'n Ondersoek na die verband tussen leierskappotensiaal en sekere biografiese veranderlikes onder 'n groep universiteitstudente

The original publication is available at http://www.sajip.co.zaThe study investigates whether university students, classified as leaders and non-leaders differ with respect to their responses to a number of biographical items. The results indicate that the following biographical variables do differentiate between leaders and non-leaders: educational qualifications and occupation of father, number of times the family moved, class position and leader activities during high school, parents’ motivation of and interest in child, extent of freedom enjoyed during childhood, membership of social, religious and other organizations during high school, number of hobbies and extent of confidence experienced in strange situations. Not all the items were found to be equally relevant in die case of female and male leaders, however.Publisher's versio

The end of essentialist gods and Ubuntu: a feminist critical investigation

Abstract:The focus on god and Ubuntu constructs affirms the fact that people are natural social constructivists involved in a continuous process of conceptualising ideas that give meaning to their contexts. The juxtaposing of these two constructs extends what is known of new god ideas to that of Ubuntu or African ‘humanness.’ Whereas ideology criticism served as the broad overarching hermeneutical tool for this study, feminism was used as the specific interpretative framework to critically scrutinise mostly patriarchally biased conceptualisations of god and Ubuntu. In contrast to Western feminism, African womanism, with its emphasis on African Motherhood/Womanhood, contributed to a much needed contextual and culturally sensitive analysis of Ubuntu in particular. It was concluded that there are various god and Ubuntu constructs and that it is no longer tenable to claim a single (dogmatic/essentialist) god or a single (dogmatic) Ubuntu to structure reality meaningfully. ‘Truth’ lives only momentarily as history continues to unfold and people find new ways in their search for meaning

Bone density and depression in premenopausal South African women: a pilot study

Objective: It is posited that the effect of depression on BMD is dependent on the severity of depression. Conflicting evidence exists regarding this possible association. This study investigated the association between depression and low bone mineral density (BMD). Methods: The hypothesis was investigated in a random sample of volunteers (n=40) and in premenopausal female psychiatric patients (n=5) diagnosed with recurrent severe major depression. The outcome measures were BMD (DEXA); depression (Beck Depression Inventory and Psychological General Well-being Scale) and 24-hour saliva cortisol levels (ELISA). In a comparison of women (4 of the 40 i.e. “control” subjects) with negligible symptoms of depression and the five patients with severe recurrent major depression- BMD, depression, saliva cortisol and bone turnover markers were measured and compared. Pro-inflammatory status (IL-1 and TNF-alpha) was investigated in the psychiatric patients only. Results: In the random – non clinical - sample of women (n=40), 26 exhibited normal BMD and 14 exhibited low BMD. Depressive symptoms and cortisol levelswere not significantly different between these two groups. Women with severe recurrent major depression(n=5) exhibited lower median BMD T-scores, higher overall bone turnover and higher 24-hour cortisol levels compared to “control” subjects (n=4). The psychiatric patients also exhibited elevated IL-1 levels. Conclusion: The effect of depression on BMD may be dependent on the depression severity. IL-1 and cortisol are possible mediators in depression-induced BMD loss.Key words: Bone mineral density; Cortisol; Depression; Pro-inflammatory cytokine

Out-of-Distribution Detection of Melanoma using Normalizing Flows

Generative modelling has been a topic at the forefront of machine learning research for a substantial amount of time. With the recent success in the field of machine learning, especially in deep learning, there has been an increased interest in explainable and interpretable machine learning. The ability to model distributions and provide insight in the density estimation and exact data likelihood is an example of such a feature. Normalizing Flows (NFs), a relatively new research field of generative modelling, has received substantial attention since it is able to do exactly this at a relatively low cost whilst enabling competitive generative results. While the generative abilities of NFs are typically explored, we focus on exploring the data distribution modelling for Out-of-Distribution (OOD) detection. Using one of the state-of-the-art NF models, GLOW, we attempt to detect OOD examples in the ISIC dataset. We notice that this model under performs in conform related research. To improve the OOD detection, we explore the masking methods to inhibit co-adaptation of the coupling layers however find no substantial improvement. Furthermore, we utilize Wavelet Flow which uses wavelets that can filter particular frequency components, thus simplifying the modeling process to data-driven conditional wavelet coefficients instead of complete images. This enables us to efficiently model larger resolution images in the hopes that it would capture more relevant features for OOD. The paper that introduced Wavelet Flow mainly focuses on its ability of sampling high resolution images and did not treat OOD detection. We present the results and propose several ideas for improvement such as controlling frequency components, using different wavelets and using other state-of-the-art NF architectures

