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Träfflista för sökning "WFRF:(Dittmann J.) "

Sökning: WFRF:(Dittmann J.)

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1.
  • Aad, G, et al. (författare)
  • 2015
  • swepub:Mat__t
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2.
  • Aaltonen, T., et al. (författare)
  • Combination of Tevatron Searches for the Standard Model Higgs Boson in the W+W- Decay Mode
  • 2010
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:6, s. 061802-
  • Tidskriftsartikel (refereegranskat)abstract
    • We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb(-1) of p (p) over bar collisions at root s = 1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard model Higgs boson in the mass range 162-166 GeV at the 95% C.L.
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3.
  • Aaltonen, T., et al. (författare)
  • Evidence for a Particle Produced in Association with Weak Bosons and Decaying to a Bottom-Antibottom Quark Pair in Higgs Boson Searches at the Tevatron
  • 2012
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 109:7, s. 071804-
  • Tidskriftsartikel (refereegranskat)abstract
    • We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from Fermilab Tevatron p (p) over bar collisions at root s = 1.96 TeV, correspond to integrated luminosities of up to 9.7 fb(-1). The searches are conducted for a Higgs boson with mass in the range 100-150 GeV/c(2). We observe an excess of events in the data compared with the background predictions, which is most significant in the mass range between 120 and 135 GeV/c(2). The largest local significance is 3.3 standard deviations, corresponding to a global significance of 3.1 standard deviations. We interpret this as evidence for the presence of a new particle consistent with the standard model Higgs boson, which is produced in association with a weak vector boson and decays to a bottom-antibottom quark pair.
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4.
  • Aaltonen, T., et al. (författare)
  • Tevatron Run II combination of the effective leptonic electroweak mixing angle
  • 2018
  • Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Drell-Yan lepton pairs produced in the process p (p) over bar -> l(+)l(-) + X through an intermediate gamma*/Z boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the electroweak force and the associated mixing of its neutral gauge bosons. The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter sin(2) theta(lept)(eff) using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to 9-10 fb(-1) of integrated luminosity. The combination of these measurements yields the most precise result from hadron colliders, sin(2)theta(lept)(eff) = 0.23148 +/- 0.00033. This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders. The standard model inference of the on-shell electroweak mixing parameter sin(2) theta(W), or equivalently the W-boson mass M-W, using the ZFITTER software package yields sin(2) theta(W) = 0.22324 +/- 0.00033 or equivalently, M-W = 80.367 +/- 0.017 GeV/c(2).
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5.
  • Aaltonen, T., et al. (författare)
  • Combination of CDF and D0 measurements of the W boson helicity in top quark decays
  • 2012
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 85:7, s. 071106-
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7-5.4 fb(-1) of p (p) over bar collisions collected during Run II of the Fermilab Tevatron collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f(0)) and right-handed (f(+)) helicities, we find f(0) = 0.722 +/- 0.081[+/- 0.062(stat) +/- 0.052(syst)] and f(+) = -0.033 +/- 0.046[+/- 0.034(stat) +/- 0.031(syst)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f(0) = 0.682 +/- 0.057[+/- 0.035(stat) +/- 0.046(syst)] for fixed f(+) and f(+) = -0.015 +/- 0.035[+/- 0.018(stat) +/- 0.030(syst)] for fixed f(0). The results are consistent with standard model expectations.
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6.
  • Aaltonen, T., et al. (författare)
  • Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron
  • 2018
  • Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 120:4
  • Tidskriftsartikel (refereegranskat)abstract
    • The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of root s = 1.96 TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is A(FB)(t (t) over bar) = 0.128 +/- 0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions.
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7.
