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Exploring the efficacy of hypochlorous acid as a cost effective environmental decontaminant in dentistry: a scoping review
No full textDental procedures result in the production of bioaerosols that contaminate various environmental surfaces in the dental clinic. In order to maintain a safe environment in the dental clinic and prevent cross contamination, it is important to find alternative disinfection methods and agents to ensure effective decontamination. Hypochlorous acid (HOCl) is a cost-effective antimicrobial agent that can be used for infection control. The purpose of this scoping review is to provide evidence from the literature supporting the routine use of HOCl as a biodecontamination and disinfection agent in dental clinics. An electronic search was completed on the following databases: PubMed, Web of Science, Scopus, Wiley, and Science Direct. The studies were included based on their titles, abstract, and relevance to HOCl and the ability to render pathogens deactivated after exposure to HOCl vapor. The search focused on studies in the past 5 years. The search resulted in a total of 15 articles being selected after exclusions based on duplications, title, and abstract assessment. The articles included studies that used various HOCl concentrations and expanded on the inactivation of several pathogens. The reviewed studies highlight HOCl’s broad-spectrum antimicrobial efficacy, with significant reductions in severe acute respiratory syndrome coronavirus 2, methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and Clostridioides difficile, reinforcing its role in optimizing disinfection protocols across healthcare and occupational settings. The articles selected provided clear evidence that under correct and established parameters, HOCl can provide a cheaper safer alternative to most disinfectants. Further studies are recommended on applications methods in clinical settings
Imagined homes, concrete houses, and bureaucratic subjects: Citizen-state encounters in Eastridge, Cape Town
No full textEastridge is a low-cost housing development in Cape Town constructed and managed by the Cape Town Community Housing Company, a state-owned but privately managed company. The residents of Eastridge, most of whom have been living in their houses for 23 years, were recently declared ‘unlawful occupants’ in houses they expected to be the legal owners of years ago. Through a protracted struggle to receive permanent legal title over their homes the residents of Eastridge encounter the state in ways that are destabilising and violent at the same time as being intimate and mundane. Using ethnographic and oral history data gathered from three households in Eastridge I explore the ways in which families encounter and navigate the complex network of institutions, sites, agents, and artefacts that make up the imagined ‘state’ (Wafer and Oldfield, 2015). I argue that these everyday encounters with the state produce both the specific identity of the imagined state as well as particular forms of citizen subjectivity. The aim of this paper is to contribute to a better understanding of the landscape of political possibility through which citizens navigate by investigating the everyday encounters between citizens and the state. This is done through an analysis of everyday practices of homemaking, family relations, and getting by from day-to-day in a context of uncertainty
The multiple classes of ultra-diffuse galaxies: can we tell them apart?
No full textThis study compiles stellar populations and internal properties of ultra-diffuse galaxies (UDGs) to highlight correlations with their local environment, globular cluster (GC) richness, and star formation histories. Complementing our sample of 88 UDGs, we include 36 low surface brightness dwarf galaxies with UDG-like properties, referred to as NUDGes (nearly UDGs). All galaxies were studied using the same spectral energy distribution fitting methodology to explore what sets UDGs apart from other galaxies. We show that NUDGes are similar to UDGs in all properties except for being, by definition, smaller and having higher surface brightness. We find that UDGs and NUDGes show similar behaviours in their GC populations, with the most metal-poor galaxies hosting consistently more GCs on average. This suggests that GC content may provide an effective way to distinguish extreme galaxies within the low surface brightness regime alongside traditional parameters like size and surface brightness. We confirm previous results using clustering algorithms that UDGs split into two main classes, which might be associated with the formation pathways of a puffy dwarf and a failed galaxy. The clustering applied to the UDGs + NUDGes data set yields an equivalent result. The difference in mass contained in the GC system suggests that galaxies in different environments have not simply evolved from one another but may have formed through distinct processes
Structural and thermodynamic properties of Tb2Ni2X, (X=Al, Ga
