167 research outputs found

    A Fusion Scheme of Local Manifold Learning Methods

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    Spectral analysis‐based dimensionality reduction algorithms, especially the local manifold learning methods, have become popular recently because their optimizations do not involve local minima and scale well to large, high‐dimensional data sets. Despite their attractive properties, these algorithms are developed based on different geometric intuitions, and only partial information from the true geometric structure of the underlying manifold is learned by each method. In order to discover the underlying manifold structure more faithfully, we introduce a novel method to fuse the geometric information learned from different local manifold learning algorithms in this chapter. First, we employ local tangent coordinates to compute the local objects from different local algorithms. Then, we utilize the truncation function from differential manifold to connect the local objects with a global functional and finally develop an alternating optimization‐based algorithm to discover the low‐dimensional embedding. Experiments on synthetic as well as real data sets demonstrate the effectiveness of our proposed method

    Deformable Generator Network: Unsupervised Disentanglement of Appearance and Geometry

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    We present a deformable generator model to disentangle the appearance and geometric information for both image and video data in a purely unsupervised manner. The appearance generator network models the information related to appearance, including color, illumination, identity or category, while the geometric generator performs geometric warping, such as rotation and stretching, through generating deformation field which is used to warp the generated appearance to obtain the final image or video sequences. Two generators take independent latent vectors as input to disentangle the appearance and geometric information from image or video sequences. For video data, a nonlinear transition model is introduced to both the appearance and geometric generators to capture the dynamics over time. The proposed scheme is general and can be easily integrated into different generative models. An extensive set of qualitative and quantitative experiments shows that the appearance and geometric information can be well disentangled, and the learned geometric generator can be conveniently transferred to other image datasets to facilitate knowledge transfer tasks.Comment: version

    The antibacterial activity and mechanism of imidazole chloride ionic liquids on Staphylococcus aureus

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    Ionic liquids (ILs) have garnered increasing attention in the biomedical field due to their unique properties. Although significant research has been conducted in recent years, there is still a lack of understanding of the potential applications of ILs in the biomedical field and the underlying principles. To identify the antibacterial activity and mechanism of ILs on bacteria, we evaluated the antimicrobial potency of imidazole chloride ILs (CnMIMCl) on Staphylococcus aureus (S. aureus). The toxicity of ILs was positively correlated to the length of the imidazolidinyl side chain. We selected C12MIMCl to study the mechanism of S. aureus. Through the simultaneous change in the internal and external parts of S. aureus, C12MIMCl caused the death of the bacteria. The production of large amounts of reactive oxygen species (ROS) within the internal parts stimulated oxidative stress, inhibited bacterial metabolism, and led to bacterial death. The external cell membrane could be destroyed, causing the cytoplasm to flow out and the whole cell to be fragmented. The antibacterial effect of C12MIMCl on skin abscesses was further verified in vivo in mice

    Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

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    The production of tt‟ , W+bb‟ and W+cc‟ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓΜ , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of tt‟t\overline{t}, W+bb‟W+b\overline{b} and W+cc‟W+c\overline{c} is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ±\pm 0.02 \mbox{fb}^{-1}. The WW bosons are reconstructed in the decays W→ℓΜW\rightarrow\ell\nu, where ℓ\ell denotes muon or electron, while the bb and cc quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions

    Measurement of the J/ψ pair production cross-section in pp collisions at s=13 \sqrt{s}=13 TeV

