16918 research outputs found
Sort by
Realities of using self-administered smartphone surveys to solve sustainability challenges
No full textTo fill data gaps in human-environment systems, especially in difficult-to-access locations, novel tools are needed to collect (near) real-time data from diverse populations across the globe. Here we discuss the practicalities, constraints, and lessons learnt from six field studies using high spatial and temporal smartphone surveys in six different countries. We suggest that high spatiotemporal, self-administered smartphone surveys will produce novel insights into human behaviour, attitudes, and socio-economic characteristics that, when matched with high spatiotemporal resolution environmental data (e.g., from remote sensing), can be used to address sustainability challenges for global communities. Furthermore, we highlight the need for continuous refinement and improvement in future developments to enhance the efficacy of this methodology. By sharing the practical implications and constraints associated with smartphone surveys, this article contributes to the evolving landscape of data collection methods
Aloe ferox, Agathosma betulina, and Bulbine frutescens extracts show antifungal activity at concentrations favourable to the proliferation of epidermal cells
No full textIntroduction: The increasing prevalence of antifungal resistance presents an enormous challenge to healthcare professionals. The adverse effects and resistance of current antifungal drugs have prompted the need for alternate antifungal therapy in the form of natural products. Although anecdotal reports have suggested that Aloe ferox, Agathosma betulina, and Bulbine frutescens have been used to successfully treat fungal skin infections, little scientific evidence is available to validate these claims. Therefore, this study aimed to determine whether the concentrations of A ferox, A betulina, and B frutescens hydroethanolic extracts showing antifungal activity against skin-related Candida species are cytotoxic to normal human epidermal cells. Methods: Crystal violet and lactate dehydrogenase assays were employed to determine cell viability and cytotoxicity on the human epidermal cells. Broth microdilutions were performed to evaluate the susceptibility of Candida species to plant extracts. Results: Candida spp. inhibition was observed at a concentration of 200 µg/ml, while optimum extract concentrations for cell proliferation ranged between 200 and 400 µg/ml for B frutescens and 200 µg/ml for A ferox and A betulina. This suggests that these plants could prove to be effective as antifungal agents at a dosage of 200 µg/ml while still supporting the growth of epidermal cells at the same concentration, which is an important process in maintaining healthy skin. Conclusions: These findings from this study lay a foundation for further studies confirming the applicability of these medicinal plants as safe alternative antifungal treatments that promote skin cell proliferation, regeneration, and enhance tissue repair
Nanoscale mapping of ZrSiO4phases in naturally shocked zircon using electron energy loss spectroscopy
No full textCoexistence in natural samples of zircon (ZrSiO4) and reidite (a high-pressure polymorph of ZrSiO4) is attributed to the effects of hypervelocity impact events. The grains and intergrowths in those minerals can be merely a few nanometers in size, which makes phase identification by standard methods of structure analysis difficult. However, analytical scanning transmission electron microscopy (STEM) utilizing electron energy loss spectroscopy (EELS) can provide important information on phase transition mechanisms and pressure-temperature conditions associated with the shock event at the nanoscale. Here we demonstrate that the valence as well as oxygen core-loss EELS can be employed for nanoscale mapping of zirconreidite distributions in zircon-reidite aggregates. Moreover, other accompanying phases, e. g., baddeleyite, could also be identified and mapped by this method. We further compare the EELS maps with a 4D-STEM nanobeam precession electron diffraction data, and demonstrate the advantages of the EELS mapping, which provides spatial resolution down to the nanometer scale and is independent of crystal orientation
The superMIGHTEE project: meerkat and GMRT together to unveil the deep radio sky
No full textAn international team of researchers has come together to undertake an ultra-broadband exploration of the deep radio sky. The superMIGHTEE project combines data from the MIGHTEE project, using the precursor Square Kilometre Array MeerKAT telescope in South Africa, with observations from the upgraded Giant Metrewave Radio Telescope (uGMRT) in India to produce deep images at several μJy sensitivity over a frequency range of 200 MHz-2.5 GHz, with an angular resolution of a few arcseconds. This paper describes the initial superMIGHTEE uGMRT data release, comprising total intensity continuum images covering a total of 9.9 deg2 at 650 MHz and 6.9 deg2 at 400 MHz in the XMM-LSS, COSMOS, and E-CDFS deep fields. The associated radio source catalogues include 27,101 sources at 650 MHz and 10,946 sources at 400 MHz. The redshift distribution of the sources extends to z ∼ 4 with a median value of z = 1. An overview of the broadband spectra of the sources, in combination with the MeerKAT MIGHTEE 1280 MHz data, reveals