487 research outputs found

    Weblog patterns and human dynamics with decreasing interest

    Full text link
    Weblog is the fourth way of network exchange after Email, BBS and MSN. Most bloggers begin to write blogs with great interest, and then their interests gradually achieve a balance with the passage of time. In order to describe the phenomenon that people's interest in something gradually decreases until it reaches a balance, we first propose the model that describes the attenuation of interest and reflects the fact that people's interest becomes more stable after a long time. We give a rigorous analysis on this model by non-homogeneous Poisson processes. Our analysis indicates that the interval distribution of arrival-time is a mixed distribution with exponential and power-law feature, that is, it is a power law with an exponential cutoff. Second, we collect blogs in ScienceNet.cn and carry on empirical studies on the interarrival time distribution. The empirical results agree well with the analytical result, obeying a special power law with the exponential cutoff, that is, a special kind of Gamma distribution. These empirical results verify the model, providing an evidence for a new class of phenomena in human dynamics. In human dynamics there are other distributions, besides power-law distributions. These findings demonstrate the variety of human behavior dynamics.Comment: 8 pages, 1 figure

    The CDF dijet excess from intrinsic quarks

    Get PDF
    The CDF collaboration reported an excess in the production of two jets in association with a WW. We discuss constraints on possible new particle state interpretations of this excess. The fact of no statistically significant deviation from the SM expectation for {ZZ+dijet} events in CDF data disfavors the new particle explanation. We show that the nucleon intrinsic strange quarks provide an important contribution to the WW boson production in association with a single top quark production. Such {WW+t} single top quark production can contribute to the CDF {WW+dijet} excess, thus the nucleon intrinsic quarks can provide a possible explanation to the CDF excess in {WW+dijet} but not in {ZZ+dijet} events.Comment: 4 latex pages, 1 figure. Version for journal publicatio

    Partial Wave Analysis of J/ψγ(K+Kπ+π)J/\psi \to \gamma (K^+K^-\pi^+\pi^-)

    Full text link
    BES data on J/ψγ(K+Kπ+π)J/\psi \to \gamma (K^+K^-\pi^+\pi^-) are presented. The KKˉK^*\bar K^* contribution peaks strongly near threshold. It is fitted with a broad 0+0^{-+} resonance with mass M=1800±100M = 1800 \pm 100 MeV, width Γ=500±200\Gamma = 500 \pm 200 MeV. A broad 2++2^{++} resonance peaking at 2020 MeV is also required with width 500\sim 500 MeV. There is further evidence for a 2+2^{-+} component peaking at 2.55 GeV. The non-KKˉK^*\bar K^* contribution is close to phase space; it peaks at 2.6 GeV and is very different from KKˉK^{*}\bar{K^{*}}.Comment: 15 pages, 6 figures, 1 table, Submitted to PL

    Global surveillance of cancer survival 1995-2009: analysis of individual data for 25,676,887 patients from 279 population-based registries in 67 countries (CONCORD-2)

    Get PDF
    BACKGROUND: Worldwide data for cancer survival are scarce. We aimed to initiate worldwide surveillance of cancer survival by central analysis of population-based registry data, as a metric of the effectiveness of health systems, and to inform global policy on cancer control. METHODS: Individual tumour records were submitted by 279 population-based cancer registries in 67 countries for 25·7 million adults (age 15-99 years) and 75,000 children (age 0-14 years) diagnosed with cancer during 1995-2009 and followed up to Dec 31, 2009, or later. We looked at cancers of the stomach, colon, rectum, liver, lung, breast (women), cervix, ovary, and prostate in adults, and adult and childhood leukaemia. Standardised quality control procedures were applied; errors were corrected by the registry concerned. We estimated 5-year net survival, adjusted for background mortality in every country or region by age (single year), sex, and calendar year, and by race or ethnic origin in some countries. Estimates were age-standardised with the International Cancer Survival Standard weights. FINDINGS: 5-year survival from colon, rectal, and breast cancers has increased steadily in most developed countries. For patients diagnosed during 2005-09, survival for colon and rectal cancer reached 60% or more in 22 countries around the world; for breast cancer, 5-year survival rose to 85% or higher in 17 countries worldwide. Liver and lung cancer remain lethal in all nations: for both cancers, 5-year survival is below 20% everywhere in Europe, in the range 15-19% in North America, and as low as 7-9% in Mongolia and Thailand. Striking rises in 5-year survival from prostate cancer have occurred in many countries: survival rose by 10-20% between 1995-99 and 2005-09 in 22 countries in South America, Asia, and Europe, but survival still varies widely around the world, from less than 60% in Bulgaria and Thailand to 95% or more in Brazil, Puerto Rico, and the USA. For cervical cancer, national estimates of 5-year survival range from less than 50% to more than 70%; regional variations are much wider, and improvements between 1995-99 and 2005-09 have generally been slight. For women diagnosed with ovarian cancer in 2005-09, 5-year survival was 40% or higher only in Ecuador, the USA, and 17 countries in Asia and Europe. 5-year survival for stomach cancer in 2005-09 was high (54-58%) in Japan and South Korea, compared with less than 40% in other countries. By contrast, 5-year survival from adult leukaemia in Japan and South Korea (18-23%) is lower than in most other countries. 5-year survival from childhood acute lymphoblastic leukaemia is less than 60% in several countries, but as high as 90% in Canada and four European countries, which suggests major deficiencies in the management of a largely curable disease. INTERPRETATION: International comparison of survival trends reveals very wide differences that are likely to be attributable to differences in access to early diagnosis and optimum treatment. Continuous worldwide surveillance of cancer survival should become an indispensable source of information for cancer patients and researchers and a stimulus for politicians to improve health policy and health-care systems

