Search results for "elemental"

showing 10 items of 131 documents

Macroalgal responses to ocean acidification depend on nutrient and light levels

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 …

Ocean Acidification International Coordination Centre (OA-ICC)TemperateSalinityChlorophyll aFucoxanthininorganicAlkalinityPhotosynthetic efficiency standard errorChlorophyll cNitrogen content per dry mass standard errorLight saturation point standard errorPhenolics allTemperature waterCarbon inorganic dissolvedMacroalgaeCalculated using seacarb after Nisumaa et al 2010Carbon Nitrogen ratioAragonite saturation stateAlkalinity totalallCarbon per dry massSalinity standard errortotalCarbon content per dry mass standard errorPhenolics all standard errorCO2 ventChromistapHMaximum photochemical quantum yield of photosystem II standard errorTemperaturePartial pressure of carbon dioxide (water) at sea surface temperature (wet air) standard errordissolvedAntioxidant activity standard errorCarbonate ionMaximum photochemical quantum yield of photosystem IIPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Field experimentstandard errorNitrogen content per dry massElectron transport rate standard errorFucoxanthin standard errorEarth System ResearchViolaxanthinPhenolicsChlorophyll a standard errorCarbon dioxide standard errorPotentiometric titrationCalcite saturation stateCarbon/Nitrogen ratio standard errorNitrogenOchrophytaPotentiometricper dry masswaterChlorophyll c standard errorBenthosAlkalinity total standard errorAntioxidant activityElectron transport rateLight saturation pointOcean Acidification International Coordination Centre OA ICCMacro-nutrientsMediterranean SeaNitrogen per dry massBicarbonate ionTemperature water standard errorCalculated using seacarb after Nisumaa et al. (2010)Primary production PhotosynthesisSpeciespH standard errorCalcite saturation state standard errorCystoseira compressaCalculated using CO2SYSNon photochemical quenchingCarbon content per dry massCarbonate system computation flagViolaxanthin standard errorPrimary production/PhotosynthesisFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonCarbon/Nitrogen ratioBiomass/Abundance/Elemental compositionTreatmentPartial pressure of carbon dioxide water at sea surface temperature wet airAragonite saturation state standard errorCarbon dioxideMacro nutrientsCarbonate ion standard errorSingle speciesFugacity of carbon dioxide water at sea surface temperature wet airPadina pavonicaBiomass Abundance Elemental compositionCoast and continental shelfPhotosynthetic efficiencyBicarbonate ion standard errorNon photochemical quenching standard error
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Seagrass ecosystem response to long-term high CO2 in a Mediterranean volcanic vent

2014

We examined the long-term effect of naturally acidified water on a Cymodocea nodosa meadow growing at a shallow volcanic CO2 vent in Vulcano Island (Italy). Seagrass and adjacent unvegetated habitats growing at a low pH station (pH = 7.65 ± 0.02) were compared with corresponding habitats at a control station (pH = 8.01 ± 0.01). Density and biomass showed a clear decreasing trend at the low pH station and the below- to above-ground biomass ratio was more than 10 times lower compared to the control. C content and delta 13C of leaves and epiphytes were significantly lower at the low pH station. Photosynthetic activity of C. nodosa was stimulated by low pH as seen by the significant increase in…

Ocean Acidification International Coordination Centre (OA-ICC)TemperateSalinityChlorophyll ainorganicAlkalinityLight saturation point standard errorPhotosynthetic quantum efficiencyMediterranean Sea Acidification in a Changing Climate MedSeATemperature waterCarbon inorganic dissolvedCalculated using seacarb after Nisumaa et al 2010IrradianceRespiration rate carbonAragonite saturation stateBiomassAlkalinity totalIrradiance standard errortotalCO2 ventCymodocea nodosapHRespirationEpiphytes loadMaximum photochemical quantum yield of photosystem II standard errorNet community production of carbonTemperaturePartial pressure of carbon dioxide (water) at sea surface temperature (wet air) standard errordissolvedRespiration rate carbon standard errorCarbonate ionMaximum photochemical quantum yield of photosystem IIPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Net community production of carbon standard errorIlluminance standard errorSoft bottom communitystandard errorCarbon inorganic dissolved standard errorRespiration rateElectron transport rate standard errorEarth System Researchδ13CPhotosynthetic quantum efficiency standard errorField observationChlorophyll a standard errorGross primary production of carbonBiomass standard errorCalcium carbonatePotentiometric titrationCalcite saturation stateShoot densityPotentiometricwaterIlluminanceOxygen standard errorBenthosAlkalinity total standard errorMediterranean Sea Acidification in a Changing Climate (MedSeA)Electron transport rateLight saturation pointOcean Acidification International Coordination Centre OA ICCMediterranean SeaGross primary production of carbon standard errorBicarbonate ionSoft-bottom communityδ13C standard errorTemperature water standard errorCalculated using seacarb after Nisumaa et al. (2010)Primary production PhotosynthesisSpeciespH standard errorCarbonate system computation flagloadPrimary production/PhotosynthesisFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonBiomass/Abundance/Elemental compositionTreatmentEpiphytes load standard errorOxygenPartial pressure of carbon dioxide water at sea surface temperature wet airEpiphytes loadCarbon dioxideCarbon standard errorEntire communityFugacity of carbon dioxide water at sea surface temperature wet airGroupBiomass Abundance Elemental compositionCoast and continental shelfEpiphytesShoot density standard errorCalcium carbonate standard error
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Decline in Coccolithophore Diversity and Impact on Coccolith Morphogenesis Along a Natural CO2 Gradient

