South African Bantu Research Articles

Genetic substructure and complex demographic history of South African Bantu speakers

South Eastern Bantu-speaking (SEB) groups constitute more than 80% of the population in South Africa. Despite clear linguistic and geographic diversity, the genetic differences between these groups have not been systematically investigated. Based on genome-wide data of over 5000 individuals, representing eight major SEB groups, we provide strong evidence for fine-scale population structure that broadly aligns with geographic distribution and is also congruent with linguistic phylogeny (separation of Nguni, Sotho-Tswana and Tsonga speakers). Although differential Khoe-San admixture plays a key role, the structure persists after Khoe-San ancestry-masking. The timing of admixture, levels of sex-biased gene flow and population size dynamics also highlight differences in the demographic histories of individual groups. The comparisons with five Iron Age farmer genomes further support genetic continuity over ~400 years in certain regions of the country. Simulated trait genome-wide association studies further show that the observed population structure could have major implications for biomedical genomics research in South Africa.

The Interactive Influence of Climate and Energetic Factors on Human Nasal Morphology

Cold‐dry environments require considerable transfers of heat and moisture from the respiratory tract to inspired air in order to prevent thermal damage and desiccation of the lungs. Accordingly, humans indigenous to cold‐dry environments typically exhibit narrow nasal passages, as these enhance intranasal air‐conditioning by increasing contact between respired air and the heat/moisture‐rich nasal mucosa. Yet, cold‐dry environments are also metabolically expensive due to thermoregulatory demands, requiring greater oxygen intake than in tropical environments. Thus, humans from colder environments are also predicted to possess larger nasal passages (i.e., cross‐sectional areas) in order to transmit larger volumes of air during each breath. Still, despite substantial evidence that both climate and metabolism likely influence nasal size and shape, virtually no research has investigated the interplay of these two factors on nasal anatomy. Here it is hypothesized that climate‐mediated nasal narrowing may necessitate a compensatory increase in nasal height to ensure the airways remain large enough to transmit a metabolically adequate volume of oxygen. To test this, we collected 17 linear measurements from the nasal skeleton of 119 modern humans from 10 climatically diverse geographic areas (Arctic Circle, Europe, Iran, Australia, North Africa, Khoisan, South African Bantu, East Africa, West Africa, Papua New Guinea). Measurements of associated postcranial elements were then used to estimate body mass and basal metabolic rate (BMR) for each individual. Climatic data (i.e., monthly air temperature and absolute humidity) were similarly collected for the geographic provenance of each individual. These morphological, energetic, and climatic data were subsequently employed in multivariate analyses to assess potential interactive influences of climate and metabolism on nasal morphology. Our results indicate that most measurements of nasal complex breadth are significantly correlated with climate (all r‐values >0.45, all p‐values <0.009), but not BMR. Conversely, nasal height is more strongly correlated with BMR (r=0.47, p=0.02) than climate. Additionally, nasal passage cross‐sectional area demonstrates a positive association with BMR (r=0.74, p=0.0007), while passage cross‐sectional shape exhibits a significant relationship with climate (r=0.52, p=0.0017) with taller/narrower airways found in colder‐drier environments. Our results support assertions that nasal narrowing in colder climates necessitates a concomitant increase in nasal height to maintain an overall airway size capable of meeting energetic demands for oxygen intake. Moreover, these patterns of nasal morphology appear consistent with well‐established ecogeographic distributions in human body size/shape attributed to Bergmann’s and Allen’s Rules. Thus, future research employing larger and more diverse samples appears poised to provide far‐reaching insights regarding climatic adaptation during human evolution.

Synthesised bigrams using word embeddings for code-switched ASR of four South African language pairs

