1834 research outputs found
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Incentive-compatible mechanism for transmission scheduling of delay-sensitive medical packets in e-health networks
No full textIn this paper, an incentive-compatible mechanism for transmission scheduling in electronic health (e-health) networks with delay-sensitive medical packets is studied. Unlike existing works in the literature, we focus on the beyond wireless body area network (beyond-WBAN) communications. In the considered system, medical packets arrive randomly at each gateway (which ordinarily stands for one patient), and their transmission requests are reported to the network regulator (i.e., the base station) with specific delay sensitivities that reflect their medical signal severities. The base station then determines the order of transmission by formulating a priority queue. With the construction of the packets' utility and the base station's profit functions, we analyze the characteristics of the service system and design an incentive-compatible mechanism such that all gateways will be forced to report the actual delay sensitivities of their medical packets. Theoretical analyses show that our proposed mechanism can maximize the profit of the base station (i.e., minimize the total waiting cost from all medical packet transmissions) while guaranteeing higher service priorities to more emergent medical packets. Numerical results examine the properties of the proposed mechanism, and demonstrate its feasibility in providing economic incentives for all individuals.National Research Foundation (South Africa
The Molecular Epidemiology and Genetic Environment of Carbapenemases Detected in Africa
No full textResearch articles describing carbapenemases and their genetic environments in Gram-negative bacteria were reviewed to determine the molecular epidemiology of carbapenemases in Africa. The emergence of resistance to the carbapenems, the last resort antibiotic for difficult to treat bacterial infections, affords clinicians few therapeutic options, with a resulting increase in morbidities, mortalities, and healthcare costs. However, the molecular epidemiology of carbapenemases throughout Africa is less described. Research articles and conference proceedings describing the genetic environment and molecular epidemiology of carbapenemases in Africa were retrieved from Google Scholar, Scifinder, Pubmed, Web of Science, and Science Direct databases. Predominant carbapenemase genes so far described in Africa include the blaOXA-48 type, blaIMP, blaVIM, and blaNDM in Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter cloacae, Citrobacter spp., and Escherichia coli carried on various plasmid types and sizes, transposons, and integrons. Class D and class B carbapenemases, mainly prevalent in A. baumannii, K. pneumoniae, E. cloacae, Citrobacter spp., and E. coli were the commonest carbapenemases. Carbapenemases are mainly reported in North and South Africa as under-resourced laboratories, lack of awareness and funding preclude the detection and reporting of carbapenemase-mediated resistance. Consequently, the true molecular epidemiology of carbapenemases and their genetic environment in Africa is still unknownNational Research Foundation (South Africa
Efficacy of Phenotypic, PCR and MALDI-ToF Identification Methods for Campylobacter spp
No full textThis study compared phenotypic and genotypic identification methods of Campylobacter spp. against the polymerase chain reaction (PCR) in terms of sensitivity, specificity, positive-predictive value and negative-predictive value. Thermophilic Campylobacter isolates were identified using conventional biochemical tests, specifically hippurate hydrolysis, matrix assisted laser desorption ionization- time of flight (MALDI-ToF) mass spectrometry and PCR with primers unique to C. jejuni and C. coli. MALDI-ToF was shown to be superior to biochemical tests for identification of C. coli but equivalent to biochemical tests for C. jejuni.National Research Foundation (South Africa
Is Zimbabwe ready to transition from anonymous unlinked sero-surveillance to using prevention of mother to child transmission of HIV (PMTCT) program data for HIV surveillance?: results of PMTCT utility study, 2012
No full textBackground: Prevention of mother-to-child transmission of HIV (PMTCT) programs collect socio-demographic and HIV testing information similar to that collected by unlinked anonymous testing sero-surveillance (UAT) in antenatal settings. Zimbabwe evaluated the utility of PMTCT data in replacing UAT.
Methods: A UAT dataset was created by capturing socio-demographic, testing practices from the woman’s booking-card and testing remnant blood at a laboratory from 1 June to 30 September 2012. PMTCT data were collected retrospectively from ANC registers. UAT and PMTCT data were linked by bar-code labels that were temporarily affixed to the ANC register. A questionnaire was used to obtain facility-level data at 53 sites.
