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’Emulsion locks’ for the containment of hydrocarbons during surfactant flushing

Journal of Environmental Sciences 2020年第4期32卷 98-109页

作者： kristine lamont Alejandro GMarangoni Erica Pensini University of Guelph School of Engineering50 Stone Road EastGwelph ONNIG 2W1Canada University of Guelph Food Science Department50 Stone Road EastGuelph ONNIG 2WlCanada

Reversible double water in oil in water(W/O/W)emulsions were developed to contain subsurface hydrocarbon spills during their remediation using surfactant flushing.Double emulsions were prepared by emulsifying CaCl2 solutions in canola oil,and subsequently by emulsifying the W/O emulsions in aqueous sodium alginate solutions.The formation of double emulsions was confirmed with confocal and optical microscopy.The double emulsions reversed and gelled when mixed with the surfactants sodium dodecyl sulfate(SDS)and cocamidopropyl betaine(CPB).Gels can act as’emulsion locks’to prevent spreading of the hydrocarbon plume from the areas treated with surfactant flushing,as shown in sand column tests.Shear rheology was used to quantify the viscoelastic moduli increase(gelation)upon mixing the double emulsion with SDS and CPB.SDS was more effective than CPB in gelling the double emulsions.CPB and SDS could adsorb at the interface between water and model hydrocarbons(toluene and motor oil),lowering the interfacial tension and rigidifying the interface(as shown with a Langmuir trough).Bottle tests and optical microscopy showed that SDS and CPB produced W/O and O/W emulsions,with either toluene or motor oil and water.The emulsification of motor oil and toluene in water with SDS and CPB facilitated their flow through sand columns and their recovery.Toluene recovery from sand columns was quantitated using Gas-Chromatography MassSpectroscopy(GC-MS).The data show that SDS and CPB can be used both for surfactant flushing and to trigger the gelation of’emulsion locks’.Ethanol also gelled the emulsions at100 mL/L.

关键词： Remediation Emulsion Hydrocarbons Surfactant Rheology Langmuir trough

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Tyrosine phosphorylation and bacterial virulence

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International Journal of Oral Science 2012年第1期4卷 1-6页

作者： Sarah E Whitmore Richard J lamont Center for Oral Health and Systemic Disease School of DentistryUniversity of Louisville

Protein phosphorylation on tyrosine has emerged as a key device in the control of numerous cellular functions in bacteria.In this article,we review the structure and function of bacterial tyrosine kinases and phosphatases.Phosphorylation is catalyzed by autophosphorylating adenosine triphosphate-dependent enzymes（bacterial tyrosine（BY） kinases） that are characterized by the presence of Walker motifs.The reverse reaction is catalyzed by three classes of enzymes：the eukaryotic-like phosphatases（PTPs） and dual-specific phosphatases;the low molecular weight protein-tyrosine phosphatases（LMW-PTPs）;and the polymerase-histidinol phosphatases（PHP）.Many BY kinases and tyrosine phosphatases can utilize host cell proteins as substrates,thereby contributing to bacterial pathogenicity.Bacterial tyrosine phosphorylation/dephosphorylation is also involved in biofilm formation and community development.The Porphyromonas gingivalis tyrosine phosphatase Ltp1 is involved in a restraint pathway that regulates heterotypic community development with Streptococcus gordonii.Ltp1 is upregulated by contact with S.gordonii and Ltp1 activity controls adhesin expression and levels of the interspecies signal AI-2.

关键词： oral biofilm Porphyromonas gingivalis Streptococcus tyrosine phosphorylation virulence

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Sympathetically evoked Ca2+signaling in arterial smooth muscle

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Acta Pharmacologica Sinica 2006年第12期27卷 1515-1525页

作者： Joseph ZACHARIA Christine lamont Withrow Gil WIER Department of Physiology University of Maryland School of MedicineBaltimoreMaryland 21201USA Department of Pharmacology Key Laboratory of Environment and Genes Related to Diseases of Ministry of EducationSchool of MedicineXi-an Jiaotong UniversityXi-an 710061China Department of Physiology University of Maryland School of MedicineBaltimoreMerryland 21201USA

