343 research outputs found
Autoimmune Memory T Helper 17 Cell Function and Expansion Are Dependent on Interleukin-23
SummaryInterleukin-23 (IL-23) is essential for the differentiation of pathogenic effector T helper 17 (Th17) cells, but its role in memory Th17 cell responses is unclear. Using the experimental autoimmune encephalomyelitis (EAE) model, we report that memory Th17 cells rapidly expanded in response to rechallenge and migrated to the CNS in high numbers, resulting in earlier onset and increased severity of clinical disease. Memory Th17 cells were generated from IL-17+ and RORγt+ precursors, and the stability of the Th17 cell phenotype depended on the amount of time allowed for the primary response. IL-23 was required for this enhanced recall response. IL-23 receptor blockade did not directly impact IL-17 production, but did impair the subsequent proliferation and generation of effectors coexpressing the Th1 cell-specific transcription factor T-bet. In addition, many genes required for cell-cycle progression were downregulated in Th17 cells that lacked IL-23 signaling, showing that a major mechanism for IL-23 in primary and memory Th17 cell responses operates via regulation of proliferation-associated pathways
Shrinking a large dataset to identify variables associated with increased risk of Plasmodium falciparum infection in Western Kenya
Large datasets are often not amenable to analysis using traditional single-step approaches. Here, our general objective was to apply imputation techniques, principal component analysis (PCA), elastic net and generalized linear models to a large dataset in a systematic approach to extract the most meaningful predictors for a health outcome. We extracted predictors for Plasmodium falciparum infection, from a large covariate dataset while facing limited numbers of observations, using data from the People, Animals, and their Zoonoses (PAZ) project to demonstrate these techniques: data collected from 415 homesteads in western Kenya, contained over 1500 variables that describe the health, environment, and social factors of the humans, livestock, and the homesteads in which they reside. The wide, sparse dataset was simplified to 42 predictors of P. falciparum malaria infection and wealth rankings were produced for all homesteads. The 42 predictors make biological sense and are supported by previous studies. This systematic data-mining approach we used would make many large datasets more manageable and informative for decision-making processes and health policy prioritization
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 the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV
Isolated photon production is measured in proton-proton and lead-lead
collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the
pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80
GeV with the CMS detector at the LHC. The measured ET spectra are found to be
in good agreement with next-to-leading-order perturbative QCD predictions. The
ratio of PbPb to pp isolated photon ET-differential yields, scaled by the
number of incoherent nucleon-nucleon collisions, is consistent with unity for
all PbPb reaction centralities.Comment: Submitted to Physics Letters
Saethre-Chotzen syndrome : cranofacial anomalies caused by genetic changes in the TWIST gene
In this thesis, one of the most frequently occurring and most variable craniosynostosis
syndromes was investigated; Saethre-Chotzen syndrome. Craniosynostosis is the premature
obliteration of cranial sutures in the developing embryo. It can also occur in the first few
months of life. Saethre-Chotzen syndrome is, besides craniosynostosis, characterized by
specific facial and limb abnormalities, of which the most frequently reported are ptosis,
prominent crus helicis, cutaneous syndactyly of digit 2 and 3 on both hands and feet, and
broad halluces. Saethre-Chotzen syndrome has been linked to the TWIST gene on
chromosome 7p21.1. Mutations in and variably sized deletions of this gene can be found in
patients with clinical features of Saethre-Chotzen syndrome. The latter, TWIST deletions,
often also include part of the surrounding chromosome 7p and are reported to be associated
with mental retardation. In Saethre-Chotzen patients, in whom neither a mutation nor a
deletion of TWIST had been found, the FGFR3 P250R mutation was in some cases detected.
This mutation has specifically been linked to Muenke syndrome that is characterized by unior
bicoronal synostosis and slight facial dysmorphology. However, a Saethre-Chotzen like
phenotype can also result from this mutation.
Because of the possible overlap of Saethre-Chotzen with Muenke syndrome, these syndromes
were studied in order to provide clinical criteria that discriminate between the two (chapter 4).
Many phenotypic features occur in both syndromes. In addition, although unicoronal
synostosis occurs slightly more frequently in Muenke syndrome, unicoronal and bicoronal
synostosis are seen in both syndromes. The discrimination between Saethre-Chotzen and
Muenke is often not made easily and the associated genes, TWIST and FGFR3, respectively,
are simultaneously tested for pathogenic m
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