Decision tree analysis for age estimation in living individuals: integrating cervical and dental radiographic evaluations within a South African population

Age estimation in living individuals around the age of 18 years is medico-legally important in undocumented migrant cases and in countries like South Africa where many individuals are devoid of identification documents. Establishing whether an individual is younger than 18 years largely influences the legal procedure that should be followed in dealing with an undocumented individual. The aim of this study was to combine dental third molar and anterior inferior apophysis ossification data for purposes of age estimation, by applying a decision tree analysis. A sample comprising of 871 black South African individuals (n = 446 males, 425 = females) with ages ranging between 15 and 24 years was analyzed using panoramic and cephalometric radiographs. Variables related to the left upper and lower third molars and cervical vertebral ring apophysis ossification of C2, C3, and C4 vertebrae analyzed in previous studies were combined in a multifactorial approach. The data were analyzed using a pruned decision tree function for classification. Male and female groups were handled separately as a statistically significant difference was found between the sexes in the original studies. A test sample of 30 individuals was used to determine if this approach could be used with confidence in estimating age of living individuals. The outcomes obtained from the test sample indicated a close correlation between the actual ages (in years and months) and the predicted ages (in years only), demonstrating an average age difference of 0.47 years between the corresponding values. This method showed that the application of decision tree analysis using the combination of third molar and cervical vertebral development is usable and potentially valuable in this application.

Phototherapy for atopic dermatitis: A survey of European practice

BACKGROUND

Phototherapy is used to treat atopic dermatitis (AD). Evidence for its efficacy, impact on quality of life, cost-effectiveness and short- and long-term safety with real-life usage is weak.

OBJECTIVES

We established a taskforce to examine how phototherapy is currently being used as a treatment for AD across the United Kingdom and Europe to inform our understanding and guide future research into management of patients with AD using UV-based phototherapies.

METHODS

An anonymous electronic multiple-response survey exploring phototherapy prescribing practices and experience of phototherapy modalities was developed by the study authors and sent to members of phototherapy networks from the United Kingdom and Europe. Responses were received between February and July 2021.

RESULTS

About 144 respondents from 27 European countries completed the survey. NBUVB was the most widely used [n = 138 (96%)]. Home-based NBUVB was available in 8/27 countries (25/144 respondents, 17%). Oral psoralen-UVA (PUVA) was more widely available than bath PUVA (n = 106, 74% vs. n = 60, 42%) and used mainly in adult patients. 49/144 (34%) of respondents had access to UVA1. Phototherapy would be considered instead of systemic treatment in 96% of adults and 82% of children for NBUVB, versus 40% of adults and 3% of children for PUVA. Starting doses, standard dosing increments, length of treatment courses, lifetime limits for treatments and thresholds for performing annual skin assessments varied between responders.

CONCLUSIONS

NBUVB was the most widely used phototherapy for AD in adult and paediatric patients, while PUVA and UVA1 were less used. Prescribing practices varied considerably, highlighting the lack of consensus practice in many different aspects of phototherapy for the treatment of AD in children and adults. This indicates that further studies are required to determine optimal phototherapeutic regimens for AD and informs our understanding of parameters that should be included in future high-quality randomized controlled trials (RCT) of phototherapy.

Violence against children: A review of cases at a forensic anthropology unit, Johannesburg, South Africa

South Africa is experiencing a scourge of violence against women and children, with alarming levels of violence, and as such, juvenile cases are sometimes encountered in a forensic anthropological setting. The aim of this research was to assess the cases of juveniles (under 20 years) presenting at the Human Variation and Identification Research Unit (HVIRU) for a 6-year period (2016-2022), in order to assess patterns and types of cases referred. A total of 19 cases were assessed, of which 10 were 16-20 years old, 3 between the ages of 5 and 15 years and 6 less than 5 years old at the time of death. Of the 14 children with known sex, 12 were female with features suggesting that they fell prey to sexual violence. Many of the individuals were either known (and referred for trauma analysis) or identified following investigation. Of the 19 juveniles, 11 (58 %) had evidence of perimortem trauma (sharp and/or blunt), attesting to the violent nature of their deaths. Two cases had both sharp and blunt force trauma, of which one is a possible case of dismemberment. The remains of two individuals showed signs of perimortem burning, which may or may not be related to the cause of death. Three individuals had signs of antemortem (healed) trauma, which may suggest a longer period of abuse. Five of the individuals showed signs of disease - two had cribra orbitalia, while two others had various porous lesions indicative of chronic disease or malnutrition. One individual had advanced osteomyelitis, suggesting a natural cause of death. Some of these cases had unusual trauma and pathology, highlighting the contribution of forensic anthropologists.

Diffuse Idiopathic Skeletal Hyperostosis (DISH): New evidence from micro-XCT scanning

OBJECTIVE

To observe and describe the development and underlying structure of the spinal manifestations of individuals osteologically diagnosed with DISH (Diffuse Idiopathic Skeletal Hyperostosis), using micro-XCT imaging.

MATERIALS

A total of 72 individuals with DISH were identified in two modern skeletal collections in South Africa.

METHODS

Vertebral columns affected by DISH were scanned at the micro-focus x-ray computed tomography facility at the Nuclear Energy Corporation of South Africa. Four features were macroscopically examined: (1) the origin of the new bone growth; (2) retention of the original vertebral cortex at the site of the new bone formation associated with DISH; (3) evidence of trabecular bone with or without sclerosis on the anterolateral surface of affected vertebrae; and (4) abnormal areas of osteosclerosis beyond features associated with DISH.

RESULTS

Considerable variation across and between the four recorded features was found. Of note, 81% (n = 58) of individuals had both developed trabecular bone within the flowing new bone formation (feature 3), without retention of the original vertebral cortex (feature 2).

