Bibliographic record
Abstract
Environmental hypoxia is a phenomenon in which low oxygen conditions force organisms to respond behaviourally and physiologically to survive in an otherwise lethal habitat. Animals display different mechanisms to cope with the harsh living conditions of a hypoxic environment, most of which can be summarized as: (i) improvement of oxygen transport capacity, (ii) improvement of oxygen storage, and (iii) supply of energy via anaerobic metabolism. Daphnia respond to hypoxia by increasing the expression of extracellular hemoglobin (Hb), an oxygen transport/storage protein. It is generally thought that this upregulation is used as a strategy to sustain sufficient oxygenation to tissues, allowing Daphnia to stay systemically normoxic even when the environment is hypoxic. Although the changes/differences in Hb levels have been studied in many contexts, very little has been done exploring the basic properties of energy metabolism in Daphnia. My focus was on the link between the Hb response and the metabolic phenotype. I sampled different Daphnia species from 20 lakes in the Frontenac Arch Biosphere. The resulting metabolite analyses support the idea that the benefit of Hb is facilitating oxygen delivery rather than to increase oxygen storage. I found a distinct lack of coordination in the responses of the glycolytic enzymes relative to Hb. Daphnia pulicaria from four lakes appeared to demonstrate one of two strategies in relation to coordination of glycolytic genes and Hb. In some lakes D. pulicaria showed a pronounced induction of Hb without changes in glycolytic enzymes, whereas other lakes showed a blunted Hb response but pronounced glycolytic response. Serial sampling showed the Hb response early in the season (May-June) and a glycolytic response later in the season (September- October). Further studies should include transcriptome analyses exploring if lake-by-lake differences are due to microevolutionary variation or phenotypic responses to different degrees and durations of oxygen stress.
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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) | 0.000 | 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".