Antioxidant Defence Response in Non-Target Fishes Following Pharmaceutical Wastewater Effluent Exposure
Notice bibliographique
Résumé
The Grand River watershed extends throughout the majority of Southern Ontario with its \nfinal outlet at Lake Erie and accommodates thirty wastewater treatment plants (WWTP) with \nvarying types and degrees of treatment. Many WWTPs are currently unable to effectively \neliminate several contaminants of concern (CECs) from their final effluent, leading to measurable \nconcentrations in surface waters and ultimately chronically exposing aquatic species to mixtures \nof CECs. Exposures to CECs have reported impacts on oxidative stress, measurable through \nreactive oxygen species (ROS) and the antioxidant defense response which helps reduce the \ntoxicity of ROS generated molecules. This thesis aims to investigate the effects of WWTP effluent \non four Etheostoma (Darter) species endemic to the Grand River. Objectives were to examine if \nincreased antioxidative response markers are present in the brains of darters downstream from the \neffluent outfall compared to clean reference site upstream relative to the Waterloo, ON WWTP \nbetween two separate years (Fall 2020 and Fall 2021). This was assessed using transcriptional \nanalysis and enzymatic analysis of antioxidant enzymes (SOD, GPX, CAT) and an enzyme \ninvolved in serotonin synthesis (TPH). In fall 2020, significant differences in transcript expression \nof markers were found among sites and sexes in greenside darters (GSD) with SOD and CAT \nshowing increased expression downstream. Changes in transcript expression aligned with \nantioxidative enzyme activity where interactive effects with sex-related differences were observed \nin fish collected the Fall of 2020. In contrast, transcription markers measured in Fall 2021 were \nincreased upstream compared to species below the effluent outfall. \nField research is essential to understand subtle effects of wastewater effluent on non-target \nspecies, meaning a species that is not intentionally targeted by CECs. Using in vitro studies to \nsupplement in vivo studies provide a better understanding in the mechanisms for any observed \nphenotypic response. Therefore, this thesis also aimed to investigate the mechanism in alterations \nin antioxidant response by exposing isolated brain primary cell culture collected from zebrafish \nand darters to environmentally relevant concentrations of venlafaxine. Antioxidant response of the \ncells was assessed through cell viability, and antioxidant enzyme activity. Antioxidant enzyme \nactivity of SOD and CAT were both increased in zebrafish, RBD, and GSD isolated brain cultures \nexposed to 0.01-1 ug/L of venlafaxine. This response supplements the observed changes in \nantioxidant response of darters in the Grand River as they are chronically exposed to contaminated \neffluent containing notably high concentrations of pharmaceuticals. \nOverall, this thesis demonstrates how yearly varying abiotic factors such as observed \ntemperature increases in Fall 2021, species-specific differences, sex-differences, and venlafaxine \nhave roles in increased antioxidant response observed in non-target species. Continued \ninvestigation on the impacts of pharmaceutical exposures in non-target organisms is crucial to \nfurther the knowledge of WWTP effluent impacts.
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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 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 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 ».