A Novel In Situ Tool for the Exposure and Analysis of Microorganisms in Natural Aquatic Systems
Bibliographic record
Abstract
To evaluate the effects of contaminants or nutrient limitation in natural waters, it is often desirable to perform controlled exposures of organisms. While in situ exposures are routine for caged organisms or macrophytes, they are extremely difficult to perform for microorganisms, mainly due to difficulties in designing an exposure device that isolates the cells while allowing rapid equilibration with the external media. In this paper, a stirred underwater biouptake system (SUBS) based on the diffusion of chemicals across a semipermeable membrane housing a controlled population of microorganisms is reported. Cd diffusion through the semipermeable membrane was evaluated by voltammetry using a microelectrode. Comparison of stirred and unstirred solutions demonstrated a significantly increased diffusive flux in the presence of stirring. Lab tests using Chlamydomonas reinhardtii showed that diffusion across the semipermeable membrane was not limiting with respect to the biouptake of Cd. The SUBS device was field tested and the results of viability studies and trace metal biouptake by C. reinhardtii are reported. No diffusion limitation due to the SUBS was observed for Cd under the tested field conditions. The SUBS device was also shown to be useful for field exposures and subsequent measurements of trace metal uptake and viability. The results support the future use of the SUBS for the in situ measurement of phytochelatin/metallothionein production, photosynthetic efficiency, or reporter gene induction of controlled organisms.
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 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 | 0.001 |
| 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 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".