Academy of Science of South Africa (ASSAf): Open Journal Systems
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Response of ants, beetles and spiders to disturbance varies among taxa in a South African savannah biome
No full textSavannahs are structurally complex ecosystems consisting of a diverse community of plants and animals such as arthropods. Arthropods are essential in many ecosystem processes that help maintain life on Earth. The anthropogenic conversion of natural landscapes into croplands, residential and industrial areas has a negative impact on surface-active arthropods that have limited dispersal abilities and narrow habitat preferences. This study investigated the effect of disturbance on assemblages of ants, beetles and spiders in the savannah vegetation in Mpumalanga province, South Africa. We compared species richness, abundance and composition of these three taxa between the pristine savannah and the savannah that is exposed to a variety of anthropogenic activities (disturbed savannah). Arthropods were collected using pitfall traps in 15 sites in pristine savannah and 15 sites in disturbed savannah. We found that disturbance affects species richness and abundance of these taxa differently. Disturbance did not affect species richness of spiders and abundance of beetles, while greater species richness of ants and beetles, as well as abundance of ants and spiders was in disturbed than in pristine savannah. Furthermore, the species compositions of all taxa were different between disturbed and pristine savannah. The disturbed savannah had twice more unique indicator species than the pristine savannah. Differences in assemblages of arthropods between pristine and disturbed habitats suggest that it may be important to consider habitats in and outside protected areas in the conservation of arthropods, particularly in areas with greater percentage of natural and semi-natural landscapes occurring outside protected areas
Can Themba: The Making and Breaking of the Intellectual Tsotsi, a Biography (Siphiwo Mahala)
No full textAddressing missed visits to improve retention of young South African women in clinical trials
No full textIn clinical trials, a vital protocol requirement for participants is adherence to scheduled visits. A substantial number of missed visits and the resultant missing data could affect generalisability of the findings and undermine the scientific conclusions. We aimed to investigate the extent of and reasons for missed visits in the Evidence for Contraceptive Options and HIV Outcomes (ECHO) trial in order to optimise recruitment and retention practices. Despite being a multi-country study, we investigated missed visits only at Setshaba Research Centre in Soshanguve, Tshwane, South Africa. Of 810 participants enrolled at Setshaba Research Centre, 94 (11.6%) participants missed visits and 231 missed visits were recorded. Of the 94 participants who missed visits, 53 (56.4%) missed at least two visits; 37 (39.4%) missed three or more visits, and of these, 32 (86.5%) missed at least two visits for the same reason. Overall, the main reasons for missed visits were: participant had to work (60; 26.0%), unable to contact participant (60; 26.0%), participant relocated (32; 13.9%), and participant travelled out of area (23; 10%). The large proportion of participants who missed two or more visits indicates that participants who miss a single visit are likely to miss even more, often for the same reason. Site staff need to be vigilant to detect any trends in missed visits early and innovative in developing personalised strategies to minimise missed visits and retain participants until completion of their scheduled visits.
Significance:
Despite trial site staff developing strategies to minimise missed visits, they will not be able to anticipate all scenarios.
Participants’ work commitments, loss of contact with participants, and participants’ travel/relocation to distant areas were the main reasons for missing visits, and site staff need to consider the potential for these to arise during the course of the study when assessing potential participants at enrolment and at each follow-up visit.
Case report forms designed for multi-country studies should be adapted to reflect the most likely reasons for missed visits for the local situation, so that trends in missed visits can be identified and addressed early
Monitoring seasonal variations of haloacetic acids (HAAS) in low-TOC and low-chlorine networks and assessing risk to public health: Muş, Türkiye case
No full textChlorine not only removes parasitic pathogenic microorganisms in water, but also causes the formation of disinfection by-products (DBPs) that can be carcinogenic to humans, due to reacting with natural organic matter (NOMs) in raw water sources. Haloacetic acids (HAAs) are one of the most well-known and common disinfection by-product groups (DBPs) in the literature. In the risk definitions of the EPA, some of its components have been identified as carcinogenic. Therefore, determination of HAA concentration in water and execution of a risk analysis are very important in terms of determining the possible effects on public health. This study aimed to monitor the seasonal and spatial variations of haloacetic acids (HAAs) in 2 different water supplies (surface and groundwater) serving the city center of Muş Province, Türkiye, and to demonstrate their public health implications. In this context, an analytical study was conducted covering 4 seasons. According to the results, although the amount of NOM in water bodies was less than 1 mg‧L−1, the HAA5 content may occasionally exceed the USEPA limits of 60 µg‧L−1, but did not exceed the Canadian 80 µg‧L−1 limit. When the WHO limit values were examined on a component basis, it was determined that the MCAA concentrations in both water sources sometimes exceeded the limit of 20 µg‧L−1 in the July and October sampling periods. The risk level related to maximum DCAA level in the main network by means of ingestion pathway was found to be 18.7 times higher for women and 16.5 times higher for men when compared with USEPA risk criteria. Also, in the Muratpaşa water network, risk from DCAA exceeds the USEPA risk level 15.2-fold in women and 13.4-fold in men. However, since it was also found that the level of free chlorine in the network does not meet the required level, it should be noted that there may be an increase in the risk level if there is adequate chlorination in the supply
The effect of COVID-19 lockdown on the epidemiology of maxillofacial trauma at tertiary health facilities in Pretoria
Get PDFBackground: COVID-19 restrictions have reduced the number of consultations of patients including Maxillo-facial trauma patients.
