2,341 research outputs found

    Untreated Municipal Solid Waste Incineration Ashes for Cement Replacement

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    This paper characterised the two different ashes, namely Boiler Ash (BOA) and Residue Ash (RA), collected from Qatar's Municipal Solid Waste Incineration (MSWI) plant through a range of detailed analyses (chemical, physical and morphological). The potential utilisation of these raw MSWI ashes as supplementary cementitious material (SCM) in cement-based composites has been investigated by replacement with 0%, 10%, 20%, and 30% by weight of cement. The effect of the replacement levels on workability, setting time, and strength was investigated. Test results showed that setting time increased and workability decreased with the increase of BOA content. On the contrary, RA substitution decreased the setting time and increased the workability. The highest compressive strength was obtained in RA-incorporated mortars at a 10% replacement ratio. Beyond the 10% replacement ratio, RA incorporation significantly reduced the strength. Due to BOA's high unburned carbon content, BOA substitutions reduced the strength of the mortars. However, the impact of the replacement ratio was not as strong as those in RA mortars. Considering setting time, workability, and compressive strength, BOA and RA's optimum percentage of cement replacement was 20% and 10%, respectively. Heavy metal and salt leaching from MSWI ash-incorporated mortars were evaluated by the monolithic tank test. Results indicated that most toxic metals and salts, except Ba and Cl-, were stabilised in the cement matrix

    Neurospora from natural populations: Population genomics insights into the Life history of a model microbial Eukaryote

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    The ascomycete filamentous fungus Neurospora crassa played a historic role in experimental biology and became a model system for genetic research. Stimulated by a systematic effort to collect wild strains initiated by Stanford geneticist David Perkins, the genus Neurospora has also become a basic model for the study of evolutionary processes, speciation, and population biology. In this chapter, we will first trace the history that brought Neurospora into the era of population genomics. We will then cover the major contributions of population genomic investigations using Neurospora to our understanding of microbial biogeography and speciation, and review recent work using population genomics and genome-wide association mapping that illustrates the unique potential of Neurospora as a model for identifying the genetic basis of (potentially adaptive) phenotypes in filamentous fungi. The advent of population genomics has contributed to firmly establish Neurospora as a complete model system and we hope our review will entice biologists to include Neurospora in their research

    Probabilistic Clustering of Time-Evolving Distance Data

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    We present a novel probabilistic clustering model for objects that are represented via pairwise distances and observed at different time points. The proposed method utilizes the information given by adjacent time points to find the underlying cluster structure and obtain a smooth cluster evolution. This approach allows the number of objects and clusters to differ at every time point, and no identification on the identities of the objects is needed. Further, the model does not require the number of clusters being specified in advance -- they are instead determined automatically using a Dirichlet process prior. We validate our model on synthetic data showing that the proposed method is more accurate than state-of-the-art clustering methods. Finally, we use our dynamic clustering model to analyze and illustrate the evolution of brain cancer patients over time

    The Age of the Galactic Disk

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    I review different methods devised to derive the age of the Galactic Disk, namely the Radio-active Decay (RD), the Cool White Dwarf Luminosity Function (CWDLF), old opne clusters (OOC) and the Color Magnitude Diagram (CMD) of the stars in the solar vicinity. I argue that the disk is likely to be 8-10 Gyr old. Since the bulk of globulars has an age around 13 Gyr, the possibility emerges that the Galaxy experienced a minimum of Star Formation at the end of the halo/bulge formation. This minimum might reflect the time at which the Galaxy started to acquire material to form the disk inside-out.Comment: 10 pages, 4 figure, invited review, in "The chemical evolution of the Milky Way : Stars vs Clusters, Vulcano (Italy), 20-24 September 199

    Targeting the rheumatoid arthritis synovial fibroblast via cyclin dependent kinase inhibition: An early phase trial

