16918 research outputs found
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Stonefly systematics: past, present, and future
No full textStoneflies (Insecta: Plecoptera) are a widespread group of freshwater insects known for their ecological significance and sensitivity to environmental change. This diverse order encompasses over 4,000 species across 17 families, with the number of described species predicted to increase substantially over the coming years. This review surveys the past and present landscape of stonefly systematics, emphasizing recent advancements in our understanding of the phylogenetic relationships within this group to the ordinal, subordinal, and family level. We highlight the need for expanded biodiversity surveys, particularly in underexplored regions such as high-elevation ecosystems, the Southern Hemisphere, and the Arctic, and identify the key challenges impeding the advancement of systematic research, in particular the decline in taxonomic expertise. Looking forward, we outline a vision for the future of stonefly systematic research, advocating for increased inclusivity, collaborative research efforts, and the integration of advanced molecular methodologies
The role of learning communities in addressing primary school dropout: an exploratory study of a learning community in a low-income primary school in Cape Town, South Africa.
No full textThis research responds to an identified concern in the literature that primary school dropout may be a relatively understudied phenomenon requiring due attention. Accordingly, this research undertaking explored the present role of learning communities in addressing voluntary withdrawal or dropout in a low-income primary school educational context in post-apartheid South Africa. This research is important especially in a country where, for the majority of South African learners, educational inequality continues to prevail across postapartheid educational landscapes. Within an interpretive paradigm, and as a qualitative case study, the underpinnings of Epstein’s model pertaining to school, home and community partnerships have been explored to broadly guide this research undertaking, and participant perception was invited through semi-structured interviews. Key findings draw attention to possible collaborative solutions to the unrelenting problem of voluntary learner withdrawal in low- income primary school educational contexts. Most notably, key findings suggest that the formation of educational communities comprising educators, parents and caregivers, and the learners themselves potentially has a high social and educational value towards the success of learners. Findings also draw attention to the value of an extended educational community in which district officials and community organizations, for example, could contribute towards authentic lifelong learning strategies towards educator and learner success
Characterization of Zalaria obscura Y1223 hydrolases: implications for lignocellulose conversion
No full textOverconsumption of fossil fuel reserves and its adverse effects has sparked interest in the production of second-generation biofuels due to the abundance of lignocellulosic waste and potential energy crops. However, processing costs associated with depolymerization of the cellulose crystalline structure have stalled advancement in cellulosic ethanol production. Current investigations range from identification of novel enzymes for lignocellulose hydrolysis to consolidation of enzyme production into a singular alcohol producing microorganism to potentially reduce cost for commercial processing. In this study, a total of 828 non-Saccharomyces and black yeasts were screened for cellulolytic and xylanolytic enzyme activities, whereby 60 isolates were identified that exhibited activity for at least one of the enzymes tested. In doing so, a novel Zalaria obscura strain (Z. obscura Y1223) was identified and assessed for enzyme activity in multiple growth media. Semi-quantitative assays showed that Z. obscura Y1223 produced cellulases optimally in media containing yeast extract, peptone and oat bran, with a pH range between pH 5 and 6 and at 30 °C. Maximum xylanase activity (20.5 U/L/OD600) was attained using synthetic complete media supplemented with xylo-oligosaccharides and maximum cellulase activity (7.51 U/L/OD600 endoglucanase, 1.302 U/L/OD600 β-glucosidase) was attained when grown in media containing yeast extract, peptone and oat bran. To our knowledge, this is the first study to quantify the cellulolytic and xylanolytic enzyme activities of a Zalaria spp., which provides key insight into the availability of unexplored cellulolytic enzymes that could inform the design of organisms engineered for consolidated bioprocessing
The artistic and aesthetic mechanisms of narrative experimentation in the novel "Jabalu Al-Zumurrud" by Mansoura Ez El-Din: A critical and analytical study
