The influence of geochemistry on health risks to animals and humans in geographically localised livestock production systems

(South African J of Animal Science, 2000, 30, Supplement 1: 82-84

School self-evaluation for school improvement: Examining the measuring properties of the LEAD surveys

Research evidence suggests school self-evaluation with the participation of school stakeholders could improve teaching and learning. Identification and use of appropriate self-evaluation frameworks, however, is not an easy task for schools. Such a framework, the LEAD School Effectiveness Surveys, has been developed by Independent Schools Victoria in Australia. The LEAD suite of school stakeholder surveys enables schools to evaluate their overall effectiveness in several domains and make informed decisions for school improvement. This article evaluates the reliability as well as the face, content and construct validity of the LEAD surveys and discusses the ways in which school self-evaluation results could contribute to school improvement. Data were gathered from a total of 119,749 students, teaching staff, general and parents taking the LEAD Surveys in 112 independent (non-government) schools and followed a five-year longitudinal design from 2009 to 2013. The results support the reliability as well as the face, content and construct validity of the LEAD surveys. The importance of evaluating the measuring properties of instruments used for school self-evaluation is discussed and suggestions for school self-evaluation are provided. Independent Schools Victoria (Australia

The effect of infusions of adrenaline, noradrenaline and dopamine on cerebral autoregulation under isoflurane anaesthesia in an ovine model

Publisher's copy made available with the permission of the publisher © Australian Society of AnaesthetistsThe effects of infusions of adrenaline, noradrenaline and dopamine on cerebral autoregulation under steady-state isoflurane anaesthesia were compared with the awake state. Six studies each were conducted in two cohorts of adult ewes: awake sheep and those anaesthetized with 2% isoflurane anaesthesia. In random order, each animal received ramped infusions of adrenaline, noradrenaline (0-40 µg/min) and dopamine (0-40 µg/kg/min). Cerebral blood flow was measured continuously from changes in Doppler velocities in the sagittal sinus. Autoregulation was determined by linear regression analysis between cerebral blood flow and mean arterial pressure. Isoflurane did not significantly alter cerebral blood flow relative to pre-anaesthesia values (P>0.05). All three catecholamines significantly and equivalently increased MAP from baseline in a dose dependent manner in both the awake and isoflurane cohorts. Although adrenaline significantly increased cerebral blood flow from baseline in the awake cohort (P0.05). Over a specific dose range, systemic hypertension induced by adrenaline, noradrenaline and dopamine did not significantly increase cerebral blood flow under 2% isoflurane anaesthesia. The concomitant administration of isoflurane and the catecholamines was not associated with altered autoregulatory function compared to the awake state.http://www.aaic.net.au/Article.asp?D=200236

Food items consumed by students attending schools in different socio-economic areas in Cape Town, South Africa

Objective: We investigated the food consumption patterns of adolescent students at schools. Our findings are intended to reveal the overall nutritional quality of foods eaten by students at school, including foods brought to school and foods purchased at school. Methods: A questionnaire was completed by 476 students, mostly from grades 7 and 10, from 14 schools in Cape Town, South Africa. The schools were representative of the various ethnic groups and socioeconomic strata of the population. The questionnaire requested information on eating habits at school, foods brought to school and food purchases, and breakfast consumption before school. We also tested whether students knew which foods are healthy and which are less healthy choices. Results: The students were mostly 12 to 16 y of age (mean age 14.5 y). The large majority had breakfast before school (77.8%) and ate at school (79.7%). Food was brought to school by 41% to 56%, whereas 69.3% purchased food at school, mainly at the school store (tuck shop). Predefined “unhealthy” foods brought to school outnumbered “healthy” ones by 2 to 1. Among students who purchased food at school, 70.0% purchased no healthy items, whereas 73.2% purchased two or more unhealthy items. With six foods 84% of students correctly stated whether they were healthy or unhealthy; however, with cola drinks, samoosas (deep-fried pastry with spicy filling), and pies, only 47% to 61% knew that these were less healthy choices. Students’ scores on this question were unrelated to whether they purchased healthy or unhealthy foods. Students who attended schools of high socioeconomic status were twice as likely to bring food to school (64.7% versus 31.0%, P < 0.001), scored higher marks on the quiz of healthy versus unhealthy foods (P < 0.01), but were no more likely to purchase healthy food. Conclusions: The large majority of food eaten by adolescent students in Cape Town is classified as being unhealthy choices. This applies to foods brought to school and food purchases. Consideration needs to be given to policy measures to improve this situation and to improve education of students and their parents

A Comparison of Three Dry Matter Forage Production Methods Used in South Africa

A common method for determining forage production of rangelands is by clipping and weighing forage from quadrats with predetermined areas. This technique is however time consuming. Other techniques which require less time and labour include amongst others using the disk pasture meter or phytomass derived from the vegetation classification program PHYTOTAB, in conjunction with the Plant Number Scale, which is used to determine vegetation canopy cover. The phytomass determined using PHYTOTAB/Plant Number Scale and the disk pasture meter was compared to the phytomass obtained from the actual clipping and weighing of forage. Tests showed that there were indeed statistically significant differences between the mean phytomass values of the three techniques. Considerable variation was shown in the results of the disk pasture meter readings compared to the other two techniques. The phytomass values obtained using the disk pasture meter were significantly higher than the phytomass determined using both the PHYTOTAB/Plant Number Scale and the clipping and weighing techniques. Results further indicated a significant similarity in the phytomass determined using the PHYTOTAB/Plant Number Scale and the clipping and weighing technique. The results of this pilot study need further investigation

Vitamin D status and supplementation in adult patients receiving extracorporeal membrane oxygenation

The prevalence of vitamin D deficiency in critical illness is known to be high and associated with adverse clinical outcomes. Patients receiving extracorporeal membrane oxygenation (ECMO) may be at increased risk of vitamin D deficiency due to high severity of acute illness. Challenges with drug dosing in ECMO patients are recognised due to increased volume of distribution and drug absorption to circuit components. To describe the prevalence of vitamin D deficiency in ECMO patients and the effect of intramuscular dosing of cholecalciferol on levels of vitamin D metabolites, and to compare these data with intensive care unit (ICU) patients not receiving ECMO, two prospective studies were performed sequentially: an observational study of 100 consecutive ICU patients and an interventional study assessing effects of intramuscular cholecalciferol in 50 ICU patients. The subgroup of patients who required ECMO support in each of these studies was analysed and compared to patients who did not receive ECMO. Twenty-four ECMO patients, 12 from the observational study and 12 from the interventional study (who received intramuscular cholecalciferol) were studied-21/24 (88%) ECMO patients were vitamin D deficient at baseline compared to 65/126 (52%) of non-ECMO patients (P=0.006). Of the 12 ECMO patients who received cholecalciferol, six patients (50%) achieved correction of deficiency compared to 36/38 (95%) non-ECMO patients (P=0.001). The prevalence of vitamin D deficiency is higher in ECMO patients compared to other critically ill adults. Correction of deficiency with single dose cholecalciferol is not reliable;higher or repeated doses should be considered to correct deficiency