418 research outputs found
Verification of Java Bytecode using Analysis and Transformation of Logic Programs
State of the art analyzers in the Logic Programming (LP) paradigm are
nowadays mature and sophisticated. They allow inferring a wide variety of
global properties including termination, bounds on resource consumption, etc.
The aim of this work is to automatically transfer the power of such analysis
tools for LP to the analysis and verification of Java bytecode (JVML). In order
to achieve our goal, we rely on well-known techniques for meta-programming and
program specialization. More precisely, we propose to partially evaluate a JVML
interpreter implemented in LP together with (an LP representation of) a JVML
program and then analyze the residual program. Interestingly, at least for the
examples we have studied, our approach produces very simple LP representations
of the original JVML programs. This can be seen as a decompilation from JVML to
high-level LP source. By reasoning about such residual programs, we can
automatically prove in the CiaoPP system some non-trivial properties of JVML
programs such as termination, run-time error freeness and infer bounds on its
resource consumption. We are not aware of any other system which is able to
verify such advanced properties of Java bytecode
Clinicopathologic significance of sialyl Le xexpression in advanced gastric carcinoma
Sialyl Lewis xantigen (SLX) is a carbohydrate antigen that serves as a ligand for selectin, an adhesion molecule expressed on vascular endothelial cells. The expression of SLX in 245 patients with advanced gastric carcinoma was examined immunohistochemically, and its clinicopathologic significance was analysed. We classified the patients with advanced gastric carcinoma into 91 with differentiated type and 154 with undifferentiated type. SLX expressed in 135 of 245 patients (55%), comprising 68 (75%) patients with differentiated carcinoma and 67 (44%) with undifferentiated carcinoma. The positive rate for SLX expression was significantly higher among patients with differentiated carcinoma than among those in undifferentiated carcinoma (P < 0.0001). With differentiated carcinoma, the incidence of lymph node metastasis, advanced tumour stage (stage III and IV) and liver recurrence was significantly higher in SLX-positive patients than in SLX-negative ones (P < .0001, P = 0.0065 and P = 0.028, respectively). Moreover, the prognoses were better in patients with SLX-negative tumours than in those with SLX-positive tumours (P = 0.019). With undifferentiated carcinoma, there were no significant correlations between SLX expression and any clinicopathological features or prognoses. The clinicopathologic significance of SLX expression in gastric carcinoma patients depends on histologic type. SLX expression may be of great relevance in predicting liver metastases in patients with differentiated carcinoma. © 2000 Cancer Research Campaign http://www.bjcancer.co
ASCA and XMM-Newton Observations of A2029
The X-ray data of A2029 obtained with XMM-Newton show no evidence of an
embedded AGN in the central region of this cluster, which was suggested from
the analysis of restored ASCA image data, although some hot spots are seen
within or around the central cD galaxy. The absence of AGN at the cluster
center is consistentent with the result of Chandra observations. Radial
profiles of the iron abundance and the 2D (surface) temperature obtained from
the XMM-Newton data are in good agreement with the Chandra data as a whole.Comment: 8 pages, 13 figures, accepted for publication in Advances in Space
Researc
Economic evidence for the prevention and treatment of atopic eczema: a protocol for a systematic review
Background: Eczema, synonymous with atopic eczema or atopic dermatitis, is a chronic skin disease that has a similar impact on health-related quality of life as other chronic diseases. The proposed research aims to provide a comprehensive systematic assessment of the economic evidence base available to inform economic modelling and decision making on interventions to prevent and treat eczema at any stage of the life course. Whilst the Global Resource of Eczema Trials (GREAT) database collects together the effectiveness evidence for eczema there is currently no such systematic resource on the economics of eczema. It is important to gain an overview of the current state of the art of economic methods in the field of eczema in order to strengthen the economic evidence base further. Methods/design: The proposed study is a systematic review of the economic evidence surrounding interventions for the prevention and treatment of eczema. Relevant search terms will be used to search MEDLINE, EMBASE, Database of Abstracts of Reviews of Effects, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, Health Technology Assessment, Cumulative Index to Nursing and Allied Health Literature, Econ Lit, Scopus, Cost-Effectiveness Analysis Registry and Web of Science in order to identify relevant evidence. To be eligible for inclusion studies will be primary empirical studies evaluating the cost, utility or full economic evaluation of interventions for preventing or treating eczema. Two reviewers will independently assess studies for eligibility and perform data abstraction. Evidence tables will be produced presenting details of study characteristics, costing methods, outcome methods and quality assessment. The methodological quality of studies will be assessed using accepted checklists. Discussion: The systematic review is being undertaken to identify the type of economic evidence available, summarise the results of the available economic evidence and critically appraise the quality of economic evidence currently available to inform future economic modelling and resource allocation decisions about interventions to prevent or treat eczema. We aim to use the review to offer guidance about how to gather economic evidence in studies of eczema and/or what further research is necessary in order to inform this
Specializing Interpreters using Offline Partial Deduction
We present the latest version of the Logen partial evaluation system for logic programs. In particular we present new binding-types, and show how they can be used to effectively specialise a wide variety of interpreters.We show how to achieve Jones-optimality in a systematic way for several interpreters. Finally, we present and specialise a non-trivial interpreter for a small functional programming language. Experimental results are also presented, highlighting that the Logen system can be a good basis for generating compilers for high-level languages
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Cannabidivarin is anticonvulsant in mouse and rat in vitro and in seizure models
Summary
Background and purpose: Phytocannabinoids in Cannabis sativa have diverse
pharmacological targets extending beyond cannabinoid receptors and several exert notable
anticonvulsant effects. For the first time, we investigated the anticonvulsant profile of the
phytocannabinoid cannabidivarin (CBDV) in vitro and in in vivo seizure models.
