| 1. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 2. |
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| 3. |
- Adloff, C, et al.
(författare)
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A measurement of the t dependence of the helicity structure of diffractive rho meson electroproduction at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 539:1-2, s. 25-39
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Tidskriftsartikel (refereegranskat)abstract
- The helicity structure of the diffractive electroproduction of rho mesons, e + p --> e + rho + Y, is studied in a previously unexplored region of large four-momentum transfer squared at the proton vertex, t: 0 < t' < 3 GeV2, where t' = - min. The data used are collected with the HI detector at HERA in the kinematic domain 2.5 < Q(2) < 60 GeV2, 40 < W < 120 GeV No t dependence of the r(00)(04) spin density matrix element is found. A significant t dependent helicity non-conservation from the virtual photon to the rho meson is observed for the spin density matrix element combinations r(00)(5) + 2r(11)(5) and r(00)(1) + 2r(11)(1). These t dependences are consistently described by a perturbative QCD model based on the exchange of two gluons.
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| 4. |
- Adloff, C, et al.
(författare)
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Diffractive photoproduction of psi(2S) mesons at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 541:3-4, s. 251-264
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Tidskriftsartikel (refereegranskat)abstract
- Results on diffractive photoproduction of psi(2S) mesons are presented using data collected between 1996 and 2000 with the H1 detector at the HERA ep collider. The data correspond to an integrated luminosity of 77 pb(-1). The energy dependence of the diffractive psi(2S) cross section is found to be similar to or possibly somewhat steeper than that for J/psi mesons. The dependences of the elastic and proton dissociative psi(2S) photoproduction cross sections on the squared momentum transfer t at the proton vertex are measured. The t-dependence of the elastic channel, parametrised as e(bt), yields b(el)(psi(2S)) = (4.31 +/- 0.57 +/- 0.46) GeV-2, compatible with that of the J/psi. For the proton dissociative channel the result b(pd)(psi(2S)) = (0.59 +/- 0.13 +/- 0.12) GeV-2 is 2.3 standard deviations smaller than that measured for the J/psi. With proper account of the individual wavefunctions theoretical predictions based on perturbative QCD are found to describe the measurements well. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 5. |
- Adloff, C, et al.
(författare)
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Energy flow and rapidity gaps between jets in photoproduction at HERA
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 24:4, s. 517-527
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Tidskriftsartikel (refereegranskat)abstract
- Dijet events in photon-proton collisions in which there is a large pseudorapidity separation, Deltaeta > 2.5 between the two highest E-T jets are studied with the H1 detector at HERA. The inclusive dijet cross sections are measured as functions of the longitudinal momentum fractions of the proton and photon which participate in the production of the jets, x(p)(jets) and x(gamma)(jets) respectively, Deltaeta, the pseudorapidity P separation between the two highest E-T jets, and E-T(gap), the total summed transverse energy between the jets. Rapidity gap events are defined as events in which E-T(gap) is less than E-T(cut), for E-T(cut) varied between jets 0.5 and 2.0 GeV. The fraction of dijet events with a rapidity gap is measured differentially in Deltaeta, x(p)(jets) and x(gamma)(jets). An excess of events with rapidity gaps at low values of E-T(cut) is observed above the expectation from standard photoproduction processes. This excess can be explained by the exchange of a strongly interacting colour singlet object between the jets.
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| 6. |
- Adloff, C, et al.
(författare)
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Inelastic leptoproduction of J/psi mesons at HERA
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 25:1, s. 41-53
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Tidskriftsartikel (refereegranskat)abstract
- The leptoproduction of J/psi mesons is studied in inelastic reactions for four momentorri transfers 2 < Q(2) < 100GeV(2). The data were taken with the H1 detector at the electron proton collider HERA and correspond to an integrated luminosity of 77 pb(-1). Single differential and double differential cross sections are measured with increased precision compared with previous analyses. New leading order calculations within the non-relativistic QCD factorisation approach including colour octet and colour singlet contributions are compared with the data and are found to give a reasonable description of most distributions. An exception is the shape of the distribution in the J/psi fractional energy. z, which deviates significantly from that of the data. Comparisons with photoproduction are made and the polarisation of the produced J/psi meson is analysed.
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| 7. |
- Adloff, C, et al.
(författare)
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Inelastic photoproduction of J/psi mesons at HERA
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 25:1, s. 25-39
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Tidskriftsartikel (refereegranskat)abstract
- An analysis of inelastic photoproduction of J/psi mesons is presented using data collected at the ep collider HERA corresponding to an integrated luminosity of above 80 pb(-1), Differential and double I < P-t/psi(2) < differential cross sections are measured in a wide kinematic region: 60 < W-gammap < 260 GeV, 1 p(t,psi)(2) < 60 GeV2 and 0.05 < z < 0.9. where z is the fraction of the energy of the exchanged photon transferred to the J/psi meson in the rest frame of the target proton. Cross sections at z less than or similar to 0.3 are presented for the first time. Theoretical calculations within the Colour Singlet Model at NLO for direct photon processes are shown to give a good description of the data in the medium z region (0.3 < z < 0.9) up to the highest p(t,psi)(2) values. A calculation using a k(t) factorisation approach in LO in the Colour Singlet Model is also able to describe these data. The data in the full z range are also compared to LO calculations within a non-relativistic QCD framework including colour octet and colour singlet contributions for direct and resolved photons. It seems possible to reconcile data and theory with modest contributions from colour octet processes. The polarisation of the J/psi meson is measured as a function of z and p(t,psi) and is reasonably described by the theoretical predictions.
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| 8. |
- Adloff, C, et al.
(författare)
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Measurement and QCD analysis of neutral and charged current cross sections at HERA
- 2003
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 30:1, s. 1-32
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Tidskriftsartikel (refereegranskat)abstract
- The inclusive e(+)p single and double differential cross sections for neutral and charged current processes axe measured with the H1 detector at HERA. The data were taken in 1999 and 2000 at a centre-of-mass energy of roots = 319 GeV and correspond to an integrated luminosity of 65.2 pb(-1). The cross sections are measured in the range of four-momentum transfer squared Q(2) between 100 and 30 000 GeV2 and Bjorken x between 0.0013 and 0.65. The neutral current analysis for the new e(+)p data and the earlier e-p data taken in 1998 and 1999 is extended to small energies of the scattered electron and therefore to higher values of inelasticity y, allowing a determination of the longitudinal structure function F-L at high Q(2) (110 - 700 GeV2). A new measurement of the structure function x (F) over tilde (3) is obtained using the new e(+)p and previously published e p neutral current cross section data at high Q(2). These data together with H1 low Q(2) precision data are further used to perform new next-to-leading order QCD analyses in the framework of the Standard Model to extract flavour separated parton distributions in the proton.
