1. |
- Kumarathunge, Dushan P., et al.
(författare)
-
Acclimation and adaptation components of the temperature dependence of plant photosynthesis at the global scale
- 2019
-
Ingår i: New Phytologist. - : John Wiley & Sons. - 0028-646X .- 1469-8137. ; 222:2, s. 768-784
-
Tidskriftsartikel (refereegranskat)abstract
- The temperature response of photosynthesis is one of the key factors determining predicted responses to warming in global vegetation models (GVMs). The response may vary geographically, owing to genetic adaptation to climate, and temporally, as a result of acclimation to changes in ambient temperature. Our goal was to develop a robust quantitative global model representing acclimation and adaptation of photosynthetic temperature responses.We quantified and modelled key mechanisms responsible for photosynthetic temperature acclimation and adaptation using a global dataset of photosynthetic CO2 response curves, including data from 141 C3 species from tropical rainforest to Arctic tundra. We separated temperature acclimation and adaptation processes by considering seasonal and common-garden datasets, respectively.The observed global variation in the temperature optimum of photosynthesis was primarily explained by biochemical limitations to photosynthesis, rather than stomatal conductance or respiration. We found acclimation to growth temperature to be a stronger driver of this variation than adaptation to temperature at climate of origin.We developed a summary model to represent photosynthetic temperature responses and showed that it predicted the observed global variation in optimal temperatures with high accuracy. This novel algorithm should enable improved prediction of the function of global ecosystems in a warming climate.
|
|
2. |
- Abraham-Nordling, Mirna, et al.
(författare)
-
Incidence of hyperthyroidism in Stockholm, Sweden, 2003-2005
- 2008
-
Ingår i: European Journal of Endocrinology. - 1479-683X. ; 158:6, s. 823-827
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the incidence of hyperthyroidism in Stockholm County in those patients who were diagnosed with hyperthyroidism for the First time during the years 2003-2005. Design: All new cases of hyperthyroidism >= 18 years of age were prospectively registered to calculate the total incidence of hyperthyroidism, as well as the incidence of the subgroups: Graves' disease (GD), toxic multinodular goitre and solitary toxic adenoma (STA). Eight specialized units/hospitals in Stockholm County participated in the registration. The participating physicians were all specialists in medical endocrinology. oncology, nuclear medicine or surgery. Results: Duringa 3-year period, 1431 new patients of hyperthyroidism were diagnosed in a well-defined adult population (>18 years of age) of in average 1 457 036 inhabitants. This corresponds to a mean annual incidence of hyperthyroidism of 32.7/100 000. The incidence of GD was 24.5/100 000 per year. toxic nodular goitre was 3.3/100 000 per year and STA was 4.9/100 000 per year. Conclusions: The total incidence of hyperthyroidism in Stockholm County was found to be 32.7/100 000 per year. of which 75% had GD. There were a higher percentage of smokers among the patients with hyperthyroidism compared with the overall population in Stockholm, but no difference in the frequency of smoking between patients with GD and toxic nodular goitre.
|
|
3. |
|
|
4. |
- Ahlberg, Erik, et al.
(författare)
-
"Vi klimatforskare stödjer Greta och skolungdomarna"
- 2019
-
Ingår i: Dagens nyheter (DN debatt). - 1101-2447.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN DEBATT 15/3. Sedan industrialiseringens början har vi använt omkring fyra femtedelar av den mängd fossilt kol som får förbrännas för att vi ska klara Parisavtalet. Vi har bara en femtedel kvar och det är bråttom att kraftigt reducera utsläppen. Det har Greta Thunberg och de strejkande ungdomarna förstått. Därför stödjer vi deras krav, skriver 270 klimatforskare.
|
|
5. |
|
|
6. |
- Jakobsson, Martin, 1966-, et al.
