Sensitivity study of reduced models of the activated sludge process, for the purposes of parameter estimation and process optimisation: Benchmark process with ASM1 and UCT reduced biological models

The problem of derivation and calculation of sensitivity functions for all parameters of the mass balance reduced model of the COST benchmark activated sludge plant is formulated and solved. The sensitivity functions, equations and augmented sensitivity state space models are derived for the cases of ASM1 and UCT reduced biological models. Matlab software forsensitivity function calculation and sensitivity model simulation is developed. The results are described and discussed. The behaviour of the sensitivity functions is used to determine which parameters of the reduced model need to be estimated in order to fit the reduced model behaviour to the real data for the process behaviour

Towards task shifting? A comparison of the accuracy of acute trauma-radiograph reporting by medical officers and senior radiographers in an African hospital

Introduction: Due to the universal shortage of radiologists, medical officers are largely responsible for acute trauma radiograph reporting in public sector healthcare facilities in well-resourced countries. In poorly-resourced countries, a shortage of medical officers results in most acute trauma radiographs being unreported. In the European Union (EU), experienced radiographers with no specific training have been shown to be more accurate than medical officers in trauma radiograph reporting, while EU radiographers who receive additional training can reach accuracies comparable to radiologists. In some EU countries, the role of the radiographer has been extended to include trauma reporting. However, there has been no study of the accuracy of trauma radiograph reporting by radiographers in Africa, where task-shifting could yield potentially greater benefits, due to shortages of both radiologists and medical officers. The aim of this study was therefore to compare the accuracy of acute traumaradiograph reporting by medical officers and senior radiographers in an African setting. Methods: A prospective study was conducted at a South African hospital from November 2013-April 2014. Medical officers and senior radiographers reported the same set of appendicular skeleton trauma radiographs. Reporting accuracy, sensitivity and specificity were calculated using a consultant radiologist's report as the reference standard. Differences were evaluated using the Mann-Whitney U test, with p < 0.05 significant. Results: Senior radiographers achieved significantly higher reporting accuracy and sensitivity than medical officers (81.5% vs 67.8%, p = 0.002). Conclusion: Senior radiographers represent a potentially important resource for acute trauma-radiograph reporting in the public healthcare sector in Africa

How school role players perceive distributed school governance?

Abstract: Amendments to the South African Schools Act –SASA, (Act 84 of 1996), have changed public school governance. These changes have had a domino effect on how public schools function today. School Governing Bodies (SGB) as the major role-players in public school governance have experienced its effect. In this article we explore the perceptions of school role-players involved in school governance in Gauteng (a province in South Africa)

Is the school a playground for politics?

Abstract: South African public schools’ capacity to govern themselves is an enduring concern of academic inquiry within the social sciences. Yet, the framing of this concern into an imagery where the state’s political agenda is directly related to its ability to draw upon, influence and withdraw the self-governing capacities of communities in relation to public school governance is more recent

The law of culpable homicide in South Africa : with reference to the law of manslaughter in English law and the law related to negligent killing in German law

Culpable homicide is the unlawful negligent killing of a fellow human being. As such it is in many respects a 'residual' crime being the verdict prosecutors may expect when they are unable to prove the intention to kill when prosecuting for murder. A feature of this was that in the past when defences such as, for instance, intoxication or provocation were raised at murder trials, convictions of culpable homicide were almost automatic. In recent years, under the influence of the 'purist' current in our Criminal law, intoxication has become a defence to culpable homicide and provocation resulting in loss of self-control has also become a defence to culpable homicide. These developments are unacceptable to some writers on criminal law and a move away from the purist approach to the 'traditional' or pragmatic approach is to be expected. Greater emphasis will be placed on practical results than on the achievement of logical consistency. This could result in the law of culpable homicide becoming more socially effective than it is at present

Syntax highlighting as an influencing factor when reading and comprehending source code

