14 research outputs found
An economic impact analysis of the Comrades Marathon on the city of Durban.
No full textThesis (M.Sport Sc.)-University of KwaZulu-Natal, Westville, 2009.Sport has become a major industry as well as a key cultural preoccupation in contemporary society. Cities are increasingly using major sporting events and activities to re-image themselves, promote urban development and fund economic growth and regeneration. Major sport events are often recognised for their ability to generate significant economic benefits for the host destination. The major difference between this study and other economic impact studies is that the event is tracked over a two-year period. This afforded the author the opportunity to compare and note the variations in the data over the two years. Initially, the study purports to analyse the economic impact of the Comrades Marathon on the City of Durban. A secondary objective is to demonstrate the value of such a major sporting event to the regional and provincial governments as well as the formal and informal businesses in the city. Durban like other key cities in the world is and will increasingly be confronted by two main and related challenges. Firstly, there is need to successfully compete in a universal economy characterised by increased competition and globalization. Secondly, there is need to eliminate poverty and address issues of inequality and marginalization. Thus, the Comrades Marathon, as a major sporting event, can be seen as a primary driver to create jobs and contribute to competitiveness. As stated the research was conducted over two years viz. 2004 and 2005 thus representing an "up" and a "down" run. The questionnaire method and interviews were employed for this study and were administered to accommodate the alternate runs. The questionnaire requested data on the age, gender, occupations, income levels, spending patterns and the types of activities that the population found attractive. The population consisted of foreign runners and supporters, runners and supporters that reside in other provinces of South Africa, stall holders at the Comrades Expo that is normally held over three days prior to the race, representatives of the sponsors of the event and vendors. The sample was selected randomly from the population. Face-to-face interviews were conducted with representatives from the hotel industry in Durban, the Acting-Chief Executive Officer and committee members of the Comrades Marathon Association and the Marketing Managers/Public Relations Officers of three major shopping malls located in Durban. Turco, Swart, Bob and Moodley (2003) reported that the leverage ratio that is public sector input against private sector response indicated that the 2001 Comrades Marathon together with other major sporting events held in the city were successful and contributed significantly to the Durban economy. The leverage ratio is illustrative of the amount of money that was accrued to the private sector with every Rand spend by the public sector. Consideration was given to the total revenue generated by peoples' average spending at the events and the total amount accruing to the accommodation industry. Cognisance must be taken that the leverage ratio does not consider overall spending in Durban as well as other general multipliers such as revenue generated from transport, other financial transactions, product suppliers, guided tours, established businesses and informal traders. The findings showed that the leverage ratio for 2004 was computed to be 1:216.38 that is for every Rand spent by the public sector on the event R216.38 was generated by the private sector. In addition, the leverage ratio for 2005 was computed to be 1:434.49 that is for every Rand spend by the public sector on the event R434.49 was generated by the private sector. Thus, the expenditure was considerably higher in 2005 with an upsurge of R31 819 272 that is an increase of 33%. The fundamental idea behind the economic impact of sporting events is that it injects a significant increase in the demand of goods and services into the economy. This effect is not simply the direct effect of consumer spending but also the indirect effects caused by the stimulus to the economic activities induced by the direct effects
Identification of side- and shear-dependent microRNAs regulating porcine aortic valve pathogenesis
No full textabstract: Aortic valve (AV) calcification is an inflammation driven process that occurs preferentially in the fibrosa. To explore the underlying mechanisms, we investigated if key microRNAs (miRNA) in the AV are differentially expressed due to disturbed blood flow (oscillatory shear (OS)) experienced by the fibrosa compared to the ventricularis. To identify the miRNAs involved, endothelial-enriched RNA was isolated from either side of healthy porcine AVs for microarray analysis. Validation using qPCR confirmed significantly higher expression of 7 miRNAs (miR-100, -130a, -181a/b, -199a-3p, -199a-5p, and -214) in the fibrosa versus the ventricularis. Upon bioinformatics analysis, miR-214 was selected for further investigation using porcine AV leaflets in an ex vivo shear system. Fibrosa and ventricularis sides were exposed to either oscillatory or unidirectional pulsatile shear for 2 days and 3 & 7 days in regular and osteogenic media, respectively. Higher expression of miR-214, increased thickness of the fibrosa, and calcification was observed when the fibrosa was exposed to OS compared to the ventricularis. Silencing of miR-214 by anti-miR-214 in whole AV leaflets with the fibrosa exposed to OS significantly increased the protein expression of TGFβ1 and moderately increased collagen content but did not affect AV calcification. Thus, miR-214 is identified as a side- and shear-dependent miRNA that regulates key mechanosensitive gene in AV such as TGFβ1.The final version of this article, as published in Scientific Reports, can be viewed online at: https://www.nature.com/articles/srep2539