'n Vergelyking van drie verskillende tegnieke die berekening van glomerulere filtrasiespoed

The clearance of inulin, creatinine and radioactive tracers from the blood may be used to measure glomerular filtration rate (GFR). These techniques, however, are usually invasive and time-consuming. Although the clearance of a radioactive tracer is usually applied in nuclear medicine for the determination of GFR, it is also possible to convert the concentration of the tracer in the kidneys to absolute GFR by means of a regression equation. As this new technique is much faster, we have compared it with the conventional technique. A good correlation was found with the standard radionuclide techniques (r = 0,91), but the reference method was underestimated on the average by 14 ml/min. The new regression equation derived in our clinic will ensure future accurate GFR measurements within 6 minutes

Sacroiliac tuberculosis masquerading as mechanical lower back pain in a collegiate basketball athlete: a case presentation

Background: Sacroiliac tuberculosis is a rare condition for which early diagnosis and effective management frequently proves challenging. This report describes a case that was initially overlooked due to its presentation and unreported constitutional symptoms.Aim: To alert clinicians about skeletal tuberculosis, an often neglected diagnostic differential, which requires a high index of clinical suspicion, especially for patients from endemic areas.Findings: This patient’s presentation (sports injury) and unreported constitutional symptoms resulted in a delay in the diagnosis and initial institution of treatment.Implications: This report illustrates the importance of specifically asking about constitutional symptoms, even in sports injury settings and being mindful of infectious diseases or other chronic medical conditions, which may masquerade as common sports injuries.Keywords: skeletal tuberculosis, sacroiliitis, hip pai

Investigating and Improving Latent Density Segmentation Models for Aleatoric Uncertainty Quantification in Medical Imaging

Data uncertainties, such as sensor noise or occlusions, can introduce irreducible ambiguities in images, which result in varying, yet plausible, semantic hypotheses. In Machine Learning, this ambiguity is commonly referred to as aleatoric uncertainty. Latent density models can be utilized to address this problem in image segmentation. The most popular approach is the Probabilistic U-Net (PU-Net), which uses latent Normal densities to optimize the conditional data log-likelihood Evidence Lower Bound. In this work, we demonstrate that the PU- Net latent space is severely inhomogenous. As a result, the effectiveness of gradient descent is inhibited and the model becomes extremely sensitive to the localization of the latent space samples, resulting in defective predictions. To address this, we present the Sinkhorn PU-Net (SPU-Net), which uses the Sinkhorn Divergence to promote homogeneity across all latent dimensions, effectively improving gradient-descent updates and model robustness. Our results show that by applying this on public datasets of various clinical segmentation problems, the SPU-Net receives up to 11% performance gains compared against preceding latent variable models for probabilistic segmentation on the Hungarian-Matched metric. The results indicate that by encouraging a homogeneous latent space, one can significantly improve latent density modeling for medical image segmentation.Comment: 12 pages incl. references, 11 figure

Development of a clinical feeding assessment scale for very young infants in South Africa

