Academy of Science of South Africa (ASSAf): Open Journal Systems
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In vitro liquid mass production of a South African isolate of Heterorhabditis zealandica
No full textDeveloping repeatable protocols for the in vitro liquid mass production of entomopathogenic nematodes (EPNs) is a difficult task and depends on the nematode species being cultured. Of critical importance is the establishment of a monoxenic population of nematodes as a stock culture for optimisation and experimental purposes. Establishing a new stock inoculum culture flask of pure infective juveniles (IJs) is challenging, particularly for the Heterorhabditis species, due to their affinity for developing into an amphimictic second generation that does not copulate in liquid culture flasks. Developing mass production protocols for multiple EPNs is advisable because different pest insects are susceptible to different species of EPN. This study attempted to mass-produce a South African isolate of Heterorhabditis zealandica and its symbiotic bacteria, Photorhabdus thracensis, using in vitro liquid culture technology methods previously developed for Steinernema species. The results indicate that the pre-culture protocols developed for Steinernema species are applicable to a H. zealandica isolate. Moreover, the results, in terms of the protein source optimisation experiments, confirm that different EPN species have different culture conditions and nutrient requirements, with H. zealandica seeming to prefer soy-based protein instead of egg yolk, having higher recovery and producing more hermaphrodites, using soy protein. This study illustrates the importance of developing dependable and infallible preculture methods, prior to the flask mass production process
SA Rugby Injury and Illness Surveillance and Prevention Project (SARIISPP): The Currie Cup Injury Surveillance Report 2022
Get PDFThe content of the report is based on data collected by the SA Rugby Injury and Illness Surveillance and Prevention Project (SARIISPP) steering group
Antibiotics in water bodies, cyanobacterial toxicity and odorous compounds release: a review
No full textThe present study aimed to propose a new cause of odorous compounds release, i.e., the presence of antibiotics in water bodies and its toxicity to cyanobacteria, known to be the main producer of geosmin (GEO) and 2-methylisoborneol (2-MIB). Therefore, a literature review was carried out regarding the problems caused by antibiotics in aquatic environment, including cyanobacterial blooms and GEO and 2-MIB release. In addition, a bibliometric analysis was performed using the VOSviewer software based on the results obtained from the Web of Science (WOS) database. This review aims to build a scientific understanding of the problem, presenting interesting points that converge with the proposed association. It is worth mentioning that no work has been found in the literature that has proposed this relationship. Thus, based on the bibliographic survey, observations and information acquired in recent years about cyanobacterial blooms and environmental contamination by pharmaceutical drugs, one of the main causes of an earthy and musty flavour and odour in a drinking water supply is the toxicity imposed by the presence of antibiotics in aquatic environments on cyanobacteria
Professor Willemien du Plessis: a Personal Reflection
No full textA personal dedication to Prof Willemien du Plessis
Diversity of insect pests of common bean and pigeon pea in the Republic of Congo revealed by DNA barcoding
No full textIn Central Africa, the development of leguminous crops is accompanied by a proliferation of pests, such as seed-beetles (Coleoptera: Chrysomelidae: Bruchinae). Integrated biological control against insect pests requires a preliminary phase of early detection and monitoring of potential invasive species, which is often limited by the availability of diagnostic morphological characteristics. DNA barcoding represents a powerful molecular tool for identifying specimens, and the mitochondrial sequences produced can provide information concerning the origins of introduced species. In this study, we characterized the diversity of insect pests present in farmer storage sites and plots of common bean and pigeon pea, by using DNA barcoding of specimens sampled in the five main agricultural regions of the Republic of Congo. The cosmopolitan seed-beetle species Acanthoscelides obtectus (Say, 1831) (Coleoptera: Chrysomelidae: Bruchinae) was recognized as the major pest sampled on common bean. The sub-Saharan species Specularius erythraeus (Pic, 1908) (Coleoptera: Chrysomelidae: Bruchinae) was the main species found in pigeon pea plots, sometimes co-occurring with the cosmopolitan species Callosobruchus maculatus (Fabricius, 1775) (Coleoptera: Chrysomelidae: Bruchinae). A fourth bruchine, Zabrotes subfasciatus (Boheman, 1833), and two moth species were also recognized: a species of the genus Mussidia Ragonot, 1888 (Pyralidae) and the cosmopolitan pest of stored food, Cadra cautella (Walker, 1863) (Pyralidae). These results differ from species lists compiled in the 1980s, thus providing updated knowledge concerning the pest species present in this region and fundamental information for choosing appropriate methods of control
JUDICIAL REVIEW IN SOUTH AFRICA AND INDIA: ADVANCING CONSTITUTIONALISM OR UNDUE ACTIVISM?
