631 research outputs found

    Effects of long-term removal of sheep grazing on the seedbanks of high-level grasslands and blanket bogs

    Get PDF
    Many areas of vegetation in the British uplands have reduced species diversity as a result of sheep overgrazing. It has been suggested that abandonment or re-wilding strategies might be used to reverse this. A likely first step would be the removal or reduction of grazing livestock from upland areas, with a presumption that this would lead to a recovery in species richness. However, we do not know if this would work, or the timescales involved. One of the important areas where more knowledge is needed is information on the size and composition of soil seedbanks as regeneration from zseed is a likely pathway of recovery. Here, we compared seedbanks in both grazed and ungrazed plots in five experiments at Moor House NNR in the northern Pennines; these sheep grazing exclusion experiments were started 52 and 63/64 years ago. Soil samples (n=10) were collected from both grazed and ungrazed plots in each experiment, and seed emergence counted in glasshouse trials. We detected only seeds of common species and very few dicotyledonous species. This suggests that the soil seedbank is unlikely to be a reliable source of the less common species for ecological restoration in these upland communities, suggesting an extinction debt. Therefore, seed addition and the creation of suitable safe-sites for germination may be needed in conjunction with grazing controls to allow the establishment of plants that will increase the species richness of the vegetation. However, this interventionist restoration approach remains to be tested

    Understanding System Complexity in the Non-Destructive Testing of Advanced Composite Products

    Get PDF
    Non-destructive testing (NDT) is a quality control measure designed to ensure the safety of products according to established variability thresholds. With the development of advanced technologies and a lack of formalised knowledge of the state-of-the-art, the National Composites Centre, Bristol, has identified that the increasing complexity of composite products will lead to some severe inspection challenges. To address the apparent knowledge gap and understand system complexity, a formulaic approach to introduce intelligence and improve the robustness of NDT operations is presented. The systemic development of a high-fidelity knowledge base (KB) involves the establishment of a capability matrix that maps material, component, and defect configuration to the capabilities and limitations of selected detection methods. Population and validation are demonstrated through the experimental testing of reference standards and evaluated against an assessment criteria. System complexity in ultrasonic testing operations focusses on capturing the inherent risks in inspection and the designation of evidence-based path plans for automation platforms. Anticipated deployment of the validated applicability data within the KB will allow for road-mapping of the inspection technique development and will provide opportunities for knowledge-based decision making. Moreover, the KB highlights the need for Design for Inspection, providing measurable data that the methodology should not be ignored

    Long-term effects of sheep-grazing and its removal on vegetation dynamics of British upland grasslands and moorlands; local management cannot overcome large-scale trends

    Get PDF
    The upland and mountainous regions of northern Europe provide a wide variety of ecosystem services. However, these ecosystem services are highly vulnerable to environmental and land-use change. To ensure their future conservation, it is therefore, essential to understand whether upland plant communities will respond positively or negatively to a range of environmental factors such as grazing pressure and landscape-scale factors such as changes in atmospheric SO2 and NOx deposition. To understand this, here, we describe the long-term trends in four UK upland communities (high-level grassland, intermediate grassland, blanket bog, high-level bog) using four replicated long-term experiments examining the effects of sheep grazing compared to no-sheep grazing in Moor House (from 1954 to 2016). Our results showed that species richness and abundance recovered in grazed plots after 2000, with improvements in species richness and abundance of vascular plants, mosses, and liverworts. Unfortunately, no improvement was found for lichens. Species richness, vascular plants, and mosses recovered the fastest, and much faster than liverworts. There was no evidence of slower recovery of species richness and abundance in plots where sheep grazing was removed. These results are consistent with longitudinal studies suggesting recovery after 2000 as a result of reduced atmospheric deposition. Although trends in diversity and abundance in the grazed and ungrazed plots were not identical, they were not markedly different either. The similar richness and abundance trends in the grazed and ungrazed plots found in each plant community suggest that within-community dynamics may overcome initial differences between the grazing treatments over time. In contrast, differences in richness and abundance among plant communities over time suggest that some landscape-scale trends, such as those caused by a reduction in nutrient inputs, initiate community-dependent recovery

    Analysis of Nkx3.1:Cre-driven Erk5 deletion reveals a profound spinal deformity which is linked to increased osteoclast activity

    Get PDF
    Extracellular signal-regulated protein kinase 5 (ERK5) has been implicated during development and carcinogenesis. Nkx3.1-mediated Cre expression is a useful strategy to genetically manipulate the mouse prostate. While grossly normal at birth, we observed an unexpected phenotype of spinal protrusion in Nkx3.1:Cre;Erk5fl/fl (Erk5fl/fl) mice by ~6–8 weeks of age. X-ray, histological and micro CT (µCT) analyses showed that 100% of male and female Erk5fl/fl mice had a severely deformed curved thoracic spine, with an associated loss of trabecular bone volume. Although sex-specific differences were observed, histomorphometry measurements revealed that both bone resorption and bone formation parameters were increased in male Erk5fl/fl mice compared to wild type (WT) littermates. Osteopenia occurs where the rate of bone resorption exceeds that of bone formation, so we investigated the role of the osteoclast compartment. We found that treatment of RANKL-stimulated primary bone marrow-derived macrophage (BMDM) cultures with small molecule ERK5 pathway inhibitors increased osteoclast numbers. Furthermore, osteoclast numbers and expression of osteoclast marker genes were increased in parallel with reduced Erk5 expression in cultures generated from Erk5fl/fl mice compared to WT mice. Collectively, these results reveal a novel role for Erk5 during bone maturation and homeostasis in vivo