BACKGROUND : There is a need for validated neonatal feeding assessment instruments in South Africa. A locally developed instrument may contribute to standardised evaluation procedures of high-risk neonates and address needs in resource constrained developing settings. OBJECTIVE : The aim of the study was to develop and validate the content of a clinical feeding assessment scale to diagnose oropharyngeal dysphagia (OPD) in neonates. METHOD : The Neonatal Feeding Assessment Scale (NFAS) was developed using the Delphi method. Five international and South African speech-language therapists (SLTs) formed the expert panel, participating in two rounds of electronic questionnaires to develop and validate the content of the NFAS. RESULTS : All participants agreed on the need for the development of a valid clinical feeding assessment instrument to use with the neonatal population. The initial NFAS consisted of 240 items across 8 sections, and after the Delphi process was implemented, the final format was reduced to 211 items across 6 sections. The final format of the NFAS is scored using a binary scoring system guiding the clinician to diagnose the presence or absence of OPD. All members agreed on the format, the scoring system and the feeding constructs addressed in the revised final format of the NFAS. CONCLUSION : The Delphi method and the diverse clinical and research experience of participants could be integrated to develop the NFAS which may be used in clinical practice in South Africa or similar developing contexts. Because of demographically different work settings marked by developed versus developing contexts, participants did not have the same expectations of a clinical dysphagia assessment. The international participants contributed to evidence-based content development. Local participants considered the contextual challenges of South African SLTs entering the field with basic competencies in neonatal dysphagia management, thereby justifying a comprehensive clinical instrument. The NFAS is aimed at clinicians working in Neonatal Intensive Care Units where they manage large caseloads of high-risk neonates. Further validation of the NFAS is recommended to determine its criterion validity in comparison with a widely accepted standard such as the modified barium swallow study.http://www.sajcd.org.zaam2016Speech-Language Pathology and Audiolog

A daily physical activity and diet intervention for individuals with type 2 diabetes mellitus : a randomized controlled trial

Urbanisation, a sedentary lifestyle and increasing obesity due to westernization and changed eating habits have been identified as independent risk factors for diabetes in the South African population. To establish the effectiveness of a daily walk and diet education intervention program. A randomized controlled trial was performed. The study population consisted of men and women of all races, ages 40 to 65 with Type 2 Diabetes Mellitus (DM) of duration at least one year attending the Steve Biko Diabetes Outpatient clinic. Patients of all weights were considered. Patients who had an HbA1c > 8 – 9.5% were included in the sample group. Four weekly group classes consisted of education considered essential for ongoing nutrition self-management and physical activity. Yamax pedometers and walk prescriptions based on the average number of steps walked in three days were used. The participants had a follow-up assessment at 16 weeks and one year. The intervention and control groups were compared with respect to changes from baseline, using analysis of covariance (ANCOVA) with baseline values as covariates. The difference between the intervention and control groups in the change in HbA1c from the baseline was significant at the 16-week follow-up assessment (p=0.041) and in the total cholesterol and LDL-cholesterol at the one-year follow-up assessment (p =0.047; p =0.014). These results suggest that HbA1c can be improved over a period of four months. More frequent contact with the patients is necessary.http://www.sajp.co.za/index.php/sajpam201

A daily physical activity and diet intervention for individuals with type 2 diabetes mellitus : a randomized controlled trial

Urbanisation, a sedentary lifestyle and increasing obesity due to westernization and changed eating habits have been identified as independent risk factors for diabetes in the South African population. To establish the effectiveness of a daily walk and diet education intervention program. A randomized controlled trial was performed. The study population consisted of men and women of all races, ages 40 to 65 with Type 2 Diabetes Mellitus (DM) of duration at least one year attending the Steve Biko Diabetes Outpatient clinic. Patients of all weights were considered. Patients who had an HbA1c > 8 – 9.5% were included in the sample group. Four weekly group classes consisted of education considered essential for ongoing nutrition self-management and physical activity. Yamax pedometers and walk prescriptions based on the average number of steps walked in three days were used. The participants had a follow-up assessment at 16 weeks and one year. The intervention and control groups were compared with respect to changes from baseline, using analysis of covariance (ANCOVA) with baseline values as covariates. The difference between the intervention and control groups in the change in HbA1c from the baseline was significant at the 16-week follow-up assessment (p=0.041) and in the total cholesterol and LDL-cholesterol at the one-year follow-up assessment (p =0.047; p =0.014). These results suggest that HbA1c can be improved over a period of four months. More frequent contact with the patients is necessary.http://www.sajp.co.za/index.php/sajpam201