| 1. |
- Damgaard, P. D., et al.
(författare)
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137 ancient human genomes from across the Eurasian steppes
- 2018
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 557:7705, s. 369-374
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Tidskriftsartikel (refereegranskat)abstract
- For thousands of years the Eurasian steppes have been a centre of human migrations and cultural change. Here we sequence the genomes of 137 ancient humans (about 1x average coverage), covering a period of 4,000 years, to understand the population history of the Eurasian steppes after the Bronze Age migrations. We find that the genetics of the Scythian groups that dominated the Eurasian steppes throughout the Iron Age were highly structured, with diverse origins comprising Late Bronze Age herders, European farmers and southern Siberian hunter-gatherers. Later, Scythians admixed with the eastern steppe nomads who formed the Xiongnu confederations, and moved westward in about the second or third century bc, forming the Hun traditions in the fourthfifth century ad, and carrying with them plague that was basal to the Justinian plague. These nomads were further admixed with East Asian groups during several short-term khanates in the Medieval period. These historical events transformed the Eurasian steppes from being inhabited by Indo-European speakers of largely West Eurasian ancestry to the mostly Turkic-speaking groups of the present day, who are primarily of East Asian ancestry.
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| 2. |
- Damgaard, P. D., et al.
(författare)
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The first horse herders and the impact of early Bronze Age steppe expansions into Asia
- 2018
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 360:6396
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Tidskriftsartikel (refereegranskat)abstract
- The Yamnaya expansions from the western steppe into Europe and Asia during the Early Bronze Age (similar to 3000 BCE) are believed to have brought with them Indo-European languages and possibly horse husbandry. We analyzed 74 ancient whole-genome sequences from across Inner Asia and Anatolia and show that the Botai people associated with the earliest horse husbandry derived from a hunter-gatherer population deeply diverged from the Yamnaya. Our results also suggest distinct migrations bringing West Eurasian ancestry into South Asia before and after, but not at the time of, Yamnaya culture. We find no evidence of steppe ancestry in Bronze Age Anatolia from when Indo-European languages are attested there. Thus, in contrast to Europe, Early Bronze Age Yamnaya-related migrations had limited direct genetic impact in Asia.
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| 3. |
- Sikora, M., et al.
(författare)
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The population history of northeastern Siberia since the Pleistocene
- 2019
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 570:7760
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Tidskriftsartikel (refereegranskat)abstract
- Northeastern Siberia has been inhabited by humans for more than 40,000 years but its deep population history remains poorly understood. Here we investigate the late Pleistocene population history of northeastern Siberia through analyses of 34 newly recovered ancient genomes that date to between 31,000 and 600 years ago. We document complex population dynamics during this period, including at least three major migration events: an initial peopling by a previously unknown Palaeolithic population of 'Ancient North Siberians' who are distantly related to early West Eurasian hunter-gatherers; the arrival of East Asian-related peoples, which gave rise to 'Ancient Palaeo-Siberians' who are closely related to contemporary communities from far-northeastern Siberia (such as the Koryaks), as well as Native Americans; and a Holocene migration of other East Asian-related peoples, who we name 'Neo-Siberians', and from whom many contemporary Siberians are descended. Each of these population expansions largely replaced the earlier inhabitants, and ultimately generated the mosaic genetic make-up of contemporary peoples who inhabit a vast area across northern Eurasia and the Americas.
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| 4. |
- Allentoft, M. E., et al.
(författare)
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Population genomics of Bronze Age Eurasia
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 522:7555
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Tidskriftsartikel (refereegranskat)abstract
- The Bronze Age of Eurasia (around 3000-1000 BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highly dynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic structure in both Europe and Asia. Our findings are consistent with the hypothesized spread of Indo-European languages during the Early Bronze Age. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency in the Bronze Age, but not lactose tolerance, indicating a more recent onset of positive selection on lactose tolerance than previously thought.
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| 5. |
- Gromov, K., et al.
(författare)
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Varying but reduced use of postoperative mobilization restrictions after primary total hip arthroplasty in Nordic countries: a questionnaire-based study
- 2019
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 90:2, s. 143-147
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose Mobilization has traditionally been restricted following total hip arthroplasty (THA) in an attempt to reduce the risk of dislocation and muscle detachment. However, recent studies have questioned the effect and rationale underlying such restrictions. We investigated the use of postoperative restrictions and possible differences in mobilization protocols following primary THA in Denmark (DK), Finland (FIN), Norway (NO), and Sweden (SWE).Patients and methods All hospitals performing primary THA in the participating countries were identified from the latest national THA registry report. A questionnaire containing questions regarding standard surgical procedure, use of restrictions, and postoperative mobilization protocol was distributed to all hospitals through national representatives for each arthroplasty registry.Results 83% to 94% (n = 167) of the 199 hospitals performing THA in DK, FIN, NO, and SWE returned correctly filled out questionnaires. A posterolateral approach was used by 77% of the hospitals. 92% of the hospitals had a standardized mobilization protocol. 50%, 41%, 19%, and 38% of the hospitals in DK, FIN, NO, and SWE, respectively, did not have any postoperative restrictions. If utilized, restrictions were applied for a median of 6 weeks. Two-thirds of all hospitals have changed their mobilization protocol within the last 5 yearsall but 2 to a less restrictive protocol.Interpretation Use of postoperative restrictions following primary THA differs between the Nordic countries, with 19% to 50% allowing mobilization without any restrictions. There has been a strong tendency towards less restrictive mobilization over the last 5 years.
