Experimental Evidence of the Tolerance to Chlorate of the Aquatic Macrophyte Egeria densa in a Ramsar Wetland in Southern Chile

Urea and heavy metals (Ni2+ and Cu2+) higher concentration infl uence on the photosynthetic pigments’ content, lipids peroxidation intensity and urease ferments activity in the submerged aquatic macrophyte – Egeria densa Planch. have been studied. It has been shown that addition of metals to the medium with urea tends to strengthen its toxic effect upon plants. It has been found that four-day long hatching of plants in the medium with urea and nickel lead to the oxidative stress development in Canada water weed leaves. Copper concentration equal to 100 mkmol/l appeared to be lethal for plants.

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Recovery of black-necked swans, macrophytes and water quality in a Ramsar wetland of southern Chile: Assessing resilience following sudden anthropogenic disturbances

The Science of The Total Environment ◽

10.1016/j.scitotenv.2018.01.333 ◽

2018 ◽

Vol 628-629 ◽

pp. 291-301 ◽

Cited By ~ 7

Author(s):

Eduardo Jaramillo ◽

Nelson A. Lagos ◽

Fabio A. Labra ◽

Enrique Paredes ◽

Emilio Acuña ◽

...

Keyword(s):

Water Quality ◽

Anthropogenic Disturbances ◽

Southern Chile ◽

Ramsar Wetland

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Dietary habits of the black-necked swan Cygnus melancoryphus (Birds: Anatidae) and variability of the aquatic macrophyte cover in the Río Cruces wetland, southern Chile

PLoS ONE ◽

10.1371/journal.pone.0226331 ◽

2019 ◽

Vol 14 (12) ◽

pp. e0226331

Author(s):

Carlos Velásquez ◽

Eduardo Jaramillo ◽

Patricio Camus ◽

Fabio Labra ◽

Cristina San Martín

Keyword(s):

Dietary Habits ◽

Aquatic Macrophyte ◽

Southern Chile ◽

Macrophyte Cover

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Photosynthesis in the Aquatic Macrophyte Egeria densa. III. Gas Exchange Studies

Functional Plant Biology ◽

10.1071/pp9790499 ◽

1979 ◽

Vol 6 (4) ◽

pp. 499 ◽

Cited By ~ 17

Author(s):

JA Browse ◽

FI Dromgoole ◽

JMA Brown

Keyword(s):

Gas Exchange ◽

Aquatic Macrophyte ◽

Ambient Medium ◽

Co2 Concentration ◽

Co2 Assimilation ◽

Open Circuit ◽

Co2 Uptake ◽

Total Resistance ◽

Egeria Densa ◽

Co2 Response

When free CO2 alone was present in the ambient medium, photosynthesis by Egeria densa Planch displayed an apparent Km of 77 μM. A light- and CO2-saturated rate of 100 μmol C (mg Chl)-1 h-1 was achieved only in 400 μM CO2(aq) [c. 1% CO2(g)]. The CO2 response data and other considerations suggest that, although the carboxylation and mesophyll resistances (3800 s m-1 and <9000 s m-1 respectively) are considerably higher than in aerial plant leaves, the boundary layer is the highest component (> 27 000 s m-1) of the total resistance. An increase in the total resistance of 7200 s m-1 between 0.02 and 0.21 atm O2 (2 and 21 kPa O2) is attributed to photorespiration. Closed and open circuit gas exchange experiments demonstrated that bicarbonate is taken up by the plant cells and does not act merely as a reservoir of inorganic carbon for production of CO2 at the plasmalemma. Bicarbonate stimulated photosynthesis, even when the free CO2 concentration was below the CO2 compensation point. The total resistance to bicarbonate uptake appears to be 8-12 times that for CO2 uptake presumably due to the processes of active uptake, transport and/or conversion to CO2 involved in bicarbonate but not CO2 assimilation.

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Photosynthetic rate of the aquatic macrophyte Egeria densa Planch. (Hydrocharitaceae) in two rivers from the Itanhaém River Basin in São Paulo State, Brazil

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132004000100021 ◽

2004 ◽

Vol 47 (1) ◽

pp. 153-162 ◽

Cited By ~ 8

Author(s):

Maura Maria Pezzato ◽

Antonio Fernando Monteiro Camargo

Keyword(s):

River Basin ◽

Photosynthetic Rate ◽

Aquatic Macrophyte ◽

Electric Energy ◽

Egeria Densa ◽

Gross Photosynthesis ◽

Paulo State ◽

Total Phosphorous ◽

Water And Sediment ◽

Multiple Uses

Egeria densa is a submerged aquatic macrophyte which, in Brazil, causes problems specially for electric energy generation. The purpose of this study was to evaluate the photosynthetic rate of E. densa in two rivers (Aguapeú and Mambu) with different limnological features, both located in the Itanhaém River Basin. This species is abundant in both rivers without causing damages to their multiple uses. Photosynthetic rates were analysed in February, May, August and November 1998 and limnological variables of the water and sediment were also measured. The highest value of gross photosynthesis (GP) was detected in May (10.06 in Aguapeú and 6.10 mgO2/gDW/h in Mambu), when under-water photosynthetic active radiation (PAR) was also high (1,126.7 and 895.8 m mol/m/s, respectively). GP, total phosphorous, total CO2 and PAR were always higher in Aguapeú River.

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How do memory modules differentially contribute to familiarity and recollection?

Behavioral and Brain Sciences ◽

10.1017/s0140525x19001833 ◽

2019 ◽

Vol 42 ◽

Author(s):

Olya Hakobyan ◽

Sen Cheng

Keyword(s):

Recognition Memory ◽

Experimental Evidence ◽

Subjective Experience ◽

Target Article ◽

Memory Modules ◽

Familiarity And Recollection ◽

Memory Contents

Abstract We fully support dissociating the subjective experience from the memory contents in recognition memory, as Bastin et al. posit in the target article. However, having two generic memory modules with qualitatively different functions is not mandatory and is in fact inconsistent with experimental evidence. We propose that quantitative differences in the properties of the memory modules can account for the apparent dissociation of recollection and familiarity along anatomical lines.

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Redox Reactions in Lipid Membranes as a Model for Primordial Energy-Conserving Systems

International Astronomical Union Colloquium ◽

10.1017/s0252921100014950 ◽

1997 ◽

Vol 161 ◽

pp. 437-442

Author(s):

Salvatore Di Bernardo ◽

Romana Fato ◽

Giorgio Lenaz

Keyword(s):

Experimental Evidence ◽

Lipid Membranes ◽

Energy Supply ◽

Redox Reactions ◽

Living Systems ◽

Asymmetric Distribution ◽

Conservation Of Energy ◽

Asymmetrical Distribution ◽

Energy Conserving ◽

Living Organisms

AbstractOne of the peculiar aspects of living systems is the production and conservation of energy. This aspect is provided by specialized organelles, such as the mitochondria and chloroplasts, in developed living organisms. In primordial systems lacking specialized enzymatic complexes the energy supply was probably bound to the generation and maintenance of an asymmetric distribution of charged molecules in compartmentalized systems. On the basis of experimental evidence, we suggest that lipophilic quinones were involved in the generation of this asymmetrical distribution of charges through vectorial redox reactions across lipid membranes.

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