No full textThis study is intended to highlight the artistic and aesthetic mechanisms of narrative experimentation, in the contemporary Arabic novel. It seeks to identify what experimentation is and what are its main functions. Experimentation is the core of creativity and its main catalyst, as it transcends the stereotypical and static aspects in the form and themes of the traditional novel. After all, the novel is the most extended and renewable form of literature. In the structure and content of narrative discourse, experimentation also intends to deviate from the paradigm, to depart from the authority of the sanctities, to raise questions, to destabilize the constants, and in so doing creates a new aesthetic thought. Furthermore, this study also aims to analyse the technical procedures that enhance the anecdotal text, through the analysis of Jabalu Al-Zumurrud "The Emerald Mountain" by the Arab female author, Mansoura Ez El-Din. It is a philosophical novel whose narrative component and anecdotal structure abound with aesthetic qualities, and it is a creative combination of realism and exoticism. It is also a counter-epic narrative to the classical Arabic work Alf laila wa laila (A thousand nights and a night), a novel in which, the narration, the nights and mystic contemplation are intertwined. From this point of view, this research further aims to discover the techniques of experimentation that shaped the narrative imagination and resulted in drastic changes in the narrative vision, scope, and structure of the Arabic novel
Enhancing Fusarium oxysporum tolerance in Phaseolus vulgaris: Isolation and characterization of bacterial endophytes
No full textResearch surrounding microbial biocontrol has garnered considerable attention in the last few years due to the numerous advantages as opposed to synthetic agrochemicals. Phaseolus vulgaris is an important legume that is cultivated worldwide, especially in third-world countries. The growth and yield of this crop are often severely limited by the pathogen Fusarium oxysporum. The aim of the study is to investigate the biological control potential of six plant bacterial isolates against F. oxysporum, both in vitro and in vivo. Six bacterial endophytes were isolated from Ledebouria ovatifolia leaves (E1), Solanum dulcamara leaves (E2), Cortalaria retusa leaves (E3), Euphorbia prostrata roots (R1), Solanum nigrum roots (R2), and Helichrysum splendidum roots (R3). These isolates were characterized for any biocontrol activity they might have against F. oxysporum PPR1. Isolation, characterization, identification, and biocontrol antagonistic assays were carried out in vitro against F. oxysporum, following standard protocols. The isolates were identified using 16S rRNA gene PCR sequencing. A phylogenetic analysis indicated that the leaf isolates displayed a close relationship with Bacillus altitudinis (E1), Streptomyces bikiensis strain SBM (E2), and Pseudomonas rhodesiae (E3). Root isolates displayed a close relationship with Enterobacter kobei (R1), Enterobacter sp. (R2), and Pseudomonas sp. strain (R3). Five out of the six isolates exhibited catalase activity and zinc solubilization activity, whereas all isolates exhibited siderophore production activity. Most of the tested isolates were able to produce the extracellular hydrolytic enzymes protease and amylase. The isolates exhibiting the highest hydrolytic enzyme activities were able to significantly inhibit F. oxysporum growth in vitro. E. kobei exhibited the most promising plant growth-promoting activity, hydrolytic enzyme activity, F. oxysporum antagonism, and increased seedling growth of P. vulgaris. These results suggest that E. kobei represents a good biocontrol candidate against F. oxysporum. The ability of this bacterial isolate to colonize and its promising biological activities suggest it has enormous potential to be used as both a biopesticide and plant growth stimulator
Enhancing schools’ responsibility for promoting health and wellbeing from a pro-active, transformative perspective: a participatory-process-orientated approach
No full textIn the Care and Support for Teaching and Learning (CSTL) Conceptual Policy Framework, an integrative framework for the development of inclusive, rights-based schools, health promotion is identified as a key priority area. In the South African context, health promotion in schools has been foregrounded since 1999 and in 2012 the Integrated School Health Policy was developed. The application of the whole-school approach has made a valuable contribution to address health issues and create awareness of preventative interventions. However, schools are not equipped to take responsibility for the promotion of health and wellbeing from a pro-active and transformative perspective. In response to this limitation, participatory action research was conducted to establish how the the development of a holistic school wellbeing (HSWB) process aimed at enhancing health and wellbeing from a pro-active and transformative perspective, enabled six South African schools to sustain this process over a period of seven years. In this article, the development of the HSWB process is described and presented as as a basis for indicating what a participatory- process-orientated approach aimed at enhancing schools’ responsibility to promote health and wellbeing from a pro-active transformative perspective, could encompass
Exploring Paenibacillus terrae B6a as a sustainable biocontrol agent for Fusarium proliferatum
No full textThe reliance on chemical fungicides for crop protection has raised environmental and health concerns, prompting the need for sustainable and eco-friendly alternatives. Biological control, using antagonistic microorganisms like Paenibacillus terrae B6a, offers an eco-friendly approach to managing disease causing phytopathogens. The objective of the study was to assess the efficacy of P. terrae B6a as a biocontrol agent against Fusarium proliferatum PPRI 31301, focusing on its in vitro antagonistic activity, its impact on fungal morphology and enzymatic content, and its ability to mitigate pathogen-induced stress in maize plants. In vitro antagonistic activity of B6a against F. proliferatum was carried out using standard protocol. In planta assay was carried out by bio-priming of maize seeds with 1 × 106 CFU/mL of B6a and infected with F. proliferatum for 7 days. Biochemical, enzymatic and