Control algorythm of a smart grid device for optimal radial feeder load reconfiguration

Abstract Secondary distribution network, generally speaking, performs as well as the performance of its LV feeders. The main problem a feeder is experiencing is the load unbalancing due to the stochastic nature of its individual single-phase loads: bigger losses in certain phase accompanied with bed voltage regulation and voltage unbalance. The aim of this paper is to address the issue of automatic balancing as progressing from the end of the feeder towards the front using smart device based on three-ways switch selector and artificial intelligence algorithm to minimize the neutral current

Prevalence of a postoperative troponin leak in patients with cardiac risk factors undergoing knee and hip arthroplasty in a South African population

Background. Patients undergoing arthroplasty may have comorbidities that put them at risk of myocardial injury after non-cardiac surgery (MINS). MINS, a new clinical concept that has a different pathophysiology from conventional myocardial infarction, is related to a supply-demand mismatch ischaemia in the perioperative setting. MINS is often a silent event, and the diagnosis relies on cardiac biomarker testing such as troponin T. The incidence is estimated at 40%, with a fourfold increase in morbidity and mortality risk 1 year post surgery.Objectives. To determine the prevalence of postoperative troponin leak in a single-centre arthroplasty unit in patients with various cardiac risk factors undergoing hip or knee arthroplasty and investigate the differences in troponin T levels between comorbidities and different types of arthroplasty, i.e. total hip replacement (THR), total knee replacement (TKR) and neck of femur (NoF) fracture hip replacement.Methods. A prospective, cross-sectional study of patients with one or more cardiac risk factors undergoing replacement surgery was conducted from October 2017 to April 2018. Troponin levels of all included patients were recorded on days 1 and 3 post surgery using a high-sensitivity cardiac troponin T assay (Roche hs-cTnT). A level of >15 ng/L is considered abnormal and termed a positive troponin leak, while >100 ng/L is considered suspected acute coronary syndrome (ACS).Results. One hundred and sixty patients (n=66 THR, n=55 NoF hip replacement, n=39 TKR) were included. Sixty-eight patients (42%) had a positive troponin leak, and in 6 of these cases ACS was suspected. The highest prevalence of troponin leak was recorded in patients undergoing NoF hip replacement (62%), followed by TKR (46%) and then THR (24%). Sixty-two patients (38%) had positive troponin levels on day 1 and 53 patients (33%) had positive levels on day 3. Important patient cardiac risk factors were identified in the presence of a positive troponin leak, with ischaemic heart disease, hypertension, diabetes, renal disease, age >65 years and atrial fibrillation being statistically most likely.Conclusions. Postoperative troponin surveillance is an inexpensive and reliable way to identify patients at risk of MINS and subsequently enhance early detection, medical optimisation and referral strategies. Simple interventions may improve outcomes and contribute to lower ACS rates and the timeous prevention of other complications. The prevalence of MINS in orthopaedic-specific patients in South Africa (SA) and other resource-constrained developing countries is unknown. Our finding of 42% positive troponin leaks raises awareness of this issue, and we recommend routine postoperative troponin surveillance for all arthroplasty units in SA.

Life within chronic care: is this a service or sentence?

Background: Understanding the meaning of one’s lived experiences improves one’s understanding of what it means to be human, in association with the social, cultural and historical context in which being a human occurs. The authors in this study describe the lived experiences of residents within a chronic care facility including the practitioner and family perspectives.Methods: A qualitative approach was employed with a single-site, descriptive, instrumental case study design. Purposive sampling was utilised to select the chronic facility. Multiple sources of evidence included narratives, semi-structured interviews with staff, residents and family members, and activity profiles of the residents augmented by an ergonomic evaluation of the facility. Content analysis using within-case analysis was implemented.Results: The greatest impact on the quality of the resident’s lived experiences emanates from the physical, organisational and social environments in which they reside. Limited resources, poor staff attitudes and routines that are enforced both on the staff of the facility and the residents appear to reduce optimal functioning within the facility. Furthermore the residents’ intrinsic motivation, presence of enforced idleness, learned helplessness and institutionalisation is often intensified and becomes characteristic of the residents lived experiences.Discussion: The lived experiences of the residents are described according to quality of life indicators that were identified during the study and supported by literature. These include the influence of the physical, social and organizational environments on the residents’ functional status, which comprises physical well-being and emotional well-being and engagement in meaningful occupations including social interaction and relationships with other individuals.Conclusions: Findings of this study may be valuable in understanding and facilitating a positive change in service delivery within chronic care centres.Keywords: chronic care, institutionalisation, lived experiences, residents, occupational deprivatio

