250 research outputs found

    Report and preliminary results of SONNE cruise SO175, Miami - Bremerhaven, 12.11 - 30.12.2003 : (GAP, Gibraltar Arc Processes)

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    Expedition SO175 using FS Sonne aimed for a multidisciplinerary geoscientific approach with an international group of researchers. Methods covered the entire span from geophysical data acquisition (seafloor mapping, echography, seismic reflection), sediment coring at sites of active fluid venting, in situ heat flow measurements across the entire length of the Gibraltar thrust wedge, the deformation front, landslide bodies, and mud volcanoes, and finally the deployment of a long-term pore pressure probe. Video-supported operations helped to identify fluid vent sites, regions with tectonic activity, and other attractive high priority targets. Qualitative and quantitative examinations took place on board and are continued on land with respect to pore pressure variation, geomicrobiology, sediment- and fluid mobilization, geochemical processes, faunal assemblages (e.g. cold water corals), and gas hydrates (flammable methane-ice-crystals). Main focus of the expedition has been a better understanding of interaction between dynamic processes in a seismically active region region with slow plate convergence. In the context of earthquake nucleation and subduction zone processes, the SO175 research programme had a variety of goals, such as: ‱ To test the frictional behaviour of the abyssal plain sediments. ‱ To explore the temperature field of the 1755 thrust earthquake event via heat flow measurements. ‱ To assess the role of fluid venting and gas hydrate processes control slope stability and mud volcanic activity along the Iberian continental margin. ‱ To measure isotope geochemistry of pore waters and carbonates of deep fluids. ‱ To quantify microbial activity in Gibraltar wedge sediments. ‱ To test whether microseismicity in the area corresponds to in situ pore pressure changes. ‱ To find out if enhanced heat flow max be indicative of active subduction. Initial tentative results during the cruise suggest that there is a component of active thrusting at the base of the wedge, as attested by heat flow data. Based on mostly geochemical evidence, mud volcanism was found less active than previously assumed. Highlights from post-cruise research include the successful deployment of the long-term station and high frictional resistance of all incoming sediment on the three abyssal plains

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology: Gnaiger Erich et al ― MitoEAGLE Task Group

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    Comprehensive analysis of local and nonlocal amplitudes in the B0→K∗0ÎŒ+Ό−B^0\rightarrow K^{*0}\mu^+\mu^- decay

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    International audienceA comprehensive study of the local and nonlocal amplitudes contributing to the decay B0→K∗0(→K+π−)ÎŒ+Ό−B^0\rightarrow K^{*0}(\to K^+\pi^-) \mu^+\mu^- is performed by analysing the phase-space distribution of the decay products. The analysis is based on \proton\proton collision data corresponding to an integrated luminosity of 8.4fb−1^{-1} collected by the LHCb experiment. This measurement employs for the first time a model of both one-particle and two-particle nonlocal amplitudes, and utilises the complete dimuon mass spectrum without any veto regions around the narrow charmonium resonances. In this way it is possible to explicitly isolate the local and nonlocal contributions and capture the interference between them. The results show that interference with nonlocal contributions, although larger than predicted, only has a minor impact on the Wilson Coefficients determined from the fit to the data. For the local contributions, the Wilson Coefficient C9C_9, responsible for vector dimuon currents, exhibits a 2.1σ2.1\sigma deviation from the Standard Model expectation. The Wilson Coefficients C10C_{10}, C9â€ČC_{9}' and C10â€ČC_{10}' are all in better agreement than C9C_{9} with the Standard Model and the global significance is at the level of 1.5σ1.5\sigma. The model used also accounts for nonlocal contributions from B0→K∗0[τ+τ−→Ό+Ό−]B^{0}\to K^{*0}\left[\tau^+\tau^-\to \mu^+\mu^-\right] rescattering, resulting in the first direct measurement of the bsττb s\tau\tau vector effective-coupling C9τC_{9\tau}

    Transverse polarisation measurement of Λ\Lambda hyperons in ppNe collisions at sNN\sqrt{s_{NN}}=68.4 GeV with the LHCb detector

