| 1. |
- Abazov, V. M., et al.
(author)
-
The upgraded DO detector
- 2006
-
In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 565:2, s. 463-537
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Journal article (peer-reviewed)abstract
- The DO experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid -argon calorimeters and central muon detector, remaining from Run 1, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to DO.
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| 2. |
- Abazov, V. M., et al.
(author)
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Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV using secondary vertex b tagging
- 2006
-
In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 74:11, s. 112004-
-
Journal article (peer-reviewed)abstract
- We report a new measurement of the t (t) over bar production cross section in p (beta) over bar collisions at a center-of-mass energy of 1.96 TeV using events with one charged lepton (electron or muon), missing transverse energy, and jets. Using 425 pb(-1) of data collected using the D0 detector at the Fermilab Tevatron Collider, and enhancing the t (t) over bar content of the sample by tagging b jets with a secondary vertex tagging algorithm, the t (t) over bar production cross section is measured to be sigma(p (t) over bar -> t (t) over bar +X)=6.6 +/- 0.9(stat+syst) +/- 0.4(lum) pb. This cross section is the most precise D0 measurement to date for t (t) over bar production and is in good agreement with standard model expectations.
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| 3. |
- Iablonskyi, D., et al.
(author)
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Interatomic Coulombic Decay Processes after Multiple Valence Excitations in Ne Clusters
- 2015
-
In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 635, s. 112067-112067
-
Conference paper (peer-reviewed)abstract
- We present a comprehensive analysis of autoionization processes in Ne clusters (similar to 5000 atoms) after multiple valence excitations by free electron laser radiation. The evolution from 2-body interatomic Coulombic decay (ICD) to 3-body ICD is demonstrated when changing from surface to bulk Frenkel exciton excitation. Super Coster-Kronig type 2-body ICD is observed at Wannier exciton which quenches the main ICD channel.
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| 4. |
- Iablonskyi, D., et al.
(author)
-
Slow Interatomic Coulombic Decay of Multiply Excited Neon Clusters
- 2016
-
In: Physical Review Letters. - 0031-9007. ; 117:27
-
Journal article (peer-reviewed)abstract
- Ne clusters (∼5000 atoms) were resonantly excited (2p→3s) by intense free electron laser (FEL) radiation at FERMI. Such multiply excited clusters can decay nonradiatively via energy exchange between at least two neighboring excited atoms. Benefiting from the precise tunability and narrow bandwidth of seeded FEL radiation, specific sites of the Ne clusters were probed. We found that the relaxation of cluster surface atoms proceeds via a sequence of interatomic or intermolecular Coulombic decay (ICD) processes while ICD of bulk atoms is additionally affected by the surrounding excited medium via inelastic electron scattering. For both cases, cluster excitations relax to atomic states prior to ICD, showing that this kind of ICD is rather slow (picosecond range). Controlling the average number of excitations per cluster via the FEL intensity allows a coarse tuning of the ICD rate.
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| 5. |
- Sanchez-Gonzalez, A., et al.
(author)
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Auger electron and photoabsorption spectra of glycine in the vicinity of the oxygen K-edge measured with an X-FEL
- 2015
-
In: Journal of Physics B-Atomic Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 48:23
-
Journal article (peer-reviewed)abstract
- We report the first measurement of the near oxygen K-edge auger spectrum of the glycine molecule. Our work employed an x-ray free electron laser as the photon source operated with input photon energies tunable between 527 and 547 eV. Complete electron spectra were recorded at each photon energy in the tuning range, revealing resonant and non-resonant auger structures. Finally ab initio theoretical predictions are compared with the measured above the edge auger spectrum and an assignment of auger decay channels is performed.
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| 6. |
- Düsterer, S, et al.
(author)
-
Two-color XUV+NIR femtosecond photoionization of neon in the near-threshold region
- 2019
-
In: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 21
-
Journal article (peer-reviewed)abstract
- Results of angle-resolved electron spectroscopy of near-threshold photoionization of Ne atoms by combined femtosecond extreme ultraviolet and near infrared fields are presented. The dressed-electron spectra show an energetic distribution into so-called sidebands, being separated by the photon energy of the dressing laser. Surprisingly, for the low kinetic energy (few eV) sidebands, the photoelectron energy varies as a function of the emission angle. Such behavior has not yet been observed in sideband creation and has not been predicted in commonly used theoretical descriptions such as strong field approximation and soft photon approach. Describing the photoionization with a time-dependent Schrödinger equation allows a qualitative description of the observed effect, as well as the prediction of fine structure in the sideband distribution.
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| 7. |
- Fukuzawa, H., et al.
