Évaluation des effets combinés du manganèse et d’un stress thermique sur les capacités métaboliques de l’omble chevalier (Salvelinus alpinus).
Bibliographic record
Abstract
Dans la région du Nord-du-Québec, la pollution par les rejets miniers est un problème d’intérêt environnemental auquel les organismes aquatiques doivent faire face. En plus des activités anthropiques, la variation de la température de l’eau est une autre source de stress pour les poissons. Plusieurs études s’intéressent aux effets des stress environnementaux chez les poissons. Cependant, très peu se sont intéressées aux impacts sur leur métabolisme énergétique. Cette étude a pour objectif d’évaluer les impacts d’une contamination de manganèse (Mn) et de la température sur les capacités métaboliques de l’omble chevalier (Salvelinus alpinus). Dans ce projet, des juvéniles d’omble chevalier ont été acclimatés à deux températures (7 °C et 16 °C) avec ou sans Mn (1 mg Mn/L) pour une période de huit semaines. Les concentrations de Mn ont été mesurés dans les branchies, le rein, le foie et le muscle, tandis que les activités enzymatiques de la respiration cellulaire, de la glycolyse et du métabolisme des lipides ont été mesurés dans le foie et le muscle seulement. Cette étude a démontré que la bioaccumulation du Mn dans les branchies et le rein était significativement plus élevée chez les ombles chevalier acclimatés à 7 °C comparativement à 16 °C. Le Mn a diminué les activités de la cytochrome c oxydase (CCO) et de la citrate synthase (CS) avec une augmentation de la température, tandis que l’activité de la phosphofructokinase (PFK) a augmenté dans les mêmes conditions. Ces résultats suggèrent que le Mn, en combinaison avec une température élevée, provoque une diminution de la capacité aérobie. La glycolyse aérobie a été stimulée par cette diminution, tandis que le métabolisme des lipides n’a démontré aucun ajustement métabolique. In the northern Quebec region, pollution from mining discharges is an environmental problem that aquatic organisms must face. In addition to anthropogenic activities, variations in water temperature are another source of stress for fish. Many studies have examined the effects of environmental stresses on fish. However, very few have focused on their impacts on energy metabolism. The aim of this study was to assess the impact of manganese (Mn) contamination and temperature on the metabolic capacity of Arctic char (Salvelinus alpinus). In this project, Arctic char juveniles were acclimatized to two temperatures (7 °C and 16 °C) in the presence or absence of Mn (1 mg Mn/L) for a period of eight weeks. Mn concentrations were measured in gills, kidney, liver and muscle, while the enzymatic activities of cellular respiration, glycolysis and lipid metabolism were measured in liver and muscle only. This study showed that Mn bioaccumulation in gills and kidney was significantly higher in Arctic char acclimatized at 7 °C compared to 16 °C. Mn decreased cytochrome c oxidase (CCO) and citrate synthase (CS) activities with increasing temperature, while phosphofructokinase (PFK) activity was increased under the same conditions. These results suggest that Mn, in combination with elevated temperature, causes a decrease in aerobic capacity. Aerobic glycolysis was stimulated by this decrease, while lipid metabolism showed no metabolic adjustment.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 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".