Response of the sea‐ice diatom<i>Fragilariopsis cylindrus</i>to simulated polar night darkness and return to light
Bibliographic record
Abstract
Abstract Arctic photoautotrophic communities must survive through polar night darkness until light returns in spring. We tracked changes in the cellular resource allocations and functional capacities of a polar sea‐ice diatom, Fragilariopsis cylindrus , to understand acclimation processes in both darkness and during the subsequent return to light. We measured parameters at specific time‐points over 3 months of darkness, and then over 6 d after a return to light. Measured parameters included cell number and size, cellular carbon and nitrogen quotas, lipid and pigment contents, concentration of key proteins of the photosynthetic system, photosynthetic parameters based on both variable fluorescence and carbon assimilation, and the level of nonphotochemical quenching. A stable functional state was reached within a few days after the transition to dark and was then maintained throughout 3 months of darkness. The dark period resulted in a decrease of lipid droplet cell quota (−6%), chlorophyll a cell quota (−41%) and the maximum carbon fixation rate per cell (−98%). Return to light after 1.5 months of darkness resulted in a strong induction of nonphotochemical quenching of excitation and a fast recovery of the maximum carbon fixation rate within 1 d, followed by a rapid increase in the cell number. Return to light after 3 months of darkness showed an increase of mortality or a profound downregulation induced over longer periods of darkness.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".