Autonomous light-weight heliostat with rim drives

Several approaches for cost reduction of heliostats, which fit well to each other, are combined to a new heliostat concept to achieve the current challenging cost objectives: The wind loads are reduced by appropriate manipulators which reduces weight and cost of the heliostat structure and the ground anchor foundation. Laminated mirror facets are of high reflectivity and shape accuracy and of low weight. The low weight is advantageous for the dimensioning of the bearings and regarding energy consumption. Energy consumption is further reduced by a highly efficient drive train. Thus, small capacity of the wireless energy supply of the autonomous heliostat is sufficient which reduces significantly its cost. By the combination of horizontal primary axis with rims and winch wheels a cheap and precise solution for the drives was found. Ray tracing calculations show that the losses due to the compromised angle range are negligible. With the new heliostat concept the current cost goals seem to be achievable

Shrinking risk profiles after deworming of children in Port Elizabeth, South Africa, with special reference to Ascaris lumbricoides and Trichuris trichiura

Risk maps facilitate discussion among different stakeholders and provide a tool for spatial targeting of health interventions. We present maps documenting shrinking risk profiles after deworming with respect to soil-transmitted helminthiasis among schoolchildren from disadvantaged neighbourhoods in Port Elizabeth, South Africa. Children were examined for soil-transmitted helminth infections using duplicate Kato-Katz thick smears in March 2015, October 2015 and May 2016, and subsequently treated with albendazole after each survey. The mean infection intensities for Ascaris lumbricoides were 9,554 eggs per gram of stool (EPG) in March 2015, 4,317 EPG in October 2015 and 1,684 EPG in March 2016. The corresponding figures for Trichuris trichiura were 664 EPG, 331 EPG and 87 EPG. Repeated deworming shrank the risk of soil-transmitted helminthiasis, but should be complemented by other public health measures

Disease, activity and schoolchildren's health (DASH) in Port Elizabeth, South Africa: a study protocol

BACKGROUND: An in-depth epidemiological investigation on intestinal parasite infections in an impoverished area of Port Elizabeth, South Africa provides a unique opportunity for research on its impact on children's physical fitness, cognitive performance and psychosocial health. Additionally, we will screen risk factors for the development of diabetes and hypertension in adulthood. METHODS/DESIGN: A 2-year longitudinal cohort study will be conducted, consisting of three cross-sectional surveys (baseline and two follow-ups), in eight historically black and coloured (mixed race) primary schools located in different townships in Port Elizabeth, South Africa. Approximately 1000 Grade 4 primary schoolchildren, aged 8 to 12 years, will be enrolled and followed. At each survey, disease status, anthropometry and levels of physical fitness, cognitive performance and psychosocial health will be assessed. After each survey, individuals diagnosed with parasitic worm infections will be treated with anthelminthic drugs, while children with other infections will be referred to local clinics. Based on baseline results, interventions will be tailored to the local settings, embedded within the study and implemented in half of the schools, while the remaining schools will serve as controls. Implementation of the interventions will take place over two 8-week periods. The effect of interventions will be determined with predefined health parameters. DISCUSSION: This study will shed new light on the health burden incurred by children in deprived urban settings of South Africa and provide guidance for specific health interventions. Challenges foreseen in the conduct of this study include: (i) difficulty in obtaining written informed consent from parents/guardians; (ii) administration of questionnaires in schools where three languages are spoken (Afrikaans, Xhosa and English); (iii) challenges in grasping concepts of psychosocial health among schoolchildren using a questionnaire; and (iv) loss to follow-up due to the study setting where illiteracy, mobility and violence are common. Finally, designing the health interventions together with local principals and teachers will allow all concerned with the research to bolster a sense of community ownership and sustained use of the interventions after the study has ceased

Intestinal parasites, growth and physical fitness of schoolchildren in poor neighbourhoods of Port Elizabeth, South Africa: a cross-sectional survey