Aim: To analyse and compare the epidemiology of maxillofacial trauma during four months of the lockdown period and compare it with the same months from the previous year (2019 and 2020).
Materials and Method: A retrospective record-based study was conducted with data drawn from all maxillofacial trauma patients who presented in the maxillofacial and oral surgery unit, of the University of Pretoria (UP) and Steve Biko Academic Hospital (SBAH) from April to July of 2019 and April to July of 2020. Data collected included age, gender, aetiology of injury, site of injury, severity and extent of injury, fracture pattern and site, waiting period for treatment and month of injury. Chi-square test was used to evaluate the association between variables. The level of significant was set at p ≤ 0.05.
Results: A total of 197 patients were seen in the two institutions with maxillofacial injuries for the years 2019 and 2020 with ages ranging from 1 to 81 years and a mean of 36.24. Most patients were males 167(85%). Many patients were seen in 2019 at 139(71%). There was no association between the fracture site and the aetiology. The mandible was significantly the most common site of injury and more conservative treatment was done as compared to other forms of treatment (p < 0.05).
Conclusion: More Maxillofacial cases were seen in 2019 than in 2020 with more males as compared to females. The majority of injuries were assaults followed by motor vehicle accidents (MVA). The mandible was the common site of injury. More conservative treatment was done compared to other forms of treatment
What’s new for the clinician – summaries of recently published papers
Get PDFPain is an important physiological and emotional experience, whose intensity may vary with age, gender, emotional state, cultural background and previous pain experience.1 Almost 95% of patients undergoing orthodontic treatment have reported varying degrees of pain. After an orthodontic force is applied, an immediate and a delayed painful response occurs. While the cause of the immediate response was to be the compression of the periodontal ligament (PDL), the delayed response was attributed to the hyperalgesia of the PDL. This hyperalgesia is associated with prostaglandins which make the PDL sensitive to algogens released in the environment, such as histamine, bradykinin, serotonin and substance
Wild olive seed weevil, Anchonocranus oleae Marshall (Coleoptera: Curculionidae), in cultivated olives in South Africa
No full textWild olive seed weevil, Anchonocranus oleae Marshall, larvae as well as oviposition and feeding damage were recorded in cultivated olives during a recent study on olive seed wasps. Prematurely dropped fruit and fruit picked at harvest in two orchards near Stellenbosch and Agter-Paarl were examined regularly for olive seed wasp infestation over three seasons. In addition, olives were collected in the olive growing regions of the Western Cape province for a survey to determine olive seed wasp distribution. DNA barcoding was used to confirm the identity of weevil larvae in kernels. The number of A. oleae larvae found in olive seeds and the number of olives with weevil oviposition or feeding damage in this study were low. The presence of larvae and weevil damage in two orchards in the survey with no wild olive trees in close proximity suggest that the weevil could breed and persist in cultivated olive orchards. Currently A. oleae is not of economic concern, but if infested olives are discarded at harvest and left in orchards, the weevils could complete their development in the kernels and numbers could eventually increase to damaging levels
THE RELATIONSHIP BETWEEN THE DIFFERENT TYPES OF TERMS IMPLIED INTO CONTRACTS (PART II)
No full textIn the first part of this contribution, I showed that the different categories of implied terms of a contract flow into each other in three respects. This raises the question whether the present approach of our courts to implied terms is satisfactory, especially given that it results in a blurring of borders between tacit and ex lege terms.Two alternative approaches to the present understanding of the borderlines between different types of implied terms will be considered in this final part of this article, before conclusions are drawn
PATRIARCHY AND THE BILL OF RIGHTS
No full textIn this note the writer has deliberately avoided dealing with the heavily contested issues relating to the substantive rights and duties of spouses in marriages as these issues have already been dealt with in recent legislation (see s 6 of the Recognition of Customary Marriages Act 120 of 1998). This Act has incorporated some provisions of the Matrimonial Property Act (88 of 1984). The thorny issue of succession will soon be satisfactorily resolved in terms of the recommendation of the South African Law Commission.This note is about African religion and the role played by the elders in that context. In a recent decision of the Constitutional Court, religion has been defined as a means of giving content to the constitutional value of human dignity in an open and democratic society (see the judgment of Ngcobo J in Prince v President of the Law Society of the Cape of Good Hope 2002 3 BCLR 231 (CC)). There is no general agreement as to what constitutes religion (see the definition adopted by Nafzinger “The Functions of Religion in International Legal System” in Jaris and Evans (eds) Religion and International Law (1999) 158)