2,545 research outputs found

    Briefing: community resilience to extreme weather

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    The global climate is changing in ways that are likely to have a significant impact on society and the natural and built environments over the coming decades. Extreme weather events, both globally and in the UK, appear to be increasing in frequency and severity, and there is growing concern that the cost of managing them and their impacts will increase. Preparedness and resilience measures can help to mitigate impacts and associated costs to both infrastructure and to people. A new multi-institutional research programme involving 13 universities in the UK called Crew (community resilience to extreme weather) has recently started, which will develop a tool kit to support decision making and will therefore improve the capacity for resilience of local communities to the impacts of future extreme weather. The broad aim is to develop a set of web-based tools for mapping potential future extreme weather events, for assessing their impacts under a range of scenarios, and to evaluate and offer a range of potential coping measures. As part of this the project will identify existing coping measures for dealing with extreme weather events at the levels of the community, buildings and individuals. The work will assess coping measures in terms of their suitability for the climate and buildings in the UK, their effectiveness for risk reduction and technical aspects that may affect their uptake. This will therefore provide the basis for the development of more effective coping measures for the community, including households, small businesses and local policy makers

    Detection of an energetic flare from the M5V secondary star in the Polar MQ Dra

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    MQ Dra is a strongly magnetic Cataclysmic Variable whose white dwarf accretes material from its secondary star through a stellar wind at a low rate. TESS observations were made of MQ Dra in four sectors in Cycle 2 and show a short duration, high energy flare (similar to 10(35) erg) which has a profile characteristic of a flare from the M5V secondary star. This is one of the few occasions where an energetic flare has been seen from a Polar. We find no evidence that the flare caused a change in the light curve following the event and consider whether a coronal mass ejection was associated with the flare. We compare the frequency of energetic flares from the secondary star in MQ Dra with M dwarf stars and discuss the overall flare rate of stars with rotation periods shorter than 0.2 d and how such fast rotators can generate magnetic fields with low differential rotation rates

    Identification of Cell Cycle–Regulated Genes Periodically Expressed in U2OS Cells and their Regulation by FOXM1 and E2F Transcription Factors

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    We identify the cell cycle–regulated mRNA transcripts genome-wide in the osteosarcoma-derived U2OS cell line. This results in 2140 transcripts mapping to 1871 unique cell cycle–regulated genes that show periodic oscillations across multiple synchronous cell cycles. We identify genomic loci bound by the G2/M transcription factor FOXM1 by chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) and associate these with cell cycle–regulated genes. FOXM1 is bound to cell cycle–regulated genes with peak expression in both S phase and G2/M phases. We show that ChIP-seq genomic loci are responsive to FOXM1 using a real-time luciferase assay in live cells, showing that FOXM1 strongly activates promoters of G2/M phase genes and weakly activates those induced in S phase. Analysis of ChIP-seq data from a panel of cell cycle transcription factors (E2F1, E2F4, E2F6, and GABPA) from the Encyclopedia of DNA Elements and ChIP-seq data for the DREAM complex finds that a set of core cell cycle genes regulated in both U2OS and HeLa cells are bound by multiple cell cycle transcription factors. These data identify the cell cycle–regulated genes in a second cancer-derived cell line and provide a comprehensive picture of the transcriptional regulatory systems controlling periodic gene expression in the human cell division cycle

    Kepler Observations of V447 Lyr: An Eclipsing U Gem Cataclysmic Variable

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    We present the results of an analysis of data covering 1.5 years of the dwarf nova V447 Lyr. We detect eclipses of the accretion disk by the mass donating secondary star every 3.74 hrs which is the binary orbital period. V447 Lyr is therefore the first dwarf nova in the Kepler field to show eclipses. We also detect five long outbursts and six short outbursts showing V447 Lyr is a U Gem type dwarf nova. We show that the orbital phase of the mid-eclipse occurs earlier during outbursts compared to quiescence and that the width of the eclipse is greater during outburst. This suggests that the bright spot is more prominent during quiescence and that the disk is larger during outburst than quiescence. This is consistent with an expansion of the outer disk radius due to the presence of high viscosity material associated with the outburst, followed by a contraction in quiescence due to the accretion of low angular momentum material. We note that the long outbursts appear to be triggered by a short outburst, which is also observed in the super-outbursts of SU UMa dwarf novae as observed using Kepler.Comment: Accepted by MNRA

    Simulating the evolutionary trajectories of metabolic pathways for insect symbionts in the genus Sodalis

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    Insect-bacterial symbioses are ubiquitous, but there is still much to uncover about how these relationships establish, persist and evolve. The tsetse endosymbiont Sodalis glossinidius displays intriguing metabolic adaptations to its microenvironment, but the process by which this relationship evolved remains to be elucidated. The recent chance discovery of the free-living species of the genus Sodalis, Sodalis praecaptivus, provides a serendipitous starting point from which to investigate the evolution of this symbiosis. Here, we present a flux balance model for S. praecaptivus and empirically verify its predictions. Metabolic modelling is used in combination with a multi-objective evolutionary algorithm to explore the trajectories that S. glossinidius may have undertaken from this starting point after becoming internalized. The order in which key genes are lost is shown to influence the evolved populations, providing possible targets for future in vitro genetic manipulation. This method provides a detailed perspective on possible evolutionary trajectories for S. glossinidius in this fundamental process of evolutionary and ecological change

    Long Spin Coherence and Relaxation Times in Nanodiamonds Milled from Polycrystalline 12^{12}C Diamond

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    The negatively charged nitrogen-vacancy centre (NV−^-) in diamond has been utilized in a wide variety of sensing applications. The centre's long spin coherence and relaxation times (T2∗T_2^*, T2T_2 and T1T_1) at room temperature are crucial to this, as they often limit sensitivity. Using NV−^- centres in nanodiamonds allows for operations in environments inaccessible to bulk diamond, such as intracellular sensing. We report long spin coherence and relaxation times at room temperature for single NV−^- centres in isotopically-purified polycrystalline ball-milled nanodiamonds. Using a spin-locking pulse sequence, we observe spin coherence times, T2T_2, up 786 ±\pm 200 μ\mus. We also measure T2∗T_2^* times up to 2.06 ±\pm 0.24 μ\mus and T1T_1 times up to 4.32 ±\pm 0.60 ms. Scanning electron microscopy and atomic force microscopy measurements show that the diamond containing the NV−^{-} centre with the longest T1T_1 time is smaller than 100 nm. EPR measurements give an Ns_{s}0^{0} concentration of 0.15 ±\pm 0.02 ppm for the nanodiamond sample.Comment: 13 pages, 3 figure
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