| 1. |
- Fages, A., et al.
(författare)
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Tracking Five Millennia of Horse Management with Extensive Ancient Genome Time Series
- 2019
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Ingår i: Cell. - : Elsevier BV. - 0092-8674. ; 177:6
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Tidskriftsartikel (refereegranskat)abstract
- Horse domestication revolutionized warfare and accelerated travel, trade, and the geographic expansion of languages. Here, we present the largest DNA time series for a non-human organism to date, including genome-scale data from 149 ancient animals and 129 ancient genomes (>= 1-fold coverage), 87 of which are new. This extensive dataset allows us to assess the modem legacy of past equestrian civilisations. We find that two extinct horse lineages existed during early domestication, one at the far western (Iberia) and the other at the far eastern range (Siberia) of Eurasia. None of these contributed significantly to modern diversity. We show that the influence of Persian-related horse lineages increased following the Islamic conquests in Europe and Asia. Multiple alleles associated with elite-racing, including at the MSTN "speed gene," only rose in popularity within the last millennium. Finally, the development of modem breeding impacted genetic diversity more dramatically than the previous millennia of human management.
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| 2. |
- Gisselbrecht, M., et al.
(författare)
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Attosecond insight into electron correlation
- 2019
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Ingår i: Proceedings 2015 European Conference on Lasers and Electro-Optics - European Quantum Electronics Conference, CLEO/Europe-EQEC 2015. - 9781467374750
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Konferensbidrag (refereegranskat)abstract
- Photoionization with a single photon is one of the fundamental processes in nature, in which one electron is ripped away from its atom. Traditionally studied in the energy domain, this process was believed to be instantaneous, but recent advances in the production of attosecond pulses (1 as 10−18 s) in the eXtreme UltraViolet (XUV) have renewed interest in understanding the temporal aspects of electron emission in atoms, molecules and the solid state [1–8]. We present here our progress in understanding the influence of electronic correlations on the attosecond photoionization dynamics.
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| 3. |
- Greer, M., et al.
(författare)
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Lung transplantation after allogeneic stem cell transplantation: a pan-European experience
- 2018
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 51:2
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Tidskriftsartikel (refereegranskat)abstract
- Late-onset noninfectious pulmonary complications (LONIPCs) affect 6% of allogeneic stem cell transplantation (SCT) recipients within 5 years, conferring subsequent 5-year survival of 50%. Lung transplantation is rarely performed in this setting due to concomitant extrapulmonary morbidity, excessive immunosuppression and concerns about recurring malignancy being considered contraindications. This study assesses survival in highly selected patients undergoing lung transplantation for LONIPCs after SCT. SCT patients undergoing lung transplantation at 20 European centres between 1996 and 2014 were included. Clinical data pre- and post-lung transplantation were reviewed. Propensity score-matched controls were generated from the Eurotransplant and Scandiatransplant registries. Kaplan-Meier survival analysis and Cox proportional hazard regression models evaluating predictors of graft loss were performed. Graft survival at 1, 3 and 5 years of 84%, 72% and 67%, respectively, among the 105 SCT patients proved comparable to controls (p=0.75). Sepsis accounted for 15 out of 37 deaths (41%), with prior mechanical ventilation (HR 6.9, 95% CI 1.0-46.7; p<0.001) the leading risk factor. No SCT-specific risk factors were identified. Recurring malignancy occurred in four patients (4%). Lung transplantation <2 years post-SCT increased all-cause 1-year mortality (HR 7.5, 95% CI 2.3-23.8; p=0.001). Lung transplantation outcomes following SCT were comparable to other end-stage diseases. Lung transplantation should be considered feasible in selected candidates. No SCT-specific factors influencing outcome were identified within this carefully selected patient cohort.
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| 4. |
- Harth, A., et al.
(författare)
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Few-cycle high-repetition rate OPCPA for multiphoton PEEM towards atto-PEEM
- 2016
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Ingår i: International Conference on Ultrafast Phenomena, UP 2016. - 9781943580187 ; Part F20-UP 2016
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Konferensbidrag (refereegranskat)abstract
- We present a few-cycle high-repetition rate optical parametric amplifier for multiphoton PEEM experiments on semiconductor nanowires. This parametric amplifier is also used for the generation of high-order harmonics at 200kHz for future atto-PEEM experiments.
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| 5. |
- Lorek, Eleonora, et al.
