| 1. |
- Aaron, F. D., et al.
(författare)
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Combined measurement and QCD analysis of the inclusive e(+/-)p scattering cross sections at HERA
- 2010
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :1
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Tidskriftsartikel (refereegranskat)abstract
- A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised e(+/-)p scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q(2), and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions, HERAPDF1.0, with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result.
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| 2. |
- Aaron, F. D., et al.
(författare)
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Events with an isolated lepton and missing transverse momentum and measurement of W production at HERA
- 2010
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2010:3, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- A search for events containing an isolated electron or muon and missing trans verse momentum produced in e(+/-)p collisions is performed with the H1 and ZEUS detectors at HERA. The data were taken in the period 1994-2007 and correspond to an integrated luminosity of 0.98 fb(-1). The observed event yields are in good overall agreement with the Standard Model prediction, which is dominated by single W production. In the e(+)p data, at large hadronic transverse momentum P-T(X) > 25GeV, a total of 23 events are observed compared to a prediction of 14.0 +/- 1.9. The total single W boson production cross section is measured as 1.06 +/- 0.16 (stat.) +/- 0.07 (sys.) pb, in agreement with an Standard Model (SM) expectation of 1.26 +/- 0.19 pb.
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| 3. |
- Aaron, F. D., et al.
(författare)
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Diffractive electroproduction of rho and phi mesons at HERA
- 2010
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2010:5, s. 1-111
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Tidskriftsartikel (refereegranskat)abstract
- Diffractive electroproduction of rho and phi mesons is measured at HERA with the H1 detector in the elastic and proton dissociative channels. The data correspond to an integrated luminosity of 51 pb(-1). About 10500 rho and 2000 phi events are analysed in the kinematic range of squared photon virtuality 2.5 <= Q(2) <= 60 GeV2, photon-proton centre of mass energy 35 <= W <= 180 GeV and squared four-momentum transfer to the proton vertical bar t vertical bar <= 3 GeV2. The total, longitudinal and transverse cross sections are measured as a function of Q(2), W and vertical bar t vertical bar. The measurements show a transition to a dominantly "hard" behaviour, typical of high gluon densities and small q (q) over bar dipoles, for Q(2) larger than 10 to 20 GeV2. They support flavour independence of the diffractive exchange, expressed in terms of the scaling variable (Q(2) + M-V(2))/4, and proton vertex factorisation. The spin density matrix elements are measured as a function of kinematic variables. The ratio of the longitudinal to transverse cross sections, the ratio of the helicity amplitudes and their relative phases are extracted. Several of these measurements have not been performed before and bring new information on the dynamics of diffraction in a QCD framework. The measurements are discussed in the context of models using generalised parton distributions or universal dipole cross sections.
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| 4. |
- Aaron, F. D., et al.
(författare)
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Jet production in ep collisions at high Q(2) and determination of alpha(s)
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 65:3-4, s. 363-383
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Tidskriftsartikel (refereegranskat)abstract
- The production of jets is studied in deep-inelastic e(+/-) p scattering at large negative four momentum transfer squared 150 < Q(2) < 15000 GeV2 using HERA data taken in 1999-2007, corresponding to an integrated luminosity of 395 pb(-1). Inclusive jet, 2-jet and 3-jet cross sections, normalised to the neutral current deep-inelastic scattering cross sections, are measured as functions of Q(2), jet transverse momentum and proton momentum fraction. The measurements are well described by perturbative QCD calculations at next-to-leading order corrected for hadronisation effects. The strong coupling as determined from these measurements
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| 5. |
- Aaron, F. D., et al.
(författare)
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Jet production in ep collisions at low Q(2) and determination of alpha(s)
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 67:1-2, s. 1-24
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Tidskriftsartikel (refereegranskat)abstract
- The production of jets is studied in deep-inelastic e(+) p scattering at low negative four momentum transfer squared 5 < Q(2) < 100 GeV2 and at inelasticity 0.2 < y < 0.7 using data recorded by the H1 detector at HERA in the years 1999 and 2000, corresponding to an integrated luminosity of 43.5 pb(-1). Inclusive jet, 2-jet and 3-jet cross sections as well as the ratio of 3-jet to 2-jet cross sections are measured as a function of Q(2) and jet transverse momentum. The 2-jet cross section is also measured as a function of the proton momentum fraction xi. The measurements are well described by perturbative quantum chromodynamics at next-to-leading order corrected for hadronisation effects and are subsequently used to extract the strong coupling as.
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| 6. |
- Aaron, F. D., et al.
(författare)
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Measurement of the charm and beauty structure functions using the H1 vertex detector at HERA
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 65:1-2, s. 89-109
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Tidskriftsartikel (refereegranskat)abstract
- Inclusive charm and beauty cross sections are measured in e (-) p and e (+) p neutral current collisions at HERA in the kinematic region of photon virtuality 5a parts per thousand currency signQ (2)a parts per thousand currency sign2000 GeV2 and Bjorken scaling variable 0.0002a parts per thousand currency signxa parts per thousand currency sign0.05. The data were collected with the H1 detector in the years 2006 and 2007 corresponding to an integrated luminosity of 189 pb(-1). The numbers of charm and beauty events are determined using variables reconstructed by the H1 vertex detector including the impact parameter of tracks to the primary vertex and the position of the secondary vertex. The measurements are combined with previous data and compared to QCD predictions.