Level of colorectal cancer awareness: a cross sectional exploratory study among multi-ethnic rural population in Malaysia
No full textTargeted Disruption of TCF12 Reveals HEB as Essential in Human Mesodermal Specification and Hematopoiesis
No full textHematopoietic stem cells arise from mesoderm-derived hemogenic endothelium (HE) during embryogenesis in a process termed endothelial-hematopoietic transition (EHT). To better understand the gene networks that control this process, we investigated the role of the transcription factor HEB (TCF12) by disrupting the TCF12 gene locus in human embryonic stem cells (hESCs) and inducing them to differentiate toward hematopoietic outcomes. HEB-deficient hESCs retained key features of pluripotency, including expression of SOX2 and SSEA-4 and teratoma formation, while NANOG expression was reduced. Differentiation of HEB−/− hESCs toward hematopoietic fates revealed a severe defect in mesodermal development accompanied by decreased expression of regulators of mesoendodermal fate choices. We also identified independent defects in HE formation at the molecular and cellular levels, as well as a failure of T cell development. All defects were largely rescued by re-expression of HEB. Taken together, our results identify HEB as a critical regulator of human mesodermal and hematopoietic specification
Numerical Simulation of a Marine Current Turbine in Turbulent Flow
No full textThe copyright of this thesis rests with the author and no quotation from it or information derived from it may be published without the prior written consent of the authorThe marine current turbine (MCT) is an exciting proposition for the extraction of renewable tidal and marine current power. However, the numerical prediction of the performance of the MCT is difficult due to its complex geometry, the surrounding turbulent flow and the free surface. The main purpose of this research is to develop a computational tool for the simulation of a MCT in turbulent flow and in this thesis, the author has modified a 3D Large Eddy Simulation (LES) numerical code to simulate a three blade MCT under a variety of operating conditions based on the Immersed Boundary Method (IBM) and the Conservative Level Set Method (CLS).
The interaction between the solid structure and surrounding fluid is modelled by the immersed boundary method, which the author modified to handle the complex geometrical conditions. The conservative free surface (CLS) scheme was implemented in the original Cgles code to capture the free surface effect.
A series of simulations of turbulent flow in an open channel with different slope conditions were conducted using the modified free surface code. Supercritical flow with Froude number up to 1.94 was simulated and a decrease of the integral constant in the law of the wall has been noticed which matches well with the experimental data.
Further simulations of the marine current turbine in turbulent flow have been carried out for different operating conditions and good match with experimental data was observed for all flow conditions. The effect of waves on the performance of the turbine was also investigated and it has been noticed that this existence will increase the power performance of the turbine due to the increase of free stream velocity
Reporting of sex and gender in randomized controlled trials in Canada: a cross-sectional methods study
No full textBackground: Accurate reporting on sex and gender in health research is integral to ensuring that health interventions are safe and effective. In Canada and internationally, governments, research organizations, journal editors, and health agencies have called for more inclusive research, provision of sex-disaggregated data, and the integration of sex and gender analysis throughout the research process. Sex and gender analysis is generally defined as an approach for considering how and why different subpopulations (e.g., of diverse genders, ages, and social locations) may experience health conditions and interventions in different or similar ways. The objective of this study was to assess the extent and nature of reporting about sex and/or gender, including whether sex and gender analysis (SGA) was carried out in a sample of Canadian randomized controlled trials (RCTs) with human participants.Methods: We searched MEDLINE from 01 January 2013 to 23 July 2014 using a validated filter for identification of RCTs, combined with terms related to Canada. Two reviewers screened the search results to identify the first 100 RCTs that were either identified in the trial publication as funded by a Canadian organization or which had a first or last author based in Canada. Data were independently extracted by two people from 10% of the RCTs during an initial training period; once agreement was reached on this sample, the remainder of the data extraction was completed by one person and verified by a second.Results: The search yielded 1433 records. We screened 256 records to identify 100 RCTs which met our eligibility criteria. The median sample size of the RCTs was 107 participants (range 12–6085). While 98% of studies described the demographic composition of their participants by sex, only 6% conducted a subgroup analysis across sex and 4% reported sex-disaggregated data. No article defined “sex” and/or “gender”. No publication carried out a comprehensive sex and gender analysis.Conclusions: Findings highlight poor uptake of sex and gender considerations in the Canadian RCT context and underscore the need for better articulated guidance on sex and gender analysis to improve reporting of evidence, inform policy development, and guide future research
Lumped-Parameter Modelling of Cardiovascular System Dynamics under Different Healthy and Diseased Conditions
