2,214 research outputs found

    Ferroelectric phase transition and the lattice thermal conductivity of Pb1-xGexTe alloys

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    We show how tuning the proximity to the soft optical mode phase transition via chemical composition affects the lattice thermal conductivity Îș of Pb1-xGexTe alloys. Using first-principles virtual-crystal simulations, we find that the anharmonic contribution to Îș is minimized at the phase transition due to the maximized acoustic-optical anharmonic interaction. Mass disorder significantly lowers and flattens the dip in the anharmonic Îș over a wide composition range, thus shifting the Îș minimum away from the phase transition. The total Îș and its anharmonic contribution vary continuously between the rocksalt and rhombohedral phases as expected for the second-order phase transition. The actual phase and its strength of resonant bonding play a less prominent role in reducing the Îș of Pb1-xGexTe alloys than the proximity to the phase transition and the atomic mass. Our results show that alloys with soft optical mode transitions are promising materials for achieving low thermal conductivity and possibly high thermoelectric efficiency

    Innovative development of the Octopus (cf) tetricus fishery in Western Australia

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    In 2010 the broad-scale introduction of a new gear type, the trigger trap, saw a 260% (33 t in 2009 to 119 t in 2010) increase in octopus landings in the Western Australian Developmental Octopus Fishery (DOF). Deployed in waters previously unfished by the DOF, initial catches demonstrated that trigger traps were more efficient and captured a different component of the population, compared to open-ended shelter pots traditionally used in the fishery. This shift caused a surge of interest in commercial octopus fishing

    Review of Engaging Education: Developing Emotional Literacy, Equity and Co-education. Brian Matthews. (Book Review)

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    The book is only about a fraction of its title Engaging Education. His section on ‘engaging the emotions’ sums this up: whereas the book is largely about engaging the emotions positively, the definition of ‘Engaging’ is more far reaching: “that pupils should be involved in their learning; be active and absorbed and not just passive recipients of a set curriculum. Additionally, they should feel engaged in the processes of education and have some input into creating their own agendas for learning” (p.2). Exploring the full impact of this statement across the curriculum really needs a different book

    Understanding Schools and Schooling. (Book Review)

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    A review of a book written by Clive Chitty (2002 with a useful focus on issues of equity and social justice, including prejudice, discrimination and bullying in secondary schools. Education policy makers need to explore the extent to which it is important to produce interested, motivated and socially balanced young adults. It is well researched and documented

    On acceptance conditions for membrane systems: characterisations of L and NL

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    In this paper we investigate the affect of various acceptance conditions on recogniser membrane systems without dissolution. We demonstrate that two particular acceptance conditions (one easier to program, the other easier to prove correctness) both characterise the same complexity class, NL. We also find that by restricting the acceptance conditions we obtain a characterisation of L. We obtain these results by investigating the connectivity properties of dependency graphs that model membrane system computations

    Distinct and complementary functions of MDA5 and TLR3 in poly(I:C)-mediated activation of mouse NK cells

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    The double-stranded RNA (dsRNA) analogue poly(I:C) is a promising adjuvant for cancer vaccines because it activates both dendritic cells (DCs) and natural killer (NK) cells, concurrently promoting adaptive and innate anticancer responses. Poly(I:C) acts through two dsRNA sensors, Toll-like receptor 3 (TLR3) and melanoma differentiation-associated protein-5 (MDA5). Here, we investigated the relative contributions of MDA5 and TLR3 to poly(I:C)-mediated NK cell activation using MDA5−/−, TLR3−/−, and MDA5−/−TLR3−/− mice. MDA5 was crucial for NK cell activation, whereas TLR3 had a minor impact most evident in the absence of MDA5. MDA5 and TLR3 activated NK cells indirectly through accessory cells and induced the distinct stimulatory cytokines interferon-α and interleukin-12, respectively. To identify the relevant accessory cells in vivo, we generated bone marrow chimeras between either wild-type (WT) and MDA5−/− or WT and TLR3−/− mice. Interestingly, multiple accessory cells were implicated, with MDA5 acting primarily in stromal cells and TLR3 predominantly in hematopoietic cells. Furthermore, poly(I:C)-mediated NK cell activation was not notably impaired in mice lacking CD8α DCs, providing further evidence that poly(I:C) acts through diverse accessory cells rather than solely through DCs. These results demonstrate distinct yet complementary roles for MDA5 and TLR3 in poly(I:C)-mediated NK cell activation
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