The burden of history: Namibia and Germany from colonialism to postcolonialism

When former German Foreign Minister Joseph ‘Joschka’ Fischer visited Windhoek in October 2003, he went on record to say that there would be no apology that might give grounds for reparations for the first genocide of the 20th century, which was committed by German colonial troops in Namibia in 1904–1908. Fischer’s rather undiplomatic words are indicative of the intense and heated historical and present relations between Germany and her erstwhile colony

Age-related efficiency loss of household refrigeration appliances: Development of an approach to measure the degradation of insulation properties

Despite the omnipresence of household refrigeration appliances, there is still a lack of knowledge about their age-related efficiency loss over time. Past studies provide basic evidence for increasing electricity consumption of cooling appliances with ageing but fail to investigate the associated technical wear. Concentrating on the degradation of the thermal insulation, we first determined the ageing process of sealed samples of polyurethane rigid foam by investigating changes in cell gas composition and thermal conductivity over time. Simultaneously, the main challenge was to develop an approach that investigates the age-related efficiency loss of the insulation without its destruction. This testing procedure is referred to as the Bonn method. The non-destructive Bonn method was applied to varying refrigerator models in a series of successive experiments to evaluate the insulation degradation over time. Subsequently, the physical relationship between the test value of the Bonn method and the heat transfer through the multi-layered compartment walls of domestic refrigeration appliances was established, ultimately characterising the degrading insulation in terms of increasing heat transfer. Our results give substantiated evidence that the efficiency loss of cooling appliances is greatly influenced by insulation degradation over time. The ageing of sealed samples of polyurethane rigid foam indicates a large initial increase of thermal conductivity by 15% within the first year, corresponding to a change in cell gas composition. These results are in line with those of the Bonn method, emphasising an increasing heat flow through the multi-layered compartment walls of domestic refrigerators with ageing. Therewith, the present study is of significance to a wide range of stakeholders and forms the basis for future research.BMWi, 03ET1544, ALGE: Alterungsmechanismen von Haushaltskältegeräte

Der Abklärungsprozess in der Invalidenversicherung bei Rentenentscheiden : Prozesse, Akteure, Wirkungen

Forschungsbericht Nr. 4/1

Parallel Structural Evolution of Mitochondrial Ribosomes and OXPHOS Complexes

The five macromolecular complexes that jointly mediate oxidative phosphorylation (OXPHOS) in mitochondria consist of many more subunits than those of bacteria, yet, it remains unclear by which evolutionary mechanism(s) these novel subunits were recruited. Even less well understood is the structural evolution of mitochondrial ribosomes (mitoribosomes): while it was long thought that their exceptionally high protein content would physically compensate for their uniquely low amount of ribosomal RNA (rRNA), this hypothesis has been refuted by structural studies. Here, we present a cryo- electron microscopy structure of the 73S mitoribosome from Neurospora crassa, together with genomic and proteomic analyses of mitoribosome composition across the eukaryotic domain. Surprisingly, our findings reveal that both structurally and compositionally, mitoribosomes have evolved very similarly to mitochondrial OXPHOS complexes via two distinct phases: A constructive phase that mainly acted early in eukaryote evolution, resulting in the recruitment of altogether approximately 75 novel subunits, and a reductive phase that acted during metazoan evolution, resulting in gradual length-reduction of mitochondrially encoded rRNAs and OXPHOS proteins. Both phases can be well explained by the accumulation of (slightly) deleterious mutations and deletions, respectively, in mitochondrially encoded rRNAs and OXPHOS proteins. We argue that the main role of the newly recruited (nuclear encoded) ribosomal- and OXPHOS proteins is to provide structural compensation to the mutationally destabilized mitochondrially encoded components. While the newly recruited proteins probably provide a selective advantage owing to their compensatory nature, and while their presence may have opened evolutionary pathways toward novel mitochondrion-specific functions, we emphasize that the initial events that resulted in their recruitment was nonadaptive in nature. Our framework is supported by population genetic studies, and it can explain the complete structural evolution of mitochondrial ribosomes and OXPHOS complexes, as well as many observed functions of individual proteins

Degradation of protein translation machinery by amino acid starvation-induced macroautophagy

Macroautophagy is regarded as a nonspecific bulk degradation process of cytoplasmic material within the lysosome. However, the process has mainly been studied by nonspecific bulk degradation assays using radiolabeling. In the present study we monitor protein turnover and degradation by global, unbiased approaches relying on quantitative mass spectrometry-based proteomics. Macroautophagy is induced by rapamycin treatment, and by amino acid and glucose starvation in differentially, metabolically labeled cells. Protein dynamics are linked to image-based models of autophagosome turnover. Depending on the inducing stimulus, protein as well as organelle turnover differ. Amino acid starvation-induced macroautophagy leads to selective degradation of proteins important for protein translation. Thus, protein dynamics reflect cellular conditions in the respective treatment indicating stimulus-specific pathways in stress-induced macroautophagy

A hip-hopera in Cape Town: The aesthetics, and politics of performing ‘Afrikaaps’

This paper looks into the aesthetics and politics of the ‘hip-hopera’ Afrikaaps. Afrikaaps was produced in 2010 by a group of musicians and spoken-word artists from Cape Town and the rural Western Cape Province of South Africa. The show premiered at an annual Afrikaans cultural festival; it then had a three week-run at a theatre, located in a predominantly white, English-speaking part of Cape Town, followed by different sets of performance in South Africa and abroad and the documentary by a Cape Town film maker. Dylan Valley’s (2011) film follows this group of local artists creating the stage production as they trace the roots of Afrikaans to Khoi-San and slaves in the Cape. The production aimed to ‘reclaim and liberate Afrikaans from its reputation as the language of the oppressor, taking it back for all who speak it.’ (Valley 2011) The paper presents an analysis of how visual and musical aesthetics converge in the performed production of history, as creolization, and ethnically-specific ‘heritage’, and how the self-stylization is employed in attempts at authenticating a recently asserted linguistic and cultural ‘identity’