CONCLUSIONS

Possible localised erosive/inflammatory processes destroyed the original cortex of the vertebral body and resulted in the expansion of trabeculae with new bone formation.

SIGNIFICANCE

Micro-XCT imaging shed new light on the development of DISH, adding to literature suggesting that it could be an inflammatory disease.

LIMITATIONS

Clinical histories of the individuals were not known.

SUGGESTIONS FOR FURTHER RESEARCH

The role of chronic inflammatory disease in the development of DISH should be further explored including both the extra-spinal and spinal manifestations.

Newborn bacille Calmette-Guérin vaccination induces robust infant interferon-γ-expressing natural killer cell responses to mycobacteria

OBJECTIVES

The bacille Calmette-Guérin (BCG) vaccine is usually administered at birth to protect against severe forms of tuberculosis in children. BCG also confers some protection against other infections, possibly mediated by innate immune training. We investigated whether newborn BCG vaccination modulates myeloid and natural killer (NK) cell responses to mycobacteria.

METHODS

BCG vaccination was either administered at birth or delayed to 6 or 10 weeks of age in 130 South African infants. Whole blood was stimulated with BCG and clusters of differentiation (CD)4⁺ T, myeloid, and NK cell responses were measured by flow cytometry; the levels of secreted cytokines were measured by a multiplex bead array.

RESULTS

Newborn BCG vaccination was associated with significantly higher frequencies of BCG-reactive, cytokine-expressing CD4⁺ T cells, and interferon (IFN)-γ-expressing NK cells than in unvaccinated infants but no differences in cytokine-expressing CD33⁺ myeloid cells were observed. The induction of BCG-reactive IFN-γ-expressing NK cells was not associated with the markers of NK cell maturation, differentiation, or cytokine receptor expression. BCG-reactive NK cell responses correlated directly with the levels of secreted interleukin (IL)-2 and IFN-γ and the innate pro-inflammatory cytokines IL-6, IL-1β, and tumor necrosis factor (TNF) in BCG-vaccinated infants only.

CONCLUSION

We showed that BCG-reactive IFN-γ-expressing NK cells are strongly induced by BCG vaccination in infants and are likely amplified through bystander cytokines.

Effects of BCG vaccination on donor unrestricted T cells in two prospective cohort studies

BACKGROUND

Non-protein antigen classes can be presented to T cells by near-monomorphic antigen-presenting molecules such as CD1, MR1, and butyrophilin 3A1. Such T cells, referred to as donor unrestricted T (DURT) cells, typically express stereotypic T cell receptors. The near-unrestricted nature of DURT cell antigen recognition is of particular interest for vaccine development, and we sought to define the roles of DURT cells, including MR1-restricted MAIT cells, CD1b-restricted glucose monomycolate (GMM)-specific T cells, CD1d-restricted NKT cells, and γδ T cells, in vaccination against Mycobacterium tuberculosis.

METHODS

We compared and characterized DURT cells following primary bacille Calmette-Guerin (BCG) vaccination in a cohort of vaccinated and unvaccinated infants, as well as before and after BCG-revaccination in adults.

FINDINGS

BCG (re)vaccination did not modulate peripheral blood frequencies, T cell activation or memory profiles of MAIT cells, CD1b-restricted GMM-specific and germline-encoded mycolyl-reactive (GEM) cells or CD1d-restricted NKT cells. By contrast, primary BCG vaccination was associated with increased frequencies of γδ T cells as well as a novel subset of CD26⁺CD161⁺TRAV1-2^- IFN-γ-expressing CD4⁺ T cells in infants.

INTERPRETATION

Our findings, that most DURT cell populations were not modulated by BCG, do not preclude a role of BCG in modulating other qualitative aspects of DURT cells. More studies are required to understand the full potential of DURT cells in new TB vaccine strategies.

FUNDING

Aeras, the National Institutes of Health, and the Bill and Melinda Gates Foundation.

Infectious disease and nutritional deficiencies in early industrialized South Africa

OBJECTIVE

Real industrialization was late to arrive in South Africa and was associated with the development of mining in its northern regions. This paper explores the development and spread of infectious diseases (particularly tuberculosis), against the backdrop of metabolic disease.

MATERIALS

Published data regarding skeletons from various mining sites and historical information are collated, including information from the early accessions into the Raymond A. Dart Collection.

METHODS

While findings from several sites (e.g., Gladstone at Kimberley, Koffiefontein, Witwatersrand Deep Mine and Lancaster Mine) have been described individually, they have not been assessed collectively. This paper provides a broad overview by collating information from these sites, in comparison with a rural, pre-industrialized population.

RESULTS

Malnutrition, including scurvy, was common in most mining groups. Tuberculosis was rare in earlier mining groups, and the first possible skeletal cases only occurred after the establishment of closed housing compounds. From there it spread rapidly across the subcontinent.

CONCLUSIONS

Nutritional insufficiencies / metabolic disease and high death rates, due to trauma and infectious diseases, were common. Tuberculosis in South Africa is closely associated with development of the mining industry.

SIGNIFICANCE

This research highlights the development of tuberculosis in South Africa and its association with the mining industry. The role of migrant labor and the associated housing practices is elucidated.

LIMITATIONS

Sample sizes are limited, but the findings of this study are supported by documentary evidence.

FUTURE RESEARCH

Sample sizes should be increased, and the association between closed compound living and the development of disease further explored.

