265 research outputs found
Identification of Escherichia coli from broiler chickens in Jordan, their antimicrobial resistance, gene characterization and the associated risk factors
Avian pathogenic Escherichia coli (APEC) is the principle cause of colibacillosis affecting poultry. The main challenge to the poultry industry is antimicrobial resistance and the emergence of multidrug resistant bacteria that threaten the safety of the food chain. Risk factors associated with emergence of antimicrobial resistance among avian pathogenic E. coli were correlated with the inappropriate use of antimicrobials along with inadequate hygienic practices, which encourages the selection pressure of antimicrobial resistant APEC. The aim of this study was to isolate, identify, serogroup and genotype APEC from broilers, assess their antibiotic resistance profile, expressed genes and the associated risk factors
Paleoseismic History of the Dead Sea Fault Zone
International audienceThe aim of this entry is to describe the DSF as a transform plate boundary pointing out the rate of activedeformation, fault segmentation, and geometrical complexities as a control of earthquake ruptures. Thedistribution of large historical earthquakes from a revisited seismicity catalogue using detailedmacroseismic maps allows the correlation between the location of past earthquakes and fault segments.The recent results of paleoearthquake investigations (paleoseismic and archeoseismic) with a recurrenceinterval of large events and long-term slip rate are presented and discussed along with the identification ofseismic gaps along the fault. Finally, the implications for the seismic hazard assessment are also discussed
Search for Production via Trilepton Final States in collisions at TeV
We have searched for associated production of the lightest chargino,
, and next-to-lightest neutralino, , of the
Minimal Supersymmetric Standard Model in collisions at
\mbox{ = 1.8 TeV} using the \D0 detector at the Fermilab Tevatron
collider. Data corresponding to an integrated luminosity of 12.5 \ipb
were examined for events containing three isolated leptons. No evidence for
pair production was found. Limits on
BrBr are
presented.Comment: 17 pages (13 + 1 page table + 3 pages figures). 3 PostScript figures
will follow in a UUEncoded, gzip'd, tar file. Text in LaTex format. Submitted
to Physical Review Letters. Replace comments - Had to resumbmit version with
EPSF directive
Search for Top Squark Pair Production in the Dielectron Channel
This report describes the first search for top squark pair production in the
channel stop_1 stopbar_1 -> b bbar chargino_1 chargino_1 -> ee+jets+MEt using
74.9 +- 8.9 pb^-1 of data collected using the D0 detector. A 95% confidence
level upper limit on sigma*B is presented. The limit is above the theoretical
expectation for sigma*B for this process, but does show the sensitivity of the
current D0 data set to a particular topology for new physics.Comment: Five pages, including three figures, submitted to PRD Brief Report
Measurement of the Boson Mass
A measurement of the mass of the boson is presented based on a sample of
5982 decays observed in collisions at
= 1.8~TeV with the D\O\ detector during the 1992--1993 run. From a
fit to the transverse mass spectrum, combined with measurements of the
boson mass, the boson mass is measured to be .Comment: 12 pages, LaTex, style Revtex, including 3 postscript figures
(submitted to PRL
Probing BFKL Dynamics in the Dijet Cross Section at Large Rapidity Intervals in ppbar Collisions at sqrt{s}=1800 and 630 GeV
Inclusive dijet production at large pseudorapidity intervals (delta_eta)
between the two jets has been suggested as a regime for observing BFKL
dynamics. We have measured the dijet cross section for large delta_eta in ppbar
collisions at sqrt{s}=1800 and 630 GeV using the DO detector. The partonic
cross section increases strongly with the size of delta_eta. The observed
growth is even stronger than expected on the basis of BFKL resummation in the
leading logarithmic approximation. The growth of the partonic cross section can
be accommodated with an effective BFKL intercept of
a_{BFKL}(20GeV)=1.65+/-0.07.Comment: Published in Physical Review Letter
Second Generation Leptoquark Search in p\bar{p} Collisions at = 1.8 TeV
We report on a search for second generation leptoquarks with the D\O\
detector at the Fermilab Tevatron collider at = 1.8 TeV.
This search is based on 12.7 pb of data. Second generation leptoquarks
are assumed to be produced in pairs and to decay into a muon and quark with
branching ratio or to neutrino and quark with branching ratio
. We obtain cross section times branching ratio limits as a function
of leptoquark mass and set a lower limit on the leptoquark mass of 111
GeV/c for and 89 GeV/c for at the 95%\
confidence level.Comment: 18 pages, FERMILAB-PUB-95/185-
Measurement of the Top Quark Mass Using Dilepton Events
The D0 collaboration has performed a measurement of the top quark mass based
on six candidate events for the process t tbar -> b W+ bbar W-, where the W
bosons decay to e nu or mu nu. This sample was collected during an exposure of
the D0 detector to an integrated luminosity of 125 pb^-1 of sqrt(s)=1.8 TeV
p-pbar collisions. We obtain mt = 168.4 +- 12.3 (stat) +- 3.7 (sys) GeV/c^2,
consistent with the measurement obtained using single-lepton events.
Combination of the single-lepton and dilepton results yields mt = 172.0 +- 7.5
GeV/c^2.Comment: 12 pages, 3 figure
The Azimuthal Decorrelation of Jets Widely Separated in Rapidity
This study reports the first measurement of the azimuthal decorrelation
between jets with pseudorapidity separation up to five units. The data were
accumulated using the D{\O}detector during the 1992--1993 collider run of the
Fermilab Tevatron at 1.8 TeV. These results are compared to
next--to--leading order (NLO) QCD predictions and to two leading--log
approximations (LLA) where the leading--log terms are resummed to all orders in
. The final state jets as predicted by NLO QCD
show less azimuthal decorrelation than the data. The parton showering LLA Monte
Carlo {\small HERWIG} describes the data well; an analytical LLA prediction
based on BFKL resummation shows more decorrelation than the data.Comment: 6 pages with 4 figures, all uuencoded and gzippe
Jet Production via Strongly-Interacting Color-Singlet Exchange in Collisions
A study of the particle multiplicity between jets with large rapidity
separation has been performed using the D{\O}detector at the Fermilab Tevatron
Collider operating at TeV. A significant excess of
low-multiplicity events is observed above the expectation for color-exchange
processes. The measured fractional excess is , which is consistent with a strongly-interacting
color-singlet (colorless) exchange process and cannot be explained by
electroweak exchange alone. A lower limit of 0.80% (95% C.L.) is obtained on
the fraction of dijet events with color-singlet exchange, independent of the
rapidity gap survival probability.Comment: 15 pages (REVTeX), 3 PS figs (uuencoded/tar compressed, epsf.sty)
Complete postscript available at http://d0sgi0.fnal.gov/d0pubs/journals.html
Submitted to Physical Review Letter
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