BACKGROUND: As traditional lifestyle and diets change with social and economic development, disadvantaged communities in low- and middle-income countries increasingly face a double burden of communicable and non-communicable diseases. We studied the relationship between physical fitness and infections with soil-transmitted helminths (STHs), intestinal protozoa and Helicobacter pylori among schoolchildren in Port Elizabeth, South Africa. METHODS: We conducted a cross-sectional survey among 1009 children, aged 9 to 12 years, from eight primary schools in socioeconomically disadvantaged neighbourhoods of Port Elizabeth. Physical fitness was determined using field-deployable tests of the Eurofit fitness test battery. Stool samples were analysed with the Kato-Katz thick smear technique to diagnose STHs and with rapid diagnostic tests (RDTs) to detect intestinal protozoa and H. pylori infections. Haemoglobin (Hb) levels were assessed and anthropometric indicators determined. RESULTS: Complete data were available for 934 children (92 %). In two schools, high STH prevalences were found (Ascaris lumbricoides 60 and 72 %; Trichuris trichiura 65 % each). For boys and girls co-infected with A. lumbricoides and T. trichiura (n = 155) the maximal oxygen uptake (VO2 max) was estimated to be 50.1 and 47.2 ml kg(-1) min(-1), compared to 51.5 and 47.4 ml kg(-1) min(-1) for their non-infected peers (n = 278), respectively. On average, children without helminth infections had greater body mass (P = 0.011), height (P = 0.009) and a higher body mass index (P = 0.024) and were less often stunted (P = 0.006), but not significantly less wasted compared to their peers with a single or dual species infection. Among 9-year-old boys, a negative correlation between helminth infections and VO2 max, grip strength and standing broad jump distance was observed (P = 0.038). The overall mean Hb level was 122.2 g l(-1). In the two schools with the highest prevalence of STHs the Hb means were 119.7 and 120.5 g l(-1), respectively. CONCLUSIONS: Intestinal parasite infections appear to have a small but significant negative effect on the physical fitness of infected children, as expressed by their maximal oxygen uptake. We observed a clear impact on anthropometric indicators

Associations between selective attention and soil-transmitted helminth infections, socioeconomic status, and physical fitness in disadvantaged children in Port Elizabeth, South Africa: an observational study

BACKGROUND: Socioeconomically deprived children are at increased risk of ill-health associated with sedentary behavior, malnutrition, and helminth infection. The resulting reduced physical fitness, growth retardation, and impaired cognitive abilities may impede children's capacity to pay attention. The present study examines how socioeconomic status (SES), parasitic worm infections, stunting, food insecurity, and physical fitness are associated with selective attention and academic achievement in school-aged children. METHODOLOGY: The study cohort included 835 children, aged 8-12 years, from eight primary schools in socioeconomically disadvantaged neighborhoods of Port Elizabeth, South Africa. The d2-test was utilized to assess selective attention. This is a paper and pencil letter-cancellation test consisting of randomly mixed letters d and p with one to four single and/or double quotation marks either over and/or under each letter. Children were invited to mark only the letters d that have double quotation marks. Cardiorespiratory fitness was assessed via the 20 m shuttle run test and muscle strength using the grip strength test. The Kato-Katz thick smear technique was employed to detect helminth eggs in stool samples. SES and food insecurity were determined with a pre-tested questionnaire, while end of year school results were used as an indicator of academic achievement. PRINCIPAL FINDINGS: Children infected with soil-transmitted helminths had lower selective attention, lower school grades (academic achievement scores), and lower grip strength (all p<0.05). In a multiple regression model, low selective attention was associated with soil-transmitted helminth infection (p<0.05) and low shuttle run performance (p<0.001), whereas higher academic achievement was observed in children without soil-transmitted helminth infection (p<0.001) and with higher shuttle run performance (p<0.05). CONCLUSIONS/SIGNIFICANCE: Soil-transmitted helminth infections and low physical fitness appear to hamper children's capacity to pay attention and thereby impede their academic performance. Poor academic achievement will make it difficult for children to realize their full potential, perpetuating a vicious cycle of poverty and poor health. TRIAL REGISTRATION: ClinicalTrials.gov ISRCTN68411960

Association between gastrointestinal tract infections and glycated hemoglobin in school children of poor neighborhoods in Port Elizabeth, South Africa