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    A measurement of the transverse polarization of the Λ\Lambda and Λˉ\bar{\Lambda}hyperons in ppNe fixed-target collisions at sNN\sqrt{s_{NN}}=68.4 GeV is presented using data collected by the LHCb detector. The polarization is studied using the decay Λ→pπ−\Lambda \rightarrow p \pi^- together with its charge conjugated process, the integrated values measured are PΛ=0.029±0.019 (stat)±0.012 (syst) , P_{\Lambda} = 0.029 \pm 0.019 \, (\rm{stat}) \pm 0.012 \, (\rm{syst}) \, , PΛˉ=0.003±0.023 (stat)±0.014 (syst)  P_{\bar{\Lambda}} = 0.003 \pm 0.023 \, (\rm{stat}) \pm 0.014 \,(\rm{syst}) \, Furthermore, the results are shown as a function of the Feynman xx variable, transverse momentum, pseudorapidity and rapidity of the hyperons, and are compared with previous measurements.A measurement of the transverse polarization of the Λ\Lambda and Λˉ\bar{\Lambda} hyperons in ppNe fixed-target collisions at sNN\sqrt{s_{NN}} = 68.4 GeV is presented using data collected by the LHCb detector. The polarization is studied using the decay Λ→pπ−\Lambda \rightarrow p \pi^- together with its charge conjugated process, the integrated values measured are PΛ=0.029±0.019 (stat)±0.012 (syst) , P_{\Lambda} = 0.029 \pm 0.019 \, (\rm{stat}) \pm 0.012 \, (\rm{syst}) \, , PΛˉ=0.003±0.023 (stat)±0.014 (syst) . P_{\bar{\Lambda}} = 0.003 \pm 0.023 \, (\rm{stat}) \pm 0.014 \,(\rm{syst}) \,. Furthermore, the results are shown as a function of the Feynman~xx~variable, transverse momentum, pseudorapidity and rapidity of the hyperons, and are compared with previous measurements

    Probing the nature of the χc1(3872)\chi_{c1}(3872) state using radiative decays

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    International audienceThe radiative decays χc1(3872)→ψ(2S)Îł\chi_{c1}(3872)\rightarrow\psi(2S)\gamma and χc1(3872)→J/ÏˆÎł\chi_{c1}(3872)\rightarrow J/\psi\gamma are used to probe the~nature of the~χc1(3872)\chi_{c1}(3872) state using proton-proton collision data collected with the LHCb detector, corresponding to an~integrated luminosity of~9fb−1^{-1}. Using the~B+→χc1(3872)K+B^+\rightarrow \chi_{c1}(3872)K^+decay, the χc1(3872)→ψ(2S)Îł\chi_{c1}(3872)\rightarrow \psi(2S)\gamma process is observed for the first time and the ratio of its partial width to that of the χc1(3872)→J/ÏˆÎł\chi_{c1}(3872)\rightarrow J/\psi\gamma decay is measured to be Γχc1(3872)→ψ(2S)ÎłÎ“Ï‡c1(3872)→J/ÏˆÎł=1.67±0.21±0.12±0.04, \frac{\Gamma_{\chi_{c1}(3872)\rightarrow \psi(2S)\gamma}} {\Gamma_{\chi_{c1}(3872)\rightarrow J/\psi\gamma}} = 1.67 \pm 0.21 \pm 0.12 \pm0.04 , where the first uncertainty is statistical, the second systematic and the third is due to the uncertainties on the branching fractions of the ψ(2S)\psi(2S) and J/ψJ/\psi mesons. The measured ratio makes the interpretation of the χc1(3872)\chi_{c1}(3872) state as a~pure D0Dˉ∗0+Dˉ0D∗0D^0\bar{D}^{*0}+\bar{D}^0D^{*0} molecule questionable and strongly indicates a sizeable compact charmonium or tetraquark component within the χc1(3872)\chi_{c1}(3872) state

    Measurement of D0−D‟0D^0-\overline{D}^0 mixing and search for CPCP violation with D0→K+π−D^0\rightarrow K^+\pi^- decays

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    International audienceA measurement of the time-dependent ratio of the D0→K+π−D^0\rightarrow K^+\pi^- to D‟0→K+π−\overline{D}^0\rightarrow K^+\pi^- decay rates is reported. The analysis uses a sample of proton-proton collisions corresponding to an integrated luminosity of 6 fb−1^-1 recorded by the LHCb experiment from 2015 through 2018 at a center-of-mass energy of 13 TeV. The D0D^0 meson is required to originate from a D∗+→D0π+D^{*+}\rightarrow D^0\pi^+ decay, such that its flavor at production is inferred from the charge of the accompanying pion. The measurement is performed simultaneously for the K+π−K^+\pi^- and K−π+K^-\pi^+ final states, allowing both mixing and CPCP-violation parameters to be determined. The value of the ratio of the decay rates at production is determined to be RKπ=(343.1±2.0)×10−5R_{K\pi} = (343.1 \pm 2.0) \times 10^{-5}. The mixing parameters are measured to be cKπ=(51.4±3.5)×10−4c_{K\pi} = (51.4 \pm 3.5) \times 10^{-4} and cKπâ€Č=(13±4)×10−6c_{K\pi}^{\prime} = (13 \pm 4) \times 10^{-6}, where RKπcKπ\sqrt{R_{K\pi}}c_{K\pi} is the linear coefficient of the expansion of the ratio as a function of decay time in units of the D0D^0 lifetime, and cKπâ€Čc_{K\pi}^{\prime} is the quadratic coefficient, both averaged between the K+π−K^+\pi^- and K−π+K^-\pi^+ final states. The precision is improved relative to the previous best measurement by approximately 60%. No evidence for CPCP violation is found

