Coordinated, Long-Range, Solid Substrate Movement of the Purple Photosynthetic Bacterium Rhodobacter capsulatus
Bibliographic record
Abstract
The long-range movement of Rhodobacter capsulatus cells in the glass-agar interstitial region of borosilicate Petri plates was found to be due to a subset of the cells inoculated into plates. The macroscopic appearance of plates indicated that a small group of cells moved in a coordinated manner to form a visible satellite cluster of cells. Satellite clusters were initially separated from the point of inoculation by the absence of visible cell density, but after 20 to 24 hours this space was colonized by cells apparently shed from a group of cells moving away from the point of inoculation. Cell movements consisted of flagellum-independent and flagellum-dependent motility contributions. Flagellum-independent movement occurred at an early stage, such that satellite clusters formed after 12 to 24 hours. Subsequently, after 24 to 32 hours, a flagellum-dependent dispersal of cells became visible, extending laterally outward from a line of flagellum-independent motility. These modes of taxis were found in several environmental isolates and in a variety of mutants, including a strain deficient in the production of the R. capsulatus acyl-homoserine lactone quorum-sensing signal. Although there was great variability in the direction of movement in illuminated plates, cells were predisposed to move toward broad spectrum white light. This predisposition was increased by the use of square plates, and a statistical analysis indicated that R. capsulatus is capable of genuine phototaxis. Therefore, the variability in the direction of cell movement was attributed to optical effects on light waves passing through the plate material and agar medium.
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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".