UV‐Acclimation of Cultured Phytoplankton Exposed to Natural and Enhanced UVB Radiation and Methodological Aspects of MAA Quantification
Bibliographic record
Abstract
Abstract Bloom‐forming dinoflagellates often synthesize high concentrations of mycosporine‐like amino acids (MAAs) as a protection from high PAR and UV radiation, which may afford them a competitive advantage over other species. Photoprotection and long‐term acclimation to natural and enhanced UVB radiation were examined during 4 weeks in three dinoflagellates and one diatom. Semi‐continuous, nutrient‐replete cultures were maintained outdoors under natural light, with or without additional UVB (from lamps). The photosynthetic performance (XE‐PAM fluorometry) and the concentration and composition of MAAs and photoprotective carotenoids (PPCs; comprising xanthophylls) were followed weekly. A great variety of MAAs was found in the dinoflagellates (up to 10, identified by cochromatography and LC–MS). Large differences between sp. (and between two strains of the same sp.) were observed. In most cases, the composition and concentration of MAAs and PPCs increased under enhanced UVB. Growth rate and photosynthetic performance were sometime lower under enhanced UVB, while in other cases photoacclimation seemed to occur. The least affected sp. was Alexandrium tamarense who responded most rapidly to enhanced UVB. The algae also responded to changes in natural incident radiation. Some methodological aspects of MAA quantification were also investigated (with four species of dinoflagellates). Our results indicate how freezing (liquid‐N) likely breaks the cells, mobilizing the water‐soluble MAAs in the filter moist (otherwise highly packaged in fresh cells), while the organelles containing the pigments remain relatively intact. The implications of standard sample handling on the evaluation of MAA concentration in algae and on the estimation of the absorption of suspended material in water from in vivo spectroscopy (filter pad technique) will also be discussed.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".