Academy of Science of South Africa (ASSAf): Open Journal Systems
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Mosquito community composition in Central District, Botswana: insights from a malaria endemic to non-endemic gradient
No full textSpatial distribution of vector mosquitoes plays a critical role in the dynamics of associated diseases’ spread across diverse landscapes. In Botswana, six Districts are implicated as malaria endemic zones, one of which is the Central District comprising both malaria endemic and non-endemic sub-districts. Despite being the biggest in the country, mosquito diversity in this District is under-explored, more so in the malaria non-endemic sub-districts. Here, we thus sampled mosquito adults and larvae from the malaria endemic sub-district of Bobirwa and non-endemic sub-districts of Palapye and Serowe, to determine spatial mosquito abundance and diversity in the District. Overall, all the sub-districts had a representation of key mosquito taxa of medical and economic importance (Aedes, Culex and Anopheles), irrespective of malarial endemicity status. Bobirwa had the highest number of mosquitoes sampled (429) although the greatest species richness (0.8511) was observed from Palapye. Moreover, Palapye also recorded a species from another genus, Culiseta longiareolata, a known natural vector of avian malaria parasites. Given global climate shift projections for the region, there is a need for continuous area-wide surveillance for vector mosquitoes and associated parasites in curbing the risk of emerging and re-emerging infections. While the Anopheles-centric approach to mosquito control is still necessary, a holistic approach, incorporating other vector incriminated mosquito species is warranted, particularly given shifting climates and the presence of invasive disease associated vector mosquito species
Formulation of eucalyptus oil-zinc sulfide hybrid nanoemulsion and evaluation of its larvicidal potential against Aedes aegypti
No full textThe growing threat of vector- borne diseases and environmental pollution has prompted the nanotechnology based investigations. The present study aimed to use one of the nanotechnological applications with larvicidal potential against Aedes aegypti by preparing aqueous hybrid nanoemulsion of zinc sulfide nanoparticles and Eucalyptus globulus oil. The mean droplet size of prepared and most stable hybrid nanoemulsion (9.5 ppm) was found to be 60±10.00 nm with rectangular shape. The hybrid nanoemulsion exhibited LC50 and LC90 values of 7.63 and 9.22 ppm respectively against larval stages of Aedes aegypti. The findings obtained from the larvicidal assay were corroborated with SEM, histological and biochemical profiles of Aedes larvae after treating with hybrid nanoemulsion. Under simulated conditions, nanohybrid treatment demonstrated optimum larvicidal potency after 48 hrs of exposure. Further, biosaftey studies of hybrid nanoemulsion were carried out against Scapholebris kingi and this larvicidal concentration of nanohybrid was found to be non-toxic to this species. Thus, the following research explains the larvicidal efficacy of zinc sulfide based hybrid nanoemulsion of eucalyptus oil formulated during the present study is a step towards safe and efficient approach against dengue spreading vector mosquito, Aedes aegypti
Consent and Other Ancillary Matters as Requirements of a Customary Marriage: LNM v MMM (2020/11024) [2021] ZAGPJHC 563 (11 June 2021):
No full textConsent may be seen as a fundamental human right. On the issue of marriage, people should only be married with their consent. A marriage without consent is a forced marriage. Section 3(1)(a)(ii) of the Recognition of Customary Marriages Act 120 of 1998 not only requires consent, but also requires specific consent for a marriage to take place under customary law. The Act is clear that consent to being married under customary law is one of the requirements for validity. If specific consent is lacking, there cannot be a valid customary marriage. This case note focusses on the decision in LNM v MMM where specific consent was one of the issues. It discusses whether consent of the guardian is still a requirement for customary marriages under the Act. It also discusses the required specific consent in detail and then considers the form that specific consent should take, noting that specific consent should not be inferred from the act of negotiating and delivering ilobolo as African people do for a civil marriage. In LNM v MMM the court also held that the handing over of the bride is "not imperative". By this, the court meant that the handing over of the bride was an unnecessary custom. This is not in accordance with the cases referred to in the judgment. This case note will respond to this. Should a customary marriage without specific consent to marry under customary law be annulled
Data sharing: A Long COVID perspective, challenges, and road map for the future
No full text‘Long COVID’ is the term used to describe the phenomenon in which patients who have survived a COVID-19 infection continue to experience prolonged SARS-CoV-2 symptoms. Millions of people across the globe are affected by Long COVID. Solving the Long COVID conundrum will require drawing upon the lessons of the COVID-19 pandemic, during which thousands of experts across diverse disciplines such as epidemiology, genomics, medicine, data science, and computer science collaborated, sharing data and pooling resources to attack the problem from multiple angles. Thus far, there has been no global consensus on the definition, diagnosis, and most effective treatment of Long COVID. In this work, we examine the possible applications of data sharing and data science in general with a view to, ultimately, understand Long COVID in greater detail and hasten relief for the millions of people experiencing it. We examine the literature and investigate the current state, challenges, and opportunities of data sharing in Long COVID research.