Inflammatory Determinants of Differential Tuberculosis Risk in Pre-Adolescent Children and Young Adults

The risk of progression from Mycobacterium tuberculosis (M.tb) infection to active tuberculosis (TB) disease varies markedly with age. TB disease is significantly less likely in pre-adolescent children above 4 years of age than in very young children or post-pubescent adolescents and young adults. We hypothesized that pro-inflammatory responses to M.tb in pre-adolescent children are either less pronounced or more regulated, than in young adults. Inflammatory and antimicrobial mediators, measured by microfluidic RT-qPCR and protein bead arrays, or by analyzing published microarray data from TB patients and controls, were compared in pre-adolescent children and adults. Multivariate analysis revealed that M.tb-uninfected 8-year-old children had lower levels of myeloid-associated pro-inflammatory mediators than uninfected 18-year-old young adults. Relative to uninfected children, those with M.tb-infection had higher levels of similar myeloid inflammatory responses. These inflammatory mediators were also expressed after in vitro stimulation of whole blood from uninfected children with live M.tb. Our findings suggest that myeloid inflammation is intrinsically lower in pre-pubescent children than in young adults. The lower or more regulated pro-inflammatory responses may play a role in the lower risk of TB disease in this age group.

An evaluation of the Acsádi and Nemeskéri Complex Method of adult age estimation in a modern South African skeletal sample

The Acsádi and Nemeskéri Complex Method is a multifactorial adult age estimation method that makes use of weighting systems. The Complex Method employs the use of four skeletal elements in assessing age, including the degree of endocranial suture closure, age-related changes to the pubic symphyseal surface, and the internal structural changes observable in the proximal humerus and femur. Acsádi and Nemeskéri reported a very optimistic error margin of ±2.5 years when all four skeletal elements were used. Despite these promising results, the Complex Method's effectiveness has been questioned, suggesting that it results in a constant over- and underestimation of age in younger and older groups, respectively. In this study, the Complex Method was tested on a modern South African skeletal sample (n = 313) with individuals of known age-at-death. Results from this study to some extent justify the critique levelled against the Complex Method's tendency to over- and underestimate age. Nevertheless, the Complex Method still performed surprisingly well for certain skeletal element combinations. Contrary to Acsádi and Nemeskéri's findings, the use of all four skeletal elements did not provide more accurate age estimates. For the most part, combinations making use of three or two skeletal elements outperformed the use of all four skeletal indicators. Results from this study indicate caution in using a blanket approach when it comes to deciding on the best combination of skeletal elements used in multifactorial methods. It is suggested that the Complex Method may be optimised by making use of sex- and population-specific skeletal element combinations and weighting systems in the future.

Fetal public Vγ9Vδ2 T cells expand and gain potent cytotoxic functions early after birth

Vγ9Vδ2 T cells are a major human blood γδ T cell population that respond in a T cell receptor (TCR)-dependent manner to phosphoantigens which are generated by a variety of microorganisms. It is not clear how Vγ9Vδ2 T cells react toward the sudden microbial exposure early after birth. We found that human Vγ9Vδ2 T cells with a public/shared fetal-derived TCR repertoire expanded within 10 wk postpartum. Such an expansion was not observed in non-Vγ9Vδ2 γδ T cells, which possessed a private TCR repertoire. Furthermore, only the Vγ9Vδ2 T cells differentiated into potent cytotoxic effector cells by 10 wk of age, despite their fetal origin. Both the expansion of public fetal Vγ9Vδ2 T cells and their functional differentiation were not affected by newborn vaccination with the phosphoantigen-containing bacillus Calmette-Guérin (BCG) vaccine. These findings suggest a strong and early priming of the public fetal-derived Vγ9Vδ2 T cells promptly after birth, likely upon environmental phosphoantigen exposure.

Inter-population variation of histomorphometric variables used in the estimation of age-at-death

Population variation of several microscopic structures used in age-at-death estimation was assessed for three different population samples. The aim of the study was to determine if the need exists for population-specific standards when dealing with individuals of African and European origin. A total sample 223 bone sections from the anterior cortex of the femur (n = 99 black South Africans, n = 94 white South Africans and n = 30 Danish individuals) were analysed using a stereological protocol. Variables assessed included the average number of osteons per grid area (OPD), osteon size and Haversian canal size. ANCOVA was employed for assessment of statistically significant differences. The results indicated that OPD differed significantly between the three groups, but that osteon size was similar for all individuals. Haversian canal size showed unpredictable changes with age and high levels of variation, making it unsuitable to use for age estimation as a single factor. As there are conflicting opinions in the literature on whether to use population-specific equations for the estimation of age-at-death or not, this paper provided additional insight into the use of specific variables and its related variation between groups.

Treated acid mine drainage and stream recovery: Downstream impacts on benthic macroinvertebrate communities in relation to multispecies toxicity bioassays

The success and long term effectiveness of extensive and expensive engineering solutions to restore streams impacted by Acid Mine Drainage (AMD) is rarely tested. Concentrations of pollutants were measured in water along a longitudinal gradient from a stretch of the Tweelopie stream, South Africa, that receives pH-treated acid mine drainage (AMD) from an abandoned gold mine. The biotoxic effects of treated AMD were determined through macroinvertebrate biotic indices (SASS5) and a battery of toxicity bioassays. These included the L. sativa, A. cepa, D. magna toxicity and Ames mutagenicity tests, as well as an in vitro human liver cancer cell line HepG2. Even though the Tweelopie stream was moderately to severely degraded by multiple anthropogenic stressors, the impact of the treated AMD was masked by the improvement in the system downstream after mixing with the domestic wastewater effluent receiving stream, and subsequent further dilution as a result of the karst springs downstream. The general improvement of the system downstream was clearly shown by the decrease in the ecotoxicity and mutagenicity in relation to the in-stream macroinvertebrates. PCA multivariate analysis successfully displayed associations between the different environmental variables and the decrease in toxicity and subsequent ecosystem improvement downstream. This study indicated that environmental management of AMD remediation should consider long term assessment strategies, including multiple factors, to promote biological ecosystem recovery.

