88 research outputs found

    THE DRAINING OF THE MARSHLANDS OF EAST YORKSHIRE

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    PhDHolderness, the Vale of York, and the Vale of Pickering are three fairly typical marshland areas, and all three were originally wasteland. Medieval reclamation improved the siltlands of each area for arable and pasture, but the peatlands remained waterlogged for three-quarters of the year and were used mainly for summer pasture and as sources of fish, fowl and fuel, until the mid-eighteenth century. Between 176o and 1900 they were drained by the use of large-scale engineering methods. Improvements were greatest in Holderness, while in the other two areas much still remained to be done in the twentieth century. There are various reasons both for the similarities and differences in the drainage history of the three regions, and for the differences between these regions and the other marshland areas of England and Wales. Location, size, the existence or otherwise of a frontage on tidal water and the resulting existence of a 'Court of sewers.. -farming systems, patterns of ownership, navigation interests, and the influence of settlements, as well an the physical geography, am all shown to have had an influence both on the pace of improvement and on the pattern of drains developed. The present geography of the three areas shows clear traces of the earlier stages In their history

    Partial Substitution of Cu Sites by Mg for the Improvement of CuWO4 Photoanodes Performance

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    The photoelectrochemical properties of CuWO4 (Mg x%) thin-films obtained by solution-based methods are investigated as a function of the material composition. The thin-films are prepared by spin-coating a single precursor solution onto FTO-coated glass substrates, followed by an annealing process at 550 °C. XRD, Raman, XPS, and electrochemical data studies indicate the formation of single-phase CuWO4 (Mg x%), with Mg2+ partially substituting Cu2+ sites. Photoelectrochemical studies under monochromatic illumination show an 88.2% increase in photocurrent responses and a 2-fold increase in charge carriers bulk separation efficiency at 1.0 V vs RHE, upon replacing 2.5% of Cu by Mg. DFT calculations reveal that Mg incorporation rearranges electron density, shifting the position of magnesium toward an axial oxygen atom, increasing the covalent nature of the bond and decreasing the Cu–O bond length. It is proposed that a change in the localization of the electron density away from the sphere of influence of the oxygen atom, and toward the shared space of the covalent bond, leads to better carrier mobility and the generation of higher photocurrents

    Identification of africanized honey bee (Hymenoptera: apidae) mitochondrial DNA: validation of a rapid polymerase chain reaction-based assay

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    Polymerase chain reaction (PCR)-ampliÞed mitochondrialDNA(mtDNA)assays have been used in studies of the Africanization process in neotropical feral and managed honey bee populations. The approach has been adopted, in conjunction with morphometric analysis, to identify Africanized bees for regulatory purposes in the United States such as in California. In this study, 211 Old World colonies, representing all known introduced subspecies in the United States, and 451 colonies from non-Africanized areas of the southern United States were screened to validate a rapid PCR-based assay for identiÞcation of Africanized honey bee mtDNA. This PCR-based assay requires a single enzyme digestion (BglII) of a single PCR-ampliÞed segment of the cytochrome b gene. The BglII polymorphism discriminates the mitochondrial haplotype (mitotype) of Apis mellifera scutellata L. (ancestor of Africanized bees) from that of A. m. mellifera, A. m. caucasia, A. m. ligustica, A. m. carnica, A. m. lamarcki, A. m. cypria, A. m. syriaca, and some A. m. iberiensis, but not from that of A. m. intermissa and some A. m. iberiensis. Nonetheless, given the very low frequency ( 1%) of African non-A. m. scutellata mitotype present before arrival of Africanized bees in the United States, cytochrome b/BglII assay can be used to identify maternally Africanized bees with a high degree of reliability

    Genome-wide identification of host-segregating SNPs for source attribution of clinical Campylobacter coli isolates

