Anomalous Magnetic Orientations of Magnetosome Chains in a Magnetotactic Bacterium: Magnetovibrio blakemorei Strain MV-1
Bibliographic record
Abstract
There is a good deal of published evidence that indicates that all magnetosomes within a single cell of a magnetotactic bacterium are magnetically oriented in the same direction so that they form a single magnetic dipole believed to assist navigation of the cell to optimal environments for their growth and survival. Some cells of the cultured magnetotactic bacterium Magnetovibrio blakemorei strain MV-1 are known to have relatively wide gaps between groups of magnetosomes that do not seem to interfere with the larger, overall linear arrangement of the magnetosomes along the long axis of the cell. We determined the magnetic orientation of the magnetosomes in individual cells of this bacterium using Fe 2p X-ray magnetic circular dichroism (XMCD) spectra measured with scanning transmission X-ray microscopy (STXM). We observed a significant number of cases in which there are sub-chains in a single cell, with spatial gaps between them, in which one or more sub-chains are magnetically polarized opposite to other sub-chains in the same cell. These occur with an estimated frequency of 4.0±0.2%, based on a sample size of 150 cells. We propose possible explanations for these anomalous cases which shed insight into the mechanisms of chain formation and magnetic alignment.
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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".