Academy of Science of South Africa (ASSAf): Open Journal Systems
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Effects of leachate concentration, carbon dioxide and aeration flow rate on chlorophyll and carotenoid productivity and bioremediation potential of the microalga Chlorella minutissima
No full textThe use of microalgae cultures to process effluents from industries, leachates, and tanneries, among others, quantified by the reduction of metallic materials in the medium and the reduction of chemical oxygen demand (COD), helps reduce the environmental impact caused by human development. In addition, with the growth of the culture, it is possible to produce a significant amount of chlorophyll, a carotenoid of high value in the cosmetics and food industries that are used as a natural pigment. In this context, this work presents a study conducted to verify the bioremediation and chlorophyll production potential of the cultivation of the microalgae Chlorella minutíssima, using the Taguchi method. The microalgae Chlorella minutissima has given good results in the bioremediation of leachate, as a mean reduction of 33% in COD was obtained, as well as a 92% reduction in the toxic components. In addition, statistical analysis revealed that the four process factors were significant factors for chlorophyll a, chlorophyll b and carotenoid productivity (p < 0.05). Finally, it was observed that the maximum chlorophyll a (111.9 ± 0.8 mg‧L−1‧d−1), chlorophyll b (66.1 ± 1.7 mg‧L−1‧d−1), and carotenoid (31.9 ± 0.03 mg‧L−1‧d−1) values obtained occurred in Experiment 8, which is closer to the ideal conditions identified by statistical analysis, revealing the effectiveness of the use of the Taguchi method for the design of experiments
A timely, deeper, and complex analysis of dysfunctionality in South African public universities
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A 30-year Review of Ameloblastoma: A tertiary hospital-based study
Get PDFIntroduction
The clinical, histological and radiographic presentation of ameloblastoma is well described in literature. This odontogenic tumour commonly affect the mandible, locally aggressive and destructive resulting in disfigurement. It arises from dental tissues at various phases of tooth development. They are generally asymptomatic, slow growing, locally invasive and rarely malignant with a high recurrence rate.
Objective
To test the hypotheses that ameloblastomas were predominant in the mandible. among black Africans, male and the young.
Study Design
Retrospective review of ameloblastoma cases spanned between 1991 and 2022.
Methods
Data analysis was based on 185 histologically confirmed cases. Appropriate descriptive and inferential statistics were undertaken on, age, gender, clinical, radiographic and histological characteristics.
Results
The average age was 28.81 (14.53), ranging between 3-75 years. The overall male to female ratio stood at 1.18:1. Ameloblastomas were prevalent in the mandible 174(94.1%), diagnosed as conventional variant 155(83.7%) and acanthomatous subtype. Radiographically, the lesions appeared as multilocular 97(55.4%), radiolucent 100(54.1%) and expansile 129(67.7%). The average size of the lesions was 77.43 ± 33.83 mm, with a range of 184 mm.
Conclusion
Our results validate the hypothesis that ameloblastoma is highly prevalent among black Africans of younger age. The radiographic, clinical, and histological characteristics of ameloblastoma in our population are comparable to the vast literature
Effect of separated instruments on periapical pH using calcium hydroxide as an intracanal medicament in curved root canals: Separated instruments and pH
No full textObjective: To evaluate the effect of intracanal separated instruments with different lengths on periapical pH levels using calcium hydroxide (CH) as an intracanal medicament in curved root canals.
Materials and Methods: 120 teeth (root canal curvature >25˚) were divided into six groups following the root canal preparation. In Group 1, 2 mm and in Group 2, 4 mm NiTi instruments were separated in the apical portion of the root canals and CH paste was applied. In Groups 3 and 4, no separated instrument but CH was applied. In Groups 5 and 6, neither a separated instrument nor CH. The samples were placed inside a glass tubes with distilled water. pH of this distilled water was measured at different time-points.
Results: At all-time points, pH values between the experimental groups were similar except at 1-day (Group 1 < Group 2, P<0.05). At the 2-day and 30-day time points, Group 3 showed higher pH values than Group 1 (P<0.05). At 7-day and 14-day points, pH values were similar.
Conclusions: The presence of a separated instrument with different lengths in curved root canals did not have a significant effect on the pH increase caused by CH used as an intracanal medicament
A checklist of the dacine fruit flies (Diptera, Tephritidae, Dacinae) of Mozambique
No full textHere we present a checklist of all records of dacine fruit flies (Diptera: Tephritidae: Dacinae) from Mozambique, based on verified specimen records in natural history collections and literature records. In total, 57 Dacinae species are recorded from Mozambique, of which only one is considered endemic. This relatively low species diversity compared to other African countries appears to be related to incomplete sampling. For each species the localities from which it was recorded are given (including geocoordinates), or a general distribution is provided. The checklist is discussed briefly in terms of species richness, endemism and geographic distribution
PROTECTING THE RIGHT TO IDENTITY AGAINST CATFISHING: WHAT’S THE CATCH?