No full textThe research reported in this thesis presents a comprehensive investigation into the structural, magnetic, and thermodynamic properties of the ternary polycrystalline Tb2Ni2X (X = Al, Ga) compounds through measurements of X-ray diffraction (XRD), magnetic susceptibility, χ (T), magnetization, M (µ0H), and heat capacity, Cp(T). The compounds were synthesized using an arc-melting furnace, and the ingots were cut using a slow cutter to ensure the formation of high-quality samples for further analysis. XRD analysis confirms the orthorhombic W2CoB2-type structure with the space group Immm. χ(T) at high temperature for both compounds follows the Curie–Weiss relationship giving an effective magnetic moment values µef f = 10.172(1) µB and 10.520(4) µB for Tb2Ni2Al and Tb2Ni2Ga compounds, respectively, which are close to that expected for the trivalent Tb ion of 10.72 µB. Negative Weiss temperature, θp was obtained for both compounds as expected for AFM exchange interactions between the Tb moments. χ (T) [Cp(T)] data indicate that both compounds order antiferromagnetically at TN = 41 K [40.4 K] and 41.5 K [41.4 K] for the Al and Ga compounds, respectively. χ(T) data in field-cooled (FC) and zero-field-cooled (ZFC) modes showed bifurcation below TN . M(µ0H) of Al compound exhibits hysteresis below 3 T, indicating magnetic domain structures and coercivity effects, while M(µ0H) for the Ga compound exhibits metamagnetic behavior above 6 T, suggesting a field-induced transition from antiferromagnetic to ferromagnetic states. Cp(T) data of the nonmagnetic counterparts Tb2Ni2X (X = Al, Ga) are well described by the Debye model given a Debye temperature, θD = 236.9(4) K and 225.3(2) K for the Al and Ga compounds, respectively. The low-temperature of the 4f-magnetic contribution to the total heat capacity, C4f (T) data can be well approximated according to the antiferromagnetic spin–wave dispersion, giving an energy gap, ∆sw = 47(3) K and 26(2) K for Al and Ga compounds, respectively. The 4f–magnetic entropy, S4f (T) for both compounds reaches the values of 2Rln(2) close to their respective TN values indicating a ground state doublet for these compounds
Exploring the role of teachers in facilitating science practical work: from traditional to virtual laboratory
No full textFor many centuries, the value of practical work has been a fundamental component of science education. This is supported by case studies performed by Isozaki (2017) on laboratory work between 1880 and 1930. The first aim of the Curriculum Assessment Policy Statement (CAPS) on Senior Phase Natural Sciences requires learners to do science which means learners must learn science process skills such as planning and implementing simple investigations (DBE, 2011). CAPS further calls on teacher to make all provisions for learners to learn science process skills, but the challenge is explicitly stated by the National Education Infrastructure Management System (2022) report which refers to the fact that 20% of the South African public schools don’t have laboratory infrastructure. Therefore, virtual practical work is an option worth exploring for the purposes of this study and according to Radhamani et al. (2014), virtual practical work offers a cost-effective and safest method of conducting practical work. Social Constructivism and Technological Pedagogical Content Knowledge (TPACK) are the theoretical frameworks drawn that underpins this study. These theories were used to illuminate the teacher’s ability to conduct practical work within contexts that require the facilitation of practical work and how intrinsic and extrinsic factors, combined with the teachers’ own agency, can guide the integration of technology to facilitate practical work within a virtual learning environment. It is for this reason that the study’s aim is to explore the role of teachers in facilitating practical work, looking at the transition from traditional to virtual. A research design acts as a conceptual blueprint in which specific sets of protocols and techniques outlines how data is gathered and examined (Creswell, 2014). This study used a qualitative approach. In this study the population was drawn from six teachers in four primary schools and 35 learners located in the Ekurhuleni North District, Gauteng Province, and were selected due to the dynamism of their programme of conducting practical work both traditionally and virtually. Non-participant observations of teachers at the schools, focus groups with learners, and semi-structured interviews with school teachers were all used to collect data for the purpose of this study. A qualitative approach was used to analyse the data. The findings and recommendations of the study were shared with the schools concerned in order to contribute towards practices that will assist the teachers in integrating technology so that virtual learning can be experienced by both teachers and learners
Millennials’ experiences and satisfaction with chatbots: a study of self-service technology in emerging markets
