scholarly journals Event history and down-pressure re-equilibration of highly chromian, garnet-rich peridotite xenoliths from South African kimberlites

Author(s):  
Jeanne Cilliers

Very little is known about what family life looked like for settlers in colonial South Africa during the 18th or 19th century, nor how events over these centuries might have affected demographic change. The primary reason for this lacuna is a shortage of adequate data. Historians and genealogists have, over the last century, worked to combine the rich administrative records that are available in the Cape Archives in Cape Town and beyond, into a single genealogical volume of all settlers living in the 18th, 19th and early 20th century. Until recently, this valuable resource was not in a format that would enable its use for the type of event-history analyses that have come to dominate the field of contemporary historical demography. This is now changing with the introduction of the South African Families database (SAF). SAF is one of very few databases known to document a full population of immigrants and their families over several generations. This article introduces provides a brief background to, and technical overview of, the construction of the SAF. It discusses both the merits and limitations of its use in longitudinal demographic studies and offers a look into the types of studies it can enable.


Author(s):  
N. H. Olson ◽  
T. S. Baker ◽  
Wu Bo Mu ◽  
J. E. Johnson ◽  
D. A. Hendry

Nudaurelia capensis β virus (NβV) is an RNA virus of the South African Pine Emperor moth, Nudaurelia cytherea capensis (Lepidoptera: Saturniidae). The NβV capsid is a T = 4 icosahedron that contains 60T = 240 subunits of the coat protein (Mr = 61,000). A three-dimensional reconstruction of the NβV capsid was previously computed from visions embedded in negative stain suspended over holes in a carbon film. We have re-examined the three-dimensional structure of NβV, using cryo-microscopy to examine the native, unstained structure of the virion and to provide a initial phasing model for high-resolution x-ray crystallographic studiesNβV was purified and prepared for cryo-microscopy as described. Micrographs were recorded ∼1 - 2 μm underfocus at a magnification of 49,000X with a total electron dose of about 1800 e-/nm2.


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