108 research outputs found

    Concussion in sport: what is known and what is new?

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    The aim of this article was to summarise the latest definition of concussion, signs of concussion, as well as important facts on recovery and graduated return to play, for different age groups. New technologies available to the sports physician are listed.Keywords: concussion, diagnosis, return to play, sign

    The influence of service brand equity on the strength of brand relationships in the fast food industry

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    The South African fast food industry is growing fast and rivals are competing fiercely, providing customers with an array of different choices. Given this situation, it has become increasingly important for fast food organisations to focus on elevating and sustaining a competitive advantage. One way of doing this is by maximising brand equity. In doing so, organisations can differentiate themselves in the minds of customers by encouraging a relationship with their brand. The aim of this study is to determine the influence of service brand equity on customers’ relationships with their fast food brand. The population comprised fast food customers residing in the North West Province of South Africa. A cross-sectional descriptive design was followed, and a convenience sample was used to select respondents. Data were obtained by means of a self-administered questionnaire, realising 379 responses. A multiple regression analysis indicates that three brand equity dimensions, namely brand awareness, brand association and brand trust, significantly and positively influence the strength of the relationships that respondents have with their favourite fast food brand (with brand trust being the most influential dimension). Fast food outlets can, therefore, strengthen their customers’ brand relationships by focusing specifically on improving these three dimensions.Key words: service brand equity, brand awareness, perceived quality, brand differentiation, brand associations, brand trust, brand relationships, fast food industry, fast food outlet

    Sequence-based prediction for vaccine strain selection and identification of antigenic variability in foot-and-mouth disease virus

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    Identifying when past exposure to an infectious disease will protect against newly emerging strains is central to understanding the spread and the severity of epidemics, but the prediction of viral cross-protection remains an important unsolved problem. For foot-and-mouth disease virus (FMDV) research in particular, improved methods for predicting this cross-protection are critical for predicting the severity of outbreaks within endemic settings where multiple serotypes and subtypes commonly co-circulate, as well as for deciding whether appropriate vaccine(s) exist and how much they could mitigate the effects of any outbreak. To identify antigenic relationships and their predictors, we used linear mixed effects models to account for variation in pairwise cross-neutralization titres using only viral sequences and structural data. We identified those substitutions in surface-exposed structural proteins that are correlates of loss of cross-reactivity. These allowed prediction of both the best vaccine match for any single virus and the breadth of coverage of new vaccine candidates from their capsid sequences as effectively as or better than serology. Sub-sequences chosen by the model-building process all contained sites that are known epitopes on other serotypes. Furthermore, for the SAT1 serotype, for which epitopes have never previously been identified, we provide strong evidence - by controlling for phylogenetic structure - for the presence of three epitopes across a panel of viruses and quantify the relative significance of some individual residues in determining cross-neutralization. Identifying and quantifying the importance of sites that predict viral strain cross-reactivity not just for single viruses but across entire serotypes can help in the design of vaccines with better targeting and broader coverage. These techniques can be generalized to any infectious agents where cross-reactivity assays have been carried out. As the parameterization uses pre-existing datasets, this approach quickly and cheaply increases both our understanding of antigenic relationships and our power to control disease

    Binding Site Alteration Is Responsible for Field-Isolated Resistance to Bacillus thuringiensis Cry2A Insecticidal Proteins in Two Helicoverpa Species

