| 1. |
|
|
| 2. |
- Blomdin, Robin, 1986-, et al.
(författare)
-
Glacial geomorphology of the Altai and Western Sayan Mountains, Central Asia
- 2016
-
Ingår i: Journal of Maps. - : Informa UK Limited. - 1744-5647. ; 12:1, s. 123-136
-
Tidskriftsartikel (refereegranskat)abstract
- In this article, we present a map of the glacial geomorphology of the Altai andWestern Sayan Mountains, covering an area of almost 600,000 km2. Although numerous studies provide evidence for restricted Pleistocene glaciations in this area, others have hypothesized the past existence of an extensive ice sheet. To provide a framework for accurate glacial reconstructions of the Altai and Western Sayan Mountains, we present a map at a scale of 1:1,000,000 based on a mapping from 30 m resolution ASTER DEM and 15 m/30 mresolution Landsat ETM+ satellite imagery. Four landform classes have been mapped: marginal moraines, glacial lineations, hummocky terrain, and glacial valleys. Our mapping reveals an abundance of glacial erosional and depositional landforms. The distribution of these glacial landforms indicates that the Altai and Western Sayan Mountains have experienced predominantly alpine-style glaciations, with some small ice caps centred on the higher mountain peaks. Large marginal moraine complexes mark glacial advances in intermontane basins. By tracing the outer limits of present-day glaciers, glacial valleys, and moraines, we estimate that the past glacier coverage have totalled to 65,000 km2 (10.9% of the mapped area), whereas present-day glacier coverage totals only 1300 km2 (0.2% of the mapped area). This demonstrates the usefulness of remote sensing techniques for mapping the glacial geomorphology in remote mountain areas and for quantifying the past glacier dimensions. The glacial geomorphological map presented here will be used for further detailed reconstructions of the paleoglaciology and paleoclimate of the region.
|
|
| 3. |
- Blomdin, Robin, et al.
(författare)
-
Timing and dynamics of glaciation in the Ikh Turgen Mountains, Altai region, High Asia
- 2018
-
Ingår i: Quaternary Geochronology. - : Elsevier BV. - 1871-1014 .- 1878-0350. ; 47, s. 54-71
-
Tidskriftsartikel (refereegranskat)abstract
- Spanning the northern sector of High Asia, the Altai region contains a rich landform record of glaciation. We report the extent, chronologies, and dynamics of two paleoglaciers on opposite flanks of the Ikh Turgen mountains (In Russian: Chikhacheva Range), straddling the border between Russia and Mongolia, using a combination of remote sensing-based glacial geomorphological mapping, 10Be surface exposure dating, and geomorphometric analysis. On the eastern side (Mongolia), the Turgen-Asgat paleoglacier, with its potential for developing a large accumulation area (∼257 km2), expanded 40 km down valley, and mean ages from a latero-frontal moraine indicate deglaciation during marine oxygen isotope stage (MIS) 3 (45.1 ± 1.8 ka, n = 4) and MIS 2 (22.8 ± 3.3 ka, n = 5). These minimum age constraints are consistent with other 10Be glacial chronologies and paleoclimate records from the region, which indicates glacier culmination during cold and wet conditions coinciding with MIS 3 (piedmont-style glaciation; inferred for a few sites across the region) and glacier culmination during cold and dry conditions coinciding with MIS 2 (mainly valley-style glaciation; inferred from several sites across the region). On the western side (Russia), the Boguty paleoglacier had a smaller accumulation area (∼222 km2), and advanced 30 km down valley across a low gradient forefield. Surface exposure ages from two moraine complexes on this side of the mountains exhibit wide scatter (∼14–53 ka, n = 8), making paleoclimate inferences and comparison to other proxies difficult. Ice surface profile reconstructions imply that the two paleoglaciers likely shared an ice divide. © 2018 Elsevier B.V.
|
|
| 4. |
- Bohlin, Karl, 1989, et al.
(författare)
-
Karbonatisering av slagg- och flygaskebetong - och dess inverkan på transportegenskaper
- 2016
-
Ingår i: Bygg och teknik. ; :7, s. 48-52
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Betong som innehåller alternativa bindemedel har en rad önskvärda och positiva egenskaper, vilka bland andra är mindre koldioxidutsläpp, lägre värmeutveckling och högre motståndskraft mot syra-, sulfat- och kloridattack. Dock kan alternativa bindemedel också påverka andra egenskaper, t.ex. ökad karbonatiseringshastighet eller reducerad hållfasthet. För att analysera dessa egenskaper har en studie där inverkan av karbonatisering hos betong med slagg och flygaska genomförts. Hur karbonatiseringen i sin tur påverkar transportegenskaper hos betongen har också undersökts. Syftet var att genomföra en förstudie med accelererade karbonatiseringstester för att ge en större förståelse om effekterna av mineraliska tillsatsmaterial.
|
|
| 5. |
|
|
| 6. |
- Gribenski, Natacha, 1986-, et al.