No full textPurpose: The study aims to explore the influence of selected precursors to self-service technology customer experience (when using chatbots) and the role of trustworthiness, control and self-service technology customer experience on self-service technology satisfaction. Design/methodology/approach: The study applied an explanatory research design and data collection was secured through self-administered questionnaires from millennials who engaged with a chatbot over six months. A total of 359 responses were used for data analysis. The measurement and structural models were assessed using structural equation modelling. Findings: Perceived usefulness, perceived playfulness and perceived ease of use significantly and positively influence chatbot self-service technology experience. Moreover, trustworthiness, chatbot self-service technology experience and control significantly and positively influence self-service technology satisfaction. Research limitations/implications: The tested model validates the hypothesised relationships between perceived usefulness, perceived playfulness, perceived ease of use, self-service technology experience, trustworthiness, control and chatbot self-service technology satisfaction. As such, chatbot users’ self-service technology experiences are directly linked to their three precursors and postcedent, self-service technology satisfaction. Conclusively, self-service technology satisfaction is directly guided by users’ trustworthiness and control when engaging with chatbots. Practical implications: The study’s results can assist businesses to better understand the drivers of millennials’ self-service technology experiences with chatbots. Furthermore, it can guide these businesses on the critical importance of trustworthiness, self-service technology experience and control as drivers of self-service technology satisfaction. Originality/value: Limited studies have examined how millennials’ self-service technology experiences relate to selected precursors and postcedents in emerging African markets
Development, implementation, and evaluation of an innovative clinical trial operations training program for Africa (clinops)
No full textBackground: Africa’s involvement in clinical trials remains very low. Although the crucial role of training initiatives in building clinical trial capacity in Africa has been documented, current efforts fall short as they lack alignment with local contexts. This study aimed to design, develop, implement, and evaluate an innovative clinical trial operations training program for Africa. Methods: We developed ClinOps, a novel 10-week clinical trial operations training program for study coordinators in Africa to enhance their expertise in four fundamental areas: designing, conducting, managing, and reporting clinical trials. To streamline the learning process, we used cloud-based applications that minimize the need for software installations while maximizing student engagement. VoiceThread facilitated interactive content that could be accessed offline. Moodle, an open-source learning management system, offered a platform for sharing learning tools, mentorship, and rubric-driven competency assessments, including quizzes, forums, tutorials, and group assignments. We utilized Zoom for live tutorials and mentoring as required. Effectiveness of the program was evaluated through quantitative pre- and post-surveys, qualitative end-course evaluations, and a comprehensive monitoring and evaluation framework. The pre- and post-surveys measured changes in trainees’ confidence in clinical trial domains and leadership and coordination skills. End-course evaluations gathered feedback on the course content, organization, technology, and instructional methods. We used Wilcoxon rank test to analyze pre- and post-survey scores and thematic analysis to analyze the qualitative data. Results: In the initial cohort, 88 study coordinators from 19 countries participated, including 56 (64%) females, with 57 (65%) actively employed as study coordinators during the training, and 85 (97%) possessing prior experience in clinical trial roles. Among these, 71 (81%) successfully completed the course, with 69 (97%) also completing the post-course assessment. Post-training scores demonstrated substantial improvement compared to pre-training scores in each competency area, including in designing (pre-post training median score = 3.6 vs. 4.6, median difference = 1.0, 95% CI 0.8–1.1, p < 0.001), managing (pre-posttest median score = 3.4 vs. 4.2, median difference = 0.6, 95% CI 0.4–0.8, p < 0.001), conducting (pre-post training median score = 3.9 vs. 4.7, median difference = 0.9, 95% CI 0.6-1.0, p < 0.001), and reporting (pre-posttest median score = 3.0 vs. 4.5, median difference = 1.0, 95% CI 0.9–1.5, p < 0.001) clinical trials. The monitoring and evaluation data confirm the program’s adherence to training best practices, including alignment with local priorities, country ownership, pedagogic innovation, institutional capacity building, sustainability, and ongoing partnerships. The end-course evaluation reflects participants’ positive feedback on the program’s structure, content, relevance to their current roles, and overall delivery methods. Conclusion: The ClinOps program, designed by experts from academia and product development partners, enhanced participants’ clinical trial competencies. To effectively build clinical trials capacity on the continent, training programs should provide thorough competency development in designing, conducting, managing, and reporting trials
