Identification d’ondes UBF dans la magnétosphère en utilisant la matrice interspectrale

Various methods of measurement of the cross spectral matrix of stationary signals are recalled. The study of these matrices enables us to determine the number of independent and simultaneous signal sources. This method of determination of the number of sources is applied to natural magnetic signals of the pc 1 type, recorded on the ground or on satellite. Signals may present, as well on the ground as in the magnetosphere, a complex structure, which is due to the superposition of several independent and simultaneous sources.     

Randomized dining philosophers without fairness assumption

We consider Lehmann-Rabins randomized solution to the well-known problem of the dining philosophers. Up to now, such an analysis has always required a fairness assumption on the scheduling mechanism: if a philosopher is continuously hungry then he must eventually be scheduled. In contrast, we modify here the algorithm in order to get rid of the fairness assumption, and we claim that the spirit of the original algorithm is preserved. We prove that, for any (possibly unfair) scheduling, the modified algorithm converges: every computation reaches with probability 1 a configuration where some philosopher eats. Furthermore, we are now able to evaluate the expected time of convergence in terms of the number of transitions. We show that, for some malicious scheduling, this expected time is at least exponential in the number N of philosophers.Received: 14 June 2002, Accepted: 1 October 2003, Published online: 6 February 2004This paper is a revised and extended version of a communication given by the same authors, at 2nd IFIP Int. Conf. on Theoretical Computer Science (TCS@2002).     

Suspension Plasma Spraying of YPSZ Coatings: Suspension Atomization and Injection

Among processes evaluated to produce some parts of or the whole solid-oxide fuel cell, Suspension Plasma Spraying (SPS) is of prime interest. Aqueous suspensions of yttria partially stabilized zirconia atomized into a spray by an internal-mixing co-axial twin-fluid atomizer were injected into a DC plasma jet. The dispersion and stability of the suspensions were enhanced by adjusting the amount of dispersant (ammonium salt of polyacrylic acid, PAA). A polyvinyl alcohol (PVA) was further added to the suspension to tailor its viscosity. The PVA also improved the dispersion and stability of the suspensions. The atomization of optimized formulations is described implementing Weber and Ohnesorge dimensionless numbers as well as gas-to-liquid mass ratio (ALR) value. Drop size distributions changed from monomodal distributions at low We to multimodal distributions when We number increases. The viscosity of the suspensions has a clear influence on the drop size distribution and suspension spray pattern. The secondary fragmentation of the drops due to the plasma jet was evidenced and the final size of the sheared drops was shown to depend on the characteristics of the suspension. Rather dense zirconia coatings have been prepared, which is a promising way to produce electrolyte.     

Obstacles and opportunities for reducing dwelling size to shrink the environmental footprint of housing: tenants’ residential preferences and housing choice

The environmental footprint of housing is greatly influenced by the size of a dwelling. Housing size is the result of households’ dwelling selections; accordingly, it is critical to consider residential preferences and choices to inform efforts towards housing sustainability. This study aimed to understand tenants’ preferences for and choices of housing size as one amongst several dwelling characteristics and identify obstacles and opportunities for reducing size in the light of promoting sustainable housing. We employed logistic regression models to analyse a survey with 878 Swiss tenants, and our results identify preference for large dwellings as a major obstacle for reducing dwelling size among affluent tenants. Conversely, tenants with lower income might be forced to move to a smaller dwelling due to financial constraints or attribute higher importance to the financial benefit of lower rents. However, financial disincentives along with substantial non-monetary costs of moving, such as the disruption of local bonds and the difficulty of finding a satisfactory dwelling, can outweigh the benefits of moving to a smaller dwelling. To overcome such obstacles, we suggest offering incentives and other facilitating measures for downsizing moves as well as ensuring an adequate supply of smaller dwellings capable of providing high living quality. We highlight the potential of studying housing functions to conceptualize dwellings fulfilling these requirements.

     

Endothelial Cells as Tools to Model Tissue Microenvironment in Hypoxia-Dependent Pathologies

Endothelial cells (ECs) lining the blood vessels are important players in many biological phenomena but are crucial in hypoxia-dependent diseases where their deregulation contributes to pathology. On the other hand, processes mediated by ECs, such as angiogenesis, vessel permeability, interactions with cells and factors circulating in the blood, maintain homeostasis of the organism. Understanding the diversity and heterogeneity of ECs in different tissues and during various biological processes is crucial in biomedical research to properly develop our knowledge on many diseases, including cancer. Here, we review the most important aspects related to ECs’ heterogeneity and list the available in vitro tools to study different angiogenesis-related pathologies. We focus on the relationship between functions of ECs and their organo-specificity but also point to how the microenvironment, mainly hypoxia, shapes their activity. We believe that taking into account the specific features of ECs that are relevant to the object of the study (organ or disease state), especially in a simplified in vitro setting, is important to truly depict the biology of endothelium and its consequences. This is possible in many instances with the use of proper in vitro tools as alternative methods to animal testing.     