BACKGROUND: Low- and middle-income countries are facing a dual disease burden with infectious diseases (e.g., gastrointestinal tract infections) and non-communicable diseases (e.g., diabetes) being common. For instance, chronic parasite infections lead to altered immune regulatory networks, anemia, malnutrition, and diarrhea with an associated shift in the gut microbiome. These can all be pathways of potential relevance for insulin resistance and diabetes. The aim of this study was to investigate the association between common gastrointestinal tract infections and glycemia in children from non-fee paying schools in South Africa. METHODOLOGY: We conducted a cross-sectional survey among 9- to 14-year-old school children in Port Elizabeth. Stool and urine samples were collected to assess infection status with parasitic worms (e.g., Ascaris lumbricoides, Enterobius vermicularis, and Trichuris trichiura), intestinal protozoa (e.g., Cryptosporidium parvum and Giardia intestinalis), and the bacterium Helicobacter pylori. Glycated hemoglobin (HbA1c) was measured in finger prick derived capillary blood. All children at schools with a high prevalence of helminth infections and only infected children at the schools with low infection rates were treated with albendazole. The association of anthelmintic treatment with changes in HbA1c 6 months after the drug intervention was also investigated. FINDINGS: A high prevalence of 71.8% of prediabetes was measured in this group of children, with only 27.8% having HbA1c in the normal range. H. pylori was the predominant infectious agent and showed an independent positive association with HbA1c in a multivariable regression analysis (β = 0.040, 95% confidence interval (CI) 0.006-0.073, p<0.05). No association of HbA1c with either any other infectious agent or albendazole administration was found. CONCLUSION: The role of H. pylori in diabetes needs confirmation in the context of longitudinal treatment interventions. The specific effect of other gastrointestinal tract infections on glycemia remains unclear. Future studies should integrate the measurement of biomarkers, including immunological parameters, to shed light on the potential mediating mechanisms between parasite infections and diabetes

Cricket: Nature and incidence of fast-bowling injuries at an elite, junior level and associated risk factors

Objective. To compile an injury profile of 46 fast bowlers aged 11 - 18 years, and to identify the associated risk factors for injury during one academy cricket season. Methods. The fast bowlers selected were tested and observed for one academy cricket season (March - November). Subjects were grouped into injury classifications (uninjured=S1; injured but able to play=S2; injured and unable to play=S3). Anthropometrical and postural data for the subjects were collected preseason (T1). Physical fitness screenings were conducted and the relationship between fitness and occurrence of injuries was assessed. Additional factors such as bowling techniques and bowling workload were assessed. A regression analysis was conducted to analyse the relationship between bowling workload and weeks incapacitated. Results. Fifteen per cent of the subjects remained injury free for the duration of the season. The incidence of serious injury (S3) showed a statistical and moderate, practical significant increase (V=0.23, df&#8805;2) throughout the data collection period (4% at T1 - 30% at T3 (post-season)). The most common injuries were to the knee (41%) and lower back (37%), occurring from mid-season (T2) to T3. The nature of the injuries was predominantly strains (39%) and ‘other' (39%), with the highest reported incidence during the period T1 - T3. Sprains followed, with an overall incidence of 14%. Subjects were incapacitated approximately 1 out of every 7 weeks of play. The S1 and S2 bowlers performed consistently better than the S3 bowlers in all the fitness variables tested. Bowling workload presented a statistically significant (

Expectations and experiences of talent management across South Africa and the effect on retention

The “war on talent” is intensifying and effective talent management strategies are imperative for business success. This study explores the expectations and experiences of talent management strategies amongst employees across South Africa and their impact on retention. The literature review covers the constructs of talent management, working environment, rewards, leadership, race, age and gender as well as retention. A quantitative survey approach with comparative studies was adopted. A snowball convenience sampling method was used with links to an on-line questionnaire e-mailed to potential respondents. A total of 711 useable responses were received. Statistical analysis included factor analysis, Cronbach alpha reliability testing, mean factor scores, paired samplet-tests, Pearson’s correlations, T-tests and ANOVAs. The study found that leadership was the factor rated as most important followed by working environment and development. Respondents reported significant differences between expectations and employer ratings on all factors, with cash rewards being the greatest source of dissatisfaction. Experiences of work environment, leadership and development indicated stronger correlations to retention than cash rewards. Women, millennials and non-whites demonstrated the highest retention risks. A significant negative correlation was found between the respondents’ reported experience of leadership, work environment and development and the importance they attached to cash rewards. The study supports Hertzberg’s classification of cash rewards as a hygiene factor and Alderfer’s ERG theory’s concept of frustration-regression. This has significant implications for the focus of talent and retention strategies, and it is proposed that improving the quality of leadership, work environments and development opportunities will decrease the current over-reliance on monetary rewards as a retention tool