800 research outputs found

    Characterizing the Empirical Drivers of the Carbon Fluxes of an Inland Salt Marsh

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    Wetlands promote carbon sequestration through saturated, anoxic soils. However, the persistent presence of water results in reduce conditions, which promotes methane (CH4) production. The climatological variables responsible for the source/sink behavior are still unclear. This study quantifies temporal changes in the empirical drivers of the carbon fluxes of a constructed inland salt marsh in Camillus, New York. The mean CH4 (0.328 ÎŒmol·m-2 ·s-1 ) and carbon dioxide (CO2) (0.195 ÎŒmol·m-2 ·s-1 ) emissions from June 27, 2019 to November 11, 2019 show the site’s slight carbon source behavior. Latent heat flux had the strongest relationship with CH4 and gross primary production (GPP), while air temperature best explained ecosystem respiration (Re). The lag responses of Re (3-hours) and CH4 (5-hours) from air temperature are likely attributed to the lag response between the air and soil temperature. Whereas the lag response of GPP (1-hour), Re (2-hours), and CH4 (1-day) from rainfall events are likely a reflection of an increase in dissolved oxygen and soil moisture content

    A comparison of methodologies for the staining and quantification of intracellular components of Arbuscular Mychorrizal (AM) fungi in the root cortex of two varieties of winter wheat

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    © 2019 The Authors. The definitive peer reviewed, edited version of this article is published in Access Microbiology, https://doi.org/10.1099/acmi.0.000083. This is an open-access article distributed under the terms of the Creative Commons Attribution License.Arbuscular Mychorrizal (AM) fungi are one of the most common fungal organisms to exist in symbiosis with terrestrial plants facilitating the growth and maintenance of arable crops. Wheat has been studied extensively for AM fungal symbiosis using the carcinogen trypan blue as the identifying stain for fungal components, namely arbuscles, vesicles and hyphal structures. The present study uses SheafferŸ blue ink with a lower risk as an alternative to this carcinogenic stain. Justification for this is determined by stained wheat root sections (n = 120), with statistically significant increases in the observed abundance of intracellular root cortical fungal structures stained with SheafferŸ blue ink compared to trypan blue for both Zulu (P = 0.003) and Siskin (P = 0.0003) varieties of winter wheat. This new alternative combines an improved quantification of intracellular fungal components with a lower hazard risk at a lower cost.Peer reviewe

    Tillage, Glyphosate and Beneficial Arbuscular Mycorrhizal Fungi: Optimising Crop Management for Plant–Fungal Symbiosis

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    Zero till cropping systems typically apply broad-spectrum herbicides such as glyphosate as an alternative weed control strategy to the physical inversion of the soil provided by cultivation. Glyphosate targets 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase in plants. There is growing evidence that this may have a detrimental impact on non-target organisms such as those present in the soil microbiome. Species of commercial importance, such as arbuscular mycorrhizal (AM) fungi that form a symbiotic relationship with plant roots are an important example. This study investigates the impact of soil cultivation and glyphosate application associated with conventional tillage (CT) and zero tillage (ZT) respectively on AM fungi populations under field and glasshouse conditions. Topsoil (<10 cm) was extracted from CT and ZT fields cropped with winter wheat, plus non-cropped control plots within the same field boundary, throughout the cropping year. Glyphosate was applied in glasshouse experiments at rates between 0 and 350 g L−1. Ergosterol, an indicator of fungal biomass, was measured using high performance liquid chromatography before and after glyphosate application. Fungal root arbuscules, an indicator of AM fungi–root symbiosis, were quantified from the roots of wheat plants. Under glasshouse conditions root arbuscules were consistently higher in wheat grown in ZT field extracted soils (P = 0.01) compared to CT. Glyphosate application however inhibited fungal biomass in both the ZT (P < 0.00001) and CT (P < 0.001) treatments. In the absence of glyphosate, the number of stained root arbuscules increased significantly. Ergosterol levels, used as a proxy for fungal biomass, remained lower in the soil post glyphosate application. The results suggest that CT has a greater negative impact on AM fungal growth than ZT and glyphosate, but that glyphosate is also detrimental to AM fungal growth and hinders subsequent population recovery.Peer reviewedFinal Published versio