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| 9. |
- Adloff, C, et al.
(författare)
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Measurement of D*(+/-) meson production and F-2(c) in deep-inelastic scattering at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 528:3-4, s. 199-214
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Tidskriftsartikel (refereegranskat)abstract
- The inclusive production of D*+/-(2010) mesons in deep-inelastic scattering is studied with the HI detector at HERA. In the kinematic region 1 < Q(2) < 100 GeV2 and 0.05 < y < 0.7 an e(+) p cross section for inclusive D*+/- meson production of 8.50 +/- 0.42(stat.)(-100)(+1.21)(syst.) nb is measured in the visible range p(tD*) > 1.5 GeV and eta(D*) < 1.5. Single and double differential inclusive D*+/- meson cross sections are compared to perturbative QCD calculations in two different evolution schemes, The charm contribution to the proton structure, F-c(2)(x, Q(2)), is determined by extrapolating the visible charm cross section to the full phase space. This contribution is found to rise from about 10% at Q(2) = 1.5 GeV2 to more than 25% at Q(2) = 60 GeV2 corresponding to x values ranging from 5 x 10(-5) to 3 x 10(-3). (C) 2002 Elsevier Science B.V. All rights reserved.
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| 10. |
- Adloff, C, et al.
(författare)
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Measurement of dijet cross sections in photoproduction at HERA
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 25:1, s. 13-23
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Tidskriftsartikel (refereegranskat)abstract
- Dijet cross sections as functions of several jet observables are measured in photoproduction using the HI detector at HERA. The data sample comprises e(+)p data with an integrated luminosity of 319 pb(-1). Jets are selected using the inclusive k(perpendicular to) algorithm with a minimum transverse energy of 25 GeV for the leading jet. The phase space covers longitudinal proton momentum fraction x(p) and photon longitudinal momentum fraction x(gamma) in the ranges 0.05 < x(p) < 0.6 and 0.1 < x(gamma) < 1. The predict ions of next-to-leading order perturbative QCD, including recent photon and proton parton densities, are found to be compatible with the data in a wide kinematical range.
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| 11. |
- Adloff, C, et al.
(författare)
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Measurement of dijet electroproduction at small jet separation
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 24:1, s. 33-41
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Tidskriftsartikel (refereegranskat)abstract
- Deep-inelastic scattering data in the range 150 < Q(2) < 35000 GeV2 are used to investigate the minimum jet separation necessary to allow accurate description of the rate of dijet production using next-to-leading order perturbative QCD calculations. The required jet separation is found to be small, allowing about 1/3 of DIS data to be classified as dijet, as opposed to approximately 1/10 with more typical jet analyses. A number of precision measurements made using this dijet sample are well described by the calculations. The data are also described by the combination of leading order matrix elements and parton showers, as implemented in the QCD based Monte Carlo model RAPGAP.
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| 12. |
- Adloff, C, et al.
(författare)
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Measurement of inclusive jet cross-sections in deep-inelastic ep scattering at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 542:3-4, s. 193-206
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Tidskriftsartikel (refereegranskat)abstract
- A measurement of inclusive jet cross-sections in deep-inelastic ep scattering at HERA is presented based on data with an integrated luminosity of 21.1 pb(-1). The measurement is performed for photon virtualities Q(2) between 5 and 100 GeV2, differentially in Q(2), in the jet transverse energy E-T, in E-T(2)/Q(2) and in the pseudorapidity eta(lab). With the renormalization scale mu(R) = E-T, perturbative QCD calculations in next-to-leading order (NLO) give a good description of the data in most of the phase space. Significant discrepancies are observed only for jets in the proton beam direction with ET below 20 GeV and Q2 below 20 GeV2. This corresponds to the region in which NLO corrections are largest and further improvement of the calculations is thus of particular interest.
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| 13. |
- Adloff, C, et al.
(författare)
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Measurement of inclusive jet cross sections in photoproduction at HERA
- 2003
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 29:4, s. 497-513
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Tidskriftsartikel (refereegranskat)abstract
- Inclusive jet cross sections are measured in photoproduction at HERA using the H1 detector. The data sample of e(+)p --> e(+) + jet + X events in the kinematic range of photon virtualities Q(2) less than or equal to 1GeV(2) and photon-proton centre-of-mass energies 95 less than or equal to W-gammap less than or equal to 285GeV represents an integrated luminosity of 24.1pb(-1). Jets are defined using the inclusive k(perpendicular to) algorithm. Single- and multi-differential cross sections are measured as functions of jet transverse energy E-T(jet) and pseudorapidity eta(jet) in the domain 5 less than or equal to E-T(jet) less than or equal to 75GeV and -1 less than or equal to eta(jet) less than or equal to 2.5. The cross sections are found to be in good agreement with next-to-leading order perturbative QCD calculations corrected for fragmentation and underlying event effects. The cross section differential in E-T(jet), which varies by six orders of magnitude over the measured range, is compared with similar distributions from p (p) over bar colliders at equal and higher energies.
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| 14. |
- Adloff, C, et al.
(författare)
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Search for excited electrons at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 548:1-2, s. 35-44
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Tidskriftsartikel (refereegranskat)abstract
- A search for excited electron (e*) production is described in which the electroweak decays e* --> egamma, e* --> eZ and e* ---> nuW are considered. The data used correspond to an integrated luminosity of 120 pb(-1) taken in e(+/-)p collisions from 1994 to 2000 with the H1 detector at HERA at centre-of-mass energies of 300 and 318 GeV. No evidence for a signal is found. Mass dependent exclusion limits are derived for the ratio of the couplings to the compositeness scale, f/A. These limits extend the excluded region to higher masses than has been possible in previous direct searches for excited electrons. (C) 2002 Published by Elsevier Science B.V.
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| 15. |
- Adloff, C, et al.
(författare)
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Search for excited neutrinos at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 525:1-2, s. 9-16
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Tidskriftsartikel (refereegranskat)abstract
- We present a search for excited neutrinos using e(-) p data taken by the H1 experiment at HERA at a center-of-mass energy of 318 GeV with an integrated luminosity of 15 pb(-1). No evidence for excited neutrino production is found. Mass dependent exclusion limits are determined for the ratio of the coupling to the compositeness scale, f/Lambda, independently of the relative couplings to the SU(2) and U(1) gauge bosons. These limits extend the excluded region to higher masses than has been possible in previous searches at other colliders.
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| 16. |
- Adloff, C, et al.
