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The aim of this study was to validate the Teacher Stress Inventory (TSI) for use in a South African context. The process of scale validation also sheds significant light on this culturally diverse group of participants' levels of psychological wellbeing and physical health, and its association with the level of stress that teachers reported. Using a cross-sectional survey design, Caucasian (n = 209) and African (n = 200) educators' subsiding in the North-West Province of South Africa, completed the TSI, together with a number of self-report and physiological measures of stress and well-being. In contrast to the five factors of the TSI identified in US samples, statistical analysis yielded a two-factor model (i.e. "General circumstance-related stress and Learner-related stress") with satisfactory reliability indices. Significant correlation with measures of psychological and physiological health also reflected positively on the criterion-related validity of the scale. The TSI proved to be a useful, brief self-report questionnaire for the assessment of teacher stress in this cohort of South African teachers.

Low-cost ambient sensors have been identified as a promising technology for monitoring air pollution at a high spatio-temporal resolution. However, the pollutant data captured by these cost-effective sensors are less accurate than their conventional counterparts and require careful calibration to improve their accuracy and reliability. In this paper, we propose to leverage temporal information, such as the duration of time a sensor has been deployed and the time of day the reading was taken, in order to improve the calibration of low-cost sensors. This information is readily available and has so far not been utilized in the reported literature for the calibration of cost-effective ambient gas pollutant sensors. We make use of three data sets collected by research groups around the world, who gathered the data from field-deployed low-cost CO and NO2 sensors co-located with accurate reference sensors. Our investigation shows that using the temporal information as a co-variate can significantly improve the accuracy of common machine learning-based calibration techniques, such as Random Forest and Long Short-Term Memory. [ABSTRACT FROM AUTHOR]

Background: Haemophilia A (HA) is a bleeding disorder, due to a deficiency in factor VIII (FVIII). These patients are unable to produce a stable fibrin clot in the propagation phase of coagulation as they do not generate sufficient thrombin. The primary treatment for HA in South Africa remains replacement therapy with standard half-life FVIII clotting factor concentrate, aimed at reducing bleeding episodes. Objectives: To evaluate the effect of varying concentrations of FVIII on whole blood (WB) clot architecture and kinetics during clot formation in patients with severe HA. Design: A cross-sectional study where blood from 20 patients with HA was exposed to FVIII ex vivo and compared to a control group of 20 healthy individuals. Methods: Scanning electron microscopy (SEM) was used to study WB clot architecture and thromboelastography® (TEG®) was used to quantify WB clot kinetics. Results: Scanning electron microscopy studies revealed that patients with HA have sparse, disorganized fibrin networks with limited crosslinking and red blood cells (RBCs) stacked in rouleaux formation. Haemophilia A blood spiked to a 10 to 15 IU/dL FVIII concentration showed improvements in the organisation of the fibrin network with some altered RBCs. In addition, blood spiked to a 30 to 35 IU/dL FVIII concentration showed an increase in fibrin formation with normal RBCs. Thromboelastography® showed that patients with HA had an increased clot initiation time and decreased clot strength. When spiked to a 10 to 15 IU/dL FVIII concentration the clot kinetic profile showed normalization. However, an increase in FVIII concentration higher than 30 IU/dL showed altered clot architecture and kinetics. Conclusion: Based on the current study, FVIII levels at 10 to 15 IU/dL improved clot kinetics but did not normalize the architecture. It may be sufficient for prevention of haemorrhages. Factor VIII levels at 30 to 35 IU/dL resulted in rapid but weaker clot formation. However, at this concentration the clot architecture was normalised which is important for haemostasis. Here it was also evident that the findings of these two modalities (TEG® and SEM) should not be separated but interpreted in conjunction with each other. [ABSTRACT FROM AUTHOR]

This article points out that the "in loco parentis" maxim is partly to blame for introducing the confusing "reasonable parent" doctrine as the test for delictual negligence of educators in the school context. It is argued that the standard of care exercised by parents over their children is not appropriate to determine the negligence of educators. The correct standard of care of educators is that of the reasonable educator. "In loco parentis" should not be used with reference to the negligence of educators. The maxim denotes nothing more than that for a specific period of time during the school day, a child will be placed by the parent under the physical control of the school authorities.