Temperature acclimation influences temperature-related behaviour as well as oxygen-transport physiology and biochemistry in the water flea<i>Daphnia magna</i>
Bibliographic record
Abstract
To evaluate the role of temperature in oxygen transport in the water flea Daphnia magna, temperature-related behaviour as well as oxygen-transport physiology and biochemistry were investigated in animals long-term acclimated to moderate temperatures: 10, 20, or 30°C (normoxia) or 20°C (hypoxia). Study of the behaviour of animal groups within a normoxic thermal gradient showed their preferred temperatures and distribution patterns to be connected with acclimation conditions; for example, cold-acclimated individuals, with their relatively high metabolic rates and low oxygen-transport capacities, crowded at low temperatures where the oxygen concentration was high. One key to explaining these data is to assume a strategy of avoiding oxygen shortage. Both temperature and hypoxia acclimation also modified oxygen-transport variables such as oxygen consumption, ventilation and circulation rates, or the concentration and oxygen affinity of haemoglobin. Characteristic features of cold-acclimated D. magna were relatively high oxygen-consumption and heart rates and a low concentration and oxygen affinity of haemoglobin. Hypoxia-acclimated D. magna showed relatively low convective rates (frequency of thoracic-limb movements, heart rate) but a high concentration and oxygen affinity of haemoglobin. Additional experiments showed that independently of each other, temperature and ambient oxygen concentration modify haemoglobin quantity and quality, the former possibly acting via a temperature-induced hypoxia. The varying oxygen affinity is probably due to alterations of haemoglobin subunit composition, with the particular participation of subunits A, E, and G as revealed by two-dimensional gel electrophoresis.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.002 | 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 teacher head, 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".