Age estimation using bone mineral density in South Africans

The use of bone mineral density (BMD) to predict age-at-death in skeletal remains provides a usable alternative to other methods because the values obtained are not observer-dependent. The aim of this study was to investigate the usability of BMD to estimate age in South African populations, and to assess inter-population variation and sex-specific differences in BMD values from the proximal end of the femur. In order to estimate age, regression analysis was done for the construction of population dependent formulae. The sample comprised of a total of 123 femora of black and white South Africans. DXA scans were performed using the Hologic Discovery system. Data analysis was done by employing independent-samples t-tests and correlation/regression analyses. The results indicated a statistically significant difference between black and white South Africans. Male groups were also significantly different from one another, but black and white females showed no significant differences. Linear regression analysis revealed a significant correlation between BMD values and age for the white population and the combined sample, but not for the black population. Bootstrapping were employed to confirm validity of the results. In conclusion, this study showed that the use of DXA measurements of the femur for estimating age may be used for the estimation of age-at-death in white South Africans, but more research is needed to better understand the relationship between bone mineral density and age in black South Africans.

Revisiting historical Khoe-San skeletal remains in European collections: A search for identity through craniometric analysis

As the identity of a large number of Khoe-San skeletal material in European collections recently came into question during its documentation, a re-evaluation of the remains by employing a non-invasive method such as craniometrics was done to investigate the biological affinity. For this purpose, gene flow and population diversity present within the group, as well as between the study sample (N=63) and other modern and historic population groups from southern, central and east Africa were explored. Available comparative groups included the historic Khoe-San from Riet River (N=31), the Sotho-Tswana from southern Africa (N=61), the Basuku from central Africa (N=66) and the Bahutu (N=53) and Teita (N=24) from east Africa. Ten craniometric variables were selected and used to perform population structure analysis based on model bound quantitative genetics and multiple discriminant function analysis (MDA). Quantitative genetic distances revealed that the Khoe-San sample was closest to the Riet River group. Residual variance analysis performed on two-sample subsets of the Khoe-San group (Cape KS and Various KS) showed a higher level of heterogeneity in the Cape KS than seen in the Khoe-San from various other areas in southern Africa. MDA revealed that Khoe-San intra-sample variance is relatively high, with 44% of the sample (sexes pooled) classified into the Riet River group. The remaining individuals were classified (in decreasing order) into Bahutu (24%), Basuku (24%) and Sotho-Tswana (8%). Although the Khoe-San specimens are closest to the Riet River group, they are clearly not homogenous. Their high level of phenotypic diversity most likely originated from a complex population history involving many group interactions driven by social and political marginalization.

Decomposition patterns of buried remains at different intervals in the Central Highveld region of South Africa

Burial of remains is an important factor when one attempts to establish the post-mortem interval as it reduces, and in extreme cases, excludes oviposition by Diptera species. This in turn leads to modification of the decomposition process. The aim of this study was to record decomposition patterns of buried remains using a pig model. The pattern of decomposition was evaluated at different intervals and recorded according to existing guidelines. In order to contribute to our knowledge on decomposition in different settings, a quantifiable approach was followed. Results indicated that early stages of decomposition occurred rapidly for buried remains within 7-33 days. Between 14 and 33 days, buried pigs displayed common features associated with the early to middle stages of decomposition, such as discoloration and bloating. From 33 to 90 days advanced decomposition manifested on the remains, and pigs then reached a stage of advanced decomposition where little change was observed in the next ±90-183 days after interment. Throughout this study, total body scores remained higher for surface remains. Overall, buried pigs followed a similar pattern of decomposition to those of surface remains, although at a much slower rate when compared with similar post-mortem intervals in surface remains. In this study, the decomposition patterns and rates of buried remains were mostly influenced by limited insect activity and adipocere formation which reduces the rate of decay in a conducive environment (i.e. burial in soil).

A discussion of current issues and concepts in the practice of skull-photo/craniofacial superimposition

A recent review paper on cranio-facial superimposition (CFS) stated that "there have been specific conceptual variances" from the original methods used in the practice of skull-photo superimposition, leading to poor results as far as accuracy is concerned. It was argued that the deviations in the practice of the technique have resulted in the reduced accuracies (for both failure to include and failure to exclude) that are noted in several recent studies. This paper aims to present the results from recent research to highlight the advancement of skull-photo/cranio-facial superimposition, and to discuss some of the issues raised regarding deviations from original techniques. The evolving methodology of CFS is clarified in context with the advancement of technology, forensic science and specifically within the field of forensic anthropology. Developments in the skull-photo/cranio-facial superimposition techniques have largely focused on testing reliability and accuracy objectively. Techniques now being employed by forensic anthropologists must conform to rigorous scientific testing and methodologies. Skull-photo/cranio-facial superimposition is constantly undergoing accuracy and repeatability testing which is in line with the principles of the scientific method and additionally allows for advancement in the field. Much of the research has indicated that CFS is useful in exclusion which is consistent with the concept of Popperian falsifiability - a hypothesis and experimental design which is falsifiable. As the hypothesis is disproved or falsified, another evolves to replace it and explain the new observations. Current and future studies employing different methods to test the accuracy and reliability of skull-photo/cranio-facial superimposition will enable researchers to establish the contribution the technique can have for identification purposes.

Geometric morphometric assessment of sexually dimorphic characteristics of the distal humerus

A number of recent studies investigated the use of morphological characteristics of the distal humerus to estimate the sex of unknown individuals. Using visual assessment, accuracies ranging from 74% to more than 90% were reported. The aim of this study was to assess these traits with geometric morphometrics, in order to determine if they corroborate the findings described with pure visual assessment. A total sample of 155 female and 175 male humeri of South Africans were used. All humeri were photographed in standardized positions from a posterior and inferior view, and homologous landmarks assigned. Olecranon fossa shape, angle of the medial epicondyle and trochlear symmetry were assessed. Males and females could be separated with accuracies ranging from 78% to 91%. The results of this study confirm the existence of these traits and their usability in assessment of sex from skeletal remains, and the observed anatomical characteristics largely agree with what have been described by visual assessment.