  • Aaltonen, T., et al. (författare)
  • Higgs boson studies at the Tevatron
  • 2013
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:5, s. 052014-
  • Tidskriftsartikel (refereegranskat)abstract
    • We combine searches by the CDF and D0 Collaborations for the standard model Higgs boson with mass in the range 90-200 GeV/c(2) produced in the gluon-gluon fusion, WH, ZH, t (t) over barH, and vector boson fusion processes, and decaying in the H -> b (b) over bar, H -> W+W-, H -> ZZ, H -> tau(+)tau(-), and H -> gamma gamma modes. The data correspond to integrated luminosities of up to 10 fb(-1) and were collected at the Fermilab Tevatron in p (p) over bar collisions at root s = 1.96 TeV. The searches are also interpreted in the context of fermiophobic and fourth generation models. We observe a significant excess of events in the mass range between 115 and 140 GeV/c(2). The local significance corresponds to 3.0 standard deviations at m(H) = 125 GeV/c(2), consistent with the mass of the Higgs boson observed at the LHC, and we expect a local significance of 1.9 standard deviations. We separately combine searches for H -> b (b) over bar, H -> W+W-, H -> tau(+)tau(-), and H -> gamma gamma. The observed signal strengths in all channels are consistent with the presence of a standard model Higgs boson with a mass of 125 GeV/c(2).
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8.
  • Aaltonen, T., et al. (författare)
  • Combination of CDF and D0 W-Boson mass measurements
  • 2013
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:5, s. 052018-
  • Tidskriftsartikel (refereegranskat)abstract
    • We summarize and combine direct measurements of the mass of the W boson in root s = 1.96 TeV proton-antiproton collision data collected by CDF and D0 experiments at the Fermilab Tevatron Collider. Earlier measurements from CDF and D0 are combined with the two latest, more precise measurements: a CDF measurement in the electron and muon channels using data corresponding to 2.2 fb(-1) of integrated luminosity, and a D0 measurement in the electron channel using data corresponding to 4.3 fb(-1) of integrated luminosity. The resulting Tevatron average for the mass of the W boson is M-W = 80387 +/- 16 MeV. Including measurements obtained in electron-positron collisions at LEP yields the most precise value of M-W = 80385 +/- 15 MeV.
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9.
  • Aaltonen, T., et al. (författare)
  • Combination of measurements of the top-quark pair production cross section from the Tevatron Collider
  • 2014
  • Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:7
  • Tidskriftsartikel (refereegranskat)abstract
    • We combine six measurements of the inclusive top-quark pair (t(sic)) production cross section (sigma(t)(sic)) from data collected with the CDF and D0 detectors at the Fermilab Tevatron with proton-antiproton collisions at root s = 1.96 TeV. The data correspond to integrated luminosities of up to 8.8 fb(-1). We obtain a value of sigma tt = 7.60 +/- 0.41 pb for a top-quark mass of m(t) = 172.5 GeV. The contributions to the uncertainty are 0.20 pb from statistical sources, 0.29 pb from systematic sources, and 0.21 pb from the uncertainty on the integrated luminosity. The result is in good agreement with the standard model expectation of 7.35(-0.33)(+0.28) pb at next-to-next-to-leading order and next-to-next-to leading logarithms in perturbative QCD.
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10.
  • Aaltonen, T., et al. (författare)
  • Observation of s-Channel Production of Single Top Quarks at the Tevatron
  • 2014
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:23
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb(-1) per experiment. The measured cross section is sigma(s) = 1.29(-0.24)(+0.26) pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is 1.8 x 10(-10), corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks.
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11.
  • Aaltonen, T., et al. (författare)
  • Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element V-tb
  • 2015
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 115:15
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb(-1) per experiment. The t-channel cross section is measured to be sigma(t) = 2.25(-0.31)(+0.29) pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s + t channel cross section measurement resulting in sigma(s+t) = 3.30(-0.40)(+0.52) pb, without assuming the standard model value for the ratio sigma(s)/sigma(t). The resulting value of the magnitude of the top-to-bottom quark coupling is vertical bar V-tb vertical bar = 1.02(-0.05)(+0.06), corresponding to vertical bar V-tb vertical bar > 0.92 at the 95% C. L.
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12.