Results: Pooled HIV prevalence was 15.8 % (95 % CI 15.3–16.4) among 17,349 women sampled by UAT, and 16.3 % (95 % CI 15.8 %–16.9 %) among 17,150 women in PMTCT datasets for 53 sites. Pooled national percent-positive agreement (PPA) was 91.2 %, and percent-negative agreement (PNA) was 98.7 % for 16,782 women with matched UAT and PMTCT data. Based on UAT methods, overall median prevalence was 12.9 % (Range 4.0 %–19.4 %) among acceptors and refusers of HIV test in PMTCT compared to 12.5 % ((Range 3.4 %–19.5 %) among acceptors in ANC registers. There were variations in prevalence by site.
Conclusion: Although, there is no statistical difference between pooled HIV prevalence in UAT compared to PMTCT program, the overall PPA of 91.2 % and PNA of 98.7 % fall below World Health Organisation (WHO) benchmarks of 97.6 % and 99.6 % respectively. Zimbabwe will need to strengthen quality assurance (QA) of rapid HIV testing and data collection practices. Sites with good performance should be prioritised for transitioning.National Research Foundation (South Africa
How to build science-action partnerships for local land use planning and management: Lessons from Durban, South Africa
No full textThe gap between scientific knowledge and implementation in the fields of biodiversity conservation, environmental management, and climate change adaptation has resulted in many calls from practitioners and academics to provide practical solutions responding effectively to the risks and opportunities of global environmental change, e.g., Future Earth. We present a framework to guide the implementation of science-action partnerships based on a real-world case study of a partnership between a local municipality and an academic institution to bridge the science-action gap in the eThekwini Municipal Area, South Africa. This partnership aims to inform the implementation of sustainable land-use planning, biodiversity conservation, environmental management, and climate change adaptation practice and contributes to the development of human capacity in these areas of expertise. Using a transdisciplinary approach, implementation-driven research is being conducted to develop several decision-making products to better inform land-use planning and management. Lessons learned through this partnership are synthesized and presented as a framework of enabling actions operating at different levels, from the individual to the interorganizational. Enabling actions include putting in place enabling organizational preconditions, assembling a functional well-structured team, and actively building interpersonal and individual collaborative capacity. Lessons learned in the case study emphasize the importance of building collaborative capacity and social capital, and paying attention to the process of transdisciplinary research to achieve more tangible science, management, and policy objectives in science-action partnerships. By documenting and reflecting on the process, this case study provides conceptual and practical guidance on bridging the science-action gap through partnerships.National Research Foundation (South Africa
Sex isn’t better than love” Exploring South African Indian teenage male and female desires beyond danger
No full textThis article analyses how South African Indian teenage men and women conceptualise desire, sex and love, their resistance to and accommodation of gender inequalities within relationship dynamics. It calls attention to a reconceptualisation of childhoods that extends agency to sexuality beyond a preoccupation with sexual danger. By focusing on the diversity of sexual meanings, attention is given to the plurality of childhood sexual experiences among South African Indian teenagers. Finally, the article argues that deeper insight into teenage pleasure and power can sharpen interventions that promote healthy teenage sexualities.National Research Foundation (South Africa
Men Managing, not teaching Foundation Phase: Primary school teacher’s construction of teaching in the early years of primary schooling
No full textIn this article we argue that eliminating the divisions of labour between men and women could work towards counteracting gender inequality within professions. Globally women are over-represented in the teaching of young children in the early years of primary school, or Foundation Phase (FP), as it is known in South Africa. We are concerned to go beyond essentialist understandings of gender by exploring how male and female primary school teachers at five selected schools in South Africa are sometimes complicit in reproducing men as managers. Men tend to be positioned within dominant notions of masculinity which serve to reproduce masculine power in the realm of school management whilst FP teaching is characterised as “women’s work”. Teachers of both genders are complicit in safeguarding the FP as a nurturing female domain, whilst reproducing gendered binaries and unequal relations of power. We argue that there is a need to create alternate masculinities that leave behind rigid notions of appropriate gender performances and address current social challenges such as violence, health and gender transformation in South Africa.National Research Foundation (South Africa
Testing a dualmodality system that combines fullfield digital mammography and automated breast ultrasound.
