633 research outputs found

    Nociceptin Is a Chemorepellent in \u3ci\u3eTetrahymena thermophila\u3c/i\u3e

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    Tetrahymena thermophila are free-living, ciliated, eukaryotic organisms that respond to stimuli by moving toward chemoattractants and avoiding chemorepellents. Chemoattractant responses involve faster ciliary beating, which propels the organisms forward more rapidly. Chemorepellent signaling involves ciliary reversal, which disrupts forward swimming, and causes the organism to jerk back and forth, swim in small circles, or spin in an attempt to get away from the repellent. Many food sources, such as proteins, are chemoattractants for Tetrahymena, while a variety of compounds are repellents. Repellents in nature are thought to come from the secretions of predators, or from ruptured organisms, which may serve as “danger” signals. Several hormones involved in human pain signaling have been shown to be chemorepellents in Tetrahymena, including substance P, ACTH, PACAP, VIP, and nociceptin. We have been studying the response of Tetrahymena to nociceptin, using pharmacological inhibitors in order to elucidate components of the nociceptin signaling pathway. We have found that G-protein inhibitors and a number of mammalian tyrosine kinase inhibitors have no effect on nociceptin avoidance. However, the tyrosine kinase inhibitor, genistein, inhibits avoidance to nociceptin, likely by an unrelated mechanism. Nociceptin avoidance is also inhibited by the calcium chelator, EGTA, and partially inhibited by the ER calcium ATPase inhibitor, thapsigargin. Whole cell electrophysiology experiments in a calcium-containing buffer show that addition of 50 ÎŒM nociceptin to the buffer causes a sustained depolarization of approximately 30 mV. This depolarization is nearly eliminated in the presence of EGTA, further supporting the hypothesis that calcium is involved in nociceptin signaling. J-113397, an inhibitor of the human nociceptin receptor, also inhibits nociceptin avoidance in Tetrahymena, though other nociceptin antagonists we tested had no effect on avoidance. Further experimentation on this organism will give a more complete picture of the signaling pathway, as well as allowing greater comparison between nociceptin avoidance in Tetrahymena and nociceptin signaling in vertebrates

    Nociceptin Signaling Involves a Calcium-Based Depolarization in Tetrahymena thermophila

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    Tetrahymena thermophila are free-living, ciliated eukaryotes. Their behavioral response to stimuli is well characterized and easily observable, since cells swim toward chemoattractants and avoid chemorepellents. Chemoattractant responses involve increased swim speed or a decreased change in swim direction, while chemorepellent signaling involves ciliary reversal, which causes the organism to jerk back and forth, swim in small circles, or spin in an attempt to get away from the repellent. Many food sources, such as proteins, are chemoattractants for these organisms, while a variety of compounds are repellents. Repellents in nature are thought to come from the secretions of predators or from ruptured organisms, which may serve as “danger” signals. Interestingly, several peptides involved in vertebrate pain signaling are chemorepellents in Tetrahymena, including substances P, ACTH, PACAP, VIP, and nociceptin. Here, we characterize the response of Tetrahymena thermophila to three different isoforms of nociceptin. We find that G-protein inhibitors and tyrosine kinase inhibitors do not affect nociceptin avoidance. However, the calcium chelator, EGTA, and the SERCA calcium ATPase inhibitor, thapsigargin, both inhibit nociceptin avoidance, implicating calcium in avoidance. This result is confirmed by electrophysiology studies which show that 50”M nociceptin-NH2 causes a sustained depolarization of approximately 40 mV, which is eliminated by the addition of extracellular EGTA

    Nociceptin Signals Through Calcium in \u3ci\u3eTetrahymena thermophila\u3c/i\u3e

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    Tetrahymena thermophila are free-living, ciliated, eukaryotic organisms that respond to stimuli by moving toward chemoattractants and avoiding chemorepellents. Chemoattractant responses involve faster ciliary beating, which propels the organisms forward more rapidly. Chemorepellents signaling involves ciliary reversal, which disrupts forward swimming, and causes the organisms to jerk back and forth, swim in small circles, or spin in an attempt to get away from the repellent. Many food sources, such as proteins, are chemoattractants for these organisms, while a variety of compounds are repellents. Repellents in nature are thought to come from the secretions of predators, or from ruptured organisms, which may serve as danger signals. Interestingly, several hormones involved in human pain signaling have been shown to be chemorepellents in Tetrahymena, including substance P, ACTH, PACAP, VIP, and nociceptin. Recently, we have been studying Tetrahymena response to nociceptin, using pharmacological inhibitors in order to elucidate components of the nociceptin signaling pathway. We have found that G-protein inhibitors and a number of mammalian tyrosine kinase inhibitors have no effect on nociceptin avoidance. However, the tyrosine kinase inhibitor, genistein, inhibits avoidance to nociceptin. Nociceptin avoidance is also inhibited by the calcium chelator, EGTA, which implicates calcium in the avoidance response. Electrophysiology studies done in a calcium-containing buffer show that 50 ÎŒM nociceptin causes a sustained depolarization of approximately 30 mV, further supporting the hypothesis that calcium is involved in nociceptin signaling. J-113397, an inhibitor of the human nociceptin receptor, also inhibits nociceptin avoidance in Tetrahymena. We are currently working to determine whether other inhibitors of the human nociceptin receptor have any effect on Tetrahymena, in order to get a more complete picture of the signaling pathway