  • Aaltonen, T., et al. (författare)
  • Tevatron Constraints on Models of the Higgs Boson with Exotic Spin and Parity Using Decays to Bottom-Antibottom Quark Pairs
  • 2015
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:15
  • Tidskriftsartikel (refereegranskat)abstract
    • Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value J(P) = 0(+). Both collaborations analyzed approximately 10 fb(-1) of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with J(P) = 0(-) and J(P) = 2(+) are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from those predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the J(P) = 0(-) hypothesis and the J(P) = 2(+) hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the J(P) = 0(-) and J(P) = 2(+) hypotheses, respectively.
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13.
  • Ahmed, M., et al. (författare)
  • Search for the lepton-family-number nonconserving decay μ +→e +γ
  • 2002
  • Ingår i: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 65:11
  • Tidskriftsartikel (refereegranskat)abstract
    • The MEGA experiment, which searched for the muon- and electron-number violating decay μ +→e + γ, is described. The spectrometer system, the calibrations, the data taking procedures, the data analysis, and the sensitivity of the experiment are discussed. The most stringent upper limit on the branching ratio, B(μ + →e + γ)<1.2×10 -11 with 90% confidence, is derived from a likelihood analysis.
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14.
  • Coll, M., et al. (författare)
  • Towards Oxide Electronics: a Roadmap
  • 2019
  • Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 482, s. 1-93
  • Tidskriftsartikel (refereegranskat)abstract
    • At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore’s law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and heterostructures, in sectors as data storage and computing, optics and plasmonics, magnonics, energy conversion and harvesting, and power electronics.
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15.
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16.
  • Garcia-Salicetti, S., et al. (författare)
  • Biosecure reference systems for on-line signature verification : A study of complementarity
  • 2007
  • Ingår i: Annales des télécommunications. - : Springer. - 0003-4347 .- 1958-9395. ; 62:1-2, s. 36-61
  • Tidskriftsartikel (refereegranskat)abstract
    • In this paper, we present an integrated research study in On-line Signature Verification undertaken by several teams that participate in the BioSecure Network of Excellence. This integrated work, started during the First BioSecure Residential Workshop, has as main objective the development of an On-line Signature Verification evaluation platform. As a first step, four On-line Signature Verification Systems based on different approaches are evaluated and compared following the same experimental protocol on MCYT signature database, which is the largest existing on-line western signature database publicly available with 16 500 signatures from 330 clients. A particular focus of work documented in this paper is multi-algorithmic fusion in order to study the complementarity of the approaches involved. To this end, a simple fusion method based on the Mean Rule is used after a normalization phase.
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17.
  • Lunnan, Ragnhild, et al. (författare)
  • Hydrogen-poor Superluminous Supernovae from the Pan-STARRS1 Medium Deep Survey
  • 2018
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 852:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We present light curves and classification spectra of 17 hydrogen-poor superluminous supernovae (SLSNe) from the Pan-STARRS1 Medium Deep Survey (PS1 MDS). Our sample contains all objects from the PS1. MDS sample with spectroscopic classification that are similar to either of the prototypes SN 2005ap or SN 2007bi, without an explicit limit on luminosity. With a redshift range 0.3 < z < 1.6, PS1. MDS is the first SLSN sample primarily probing the high-redshift population; our multifilter PS1 light curves probe the rest-frame UV emission, and hence the peak of the spectral energy distribution. We measure the temperature evolution and construct bolometric light curves, and find peak luminosities of (0.5-5) x 10(44) erg s(-1) and lower limits on the total radiated energies of (0.3-2) x 10(51) erg. The light curve shapes are diverse, with both rise and decline times spanning a factor of similar to 5 and several examples of double-peaked light curves. When correcting for the flux-limited nature of our survey, we find a median peak luminosity at 4000 angstrom of M-4000 = -21.1 mag and a spread of sigma = 0.7 mag.
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18.
