Publications by authors named "Botha A"

Riverine fungi have the capacity for both pathogenicity, pertinent for countries with elevated immunosuppressed individuals, and bioremediation potential. The purpose was (i) to screen for the presence of clinically relevant riverine fungi and associations with anthropogenic influence, and (ii) the acclimatisation of environmental communities toward potential bioremediation application. Communities were harvested from polluted rivers in Stellenbosch, South Africa, and mycobiomes characterised by high-throughput amplicon sequencing.

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Emergomyces africanus is a thermally dimorphic pathogen causing severe morbidity and mortality in immunocompromized patients. Its transition to a pathogenic yeast-like phase in the human host is a notable virulence mechanism. Recent studies suggest polyamines as key players in dimorphic switching, yet their precise functions remain enigmatic.

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The conversion of a soluble protein into polymeric amyloid structures is a process that is poorly understood. Here, we describe a fully redox-regulated amyloid system in which cysteine oxidation of the tumor suppressor protein p16 leads to rapid amyloid formation. We identify a partially-structured disulfide-bonded dimeric intermediate species that subsequently assembles into fibrils.

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Purpose: Prostate cancer disproportionately affects men of African descent, yet their representation in tissue-based studies is limited. This multinational, multicenter pilot study aims to establish the groundwork for collaborative research on prostate cancer in sub-Saharan Africa.

Methods: The Men of African Descent and Carcinoma of the Prostate network formed a pathologist working group representing eight institutions in five African countries.

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The ecosystem services framework is essential for biodiversity conservation, emphasizing the role of nature in achieving sustainable development goals (SDGs). This study offers a global view on vulture-associated ecosystem services and their SDG contributions, based on insights from 206 experts. The findings reveal global consensus on the importance of vultures in regulation and maintenance services, such as waste recycling and disease control.

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In recent decades, scarcity of available resources, population growth and the widening in the consumption of processed foods and of animal origin have made the current food system unsustainable. High-income countries have shifted towards food consumption patterns which is causing an increasingly process of environmental degradation and depletion of natural resources, with the increased incidence of malnutrition due to excess (obesity and non-communicable disease) and due to chronic food deprivation. An urgent challenge is, therefore, to move towards more healthy and sustainable eating choices and reorientating food production and distribution to obtain a human and planetary health benefit.

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Previous studies have shown a correlation between nitrogen levels and Cryptococcus neoformans pathogenicity. Here we report on the in vivo effects of cryptococcal pre-exposure to ecologically relevant nitrogen levels. C.

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Background: Russian wheat aphid (Diuraphis noxia Kurd.) is a severe pest to wheat, and even though resistance varieties are available to curb this pest, they are becoming obsolete with the development of new virulent aphid populations. Unlike many other aphids, D noxia only harbours a single endosymbiont, Buchnera aphidicola.

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Emergomyces africanus is a recently identified thermally-dimorphic fungal pathogen that causes disseminated infection in people living with advanced HIV disease. Known as emergomycosis, this disseminated disease is associated with very high case fatality rates. Over the last decade, improved diagnostics and fungal identification in South Africa resulted in a dramatic increase in the number of reported cases.

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The conversion of natural habitats to farmland is a major cause of biodiversity loss and poses the greatest extinction risk to birds worldwide. Tropical raptors are of particular concern, being relatively slow-breeding apex predators and scavengers, whose disappearance can trigger extensive cascading effects. Many of Africa's raptors are at considerable risk from habitat conversion, prey-base depletion and persecution, driven principally by human population expansion.

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Background: Antimicrobial stewardship principles guide the clinical use of antimicrobials, including vancomycin, but paediatric vancomycin prescribing practices have not been evaluated in South Africa.

Objectives: To document the use, prescribing practices and monitoring of intravenous vancomycin and the spectrum of bacteria isolated on microbiological culture in children treated with intravenous vancomycin during a 12-month period at Red Cross War Memorial Children's Hospital (RCWMCH).

Method: A retrospective audit of intravenous vancomycin use in children admitted to RCWMCH during 2019 was performed.

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During the course of independent studies in Europe, North America, and Africa, seven yeast strains were isolated from insect frass, decaying wood, tree flux, and olive oil sediment. Phylogenetic analysis of two barcoding DNA regions (internal transcribed spacer and the D1/D2 domain of the LSU rRNA gene) revealed that they belong to two closely related undescribed species distinct from all genera in the family Debaryomycetaceae. For reliable taxonomic placement the genomes of four strains of the two novel species and six type strains of closely related species were sequenced.

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Sugarcane is an economically important crop plant across the globe as it is the primary source of sugar and biofuel. Its growth and development are greatly influenced by water availability; therefore, in periods of water scarcity, yields are severely compromised. Small Ubiquitin-Like Modifier (SUMO) proteases play an important role in stress responses by regulating the SUMO-related post-translational modification of proteins.