No full textCatfishing is a common social media phenomenon affecting a person’s right to identity. It involves using a person’s image without their consent to create a fake social media profile. Catfishing has legal implications because a person’s image is a facet of the right to identity and using an image without a person’s consent interferes with their right to identity and dignity. While catfishing is a novel legal issue in South Africa, courts and legislators in the United States (US) have addressed catfishing. In the US states of California and Oklahoma, catfishing is tackled through statutory interventions directed at online impersonation and catfishing. Accordingly, victims of catfishing have remedies in addition to the existing causes of action related to common-law torts and breaches of the right to publicity. This comparative study analyses the remedies available to US victims of catfishing to ascertain whether South African victims have adequate statutory and common-law remedies against catfishing, to protect their identity from interference with their subjective right, and from assaults to their dignity
DOMAIN NAME PROTECTION IN SOUTH AFRICA
No full textThis paper investigates the legal mechanisms that are available when one is dealing with domain name disputes. It describes the domain name system and contrasts this with other forms of intellectual property. The different types of domain name conflicts are discussed and the legal measures available for protection of domain names as intellectual property are highlighted. Reference is made to national protection measures such as the Trade Marks Act 194 of 1993 and common law protection of intellectual property. Certain international legal mechanisms such as the World Intellectual Property Organisation’s rules with regard to online domain name dispute resolution and the United State’s Anticybersquatter Consumer Protection Act of 1999 are also discussed as these measures have a direct influence on some domain names of South African businesses. Lastly the changes to domain name dispute resolution procedures envisaged by the Electronic Communications and Transactions Act 25 of 2002 are discussed.Since the advent of e-commerce a new species of highly valuable intellectual property has developed. Although there are remarkable similarities between domain names and “common law trade marks” and trade marks protected by the Trade Marks Act 194 of 1993 there are also important differences, which cause uncertainty and confusion when disputes involving domain names arise. These differences flow mainly from the unique characteristics of domain names. The purpose of this note is to investigate the domain name system as it is used in South Africa, to compare domain names and trade marks, and to look at the protection mechanisms which an aggrieved party may have at his or her disposal if he should find that his business name or trade mark (or something similar) is being used by a domain name registrant in a way that conflicts with his interests. In addition, a short comparison of how these problems are addressed by the international community, particularly the USA and Britain, will be made
COVID-19, kovhidhi, dzihwamupengo: Language use, language change, and pandemic perceptions among Shona-speakers in Gweru, Zimbabwe
No full textThrough an examination of the linguistic practices encountered and used by Shona language-speakers in the Zimbabwean city of Gweru, this study explores intersections between language use, language change, and perceptions of the COVID pandemic—as caused by the virus referred to by Gweru’s Shona-speakers as, variously, “COVID-19” in its English-language representation or “kovhidhi” or “dzihwamupengo” in its two most common Shona-language representations. The study is anchored in conceptions of the impacts that natural disasters and pandemics have on language and on communication needs, and in theories of semiotics and language change. The research finds that the predominant terms used by Gweru’s Shona-speakers in relation to the pandemic carry connotations that, in the Zimbabwean socio-cultural context, potentially undermine optimal responses to the pandemic. The article concludes by emphasising the importance of careful management of language as a critical resource in the fight against natural disasters and pandemics
Getting Ahead of the 'Game': The Reclassification of Wild Animals Contained in Protected Areas as Res Publicae"
No full textThe common law "escape rule" determines that if a wild animal escapes from its controlled environment and reverts to its natural state of freedom, it is res nullius and may be acquired by another party by occupatio. To place the owners of game in a more favourable position when their game escapes from its enclosure, the aforementioned common law rule was amended by the Game Theft Act 105 of 1991 (GTA). Sections of the Game Theft Act 105 of 1991 came under discussion in Eastern Cape Parks and Tourism Agency v Medbury (Pty) Ltd (Wildlife Ranching South Africa amicus curiae) 2016 4 SA 457 (ECG) and later in Eastern Cape Parks and Tourism Agency v Medbury (Pty) Ltd t/a Crown River Safari 2018 4 SA 206 (SCA). Two separate issues came before the courts. First, whether a certificate in terms of section 2(2)(a) of the GTA is a prerequisite for the operation of section (2)(1)(a) of the GTA; and second, whether the common law must be developed to provide that wild animals that are sufficiently contained in a protected area managed by an organ of state charged with the management thereof in terms of relevant nature conservation legislation in order to promote conservation, are res publicae owned by such organ of state. Neither one of the cases thoroughly considered the second issue before the court. Therefore, the purpose of this contribution is to investigate the possibility of developing the common law to provide that wild animals that are sufficiently contained in a protected area managed by an organ of state charged with the management thereof in terms of relevant nature conservation legislation in order to promote conservation are res publicae owned by such organ of state. In Roman Law res publicae were classified as public things that were out of commerce and intended for public use. They are often referred to as state property, but they belong to the entire civil community and their common interests in these things are safeguarded by the state. This proposed development bears some resemblance to the international environmental law principle known as the public trust doctrine. The public trust doctrine determines that a country's sovereign acts as the guardian of the public interest in natural resources by holding them in trust for the benefit of the nation as a whole. The article provides a theoretical analysis of the proposed development of the common law by exploring (a) the significance of biodiversity conservation and protected areas in South Africa; (b) the application of the GTA in the context of protected areas; (c) the concepts of res nullius, res publicae and the public trust doctrine and (d) the development of the common law in South Africa