(författare)
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High-Order Harmonic Generation and Plasmonics
- 2015
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Ingår i: Nano-Structures for Optics and Photonics : Optical Strategies for Enhancing Sensing, Imaging, Communication and Energy Conversion - Optical Strategies for Enhancing Sensing, Imaging, Communication and Energy Conversion. - Dordrecht : Springer Netherlands. - 9789401791328 - 9789401791335 ; , s. 531-531
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Bokkapitel (refereegranskat)abstract
- Attosecond pulses allow for imaging of very fast processes, like electron dynamics. Stockman et al. suggested to use these pulses in connection with a Photoemission electron microscope (PEEM) to study the ultrafast dynamics of plasmons (Stockman et al. Nat Photonics 1:539–544, 2007). For efficient plasmon studies, the repetition rate of the attosecond pulses used needs to be higher than a few kHz (Mikkelsen et al. Rev Sci Instrum 80:123703, 2009). Attosecond pulses are produced in a process called high-order harmonic generation (HHG) (Paul et al. Science 292(5522):1689–1692, 2001; Ferray et al. J Phys B At Mol Opt Phys 21:L31–L35, 1988). In HHG, a strong laser field allows an electron to tunnel out, get accelerated and recombine with a high kinetic energy resulting in extreme ultraviolet attosecond pulses. The large intensity needed to drive the process normally limits the repetition rate of the laser to a few kHz. Using a tight focusing scheme (Heyl et al. Phys Rev Lett 107:033903, 2011; Vernaleken et al. Opt Lett 36:3428–3430, 2011), we, however, generate harmonics at a repetition rate of 200 kHz, both with a commercial turn-key laser and with an advanced laser system. Suitable nanostructures for a strong field enhancement are produced in-house and the field enhancement is studied with PEEM in a non-time resolved manner. With high-order harmonics produced at a high repetition rate, we hope to be able to follow also the ultrafast dynamics of plasmons in these structures (Mårsell et al. Ann der Phys 525:162–170, 2013).
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| 6. |
- Arnold, C. L., et al.
(författare)
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Energy scaling of gas nonlinear optics
- 2017
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Ingår i: 30th Annual Conference of the IEEE Photonics Society, IPC 2017. - 9781509065783 ; 2017-January, s. 503-504
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Konferensbidrag (refereegranskat)abstract
- Nonlinear light-matter interactions, such as filamentation or high-order harmonic generation, are at the heart of nonlinear optics. Scaling of such effects is crucial to benefit optimally from novel laser developments. We introduce and discuss a general scaling model for nonlinear light-matter interactions in gases.
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| 7. |
- Heyl, C. M., et al.
(författare)
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High-average power high-harmonic and attosecond sources : Status and prospects
- 2016
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Ingår i: Compact EUV and X-ray Light Sources, EUVXRAY 2016. - 9781943580095 ; Part F14-EUVXRAY 2016
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Konferensbidrag (refereegranskat)abstract
- Experiments employing extreme ultraviolet sources based on high harmonic generation often suffer from photon flux limitations. We discuss current status and prospects for scaling such sources to higher repetition rate, pulse energy and average power.
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| 8. |
- Heyl, C. M., et al.
(författare)
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Noncollinear optical gating - A method for intra-cavity single attosecond pulse generation?
- 2019
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Ingår i: Proceedings 2015 European Conference on Lasers and Electro-Optics - European Quantum Electronics Conference, CLEO/Europe-EQEC 2015. - 9781467374750
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Konferensbidrag (refereegranskat)abstract
- The process of high-order harmonic generation requires laser intensities around 1014 W/cm2, most easily reached with laser pulses of high energy, thus implicitly limiting the repetition rate of attosecond sources. A route towards multi-MHz attosecond sources relies on HHG inside a passive enhancement cavity [1]. Although successfully demonstrated for attosecond pulse trains, the generation of single attosecond pulses (SAPs) inside a cavity remains an unsolved challenge, mainly limited by dispersion management and out-coupling problems. We recently proposed a new gating concept for SAP generation [2], noncollinear optical gating (NOG) which has the potential to facilitate SAP gating and efficient out-coupling at once. Similar to the recently introduced attosecond lighthouse [3] NOG employs attosecond angular streaking [4] and combines this concept with noncollinear HHG, proposed earlier [5] as out-coupling method for intra cavity HHG.
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| 9. |
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| 10. |
- Heyl, C. M., et al.
(författare)
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Scale-invariant nonlinear optical effects in gases
- 2016
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Ingår i: 2016 Conference on Lasers and Electro-Optics, CLEO 2016. - 9781943580118
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Konferensbidrag (refereegranskat)abstract
- A general scaling formalism for nonlinear light-matter interactions in gases is presented and experimentally verified. The formalism enables to conveniently extrapolate nonlinear phenomena, such as filamentation or high-order harmonic generation, to new laser parameters.