    Measurement of D0−D‟0D^0-\overline{D}^0 mixing and search for CPCP violation with D0→K+π−D^0\rightarrow K^+\pi^- decays

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    International audienceA measurement of the time-dependent ratio of the D0→K+π−D^0\rightarrow K^+\pi^- to D‟0→K+π−\overline{D}^0\rightarrow K^+\pi^- decay rates is reported. The analysis uses a sample of proton-proton collisions corresponding to an integrated luminosity of 6 fb−1^-1 recorded by the LHCb experiment from 2015 through 2018 at a center-of-mass energy of 13 TeV. The D0D^0 meson is required to originate from a D∗+→D0π+D^{*+}\rightarrow D^0\pi^+ decay, such that its flavor at production is inferred from the charge of the accompanying pion. The measurement is performed simultaneously for the K+π−K^+\pi^- and K−π+K^-\pi^+ final states, allowing both mixing and CPCP-violation parameters to be determined. The value of the ratio of the decay rates at production is determined to be RKπ=(343.1±2.0)×10−5R_{K\pi} = (343.1 \pm 2.0) \times 10^{-5}. The mixing parameters are measured to be cKπ=(51.4±3.5)×10−4c_{K\pi} = (51.4 \pm 3.5) \times 10^{-4} and cKπâ€Č=(13±4)×10−6c_{K\pi}^{\prime} = (13 \pm 4) \times 10^{-6}, where RKπcKπ\sqrt{R_{K\pi}}c_{K\pi} is the linear coefficient of the expansion of the ratio as a function of decay time in units of the D0D^0 lifetime, and cKπâ€Čc_{K\pi}^{\prime} is the quadratic coefficient, both averaged between the K+π−K^+\pi^- and K−π+K^-\pi^+ final states. The precision is improved relative to the previous best measurement by approximately 60%. No evidence for CPCP violation is found

    Measurement of D0−D‟0D^0-\overline{D}^0 mixing and search for CPCP violation with D0→K+π−D^0\rightarrow K^+\pi^- decays

    No full text
    International audienceA measurement of the time-dependent ratio of the D0→K+π−D^0\rightarrow K^+\pi^- to D‟0→K+π−\overline{D}^0\rightarrow K^+\pi^- decay rates is reported. The analysis uses a sample of proton-proton collisions corresponding to an integrated luminosity of 6 fb−1^-1 recorded by the LHCb experiment from 2015 through 2018 at a center-of-mass energy of 13 TeV. The D0D^0 meson is required to originate from a D∗+→D0π+D^{*+}\rightarrow D^0\pi^+ decay, such that its flavor at production is inferred from the charge of the accompanying pion. The measurement is performed simultaneously for the K+π−K^+\pi^- and K−π+K^-\pi^+ final states, allowing both mixing and CPCP-violation parameters to be determined. The value of the ratio of the decay rates at production is determined to be RKπ=(343.1±2.0)×10−5R_{K\pi} = (343.1 \pm 2.0) \times 10^{-5}. The mixing parameters are measured to be cKπ=(51.4±3.5)×10−4c_{K\pi} = (51.4 \pm 3.5) \times 10^{-4} and cKπâ€Č=(13±4)×10−6c_{K\pi}^{\prime} = (13 \pm 4) \times 10^{-6}, where RKπcKπ\sqrt{R_{K\pi}}c_{K\pi} is the linear coefficient of the expansion of the ratio as a function of decay time in units of the D0D^0 lifetime, and cKπâ€Čc_{K\pi}^{\prime} is the quadratic coefficient, both averaged between the K+π−K^+\pi^- and K−π+K^-\pi^+ final states. The precision is improved relative to the previous best measurement by approximately 60%. No evidence for CPCP violation is found
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