(författare)
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Search for new physics in e +/- q contact interactions at HERA
- 2003
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 568:1-2, s. 35-47
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Tidskriftsartikel (refereegranskat)abstract
- Deep-inelastic e(+/-) p scattering at high squared momentum transfer Q(2) up to 30 000 GeV2 is used to search for eq contact interactions associated to scales far beyond the HERA centre of mass energy. The neutral current cross section measurements dsigma / dQ(2), corresponding to integrated luminosities of 16.4 pb(-1) of e(-) p data and 100.8 pb(-1) of e(+) p data, are well described by the Standard Model and are analysed to set constraints on new phenomena. For conventional contact interactions lower limits are set on compositeness scales A ranging between 1.6-5.5 TeV. Couplings and masses of leptoquarks and squarks in R-parity violating supersymmetry are constrained to M / lambda > 0.3-1.4 TeV. A search for low scale quantum gravity effects in models with large extra dimensions provides limits on the effective Planck scale of MS > 0.8 TeV. A form factor analysis yields a bound on the radius of light quarks of R-q < 1.0 10(-18) m. (C) 2003 Published by Elsevier B.V.
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| 17. |
- Adloff, C, et al.
(författare)
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Search for odderon-induced contributions to exclusive pi(0) photoproduction at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 544:1-2, s. 35-43
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Tidskriftsartikel (refereegranskat)abstract
- A search for contributions to the reaction ep --> epi(0)N* from photon-odderon fusion in the photoproduction regime at HERA is reported, at an average photon-proton centre-of-mass energy = 215 GeV. The measurement proceeds via detection of the pi(0) decay photons, a leading neutron from the N* decay, and the scattered electron. No pi(0) signal is observed and an upper limit on the cross section for the photon-odderon fusion process of sigma(gammap --> pi(0)N*) < 49 nb at the 95% confidence level is derived, integrated over the experimentally accessible range of the squared four-momentum transfer at the nucleon vertex 0.02 < < 0.3 GeV2. This excludes a recent prediction from a calculation based on a non-perturbative QCD model of a photon-odderon fusion cross section above 200 nb. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 18. |
- Adloff, C, et al.
(författare)
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Search for QCD instanton-induced processes in deep-inelastic scattering at HERA
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 25:4, s. 495-509
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Tidskriftsartikel (refereegranskat)abstract
- Signals of QCD instanton-induced processes are searched for in deep-inelastic scattering (DIS) at the electron-proton collider HERA in a kinematic region defined by the Bjorken-scaling variables x > 10(-3), 0.1 < y < 0.6 and photon virtualities 10 less than or similar to Q(2) < 100 GeV2. Several observables characterising hadronic final state properties of QCD instanton-induced events are exploited to identify a potentially instanton-enriched domain. While an excess of events with instanton-like topology is observed it cannot be claimed significant given the uncertainty of the standard DIS background simulation. Upper limits on the cross-section for instanton-induced processes of between 60 pb and 1000 pb are set dependent on the kinematic domain considered. The data do not exclude the cross-section predicted by instanton perturbation theory for small instanton sizes. At large instanton sizes a naive extrapolation of instanton perturbation theory yields a cross-section in the range of sensitivity of this study. Such a cross-section is not observed, in agreement with non-perturbative lattice simulations of the QCD vacuum.
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| 19. |
- Aktas, A, et al.
(författare)
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Diffractive photoproduction of J/psi mesons with large momentum transfer at HERA
- 2003
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 568:3-4, s. 205-218
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Tidskriftsartikel (refereegranskat)abstract
- The diffractive photoproduction of J/psi mesons is measured with the HI detector at the ep collider HERA using an integrated luminosity of 78 pb(-1). The differential cross section dsigma(gammap --> J/psiY)/dt is studied in the range 2 < < 30 GeV2, where t is the square of the four-momentum transferred at the proton vertex. The cross section is also presented as a function of the photon-proton centre-of-mass energy W-gammap in three t intervals, spanning the range 50 < W-gammap < 200 GeV. A fast rise of the cross section with W-gammap is observed for each t range and the slope for the effective linear Pomeron trajectory is measured to be alpha' = -0.0135 +/- 0.0074(stat.) +/- 0.0051(syst.) GeV-2. The measurements are compared with perturbative QCD models based on BFKL and DGLAP evolution. The data are found to be compatible with s-channel helicity conservation. (C) 200 Published by Elsevier B.V.
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| 20. |
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| 21. |
- Andersson, Magnus, et al.
(författare)
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Structural Dynamics of Light-Driven Proton Pumps
- 2009
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Ingår i: Structure. - : Elsevier BV. - 0969-2126 .- 1878-4186. ; 17:9, s. 1265-1275
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Tidskriftsartikel (refereegranskat)abstract
- Bacteriorhodopsin and proteorhodopsin are simple heptahelical proton pumps containing a retinal chromophore covalently bound to helix G via a protonated Schiff base. Following the absorption of a photon, all-trans retinal is isomerized to a 13-cis conformation, initiating a sequence of conformational changes driving vectorial proton transport. In this study we apply time-resolved wide-angle X-ray scattering to visualize in real time the helical motions associated with proton pumping by bacteriorhodopsin and proteorhodopsin. Our results establish that three conformational states are required to describe their photocycles. Significant motions of the cytoplasmic half of helix F and the extracellular half of helix C are observed prior to the primary proton transfer event, which increase in amplitude following proton transfer. These results both simplify the structural description to emerge from intermediate trapping studies of bacteriorhodopsin and reveal shared dynamical principles for proton pumping.
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| 22. |
- Andreev, V, et al.
(författare)
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Isolated electrons and muons in events with missing transverse momentum at HERA
- 2003
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 561:3-4, s. 241-257
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Tidskriftsartikel (refereegranskat)abstract
- A search for events with a high-energy isolated electron or muon and missing transverse momentum has been performed at the electron-proton collider HERA using an integrated luminosity of 13.6 pb(-1) in e(-) p scattering and 104.7 pb(-1) in e(+) p scattering. Within the Standard Model such events are expected to be mainly due to W boson production with subsequent leptonic decay. In e(-) p interactions one event is observed in the electron channel and none in the muon channel, consistent with the expectation of the Standard Model. In the e(+) p data a total of 18 events are seen in the electron and muon channels compared to an expectation of 12.4 +/- 1.7 dominated by W production (9.4 +/- 1.6). Whilst the overall observed number of events is broadly in agreement with the number predicted by the Standard Model, there is-an excess of events with transverse momentum of the hadronic system greater than 25 GeV with 10 events found compared to 2.9 +/- 0.5 expected. The results are used to determine the cross-section for events with an isolated electron or muon and missing transverse momentum. (C) 2003 Published by Elsevier Science B.V.
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| 23. |
- Arbajian, Elsa, et al.
