A comparative study of multiple imputation and subset correspondence analysis in dealing with missing data

Methods: Multiple imputation and subset correspondence analysis are applied to a set of child asthma data that is mainly categorical and suffers from non-response. Differences in the methods and in the outcomes they produce are studied. In addition, the inclusion of interactions in a subset correspondence analysis is illustrated. Results: Despite the vast differences in the two approaches, they yielded similar results in the identification of genetic, environmental and socio-economic factors that affect childhood asthma. A number of exposure related variables were found to be associated with the greater severity of asthma. It was also found that a finer distinction between the asthma severity levels and their associations with factors was possible with a subset correspondence analysis, compared to the multiple imputation approach. Conclusions: Both multiple imputation and subset correspondence analysis were able to identify several factors associated with childhood asthma while at the same time successfully managing the missing data. This offers the researcher a choice to select the method that best suits his/her study

Other manifestations of HIV vasculopathy

Descriptions of the numerous manifestations of human immunodeficiency virus (HIV) infection affecting almost every organ system have abounded in recent publications. Multiple radiological, clinical and postmortem reports have recorded the cerebral, pulmonary, cardiac, renal, rheumatological and gastrointestinal pathologies in HIV-infected individuals, ranging from the bizarre to the mundane. Large-vessel HIV-related vascular manifestations have previously been reported in the surgical literature. We describe and review the manifestations of HIV-associated vasculopathy as it pertains to the cerebral, cardiovascular, mesenteric and renal circulations

Analysis of a period of elevated ozone concentration reported over the Vaal Triangle on 2 June 2013

A peak in the ambient ozone concentration was observed at three of the six ambient air quality monitoring stations in the Vaal Triangle Airshed Priority Area on the second of June 2013. The ozone peak was associated with elevated concentrations of particulate matter, including PM10, PM2.5 and black carbon, but not sulphur dioxide, oxides of nitrogen, carbon monoxide nor benzene. Back trajectory analysis using Hysplit showed that the air masses containing the high levels of ozone passed over areas influenced by coal fired power stations in the Waterberg, metal processing in the Bojanala region and high intensity fires 30km to 50km upwind of the stations

High prevalence of hookah smoking among secondary school students in a disadvantaged community in Johannesburg

Smoking of hookahs (also known as water-pipes) represents an emerging trend in tobacco use. Hookah smokers are at risk for the same diseases caused by cigarette smoking – cancer, respiratory and heart diseases, and pregnancy-related complications. Globally, the highest rates occur in the North African and East Mediterranean regions and among young people in the USA and European countries. There has been little research on hookah smoking in southern Africa

Radiographic outcomes among South African coal miners

Objectives : This study, the first to document the prevalence of pneumoconiosis among a living South African coal mining cohort, describes dose–response relationships between coal workers’ pneumoconiosis and respirable dust exposure, and relationships between pneumoconiosis and both lung function deterioration and respiratory symptoms. Methods : A total of 684 current miners and 188 ex-miners from three bituminous-coal mines in Mpumalanga, South Africa, was studied. Chest radiographs were read according to the International Labour Organization (ILO) classification by two experienced readers, one an accredited National Institute for Occupational Safety and Health (NIOSH) “B” reader. Interviews were conducted to assess symptoms, work histories (also obtained from company records), smoking, and other risk factors. Spirometry was performed by trained technicians. Cumulative respirable dust exposure (CDE) estimates were constructed from historical company-collected sampling and researcher-collected personal dust measurements. κ-Statistics compared the radiographic outcomes predicted by the two readers. An average profusion score was used in the analysis for the outcomes of interest. Because of possible confounding by employment status, most analyses were stratified on current and ex-miner status. Results : The overall prevalence of pneumoconiosis was low (2%–4%). The degree of agreement between the two readers for profusion was moderate to high (κ=0.58). A significant association ( P <0.001) and trend ( P <0.001) was seen for pneumoconiosis with increasing categories of CDE among current miners only. A significant ( P <0.0001) additional 58 mg-years/m 3 CDE was seen among those with pneumoconiosis compared to those without. CDE contributed to a statistically significant 0.19% and 0.11% greater decline in the percent predicted 1-second forced expiration volume (FEV 1 ) and forced vital capacity (FVC), respectively, among current miners with pneumoconiosis than among those without. Logistic regression models showed no significant relationships between pneumoconiosis and symptoms. Conclusions : The overall prevalence of pneumoconiosis, although significantly associated with CDE, was low. The presence of pneumoconiosis is associated with meaningful health effects, including deterioration in lung function. Intervention measures that control exposure are indicated, to reduce these functional effects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47414/1/420_2004_Article_532.pd

Predictors of subjective well-being among older Ghanaians

Background: Later years of life are accompanied by many physical, emotional and environmental changes which may impact on the well-being of the individual. Many factors are known to influence the subjectivewell-being of older adults, but most, if not all of this information was the result of studies in the Western world. This study aimed at obtaining and documenting the predictors of subjective well-being (SWB) among older Ghanaians.Methods: Data for the study was obtained from the WHO SAGE study. The single item measure of life satisfaction was used to determine subjective wellbeing. Descriptive statistics as well as logistic regression analysis were carried out to determine the predictors of SWB.Results: A total of 4724 individuals aged 50 years and above responded to the questionnaires. Of these 50.4% were males. Following multivariate logistic regression analysis, age, sex, educational level, income and ethnicbackground were found to significantly affect the SWB of older Ghanaians. Being male was associated with higher level of SWB (OR=1.68; CI: 1.39 – 2.03). For those 50 years and above, being younger (50-59 years) was also associated with a high level of SWB (OR=17.72; CI: 10.13-30.98). Earning a low income and having low educational level were both associatedwith low levels of SWB (OR=0.304; CI: 0.22-0.42; and OR=0.47; CI: 0.37-0.60 respectively). Ewes (p=0.027), Grumas (p=0.002) and  Mole-Dagbons (p=0.04) had significantly higher SWB compared to the other ethnic groups.Conclusion: Among older Ghanaians, factors that positively influence SWB are younger age, male sex, high educational level and high income.Keywords: Subjective well-being, Life satisfaction, Older Ghanaians, SAGE study, Predictor

