The lexicographic treatment of the demonstrative copulative in Sesotho sa Leboa — an exercise in multiple cross-referencing

In this research article an in-depth investigation is presented of the lexicographic treatment of the demonstrative copulative (DC) in Sesotho sa Leboa. This one case study serves as an example to illustrate the so-called 'paradigmatic lemmatisation' of closed-class words in the African languages. The need for such an approach follows a discussion, in Sections 1 and 2 respectively, of the present and missing directions in African-language metalexicography. A theoretical conspectus of the DC in Sesotho sa Leboa is then offered in Section 3, while Section 4 examines the treatment of the DC in the four existing desktop dictionaries for this language. The outcomes from the two latter sections are then used in Section 5, which analyses the problems of and options for a sound lexicographic treatment of the DC in bilingual and monolingual dictionaries. The next two sections proceed with a review of the practical implementation of the DC lemmatisation suggestions in PyaSsaL, i.e. the Pukuntšutlhaloši ya Sesotho sa Leboa 'Explanatory Sesotho sa Leboa Dictionary' — with Section 6 focussing on the hardcopy and Section 7 on the online version. In the process, the very first fully monolingual African-language dictionary on the Internet is introduced. Section 8, finally, concludes briefly. Keywords: lexicography, paradigmatic lemmatisation, african languages, sesotho sa leboa (northern sotho, sepedi), demonstrative copulative, cross-referencing, corpus, monolingual dictionary, bilingual dictionar

Paleoproterozoic snowball Earth: Extreme climatic and geochemical global change and its biological consequences

Geological, geophysical, and geochemical data support a theory that Earth experienced several intervals of intense, global glaciation (“snowball Earth” conditions) during Precambrian time. This snowball model predicts that postglacial, greenhouse-induced warming would lead to the deposition of banded iron formations and cap carbonates. Although global glaciation would have drastically curtailed biological productivity, melting of the oceanic ice would also have induced a cyanobacterial bloom, leading to an oxygen spike in the euphotic zone and to the oxidative precipitation of iron and manganese. A Paleoproterozoic snowball Earth at 2.4 Giga-annum before present (Ga) immediately precedes the Kalahari Manganese Field in southern Africa, suggesting that this rapid and massive change in global climate was responsible for its deposition. As large quantities of O(2) are needed to precipitate this Mn, photosystem II and oxygen radical protection mechanisms must have evolved before 2.4 Ga. This geochemical event may have triggered a compensatory evolutionary branching in the Fe/Mn superoxide dismutase enzyme, providing a Paleoproterozoic calibration point for studies of molecular evolution

Hepatitis B Virus Research in South Africa

Despite being vaccine-preventable, hepatitis B virus (HBV) infection remains the seventh leading cause of mortality in the world. In South Africa (SA), over 1.9 million people are chronically infected with HBV, and 70% of all Black chronic carriers are infected with HBV subgenotype A1. The virus remains a significant burden on public health in SA despite the introduction of an infant immunization program implemented in 1995 and the availability of effective treatment for chronic HBV infection. In addition, the high prevalence of HIV infection amplifies HBV replication, predisposes patients to chronicity, and complicates management of the infection. HBV research has made significant progress leading to better understanding of HBV epidemiology and management challenges in the SA context. This has led to recent revision of the national HBV infection management guidelines. Research on developing new vaccines and therapies is underway and progress has been made with designing potentially curative gene therapies against HBV. This review summarizes research carried out in SA on HBV molecular biology, epidemiology, treatment, and vaccination strategies