Links between production systems and transport : the example of German and French industries

Changes in transportation are closely linked to the economic and logistical characteristics of the production system. The aim of this paper is, on the basis of data on the economic context and surveys conducted in France (the 1988 Shipper survey and the 2004 ECHO survey) and in Germany (the 2005 DLR survey), to show the major changes that have occurred in the two countries at both micro- and macro-economic levels and how these have affected transport demand. The first level of analysis relates to changes in the economic fabric. In particular, we have demonstrated the growing proportion of small and medium-sized firms at a time when large production units, which are those that are best able to concentrate their freight and use modes other than the road, are becoming fewer and fewer. At the same time, economic links are becoming more complex and, in the case of France, we have shown the increasing role played by wholesale traders in the distribution of goods. The constant reduction in transport costs and the opening up of markets is another structural factor whose impacts in both France and Germany we have also analysed. In addition to these economic changes, the internal modes of production of firms have also changed. Production is becoming more diversified and Just-in-time practices are spreading. The fragmentation of freight flows is thus occurring both in space and in time, which also has a major effect on the characteristics of the flows generated by firms and changes in transport. In the case of all these changes we have attempted to show the differences and similarities between the ways transport has changed in the two countries.TRANSPORT DE MARCHANDISES ; ALLEMAGNE ; FRANCE

Clustering of the K⁺ channel GORK of Arabidopsis parallels its gating by extracellular K⁺

GORK is the only outward-rectifying Kv-like K<sup>+</sup> channel expressed in guard cells. Its activity is tightly regulated to facilitate K<sup>+</sup> efflux for stomatal closure and is elevated in ABA in parallel with suppression of the activity of the inward-rectifying K<sup>+</sup> channel KAT1. Whereas the population of KAT1 is subject to regulated traffic to and from the plasma membrane, nothing is known about GORK, its distribution and traffic in vivo. We have used transformations with fluorescently-tagged GORK to explore its characteristics in tobacco epidermis and Arabidopsis guard cells. These studies showed that GORK assembles in puncta that reversibly dissociated as a function of the external K<sup>+</sup> concentration. Puncta dissociation parallelled the gating dependence of GORK, the speed of response consistent with the rapidity of channel gating response to changes in the external ionic conditions. Dissociation was also suppressed by the K<sup>+</sup> channel blocker Ba<sup>2+</sup>. By contrast, confocal and protein biochemical analysis failed to uncover substantial exo- and endocytotic traffic of the channel. Gating of GORK is displaced to more positive voltages with external K<sup>+</sup>, a characteristic that ensures the channel facilitates only K<sup>+</sup> efflux regardless of the external cation concentration. GORK conductance is also enhanced by external K<sup>+</sup> above 1 mM. We suggest that GORK clustering in puncta is related to its gating and conductance, and reflects associated conformational changes and (de)stabilisation of the channel protein, possibly as a platform for transmission and coordination of channel gating in response to external K<sup>+</sup>

Photoinitiated polymerization of a dental formulation: 1. Influence of photoinitiating system, temperature and luminous intensity

The photoinitiated polymerization of a dental formulation is composed of Mixture of monomers 75%Bis-GMA/25%TEGDMA and CQ/DMAEMA as radical photoinitiator was studied by using isothermal photocalorimetry. The effect of temperature, light intensity and photoinitiating system concentration on reaction was investigated. A maximum conversion was obtained for a photoinitiator system concentration of 1% (w/w) and for the highest light intensity studied. It should be noted that a correlation between the glass transition temperature of the final polymer and the conversion has been studied.Keywords: dental composite; photopolymerization; dimethacrylate resin; photoinitiator syste

Analyse multi-échelles des déformations/contraintes sur des assemblages électroniques complexes : application à la technologie flip-chip

