Connaissance projet

Question 1

Le cascudo serait plus resistant. qu’est ce qui fait qu’un animal peut être plus resistant qu’un autre ? comment on le détecte

Answer 1

—ome authors suggest that the liver of herbivorous bottom fish possess an antioxidant defence mechanism that is more efficient than piscivorous fish .

e know that because like since the antioxidant enzymes were less altered in H. commersoni (herbivorus) exposed to DDT and methylmercury (Bussolaro et al., 2010). In this sense, our data indicate that H. intermedius, a piscivorous species, has a greater oxidative stress response than H. affinis,

Question 2

Quel métaux penses tu qui aura le plus d’effet ?

Question 3

Et hypostomus affinis, idée de quelle sera l’autre espèce ? Astyanax ?

Question 4

Pourquoi ne pas prendre la même espèce ?

Answer 4

Hypostomus affinis : preference pour …..ne se retrouve pas aprtout . Plus difficile au rio paraopeba

Question 5

Dans l’étude weber et al., quelle était la différence de metaux entre P1 et P2 pour l’eau et les sédiments

Answer 5

The metal loads of Fe, Pb, Ni, and As in the water showed no statistical differences between sites, (p > 0.05), but Mn was higher in S2 site (p = 0.001). Regarding sediment, Ni (p = 0.001), Pb (p = 0.001), and As (p = 0.001) were statistically higher in S2, but Fe and Mn showed no significant differences among sites (

Question 6

Pourquoi prendre différents biomarquers de stress ?

Question 7

A quel bassin apartient le rio doce ?
Le rio paraopeba

Question 8

Penses tu trouve rbeaucoup de fer dans P1 ?

Answer 8

he iron (Fe) levels at both sites were high because this region of the iron quadragle has high levels of iron in the soil

Question 9

que sont les effets à une haute exposition au Mn ?

Answer 9

anganese, which is an essential metal, was found in high concentrations in waters at Doce River. A study with Oreochromis niloticus showed that fishes exposed to manganese at high concentrations can promote DNA damage and activates oxidative stress in the liver

Question 10

A quels metals est due la Melattotionein

Answer 10

Fe and Mg, which exhibited similar concentrations between sites, do not appear to induce the expression of metallothionein (Sevcikova et al., 2011). The high levels of hepatic metallothionein in the two species of the present study may be related to the action of several metals acting together, as observed in some rivers polluted by metal

Question 11

what are heat shock protein

Answer 11

—Heat shock proteins (HSPs) are a family of proteins produced by cells in response to exposure to stressful condition

hsp perform important functions in the folding and unfolding or translocation of proteins, as well as in the assembly and disassembly of protein complexes

Question 12

que sont les The condition factor (K) and Hepato-somatic index (HSI) ?

Pourquoi les utiliser

Question 12

qu’est ce que le CYP1A et que fait iln

Answer 12

–, CYP1A is an enzyme that plays a role in the biotransformation of environmental toxicants and carcinogens, including heavy metals and is widely used in ecotoxicological field studies

Question 13

Que sont les concentrations de metaux lourds du Rio dosse maintenant ?

Answer 13

Macêdo et al., : Herein, with water samples collected 32 months after the disaster, we found lower concentrations of Fe, Mn, Cd, and Al when compared with the concentrations of these metals right after the rupture. However, the concentrations of Fe, Cd, and Hg are still higher than those found before the rupture

Question 15

que répondre si on te dit que les concentrations sont pas si grosses ?

Answer 15

n addition, the environment is being influenced by distinct heavy metal mixtures at each sampling site as evidenced by the PCA analyses. Therefore, exposure of organisms to this complex mixture of chemical contaminants can cause toxic effects even if these individual contaminants are present at low concentrations

Mixtures of toxic elements such as Hg, Pb, Cd, or metal-associated toxicants, such as methylmercury, tributyltin, and alkali may occur in polluted aquatic environments and may be expected to cause combined toxicity

Moreover, studies have shown that the combination of heavy metals has an effect on the bioaccumulation of these pollutants in fish organ

Question 16

que signifie un detachment of the epithelium

Answer 16

The observed detachment of the epithelium has been described as a defense mechanism that leads to a decreased toxicant entry through the gills by the increasing the distance between the toxicant and blood in the primary and secondary lamellae

Question 17

que sont les MRC ? que sont leurs rôles dans les branchies

Answer 17

Mitochondria Rich Cell

MRCs are large round cells typically distributed on the posterior edge of the primary lamellar epithelium and in the interlamellar mass in teleost gills (Macirella and Brunelli, 2017). They facilitate the transport of ions through the gill epithelium
n increase in number (P4 group), disorganization and hypertrophy (P2 and P3 groups) of MRC and NKA, as observed through immunolabeling, may be associated with a protective mechanism against pollution that is caused mainly by heavy metals, which may involve physiological and morphological adjustments to maintain optimum ion uptake

the distribution and increase in the number of MRCs in fish gills can be considered as an adaptive response against the exposure to heavy metals in their habitat, which was triggered by the body’s attempt to correct the ionic imbalance brought about by pollution.