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Withania somnifera (L.) Dunal (Ashwagandha) has been used in herbal medicines worldwide and in the Indian traditional medicinal system for 3000 years. It is a member of the Solanaceae family distributed across Asia, Africa, Australia, and Europe.

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AbstractReduced energy intake can compromise the ability of a mammal to maintain body temperature within a narrow 24-h range, leading to heterothermy. To investigate the main drivers of heterothermy in a bulk grazer, we compared abdominal temperature, body mass, body condition index, and serum leptin levels in 11 subadult Cape buffalo () during a drought year and a nondrought year. Low food availability during the drought year (as indexed by grass biomass, satellite imagery of vegetation greenness, and fecal chlorophyll) resulted in lower body condition index, lower body mass relative to that expected for an equivalent-aged buffalo, and lower leptin levels.

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Background/aims: Extended wireless pH monitoring (WPM) is used to investigate gastroesophageal reflux disease (GERD) as subsequent or alternative investigation to 24-hour catheter-based studies. However, false negative catheter studies may occur in patients with intermittent reflux or due to catheter-induced discomfort or altered behavior. We aim to investigate the diagnostic yield of WPM after a negative 24-hour multichannel intraluminal impedance pH (MII-pH) monitoring study and to determine predictors of GERD on WPM given a negative MII-pH.

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Objective: To enhance the predictive power of the Fit between Individuals, Task and Technology (FITT) framework in mobile, individual consumer settings by restructuring to prominently emphasise .

Design: A mixed study involving a quantitative survey of 679 potential patients (adopters) and a qualitative content analysis of ten semi-structured interviews with clinic assistants.

Setting: For the survey, three combined random samples of potential patients from Atteridgeville, Bapong and Garankuwa (South Africa).

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Background: Squamous cell carcinoma (SCC) is a non-melanoma skin cancer with several risk factors including age and sun exposure. The degree of histological differentiation is considered an independent predictor of recurrence, metastasis, and survival. MicroRNAs (miRNAs) are small non-coding RNAs that play an important role in regulating gene expression, culminating in the initiation and progression of multiple tumors.

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The ordinary (superconductor-insulator-superconductor) Josephson junction cannot exhibit chaos in the absence of an external ac drive, whereas in the superconductor-ferromagnet-superconductor Josephson junction, known as the φ_{0} junction, the magnetic layer effectively provides two extra degrees of freedom that can facilitate chaotic dynamics in the resulting four-dimensional autonomous system. In this work, we use the Landau-Lifshitz-Gilbert model for the magnetic moment of the ferromagnetic weak link, while the Josephson junction is described by the resistively capacitively shunted-junction model. We study the chaotic dynamics of the system for parameters surrounding the ferromagnetic resonance region, i.

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River water is an essential human resource that may be contaminated with hazardous microorganisms. However, the risk of yeast infection through river water exposure is unclear because it is highly dependant on individual susceptibility and has therefore not been well-studied, to date. To evaluate this undefined risk, we analysed the fungal communities in less polluted (LP) and highly polluted (HP) river water, as determined using principal coordinate analysis of pollution indicators.

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Background: Epiphrenic oesophageal diverticula are rare and often asymptomatic. When symptoms are present, minimally invasive diverticulectomy is considered the gold standard of treatment. While there is an agreement on the pre-operative assessment, no consensus is achieved when it comes to surgical technique.

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Article Synopsis
  • Peroral endoscopic myotomy (POEM) is an effective, minimally invasive treatment for achalasia, yet it has high postoperative reflux rates, which can be addressed by using functional luminal imaging probes (FLIP) during the procedure.
  • A study involving 142 patients across two UK medical centers showed that 90% had successful outcomes (Eckardt scores under 3) at 6 weeks post-surgery, with further improvements in symptom resolution rates in later cases.
  • Shorter myotomies (less than 7 cm) demonstrated higher clinical success and lower proton-pump inhibitor usage, indicating tailoring myotomy length using FLIP data could enhance patient outcomes, though more research is necessary for refining optimal techniques.
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Unlabelled: Wastewater stabilization ponds (WSPs) rely on the metabolic activities of the inhabiting microbiota to treat wastewater. A selected consortium of and were used to manipulate the natural resident microalgae assemblage to improve the treatment performance of a domestic wastewater pond treatment system in a coastal region. Since information is lacking about the resulting influence on the composition or succession of the phytoplankton or associated microbiota assemblage, the current study aimed to determine how dosing with the microalgae and change the efficiency of wastewater effluent treatment, as well as the composition and succession of the natural occurring phytoplankton and microbial assemblage throughout WSP system.

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Elevated atmospheric CO concentrations (eCO) regulate plant architecture and susceptibility to insects. We explored the mechanisms underpinning these responses in wild type (WT) peas and mutants defective in either strigolactone (SL) synthesis or signaling. All genotypes had increased shoot height and branching, dry weights and carbohydrate levels under eCO, demonstrating that SLs are not required for shoot acclimation to eCO.

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