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| 6. |
- Holland, D. M. P., et al.
(författare)
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An experimental and theoretical study of the valence shell photoelectron spectra of 2-chloropyridine and 3-chloropyridine
- 2017
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 147:16
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Tidskriftsartikel (refereegranskat)abstract
- The valence shell photoelectron spectra of 2-chloropyridine and 3-chloropyridine have been studied both experimentally and theoretically. Synchrotron radiation has been employed to record angle resolved photoelectron spectra in the photon energy range 20-100 eV, and these have enabled anisotropy parameters and branching ratios to be derived. The experimental results have been compared with theoretical predictions obtained using the continuum multiple scattering X alpha approach. This comparison shows that the anisotropy parameter associated with the nominally chlorine lone-pair orbital lying in the molecular plane is strongly affected by the atomic Cooper minimum. In contrast, the photoionization dynamics of the second lone-pair orbital, orientated perpendicular to the molecular plane, seem relatively unaffected by this atomic phenomenon. The outer valence ionization has been studied theoretically using the third-order algebraic-diagrammatic construction (ADC(3)) approximation scheme for the one-particle Green's function, the outer valence Green's function method, and the equation-of-motion (EOM) coupled cluster (CC) theory at the level of the EOM-IP-CCSD and EOM-EE-CC3 models. The convergence of the results to the complete basis set limit has been investigated. The ADC(3) method has been employed to compute the complete valence shell ionization spectra of 2-chloropyridine and 3-chloropyridine. The relaxation mechanism for ionization of the nitrogen sigma-type lone-pair orbital (sigma(N) (LP)) has been found to be different to that for the corresponding chlorine lone-pair (sigma(Cl) (LP)). For the sigma(N) (LP) orbital, pi-pi* excitations play the main role in the screening of the lone-pair hole. In contrast, excitations localized at the chlorine site involving the chlorine pi(Cl) (LP) lone-pair and the Cl 4p Rydberg orbital are the most important for the sigma(Cl) (LP) orbital. The calculated photoelectron spectra have allowed assignments to be proposed for most of the structure observed in the experimental spectra. The theoretical work also highlights the formation of satellite states, due to the breakdown of the single particle model of ionization, in the inner valence region.
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| 7. |
- Trofimov, A. B., et al.
(författare)
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Ionization of pyridine : Interplay of orbital relaxation and electron correlation
- 2017
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Ingår i: Journal of Chemical Physics. - : AMER INST PHYSICS. - 0021-9606 .- 1089-7690. ; 146:24
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Tidskriftsartikel (refereegranskat)abstract
- The valence shell ionization spectrum of pyridine was studied using the third-order algebraic-diagrammatic construction approximation scheme for the one-particle Green's function and the outer-valence Green's function method. The results were used to interpret angle resolved photoelectron spectra recorded with synchrotron radiation in the photon energy range of 17-120 eV. The lowest four states of the pyridine radical cation, namely, (2)A(2)(1a(2)(-1)), (2)A(1)(7a(1)(-1)), B-2(1)(2b(1)(-1)), and B-2(2)(5b(2)(-1)), were studied in detail using various high-level electronic structure calculation methods. The vertical ionization energies were established using the equation-of-motion coupled-cluster approach with single, double, and triple excitations (EOM-IP-CCSDT) and the complete basis set extrapolation technique. Further interpretation of the electronic structure results was accomplished using Dyson orbitals, electron density difference plots, and a second-order perturbation theory treatment for the relaxation energy. Strong orbital relaxation and electron correlation effects were shown to accompany ionization of the 7a1 orbital, which formally represents the nonbonding sigma-type nitrogen lone-pair (n sigma) orbital. The theoretical work establishes the important roles of the pi-system (pi-pi* excitations) in the screening of the n sigma-hole and of the relaxation of the molecular orbitals in the formation of the 7a(1)(n sigma)(-1) state. Equilibrium geometric parameters were computed using the MP2 (second-order Moller-Plesset perturbation theory) and CCSD methods, and the harmonic vibrational frequencies were obtained at the MP2 level of theory for the lowest three cation states. The results were used to estimate the adiabatic 0-0 ionization energies, which were then compared to the available experimental and theoretical data. Photoelectron anisotropy parameters and photoionization partial cross sections, derived from the experimental spectra, were compared to predictions obtained with the continuum multiple scattering approach.
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| 8. |
- Cavaglià, A., et al.
(författare)
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On the exact interpolating function in ABJ theory
- 2016
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; 2016:12
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Tidskriftsartikel (refereegranskat)abstract
- Based on the recent indications of integrability in the planar ABJ model, we conjecture an exact expression for the interpolating function h(λ1, λ2) in this theory. Our conjecture is based on the observation that the integrability structure of the ABJM theory given by its Quantum Spectral Curve is very rigid and does not allow for a simple consistent modification. Under this assumption, we revised the previous comparison of localization results and exact all loop integrability calculations done for the ABJM theory by one of the authors and Grigory Sizov, fixing h(λ1, λ2). We checked our conjecture against various weak coupling expansions, at strong coupling and also demonstrated its invariance under the Seiberg-like duality. This match also gives further support to the integrability of the model. If our conjecture is correct, it extends all the available integrability results in the ABJM model to the ABJ model.
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| 9. |
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