Question 18

Cite des metaux qui se sont montrés toxiques pour les branchies

Answer 18

Cu, Cd, Fe, and Ni

Question 19

Que penses tu que sera l’impact du methyl mercury ?

Answer 19

On étudie des cas de mines de fer et une étude de notre laboratoire ne voyait pas de différence entre les sites contminité ou non de mercure, et montrait des concentrations basses.

Cependant, les sites sont pas très loin d’une mine d’or, donc des pollultions entre l’étude de notre labo et maintenant sont possibles, mais ce serait pas due à la mine

y, mainly iron ore (Timbopeba, Germano and Alegria mines), and in addition, it is also full of manganese and gold, which follows that there is evident predatory exploration activities (prospectors)

Question 20

Que sont les causes de la rupture du barrage de rio doce

Answer 20

Pas clair Several aspects have been evocated including foundation failure or bad impoundment management, fast increase of tailing deposition, poor management, and human inadequate practices.

n 2008, the Fundão dam had presented several anomalies related to drainage construction defects, upwellings, mud and water management errors and” (do Carmo et al., 2017) As the dam embankment continued, surface upwellings began to appear at the retreat of the left shoulder at various elevations and on various occasions during 2013. The saturated mass with sandy tailings was growing, and in August 2014, the drainage carpet controlling this saturation reached its maximum capacity. Meanwhile, the mud under the landfill was responding to the increase in the load that was being deposited by the embankment. The way in which it responded, and the consequent effect on the sands, was what finally made the sands liquefy.” (Carmoe t al., 2017)

Question 21

quelles sont le type de pollution qu’on retrouve au rio paraopeba

Answer 21

Até o ano de 2011, os principais responsáveis pela degradação das águas eram os lançamentos de esgotos domésticos e industriais, além do uso e ocupação inadequados do solo nas áreas urbana e rural, notadamente no que diz respeito à ausência ou insuficiência de cobertura vegetal

Question 22

comment la caspase 3 declenche l’apoptose

Answer 22

Caspase-3 cleaves structural and regulatory proteins, which causes cellular shrinkage, DNA fragmentation, and membrane blebbing.

Question 23

que sont les genes de eregulation de L’apoptose ? de la necrose ?

Answer 23

Necroptosis is regulated by LEF1, RIP1, and RIP3, and finally

apoptosis regulation are caspases, TP53, FAS, BCL-2

Question 24

Quelle est l’autre fonction de la metallotionein dans la protection cotnre les metaux

Answer 24

-Antioxidant: Provide metal cofactor for antioxidant enzyme
- Anti inflammation : scavenge ROS

Question 25

avec quel metaux lourds la mettallotionein peut se lier

Answer 25

Zn, Cu,Cd2, fe ,mn

Question 26

Que sont les roles dans la cellule et à l’exterieur de la cellule de HMGB1

Answer 26

Inside the cells, HMGB1 binds DNA and plays a role in transcriptional regulation , once released it plays a role of HMGB1 serves as a cytokine and is a late mediator of the effects of LPS As such, HMGB1 has been implicated as a cause of inflammation secondary to necrotic cell death nside the cell, HMGB1 binds DNA and regulates transcription, whereas outside the cell, it serves as a cytokine and mediates the late effects of LPS

Question 27

Combien d’espèces au rio doce

Answer 27

https://www.scielo.br/j/ni/a/VyNZ7CNX5PR5fgGqk3KqHwM/

Question 28

Quels metaux la metallotioneine elimine

Answer 28

Metallothioneins are low-molecular weight, heat-stable and cysteine-rich peptides which plays an important role in homeostasis of essential metals such as Cu and Zn, and detoxification of non-essential metals such as Cd, Pb and Hg

Question 29

Pourquoi l’ATPase diminue ?

Answer 29

Generally, inhibition of ATPase activities is observed following metal exposures in fish tissues though some increases in enzyme activity may also occur particularly after chronic metal exposures, possibly as a result of an adaptation mechanism (Atli and Canli, 2007).

Question 30

Parmi les 3 biomarkers d’antioxidants, si tu devais en choisir un ce serait lequel ? pourquoi ?

Answer 30

CAT (justifierO

Question 31

Pourquoi des fois il y’a moisn de CAT quand exposés aux polluants ?

Answer 31

voir doc propre 3

Question 32

que fait le gsh

Answer 32

GSH is an extremely important cell protectant since it directly quenches the reactive hydroxyl radicals.

Question 33

Pourquoi les branchies ont moins de GSH face à des polluants

Answer 33

voir doc propre 3

Question 34

def parenchyme

Answer 34

–

Question 35

Comment fonctionnent les enzymatics free oxidants vs non enzymatic free oxidant

Answer 35

– enzymatic : breaking up and eliminating free radicals
non enzymatic : free radicals work as interrupters of free radical chain reaction