Search results for "Functional Groups"

showing 9 items of 19 documents

Morphological analysis of phytoplankton as a tool to assess ecological state of aquatic ecosystems: the case of Lake Arancio, Sicily, Italy

2013

Phytoplankton requires a sufficient supply of light and nutrients to grow. At the same time it is largely entrained in water motion and is subject to grazing from planktonic herbivores. The pelagic life of lake phytoplankton is based on 4 pillars: living in suspension, light harvesting, nutrient uptake, and escape from grazing. Environmental variability and the uneven distribution of resources among and within the different aquatic ecosystems exert a selective pressure on these organisms, which are formed by a single cell or by colonies with either relatively low or high numbers of cells. Phytoplankton displays an amazing morphological variability representing an adaptation to spatial and t…

Mediterranean climateHerbivoreC-S-R strategies freshwater phytoplankton functional groups maximal linear dimension shape size surface volumeVolumeEcologyC-S-R strategieAquatic ecosystemMaximal linear dimensionShapePelagic zoneAquatic SciencePlanktonBiologySurfaceNutrientSizeSettore BIO/03 - Botanica Ambientale E ApplicataPhytoplanktonFunctional groupFreshwater phytoplanktonWater Science and TechnologyTrophic levelInland Waters
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Phytoplankton responses to human impacts at different scales

2012

This book: Deals with eutrophication impact on ecosystem functioning with a different focus and broader perspective. Takes into account the effects of multiple stressors on microalgal assemblages. Includes specific contributions on the autoecology and taxonomy of dinoflagellates and cyanobacteria. Features examples of applications of the morphology-, morpho-functional and functional groups (FG), (MFG) and (MBFG) Phytoplankton responses to human impact at different scales provides a state-of-the-art review of changes in the phytoplankton assemblages determined by human alterations of lakes and rivers. A wide spectrum of case studies describe the effects due to eutrophication and climate chan…

OceanographyEcologyPhytoplanktonSettore BIO/03 - Botanica Ambientale E ApplicataEnvironmental scienceAnthropogenic Impacts Climate Change Effects Phytoplankton Functional Groups Phytoplankton Molecular Taxonomy Phytoplankton Responses
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Dynamics and reactivity in Thermus aquaticus N6-adenine methyltransferase.

2014

M.TaqI is a DNA methyltransferase from Thermus aquaticus that catalyzes the transfer of a methyl group from S-adenosyl-l-methionine to the N6 position of an adenine, a process described only in prokaryotes. We have used full atomistic classical molecular dynamics simulations to explore the protein–SAM–DNA ternary complex where the target adenine is flipped out into the active site. Key protein–DNA interactions established by the target adenine in the active site are described in detail. The relaxed structure was used for a combined quantum mechanics/molecular mechanics exploration of the reaction mechanism using the string method. According to our free energy calculations the reaction takes…

Reaction mechanismSite-Specific DNA-Methyltransferase (Adenine-Specific)BioinformaticsStereochemistryProtein ConformationMolecular Dynamics SimulationBiochemistryCatalysisMolecular dynamicschemistry.chemical_compoundColloid and Surface ChemistryReaction rate constantAbstractingA-DNAThermusTernary complexThermus aquaticusbiologyActive siteGeneral ChemistryDNAbiology.organism_classificationchemistryFunctional groupsbiology.proteinAmino acidsNucleic Acid ConformationQuantum TheoryThermodynamicsMethyl groupJournal of the American Chemical Society
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Equilibrium/steady-state concept in phytoplankton ecology

2003

This paper summarises the outcomes of the 13th Workshop of the International Association of Phytoplankton Taxonomy and Ecology (IAP). The authors mostly addressed their contributions on the following topics: the effect of trophic state on the attainment of a steady-state; the establishment of equilibria in deep and shallow lakes; the role of spatial heterogeneity, disturbance, and stress in the establishment of equilibrium assemblages; the mechanisms leading to the steady state; the frequency and longevity of equilibrium phases, and the role of morphological and physiological plasticity of phytoplankton in maintaining the (apparently) same populations under different environmental condition…

Settore BIO/03 - Botanica Ambientale E ApplicataAquatic Scienceequilibrium steady-state functional groups phytoplankton associationsHydrobiologia
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Comparing biological classifications of freshwater phytoplankton: a case study from South China

