PCO2 method for measuring photosynthesis and respiration in freshwater lakes
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
A method for measuring net community photosynthesis and respiration based on changes in PCO2 is described. Samples were incubated in serum stoppered bottles and successive pCO2 measurements taken from the bottle headspace. At the end of the incubation, samples were acidified with concentrated phosphoric acid and total dissolved inorganic carbon (DIC) was determined. Alkalinity was calculated from PCO2 and DIC. Alkalinity was assumed to remain constant for the duration of the experiment so that DIC could be calculated from PCO2 and alkalinity for each measurement. Uptake rates were calculated from the slope of Δ DIC over time. The assumption of alkalinity change being <15% of photosynthesis was tested using axenic chemostat cultures of Chlamydomonas reinhardtii at different nitrogen:phosphorus ratios. For all cultures, alkalinity change represented <10% of particulate carbon turnover. Alkalinity-adjusted rates were found to be not significantly different from non-alkalinity-adjusted rates. Incubations from Lakes 227 and 240 in the Experimental Lakes Area and from Station 928 in Lake Malawi typified photosynthesis–irradiance curves. 14C uptake in Lake Malawi was found to be closer to gross community photosynthesis than to net photosynthesis. Field incubations using this method were 6–11 h and required the constant presence of a researcher; however, the method can be automated.
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.
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 | 0.007 | 0.001 |
| 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 it