(författare)
-
Complex patterns of glacier advances during the late glacial in the Chagan Uzun Valley, Russian Altai
- 2016
-
Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 149, s. 288-305
-
Tidskriftsartikel (refereegranskat)abstract
- The Southern part of the Russian Altai Mountains is recognized for its evidence for catastrophic glacial lake outbursts. However, little is known about the late Pleistocene paleoglacial history, despite the interest in such reconstructions for constraining paleoclimate. In this study, we present a detailed paleoglaciological reconstruction of the Chagan Uzun Valley, in the Russian Altai Mountains, combining for the first time detailed geomorphological mapping, sedimentological logging, and in situ cosmogenic 10Be and 26Al surface exposure dating of glacially-transported boulders. The Chagan Uzun Valley exhibits the most impressive glacial landforms of this sector of the Altai, with extensive lobate moraine belts deposited in the intramontane Chuja Basin, reflecting a series of pronounced former glacial advances. Observations of “hillside-scale” folding and extensive faulting of pre-existing soft sediments within the outer moraine belts, together with the geomorphology, strongly indicate that these moraine belts were formed during surge-like events. Identification of surge-related features is essential for paleoclimate inference because these features correspond to a glacier system that is not in equilibrium with the contemporary climate, but instead largely influenced by various internal and external factors. Therefore, no strict relationship can be established between climatic variables and the pronounced distal glacial extent observed in the Chagan Uzun Valley/Chuja basin. In contrast, the inner (up-valley) glacial landforms of the Chagan Uzun valley were likely deposited during retreat of temperate valley glaciers, close to equilibrium with climate, and so most probably triggered by a general warming. Cosmogenic ages associated with the outermost, innermost, and intermediate stages all indicate deposition times clustered around 19 ka. However, the actual deposition time of the outermost moraine may slightly predate the 10Be ages due to shielding caused by subsequent lake water coverage. This chronology indicates a Marine Isotope Stage (MIS) 2 last maximum extent of the Chagan Uzun Glacier, and an onset of the deglaciation around 19 ka. This is consistent with other regional paleoclimate proxy records and with the Northern Hemisphere glaciation chronology. Finally, this study also highlights the highly dynamic environment in this area, with complex interactions between glacial events and the formation and drainage of lakes.
|
|
| 7. |
- Gribenski, Natacha, et al.
(författare)
-
Re-evaluation of MIS 3 glaciation using cosmogenic radionuclide and single grain luminescence ages, Kanas Valley, Chinese Altai
- 2018
-
Ingår i: Journal of Quaternary Science. - : Wiley. - 0267-8179 .- 1099-1417. ; 33:1, s. 55-67
-
Tidskriftsartikel (refereegranskat)abstract
- Previous investigations observed a period of major glacial advances in Central Asia during marine oxygen isotope stage (MIS) 3 (57–29 ka), out of phase with global ice volume records. We have re-examined the Kanas moraine complex in the Altai Mountains of Central Asia, where an MIS 3 glaciation had been previously inferred. New and consistent cosmogenic exposure and single-grain luminescence ages indicate that the Kanas complex was formed during MIS 2 (29–12 ka), which brings its timing in line with the global ice volume record. We also identified a lateral moraine from a more extensive ice extent that dates to late MIS 5/MIS 4. To place our results in a wider contextual framework, we review the chronologies of another 26 proposed major MIS 3 glacial advances in Central Asia. For most of these sites, we find that the chronological data do not provide an unequivocal case for MIS 3 glaciation. Copyright © 2017 John Wiley & Sons, Ltd.
|
|
| 8. |
|
|
| 9. |
- Jansson, Helen, 1964, et al.
(författare)
-
Carbonation of concrete with mineral additions
- 2017
-
Ingår i: Nordic Concrete Research. - 0800-6377. - 9788282080569 ; , s. 101-104
-
Konferensbidrag (refereegranskat)abstract
- This study investigated how mineral addition, fly ash and slag (GGBS), influences carbonation, and how carbonation affects chloride migration and transport properties in mortar. Accelerated carbonation, Rapid Chloride Migration (RCM), capillary absorption tests (NT Build 368) and compressive strength tests (SS-EN 196-1) were conducted in a comparative study of mortar mixtures with different levels of mineral addition and w/b ratios. Carbonation rate increased and compressive strength was reduced with increased amount of mineral addition. The results also showed an interdependence between different deteriorating processes. Carbonation reduced the porosity, rate of reaching saturation and connectivity of the pore structure.
|
|
| 10. |
- Lloyd-Price, Jason, et al.
(författare)
-
Multi-omics of the gut microbial ecosystem in inflammatory bowel diseases
- 2019
-
Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 569:7758, s. 655-661
-
Tidskriftsartikel (refereegranskat)abstract
- Inflammatory bowel diseases, which include Crohn's disease and ulcerative colitis, affect several million individuals worldwide. Crohn's disease and ulcerative colitis are complex diseases that are heterogeneous at the clinical, immunological, molecular, genetic, and microbial levels. Individual contributing factors have been the focus of extensive research. As part of the Integrative Human Microbiome Project (HMP2 or iHMP), we followed 132 subjects for one year each to generate integrated longitudinal molecular profiles of host and microbial activity during disease (up to 24 time points each; in total 2,965 stool, biopsy, and blood specimens). Here we present the results, which provide a comprehensive view of functional dysbiosis in the gut microbiome during inflammatory bowel disease activity. We demonstrate a characteristic increase in facultative anaerobes at the expense of obligate anaerobes, as well as molecular disruptions in microbial transcription (for example, among clostridia), metabolite pools (acylcarnitines, bile acids, and short-chain fatty acids), and levels of antibodies in host serum. Periods of disease activity were also marked by increases in temporal variability, with characteristic taxonomic, functional, and biochemical shifts. Finally, integrative analysis identified microbial, biochemical, and host factors central to this dysregulation. The study's infrastructure resources, results, and data, which are available through the Inflammatory Bowel Disease Multi'omics Database (http://ibdmdb.org), provide the most comprehensive description to date of host and microbial activities in inflammatory bowel diseases.
|
|