(författare)
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Methylation patterns and chromatin accessibility in neuroendocrine lung cancer
- 2020
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 12:8, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- Lung cancer is the worldwide leading cause of death from cancer. Epigenetic modifications such as methylation and changes in chromatin accessibility are major gene regulatory mechanisms involved in tumorigenesis and cellular lineage commitment. We aimed to characterize these processes in the context of neuroendocrine (NE) lung cancer. Illumina 450K DNA methylation data were collected for 1407 lung cancers including 27 NE tumors. NE differentially methylated regions (NE-DMRs) were identified and correlated with gene expression data for 151 lung cancers and 31 human tissue entities from the Genotype-Tissue Expression (GTEx) consortium. Assay for transposase-accessible chromatin sequencing (ATAC-seq) and RNA sequencing (RNA-seq) were performed on eight lung cancer cell lines, including three NE cell lines, to identify neuroendocrine specific gene regulatory elements. We identified DMRs with methylation patterns associated with differential gene expression and an NE tumor phenotype. DMR-associated genes could further be split into six functional modules, including one highly specific gene module for NE lung cancer showing high expression in both normal and malignant brain tissue. The regulatory potential of NE-DMRs was further validated in vitro using paired ATAC-and RNA-seq and revealed both proximal and distal regulatory elements of canonical NE-marker genes such as CHGA, NCAM1, INSM1, as well as a number of novel candidate markers of NE lung cancer. Using multilevel genomic analyses of both tumor bulk tissue and lung cancer cell lines, we identified a large catalogue of gene regulatory elements related to the NE phenotype of lung cancer.
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| 24. |
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| 25. |
- Berg, Rand Wilcox Vanden, et al.
(författare)
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Brain tissue saving effects by single-dose intralesional administration of Neuroprotectin D1 on experimental focal penetrating brain injury in rats
- 2019
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Ingår i: Journal of Clinical Neuroscience. - : Elsevier BV. - 0967-5868 .- 1532-2653. ; 64, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI)is followed by a secondary inflammation in the brain. Neuroprotectin D1 (NPD1)is synthesized from docosahexaenoic acid (DHA)and has anti-inflammatory and antiapoptotic effects in experimental models of neurodegenerative disease and brain ischemia-reperfusion. It is not known whether intralesional administration of NPD1 ameliorates inflammation and cell death after severe TBI. We therefore investigated the effects of NPD1 following a severe form of focal penetrating TBI. A total of 30 male Sprague-Dawley rats weighing between 350 and 450 g were exposed to focal penetrating TBI or sham surgery. The rats were randomized to NPD1 treatment (50 ng intralesionally, immediately following TBI)or no treatment. The rats were sacrificed at 24 or 72 h. All subgroups consisted of 5 rats. Brains were removed, fresh frozen, cut in 14-µm coronal sections and subjected to Fluoro-Jade, TUNEL, MnSOD, 3-NT, COX-2, Ox-42 and NF-κB immuno-staining and lesion size analyses. NPD1 decreased the lesion area at 72 h compared to no treatment with a mean change 42% (NPD1 14.1 mm 2 ; no treatment 24.5 mm 2 )(p < 0.01). No difference was detected in markers for neuronal degeneration, apoptosis, anti-inflammatory or antioxidative enzymes, or immune cells. In conclusion, single-dose intralesional administration of NPD1 had brain tissue sparing effects after focal penetrating TBI, which may be beneficial in preventing brain tissue damage, making NPD1 a potential candidate for further clinical applications. Exact mechanisms of action could not be determined and it is possible that continuous or multiple administration regimens may increase efficacy in sequential preclinical studies.
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| 26. |
- Cerratto-Pargman, Teresa, et al.
(författare)
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Make IT Happen : Slutrapport 2020-02-30
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport är en utvärdering av utvecklingsprojektet “Make IT happen” som löpte från januari 2018 till december 2019 och som syftade till att ge grundskolans lärare, verksamma i 8 kommuner i region Kronoberg, möjlighet att höja sin digitala kompetens inom programmering och datalogiskt tänkande. Utvärderingen baseras på kvantitativ och kvalitativ analys av enkäter (före och efter projektet), lärares skriftliga reflektioner (under projektet) samt lärares lektionsplaneringar vid slutet av projektet. Total har vi analyserat material från 218 lärare. Analysen av enkäterna visar att “Make IT happen” har varit uppskattat av deltagarna som menar att projektet har hjälpt dem att komma igång med programmering och datalogiskt tänkande i klassrummet. Av utvärderingen framgår det att en betydande andel av de som fyllde i utvärderingarna (33%) anser sig ha behov av kunskaper, lektionstips, tid och idéer - eller av direkta resurser som datorer, pengar eller personal. En något lägre andel av lärarna ansåg inte att de hade några direkta behov för att kunna genomföra undervisning inom programmering efter utbildningen. Analysen av lektionsplaneringar som lämnats in vid sista utbildningstillfälle visar att deltagarna oftast har replikerat uppgifter som de har fått under träffarna; endast några enstaka lärare har försökt skapa helt nya uppgifter. Detta tyder på att de flesta behöver känna sig tryggare med programmering innan de kan transformera sin egen undervisningspraxis. I förhållande till projektets mål kan vi konstatera att “Make IT happen” har bidragit till att öka antalet lärare som utnyttjar möjligheterna med programmering i undervisningen. Mer specifikt har projektet bidragit till att ge deltagarna baskunskaper inom programmering och datalogiskt tänkande samt ett meningsfullt didaktiskt material för lärare som undervisar i matematik och teknik. Projektet har i mångt och mycket bidragit till att fördjupa förståelsen för- och användningen av programmering i klassrummet.
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| 27. |
- Cerratto-Pargman, Teresa, et al.
(författare)
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Teaching Computational Thinking in K-9 : Tensions at the Intersection of Technology and Pedagogical Knowledge
- 2020
-
Ingår i: The Interdisciplinarity of the Learning Sciences, 14th International Conference of the Learning Sciences (ICLS) 2020. - Nashville, Tennessee, USA : International Society of the Learning Sciences. ; , s. 2409-2410, s. 2409-2410
-
Konferensbidrag (refereegranskat)abstract
- This work draws attention to the question of how in-service teachers learn to teach computational thinking and programming across subjects in K-9 education. Drawing on qualitative analyses of 298 reflective notes provided by 120 in-service teachers attending a professional development program, we pay attention to the following emergent themes: i)developing an understanding of the subject of computational thinking in K-9, ii)connecting programming with the teachers’ own subject matters, iii)understanding the purpose of teaching computational thinking. These themes point at the importance of scaffolding in-service teachers to learn to program with educational materials, tools and programming environments but also with a sound and inspirational pedagogy that addresses the fundamental questions of: what, how and why programming and computational thinking should be part of the compulsory school curriculum?
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| 28. |
- Davidsson, Mattias, 1973-
(författare)
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A Mobile Application with Embodied Multimodal Interactions for Understanding Representations of Motion in Physics
- 2012
-
Ingår i: IADIS International Conference Mobile Learning 2012 Berlin, Germany11-13 March 2012.
