96 research outputs found

    Statistics of the dissipated energy in driven single-electron transitions

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    We analyze the distribution of heat generated in driven single-electron transitions and discuss the related non-equilibrium work theorems. In the adiabatic limit, the heat distribution is shown to become Gaussian, with the heat noise that, in spite of thermal fluctuations, vanishes together with the average dissipated energy. We show that the transitions satisfy Jarzynski equality for arbitrary drive and calculate the probability of the negative heat values. We also derive a general condition on the heat distribution that generalizes the Bochkov-Kuzovlev equality and connects it to the Jarzynski equality.Comment: 5 pages, 2 figure

    Dynamic force spectroscopy of DNA hairpins. II. Irreversibility and dissipation

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    We investigate irreversibility and dissipation in single molecules that cooperatively fold/unfold in a two state manner under the action of mechanical force. We apply path thermodynamics to derive analytical expressions for the average dissipated work and the average hopping number in two state systems. It is shown how these quantities only depend on two parameters that characterize the folding/unfolding kinetics of the molecule: the fragility and the coexistence hopping rate. The latter has to be rescaled to take into account the appropriate experimental setup. Finally we carry out pulling experiments with optical tweezers in a specifically designed DNA hairpin that shows two-state cooperative folding. We then use these experimental results to validate our theoretical predictions.Comment: 28 pages, 12 figure

    Energetics and performance of a microscopic heat engine based on exact calculations of work and heat distributions

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    We investigate a microscopic motor based on an externally controlled two-level system. One cycle of the motor operation consists of two strokes. Within each stroke, the two-level system is in contact with a given thermal bath and its energy levels are driven with a constant rate. The time evolution of the occupation probabilities of the two states are controlled by one rate equation and represent the system's response with respect to the external driving. We give the exact solution of the rate equation for the limit cycle and discuss the emerging thermodynamics: the work done on the environment, the heat exchanged with the baths, the entropy production, the motor's efficiency, and the power output. Furthermore we introduce an augmented stochastic process which reflects, at a given time, both the occupation probabilities for the two states and the time spent in the individual states during the previous evolution. The exact calculation of the evolution operator for the augmented process allows us to discuss in detail the probability density for the performed work during the limit cycle. In the strongly irreversible regime, the density exhibits important qualitative differences with respect to the more common Gaussian shape in the regime of weak irreversibility.Comment: 21 pages, 7 figure

    Cytogenetic Studies of Normal and Cleft-Palate Epitheliums in Mice

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    This study investigated teratogenic activity on a cellular level through analysis of the cytogenetic complex in cleft-palate epithelial cells from the progenies of mice treated with cortisone. Analysis showed no detectable aberration from a normal chromosomal complement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68120/2/10.1177_00220345690480041601.pd

    A family case of fertile human 45,X,psu dic(15;Y) males

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    We report on a familial case including four male probands from three generations with a 45,X,psu dic(15;Y)(p11.2;q12) karyotype. 45,X is usually associated with a female phenotype and only rarely with maleness, due to translocation of small Y chromosomal fragments to autosomes. These male patients are commonly infertile because of missing azoospermia factor regions from the Y long arm. In our familial case we found a pseudodicentric translocation chromosome, that contains almost the entire chromosomes 15 and Y. The translocation took place in an unknown male ancestor of our probands and has no apparent effect on fertility and phenotype of the carrier. FISH analysis demonstrated the deletion of the pseudoautosomal region 2 (PAR2) from the Y chromosome and the loss of the nucleolus organizing region (NOR) from chromosome 15. The formation of the psu dic(15;Y) chromosome is a reciprocal event to the formation of the satellited Y chromosome (Yqs). Statistically, the formation of 45,X,psu dic(15;Y) (p11.2;q12) is as likely as the formation of Yqs. Nevertheless, it has not been described yet. This can be explained by the dicentricity of this translocation chromosome that usually leads to mitotic instability and meiotic imbalances. A second event, a stable inactivation of one of the two centromeres is obligatory to enable the transmission of the translocation chromosome and thus a stably reduced chromosome number from father to every son in this family

    MCC950/CRID3 potently targets the NACHT domain of wild-type NLRP3 but not disease-associated mutants for inflammasome inhibition

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    The nucleotide-binding-domain (NBD)-and leucine-rich repeat (LRR)-containing (NLR) family, pyrin-domain-containing 3 (NLRP3) inflammasome drives pathological inflammation in a suite of autoimmune, metabolic, malignant, and neurodegenerative diseases. Additionally, NLRP3 gain-of-function point mutations cause systemic periodic fever syndromes that are collectively known as cryopyrin-associated periodic syndrome (CAPS). There is significant interest in the discovery and development of diarylsulfonylurea Cytokine Release Inhibitory Drugs (CRIDs) such as MCC950/CRID3, a potent and selective inhibitor of the NLRP3 inflammasome pathway, for the treatment of CAPS and other diseases. However, drug discovery efforts have been constrained by the lack of insight into the molecular target and mechanism by which these CRIDs inhibit the NLRP3 inflammasome pathway. Here, we show that the NAIP, CIITA, HET-E, and TP1 (NACHT) domain of NLRP3 is the molecular target of diarylsulfonylurea inhibitors. Interestingly, we find photoaffinity labeling (PAL) of the NACHT domain requires an intact (d)ATP-binding pocket and is substantially reduced for most CAPS-associated NLRP3 mutants. In concordance with this finding, MCC950/CRID3 failed to inhibit NLRP3-driven inflammatory pathology in two mouse models of CAPS. Moreover, it abolished circulating levels of interleukin (IL)-1 beta and IL-18 in lipopolysaccharide (LPS)-challenged wild-type mice but not in Nlrp3(L351P) knock-in mice and ex vivo-stimulated mutant macrophages. These results identify wild-type NLRP3 as the molecular target of MCC950/CRID3 and show that CAPS-related NLRP3 mutants escape efficient MCC950/CRID3 inhibition. Collectively, this work suggests that MCC950/CRID3-based therapies may effectively treat inflammation driven by wild-type NLRP3 but not CAPS-associated mutants

    Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

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    A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaboration at CERN. The following kinematic domain is covered by the data: photon virtuality Q2>1Q^{2}>1 (GeV/cc)2^2, invariant mass of the hadronic system W>5W > 5 GeV/c2c^2, Bjorken scaling variable in the range 0.003<x<0.40.003 < x < 0.4, fraction of the virtual photon energy carried by the hadron in the range 0.2<z<0.80.2 < z < 0.8, square of the hadron transverse momentum with respect to the virtual photon direction in the range 0.02 (GeV/c)2<PhT2<3c)^2 < P_{\rm{hT}}^{2} < 3 (GeV/cc)2^2. The multiplicities are presented as a function of PhT2P_{\rm{hT}}^{2} in three-dimensional bins of xx, Q2Q^2, zz and compared to previous semi-inclusive measurements. We explore the small-PhT2P_{\rm{hT}}^{2} region, i.e. PhT2<1P_{\rm{hT}}^{2} < 1 (GeV/cc)2^2, where hadron transverse momenta are expected to arise from non-perturbative effects, and also the domain of larger PhT2P_{\rm{hT}}^{2}, where contributions from higher-order perturbative QCD are expected to dominate. The multiplicities are fitted using a single-exponential function at small PhT2P_{\rm{hT}}^{2} to study the dependence of the average transverse momentum ⟹PhT2⟩\langle P_{\rm{hT}}^{2}\rangle on xx, Q2Q^2 and zz. The power-law behaviour of the multiplicities at large PhT2P_{\rm{hT}}^{2} is investigated using various functional forms. The fits describe the data reasonably well over the full measured range.Comment: 28 pages, 20 figure

    Corrigendum to "Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section" [Phys. Lett. B 793 (2019) 188]

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    Light isovector resonances in π-p →π-π-π+p at 190 GeV/c

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    We have performed the most comprehensive resonance-model fit of π-π-π+ states using the results of our previously published partial-wave analysis (PWA) of a large data set of diffractive-dissociation events from the reaction π-+p→π-π-π++precoil with a 190 GeV/c pion beam. The PWA results, which were obtained in 100 bins of three-pion mass, 0.5<2.5 GeV/c2, and simultaneously in 11 bins of the reduced four-momentum transfer squared, 0.1<1.0 (GeV/c)2, are subjected to a resonance-model fit using Breit-Wigner amplitudes to simultaneously describe a subset of 14 selected waves using 11 isovector light-meson states with JPC=0-+, 1++, 2++, 2-+, 4++, and spin-exotic 1-+ quantum numbers. The model contains the well-known resonances π(1800), a1(1260), a2(1320), π2(1670), π2(1880), and a4(2040). In addition, it includes the disputed π1(1600), the excited states a1(1640), a2(1700), and π2(2005), as well as the resonancelike a1(1420). We measure the resonance parameters mass and width of these objects by combining the information from the PWA results obtained in the 11 tâ€Č bins. We extract the relative branching fractions of the ρ(770)π and f2(1270)π decays of a2(1320) and a4(2040), where the former one is measured for the first time. In a novel approach, we extract the tâ€Č dependence of the intensity of the resonances and of their phases. The tâ€Č dependence of the intensities of most resonances differs distinctly from the tâ€Č dependence of the nonresonant components. For the first time, we determine the tâ€Č dependence of the phases of the production amplitudes and confirm that the production mechanism of the Pomeron exchange is common to all resonances. We have performed extensive systematic studies on the model dependence and correlations of the measured physical parameters

    Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of ρ0\rho^0 mesons

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    The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure of the nucleon and the related phenomena. The COMPASS collaboration has performed the first measurement of the Collins and Sivers asymmetries for inclusively produced ρ0\rho^0 mesons. The analysis is based on the data set collected in deep inelastic scattering in 20102010 using a 160  GeV/c160\,\,\rm{GeV}/c ÎŒ+\mu^+ beam impinging on a transversely polarized NH3\rm{NH}_3 target. The ρ0\rho^{0} mesons are selected from oppositely charged hadron pairs, and the asymmetries are extracted as a function of the Bjorken-xx variable, the transverse momentum of the pair and the fraction of the energy zz carried by the pair. Indications for positive Collins and Sivers asymmetries are observed
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