Syntax highlighting or syntax colouring, plays a vital role in programming development environments by colour-coding various code elements differently. The supposition is that this syntax highlighting assists programmers when reading and analysing code. However, academic text books are largely only available in black-and-white which could influence the comprehension of novice and beginner programmers. This study investigated whether student programmers experience more difficulty in reading and comprehending source code when it is presented without syntax highlighting. Number of fixations, fixation durations and regressions were all higher for black-and-white code than for colour code but not significantly so. Subjectively students indicated that the colour code snippets were easier to read and more aesthetically pleasing. Based on the analysis it could be concluded that students do not experience significantly more difficulty when reading code in black-and-white as printed in text books

Gender, careers, and kids: A qualitative study of the partners of international employees

This paper examines the relocation experiences of sixteen women and men who moved with their children to Aotearoa New Zealand when their partners took up career positions in that country. It analyses the relative weight they gave to their careers and their relationships with their partners as they responded to the challenges posed by these transitions. Attention to the interests of children is also identified as significant in their career decisions. Interviews with similar numbers of women and men whose partners were globally mobile employees enables analysis of the diverse ways in which gender shapes career pathways during a period of transition. The findings contribute to a complex analysis of the situation of those previously referred as a ‘trailing’ or ‘accompanying’ spouse when a dual career couple engages in international relocation

LOOKING INSIDE VOTIVE CREATURES: COMPUTED TOMOGRAPHY (CT) SCANNING OF ANCIENT EGYPTIAN MUMMIFIED ANIMALS IN IZIKO MUSEUMS OF SOUTH AFRICA: A PRELIMINARY REPORT

The ancient Egyptians mummified many more animals than humans. The study of ancient Egyptian animal mummies is varied and extensive. Currently new methodologies and modern technology are being used to unlock the secrets of animal mummies. Recently five animal mummies housed in the Egyptian collection of Iziko Museums of South Africa in Cape Town were scanned using a state of the art computed tomography (CT) scanner at Stellenbosch University. Preliminary results revealed two complete bird skeletons, a claw, a fake and the partial skeleton of what appears to be a cat

ANTERIOR CERVICAL SURGICAL RETRACTOR DESIGN

INTRODUCTION During anterior cervical surgeries such as discectomies and corpectomies (removal of the disc separating two vertebrae and removal of the vertebral body itself, respectively1), surgeons implement a retractor device to broaden the view of the spinal area on which they are operating.  The current devices have flaws; including a lack of stability, complicated mechanisms, multiple pieces, or difficulty stacking, and a new retractor is needed.  Stacking, occurs in a multiple level surgery, when more than two or more devices are needed simultaneously to hold the area open.  Our design utilizes the distraction screw to stabilize the retractor in position, without the impediment of the device becoming an obstacle for the surgeons to manoeuvre around. METHODS Based on the expertise of the experienced surgeons, multiple models will be drawn.  The most practical concept will then be developed on autoCAD software.  The lower width of the blades uses a simple rotation-linear motion system.  Meanwhile, the upper part of the blade is rotated about the lower part, allowing the blade to be used at an angle. RESULTS A physical model of the device (as seen in Figure 1 below) has yet to be printed and tested.  Nevertheless, the new model is placed within the patient, allowing the surgeons to work without worrying about the device being an obstruction.  The blades are angled wider at the top and narrower at the bottom), making it easier for the surgeons’ hands to fit in the small void in the patient’s neck. DISCUSSION AND CONCLUSIONS Since a prototype has not been created or clinically tested yet, all results and conclusions are merely speculations.  Our new device is: simple to use, less obstructive, and able to provide a broader view of the operating area.  In addition, in the rare event that these longer blades require stacking, it is very simple to implement.  The surgeon will simply place a second retractor on the second distraction screw. Since every patient is a different size, the blades must be interchangeable.  This way the surgeon can choose what length and height he/she wants the blade to be for each surgery.  Similar to the previous devices, the blades are curved at the bottom with teeth; this helps the device bite into the soft tissue and minimize slipping.  The blades will be made of titanium, which is strong, radiolucent, and easy to sterilize