5,548 research outputs found
Systematic review with meta-analysis: the impact of a depressive state on disease course in adult inflammatory bowel disease
Background
Despite a higher prevalence of psychosocial morbidity in Inflammatory Bowel Disease (IBD), the association between depressive state and disease course in IBD is poorly understood.
Aim
To investigate the impact of depressive state on disease course in IBD.
Methods
We conducted a systematic review in MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews and PsychINFO for prospective studies evaluating the impact of baseline depressive state on subsequent disease course in adult IBD.
Results
Eleven studies matched our entry criteria, representing 3194 patients with IBD. Three reported on patients with ulcerative colitis (UC), four included patients with Crohn's disease (CD) exclusively, and four studies included both UC and CD. Five studies reported an association between depressive state and disease course. None of the UC‐specific studies found any association. In three of four CD‐specific studies, a relationship between depressive state and worsening disease course was found. In four of five studies including patients in remission at baseline, no association between depressive state and disease course was found. Pooled analysis of IBD studies with patients in clinical remission at baseline identified no association between depressive state and disease course (HR 1.04, 95%CI: 0.97‐1.12).
Conclusion
There is limited evidence to support an association between depressive state and subsequent deterioration in disease course in IBD, but what data that exist are more supportive of an association with CD than UC. Baseline disease activity may be an important factor in this relationship. Further studies are needed to understand the relationship between mental health and outcomes in IBD
Differentiate to thrive: lessons from the Legionella pneumophila life cycle
When confronted by disparate environments, microbes routinely alter their physiology to tolerate or exploit local conditions. But some circumstances require more drastic remodelling of the bacterial cell, as sporulation by the Bacillus and Streptomyces species of soil bacteria vividly illustrates. Cellular differentiation is also crucial for pathogens, the challenge for which is to colonize one host, then be transmitted to the next. Using the Gram-negative Legionella pneumophila as a model intracellular pathogen, we describe how biogenesis of the replication vacuole is determined by the developmental state of the bacterium. Subsequently, when replicating bacteria have exhausted the nutrient supply, the pathogens couple their conversion to stationary phase physiology with expression of traits that promote transmission to a new host. The cellular differentiation of L. pneumophila is co-ordinated by a regulatory circuit that integrates several elements that are broadly conserved in the microbial world. The alarmone (p)ppGpp promotes transcription directed by the alternative sigma factors RpoS, FliA and, probably, RpoN, and also post-transcriptional control mediated by a two-component regulatory system, LetA/S (GacA/S), and an mRNA-binding protein, CsrA (RsmA). By applying knowledge of microbial differentiation in combination with tools to screen the complete genomes of pathogens, experiments can be designed to identify two distinct classes of virulence traits: factors that promote replication and those dedicated to transmission.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72854/1/j.1365-2958.2004.04129.x.pd
Search for the Higgs boson in events with missing transverse energy and b quark jets produced in proton-antiproton collisions at s**(1/2)=1.96 TeV
We search for the standard model Higgs boson produced in association with an
electroweak vector boson in events with no identified charged leptons, large
imbalance in transverse momentum, and two jets where at least one contains a
secondary vertex consistent with the decay of b hadrons. We use ~1 fb-1
integrated luminosity of proton-antiproton collisions at s**(1/2)=1.96 TeV
recorded by the CDF II experiment at the Tevatron. We find 268 (16) single
(double) b-tagged candidate events, where 248 +/- 43 (14.4 +/- 2.7) are
expected from standard model background processes. We place 95% confidence
level upper limits on the Higgs boson production cross section for several
Higgs boson masses ranging from 110 GeV/c2 to 140 GeV/c2. For a mass of 115
GeV/c2 the observed (expected) limit is 20.4 (14.2) times the standard model
