Innovation in telecommunication and interfirm cooperative agreements

The purpose of this paper is to analyse the evolution towards the new paradigm of information and communication technology (ict) and its consequences in terms of strategies, in particular the development of cooperative agreements between telecommunication firms. To analyse the characteristics ofict paradigm we rely on some recent contributions in economics of technological change. We discuss in a second step the following proposition: an agreement is a flexible means to cope with increasing uncertainties and the durability of an agreement is conditioned by the search for a particular type of flexibility: dynamic and pro-active flexibility based on learning processes.     

PPARdelta in Affected Atopic Dermatitis and Psoriasis: A Possible Role in Metabolic Reprograming

Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors expressed in the skin. Three PPAR isotypes, α (NRC1C1), β or δ (NRC1C2) and γ (NRC1C3), have been identified. After activation through ligand binding, PPARs heterodimerize with the 9-cis-retinoic acid receptor (RXR), another nuclear hormone receptor, to bind to specific PPAR-responsive elements in regulatory regions of target genes mainly involved in organogenesis, cell proliferation, cell differentiation, inflammation and metabolism of lipids or carbohydrates. Endogenous PPAR ligands are fatty acids and fatty acid metabolites. In past years, much emphasis has been given to PPARα and γ in skin diseases. PPARβ/δ is the least studied PPAR family member in the skin despite its key role in several important pathways regulating inflammation, keratinocyte proliferation and differentiation, metabolism and the oxidative stress response. This review focuses on the role of PPARβ/δ in keratinocytes and its involvement in psoriasis and atopic dermatitis. Moreover, the relevance of targeting PPARβ/δ to alleviate skin inflammation is discussed.     

Nano‐Architectured Composite Anode Enabling Long‐Term Cycling Stability for High‐Capacity Lithium‐Ion Batteries

Failure mechanisms associated with silicon‐based anodes are limiting the implementation of high‐capacity lithium‐ion batteries. Understanding the aging mechanism that deteriorates the anode performance and introducing novel‐architectured composites offer new possibilities for improving the functionality of the electrodes. Here, the characterization of nano‐architectured composite anode composed of active amorphous silicon domains (a‐Si, 20 nm) and crystalline iron disilicide (c‐FeSi₂, 5–15 nm) alloyed particles dispersed in a graphite matrix is reported. This unique hierarchical architecture yields long‐term mechanical, structural, and cycling stability. Using advanced electron microscopy techniques, the nanoscale morphology and chemical evolution of the active particles upon lithiation/delithiation are investigated. Due to the volumetric variations of Si during lithiation/delithiation, the morphology of the a‐Si/c‐FeSi₂ alloy evolves from a core‐shell to a tree‐branch type structure, wherein the continuous network of the active a‐Si remains intact yielding capacity retention of 70% after 700 cycles. The root cause of electrode polarization, initial capacity fading, and electrode swelling is discussed and has profound implications for the development of stable lithium‐ion batteries.     

Design of heterogeneous mechanical tests: Numerical methodology and experimental validation

Standard material parameters identification strategies for constitutive equations generally use an extensive number of classical tests for collecting the required experimental data. Recently, new specimen geometries for heterogeneous tests were designed to enhance the richness of the strain field and capture supplementary strain states using full‐field measurement techniques. The butterfly specimen is an example of such a geometry, designed through a numerical optimization procedure where an indicator capable of evaluating the heterogeneity and the richness of strain information is used. The aim of this work is to experimentally validate the heterogeneous butterfly mechanical test in the parameter identification framework. Blanks of mild steel DC04 are cut with the butterfly geometry, and specific grips are designed. Tests are performed with Digital Image Correlation technique, and a Finite Element Model Update inverse strategy is used for the parameter identification, as well as the calculation of the indicator. The identification strategy is accomplished with the data obtained from the experimental tests, and the results are compared with quasi‐homogeneous tests.     

Selected Extended Papers of VSTTE 2016

This special issue collects current efforts to advance the state of the art in the science and technology of software verification, through the interaction of theory development, tool evolution, and experimental validation.     

Low temperature water gas shift: Type and loading of metal impacts forward decomposition of pseudo-stabilized formate over metal/ceria catalysts

A similar degree of surface shell reduction of ceria was obtained for a series of metal/ceria catalysts. Surface formate species were generated by reaction of CO with bridging OH groups associated with the Ce³⁺ defects. Forward decomposition of the pseudo-stable formates was followed in flowing H₂O, leading to the production of surface carbonate species. The forward formate decomposition rate was enhanced changing the promoter from Au to Pt, and by increasing the promoter loading (from 0.5 to 2.5%). Results suggest that formate CH bond breaking is not only facilitated by H₂O, but it is further enhanced by type and loading of metal promoter. From earlier kinetic isotope effect and isotopic tracer studies, the rate-limiting step of the forward formate decomposition (WGS reaction) was considered to be associated with CH bond rupture of the formate. The results can explain the promotion in the WGS rates observed for these samples by changing from Au to Pt and by increasing the promoter loading.     

Proton Transport in Electrospun Hybrid Organic–Inorganic Membranes: An Illuminating Paradox

Chemistry and processing have to be judiciously combined to structure the membranes at various length scales to achieve efficient properties for polymer electrolyte membrane fuel cell to make it competitive for transport. Characterizing the proton transport at various length and space scales and understanding the interplays between the nanostructuration, the confinement effect, the interactions, and connectivity are consequently needed. The goal here is to study the proton transport in multiscale, electrospun hybrid membranes (EHMs) at length scales ranging from molecular to macroscopic by using complementary techniques, i.e., electrochemical impedance spectroscopy, pulsed field gradient‐NMR spectroscopy, and quasielastic neutron scattering. Highly conductive hybrid membranes (EHMs) are produced and their performances are rationalized taken into account the balances existing between local interaction driven mobility and large‐scale connectivity effects. It is found that the water diffusion coefficient can be locally decreased (2 × 10^?6 cm² s^?1) due to weak interactions with the silica network, but the macroscopic diffusion coefficient is still high (9.6 × 10^?6 cm² s^?1). These results highlight that EHMs have slow dynamics at the local scale without being detrimental for long‐range proton transport. This is possible through the nanostructuration of the membranes, controlled via processing and chemistry.     

Analysis of an intact G-protein coupled receptor by MALDI-TOF mass spectrometry: molecular heterogeneity of the tachykinin NK-1 receptor

Integral membrane proteins are among the most challenging targets for biomedical research as most important cellular functions are tied to these proteins. To analyze intrinsically their structure/function, their transduction mechanism, or both, these proteins are commonly expressed in cultured cells as recombinant proteins. However, it is not possible to check whether these recombinant proteins are homogeneously or heterogeneously expressed. Owing to difficulties in their purification, very few mass spectrometry studies have been performed with those proteins and even less with G-protein coupled receptors. Here we have set up a procedure that is highly compatible with MALDI-TOF mass spectrometry to analyze an intact histidine-tagged G-protein coupled, namely, the tachykinin NK-1 receptor expressed in CHO cells, solubilized and purified using cobalt or nickel chelating magnetic beads. The metal-chelating magnetic beads containing the receptor were directly spotted on the MALDI plate for analysis. SDS-PAGE, combined with in-gel digestion analyzed by mass spectrometry, Western blot ((His)6 and FLAG M2 tags), photoaffinity labeling with a radioactive agonist, and Edman sequencing, confirmed the identity of the purified protein as the human tachykinin NK-1 receptor. Mass spectrometry study of both the glycosylated and deglycosylated intact protein forms revealed the existence of several receptor species that is tempting to correlate with the unusual pharmacological behavior of the receptor.