(author)
-
Deep Inner-Shell Multiphoton Ionization by Intense X-Ray Free-Electron Laser Pulses
- 2013
-
In: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 110:17
-
Journal article (peer-reviewed)abstract
- We have investigated multiphoton multiple ionization dynamics of xenon atoms using a new x-ray free-electron laser facility, SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan, and identified that Xen+ with n up to 26 is produced at a photon energy of 5.5 keV. The observed high charge states (n >= 24) are produced via five-photon absorption, evidencing the occurrence of multiphoton absorption involving deep inner shells. A newly developed theoretical model, which shows good agreement with the experiment, elucidates the complex pathways of sequential electronic decay cascades accessible in heavy atoms. The present study of heavy-atom ionization dynamics in high-intensity hard-x-ray pulses makes a step forward towards molecular structure determination with x-ray free-electron lasers. DOI: 10.1103/PhysRevLett.110.173005
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| 8. |
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| 9. |
- Mazza, T., et al.
(author)
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Mapping Resonance Structures in Transient Core-Ionized Atoms
- 2020
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In: Physical Review X. - 2160-3308. ; 10:4
-
Journal article (peer-reviewed)abstract
- The nature of transient electronic states created by photoabsorption critically determines the dynamics of the subsequently evolving system. Here, we investigate K-shell photoionized atomic neon by absorbing a second photon within the Auger-decay lifetime of 2.4 fs using the European XFEL, a unique high-repetition-rate, wavelength-tunable x-ray free-electron laser. By high-resolution electron spectroscopy, we map out the transient Rydberg resonances unraveling the details of the subsequent decay of the hollow atom. So far, ultra-short-lived electronic transients, which are often inaccessible by experiments, were mainly inferred from theory but are now addressed by nonlinear x-ray absorption. The successful characterization of these resonances with femtosecond lifetimes provides the basis for a novel class of site-specific, nonlinear, and time-resolved studies with strong impact for a wide range of topics in physics and chemistry.
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| 10. |
- Motomura, K., et al.
(author)
-
Sequential multiphoton multiple ionization of atomic argon and xenon irradiated by X-ray free-electron laser pulses from SACLA
- 2013
-
In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:16
-
Journal article (peer-reviewed)abstract
- We have investigated multiphoton multiple ionization of argon and xenon atoms at 5 keV using a new x-ray free electron laser (XFEL) facility, the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan. The experimental results are compared with the new theoretical results presented here. The absolute fluence of the XFEL pulse has been determined with the help of the calculations utilizing two-photon processes in the argon atom. The high charge states up to +22 observed for Xe in comparison with the calculations point to the occurrence of sequential L-shell multiphoton absorption and of resonance-enabled x-ray multiple ionization.
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| 11. |
- Takanashi, T, et al.
(author)
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Time-Resolved Measurement of Interatomic Coulombic Decay Induced by Two-Photon Double Excitation of Ne2
- 2017
-
In: Physical Review Letters. - 0031-9007. ; 118:3
-
Journal article (peer-reviewed)abstract
- The hitherto unexplored two-photon doubly excited states [Ne∗(2p-13s)]2 were experimentally identified using the seeded, fully coherent, intense extreme ultraviolet free-electron laser FERMI. These states undergo ultrafast interatomic Coulombic decay (ICD), which predominantly produces singly ionized dimers. In order to obtain the rate of ICD, the resulting yield of Ne2+ ions was recorded as a function of delay between the extreme ultraviolet pump and UV probe laser pulses. The extracted lifetimes of the long-lived doubly excited states, 390(-130/+450) fs, and of the short-lived ones, less than 150 fs, are in good agreement with ab initio quantum mechanical calculations.
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| 12. |
- Zettergren, Henning, et al.
(author)
-
Roadmap on dynamics of molecules and clusters in the gas phase
- 2021
-
In: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6060 .- 1434-6079. ; 75:5
-
Journal article (peer-reviewed)abstract
- This roadmap article highlights recent advances, challenges and future prospects in studies of the dynamics of molecules and clusters in the gas phase. It comprises nineteen contributions by scientists with leading expertise in complementary experimental and theoretical techniques to probe the dynamics on timescales spanning twenty order of magnitudes, from attoseconds to minutes and beyond, and for systems ranging in complexity from the smallest (diatomic) molecules to clusters and nanoparticles. Combining some of these techniques opens up new avenues to unravel hitherto unexplored reaction pathways and mechanisms, and to establish their significance in, e.g. radiotherapy and radiation damage on the nanoscale, astrophysics, astrochemistry and atmospheric science.
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| 13. |
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| 14. |
- Berglund, Mats, et al.