No full textCardiovascular disease is the most common cause of death in the modern society, and research into the diagnosis and treatment of cardiovascular diseases is an urgent task. Lumped-parameter mathematical modelling as an efficient and effective research technique has been extensively applied in the cardiovascular dynamics research, and has achieved enormous success in assisting the cardiovascular physiology study. This thesis reports a coherent work of lumped-parameter cardiovascular modelling based on some selected works that the author has conducted and published in the past several years. After a critical and comprehensive review of the concurrent lumped-parameter modelling technique, an improved lumped-parameter model that effectively describes the important cardiovascular features of heart valve dynamics and atrial-ventricular septum motion is presented. The model is then adapted to study several application cases of typical heart failure condition with ventricular assist device support, and extension of the lumped-parameter modelling for the optimisation of a pulsatile bioreactor in cardiovascular tissue engineering study. Some on-going works and future directions are also introduced. The reported modelling studies are useful for the cardiovascular physiology research and design optimisation of cardiovascular prosthetic organs
Management and Outcomes Following Surgery for Gastrointestinal Typhoid: An International, Prospective, Multicentre Cohort Study
No full textBackground: Gastrointestinal perforation is the most serious complication of typhoid fever, with a high disease burden in low-income countries. Reliable, prospective, contemporary surgical outcome data are scarce in these settings. This study aimed to investigate surgical outcomes following surgery for intestinal typhoid. Methods: Two multicentre, international prospective cohort studies of consecutive patients undergoing surgery for gastrointestinal typhoid perforation were conducted. Outcomes were measured at 30 days and included mortality, surgical site infection, organ space infection and reintervention rate. Multilevel logistic regression models were used to adjust for clinically plausible explanatory variables. Effect estimates are expressed as odds ratios (ORs) alongside their corresponding 95% confidence intervals. Results: A total of 88 patients across the GlobalSurg 1 and GlobalSurg 2 studies were included, from 11 countries. Children comprised 38.6% (34/88) of included patients. Most patients (87/88) had intestinal perforation. The 30-day mortality rate was 9.1% (8/88), which was higher in children (14.7 vs. 5.6%). Surgical site infection was common, at 67.0% (59/88). Organ site infection was common, with 10.2% of patients affected. An ASA grade of III and above was a strong predictor of 30-day post-operative mortality, at the univariable level and following adjustment for explanatory variables (OR 15.82, 95% CI 1.53–163.57, p = 0.021). Conclusions: With high mortality and complication rates, outcomes from surgery for intestinal typhoid remain poor. Future studies in this area should focus on sustainable interventions which can reduce perioperative morbidity. At a policy level, improving these outcomes will require both surgical and public health system advances
Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy
No full textBackground
The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy.
Methods
In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation.
Results
Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89·6 per cent) compared with that in countries with a middle (753 of 1242, 60·6 per cent; odds ratio (OR) 0·17, 95 per cent c.i. 0·14 to 0·21, P < 0·001) or low (363 of 860, 42·2 per cent; OR 0·08, 0·07 to 0·10, P < 0·001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high‐HDI countries (risk difference −9·4 (95 per cent c.i. −11·9 to −6·9) per cent; P < 0·001), but the relationship was reversed in low‐HDI countries (+12·1 (+7·0 to +17·3) per cent; P < 0·001). In multivariable models, checklist use was associated with a lower 30‐day perioperative mortality (OR 0·60, 0·50 to 0·73; P < 0·001). The greatest absolute benefit was seen for emergency surgery in low‐ and middle‐HDI countries.
Conclusion
Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low‐HDI countries was half that in high‐HDI countries
Global warming and malaria: a call for accuracy
No full textFor more than a decade, malaria has held a prominent place in speculations on the impacts of global climate change. Mathematical models that “predict? increases in the geographic distribution of malaria vectors and the prevalence of the disease have received wide publicity. Efforts to put the issue into perspective1, 2, 3, 4 and 5 are rarely quoted and have had little influence on the political debate. The model proposed by Frank C Tanser and colleagues6 in The Lancet and the accompanying Commentary by Simon Hales and Alistair Woodward7 are typically misleading examples.The relation between climate and malaria transmission is complex and varies according to location,2 yet Tanser et al base their projections on thresholds derived from a mere 15 African locations. Slight adjustments of values assigned to such thresholds and rules can influence spatial predictions strongly.8 The authors invest considerable effort in assessing the sensitivity of their model to climate change scenarios but do not report the internal sensitivities to thresholds and rules. The predictive skill of their model is low (63% sensitivity, 95% CI 61–65%) but they consider projections acceptable if prevalence is projected “to within a month? (presumably +/- 1 month?), thereby biasing their model towards success. A model covering an entire year in a parasite-positive site would always be correct, although in such areas it would be relatively insensitive to climate. By contrast, sites in which transmission is seasonal would provide a more reliable test of accuracy, but estimation is more difficult because climate sensitivity is greater. Furthermore, because parasite clearance in communities is not instantaneous,9 spot samples of parasitaemia on survey dates are not a suitable indicator of the duration of the transmission season. Lastly, “person/months? are unsuitable