| 1. |
- Donis, Daphne, et al.
(författare)
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Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer
- 2021
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Ingår i: Limnology and Oceanography. - : John Wiley & Sons. - 0024-3590 .- 1939-5590. ; 66:12, s. 4314-4333
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Tidskriftsartikel (refereegranskat)abstract
- To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L-1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4 degrees C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature.
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| 2. |
- Leenhardt, R., et al.
(författare)
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A guide for assessing the clinical relevance of findings in small bowel capsule endoscopy : analysis of 8064 answers of international experts to an illustrated script questionnaire
- 2021
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Ingår i: Clinics and Research in Hepatology and Gastroenterology. - : Elsevier BV. - 2210-7401. ; 45:6
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Tidskriftsartikel (refereegranskat)abstract
- Background and aim: Although recommended, the P-score used for assessing the pertinence / relevance of findings seen in small bowel (SB) capsule endoscopy (CE) is based on a low level of knowledge. The aim of this study was to evaluate the clinical relevance of the most frequent SBCE findings through an illustrated script questionnaire. Materials and Methods: Sixteen types of SBCE findings were illustrated four times each in three different settings (occult and overt obscure gastrointestinal bleeding and suspected Crohn's disease), and with a variable number (n = 1/n = 2–5/n ≥ 6), thus providing a questionnaire with 192 scenarios and 576 illustrated questions. Fifteen international experts were asked to rate the finding's relevance for each question as very unlikely (−2) / unlikely (−1) / doubtful (0) / likely (+1) / very likely (+2). The median score (≤−0.75, between -0.75 and 0.75, or ≥0.75) obtained for each scenario determined a low (P0), intermediate (P1) or high (P2) relevance, respectively. Results: 8064 answers were analyzed. Participation and completion rates were 93% and 100%, respectively. In overt or occult OGIB, resultant P2 findings were 'typical angiectasia', 'deep ulceration', 'stenosis', and'blood', whatever their numbers, and 'superficial ulcerations' when multiple. While in suspected CD, consensus P2 lesions were 'deep ulceration' and 'stenosis' whatever their numbers, and 'aphthoid erosions' and 'superficial ulcerations' when multiple. Conclusion: This study establishes a guide for the evaluation of relevance of SBCE findings. It represents a step forward for SB-CE interpretation and is intended to be used as a tool for teaching and academic research.
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| 3. |
- Mantzouki, Evanthia, et al.
(författare)
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Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins
- 2018
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Ingår i: Toxins. - : MDPI. - 2072-6651. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.
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