Particulate distribution and relationship to endotoxin in poultry production operations
Bibliographic record
Abstract
This thesis dissertation assessed workers who work in poultry barns and their occupational environment in relation to the type of bird housing in which they were exposed (cage-housed birds (CH) or floor-housed birds (FH)) and examined the environmental variables including dust and endotoxin and potential relationships to respiratory symptoms of workers.A cross sectional study was undertaken to assess the environmental exposure levels and respiratory health effects of workers who worked in CH and FH poultry operations.The respiratory results suggested an asthma-like syndrome in these workers.Workers who worked in CH facilities reported greater current and chronic respiratory symptoms and significantly greater current and chronic phlegm as compared to workers from FH facilities.Workers from CH poultry facilities were exposed to greater endotoxin load than workers from FH facilities, but workers from FH operations were exposed to greater levels of total dust.It was found that endotoxin load (EU/mg) was a significant predictor of chronic phlegm for all poultry workers.The effects on dust and endotoxin measurements when utilizing a Marple impactor with greased or ungreased impaction surfaces when sampling in an agricultural environment were unknown, and the potential for effects was tested.There were no significant differences in the aerosol mass median aerodynamic diameters between the greased and ungreased Marple impactors.Endotoxin analysis results appeared to be influenced by impaction grease particularly when very low amounts of endotoxin were present.Size fractioning the dust and endotoxin using Marple impactors in CH and FH poultry operations showed that endotoxin load (EU/mg) was significantly higher in the respirable fraction of area samples in CH poultry operations as compared to FH operations.There were no differences in endotoxin load in the non-respirable size fractions for area samples between CH and FH operations.FH poultry operations had significantly greater dust mass and dust concentration in both respirable and non-respirable fractions for FH operations.There was significantly greater endotoxin load (EU/mg) in the 3.5-6.0micron size fraction for the CH poultry operations as compared to the FH operations.SUMMARY ....
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 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 | 0.001 |
| 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 | 0.001 | 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".