1,743 research outputs found
Novel Campylobacter concisus lipooligosaccharide is a determinant of inflammatory potential and virulence
This work was supported in part by Department of Veterans Affairs Merit Review award BX000727 (to G.A.J.). The authors also acknowledge National Institutes of Health National Center for Research Resources Shared Instrumentation Grant S10 RR029446 (to H. E. Witkowska) for acquisition of the Synapt G2 high definition mass spectrometer, which is located at the University of California, San Francisco Sandler-Moore Mass Spectrometry Core Facility and supported by the Sandler Family Foundation, the Gordon and Betty Moore Foundation, National Institutes of Health/National Cancer Institute Cancer Center Support Grant P30 CA082103, and the Canary Foundation. G.A.J. is a recipient of the Senior Research Career Scientist award from the Department of Veterans Affairs. R.H. is funded by a Career Researcher Fellowship from NHS Research Scotland. The BISCUIT study was funded by a Clinical Academic Training Fellowship from the Chief Scientist Office (CAF/08/01). This is paper number 116 from the Center for Immunochemistry. The contents of this article do not represent the views of the Department of Veterans Affairs or the United States Government. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. K.B. acknowledges funding from the Child Health Research Charitable Incorporated Organisation and the Bogue Fellowship for travel. The authors declare that they have no conflicts of interest with the contents of this article.Peer reviewe
An ER surface retrieval pathway safeguards the import of mitochondrial membrane proteins in yeast
The majority of organellar proteins are translated on cytosolic ribosomes and must be sorted correctly to function.Targeting routes have been identified for organelles such as peroxisomes and the endoplasmic reticulum (ER). However, little is known about the initial steps of targeting of mitochondrial proteins. In this study, we used a genome-wide screen in yeast and identified factors critical for the intracellular sorting of themitochondrial innermembrane protein Oxa1.The screen uncovered an unexpected path, termed ER-SURF, for targeting ofmitochondrialmembrane proteins.This pathway retrieves mitochondrial proteins from the ER surface and reroutes them to mitochondria with the aid of the ER-localized chaperone Djp1. Hence, cells use the expanse of the ERsurfaces as a fail-safe tomaximize productive mitochondrial protein targeting
Tests of model of color reconnection and a search for glueballs using gluon jets with a rapidity gap
Gluon jets with a mean energy of 22 GeV and purity of 95% are selected from
hadronic Z0 decay events produced in e+e- annihilations. A subsample of these
jets is identified which exhibits a large gap in the rapidity distribution of
particles within the jet. After imposing the requirement of a rapidity gap, the
gluon jet purity is 86%. These jets are observed to demonstrate a high degree
of sensitivity to the presence of color reconnection, i.e. higher order QCD
processes affecting the underlying color structure. We use our data to test
three QCD models which include a simulation of color reconnection: one in the
Ariadne Monte Carlo, one in the Herwig Monte Carlo, and the other by Rathsman
in the Pythia Monte Carlo. We find the Rathsman and Ariadne color reconnection
models can describe our gluon jet measurements only if very large values are
used for the cutoff parameters which serve to terminate the parton showers, and
that the description of inclusive Z0 data is significantly degraded in this
case. We conclude that color reconnection as implemented by these two models is
disfavored. The signal from the Herwig color reconnection model is less clear
and we do not obtain a definite conclusion concerning this model. In a separate
study, we follow recent theoretical suggestions and search for glueball-like
objects in the leading part of the gluon jets. No clear evidence is observed
for these objects.Comment: 42 pages, 18 figure
A study of charm production in beauty decays with the OPAL detector at LEP
Using an inclusive method, BR(b -> D\bar{D}X) has been measured in hadronic
Z^0 decays with the OPAL detector at LEP. The impact parameter significance of
tracks opposite tagged b-jets is used to differentiate b -> D\bar{D}X decays
from other decays. Using this result, the average number of charm and
anti-charm quarks produced per beauty quark decay, n_c, is determined.Comment: 20 pages, 4 figure
W Boson Polarisation at LEP2
Elements of the spin density matrix for W bosons in e+e- -> W+W- -> qqln
events are measured from data recorded by the OPAL detector at LEP. This
information is used calculate polarised differential cross-sections and to
search for CP-violating effects. Results are presented for W bosons produced in
e+e- collisions with centre-of-mass energies between 183 GeV and 209 GeV. The
average fraction of W bosons that are longitudinally polarised is found to be
(23.9 +- 2.1 +- 1.1)% compared to a Standard Model prediction of (23.9 +-
0.1)%. All results are consistent with CP conservation.Comment: 20 pages, 3 figures, Submitted to Phys. Letts.
Search for Yukawa Production of a Light Neutral Higgs Boson at LEP
Within a Two-Higgs-Doublet Model (2HDM) a search for a light Higgs boson in
the mass range of 4-12 GeV has been performed in the Yukawa process e+e- -> b
bbar A/h -> b bbar tau+tau-, using the data collected by the OPAL detector at
LEP between 1992 and 1995 in e+e- collisions at about 91 GeV centre-of-mass
energy. A likelihood selection is applied to separate background and signal.
The number of observed events is in good agreement with the expected
background. Within a CP-conserving 2HDM type II model the cross-section for
Yukawa production depends on xiAd = |tan beta| and xihd = |sin alpha/cos beta|
for the production of the CP-odd A and the CP-even h, respectively, where tan
beta is the ratio of the vacuum expectation values of the Higgs doublets and
alpha is the mixing angle between the neutral CP-even Higgs bosons. From our
data 95% C.L. upper limits are derived for xiAd within the range of 8.5 to 13.6
and for xihd between 8.2 to 13.7, depending on the mass of the Higgs boson,
assuming a branching fraction into tau+tau- of 100%. An interpretation of the
limits within a 2HDM type II model with Standard Model particle content is
given. These results impose constraints on several models that have been
proposed to explain the recent BNL measurement of the muon anomalous magnetic
moment.Comment: 24 pages, 9 figures, Submitted to Euro. Phys. J.
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