Medium effects in high energy heavy-ion collisions

The change of hadron properties in dense matter based on various theoretical approaches are reviewed. Incorporating these medium effects in the relativistic transport model, which treats consistently the change of hadron masses and energies in dense matter via the scalar and vector fields, heavy-ion collisions at energies available from SIS/GSI, AGS/BNL, and SPS/CERN are studied. This model is seen to provide satisfactory explanations for the observed enhancement of kaon, antikaon, and antiproton yields as well as soft pions in the transverse direction from the SIS experiments. In the AGS heavy-ion experiments, it can account for the enhanced $K^+/\pi^+$ ratio, the difference in the slope parameters of the $K^+$ and $K^-$ transverse kinetic energy spectra, and the lower apparent temperature of antiprotons than that of protons. This model also provides possible explanations for the observed enhancement of low-mass dileptons, phi mesons, and antilambdas in heavy-ion collisions at SPS energies. Furthermore, the change of hadron properties in hot dense matter leads to new signatures of the quark-gluon plasma to hadronic matter transition in future ultrarelativistic heavy-ion collisions at RHIC/BNL.Comment: RevTeX, 65 pages, including 25 postscript figures, invited topical review for Journal of Physics G: Nuclear and Particle Physic

Fluctuations In ``BR-Scaled'' Chiral Lagrangians

We develop arguments for "mapping" the effective chiral Lagrangian whose parameters are given by "BR scaling" to a Landau Fermi-liquid fixed-point theory for nuclear matter in describing fluctuations in various flavor (e.g., strangeness) directions. We use for this purpose the effective Lagrangian used by Furnstahl, Tang and Serot that incorporates the trace anomaly of QCD in terms of a light-quark (quarkonium) degree of freedom with the heavy (gluonium) degree of freedom integrated out. The large anomalous dimension $d_{an}\approx 5/3$ for the scalar field found by Furnstahl et al to be needed for a correct description of nuclear matter is interpreted as an indication for a strong-coupling regime and the ground state given by the BR-scaled parameters is suggested as the background around which fluctuations can be rendered weak so that mean-field approximation is reliable. We construct a simple model with BR scaled parameters that provides a satisfactory description of the properties of matter at normal nuclear matter density. Given this, fluctuations around the BR scaled background are dominated by tree diagrams. Our reasoning relies heavily on recent developments in the study of nucleon and kaon properties in normal and dense nuclear matter, e.g., nucleon and kaon flows in heavy-ion processes, kaonic atoms, and kaon condensation in dense compact-star matter.Comment: 33 pages, Latex, 5 Postscript figure

Tumor Necrosis Factor α Inhibits Expression of the Iron Regulating Hormone Hepcidin in Murine Models of Innate Colitis

Background: Abnormal expression of the liver peptide hormone hepcidin, a key regulator of iron homeostasis, contributes to the pathogenesis of anemia in conditions such as inflammatory bowel disease (IBD). Since little is known about the mechanisms that control hepcidin expression during states of intestinal inflammation, we sought to shed light on this issue using mouse models. Methodology/Principal Findings: Hepcidin expression was evaluated in two types of intestinal inflammation caused by innate immune activation—dextran sulfate sodium (DSS)-induced colitis in wild-type mice and the spontaneous colitis occurring in T-bet/Rag2-deficient (TRUC) mice. The role of tumor necrosis factor (TNF) $\alpha$ was investigated by in vivo neutralization, and by treatment of a hepatocyte cell line, as well as mice, with the recombinant cytokine. Expression and activation of Smad1, a positive regulator of hepcidin transcription, were assessed during colitis and following administration or neutralization of TNF$\alpha$. Hepcidin expression progressively decreased with time during DSS colitis, correlating with changes in systemic iron distribution. TNF$\alpha$ inhibited hepcidin expression in cultured hepatocytes and non-colitic mice, while TNF$\alpha$ neutralization during DSS colitis increased it. Similar results were obtained in TRUC mice. These effects involved a TNF$\alpha$-dependent decrease in Smad1 protein but not mRNA. Conclusions/Significance: TNF$\alpha$ inhibits hepcidin expression in two distinct types of innate colitis, with down-regulation of Smad1 protein playing an important role in this process. This inhibitory effect of TNF$\alpha$ may be superseded by other factors in the context of T cell-mediated colitis given that in the latter form of intestinal inflammation hepcidin is usually up-regulated

Identification of Functional and Expression Polymorphisms Associated With Risk for Antineutrophil Cytoplasmic Autoantibodyâ Associated Vasculitis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136726/1/art40034_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136726/2/art40034-sup-0002-suppinfo02.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136726/3/art40034-sup-0001-suppinfo01.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136726/4/art40034.pd

Phytoplankton composition and abundance assessment in the Nador lagoon (Mediterranean coast of Morocco)

We evaluated phytoplankton abundance, composition and trophic state of the Nador lagoon (Morocco) on the basis of data taken in the period November 2007 to August 2008. Sampling was performed at 11 stations (bottle samples at 0.5 m depth and horizontal plankton net tows with mesh size of 20 mm). Among seven identified phytoplankton classes, diatoms and dinoflagellates dominated with 133 and 169 species, respectively. Frequent phytoplankton blooms were contributed by one to three species in the lagoon. Abundance and seasonality of phytoplankton characterized the Nador lagoon as a highly eutrophicated environment