14 research outputs found

    Britain’s highest bog: can we unlock its secrets?

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    The Glenfeshie Mòine Mhór (Great Moss) is Britain’s highest bog, the largest bog in the Cairngorm Mountains (Scotland) and a water source area for the River Spey. The area was managed primarily for sport hunting for about two centuries, but deer numbers have been heavily reduced in the last decade to allow regeneration of natural woodland and the return to more natural condition of all ecosystems including peatland. However, it may not be realistic to expect spontaneous improvement in peatland condition and ecosystem services provision in the harsh environment of the Mòine Mhór, which retains snow cover for more than half the year and differs floristically from lower-altitude bogs. To understand whether and where management intervention may be required, we need first to understand how the system works at scales ranging from microform to macrotope, and from sub-catchment to whole-system level. Multi-disciplinary condition and process studies (involving various collaborators) are in progress, with a current emphasis on streamflow generation and fluvial carbon loads. This presentation develops two sub-themes. First, ground survey and GIS analysis are used to address the questions: what are the special features of this bog; what is the nature and extent of degradation; and what are the implications for water delivered to the outflow streams? Secondly, a striking feature is the bare peat patches which were favourite resting places for deer on warm, dry summer days. The occurrence of seasonally extreme surface conditions seems a likely factor in preventing their recolonisation by bog plants now. Information about these conditions that cannot readily be accessed through direct observation, originating from temperature sensors and delivered at 60-minute intervals via a low power internet link, is explored in this context. Finally, we discuss aspects of the suitability of our investigation methods for remote and intermittently accessible field sites such as the Mòine Mhór

    Poster Abstract:Deploying a 6LoWPAN, CoAP, low power, wireless sensor network

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    In order to integrate equipment from different vendors, wireless sensor networks need to become more standardized. Using IP as the basis of low power radio networks, together with application layer standards designed for this purpose is one way forward. This research focuses on implementing and deploying a system using Contiki, 6LoWPAN over an 868 MHz radio network, together with CoAP as a standard application layer protocol. A system was deployed in the Cairngorm mountains in Scotland as an environmental sensor network, measuring streams, temperature profiles in peat and periglacial features. It was found that RPL provided an effective routing algorithm, and that the use of UDP packets with CoAP proved to be an energy efficient application layer. This combination of technologies can be very effective in large area sensor networks

    Utilizing UV-LED pulse width modulation on TiO2 advanced oxidation processes to enhance the decomposition efficiency of pharmaceutical micropollutants

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    The final publication is available at Elsevier via https://doi.org/10.1016/j.cej.2018.12.065. © 2018 This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The presence of pharmaceutical and personal care products (PPCPs) in aquatic systems has been a growing cause for concern. Advanced oxidation processes such as UV/TiO2 (ultraviolet light/titanium dioxide) can break down PPCPs into smaller constituents, reducing the pharmaceutical activity. However, this process is limited by low photonic efficiency under UV systems. Controlled periodic illumination (CPI) is a promising solution to overcome the issues concerning low photonic efficiencies. Using a CPI controlled UV-LED/TiO2 process, a mixture of eighteen PPCP compounds were analyzed for their degradation removal on porous titanium – titanium dioxide (PTT) substrates. The kinetic rate constants of PPCPs may be analyzed using multiple regression analysis with parameters such as net charge at experimental pH, solubility, and molecular weight. Negatively charged PPCP compounds were found to have the highest removal compared to neutral and positively charged compounds due to electrostatic attraction forces. Decreasing the duty cycle under CPI or the UV-LED illumination period did not significantly change the individual and cumulative PPCP compound removal, suggesting that the CPI controlled UV-LED/TiO2 processes using PTT substrates were effective in reducing energy requirements without sacrificing removal performance.Natural Sciences and Engineering Research Council [STPGP430654-12]Schwartz-Resiman FoundationWaterloo-Technion Research Co-operation Progra

    How Does the VSG Coat of Bloodstream Form African Trypanosomes Interact with External Proteins?