    A screen for kinase inhibitors identifies antimicrobial imidazopyridine aminofurazans as specific inhibitors of the Listeria monocytogenes PASTA kinase PrkA

    Get PDF
    Bacterial signaling systems such as protein kinases and quorum sensing have become increasingly attractive targets for the development of novel antimicrobial agents in a time of rising antibiotic resistance. The family of bacterial Penicillin-binding-protein And Serine/Threonine kinase-Associated (PASTA) kinases is of particular interest due to the role of these kinases in regulating resistance to β-lactam antibiotics. As such, small-molecule kinase inhibitors that target PASTA kinases may prove beneficial as treatments adjunctive to β-lactam therapy. Despite this interest, only limited progress has been made in identifying functional inhibitors of the PASTA kinases that have both activity against the intact microbe and high kinase specificity. Here, we report the results of a small-molecule screen that identified GSK690693, an imidazopyridine aminofurazan-type kinase inhibitor that increases the sensitivity of the intracellular pathogen Listeria monocytogenes to various β-lactams by inhibiting the PASTA kinase PrkA. GSK690693 potently inhibited PrkA kinase activity biochemically and exhibited significant selectivity for PrkA relative to the Staphylococcus aureus PASTA kinase Stk1. Furthermore, other imidazopyridine aminofurazans could effectively inhibit PrkA and potentiate β-lactam antibiotic activity to varying degrees. The presence of the 2-methyl-3-butyn-2-ol (alkynol) moiety was important for both biochemical and antimicrobial activity. Finally, mutagenesis studies demonstrated residues in the back pocket of the active site are important for GSK690693 selectivity. These data suggest that targeted screens can successfully identify PASTA kinase inhibitors with both biochemical and antimicrobial specificity. Moreover, the imidazopyridine aminofurazans represent a family of PASTA kinase inhibitors that have the potential to be optimized for selective PASTA kinase inhibition

    Temporal and spatial variation in distribution of fish environmental DNA in England’s largest lake

    Get PDF
    Environmental DNA offers great potential as a biodiversity monitoring tool. Previous work has demonstrated that eDNA metabarcoding provides reliable information for lake fish monitoring, but important questions remain about temporal and spatial repeatability, which is critical for understanding the ecology of eDNA and developing effective sampling strategies. Here, we carried out comprehensive spatial sampling of England's largest lake, Windermere, during summer and winter to 1) examine repeatability of the method, 2) compare eDNA results with contemporary gill-net survey data, 3) test the hypothesis of greater spatial structure of eDNA in summer compared to winter due to differences in water mixing between seasons, and 4) compare the effectiveness of shore and offshore sampling for species detection. We find broad consistency between results from three sampling events in terms of species detection and abundance, with eDNA detecting more species than established methods and being significantly correlated to rank abundance determined by long-term data. As predicted, spatial structure was much greater in the summer, reflecting less mixing of eDNA than in the winter. For example Arctic charr, a deep-water species, was only detected in deep, mid-lake samples in the summer, while littoral or benthic species such as minnow and stickleback were more frequently detected in shore samples. By contrast in winter, the eDNA of these species was more uniformly distributed. This has important implications for design of sampling campaigns, for example, deep-water species could be missed and littoral/benthic species over-represented by focusing exclusively on shoreline samples collected in the summer

    Sheep Updates 2005 - Part 3

    Get PDF
    This session covers seven papers from different authors: CUSTOMER 1. Benefits VIAscanR to producers and WAMMCO, Rob Davidson, Supply Development Manager, David Pethick, School of Veterinary and Biomedical Studies, Murdock University. 2. Healthy fats in lamb: how WA lambs compare with others, C. F. Engelke Animal Biology, University of Western Australia, bCSIRO Livestock Industries, Western Australia B.D. Siebert, Department of Animal Science, University of Adelaide, South Australia, K. Gregg, Centre for High-Throughput Agricultural Genetic Analysis, Murdoch University, Western Australia. A-D.G. Wright CSIRO Livestock Industries, Western Australia, P.E Vercoe Animal Biology, University of Western Australia 3. Shelf life of fresh lamb meat: lamb age & electrical stimulation, Dr Robin Jacob, Department of Agriculture, Western Australia 4. Pastures from space - An evaluation of adoption of by Australian woolgrowers, Russell Barnett, Australian Venture Consultants, Joanne Sneddon, University of Western Australia 5. Your clients can learn from ASHEEP\u27s example, Sandra Brown Department of Agriculture Western Australia 6. Lifetime Wool - Farmers attitudes affect their adoption of recommended ewe management, G. Rose Department of Agriculture Western Australia, C. Kabore, Kazresearch, Lower Templestowe Vic, J. Dart, Clear Horizons, Hastings Vic 7. Sustainable certification of Australian Merino, what will customers be looking for? Stuart Adams, i-merino / iZWool International Pty Lt
    corecore