Experimental approach: The effect of CBDV (1-100μM) on epileptiform local field
potentials (LFPs) induced in rat hippocampal brain slices by 4-AP application or Mg2+-free
conditions was assessed by in vitro multi-electrode array recordings. Additionally, the
anticonvulsant profile of CBDV (50-200 mg kg-1) in vivo was investigated in four rodent
seizure models: maximal electroshock (mES) and audiogenic seizures in mice, and
pentylenetetrazole (PTZ) and pilocarpine-induced seizures in rat. CBDV effects in
combination with commonly-used antiepileptic drugs were investigated in rat seizures.
Finally, the motor side effect profile of CBDV was investigated using static beam and gripstrength
assays.
Key results: CDBV significantly attenuated status epilepticus-like epileptiform LFPs
induced by 4-AP and Mg2+-free conditions. CBDV had significant anticonvulsant effects in
mES (≥100 mg kg-1), audiogenic (≥50 mg kg-1) and PTZ-induced seizures (≥100 mg kg-1).
CBDV alone had no effect against pilocarpine-induced seizures, but significantly attenuated
these seizures when administered with valproate or phenobarbital at 200 mg kg-1 CBDV.
CBDV had no effect on motor function.
Conclusions and Implications: These results indicate that CBDV is an effective
anticonvulsant across a broad range of seizure models, does not significantly affect normal
motor function and therefore merits further investigation in chronic epilepsy models to justify
human trials
Homeomorphic Embedding for Online Termination of Symbolic Methods
Well-quasi orders in general, and homeomorphic embedding in particular, have gained popularity to ensure the termination of techniques for program analysis, specialisation, transformation, and verification. In this paper we survey and discuss this use of homeomorphic embedding and clarify the advantages of such an approach over one using well-founded orders. We also discuss various extensions of the homeomorphic embedding relation. We conclude with a study of homeomorphic embedding in the context of metaprogramming, presenting some new (positive and negative) results and open problems
Cell Migration in the Immune System: the Evolving Inter-Related Roles of Adhesion Molecules and Proteinases
Leukocyte extravasation into perivascular tissue during inflammation and lymphocyte homing
to lymphoid organs involve transient adhesion to the vessel endothelium, followed by transmigration
through the endothelial cell (EC) layer and establishment of residency at the tissue site
for a period of time. In these processes, leukocytes undergo multiple attachments to, and detachments
from, the vessel-lining endothelial cells, prior to transendothelial cell migration. Transmigrating
leukocytes must traverse a subendothelial basement membrane en route to perivascular
tissues and utilize enzymes known as matrix metalloproteinases to make selective clips in the
extracellular matrix components of the basement membrane. This review will focus on the evidence
for a link between adhesion of leukocytes to endothelial cells, the induction of matrix
metalloproteinases mediated by engagement of adhesion receptors on leukocytes, and the ability
to utilize these matrix metalloproteinases to facilitate leukocyte invasion of tissues. Leukocytes
with invasive phenotypes express high levels of MMPs, and expression of MMPs
enhances the migratory and invasive properties of these cells. Furthermore, MMPs may be used
by lymphocytes to proteolytically cleave molecules such as adhesion receptors and membrane
bound cytokines, increasing their efficiency in the immune response. Engagement of leukocyte
adhesion receptors may modulate adhesive (modulation of integrin affinities and expression),
synthetic (proteinase induction and activation), and surface organization (clustering of proteolyric
complexes) behaviors of invasive leukocytes. Elucidation of these pathways will lead to
better understanding of controlling mechanisms in order to develop rational therapeutic
approaches in the areas of inflammation and autoimmunity
A Symmetric Approach to Compilation and Decompilation
Just as specializing a source interpreter can achieve compilation from a source language to a target language, we observe that specializing a target interpreter can achieve compilation from the target language to the source language. In both cases, the key issue is the choice of whether to perform an evaluation or to emit code that represents this evaluation. We substantiate this observation by specializing two source interpreters and two target interpreters. We first consider a source language of arithmetic expressions and a target language for a stack machine, and then the lambda-calculus and the SECD-machine language. In each case, we prove that the target-to-source compiler is a left inverse of the source-to-target compiler, i.e., it is a decompiler. In the context of partial evaluation, compilation by source-interpreter specialization is classically referred to as a Futamura projection. By symmetry, it seems logical to refer to decompilation by target-interpreter specialization as a Futamura embedding
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