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    Variations on the statement "the variant surface glycoprotein (VSG) coat that covers the external face of the mammalian bloodstream form of Trypanosoma brucei acts a physical barrier" appear regularly in research articles and reviews. The concept of the impenetrable VSG coat is an attractive one, as it provides a clear model for understanding how a trypanosome population persists; each successive VSG protects the plasma membrane and is immunologically distinct from previous VSGs. What is the evidence that the VSG coat is an impenetrable barrier, and how do antibodies and other extracellular proteins interact with it? In this review, the nature of the extracellular surface of the bloodstream form trypanosome is described, and past experiments that investigated binding of antibodies and lectins to trypanosomes are analysed using knowledge of VSG sequence and structure that was unavailable when the experiments were performed. Epitopes for some VSG monoclonal antibodies are mapped as far as possible from previous experimental data, onto models of VSG structures. The binding of lectins to some, but not to other, VSGs is revisited with more recent knowledge of the location and nature of N-linked oligosaccharides. The conclusions are: (i) Much of the variation observed in earlier experiments can be explained by the identity of the individual VSGs. (ii) Much of an individual VSG is accessible to antibodies, and the barrier that prevents access to the cell surface is probably at the base of the VSG N-terminal domain, approximately 5 nm from the plasma membrane. This second conclusion highlights a gap in our understanding of how the VSG coat works, as several plasma membrane proteins with large extracellular domains are very unlikely to be hidden from host antibodies by VSG.The authors’ lab is funded by the Wellcome Trust (093008/Z10/Z) and the Medical Research Council (MR/L008246/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.This is the final version of the article. It was first available from PLOS via http://dx.doi.org/10.1371/journal.ppat.100525

    New genetic loci link adipose and insulin biology to body fat distribution.

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    Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

    Theory and practice of hydrostatic lysimeters for direct measurement of net seepage in a patterned mire in north Scotland

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    International audienceA novel design of lysimeter for use in mires (peatlands) with shallow water tables is described. It employs an hydraulic mechanism for the automatic equilibration of soil moisture distribution between the outside and the inside of the lysimeter tank but uses no electronic components or electrical power; and it can be installed with minimal disturbance in surfaces with poor load-bearing capacity. The system was deployed on a mire in northern Scotland to investigate the distribution of shallow seepage associated with catenary arrays of different types of surface (microtopes). During the three-year period 15 November 1988 to 19 November 1991, the fraction of rainfall dispersed as seepage was 52% in a pool system; 62% in ridge-furrow microtopography; and 59-67% in unpatterned sloping mire. The data provide preliminary confirmation of the hypothesis of K. E. Ivanov that different microtopes within the same mire differ in their hydrological norms; and suggest that the range of ecohydrological differences at the study site may be similar to those obtained by Ivanov in western Siberia. Details of lysimeter design, construction, installation and operation are appended together with a discussion of the theory of the lysimeter. Keywords: acrotelm, blanket mire, ecohydrology, evapotranspiration, pool system, valleyside flowe, water balanc

    Photocatalytic Degradation of Microcystins by TiO<sub>2</sub> Using UV-LED Controlled Periodic Illumination

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    Toxic microcystins (MCs) produced by freshwater cyanobacteria such as Microcystis aeruginosa are of concern because of their negative health and economic impacts globally. An advanced oxidation process using UV/TiO2 offers a promising treatment option for hazardous organic pollutants such as microcystins. The following work details the successful degradation of MC-LA, MC-LR, and MC-RR using a porous titanium&#8315;titanium dioxide (PTT) membrane under UV-LED light. Microcystin quantitation was achieved by sample concentration and subsequent LC&#8315;MS/MS analysis. The PTT membrane offers a treatment option that eliminates the need for the additional filtration or separation steps required for traditional catalysts. Controlled periodic illumination was successfully used to decrease the total light exposure time and improve the photonic efficiency for a more cost-effective treatment system. Individual degradation rates were influenced by electrostatic forces between the catalyst and differently charged microcystins, which can potentially be adjusted by modifying the solution pH and the catalyst&#8217;s isoelectric point
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