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- Feuerborn, Tatiana Richtman, 1993-
(author)
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Genomic insights into the population history of circumpolar Arctic dogs
- 2020
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Doctoral thesis (other academic/artistic)abstract
- The Siberian and North American Arctic have both borne witness to numerous migrations of humans and with them their dogs. This PhD thesis is based on whole genome data from 22 Siberian dogs and 72 North American Arctic dogs, in addition to 186 mitochondrial genomes Siberian and North American Arctic dogs. Mitochondrial genome data allowed for the identification of migration events that introduced distinct dog populations to North America, associated with different cultural complexes arriving to the region. A novel mitochondrial clade was also identified in dogs from eastern Siberia and Alaska. Genetic analysis was performed to confirm the macroscopic identification of fur used to make clothing in the Arctic in conjunction with stable isotope analyses to explore dietary differences of dog populations across the circumpolar region. The whole genome data generated for this PhD also detected and explored evidence for several gene flow events from West Eurasian dogs into the dogs of Siberia starting 10,900 BP. There was an additional gene flow event that introduced Near East related ancestry to the dogs of the Siberian Steppe before the Late Bronze Age. Dogs carrying this West Eurasian ancestry spread throughout Siberia, reaching northwestern Siberia by the Iron Age, by 2,000 BP. Further gene flow was detected later in Siberia from West Eurasia a thousand years later. North American Arctic dogs universally carry the Near East related ancestry that is seen in Siberian dogs starting in the Bronze Age, showing it had reached the Bering Strait before the ancestors of the Inuit departed Siberia for Alaska. Once in North America Inuit dogs experienced several other gene flow events from pre-contact subarctic dogs, modern European dogs, and wolves. The population structure seen in North American Arctic dogs reflects geography and the subsequent isolation as well as population turnover events associated with catastrophic epidemics in the dog populations. Finally, a simple method was developed to evaluate and remove human contamination from ancient DNA datasets originating from faunal taxa. All together this thesis has compiled genomic information from 94 Arctic dogs to shed light upon the genetic history of these dogs from the early Holocene through to the present day. This dataset has been able to provide insight not only into past dynamics of Arctic dogs but also a much needed resource for understanding and preserving the indigenous dog populations still present in the Arctic that face continued challenges of globalisation and climate change.
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| 2. |
- de Jong, R. S., et al.
(author)
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4MOST : Project overview and information for the First Call for Proposals
- 2019
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In: The Messenger. - : European Southern Observatory. - 0722-6691. ; 175, s. 3-11
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Journal article (other academic/artistic)abstract
- We introduce the 4-metre Multi-Object Spectroscopic Telescope (4MOST), a new high-multiplex, wide-field spectroscopic survey facility under development for the four-metre-class Visible and Infrared Survey Telescope for Astronomy (VISTA) at Paranal. Its key specifications are: a large field of view (FoV) of 4.2 square degrees and a high multiplex capability, with 1624 fibres feeding two low-resolution spectrographs (R = λ/Δλ ~ 6500), and 812 fibres transferring light to the high-resolution spectrograph (R ~ 20 000). After a description of the instrument and its expected performance, a short overview is given of its operational scheme and planned 4MOST Consortium science; these aspects are covered in more detail in other articles in this edition of The Messenger. Finally, the processes, schedules, and policies concerning the selection of ESO Community Surveys are presented, commencing with a singular opportunity to submit Letters of Intent for Public Surveys during the first five years of 4MOST operations.
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| 3. |
- Kuzniar, Marek
(author)
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On Pathophysiology and Treatment of Aortic Disease
- 2022
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Doctoral thesis (other academic/artistic)abstract
- Pathophysiological processes underlying abdominal aortic aneurysm (AAA) formation and aortic dissections (AD) are largely unknown. Molecular imaging of the inflammatory component may improve our understanding of AAA and AD pathophysiology. The aims of this thesis were to evaluate the feasibility of positron emission tomography/magnetic resonance imaging (PET/MRI) to study in vivo pathophysiological changes of these aortic pathologies, and to study the outcomes after complex contemporary endovascular treatment thereof.In Paper I, we evaluated the feasibility of 18-F-fluorodeoxyglucose (FDG) PET/MRI to identify markers for inflammation in asymptomatic medium-large AAA. We identified FDG uptake and gadolinium enhancement (GE) in the aneurysmal wall, however FDG uptake corresponded rarely with mural inflammatory changes on MRI. In Paper II, we investigated whether inflammatory activity by means of FDG-PET/MRI can be detected in small to medium sized AAA, confirming the presence of inflammatory markers in the majority of patients. In Paper III, FDG-PET/MRI was used to characterize the inflammation and its transformation from acute to chronic phase in acute Stanford type B dissections. Highly increased FDG-activity was present in the dissected descending aorta in the acute phase, which markedly decreased over the course of a few months. MRI inflammatory changes were present in 60% of patients.In Paper IV, we evaluated the outcome and aortic remodelling after thoracic endovascular aortic repair (TEVAR) for chronic dissections. High rate of false lumen thrombosis occurred for dissections localized to the thoracic aorta covered by the stent-graft, but was more uncommon for extensive dissections distally. Aortic remodelling and sac shrinkage occurred in the thoracic aorta, but not distally. Reintervention rates were substantial (one third of cases). Paper V evaluated outcome of complex endovascular repair of post-dissection aneurysms of the arch and thoraco-abdominal aorta. Results were comparable to other recent reports using this new approach, however occurrence of retrograde Stanford type A dissection following arch fenestrated repair warrants caution.In conclusion, FDG-PET/MRI is a promising technique for studying inflammation in AAAs and ADs in vivo. For chronic aortic dissections, endovascular treatment results in good short-term outcome, but in the long-term re-interventions were common and adequate follow-up is thus of importance
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