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| 11. |
- Heyl, C. M., et al.
(författare)
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Scale-invariant nonlinear optics in gases
- 2016
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Ingår i: Optica. - 2334-2536. ; 3:1, s. 75-81
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Tidskriftsartikel (refereegranskat)abstract
- Nonlinear optical methods have become ubiquitous in many scientific areas, from fundamental studies of timeresolved electron dynamics to microscopy and spectroscopy applications. They are, however, often limited to a certain range of parameters such as pulse energy and average power. Restrictions arise from, for example, the required field intensity as well as from parasitic nonlinear effects and saturation mechanisms. Here, we identify a fundamental principle of nonlinear light-matter interaction in gases and show that paraxial nonlinear wave equations are scaleinvariant if spatial dimensions, gas density, and laser pulse energy are scaled appropriately. As an example, we apply this principle to high-order harmonic generation and provide a general method for increasing peak and average power of attosecond sources. In addition, we experimentally demonstrate the implications for the compression of short laser pulses. Our scaling principle extends well beyond those examples and includes many nonlinear processes with applications in different areas of science.
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| 12. |
- Heyl, C. M., et al.
(författare)
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Scaling Nonlinear Optics in Gases
- 2016
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Ingår i: High Intensity Lasers and High Field Phenomena, HILAS 2016. - 9781943580095 ; Part F15-HILAS 2016
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Konferensbidrag (refereegranskat)abstract
- Extrapolating nonlinear phenomena, such as filamentation, to new parameters as e.g. to higher pulse energy is often challenging. We here present a general scaling model for nonlinear light-matter interactions in gases and proof it experimentally.
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| 13. |
- Jimenez-Galan, A., et al.
(författare)
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Phase Measurement of a Fano Resonance Using Tunable Attosecond Pulses
- 2015
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 635, s. 092137-092137
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Konferensbidrag (refereegranskat)abstract
- We study photoionization of argon atoms close to the 3s(2)3p(6) -> 3s(1)3p(6)4p Fano resonance using an attosecond pulse train and a weak infrared probe field. An interferometric technique combined with tunable attosecond pulses allows us to determine the phase of the photoionization amplitude as a function of photon energy. We interpret the experimental results using an analytical two-photon model based on the Fano formalism and obtain quantitative agreement.
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| 14. |
- Kovács, K, et al.
(författare)
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Multi-parameter optimization of a loose focusing high flux high-harmonic beamline
- 2019
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 52:5, s. 055402-055402
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Tidskriftsartikel (refereegranskat)abstract
- We perform a multi-dimensional parameter scan in the generation of high-order harmonics, with the main purpose to find the macroscopic conditions that optimize the harmonic yield in a specific spectral domain, around 40 eV for this particular case. The scanned parameters are the laser pulse energy, gas pressure, interaction cell position relative to focus and the cell length, while the fixed parameters are chosen to model a loose focusing configuration which is used in many existing laboratories. We performed the simulations with a 3D non-adiabatic model complemented by a detailed analysis of the phase matching mechanisms involved in an efficient harmonic generation. Based on the results we identify a range of parameter combinations that lead to a high yield in the specified spectral domain. The method and results presented here can be the framework for the design and construction of high flux high-order harmonic generation beamlines.
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| 15. |
- Major, B., et al.
(författare)
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Macroscopic Optimization of High Harmonic Generation for High Power Laser Pulses
- 2016
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Ingår i: High Intensity Lasers and High Field Phenomena, HILAS 2016. - 9781943580095 ; Part F15-HILAS 2016
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Konferensbidrag (refereegranskat)abstract
- We study upscaling of gas high harmonic generation, to make efficient use of the ever increasing laser pulse powers. Loose focusing geometries optimizing phasematching are investigated and compared in HHG efficiency to shorter focusing arrangements.
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| 16. |
- Zhong, S., et al.
(författare)
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Probing photoionization dynamics by high-spectral-resolution attosecond spectroscopy
- 2018
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Ingår i: Optics InfoBase Conference Papers. - 9781557528209 ; Part F115-LS 2018
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Konferensbidrag (refereegranskat)abstract
- Photoionization time delays are measured with two-color (XUV+IR) interferometric techniques. The combination of attosecond temporal resolution and high spectral resolution from narrowband harmonics allows the study of ultrafast dynamics in both time and frequency domain.
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