| 1. |
- Feng, Shaohong, et al.
(författare)
-
Dense sampling of bird diversity increases power of comparative genomics
- 2020
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 587:7833
-
Tidskriftsartikel (refereegranskat)abstract
- Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity(1-4). Sparse taxon sampling has previously been proposed to confound phylogenetic inference(5), and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic and molecular diversity, by analysing 363 genomes from 92.4% of bird families-including 267 newly sequenced genomes produced for phase II of the Bird 10,000 Genomes (B10K) Project. We use this comparative genome dataset in combination with a pipeline that leverages a reference-free whole-genome alignment to identify orthologous regions in greater numbers than has previously been possible and to recognize genomic novelties in particular bird lineages. The densely sampled alignment provides a single-base-pair map of selection, has more than doubled the fraction of bases that are confidently predicted to be under conservation and reveals extensive patterns of weak selection in predominantly non-coding DNA. Our results demonstrate that increasing the diversity of genomes used in comparative studies can reveal more shared and lineage-specific variation, and improve the investigation of genomic characteristics. We anticipate that this genomic resource will offer new perspectives on evolutionary processes in cross-species comparative analyses and assist in efforts to conserve species. A dataset of the genomes of 363 species from the Bird 10,000 Genomes Project shows increased power to detect shared and lineage-specific variation, demonstrating the importance of phylogenetically diverse taxon sampling in whole-genome sequencing.
|
|
| 2. |
- Bentley, Michael J., et al.
(författare)
-
A community-based geological reconstruction of Antarctic Ice Sheet deglaciation since the Last Glacial Maximum
- 2014
-
Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 100, s. 1-9
-
Tidskriftsartikel (refereegranskat)abstract
- A robust understanding of Antarctic Ice Sheet deglacial history since the Last Glacial Maximum is important in order to constrain ice sheet and glacial-isostatic adjustment models, and to explore the forcing mechanisms responsible for ice sheet retreat. Such understanding can be derived from a broad range of geological and glaciological datasets and recent decades have seen an upsurge in such data gathering around the continent and Sub-Antarctic islands. Here, we report a new synthesis of those datasets, based on an accompanying series of reviews of the geological data, organised by sector. We present a series of timeslice maps for 20 ka, 15 ka, 10 ka and 5 ka, including grounding line position and ice sheet thickness changes, along with a clear assessment of levels of confidence. The reconstruction shows that the Antarctic Ice sheet did not everywhere reach the continental shelf edge at its maximum, that initial retreat was asynchronous, and that the spatial pattern of deglaciation was highly variable, particularly on the inner shelf. The deglacial reconstruction is consistent with a moderate overall excess ice volume and with a relatively small Antarctic contribution to meltwater pulse la. We discuss key areas of uncertainty both around the continent and by time interval, and we highlight potential priorities for future work. The synthesis is intended to be a resource for the modelling and glacial geological community.
|
|
| 3. |
- Wong, Ian W. Y., et al.
(författare)
-
Gastroesophageal reflux disease and chronic sinusitis: In search of an esophageal-nasal reflex
- 2010
-
Ingår i: American Journal of Rhinology & Allergy. - : SAGE Publications. - 1945-8924 .- 1945-8932. ; 24:4, s. 255-259
-
Tidskriftsartikel (refereegranskat)abstract
- Background: This study was performed to explore whether or not a neural reflex linking the esophagus and the nasal airway exists, as a pathogenic mechanism accounting for the association between gastroesophageal reflux (GER) disease and chronic rhinosinusitis (CRS). A prospective trial of healthy human volunteers was performed. Methods: Ten healthy volunteers without GER or sinonasal disease were investigated using an acid infusion challenge test. Normal saline and hydrochloric acid were infused into the lower esophagus through an esophageal manometry catheter. Nasal responses in symptom score, nasal inspiratory peak flow, and mucus production were analyzed after the esophageal challenge. Results: A tendency for an increase in nasal mucus production was observed after esophageal stimulation with both normal saline and HCl. This returned to baseline level 45 minutes after the acid infusion. A similar trend was also observed with the measurements of nasal symptom scores and, to a lesser extent, nasal inspiratory peak flow. Conclusion: These results support the possibility that a neural reflex exists between the esophagus and the paranasal sinuses via the vagus nerve. If indeed present, the reflex-mediated rhinitis derived from this neuropathic inflammation may contribute to the development of CRS in patients with GER. Further study is required to define the relationship between GER and CRS. (Am J Rhinol Allergy 24, 255-259, 2010; doi: 10.2500/ajra.2010.24.3490)
|
|
