Prevalence of gastrointestinal pathogens in sub-saharan africa: Systematic review and meta-analysis

© S.M. Fletcher et al., 2011. A significant proportion of vulnerable people in sub-Saharan Africa (SSA) remain at risk for contracting diarrhoeal diseases due to the presence of many risk factors facilitating their transmission. A systematic review of published articles from the SSA region was done to determine the prevalence and types of diarrhoeal pathogens in circulation, based on a search of databases, including EBSCO host, PubMed, Scopus, Science Direct, Google scholar and Web of Science was done between September 2009 and December 2010. Data were summarized from 27 studies, with pooled data analysed and reported. Pathogens were isolated from between 26.8-65.6% of cases, with an overall isolation rate of 55.7% (95% CI, 48.2-62.9%). Isolation rates were highest amongst adult cases followed by children, and the odds of isolating a pathogen was greater in diarrhoeal cases (Odds Ratio 4.93 (95% CI, 1.99 to 12.23), than in asymptomatic controls. Overall isolation ranged from 8% to 99%; and heterogeneity testing suggests differences between age groups (Q=5.806; df=2, P=0. 055). Mixed E. coli spp., (29.95%), Cryptosporidium (21.52%), Cyclospora (18%), Entamoeba. (13.8%), Shigella spp. (10.49%), Salmonella spp. (8.36%), and Campylobacter spp. (8.33%), were most commonly reported, and rotavirus was the most common virus isolated. This is the first review to look at the range of enteric pathogens circulating in SSA, and has confirmed high rates of isolation of pathogens from diarrhoeal cases. Public health practitioners can use this information to understanding the challenges related to diarrhoeal illness and set priorities for their prevention and control

Does loyalty pay? First-time versus repeat visitors at a national arts festival

The aim of this research is to segment visitors to one of South Africa’s biggest arts festivals based on the frequency of visits in order to distinguish between fi rst-time and repeat festival attendees. Both first-time and repeat visitor groups play a fundamental role in the overall well-being and success of a festival, and festival organisers must strive to achieve a balance between first-time and repeat visitors. Festival managers should therefore be aware of the festival attributes that differentiate between the first-time visitor group and repeat visitors attending the festival. These differences include socio-demographics, behavioural characteristics, destination perception, perceived value and travel motivations. This article therefore compares first-time and repeat visitors to the Klein Karoo National Arts Festival based on these categories. A questionnaire survey (N = 555) was conducted at the festival, and the findings indicate that there are significant differences between first-time and repeat visitors at the festival. First-time visitors spend a significant amount of money during the festival and are mainly motivated by Relaxation and socialisation and Festival shows/productions ,while repeat visitors are loyal visitors who stay longer and spend more money, especially on tickets supporting the festival’s shows/productions. Results reveal that both first-time and repeat visitor groups are important for the long-term sustainability of the festival. This method of segmentation has proved to be successful and is used as the basis for proposing managerial and marketing implications for the festival organisers

Inhibition of food intake in obese subjects by peptide YY3-36

Background: The gut hormone fragment peptide YY3-36 (PYY) reduces appetite and food intake when infused into subjects of normal weight. In common with the adipocyte hormone leptin, PYY reduces food intake by modulating appetite circuits in the hypothalamus. However, in obesity there is a marked resistance to the action of leptin, which greatly limits its therapeutic effectiveness. We investigated whether obese subjects were also resistant to the anorectic effects of PYY.Methods: We compared the effects of PYY infusion on appetite and food intake in 12 obese and 12 lean subjects in a double-blind, placebo-controlled, crossover study. The plasma levels of PYY, ghrelin, leptin, and insulin were also determined.Results: Caloric intake during a buffet lunch offered two hours after the infusion of PYY was decreased by 30 percent in the obese subjects (P<0.001) and 31 percent in the lean subjects (P<0.001). PYY infusion also caused a significant decrease in the cumulative 24-hour caloric intake in both obese and lean subjects. PYY infusion reduced plasma levels of the appetite-stimulatory hormone ghrelin. Endogenous fasting and postprandial levels of PYY were significantly lower in obese subjects (the mean [+/-SE] fasting PYY levels were 10.2+/-0.7 pmol per liter in the obese group and 16.9+/-0.8 pmol per liter in the lean group, P<0.001). Furthermore, the fasting PYY levels correlated negatively with the body-mass index (r=-0.84, P<0.001).Conclusions: We found that obese subjects were not resistant to the anorectic effects of PYY. Endogenous PYY levels were low in the obese subjects, suggesting that PYY deficiency may contribute to the pathogenesis of obesity

Applicability of the Organisational Climate Description Questionnaire – Rutgers Elementary: A South African case study