a clear change in spectral properties at the transition from an active galactic nuclei-dominated population to a population dominated by star-forming galaxies at flux densities of a few mJy. At higher frequencies, the star-forming galaxy population exhibits an optically thin synchrotron spectral index indicative of energy injection from supernovae. At lower frequencies, the spectra flatten significantly with decreasing flux density, and the fraction of sources with peaked spectra increases. This is the first superMIGHTEE uGMRT data release. Subsequent releases will include spectro-polarimetric and spectral line image cubes, as well as images at lower frequencies. The goal of the superMIGHTEE ultra-wideband data set is to enhance our understanding of the evolution of active galactic nuclei and star-forming galaxies over cosmic time, shed light on the evolution of neutral hydrogen, and explore the origins and evolution of cosmic magnetic fields in clusters, filaments, and galaxies
High-dimensional bayesian modelling approaches for 21cm cosmology
No full textThe 21cm hyperfine transition of neutral hydrogen, HI, is an invaluable source of cosmological information, with its detection offering the opportunity to constrain models of the Universe, and thereby improving our understanding of its evolution. Numerous, and ever more sensitive, experiments target this signal across a range of frequencies, and, correspondingly, a range of redshifts, from Cosmic Dawn, to the Dark Ages, the Epoch of Reionisation, and the present-day Universe. Common among these experiments, however, are numerous performance-limiting effects, be it signal chain systematics, foreground contamination, etc. This work focuses on the mitigation of these examples in two different 21 cm experiments — signal chain systematics in simulated Hydrogen Epoch of Reionisation Array (HERA) data, and the separation of foregrounds from the 21 cm signal in the MeerKAT Large Area Synoptic Survey (MeerKLASS), both in a statistically rigorous Bayesian framework. The first chapter statistically models signal chain systematics in simulated HERA visibilities, namely cable reflections and antenna cross-coupling. We employ a Hamiltonian Monte Carlo (HMC) sampler to constrain our forward-model of the systematics-corrupted autocorrelation and cross-correlation visibilities as observed in HERA, and use our results to remove the systematics from mock data. This method allows us to not only recover the underlying power spectra, but to also provide rigorously propagated statistical uncertainties, a property which is important in the reporting of upper limits on the Epoch of Reionisation (EoR) signal. In the presence of high noise, we are able to effectively mitigate the systematics down to the noise level. Incoherent averaging of the recovered visibilities further reduces the noise, suggesting there is minimal residual systematics present. In cases of negligible noise, the majority of the systematics can be mitigated, but a fair amount of residual systematics remain, primarily due to the density of the systematics, i.e. confusion between systematics. However, this work performs similarly in terms of recovery in comparison to the currently implemented filtering and f itting methods in the HERA observational pipeline, but with the addition of statistical uncertainty estimates being placed on the recovered visibilities and power spectra. There is no significant signal loss in any of our results, an important consideration in the recovery of the weak Hi signal. The second chapter separates the 21 cm signal from the orders-of-magnitude more powerful foregrounds in simulated single-dish intensity maps, with future applications to MeerKLASS (MeerKAT Large Area Synoptic Survey) data being the intended outcome of this work
Possibilities for unemployed youth in the green economy: an ecological social work perspective
No full textThis article considers the question: What are the existing guidelines for community-based strategies to empower youth to participate in a green economy? South African youth is a particularly vulnerable group due to sociopolitical and economic reasons including systemic marginalisation, high unemployment rates, insufficient opportunities, and environmental degradation that threaten their and future generations’ well-being. Currently, most South African youth are faced with high levels of early school dropout, unemployment, substance use and abuse, crime and violence, high-risk behaviours, and socioeconomic challenges that limit their development. This is true for youth in both urban and rural areas, who have been challenged by, among other factors, a long-standing lack of access to resources and support services that have resulted in self-destructive behaviours. Drawing a link between social and environmental justice, social work places value on the empowerment of marginalised youth, as well as on the importance of participatory environmental initiatives through collaborative action for sustainable change with youth as change agents. Social work practice guidelines to effectively facilitate youth participation in environmental initiatives are, however, lacking. This includes various skills and enterprise development programmes focused on schools, youth, and the community at large. Using a scoping review, evidence of existing international and local guidelines for a community-based strategy aimed at youth participation in the green economy are presented and recommendations made for ecological social work practice and education