No full textThe Supreme Court of India and the Constitutional Court of South Africa, as apex courts, also function as guardians of the constitutions of each respective country. This article seeks to establish the extent to which judicial review in India and South Africa can be said to be more aligned with constitutionalism or undue activism. An assessment of the aforesaid is determined with regard to the transformative and progressive constitutional interpretation approach adopted by the aforesaid courts which also gives impetus to the living tree doctrine, the role that dignity plays in giving substantive meaning to democracy, ineptitude, and or corruption on the part of the executive precluding the effective realisation of socio-economic rights as well as parliament’s failure to hold members of the executive to account. The extent to which constitutionalism, as opposed to undue activism, has been advanced by the aforesaid courts is demonstrated with reference to specific cases
THE MANTLE OF THE SHOP STEWARD IS NOT AN EASY ONE TO WEAR NUMSA obo Motloba v Johnson Control Automotive SA (Pty) Ltd (2017) 38 ILJ 1626 (LAC) Revisited
No full textNUMSA obo Motloba v Johnson Controls Automotive SA (Pty) Ltd (2017) 38 ILJ 1626 (LAC) (Motloba) raises four discrete, yet interrelated issues that require close examination. The first relates to the constitutional and statutory protection accorded to trade union membership and activities. The second engages the exercise of organisational rights in the workplace. With the demise of the duty to bargain, created to breathe life into collective bargaining and provide the lifeblood to recognised trade unions in the workplace. The third brings to the surface the recurrent headache for management concerning the dual and contradictory role of the shop stewards on the shop floor. The point of immediate relevance is that, while conducting union activities, a shop steward in theory, at least, operates on equal footing with management. It merits emphasising that the theory becomes murky when the union official is also an employee. (Re Workers’ Compensation Board and Workers’ Compensation Board Employees Union (1990) 15 LAC (4th) 332, 335). Put simply, “the ordinary rules applicable to the normal employer-employee relationship are then somewhat relaxed” (FAWU v Haverstime Corporation (Pty) Ltd [2007] BLLR 638 (LC) par 42 (Haverstime)). Be that as it may, a shop steward is still an employee of a company with the usual obligation to conform to all workplace rules.Fourth, and possibly most important, shop stewards’ propensity for an “anything goes approach” in their dealing with management. The contentious issue encountered here concerns the tendency of shop stewards to exceed the bounds of acceptable conduct in fulfilling their representational responsibilities. As a result, trade union representatives have been disciplined and in extreme cases dismissed for misconduct. Accordingly, the marginal line separating insubordination and insolence, the interconnected acts of intimidation and assault, disruptive conduct in the course of collective bargaining process, misconduct at disciplinary or arbitration proceedings as well as the breakdown of the trust relationship and intolerability occasioned by dishonesty deserve critical scrutiny
Is the Writing on the Wall for the Genetic Link Requirement in Surrogacy Agreements?
No full textFor a valid surrogate motherhood agreement, section 294 of the Children's Act 38 of 2005 provides that the child born of the surrogacy arrangement must be conceived with the gamete of at least one of the commissioning parents. This ensures that a genetic link exists between a commissioning parent and the resultant child. In 2015, in the case of AB v Minister of Social Development 2016 2 SA 27 (GP), the constitutionality of the impugned provision was successfully challenged in the High Court; however, the applicant failed to convince the majority in the Constitutional Court (AB v Minister of Social Development 2017 3 SA 570 (CC)) that the removal of the genetic-link requirement would be in the resultant child's best interests. In 2023 another "double-donor" surrogacy matter is set to be decided by the High Court. The applicant's situation raises the question of whether the genetic-link requirement between commissioning parents and the resultant child should be extended to include a "sibling link". This would be applicable in situations where parents will lack a genetic link with the resultant child, but the child will still share a genetic link with an existing sibling. This article assesses the merits of the "sibling link" argument by considering the latest psychological evidence. This evidence confirms that donor-conceived surrogate children are well-adjusted and exhibit high self-esteem, despite lacking a biological and gestational link to their parents. It is argued that the reading in of a "sibling clause" into section 294 may be too narrow, and instead a reading in of a sentence that will allow the court "on good cause shown" to dispose of the genetic link requirement should be preferred