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    The production cross-section of J/ψ pairs is measured using a data sample of pp collisions collected by the LHCb experiment at a centre-of-mass energy of s=13 \sqrt{s}=13 TeV, corresponding to an integrated luminosity of 279 ±11 pb−1^{−1}. The measurement is performed for J/ψ mesons with a transverse momentum of less than 10 GeV/c in the rapidity range 2.0 < y < 4.5. The production cross-section is measured to be 15.2 ± 1.0 ± 0.9 nb. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the J/ψ pair are measured and compared to theoretical predictions.The production cross-section of J/ψJ/\psi pairs is measured using a data sample of pppp collisions collected by the LHCb experiment at a centre-of-mass energy of s=13 TeV\sqrt{s} = 13 \,{\mathrm{TeV}}, corresponding to an integrated luminosity of 279±11 pb−1279 \pm 11 \,{\mathrm{pb^{-1}}}. The measurement is performed for J/ψJ/\psi mesons with a transverse momentum of less than 10 GeV/c10 \,{\mathrm{GeV}}/c in the rapidity range 2.0<y<4.52.0<y<4.5. The production cross-section is measured to be 15.2±1.0±0.9 nb15.2 \pm 1.0 \pm 0.9 \,{\mathrm{nb}}. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the J/ψJ/\psi pair are measured and compared to theoretical predictions

    Measurement of forward W→eÎœW\to e\nu production in pppp collisions at s=8 \sqrt{s}=8\,TeV

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    A measurement of the cross-section for W→eÎœW \to e\nu production in pppp collisions is presented using data corresponding to an integrated luminosity of 2 2\,fb−1^{-1} collected by the LHCb experiment at a centre-of-mass energy of s=8 \sqrt{s}=8\,TeV. The electrons are required to have more than 20 20\,GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive WW production cross-sections, where the WW decays to eÎœe\nu, are measured to be \begin{align*} \begin{split} \sigma_{W^{+} \to e^{+}\nu_{e}}&=1124.4\pm 2.1\pm 21.5\pm 11.2\pm 13.0\,\mathrm{pb},\\ \sigma_{W^{-} \to e^{-}\bar{\nu}_{e}}&=\,\,\,809.0\pm 1.9\pm 18.1\pm\,\,\,7.0\pm \phantom{0}9.4\,\mathrm{pb}, \end{split} \end{align*} where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W+/W−W^{+}/W^{-} cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of WW boson branching fractions is determined to be \begin{align*} \begin{split} \mathcal{B}(W \to e\nu)/\mathcal{B}(W \to \mu\nu)=1.020\pm 0.002\pm 0.019, \end{split} \end{align*} where the first uncertainty is statistical and the second is systematic.A measurement of the cross-section for W→eÎœW \to e\nu production in pppp collisions is presented using data corresponding to an integrated luminosity of 2 2\,fb−1^{-1} collected by the LHCb experiment at a centre-of-mass energy of s=8 \sqrt{s}=8\,TeV. The electrons are required to have more than 20 20\,GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive WW production cross-sections, where the WW decays to eÎœe\nu, are measured to be \begin{equation*} \sigma_{W^{+} \to e^{+}\nu_{e}}=1124.4\pm 2.1\pm 21.5\pm 11.2\pm 13.0\,\mathrm{pb}, \end{equation*} \begin{equation*} \sigma_{W^{-} \to e^{-}\bar{\nu}_{e}}=\,\,\,809.0\pm 1.9\pm 18.1\pm\,\,\,7.0\pm \phantom{0}9.4\,\mathrm{pb}, \end{equation*} where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W+/W−W^{+}/W^{-} cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of WW boson branching fractions is determined to be \begin{equation*} \mathcal{B}(W \to e\nu)/\mathcal{B}(W \to \mu\nu)=1.020\pm 0.002\pm 0.019, \end{equation*} where the first uncertainty is statistical and the second is systematic.A measurement of the cross-section for W → eÎœ production in pp collisions is presented using data corresponding to an integrated luminosity of 2 fb−1^{−1} collected by the LHCb experiment at a centre-of-mass energy of s=8 \sqrt{s}=8 TeV. The electrons are required to have more than 20 GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive W production cross-sections, where the W decays to eÎœ, are measured to be σW+→e+Îœe=1124.4±2.1±21.5±11.2±13.0pb, {\sigma}_{W^{+}\to {e}^{+}{\nu}_e}=1124.4\pm 2.1\pm 21.5\pm 11.2\pm 13.0\kern0.5em \mathrm{p}\mathrm{b}, σW−→e−Μ‟e=809.0±1.9±18.1±7.0±9.4 pb, {\sigma}_{W^{-}\to {e}^{-}{\overline{\nu}}_e}=809.0\pm 1.9\pm 18.1\pm \kern0.5em 7.0\pm \kern0.5em 9.4\,\mathrm{p}\mathrm{b}, where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination

