14 research outputs found

    Total organic carbon and pyrolysis analysis of the Lower Cretaceous in Compton Bay and Atherfield, Isle of Wight (England)

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordThe Wessex Basin (United Kingdom) includes hundreds of meters of Lower Cretaceous clays, silts, and sands deposited in a wide range of depositional environments. Studies have investigated these depositional systems from the organic matter (OM) perspective. However, questions remain concerning the composition, source, and the overall depositional constraints on the distribution of sedimentary OM in this area. Elemental (carbonate % and total organic carbon - TOC) and pyrolysis analyses were conducted on representative lithofacies of the Lower Cretaceous from the Wessex Basin at the Compton Bay and Atherfield sections, Isle of Wight. The highest TOC contents were determined in the upper part of the Ferruginous Sands and Sandrock formations. These elevated TOC intervals are associated with predominantly estuarine deposition. Except for one sample from the Vectis Formation, Hydrogen Index (HI) in all studied units is low and indicates Type IV kerogen assemblages, interpreted to be linked with strongly variable climates (with pronounced dry periods) and significant water table fluctuations in the source area and during transport. The one sample with a Type II-III kerogen assemblage from the lagoonal Vectis Formation supports previous studies which suggested that OM in the Vectis Formation varied vertically as a function of fluvial sediment and terrestrial organic matter input to the lagoonal environment with changes in salinity, sediment resuspension, and turbulence as a result controlling the abundance of dinoflagellate cysts

    Invasive fungal infections in neutropenic enterocolitis: A systematic analysis of pathogens, incidence, treatment and mortality in adult patients

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    BACKGROUND: Neutropenic enterocolitis is a life-threatening complication most frequently occurring after intensive chemotherapy in acute leukaemias. Gramnegative bacteria constitute the most important group of causative pathogens. Fungi have also been reported, but their practical relevance remains unclear. The guidelines do not address concrete treatment recommendations for fungal neutropenic enterocolitis. METHODS: Here, we conducted a metaanalysis to answer the questions: What are frequency and mortality of fungal neutropenic enterocolitis? Do frequencies and microbiological distribution of causative fungi support empirical antimycotic therapy? Do reported results of antimycotic therapy in documented fungal neutropenic enterocolitis help with the selection of appropriate drugs? Following a systematic search, we extracted and summarised all detail data from the complete literature. RESULTS: Among 186 articles describing patients with neutropenic enterocolitis, we found 29 reports describing 53 patients with causative fungal pathogens. We found no randomised controlled trial, no good quality cohort study and no good quality case control study on the role of antifungal treatment. The pooled frequency of fungal neutropenic enterocolitis was 6.2% calculated from all 860 reported patients and 3.4% calculated from selected representative studies only. In 94% of the patients, Candida spp. were involved. The pooled mortality rate was 81.8%. Most authors did not report or perform antifungal therapy. CONCLUSION: In patients with neutropenic enterocolitis, fungal pathogens play a relevant, but secondary role compared to bacteria. Evidence concerning therapy is very poor, but epidemiological data from this study may provide helpful clues to select empiric antifungal therapy in neutropenic enterocolitis

    Stratigraphic relations of the Lower Greensand (Lower Cretaceous) of the Calne area, Wiltshire

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    The Lower Greensand (Aptian-Albian) around Calne, lies on Jurassic Lower Kimmeridge Clay (mid-Aulacostephanoides mutabilis Zone) and comprises a lower, relatively clean, fine to medium grained sand, overlain by iron-rich poorly-sorted, medium to coarse grained sandstone. The upper beds are identified as the Carstone, but the lower sands are lithologically different from the closely adjacent Lower Greensand occurrences on the margins of the Wessex Basin. They are here named the Calne Sands Formation of the Lower Greensand Group (equivalent to part of the Folkestone Beds Formation of SE England). The Calne Sands form an areally-restricted sequence with sand-grade sediment coarsening upwards and a concomitant increase in clay content. Palynological evidence indicates that they are referable to the Hypacanthoplites jacobi Zone. The age and sedimentary facies contrast with the nearby Seend Ironsand (Parahoplites nutfieldiensis Zone). Both occurrences however are interpreted as transgressive deposits infilling NW-SE palaeovalleys cut into Jurassic basement. -from Author

    Agrobacterium-mediated transformation as a tool for functional genomics in fungi.

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    Item does not contain fulltextIn the era of functional genomics, the need for tools to perform large-scale targeted and random mutagenesis is increasing. A potential tool is Agrobacterium-mediated fungal transformation. A. tumefaciens is able to transfer a part of its DNA (transferred DNA; T-DNA) to a wide variety of fungi and the number of fungi that can be transformed by Agrobacterium-mediated transformation (AMT) is still increasing. AMT has especially opened the field of molecular genetics for fungi that were difficult to transform with traditional methods or for which the traditional protocols failed to yield stable DNA integration. Because of the simplicity and efficiency of transformation via A. tumefaciens, it is relatively easy to generate a large number of stable transformants. In combination with the finding that the T-DNA integrates randomly and predominantly as a single copy, AMT is well suited to perform insertional mutagenesis in fungi. In addition, in various gene-targeting experiments, high homologous recombination frequencies were obtained, indicating that the T-DNA is also a useful substrate for targeted mutagenesis. In this review, we discuss the potential of the Agrobacterium DNA transfer system to be used as a tool for targeted and random mutagenesis in fungi
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