422 research outputs found

    Relational semantics of linear logic and higher-order model-checking

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    In this article, we develop a new and somewhat unexpected connection between higher-order model-checking and linear logic. Our starting point is the observation that once embedded in the relational semantics of linear logic, the Church encoding of any higher-order recursion scheme (HORS) comes together with a dual Church encoding of an alternating tree automata (ATA) of the same signature. Moreover, the interaction between the relational interpretations of the HORS and of the ATA identifies the set of accepting states of the tree automaton against the infinite tree generated by the recursion scheme. We show how to extend this result to alternating parity automata (APT) by introducing a parametric version of the exponential modality of linear logic, capturing the formal properties of colors (or priorities) in higher-order model-checking. We show in particular how to reunderstand in this way the type-theoretic approach to higher-order model-checking developed by Kobayashi and Ong. We briefly explain in the end of the paper how his analysis driven by linear logic results in a new and purely semantic proof of decidability of the formulas of the monadic second-order logic for higher-order recursion schemes.Comment: 24 pages. Submitte

    Collusions Between Patients and Clinicians in End-of-Life Care: Why Clarity Matters.

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    Collusion, an unconscious dynamic between patients and clinicians, may provoke strong emotions, unreflected behaviors, and a negative impact on care. Collusions, prevalent in the health care setting, are triggered by situations which signify an unresolved psychological issue relevant for both, patient and clinician. After an introductory definition of collusion, two archetypal situations of collusion-based on material from a regular supervision of a palliative care specialist by a liaison psychiatrist-and means of working through collusion are presented. The theoretical framework of collusion is then described and the conceptual shortcomings of the palliative care literature in this respect discussed, justifying the call for more clarity. Finally, cultural aspects and societal injunctions on the dying, contributing to the development of collusion in end-of-life care, are discussed

    The Effects of Cellulase on Cell Wall Structure and the Rumen Digestion of Alfalfa Silage

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    First- and second-cut alfalfa (Medicago sativa) was ensiled with no additive, microbial (Lactobacillus casei) inoculant, cellulase derived from Acremonium celluloytics Y-94, co-addition of inoculant and cellulase, and formic acid. The resultant silages were digested in the rumen of a dairy cow. The alfalfa and the silages were then examined with scanning electron microscope (SEM) and their chemical characteristics analyzed to evaluate the effects of cellulase on the quality of alfalfa silage and its cell wall structure. The addition of cellulase lend to both a greater loss of parenchymal tissue and decrease in digestibility during rumen degradation than did the other additives moreover, photos taken during SEM examination also showed that cellulase affected cell wall decomposition. The results of this study may suggest that the addition of cellulase affects fiber digestion by ruminant animals

    The Effect of Cellulase on Cell Wall Structure and the Rumen Digestion of Timothy Silage

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    The objective of this study was to determine the effect of additives on the structure changes of related tissues during the ensiling process and the rumen digestion of timothy. In the first cut-timothy, the addition of LC+AC improved the fermentation qualities of the silage. Addition of cellulase resulted in significant decreases in NDF, ADF, cellulose, and hemicellulose content. SEM examination of the samples suggests that the degradation of parenchymal tissues was enhanced by the cellulase, but no significant differences were observed among the additives in the rumen digestion. The NDF and cellulose digestibility of the AC- and LC+AC-treated silages were lower than those of the other silages. In the second one, after digestion in the rumen, there was a marked loss of inner parenchymal tissues in AC and LC+AC-treated silages

    Molecular bases of thermophily in hyperthermophiles

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    I reflect on some of our studies on the hyperthermophilic archaeon, Thermococcus kodakarensis KOD1 and its enzymes. The strain can grow at temperatures up to 100 ℃, and also represents one of the simplest forms of life. As expected, all enzymes, DNA, RNA, cytoplasmic membrane, and cytoplasmic solute displayed remarkable thermostability, and we have determined some of the basic principles that govern this feature. To our delight, many of the enzymes exhibited unique biochemical properties and novel structures not found in mesophilic proteins. Here, I will focus on some enzymes whose three-dimensional structures are characteristic of thermostable enzymes. I will also add some examples on the stabilization of DNA, RNA, cytoplasmic membrane, and cytoplasmic solute

    Sarcomere length-dependent Ca2+ activation in skinned rabbit psoas muscle fibers: coordinated regulation of thin filament cooperative activation and passive force

