Functional histology of the integument of the thin-spined porcupine, <i>Chaetomys subspinosus</i>
Bibliographic record
Abstract
This study examines the functional histology of the thin-spined porcupine's ( Chaetomys subspinosus (Olfers, 1818)) quills and integument, and compares them with the North American porcupine ( Erethizon dorsatum (Linnaeus, 1758)) equivalents. Erethizon quills disseminate warnings to potential predators. An olfactory warning is generated by sebaceous glands of the lower back, disseminated by osmetrichial specializations of lower-back quills. Chaetomys skin lacks functional sebaceous glands, and generates no warning odor. Erethizon quills also carry a visual warning, effective even in dim light. Chaetomys quills carry no warning color. The straight, stiff quills of Erethizon are tipped with one-way barbs and can be elevated to 90°. A protective collagenous spool at the base of the quill prevents back-stabbing on impact. Chaetomys quills lack barbs and the basal collagenous spool is poorly developed. The quill shafts are wavy and angled at the base, allowing them to act as shock absorbers during a fall from a tree. Nevertheless, Chaetomys quills of the head and shoulders can be elevated to 90° to function as stabbing devices. Major defensive quills of Erethizon protect the back; in Chaetomys, the front. Though both species have 1–3 arrector muscles, they differ in the details of quill stabilization. The Chaetomys quill surface has regional cuticular patterns, of which the distal, longest region is highly pitted. The function of the pitted region remains a mystery.
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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) | 0.002 | 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".