6,190 research outputs found

    The nuclear equation of state probed by K+K^+ production in heavy ion collisions

    Full text link
    The dependence of K+K^+ production on the nuclear equation of state is investigated in heavy ion collisions. An increase of the excitation function of K+K^+ multiplicities obtained in heavy (Au+AuAu+Au) over light (C+CC+C) systems when going far below threshold which has been observed by the KaoS Collaboration strongly favours a soft equation of state. This observation holds despite of the influence of an in-medium kaon potential predicted by effective chiral models which is necessary to reproduce the experimental K+K^+ yields. Phase space effects are discussed with respect to the K+K^+ excitation function.Comment: 14 pages Revtex, 6 figures, Proceedings to the XXXIX Interantional Winter Meeting on Nuclear Physics, Bormio, Italy, 200

    On the Inability of Markov Models to Capture Criticality in Human Mobility

    Get PDF
    We examine the non-Markovian nature of human mobility by exposing the inability of Markov models to capture criticality in human mobility. In particular, the assumed Markovian nature of mobility was used to establish a theoretical upper bound on the predictability of human mobility (expressed as a minimum error probability limit), based on temporally correlated entropy. Since its inception, this bound has been widely used and empirically validated using Markov chains. We show that recurrent-neural architectures can achieve significantly higher predictability, surpassing this widely used upper bound. In order to explain this anomaly, we shed light on several underlying assumptions in previous research works that has resulted in this bias. By evaluating the mobility predictability on real-world datasets, we show that human mobility exhibits scale-invariant long-range correlations, bearing similarity to a power-law decay. This is in contrast to the initial assumption that human mobility follows an exponential decay. This assumption of exponential decay coupled with Lempel-Ziv compression in computing Fano's inequality has led to an inaccurate estimation of the predictability upper bound. We show that this approach inflates the entropy, consequently lowering the upper bound on human mobility predictability. We finally highlight that this approach tends to overlook long-range correlations in human mobility. This explains why recurrent-neural architectures that are designed to handle long-range structural correlations surpass the previously computed upper bound on mobility predictability

    Ultrahigh Surface Area Three-Dimensional Porous Graphitic Carbon from Conjugated Polymeric Molecular Framework

    Get PDF
    Porous graphitic carbon is essential for many applications such as energy storage devices, catalysts, and sorbents. However, current graphitic carbons are limited by low conductivity, low surface area, and ineffective pore structure. Here we report a scalable synthesis of porous graphitic carbons using a conjugated polymeric molecular framework as precursor. The multivalent cross-linker and rigid conjugated framework help to maintain micro- and mesoporous structures, while promoting graphitization during carbonization and chemical activation. The above unique design results in a class of highly graphitic carbons at temperature as low as 800 ??C with record-high surface area (4073 m2 g-1), large pore volume (2.26 cm-3), and hierarchical pore architecture. Such carbons simultaneously exhibit electrical conductivity >3 times more than activated carbons, very high electrochemical activity at high mass loading, and high stability, as demonstrated by supercapacitors and lithium-sulfur batteries with excellent performance. Moreover, the synthesis can be readily tuned to make a broad range of graphitic carbons with desired structures and compositions for many applications.clos

    Three-dimensionally Ordered Macroporous Structure Enabled Nanothermite Membrane of Mn2O3/Al

    Get PDF
    Mn2O3 has been selected to realize nanothermite membrane for the first time in the literature. Mn2O3/Al nanothermite has been synthesized by magnetron sputtering a layer of Al film onto three-dimensionally ordered macroporous (3DOM) Mn2O3 skeleton. The energy release is significantly enhanced owing to the unusual 3DOM structure, which ensures Al and Mn2O3 to integrate compactly in nanoscale and greatly increase effective contact area. The morphology and DSC curve of the nanothermite membrane have been investigated at various aluminizing times. At the optimized aluminizing time of 30 min, energy release reaches a maximum of 2.09 kJ∙g−1, where the Al layer thickness plays a decisive role in the total energy release. This method possesses advantages of high compatibility with MEMS and can be applied to other nanothermite systems easily, which will make great contribution to little-known nanothermite research

    Single Spin Asymmetries of Inclusive Hadrons Produced in Electron Scattering from a Transversely Polarized 3^3He Target

    Full text link
    We report the first measurement of target single-spin asymmetries (AN_N) in the inclusive hadron production reaction, e e~+ 3Heh+X~^3\text{He}^{\uparrow}\rightarrow h+X, using a transversely polarized 3^3He target. The experiment was conducted at Jefferson Lab in Hall A using a 5.9-GeV electron beam. Three types of hadrons (π±\pi^{\pm}, K±\text{K}^{\pm} and proton) were detected in the transverse hadron momentum range 0.54 <pT<<p_T< 0.74 GeV/c. The range of xFx_F for pions was -0.29 <xF<<x_F< -0.23 and for kaons -0.25 <xF<<x_F<-0.18. The observed asymmetry strongly depends on the type of hadron. A positive asymmetry is observed for π+\pi^+ and K+\text{K}^+. A negative asymmetry is observed for π\pi^{-}. The magnitudes of the asymmetries follow Aπ<Aπ+<AK+|A^{\pi^-}| < |A^{\pi^+}| < |A^{K^+}|. The K^{-} and proton asymmetries are consistent with zero within the experimental uncertainties. The π+\pi^{+} and π\pi^{-} asymmetries measured for the 3^3He target and extracted for neutrons are opposite in sign with a small increase observed as a function of pTp_T.Comment: Updated version, submitted to Phys. Rev.