antioxidants activities of bio-primed maize roots under F. proliferatum infection was carried out using spectrophotometric methods. In vitro antagonistic assays using dual culture and intracellular crude metabolites inhibited 70.15 and 71.64%, respectively, of F. proliferatum. Furthermore, B6a altered the morphology and mycelia structure of F. proliferatum under High resolution scanning electron microscopy (HR-SEM). This was supported by an increase (p < 0.05) in the chitin contents (48.03%) and a decrease (p < 0.05) in the extracellular polysaccharide content (48.99%) and endo-β-1,4-glucanase activity (42.32%). The infection of maize seeds with F. proliferatum resulted in a significant decrease (p < 0.05) in root lengths (37%). Relative to the control and the infected seeds, bio-priming with B6a shows a significant increase (p < 0.05) in the root lengths (44.99%), with a significant decrease (p < 0.05) in reactive oxygen species (ROS)-induced oxidative damage. In conclusion, P. terrae B6a may be a good biocontrol candidate and may be formulated into a bio-fungicide to control F. proliferatum and other related phytopathogens in economically important crops
Mass mortality of African Penguins (Spheniscus demersus) caused by Cape honeybees (Apis mellifera capensis)
No full textThe African Penguin (Spheniscus demersus) is a seabird endemic to southern Africa and is currently classified as critically endangered, with fewer than 10,000 breeding pairs left in the wild. Sixty-four African Penguins were found dead at a mainland colony in South Africa in September 2021 after being attacked by Cape honeybees (Apis mellifera capensis), a subspecies endemic to the southern coast of South Africa. An additional adult penguin was found alive with red-stained urine and died shortly after rescue. Post-mortem examination revealed bee stingers embedded in featherless facial areas, accompanied by localised erythema and swelling. The number of stingers ranged from 2 to 35 per penguin (on average 3.5 ± 2.7 stingers/kg in adult males and 4.1 ± 3.6 stingers/kg in adult females), suggesting the species may have a low tolerance to bee venom. Internal lesions were consistent with those previously reported in bee envenomation in other birds and mammals, including severe pulmonary congestion and oedema, systemic shock, and acute kidney injury. The
cause of the bee attacks remains unclear but may relate to disturbance by humans or penguins. Habitat degradation and proximity to human activity can increase the risk of bee attacks. Management strategies should include buffer zones for beekeeping, removing or relocating highrisk hives, and educating residents about the risks of beekeeping near colonies. Understanding the drivers of bee defensiveness will be important to prevent further incidents and ensure this endemic bee subspecies does not become an added threat to the African Penguin
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No full textA collection of digitised photographs taken at the University of the Western Cape in Bellville, South Africa, c1991
Land use and land cover changes in sub-catchments of Zimbabwe and their implications on wetland and catchment soil water conditions
No full textThis study evaluated land use and land cover changes in the Shashe and Tugwi and Zibagwe sub-catchments from 2017 to 2023, with a focus on their impacts on dry season wetland extent and condition. Utilizing the Google Earth Engine Cloud Computing platform, Sentinel-2 Level 1C data were processed using Support Vector Machine (SVM) classification algorithm to analyse these changes. The Soil Moisture Active Passive level 4 (SMAP L4) soil moisture and the Normalised Difference Vegetation Index (NDVI) were computed to determine the influence of catchment level land cover change on soil moisture conditions. This study considered the influence of land cover on wetland conditions and catchment level soil moisture levels which got minimum attention in previous wetland studies. The study highlights that bare land in Tugwi and Zibagwe increased more rapidly (601.1 %) than in the drier Shashe sub-catchment. However, the wetland area decreased more in Shashe, indicating greater wetland degradation despite the slight difference (0.4 %). The analysis revealed that wetlands experienced an overall 11.8 % loss in Shashe and 11.4 % loss in Tugwi-Zibagwe. Results indicate that 5.2 %, 3.4 % and 2.3 % of the wetland area was replaced by grassland, shrubland and bare land respectively in Tugwi and Zibagwe combined whilst 4.8 %, 3.6 % and 2.32 % of the wetland area were replaced by bare land, grassland and shrubland respectively in Shashe. Statistically significant weak positive correlations were confirmed between soil moisture and NDVI in Tugwi and Zibagwe combined (r = 0.28; p = 0.04) and Shashe (r = 0.43; p = 0.02). Rainfall had stronger correlation with soil moisture in Tugwi and Zibagwe (r = 0.43; p = 0.19) and Shashe (r = 0.62; p = 0.38) which were not statistically significant indicating more influence of land cover on soil moisture than rainfall. The findings accentuate the critical need for sustainable land use practices to mitigate the adverse effects on natural land cover and wetland ecosystems. The rapid expansion of bare land and reduction in wetlands underscore the pressing challenges posed by land cover changes, particularly in regions experiencing increasing aridity. •Land use and cover changes in the three sub-catchments are assessed.•The influence of land cover change on wetland extent and soil moisture conditions are analysed.•The relationship between root zone soil moisture and rainfall and land cover change is analysed