(author)
-
Self-reported disability in relation to alcohol and other drug use and mental health among emerging adults : an international comparison
- 2012
-
In: Alcoholism. - : John Wiley & Sons. - 0145-6008 .- 1530-0277. ; 36:s1, s. 284A-284A
-
Journal article (other academic/artistic)abstract
- The present study includes baseline data from 2867 students (77.8% from Sweden, 22.2% from US) and evaluates the relationships among self-reported disabilities, alcohol use, other substance use, and psychosocial adjustment. There were 114 (4.6%) ‘‘hard-of-hearing’’ (HH) students, 129 (5.2%) reported visual disabilities, 33 (1.3%) reported motor disabilities, 223 (9.0%) reported a reading/writing disability, and 97 (3.6%) reported they had ‘‘other’’ disabilities. Of these, 70 (14.1%) reported more than one disability. Presence of a disability was significantly higher among Sweden students (2 (1)=19.93, p< 0.001), with 19.1% of Sweden students and 11.5% of US students reporting at least one disability. Reporting any type of disability was associated with significantly greater alcohol use frequency, intensity, and related problems (all p < 0.02), significantly more mental health symptoms and conduct problems (p < 0.005), and significantly greater likelihood of illicit and prescription drug use (all p < 0.001). With respect to specific disabilities, individuals with motor disabilities reported the highest levels of alcohol use and mental health symptoms, whereas individuals who reported ‘‘other’’ disabilities had higher rates of illicit drug use and conduct problems. Further, there was a significantly positive correlation between the number of disabilities and intensity of alcohol use, mental health symptoms, conduct problems, illicit and prescription drug use, and alcohol related problems (all p < 0.001). The association between conduct problems and disability (any disability and number of disabilities) was moderated by country of origin, gender, and drinking for coping reasons on the Drinking Motives Questionnaire. Participants in Sweden, males, and those who drank for coping reasons were more likely to report a relationship between disability and conduct problems (p < 0.001). Participants who drank for coping reasons were also more likely to report a relationship between disability and alcohol related problems (p=0.001). These findings indicate students with disabilities are an important risk group for preventive interventions for alcohol, substance, and mental health problems, and may benefit from interventions which target healthy coping skills. This research was supported by NIAAA # 5R01AA018276 awarded to Drs. Larimer & Berglund
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| 15. |
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| 16. |
- Düsterer, S., et al.
(author)
-
Angle resolved photoelectron spectroscopy of two-color XUV-NIR ionization with polarization control
- 2016
-
In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 49:16
-
Journal article (peer-reviewed)abstract
- Electron emission caused by extreme ultraviolet (XUV) radiation in the presence of a strong near infrared (NIR) field leads to multiphoton interactions that depend on several parameters. Here, a comprehensive study of the influence of the angle between the polarization directions of the NIR and XUV fields on the two-color angle-resolved photoelectron spectra of He and Ne is presented. The resulting photoelectron angular distribution strongly depends on the orientation of the NIR polarization plane with respect to that of the XUV field. The prevailing influence of the intense NIR field over the angular emission characteristics for He(1s) and Ne(2p) ionization lines is shown. The underlying processes are modeled in the frame of the strong field approximation (SFA) which shows very consistent agreement with the experiment reaffirming the power of the SFA for multicolor-multiphoton ionization in this regime.
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| 17. |
- Fukuzawa, H., et al.
(author)
-
Electron spectroscopy of rare-gas clusters irradiated by x-ray free-electron laser pulses from SACLA
- 2016
-
In: Journal of Physics B-Atomic Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 49:3
-
Journal article (peer-reviewed)abstract
- We have measured electron energy spectra and asymmetry parameters of Ar clusters and Xe clusters illuminated by intense x-rays at 5 and 5.5 keV. A velocity map imaging spectrometer was developed for this purpose and employed at an x-ray free-electron laser facility, SACLA in Japan. The cluster size dependence and the peak fluence dependence of the electron spectra and asymmetry parameters are discussed.
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| 18. |
- Gryzlova, E. V., et al.
(author)
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Doubly resonant three-photon double ionization of Ar atoms induced by an EUV free-electron laser
- 2011
-
In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 84:6
-
Journal article (peer-reviewed)abstract
- A mechanism for three-photon double ionization of atoms by extreme-ultraviolet free-electron laser pulses is revealed, where in a sequential process the second ionization step, proceeding via resonant two-photon ionization of ions, is strongly enhanced by the excitation of ionic autoionizing states. In contrast to the conventional model, the mechanism explains the observed relative intensities of photoelectron peaks and their angular dependence in three-photon double ionization of argon.
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| 19. |
- Ilchen, M., et al.
(author)
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X-ray spectroscopy on ultrafast-decaying core-excited atomic ions
- 2020
-
In: Charge-exchange. - : IOP Publishing. - 1742-6588. ; 1412
-
Conference paper (peer-reviewed)abstract
- Results from the first soft X-ray user experiment at the European XFEL on nonlinear photon-matter interaction will be presented. Angle-resolved electron time-of-flight spectroscopy employed at the AQS (Atomic- like Quantum Systems) endstation of the SQS (Small Quantum Systems) instrument reveals insight into the character of resonances in highly transient, core ionized neon ions, i.e. Ne:+ 1s12s22p6 → Ne+&∗ 1s02s22p6np, together with their respective relaxation dynamics. Enabled by the unique properties of the European XFEL, novel perspectives on efficient nonlinear spectroscopy will be discussed.
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| 20. |
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| 21. |
- Kelkensberg, F., et al.
