2,226 research outputs found

    On affine usages in signal-based communication

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    We describe a type system for a synchronous pi-calculus formalising the notion of affine usage in signal-based communication. In particular, we identify a limited number of usages that preserve affinity and that can be composed. As a main application of the resulting system, we show that typable programs are deterministic

    Resource Control for Synchronous Cooperative Threads

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    We develop new methods to statically bound the resources needed for the execution of systems of concurrent, interactive threads. Our study is concerned with a \emph{synchronous} model of interaction based on cooperative threads whose execution proceeds in synchronous rounds called instants. Our contribution is a system of compositional static analyses to guarantee that each instant terminates and to bound the size of the values computed by the system as a function of the size of its parameters at the beginning of the instant. Our method generalises an approach designed for first-order functional languages that relies on a combination of standard termination techniques for term rewriting systems and an analysis of the size of the computed values based on the notion of quasi-interpretation. We show that these two methods can be combined to obtain an explicit polynomial bound on the resources needed for the execution of the system during an instant. As a second contribution, we introduce a virtual machine and a related bytecode thus producing a precise description of the resources needed for the execution of a system. In this context, we present a suitable control flow analysis that allows to formulte the static analyses for resource control at byte code level

    On Observing Dynamic Prioritised Actions in SOC

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    We study the impact on observational semantics for SOC of priority mechanisms which combine dynamic priority with local pre-emption. We define manageable notions of strong and weak labelled bisimilarities for COWS, a process calculus for SOC, and provide alternative characterisations in terms of open barbed bisimilarities. These semantics show that COWS’s priority mechanisms partially recover the capability to observe receive actions (that could not be observed in a purely asynchronous setting) and that high priority primitives for termination impose specific conditions on the bisimilarities

    Batalin-Vilkovisky Integrals in Finite Dimensions

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    The Batalin-Vilkovisky method (BV) is the most powerful method to analyze functional integrals with (infinite-dimensional) gauge symmetries presently known. It has been invented to fix gauges associated with symmetries that do not close off-shell. Homological Perturbation Theory is introduced and used to develop the integration theory behind BV and to describe the BV quantization of a Lagrangian system with symmetries. Localization (illustrated in terms of Duistermaat-Heckman localization) as well as anomalous symmetries are discussed in the framework of BV.Comment: 35 page

    A nature‐inspired nrf2 activator protects retinal explants from oxidative stress and neurodegeneration

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    Oxidative stress (OS) plays a key role in retinal dysfunctions and acts as a major trigger of inflammatory and neurodegenerative processes in several retinal diseases. To prevent OS‐induced retinal damage, approaches based on the use of natural compounds are actively investigated. Recently, structural features from curcumin and diallyl sulfide have been combined in a nature‐inspired hybrid (NIH1), which has been described to activate transcription nuclear factor erythroid‐ 2‐related factor‐2 (Nrf2), the master regulator of the antioxidant response, in different cell lines. We tested the antioxidant properties of NIH1 in mouse retinal explants. NIH1 increased Nrf2 nuclear translocation, Nrf2 expression, and both antioxidant enzyme expression and protein levels after 24 h or six days of incubation. Possible toxic effects of NIH1 were excluded since it did not alter the expression of apoptotic or gliotic markers. In OS‐treated retinal explants, NIH1 strengthened the antioxidant response inducing a massive and persistent expression of antioxidant enzymes up to six days of incubation. These effects resulted in prevention of the accumulation of reactive oxygen species, of apoptotic cell death, and of gliotic reactivity. Together, these data indicate that a strategy based on NIH1 to counteract OS could be effective for the treatment of retinal diseases

    Review of experimental cyclic tests on unreinforced and strengthened masonry spandrels and numerical modelling of their cyclic behaviour

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    A reliable numerical modelling for the cyclic behaviour of unreinforced and strengthened masonry spandrels is herein presented. The proposed numerical model is adapted from Tomazevic-Lutman\u2019s model for masonry piers in shear and it has been validated upon an experimental campaign conducted at Department of Engineering and Architecture of University of Trieste. The tests were conducted on Hshaped full-scale specimens imposing vertical displacements of increasing amplitude on one leg. Four unreinforced masonry specimens arranged with different masonry material (bricks and stones) and lintel supports (wooden lintel, masonry arch) were considered. Each specimen was then reinforced with a different strengthening technique (tensioned bars, steel profiles, CFRP laminates) and re-tested. Analytical relationships were proposed, based on those available in some Codes of Practice, to estimate the maximum shear resistance of URM and RM spandrels. These relationships provide resistance values in good agreement with the experimental results and can be correctly employed to define the cyclic model of the spandrel to be used in the numerical simulation. The cyclic shear-displacement curves obtained through the numerical model are in good agreement with those of the experimental tests and very good assessment of the dissipated energy was obtained

    CXCL5-mediated accumulation of mature neutrophils in lung cancer tissues impairs the differentiation program of anticancer CD8 T cells and limits the efficacy of checkpoint inhibitors

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    Lung tumor-infiltrating neutrophils are known to support growth and dissemination of cancer cells and to suppress T cell responses. However, the precise impact of tissue neutrophils on programming and differentiation of anticancer CD8 T cells in vivo remains poorly understood. Here, we identified cancer cell-autonomous secretion of CXCL5 as sufficient to drive infiltration of mature, protumorigenic neutrophils in a mouse model of non-small cell lung cancer (NSCLC). Consistently, CXCL5 transcripts correlate with neutrophil density and poor prognosis in a large human lung adenocarcinoma compendium. CXCL5 genetic deletion, unlike antibody-mediated depletion, completely and selectively prevented neutrophils accumulation in lung tissues. Depletion of tumor-infiltrating neutrophils promoted expansion of tumor-specific CD8 T cells, differentiation into effector cells and acquisition of cytolytic functions. Transfer of effector CD8 T cells into neutrophil-rich tumors, inhibited IFN-ϒ production, indicating active suppression of effector functions. Importantly, blocking neutrophils infiltration in the lung, overcame resistance to checkpoint blockade. Hence, this study demonstrates that neutrophils curb acquisition of cytolytic functions in lung tumor tissues and suggests targeting of CXCL5 as a strategy to restore anti-tumoral T cell functions

    An Elementary Affine λ-Calculus with Multithreading and Side Effects

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    International audienceLinear logic provides a framework to control the complexity of higher-order functional programs. We present an extension of this framework to programs with multithreading and side effects focusing on the case of elementary time. Our main contributions are as follows. First, we introduce a modal call-by-value λ-calculus with multithreading and side effects. Second, we provide a combinatorial proof of termination in elementary time for the language. Third, we introduce an elementary affine type system that guarantees the standard subject reduction and progress properties. Finally, we illustrate the programming of iterative functions with side effects in the presented formalism
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