Effects of preharvest treatment, disinfections, packaging and storage environment on quality of tomato

The major objective of this study was to explore the significance of an integrated agro technology in maintenance of postharvest quality of tomato. Preharvest ComCat® treated tomatoes and untreated controls were evaluated for changes in physiological, chemical, and microbiological quality during storage at 13 °C and room temperature (16.9-25.2 °C) and a relative humidity of 34-76%. Effects of disinfection coupled with packaging were evaluated. Physiological weight loss, total soluble solids, peroxidase activity and marketability were maintained better in anolyte disinfected tomatoes. At harvest, ComCat® treated tomatoes had lower pH, glucose and microbial populations, and higher total soluble solids, total titratable acids, sucrose, peroxidase activity than controls. The total soluble solids were better retained in ComCat® treated tomatoes than in control, while the sucrose and glucose contents remained lower after ripening. Peroxidase activities were lower in ripening ComCat® treated tomatoes, and difference in polygalactronase activity was only visible after 30 days. The microbial populations were lower in ComCat® treated fruit. Marketability of ComCat® treated tomatoes was better than that of the control. Integrated technology covering preharvest ComCat® application, disinfection with anolyte water and packaging combined with cold storage at 13 °C maintained the superior quality of tomato.

An investigation into the accuracy and reliability of skull-photo superimposition in a South African sample

One of the aims of forensic science is to determine the identities of victims of crime. In some cases the investigators may have ideas as to the identities of the victims and in these situations, ante mortem photographs of the victims could be used in order to try and establish identity through skull-photo superimposition. The aim of this study was to evaluate the accuracy of a newly developed digital photographic superimposition technique on a South African sample of cadaver photographs and skulls. Forty facial photographs were selected and for each photo, 10 skulls (including the skull corresponding to the photo) were used for superimposition. The investigator did not know which of the 10 skulls corresponded to the photograph in question. The skulls were scanned 3-dimensionally, using a Cyberware™ Model 3030 Colour-3D Scanhead scanner. The photos were also scanned. Superimposition was done in 3D Studio Max and involved a morphological superimposition, whereby a skull is superimposed over the photo and assessed for a morphological match. Superimposition using selected anatomical landmarks was also performed to assess the match. A total of 400 skull-photo superimpositions were carried out using the morphological assessment and another 400 using the anatomical landmarks. In 85% of cases the correct skull was included in the possible matches for a particular photo using morphological assessment. However, in all of these cases, between zero and three other skulls out of 10 possibilities could also match a specific photo. In the landmark based assessment, the correct skull was included in 80% of cases. Once again, however, between one and seven other skulls out of 10 possibilities also matched the photo. This indicates that skull-photo superimposition has limited use in the identification of human skeletal remains, but may be useful as an initial screening tool. Corroborative techniques should also be used in the identification process.

Case report: Forensic anthropological assessment in a suspected case of child abuse from South Africa

Not many case reports of suspected child abuse as assessed solely on skeletal remains are available. Forensic anthropologists have intimate knowledge of normal skeletal anatomy, bone trauma and processes of healing of bone and may therefore be of help in suspected cases of child abuse. Patterns of trauma in juvenile skeletal remains which are suggestive of abuse include fractures in different phases of healing, multiple fractures, typical fractures on ribs and long bones and severe, complicated cranial fractures. The aim of this paper is to report on the findings of the analysis of the skeletal remains of a 3.5 years old boy. Forensic pathological examination indicated that the boy had died from a massive cranial fracture, with multiple injuries present to the rest of the body. After the body had been buried for some time, it was exhumed and we were requested to look for signs of chronic, long-term abuse. Findings included a massive cranial fracture, another fracture in the roof of the orbit, two areas of non-specific subperiosteal bone growth and several untreated carious teeth. No clear healed fracture could be found, except for a possible healed cranial base fracture which stretched transversely across the petrosal bone. This area showed signs of recent bone activity. The court decided that this was not enough evidence of chronic abuse and found the accused guilty of murder but not of chronic child abuse. This case illustrates the difficulty to obtain clear signs of chronic injury on juvenile remains.

Facial reconstruction: soft tissue thickness values for South African black females

In forensic science, investigators frequently have to deal with unidentified skeletonised remains. When conventional methods of identification are unsuccessful, forensic facial reconstruction (FFR) may be used, often as a last resort, to assist the process. FFR relies on the relationships between the facial features, subcutaneous soft tissues and underlying bony structure of the skull. The aim of this study was to develop soft tissue thickness (STT) values for South African black females for application to FFR, to compare these values to existing literature or databases and to add these values to existing population data. Computerised tomography scanning was used to determine average population-specific STT values at 28 facial landmarks of 154 black females. Descriptive statistics are provided for these STT values, which were also compared to those reported in three other comparable databases. Many of these STT values are significantly different from those reported for comparable groups, suggesting that individuals from different geographical areas have unique facial features thus requiring population-specific STT values. Repeatability tests indicated that most measurements could be recorded with a high degree of reliability.

A geometric morphometric study into the sexual dimorphism of the human scapula

Sex determination is vital when attempting to establish identity from skeletal remains. Two approaches to sex determination exists: morphological and metrical. The aim of this paper was to use geometric morphometrics to study the shape of the scapula and its sexual dimorphism. The sample comprised 45 adult black male and 45 adult black female scapulae of known sex. The scapulae were photographed and 21 homologous landmarks were plotted to use for geometric morphometric analysis with the 'tps' series of programs, as well as the IMP package. Consensus thin-plate splines and vector plots for males and females were compared. The CVA and TwoGroup analyses indicated that significant differences exist between males and females. The lateral and medial borders of females are straighter while the supraspinous fossa is more convexly curved than that of males. More than 91% of the females and 95% of the males were correctly assigned. Hotelling's T(2)-test yielded a significant p-value of 0.00039. In addition, 100 equidistant landmarks representing the curve only were also assigned. These, however, yielded considerably poorer results. It is concluded that it is better to use homologous landmarks rather than curve data only, as it is most probable that the shape of the outline relative to the fixed homologous points on the scapula is sexually dimorphic.