  • Walden, L., et al. (författare)
  • Multi-scale mapping of Australia's terrestrial and blue carbon stocks and their continental and bioregional drivers
  • 2023
  • Ingår i: Communications Earth & Environment. - 2662-4435. ; 4:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Multi-scale spatial machine learning of soil carbon stocks in Australia's terrestrial and coastal marine ecosystems reveals eight bio-regions and their underlying subregional drivers that can help inform strategies for conservation and climate change mitigation. The soil in terrestrial and coastal blue carbon ecosystems is an important carbon sink. National carbon inventories require accurate assessments of soil carbon in these ecosystems to aid conservation, preservation, and nature-based climate change mitigation strategies. Here we harmonise measurements from Australia's terrestrial and blue carbon ecosystems and apply multi-scale machine learning to derive spatially explicit estimates of soil carbon stocks and the environmental drivers of variation. We find that climate and vegetation are the primary drivers of variation at the continental scale, while ecosystem type, terrain, clay content, mineralogy and nutrients drive subregional variations. We estimate that in the top 0-30 cm soil layer, terrestrial ecosystems hold 27.6 Gt (19.6-39.0 Gt), and blue carbon ecosystems 0.35 Gt (0.20-0.62 Gt). Tall open eucalypt and mangrove forests have the largest soil carbon content by area, while eucalypt woodlands and hummock grasslands have the largest total carbon stock due to the vast areas they occupy. Our findings suggest these are essential ecosystems for conservation, preservation, emissions avoidance, and climate change mitigation because of the additional co-benefits they provide.
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19.
  • Walsh, Roddy, et al. (författare)
  • Enhancing rare variant interpretation in inherited arrhythmias through quantitative analysis of consortium disease cohorts and population controls
  • 2021
  • Ingår i: Genetics in Medicine. - : Nature Publishing Group. - 1098-3600 .- 1530-0366. ; 23:1, s. 47-58
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Stringent variant interpretation guidelines can lead to high rates of variants of uncertain significance (VUS) for genetically heterogeneous disease like long QT syndrome (LQTS) and Brugada syndrome (BrS). Quantitative and disease-specific customization of American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines can address this false negative rate.Methods: We compared rare variant frequencies from 1847 LQTS (KCNQ1/KCNH2/SCN5A) and 3335 BrS (SCN5A) cases from the International LQTS/BrS Genetics Consortia to population-specific gnomAD data and developed disease-specific criteria for ACMG/AMP evidence classes-rarity (PM2/BS1 rules) and case enrichment of individual (PS4) and domain-specific (PM1) variants.Results: Rare SCN5A variant prevalence differed between European (20.8%) and Japanese (8.9%) BrS patients (p = 5.7 x 10(-18)) and diagnosis with spontaneous (28.7%) versus induced (15.8%) Brugada type 1 electrocardiogram (ECG) (p = 1.3 x 10(-13)). Ion channel transmembrane regions and specific N-terminus (KCNH2) and C-terminus (KCNQ1/KCNH2) domains were characterized by high enrichment of case variants and >95% probability of pathogenicity. Applying the customized rules, 17.4% of European BrS and 74.8% of European LQTS cases had (likely) pathogenic variants, compared with estimated diagnostic yields (case excess over gnomAD) of 19.2%/82.1%, reducing VUS prevalence to close to background rare variant frequency.Conclusion: Large case-control data sets enable quantitative implementation of ACMG/AMP guidelines and increased sensitivity for inherited arrhythmia genetic testing.
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20.
  • Chakraborti, Sayan, et al. (författare)
  • A MISSING-LINK IN THE SUPERNOVA-GRB CONNECTION : THE CASE OF SN 2012ap
  • 2015
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 805:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Gamma-ray bursts (GRBs) are characterized by ultra-relativistic outflows, while supernovae are generally characterized by non-relativistic ejecta. GRB afterglows decelerate rapidly, usually within days, because their low-mass ejecta rapidly sweep up a comparatively larger mass of circumstellar material. However, supernovae with heavy ejecta can be in nearly free expansion for centuries. Supernovae were thought to have non-relativistic outflows except for a few relativistic ones accompanied by GRBs. This clear division was blurred by SN 2009bb, the first supernova with a relativistic outflow without an observed GRB. However, the ejecta from SN 2009bb was baryon loaded and in nearly free expansion for a year, unlike GRBs. We report the first supernova discovered without a GRB but with rapidly decelerating mildly relativistic ejecta, SN 2012ap. We discovered a bright and rapidly evolving radio counterpart driven by the circumstellar interaction of the relativistic ejecta. However, we did not find any coincident GRB with an isotropic fluence of more than one-sixth of the fluence from GRB 980425. This shows for the first time that central engines in SNe Ic, even without an observed GRB, can produce both relativistic and rapidly decelerating outflows like GRBs.
