(2R*,3R*,4aS*,6aR*,11aS*,11bS*)-Methyl 2-acet­oxy-11b-hydr­oxy-3,7-dimethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodeca­hydro­phenanthro[3,2-b]furan-3-carboxyl­ate

In the title compound, C22H30O6, the conformation of the mol­ecule is dictated by an intra­molecular C—H⋯O contact. The crystal structure is stabilized via inter­molecular C—H⋯O, O—H⋯O and C—H⋯π contacts

Whole-genome sequencing for an enhanced understanding of genetic variation among South Africans

The Southern African Human Genome Programme is a national initiative that aspires to unlock the unique genetic character of southern African populations for a better understanding of human genetic diversity. In this pilot study the Southern African Human Genome Programme characterizes the genomes of 24 individuals (8 Coloured and 16 black southeastern Bantu-speakers) using deep whole-genome sequencing. A total of ~16 million unique variants are identified. Despite the shallow time depth since divergence between the two main southeastern Bantu-speaking groups (Nguni and Sotho-Tswana), principal component analysis and structure analysis reveal significant (p < 10−6) differentiation, and FST analysis identifies regions with high divergence. The Coloured individuals show evidence of varying proportions of admixture with Khoesan, Bantu-speakers, Europeans, and populations from the Indian sub-continent. Whole-genome sequencing data reveal extensive genomic diversity, increasing our understanding of the complex and region-specific history of African populations and highlighting its potential impact on biomedical research and genetic susceptibility to disease

The intersection of archaeology, oral tradition and history in the South African interior.

The historical entanglement of indigenous and colonial societies in South Africa created not only multiple points of social and cultural interaction, but also a repository of interconnected material, oral and documentary records. A multi-source, comparative approach across disciplinary boundaries is, therefore, essential to achieve a full and seamless account of late precolonial and early colonial African history. Oral tradition could serve as a bridge between archaeology and text-based history, thereby enabling historically known political lineages to be connected with the archaeological ruins of specific precolonial African towns. Similarly, documentary sources on African societies of the interior are often very limited in scope even deep into the nineteenth century, as a result of which the complementary use of archaeological methods and data becomes a methodological imperative. Three case studies from the South African interior, Marothodi, Kaditshwene and Magoro Hill, are presented to illustrate the explanatory potential of an interdisciplinary approach to the study of the more recent African past

A reinvestigation of the ferrocene oxidation by iron(III) chloride in 2-butanone-ethanol

[[abstract]]The reaction of ferrocene with iron(III) chloride (4:3) in 2-butanone-ethanol-diethyl ether affords diferricenium μ-oxo-bis(trichloroferrate) with the anionic iron centres in the iron(III) oxidation state. The structure, determined by X-ray diffractometry, is corroborated by analytical and spectroscopic evidence[[notice]]補正完畢[[incitationindex]]SC

All is Number

Rational numbers, which correctly describe many recognizable patterns in the physical world, are often seen to converge in the process to irrational limits or even singularities. As a common example, atomic numbers are well known as fundamental parameters in chemistry, but by demonstrating that the periodicity of atomic matter is simulated by the convergence of rational fractions, from unity to the golden ratio, the importance of limiting processes and irrational limits in the modelling of chemical systems and of phenomena such as superconduction is emphasized. Other limiting formulae feature in atomic spectral series, radioactive decay, circular measure, absolute temperature, the speed of light, structure of the solar system and gravitational collapse. In virtually all cases the convergence involves the irrational golden ratio and the golden spiral, the essential properties of which are briefly reviewed in summary of the arguments developed in this volume. The suspicion that molecular shape should have a related number basis could not be substantiated. Only in the double-helical base pairing of DNA could any correlation between molecular structure and number theory be demonstrated. It is tempting to conjecture that the ubiquitous appearance of irrational limits signals the inadequacy of the R3 number system to provide a detailed account of the four-dimensional world.http://www.springer.com/series/430hj201