A report on the high incidence of supernumerary teeth in skeletal remains from a 19th century mining community from Kimberley, South Africa

INTRODUCTION

Supernumerary teeth can be described as the presence of more than 20 deciduous, or 32 permanent teeth in one individual. This condition occurs in 0.1% - 3.7% of individuals within most populations.

AIM

The purpose of this study was to examine the incidence of hyperdontia in a 19th century mining community from Kimberley.

MATERIALS AND METHODS

The Sol Plaatjie municipality disturbed several unmarked graves outside the fenced Gladstone cemetery in Kimberley, South Africa. The remains belonged to mine workers and other individuals who died in the Kimberley and surrounding hospitals between 1897 and 1900. The well preserved teeth of 76 adult males and 13 adult females were examined and counted.

RESULTS

Supernumerary teeth were documented in 6.7% (N = 6) of the study population. This was high when considering the incidence of this condition in other population groups. Two of the seven individuals affected by the condition presented with multiple non-syndromal supernumerary teeth.

CONCLUSION

The Gladstone sample population was mostly composed of migrant workers, and it is proposed that, although several factors may influence the development of supernumerary teeth, the possibility of a genetic relationship between some of these individuals should be considered to be responsible for the high incidence of hyperdontia in this sample.

Life expectancy of the 20th century Venda: a compilation of skeletal and cemetery data

Little information is available on the 20th century mortality rates of rural black South African groups, such as the Venda. The purpose of this study was to apply abridged life tables in order to estimate life expectancy from both skeletal remains and death registry information of modern South African communities. Comparisons were also made with prehistoric and contemporary groups as a means to better evaluate life expectancy for this time period. The sample consisted of 160 skeletons of known Venda origin and burial registry information for 1364 black South Africans from the Rebecca Street and Mamelodi Cemeteries in Pretoria, South Africa. Standard anthropological techniques were applied to determine sex and estimate age from the skeletal remains. The stationary and non-stationary life table models were used to analyse the data. A high rate of child mortality, low juvenile and adult mortality with a steady increase in mortality after the age of 30 years was observed for both the Venda and the cemetery samples. Throughout the 20th century, life expectancy was shown to increase for black South Africans. However, due to the widespread HIV infection/AIDS of the 21st century, infant and young adult mortality rates continue to rise at such a speed that the decline in mortality seen for South Africans in the last 50 years will most likely to be lost in the next decade due to this disease.

Interpretation of ante-mortem stature estimates in South Africans

When human skeletal remains of unknown individuals are analysed, the estimation of ante-mortem stature forms a key part of the report. However, for many people it may be difficult to judge the height of their missing relative in metric values. In this paper, we report on the statures of 2052 black, 483 coloured and 880 white South Africans of both sexes, measured during the last few years. It is shown that the statures of whites are significantly higher than those of the other two groups. The statures of the black and coloured groups are similar. It is proposed that the stature estimates provided in forensic reports are interpreted as tall, medium or short, based on whether they fall in the upper 25%, middle 50% or lower 25% of the distribution for the specific population.

Investigation into the usability of geometric morphometric analysis in assessment of sexual dimorphism

Understanding sexual dimorphism is very important in studies of human evolution and skeletal biology. Sexual dimorphic characteristics can be studied morphologically and metrically, although morphologic studies pose several problems such as difficulties with quantification and interobserver error. Geometric morphometrics is a relatively new method that allows better assessment of morphologic characteristics. This paper aims to investigate the usability of this method by assessing three different morphologic characteristics in a sample of South African blacks: shape of the greater sciatic notch, mandibular ramus flexure, and shape of the orbits. Relative warps, thin-plate splines, and canonical variates analysis (CVA) analyses were performed. As expected, the shape of the greater sciatic notch provided the best separation between the sexes. Surprisingly, however, the shape of the orbits performed better that ramus flexure. Several possible explanations for this result are possible, which include the possibility that orbit shape is more sexually dimorphic than previously expected, or that biological reality is not reflected by this technique. More research is, however, needed.

Geometric morphometric analysis of mandibular ramus flexure

Many characteristics of the human skeleton can only be assessed morphologically, which may be problematic due to factors such as interobserver error and difficulties with standardization. Flexure of the mandibular ramus is one of these traits, and various researchers found widely differing results using this morphological feature. The aim of this study was to determine whether differences between male and female mandibular rami could be observed using the computerized method of geometric morphometrics, a valuable tool that helps quantify shape differences. Twenty-eight mandibular rami of black females and 43 of black males were photographed in a standard plane and assessed. It was found that the females were more scattered on the graph (more variable in shape), while the males clustered more around the center point where the two axes met (shape more constant). There was, however, considerable overlap between the sexes. Although different tendencies exist between the rami of males (being more flexed) and females (tending to be straight), the extent of these differences is not adequate to predict the sex of a single individual.

Assessment of the quality of interaction in distance learning programmes utilising the Internet (WebCT) or interactive television (ITV)

INTRODUCTION

This study focuses on the quality of interaction in interactive TV (ITV), WebCT bulletin boards (BBs) and chat rooms (CRs) and addresses the question of how effectively new collaborative electronic technologies have been married with new pedagogical ideas to create effective learning for distance education students.

METHODS

Fifteen (out of 68) BB, 14 (out of 32) CR and 13 (out of 25) ITV conversations were randomly selected for coding using a modified exchange structure analysis. The roles that students and lecturers took in the conversations were determined from this.