-
Konferensbidrag (refereegranskat)abstract
- Current research in the Learning Sciences points out different methods and approaches to enhance and assist students in their learning and understanding of mathematical representations of the underlying physics of everyday situations. One of the aims of this paper is to address how mobile applications can be designed to support some of the pedagogical challenges associated with learners´ understanding of different graphical representations of motion – e.g. displacement as a function of time, velocity as a function of time, and how these couple to the actual motion, to each other, as well as to other mathematical representations of motion such as functions, equations and descriptive text. A prototype design is presented including a new type of application, or app, for mobile and in classroom use, using touch- and gesture based technology. One of the specific aims of this set of applications is to spur the learners exposure to, interaction with, as well as creation of multiple and multimodal representations of physical everyday phenomena involving motion, in a personal inquiry-based approach that could involve both informal as well as formal learning activities.
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| 29. |
- Davidsson, Mattias, 1973-
(författare)
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Embodied learning on the edge of mobile
- 2015
-
Ingår i: Mobile learning and STEM. - New York, NY: Routledge, 2016. : Routledge. - 9781317596523 - 9781138817029 - 9781315745831 ; , s. 199-208
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Mobile, as in mobile learning, could be defined as a specific upper limit on the screen size of any device. It could also relate to a specific tool being more, rather than less, mobile. This chapter will focus on the concept of embodied learning, the idea that the learning process is enhanced if your body is involved in the actual learning process, and how it possibly balances on the “edge of mobile” – the meaning of which will be presented below. The main point revolves around the design and test of a specific application developed for learning about the physics of motion by moving your finger on a tablet screen. One of the interesting questions at the present stage of the research is whether the tablet screen size, claimed to be on the absolute upper limit of being mobile, is on the lower limit when it comes to the scale of bodily movement needed for embodied learning to contribute positively in the learning process. It might thus be on the “edge of mobile.” To find out we need to further increase our knowledge of embodied learning. I will therefore discuss further possibilities of investigation when it comes to applications used for embodied learning on hardware platforms such as digital interactive whiteboards, Leap Motion, Google Glass, and more. These will make it possible to test the applications on different scales of bodily movement. It also makes it possible to try out different types of embodied learning activities, using your hand, finger, or even your entire body while walking, gesturing, running, or perhaps jumping off a cliff. © 2016 Taylor & Francis. All rights reserved.
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| 30. |
- Davidsson, Mattias, 1973-, et al.
(författare)
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Exploring the Use of Augmented Reality to Support Science Education in Secondary Schools
- 2012
-
Ingår i: 2012 IEEE Seventh International Conference on Wireless, Mobile and Ubiquitous Technology in Education - Proceedings. - Los Alamitos : IEEE Press. - 9780769546629 ; , s. 218-220
-
Konferensbidrag (refereegranskat)abstract
- During the last 2 years we have conducted several trials exploring how augmented reality and mobile technologies can be used to support learning and teaching in science education. In particular, we present the on-going efforts that are part of the EU funded project Science Center To Go. We provide an overview of the different activities, the lessons learned and what we propose as ways to forward making the technology, mobile, affordable and in the long term – ubiquitous available.
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| 31. |
- Davidsson, Mattias
(författare)
-
Finger Velocity : A Multimodal Touch Based Tablet Application for Learning the Physics of Motion
- 2014
-
Ingår i: Mobile as Mainstream - Towards Future Challenges in Mobile Learning. - Cham : Springer. - 9783319134154 ; , s. 238-249
-
Konferensbidrag (refereegranskat)abstract
- A prototype multimodal tablet application for learning the physics of motion has been developed tested and evaluated. By moving their finger across the screen the application enables the user to map its position and velocity in real-time in terms of graphs. The learning outcome of those test subjects using the application was compared to a group that did not use the application but had it shown to them, at the same time as getting an explanation of all the physics involved. There was a small but not significant difference in performance between these groups on a post-test. However, a larger (arguably significant) difference was seen between the male and female test subjects for the sub-set of questions of a more analytical nature. These were the questions targeted in this paper.
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| 32. |
- Davidsson, Mattias
(författare)
-
Jet Production and Parton Dynamics in Deep Inelastic Scattering
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hard QCD processes have been studied by measuring the di-jet event rate for deep inelastic scattering in the kinematic range 5 < Q2 < 100 GeV2 and 10-4 < x < 10-2. The jets we re reconstructed using the cone algorithm in the hadronic center-of-mass frame in which the transverse momentum of the jets were required to be greater than 5 GeV. The result of the investigation is that using Leading Order QCD calculations together with pure DGLAP parton showering we can not reproduce the relative rate of hard di-jet events in DIS. To accomplish this the transverse momentum ordering in the parton ladder has to be broken as can be achieved by the inclusion of a component which resolves the photon in the DGLAP picture, or by using the Color Dipole Model for the higher order QCD radiation.
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| 33. |
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| 34. |
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| 35. |
- Günther, Mattias, et al.
(författare)
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Cox‐2 Regulation Differs Between Sexes in the Secondary Inflammatory Response Following Experimental Penetrating Focal Brain Injury in Rats
- 2014
-
Ingår i: Journal of Neurotrauma. ; 31:5, s. A-18
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Traumatic brain injury (TBI) is followed by secondary neuronal degeneration, largely dependent on an inflammatory response. This response is probably gender specific, since females are generally better protected than males in animal models and human epidemiological studies of TBI. The reasons are not fully known. We examined aspects of the inflammatory response following experimental TBI in male and female rats to explore possible gender differences. A penetrating brain injury model was used to produce focal TBI in male (n=10) and female (n=10) rats. After 24 h and 72 h the brains were removed and subjected to immunohistochemical analyses and in situ hybridization. Cox‐2 mRNA was elevated in the perilesional area compared to the un‐injured contralateral side, and significantly higher in males compared to females at 24 h and 72 h (p
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| 36. |
- Günther, Mattias, et al.
(författare)
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Neuroprotective effects of N-acetylcysteine amide on experimental focal penetrating brain injury in rats
- 2014
-
Ingår i: Neuroscience Meeting, Washington DC, 2014 Nov 15-21. ; , s. 486.06-
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background The beneficial effects of N-acetylcysteine (NAC) on CNS ischemia and after TBI in animal models are well documented. However, the bioavailability of NAC is very low. N-acetylcysteine Amide (NACA) is a newly modified form of N-acetylcysteine that contains an amide group in place of the carboxyl group of NAC. NACA has more efficient membrane permeation and crosses the blood brain barrier. We examined the effects of NACA in the secondary inflammatory response following focal penetrating TBI in rats. Material and methods Focal penetrating TBI were produced in a total of 24 male Sprague-Dawley rats randomly selected for treatment (n=5), non-treatment (n=5) and sham (n=4). The treated animals were given NACA 300 mg/kg ip after 5 min and in the 24h survival group a bolus of 300 mg/kg ip after 4h. After 2h and 24h the brains were removed, cut in 14 µm coronal sections and subjected to immunohistochemistry, immunofluorescence, Fluoro-Jade and TUNEL analyses. Results NACA treatment decreased neuronal degeneration by Fluoro-Jade at 24h (p
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| 37. |
- Hage, Camilla, et al.
