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21.
Patrick Heymans Quentin Boucher Andreas Classen Arnaud Bourdoux Laurent Demonceau 《International Journal on Software Tools for Technology Transfer (STTT)》2012,14(5):553-566
Software product line engineering seeks to systematise reuse when developing families of similar software systems so as to minimise development time, cost and defects. To realise variability at the code level, product line methods classically advocate usage of inheritance, components, frameworks, aspects or generative techniques. However, these might require unaffordable paradigm shifts for developers if the software was not thought at the outset as a product line. Furthermore, these techniques can be conflicting with a company’s coding practices or external regulations. These concerns were the motivation for the industry–university collaboration described in this paper in which we developed a minimally intrusive coding technique based on tags. The approach was complemented with traceability from code to feature diagrams which were exploited for automated configuration. It is supported by a toolchain and is now in use in the partner company for the development of flight-grade satellite communication software libraries. 相似文献
22.
Yliès Falcone Jean-Claude Fernandez Laurent Mounier 《International Journal on Software Tools for Technology Transfer (STTT)》2012,14(3):349-382
The underlying property, its definition, and representation play a major role when monitoring a system. Having a suitable and convenient framework to express properties is thus a concern for runtime analysis. It is desirable to delineate in this framework the sets of properties for which runtime analysis approaches can be applied to. This paper presents a unified view of runtime verification and enforcement of properties in the Safety-Progress classification. First, we extend the Safety-Progress classification of properties in a runtime context. Second, we characterize the set of properties which can be verified (monitorable properties) and enforced (enforceable properties) at runtime. We propose in particular an alternative definition of ??property monitoring?? to the one classically used in this context. Finally, for the delineated sets of properties, we define specialized verification and enforcement monitors. 相似文献
23.
Stress-sensitivity mapping for surface acoustic waves on quartz 总被引:1,自引:0,他引:1
Bigler E Hauden D Theobald G 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1989,36(1):57-62
A model is presented, relating the velocity shifts of surface acoustic waves (SAW) to the six tensor components of quasistatic stresses. Stress sensitivity is then defined through six independent coefficients, whatever the origin of the stress (direct external forces, thermoelastic stresses) might be. These coefficients, depending on crystal anisotropy, are computed for different cut angles and propagation directions of quartz crystal, and represented as a contour-line mapping. The determination of SAW quartz cuts compensated for both planar isotropic stresses and first-order temperature effects make it possible to define a family of quartz cuts with potentially low stress and temperature sensitivities for oscillator applications. 相似文献
24.
Vronique Gasser Laurianne Kuhn Thibaut Hubert Laurent Aussel Philippe Hammann Isabelle J. Schalk 《International journal of molecular sciences》2021,22(6)
Bacteria access iron, a key nutrient, by producing siderophores or using siderophores produced by other microorganisms. The pathogen Pseudomonas aeruginosa produces two siderophores but is also able to pirate enterobactin (ENT), the siderophore produced by Escherichia coli. ENT-Fe complexes are imported across the outer membrane of P. aeruginosa by the two outer membrane transporters PfeA and PirA. Iron is released from ENT in the P. aeruginosa periplasm by hydrolysis of ENT by the esterase PfeE. We show here that pfeE gene deletion renders P. aeruginosa unable to grow in the presence of ENT because it is unable to access iron via this siderophore. Two-species co-cultures under iron-restricted conditions show that P. aeruginosa strongly represses the growth of E. coli as long it is able to produce its own siderophores. Both strains are present in similar proportions in the culture as long as the siderophore-deficient P. aeruginosa strain is able to use ENT produced by E. coli to access iron. If pfeE is deleted, E. coli has the upper hand in the culture and P. aeruginosa growth is repressed. Overall, these data show that PfeE is the Achilles’ heel of P. aeruginosa in communities with bacteria producing ENT. 相似文献
25.
Julien Orlans Carole Vincent-Monegat Isabelle Rahioui Catherine Sivignon Agata Butryn Laurent Soulre Anna Zaidman-Remy Allen M. Orville Abdelaziz Heddi Pierre Aller Pedro Da Silva 《International journal of molecular sciences》2021,22(9)
Peptidoglycan recognition proteins (PGRPs) are ubiquitous among animals and play pivotal functions in insect immunity. Non-catalytic PGRPs are involved in the activation of immune pathways by binding to the peptidoglycan (PGN), whereas amidase PGRPs are capable of cleaving the PGN into non-immunogenic compounds. Drosophila PGRP-LB belongs to the amidase PGRPs and downregulates the immune deficiency (IMD) pathway by cleaving meso-2,6-diaminopimelic (meso-DAP or DAP)-type PGN. While the recognition process is well analyzed for the non-catalytic PGRPs, little is known about the enzymatic mechanism for the amidase PGRPs, despite their essential function in immune homeostasis. Here, we analyzed the specific activity of different isoforms of Drosophila PGRP-LB towards various PGN substrates to understand their specificity and role in Drosophila immunity. We show that these isoforms have similar activity towards the different compounds. To analyze the mechanism of the amidase activity, we performed site directed mutagenesis and solved the X-ray structures of wild-type Drosophila PGRP-LB and its mutants, with one of these structures presenting a protein complexed with the tracheal cytotoxin (TCT), a muropeptide derived from the PGN. Only the Y78F mutation abolished the PGN cleavage while other mutations reduced the activity solely. Together, our findings suggest the dynamic role of the residue Y78 in the amidase mechanism by nucleophilic attack through a water molecule to the carbonyl group of the amide function destabilized by Zn2+. 相似文献
26.
