| 1. |
- Bigelow, NH, et al.
(författare)
-
Climate change and Arctic ecosystems: 1. Vegetation changes north of 55 degrees N between the last glacial maximum, mid-Holocene, and present
- 2003
-
Ingår i: Journal of Geophysical Research. - 2156-2202. ; 108:D19
-
Forskningsöversikt (refereegranskat)abstract
- [1] A unified scheme to assign pollen samples to vegetation types was used to reconstruct vegetation patterns north of 55degreesN at the last glacial maximum (LGM) and mid-Holocene (6000 years B. P.). The pollen data set assembled for this purpose represents a comprehensive compilation based on the work of many projects and research groups. Five tundra types (cushion forb tundra, graminoid and forb tundra, prostrate dwarf-shrub tundra, erect dwarf-shrub tundra, and low- and high-shrub tundra) were distinguished and mapped on the basis of modern pollen surface samples. The tundra-forest boundary and the distributions of boreal and temperate forest types today were realistically reconstructed. During the mid-Holocene the tundra-forest boundary was north of its present position in some regions, but the pattern of this shift was strongly asymmetrical around the pole, with the largest northward shift in central Siberia (similar to200 km), little change in Beringia, and a southward shift in Keewatin and Labrador (similar to200 km). Low- and high-shrub tundra extended farther north than today. At the LGM, forests were absent from high latitudes. Graminoid and forb tundra abutted on temperate steppe in northwestern Eurasia while prostrate dwarf-shrub, erect dwarf-shrub, and graminoid and forb tundra formed a mosaic in Beringia. Graminoid and forb tundra is restricted today and does not form a large continuous biome, but the pollen data show that it was far more extensive at the LGM, while low- and high-shrub tundra were greatly reduced, illustrating the potential for climate change to dramatically alter the relative areas occupied by different vegetation types.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Ozen, G, et al.
(författare)
-
Risk of diabetes mellitus associated with disease-modifying antirheumatic drugs and statins in rheumatoid arthritis
- 2017
-
Ingår i: Annals of the rheumatic diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 76:5, s. 848-854
-
Tidskriftsartikel (refereegranskat)abstract
- To investigate the rate of incident diabetes mellitus (DM) in patients with rheumatoid arthritis (RA) and the impact of disease-modifying antirheumatic drug (DMARD) and statin treatments.MethodsWe studied patients with RA and ≥1 year participation in the National Data Bank for Rheumatic Diseases without baseline DM from 2000 through 2014. DM was determined by self-report or initiating DM medication. DMARDs were categorised into four mutually exclusive groups: (1) methotrexate monotherapy (reference); (2) any abatacept with or without synthetic DMARDs (3) any other DMARDs with methotrexate; (4) all other DMARDs without methotrexate; along with separate statin, glucocorticoid and hydroxychloroquine (yes/no) variables. Time-varying Cox proportional hazard models were used to adjust for age, sex, socioeconomic status, comorbidities, body mass index and RA severity measures.ResultsDuring a median (IQR) 4.6 (2.5–8.8) years of follow-up in 13 669 patients with RA, 1139 incident DM cases were observed. The standardised incidence ratio (95% CI) of DM in patients with RA (1.37, (1.29 to 1.45)) was increased compared with US adult population. Adjusted HR (95% CI) for DM were 0.67 (0.57 to 0.80) for hydroxychloroquine, 0.52 (0.31 to 0.89) for abatacept (compared with methotrexate monotherapy), 1.31 (1.15 to 1.49) for glucocorticoids and 1.56 (1.36 to 1.78) for statins. Other synthetic/biological DMARDs were not associated with any risk change. Concomitant use of glucocorticoids did not alter DM risk reduction with hydroxychloroquine (HR 0.69 (0.51 to 0.93)).ConclusionsIn RA, incidence of DM is increased. Hydroxychloroquine and abatacept were associated with decreased risk of DM, and glucocorticoids and statins with increased risk.
|
|