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21.
  • Soderberg, A. M., et al. (författare)
  • PANCHROMATIC OBSERVATIONS OF SN 2011dh POINT TO A COMPACT PROGENITOR STAR
  • 2012
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 752:2, s. 78-
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the discovery and detailed monitoring of X-ray emission associated with the Type IIb SN 2011dh using data from the Swift and Chandra satellites, placing it among the best-studied X-ray supernovae (SNe) to date. We further present millimeter and radio data obtained with the Submillimeter Array, the Combined Array for Research in Millimeter-wave Astronomy, and the Expanded Very Large Array during the first three weeks after explosion. Combining these observations with early optical photometry, we show that the panchromatic data set is well described by non-thermal synchrotron emission (radio/mm) with inverse Compton scattering (X-ray) of a thermal population of optical photons. In this scenario, the shock partition fractions deviate from equipartition by a factor, (epsilon(e)/epsilon(B)) similar to 30. We derive the properties of the shock wave and the circumstellar environment and find a time-averaged shock velocity of (v) over bar approximate to 0.1c and a progenitor mass-loss rate of (M) over dot approximate to 6x10(-5) M-circle dot yr(-1) (for an assumed wind velocity, v(w) = 1000 km s(-1)). We show that these properties are consistent with the sub-class of Type IIb SNe characterized by compact progenitors (Type cIIb) and dissimilar from those with extended progenitors (Type eIIb). Furthermore, we consider the early optical emission in the context of a cooling envelope model to estimate a progenitor radius of R-* approximate to 10(11) cm, in line with the expectations for a Type cIIb SN. Together, these diagnostics are difficult to reconcile with the extended radius of the putative yellow supergiant progenitor star identified in archival Hubble Space Telescope observations, unless the stellar density profile is unusual. Finally, we searched for the high-energy shock breakout pulse using X-ray and gamma-ray observations obtained during the purported explosion date range. Based on the compact radius of the progenitor, we estimate that the shock breakout pulse was detectable with current instruments but likely missed due to their limited temporal/spatial coverage. Future all-sky missions will regularly detect shock breakout emission from compact SN progenitors enabling prompt follow-up observations with sensitive multi-wavelength facilities.
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22.
  • Voß, Björn, et al. (författare)
  • Insights into the Physiology and Ecology of the Brackish-Water-Adapted Cyanobacterium Nodularia spumigena CCY9414 Based on a Genome-Transcriptome Analysis
  • 2013
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:3
  • Tidskriftsartikel (refereegranskat)abstract
    • Nodularia spumigena is a filamentous diazotrophic cyanobacterium that dominates the annual late summer cyanobacterial blooms in the Baltic Sea. But N. spumigena also is common in brackish water bodies worldwide, suggesting special adaptation allowing it to thrive at moderate salinities. A draft genome analysis of N. spumigena sp. CCY9414 yielded a single scaffold of 5,462,271 nucleotides in length on which genes for 5,294 proteins were annotated. A subsequent strand-specific transcriptome analysis identified more than 6,000 putative transcriptional start sites (TSS). Orphan TSSs located in intergenic regions led us to predict 764 non-coding RNAs, among them 70 copies of a possible retrotransposon and several potential RNA regulators, some of which are also present in other N2-fixing cyanobacteria. Approximately 4% of the total coding capacity is devoted to the production of secondary metabolites, among them the potent hepatotoxin nodularin, the linear spumigin and the cyclic nodulapeptin. The transcriptional complexity associated with genes involved in nitrogen fixation and heterocyst differentiation is considerably smaller compared to other Nostocales. In contrast, sophisticated systems exist for the uptake and assimilation of iron and phosphorus compounds, for the synthesis of compatible solutes, and for the formation of gas vesicles, required for the active control of buoyancy. Hence, the annotation and interpretation of this sequence provides a vast array of clues into the genomic underpinnings of the physiology of this cyanobacterium and indicates in particular a competitive edge of N. spumigena in nutrient-limited brackish water ecosystems.