    Double Spin Asymmetries of Inclusive Hadron Electroproductions from a Transversely Polarized 3He^3\rm{He} Target

    Get PDF
    We report the measurement of beam-target double-spin asymmetries (ALTA_\text{LT}) in the inclusive production of identified hadrons, e \vec{e}~+ 3Heh+X~^3\text{He}^{\uparrow}\rightarrow h+X, using a longitudinally polarized 5.9 GeV electron beam and a transversely polarized 3He^3\rm{He} target. Hadrons (π±\pi^{\pm}, K±K^{\pm} and proton) were detected at 16^{\circ} with an average momentum =2.35 GeV/c and a transverse momentum (pTp_{T}) coverage from 0.60 to 0.68 GeV/c. Asymmetries from the 3He^3\text{He} target were observed to be non-zero for π±\pi^{\pm} production when the target was polarized transversely in the horizontal plane. The π+\pi^{+} and π\pi^{-} asymmetries have opposite signs, analogous to the behavior of ALTA_\text{LT} in semi-inclusive deep-inelastic scattering.Comment: Published in PRC (92.015207), nuclear experiment, high-energy experimen

    Efficacy and Safety of Upadacitinib Treatment in Adolescents With Moderate-to-Severe Atopic Dermatitis

    Get PDF
    Importance: Atopic dermatitis onset usually occurs in childhood. Persistence of disease into adolescence and adulthood is common. It is important to evaluate new treatment options in adolescents because of the high unmet need in this population. Objective: To assess the efficacy and safety of upadacitinib to treat moderate-to-severe atopic dermatitis in adolescents. Design, setting, and participants: Prespecified analysis of adolescents enrolled in 3 randomized, double-blind, placebo-controlled phase 3 clinical trials in more than 20 countries across Europe, North and South America, Oceania, the Middle East, and the Asia-Pacific region from July 2018 through December 2020. Participants were adolescents aged 12 to 17 years with moderate-to-severe atopic dermatitis. Data analysis was performed from April to August 2021. Interventions: Patients were randomized (1:1:1) to once-daily oral upadacitinib 15 mg, upadacitinib 30 mg, or placebo alone (Measure Up 1 and Measure Up 2) or with topical corticosteroids (AD Up). Main outcomes and measures: Safety and efficacy, including at least a 75% improvement in the Eczema Area and Severity Index from baseline and validated Investigator Global Assessment for Atopic Dermatitis score of 0 (clear) or 1 (almost clear) at week 16 (coprimary end points). Results: A total of 552 adolescents (290 female; 262 male) were randomized. Mean (SD) age was 15.4 (1.8), 15.5 (1.7), and 15.3 (1.8) years for adolescents in Measure Up 1, Measure Up 2, and AD Up, respectively. In Measure Up 1, Measure Up 2, and AD Up, respectively, a greater proportion of adolescents (% [95% CI]) achieved at least 75% improvement in the Eczema Area and Severity Index at week 16 with upadacitinib 15 mg (73% [63%-84%], 69% [57%-81%], 63% [51%-76%]), and upadacitinib 30 mg (78% [68%-88%], 73% [62%-85%], 84% [75%-94%]), than with placebo (12% [4%-20%], 13% [5%-22%], 30% [19%-42%]; nominal P < .001 for all comparisons vs placebo). Similarly, a greater proportion of adolescents treated with upadacitinib achieved a validated Investigator Global Assessment for Atopic Dermatitis score of 0 or 1 at week 16 and improvements in quality of life with upadacitinib than with placebo. Upadacitinib was generally well tolerated in adolescents. Acne was the most common adverse event, and all acne events were mild or moderate. Conclusions and relevance: In this analysis of 3 randomized clinical trials, upadacitinib was an effective treatment for adolescents with moderate-to-severe atopic dermatitis, with an acceptable safety profile.info:eu-repo/semantics/publishedVersio

    Single Spin Asymmetries in Charged Kaon Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely Polarized 3He^3{\rm{He}} Target

    Full text link
    We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He^3{\rm{He}} target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1<<xbjx_{bj}<<0.4 for K+K^{+} and KK^{-} production. While the Collins and Sivers moments for K+K^{+} are consistent with zero within the experimental uncertainties, both moments for KK^{-} favor negative values. The Sivers moments are compared to the theoretical prediction from a phenomenological fit to the world data. While the K+K^{+} Sivers moments are consistent with the prediction, the KK^{-} results differ from the prediction at the 2-sigma level.Comment: 6 pages, 3 figure

    A Cellular Pathway Involved in Clara Cell to Alveolar Type II Cell Differentiation after Severe Lung Injury

    Get PDF
    Regeneration of alveolar epithelia following severe pulmonary damage is critical for lung function. We and others have previously shown that Scgb1a1-expressing cells, most likely Clara cells, can give rise to newly generated alveolar type 2 cells (AT2s) in response to severe lung damage induced by either influenza virus infection or bleomycin treatment. In this study, we have investigated cellular pathway underlying the Clara cell to AT2 differentiation. We show that the initial intermediates are bronchiolar epithelial cells that exhibit Clara cell morphology and express Clara cell marker, Scgb1a1, as well as the AT2 cell marker, pro-surfactant protein C (pro-SPC). These cells, referred to as pro-SPC[superscript +] bronchiolar epithelial cells (or SBECs), gradually lose Scgb1a1 expression and give rise to pro-SPC[superscript +] cells in the ring structures in the damaged parenchyma, which appear to differentiate into AT2s via a process sharing some features with that observed during alveolar epithelial development in the embryonic lung. These findings suggest that SBECs are intermediates of Clara cell to AT2 differentiation during the repair of alveolar epithelia following severe pulmonary injury.Singapore-MIT Alliance for Research and Technology Center. Infectious Disease Research Grou
    corecore