    Roadmap fĂŒr strombasierte Kraftstoffe 03EIV116A-G

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    Synthetische Kraftstoffe können die Defossilisierung des Verkehrssektors mit vorantreiben. Besonders bei hohen Transportvolumina oder fĂŒr große Entfernungen sind diese Kraftstoffe eine vielversprechende Option, etwa in der Luft- und Schifffahrt oder zu Teilen im Schwerlastverkehr. Auf Basis von Strom aus erneuerbaren Energien hergestellte Kraftstoffe sollen in Zukunft entscheidend dazu beitragen, die CO2-Bilanz zu verbessern und KlimaneutralitĂ€t im Verkehrssektor zu erreichen. Die Forschung dockt damit an die Schnittstelle zwischen Energie- und Verkehrssektor an. Im Rahmen der BMWK-Forschungsinitiative Energiewende im Verkehr (EiV) haben von 2018 bis 2023 insgesamt 16 industriegefĂŒhrte F&E-Projekte die Entwicklung synthetischer Kraftstoffe fĂŒr den Luft-, See- und Straßenverkehr deutlich vorangebracht. In den Projekten wurde eine Vielzahl verschiedener Kraftstoffe, Herstellverfahren und Anwendungen betrachtet. Dabei war es die Aufgabe der „Begleitforschung Energiewende im Verkehr“ (BEniVer), als einer der 16 EiV-ProjektverbĂŒnde, die Projektergebnisse der technischen Forschungsvorhaben der Förderinitiative auf Basis eigenstĂ€ndiger wissenschaftlicher Analysen vergleichbar zu machen. Dazu wurden einheitliche Rahmenannahmen und MethodikleitfĂ€den entwickelt. Die Ergebnisse der Forschungsprojekte wurden in einer Gesamtbetrachtung zusammengefĂŒhrt und dienten als Grundlage fĂŒr technische, ökonomische und ökologische Bewertungen. Dabei beruhten die technologie-orientierten Bottom-Up-Analysen auf den neuesten Forschungsarbeiten. Diese wurden mit systemorientierten Top-Down-Analysen des Energie- und Verkehrssystems sowie möglichen Transformationspfaden auf dem Weg zur KlimaneutralitĂ€t kombiniert. Weitere Analysen zur Akzeptanz und zur MarkteinfĂŒhrung adressieren zudem gesellschaftliche Dimensionen und Auswirkungen der EinfĂŒhrung von strombasierten Kraftstoffen. Auf Basis der ganzheitlichen Analysen wurden Schlussfolgerungen abgeleitet. Als Ergebnis der langjĂ€hrigen und fachĂŒbergreifende Begleitung der EiV-Forschungsvorhaben ist mit der Roadmap fĂŒr strombasierte Kraftstoffe ein Leitfaden entstanden mit Handlungsoptionen fĂŒr die Erforschung, Entwicklung, Produktion und MarkteinfĂŒhrung dieser Kraftstoffe

    Forschungsinitiative Energiewende im Verkehr, Kurzbericht zur „Roadmap fĂŒr strombasierte Kraftstoffe“ 03EIV116A-G