(author)
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Molecular Dissociative Ionization and Wave-Packet Dynamics Studied Using Two-Color XUV and IR Pump-Probe Spectroscopy
- 2009
-
In: Physical Review Letters. - 1079-7114. ; 103:12
-
Journal article (peer-reviewed)abstract
- We present a combined theoretical and experimental study of ultrafast wave-packet dynamics in the dissociative ionization of H-2 molecules as a result of irradiation with an extreme-ultraviolet (XUV) pulse followed by an infrared (IR) pulse. In experiments where the duration of both the XUV and IR pulses are shorter than the vibrational period of H-2+, dephasing and rephasing of the vibrational wave packet that is formed in H-2+ upon ionization of the neutral molecule by the XUV pulse is observed. In experiments where the duration of the IR pulse exceeds the vibrational period of H-2+ (15 fs), a pronounced dependence of the H+ kinetic energy distribution on XUV-IR delay is observed that can be explained in terms of the adiabatic propagation of the H-2+ wave packet on field-dressed potential energy curves.
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| 22. |
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| 23. |
- Kornilov, O., et al.
(author)
-
Coulomb explosion of diatomic molecules in intense XUV fields mapped by partial covariance
- 2013
-
In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:16
-
Journal article (peer-reviewed)abstract
- Single-shot time-of-flight spectra for Coulomb explosion of N-2 and I-2 molecules have been recorded at the Free Electron LASer in Hamburg (FLASH) and have been analysed using a partial covariance mapping technique. The partial covariance analysis unravels a detailed picture of all significant Coulomb explosion pathways, extending up to the N4+-N5+ channel for nitrogen and up to the I8+-I9+ channel for iodine. The observation of the latter channel is unexpected if only sequential ionization processes from the ground state ions are considered. The maximum kinetic energy release extracted from the covariance maps for each dissociation channel shows that Coulomb explosion of nitrogen molecules proceeds much faster than that of the iodine. The N-2 ionization dynamics is modelled using classical trajectory simulations in good agreement with the outcome of the experiments. The results suggest that covariance mapping of the Coulomb explosion can be used to measure the intensity and pulse duration of free-electron lasers.
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| 24. |
- Larimer, M.E., et al.
(author)
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An international comparison of a web-based personalized feedback intervention in high school students USA and Sweden
- 2013
-
In: Alcoholism. - : John Wiley & Sons. - 0145-6008 .- 1530-0277. ; 37:s2, s. 260A-260A
-
Journal article (other academic/artistic)abstract
- A key developmental period for alcohol misuse is emerging adulthood (roughly ages 18–25). Personalized Feedback Interventions (PFI) are effective in reducing alcohol-related harmin college populations, however little research has evaluated PFIs given during high school.Moreover, cultural differences influence both alcohol misuse and response to interventions. The purpose of this study is to evaluate the efficacy of a web-based PFI given to high school seniors (ages 17-19) in the USA and Sweden. 1181 participants (42.3%male; 28.3%risky drinkers based on AUDIT-C) in the USA and 2171 in Sweden (44.1%male; 52.3% risky drinkers based on AUDIT-C) were assessed during their high school senior year. Approximately 1/3 were randomized to receive PFI. Approximately 1 week after viewing the PFI, participants were asked to complete a post-feedback satisfaction survey (3 subscales: information motivated change, shared information with friends, information was educational), and their “stage” on the readiness to change scale. Results showed 1) information motivated change subscale was associated with increases in contemplation and action stages of change and decreases in precontemplation; Swedish participants and those with higher AUDIT-C scores had lower scores; (2) USA sample was less likely to share information with friends; those with higher AUDIT-C scores were more likely to share information with friends; and (3) those with higher AUDIT-C scores were less likely to find information educational. Participants completed 6- and 12- month follow up surveys. After controlling for key baseline variables and using appropriate distributions for analyses, 6 month outcomes from 2236 participants (852 in USA; 1384 in Sweden; 731 received PFI), found those who received PFI drank significantly less alcohol per occasion (typical and peak), had lower blood alcohol concentration (typical and peak) and drank on fewer occasions than those who did not receive the PFI (effect size range: d = .12 to d = .22). There were no significant effects of PFI on alcohol-related problems or readiness to change and no significant interactions between country of residence and intervention on drinking outcomes. Results suggest web-based PFIs given during senior year of high school are efficacious in reducing alcohol use during transition to adulthood. Twelve-month outcomes and mediators will also be presented. This research was supported by NIAAA # 5R01AA018276 awarded to Drs. Larimer & Berglund.
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| 25. |
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| 26. |
- L'Huillier, A., et al.
(author)
-
Atomic physics with attosecond pulses
- 2006
-
In: International Conference on Ultrafast Phenomena, UP 2006. - 1557528101 - 9781557528100
-
Conference paper (peer-reviewed)
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| 27. |
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| 28. |
- Ma, R., et al.
