165 research outputs found

    A Logical Foundation for Environment Classifiers

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    Taha and Nielsen have developed a multi-stage calculus {\lambda}{\alpha} with a sound type system using the notion of environment classifiers. They are special identifiers, with which code fragments and variable declarations are annotated, and their scoping mechanism is used to ensure statically that certain code fragments are closed and safely runnable. In this paper, we investigate the Curry-Howard isomorphism for environment classifiers by developing a typed {\lambda}-calculus {\lambda}|>. It corresponds to multi-modal logic that allows quantification by transition variables---a counterpart of classifiers---which range over (possibly empty) sequences of labeled transitions between possible worlds. This interpretation will reduce the "run" construct---which has a special typing rule in {\lambda}{\alpha}---and embedding of closed code into other code fragments of different stages---which would be only realized by the cross-stage persistence operator in {\lambda}{\alpha}---to merely a special case of classifier application. {\lambda}|> enjoys not only basic properties including subject reduction, confluence, and strong normalization but also an important property as a multi-stage calculus: time-ordered normalization of full reduction. Then, we develop a big-step evaluation semantics for an ML-like language based on {\lambda}|> with its type system and prove that the evaluation of a well-typed {\lambda}|> program is properly staged. We also identify a fragment of the language, where erasure evaluation is possible. Finally, we show that the proof system augmented with a classical axiom is sound and complete with respect to a Kripke semantics of the logic

    E-Healthcare at an Experimental Welfare Techno House in Japan

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    An automated monitoring system for home health care has been designed for an experimental house in Japan called the Welfare Techno House (WTH). Automated electrocardiogram (ECG) measurements can be taken while in bed, in the bathtub, and on the toilet, without the subject’s awareness, and without using body surface electrodes. In order to evaluate this automated health monitoring system, overnight measurements were performed to monitor health status during the daily lives of both young and elderly subjects

    Tyrphostin AG 1478 Accelerates Hydrogen Peroxide-Induced Apoptosis in A431 Cells

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    Oxidative stress is a potent inducer of apoptosis and activates protein tyrosine kinases and cytokine receptors, such as the epidermal growth factor receptor (EGFR). Previous studies suggest that cytokine receptors are potential effectors for anti-apoptotic signals, but it has not previously been determined whether cytokine receptors regulate down-stream protein kinases. To investigate the role of EGFR on oxidative stress-induced apoptosis and its downstream protein kinases, we blocked EGFR activation with Tyrphostin AG1478, a highly selective EGFR inhibitor. We determined that Tyrphostin AG1478 accelerated hydrogen peroxide-induced apoptosis in A431 cells, with activation of caspases 3 and 9, and decreased mitochondrial membrane potential. Hydrogen peroxide induced-activation of EGFR, Akt/PKB, MAPK, and Bad (both Ser-112 and Ser-136 residues) were inhibited by Tyrphostin AG1478. These results suggest that early upstream signaling events, such as EGFR activation, exert anti-apoptotic effects by regulating MAPK, Akt/PKB, and phosphorylation of Bad

    Atomic and Electronic Structures of Unreconstructed Polar MgO(111) Thin Film on Ag(111)

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    Atomic and electronic structures of a polar surface of MgO formed on Ag(111) was investigated by using reflection high energy electron diffraction (RHEED), Auger electron spectroscopy, electron energy loss spectroscopy (EELS), and ultraviolet photoemission spectroscopy (UPS). A rather flat unreconstructed polar MgO(111) 1×\times1 surface could be grown by alternate adsorption of Mg and O2_{2} on Ag(111). The stability of the MgO(111) surface was discussed in terms of interaction between Ag and Mg atoms at the interface, and charge state of the surface atoms. EELS of this surface did not show a band gap region, and finite density of states appeared at the Fermi level in UPS. These results suggest that a polar MgO(111) surface was not an insulating surface but a semiconducting or metallic surface.Comment: 6 figures, to be published in Phys. Rev.

    Characteristics of late-onset spondyloarthritis in Japan: A retrospective cohort study

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    Spondyloarthritis may be increasingly present in older patients as life expectancy increases. We investigated clinical differences between early-onset and late-onset spondyloarthritis in Japan.We retrospectively reviewed 114 patients consecutively diagnosed with spondyloarthritis. The clinical course of each patient was observed for ?1 year. We defined early-onset and late-onset spondyloarthritis as <57 or ?57 years at a median age of this study group,respectively. We compared clinical characteristics between these 2 groups.Disease duration was significantly shorter before diagnosis in the late-onset group (P?<?.01). Inflammatory back pain (IBP) was significantly more common in the early-onset group (P?<?.01), whereas dactylitis frequency was significantly higher in the late-onset group. Significantly more patients with early-onset spondyloarthritis were human leukocyte antigen (HLA) B27-positive (P?<?.01). Articular synovitis, particularly of the wrist, was significantly more common on power Doppler ultrasound (PDUS) in the late-onset group (P?<?.01). Tenosynovitis or peritendinitis, particularly in the finger and wrist flexors were also more frequent in the late-onset group (P?<?.001 and P?<?.05, respectively). Enthesitis of the finger collateral ligament and lateral collateral ligament were significantly more common in the late-onset group (both P?<?.05). Multiple logistic regression analysis revealed that, comparatively, IBP was significantly and independently much more likely to occur in the early-onset group.The patients with late-onset spondyloarthritis had a lower frequency of IBP and HLA B27 and a higher frequency of dactylitis and PDUS findings in peripheral involvement
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