1. |
- Pärn, J., et al.
(författare)
-
Nitrogen-rich organic soils under warm well-drained conditions are global nitrous oxide emission hotspots
- 2018
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1, s. 1-8
-
Tidskriftsartikel (refereegranskat)abstract
- Nitrous oxide (N2O) is a powerful greenhouse gas and the main driver of stratospheric ozone depletion. Since soils are the largest source of N2O, predicting soil response to changes in climate or land use is central to understanding and managing N2O. Here we find that N2O flux can be predicted by models incorporating soil nitrate concentration (NO3 -), water content and temperature using a global field survey of N2O emissions and potential driving factors across a wide range of organic soils. N2O emissions increase with NO3 - and follow a bell-shaped distribution with water content. Combining the two functions explains 72% of N2O emission from all organic soils. Above 5 mg NO3 --N kg-1, either draining wet soils or irrigating well-drained soils increases N2O emission by orders of magnitude. As soil temperature together with NO3 - explains 69% of N2O emission, tropical wetlands should be a priority for N2O management.
|
|
2. |
|
|
3. |
|
|
4. |
|
|
5. |
- Pedrelli, M., et al.
(författare)
-
Athero-protective properties of plasma lipoproteins from brown bears (URSUS ARCTOS) during hibernation and active state
- 2020
-
Ingår i: Atherosclerosis. - : Elsevier. - 0021-9150 .- 1879-1484. ; 315, s. E69-E70
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background and Aims: Plasma cholesterol (TC) and triglyceride (TG) levels are twice as high in hibernating brown bears (Ursus arctos) than in healthy humans. Yet, bears display no signs of atherosclerosis. To explore this apparent paradox, lipoprotein structure and function of brown bears were analyzed and compared with those of healthy humans.Methods: Blood from the same wild free-ranging Swedish brown bears (n=10) was drawn during hibernation (winter) and active state (summer). Plasma lipoproteins were separated by size exclusion chromatography, ultracentrifugation and gel-electrophoresis. LDL binding to arterial proteoglycans (PGs) was measured. Data are presented as median (10th - 90th percentile).Results: During hibernation bear LDL carried 4.6 (2.3-5.9) mmol/L cholesterol esters (CE), 1.5 (1.1-2.4) mmol/L unesterified (UC), 3.7 (2.1-4.9) mmol/L TG and 2.5 (1.8-3.4) mmol/L phospholipid (PL). Human LDL were smaller than bear LDL, which were proportionally richer in TG (winter 31 (26-33)%, summer 30 (22-40)%vs human 9% (7-15); p<0.001) and had less CE (winter 36 (26-45)%, summer 25 (21-37)%vs human 48 (46-55)%; p<0.01)). Bear LDL were less positively charged and showed a pre-ß motility on agarose gel. Thus, bear LDL had about 10 times lower binding to PGs than human LDL.Conclusions: Despite high TC and TG levels, bear lipoproteins were less atherogenic than the human analogues. This was due to low LDL affinity for PGs, secondary to increased TG and PL, and to low positive charge. Our study provides further mechanistic insights for the atherosclerosis development, which is driven by the circulating lipoprotein composition and functions rather than plasma absolute lipid levels.
|
|
6. |
|
|
7. |
|
|
8. |
|
|
9. |
|
|