    The Tripartite Rhizobacteria-AM Fungal-Host Plant Relationship in Winter Wheat: Impact of Multi-Species Inoculation, Tillage Regime and Naturally Occurring Rhizobacteria Species

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    © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Soils and plant root rhizospheres have diverse microorganism profiles. Components of this naturally occurring microbiome, arbuscular mycorrhizal (AM) fungi and plant growth promoting rhizobacteria (PGPR), may be beneficial to plant growth. Supplementary application to host plants of AM fungi and PGPR either as single species or multiple species inoculants has the potential to enhance this symbiotic relationship further. Single species interactions have been described; the nature of multi-species tripartite relationships between AM fungi, PGPR and the host plant require further scrutiny. The impact of select Bacilli spp. rhizobacteria and the AM fungus Rhizophagus intraradices as both single and combined inoculations (PGPR[i] and AMF[i]) within field extracted arable soils of two tillage treatments, conventional soil inversion (CT) and zero tillage (ZT) at winter wheat growth stages GS30 and GS39 have been conducted. The naturally occurring soil borne species (PGPR[s] and AMF[s]) have been determined by qPCR analysis. Significant differences (p < 0.05) were evident between inocula treatments and the method of seedbed preparation. A positive impact on wheat plant growth was noted for B. amyloliquefaciens applied as both a single inoculant (PGPR[i]) and in combination with R. intraradices (PGPR[i] + AMF[i]); however, the two treatments did not differ significantly from each other. The findings are discussed in the context of the inocula applied and the naturally occurring soil borne PGPR[s] present in the field extracted soil under each method of tillage.Peer reviewedFinal Published versio

    The role of growth directors in controlling the morphology of hematite nanorods

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    The control of the growth of hematite nanoparticles from iron chloride solutions under hydrothermal conditions in the presence of two different structure promoters has been studied using a range of both structural and spectroscopic techniques including the first report of photo induced force microscopy (PiFM) to map the topographic distribution of the structure-directing agents on the developing nanoparticles. We show that the shape of the nanoparticles can be controlled using the concentration of phosphate ions up to a limit determined to be ~6 × 10−3 mol. AkaganĂ©ite (ÎČ-FeOOH) is a major component of the nanoparticles formed in the absence of structure directors but only present in the very early stages (< 8 h) of particle growth when phosphate is present. The PiFM data suggest a correlation between the areas in which phosphate ions are adsorbed and areas where akaganĂ©ite persists on the surface. In contrast, goethite (α-FeOOH) is a directly observed precursor of the hematite nanorods when 1,2-diamino propane is present. The PiFM data shows goethite in the center of the developing particles consistent with a mechanism in which the iron hydroxide re-dissolves and precipitates at the nanorod ends as hematite

    Ability grouping in the primary school: a survey

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    In 1997, the DfEE suggested that schools should consider ‘setting’ pupils by ability as it was believed that this would contribute to raising standards. This survey of primary schools aimed to establish the extent to which primary schools, with same and mixed age classes, implement different grouping practices including setting, streaming, within class ability and mixed ability groupings for different curriculum subjects. Schools were asked to complete a questionnaire indicating their grouping practices for each subject in each year group. The findings showed that schools predominantly adopted within class ability groupings, either mixed or ability grouped, for most subjects. Ability grouping (within class and setting) was most common in mathematics, followed by English and science. Its implementation increased as pupils progressed through school. The type of setting adopted, same or cross age, tended to reflect the nature of the class structures within the school

    Current and Emerging Uses of Statins in Clinical Therapeutics: A Review

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    Statins, a class of cholesterol-lowering medications that inhibit 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, are commonly administered to treat atherosclerotic cardiovascular disease. Statin use may expand considerably given its potential for treating an array of cholesterol-independent diseases. However, the lack of conclusive evidence supporting these emerging therapeutic uses of statins brings to the fore a number of unanswered questions including uncertainties regarding patient-to-patient variability in response to statins, the most appropriate statin to be used for the desired effect, and the efficacy of statins in treating cholesterol-independent diseases. In this review, the adverse effects, costs, and drug–drug and drug–food interactions associated with statin use are presented. Furthermore, we discuss the pleiotropic effects associated with statins with regard to the onset and progression of autoimmune and inflammatory diseases, cancer, neurodegenerative disorders, strokes, bacterial infections, and human immunodeficiency virus. Understanding these issues will improve the prognosis of patients who are administered statins and potentially expand our ability to treat a wide variety of diseases