Decoupling local primordial non-Gaussianity from relativistic effects in the galaxy bispectrum
No full textUpcoming galaxy surveys aim to map the Universe with unprecedented precision, depth and sky coverage. The galaxy bispectrum is a prime source of information as it allows us to probe primordial non-Gaussianity (PNG), a key factor in differentiating various models of inflation. On the scales where local PNG is strongest, Doppler and other relativistic effects become important and need to be included. Unlike for the single-tracer power spectrum, the leading order imaginary Doppler term does not cancel out in the bispectrum, leaving a smoking gun imaginary dipole signal. We investigate the detectability and importance of relativistic and local PNG contributions in the galaxy bispectrum. We compute the signal-to-noise ratio for the detection of lightcone projection effects in the bispectrum. Furthermore, we perform information matrix forecasts on the local PNG parameter, fNL, and on the parametrised amplitudes of the relativistic corrections. Finally, we quantify the bias on the measurement of fNL that arises from neglecting relativistic effects. Our results show that detections of both first- and second-order relativistic effects are promising with forthcoming spectroscopic survey specifications and are largely unaffected by the uncertainty in fNL. Conversely, we show for the first time that neglecting relativistic corrections in the galaxy bispectrum can lead to a shift >1.5σ(fNL) on the detected value of fNL, highlighting the importance of including relativistic effects in our modelling
HEALeB: healthcare 4.0 enabled by iot, ai, and blockchain
No full textAs the volume and sensitivity of medical data continue to grow, ensuring data security and effective analysis has become increasingly challenging. This paper presents the design and development of HEALeB, a comprehensive system that integrates blockchain technology and machine learning (ML) to address these challenges. Blockchain technology offers a decentralized, immutable ledger that ensures data integrity, privacy, and traceability, while ML algorithms enhance predictive analytics and decision-making capabilities. By combining these technologies, HEALeB aims to overcome critical issues such as data tampering, unauthorized access, and the underutilization of decision-support tools. The system’s design leverages blockchain to secure Electronic Health Records (EHRs) and employs ML to provide advanced analytics for personalized and precise healthcare solutions. This approach promises to improve diagnostic accuracy, optimize health management, and enhance overall healthcare quality. The paper provides a detailed exploration of HEALeB’s architecture, its implementation, and its performance evaluation, concluding with insights into the system’s impact and future research directions in the realm of Healthcare 4.
Exploring the unidimensionality of the GAD-7 for South african first responders: evidence from multiple psychometric approaches
No full textGeneralized Anxiety Disorder (GAD) is a prevalent mental health condition and the GAD-7 is widely used as a screening tool and measure of GAD severity. However, research has yielded conflicting findings regarding the factor structure of the instrument, with some studies supporting a unidimensional interpretation while others suggest a two-factor solution. These inconsistencies highlight the importance of validating the GAD-7 across diverse populations. This study aimed to assess the psychometric properties and factor structure of the GAD-7 among South African first responders (n = 429). Participants completed a demographic questionnaire along with the GAD-7, the Patient Health Questionnaire, the Post-Traumatic Stress Disorder Checklist, and subscales from the Maslach Burnout Inventory, namely Emotional Exhaustion and Depersonalization. The dimensionality of the GAD-7 was examined using Mokken Scale Analysis (MSA), parallel analysis, and Confirmatory Factor Analysis (CFA) with a Schmid-Leiman transformation. Results supported the unidimensionality of the GAD-7. MSA indicated that all items were loaded onto a single scale, with strong inter-item correlations and a high H-coefficient. The parallel analysis confirmed that only one factor was necessary, and the Schmid-Leiman transformation extracted a general factor accounting for 84% of the item variance. Furthermore, the reliability of the GAD-7 was excellent, with alpha and omega coefficients exceeding 0.90, indicating high internal consistency. The strong reliability and validity of the GAD-7 in this study reinforce its utility as a reliable tool for assessing generalized anxiety in a non-clinical setting