5,583 research outputs found

    Homotopy Type Theory in Lean

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    We discuss the homotopy type theory library in the Lean proof assistant. The library is especially geared toward synthetic homotopy theory. Of particular interest is the use of just a few primitive notions of higher inductive types, namely quotients and truncations, and the use of cubical methods.Comment: 17 pages, accepted for ITP 201

    Penetration of fusidic acid and rifampicin into cerebrospinal fluid in low-grade inflammatory meningitis caused by Staphylococcus epidermidis

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    AbstractCerebrospinal fluid (CSF) concentration-time curves of rifampicin and fusidic acid were studied in a patient with post-operative meningitis caused by Staphylococcus epidermidis. The patient was treated with this combination of antimicrobial agents because of a severe hypersensitivity reaction to vancomycin. Peak CSF concentrations of rifampicin exceeded the MIC by > 60-fold, while those of fusidic acid just reached the MIC. CSF concentrations of fusidic acid were relatively stable within the range reported for patients with uninflamed meninges, but serum levels were surprisingly low. An increase in the metabolism of fusidic acid induced by rifampicin cannot be excluded

    From Stumptown to Treetown: A Field Guide for Interpreting Portland’s History though its Heritage Trees

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    Portland’s urban forest is rooted in the city’s history. This guide is the first of its kind to use historic literature, archival collections, and living trees as evidence to interpret Portland’s history. Trees are some of our city’s oldest living artifacts and this guide will show you some of the many ways to see and interpret both history and nature in Portland

    The liminality of trajectory shifts in institutional entrepreneurship

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    In this paper, we develop a process model of trajectory shifts in institutional entrepreneurship. We focus on the liminal periods experienced by institutional entrepreneurs when they, unlike the rest of the organization, recognize limits in the present and seek to shift a familiar past into an unfamiliar and uncertain future. Such periods involve a situation where the new possible future, not yet fully formed, exists side-by-side with established innovation trajectories. Trajectory shifts are moments of truth for institutional entrepreneurs, but little is known about the underlying mechanisms of how entrepreneurs reflectively deal with liminality to conceive and bring forth new innovation trajectories. Our in-depth case study research at CarCorp traces three such mechanisms (reflective dissension, imaginative projection, and eliminatory exploration) and builds the basis for understanding the liminality of trajectory shifts. The paper offers theoretical implications for the institutional entrepreneurship literature

    From classroom reality to virtual classroom: the role of teacher-created scripts in the development of classroom simulation technology

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    This paper describes a specific kind of teacher narrative (the teacher created script) to support the design of a classroom simulation to be used in pre-service teacher education. We intend to share our experiences in exploring and developing the kind of narrative text which can be developed from a large reservoir of ethnographically generated data collected from the teachers and classrooms we have closely observed and documented over the last two decades. In particular, we explore the role which these narratives play within the development of the kind of classroom simulation we have produced. Reflection has long been acknowledged as a useful process for teachers to engage with. Also, the notion of formalising such reflections through writing has been acknowledged as a way to share, refine and articulate teaching practice. As stated by Barth (2001:66) “…with written words come the innermost secrets of schools”. This prototype simulation allows the user to adopt the role of a Kindergarten teacher using a daily literacy teaching episode we refer to as “days of the week” and encourages the user to reflect upon the decisions they make about the organisation and implementation of this recurring teaching experience. The range of options that occur in this simulation stem from the teacher-created script we developed drawing from our own teaching experiences and classroom-based research to shape this virtual classroom

    Expression of cyclin D1, D3, E, and p27 in human renal cell carcinoma analysed by tissue microarray

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    Aberrations in the GI/S transition of the cell cycle have been observed in many malignancies and seem to be critical in the transformation process. Few studies have delineated the presence of GI/S regulatory defects and their clinical relevance in renal cell carcinoma (RCC). Therefore, we have examined the protein contents of cyclin D 1, D3, E, and p27 in 218 RCCs, using tissue microarray and immunohistochemistry. The results from a subset of tumours were confirmed by Western blotting and immunohistochemical staining of regular tissue sections. Interestingly, low protein contents of cyclin D I and p27 were associated with high nuclear grade, large tumour size, and poor prognosis for patients with conventional tumours. We further observed substantial differences in the pattern of GI/S regulatory defects between the different RCC subtypes. The majority of both conventional and papillary cases expressed p27; however, chromophobe tumours generally lacked p27 staining. In addition, conventional RCCs often expressed high cyclin DI protein levels, while papillary RCCs exhibited high cyclin E. In summary, we have shown that GI/S regulatory defects are present in RCC and are associated with clinico-pathological parameters. The pattern of cell cycle regulatory defects also differed between RCC subtypes. (C) 2003 Cancer Research UK

    Step-Wise Computational Synthesis of Fullerene C60 derivatives. 1.Fluorinated Fullerenes C60F2k

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    The reactions of fullerene C60 with atomic fluorine have been studied by unrestricted broken spin-symmetry Hartree-Fock (UBS HF) approach implemented in semiempirical codes based on AM1 technique. The calculations were focused on a sequential addition of fluorine atom to the fullerene cage following indication of the cage atom highest chemical susceptibility that is calculated at each step. The effectively-non-paired-electron concept of the fullerene atoms chemical susceptibility lays the foundation of the suggested computational synthesis. The obtained results are analyzed from energetic, symmetry, and the composition abundance viewpoints. A good fitting of the data to experimental findings proves a creative role of the suggested synthesis methodology.Comment: 33 pages, 11 figures, 2 tables, 2 chart
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