2012

The use of ecological classification systems is becoming more and more widely used when studying phytoplankton. Grouping phytoplankton species into ecologically coherent groups allow to reduce redundancy and in this way, to handle a minor number of biological variables when investigating the ecological status of aquatic ecosystems. Three ecological classifications are mostly used when freshwater phytoplankton is studied: functional groups or coda, morpho-functional groups (MFGs) and morphology-based functional groups (MBFGs). In this study, these three ecological classifications were comparatively used along with two taxonomic classifications based on species and genera to analyse phytoplan…

South chinaEcologyCanonical correspondence analysisAquatic ecosystemEcology (disciplines)Settore BIO/03 - Botanica Ambientale E ApplicataPhytoplanktonFunctional groups Morpho-functional groups Morphology-based functional groups Taxonomic groups Physical constraints ReservoirsTaxonomic rankAquatic ScienceBiologyExplained variationCodaHydrobiologia
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Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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MODIFICATION OF HUMIC SUBSTANCES FOR DEVELOPMENT OF MATERIALS FOR ENVIRONMENTAL TECHNOLOGIES

2019

Humic substances are high molecular weight refractory polycationites formed during decay of living organic matter and through biosynthesis of low molecular weight organic substances (metabolites or decay products of living organisms). Presence of many functional groups in the structure of humic substances determines their ability to interact with metal ions forming stable complexes and influencing metal ion speciation in the environment and mobility, behaviour and speciation forms in the environment. Presently humic substances are a product of industrial scale and quantities in amounts of hundreds of tons are produced. The aim of this study is to analyse derivatization possibilities of humi…

chemistry.chemical_classificationMetal ions in aqueous solutionhumic substances; modification; functional groups; pollutants; remediationInner sphere electron transfercomplex mixturesMetalAcylationchemistry.chemical_compoundchemistryElemental analysisvisual_artFunctional groupvisual_art.visual_art_mediumOrganic chemistryOrganic matterDerivatizationENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference
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Sūnu daudzveidība uz atmirušās koksnes egļu mežos saistībā ar koksnes vecumu un substrāta īpašībām

2015

Atmirusī koksne ir specifisks un dinamisks substrāts. Tā kalpo kā dzīves vide daudzām retām un tieši šim substrātam specifiskām sūnu sugām, kas norāda uz nepieciešamību veikt detalizētus pētījumus par atmirušo koksni kā sūnām nozīmīgu substrātu. Pētījumā salīdzināts sūnu sugu un funkcionālo grupu sastāvs uz dažādiem atmirušās koksnes veidiem (kritalām, stumbeņiem, sausokņiem), analizēta sūnu sugu un funkcionālo grupu bagātība saistībā ar atmirušās koksnes vecumu un substrāta parametriem (izmēri, sadalīšanās pakāpe). Kopumā uz visiem atmirušās koksnes veidiem konstatētas 53 sūnu sugas (40 lapu un 13 aknu sūnas). Novērotas atšķirības sūnu sugu sastāvā starp kritalām un stāvošu atmirušo koksni…

functional groupsagecoarse woody debrisepixylic speciesBioloģija
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Study of the role of sulfur functionalities in humic acids for uranium(VI) complexation

2009

Humic substances influence the speciation and migration behavior of toxic and radiotoxic metal ions, such as actinides, in the environment. Depending on their origin, humic substances contain different amounts of sulfur ranging from 0.1 to 3.6% and 0.5 to 1.43% in soil and aquatic humic substances, respectively [1]. Reduced, intermediately oxidized and highly oxidized sulfur functionalities occur in humic substances [1]. Although sulfur functionalities occur in small concentrations, they can play an important role in the complexation of selected metal ions. Knowledge about the impact of sulfur functionalities on the metal ion complexation by humic substances and their significance compared …

inorganic chemicalsfs-TRLFScomplexationInorganic chemistryTRLFSchemistry.chemical_elementHumic substancesOxygencomplex mixturesFluorescence spectroscopysulfur functionalitiesfunctional groupsX-ray photoelectron spectroscopyXPSHumic acidPhysical and Theoretical Chemistrychemistry.chemical_classificationLigandUraniumSulfurhumic acidshumic acid model substanceschemistryHumic aciduranium(VI)sulfurThiol
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