    Mitochondrial fission and cristae disruption increase the response of cell models of Huntington's disease to apoptotic stimuli

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    Huntington's disease (HD), a genetic neurodegenerative disease caused by a polyglutamine expansion in the Huntingtin (Htt) protein, is accompanied by multiple mitochondrial alterations. Here, we show that mitochondrial fragmentation and cristae alterations characterize cellular models of HD and participate in their increased susceptibility to apoptosis. In HD cells, the increased basal activity of the phosphatase calcineurin dephosphorylates the pro-fission dynamin related protein 1 (Drp1), increasing its mitochondrial translocation and activation, and ultimately leading to fragmentation of the organelle. The fragmented HD mitochondria are characterized by cristae alterations that are aggravated by apoptotic stimulation. A genetic analysis indicates that correction of mitochondrial elongation is not sufficient to rescue the increased cytochrome c release and cell death observed in HD cells. Conversely, the increased apoptosis can be corrected by manoeuvres that prevent fission and cristae remodelling. In conclusion, the cristae remodelling of the fragmented HD mitochondria contributes to their hypersensitivity to apoptosis

    Determining Structure-Activity Relationships in Oxide Derived CuSn Catalysts During CO2 Electroreduction Using X-Ray Spectroscopy

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    The development of earth-abundant catalysts for selective electrochemical CO2 conversion is a central challenge. Cu-Sn bimetallic catalysts can yield selective CO2 reduction toward either CO or formate. This study presents oxide-derived Cu-Sn catalysts tunable for either product and seeks to understand the synergetic effects between Cu and Sn causing these selectivity trends. The materials undergo significant transformations under CO2 reduction conditions, and their dynamic bulk and surface structures are revealed by correlating observations from multiple methods—X-ray absorption spectroscopy for in situ study, and quasi in situ X-ray photoelectron spectroscopy for surface sensitivity. For both types of catalysts, Cu transforms to metallic Cu0 under reaction conditions. However, the Sn speciation and content differ significantly between the catalyst types: the CO-selective catalysts exhibit a surface Sn content of 13 at. % predominantly present as oxidized Sn, while the formate-selective catalysts display an Sn content of ≈70 at. % consisting of both metallic Sn0 and Sn oxide species. Density functional theory simulations suggest that Snή+ sites weaken CO adsorption, thereby enhancing CO selectivity, while Sn0 sites hinder H adsorption and promote formate production. This study reveals the complex dependence of catalyst structure, composition, and speciation with electrochemical bias in bimetallic Cu catalysts

    LUCIFER@LBT view of star-forming galaxies in the cluster 7C 1756+6520 at z~1.4

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    Galaxy clusters are key places to study the contribution of {\it nature} (i.e. mass, morphology) and {\it nurture} (i.e.environment) in the formation and evolution of galaxies. Recently, a number of clusters at z>>1, i.e. corresponding to the first epochs of the cluster formation, has been discovered and confirmed spectroscopically. We present new observations obtained with the {\sc LUCIFER} spectrograph at Large Binocular Telescope (LBT) of a sample of star-forming galaxies associated with a large scale structure around the radio galaxy 7C1756+6520 at z=1.42. Combining our spectroscopic data and the literature photometric data, we derived some of the properties of these galaxies: star formation rate, metallicity and stellar mass. With the aim of analyzing the effect of the cluster environment on galaxy evolution, we have located the galaxies in the plane of the so-called Fundamental Metallically Relation (FMR), which is known not to evolve with redshift up to z=2.5=2.5 for field galaxies, but it is still unexplored in rich environments at low and high redshift. We found that the properties of the galaxies in the cluster 7C 1756+6520 are compatible with the FMR which suggests that the effect of the environment on galaxy metallicity at this early epoch of cluster formation is marginal. As a side study, we also report the spectroscopic analysis of a bright AGN, belonging to the cluster, which shows a significant outflow of gas.Comment: Accepted for publication by MNRAS, 10 pages, 6 figures, 3 table
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