biopsy reached 93% sensitivity and 100% specificity. A combination of pleural fluid adenosine deaminase, differential cell count and closed needle biopsy has a high diagnostic accuracy in undiagnosed exudative pleural effusions in areas with high incidences of tuberculosis and might substitute medical thoracoscopy at considerably lower expense in resource-poor countries.

In situ production of gamma interferon, interleukin-4, and tumor necrosis factor alpha mRNA in human lung tuberculous granulomas

Human tuberculous granulomas from five adults undergoing surgery for hemoptysis were analyzed by nonradioactive in situ hybridization for tumor necrosis factor alpha (TNF-alpha), gamma interferon (IFN-gamma), and interleukin-4 (IL-4) gene expression. All of the patients produced TNF-alpha mRNA. Three patients stained positive for both IFN-gamma and IL-4 mRNA; the other two stained positive for IFN-gamma but not IL-4 mRNA. Heterogeneity between the granulomas was observed in those patients staining positive for both IFN-gamma and IL-4 mRNA; these patients exhibited granulomas having IFN-gamma and not IL-4 mRNA as well as granulomas positive for both cytokine mRNAs. There was no evidence of caseation in these granulomas, and the cytokine patterns may represent events in the evolution of the granuloma. However, in those granulomas exhibiting caseous necrosis, very little IFN-gamma or IL-4 mRNA was observed, implying that progression of the granuloma is accompanied by a down regulation of T-cell responses. TNF-alpha mRNA expression was highest in patients with both IFN-gamma and IL-4 mRNA. Populations of CD68 positive macrophage-like cells within the granulomas produce mRNA for TNF-alpha, IFN-gamma, and IL-4. This implies that macrophages within the tuberculous granuloma may not be dependent on T-cell cytokines for modulation of their function but may be able to regulate their own activation state and that of the surrounding T cells. These findings have implications on the delivery of immunotherapies to patients with tuberculosis.

Teratomas in infancy and childhood at Tygerberg Hospital, South Africa, 1973 to 1992

OBJECTIVES

To document the childhood teratomas at Tygerberg Hospital and compare the profile with other African series.

DESIGN

Retrospective review of the clinicopathologic features of 43 cases of childhood teratomas. Tumors were classified according to the World Health Organization criteria for germ cell tumors.

SETTING

Tygerberg Hospital, University of Stellenbosch, Cape Town, South Africa.

RESULTS

There were 26 mature, 15 immature, and 2 malignant teratomas. The most common sites were the ovaries and the sacrococcygeal region. Testicular teratomas were absent. The female-to-male ratio for black patients was 5.5:1. There was a peak age incidence in the first 4 years of life, with sacrococcygeal teratomas predominating. A second, smaller peak between 12 and 15 years was seen owing to ovarian teratomas. Immature teratomas presented at an earlier age than mature teratomas. The majority of ovarian teratomas occurred in patients of mixed race, whereas the extragonadal teratomas were distributed more evenly among the race groups. In black patients and patients of mixed race mature teratomas predominated, whereas in white patients immature teratomas were most common.

CONCLUSIONS

The increased occurrence of teratomas among female patients, the large number of ovarian teratomas, the absence of testicular teratomas, and the low incidence of malignant teratomas correspond to the observations of other African series. Certain differences are apparent among the three race groups, namely, a high ratio of female-to-male patients in the black group, a predominance of ovarian teratomas in the mixed-race and black groups, and a predominance of extragonadal and immature teratomas in the white group.