(författare)
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Metabolomic Profile in HFpEF vs HFrEF Patients
- 2020
-
Ingår i: Journal of Cardiac Failure. - : Elsevier BV. - 1071-9164 .- 1532-8414. ; 26:12, s. 1050-1059
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Heart failure with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF) are associated with metabolic derangements, which may have different pathophysiological implications.Methods and Results: In new-onset HFpEF (EF of >= 50%, n = 46) and HFrEF (EF of <40%, n = 75) patients, 109 endogenous plasma metabolites including amino acids, phospholipids and acylcarnitines were assessed using targeted metabolomics. Differentially altered metabolites and associations with clinical characteristics were explored. Patients with HFpEF were older, more often female with hypertension, atrial fibrillation, and diabetes compared with patients with HFrEF. Patients with HFpEF displayed higher levels of hydroxyproline and symmetric dimethyl arginine, alanine, cystine, and kynurenine reflecting fibrosis, inflammation and oxidative stress. Serine, cGMP, cAMP, L-carnitine, lysophophatidylcholine (18:2), lactate, and arginine were lower compared with patients with HFrEF. In patients with HFpEF with diabetes, kynurenine was higher (P = .014) and arginine lower (P = .014) vs patients with no diabetes, but did not differ with diabetes status in HFrEF. Decreasing kynurenine was associated with higher eGFR only in HFpEF (P-interaction = .020).Conclusions: Patients with new-onset HFpEF compared with patients with new-onset HFrEF display a different metabolic profile associated with comorbidities, such as diabetes and kidney dysfunction. HFpEF is associated with indices of increased inflammation and oxidative stress, impaired lipid metabolism, increased collagen synthesis, and downregulated nitric oxide signaling. Together, these findings suggest a more predominant systemic microvascular endothelial dysfunction and inflammation linked to increased fibrosis in HFpEF compared with HFrEF.
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| 38. |
- Holmgren, Johan, et al.
(författare)
-
Agent-based simulation of freight transport between geographical zones
- 2013
-
Ingår i: Procedia Computer Science. - : Elsevier. - 1877-0509. ; 19, s. 829-834
-
Konferensbidrag (refereegranskat)abstract
- We present TAPAS-Z, which is an agent-based freight transport analysis model for simulation of decision-making and transport activities. TAPAS-Z is a further development of a simulation model called TAPAS, and it has improved support for simulation of transport in large geographical regions. It is based on the principles that shipments are simulated for chosen supplier-consumer relations in a geographic region, and that the geographic locations of suppliers and consumers are randomly varied for each shipment. In TAPAS-Z, one supplier represents all real-world suppliers in a geographic zone, and one consumer represents all real-world consumers in a zone. In that way, TAPAS-Z is able to capture some of the diversity in freight transport that is caused by the varying geographic locations of senders and receivers, and which is important when assessing the impact of transport policy and infrastructural measures.
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| 39. |
- Jadid, Kayvan Dehlaghi, et al.
(författare)
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COX-2 inhibition by diclofenac is associated with decreased apoptosis and lesion area after experimental focal penetrating traumatic brain injury in rats
- 2019
-
Ingår i: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 10:July
-
Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI) is followed by a secondary inflammation in the brain. The inflammatory response includes prostanoid synthesis by the inducible enzyme cyclooxygenase-2 (COX-2). Inhibition of COX-2 is associated with improved functional outcome in experimental TBI models, although central nervous system-specific effects are not fully understood. Animal studies report better outcomes in females than males. The exact mechanisms for this gender dichotomy remain unknown. In an initial study we reported increased COX-2 expression in male rats, compared to female, following experimental TBI. It is possible that COX-2 induction is directly associated with increased cell death after TBI. Therefore, we designed a sequential study to investigate the blocking of COX-2 specifically, using the established COX-2 inhibitor diclofenac. Male Sprague-Dawley rats weighing between 250 and 350 g were exposed to focal penetrating TBI and randomly selected for diclofenac treatment (5 ?g intralesionally, immediately following TBI) (n = 8), controls (n = 8), sham operation (n = 8), and normal (no manipulation) (n = 4). After 24 h, brains were removed, fresh frozen, cut into 14?m coronal sections and subjected to COX-2 immunofluorescence, Fluoro Jade, TUNEL, and lesion area analyses. Diclofenac treatment decreased TUNEL staining indicative of apoptosis with a mean change of 54% (p 0.05) and lesion area with a mean change of 55% (p 0.005). Neuronal degeneration measured by Fluoro Jade and COX-2 protein expression levels were not affected. In conclusion, COX-2 inhibition by diclofenac was associated with decreased apoptosis and lesion area after focal penetrating TBI and may be of interest for further studies of clinical applications.
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| 40. |
- Karlsson Söbirk, Sara, et al.
(författare)
-
Imported leishmaniasis in Sweden 1993-2016
- 2018
-
Ingår i: Epidemiology and Infection. - 0950-2688. ; 146:10, s. 1267-1274
-
Tidskriftsartikel (refereegranskat)abstract
- In Sweden, leishmaniasis is an imported disease and its epidemiology and incidence were not known until now. We conducted a retrospective, nationwide, epidemiological study from 1993 to 2016. Probable cases were patients with leishmaniasis diagnoses reported to the Swedish Patient registry, collecting data on admitted patients in Swedish healthcare since 1993 and out-patient visits since 2001. Confirmed cases were those with a laboratory test positive for leishmaniasis during 1993-2016. 299 probable cases and 182 confirmed cases were identified. Annual incidence ranged from 0.023 to 0.35 per 100 000 with a rapid increase in the last 4 years. Of 182 laboratory-verified cases, 96 were diagnosed from 2013 to 2016, and in this group, almost half of the patients were children under 18 years. Patients presented in different healthcare settings in all regions of Sweden. Cutaneous leishmaniasis was the most common clinical manifestation and the majority of infections were acquired in Asia including the Middle East, specifically Syria and Afghanistan. Leishmania tropica was responsible for the majority of cases (42%). A combination of laboratory methods increased the sensitivity of diagnosis among confirmed cases. In 2016, one-tenth of the Swedish population were born in Leishmania-endemic countries and many Swedes travel to these countries for work or vacation. Swedish residents who have spent time in Leishmania-endemic areas, could be at risk of developing disease some time during their lives. Increased awareness and knowledge are needed for correct diagnosis and management of leishmaniasis in Sweden.
