282 research outputs found

    Revealing the news: How online news changes without you noticing

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    This paper describes an ongoing design project relating to online news and how alterations to news stories are hidden from the reader. As the delivery and consumption of news content online continues to overtake other channels in reader numbers and market penetration, so methods of transparency and reliability developed over centuries continue also to be tested by digital media. We have conducted content analysis on existing stories and examined how news organisations and channels handle rapidly evolving news stories. We have proceeded to develop low-fidelity prototypes and an interaction model to test our design approach. The outcomes are in production and will result in a digital artifact that reveals editorial changes to news items (the News Inspector). These changes will be made visible within the browser. The implications of the project relate to the wider question of news truth-telling, trust and online news credibility

    Search for rare and forbidden decays of charm and charmed-strange mesons to final states h^+- e^-+ e^+

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    We have searched for flavor-changing neutral current decays and lepton-number-violating decays of D^+ and D^+_s mesons to final states of the form h^+- e^-+ e^+, where h is either \pi or K. We use the complete samples of CLEO-c open-charm data, corresponding to integrated luminosities of 818 pb^-1 at the center-of-mass energy E_CM = 3.774 GeV containing 2.4 x 10^6 D^+D^- pairs and 602 pb^-1 at E_CM = 4.170 GeV containing 0.6 x 10^6 D^*+-_s D^-+_s pairs. No signal is observed in any channel, and we obtain 90% confidence level upper limits on branching fractions B(D^+ --> \pi^+ e^+ e^-) < 5.9 x 10^-6, B(D^+ --> \pi^- e^+ e^+) K^+ e^+ e^-) < 3.0 x 10^-6, B(D^+ --> K^- e^+ e^+) \pi^+ e^+ e^-) < 2.2 x 10^-5, B(D^+_s --> \pi^- e^+ e^+) K^+ e^+ e^-) < 5.2 x 10^-5, and B(D^+_s --> K^- e^+ e^+) < 1.7 x 10^-5.Comment: 9 pages, available through http://www.lns.cornell.edu/public/CLNS

    Higher-order multipole amplitudes in charmonium radiative transitions

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    Using 24 million ψψ(2S)\psi' \equiv \psi(2S) decays in CLEO-c, we have searched for higher multipole admixtures in electric-dipole-dominated radiative transitions in charmonia. We find good agreement between our data and theoretical predictions for magnetic quadrupole (M2) amplitudes in the transitions ψγχc1,2\psi' \to \gamma \chi_{c1,2} and χc1,2γJ/ψ\chi_{c1,2} \to \gamma J/\psi, in striking contrast to some previous measurements. Let b2Jb_2^J and a2Ja_2^J denote the normalized M2 amplitudes in the respective aforementioned decays, where the superscript JJ refers to the angular momentum of the χcJ\chi_{cJ}. By performing unbinned maximum likelihood fits to full five-parameter angular distributions, we determine the ratios a2J=1/a2J=2=0.670.13+0.19a_2^{J=1}/a_2^{J=2} = 0.67^{+0.19}_{-0.13} and a2J=1/b2J=1=2.270.99+0.57a_2^{J=1}/b_2^{J=1} = -2.27^{+0.57}_{-0.99}, where the theoretical predictions are independent of the charmed quark magnetic moment and are a2J=1/a2J=2=0.676±0.071a_2^{J=1}/a_2^{J=2} = 0.676 \pm 0.071 and a2J=1/b2J=1=2.27±0.16a_2^{J=1}/b_2^{J=1} = -2.27 \pm 0.16.Comment: 32 pages, 7 figures, acceptance updat

    Impending Regeneration Failure of the IUCN Vulnerable Borneo Ironwood (Eusideroxylon zwageri)

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    The regeneration of many climax species in tropical forest critically depends on adequate seed dispersal and seedling establishment. Here, we report the decreased abundance and increased spatial aggregation of younger trees of the Borneo ironwood (Eusideroxylon zwageri) in a protected forest in Sabah Malaysia. We observed a high level of seedling herbivory with strong density dependence, likely exacerbated by local aggregation and contributing to the progressively shrinking size distribution. We also note the largely undocumented selective herbivory by sambar deer on E. zwageri seedlings. This study highlights the combined impact of altered megafauna community on a tree population through interlinked ecological processes and the need for targeted conservation intervention for this iconic tropical tree species

    Search for CP violation in D+KK+π+D^{+} \to K^{-}K^{+}\pi^{+} decays

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    A model-independent search for direct CP violation in the Cabibbo suppressed decay D+KK+π+D^+ \to K^- K^+\pi^+ in a sample of approximately 370,000 decays is carried out. The data were collected by the LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb1^{-1}. The normalized Dalitz plot distributions for D+D^+ and DD^- are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.

