Analysis of the mero-carpopodite joint of the American lobster and snow crab. I. Apodeme surface area and muscle fibre pinnation angle
Bibliographic record
Abstract
The patterns and variability of pinnation angle along the length of apodemes, and the scaling of apodeme surface area, were investigated in the American lobster (Homarus americanus) and the snow crab (Chionoecetes opilio) to assess the morphological variation between legs and species, and how these may affect force generation. Muscle fibre pinnation angle shows general patterns of decline along the disto-proximal axis of the apodeme, but the specific patterns of each apodeme or leg are highly variable. There is only small change in pinnation angle along the length of the apodeme or between flexed and extended positions. It appears that changes in pinnation angle are not of sufficient magnitude to contribute significantly to force generation in these pinnated muscle systems. The apodeme surface area as a function of carapace size shows positive allometry for all legs of the snow crab, and for some of the apodemes of legs 2, 3, and 5 of the lobster. The flexor apodeme within the snow crab is larger than the extensor in legs 2 to 4 implying a greater force generating ability in flexion than extension, and legs 2 to 4 all possess much larger apodemes than leg 5. The lobster indicates some specialization of apodeme surface area between the legs along the length of the body, with the anterior legs having larger flexor apodemes than extensor. This pattern is reversed for the last pair of legs. This suggests that each of the four walking legs of the lobster may generate approximately equal forces in extension, while leg 4 has the ability to generate greater forces in flexion than legs 2 or 3, which in turn likely produce larger forces than leg 5. The apodeme surface area is suggested to play a much greater role in determining force generation in crustacean walking legs.
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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 | 0.001 | 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) | 0.001 | 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".