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    Introduction: Targeted biologic therapies demonstrate similar efficacies in rheumatoid arthritis despite distinct mechanisms of action. They also exhibit a ceiling effect, with 10% to 20% of patients achieving remission in clinical trials. None of these therapies target synovial fibroblasts, which drive and maintain synovitis. Seliciclib (R-roscovitine) is an orally available cyclin-dependent kinase inhibitor that suppresses fibroblast proliferation, and is efficacious in preclinical arthritis models. We aim to determine the toxicity and preliminary efficacy of seliciclib in combination with biologic therapies, to inform its potential as an adjunctive therapy in rheumatoid arthritis. Methods and analysis: TRAFIC is a non-commercial, multi-center, rolling phase Ib/IIa trial investigating the safety, tolerability, and efficacy of seliciclib in patients with moderate to severe rheumatoid arthritis receiving biologic therapies. All participants receive seliciclib with no control arm. The primary objective of part 1 (phase Ib) is to determine the maximum tolerated dose and safety of seliciclib over 4 weeks of dosing. Part 1 uses a restricted 1-stage Bayesian continual reassessment method based on a target dose-limiting toxicity probability of 35%. Part 2 (phase IIa) assesses the potential efficacy of seliciclib, and is designed as a single arm, single stage early phase trial based on a Fleming-A’Hern design using the maximum tolerated dose recommended from part 1. The primary response outcome after 12 weeks of therapy is a composite of clinical, histological and magnetic resonance imaging scores. Secondary outcomes include adverse events, pharmacodynamic and pharmacokinetic parameters, autoantibodies, and fatigue. Ethics and dissemination: The study has been reviewed and approved by the North East - Tyne & Wear South Research Ethics Committee (reference 14/NE/1075) and the Medicines and Healthcare Products Regulatory Agency (MHRA), United Kingdom. Results will be disseminated through publication in relevant peer-reviewed journals and presentation at national and international conferences. Trials Registration: ISRCTN, ISRCTN36667085. Registered on September 26, 2014; http://www.isrctn.com/ISRCTN36667085 Current protocol version: Protocol version 11.0 (March 21, 2019

    Garden varieties: how attractive are recommended garden plants to butterflies?

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    One way the public can engage in insect conservation is through wildlife gardening, including the growing of insect-friendly flowers as sources of nectar. However, plant varieties differ in the types of insects they attract. To determine which garden plants attracted which butterflies, we counted butterflies nectaring on 11 varieties of summer-flowering garden plants in a rural garden in East Sussex, UK. These plants were all from a list of 100 varieties considered attractive to British butterflies, and included the five varieties specifically listed by the UK charity Butterfly Conservation as best for summer nectar. A total of 2659 flower visits from 14 butterfly and one moth species were observed. We performed a principal components analysis which showed contrasting patterns between the species attracted to Origanum vulgare and Buddleia davidii. The “butterfly bush” Buddleia attracted many nymphalines, such as the peacock, Inachis io, but very few satyrines such as the gatekeeper, Pyronia tithonus, which mostly visited Origanum. Eupatorium cannibinum had the highest Simpson’s Diversity score of 0.75, while Buddleia and Origanum were lower, scoring 0.66 and 0.50 respectively. No one plant was good at attracting all observed butterfly species, as each attracted only a subset of the butterfly community. We conclude that to create a butterfly-friendly garden, a variety of plant species are required as nectar sources for butterflies. Furthermore, garden plant recommendations can probably benefit from being more precise as to the species of butterfly they attract

    Kondo effect in an integer-spin quantum dot

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    The Kondo effect is a key many-body phenomenon in condensed matter physics. It concerns the interaction between a localised spin and free electrons. Discovered in metals containing small amounts of magnetic impurities, it is now a fundamental mechanism in a wide class of correlated electron systems. Control over single, localised spins has become relevant also in fabricated structures due to the rapid developments in nano-electronics. Experiments have already demonstrated artificial realisations of isolated magnetic impurities at metallic surfaces, nanometer-scale magnets, controlled transitions between two-electron singlet and triplet states, and a tunable Kondo effect in semiconductor quantum dots. Here, we report an unexpected Kondo effect realised in a few-electron quantum dot containing singlet and triplet spin states whose energy difference can be tuned with a magnetic field. This effect occurs for an even number of electrons at the degeneracy between singlet and triplet states. The characteristic energy scale is found to be much larger than for the ordinary spin-1/2 case.Comment: 12 page

    Mobile DNA transposition in somatic cells

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    It had been long assumed that almost all insertions of mobile DNA elements occurred during germ-cell development rather than in somatic-cell development, but solid evidence for transposition in somatic cells is now accumulating. To add to this evidence, a recent paper in Mobile DNA reports the somatic transposition of a site-specific retrotransposon, R2, into its insertion site in 28S ribosomal DNA in Drosophila embryos

    Traumatic fracture of central venous catheter resulting in potential migration of distal fragment: a case report

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    We report a surgical retrieval of an indwelling portion of a traumatic rupture of the Central venous catheter following hair cutting by a confused patient secondary to Postoperative cognitive dysfunction. He had a dynamic compression screw for fixation of fractured neck of femur after previously failed surgical procedure. The second procedure was complicated with major blood loss, which required central venous and arterial line insertion for intra-operative and post-operative management. The patient was discharged to the ward following an uneventful stay on intensive care. While on the ward, he decided to trim his hair and in the process he inadvertently cut through the right internal jugular catheter. Complications and management resulting from embolisation of central line are reviewed
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