409Cyanophage Virus that infects cyanobacteria.
Cytochrome intermediate coenzyme of the respiratory
chain.
DAPI 4 ′,6′-diamidino-2-phénylindole, a fluorescent stain
that binds strongly to A-T rich regions in DNA.
DIC (Dissolved Inorganic Carbon) also named ΣCO 2 , this
parameter is the sum of dissolved inorganic carbon spe-
cies concentrations: DICH=+[] 23 CO []HCOC 33 −−+[]O^2
The [H 2 CO 3 ] term contains the true dissolved CO2(aq.)
(aqueous CO 2 ) and the hydrated form H 2 CO 3 i.e. the car-
bonic acid. Various bio- and physicochemical processes
affect DIC: exchange with atmosphere (CO 2 ), phyto-
plankton uptake or CO 2 release from several respiration
or fermentation pathways, precipitation or dissolution of
carbonate minerals... Proportion of the three species is
strongly related with the pH of water.
Dechlorination The process of removing the chlorine resi-
due from chlorinated compounds.
Defortunate abandoned places left to the forces of nature,
where religious settlements were built. Vassivière moun-
tain, close to Pavin (1300 m a.s.l.), could be one of them.
Degassing controversy scientific controversy about the
occurrence, the origin or the mechanism of lake degassing.
Degassing grid see sensory grid.
Degree days It is the product of the daily temperature of the
water by the number of days. For Arctic char eggs hatch
into fish larvae after 450° days.
Dehalogenase One of a group of enzymes that dehaloge-
nate organohalide substrates.
Diatom bloom A rapid increase or accumulation in the pop-
ulation of diatoms in an aquatic ecosystem.
Diatom a major group of algae, among the most common
types of phytoplankton.
Diatomite soft friable siliceous sedimentary rock or unit
made of opaline frustules of the diatom, a unicellular
aquatic plant related to the algae.
Diffuse spectral reflectance ratio of energy reflected by a
material at a specific wavelength.
Dimictic attribute of lakes mixed twice a year at homothermy
Dioxygenase One of a group of enzyme that catalyses the
incorporation of both atoms of molecular oxygen into
substrates.
Disproportionation specific type of redox reaction in
which a species is simultaneously reduced and oxidized
to form two different products.
Dissipation is the part of turbulence that is not expressed in
terms of movement but in the form of heat (related to the
viscosity of the fluid).
Dragon fantastic creature present in ancient maar-lake sto-
ries as Pavin and possibly Albano); presented as living
in the lake, it is very powerful, aerial, aquatic and/or tel-
luric creature with a poisonous breath and can be deadly
(e.g. Silvester dragon). These dragons, worshipped dur-
ing pagan times, often with human sacrifices, are often
defeated in early Christian times.
Ecosystem a biotic community and its surroundings, part
inorganic (abiotic) and part organic (biotic), the latter
including producers, consumers, and decomposers.
Electron acceptor A chemical entity that accepts electrons
transferred to it from another compound.
Electron donor A chemical entity that donates electrons to
another compound.
Enzyme A protein causing and accelerating chemical
reactions.
Epifluorescence microscopy Technique that allows obser-
vation by fluorescence of very small cells retained on a
filter.
Epilimnetic relating to epilimnion (see epilimnion).
Epilimnion the layer of water above the thermocline in
stratified lakes (see thermocline).
Epiphytic An organism that grows on a plant for support.
Equilibrium constants the value of the reaction quotient
(see reaction quotient) when the reaction has reached
equilibrium. At any given temperature, the equilibrium
constant has a value which is independent of the initial
and actual concentrations of the reactant and product
species.
Erosive layer coarse grained sediment deposit deposited
on top of an erosion surface that cuts into and eroded
part of the underlying sediments. This results in a gap
in time recording by sediment archives at the base of
the layer.
Erratic formation A term, now abandoned, that was used to
identify the deposits formed by the action of glaciers such
as moraines. Nopwadays, we would use till or moraine.
Euryarchaeota phylum within the Archaea including
methanogens.
Event stratigraphy chronologic arrangement (stratigra-
phy) that record geological rare events at any scale.
Exergonic process process in which there is a positive flow
of energy from the system to the surroundings.
FDPPMA 63 Departmental Federation of Fisheries
and Protection of the Aquatic Environment of the
Puy-de-Dôme.
Fairies fantastic creatures found in ancient Pavin legends.
They are essentially aerial and lure the passers by. They
are interpreted as C0 2 emissions.
Fantastic creatures representations of maar-lakes mis-
behaviors in ancient times stories (dragon, fairies) or in
Antique and medieval iconography (Minotaurus, Medusa,
Hydra, Mephytes).
Ferruginous enriched in dissolved ferrous iron (Fe2+).
Flow cytometry Laser-based, biophysical technology for
counting, examining and sorting microscopic particles
(after staining with fluorescent dye) by suspending them
in a stream of fluid and passing them through an opti-Glossary