    First observation of Bs -> D_{s2}^{*+} X mu nu decays

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    Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the semileptonic decays Bs -> Ds+ X mu nu and Bs -> D0 K+ X mu nu are detected. Two structures are observed in the D0 K+ mass spectrum at masses consistent with the known D^+_{s1}(2536) and $D^{*+}_{s2}(2573) mesons. The measured branching fractions relative to the total Bs semileptonic rate are B(Bs -> D_{s2}^{*+} X mu nu)/B(Bs -> X mu nu)= (3.3\pm 1.0\pm 0.4)%, and B(Bs -> D_{s1}^+ X munu)/B(Bs -> X mu nu)= (5.4\pm 1.2\pm 0.5)%, where the first uncertainty is statistical and the second is systematic. This is the first observation of the D_{s2}^{*+} state in Bs decays; we also measure its mass and width.Comment: 8 pages 2 figures. Published in Physics Letters

    First observation of the decay Bˉs0D0K0\bar{B}^0_s \to D^0 K^{*0} and a measurement of the ratio of branching fractions B(Bˉs0D0K0)B(Bˉ0D0ρ0)\frac{{\cal B}(\bar{B}^0_s \to D^0 K^{*0})}{{\cal B}(\bar{B}^0 \to D^0 \rho^0)}

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    The first observation of the decay Bˉs0D0K0\bar{B}^0_s \to D^0 K^{*0} using pppp data collected by the LHCb detector at a centre-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 36 pb1^{-1}, is reported. A signal of 34.4±6.834.4 \pm 6.8 events is obtained and the absence of signal is rejected with a statistical significance of more than nine standard deviations. The Bˉs0D0K0\bar{B}^0_s \to D^0 K^{*0} branching fraction is measured relative to that of Bˉ0D0ρ0\bar{B}^0 \to D^0 \rho^0: B(Bˉs0D0K0)B(Bˉ0D0ρ0)=1.48±0.34±0.15±0.12\frac{{\cal B}(\bar{B}^0_s \to D^0 K^{*0})}{{\cal B}(\bar{B}^0 \to D^0 \rho^0)} = 1.48 \pm 0.34 \pm 0.15 \pm 0.12, where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the ratio of the B0B^0 and Bs0B^0_s hadronisation fractions.Comment: 10 pages, 3 figures, submitted to Phys. Lett. B; ISSN 0370-269

    Clinical course and prognosis of the lymphoproliferative disease of granular lymphocytes. A multicenter study.

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    Lymphoproliferative disease of granular lymphocytes (LDGL) is a recently recognized, relatively rare atypical lymphocytosis characterized by the presence of over 2000 lymphocytes with cytoplasmic azurophilic granules/mm3 in the peripheral blood. The clinical course is heterogeneous, varying from spontaneous regression to progressive, malignant disease. As a consequence, clinical intervention is not standardized. In a worldwide multicenter study, the authors observed 151 patients with LDGL for a mean follow-up time of 29 months. Forty-three patients were asymptomatic at the time of diagnosis. In the remaining cases, clinical symptoms included fever (41 cases), infections (58), neutropenia (47), anemia (17), and thrombocytopenia (12). In 69 cases, LDGL coexisted with an associated disease. Most patients had a nonprogressive clinical course despite the presence of severe symptoms. In 19 patients, death related to LDGL occurred within 48 months. The authors investigated which features at diagnosis were significantly associated with increased mortality. In the univariate analysis, lymph node and liver enlargement, fever at presentation, skin infiltration, a low (less than or equal to 5000/mm3) or high (greater than 20,000/mm3) peripheral leukocyte count, relatively low (less than or equal to 3000) or high (greater than 7000/mm3) absolute peripheral granular lymphocyte (GL) count, and a low (less than or equal to 15%) percentage of HNK-1-positive cells were found to be predictors of increased mortality. In the multivariate analysis, significant independent predictors were fever at diagnosis, a low (less than or equal to 15%) percentage of HNK-1-positive peripheral blood mononuclear cells (PBMC) and a relatively low (less than or equal to 3000) GL count. These results showed that about 25% of the patients with LDGL were diagnosed after a routine blood count and had no clinical symptoms. The remaining patients were symptomatic, with some experiencing a fatal clinical course. The author's analysis of the significant prognostic features of LDGL may help in understanding the heterogeneous nature of this syndrom
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