Underrecognition and undertreatment of asthma in Cape Town primary school children

Background. In view of the high local prevalence of asthma, the extent of recognition and appropriate managementof childhood asthma was studied in a large suburban area of Cape Town.Design. Cross-sectional study based on random community sample of schools.Method. 1955 parents of sub B pupils from 16 schools completed a questionnaire, followed by: (f) an interview of parents of 348 symptomatic children; and (if) bronchial responsiveness testing on 254 children. the final case group consisted of 242 children with reported asthma or multiple asthma symptoms on both questionnaires. Children in whom asthma was acknowledged were compared with those in whom it was not.Results. Overall, any past or current ('ever') asthma was acknowledged by respondents in only 53% of the children, and current asthma in only 37.1%. While most children had received treatment in the previous 12 months, 66.1% of therecognised group were on current treatment (23.2% on daily treatment), compared with 37% of the unrecognised group (3% daily). Salbutamol and theophylline syrups were the most common types of medication, while inhalers and antiinflammatory medications were underused. Only a minority of parents reported the child ever having used a peak flow meter, or volunteered knowledge of preventive measures. Current treatment, and to a lesser degree recognition of asthma by parents, were more common among children on medical aid and of higher socio-eonomic status.Conclusions. These findings suggest that ways need to be found: (i) to increase the use of current asthma treatment guidelines by practitioners; (ii) to provide access to comprehensive care by children not on medical aid; and (iii) to improve education of parents in home management measures such as severity assessment and avoidance of smoking, allergen and dietary triggers

Do Multinational enterprises push up wages of domestic firms in the Italian Manufacturing sector?

This paper analyzes the effects of foreign direct investment on wages paid by domestic firms in the Italian manufacturing sector over the period 2002–2007. In particular, the authors investigate the im-pact of multinational enterprises on wages paid by local firms which operate in the same industry, known and horizontal wage spillovers, or have linkages with multinational enterprises in both downstream and upstream industries, known as vertical wage spillovers. By using a large panel dataset, consisting of 551,000 observations, the authors find evidence of wage spillovers only at inter-industry level and, more specifically, for those firms who supply their goods to multinational enterprises, described as backward wage spillovers. Moreover, findings suggest that the wage spillover effect is strongly affected by the technological gap between local and foreign firms: only workers employed in domestic firms with a low-medium technological absorptive capacity seem to benefit from the presence of multinational enterprises in terms of higher wages

Transcutanous aortic valve replacement with Medtronic CoreValve in a publicprivate partnership hospital complex

Objective: The aim of this study was to assess the initial experience of transcutaneous aortic valve implantation (TAVI) in a high risk aortic stenosis population not suitable for conventional surgical valve replacement. Background: No data exist for TAVI with Medtronic CoreValve in South Africa and especially not in a public private partnership hospital complex. Methods: Retrospective data regarding severe aortic stenosis evaluation, risk stratifi cation and management were evaluated over a 24 month period. Results: A total of 106 patients were evaluated of whom17 were accepted for surgical valve replacement (SVR) while TAVI was attempted in 25. The CoreValve was successfully implanted in 96% (24/25) of the cases. No procedural or peri-procedural deaths occurred. Threepatients required permanent pacemaker insertion in the peri-procedural period and 2 patients had vascular access complications requiring blood transfusion only. Median hospital stay was 3.7days (range: 2 - 7). Aortic valve gradient showed a signifi cant reduction after valve implantation, which was sustained during follow-up (p<0.001). NYHA class symptomatology also improved from a median of 3.3 to 1.0 (p<0.001). During follow-up there were 4 late deaths, not related to the procedure, occurring after 78 to 193 days. Average cost for private and government patients were R268 000.00 and R163 000.00 respectively. Conclusions: The CoreValve can be implanted with a high success rate. Short term mortality and morbidity are acceptable. Signifi cant symptomatic improvement is gained at follow-up. The fi nancial implications are important