(author)
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Photoelectron angular distributions for the two-photon ionization of helium by ultrashort extreme ultraviolet free-electron laser pulses
- 2013
-
In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:16
-
Journal article (peer-reviewed)abstract
- The two-photon ionization of helium atoms by ultrashort extreme-ultraviolet free-electron laser pulses, produced by the SPring-8 Compact SASE Source test accelerator, was investigated at photon energies of 20.3, 21.3, 23.0 and 24.3 eV. The angular distribution of photoelectrons generated by two-photon ionization is obtained using a velocity map imaging spectrometer. The phase-shift differences and amplitude ratios of the outgoing s and d continuum wave packets are extracted from the photoelectron angular distributions. The obtained values of the phase-shift differences are distinct from scattering phase-shift differences when the photon energy is tuned to a resonance with an excited level or Rydberg manifold. The difference stems from the co-presence of resonant and non-resonant path contributions in the two-photon ionization by femtosecond pulses. Since the relative contribution of both paths can be controlled in principle by the pulse shape, these results illustrate a new way to tailor the continuum wave packet.
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| 29. |
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| 30. |
- Mondal, S., et al.
(author)
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Photoelectron angular distributions for the two-photon sequential double ionization of xenon by ultrashort extreme ultraviolet free electron laser pulses
- 2013
-
In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:16
-
Journal article (peer-reviewed)abstract
- Xenon atoms are double-ionized by sequential two-photon absorption by ultrashort extreme ultraviolet free-electron laser pulses with a photon energy of 23.0 and 24.3 eV, produced by the SPring-8 Compact SASE Source test accelerator. The angular distributions of photoelectrons generated by two-photon double ionization are obtained using velocity map imaging. The results are reproduced reasonably well by the present theoretical calculations within the multi-configurational Dirac-Fock approach.
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| 31. |
- Raack, J., et al.
(author)
-
Present-day gully activity in Sisyphi Cavi, Mars - Flow-like features and block movements
- 2020
-
In: Icarus. - : Elsevier BV. - 0019-1035. ; 350
-
Journal article (peer-reviewed)abstract
- The continuously increasing number of multi-temporal high-resolution images from the surface of Mars offers the possibility for detailed studies of present-day surface activity. In this study we investigated all gullies in the Sisyphi Cavi region (355 degrees E, 71 degrees S) of the south polar region of Mars. This region is influenced by the seasonal deposition of a decimeters-thick translucent slab ice in late autumn/winter and its subsequent sublimation in spring. We mapped all gullies (n = 17.760) and measured their orientations. We also identified gullies with contemporary activity (n = 35) using multi-temporal HiRISE images for martian years (MY) 28 to 34. We observed two different kinds of activity: (1) dark flow-like features, and (2) movement of blocks. For both, sediment was transported from the source region (alcove and/or flanks of channels) down the gully. Using image data from HRSC, CTX, and HiRISE, we monitored the general defrosting of the study region. We also analyzed the maximum daytime surface temperatures of the complete study region based on TES data from MYs 24 to 26. To identify the origin and triggering mechanism of the observed activity, we used: (1) detailed topographic investigations (e.g., slope angles) of two extensively gullied slopes based on two HiRISE-DTMs, (2) identification of small scale displacements with Digital Image Correlation (DIC), and (3) orientation measurements of active gullies and comparison to non-active gullies. We found that for the active gullies studied, activity happens at the end of spring between L-S similar to 225 degrees and similar to 250 degrees. This is consistent with the timing of final stages of defrosting in the region. At this time, some surfaces are already defrosted while others still host the seasonal slab ice cover. For the surfaces with slab ice, dark defrosting spots (and flows, if the surface is inclined) are observed on dark dunes as well as on gully aprons and in gully channels. These spots form when, triggered by basal sublimation generated overpressure, sediment entrained in CO2-gas is transported through cracks within the ice and redeposited onto the frosted surface. We compared and linked both morphologic features (dark dune spots and dark flow-like features) and concluded that these features have comparable or even the same triggering mechanisms. Based on this extensive study, the most plausible mechanism for ongoing gully activity can be divided into two steps: 1) accumulation of material within gully channels via small dry flows on top of the slab ice (comparable to dark dune spots/flows), 2) when a critical mass is reached, the sediment flows down the still frosted gully on top of the sublimating ice or as a mixture of dry material and ice in a catastrophic flow. The triggering factor for the movement of blocks remains unclear, as their timing could not be constrained with the available data. We identified headwall erosion in one gully in the study region, whereas a discrete source could not be identified for the other sites, suggesting multiple failure mechanisms could be active in such gullies. Finally, through volume balance calculations we show that active gullies in Sisyphi Cavi could have been formed within decades to several tens of thousands of MY, but gully-morphology indicates a much-longer period for formation of the entire gully-landform.
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| 32. |
- Rolles, D., et al.
(author)
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Femtosecond x-ray photoelectron diffraction on gas-phase dibromobenzene molecules
- 2014
-
In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 47:12
-
Journal article (peer-reviewed)abstract
- We present time-resolved femtosecond photoelectron momentum images and angular distributions of dissociating, laser-aligned 1,4-dibromobenzene (C6H4Br2) molecules measured in a near-infrared pump, soft-x-ray probe experiment performed at an x-ray free-electron laser. The observed alignment dependence of the bromine 2p photoelectron angular distributions is compared to density functional theory calculations and interpreted in terms of photoelectron diffraction. While no clear time-dependent effects are observed in the angular distribution of the Br(2p) photoelectrons, other, low-energy electrons show a pronounced dependence on the time delay between the near-infrared laser and the x-ray pulse.