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| 7. |
- Aaron, F. D., et al.
(författare)
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Measurement of the D*(+/-) meson production cross section and F-2(c(c)over-bar) at high Q(2) in ep scattering at HERA
- 2010
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 686:2-3, s. 91-100
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Tidskriftsartikel (refereegranskat)abstract
- The inclusive production of D*(+/-)(2010) mesons in deep-inelastic e(+/-)p scattering is measured in the kinematic region of photon virtuality 100 < Q(2) < 1000 GeV2 and inelasticity 002 < y < 0 7 Single and double differential cross sections for inclusive D* meson production are measured in the visible range defined by vertical bar eta(D*)vertical bar < 1 5 and p(gamma)(D*) > 1 5 GeV The data were collected by the H1 experiment during the period from 2004 to 2007 and correspond to an integrated luminosity of 351 pb(-1) The charm contribution. F-2(c (c) over bar), to the proton structure function F-2 is determined. The measurements are compared with QCD predictions. (C) 2010 Elsevier B V All rights reserved
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| 8. |
- Aaron, F. D., et al.
(författare)
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Prompt photons in photoproduction at HERA
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 66:1-2, s. 17-33
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Tidskriftsartikel (refereegranskat)abstract
- The production of prompt photons is measured in the photoproduction regime of electron-proton scattering at HERA. The analysis is based on a data sample corresponding to a total integrated luminosity of 340 pb(-1) collected by the H1 experiment. Cross sections are measured for photons with transverse momentum and pseudorapidity in the range 6< E-T(gamma) < 15 GeV and -1.0< eta(gamma) < 2.4, respectively. Cross sections for events with an additional jet are measured as a function of the transverse energy and pseudorapidity of the jet, and as a function of the fractional momenta x(gamma) and x(p) carried by the partons entering the hard scattering process. The correlation between the photon and the jet is also studied. The results are compared with QCD predictions based on the collinear and on the k(T) factorization approaches.
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| 9. |
- Akopyan, Karen, et al.
(författare)
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Translocation of surface-localized effectors in type III secretion
- 2011
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 108:4, s. 1639-1644
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Tidskriftsartikel (refereegranskat)abstract
- Pathogenic Yersinia species suppress the host immune response by using a plasmid-encoded type III secretion system (T3SS) to translocate virulence proteins into the cytosol of the target cells. T3SS-dependent protein translocation is believed to occur in one step from the bacterial cytosol to the target-cell cytoplasm through a conduit created by the T3SS upon target cell contact. Here, we report that T3SS substrates on the surface of Yersinia pseudotuberculosis are translocated into target cells. Upon host cell contact, purified YopH coated on Y. pseudotuberculosis was specifically and rapidly translocated across the target-cell membrane, which led to a physiological response in the infected cell. In addition, translocation of externally added YopH required a functional T3SS and a specific translocation domain in the effector protein. Efficient, T3SS-dependent translocation of purified YopH added in vitro was also observed when using coated Salmonella typhimurium strains, which implies that T3SS-mediated translocation of extracellular effector proteins is conserved among T3SS-dependent pathogens. Our results demonstrate that polarized T3SS-dependent translocation of proteins can be achieved through an intermediate extracellular step that can be reconstituted in vitro. These results indicate that translocation can occur by a different mechanism from the assumed single-step conduit model.
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| 10. |
- Cowlrick, Ivor, et al.
(författare)
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Decision-making in the pharmaceutical industry: analysis of entrepreneurial risk and attitude using uncertain information
- 2011
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Ingår i: R &D Management. - : Blackwell Publishing. - 0033-6807 .- 1467-9310. ; 41:4, s. 321-336
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Tidskriftsartikel (refereegranskat)abstract
- The main purpose of this study was to investigate judgments made by employees from the pharmaceutical industry and allied health-care sectors in a set of four different drug discovery and development cases derived from real scenarios. Each case study related to go/no-go decisions taken from various steps in drug discovery through preclinical and clinical development (investigational new drug) on to market introduction (new drug application) and treatment of the target population. Using a web-based questionnaire, 52 respondents made five sets of judgment within each drug case whether to continue or halt further project development. For each case, additional details of the developmental scenario were disclosed to the respondent after completion of each judgment response. We also assessed to what extent the individual judgments given by the respondents were influenced by work experience and functional role, education, or their perceived entrepreneurial character. Our study demonstrates that health-care employees differ substantially in their individual intuitive judgments of benefit and risk in go/no-go decisions during the drug discovery and development process. This lack of coherence and wide variability with respect to the drug development cases selected may reflect judgment in the real world. Such judgments are usually taken from incomplete information, and individual decision-making rules vary substantially between experts in the field. Further knowledge about this inherent human functional judgment variability may be helpful to form a better understanding of individual decision-making in relation to inherent uncertainties. Additional research may also clarify how personal experience within drug discovery and development influences judgment and help to optimize decision outcomes in the drug development sector. Importantly, a deeper insight of the fundamentals and rules that shape individual and group decision-making of everyday drug discovery and development may help to optimize the decision processes in the pharmaceutical industry.
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