as a measure of transmission: an extension of season from 1 to 4 months will have more impact than from 10 to 12 months. According to their model, an extension of transmission from 11 to 12 months results in 106 more person/months in a population of 106 people, whereas an extension from 1 to 5 months gives the same increase in a population of 250·000.What Tanser and colleagues have modelled is merely the duration of the transmission season, which they interpret as “heightened transmission? and increased incidence. A greater failing is their reliance on “parasite-ratio studies?. The relations between transmission season and parasite prevalence, and parasite prevalence and clinical disease, are unclear but unlikely to be linear. Moreover, they use 1995 data for human populations, although these are projected to double by 2030. In addition, the proportion living in urban areas—with a specific climate10 and orders of magnitude less malaria transmission11 and 12—is projected to rise from 37% to 53%.13 For all these reasons, we do not accept the model as a “baseline against which interventions can be planned?.It is regrettable that many involved in this debate ignore the rich heritage of literature on the subject. For example, in 1937, in his classic textbook,14 L W Hackett stated: “Everything about malaria is so moulded and altered by local conditions that it becomes a thousand different diseases and epidemiological puzzles. Like chess, it is played with a few pieces, but is capable of an infinite variety of situations?. A pressing question in Hackett's time was the changing distribution of the disease in Europe. On the role of climate, he wrote: “Certainly, climate lays down the broad lines of malaria distribution…Nevertheless, although this is a very simple and plausible explanation…even the early malariologists felt that there was something unsatisfactory about it…malaria has not so much receded as it has contracted, oftentimes toward the north…Thus in Germany it is the northern coast which is still malarious, the south is free…There is, therefore, no climatic reason why (malaria) should have abandoned south Germany or the French Riviera?.We quote Hackett because we feel that the classic components of science—unbiased observation and systematic experimentation—cannot be sidestepped with models that omit many of his chess pieces. Yet Hales and Woodward7 begin by stating: “The present geographical distribution of malaria is explained by a combination of environmental factors (especially climate) and social factors (such as disease-control measures)?. In our opinion, “even the early malariologists? would surely disagree: much of the decline of malaria in Europe took place without control measures during a period when the climate was warming.The text by Hales and Woodward that follows displays a lack of knowledge. Thus, “Most people at risk of malaria live in areas of stable transmission…? is simply wrong. It is true that in many parts of the world malaria is termed “stable? because transmission remains relatively constant from year to year, the disease is endemic, the collective immunity is high, and epidemics are uncommon. However, in many other regions, the disease is endemic but “unstable? because annual transmission varies considerably, and the potential for epidemics is great. Climatic factors, particularly rainfall, are sometimes, but by no means always, relevant.15Again, “On the fringes of endemic zones, where transmission is limited by rainfall…there are strong seasonal patterns, and occasional major epidemics? is also wrong. In many regions, far from any “fringes?, malaria is endemic, stable, but highly seasonal. For example, in semi-arid regions of Mali, transmission is restricted to the rainy season, from July to September. The same 3 months constituted the transmission season for Plasmodium falciparum in Italy before it was eliminated.16 Paradoxically, in parts of the Sudan, rainfall is restricted to a month at most, but malaria is transmitted throughout the year. Female Anopheles gambiae survive drought and heat by resting in dwellings and other sheltered places.17 Blood feeding and transmission continue, but the mosquitoes do not develop eggs until the rains return. This phenomenon, termed gonotrophic dissociation, is remarkably similar to the winter survival strategy of Anopheles atroparvus, the principal vector of malaria in Holland until the mid 20th century.16By contrast, malaria is unstable in many regions that normally have abundant rainfall, and epidemics occur during periods of drought. An illustrative example is the catastrophic 1934–35 epidemic in Ceylon (now Sri Lanka), estimated to have killed 100·000 people.18 Worst hit was the south-western quadrant of the country, where average annual rainfall is greater than 250 cm, and malaria was endemic, but unstable and relatively infrequent. The dominant vector, Anopheles culicifacies, breeds along the banks of rivers and tends to be scarce in normal years. In the years 1928–33 there was abundant rainfall, river flow was high, A culicifacies was rare, and the human population was exceptionally malaria-free. However, after failure of two successive monsoons, the drying rivers produced colossal numbers of A culicifacies, and the resulting epidemic was exacerbated by the low collective immunity. In the drier parts of the island, where A culicifacies was dominant but transmission was more stable, immunity protected the population from the worst ravages of the disease.Hales and Woodward state that “the underlying problem? of the future “extension of seasonality? of malaria is “pollution of the atmosphere?, and call for rich countries to “recognise their obligations to the poorest by substantially reducing fossil-fuel consumption?. We understand public anxiety about climate change, but are concerned that many of these much-publicised predictions are ill informed and misleading. We urge those involved to pay closer attention to the complexities of this challenging subject. <br/
