Bacterial ecology of ancient Saharan salt-enrichment ponds at Teguidda-n-Tessoumt

Little is known about the bacterial ecology of evaporative salt-mining sites (salterns) of which Teguidda-n-Tessoumt at the fringe of the West-African Saharan desert in Niger is a spectacular example with its many-centuries-old and very colorful evaporation ponds. During the different enrichment steps of the salt produced as a widely traded feed supplement for cattle, animal manure is added to the crude brine, which is then desiccated and repeatedly crystallized. This study describes the dominant Bacteria and Archaea communites in the brine from the evaporation ponds and the soil from the mine, which were determined by PCR-DGGE of 16S rDNA. Correspondence analysis of the DGGE-community fingerprints revealed a change in community structure of the brine samples during the sequential evaporation steps which was, however, unaffected by the brine's pH and electric conductivity (EC). The Archaea community was dominated by a phylogenetically diverse group of methanogens, while the Bacteria community was dominated by gamma proteobacteria. Microorganisms contained in the purified salt product have the potential to be broadly disseminated and are fed to livestock across the region. In this manner, the salt mines represent an intriguing example of long-term human activity that has contributed to the continual selection, cultivation, and dissemination of cosmopolitan microorganisms.

Difference and equality: A critical theorist analysis of post-modern philosophy

The following paper is a critical theorist analysis of post-structuralist philosophy. It examines the omission of an economic critique in post-structuralism and describes this omission as the result of a particular flaw in Nietzsche's epistemological work, an error which has persisted all the way down through deconstruction, post-colonialism, and cultural studies. The paper seeks to reintroduce an economic critique of capitalism back into the social critique of post-structuralism, with the promise that the combination of the two will prove stronger than either critical theory or post-structuralism alone. To achieve this it reinterprets Marx' concept of metabolism as a critical economic category that mirrors post-structuralism's concept of differance.