(författare)
-
An Arctic Ocean ice shelf during MIS 6 constrained by new geophysical and geological data
- 2010
-
Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 29:25-26, s. 3505-3517
-
Tidskriftsartikel (refereegranskat)abstract
- The hypothesis of floating ice shelves covering the Arctic Ocean during glacial periods was developed in the 1970s. In its most extreme form, this theory involved a 1000 m thick continuous ice shelf covering the Arctic Ocean during Quaternary glacial maxima including the Last Glacial Maximum (LGM). While recent observations clearly demonstrate deep ice grounding events in the central Arctic Ocean, the ice shelf hypothesis has been difficult to evaluate due to a lack of information from key areas with severe sea ice conditions. Here we present new data from previously inaccessible, unmapped areas that constrain the spatial extent and timing of marine ice sheets during past glacials. These data include multibeam swath bathymetry and subbottom profiles portraying glaciogenic features on the Chukchi Borderland, southern Lomonosov Ridge north of Greenland, Morris Jesup Rise, and Yermak Plateau. Sediment cores from the mapped areas provide age constraints on the glaciogenic features. Combining these new geophysical and geological data with earlier results suggests that an especially extensive marine ice sheet complex, including an ice shelf, existed in the Amerasian Arctic Ocean during Marine Isotope Stage (MIS) 6. From a conceptual oceanographic model we speculate that the cold halocline of the Polar Surface Water may have extended to deeper water depths during MIS 6 inhibiting the warm Atlantic water from reaching the Amerasian Arctic Ocean and, thus, creating favorable conditions for ice shelf development. The hypothesis of a continuous 1000 m thick ice shelf is rejected because our mapping results show that several areas in the central Arctic Ocean substantially shallower than 1000 m water depth are free from glacial influence on the seafloor.
|
|
7. |
|
|
8. |
- Träisk, Frank, et al.
(författare)
-
Thyroid-Associated Ophthalmopathy after Treatment for Graves´Hyperthyroidism with Antithyroid Drugs or lodine-131
- 2009
-
Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 94:10, s. 3700-3707
-
Tidskriftsartikel (refereegranskat)abstract
- Context: Previous randomized trials have suggested an association between radioiodine treatment for Graves' hyperthyroidism and thyroid-associated ophthalmopathy (TAO). Objectives: The aim of the study was to compare the occurrence of worsening or development of TAO in patients who were treated with radioiodine or antithyroid drugs. Design: We conducted a randomized trial (TT 96) with a follow-up of 4 yr. Patients, Setting, and Intervention: Patients with a recent diagnosis of Graves' hyperthyroidism were randomized to treatment with iodine-131 (163 patients) or 18 months of medical treatment (150 patients). Early substitution with T-4 was given in both groups. Main Outcome Measure: Worsening or development of TAO was significantly more common in the iodine-131 treatment group (63 patients; 38.7%) compared with the medical treatment group (32 patients; 21.3%) (P < 0.001). Results: The risk for de novo development of TAO was greater in patients treated with iodine-131 (53 patients) than with medical treatment(23patients). However, worsening of TAO in the 41 patients who had ophthalmopathy already before the start of treatment was not more common in the radioiodine group (10 patients) than in the medical group (nine patients). Smoking was shown to influence the risk of worsening or development of TAO, and smokers treated with radioiodine had the overall highest risk for TAO. However, in the group of smokers, worsening or development of TAO was not significantly associated with the choice of treatment for hyperthyroidism. Conclusions: Radioiodine treatment is a significant risk factor for development of TAO in Graves' hyperthyroidism. Smokers run the highest risk for worsening or development of TAO irrespective of treatment modality.
|
|
9. |
|
|
10. |
- Wallin, Paul, 1961-, et al.
(författare)
-
Re-dating Ahu Nau Nau and the Settlement at 'Anakena, Rapa Nui
- 2010
-
Ingår i: The Gotland Papers. - Visby : Gotland University. - 9789186343071 ; , s. 37-46
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The building phase and early use of Ahu Nau Nau have been re-dated by nine charcoal and rat bone samples. The new dates in comparison with earlier data suggest that the ahu was constructed around 650-550 BP. It is also suggested that a settlement dated to c. 950-900 BP preceded the ahu-building phase. A new question in light of recent research might be raised: Is the earliest settlement on Rapa Nui found at ´Anakena or should we look elsewhere?
|
|