Code-switching is the phenomenon whereby multilingual speakers spontaneously alternate between more than one language during discourse and is widespread in multilingual societies. Current state-of-the-art automatic speech recognition (ASR) systems are optimised for monolingual speech, but performance degrades severely when presented with multiple languages. We address ASR of speech containing switches between English and four South African Bantu languages. No comparable study on code-switched speech for these languages has been conducted before and consequently no directly applicable benchmarks exist. A new and unique corpus containing 14.3 hours of spontaneous speech extracted from South African soap operas was used to perform our study. The varied nature of the code-switching in this data presents many challenges to ASR. We focus specifically on how the language model can be improved to better model bilingual language switches for English-isiZulu, English-isiXhosa, English-Setswana and English-Sesotho. Code-switching examples in the corpus transcriptions were extremely sparse, with the majority of code-switched bigrams occurring only once. Furthermore, differences in language typology between English and the Bantu languages and among the Bantu languages themselves contribute further challenges. We propose a new method using word embeddings trained on text data that is both out-of-domain and monolingual for the synthesis of artificial bilingual code-switched bigrams to augment the sparse language modelling training data. This technique has the particular advantage of not requiring any additional training data that includes code-switching. We show that the proposed approach is able to synthesise valid code-switched bigrams not seen in the training set. We also show that, by augmenting the training set with these bigrams, we are able to achieve notable reductions for all language pairs in the overall perplexity and particularly substantial reductions in the perplexity calculated across a language switch boundary (between 5 and 31%). We demonstrate that the proposed approach is able to reduce the unseen code-switched bigram types in the test sets by up to 20.5%. Finally, we show that the augmented language models achieve reductions in the word error rate for three of the four language pairs considered. The gains were larger for language pairs with disjunctive orthography than for those with conjunctive orthography. We conclude that the augmentation of language model training data with code-switched bigrams synthesised using word embeddings trained on out-of-domain monolingual text is a viable means of improving the performance of ASR for code-switched speech.

Organic Cation Transporter 2 (OCT2/SLC22A2) Gene Variation in the South African Bantu-Speaking Population and Functional Promoter Variants.

SLC22A2 facilitates the transport of endogenous and exogenous cationic compounds. Many pharmacologically significant compounds are transported by SLC22A2, including the antidiabetic drug metformin, anticancer agent cisplatin, and antiretroviral lamivudine. Genetic polymorphisms in SLC22A2 can modify the pharmacokinetic profiles of such important medicines and could therefore prove useful as precision medicine biomarkers. Since the frequency of SLC22A2 polymorphisms varies among different ethnic populations, we evaluated these in South African Bantu speakers, a majority group in the South African population, who exhibit unique genetic diversity, and we subsequently functionally characterized promoter polymorphisms. We identified 11 polymorphisms within the promoter and 9 single-nucleotide polymorphisms (SNPs) within the coding region of SLC22A2. While some polymorphisms appeared with minor allele frequencies similar to other African and non-African populations, some differed considerably; this was especially notable for three missense polymorphisms. In addition, we functionally characterized two promoter polymorphisms; rs138765638, a three base-pair deletion that bioinformatics analysis suggested could alter c-Ets-1/2, Elk1, and/or STAT4 binding, and rs59695691, an SNP that could abolish TFII-I binding. Significantly higher luciferase reporter gene expression was found for rs138765638 (increase of 37%; p = 0.001) and significantly lower expression for rs59695691 (decrease of 25%; p = 0.038), in comparison to the wild-type control. These observations highlight the importance of identifying and functionally characterizing genetic variation in genes of pharmacological significance. Finally, our data for SLC22A2 attest to the importance of considering genetic variation in different populations for drug safety, response, and global pharmacogenomics, through, for example, projects such as the Human Heredity and Health in Africa initiative.

Deverbal nominals derived from intransitive state verbs in isiXhosa: A Generative Lexicon approach

The relationship between deverbative noun classification and the semantic meaning of the derived deverbal nominal has been the focus of many studies in linguistics from very divergent perspectives. This article maintains that the descriptive analysis of deverbal nominals in Bantu languages does not fully interrogate the predicate argument structure of the verbs that host these deverbal nominals. An investigation of how the syntactic properties of verbs from which deverbal nominals are derived is invoked within the paradigm of decompositional lexical semantics so as to explain the argument structure, event structure and qualia properties of deverbal nominals. This is demonstrated in this article, firstly, by the Bantu languages of sub-Saharan Africa. Secondly, this article explores the descriptive nature of deverbal nominals as they manifest themselves either inflectionally or derivationally in the South African Bantu languages, with emphasis on isiXhosa. Thirdly, deverbal nominals drawing on Pustejovsky’s Generative Lexicon paradigm are analysed. Lastly, the findings of the analyses of deverbal nominals derived from intransitive state verbs demonstrate the need for further research on deverbal nominals.

Tswana finite state tokenisation

Tswana, a Bantu language in the Sotho group, is characterised by an agglutinative morphology and a disjunctive orthography, which mainly affects the verb category. In particular, verbal prefixes are usually written disjunctively, while suffixes follow a conjunctive writing style. Therefore, Tswana tokenisation cannot be based solely on whitespace, as is the case in many alphabetic, segmented languages, including the conjunctively written Nguni group of South African Bantu languages. This paper shows how a combination of two finite state tokeniser transducers and a finite state morphological analyser are combined to solve the Tswana (verb) tokenisation problem. The approach has the important advantage of bringing the processing of Tswana, beyond the morphological analysis level, in line with what is appropriate for the Nguni languages. This means that the challenge of the disjunctive orthography is met at the tokenisation/morphological analysis level and does not in principle propagate to subsequent levels of analysis such as POS tagging and shallow parsing, etc. The tokenisation approach is novel and, when implemented and evaluated, yields an F1-score of 95 % with respect to a hand tokenised gold standard.