An in vivo detection system for transient and low‐abundant protein interactions and their kinetics in budding yeast

Methylation tracking (M‐Track) is a protein‐proximity assay in Saccharomyces cerevisiae, allowing the detection of transient protein–protein interactions in living cells. The bait protein is fused to a histone lysine methyl transferase and the prey protein to a methylation acceptor peptide derived from histone 3. Upon interaction, the histone 3 fragment is stably methylated on lysine 9 and can be detected by methylation‐specific antibodies. Since methylation marking is irreversible in budding yeast and only takes place in living cells, the occurrence of artifacts during cell lysate preparation is greatly reduced, leading to a more accurate representation of native interactions. So far, this method has been limited to highly abundant or overexpressed proteins. However, many proteins of interest are low‐abundant, and overexpression of proteins may interfere with their function, leading to an artificial situation. Here we report the generation of a toolbox including a novel cleavage‐enrichment system for the analysis of very low‐abundant proteins at their native expression levels. In addition, we developed a system for the parallel analysis of two prey proteins in a single cell, as well as an inducible methylation system. The inducible system allows precise control over the time during which the interaction is detected and can be used to determine interaction kinetics. Furthermore, we generated a set of constructs facilitating the cloning‐free genomic tagging of proteins at their endogenous locus by homologous recombination, and their expression from centromeric plasmids. GenBank submissions: pCK900; KM407502, pCK901; KM407503, pCK902; KM407504, pCK903; KM407505, pCK904; KM407506, pCK905; KM407507, pCK906; KM407508, pCK907; KM407509, pCK908; KM407510, pCK909; KM407511, pCK910; KM407512, pCK911; KM407513. © 2015 The Authors. Yeast published by John Wiley & Sons Ltd.     

Two-Dimensional Ordering of Coumarin at the Indium Amalgam–Electrolyte Interface

The two-dimensional condensation of coumarin was investigated at the indium amalgam-aqueous solution interface by capacitance-potential and charge-time measurements. Two distinct adsorption states were found for saturated coumarin solutions in 0.5 M NaF at 10 °C. Similar to the adsorption behavior on mercury, coumarin molecules can form a monolayer presenting the characteristics of a two-dimensional condensed layer. An increase of the indium content of the amalgam leads to an extension of the stability range of the condensed monolayer at most negative potentials. The shift of the transition potential parallels the variation of the pzc of the amalgams. The kinetics of condensation of coumarin were investigated by the potential step technique at a 50% In-Hg electrode. Mononuclear transients leading to the condensed film are observed in a wide range of the overvoltage. A comparison of the data obtained at the amalgam and mercury electrodes shows that the growth rate is independent of the nature of the electrode and that the detection of a single event takes place at lower supersaturations at the amalgam electrode.     

An Empirical Study of Individual Competencies in Distribution Centres to Enable Continuous Innovation

Individual competencies are the complex combination of knowledge, skills and abilities demonstrated by employees that are critical to the effective and efficient functioning of the organization. As firms pursue strategies and commitment to continuously innovate, the major resource to enable this process lies in the people within the organization. Logistics firms in developed economies such as Singapore and Australia are embarking on these strategies to remain competitive. The key objective of this paper is to investigate the competencies that are inherent in employees of distribution centres as part of the logistic function that are rapidly growing and innovating. The study adopts an iterative process of data collection by conducting ten case studies in Singapore and Australia and interviews with senior managers. The findings show several competencies apparent in employees of the firms studied. These underpinned collective behaviours and organizational capabilities needed for continuous innovation. This study provides important lessons for managers in logistics organizations in Australia and Singapore and demonstrates how differing extents of competencies and behaviours of employees can impact on the operations of firms and their capacities to innovate.     

Structure and water—oil emulsifying properties of asphaltenes

Alphaltenes were selected on the basis of their capacity to form water—oil emulsions. They were characterized by electron microscopy, surface group analysis, g.p.c. and low-angle X-ray scattering. It appears that the high stability of water-oil emulsions is related to the ‘structuring’ capacity of asphaltenes at the water-oil interface. Some asphaltenes are able to form regularly stacked layers, resembling the behaviour of surfactant liquid crystals.