RESULTS

The percentage of turns made by lecturers as opposed to students was 51% in CRs, 14% in BBs and 68% in ITV. The percentage of turns spent on actual coursework was 73% in CRs, 89% in BBs and 82% in ITV. Comparisons between tutors' and students' roles within as well as between ITV, BBs and CRs were all statistically significant with P < 0.05. In CRs the main roles of both students and lecturers were those of elaborators, inquirers and explainers. In BBs the main roles of students and lecturers were those of explainers and evaluators. In ITV sessions students' main roles were those of elaborators and explainers, whereas lecturers' main roles were those of lecturers, elaborators, inquirers and evaluators.

CONCLUSION

In terms of creating a constructivist and active learning community that can operate within a distance learning paradigm, WebCT appears superior to ITV.

Muti murders form South Africa: A case report

In Southern Africa, human body parts are sometimes used for medicinal (muti) purposes. The human body is seen as being very powerful. Although ritual killing for this purpose is not common, some cases have been reported. This paper reports on an unusual muti murder, where the remains of two individuals were found in a medicine man's house. Three pots were found, two of which were constructed around human skulls. Various objects, such as coins, bullets, stones, human and animal bones were found inside the pots. They were decorated with beadwork, whistles, skin bangles, etc. Osteological analysis revealed that the human remains probably belonged to a young, white adult male individual, and a juvenile individual of Negroid descent. All associated objects probably have ritual significance, and some of these are discussed.

Metric analysis of sex differences in South African black and white pelves

Sex determination of unknown skeletal material is one of the most vital determinations made by forensic anthropologists. Numerous studies have focussed on the differences, both osteometric and morphological, between the sexes of a particular racial phenotype and population. Previous work by a variety of researchers has underscored the necessity of population specific standards. The purpose of this research is to metrically assess sex differences in the pelvis of South African whites and blacks and develop standards tailored to these groups. Data were collected from 400 known sex/race skeletons from the Pretoria and Dart Collections. Nine measurements (traditional and newly developed) were taken and subjected to SPSS stepwise and direct discriminant analysis. Results indicated that there are significant differences (p < or = 0.001) between the sexes of both races for most measurements. Discriminant function analysis selected ischial length as the most sexually dimorphic dimension in whites (averaged 86% accuracy), while acetabulum diameter was most diagnostic in blacks (averaged 84% accuracy). Six functions were developed from the pelvic dimensions. Highest accuracy was achieved from Function 1 (including all dimensions) which averaged 95.5% correct classification in whites and 94% in blacks. Functions based on selected parts of the pelvis were not as effective and ranged from 73-86% in whites and 72-84% in blacks. This research provided evidence of the significant sex differences that exist between the pelves of South African whites and blacks whilst measurements used here for discriminant function analysis gave classifications with high accuracies. These results can be used to aid in the identification of human skeletal remains in South Africa.

Paleoparasitological Analysis of Coprolites from K2, an Iron Age Archaeological Site in South Africa: The First Finding of Dicrocoelium Sp. Eggs

Until now, Dicrocoelium sp. eggs have only been recorded from European and 1 North American archaeological sites. We present evidence for the first record of Dicrocoelium sp. from an African archaeological site. A paleoparasitological study was conducted on 7 coprolite samples from K2, a Late Iron Age site on the farm Greefswald, in the Northern Province of South Africa. Standard parasitological analysis revealed the presence of Dicrocoelium sp. and Trichuris sp. eggs. Today, the parasite does not occur in this region. Trichurid eggs are a relatively common find in paleoparasitological analysis. The presence of Dicrocoelium sp. provides new clues about the antiquity of this parasite, as well as aspects of ancient environment, climate, and interactions among humans, animals, and parasites.

Assessment of microbial infection risks posed by ingestion of water during domestic water use and full-contact recreation in a mid-southern African region

A customised Water-related Quantitative Microbial Risk Assessment (WRQMRA) process was used to determine risk of infection to water ingested by users in the south-eastern Free State, South Africa. The WRQMRA consisted of an observed-adverse-effect-level approach (OAELA) and a quantitative microbial risk assessment (QMRA). The OAELA was based on the occurrence of E. coli in the study waters to determine the possible risk of infection and the QMRA probable risk of infection by salmonellae. The WRQMRA was applied to recreational surface resource waters as well as waters from an unprotected spring and waters from the treated municipal supply that were stored in containers for domestic purposes. E. coli numbers were measured against expected infection levels expressed in water quality guidelines, while Salmonella counts were calculated to give the probable infection risk (Pi). Ingestion was based on intake volumes compiled for the various water uses. E. coli occurred in numbers <10(6) in the surface waters, while the untreated spring and treated supply water contained E. coli of <10(2) and <10(1) respectively. Salmonella occurred in numbers of <10(3) in recreational waters, and <10(-1) in water used for domestic purposes. A single exposure to the mean (as well as 95th percentile) risk was calculated using a beta-Poisson dose-response model at ingestion volumes of 100 mL (for full-contact recreation) and 1,318 mL (for domestic water use). Both the OAELA and the QMRA approaches indicated a risk of infection to recreational and domestic water users, even for a single exposure event, with the OAELA either over- or under-estimating the risk of infection for singular exposure events. This indicated that this method, used on its own, could not reliably predict a realistic risk of infection. It is recommended that the full WRQMRA process be used, and further developed to address several uncertainties that became evident during this study.

Geometric morphometric analysis of the greater sciatic notch in South Africans

The width of the greater sciatic notch of the pelvis is a characteristic commonly used to determine sex in unknown individuals. Recent research on South African skeletal material indicated that this feature may not be so reliable, especially in South African white males. In this study the greater sciatic notches of 115 known skeletons of South African origin were analysed using geometric morphometrics. Geometric morphometrics is a relatively new method that helps to quantify shape. Using this method, it was observed that South African black males have the typical narrow shape, while both the black and white females have typical wide notches. The white males, however, showed a very wide variation and their shapes scattered across the range. The shape of the greater sciatic notch is therefore not reliable to use in sex determination in this population group. Geometric morphometric analysis proved to be a valuable and reliable method to verify morphological characteristics observed with more traditional methods.