    Measurement of the B0s→Ό+Ό− Branching Fraction and Effective Lifetime and Search for B0→Ό+Ό− Decays

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    A search for the rare decays Bs0→Ό+ÎŒ- and B0→Ό+ÎŒ- is performed at the LHCb experiment using data collected in pp collisions corresponding to a total integrated luminosity of 4.4  fb-1. An excess of Bs0→Ό+ÎŒ- decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be B(Bs0→Ό+ÎŒ-)=(3.0±0.6-0.2+0.3)×10-9, where the first uncertainty is statistical and the second systematic. The first measurement of the Bs0→Ό+ÎŒ- effective lifetime, τ(Bs0→Ό+ÎŒ-)=2.04±0.44±0.05  ps, is reported. No significant excess of B0→Ό+ÎŒ- decays is found, and a 95% confidence level upper limit, B(B0→Ό+ÎŒ-)<3.4×10-10, is determined. All results are in agreement with the standard model expectations.A search for the rare decays Bs0→Ό+Ό−B^0_s\to\mu^+\mu^- and B0→Ό+Ό−B^0\to\mu^+\mu^- is performed at the LHCb experiment using data collected in pppp collisions corresponding to a total integrated luminosity of 4.4 fb−1^{-1}. An excess of Bs0→Ό+Ό−B^0_s\to\mu^+\mu^- decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be B(Bs0→Ό+Ό−)=(3.0±0.6−0.2+0.3)×10−9{\cal B}(B^0_s\to\mu^+\mu^-)=\left(3.0\pm 0.6^{+0.3}_{-0.2}\right)\times 10^{-9}, where the first uncertainty is statistical and the second systematic. The first measurement of the Bs0→Ό+Ό−B^0_s\to\mu^+\mu^- effective lifetime, τ(Bs0→Ό+Ό−)=2.04±0.44±0.05\tau(B^0_s\to\mu^+\mu^-)=2.04\pm 0.44\pm 0.05 ps, is reported. No significant excess of B0→Ό+Ό−B^0\to\mu^+\mu^- decays is found and a 95 % confidence level upper limit, B(B0→Ό+Ό−)<3.4×10−10{\cal B}(B^0\to\mu^+\mu^-)<3.4\times 10^{-10}, is determined. All results are in agreement with the Standard Model expectations

    Measurements of prompt charm production cross-sections in pp collisions at s=5 \sqrt{s}=5 TeV