The sympathetic nervous system plays an essential role in the control of totalperipheral vascular resistance and blood flow,by controlling the contraction ofsmall arteries.Perivascular sympathetic nerves release ATE norepinephrine（NE）and neuropeptide Y.This review summarizes our knowledge of the intracellularCa2+signals that are activated by ATP and NE,acting respectively on P2X1and α1-adrenoceptors in arterial smooth muscle.Each neurotransmitter produces a uniquetype of post-synaptic Ca2+signal and associated contraction.The neural releaseof ATP and NE is thought to vary markedly with the pattern of nerve activity,probably reflecting both pre-and post-synaptic mechanisms.Finally,we showthat Ca2+signaling during neurogenic contractions activated by trains of sympa-thetic nerve fiber action potentials are in fact significantly different from thatelicited by simple bath application of exogenous neurotransmitters to isolatedarteries（a common experimental technique）,and end by identifying importantquestions remaining in our understanding of sympathetic neurotransmission andthe physiological regulation of contraction of small arteries.

关键词： sympathetic nerve Ca2+ signaling arterial smooth muscles receptors junctional Ca2+ transients confocal microscope

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Baptism by fire: the pivotal role of ancient conflagrations in evolution of the Earth's flora

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National Science Review 2018年第2期5卷 237-254页

作者： Tianhua He Byron B.lamont Department of Environment and Agriculture Curtin University

Fire became a defining feature of the Earth's processes as soon as land plants evolved 420 million years ago and has played a major role in shaping the composition and physiognomy of many ecosystems ever since.However, there remains a general lack of appreciation of the place of fire in the origin, evolution, ecology and conservation of the Earth's biodiversity. We review the literature on the presence of fire throughout the Earth's history following the evolution of land plants and examine the evidence for the origin and evolution of adaptive functional traits, biomes and major plant groups in relation to fire. We show that:(1) fire activities have fluctuated throughout geological time due to variations in climate, and more importantly in atmospheric oxygen, as these affected fuel levels and flammability;(2) fire promoted the early evolution and spread of major terrestrial plant groups;(3) fire has shaped the floristics, structure and function of major global biomes; and(4) fire has initiated and maintained the evolution of a wide array of fire-adapted functional traits since the evolution of land plants. We conclude that fire has been a fundamental agent of natural selection on terrestrial plants throughout the history of life on the Earth's land surface. We suggest that a paradigm shift is required to reassess ecological and evolutionary theories that exclude a role for fire,and also there is a need to review fire-suppression policies on ecosystem management and biodiversity conservation in global fire-prone regions.

关键词： angiosperms ecosystems fossil charcoal palaeo-atmospheric oxygen terrestrial floras wildfire

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The Consolations of Boethius

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Frontiers of Philosophy in China 2014年第1期9卷 69-86页

作者： John lamont Faculty of Theology and Philosophy Australian Catholic University Fitzroy Victoria 3065Australia

The paper considers the account of happiness given in Boethius＇s Consolations of Philosophy. This account claims that happiness requires security of possession, and argues from this requirement to the conclusion that worldly goods, which of their nature cannot be securely possessed, cannot provide happiness. This argument is shown to depend on assuming a life-driven account of human motivation, rather than a goods-driven account of human motivation. The life-driven account, according to which voluntary actions are ultimately motivated by the pursuit of a certain kind of life, is defended against the goods-driven account, according to which actions are motivated by the pursuit of goods the enjoyment of which can only be episodes in a human life. It is claimed that Boethius is right in holding a life-driven account, and that his account of happiness follows from it.

关键词： happiness hedonism utilitarianism virtue action Boethius,MacIntyre

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Evidence-based management of gastrointestinal diseases

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Gastroenterology Report 2015年第1期3卷 1-2页

作者： J.Thomas lamont Division of Gastroenterology Beth Israel Deaconess Medical CenterHarvard Medical SchoolDA-501330 Brookline AvenueBostonMA 02215USA

This special issue of Gastroenterology Report is directed at“Evidence-based management of gastrointestinal(GI)diseases”.Gastroenterologists are now using a range of diagnostic tests and therapies that were largely unavailable twenty years ago.Ours is a fast-moving field,with innovations being developed at a rapid pace.Included in this issue are authoritative reviews on how to manage a wide variety of conditions that affect the GI and biliary tracts using both established and emerging technologies,with emphasis on evidence to support the best practices and to achieve the best possible outcomes for our patients;for example,much has changed as regards our diagnostic accuracy in celiac disease.