No full textPurpose: The aim of this study was to test a novel dual-modality imaging system that combines full-field digital mammography (FFDM) and automated breast ultrasound (ABUS) in a single platform. Our Aceso system, named after the Greek goddess of healing, was specifically designed for the early detection of cancer in women with dense breast tissue.
Materials and Methods: Aceso was first tested using two industry standards: a Contrast Detail Mammography (CDMAM) phantom as endorsed by European Reference Organisation for Quality Assured Breast Screening and Diagnostic Services was used to assess the FFDM images; and the CIRS 040GSE ultrasound phantom was imaged to evaluate the quality of the ABUS images. In addition, 58 women participated in a clinical trial: 51 were healthy volunteers aged between 40 and 65, while 7 were patients referred by the breast clinic, 6 of whom had biopsy-proven breast cancer.
Results: The CDMAM tests showed that the FFDM results were “acceptable” but fell short of “achievable” which was attributed to the low dose used. The ABUS images had good depth penetration (80 mm) and adequate axial resolution (0.5 mm), but the lateral resolution of 2 mm was judged to be too coarse. In a 42-year-old volunteer with extremely dense breast tissue, the ABUS modality detected a lesion (a benign cyst) that was mammographically occult in the FFDM image. For a 73-year-old patient with fatty breasts, a malignant lesion was successfully detected and co-registered in the FFDM and ABUS images. On average, each woman spent less than 11 min in the acquisition room.
Conclusions: While there is room for improvement in the quality of both the FFDM and ABUS images, Aceso has demonstrated its ability to acquire clinically meaningful images for a range of women with varying breast densities and, therefore, has potential as a screening device.National Research Foundation (South Africa
Online SSVEP-based BCIusing Riemannian Geometry
No full textChallenges for the next generation of Brain Computer Interfaces (BCI) are to mitigate the common sources of variability (electronic, electrical, biological) and to develop online and adaptive systems following the evolution of the subject׳s brain waves. Studying electroencephalographic (EEG) signals from their associated covariance matrices allows the construction of a representation which is invariant to extrinsic perturbations. As covariance matrices should be estimated, this paper first presents a thorough study of all estimators conducted on real EEG recording. Working in Euclidean space with covariance matrices is known to be error-prone, one might take advantage of algorithmic advances in Riemannian geometry and matrix manifold to implement methods for Symmetric Positive-Definite (SPD) matrices. Nonetheless, existing classification algorithms in Riemannian spaces are designed for offline analysis. We propose a novel algorithm for online and asynchronous processing of brain signals, borrowing principles from semi-unsupervised approaches and following a dynamic stopping scheme to provide a prediction as soon as possible. The assessment is conducted on real EEG recording: this is the first study on Steady-State Visually Evoked Potential (SSVEP) experimentations to exploit online classification based on Riemannian geometry. The proposed online algorithm is evaluated and compared with state-of-the-art SSVEP methods, which are based on Canonical Correlation Analysis (CCA). It is shown to improve both the classification accuracy and the information transfer rate in the online and asynchronous setup.National Research Foundation (South Africa
Performance evaluation of a wiener model predictive control for a coagulation chemical dosing unit in water treatment plants
No full textCoagulation process control is an essential operation in water treatment plants. It is a challenging control problem due to the nonlinear and physicochemical nature of the coagulation process. The paper presents the application of the Wiener model predictive control (WMPC) algorithm to a coagulation chemical dosing unit for water treatment plants in order to keep the surface charge and pH level of the dosed water at the reference tra jectory set by the operator of the plant. Wiener models with di§erent nonlinear estimators are compared and evaluated. A Wiener model with a wavelet network estimator presented the highest goodness of Öt (98%), and was thus selected as the best prediction model. Simulation results show that the proposed control strategy has good set-point tracking, as well as noise and disturbance rejection performancesNational Research Foundation (South Africa