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Multispectral Plant Disease Detection with Vision Transformer–Convolutional Neural Network Hybrid Approaches
Get PDFPlant diseases pose a critical threat to global agricultural productivity, demanding timely detection for effective crop yield management. Traditional methods for disease identification are laborious and require specialised expertise. Leveraging cutting-edge deep learning algorithms, this study explores innovative approaches to plant disease identification, combining Convolutional Neural Networks (CNNs) and Vision Transformers (ViTs) to enhance accuracy. A multispectral dataset was meticulously collected to facilitate this research using six 50 mm filter filters, covering both the visible and several near-infrared (NIR) wavelengths. Among the models employed, ViT-B16 notably achieved the highest test accuracy, precision, recall, and F1 score across all filters, with averages of 83.3%, 90.1%, 90.75%, and 89.5%, respectively. Furthermore, a comparative analysis highlights the pivotal role of balanced datasets in selecting the appropriate wavelength and deep learning model for robust disease identification. These findings promise to advance crop disease management in real-world agricultural applications and contribute to global food security. The study underscores the significance of machine learning in transforming plant disease diagnostics and encourages further research in this field
Diversification of the African legless skinks in the subfamily Acontinae (Family Scincidae)
Get PDFCladogenic diversification is often explained by referring to climatic oscillations and geomorphic shifts that cause allopatric speciation. In this regard, southern Africa retains a high level of landscape heterogeneity in vegetation, geology, and rainfall patterns. The legless skink subfamily Acontinae occurs broadly across the southern African subcontinent and therefore provides an ideal model group for investigating biogeographic patterns associated with the region. A robust phylogenetic study of the Acontinae with comprehensive coverage and adequate sampling of each taxon has been lacking up until now, resulting in unresolved questions regarding the subfamily’s biogeography and evolution. In this study, we used multi-locus genetic markers (three mitochondrial and two nuclear) with comprehensive taxon coverage (all currently recognized Acontinae species) and adequate sampling (multiple specimens for most taxa) of each taxon to infer a phylogeny for the subfamily
Comparative situational analysis of comprehensive abortion care in four Southern African countries
Get PDFWe report on a comparative situational analysis of comprehensive abortion care (CAC) in Botswana, Eswatini, Lesotho and Namibia. We conducted systematic literature searches and country consultations and used a reparative health justice approach (with four dimensions) for the analysis. The following findings pertain to all four countries, except where indicated. Individual material dimension: pervasive gender-based violence (GBV); unmet need for contraception (15−17%); high HIV prevalence; poor abortion access for rape survivors; fees for sexual and reproductive health (SRH) services (Eswatini). Collective material dimension: no clear national budgeting for SRH; over-reliance on donor funding (Eswatini; Lesotho); no national CAC guidelines or guidance on legal abortion access; poor data collection and management systems; shortage and inequitable distribution of staff; few facilities providing abortion care. Individual symbolic dimension: gender norms justify GBV; stigma attached to both abortion and unwed or early pregnancies. Collective symbolic dimension: policy commitments to reducing unsafe abortion and to post-abortion care, but not to increasing access to legal abortion; inadequate research; contradictions in abortion legislation (Botswana); inadequate staff training in CAC. Political will to ensure CAC within the country’s legislation is required. Reparative health
The Case for a Cray on a Chip
No full textMoore’s Law is usually interpreted as a prediction of how many transistors you can buy for the same money at some future date. It can also be interpreted as how long you need to wait until a given number of transistors falls below a target price. An example of this reverse-application of Moore’s Law is transitions such as the emergence of microprocessors competitive with traditional larger-scale computers and the emergence of smartphones. Since the late 1990s, it has become increasingly common for growth in transistors to equate to more CPUs (cores) per die. Recent designs have over 50 billion transistors and far more potential parallelism than can be supported by memory. I argue the case for a rebalancing of design goals with a much larger, faster on-chip memory and a CPU that is designed around this memory system. The proposal: a Cray-class vector CPU on a die with 1 Gibyte of static RAM, or Crayon (for Cray on a chip). The kind of organization classically used by Cray vector supercomputers is feasible to achieve on a single chip. I argue that a design like this can use the available memory bandwidth, as opposed to over-CPU designs with a large number of cores and GPU threads that are memory limited and propose how such a design could be used
The Emancipatory Nature of Transformative Agency