Knowledge of mental disorders in primary healthcare nurses in the Western Cape, South Africa
No full textBackground: Mental disorders remain a global health burden. The integration of mental health services into primary healthcare (PHC) can contribute to reduction of this burden. However, studies have reported PHC nurses’ lack of knowledge of mental disorders, which leads to their negative attitudes towards people with mental disorders preventing them from seeking help. Objectives: The objective of this study is to assess the knowledge levels of PHC nurses regarding mental disorders in the Western Cape, South Africa. Method: A quantitative descriptive survey was conducted. A self-administered questionnaire was used to collect data from a sample of 246 PHC nurses in the Cape Town metropole. Data were analysed using descriptive statistics, Chi-square tests and independent sample tests. A cut-off value of ≥ 80% was used to determine the sufficient levels of knowledge. Results: The average knowledge score (15.6; 78.0%) was below the cut-off value of ≥ 80%, indicating insufficient levels of knowledge. Sufficient levels of knowledge were found for over half of the respondents (139, 59.4%). Most of the respondents were knowledgeable about the symptoms of depression (221, 94.4 %), bipolar (217, 92.7%), schizophrenia (213, 91.0%) and anxiety disorders (209, 89.3%). Conclusion: Over half of the PHC nurses could identify the signs and symptoms of common mental disorders. However, the knowledge of dysthymia and psychosis requires more attention. Contribution: This study contributes to the existing body of knowledge in nursing practice and education related to mental disorders
IP case law development
No full textThis Paper identifies and analyses the decisions of the Supreme Court of India (hereinafter, the Supreme Court) relating to intellectual property (IP) reported1 in the year 2024. The paper seeks to answer the following questions: (i) how the Supreme Court interpreted-constructed the text of the IP statutes through her law declaring power under Article 141 of the Constitution of India; (ii) what has been the approach of the Supreme Court in deciding these cases in the year 2024; and (iii) whether or not the Supreme Court has contributed to the development of IP jurisprudence in the year 2024 through these decisions. © 2025, National Institute of Science Communication and Policy Research
Impacts of diagenetic alterations on siliciclastic sediments of the pletmos basin: implications for reservoir quality
No full textThe Pletmos sub-basin of Outeniqua Basin, South Africa hosts heterogeneous siliciclastic reservoirs sediments deposited under a complex tectonic setting and its diagenetic processes remain largely undefined. This study focuses on Cretaceous reservoir sediments, aiming to evaluates the impact of diagenetic alterations on the reservoir quality. Despite the basin’s recognition as a prolific hydrocarbon prospect, no detailed investigation into the diagenetic evolution of its reservoir rocks is available. This is the first integrated Petro-sedimentological characteristics in the basin, combining petrographic and petrophysical data derived from conventional core samples of 100% recovery and well logs data from three exploratory wells. The siliciclastic reservoirs are primarily composed of moderately to poorly sorted feldspathic litharenites and lithic arkoses sandstones deposited in fluvial environment. Two major porosity–permeability trends are identified; due to primary intergranular pore networks and secondary porosity generated by mineral dissolution. High effective porosity is attributed to the coexistence of preserved primary pores and timely development of secondary porosity, supporting enhanced fluid migration and reservoir quality. Diagenetic processes include early mechanical compaction, quartz and clay cementation, calcite and iron oxide precipitation, and extensive feldspar dissolution into kaolinite. Authigenic chlorite coatings, variations in quartz and calcite cementation are especially influential in porosity distribution. These changes reflect eogenetic and mesogenetic phases, which significantly modify petrophysical properties. The reservoir porosity ranges between 13.5 and 16.3%, primarily controlled by grain compaction, quartz, calcite cementation, and mineral dissolution. Diagenesis directly influences reservoir quality, making this study a valuable reference for reservoir assessment, exploration, and regional diagenetic comparison
Oral disease must be central in policies to improve global health
No full textOral diseases affect almost one in two people.Worldwide and negatively affect quality of life, resulting in substantial financial and social burden across all countries, but in the global health policy discourse they remain largely ignored. Oral diseases were not mentioned in the recently released zero draft of the political declaration for the 2025 united nations high level meeting on non-communicable diseases. This omission has deep roots. Dentistry and
medicine evolved as separate professions, creating educational and institutional silos that left oral health seen as specialised but not integral to overall health or health systems