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    International audienceCampylobacter is among the most common causes of gastroenteritis worldwide. Campylobacter jejuni and Campylobacter coli are the most common species causing human-disease. DNA-sequence-based methods for strain characterization have focussed largely on C. jejuni, responsible for 80-90% of infections, meaning that C. coli epidemiology has lagged behind. Here we have analyzed the genome of 450 C. coli isolates to determine genetic markers that can discriminate isolates sampled from 3 major reservoir hosts (chickens, cattle and pigs). These markers were then applied to identify the source of infection of 147 C. coli from French clinical cases. Using STRUCTURE software, 259 potential host-segregating markers were revealed by probabilistic characterization of SNP frequency variation in strain collections from three different hosts. These SNPs were found in 41 genes or intergenic regions, mostly coding for proteins involved in motility and membrane functions. Source attribution of clinical isolates based on the differential presence of these markers confirmed chicken as the most common source of C. coli infection in France.IMPORTANCE Genome-wide and source attribution studies based on Campylobacter species have shown their importance for the understanding of foodborne infections. Although the use of MLST based on 7 genes from C. jejuni is a powerful method to structure populations, when applied to C. coli results have not clearly demonstrated their robustness. Therefore, we aim here to provide more accurate data based on the identification of single-nucleotide polymorphisms. Results from this study reveal an important number of host-segregating SNPs, found in proteins implied in motility, membrane functions or DNA repair systems. These findings offer new interesting opportunities for further study on C. coli adaptation to its environment. Additionally, the results demonstrate that poultry is potentially the main reservoir of C. coli in France

    Mouse models of cystic fibrosis: Phenotypic analysis and research applications

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    AbstractGenetically modified mice have been studied for more than fifteen years as models of cystic fibrosis (CF). The large amount of experimental data generated illuminates the complex multi-organ pathology of CF and raises new questions relevant to human disease. CF mice have also been used to test experimental therapies prior to clinical trials. This review recapitulates the major phenotypic traits of CF mice and highlights important new findings including aberrant alveolar macrophages, bone and cartilage abnormalities and abnormal bioactive lipid metabolism. Novel data are presented on the intestinal and nasal physiology of F508del-CFTR CF mice backcrossed onto different genetic backgrounds. Caveats, and sources of variability including age, gender and animal husbandry, are discussed. Interspecies differences limit comparison of lung pathology in CF mice to the human disease. The recent development of genetically modified pigs and ferrets heralds the application of more advanced animal models to CF research and drug development

    Report on the ISIKLE Project: Increasing and Evaluating Student Impact in Knowledge and Learning Exchange (ISIKLE)

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    This final report on the ISIKLE project which summarises the findings of the mixed-method evaluation of the work of ISIKLE over the two years from June 2020. The project was by funded by Research England and OfS to demonstrate and evaluate effective practices in student engagement in Knowledge Exchange activities to assess their economic and social benefits to individual students and to external partners and communities. The evaluation includes a Systematic Review of the literature on student knowledge exchange; narrative case studies of the innovations introduced on the ISIKLE sub-projects at UCL and University of Manchester; and both quantitative and qualitative evaluations of the impacts of the programmes on students and external partner

    Development of a modified Cambridge Multimorbidity Score for use with SNOMED CT:an observational English primary care sentinel network study

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    Background People with multiple health conditions are more likely to have poorer health outcomes and greater care and service needs; a reliable measure of multimorbidity would inform management strategies and resource allocation. Aim To develop and validate a modified version of the Cambridge Multimorbidity Score in an extended age range, using clinical terms that are routinely used in electronic health records across the world (Systematized Nomenclature of Medicine — Clinical Terms, SNOMED CT). Design and setting Observational study using diagnosis and prescriptions data from an English primary care sentinel surveillance network between 2014 and 2019. Method In this study new variables describing 37 health conditions were curated and the associations modelled between these and 1-year mortality risk using the Cox proportional hazard model in a development dataset (n = 300 000). Two simplified models were then developed — a 20-condition model as per the original Cambridge Multimorbidity Score and a variable reduction model using backward elimination with Akaike information criterion as the stopping criterion. The results were compared and validated for 1-year mortality in a synchronous validation dataset (n = 150 000), and for 1-year and 5-year mortality in an asynchronous validation dataset (n = 150 000). Results The final variable reduction model retained 21 conditions, and the conditions mostly overlapped with those in the 20-condition model. The model performed similarly to the 37- and 20-condition models, showing high discrimination and good calibration following recalibration. Conclusion This modified version of the Cambridge Multimorbidity Score allows reliable estimation using clinical terms that can be applied internationally across multiple healthcare settings
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