Idiosyncratic sound systems of the South African Bantu languages: Research and clinical implications for speech-language pathologists and audiologists.

The objective of this article is to create awareness amongst speech-language pathologists and audiologists in South Africa regarding the difference between the sound systems of Germanic languages and the sound systems of South African Bantu languages. A brief overview of the sound systems of two Bantu languages, namely isiZulu and Setswana, is provided. These two languages are representative of the Nguni language group and the Sotho group respectively.Consideration is given to the notion of language-specific symptoms of speech, language and hearing disorders in addition to universal symptoms. The possible impact of speech production, language and hearing disorders on the ability to produce and perceive speech in these languages, and the challenges that this holds for research and clinical practice, are pointed out.

Pollution Concepts and Marriage for the Southern African Iron Age

This article draws on the ethnography of South African Bantu speakers to model an archaeologically useful relationship between pollution beliefs and marriage. Typically, pollution beliefs intensify with more complex marital alliances, first with the increasing significance of relations between wives and their cattle-linked siblings, and then with a shift towards a preference for cousin marriage. The article applies the model to the Early Iron Age (ad 650–1050) record and concludes that Early Iron Age agriculturists practised non-kin marriage, but that a high bridewealth, and possibly hypogamous marriage, generated considerable structural tension in Early Iron Age society.

PRS43 - Comprehension Of Copd-Specific Terminology In Translated Patient Reported Outcomes Questionnaires

To analyze subjects’ interpretation of concepts specific to Chronic Obstructive Pulmonary Disorder (COPD) during pilot testing of translated Patient Reported Outcomes (PRO) questionnaires. As observed during pilot testing of translated COPD questionnaires, COPD-specific concepts were observed to cause more comprehension difficulties across languages, compared to observed questionnaires for other diseases. Solutions for these comprehension difficulties in COPD questionnaires will be explored. Pilot testing data for the concepts rescue medication, wheezing, the acronym COPD, and chest tightness within PROs were analyzed. Testing was conducted with five subjects per language for three questionnaires. Subjects were asked to paraphrase the COPD questionnaires in their entirety. Suggestions for improved comprehension of COPD concepts were explored, resulting from pilot testing data. Rescue medication caused difficulty within half of the languages analyzed. To improve comprehension, subjects suggested supplementing rescue medication with “(fast acting and quick relief medication)” for improved comprehension. Wheezing was a problematic concept for Spanish, South African Bantu and Indian languages. The subjects’ proposed solution for these languages was supplementation of wheezing with “(heavy breathing accompanied by a whistle sound).” Use of the COPD acronym proved problematic for 27% of languages. Even in languages where an equivalent acronym exists, comprehension issues persisted. Subjects suggested expansion of the acronym to “Chronic Obstructive Pulmonary Disorder.” Chest tightnesscaused minimal comprehension issues which were not significant enough to merit usable suggestions. Following translation of COPD questionnaires, pilot testing in the target language is essential, as concepts specific to COPD are found to be difficult. Because medical and technical concepts cannot be substituted, supplementation with brief definitions for increased comprehension and expansion of acronyms is recommended when developing source PRO questionnaires specific to COPD.

Assessment of speech in neurological disorders: Development of a Swahili screening test

The objective of this article is to create awareness amongst speech-language pathologists and audiologists in South Africa regarding the difference between the sound systems of Germanic languages and the sound systems of South African Bantu languages. A brief overview of the sound systems of two Bantu languages, namely isiZulu and Setswana, is provided. These two languages are representative of the Nguni language group and the Sotho group respectively.Consideration is given to the notion of language-specific symptoms of speech, language and hearing disorders in addition to universal symptoms. The possible impact of speech production, language and hearing disorders on the ability to produce and perceive speech in these languages, and the challenges that this holds for research and clinical practice, are pointed out.

Management and Internal Standardization of Chemistry Terminology: A Northern Sotho Case Study

One of the many implications of the process of language democratization which started post-1994 in South Africa is the empowerment of the previously marginalized South African Bantu languages to become languages of higher functions, i.e. languages of learning and teaching, and also of scientific discourse. This in turn implies the development, consolidation and especially standardization of terminology for each of these languages, and the compilation of LSP dictionaries. This article describes the terminological processing of a technical source text prior to translation, which formed part of the compilation of a Quadrilingual Explanatory Dictionary of Chemistry . It reports on the model of terminology management that was utilized and explores strategies for the internal standardization of terms in the absence of readily available, standardized chemistry terminology.

