Prevalence, transmission and evolution of avian influenza \nviruses in Newfoundland and Labrador
Bibliographic record
Abstract
The island of Newfoundland is an important location for the breeding and wintering of millions of subarctic birds. The adjacency of the island to Greenland and western Europe indicates the possibility of inter-continental viral transmission by pelagic birds. In this thesis, the prevalence and transmission of avian influenza viruses (AIVs) in 3 major bird groups (duck, gull and murre) were investigated to shed light on AIV ecology and evolution at this region. \nThe epidemiological study of AIVs in ducks (2008-2011) revealed an overall virus detection rate of 7.2%. The viral prevalence differed significantly by bird age and sampling season. Although the AIV detection rates were much lower in gulls (1.8%) and murres (3.9%) during 2009-2011, virus prevalence also displayed strong variability by bird age and season. In addition, serological study revealed a much higher frequency of AIV infection in ducks, gulls and murres compared to results by virus detection alone. \nThe gene sequences of 30 duck AIVs (2008-2011) in Newfoundland and 79 reference duck AIVs (2006-2010) from the Atlantic bird flyway of North America were analyzed to reveal their genetic structure and the extent of gene flow. The genetic structure differed amongst the 8 viral segments with the highest diversity being found in the HA and NA segments. These viruses showed rare inter-continental transmission, but frequent reassortment, and frequent interspecies and North American inter-flyway distribution. \nThe gull AIVs in Newfoundland (2009-2011) showed frequent inter-continental and cross-host group transmission. The study also revealed a larger than previously detected AIV gene reservoir in gulls in Atlantic Canada. \nThe 21 H1N2 AIVs identified from Common Murre in summer 2011 belonged to 4 genotypes. The major genotype had been circulating in the murre population for a while before detection, as indicated by its genetic heterogeneity. The murre viruses displayed a mainly waterfowl-related gene pool with considerable inter-continental and avian-gull gene reassortments. \nThe results of this thesis work provided a profile of AIV prevalence in Newfoundland, and increased our understanding of AIV ecology and evolution in wild birds of Atlantic Canada. Besides continuing the AIV surveillance in gulls, murres and dabbling ducks, future surveillance work should expand to include sea ducks and shorebirds, to better reveal the dynamics of AIV evolution and transmission in this region.
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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 | 0.001 |
| 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".