Is Greulich-Pyle age estimation applicable for determining maturation in male Africans?

Skeletal age estimation as a means of assessing development and skeletal maturation in children and adolescents is of great importance for clinical and forensic purposes. The skeletal age of a test population is estimated by comparison with established standards, the most common standards being those in the Radiographic atlas of skeletal development of the hand and wrist published by Greulich and Pyle in 1959. These standards are based on the assumption that skeletal maturity in male individuals is attained by the chronological age of 19 years. Although they have been widely tested, the applicability of these standards to contemporary populations has yet to be tested on a population of African biological origin living in South Africa. We therefore estimated the skeletal age of 131 male Africans aged between 13 and 21 years, using the Greulich-Pyle method which we applied to pre-existing hand-wrist radiographs. Estimated skeletal age was compared to the known chronological age for each radiograph. Skeletal age was on average approximately 6 months younger than chronological age. The Greulich-Pyle method underestimated skeletal age for approximately 74% of the sample and overestimated skeletal age for 26% of the sample. Skeletal maturity as characterised by complete epiphyseal fusion occurred approximately 2.1 years later than Greulich and Pyle's estimate of 19 years. Thus skeletal maturation was still in progress in a large proportion of the 20- and 21-year-old individuals in our study. The Greulich-Pyle method showed high precision but low accuracy and was therefore not directly applicable to African male individuals. Formulation of skeletal age estimation standards specific to South African populations is therefore recommended

Is Greulich-Pyle age estimation applicable for determining maturation in male Africans?

Skeletal age estimation as a means of assessing development and skeletal maturation in children and adolescents is of great importance for clinical and forensic purposes. The skeletal age of a test population is estimated by comparison with established standards, the most common standards being those in the Radiographic atlas of skeletal development of the hand and wrist published by Greulich and Pyle in 1959. These standards are based on the assumption that skeletal maturity in male individuals is attained by the chronological age of 19 years. Although they have been widely tested, the applicability of these standards to contemporary populations has yet to be tested on a population of African biological origin living in South Africa. We therefore estimated the skeletal age of 131 male Africans aged between 13 and 21 years, using the Greulich-Pyle method which we applied to pre-existing hand-wrist radiographs. Estimated skeletal age was compared to the known chronological age for each radiograph. Skeletal age was on average approximately 6 months younger than chronological age. The Greulich-Pyle method underestimated skeletal age for approximately 74% of the sample and overestimated skeletal age for 26% of the sample. Skeletal maturity as characterised by complete epiphyseal fusion occurred approximately 2.1 years later than Greulich and Pyle's estimate of 19 years. Thus skeletal maturation was still in progress in a large proportion of the 20- and 21-year-old individuals in our study. The Greulich-Pyle method showed high precision but low accuracy and was therefore not directly applicable to African male individuals. Formulation of skeletal age estimation standards specific to South African populations is therefore recommended

Trauma and violence in the Later Stone Age of southern Africa

Background. Antemortem and perimortem fractures in skeletons recovered from Later Stone Age burials in southern Africa demonstrate that people were, on occasion, the victims of severe trauma attributable to interpersonal violence. Methods. Case studies are presented of cranial vault depression fractures on 4 different individuals and a young adult female who had 2 bone arrowheads embedded in the lower vertebrae. These are compared with other cases from the literature. Results. The evidence from the archaeological skeletons suggests that interpersonal violence was a regular occurrence among prehistoric foragers. Additional cases show healed fractures of other bones, but these probably represent injuries from day-to-day activities rather than violent conflict. Discussion. The ethnographic depiction of the San as ‘harmless people’ is probably inaccurate, or, at best, only representative of the situation in northern Botswana in the 1960s. Damage to the bones indicates that the cause of the trauma was intentional violence. Explanatory models that suggest intense competition between hunter-gatherer groups are probably more accurate than ones that suggest that the groups were non-aggressive. Conclusion. Historical references to the San as aggressive and dangerous adversaries may be more accurate than revisionist historians have argued

Dynamics of Indian Ocean slavery revealed through isotopic data from the colonial era Cobern Street Burial site, Cape Town, South Africa (1750-1827)