The development of a comprehensive machine-readable lexicon for Zulu

A comprehensive machine-readable (MR) lexicon is a strategic resource in the development of language technology. Two essential aspects are the development of a comprehensive data model and its accurate and efficient implementation. This study focuses on the development of MR lexicons for the South African Bantu languages and more specifically Zulu.

Nonmetric tooth crown traits in a Sri Lankan aboriginal Vedda population

This study was conducted to determine the frequencies of non-metric tooth crown traits of Vedda of Sri Lanka and to investigate the affinities of these morphological variations with those of other world populations. Fifty dental plaster casts were observed. The Arizona State University dental anthropology system was adopted for classification of the 16 traits observed. We used 13 traits to compare the Vedda and other world populations. Using the frequencies of 13 traits, Smith Mean Measure of Divergence was calculated to determine inter-population distances. Affinities among the Vedda and other world populations were expressed in two dimensions of the principal coordinate analysis. Cusp number in mandibular second molar and hypocone absence in maxillary second molar had the highest frequency at 95.9% and 93.8%, respectively. Shovelling, double shovelling in the maxillary central incisor and deflecting wrinkle in the mandibular first molar had the lowest frequency at 0%. The principal coordinate analysis showed that Sino American and Western Eurasian populations were separated in negative and positive directions in the first principal coordinate axis. Vedda located with the Western Eurasian population groups. Sahul and Sunda Pacific populations located in the intermediate position between Sino American and Western Eurasian populations. The dental phenotype of Vedda has close affinities with those of early south Asian populations. They are far different from Sino American and Sunda pacific populations. Vedda shows closer affinities to Sahul Pacific and South African (Bantu) populations.

Semi-automatic retrieval of definitional information: a northern Sotho case study

Corpus-based terminology is currently gaining ground on the international front. It is therefore important that terminologists working on the South African Bantu languages not only take note of this development, but that they should also follow this trend, even if they do not have the same measure of access to highly sophisticated software. The aim of this article is therefore to establish whether it is possible to retrieve definitional information on key concepts from untagged, running text by making use of affordable and easily accessible software such as WordSmith Tools. In order to answer this question, a case study is done in Northern Sotho, using textual material on linguistics as basis for a special field corpus. Syntactic and lexical patterns serving as textual markers of definitional information are identified and the success rate of the computational retrieval of definitional information is analysed and evaluated. Attention is also paid to the retrieval of specifically conceptual information, which turned out to be a fortunate by-product of semi-automatic retrieval of definitional information. Finally, it is illustrated how definitional information retrieved can be utilised in the writing of a formal terminological definition. Keywords: terminology, south african bantu languages, definitional information, semi-automatic information retrieval, terminological definitions, conceptual relationships, lexical patterns, syntactic patterns, textual markers, keyword-in-context (kwic), wordsmith tools

Brief communication: Population variation in human maxillary premolar accessory ridges (MxPAR)

The purpose of this brief communication is to report the results of an analysis of maxillary premolar accessory ridges (MxPAR), a common but understudied accessory ridge that may occur both mesial and distal to the central ridge of the buccal cusp of upper premolars. We developed a new five-grade scoring plaque to better categorize MxPAR variation. Subsequently, we conducted a population analysis of MxPAR frequency in 749 dental casts of South African Indian, American Chinese, Alaskan Eskimo, Tohono O'odham (Papago), Akimel O'odham (Pima), Solomon Islander, South African Bantu, and both American and South African Whites. Northeast Asian and Asian-derived populations exhibited the highest MxPAR frequencies while Indo-European samples (South African Indians, American and South African Whites) exhibited relatively low frequencies. The Solomon Islanders and South African Bantu samples exhibited intermediate frequencies. Our analysis indicates that statistically significant differences in MxPAR frequency exist between major geographic populations. As a result, the MxPAR plaque has now been added to the Arizona State University Dental Anthropology System, an important contribution as maxillary premolar traits are underrepresented in analyses of dental morphology.

Correlation between HIV‐1 seropositivity and prevalence of a γ‐secretase polymorphism in two distinct ethnic populations

Susceptibility for human immunodeficiency virus type 1 (HIV-1) infection may be influenced by host genetics. Recent findings with a Wistar rat model raised the possibility that the gamma-secretase pathway may be associated with an individual's susceptibility to infection. A functional single-nucleotide polymorphism (SNP) in the gamma-secretase component APH1B (Phe217Leu; rs1047552) was therefore analyzed for association with HIV-1 infection. The SNP showed a tendency for association with HIV-1 infection in a Xhosa indigenous South African Bantu study (P = 0.087), and associated significantly in a Caucasian Dutch study (P = 0.049). Together, the results suggest a role for the gamma-secretase pathway in susceptibility to HIV-1 infection.