The Organisational Climate Description Questionnaire – Rutgers  Elementary (OCDQ – RE) was used to determine the current organizational climate of primary schools in North-West Province, South Africa. This questionnaire evaluates the actions of principals and educators; the current organizational climate in primary schools can be determined from the results. A quantitative research approach, with 904 teachers from 68 schools, was used to determine the applicability of the measuring instrument. Exploratory and confirmatory factor analyses revealed that certain items measuring directive behaviour in the OCDQ-RE grouped with supportive behaviour of the principal. Hence, in this study, these items were regarded as supportive towards the educators and their work by the respondents. According to Cronbach’s alpha coefficient the questionnaire can be regarded as reliable. Recommendations are made to renderthe questionnaire even more applicable for the South African context.Keywords: improving organizational climate; organizational climate; OCDQ; primary schools; school climat

Evolution of the Stellar Mass-Metallicity Relation. II. Constraints on Galactic Outflows from the Mg Abundances of Quiescent Galaxies

We present the stellar mass–[Fe/H] and mass–[Mg/H] relation of quiescent galaxies in two galaxy clusters at z ~ 0.39 and z ~ 0.54. We derive the age, [Fe/H], and [Mg/Fe] for each individual galaxy using a full-spectrum fitting technique. By comparing with the relations for z ~ 0 Sloan Digital Sky Survey galaxies, we confirm our previous finding that the mass–[Fe/H] relation evolves with redshift. The mass–[Fe/H] relation at higher redshift has lower normalization and possibly steeper slope. However, based on our sample, the mass–[Mg/H] relation does not evolve over the observed redshift range. We use a simple analytic chemical evolution model to constrain the average outflow that these galaxies experience over their lifetime, via the calculation of mass-loading factor. We find that the average mass-loading factor η is a power-law function of galaxy stellar mass, $\eta \propto {M}_{* }^{-0.21\pm 0.09}$. The measured mass-loading factors are consistent with the results of other observational methods for outflow measurements and with the predictions where outflow is caused by star formation feedback in turbulent disks

Educators and the quality of their work environment: an analysis of the organisational climate in primary schools

The prevalent organisational climate in primary schools in the North West Province was determined in order to formulate management strategies to increase the organisational climate. For this purpose, a quantitative research method, founded in post-positivistic points of departure, was applied. In the process, the Organizational Climate Description Questionnaire &ndash; Rutgers Elementary (OCDQ-RE) was applied in order to determine the behaviour of principals and school educators. The investigation indicated that the behaviour of the principals and that of the educators contributed only to an average degree to the establishment of a more effective organisational climate in the primary schools investigated. Furthermore the exploratory and confirmatory factor analyses indicated that certain items in the original climate questionnaire, which were grouped in the directive behaviour of the principal, were viewed by the respondents in South Africa as supportive but, in some instances, also as restrictive.Keywords: educational environment; effective schools; improving organisational climate; improving school climate; management styles; Organizational Climate Description Questionnaire (OCDQ); organisational climate; primary schools; school climate; teacher morale and attitude

Characterisation of medullary astrocytic populations in respiratory nuclei and alterations in sudden unexpected death in epilepsy

Central failure of respiration during a seizure is one possible mechanism for sudden unexpected death in epilepsy (SUDEP). Neuroimaging studies indicate volume loss in the medulla in SUDEP and a post mortem study has shown reduction in neuromodulatory neuropeptidergic and monoaminergic neurones in medullary respiratory nuclear groups. Specialised glial cells identified in the medulla are considered essential for normal respiratory regulation including astrocytes with pacemaker properties in the pre-Botzinger complex and populations of subpial and perivascular astrocytes, sensitive to increased pCO2, that excite respiratory neurones. Our aim was to explore niches of medullary astrocytes in SUDEP cases compared to controls. In 48 brainstems from three groups, SUDEP (20), epilepsy controls (10) and non-epilepsy controls (18), sections through the medulla were labelled for GFAP, vimentin and functional markers, astrocytic gap junction protein connexin43 (Cx43) and adenosine A1 receptor (A1R). Regions including the ventro-lateral medulla (VLM; for the pre-Bötzinger complex), Median Raphe (MR) and lateral medullary subpial layer (MSPL) were quantified using image analysis for glial cell populations and compared between groups. Findings included morphologically and regionally distinct vimentin/Cx34-positive glial cells in the VLM and MR in close proximity to neurones. We noted a reduction of vimentin-positive glia in the VLM and MSPL and Cx43 glia in the MR in SUDEP cases compared to control groups (p < 0.05-0.005). In addition, we identified vimentin, Cx43 and A1R positive glial cells in the MSPL region which likely correspond to chemosensory glia identified experimentally. In conclusion, altered medullary glial cell populations could contribute to impaired respiratory regulatory capacity and vulnerability to SUDEP and warrant further investigation