Search results for "O2"

Photocatalytic oxidation of 4-methoxybenzyl alcohol to p-anisaldehyde in a fixed bed continuous reactor,

2008

Home-prepared anatase, rutile, and brookite TiO2 catalysts for selective photocatalytic oxidation of p-methoxybenzyl alcohol in water: reactivity and…

2008

Cardiac autonomic function reveals adaptation to military training

2011

Abstract The last 4 weeks of basic military training are very stressful. We tested the hypothesis that changes in cardiac autonomic function during this period are associated with changes in maximal oxygen uptake and/or serum hormonal concentrations in male conscripts (n=22). Cardiac vagal autonomic function was assessed by measuring the high-frequency (0.15–0.4 Hz) spectral power of R–R intervals. Maximal oxygen uptake ([Vdot]O2max) and basal serum testosterone concentration were measured at the beginning and end of the period. Individual changes in vagally mediated high-frequency power (range −15% to +25%) correlated (r=0.73, P=0.001) with changes in [Vdot]O2max (range −9% to +6%) and cha…

UN MODELLO EMPIRICO DI EMISSIONE DI CO2 DAL SUOLO: CURVE DI RISPOSTA ALLA TEMPERATURA ED ALL'UMIDITÀ DEL SUOLO DI UN AGROECOSISTEMA MEDITERRANEO

2012

Il presente lavoro è stato condotto su suolo prelevato all’interno di un oliveto con l’obiettivo di valutare il tasso di respirazione attribuibile alla componente eterotrofa (microbica) in funzione dei fattori temperatura ed umidità. Il tasso di respirazione è stato monitorato su suolo incubato a cinque livelli di temperatura, 10-15-20-25-30 °C e a quattro livelli del contenuto idrico volumetrico del suolo (θ) 12,6-18,9-25,2-31,5 % (v/v). I valori di respirazione hanno presentato un range di valori variabili tra 78,20 e 14,81 µg CO2 g-1 soil d-1 rispettivamente a 30°C e 10°C e a 12,6 e 31,5 %. I valori di Q10, ovvero la risposta della respirazione in relazione agli incrementi di temperatura…

Fruit productivity and carbon gain of Opuntia ficus-indica (L.) Mill. trees

2012

Opuntia ficus-indica (OFI) tree and orchards efficiency has been poorly studied, in terms of relation between orchard lay out, light interception, and cropping efficiency. Apparently, there is no other way to increase orchard production than increasing the number either of trees ha-1 or fertile shoots tree-1, considering that a fruit count higher than 6-7 cladode-1 reduces fruit harvest size. The first option requires a reduction of unit tree size and canopy volume. The second option implies the use of large trees that often reduce their efficiency 12-15 years after planting. In 15-year-old OFI trees spaced 6 5 m apart trained to a globe and 2.5-3.0 m high, stem area index (SAI) calculated …

A system for the oxygen continuous monitoring inside the malaxation machine to enhance the Sicilian extra virgin olive oil typicality

2010

H2O2 INDUCES NECROPTOSIS IN MESOANGIOBLAST STEM CELLS

2018

Stem cells are used in regenerative medicine, but their therapeutic efficacy is compromised by their huge death during the first days post-transplantation. Indeed, the microenvironment within damaged tissues is hostile for stem cell survival mainly due to oxidative stress. H2O2 may play a relevant role in inducing death of the injected cells. The aim of our study was to determine the mechanism of mesoangioblast (A6) cell death after an H2O2 treatment. FACS analysis with annV/PI showed that H2O2 induced a dose and time-dependent decrement in A6 viability. We have also found an increase in caspases 8, 9 and 3 activity after the treatment. To assess their involvement in cell death, the pan cas…

The duality of ocean acidification as a resource and a stressor

2018

Ecologically dominant species often define ecosystem states, but as human disturbances intensify, their subordinate counterparts increasingly displace them. We consider the duality of disturbance by examining how environmental drivers can simultaneously act as a stressor to dominant species and as a resource to subordinates. Using a model ecosystem, we demonstrate that CO2-driven interactions between species can account for such reversals in dominance; i.e., the displacement of dominants (kelp forests) by subordinates (turf algae). We established that CO2 enrichment had a direct positive effect on productivity of turfs, but a negligible effect on kelp. CO2 enrichment further suppressed the …

Effects of ocean acidification on the shells of four Mediterranean gastropod species near a CO2 seep

2017

Marine CO2seeps allow the study of the long-term effects of elevated pCO2(ocean acidification) on marine invertebrate biomineralization. We investigated the effects of ocean acidification on shell composition and structure in four ecologically important species of Mediterranean gastropods (two limpets, a top-shell snail, and a whelk). Individuals were sampled from three sites near a volcanic CO2seep off Vulcano Island, Italy. The three sites represented ambient (8.15 pH), moderate (8.03 pH) and low (7.73 pH) seawater mean pH. Shell mineralogy, microstructure, and mechanical strength were examined in all four species. We found that the calcite/aragonite ratio could vary and increased signifi…

Ocean acidification as a driver of community simplification via the collapse of higher-order and rise of lower-order consumers

2017

AbstractIncreasing oceanic uptake of CO2 is predicted to drive ecological change as both a resource (i.e. CO2 enrichment on primary producers) and stressor (i.e. lower pH on consumers). We use the natural ecological complexity of a CO2 vent (i.e. a seagrass system) to assess the potential validity of conceptual models developed from laboratory and mesocosm research. Our observations suggest that the stressor-effect of CO2 enrichment combined with its resource-effect drives simplified food web structure of lower trophic diversity and shorter length. The transfer of CO2 enrichment from plants to herbivores through consumption (apparent resource-effect) was not compensated by predation, becaus…