The effects of p,p’-DDE and current-use pesticides on reproduction and health in zebra finches (taeniopygia Guttata)
Notice bibliographique
Résumé
Until the early 1970's, organochlorine (OC) insecticides were used primarily to control a wide range of pests in North America. Following several restrictions on the usage, OCs were replaced with more acutely toxic, but less persistent insecticides, primarily organophosphates and carbamates. However, many OCs, particularly DDT-related compounds, persist at high concentrations in areas of past intensive usage, such as fruit orchards. Organophosphates, such as azinphos-methyl, and fungicides, such as mancozeb, are commonly used insecticides in fruit orchards, applied alone or as tank mixtures. There are no data available on the toxicity of this common mixture or whether these currently used pesticides can have synergistic effects with DDE (a persistent metabolite of DDT). This study examined effects of DDE alone and in combination with current-use pesticides, using the Zebra finch (Taeniopygia guttata) as a laboratory model. The objectives were to determine 1) the dose-response relationship of azinphos-methyl on brain and plasma cholinesterase (ChE) activity in Zebra finches, 2) the effects of DDE, mancozeb and azinphos-methyl exposure on egg production and yolk precursor levels, and 3) the effects of DDE, mancozeb and azinphos-methyl exposure on passerine reproduction on the post-hatch period. In the first study, although, Zebra finches experienced ChE inhibition following exposure to azinphos-methyl, they appeared to be less sensitive compared to other songbird species. In addition, p,p'-DDE did not appear to affect the degree of ChE inhibition following subsequent azinphos-methyl exposure, however, it did appear to result in stimulation of the immune system. In the second study we found little evidence that dosing of breeding females with current-use pesticides, including azinphos-methyl and mancozeb, either alone or in combination with p,p'- DDE, had significant negative effects on reproductive traits (timing of laying, egg size and number, yolk precursor levels) or immune statues (percent hematocrit and leucocrit and H/L ratio) in female Zebra finches. However, birds with previous exposure to p,p'-DDE (one year prior to the start of the experiment) may be negatively impacted in terms of yolk precursor levels and immune response. In the final study, we found no evidence that dosing of adult Zebra finches with current-use pesticides, including azinphos-methyl and mancozeb, either alone or in combination with p,p'-DDE, had significant negative effects on reproductive traits or immune status in female Zebra finches. Future studies to determine potential effects of in ovo exposure to pesticides on reproduction post-fledging as well as later reproductive success would be beneficial in explaining effects of pesticides on songbirds species. In addition, the possibility of long-term exposure of p,p'-DDE on immune function should be further studied. These data are essential for developing strategies to sustain healthy songbird populations in orchards and will allow for excellent comparative data for a complimentary field study being conducted in Ontario, Canada.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».