59 research outputs found

    Toll-like receptor 2 contributes to antibacterial defence against pneumolysin-deficient pneumococci

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    Toll-like receptors (TLRs) are pattern recognition receptors that recognize conserved molecular patterns expressed by pathogens. Pneumolysin, an intracellular toxin found in all Streptococcus pneumoniae clinical isolates, is an important virulence factor of the pneumococcus that is recognized by TLR4. Although TLR2 is considered the most important receptor for Gram-positive bacteria, our laboratory previously could not demonstrate a decisive role for TLR2 in host defence against pneumonia caused by a serotype 3 S. pneumoniae. Here we tested the hypothesis that in the absence of TLR2, S. pneumoniae can still be sensed by the immune system through an interaction between pneumolysin and TLR4. C57BL/6 wild-type (WT) and TLR2 knockout (KO) mice were intranasally infected with either WT S. pneumoniae D39 (serotype 2) or the isogenic pneumolysin-deficient S. pneumoniae strain D39 PLN. TLR2 did not contribute to antibacterial defence against WT S. pneumoniae D39. In contrast, pneumolysin-deficient S. pneumoniae only grew in lungs of TLR2 KO mice. TLR2 KO mice displayed a strongly reduced early inflammatory response in their lungs during pneumonia caused by both pneumolysin-producing and pneumolysin-deficient pneumococci. These data suggest that pneumolysin-induced TLR4 signalling can compensate for TLR2 deficiency during respiratory tract infection with S. pneumoniae

    Why has research in face recognition progressed so slowly? The importance of variability

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    Despite many years of research, there has been surprisingly little progress in our understanding of how faces are identified. Here I argue that there are two contributory factors: (a) Our methods have obscured a critical aspect of the problem, within-person variability; and (b) research has tended to conflate familiar and unfamiliar face processing. Examples of procedures for studying variability are given, and a case is made for studying real faces, of the type people recognize every day. I argue that face recognition (specifically identification) may only be understood by adopting new techniques that acknowledge statistical patterns in the visual environment. As a consequence, some of our current methods will need to be abandoned

    Psychosocial Treatment of Children in Foster Care: A Review

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    A substantial number of children in foster care exhibit psychiatric difficulties. Recent epidemiologi-cal and historical trends in foster care, clinical findings about the adjustment of children in foster care, and adult outcomes are reviewed, followed by a description of current approaches to treatment and extant empirical support. Available interventions for these children can be categorized as either symptom-focused or systemic, with empirical support for specific methods ranging from scant to substantial. Even with treatment, behavioral and emotional problems often persist into adulthood, resulting in poor functional outcomes. We suggest that self-regulation may be an important mediat-ing factor in the appearance of emotional and behavioral disturbance in these children

    Psychosocial Treatment of Children in Foster Care: A Review

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    Measurement of CPCP asymmetries in D±→ηâ€Čπ±D^{\pm}\rightarrow \eta^{\prime} \pi^{\pm} and Ds±→ηâ€Čπ±D_s^{\pm}\rightarrow \eta^{\prime} \pi^{\pm} decays

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    See paper for full list of authors - All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-041.html - Submitted to Phys. Lett. BInternational audienceA search for CP violation in D±→ηâ€Čπ± and D±s→ηâ€Čπ± decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 3 fb−1, recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The measured CP-violating charge asymmetries are ACP(D±→ηâ€Čπ±)=(−0.61±0.72±0.55±0.12)% and ACP(D±s→ηâ€Čπ±)=(−0.82±0.36±0.24±0.27)%, where the first uncertainties are statistical, the second systematic, and the third are the uncertainties on the ACP(D±→K0Sπ±) and ACP(D±s→ϕπ±) measurements used for calibration. The results represent the most precise measurements of these asymmetries to date

    Observation of ηc(2S)→ppˉ\eta_{c}(2S) \to p \bar p and search for X(3872)→ppˉX(3872) \to p \bar p decays

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    The first observation of the decay ηc(2S)→ppˉ\eta_{c}(2S) \to p \bar p is reported using proton-proton collision data corresponding to an integrated luminosity of 3.0 fb−13.0\rm \, fb^{-1} recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ηc(2S)\eta_{c}(2S) resonance is produced in the decay B+→[ccˉ]K+B^{+} \to [c\bar c] K^{+}. The product of branching fractions normalised to that for the J/ψJ/\psi intermediate state, Rηc(2S){\cal R}_{\eta_{c}(2S)}, is measured to be \begin{align*} {\cal R}_{\eta_{c}(2S)}\equiv\frac{{\mathcal B}(B^{+} \to \eta_{c}(2S) K^{+}) \times {\mathcal B}(\eta_{c}(2S) \to p \bar p)}{{\mathcal B}(B^{+} \to J/\psi K^{+}) \times {\mathcal B}(J/\psi\to p \bar p)} =~& (1.58 \pm 0.33 \pm 0.09)\times 10^{-2}, \end{align*} where the first uncertainty is statistical and the second systematic. No signals for the decays B+→X(3872)(→ppˉ)K+B^{+} \to X(3872) (\to p \bar p) K^{+} and B+→ψ(3770)(→ppˉ)K+B^{+} \to \psi(3770) (\to p \bar p) K^{+} are seen, and the 95\% confidence level upper limits on their relative branching ratios are % found to be RX(3872)<0.25×10−2{\cal R}_{X(3872)}<0.25\times10^{-2} and Rψ(3770))<0.10{\cal R}_{\psi(3770))}<0.10. In addition, the mass differences between the ηc(1S)\eta_{c}(1S) and the J/ψJ/\psi states, between the ηc(2S)\eta_{c}(2S) and the ψ(2S)\psi(2S) states, and the natural width of the ηc(1S)\eta_{c}(1S) are measured as \begin{align*} M_{J/\psi} - M_{\eta_{c}(1S)} =~& 110.2 \pm 0.5 \pm 0.9 \rm \, MeV, M_{\psi(2S)} -M_{\eta_{c}(2S)} =~ & 52.5 \pm 1.7 \pm 0.6 \rm \, MeV, \Gamma_{\eta_{c}(1S)} =~& 34.0 \pm 1.9 \pm 1.3 \rm \, MeV. \end{align*}Comment: 16 pages, 2 figures All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-016.htm

    Search for CPCP violation in the phase space of D0→π+π−π+π−D^0\rightarrow\pi^+\pi^-\pi^+\pi^- decays

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    A search for time-integrated CPCP violation in the Cabibbo-suppressed decay \mbox{D^0\rightarrow\pi^+\pi^-\pi^+\pi^-} is performed using an unbinned, model-independent technique known as the energy test. This is the first application of the energy test in four-body decays. The search is performed for PP-even CPCP asymmetries and, for the first time, is extended to probe the PP-odd case. Using proton-proton collision data corresponding to an integrated luminosity of 3.0 fb−1^{-1} collected by the LHCb detector at centre-of-mass energies of s=\sqrt{s}=7 TeV and 8 TeV, the world's best sensitivity to CPCP violation in this decay is obtained. The data are found to be consistent with the hypothesis of CPCP symmetry with a pp-value of (4.6±0.5)%(4.6\pm0.5)\% in the PP-even case, and marginally consistent with a pp-value of (0.6±0.2)%(0.6\pm0.2)\% in the PP-odd case, corresponding to a significance for CPCP non-conservation of 2.7 standard deviations.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-044.htm
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