    Deciphering ryanodine receptor array operation in cardiac myocytes

    Get PDF
    Elemental calcium signals from RYR arrays operating in cardiac myocytes have been extensively characterized with ever-improving optical methods and other innovative techniques. However, the exact nature of elemental calcium signals in terms of RYR gating in situ remains an enigma. Here, we synthesize insights gleaned from recent developments in single-channel resolution of cardiac RYR organization and in visualization of calcium release events that are much smaller than calcium sparks. This synthesis leads to the proposal of a conceptual framework that promises to unify diverse observations in sparkology.PhysiologySCI(E)PubMed7EDITORIAL MATERIAL2129-13313

    The inflammatory cytokine IL-6 induces FRA1 deacetylation promoting colorectal cancer stem-like properties

    Get PDF
    Colorectal cancer (CRC) has long been known for its tight association with chronic inflammation, thought to play a key role in tumor onset and malignant progression through the modulation of cancer stemness. However, the underlying molecular and cellular mechanisms are still largely elusive. Here we show that the IL-6/STAT3 inflammatory signaling axis induces the deacetylation of FRA1 at the Lys-116 residue located within its DNA-binding domain. The HDAC6 deacetylase underlies this key modification leading to the increase of FRA1 transcriptional activity, the subsequent transactivation of NANOG expression, and the acquisition of stem-like cellular features. As validated in a large (n = 123) CRC cohort, IL-6 secretion was invariably accompanied by increased FRA1 deacetylation at K116 and an overall increase in its protein levels, coincident with malignant progression and poor prognosis. Of note, combined treatment with the conventional cytotoxic drug 5-FU together with Tubastatin A, a HDAC6-specific inhibitor, resulted in a significant in vivo synergistic inhibitory effect on tumor growth through suppression of CRC stemness. Our results reveal a novel transcriptional and posttranslational regulatory cross-talk between inflammation and stemness signaling pathways that underlie self-renewal and maintenance of CRC stem cells and promote their malignant behavior. Combinatorial treatment aimed at the core regulatory mechanisms downstream of IL-6 may offer a novel promising approach for CRC treatment

    Evidence of psi(3770) non-DD-bar Decay to J/psi pi+pi-

    Full text link
    Evidence of ψ(3770)\psi(3770) decays to a non-DDˉ{D \bar D} final state is observed. A total of 11.8±4.8±1.311.8 \pm 4.8 \pm 1.3 \psi(3770) \to \PPJP events are obtained from a data sample of 27.7 pb1\rm {pb^{-1}} taken at center-of-mass energies around 3.773 GeV using the BES-II detector at the BEPC. The branching fraction is determined to be BF(\psi(3770) \to \PPJP)=(0.34\pm 0.14 \pm 0.09)%, corresponding to the partial width of \Gamma(\psi(3770) \to \PPJP) = (80 \pm 33 \pm 23) keV.Comment: 8 pages, 7 figures, Submitted to Physics Letters

    A Study of J/psi-->gamma gamma V(rho,phi) Decays with the BESII Detector

    Full text link
    Using a sample of 58×10658\times 10^6 J/ψJ/\psi events collected with the BESII detector, radiative decays J/ψγγVJ/\psi\to\gamma\gamma V, where V=ρV=\rho or ϕ\phi, are studied. A resonance around 1420 MeV/c2^2 (X(1424)) is observed in the γρ\gamma\rho mass spectrum. Its mass and width are measured to be 1424±10(stat)±11(sys)1424\pm 10(stat)\pm 11(sys) MeV/c2^2 and 101.0±8.8±8.8 101.0\pm 8.8 \pm 8.8 MeV/c2^2, respectively, and its branching ratio B(J/ψγX(1424)γγρ)B(J/\psi\to \gamma X(1424)\to \gamma \gamma \rho) is determined to be (1.07±0.17±0.11)×104(1.07\pm0.17 \pm 0.11)\times 10^{-4}. A search for X(1424)γϕX(1424)\to \gamma\phi yields a 95% C.L. upper limit B(J/ψγX(1424)γγϕ)<0.82×104B(J/\psi\to \gamma X(1424)\to \gamma\gamma \phi) < 0.82 \times 10^{-4}.Comment: 10 pages, 5 figures, submitted to PL
    corecore