prediction.Comment: 8 pages, 2 figures, submitted to Phys. Rev. Let
Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron
We study the underlying event in proton-antiproton collisions by examining
the behavior of charged particles (transverse momentum pT > 0.5 GeV/c,
pseudorapidity |\eta| < 1) produced in association with large transverse
momentum jets (~2.2 fb-1) or with Drell-Yan lepton-pairs (~2.7 fb-1) in the
Z-boson mass region (70 < M(pair) < 110 GeV/c2) as measured by CDF at 1.96 TeV
center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan
production) or the leading jet (in high-pT jet production) in each event to
define three regions of \eta-\phi space; toward, away, and transverse, where
\phi is the azimuthal scattering angle. For Drell-Yan production (excluding the
leptons) both the toward and transverse regions are very sensitive to the
underlying event. In high-pT jet production the transverse region is very
sensitive to the underlying event and is separated into a MAX and MIN
transverse region, which helps separate the hard component (initial and
final-state radiation) from the beam-beam remnant and multiple parton
interaction components of the scattering. The data are corrected to the
particle level to remove detector effects and are then compared with several
QCD Monte-Carlo models. The goal of this analysis is to provide data that can
be used to test and improve the QCD Monte-Carlo models of the underlying event
that are used to simulate hadron-hadron collisions.Comment: Submitted to Phys.Rev.
Global Search for New Physics with 2.0/fb at CDF
Data collected in Run II of the Fermilab Tevatron are searched for
indications of new electroweak-scale physics. Rather than focusing on
particular new physics scenarios, CDF data are analyzed for discrepancies with
the standard model prediction. A model-independent approach (Vista) considers
gross features of the data, and is sensitive to new large cross-section
physics. Further sensitivity to new physics is provided by two additional
algorithms: a Bump Hunter searches invariant mass distributions for "bumps"
that could indicate resonant production of new particles; and the Sleuth
procedure scans for data excesses at large summed transverse momentum. This
combined global search for new physics in 2.0/fb of ppbar collisions at
sqrt(s)=1.96 TeV reveals no indication of physics beyond the standard model.Comment: 8 pages, 7 figures. Final version which appeared in Physical Review D
Rapid Communication
Observation of Orbitally Excited B_s Mesons
We report the first observation of two narrow resonances consistent with
states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar
collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the
Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed
as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+,
\bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1})
= 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let
Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi Decays
We measure the mean lifetime, tau=2/(Gamma_L+Gamma_H), and the width
difference, DeltaGamma=Gamma_L-Gamma_H, of the light and heavy mass eigenstates
of the B0s meson, B0sL and B0sH, in B0s -> J/psi phi decays using 1.7 fb^-1 of
data collected with the CDF II detector at the Fermilab Tevatron ppbar
collider. Assuming CP conservation, a good approximation for the B0s system in
the Standard Model, we obtain DeltaGamma = 0.076^+0.059_-0.063 (stat.) +- 0.006
(syst.) ps^-1 and tau = 1.52 +- 0.04 (stat.) +- 0.02 (syst.) ps, the most
precise measurements to date. Our constraints on the weak phase and DeltaGamma
are consistent with CP conservation.
Dedicated to the memory of our dear friend and colleague, Michael P. Schmid
Limits on Anomalous Triple Gauge Couplings in ppbar Collisions at sqrt{s}=1.96 TeV
We present a search for anomalous triple gauge couplings (ATGC) in WW and WZ
boson production. The boson pairs are produced in ppbar collisions at
sqrt{s}=1.96 TeV, and the data sample corresponds to 350 pb-1 of integrated
luminosity collected with the CDF II detector at the Fermilab Tevatron. In this
search one W decays to leptons, and the other boson (W or Z) decays
hadronically. Combining with a previously published CDF measurement of Wgamma
boson production yields ATGC limits of -0.18 < lambda < 0.17 and -0.46 < Delta
kappa < 0.39 at the 95% confidence level, using a cut-off scale Lambda=1.5 TeV.Comment: 7 pages, 3 figures. Submitted to Phys. Rev.
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