Significance:
Although millions of people across the globe have been diagnosed with Long COVID, there still exist many research gaps in our understanding of the condition and its underlying causes. This work aims to elevate the discussion surrounding data sharing and data science in the research community and to engage data sharing as an enabler to fast-track the process of finding effective treatment for Long COVID
Public health research using cell phone derived mobility data in sub-Saharan Africa: Ethical issues
No full textThe movements of humans have a significant impact on population health. While studies of such movements are as old as public health itself, the COVID-19 pandemic has raised the profile of mobility research using digital technologies to track transmission routes and calculate the effects of health policies, such as lockdowns. In sub-Saharan Africa, the high prevalence of cell phone and smartphone use is a source of potentially valuable mobility data for public health purposes. Researchers can access call data records, passively collected in real time from millions of clients by cell phone companies, and associate these records with other data sets to generate insights, make predictions or draw possible policy implications. The use of mobility data from this source could have a range of significant benefits for society, from better control of infectious diseases, improved city planning, more efficient transportation systems and the optimisation of health resources. We discuss key ethical issues raised by public health studies using mobility data from cell phones in sub-Saharan Africa and identify six key ethical challenge areas: autonomy, including consent and individual or group privacy; bias and representativeness; community awareness, engagement and trust; function creep and accountability; stakeholder relationships and power dynamics; and the translation of mobility analyses into health policy. We emphasise the ethical importance of narrowing knowledge gaps between researchers, policymakers and the general public. Given that individuals do not really provide valid consent for the research use of phone data tracking their movements, community understanding and input will be crucial to the maintenance of public trust.
Significance:
Mobility data derived from cell phones are being increasingly used for health research and public health purposes in sub-Saharan Africa, with minimal individual consent and largely without public awareness.
While such data can have significant potential public health benefits, risks and concerns related to their collection and use in sub-Saharan African contexts have not been widely discussed.
Innovative community engagement initiatives, which are appropriate and responsive to sub-Saharan African contexts, need to be developed to address ethical challenge areas and help warrant public trust in mobility research
Neoplastic tissue transfiguration in vivo by recombinant human transforming growth factor-β3
Full text linkHuman oral squamous cell carcinomas (hSCCs) are the most common head and neck cancers now presenting with more aggressive biological and clinical features due to smoking and alcohol together with widespread viremia. Transforming growth factor-β (TGF-β) proteins are powerful morphogens that induce rapid and substantial induction of endochondral bone formation but in primates only
The effect of pollution on the competitive dynamics of Anopheles arabiensis Patton, 1905 and Culex quinquefasciatus Say, 1823 (Diptera: Culicidae)
No full textCulex quinquefasciatus Say, 1823 and Anopheles arabiensis Patton, 1905 (Diptera: Culicidae) are often found breeding in the same water sources and engage in interspecific competition. Although Cx. quinquefasciatus is known to proliferate in a range of polluted environments, the ability of An. arabiensis to proliferate in polluted water has only been reported relatively recently. The effects of pollution and insecticide resistance on this competitive interaction are unknown. This study examined the effect of pollution on the dynamics of the interspecific competition. Three laboratory strains were used in this study: an insecticide susceptible and an insecticide resistant An. arabiensis, and an insecticide resistant Cx. quinquefasciatus. Larval pollutant tolerances of each strain were assessed and compared by determining the lethal concentration at 50% mortality (LC50). The larvae from each strain were exposed to either inorganic fertiliser or copper nitrate, following which eclosion success was assessed. The results showed that the insecticide resistant strains had higher emergence rates when reared in polluted conditions without competition, with the Cx. quinquefasciatus strain showing the highest rate of eclosion. This species also had a higher tolerance for metal pollution than the An. arabiensis strains. The effects of pollutants on oviposition choice were examined. Pollution altered adult oviposition choice. The effect of larval metal exposure had variable effects on the activity of metabolic detoxification enzymes. An insecticide resistant phenotype had greater tolerance to pollutants and possibly developmental advantages based on a variable detoxification response to the pollutant. Pollution can therefore alter interspecific competition dynamics between the malaria vector An. arabiensis and Cx. quinquefasciatus.
Judicial Review of the Enforcement of Sectional Title Rules: Administrative Action or Common-Law Review? Trustees for the time being of the Legacy Body Corporate v Bae Estates and Escapes (Pty) Ltd
No full textIn Bae Estates and Escapes (Pty) Ltd v Trustees for the time being of the Legacy Body Corporate 2020 4 SA 514 (WCC) the Supreme Court of Appeal (SCA) considered a resolution by the trustees of a sectional title scheme that an estate agent Bae Estates and Escapes was not allowed to enter or exercise any economic activities in the scheme. The resolution was based on a conduct rule which enabled the trustees to disallow specific estate agents to sub-let units in the scheme on a short-term basis. The Western Cape Division of the High Court found that the resolution was unlawful, wrong, procedurally unfair and arbitrary and therefore reviewable. The High Court considered two requirements of the definition of "administrative action" in the Promotion of Administrative Justice Act 3 of 2000 (PAJA) and held that the resolution of the trustees constituted administrative action in terms of PAJA and was as such reviewable under PAJA.
On appeal the Supreme Court of Appeal considered whether the trustees' conduct should be considered an administrative act reviewable under PAJA or alternatively be reviewed under the common law in terms of section 33 of the Constitution. After analysing the three requirements of administrative action to determine whether the conduct of the trustees had to be determined under PAJA, the SCA held that the conduct of the trustees did not fulfil any of these requirements and reviewed their conduct under the common law.
In this case note the three requirements for administrative action are discussed in view of the special nature of the body corporate and the rules of a sectional title scheme. The body corporate is a statutory juristic person that is automatically established on the opening of a sectional title register and therefore not consensual in nature, like common law clubs, companies or retirement schemes. Furthermore, its rules are regarded as the product of the quasi-legislative function of a statutory body, which rules must be approved by the Ombud Service for Community Schemes before the opening of the sectional title register. Although the outcome of the judgment would have been the same, the juridical basis would have been more accurate if the SCA had taken into consideration the special nature of a sectional title scheme, which brings the conduct of the trustees within the ambit of administrative action under PAJA