关键词： diseases gastrointestinal patients

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Compressional origin of the Aegean Orogeny,Greece

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Geoscience Frontiers 2022年第2期13卷 383-404页

作者： Michael P.Searle Thomas N.lamont Dept Earth Sciences Oxford UniversitySouth Parks RoadOxfordOX13ANUK School of Earth and Environmental Sciences University of St AndrewsSt AndrewsKY169ALUK

The Aegean Sea area is thought to be an actively extending back-arc region,north of the present day Hellenic volcanic arc and north-dipping subduction zone in the Eastern Mediterranean.The area shows extensive normal faulting,ductile‘extensional’shear zones and extensional S-C fabrics throughout the islands that have previously been related to regional Aegean extension associated with slab rollback on the Hellenic Subduction Zone.In this paper,we question this interpretation,and suggest the Cenozoic geodynamic evolution of the Aegean region is associated with a Late Cretaceous-Eocene NE-dipping subduction zone that was responsible for continentcontinent collision between Eurasia and Adria-Apulia/Cyclades.Exhumation of eclogite and blueschist facies rocks in the Cyclades and kyanite-sillimanite grade gneisses in the Naxos core complex have pressures that are far greater than could be accounted for purely by lithospheric extension and isostatic uplift.We identify four stages of crustal shortening that affected the region prior to regional lithospheric extension,herein called the Aegean Orogeny.This orogeny followed a classic Wilson cycle from early ophiolite obduction(ca.74 Ma)onto a previously passive continental margin,to attempted crustal subduction with HP eclogite and blueschist facies metamorphism(ca.54-45 Ma),through crustal thickening and regional kyanite-sillimanite grade Barroviantype metamorphism(ca.22-14 Ma),to orogenic collapse(<14 Ma).At least three periods of‘extensional’fabrics relate to:(1)Exhumation of blueschists and eclogite facies rocks showing tight-isoclinal folds and top-NE,base-SW fabrics,recording return flow along a subduction channel in a compressional tectonic setting(ca.50-35 Ma).(2)Extensional fabrics within the core complexes formed by exhumation of kyanite-and sillimanite gneisses showing thrust-related fabrics at the base and‘extensional’fabrics along the top(ca.18.5-14 Ma).(3)Regional ductile-brittle‘extensional’fabrics and low-angle normal faulting related to the North Cycladic D

关键词： Cyclades Ophiolite High-pressure metamorphism Core complex Compressional tectonics

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Altitude-dependent distribution of 137Cs in the environment:a case study of Aragats massif, Armenia

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Acta Geochimica 2020年第1期39卷 127-138页

作者： Konstantin Pyuskyulyan Stephen P.lamont Vovik Atoyan Olga Belyaeva Nona Movsisyan Armen Saghatelyan Armenian Nuclear Power Plant MetsamorArmenia Nuclear and Radiochemistry Los Alamos National LaboratoryLos AlamosUSA Radioecology Department Center for Ecological-Noosphere StudiesNAS RA.YerevanArmenia

This paper considers the distribution of technogenic 137Cs and naturally occurring radionuclides:238 U,232 Th and40 R concentrations in soils and 137Cs in atmospheric dry depositions by altitudinal belts of the Aragats mountain massif,Republic of Armenia.Undisturbed soil samples were collected at altitudes from 1000 to 3200 m.For the determination of geochemical variability,two soil sampling campaigns were undertaken.Atmospheric dry depositions were sampled from five stations at1100-3200 m collected onto organic fiber filters between June and December 2016.137Cs activity was measured using a high-purity Germanium detector coupled to a multichannel analyzer(Canberra).Results indicated that specific activity of 137Cs in soils at 1000 m is495-528 Bq m^-2,andat3200 mis10,500-11,470 Bq m^-2.No correlation observed for 137Cs versus naturally occurring radionuclides,which varies in distribution by altitude.Specific activities of 137Cs in dry atmospheric depositions varies from 1.06 at 846 m to2.37 Bq m^-2 per quarter at 3200 m and increases as the altitude increases.Activities of 137Cs in soil and dry atmospheric deposition correlated significantly,and 137Cs activity in soils and atmospheric dry depositions decrease as the absolute altitude decreases.The 50-year effective dose from exposure to 137Cs fallout varies with altitude from 0.007 to 1.42 m Sv.

