Marine dissolved organic phosphorus composition: insights from samples recovered using combined electrodialysis/reverse osmosis
Bibliographic record
Abstract
The dominant organic phosphorus compound classes were characterized in marine samples using a new, high recovery method for isolating and concentrating bulk dissolved organic matter (DOM) called combined electrodialysis+reverse osmosis (ED/RO). In contrast to earlier studies which use ultrafiltration (UF) to recover only the high molecular weight DOM, ED/RO is capable of isolating both low molecular weight (LMW) and high molecular weight (HMW) DOM. Samples were collected from a broad range of marine environments: along a transect incorporating coastal and offshore waters off the Southeastern United States, in Effingham Inlet, a Pacific fjord located on Vancouver Island, British Columbia and in the Amundsen Sea, Antarctica. Results from phosphorus nuclear magnetic resonance (31P NMR) analysis reveals a similar abundance of P compound classes between samples, phosphate esters (80-85%), phosphonates (5-10%) and polyphosphates (8-13%). These samples contain significantly higher proportions of polyphosphate P and P esters and lower proportions of phosphonates than measured in previous studies using the UF method. The much higher levels of polyphosphate detected in our samples suggests that polyphosphate is present mainly in the LMW DOM fraction. Polyphosphates in DOM may be present as (or derived from) dissolved nucleotides or organismal polyphosphate bodies, or both. Low molecular weight P esters are likely composed of phosphoamino acids and small carbohydrates, like simple sugar phosphates and/or dissolved nucleotides. Phosphonates in DOM are more prevalent as HMW phosphonate compounds, which suggests that LMW phosphonates are more readily utilized in marine ecosystems. Overall, the investigation of DOM across a size spectrum that includes both the HMW and the LMW fractions reveals a new picture of phosphorus distribution, cycling and bioavailability.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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".