33 research outputs found
Low Q^2 Jet Production at HERA and Virtual Photon Structure
The transition between photoproduction and deep-inelastic scattering is
investigated in jet production at the HERA ep collider, using data collected by
the H1 experiment. Measurements of the differential inclusive jet
cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the
transverse energy and the pseudorapidity of the jets in the virtual
photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3
< y < 0.6. The interpretation of the results in terms of the structure of the
virtual photon is discussed. The data are best described by QCD calculations
which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure
Hadron Production in Diffractive Deep-Inelastic Scattering
Characteristics of hadron production in diffractive deep-inelastic
positron-proton scattering are studied using data collected in 1994 by the H1
experiment at HERA. The following distributions are measured in the
centre-of-mass frame of the photon dissociation system: the hadronic energy
flow, the Feynman-x (x_F) variable for charged particles, the squared
transverse momentum of charged particles (p_T^{*2}), and the mean p_T^{*2} as a
function of x_F. These distributions are compared with results in the gamma^* p
centre-of-mass frame from inclusive deep-inelastic scattering in the
fixed-target experiment EMC, and also with the predictions of several Monte
Carlo calculations. The data are consistent with a picture in which the
partonic structure of the diffractive exchange is dominated at low Q^2 by hard
gluons.Comment: 16 pages, 6 figures, submitted to Phys. Lett.
A Search for Selectrons and Squarks at HERA
Data from electron-proton collisions at a center-of-mass energy of 300 GeV
are used for a search for selectrons and squarks within the framework of the
minimal supersymmetric model. The decays of selectrons and squarks into the
lightest supersymmetric particle lead to final states with an electron and
hadrons accompanied by large missing energy and transverse momentum. No signal
is found and new bounds on the existence of these particles are derived. At 95%
confidence level the excluded region extends to 65 GeV for selectron and squark
masses, and to 40 GeV for the mass of the lightest supersymmetric particle.Comment: 13 pages, latex, 6 Figure
Dried gel hybridization in place of Southern hybridization for detection of Listeria monocytogenes DNA fragments
P64 Ceftaroline activity against common bacterial pathogens causing skin and soft tissue infections in the Asia-Pacific region and South Africa
Comparative activity of carbapenem testing: the COMPACT study.
Objectives: Doripenem is a new carbapenem recently introduced into Europe. The COMParative Activity of
Carbapenem Testing (COMPACT) study compared the susceptibility of common Gram-negative bacilli causing
serious infections in hospitalized patients with doripenem, imipenem and meropenem.
Methods: Gram-negative isolates (4498 total: 2171 Pseudomonas species; 1910 Enterobacteriaceae; and 417
other Gram-negative bacilli) were collected from 80 centres in 16 countries in Europe, the Middle East and
Africa during 2008\u201309. The MICs of doripenem, imipenem and meropenem were determined using Etest methodology
and broth microdilution. Susceptibility was interpreted according to CLSI, EUCAST and FDA breakpoints.
Results: The MIC90s of doripenem, imipenem and meropenem for all isolates were 8, 6564 and 32 mg/L,
respectively. Doripenem had the lowest MIC90 for Pseudomonas species at 16 mg/L, with imipenem and meropenem
values of 6564 mg/L. Enterobacteriaceae were highly susceptible to all three carbapenems, with MIC90s
of doripenem, imipenem and meropenem of 0.06, 0.5 and 0.12 mg/L, respectively. Other Gram-negative
isolates, predominantly Acinetobacter baumannii, were resistant to all three carbapenems (MIC90 6564 mg/L).
Susceptibility to doripenem was observed in 14.9% of isolates resistant to imipenem and/or meropenem.
Conclusions: Doripenem showed excellent activity against Gram-negative isolates; generally it was more active
than imipenem and at least as good as meropenem. Against Pseudomonas species, doripenem was more
active than both imipenem and meropenem, with doripenem susceptibility observed for some imipenemand/
or meropenem-resistant isolates