关键词： 137Cs Distribution by altitude Naturally occurring radionuclides Topsoil Dry atmospheric depositions Gamma radiation Mountain regions

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Environmental drivers and genomic architecture of trait differentiation in fire-adapted Banksia attenuata ecotypes

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Journal of Integrative Plant Biology 2019年第4期61卷 417-432页

作者： Tianhua He Byron B.lamont Neal J.Enright Haylee M.D'Agui William Stock School of Molecular and Life Sciences Curtin University School of Veterinary and Life Sciences Murdoch University Centre for Ecosystem Management Edith Cowan University

Trait divergence between populations is considered an adaptive response to different environments,but to what extent this response is accompanied by genetic differentiation is less clear since it may be phenotypic plasticity. In this study, we analyzed phenotypic variation between two Banksia attenuata growth forms, lignotuberous(shrub) and epicormic resprouting(tree), in fire-prone environments to identify the environmental factors that have driven this phenotypic divergence. We linked genotype with phenotype and traced candidate genes using differential gene expression analysis. Fire intervals determined the phenotypic divergence between growth forms in B. attenuata. A genome-wide association study identified 69 single nucleotide polymorphisms, putatively associated with growth form, whereas no growth form-or phenotype-specific genotypes were eidentified. Genomic differentiation between the two growth forms was low(F_(st)=0.024). Differential gene expression analysis identified 37 genes/transcripts that were differentially expressed in the two growth forms. A small heat-shock protein gene, associated with lignotuber presence, was differentially expressed in the two forms.We conclude that different fire regimes induce phenotypic polymorphism in B. attenuata, whereas phenotypic trait divergence involves the differential expression of a small fraction of genes that interact strongly with the disturbance regime. Thus, phenotypic plasticity among resprouters is the general strategy for surviving varying fire regimes.

关键词： Environmental drivers genomic architecture trait differentiation

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In Vivo Phosphorylation Site Mapping and Functional Characterization of Arabidopsis Phototropin 1

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Molecular Plant 2008年第1期1卷 178-194页

作者： Stuart Sullivan Catriona E. Thomson Douglas J. lamont Matthew A. Jones John M. Christie Plant Science Group Division of Biochemistry and Molecular Biology. Institute of Biomedical and Life Sciences University of Glasgow. University Avenue. Glasgow Scotland UK FingerPrints Proteomics Facility Post-Genomics and Molecular Interactions Centre. School of Life Sciences MSI/WTB/CIR Complex University of Dundee. Dundee Scotland UK

Phototropins （phot1 and phot2） are blue-light receptor kinases controlling a range of responses that optimize the photosynthetic efficiency of plants. Light sensing is mediated by two flavin-binding motifs, known as LOVl and LOV2, located within the N-terminal region of the protein. Photoexcitation via LOV2 leads to activation of the C-terminal kinase domain and consequently receptor autophosphorylation. However, knowledge of the in-vivo phosphorylation sites for Arabidopsis phototropins is lacking and has impeded progress in elucidating the functional significance of receptor phos- phorylation. We have purified photl from Arabidopsis and identified the in-vivo sites of receptor phosphorylation by liquid chromatography tandem mass spectrometry. Arabidopsis-derived photl binds flavin mononucleotide as chromophore and is phosphorylated at four major sites located upstream of LOV2 （Ser^58, Ser^85, Ser^350, and Ser^410）, three of which are induced by blue light. Nevertheless, structure-function analysis indicates that the biological activity of photl can be attributed to a modular unit comprising the LOV2-kinase region of the protein. Thus, peptide regions upstream of LOV2, including the sites of receptor phosphorylation identified here, do not appear to be important for receptor signaling. By contrast, these regions may be necessary for maximizing stomatal performance and possibly light-induced relocalization of photl.

关键词： Phototropins (phot1 and phot2) lavin-binding motifs

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