Sexually dimorphic pelvic morphology in South African whites and blacks

It is well known that there is metric and morphologic variation in the expression of sexual dimorphism between racial phenotypes and populations. Therefore, the purpose of this research is to assess morphologic sex differences in the pelves of South African whites and blacks. Results will be used to improve the identification of human skeletal remains by producing group specific standards. Morphologic features of both left and right os coxae were studied in a sample of 400 known sex/race individuals from the Pretoria and Dart collections. Bones that were clearly pathologic or visibly deformed were excluded from the study. Data were subjected to SPSS analysis. Results indicated that overall, public bone shape was the easiest to assess and was the most consistently reliable morphological indicator of sex in both sexes and population groups. At 88% average accuracy, the most discriminating traits in whites were pubic bone shape and subpubic concavity form. In blacks, greater sciatic notch form allowed the highest separation, averaging 87.5%, followed by pubic shape at 84.5%. Important findings included the fact that there were significant differences in the accuracy of sex determination from pelvic morphology between both males and females and whites and blacks. In conclusion, this study provides quantification of individual morphological traits in the os coxae of white and black South Africans that will be of value in forensic and archaeological analyses, especially when dealing with fragmentary remains. It also demonstrates that population differences affect the expression of sexual dimorphism and must be accounted for to develop the most effective methods of analysis.

An assessment of the health status and physical characteristics of an early 20th century community a + Maroelabult in the north west province, South Africa

As a result of mining activities, two related graveyards dating from the last decade of the 19th century and first half of the 20th century had to be relocated. This provided the opportunity to study 47 skeletons of black South Africans, with the aim of obtaining information on the health status and life style of people from a rural area in a mostly pre-antibiotic era. Although the sample is too small to do a proper palaeodemographic analysis, the age spread of the individuals indicates a high infant mortality rate and generally low life expectancy. Medical services were available, as could be seen from the surgically treated forearm fracture of one individual. One individual had signs of a possible treponemal infection, while subperiosteal bone growth on the ribs of another may indicate tuberculosis. High incidences of arthritic disease and joint degeneration probably indicate a high work load. Enlarged fontanelles with delayed closure were noted in some of the infants. Data on long bone lengths also indicate that the growth of the children may have been retarded in comparison to other similarly aged children. It thus seems as though this was a community under considerable stress. A surprising find was the unusually high incidence of individuals with dental abnormalities and variations.

Metric assessment of race from the pelvis in South Africans

It is well known that there are measurable differences between whites and blacks in the size and proportions of skeletal components. There are also metric differences among populations within these racial phenotypes. The population specific quantification of this variation can be used to aid in the identification of racial affinity in the absence of a more racially definitive skeletal element like the skull. Therefore, the purpose of this research is to quantify these differences in the pelvis of South African whites and blacks. A sample of 400, ostensibly healthy known sex/race os coxae was examined. Skeletal material was obtained from the Pretoria and Dart collections. A series of 13 measurements were taken Data were subjected to SPSS stepwise and direct discriminant function analysis. Pubic length was chosen as best for discriminating between races for males and iliac breadth as best in females. Highest average accuracies (Function 1) were 88% for males (pubic length, greater sciatic notch posterior width, acetabulum diameter, total height) and 85% for females (pubic length, greater sciatic notch posterior width, acetabulum diameter, iliac breath). In conclusion, this research resulted in the development of standards of identification tailored to this population and unquestionably demonstrates that race differences in the skeleton are highly significant and must be considered in all skeletal analyses.

Long-term homocysteine-lowering treatment with folic acid plus pyridoxine is associated with decreased blood pressure but not with improved brachial artery endothelium-dependent vasodilation or carotid artery stiffness: a 2-year, randomized, placebo-controlled trial

Homocysteine is associated with atherothrombotic disease, which may be mediated through associations of homocysteine levels with blood pressure, endothelial function, or arterial stiffness. In a placebo-controlled, randomized clinical trial, we measured blood pressure, brachial artery endothelium-dependent vasodilation, and common carotid artery stiffness in 158 clinically healthy siblings of patients with premature atherothrombotic disease at baseline and after 1 and 2 years of homocysteine-lowering treatment with folic acid (5 mg) plus pyridoxine (250 mg). Intention-to-treat analyses limited to participants (n=130) who underwent at least 1 measurement after the baseline visit showed that compared with placebo, treatment with folic acid plus pyridoxine was associated with a 3.7-mm Hg (95% CI -6.8 to -0.6 mm Hg) lower systolic and a 1.9-mm Hg (95% CI -3.7 to -0.02 mm Hg) lower diastolic blood pressure over the 2-year trial period. Together with the decreased occurrence of abnormal exercise electrocardiography tests reported previously, our results support the hypothesis that homocysteine-lowering treatment with folic acid plus pyridoxine has beneficial vascular effects. Because no effects could be demonstrated on brachial artery endothelium-dependent vasodilation or on common carotid artery stiffness, the present study does not support the hypothesis that the cardiovascular effects of homocysteine are mediated through these factors, at least in clinically healthy individuals.

Traditional healers and cancer prevention

The increase in the incidence of cancer in South Africa necessitates the expansion of preventative efforts. This study shows that traditional healers in Atteridgeville are consulted by a range of people in their communities, have a basic knowledge of cancer, provide health education to their patients and are willing to participate in cancer preventative strategies. They are therefore ideally suited to augment the services of westernized health care workers. The issue of professionalization is explored and a procedure is suggested whereby the training of traditional healers can be enhanced so as to facilitate their professionalization and their collaboration with other health care workers in the prevention of cancer.