Translating technical (LSP) texts into the official South African languages: A corpus-based investigation of translators’ strategies

Translating technical texts into the South African Bantu languages, and to a lesser extent into Afrikaans, is an activity fraught with problems, the biggest one being the lack of terminology in these languages. In this article-undertaken within the framework of Corpus-based Translation Studies (CTS), and more specifically within the subfield of Applied CTS-we focus on technical translation in the official South African languages, with specific reference to the manner in which (professional) translators deal with the issue of terminology. To this end, and growing out of an earlier pilot study (Gauton et al. 2003), a multilingual corpus of ten sets of parallel texts in all eleven official South African languages was compiled and studied. Taking our cue from the general perception that the translation of terms by means of loanwords and/or transliterations is a dominant strategy, particularly in the South African Bantu languages, these strategies form the focus of the first phase of our investigation. This is followed by a comparative analysis of the translation strategies used by African language translators in finding suitable translation equivalents for English terms foreign to the African languages, using the term'formation strategies' as identified by Mtintsilana and Morris (1988) and'translation strategies' as explicated by Baker (1992) as a basis. For comparative purposes, 20 sample terms were selected from the parallel corpora. The translation strategies utilised in the translation of these terms were then identified and statistically compared. The study concludes with suggestions to African language translators of technical texts in dealing with the problem of non-equivalence encountered in this type of translation work.

Phonetics of intonation in South African Bantu languages

Much is already known about the prosodic systems of the indigenous South African languages from descriptions and analyses in the existing literature. All of the existing work has been carried out in the field of African studies or formal linguistics. In order to be able to implement the generalisations obtained into computational models in speech processing, the existing sources and results must be made accessible to researchers in these areas. In the opposite direction, the modelling of Bantu intonation in speech processing shows the need for more quantitative data. The present article presents a review of durational and pitch-related tonal aspects relating to intonation in South African Bantu languages. Its aim is, on the one hand, to make the results of Africanist and linguistic studies accessible to research in speech processing, laying a foundation on which work in the speech-processing branch of Human Language Technologies can be based. On the other hand, by pointing out gaps in our knowledge, it wants to draw attention to the fact that more quantitative research is needed in order to advance our knowledge also in the theoretical linguistic field.

On the development of a tagset for Northern Sotho with special reference to the issue of standardisation

Working with corpora in the South African Bantu languages has up till now been limited to the utilisation of raw corpora. Such corpora, however, have limited functionality. Thus the next logical step in any NLP application is the development of software for automatic tagging of electronic texts. The development of a tagset is one of the first steps in corpus annotation. The authors of this article argue that the design of a tagset cannot be isolated from the purpose of the tagset, or from the place of the tagset and its design within the bigger picture of the architecture of corpus annotation. Usage-related aspects therefore feature prominently in the design of the tagset for Northern Sotho. It is explained why this proposed tagset is biased towards human readability, rather than machine readability; this choice of a stochastic tagger is motivated, and the relationship between tokenising, tagging, morphological analysis and parsing is discussed. In order to account at least to some extent for the morphological complexity of Northern Sotho at the tagging level, a multilevel annotation is opted for: the first level comprising obligatory information and the second optional and recommended information. Finally, aspects of standardisation are considered against the background of reuse, of sharing of resources, and of possible adaptation for use by other disjunctively written South African Bantu languages. It is not the aim of this article to evaluate the results of any tagging procedure using the proposed tagset. It only describes the design and motivates the choices made with regard to the tagset design. However, an evaluation is in process and results will be published in the near future (cf. Faaß et al., s.a.).

Cattle and cattle colour terminology in South Africa

A comparison between cattle colour terminology found in the Khoikhoi languages and that found in South African Bantu languages brings noticeable similarities to light, leading to the assumption that both the cattle and the terms used to describe their characteristic features were acquired by the South Eastern Bantu-speakers through contact with Khoikhoi pastoralists. In this article we investigate the possibility that these terminological similarities are the result of mutual relatedness to a single progenitor set of terms, rather than of borrowing that took place in a restricted geographical area. To this end, three hypotheses are proposed, respectively termed the East African link-hypothesis, the Northern Botswana link-hypothesis and the Sudan link-hypothesis. We argue that the latter, pointing to a common Nilotic proto-source, represents the most plausible explanation for the origin of cattle colour terminology shared by amongst others, the South African Bantu and Khoikhoi languages.