553 research outputs found
Isolation & Characterization of Bacteria in the Built Environment: Measuring The Effect of Pharmaceuticals on Growth
This work reports the isolation and characterization of bacteria from the built environment at Gettysburg College in Gettysburg, PA. Surfaces of a water fountain on campus were swabbed and serially streaked to isolate multiple bacteria on R2A agar. Following multiple rounds of growth, the unknown microbial candidates were narrowed to two visiblydistinct organisms. Morphological characterization and phylogenetic identification based on 16S rDNA sequencing revealed that the isolates were Chryseobactierum hispalense and Microbacterium maritypicum. We report synergistic biofilm formation between Chryseobactierum hispalense and Microbacterium maritypicum. The contamination of drinking water with varying levels of personal care products and pharmaceuticals (PCPPs) is well documented. Additionally, these environmental pollutants and their derivatives affect aquatic life, as illustrated with effect of the antidepressant fluoxetine on mudsnails. To determine if previously reported contaminants affect freshwater bacteria, we assessed both planktonic growth and biofilm formation following exposure to nalidixic acid (nonfluorinated quinolone antibiotic), diphenhydramine (overthecounter drug Benadryl), and fluoxetine (Prozac)
Prototype tests for the ALICE TRD
A Transition Radiation Detector (TRD) has been designed to improve the
electron identification and trigger capability of the ALICE experiment at the
Large Hadron Collider (LHC) at CERN. We present results from tests of a
prototype of the TRD concerning pion rejection for different methods of
analysis over a momentum range from 0.7 to 2 GeV/c. We investigate the
performance of different radiator types, composed of foils, fibres and foams.Comment: Presented at the IEEE Nuclear Science Symposium and Medical Imaging
Conference, Lyon, October 15-20, 2000 (accepted for publication in IEEE TNS),
Latex (IEEEtran.cls), 7 pages, 11 eps figure
Differential directed flow in Au+Au collisions
We present experimental data on directed flow in semi-central Au+Au
collisions at incident energies from 90 to 400 A MeV. For the first time for
this energy domain, the data are presented in a transverse momentum
differential way. We study the first order Fourier coefficient v1 for different
particle species and establish a gradual change of its patterns as a function
of incident energy and for different regions in rapidity.Comment: 5 pages, Latex, 5 eps figures, accepted for publication in Phys. Rev.
C (Rapid Communications). Data files available at
http://www-linux.gsi.de/~andronic/fopi/v1.htm
Big Physics At Small Places: The Mongol Horde Model Of Undergraduate Research
A model for engaging undergraduates in cutting-edge experimental nuclear physics research at a national user facility is discussed. Methods to involve students and examples of their success are presented
Isospin-tracing: A probe of non-equilibrium in central heavy-ion collisions
Four different combinations of Ru and Zr nuclei, both
as projectile and target, were investigated at the same bombarding energy of
400 MeV using a detector. The degree of isospin mixing between
projectile and target nucleons is mapped across a large portion of the phase
space using two different isospin-tracer observables, the number of measured
protons and the yield ratio. The experimental results
show that the global equilibrium is not reached even in the most central
collisions. Quantitative measures of stopping and mixing are extracted from the
data. They are found to exhibit a quite strong sensitivity to the in-medium
(n,n) cross section used in microscopic transport calculations.Comment: 4 pages RevTeX, 3 figures (ps files), submitted to Phys. Rev. Let
Centrality dependence of charged hadron production in deuteron+gold and nucleon+gold collisions at sqrt(s_NN)=200 GeV
We present transverse momentum (p_T) spectra of charged hadrons measured in
deuteron-gold and nucleon-gold collisions at \sqrts = 200 GeV for four
centrality classes. Nucleon-gold collisions were selected by tagging events in
which a spectator nucleon was observed in one of two forward rapidity
detectors. The spectra and yields were investigated as a function of the number
of binary nucleon-nucleon collisions, \nu, suffered by deuteron nucleons. A
comparison of charged particle yields to those in p+p collisions show that the
yield per nucleon-nucleon collision saturates with \nu for high momentum
particles. We also present the charged hadron to neutral pion ratios as a
function of p_T.Comment: 330 authors, 15 pages text, 16 figures, 3 tables. Submitted to Phys.