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23.
  • Baeumer, Christoph, et al. (författare)
  • Tuning electrochemically driven surface transformation in atomically flat LaNiO3 thin films for enhanced water electrolysis
  • 2021
  • Ingår i: Nature Materials. - : Springer Science and Business Media LLC. - 1476-1122 .- 1476-4660. ; 20:5, s. 674-682
  • Tidskriftsartikel (refereegranskat)abstract
    • Structure–activity relationships built on descriptors of bulk and bulk-terminated surfaces are the basis for the rational design of electrocatalysts. However, electrochemically driven surface transformations complicate the identification of such descriptors. Here we demonstrate how the as-prepared surface composition of (001)-terminated LaNiO3 epitaxial thin films dictates the surface transformation and the electrocatalytic activity for the oxygen evolution reaction. Specifically, the Ni termination (in the as-prepared state) is considerably more active than the La termination, with overpotential differences of up to 150 mV. A combined electrochemical, spectroscopic and density-functional theory investigation suggests that this activity trend originates from a thermodynamically stable, disordered NiO2 surface layer that forms during the operation of Ni-terminated surfaces, which is kinetically inaccessible when starting with a La termination. Our work thus demonstrates the tunability of surface transformation pathways by modifying a single atomic layer at the surface and that active surface phases only develop for select as-synthesized surface terminations.
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24.
  • Cervero, A. G., et al. (författare)
  • Green Wired Networks
  • 2015
  • Ingår i: Large-scale Distributed Systems and Energy Efficiency. - Hoboken, NJ, USA : Wiley-Blackwell. - 9781118981122 - 9781118864630 ; , s. 41-80
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • This chapter first highlights the significant energy consumption of existing wired communication networks. It considers various means of operating such networks more efficiently. Then, the chapter examines the components that make up a wired communications network and their differing characteristics between the access and core, as well as patterns of traffic behavior. The chapter focuses on static (network planning) and dynamic (traffic-engineering) schemes that can be used to reduce the energy consumption of networks. It also pays attention to a number of challenges/open research questions that need to be resolved before the implementation of such schemes. These include issues with migration and resilience. The chapter then deals with economic-, regulatory-, and business-related methods. Finally, it focuses on the architecture of communication networks and the corresponding relationship with energy usage.
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25.
  • Kruse, Bastian, et al. (författare)
  • CD4+ T cell-induced inflammatory cell death controls immune-evasive tumours
  • 2023
  • Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 618:7967, s. 1033-1040
  • Tidskriftsartikel (refereegranskat)abstract
    • Most clinically applied cancer immunotherapies rely on the ability of CD8+ cytolytic T cells to directly recognize and kill tumour cells1,2,3. These strategies are limited by the emergence of major histocompatibility complex (MHC)-deficient tumour cells and the formation of an immunosuppressive tumour microenvironment4,5,6. The ability of CD4+ effector cells to contribute to antitumour immunity independently of CD8+ T cells is increasingly recognized, but strategies to unleash their full potential remain to be identified7,8,9,10. Here, we describe a mechanism whereby a small number of CD4+ T cells is sufficient to eradicate MHC-deficient tumours that escape direct CD8+ T cell targeting. The CD4+ effector T cells preferentially cluster at tumour invasive margins where they interact with MHC-II+CD11c+ antigen-presenting cells. We show that T helper type 1 cell-directed CD4+ T cells and innate immune stimulation reprogramme the tumour-associated myeloid cell network towards interferon-activated antigen-presenting and iNOS-expressing tumouricidal effector phenotypes. Together, CD4+ T cells and tumouricidal myeloid cells orchestrate the induction of remote inflammatory cell death that indirectly eradicates interferon-unresponsive and MHC-deficient tumours. These results warrant the clinical exploitation of this ability of CD4+ T cells and innate immune stimulators in a strategy to complement the direct cytolytic activity of CD8+ T cells and natural killer cells and advance cancer immunotherapies.