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| 33. |
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| 34. |
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| 35. |
- Sansone, G., et al.
(author)
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Attosecond excitation of electron wavepackets
- 2008
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In: Quantum Electronics and Laser Science Conference, QELS 2008. - 9781557528599
-
Conference paper (peer-reviewed)abstract
- We present experiments, supported by time-dependent Schrödinger simulations, on the dynamics of Helium bound states after an attosecond excitation in the presence of a strong infrared laser field.
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| 36. |
- Spokes, L., et al.
(author)
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MEAD: An interdisciplinary study of the marine effects of atmospheric deposition in the Kattegat
- 2006
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In: Environmental Pollution. - : Elsevier BV. - 0269-7491. ; 140:3, s. 453-462
-
Journal article (peer-reviewed)abstract
- This paper summarises the results of the EU funded MEAD project, an interdisciplinary study of the effects of atmospheric nitrogen deposition on the Kattegat Sea between Denmark and Sweden. The study considers emissions of reactive nitrogen gases, their transport, transformations, deposition and effects on algal growth together with management options to reduce these effects. We conclude that atmospheric deposition is an important source of fixed nitrogen to the region particularly in summer, when nitrogen is the limiting nutrient for phytoplankton growth, and contributes to the overall eutrophication pressures in this region. However, we also conclude that it is unlikely that atmospheric deposition can, on its own, induce algal blooms in this region. A reduction of atmospheric nitrogen loads to this region will require strategies to reduce emissions of ammonia from local agriculture and Europe wide reductions in nitrous oxide emissions. (c) 2005 Elsevier Ltd. All rights reserved.
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| 37. |
- Tachibana, T., et al.
(author)
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Nanoplasma Formation by High Intensity Hard X-rays
- 2015
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
-
Journal article (peer-reviewed)abstract
- Using electron spectroscopy, we have investigated nanoplasma formation from noble gas clusters exposed to high-intensity hard-x-ray pulses at similar to 5 keV. Our experiment was carried out at the SPring-8 Angstrom Compact free electron LAser (SACLA) facility in Japan. Dedicated theoretical simulations were performed with the molecular dynamics tool XMDYN. We found that in this unprecedented wavelength regime nanoplasma formation is a highly indirect process. In the argon clusters investigated, nanoplasma is mainly formed through secondary electron cascading initiated by slow Auger electrons. Energy is distributed within the sample entirely through Auger processes and secondary electron cascading following photoabsorption, as in the hard x-ray regime there is no direct energy transfer from the field to the plasma. This plasma formation mechanism is specific to the hard-x-ray regime and may, thus, also be important for XFEL-based molecular imaging studies. In xenon clusters, photo-and Auger electrons contribute more significantly to the nanoplasma formation. Good agreement between experiment and simulations validates our modelling approach. This has wide-ranging implications for our ability to quantitatively predict the behavior of complex molecular systems irradiated by high-intensity hard x-rays.
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| 38. |
- Widell, Anders, et al.
(author)
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IgM antibody to the hepatitis B core antigen in acute hepatitis determined by SPRIA--diagnostic value
- 1982
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In: Acta pathologica, microbiologica, et immunologica Scandinavica. Section B, Microbiology. - 0108-0180. ; 90:1, s. 79-84
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Journal article (peer-reviewed)abstract
- A solid phase radio-immunoassay (SPRIA) was developed for the detection of anti-HBc IgM. The assay proved sensitive and easy to perform and rheumatoid factor did not affect the test results. Anti-HBc IgM titres were followed in consecutive samples from 15 patients after uncomplicated acute hepatitis B. In the acute phase anti-HBc IgM titres ranged from 10(-5) to 10(-7) (mean 10(-6.4)). One year after onset of disease ten of the 15 had titres below 10(-4) and between two and three years after onset most patients had titres 10(-3). Anti-HBc IgM titres were determined in six episodes of acute hepatitis B, all HBsAg negative but anti-HBc positive in the first samples obtained (within 8 days) and developing anti-HBs during convalescence. Acute phase anti-HBc IgM titres in these patients ranged between 10(-5.5) and 10(-7) (mean 10(-6.5)) and were thus identical with HBsAg positive cases. When acute phase sera from 168 episodes of acute hepatitis primarily classified as non-A, non-B, were tested for anti-HBc IgM titres above 10(-5), sera from 13 episodes were positive and in seven of these hepatitis B diagnosis could be confirmed by rising anti-HBs titres in convalescence. Sera from four of the 13 patients contained HBeAg, which was thus demonstrated in the absence of HBsAg. The results show that testing for anti-HBc IgM is important for a true non-A, non-B diagnosis.
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| 39. |
- Adelow, C, et al.
(author)
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Epilepsy as a risk factor for cancer
- 2006
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In: Journal of neurology, neurosurgery, and psychiatry. - : BMJ. - 1468-330X .- 0022-3050. ; 77:6, s. 784-786
-
Journal article (peer-reviewed)
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| 40. |
- Ahmed, J., et al.