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    Synthetische Kraftstoffe können die Defossilisierung des Verkehrssektors mit vorantreiben. Besonders bei hohen Transportvolumina oder fĂŒr große Entfernungen sind diese Kraftstoffe eine vielversprechende Option, etwa in der Luft- und Schifffahrt oder zu Teilen im Schwerlastverkehr. Auf Basis von Strom aus erneuerbaren Energien hergestellte Kraftstoffe sollen in Zukunft entscheidend dazu beitragen, die CO2-Bilanz zu verbessern und KlimaneutralitĂ€t im Verkehrssektor zu erreichen. Die Forschung dockt damit an die Schnittstelle zwischen Energie- und Verkehrssektor an. Im Rahmen der BMWK-Forschungsinitiative Energiewende im Verkehr (EiV) haben von 2018 bis 2023 insgesamt 16 industriegefĂŒhrte F&E-Projekte die Entwicklung synthetischer Kraftstoffe fĂŒr den Luft-, See- und Straßenverkehr deutlich vorangebracht. In den Projekten wurde eine Vielzahl verschiedener Kraftstoffe, Herstellverfahren und Anwendungen betrachtet. Dabei war es die Aufgabe der „Begleitforschung Energiewende im Verkehr“ (BEniVer), als einer der 16 EiV-ProjektverbĂŒnde, die Projektergebnisse der technischen Forschungsvorhaben der Förderinitiative auf Basis eigenstĂ€ndiger wissenschaftlicher Analysen vergleichbar zu machen. Dazu wurden einheitliche Rahmenannahmen und MethodikleitfĂ€den entwickelt. Die Ergebnisse der Forschungsprojekte wurden in einer Gesamtbetrachtung zusammengefĂŒhrt und dienten als Grundlage fĂŒr technische, ökonomische und ökologische Bewertungen. Dabei beruhten die technologie-orientierten Bottom-Up-Analysen auf den neuesten Forschungsarbeiten. Diese wurden mit systemorientierten Top-Down-Analysen des Energie- und Verkehrssystems sowie möglichen Transformationspfaden auf dem Weg zur KlimaneutralitĂ€t kombiniert. Weitere Analysen zur Akzeptanz und zur MarkteinfĂŒhrung adressieren zudem gesellschaftliche Dimensionen und Auswirkungen der EinfĂŒhrung von strombasierten Kraftstoffen. Auf Basis der ganzheitlichen Analysen wurden Schlussfolgerungen abgeleitet. Als Ergebnis der langjĂ€hrigen und fachĂŒbergreifende Begleitung der EiV-Forschungsvorhaben ist mit der Roadmap fĂŒr strombasierte Kraftstoffe ein Leitfaden entstanden mit Handlungsoptionen fĂŒr die Erforschung, Entwicklung, Produktion und MarkteinfĂŒhrung dieser Kraftstoffe

    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

    Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

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    Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a ZZ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 <pT<100< p_{\textrm{T}} < 100 GeV and in the pseudorapidity range 2.5<η<42.5 < \eta < 4. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb−1^{-1}. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

    Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

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    The decay B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} is studied in proton-proton collisions at a center-of-mass energy of s=13\sqrt{s}=13 TeV using data corresponding to an integrated luminosity of 5 fb−1\mathrm{fb}^{-1} collected by the LHCb experiment. In the Λc+K−\Lambda_{c}^+ K^{-} system, the Ξc(2930)0\Xi_{c}(2930)^{0} state observed at the BaBar and Belle experiments is resolved into two narrower states, Ξc(2923)0\Xi_{c}(2923)^{0} and Ξc(2939)0\Xi_{c}(2939)^{0}, whose masses and widths are measured to be m(Ξc(2923)0)=2924.5±0.4±1.1 MeV,m(Ξc(2939)0)=2938.5±0.9±2.3 MeV,Γ(Ξc(2923)0)=0004.8±0.9±1.5 MeV,Γ(Ξc(2939)0)=0011.0±1.9±7.5 MeV, m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV}, where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt Λc+K−\Lambda_{c}^{+} K^{-} sample. Evidence of a new Ξc(2880)0\Xi_{c}(2880)^{0} state is found with a local significance of 3.8 σ3.8\,\sigma, whose mass and width are measured to be 2881.8±3.1±8.5 MeV2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV} and 12.4±5.3±5.8 MeV12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}, respectively. In addition, evidence of a new decay mode Ξc(2790)0→Λc+K−\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-} is found with a significance of 3.7 σ3.7\,\sigma. The relative branching fraction of B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} with respect to the B−→D+D−K−B^{-} \to D^{+} D^{-} K^{-} decay is measured to be 2.36±0.11±0.22±0.252.36 \pm 0.11 \pm 0.22 \pm 0.25, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

    Measurement of the ratios of branching fractions R(D∗)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

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    The ratios of branching fractions R(D∗)≡B(Bˉ→D∗τ−Μˉτ)/B(Bˉ→D∗Ό−ΜˉΌ)\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu}) and R(D0)≡B(B−→D0τ−Μˉτ)/B(B−→D0Ό−ΜˉΌ)\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu}) are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb−1{ }^{-1} of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ−→Ό−ΜτΜˉΌ\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}. The measured values are R(D∗)=0.281±0.018±0.024\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024 and R(D0)=0.441±0.060±0.066\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is ρ=−0.43\rho=-0.43. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

    Observation of the B0 → ρ0ρ0 decay from an amplitude analysis of B0 → (π+π−)(π+π−) decays

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    Proton–proton collision data recorded in 2011 and 2012 by the LHCb experiment, corresponding to an integrated luminosity of 3.0 fb−1 , are analysed to search for the charmless B0→ρ0ρ0 decay. More than 600 B0→(π+π−)(π+π−) signal decays are selected and used to perform an amplitude analysis, under the assumption of no CP violation in the decay, from which the B0→ρ0ρ0 decay is observed for the first time with 7.1 standard deviations significance. The fraction of B0→ρ0ρ0 decays yielding a longitudinally polarised final state is measured to be fL=0.745−0.058+0.048(stat)±0.034(syst) . The B0→ρ0ρ0 branching fraction, using the B0→ϕK⁎(892)0 decay as reference, is also reported as B(B0→ρ0ρ0)=(0.94±0.17(stat)±0.09(syst)±0.06(BF))×10−6
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