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26.
  • Müller-Engelmann, M., et al. (författare)
  • Psychometric Properties and Factor Structure of the German Version of the Clinician-Administered PTSD Scale for DSM-5
  • 2020
  • Ingår i: Assessment (Odessa, Fla.). - : SAGE Publications Inc.. - 1073-1911 .- 1552-3489. ; 27:6, s. 1128-1138
  • Tidskriftsartikel (refereegranskat)abstract
    • The Clinician-Administered PTSD Scale (CAPS) is a widely used diagnostic interview for posttraumatic stress disorder (PTSD). Following fundamental modifications in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), the CAPS had to be revised. This study examined the psychometric properties (internal consistency, interrater reliability, convergent and discriminant validity, and structural validity) of the German version of the CAPS-5 in a trauma-exposed sample (n = 223 with PTSD; n =51 without PTSD). The results demonstrated high internal consistency (αs =.65-.93) and high interrater reliability (ICCs =.81-.89). With regard to convergent and discriminant validity, we found high correlations between the CAPS severity score and both the Posttraumatic Diagnostic Scale sum score (r =.87) and the Beck Depression Inventory total score (r =.72). Regarding the underlying factor structure, the hybrid model demonstrated the best fit, followed by the anhedonia model. However, we encountered some nonpositive estimates for the correlations of the latent variables (factors) for both models. The model with the best fit without methodological problems was the externalizing behaviors model, but the results also supported the DSM-5 model. Overall, the results demonstrate that the German version of the CAPS-5 is a psychometrically sound measure.
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27.
  • Srinivasaragavan, Gokul P., et al. (författare)
  • A Sensitive Search for Supernova Emission Associated with the Extremely Energetic and Nearby GRB 221009A
  • 2023
  • Ingår i: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 949:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We report observations of the optical counterpart of the long gamma-ray burst GRB 221009A. Due to the extreme rarity of being both nearby (z = 0.151) and highly energetic (E ( gamma,iso) >= 10(54) erg), GRB 221009A offers a unique opportunity to probe the connection between massive star core collapse and relativistic jet formation across a very broad range of gamma-ray properties. Adopting a phenomenological power-law model for the afterglow and host galaxy estimates from high-resolution Hubble Space Telescope imaging, we use Bayesian model comparison techniques to determine the likelihood of an associated supernova (SN) contributing excess flux to the optical light curve. Though not conclusive, we find moderate evidence (K (Bayes) = 10(1.2)) for the presence of an additional component arising from an associated SN, SN 2022xiw, and find that it must be substantially fainter (<67% as bright at the 99% confidence interval) than SN 1998bw. Given the large and uncertain line-of-sight extinction, we attempt to constrain the SN parameters (M (Ni), M (ej), and E (KE)) under several different assumptions with respect to the host galaxy's extinction. We find properties that are broadly consistent with previous GRB-associated SNe: M (Ni) = 0.05-0.25 M (circle dot), M (ej) = 3.5-11.1 M (circle dot), and E (KE) = (1.6-5.2) x 10(52) erg. We note that these properties are weakly constrained due to the faintness of the SN with respect to the afterglow and host emission, but we do find a robust upper limit on M (Ni) of M (Ni) < 0.36 M (circle dot). Given the tremendous range in isotropic gamma-ray energy release exhibited by GRBs (seven orders of magnitude), the SN emission appears to be decoupled from the central engine in these systems.
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