(author)
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Automated diagnostic of virtualized service performance degradation
- 2018
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In: Proceedings 2018 IEEE/IFIP Network Operations and Management Symposium, NOMS 2018. - New York : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 1-9
-
Conference paper (peer-reviewed)abstract
- Service assurance for cloud applications is a challenging task and is an active area of research for academia and industry. One promising approach is to utilize machine learning for service quality prediction and fault detection so that suitable mitigation actions can be executed. In our previous work, we have shown how to predict service-level metrics in real-time just from operational data gathered at the server side. This gives the service provider early indications on whether the platform can support the current load demand. This paper provides the logical next step where we extend our work by proposing an automated detection and diagnostic capability for the performance faults manifesting themselves in cloud and datacenter environments. This is a crucial task to maintain the smooth operation of running services and minimizing downtime. We demonstrate the effectiveness of our approach which exploits the interpretative capabilities of Self- Organizing Maps (SOMs) to automatically detect and localize different performance faults for cloud services.
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| 41. |
- Ali, Mina, et al.
(author)
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The multiple myeloma risk allele at 5q15 lowers ELL2 expression and increases ribosomal gene expression
- 2018
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In: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1, s. 1649-
-
Journal article (peer-reviewed)abstract
- Recently, we identified ELL2 as a susceptibility gene for multiple myeloma (MM). To understand its mechanism of action, we performed expression quantitative trait locus analysis in CD138+ plasma cells from 1630 MM patients from four populations. We show that the MM risk allele lowers ELL2 expression in these cells (Pcombined = 2.5 × 10−27; βcombined = −0.24 SD), but not in peripheral blood or other tissues. Consistent with this, several variants representing the MM risk allele map to regulatory genomic regions, and three yield reduced transcriptional activity in plasmocytoma cell lines. One of these (rs3777189-C) co-locates with the best-supported lead variants for ELL2 expression and MM risk, and reduces binding of MAFF/G/K family transcription factors. Moreover, further analysis reveals that the MM risk allele associates with upregulation of gene sets related to ribosome biogenesis, and knockout/knockdown and rescue experiments in plasmocytoma cell lines support a cause–effect relationship. Our results provide mechanistic insight into MM predisposition.
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| 42. |
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| 43. |
- Andersson, Claes, et al.
(author)
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Relationship of Protective Behavioral Strategies to Alcohol Consequences Among Swedish High School Seniors : Moderating Role of Conduct Disorder Symptoms
- 2012
-
In: Alcoholism. - : Wiley-Blackwell. - 0145-6008 .- 1530-0277. ; 36:s1, s. 67A-67A
-
Journal article (other academic/artistic)abstract
- This observational study sought to improve our understanding of factors that contribute to risky sexual behavior among women seeking treatment for alcohol and other substance use disorders. Women were recruited at the start of outpatient (n=236) or inpatient (n=166) treatment. At intake, a Timeline Follow-back interview was used to obtain retrospective reports of daily drinking, drug use, and sexual behavior for a 90-day pre-treatment baseline period. Additional interview and questionnaire measures also were obtained. Measures were re- administered at four 90-day follow-up interviews. Among women who reported sex with a primary partner during baseline (n=261), 15% reported consistent condom use for all events with this partner, whereas 80% reported no condom use with this partner. Among women who reported sex with a non-primary partner (n=159; doesn’t include commercial sex trading), 26% reported consistent condom use and 45% reported no condom use with such partners. Significant correlates of non-use of condoms included negative beliefs and attitudes and low self-efficacy regarding condom use and AIDS prevention, as well as psychological distress, sexual impulsiveness and sensation seeking, history of severe assault by a male partner, and (with primary partners) negative partner attitudes toward condom use. Some of these correlates also predicted unprotected sex with a primary partner during the first 90 days after treatment entry, after controlling for baseline. However, unsafe sex with a non-primary partner during follow-up was most notably associated with follow-up levels of substance use, i.e., more drinks per drinking day and greater frequency of alcohol, marijuana, and cocaine use. In sum, preliminary analyses of baseline and follow-up data indicate a high prevalence of unprotected sex in this population. Identification of factors related to baseline and follow-up levels of risky behavior may suggest targets for future intervention development.
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| 44. |
- Axelsson, Paul, et al.
(author)
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Orthosis as prognostic instrument in lumbar fusion. No predictive value in 50 cases followed prospectively
- 1995
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In: Journal of Spinal Disorders. - 0895-0385. ; 8:4, s. 8-284
-
Journal article (peer-reviewed)abstract
- To evaluate pain relief in a lumbar orthosis as a predictor for good clinical results after solid fusion, all patients scheduled for such a surgical procedure were preoperatively encouraged to use an orthosis, soft or rigid, for 3 weeks. Grade of back pain relief as a percent using the orthosis was assessed by the patients and was registered before surgery. After surgery, at 1-year follow-up, patients with nonunion demonstrated radiographically were excluded from the series. Thus, 50 patients with solid fusion could be identified and followed for at least 2 years prospectively. At follow-up these 50 patients graded the pain relief induced by the fusion. In the preoperative corset test, 31 patients experienced significant back pain relief, meaning a reduction of at least 50%. No applicable correlation was found, however, between outcome in this corset test and the eventual clinical result expressed as improvement/no improvement after solid fusion. The two types of orthoses did not differ in this aspect. We conclude that the orthosis, rigid or soft, is not a useful instrument when selecting patients for lumbar fusion.
