Oral examination and radiographic evaluation of the dentition in wild cats from Namibia

Feline tooth resorption has been widely reported in domestic cats and sporadically described in other felidae. The goal of the present study was to determine the prevalence of tooth resorption and to report other dental problems in a population of wild felidae. Observations of dental disorders and anomalies were made in skulls from 73 wild felidae (cheetahs, leopards, caracals, African wildcats, and lions) originating from Namibia. In addition, radiographs were taken in 43 cases to determine signs of bone and root pathology. Radiographs showed varying stages of tooth resorption in 16.0% of the specimens. Other dental anomalies found included fused teeth, supernumerary roots, or missing teeth. The prevalence of dental resorption in wild felidae was lower than reported in the domestic cat.

Decolonising the Mind: Nationalismus im Rundfunk in Namibia und Zambia

In diesem Aufsatz wird die Rolle des Radios im Dekolonisierungsprozess analysiert. Anhand zweier Beispiele – Namibia und Zambia – wird die Vermittlung eines afrikanischen Nationalismus untersucht, der sich nach der Unabhängigkeit in Bemühungen zum nation building niederschlug. Das Radio nahm (und nimmt) als wichtigstes Massenmedium in afrikanischen Staaten dabei insofern eine zentrale Rolle ein, als die jeweiligen Ideologien über dieses Medium an eine Bevölkerung übermittelt werden sollten. Im Beitrag werden nicht nur die jeweiligen Politiken analysiert, sondern auch die Rolle und Eigenwahrnehmung der Journalisten / innen und die Programme selbst. Die Widersprüche zwischen gewünschter Politik, vorhandener Infrastruktur, Vorstellungen der Journalist/innen und den Hörerwünschen machten die Vermittlung nationalistischer Politik sowie die Herstellung eines virtuellen nationalen Raumes im Radio zu komplexen Prozessen, die nicht immer gelingen konnten.

Provenance versus weathering control on the composition of tropical river mud (southern Africa)

This study presents an integrated mineralogical-geochemical data base on fine-grained sediments transported by all major rivers of southern Africa, including the Zambezi, Okavango, Limpopo, Olifants, Orange and Kunene. Clay mineralogy, bulk geochemistry, Sr and Nd isotopic signatures of river mud, considered as proxy of suspended load, are used to investigate the influence of source-rock lithology and weathering intensity on the composition of clay and silt produced in subequatorial to subtropical latitudes. Depletion in mobile alkali and alkaline-earth metals, minor in arid Namibia, is strong in the Okavango, Kwando and Upper Zambezi catchments, where recycling is also extensive. Element removal is most significant for Na, and to a lesser extent for Sr. Depletion in K, Ca and other elements, negligible in Namibia, is moderate elsewhere. The most widespread clay minerals are smectite, dominant in muds derived from Karoo or Etendeka flood basalts, or illite and chlorite, dominant in muds derived from metasedimentary rocks of the Damara Orogen or Zimbabwe Craton. Kaolinite represents 30-40% of clay minerals only in Okavango and Upper Zambezi sediments sourced in humid subequatorial Angola and Zambia. After subtracting the effects of recycling and of local accumulation of authigenic carbonates in soils, the regional distribution of clay minerals and chemical indices consistently reflect weathering intensity primarily controlled by climate. Bulk geochemistry identifies most clearly volcaniclastic sediments and mafic sources in general, but cannot discriminate the other sources of detritus in detail. Instead, Sr and Nd isotopic fingerprints are insensitive to weathering, and thus mirror faithfully the tectonic structure of the southern African continent. Isotopic tools thus represent a much firmer basis than bulk geochemistry or clay mineralogy in the provenance study of mudrocks.

Distance from Sub-Saharan Africa Predicts Mutational Load in Diverse Human Genomes

The Out-of-Africa (OOA) dispersal ∼50,000 y ago is characterized by a series of founder events as modern humans expanded into multiple continents. Population genetics theory predicts an increase of mutational load in populations undergoing serial founder effects during range expansions. To test this hypothesis, we have sequenced full genomes and high-coverage exomes from seven geographically divergent human populations from Namibia, Congo, Algeria, Pakistan, Cambodia, Siberia, and Mexico. We find that individual genomes vary modestly in the overall number of predicted deleterious alleles. We show via spatially explicit simulations that the observed distribution of deleterious allele frequencies is consistent with the OOA dispersal, particularly under a model where deleterious mutations are recessive. We conclude that there is a strong signal of purifying selection at conserved genomic positions within Africa, but that many predicted deleterious mutations have evolved as if they were neutral during the expansion out of Africa. Under a model where selection is inversely related to dominance, we show that OOA populations are likely to have a higher mutation load due to increased allele frequencies of nearly neutral variants that are recessive or partially recessive.