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| 41. |
- Kong, Xiangrui, et al.
(författare)
-
Molecular characterization and optical properties of primary emissions from a residential wood burning boiler
- 2021
-
Ingår i: Science of the Total Environment. - : Elsevier B.V.. - 0048-9697 .- 1879-1026. ; 754
-
Tidskriftsartikel (refereegranskat)abstract
- Modern small-scale biomass burners have been recognized as an important renewable energy source because of the economic and environmental advantages of biomass over fossil fuels. However, the characteristics of their gas and particulate emissions remain incompletely understood, and there is substantial uncertainty concerning their health and climate impacts. Here, we present online measurements conducted during the operation of a residential wood-burning boiler. The measured parameters include gas and particle concentrations, optical absorption and chemical characteristics of gases and particles. Positive matrix factorization was performed to analyze data from a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) equipped with a filter inlet for gases and aerosols (FIGAERO). Six factors were identified and interpreted. Three factors were related to the chemical composition of the fuel representing lignin pyrolysis products, cellulose/hemicellulose pyrolysis products, and nitrogen-containing organics, while three factor were related to the physical characteristics of the emitted compounds: volatile compounds, semi-volatile compounds, and filter-derived compounds. An ordinal analysis was performed based on the factor fractions to identify the most influential masses in each factor, and by deconvoluting high-resolution mass spectra fingerprint molecules for each factor were identified. Results from the factor analysis were linked to the optical properties of the emissions, and lignin and cellulose/hemicellulose pyrolysis products appeared to be the most important sources of brown carbon under the tested burning conditions. It is concluded that the emissions from the complex combustion process can be described by a limited set of physically meaningful factors, which will help to rationalize subsequent transformation and tracing of emissions in the atmosphere and associated impacts on health and climate.
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| 42. |
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| 43. |
- Lidin, Erik, et al.
(författare)
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Hippocampal Expression of Cytochrome P450 1B1 in Penetrating Traumatic Brain Injury
- 2022
-
Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 23:2
-
Tidskriftsartikel (refereegranskat)abstract
- Hippocampal dysfunction contributes to multiple traumatic brain injury sequala. Female rodents’ outcome is superior to male which has been ascribed the neuroprotective sex hormones 17β-estradiol and progesterone. Cytochrome P450 1B1 (CYP1B1) is an oxidative enzyme influencing the neuroinflammatory response by creating inflammatory mediators and metabolizing neuroprotective 17β-estradiol and progesterone. In this study, we aimed to describe hippocampal CYP1B1 mRNA expression, protein presence of CYP1B1 and its key redox partner Cytochrome P450 reductase (CPR) in both sexes, as well as the effect of penetrating traumatic brain injury (pTBI). A total 64 adult Sprague Dawley rats divided by sex received pTBI or sham-surgery and were assigned survival times of 1-, 3-, 5-or 7 days. CYP1B1 mRNA was quantified using in-situ hybridization and immunohistochemistry performed to verify protein colocalization. CYP1B1 mRNA expression was present in all subregions but greatest in CA2 irrespective of sex, survival time or intervention. At 3-, 5-and 7 days post-injury, expression in CA2 was reduced in male rats subjected to pTBI compared to sham-surgery. Females subjected to pTBI instead exhibited increased expression in all CA subregions 3 days post-injury, the only time point expression in CA2 was greater in females than in males. Immunohistochemical analysis confirmed neuronal CYP1B1 protein in all hippocampal subregions, while CPR was limited to CA1 and CA2. CYP1B1 mRNA is constitutively expressed in both sexes. In response to pTBI, females displayed a more urgent but brief regulatory response than males. This indicates there may be sex-dependent differences in CYP1B1 activity, possibly influencing inflammation and neuroprotection in pTBI.
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| 44. |
- Losurdo, Michela, et al.
(författare)
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Diffuse Axonal Injury in the Rat Brain: Axonal Injury and Oligodendrocyte Activity Following Rotational Injury
- 2020
-
Ingår i: Brain Sciences. - : MDPI AG. - 2076-3425. ; 10:4
-
Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI) commonly results in primary diffuse axonal injury (DAI) and associated secondary injuries that evolve through a cascade of pathological mechanisms. We aim at assessing how myelin and oligodendrocytes react to head angular-acceleration-induced TBI in a previously described model. This model induces axonal injuries visible by amyloid precursor protein (APP) expression, predominantly in the corpus callosum and its borders. Brain tissue from a total of 27 adult rats was collected at 24 h, 72 h and 7 d post-injury. Coronal sections were prepared for immunohistochemistry and RNAscope(R) to investigate DAI and myelin changes (APP, MBP, Rip), oligodendrocyte lineage cell loss (Olig2), oligodendrocyte progenitor cells (OPCs) (NG2, PDGFRa) and neuronal stress (HSP70, ATF3). Oligodendrocytes and OPCs numbers (expressed as percentage of positive cells out of total number of cells) were measured in areas with high APP expression. Results showed non-statistically significant trends with a decrease in oligodendrocyte lineage cells and an increase in OPCs. Levels of myelination were mostly unaltered, although Rip expression differed significantly between sham and injured animals in the frontal brain. Neuronal stress markers were induced at the dorsal cortex and habenular nuclei. We conclude that rotational injury induces DAI and neuronal stress in specific areas. We noticed indications of oligodendrocyte death and regeneration without statistically significant changes at the timepoints measured, despite indications of axonal injuries and neuronal stress. This might suggest that oligodendrocytes are robust enough to withstand this kind of trauma, knowledge important for the understanding of thresholds for cell injury and post-traumatic recovery potential.
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| 45. |
- Masiello, Italo, Professor, 1969-, et al.
(författare)
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Digital transformation in schools of two southern regions of Sweden through implementation-informed approach : A mixed-methods study protocol
- 2023
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 18:12
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The enhancement of–or even a shift from–traditional teaching and learning processes to corresponding digital practices has been rapidly occurring during the last two decades. The evidence of this ongoing change is still modest or even weak. However, the adaptation of implementation science in educational settings, a research approach which arose in the healthcare field, offers promising results for systematic and sustained improvements in schools. The aim of this study is to understand how the systematic professional development of teachers and schools principals (the intervention) to use digital learning materials and learning analytics dashboards (the innovations) could allow for innovative and lasting impacts in terms of a sustained implementation strategy, improved teaching practices and student outcomes, as well as evidence-based design of digital learning material and learning analytics dashboards.Methods: This longitudinal study uses a quasi-experimental cluster design with schools as the unit. The researchers will enroll gradually 145 experimental schools in the study. In the experimental schools the research team will form a School Team, consisting of teachers/learning-technologists, school principals, and researchers, to support teachers’ use of the innovations, with student achievement as the dependent variable. For the experimental schools, the intervention is based on the four longitudinal stages comprising the Active Implementation Framework. With an anticipated student sample of about 13,000 students in grades 1–9, student outcomes data are going to be analyzed using hierarchical linear models.Discussion: The project seeks to address a pronounced need for favorable conditions for children’s learning supported by a specific implementation framework targeting teachers, and to contribute with knowledge about the promotion of improved teaching practices and student outcomes. The project will build capacity using implementation of educational technology in Swedish educational settings.
