340 research outputs found

    Factors governing the solid phase distribution of Cr, Cu and As in contaminated soil after 40 years of ageing

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    The physico-chemical factors affecting the distribution, behavior and speciation of chromium (Cr), copper (Cu) and arsenic (As) was investigated at a former wood impregnation site (Fredensborg, Denmark). Forty soil samples were collected and extracted using a sequential extraction technique known as the Chemometric Identification of Substrates and Element Distributions (CISED) and a multivariate statistical tool (redundancy analysis) was applied. CISED data was linked to water-extractable Cr, Cu and As and bioavailable Cu as determined by a whole-cell bacterial bioreporter assay. Results showed that soil pH significantly affected the solid phase distribution of all three elements on site. Additionally, elements competing for binding sites, Ca, Mg and Mn in the case of Cu, and P, in the case of As, played a major role in the distribution of these elements in soil. Element-specific distributions were observed amongst the six identified soil phases including residual pore salts, exchangeable, carbonates (tentative designation), Mn-Al oxide, amorphous Fe oxide, and crystalline Fe oxide. While Cr was strongly bound to non-extractable crystalline Fe oxide in the oxic top soil, Cu and notably, As were associated with readily extractable phases, suggesting that Cu and As, and not Cr, constitute the highest risk to environmental and human health. However, bioavailable Cu did not significantly correlate with CISED identified soil phases, suggesting that sequential extraction schemes such as CISED may not be ideally suited for inferring bioavailability to microorganisms in soil and supports the integration of receptor-specific bioavailability tests into risk assessments as a complement to chemical methods

    The Ulysses supplement to the Granat/WATCH catalog of cosmic gamma-ray bursts

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    We present 3rd interplanetary network (IPN) localization data for 56 gamma-ray bursts in the GRANAT/ WATCH catalog which occurred between 1990 November and 1994 September. These localizations are obtained by triangulation using various combinations of spacecraft in the IPN, which consisted of Ulysses, BATSE, Pioneer Venus Orbiter (PVO), Mars Observer (MO), WATCH, and PHEBUS. The intersections of the triangulation annuli with the WATCH error circles produce error boxes with areas as small as 16 sq. arcmin., reducing the sizes of the error circles by up to a factor of 800

    Human Health Risk Assessment (HHRA) for environmental development and transfer of antibiotic resistance

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    Background: Only recently has the environment been clearly implicated in the risk of antibiotic resistance to clinical outcome, but to date there have been few documented approaches to formally assess these risks. Objective: We examined possible approach

    Discrimination of conventional and organic white cabbage from a long-term field trial study using untargeted LC-MS-based metabolomics

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    The influence of organic and conventional farming practices on the content of single nutrients in plants is disputed in the scientific literature. Here, large-scale untargeted LC-MS-based metabolomics was used to compare the composition of white cabbage from organic and conventional agriculture, measuring 1,600 compounds. Cabbage was sampled in 2 years from one conventional and two organic farming systems in a rigidly controlled long-term field trial in Denmark. Using Orthogonal Projection to Latent Structures-Discriminant Analysis (OPLS-DA), we found that the production system leaves a significant (p = 0.013) imprint in the white cabbage metabolome that is retained between production years. We externally validated this finding by predicting the production system of samples from one year using a classification model built on samples from the other year, with a correct classification in 83% of cases. Thus, it was concluded that the investigated conventional and organic management practices have a systematic impact on the metabolome of white cabbage. This emphasizes the potential of untargeted metabolomics for authenticity testing of organic plant products

    Soil and climatic characteristics and farming system shape fungal communities in European wheat fields

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    Fungi play a pivotal role as highly effective decomposers of plant residues and essential mycorrhizal symbionts, augmenting water and nutrient uptake in plants and contributing to diverse functions within agroecosystems. This study examined soil fungi in 188 wheat fields across nine European pedoclimatic zones under both conventional and organic farming systems, utilizing ITS1 amplicon sequencing. The investigation aimed to quantify changes induced by the farming system in soil fungi and their correlation with soil features and climatic factors across these pedoclimatic zones, spanning from northern to southern Europe. The pedoclimatic zone emerged as a key determinant in shaping the overall composition of the fungal community. Zones characterized by moist and cool climates, along with low levels of available phosphorus and carbonate, exhibited higher fungal richness. However, variations in fungal diversity and relative abundances were observed within zones due to farming system-induced changes. Soil pH and bulk density were identified as major factors, for example, they correlate with an increase in potential pathogenic taxa (Mycosphaerella, Nectriaceae, Alternaria) in two Mediterranean zones and with an increase of potential plant growth promoting taxa (Saitozyma, Solicoccozyma) in the Boreal zone. Organic farming, in general, promoted elevated fungal richness. The Lusitanian and Nemoral zones under organic farming exhibited the highest fungal richness and diversity. In terms of organic farming, both symbiotrophs and potential pathogens increased in the Lusitanian zone, while pathotrophs were more prevalent in the Central Atlantic and South Mediterranean zones under organic farming. These findings propose potential indicators for organic farming, including fungal endophytes in zones characterized by a moist and cool climate, low available phosphorus content, and low soil pH. Organic farming may favor mycorrhizae and potential pathogens in zones with drier and warmer climates, along with higher soil pH, calcium carbonate content, and bulk density. This study provides novel insights and underscores the significance of regional climatic and edaphic conditions in shaping the soil fungal community in different farming systems within European wheat fields

    Metal stressors consistently modulate bacterial conjugal plasmid uptake potential in a phylogenetically conserved manner.

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    Published onlineJOURNAL ARTICLEThe environmental stimulants and inhibitors of conjugal plasmid transfer in microbial communities are poorly understood. Specifically, it is not known whether exposure to stressors may cause a community to alter its plasmid uptake ability. We assessed whether metals (Cu, Cd, Ni, Zn) and one metalloid (As), at concentrations causing partial growth inhibition, modulate community permissiveness (that is, uptake ability) against a broad-host-range IncP-type plasmid (pKJK5). Cells were extracted from an agricultural soil as recipient community and a cultivation-minimal filter mating assay was conducted with an exogenous E. coli donor strain. The donor hosted a gfp-tagged pKJK5 derivative from which conjugation events could be microscopically quantified and transconjugants isolated and phylogenetically described at high resolution via FACS and 16S rRNA amplicon sequencing. Metal stress consistently decreased plasmid transfer frequencies to the community, while the transconjugal pool richness remained unaffected with OTUs belonging to 12 bacterial phyla. The taxonomic composition of the transconjugal pools was distinct from their respective recipient communities and clustered dependent on the stress type and dose. However, for certain OTUs, stress increased or decreased permissiveness by more than 1000-fold and this response was typically correlated across different metals and doses. The response to some stresses was, in addition, phylogenetically conserved. This is the first demonstration that community permissiveness is sensitive to metal(loid) stress in a manner that is both partially consistent across stressors and phylogenetically conserved.The ISME Journal advance online publication, 2 August 2016; doi:10.1038/ismej.2016.98.We thank J Magid for access to the CRUCIAL field plot, LK Jensen for technical assistance in the laboratory and SM Milani for assistance in FACS sorting. This work was funded by the Villum Kann Rasmussen Foundation Center of Excellence CREAM (Center for Environmental and Agricultural Microbiology). UK is currently supported through an MRC/BBSRC grant (MR/N007174/1)

    Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

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    We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2
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