27 research outputs found

    Open-closed TQFTs extend Khovanov homology from links to tangles

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    We use a special kind of 2-dimensional extended Topological Quantum Field Theories (TQFTs), so-called open-closed TQFTs, in order to extend Khovanov homology from links to arbitrary tangles, not necessarily even. For every plane diagram of an oriented tangle, we construct a chain complex whose homology is invariant under Reidemeister moves. The terms of this chain complex are modules of a suitable algebra A such that there is one action of A or A^op for every boundary point of the tangle. We give examples of such algebras A for which our tangle homology theory reduces to the link homology theories of Khovanov, Lee, and Bar-Natan if it is evaluated for links. As a consequence of the Cardy condition, Khovanov's graded theory can only be extended to tangles if the underlying field has finite characteristic. In all cases in which the algebra A is strongly separable, i.e. for Bar-Natan's theory in any characteristic and for Lee's theory in characteristic other than 2, we also provide the required algebraic operation for the composition of oriented tangles. Just as Khovanov's theory for links can be recovered from Lee's or Bar-Natan's by a suitable spectral sequence, we provide a spectral sequence in order to compute our tangle extension of Khovanov's theory from that of Bar-Natan's or Lee's theory. Thus, we provide a tangle homology theory that is locally computable and still strong enough to recover characteristic p Khovanov homology for links.Comment: 56 pages, LaTeX2e with xypic and pstricks macro

    The Use of Scaffolding Technique to Teach Recount Text Writing

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    The purpose of this research was to investigate the effectiveness of using scaffolding technique in teaching writing especially recount text writing to Year-10 Students of SMA Karya Sekadau in Academic Year 2015/2016. It was a pre-experimental study with a single group pre-test post-test design. The sample was Year-10 students that consisted of 29 students. The data were collected by giving pre-test before the treatment and post-test after the treatment in writing test. The test was performance test in written form.. Pre-test and post-test were the same test with the same command. The data were analyzed by Effect Size (ES) formula. The finding showed that the effect size of teaching recount text writing by using scaffolding technique was 1.210 (ES > 0.5) and categorized high

    State sum construction of two-dimensional open-closed Topological Quantum Field Theories

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    We present a state sum construction of two-dimensional extended Topological Quantum Field Theories (TQFTs), so-called open-closed TQFTs, which generalizes the state sum of Fukuma--Hosono--Kawai from triangulations of conventional two-dimensional cobordisms to those of open-closed cobordisms, i.e. smooth compact oriented 2-manifolds with corners that have a particular global structure. This construction reveals the topological interpretation of the associative algebra on which the state sum is based, as the vector space that the TQFT assigns to the unit interval. Extending the notion of a two-dimensional TQFT from cobordisms to suitable manifolds with corners therefore makes the relationship between the global description of the TQFT in terms of a functor into the category of vector spaces and the local description in terms of a state sum fully transparent. We also illustrate the state sum construction of an open-closed TQFT with a finite set of D-branes using the example of the groupoid algebra of a finite groupoid.Comment: 33 pages; LaTeX2e with xypic and pstricks macros; v2: typos correcte

    The role of SAH intensity and endothelin-1 increases in aneurysmal symptomatic cerebral vasospasm

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    Larry Gray's AEC tractor - registration VJE214L - circa 1980

    The role of SAH intensity and endothelin-1 increases in aneurysmal symptomatic cerebral vasospasm

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    Molecular Alterations in the Hippocampus after Experimental Subarachnoid Hemorrhage

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