604 research outputs found

    Problems encountered by science teachers in wheelchairs

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    In this article we will take you through the real life story that transformed our thinking about supporting science trainee teachers, particularly those with special needs, in schools and other training institutions. We will then share ideas from science teachers in wheelchairs as together we build a portfolio of guidance for initial teacher training institutions, be they universities, placement and training/teaching schools

    Introduction to the IASJ Journal of Applied Jazz Research

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    Jazz research started as a duplicate of classical music research. As became clear during the Ongoing Dialogues during the annual IASJ Jazz Meetings that started in 1990, jazz research needs a dimension and a dynamic of its own. This has become \u27applied jazz research\u27, the kind of research that is directly linked to jazz performance and jazz education. The IASJ Journal of Applied Jazz research offers the platform

    Cloning, preparation and preliminary crystallographic studies of penicillin V acylase autoproteolytic processing mutants

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    The crystallization of three catalytically inactive mutants of penicillin Vacylase (PVA) from Bacillus sphaericus in precursor and processed forms is reported. The mutant proteins crystallize in different primitive monoclinic space groups that are distinct from the crystal forms for the native enzyme. Directed mutants and clone constructs were designed to study the post-translational autoproteolytic processing of PVA. The catalytically inactive mutants will provide threedimensional structures of precursor PVA forms, plus open a route to the study of enzyme-substrate complexes for this industrially important enzyme

    Forward and Backward Steps in a Fibration

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    Distributive laws of various kinds occur widely in the theory of coalgebra, for instance to model automata constructions and trace semantics, and to interpret coalgebraic modal logic. We study steps, which are a general type of distributive law, that allow one to map coalgebras along an adjunction. In this paper, we address the question of what such mappings do to well known notions of equivalence, e.g., bisimilarity, behavioural equivalence, and logical equivalence. We do this using the characterisation of such notions of equivalence as (co)inductive predicates in a fibration. Our main contribution is the identification of conditions on the interaction between the steps and liftings, which guarantees preservation of fixed points by the mapping of coalgebras along the adjunction. We apply these conditions in the context of lax liftings proposed by Bonchi, Silva, Sokolova (2021), and generalise their result on preservation of bisimilarity in the construction of a belief state transformer. Further, we relate our results to properties of coalgebraic modal logics including expressivity and completeness

    Techno-economic assessment and comparison of CO2 capture technologies for industrial processes: Preliminary results for the iron and steel sector

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    AbstractThis paper presents the methodology and the preliminary results of a techno-economic assessment of CCS implementation on the iron and steel sector. The results show that for the short-mid term, a CO2 avoidance cost of less than 50 ā‚¬ /tonne at a CO2 avoidance rate of around 50% are possible by converting the conventional blast furnace (BF) to Top Gas Recycling Blast Furnace (TGRBF). However, large additional power consumption for CO2 removal and oxygen generation, and reduction in BF gas export, makes the economic performance of the technology very sensitive to energy prices. Add-on CO2 capture for conventional BF may achieve similar costs (40ā€“50 ā‚¬ /t CO2 avoided), but the CO2 avoidance rate will be only about 15% of the specific CO2 emissions. For the long term future, although there are large uncertainties, advanced CO2 capture technologies do not seem to have significant economic advantages over conventional technologies. The results also indicate that in a carbon-constrained society, when considering new plants, smelting reduction technologies such as the COREX process, may become a strong competitor to conventional blast furnace based steel making process when equipped with CO2 capture. Although conventional iron and steel making using BF is expected to dominate the market in the long term, strong need for drastic CO2 emissions reduction may drive the sector towards large scale implementation of advanced smelting reduction technologies

    The structural characterization of a prophage-encoded extracellular DNase from Streptococcus pyogenes

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    The pathogenic bacterium Group A Streptococcus pyogenes produces several extracellular DNases that have been shown to facilitate invasive infection by evading the human host immune system. DNases degrade the chromatin in neutrophil extracellular traps, enabling the bacterium to evade neutrophil capture. Spd1 is a type I, nonspecific Ī²Ī²Ī±/metal-dependent nuclease from Streptococcus pyogenes, which is encoded by the SF370.1 prophage and is likely to be expressed as a result of prophage induction. We present here the X-ray structure of this DNase in the wild-type and Asn145Ala mutant form. Through structural and sequence alignments as well as mutagenesis studies, we have identified the key residues His121, Asn145 and Glu164, which are crucial for Spd1 nucleolytic activity and shown the active site constellation. Our wild-type structure alludes to the possibility of a catalytically blocked dimeric form of the protein. We have investigated the multimeric nature of Spd1 using size-exclusion chromatography with multi-angle light scattering (SEC-MALLS) in the presence and absence of the divalent metal ion Mg2+, which suggests that Spd1 exists in a monomeric form in solution
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