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    Background Evolution of resistance by target pests is the main threat to the long-term efficacy of crops expressing Bacillus thuringiensis (Bt) insecticidal proteins. Cry2 proteins play a pivotal role in current Bt spray formulations and transgenic crops and they complement Cry1A proteins because of their different mode of action. Their presence is critical in the control of those lepidopteran species, such as Helicoverpa spp., which are not highly susceptible to Cry1A proteins. In Australia, a transgenic variety of cotton expressing Cry1Ac and Cry2Ab (Bollgard II) comprises at least 80% of the total cotton area. Prior to the widespread adoption of Bollgard II, the frequency of alleles conferring resistance to Cry2Ab in field populations of Helicoverpa armigera and Helicoverpa punctigera was significantly higher than anticipated. Colonies established from survivors of F2 screens against Cry2Ab are highly resistant to this toxin, but susceptible to Cry1Ac. Methodology/Principal Findings Bioassays performed with surface-treated artificial diet on neonates of H. armigera and H. punctigera showed that Cry2Ab resistant insects were cross-resistant to Cry2Ae while susceptible to Cry1Ab. Binding analyses with 125I-labeled Cry2Ab were performed with brush border membrane vesicles from midguts of Cry2Ab susceptible and resistant insects. The results of the binding analyses correlated with bioassay data and demonstrated that resistant insects exhibited greatly reduced binding of Cry2Ab toxin to midgut receptors, whereas no change in 125I-labeled-Cry1Ac binding was detected. As previously demonstrated for H. armigera, Cry2Ab binding sites in H. punctigera were shown to be shared by Cry2Ae, which explains why an alteration of the shared binding site would lead to cross-resistance between the two Cry2A toxins. Conclusion/Significance This is the first time that a mechanism of resistance to the Cry2 class of insecticidal proteins has been reported. Because we found the same mechanism of resistance in multiple strains representing several field populations, we conclude that target site alteration is the most likely means that field populations evolve resistance to Cry2 proteins in Helicoverpa spp. Our work also confirms the presence in the insect midgut of specific binding sites for this class of proteins. Characterizing the Cry2 receptors and their mutations that enable resistance could lead to the development of molecular tools to monitor resistance in the [email protected]; [email protected]

    Physical and emotional health outcomes after 12 months of public-sector antiretroviral treatment in the Free State Province of South Africa: a longitudinal study using structural equation modelling

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    <p>Abstract</p> <p>Background</p> <p>African and Asian cohort studies have demonstrated the clinical efficacy of antiretroviral treatment (ART) in resource-limited settings. However, reports of the long-term changes in the physical and emotional quality of life (QoL) of patients on ART in these settings are still scarce. In this study, we assessed the physical and emotional QoL after six and 12 months of ART of a sample of 268 patients enrolled in South Africa's public-sector ART programme. The study also tested the impact of the adverse effects of medication on patients' physical and emotional QoL.</p> <p>Methods</p> <p>A stratified random sample of 268 patients undergoing ART was interviewed at baseline (< 6 months ART) and follow-up (< 12 months ART). A model of the relationships between the duration of ART, the adverse effects of medication, and physical and emotional QoL (measured using EUROQOL-5D) was tested using structural equation modelling.</p> <p>Results</p> <p>The improved physical and emotional QoL shown at baseline was sustained over the 12-month study period, because treatment duration was not significantly associated with changes in the patients' QoL. Physical QoL significantly and positively influenced the patients' emotional QoL (subjective well-being [SWB]) (β = 0.33, <it>P </it>< 0.01). Longitudinal data showed that patients reported significantly fewer adverse effects at follow-up than at baseline (β = -0.38, <it>P </it>< 0.001) and that these adverse effects negatively influenced physical (β = -0.27, <it>P </it>< 0.01) and emotional QoL (β = -0.15, <it>P </it>< 0.05).</p> <p>Conclusion</p> <p>This study provides evidence that the South African public-sector ART programme is effective in delivering sustained improvement in patient well-being. However, the results should encourage clinicians and lay health workers to be vigilant regarding the adverse effects of treatment, because they can seriously affect physical and emotional QoL.</p

    Remembering the Sea: Personal and Communal Recollections of Maritime Life in Jizan and the Farasan Islands, Saudi Arabia