2014

A natural pH gradient caused by marine CO2 seeps off Vulcano Island (Italy) was used to assess the effects of ocean acidification on coccolithophores, which are abundant planktonic unicellular calcifiers. Such seeps are used as natural laboratories to study the effects of ocean acidification on marine ecosystems, since they cause long-term changes in seawater carbonate chemistry and pH, exposing the organisms to elevated CO2 concentrations and therefore mimicking future scenarios. Previous work at CO2 seeps has focused exclusively on benthic organisms. Here we show progressive depletion of 27 coccolithophore species, in terms of cell concentrations and diversity, along a calcite saturation …

Ocean Acidification International Coordination Centre (OA-ICC)TemperateSalinityCommunity composition and diversityinorganicAlkalinityCoccospheres malformedMediterranean Sea Acidification in a Changing Climate MedSeATemperature waterCarbon inorganic dissolvedCalculated using seacarb after Nisumaa et al 2010Aragonite saturation stateAlkalinity totaltotalCO2 ventpHPelagosTemperaturedissolvedCarbonate ionPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Earth System ResearchmalformedField observationPotentiometric titrationCalcite saturation stateCoccospheresPotentiometricwaterGrowth MorphologyMediterranean Sea Acidification in a Changing Climate (MedSeA)Ocean Acidification International Coordination Centre OA ICCMediterranean SeaBicarbonate ionCalculated using seacarb after Nisumaa et al. (2010)Calculated using CO2SYSfungiCarbonate system computation flagCoccospheres corrodedFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonBiomass/Abundance/Elemental compositionPartial pressure of carbon dioxide water at sea surface temperature wet airSample IDCarbon dioxidecorrodedEntire communityGrowth/MorphologyPhytoplanktonFugacity of carbon dioxide water at sea surface temperature wet airBiomass Abundance Elemental compositionCoast and continental shelfNumber of species
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The miniaturised Mössbauer spectrometer MIMOS IIA: Increased sensitivity and new capability for elemental analysis

2010

The Miniaturised Mossbauer Spectrometers MIMOS II on board the two Mars Exploration Rovers (MER) have now been collecting valuable scientific data for more than five years. Mossbauer Spectrometers are part of two future missions: Phobos Grunt (Russian Space Agency) and a joint ESA—NASA Rover in 2018. The new advanced MIMOS IIA instrument described in this paper uses Silicon Drift Detectors (SDD) allowing also X-ray fluorescence chemical analysis (XRF) simultaneously to Mossbauer acquisitions. This paper highlights the features and technological improvements of the new spectrometer MIMOS IIA.

On boardPhysicsNuclear and High Energy PhysicsSilicon drift detectorSpectrometerElemental analysisMössbauer spectroscopyNondestructive analysisMars Exploration ProgramExploration of MarsInstrumentationRemote sensingNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
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Chemical characterization of ancient potteries from Himera and Pestavecchia necropolis (Sicily, Italy) by Inductively Coupled Plasma–Optical Emission…

2011

Abstract Thirty-eight samples of pottery were analyzed for determining chemical composition in order to establish their provenance. The potteries tested in the present research come from Himera and Pestavecchia archaeological sites. After digestion in microwave oven, the samples have been analyzed for fourteen minor elements (Ba, Cd, Co, Cr, Cu, Ga, Li, Mn, Ni, Pb, Sr, Ti, Tl, and Zn) and six major elements (Al, Ca, Fe, K, Mg, and Na). Chemical analysis was carried out by Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP–OES). The most abundant minor elements are Cr, Ba and Ni. Cr concentration ranged from 66 to 3635 mg kg − 1 , Ba concentration ranged from 388 to 2677 mg kg − 1…

PCAProvenanceChemistryMicrowave ovenAnalytical chemistryAncient potterieSettore CHIM/12 - Chimica Dell'Ambiente E Dei Beni CulturaliAnalytical Chemistryvisual_artInductively coupled plasma atomic emission spectroscopyElemental compositionClustering analysivisual_art.visual_art_mediumPotteryEmission spectrumCeramicInductively coupled plasmaICP–OESChemical compositionSpectroscopyHimeraMicrochemical Journal
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Characterization of foxing stains in early twentieth century photographic and paper materials

