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Record W7010563315

Investigation of Arterial Geometry as a Local Risk Factor for Carotid Atherosclerosis

2013· dissertation· en· W7010563315 on OpenAlexvenueno aff

Bibliographic record

VenueLibrary and Archives Canada (Government of Canada) · 2013
Typedissertation
Languageen
FieldEnvironmental Science
TopicAquatic Invertebrate Ecology and Behavior
Canadian institutionsnot available
Fundersnot available
KeywordsTortuosityConfoundingRisk factorMagnetic resonance imagingGeometric meanCarotid arteriesHemodynamicsRegressionFlow (mathematics)
DOInot available

Abstract

fetched live from OpenAlex

There is little doubt that disturbed hemodynamic forces play a role in the development of focal atherosclerotic lesions; however, these forces are difficult to measure directly. Instead, it has been proposed that artery geometry, as the primary determinant of local hemodynamics, could be a clinically feasible surrogate “local” risk factor for atherosclerosis. To date this hypothesis has not been satisfactorily tested, owing to superficial geometric surrogates of disturbed flow, small sample sizes (effect of systemic factors) and/or confounding effects of disease on geometry. The primary objective of this thesis was to test this “geometric risk hypothesis” via direct association of definitive geometric factors and an early atherosclerosis marker (e.g. wall thickness), made possible through our access to magnetic resonance imaging and risk factor data from the Atherosclerosis Risk in Communities’ Carotid MRI sub-study. First, it was shown that the 3D geometry of the carotid bifurcation could be characterized rapidly and reliably, even for routine clinical acquisitions. Second, two novel individual geometric variables were proposed, inspired by the influence of flare and tortuosity on flow separation, which were shown to improve the prediction of disturbed flow burden compared to “conventional” shape-based geometric variables. Third, these redefined geometric factors, but not their shape-based counterparts, were shown by multiple regression to be independent predictors of wall thickness, but only after thoroughly accounting for the secondary effects of wall thickening on geometry. These findings provide strong evidence for the geometric risk hypothesis of atherosclerosis in humans group study, and provide important guidance for future investigations of geometric risk; however, the incremental value of optimized geometric risk factors is questionable relative to conventional cardiovascular risk factors, which challenges their future clinical usage as additional non-modifiable local risk factors.

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.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.002
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.001
Threshold uncertainty score0.005

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.002
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0000.000
Scholarly communication0.0010.000
Open science0.0000.001
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0010.000

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.

Opus teacher head0.005
GPT teacher head0.155
Teacher spread0.150 · 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

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

Quick stats

Citations0
Published2013
Admission routes1
Has abstractyes

Explore more

Same venueLibrary and Archives Canada (Government of Canada)→Same topicAquatic Invertebrate Ecology and Behavior→French-language works237,207→