Rev. Lett. v2 has minor changes to reflect revisions during review process.
Plain text data tables for the points plotted in figures for this and
previous PHENIX publications are (or will be) publicly available at
http://www.phenix.bnl.gov/papers.htm
Azimuthal Angle Correlations for Rapidity Separated Hadron Pairs in d+Au Collisions at sqrt(s_NN) = 200 GeV
We report on two-particle azimuthal angle correlations between charged
hadrons at forward/backward (deuteron/gold going direction) rapidity and
charged hadrons at mid-rapidity in deuteron-gold (d+Au) and proton-proton (p+p)
collisions at sqrt(s_NN) = 200 GeV. Jet structures are observed in the
correlations which we quantify in terms of the conditional yield and angular
width of away side partners. The kinematic region studied here samples partons
in the gold nucleus carrying nucleon momentum fraction x~0.1 to x~0.01. Within
this range, we find no x dependence of the jet structure in d+Au collisions.Comment: 330 authors, 6 pages text, 4 figures, no tables. Submitted to Phys.
Rev. Lett. Plain text data tables for the points plotted in figures for this
and previous PHENIX publications are (or will be) publicly available at
http://www.phenix.bnl.gov/papers.htm
Role of Esrrg in the Fibrate-Mediated Regulation of Lipid Metabolism Genes in Human ApoA-I Transgenic Mice
We have used a new ApoA-I transgenic mouse model to identify by global gene expression profiling, candidate genes that affect lipid and lipoprotein metabolism in response to fenofibrate treatment. Multilevel bioinformatical analysis and stringent selection criteria (2-fold change, 0% false discovery rate) identified 267 significantly changed genes involved in several molecular pathways. The fenofibrate-treated group did not have significantly altered levels of hepatic human APOA-I mRNA and plasma ApoA-I compared with the control group. However, the treatment increased cholesterol levels to 1.95-fold mainly due to the increase in high-density lipoprotein (HDL) cholesterol. The observed changes in HDL are associated with the upregulation of genes involved in phospholipid biosynthesis and lipid hydrolysis, as well as phospholipid transfer protein. Significant upregulation was observed in genes involved in fatty acid transport and β-oxidation, but not in those of fatty acid and cholesterol biosynthesis, Krebs cycle and gluconeogenesis. Fenofibrate changed significantly the expression of seven transcription factors. The estrogen receptor-related gamma gene was upregulated 2.36-fold and had a significant positive correlation with genes of lipid and lipoprotein metabolism and mitochondrial functions, indicating an important role of this orphan receptor in mediating the fenofibrate-induced activation of a specific subset of its target genes.National Institutes of Health (HL48739 and HL68216); European Union (LSHM-CT-2006-0376331, LSHG-CT-2006-037277); the Biomedical Research Foundation of the Academy of Athens; the Hellenic Cardiological Society; the John F Kostopoulos Foundatio
Directed flow in Au+Au, Xe+CsI and Ni+Ni collisions and the nuclear equation of state
We present new experimental data on directed flow in collisions of Au+Au,
Xe+CsI and Ni+Ni at incident energies from 90 to 400A MeV. We study the
centrality and system dependence of integral and differential directed flow for
particles selected according to charge. All the features of the experimental
data are compared with Isospin Quantum Molecular Dynamics (IQMD) model
calculations in an attempt to extract information about the nuclear matter
equation of state (EoS). We show that the combination of rapidity and
transverse momentum analysis of directed flow allow to disentangle various
parametrizations in the model. At 400A MeV, a soft EoS with momentum dependent
interactions is best suited to explain the experimental data in Au+Au and
Xe+CsI, but in case of Ni+Ni the model underpredicts flow for any EoS. At 90A
MeV incident beam energy, none of the IQMD parametrizations studied here is
able to consistently explain the experimental data.Comment: RevTeX, 20 pages, 30 eps figures, accepted for publication in Phys.
Rev. C. Data files available at http://www.gsi.de/~fopiwww/pub
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