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| 45. |
- Barillot, T., et al.
(author)
-
Angular asymmetry and attosecond time delay from the giant plasmon resonance in C60 photoionization
- 2015
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In: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 91
-
Journal article (peer-reviewed)abstract
- This combined experimental and theoretical study demonstrates that the surface plasmon resonance in C 60 alters the valence photoemission quantum phase, resulting in strong effects in the photoelectron angular distribution and emission time delay. Electron momentum imaging spectroscopy is used to measure the photoelectron angular distribution asymmetry parameter that agrees well with our calculations from the time-dependent local density approximation (TDLDA). Significant structure in the valence photoemission time delay is simultaneously calculated by TDLDA over the plasmon active energies. Results reveal a unified spatial and temporal asymmetry pattern driven by the plasmon resonance and offer a sensitive probe of electron correlation. A semiclassical approach facilitates further insights into this link that can be generalized and applied to other molecular systems and nanometer-sized metallic materials exhibiting plasmon resonances.
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| 46. |
- Barillot, T., et al.
(author)
-
Attosecond time delays in C-60 valence photoemissions at the giant plasmon
- 2015
-
In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 635, s. 112074-112074
-
Conference paper (peer-reviewed)abstract
- We perform time-dependent local density functional calculations of the time delay in C-60 HOMO and HOMO-1 photoionization at giant plasmon energies. A semiclassical model is used to develop further insights.
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| 47. |
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| 48. |
- Carlsson, Ella, et al.
(author)
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An evaluation of models for Martian gully formation using remote sensing and in situ measurments of Svalbard analogs.
- 2008
-
In: Lunar and Planetary Science Conference 39. ; XXXIX:1852
-
Conference paper (other academic/artistic)abstract
- The newly discovered gully systems on Mars have been found on rather young geologi-cal surfaces such as dunes and polygons. This in combination with the general absence of superimposed impact craters suggests that the gullies are relatively young geological features. Their morphology indicates that they have been eroded by a liquid fluid, most probably water. A recent discovery suggests that gully formation is an ongoing process, which appears to occur even today. This is a paradox since water in current Martian atmospheric conditions cannot be found in a stable form on the surface due to the low pressure and temperature during normal conditions. Several formation mechanisms have been proposed for the Martian gullies such as liquid carbon dioxide reservoirs, shallow liquid water aquifer, melting ground ice, dry landslide, snow melt and deep liquid water aquifer. However, none of these models can alone explain all the gullies discovered on Mars. So far Martian gullies have only been studied from high orbit via satellites. Gullies found in Arctic climates on Earth could be an equitable analog for the Martian gullies and a com-parative analysis could help disclose the formation mechanisms of the Martian gullies as well as their eroding agent.
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| 49. |
- Cowie, A. L., et al.
(author)
-
Applying a science-based systems perspective to dispel misconceptions about climate effects of forest bioenergy
- 2021
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In: Global Change Biology Bioenergy. - : John Wiley and Sons Inc. - 1757-1693 .- 1757-1707. ; 13:8, s. 1210-1231
-
Journal article (peer-reviewed)abstract
- The scientific literature contains contrasting findings about the climate effects of forest bioenergy, partly due to the wide diversity of bioenergy systems and associated contexts, but also due to differences in assessment methods. The climate effects of bioenergy must be accurately assessed to inform policy-making, but the complexity of bioenergy systems and associated land, industry and energy systems raises challenges for assessment. We examine misconceptions about climate effects of forest bioenergy and discuss important considerations in assessing these effects and devising measures to incentivize sustainable bioenergy as a component of climate policy. The temporal and spatial system boundary and the reference (counterfactual) scenarios are key methodology choices that strongly influence results. Focussing on carbon balances of individual forest stands and comparing emissions at the point of combustion neglect system-level interactions that influence the climate effects of forest bioenergy. We highlight the need for a systems approach, in assessing options and developing policy for forest bioenergy that: (1) considers the whole life cycle of bioenergy systems, including effects of the associated forest management and harvesting on landscape carbon balances; (2) identifies how forest bioenergy can best be deployed to support energy system transformation required to achieve climate goals; and (3) incentivizes those forest bioenergy systems that augment the mitigation value of the forest sector as a whole. Emphasis on short-term emissions reduction targets can lead to decisions that make medium- to long-term climate goals more difficult to achieve. The most important climate change mitigation measure is the transformation of energy, industry and transport systems so that fossil carbon remains underground. Narrow perspectives obscure the significant role that bioenergy can play by displacing fossil fuels now, and supporting energy system transition. Greater transparency and consistency is needed in greenhouse gas reporting and accounting related to bioenergy.
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| 50. |
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