Heavy flavour energy loss from AdS/CFT: A novel diffusion coefficient

Two AdS/CFT based energy loss models are used to compute the suppression and azimuthal correlations of heavy quarks in heavy ion collisions. The model with a velocity independent diffusion coefficient is in good agreement with B and D meson data up to high $p_T$. The partonic azimuthal correlations we calculate exhibit an order of magnitude difference in low momentum correlations to pQCD calculations [arXiv:1305.3823]. We thus propose heavy flavour momentum correlations as a distinguishing observable of weakly- and strongly-coupled energy loss mechanisms.Comment: 4 pages, 2 figures. Proceedings for Strangeness in Quark Matter 2017. arXiv admin note: text overlap with arXiv:1703.0584

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

Tuning the generalized Hybrid Monte Carlo algorithm

We discuss the analytic computation of autocorrelation functions for the generalized Hybrid Monte Carlo algorithm applied to free field theory and compare the results with numerical results for the $O(4)$ spin model in two dimensions. We explain how the dynamical critical exponent $z$ for some operators may be reduced from two to one by tuning the amount of randomness introduced by the updating procedure, and why critical slowing down is not a problem for other operators.Comment: 4 pages, to be published in the Proceedings of Lattice 95, uuencoded PostScript fil

Biochemical Aspects of Genetics

It would be impossible, in the time and space available, to cover all of the noteworthy advances that have been made in biochemical genetics during the past year. We have, therefore, selected for review a number of topics that are especially active at the moment and that promise to yield important new results in the near future. At the same time, we have tried to avoid duplicating the material of other chapters in this volume which are germane to biochemical genetics. We refer, in particular, to the chapters on Metabolism of Nucleic Acids (Macromolecular DNA and RNA); Nucleic Acids and Protein Biosynthesis; The Basic Proteins of Cell Nuclei; and Chemistry of Differentiation in Lower Organisms. The reader should consult these reviews, as well as the present one, for a fuller view of current activities in this field

Exact Description of Black Holes on Branes II: Comparison with BTZ Black Holes and Black Strings

We extend our recent discussion of four-dimensional black holes bound to a two-brane to include a negative cosmological constant on the brane. We find that for large masses, the solutions are precisely BTZ black holes on the brane, and BTZ `black strings' in the bulk. For smaller masses, there are localized black holes which look like BTZ with corrections that fall off exponentially. We compute when the maximum entropy configuration changes from the black string to the black hole. We also present exact solutions describing rotating black holes on two-branes which are either asymptotically flat or asymptotically $AdS_3$. The mass and angular momentum on the brane agree with that in the bulk.Comment: 30 page