MétaCan
Menu
Back to cohort

Paraspermatogenesis in <i>Littoraria (Palustorina) articulata</i>, with reference to other Littorinidae (Littorinoidea, Caenogastropoda)

2000· article· en· W1985000317 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueInvertebrate Biology · 2000
Typearticle
Languageen
FieldEnvironmental Science
TopicAquatic Invertebrate Ecology and Behavior
Canadian institutionsUniversity of VictoriaSt. Francis Xavier University
Fundersnot available
KeywordsBiologyCytoplasmNucleusAnatomyUltrastructureCell biologyAxonemeEndoplasmic reticulumGolgi apparatusFlagellumPaleontology

Abstract

fetched live from OpenAlex

Abstract. The ultrastructure of paraspermatogenesis is examined in the littorinid subfamily Littorininae, with special emphasis on Littoraria (Palustorina) articulata (PHILIPPI 1846). In particular the study focuses on the fate of the nucleus and origin of the rod bodies during parasperm development. Parasperm of the Littorininae are rounded or oblong cells, which undergo an abortive meiosis and eliminate part of the nucleus but often retain a nuclear remnant. The cytoplasm is filled with numerous spherical vesicles in all Littorininae, but in Littoraria (and in certain species of Nodilittorina, Tectarius and Cenchritis) dense ‘rod‐bodies’ also occur. Littoraria (Palustorina) are unique in possessing a flagellum‐like structure termed the ‘pseudotrich”, which lacks an axoneme but contains microtubules during its development. Paraspermatogonia differ from euspermatogonia in the structure of the nucleus and in the extensive rough endoplasmic reticulum (RER) and swollen cytoplasm. Two types of secretions develop in Littoraria : (1) numerous, spherical granules (composed of putative glycoprotein, also seen in other Littorininae) and (2) rhomboid granules (composition uncertain but reacting positively to RNA stains; these granules arising within RER cisternae close to the nucleus). As the rhomboid granules fuse to form the larger, rod‐bodies (polygonal in cross section), the RER membrane enclosing the rod‐bodies becomes confluent with the outer nuclear membrane, thereby forming a common compartment. Results of this study clearly show that the rod‐bodies are secretions of the RER cisternae and not, as claimed in some light microscopic accounts, the product of fusion of eusperm nuclei which have entered the parasperm cytoplasm (either by active eusperm penetration or by phagocytosis). Developmental characteristics of littorinid parasperm show differences between species and may, in some cases, provide characters diagnostic of subgenera.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow), Insufficient payload (model declined to judge)
Consensus categoriesInsufficient payload (model declined to judge)
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.229
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.001
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0440.021

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.

Opus teacher head0.017
GPT teacher head0.245
Teacher spread0.227 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it