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    Production cross-sections of prompt charm mesons are measured using data from pppp collisions at the LHC at a centre-of-mass energy of 5 5\,TeV. The data sample corresponds to an integrated luminosity of 8.60±0.33 8.60\pm0.33\,pb−1^{-1} collected by the LHCb experiment. The production cross-sections of D0D^0, D+D^+, Ds+D_s^+, and D∗+D^{*+} mesons are measured in bins of charm meson transverse momentum, pTp_{\text{T}}, and rapidity, yy. They cover the rapidity range 2.0<y<4.52.0 < y < 4.5 and transverse momentum ranges 0<pT<10 GeV/c0 < p_{\text{T}} < 10\, \text{GeV}/c for D0D^0 and D+D^+ and 1<pT<10 GeV/c1 < p_{\text{T}} < 10\, \text{GeV}/c for Ds+D_s^+ and D∗+D^{*+} mesons. The inclusive cross-sections for the four mesons, including charge-conjugate states, within the range of 1<pT<8 GeV/c1 < p_{\text{T}} < 8\, \text{GeV}/c are determined to be \begin{equation*} \sigma(pp\rightarrow D^0 X) = 1190 \pm 3 \pm 64\,\mu\text{b} \end{equation*} \begin{equation*} \sigma(pp\rightarrow D^+ X) = 456 \pm 3 \pm 34\,\mu\text{b} \end{equation*} \begin{equation*} \sigma(pp\rightarrow D_s^+ X) = 195 \pm 4 \pm 19\,\mu\text{b} \end{equation*} \begin{equation*} \sigma(pp\rightarrow D^{*+} X)= 467 \pm 6 \pm 40\,\mu\text{b} \end{equation*} where the uncertainties are statistical and systematic, respectively.Production cross-sections of prompt charm mesons are measured using data from pp collisions at the LHC at a centre-of-mass energy of 5 TeV. The data sample corresponds to an integrated luminosity of 8.60 ± 0.33 pb−1^{−1} collected by the LHCb experiment. The production cross-sections of D0^{0}, D+^{+}, Ds+_{s}^{+} , and D∗+^{∗+} mesons are measured in bins of charm meson transverse momentum, pT_{T}, and rapidity, y. They cover the rapidity range 2.0 < y < 4.5 and transverse momentum ranges 0 < pT_{T} < 10 GeV/c for D0^{0} and D+^{+} and 1 < pT_{T} < 10 GeV/c for Ds+_{s}^{+} and D∗+^{∗+} mesons. The inclusive cross-sections for the four mesons, including charge-conjugate states, within the range of 1 < pT_{T} < 8 GeV/c are determined to be σ(pp→D0X)=1004±3±54ÎŒb,σ(pp→D+X)=402±2±30ÎŒb,σ(pp→Ds+X)=170±4±16ÎŒb,σ(pp→D∗+X)=421±5±36ÎŒb, \begin{array}{l}\sigma \left( pp\to {D}^0X\right)=1004\pm 3\pm 54\mu \mathrm{b},\\ {}\sigma \left( pp\to {D}^{+}X\right)=402\pm 2\pm 30\mu \mathrm{b},\\ {}\sigma \left( pp\to {D}_s^{+}X\right)=170\pm 4\pm 16\mu \mathrm{b},\\ {}\sigma \left( pp\to {D}^{\ast +}X\right)=421\pm 5\pm 36\mu \mathrm{b},\end{array} where the uncertainties are statistical and systematic, respectively.Production cross-sections of prompt charm mesons are measured using data from pppp collisions at the LHC at a centre-of-mass energy of 5 5\,TeV. The data sample corresponds to an integrated luminosity of 8.60±0.33 8.60\pm0.33\,pb−1^{-1} collected by the LHCb experiment. The production cross-sections of D0D^0, D+D^+, Ds+D_s^+, and D∗+D^{*+} mesons are measured in bins of charm meson transverse momentum, pTp_{\text{T}}, and rapidity, yy. They cover the rapidity range 2.0<y<4.52.0<y<4.5 and transverse momentum ranges 0<pT<10 GeV/c0 < p_{\text{T}} < 10\, \text{GeV}/c for D0D^0 and D+D^+ and 1<pT<10 GeV/c1 < p_{\text{T}} < 10\, \text{GeV}/c for Ds+D_s^+ and D∗+D^{*+} mesons. The inclusive cross-sections for the four mesons, including charge-conjugate states, within the range of 1<pT<8 GeV/c1 < p_{\text{T}} < 8\, \text{GeV}/c are determined to be \sigma(pp\rightarrow D^0 X) = 1004 \pm 3 \pm 54\,\mu\text{b} \sigma(pp\rightarrow D^+ X) = 402 \pm 2 \pm 30\,\mu\text{b} \sigma(pp\rightarrow D_s^+ X) = 170 \pm 4 \pm 16\,\mu\text{b} \sigma(pp\rightarrow D^{*+} X)= 421 \pm 5 \pm 36\,\mu\text{b} where the uncertainties are statistical and systematic, respectively
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