| 1. |
- Sodergren, Erica, et al.
(författare)
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The genome of the sea urchin Strongylocentrotus purpuratus.
- 2006
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 314:5801, s. 941-52
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Tidskriftsartikel (refereegranskat)abstract
- We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.
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| 2. |
- Alexanderson, Helena, et al.
(författare)
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Was southern Sweden ice free at 19–25 ka, or were the post LGM glacifluvial sediments incompletely bleached?
- 2007
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Ingår i: Quaternary Geochronology. - : Elsevier BV. - 1871-1014. ; 2:1-4, s. 229-236
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Glacifluvial deposits along an ice-marginal zone in Småland, southern Sweden, have been dated using post-IR blue OSL. To test for incomplete bleaching, we adopted two strategies: analysis of modern analogues and small-aliquot dose distributions. Samples of modern fluvial sediments show no significant incomplete bleaching; they yield equivalent doses of only 0.5-2 Gy (~0.25-4% of our glacifluvial sediment doses). Small-aliquot dose distributions do not provide any evidence for incomplete bleaching. The sediments are believed to have been deposited during deglaciation and appear to fall into two age groups: 19-25 ka (mainly sandur sediments) and 33-73 ka (mainly deltaic sediments). Compared to the expected ages (13-15 ka), even the younger glacifluvial OSL ages appear up to 10 000 years (~25 Gy) too old. The ages are nevertheless stratigraphically consistent and correspond between sites; we deduce that the 19-25 ka ages are true deposition ages. For glacifluvial sedimentation to take place on the South Swedish Upland at this time either a very early deglaciation is required, or alternatively ice-free conditions just prior to the LGM. The deltaic sediments (33-73 ka) were most likely not significantly bleached during deposition and thus they date events prior to the latest ice advance.
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| 3. |
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| 4. |
- Larsen, Nicolaj Krog, et al.
(författare)
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Late Quaternary ice sheet, lake and sea history of southwest Scandinavia - a synthesis
- 2009
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Ingår i: Boreas. - : Wiley. - 1502-3885 .- 0300-9483. ; 38:4, s. 732-761
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Forskningsöversikt (refereegranskat)abstract
- Based on a large number of new boreholes in northern Denmark, and on the existing data, a revised event-stratigraphy is presented for southwestern Scandinavia. Five significant Late Saalian to Late Weichselian glacial events, each separated by periods of interglacial or interstadial marine or glaciolacustrine conditions, are identified in northern Denmark. The first glacial event is attributed to the Late Saalian c. 160-140 kyr BP, when the Warthe Ice Sheet advanced from easterly and southeasterly directions through the Baltic depression into Germany and Denmark. This Baltic ice extended as far as northern Denmark, where it probably merged with the Norwegian Channel Ice Stream (NCIS) and contributed to a large discharge of icebergs into the Norwegian Sea. Following the break up, marine conditions were established that persisted from the Late Saalian until the end of the Early Weichselian. The next glaciation occurred c. 65-60 kyr BP, when the Sunds circle divide re ice advanced from the north into Denmark and the North Sea, where the Scandinavian and British Ice Sheets merged. During the subsequent deglaciation, large ice-dammed lakes formed before the ice disintegrated in the Norwegian Channel, and marine conditions were re-established. The following Ristinge advance from the Baltic, initiated c. 55 kyr BP, also reached northern Denmark, where it probably merged with the NCIS. The deglaciation, c. 50 kyr BP, was followed by a long period of marine arctic conditions. Around 30 kyr BP, the Scandinavian Ice Sheet expanded from the north into the Norwegian Channel, where it dammed the Kattegat ice lake. Shortly after, c. 29 kyr BP, the Kattegat advance began, and once again the Scandinavian and British Ice Sheets merged in the North Sea. The subsequent retreat to the Norwegian Channel led to the formation of Ribjerg ice lake, which persisted from 27 to 23 kyr BP. The expansion of the last ice sheet started c. 23 kyr BP, when the main advance occurred from north-northeasterly directions into Denmark. An ice-dammed lake was formed during deglaciation, while the NCIS was still active. During a re-advance and subsequent retreat c. 19 kyr BP, a number of tunnel-valley systems were formed in association with ice-marginal positions. The NCIS finally began to break up in the Norwegian Sea 18.8 kyr BP, and the Younger Yoldia Sea inundated northern Denmark around 18 kyr BP. The extensive amount of new and existing data applied to this synthesis has provided a better understanding of the timing and dynamics of the Scandinavian Ice Sheet (SIS) during the last c. 160 kyr. Furthermore, our model contributes to the understanding of the timing of the occasional release of large quantities of meltwater from the southwestern part of the SIS that are likely to enter the North Atlantic and possibly affect the thermohaline circulation.
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| 5. |
- Nafalski, Andrew, et al.
(författare)
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Collaborative Learning in Engineering Remote Laboratories
- 2009
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Konferensbidrag (refereegranskat)abstract
- This paper reports on practices in national and international on-line cooperation in engineering remote laboratories (RLs) to support student collaborative activities. A structured aid enables them, in addition to acquiring technical skills and knowledge, to develop intercultural communication skills and the global perspectives sought by their profession. The concept of a Community of Practice (CoP) is a central pedagogical consideration for collaborative learning and is discussed in the paper. After reviewing practices of others, an emphasis will be placed on a team-based laboratory environment of NetLab – a remote laboratory framework created at the University of South Australia (UniSA).
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