The Dutch East India Company (VOC) intended the Cape of Good Hope to be a refreshment stop for ships travelling between the Netherlands and its eastern colonies. The indigenous Khoisan, however, did not constitute an adequate workforce, therefore the VOC imported slaves from East Africa, Madagascar and Asia to expand the workforce. Cape Town became a cosmopolitan settlement with different categories of people, amongst them a non-European underclass that consisted of slaves, exiles, convicts and free-blacks. This study integrated new strontium isotope data with carbon and nitrogen isotope results from an 18 th -19 th century burial ground at Cobern Street, Cape Town, to identify non-European forced migrants to the Cape. The aim of the study was to elucidate individual mobility patterns, the age at which the forced migration took place and, if possible, geographical provenance. Using three proxies, 87 Sr/ 86 Sr, δ 13 C dentine and the presence of dental modifications, a majority (54.5%) of the individuals were found to be born non-locally. In addition, the 87 Sr/ 86 Sr data suggested that the non-locally born men came from more diverse geographic origins than the migrant women. Possible provenances were suggested for two individuals. These results contribute to an improved understanding of the dynamics of slave trading in the Indian Ocean world

Dynamical description of vesicle growth and shape change

We systematize and extend the description of vesicle growth and shape change using linear nonequilibrium thermodynamics. By restricting the study to shape changes from spheres to axisymmetric ellipsoids, we are able to give a consistent formulation which includes the lateral tension of the vesicle membrane. This allows us to generalize and correct a previous calculation. Our present calculations suggest that, for small growing vesicles, a prolate ellipsoidal shape should be favored over oblate ellipsoids, whereas for large growing vesicles oblates should be favored over prolates. The validity of this prediction is examined in the light of the various assumptions made in its derivation.Comment: 6 page

Corn, 1991

Harry C. Minor is an Associate Professor of Agronomy and State Extension Specialist, Carl G. Morris and Howard L. Mason are Senior Research Specialists, and Delbert R. Knerr, Alan W. Bixler, and C. Stephen Lankheit are Research Specialists in Agronomy.Compares hybrids and includes experimental procedures, yield results and seed corn company addresses.Comparing hybrids -- Experimental procedures -- Summary of results -- Yield results -- Seed corn company addresse

Functional analysis of epilepsy-associated variants in STXBP1/Munc18-1 using humanised Caenorhabditis elegans

Objective: Genetic variants in STXBP1 , which encodes the conserved exocytosis protein Munc18‐1, are associated with a variety of infantile epilepsy syndromes. We aimed to develop an in vivo Caenorhabditis elegans model that could be used to test the pathogenicity of such variants in a cost‐effective manner. Methods: The CRISPR/Cas9 method was used to introduce a null mutation into the unc‐18 gene (the C. elegans orthologue of STXBP1 ), thereby creating a paralyzed worm strain. We subsequently rescued this strain with transgenes encoding the human STXBP1/Munc18‐1 protein (wild‐type and eight different epilepsy‐associated missense variants). The resulting humanized worm strains were then analyzed via behavioral, electrophysiological, and biochemical approaches. Results: Transgenic expression of wild‐type human STXBP1 protein fully rescued locomotion in both solid and liquid media to the same level as the standard wild‐type worm strain, Bristol N2. Six variant strains (E59K, V84D, C180Y, R292H, L341P, R551C) exhibited impaired locomotion, whereas two (P335L, R406H) were no different from worms expressing wild‐type STXBP1. Electrophysiological recordings revealed that all eight variant strains displayed less frequent and more irregular pharyngeal pumping in comparison to wild‐type STXBP1‐expressing strains. Four strains (V84D, C180Y, R292H, P335L) exhibited pentylenetetrazol‐induced convulsions in an acute assay of seizure‐like activity, in contrast to worms expressing wild‐type STXBP1. No differences were seen between wild‐type and variant STXBP1 strains in terms of mRNA abundance. However, STXBP1 protein levels were reduced to 20%‐30% of wild‐type in all variants, suggesting that the mutations result in STXBP1 protein instability. Significance: The approach described here is a cost‐effective in vivo method for establishing the pathogenicity of genetic variants in STXBP1 and potentially other conserved neuronal proteins. Furthermore, the humanized strains we created could potentially be used in the future for high‐throughput drug screens to identify novel therapeutics