The γ-aminobutyric acid type A receptor (GABAAR) plays a major role in fast inhibitory synaptic transmission and is highly regulated by the neuromodulator dopamine. In this aspect, most of the attention has been focused on the classical intracellular signaling cascades following dopamine G-protein-coupled receptor activation. Interestingly, the GABAAR and dopamine D5 receptor (D5R) have been shown to physically interact in the hippocampus, but whether a functional cross-talk occurs is still debated. In the present study, we use a combination of imaging and single nanoparticle tracking in live hippocampal neurons to provide evidence that GABAARs and D5Rs form dynamic surface clusters. Disrupting the GABAAR–D5R interaction with a competing peptide leads to an increase in the diffusion coefficient and the explored area of both receptors, and a drop in immobile synaptic GABAARs. By means of patch-clamp recordings, we show that this fast lateral redistribution of surface GABAARs correlates with a robust depression in the evoked GABAergic currents. Strikingly, it also shifts in time the expression of long-term potentiation at glutamatergic synapses. Together, our data both set the plasma membrane as the primary stage of a functional interplay between GABAAR and D5R, and uncover a non-canonical role in regulating synaptic transmission. 相似文献
27.
Mohamed S. Belhaj Andr Laurent Noë l Midoux Jean-Claude Charpentier 《Chemical Engineering Communications》1981,10(4):261-267
Solubilities and diffusivities of carbon dioxide and nitrous oxide in a mixture of toluene and isopropanol organic solution of cyclohexylamine were measured at 20°C in the range of pressures of solute from 1 to 3 bars. This was performed with an original chromatographic technique taking into account the presence of the product of the reaction. 相似文献
28.
EXPERIMENTAL INFRARED DRYING STUDY OF A MODEL WATER-BASED EPOXY-AMINE PAINTING COATED ON IRON SUPPORT 总被引:1,自引:0,他引:1
The aim of this work is to study the infrared drying and curing kinetics of a model water-based epoxy-amine painting coaled on iron support. After a presentation of the model painting elaborated in our laboratory, experimental and theoretical data of the curing kinetics are presented. Then, we described the special laboratory-scale infrared dryer set up in our laboratory. This dryer was able to carry on drying experiments with uniform infrared flux densities between 0 to 25 kW,m-2 The study of the painting drying as a function of the infrared flux density and of the film thickness shows the influence of these two main physical parameters. 相似文献
29.
Although wood–plastic composites have become more accepted and used in recent years and are promoted as low‐maintenance, high‐durability building products, they do experience a color change and a loss in mechanical properties with accelerated weathering. In this study, we attempted to characterize the modulus‐of‐elasticity (MOE) loss of photostabilized high‐density polyethylene (HDPE) and composites of wood flour and high‐density polyethylene (WF/HDPE) with accelerated weathering. We then examined how weathering changed the surface chemistry of the composites and looked at whether or not the surface changes were related to the MOE loss. By examining surface chemistry changes, we hoped to begin to understand what caused the weathering changes. The materials were left unstabilized or were stabilized with either an ultraviolet absorber or pigment. After 1000 and 2000 h of accelerated weathering, the samples were tested for MOE loss. Fourier transform infrared (FTIR) spectroscopy was employed to monitor carbonyl and vinyl group formation at the surface. Changes in the HDPE crystallinity were also determined with FTIR techniques. It was determined that structural changes in the samples (carbonyl group formation, terminal vinyl group formation, and crystallinity changes) could not be reliably used to predict changes in MOE with a simple linear relationship. This indicated that the effects of crosslinking, chain scission, and crystallinity changes due to ultraviolet exposure and interfacial degradation due to moisture exposure were interrelated factors for the weathering of HDPE and WF/HDPE composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2263–2273, 2004 相似文献
30.
Pornchai Rachtanapun Susan E. M. Selke Laurent M. Matuana 《Polymer Engineering and Science》2004,44(8):1551-1560
Polymer blends, such as those resulting from recycling postconsumer plastics, often have poor mechanical properties. Microcellular foams have been shown to have the potential to improve properties, and permit higher‐value uses of mixed polymer streams. In this study, the effects of microcellular batch processing conditions (foaming time and temperature) and HDPE/PP blend compositions on the cell morphology (the average cell size and cell‐population density) and impact strength were studied. Optical microscopy was used to investigate the miscibility and crystalline morphology of the HDPE/PP blends. Pure HDPE and PP did not foam well at any processing conditions. Blending facilitated the formation of microcellular structures in polyolefins because of the poorly bonded interfaces of immiscible HDPE/PP blends, which favored cell nucleation. The experimental results indicated that well‐developed microcellular structures are produced in HDPE/PP blends at ratios of 50:50 and 30:70. The cell morphology had a strong relationship with the impact strength of foamed samples. Improvement in impact strength was associated with well‐developed microcellular morphology. Polym. Eng. Sci. 44:1551–1560, 2004. © 2004 Society of Plastics Engineers. 相似文献