Cellular and extracellular siderophores of Aspergillus nidulans and Penicillium chrysogenum

Aspergillus nidulans and Penicillium chrysogenum produce specific cellular siderophores in addition to the well-known siderophores of the culture medium. Since this was found previously in Neurospora crassa, it is probably generally true for filamentous ascomycetes. The cellular siderophore of A. nidulans is ferricrocin; that of P. chrysogenum is ferrichrome. A. nidulans also contains triacetylfusigen, a siderophore without apparent biological activity. Conidia of both species lose siderophores at high salt concentrations and become siderophore dependent. This has also been found in N. crassa, where lowering of the water activity has been shown to be the causal factor. We used an assay procedure based on this dependency to reexamine the extracellular siderophores of these species. During rapid mycelial growth, both A. nidulans and P. chrysogenum produced two highly active, unidentified siderophores which were later replaced by a less active or inactive product--coprogen in the case of P. chrysogenum and triacetylfusigen in the case of A. nidulans. N. crassa secreted coprogen only. Fungal siderophore metabolism is varied and complex

Activation of human NK cells by Plasmodium-infected red blood cells.

This chapter describes a protocol to assess activation of human NK cells following in vitro stimulation with malaria-infected red blood cells. Activation is assessed by flow cytometry, staining for cell surface expression of CD69 and accumulation of intracellular IFN-γ. Procedures are described for in vitro propagation and purification of Plasmodium falciparum parasites, separation of peripheral blood mononuclear cells from heparinized blood by density centrifugation, in vitro culture of PBMC and for staining and analysis of PBMC by flow cytometry. Some examples of typical FACS plots are shown

Testing AdS/CFT Deviations from pQCD Heavy Quark Energy Loss with Pb+Pb at LHC

Heavy quark jet quenching in nuclear collisions at LHC is predicted and compared using the classical gravity AdS/CFT correspondence and Standard Model perturbative QCD. The momentum independence and inverse quark mass dependence of the drag coefficient in AdS/CFT differs substantially from the characteristic log(pT/M)/pT variation of the drag in QCD. We propose that the measurement of the momentum dependence of the double ratio of the nuclear modification factors of charm and bottom jets is a robust observable that can be used to search for strong coupling deviations from perturbative QCD predictions.Comment: 4 pages, 2 figure

Dams, Cows, and Vulnerable People: Anthropological Contributions to Sustainable Development

It is with considerable trepidation that I agreed to address so distinguished a gathering of development economists, theoreticians, and practitioners. I was enormously honoured when Professor Naqvi invited me to make this presentation, and at the same time impressed with my own temerity at having accepted. I am not an economist; at best, I contribute to the emerging discipline of economic anthropology, that subfield of anthropology that some have baptised as the “dismal science of the 20th century.” I locate my research within a subfield of that subfield, in a specifically development anthropology, making the claim that is still received in some quarters with only partial tolerance, that anthropologists–those curious people identified in the popular mind with the recovery and study of isolated people, bones, and potsherds–have also something useful to add to both the theory and praxis of development. As a self-conscious field of inquiry, development anthropology dates only from the last 20-25 years, though its roots can be found in the late 19th century, when scientists working for the United States Bureau of American Ethnology tried to understand the Ghost Dance, a great messianic movement that spread rapidly among subjugated Native Americans who were forced on to reservations by the government and in very large part deprived of the means of social and economic reproduction.

Work producing reservoirs: Stochastic thermodynamics with generalized Gibbs ensembles

We develop a consistent stochastic thermodynamics for environments composed of thermodynamic reservoirs in an external conservative force field, that is environments described by the Generalized or Gibbs canonical ensemble. We demonstrate that small systems weakly coupled to such reservoirs exchange both heat and work by verifying a local detailed balance relation for the induced stochastic dynamics. Based on this analysis, we help to rationalize the observation that nonthermal reservoirs can increase the efficiency of thermodynamic heat engines.Comment: 6 pages, 1 figure, plus 3 page