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    This is the final version of the article. Available from the publisher via the DOI in this record.People create narratives of their maritime past through the remembering and forgetting of seafaring experiences, and through the retention and disposal of maritime artefacts that function mnemonically to evoke or suppress those experiences. The sustenance and reproduction of the resulting narratives depends further on effective media of intergenerational transmission; otherwise, they are lost. Rapid socio-economic transformation across Saudi Arabia in the age of oil has disrupted longstanding seafaring economies in the Red Sea archipelago of the Farasan Islands, and the nearby mainland port of Jizan. Vestiges of wooden boatbuilding activity are few; long-distance dhow trade with South Asia, the Arabian-Persian Gulf and East Africa has ceased; and a once substantial pearling and nacre (mother of pearl) collection industry has dwindled to a tiny group of hobbyists: no youth dive today. This widespread withdrawal from seafaring activity among many people in these formerly maritime-oriented communities has diminished the salience of such activity in cultural memory, and has set in motion narrative creation processes, through which memories are filtered and selected, and objects preserved, discarded, or lost. This paper is a product of the encounter of the authors with keepers of maritime memories and objects in the Farasan Islands and Jizan. An older generation of men recall memories of their experiences as boat builders, captains, seafarers, pearl divers and fishermen. Their recounted memories are inscribed, and Arabic seafaring terms recorded. The extent of the retention of maritime material cultural items as memorials is also assessed, and the rôle of individual, communal and state actors in that retention is considered. Through this reflection, it becomes clear that the extra-biological memory and archive of the region’s maritime past is sparse; that intergenerational transmission is failing; that the participation of state agencies in maritime heritage creation is highly limited; and that, as a result, memories current among the older generation have limited prospect of survival. These memories, recorded and interpreted here, identify the Farasan Islands as a former centre of the pearling industry in the Red Sea, and identify them and Jizan as open to far-reaching maritime-mediated cultural influences in an era before the imposition of the attributes of the modern nation-state.This study was funded by the Golden Web Foundation (UK registered charity number 1100608), with additional support from the Seven Pillars of Wisdom Trust (UK registered charity number 208669)

    The Present and Future Role of Insect-Resistant Genetically Modified Maize in IPM

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    Commercial, genetically-modified (GM) maize was first planted in the United States (USA, 1996) and Canada (1997) but now is grown in 13 countries on a total of over 35 million hectares (\u3e24% of area worldwide). The first GM maize plants produced a Cry protein derived from the soil bacteriumBacillus thuringiensis (Bt), which made them resistant to European corn borer and other lepidopteran maize pests. New GM maize hybrids not only have resistance to lepidopteran pests but some have resistance to coleopteran pests and tolerance to specific herbicides. Growers are attracted to the Btmaize hybrids for their convenience and because of yield protection, reduced need for chemical insecticides, and improved grain quality. Yet, most growers worldwide still rely on traditional integrated pest management (IPM) methods to control maize pests. They must weigh the appeal of buying insect protection “in the bag” against questions regarding economics, environmental safety, and insect resistance management (IRM). Traditional management of maize insects and the opportunities and challenges presented by GM maize are considered as they relate to current and future insect-resistant products. Four countries, two that currently have commercialize Bt maize (USA and Spain) and two that do not (China and Kenya), are highlighted. As with other insect management tactics (e.g., insecticide use or tillage), GM maize should not be considered inherently compatible or incompatible with IPM. Rather, the effect of GM insect-resistance on maize IPM likely depends on how the technology is developed and used

    Malaria in Africa: Vector Species' Niche Models and Relative Risk Maps

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    A central theoretical goal of epidemiology is the construction of spatial models of disease prevalence and risk, including maps for the potential spread of infectious disease. We provide three continent-wide maps representing the relative risk of malaria in Africa based on ecological niche models of vector species and risk analysis at a spatial resolution of 1 arc-minute (9 185 275 cells of approximately 4 sq km). Using a maximum entropy method we construct niche models for 10 malaria vector species based on species occurrence records since 1980, 19 climatic variables, altitude, and land cover data (in 14 classes). For seven vectors (Anopheles coustani, A. funestus, A. melas, A. merus, A. moucheti, A. nili, and A. paludis) these are the first published niche models. We predict that Central Africa has poor habitat for both A. arabiensis and A. gambiae, and that A. quadriannulatus and A. arabiensis have restricted habitats in Southern Africa as claimed by field experts in criticism of previous models. The results of the niche models are incorporated into three relative risk models which assume different ecological interactions between vector species. The “additive” model assumes no interaction; the “minimax” model assumes maximum relative risk due to any vector in a cell; and the “competitive exclusion” model assumes the relative risk that arises from the most suitable vector for a cell. All models include variable anthrophilicity of vectors and spatial variation in human population density. Relative risk maps are produced from these models. All models predict that human population density is the critical factor determining malaria risk. Our method of constructing relative risk maps is equally general. We discuss the limits of the relative risk maps reported here, and the additional data that are required for their improvement. The protocol developed here can be used for any other vector-borne disease
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