No full textCultural-historical activity theory (CHAT) research has established an impressive body of scholarship that advances social understanding of human agency in the transformation of society, much of which is captured in contributions to this volume (cf. Hopwood (Chapter 15); Sannino (Chapter 2); Stetsenko (Chapter 3); Bal and Bird Bear (Chapter 8)). The main tenets of this work, building on the historical legacy of Vygotsky and Marx, affirm that humans are not passive recipients of external stimuli or influences but are active co-creators of the world (s) they inhabit. They are capable of using and producing cultural tools to take power over their own volitional action (s)(cf. Sannino, 2015, Chap-ter 2 of this volume; Hopwood and Gottshalk, 2017). Vygotsky’s major legacy in coming to understand transformative agency is that the cultural tools produced and used as mediational means are critical in the emergence of transformative agency (Sannino, 2015, 2020, Chapter 2 of this volume; Stetsenko, 2019; Hopwood, Chapter 15 of this volume) and thus in the transformation of human activity. As shown by Sannino (2015, 2020), such tools offer stimulus for volitional action that can break paralysis, especially when conflicts of motives are experienced
Persistent effects of historical sea levels on the population structure of a temporary wetland copepod
Get PDFTemporary wetland ecosystems are common in arid and semi‐arid envi-ronments, and are inhabited by diverse invertebrate communities. Little is known about the dynamics of genetic connectivity in the geograph-ically scattered populations of these wetland specialists. The current study investigated the spatial genetic structure and dispersal history of a recently described calanoid copepod, Lovenula raynerae, reported from temporary wetlands in the Eastern Cape province of South Africa. We tested whether the species represents a single, well‐connected population or comprises different regional genetic groups, some of which may be rare or endangered
Evaluating the establishment of a new water hyacinth biological control agent in South Africa
Get PDFMegamelus scutellaris Berg (Hemiptera: Delphacidae) is the most recent of nine biological control agents developed to manage invasive water hyacinth, Pontederia (= Eichhornia) crassipes Mart.(Pontederiaceae), in South Africa. More than a million M. scutellaris have been mass-reared and released since the first introduction of the agent into South Africa in 2013, successfully establishing overwintering populations at 32 sites in seven of the nine provinces. Establishment has also been recorded at seven of these sites through natural dispersal from sites where they had established. Inundative releases, where large numbers of M. scutellaris are released regularly, have resulted in excellent establishment, and caused a significant reduction in water hyacinth cover in areas where, historically, biological control seemed unlikely due to excessive eutrophication. Although M. scutellaris has established well throughout South Africa through classical biological control methods, this study also showed that inundative releases of biological control agents over multiple seasons results in the most effective control of the weed, especially at cool temperate and eutrophic sites
The use of a Subjective wellbeing scale as predictor of adherence to neuroleptic treatment to determine poor prognostic factor in African population with Schizophrenia
Get PDFObjectives: To investigate and identify demographic and clinical predic-tors of subjective well-being in a sample of Xhosa people with schizo-phrenia on neuroleptic treatment. Methods: As a part of a large genetic study, 244 study participants with a confirmed diagnosis of schizophre-nia completed the translated SWN-K 20 scale. Internal consistency analysis was performed, and convergent analysis and exploratory analysis were conducted using Principal Component Analysis (PCA). Linear regression methods were used to determine predictors of SWBN in the sample population
Diverse values of nature for sustainability
Get PDFTwenty-five years since foundational publications on valuing ecosystem services for human well-being, addressing the global biodiversity crisis still implies confronting barriers to incorporating nature’s diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever. Notwithstanding agreements to incorporate nature’s values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF) and the UN Sustainable Development Goals, predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature. Arguably, a ‘values crisis’ underpins the intertwined crises of biodiversity loss and climate change, pandemic emergence and socio-environmental injustices. On the basis of more than 50,000 scientifc publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature’s diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions. Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures
An in vitro investigation of novel quinolone derivatives on selected pharmacological targets for diabetes mellitus and associated complications
Get PDFDiabetes mellitus (DM) is a group of endocrine and metabolic disorders characterised and identified by the presence of hyperglycaemia over a long period and, to an extent, accompanied by hyperlipidaemia. CVD has been reported to be the leading cause of mortality in patients with DM. Several antidiabetic agents are available for managing DM, but these agents are not for curative therapy and present with undesirable side effects. In addition, these agents become less effective as the patient's condition progresses to complete beta-cell failure. Therefore, developing newer antidiabetic agents with minimal undesirable side effects, prolonged efficacy and protection against the development of DM complications are necessary. This study was conducted to identify potential novel antidiabetic agents with cardiovascular-protective activity. The compounds of interest for the study were quinolone derivatives since quinolones have been reported to have an antihyperglycaemic effect.Thesis (MSc) -- Faculty of Pharmacy, 202