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    In skeletal muscle, active force production varies as a function of sarcomere length (SL). It has been considered that this SL dependence results simply from a change in the overlap length between the thick and thin filaments. The purpose of this study was to provide a systematic understanding of the SL-dependent increase in Ca2+ sensitivity in skeletal muscle, by investigating how thin filament “on–off” switching and passive force are involved in the regulation. Rabbit psoas muscles were skinned, and active force measurements were taken at various Ca2+ concentrations with single fibers, in the short (2.0 and 2.4 μm) and long (2.4 and 2.8 μm) SL ranges. Despite the same magnitude of SL elongation, the SL-dependent increase in Ca2+ sensitivity was more pronounced in the long SL range. MgADP (3 mM) increased the rate of rise of active force and attenuated SL-dependent Ca2+ activation in both SL ranges. Conversely, inorganic phosphate (Pi, 20 mM) decreased the rate of rise of active force and enhanced SL-dependent Ca2+ activation in both SL ranges. Our analyses revealed that, in the absence and presence of MgADP or Pi, the magnitude of SL-dependent Ca2+ activation was (1) inversely correlated with the rate of rise of active force, and (2) in proportion to passive force. These findings suggest that the SL dependence of active force in skeletal muscle is regulated via thin filament “on–off” switching and titin (connectin)-based interfilament lattice spacing modulation in a coordinated fashion, in addition to the regulation via the filament overlap

    Combining Effects and Coeffects via Grading

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    This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by the Association for Computing Machinery.Effects\textit{Effects} and coeffects\textit{coeffects} are two general, complementary aspects of program behaviour. They roughly correspond to computations which change the execution context (effects) versus computations which make demands on the context (coeffects). Effectful features include partiality, non-determinism, input-output, state, and exceptions. Coeffectful features include resource demands, variable access, notions of linearity, and data input requirements. The effectful or coeffectful behaviour of a program can be captured and described via type-based analyses, with fine grained information provided by monoidal effect annotations and semiring coeffects. Various recent work has proposed models for such typed calculi in terms of graded (strong) monads\textit{graded (strong) monads} for effects and graded (monoidal) comonads\textit{graded (monoidal) comonads} for coeffects. Effects and coeffects have been studied separately so far, but in practice many computations are both effectful and coeffectful, e.g., possibly throwing exceptions but with resource requirements. To remedy this, we introduce a new general calculus with a combined effect-coeffect system\textit{effect-coeffect system}. This can describe both the changes\textit{changes} and requirements\textit{requirements} that a program has on its context, as well as interactions between these effectful and coeffectful features of computation. The effect-coeffect system has a denotational model in terms of effect-graded monads and coeffect-graded comonads where interaction is expressed via the novel concept of graded distributive laws\textit{graded distributive laws}. This graded semantics unifies the syntactic type theory with the denotational model. We show that our calculus can be instantiated to describe in a natural way various different kinds of interaction between a program and its evaluation context.Orchard was supported by EPSRC grant EP/M026124/1 and EP/K011715/1 (whilst previously at Imperial College London), Katsumata by JSPS KAKENHI grant JP15K00014, Uustalu by Estonian Min. of Educ. and Res. grant IUT33-13 and Estonian Sci. Found. grant 9475. Gaboardi’s work was done in part while at the University of Dundee, UK supported by EPSRC grant EP/M022358/1

    Practical Implementation of Attitude-Control Algorithms for an Underactuated Satellite

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    The challenging problem of controlling the attitude of satellites subject to actuator failures has been the subject of increased attention in recent years. The problem of controlling the attitude of a satellite on all three axes with two reaction wheels is addressed in this paper. This system is controllable in a zero-momentum mode. Three-axis attitude stability is proven by imposing a singular quaternion feedback law to the angular velocity trajectories.Two approaches are proposed and compared to achieve three-axis control: The first one does not require angular velocity measurements and is based on the assumption of a perfect zero momentum, while the second approach consists of tracking the desired angular velocity trajectories. The full-state feedback is a nonlinear singular controller. In-orbit tests of the first approach provide an unprecedented practical proof of three-axis stability with two control torques. The angular velocity tracking approach is shown to be less efficient using the nonlinear singular controller. However, when inverse optimization theory is applied to enhance the nonlinear singular controller, the angular velocity tracking approach is shown to be the most efficient. The resulting switched inverse optimal controller allows for a significant enhancement of settling time, for a prescribed level of the integrated torque

    The Antigen ASB4 on Cancer Stem Cells Serves as a Target for CTL Immunotherapy of Colorectal Cancer

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    網羅的なHLAリガンドーム解析により,がん幹細胞(cancer stem cell,CSC)に特異的なASB4由来のペプチドIV9を同定し,CSCを特異的に傷害可能なCTL免疫療法となることを示した.更にCSCを標的としたCTL免疫療法が再発予防として有用であることを明らかにした
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