Search results for "O2"

Are control of extracellular acid-base balance and regulation of skeleton genes linked to resistance to ocean acidification in adult sea urchins?

2020

SCOPUS: ar.j

Seagrass response to high CO2 in volcanic vents

2012

Study of the trophic and functional organization of fish assemblages in submarine shallow CO₂ vents

2014

Naturally acidified marine ecosystems are currently investigated to evaluate the effects of ocean acidification on species, communities and ecological processes. Among these, submarine shallow CO₂ vents represent a sort of natural mesocosms, where at small spatial scales marked gradient of pH are present. The aim of this project is to study the responses of fish assemblages to pH reduction in Mediterranean shallow CO₂ vents by using several descriptors such as community structure, trophic organization, chemical characteristics and composition of carbonic structures. Moreover as in CO₂ vents concentration and bio-availability of several trace elements, also toxic ones, may increase due to di…

Effect of explosive shallow hydrothermal vents on δ13C and growth performance in the seagrass Posidonia oceanica

2010

1. Explosive volcanic submarine activity is expected to affect seagrass communities due to sudden and dramatic changes in the physical and chemical features of sea water and sediments, with possibly large ecosystem effects. However, seagrass response to the harsh environmental conditions that arise due to explosive volcanism is as yet unexplored as it is not easy to predict when and where an eruption will occur. Here, we investigate the uptake of hydrothermal carbon within the seagrass Posidonia oceanica by the analysis of d13C and growth rates in tissue laid down before and after an exceptional and massive hydrothermal gas release in the Aeolian Islands (Italy, Mediterranean Sea). 2. Hydro…

Studio della comunità associata allo strato fogliare di Posidonia oceanica in sorgenti sottomarine superficiali di CO2

2011

Stable isotope signatures of selected benthos at natural carbon dioxide vents: preliminary results on macrophytes

2013

Registration of past submarine massive outgassing events in Posidonia oceanica L. (Delile) through stable carbon isotopes

2009

Macroalgal responses to ocean acidification depend on nutrient and light levels. Frontiers in Marine Science

2015

Ocean acidification may benefit algae that are able to capitalize on increased carbon availability for photosynthesis, but it is expected to have adverse effects on calcified algae through dissolution. Shifts in dominance between primary producers will have knock-on effects on marine ecosystems and will likely vary regionally, depending on factors such as irradiance (light vs. shade) and nutrient levels (oligotrophic vs. eutrophic). Thus experiments are needed to evaluate interactive effects of combined stressors in the field. In this study, we investigated the physiological responses of macroalgae near a CO2 seep in oligotrophic waters off Vulcano (Italy). The algae were incubated in situ …

Influence of the Substituent on Selective Photocatalytic Oxidation of Aromatic Compounds in Aqueous TiO2 Suspensions.

2006

Experimental results are reported showing that the photocatalytic oxidation of aromatic compounds containing an electron-donor group (EDG) gives rise mainly to ortho- and para-monohydroxy derivatives while in the presence of an electron-withdrawing group (EWG) all the monohydroxy derivatives are obtained.

Sunlight-induced functionalisation reactions of heteroaromatic bases with aldehydes in the presence of TiO2: A hypothesis on the mechanism

2007

In previous studies we reported a new photocatalytic system involving polycrystalline TiO2 for the selective functionalisation of heteroaromatic bases with ethers and amides. In order to extend the applications of this new reaction and to better understand the mechanism involved, we have examined aromatic and aliphatic aldehydes as acyl radical sources for the nucleophilic addition to protonated N-heteroarenes in acetonitrile as the solvent and TiO2/H2O2 as the photocatalytic system. Acyl radicals may undergo decarbonylation to yield the corresponding alkyl radicals. Acyl/alkyl derivative ratios depend on the nature of the aldehydes, and present a different distribution from that obtained i…