Consumerisation in UK Higher Education Business Schools: Higher fees, greater stress and debatable outcomes

For many UK Higher Education Business Schools, the continued recruitment of UK, EU and International students is crucial for financial stability, viability and independence. Due to increasingly competitive funding models across the sector many institutional leaders and administrators are making decisions typical of highly marketised consumer environments. Thus, this paper explores, academics’ perceptions of the impact of consumerisation in UK Higher Education Business Schools. To achieve this 22 Business School academics were interviewed within three UK Higher Education institutions (HEIs) in the North of England. Participants had a minimum of three years teaching experience. Data was analysed using template analysis taking an interpretive approach. The findings indicate that academics perceived the introduction of tuition fees to have been the catalyst for students increasing demonstration of customer-like behaviour: viewing the education process as transactional, with the HEI providing a ‘paid for’ service. It is argued that these changes in UK Higher Education have created tensions between university leaders and academics, creating genuine dilemmas for those with decision-making responsibilities who must balance academic integrity and long term institutional financial viability

Accepted: 2011-10-04.) © SAJEI South Afr

Original Research: GGSTM1, GSTP1 and NQO1 polymorphisms and susceptibility to asthma among South African children Gluthathione-S-transferase (GSTM1 and GSTP1) and nicotinamide quinone oxidoreductase (NQO1) genes play an important role in cellular protection against oxidative stress, which has been linked to asthma pathogenesis. We investigated whether common, functional polymorphisms in GSTM1, GSTP1, and NQO1 influence susceptibility to asthma among schoolchildren in South Africa. Genomic deoxyribonucleic acid (DNA) was extracted from 317 primary schoolchildren, aged 9-11 years, from the urban, underprivileged socio-economic communities of Durban. GSTM1 (null vs. present genotype), GSTP1 (Ile105Val; AA →AG+GG) and the NQO1 (Pro/Ser; CC →CT/TT) genotypes were determined using polymerase chain reaction. Among the children, 30% were GSTM1 null, 65% carried the G allele for GSTP1, and 36% carried the C allele for NQO1.There was a high prevalence of asthma of any severity (46.1%), with 20.4% reporting persistent asthma. The GSTP1 AG+GG polymorphic genotype was significantly associated with persistent asthma (adjusted OR = 3.98; CI = 1.39, 11.36, p-value = 0.01). Neither the GSTM1, nor the NQO1, genotype was a significant predictor of persistent asthma. Therefore, the GSTP1 A/G variant may modulate the risk of persistent asthma among our sample

Co-infection with Anaplasma platys, Bartonella henselae and Candidatus Mycoplasma haematoparvum in a veterinarian

BACKGROUND: During a two year period, a 27-year-old female veterinarian experienced migraine headaches, seizures, including status epilepticus, and other neurological and neurocognitive abnormalities. Prior to and during her illness, she had been actively involved in hospital-based work treating domestic animals, primarily cats and dogs, in Grenada and Ireland and anatomical research requiring the dissection of wild animals (including lions, giraffe, rabbits, mongoose, and other animals), mostly in South Africa. The woman reported contact with fleas, ticks, lice, biting flies, mosquitoes, spiders and mites and had also been scratched or bitten by dogs, cats, birds, horses, reptiles, rabbits and rodents. Prior diagnostic testing resulted in findings that were inconclusive or within normal reference ranges and no etiological diagnosis had been obtained to explain the patient’s symptoms. METHODS: PCR assays targeting Anaplasma spp. Bartonella spp. and hemotopic Mycoplasma spp. were used to test patient blood samples. PCR positive amplicons were sequenced directly and compared to GenBank sequences. In addition, Bartonella alpha Proteobacteria growth medium (BAPGM) enrichment blood culture was used to facilitate bacterial growth and Bartonella spp. serology was performed by indirect fluorescent antibody testing. RESULTS: Anaplasma platys, Bartonella henselae and Candidatus Mycoplasma haematoparvum DNA was amplified and sequenced from the woman’s blood, serum or blood culture samples. Her serum was variably seroreactive to several Bartonella sp. antigens. Despite symptomatic improvement, six months of doxycycline most likely failed to eliminate the B. henselae infection, whereas A. platys and Candidatus M. haematoparvum DNA was no longer amplified from post-treatment samples. CONCLUSIONS: As is typical of many veterinary professionals, this individual had frequent exposure to arthropod vectors and near daily contact with persistently bacteremic reservoir hosts, including cats, the primary reservoir host for B. henselae, and dogs, the presumed primary reservoir host for A. platys and Candidatus Mycoplasma haematoparvum. Physicians caring for veterinarians should be aware of the occupational zoonotic risks associated with the daily activities of these animal health professionals