2016

The subject of this present work is a group of nine historical pictures shot in Palermo by the Sicilian photographer E. Interguglielmi in 1912. They are nine matte-collodion prints mounted on the original cardboard supports and all of them show foxing stains affecting the paper surface. In order to characterise the chemical composition of the supports and investigate foxing spots, non-destructive and micro-destructive analysis were carried out. X-rays fluorescence (XRF) analysis was used to characterise the elemental composition of all the mounting boards, allowing a comparison between the foxing spots and non-affected areas. Laser-Induced Breakdown Spectroscopy was used to investigate the …

PaperFoxingSurface Propertiesmedia_common.quotation_subjectXRFMineralogyPlant Science01 natural sciencesBiochemistryAnalytical ChemistryPhotographyColoring AgentsColoring AgentSpectrum Analysimedia_commonElemental compositionLIBS010405 organic chemistrySpectrum AnalysisFoxingOrganic ChemistrySpectrometry X-Ray EmissionSettore CHIM/06 - Chimica OrganicaArtHistory 20th CenturyArchaeologySettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)0104 chemical sciencesCharacterization (materials science)010404 medicinal & biomolecular chemistrySEMfungiNatural Product Research
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Vertical distribution of AhR-activating compounds in sediments contaminated by modernized pulp and paper industry

2013

Increased ethoxyresorufin-O-deethylase (EROD) activity is a sensitive biomarker of exposure to the chemicals which activate the aryl hydrocarbon receptor (AhR) and induce the cytochrome P450 system, such as many polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). Pulp bleaching was one of the main sources of PCDDs and PCDFs until elemental chlorine free (ECF) and total chlorine free bleaching processes since 1990s have remarkably decreased but not completely eliminate discharges of these chemicals. In addition, historically contaminated sediments may act as a source of these persistent contaminants. In this study, the contam…

PaperGeologic SedimentsEnvironmental EngineeringPolychlorinated Dibenzodioxinsta1172Elemental chlorine freeIndustrial Wastechemistry.chemical_compoundLimit of DetectionCytochrome P-450 CYP1A1AnimalsSoil PollutantsWaste Management and DisposalFinlandWater Science and TechnologyCivil and Structural EngineeringBenzofuransReteneGeographyEcological Modelingfood and beveragesPolychlorinated biphenylSedimentContaminationDibenzofurans PolychlorinatedPulp and paper industryPollutionPolychlorinated BiphenylsKraft processchemistryLiverReceptors Aryl HydrocarbonCesium RadioisotopesEnvironmental chemistryOncorhynchus mykissSewage treatmentPolychlorinated dibenzofuransWater Research
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An Effective Field Theory study of heavy meson-heavy antimeson molecules based on Heavy Quark Symmetries

2015

189 páginas. Tesis Doctoral del Departamento de Física Teórica de la Universidad de Valencia y del Instituto de Física Corpuscular (IFIC).

Partículas elementales:FÍSICA [UNESCO]High Energy Physics::LatticeNuclear TheoryHigh Energy Physics::PhenomenologyUNESCO::FÍSICATeoría cuántica de camposHigh Energy Physics::ExperimentHadronesNuclear Experiment
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Ultrastructural localization of Ca2(+)-binding sites in the middle ear mucosa of the rat.

1990

Cations were precipitated with potassium-pyroantimonate in the middle ear mucosa of the rat and the distribution of the formed precipitates was studied by electron microscopy. The precipitate density in various cells of the different epithelia of the middle ear mucosa was determined on electron micrographs by counting the number of precipitates per unit area. Electron spectroscopic imaging was also performed to obtain information about the spatial distribution of the precipitates and their elemental composition.

Pathologymedicine.medical_specialtyEar MiddleBiologylaw.inventionlawMiddle ear mucosamedicineAnimalsTissue DistributionElemental compositionBinding SitesMucous MembraneRats Inbred StrainsGeneral MedicineRatsmedicine.anatomical_structureOtorhinolaryngologyElectron micrographsHead and neck surgeryMiddle earBiophysicsUltrastructureCalciumCa2 bindingElectron microscopeEuropean archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery
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La duplicidad de la acción en la filosofía de Giuseppe Capograssi, a la luz de la noción de experiencia elemental de Luigi Giussani

2022

La insistencia de Giussani en el alcance crítico de la experiencia me llevó a la filosofía de Capograssi. Este alude reiteradamente a un orden de principios y evidencias profundas, cuya luz permite al sujeto ver las cosas en su verdad, bondad y belleza. La relación entre estas ideas viquianas y la noción de experiencia elemental de Giussani, en su doble nivel óntico y ontológico, se percibe en la duplicidad de la acción que, más allá de su inmediatez, se alimenta de una vis veri, verdadero motor del individuo, de ese yo metafísico que es más de lo que aparenta. Giussani's insistence on the critical scope of experience led me to Capograssi's philosophy. He repeatedly alludes to an order of p…

Philosophyexperiencia elementalUNESCO::FILOSOFÍA:FILOSOFÍA [UNESCO]CapograssifilosofíaLuigi GiussaniLawduplicidad de la acción
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