| 1. |
- Callaghan, Terry V., et al.
(författare)
-
Feedbacks and Interactions: From the Arctic Cryosphere to the Climate System
- 2011
-
Ingår i: Ambio: a Journal of Human Environment. - : Springer Science and Business Media LLC. - 0044-7447. ; 40, s. 75-86
-
Tidskriftsartikel (refereegranskat)abstract
- Changes in the Arctic's climate are a result of complex interactions between the cryosphere, atmosphere, ocean, and biosphere. More feedbacks from the cryosphere to climate warming are positive and result in further warming than are negative, resulting in a reduced rate of warming or cooling. Feedbacks operate at different spatial scales; many, such as those operating through albedo and evapotranspiration, will have significant local effects that together could result in global impacts. Some processes, such as changes in carbon dioxide (CO2) emissions, are likely to have very small global effects but uncertainty is high whereas others, such as subsea methane (CH4) emissions, could have large global effects. Some cryospheric processes in the Arctic have teleconnections with other regions and major changes in the cryosphere have been largely a result of large-scale processes, particularly atmospheric and oceanic circulation. With continued climate warming it is highly likely that the cryospheric components will play an increasingly important climatic role. However, the net effect of all the feedbacks is difficult to assess because of the variability in spatial and temporal scales over which they operate. Furthermore, general circulation models (GCMs) do not include all major feedbacks while those included may not be accurately parameterized. The lack of full coupling between surface dynamics and the atmosphere is a major gap in current GCMs.
|
|
| 2. |
- Kravchuk, Oksana, et al.
(författare)
-
Transvection in Drosophila : trans-interaction between yellow enhancers and promoter is strongly suppressed by a cis-promoter only in certain genomic regions
- 2017
-
Ingår i: Chromosoma. - : Springer Science and Business Media LLC. - 0009-5915 .- 1432-0886. ; 126:3, s. 431-441
-
Tidskriftsartikel (refereegranskat)abstract
- Transvection is a phenomenon of interallelic communication whereby enhancers of one allele can activate a promoter located on the homologous chromosome. It has been shown for many independent genes that enhancers preferentially act on the cis-linked promoter, but deletion of this promoter allows the enhancers to act in trans. Here, we tested whether this cis-preference in the enhancer-promoter interaction could be reconstituted outside of the natural position of a gene. The yellow gene was chosen as a model system. Transgenic flies were generated that carried the yellow gene modified by the inclusion of the strategically placed recognition sites for the Cre and Flp recombinases. To facilitate transvection, an endogenous Su(Hw) insulator (1A2) or gypsy insulator was placed behind the yellow gene. Independent action of the recombinases produced a pair of derivative alleles, one containing the promoter-driven yellow gene, and the other, the enhancers and promoter that failed to produce a functional yellow protein. As a result, we observed strong transvection in many genomic regions, suggesting that a complete cis-preference of the enhancer-promoter interactions is mainly restricted to genes in their natural loci.
|
|