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| 46. |
- Nordmark, Susanna, Filosofie doktor, 1968-, et al.
(författare)
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Piloting Systematic Implementation of Educational Technology in Swedish K-12 Schools : Two-Years-In Report
- 2024
-
Ingår i: Global Implementation Research and Applications. - : Springer. - 2662-9275.
-
Tidskriftsartikel (refereegranskat)abstract
- Halfway through a four-year research project supported by implementation science and the Active Implementation Frameworks (AIF), this article reports on the status of the initial two implementation stages. Our research investigates the impact of systematically preparing educators and educational institutions to integrate digital learning materials and learning analytics dashboards to enrich teaching practices and improve student performance outcomes.Furthermore, it seeks to establish a foundation for the use of innovative and validated educational technology (EdTech) through sustainable implementation strategies, evidence-based evaluation, and continuous redesign of digital learning materials. By adopting this comprehensive approach, we aim to enhance the knowledge base regarding effective digital innovation integration within educational environments.We argue that applying implementation science in educational settings facilitates the adoption of effective innovations, promotes evidence-based decision-making, and helps identify and address obstacles to change. Our ongoing research underscores the transformative impact of implementation science in education. Thus far, we have highlighted the crucial role of teacher perspectives and the necessity of co-designing technology aligned with teaching and learning objectives.This nuanced approach refutes the notion of a one-size-fits-all solution or a quick fix achievable in a single academic year. Instead, it advocates a dynamic, collaborative model that acknowledges the multifaceted nature of implementation. Our journey has reaffirmed the dedication of teachers, showcasing their readiness to invest time and effort when their professionalism is respected, and their input is genuinely valued and acted upon.
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| 47. |
- Petersson, Jonas, et al.
(författare)
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Ultrafast Electron Transfer Dynamics of a Zn(II)porphyrin-Viologen Complex Revisited S-2 vs S-1 Reactions and Survival of Excess Excitation Energy
- 2010
-
Ingår i: Journal of Physical Chemistry B. - 1520-6106 .- 1520-5207. ; 114:45, s. 14329-14338
-
Tidskriftsartikel (refereegranskat)abstract
- The photoinduced electron transfer reactions in a self-assembled 1 1 complex of zinc(II)tetrasulphonatophe nylporphyrin (ZnTPPS4-) and methylviologen (MV2+) in aqueous solution were investigated with transient absorption spectroscopy ZnTPPS4- was excited either in the Soret or one of the two Q-bands corresponding to excitation into the S-2 and S-1 states respectively The resulting electron transfer to MV2+ occurred surprisingly with the same time constant of tau(FET) = 180 fs from both electronic states The subsequent back electron transfer was rapid and the kinetics was independent of the initially excited state (tau(BET) = 700 fs) However ground state reactants in a set of vibrationally excited states were observed The amount of vibrationally excited ground states detected increased with increasing energy of the initial excited state showing that excess excitation energy survived a two-step electron transfer reaction in solution Differences in the ZnTPSS3-/MV+. spectra suggest that the forward election transfer from the S-2 state at least partially produces an electronically excited charge transfer state which effectively suppresses the influence of the inverted regime Other possible reasons for the similar election transfer rates for the different excited states are also discussed
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| 48. |
- Petersson, Jonas, et al.
(författare)
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Variation of Excitation Energy Influences the Product Distribution of a Two-Step Electron Transfer : S-2 vs S-1 Electron Transfer in a Zn(II)porphyrin-Viologen Complex
- 2009
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 131:23, s. 7940-7941
-
Tidskriftsartikel (refereegranskat)abstract
- We have, for the first time for molecular systems in solution, shown a case where the variation of excitation energy influences the product distribution of a two-step electron transfer. The photoexcitation Was to the porphyrin-localized S-2 state or either of the S-1(v = 1) or S-1(v = 0) states of an aqueous Zn(II)-meso-tetrasulphonatophenyl-porphyrin methylviologen (ZnTPPS4-/MV2+) complex. Both forward and back electron transfer occur on a subpicosecond time scale (tau(FET) = 0.2, tau(BET) 0.7 ps). The excess energy Of the higher excitations partially survives both electron transfer steps. This is seen by different distributions of unrelaxed ground states, which are generated by the back electron transfer and has unique UV-vis spectroscopic signatures. State selective electron transfer opens interesting possibilities for reaction control, and the results represent initial steps in that direction
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| 49. |
- Priestley, Michael, et al.
(författare)
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Volatility Measurements of Oxygenated Volatile Organics from Fresh and Aged Residential Wood Burning Emissions
- 2024
-
Ingår i: ACS EARTH AND SPACE CHEMISTRY. - : American Chemical Society. - 2472-3452. ; 8:2, s. 159-173
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Tidskriftsartikel (refereegranskat)abstract
- Residential wood combustion (RWC) is a dominant source of anthropogenic aerosol in urban areas. Complexities in aerosol chemical composition, semivolatile behavior, and secondary processing make estimating RWC impacts on climate and air quality challenging. A chemical ionization mass spectrometer with a filter inlet for gas and aerosols measured the gas-to-particle partitioning of organic compounds emitted from log wood and pellet burning stoves. Emissions were aged in an oxidation flow reactor to assess changes in the volatilities of the secondary aerosol. Effective saturation vapor concentrations (C*) of the measured species were derived using both the measured particle-to-gas concentration ratio (P- i/G( i)) and vapor pressure measurements (p(i)( 0)) calibrated using the maximum temperature during evaporation. These were used to derive new molecular formula (MF) parameterizations and were compared to selected previous parameterization. The fresh wood stove emissions were less volatile than those of the pellet stove (particle fractions of 0.96 vs 0.69), likely caused by poorer combustion conditions, producing a greater particle sink for organic vapors. After aging, the volatility of the emissions remained broadly similar, whereas all MF parameterizations showed increasing volatility. This was likely due to the measurement techniques capturing nonideal effects of partitioning that MF parameterizations cannot.
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- Risling, Mårten, et al.
(författare)
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Mice and (wo)men with head trauma
- 2015
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Ingår i: IHL and Gender - Swedish Experiences. - 9789163796302 ; , s. 103-110
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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