Afin de faire face à la concurrence internationale et de se positionner avantageusement sur le marché, les fabricants de composants électroniques développent continuellement de nouveaux dispositifs plus performants et plus compacts. L'intégration 3D a notamment émergé afin de contourner les limitations de la technologie planaire. Dans cette configuration, différentes puces sont interconnectées les unes avec les autres et empilées verticalement. Ces architectures peuvent être problématiques en raison de la densification des interconnexions et de la présence de matériaux hétérogènes. En effet, les variations de température induites par le procédé de fabrication et le cycle de vie génèrent des différences de dilatation thermique introduisant des contraintes internes dégradant les performances et la fiabilité de l'assemblage. C'est pourquoi il est essentiel aujourd'hui pour l'industrie électronique de pouvoir quantifier les champs de contraintes dans les composants à différentes étapes de l'assemblage, et ce pour différentes échelles d'observation. Dans ce but, la modélisation éléments finis a largement été employée afin de pouvoir prédire l'apparition de déformations/ contraintes sous différents types de chargement. Cependant, la complexité de la géométrie des assemblages électroniques est devenue telle que de nombreuses hypothèses sont nécessaires afin d'obtenir des temps de calcul acceptables. De même, des connaissances insuffisantes dans le domaine du comportement des matériaux qui constituent la structure limitent la précision des résultats obtenus. Dans cette étude, une analyse multi-échelles complète d'un assemblage flip-chip à l'aide de différentes méthodes expérimentales d'analyse de contrainte a été réalisée sur un assemblage de type flip-chip. Parmi ces techniques, la diffraction des rayons X de laboratoire, la diffraction Kossel et la microdiffraction Laue (essais réalisés sur la ligne BM32 à l'ESRF de Grenoble) ont été exploitées. La présentation décrira les moyens mis en ?uvre pour réaliser ces différentes analyses sur une architecture multi-couches et les résultats présentés seront mis en lien avec les valeurs numériques obtenus avec différentes modélisations éléments finis

X-ray Diffraction Residual Stress Measurement at Room Temperature and 77 K in a Microelectronic Multi-layered Single-Crystal Structure Used for Infrared Detection

The electronic assembly considered in this study is an infrared (IR) detector consisting of different layers, including (111) CdHgTe and (100) silicon single crystals. The processing steps and the low working temperature (77 K) induce thermomechanical stresses that can affect the reliability of the thin and brittle CdHgTe detection circuit and lead to failure. These residual stresses have been quantified in both CdHgTe and silicon circuits at room temperature (293 K) and cryogenic temperature using x-ray diffraction. A specific experimental device has been developed for 77 K measurements and a method developed for single-crystal analysis has been adapted to such structures using a laboratory four-circle diffractometer. This paper describes the methodology to obtain the deformed lattice parameter and compute the strain/ stress tensors. Whereas the stresses in the CdHgTe layer appear to be negative at room temperature (compressive values), cryogenic measurements show a tensile biaxial stress state of about 30 MPa and highlight the great impact of low temperature on the mechanical properties

Phloem sap intricacy and interplay with aphid feeding

Aphididae feed upon the plant sieve elements (SE), where they ingest sugars, nitrogen compounds and other nutrients. For ingestion, aphid stylets penetrate SE, and because of the high hydrostatic pressure in SE, phloem sap exudes out into the stylets. Severing stylets to sample phloem exudates (i.e. stylectomy) has been used extensively for the study of phloem contents. Alternative sampling techniques are spontaneous exudation upon wounding that only works in a few plant species, and the popular EDTA-facilitated exudation technique. These approaches have allowed fundamental advances on the understanding of phloem sap composition and sieve tube physiology, which are surveyed in this review. A more complete picture of metabolites, ions, proteins and RNAs present in phloem sap is now available, which has provided large evidence for the phloem role as a signalling network in addition to its primary role in partitioning of photo-assimilates. Thus, phloem sap sampling methods can have remarkable applications to analyse plant nutrition, physiology and defence responses. Since aphid behaviour is suspected to be affected by phloem sap quality, attempts to manipulate phloem sap content were recently undertaken based on deregulation in mutant plants of genes controlling amino acid or sugar content of phloem sap. This opens up new strategies to control aphid settlement on a plant host

Aluminium-induced ion transport in Arabidopsis: the relationship between Al tolerance and root ion flux

Aluminium (Al) rhizotoxicity coincides with low pH; however, it is unclear whether plant tolerance to these two factors is controlled by the same mechanism. To address this question, the Al-resistant alr104 mutant, two Al-sensitive mutants (als3 and als5), and wild-type Arabidopsis thaliana were compared in long-term exposure (solution culture) and in short-term exposure experiments (H+ and K+ fluxes, rhizosphere pH, and plasma membrane potential, Em). Based on biomass accumulation, als5 and alr104 showed tolerance to low pH, whereas alr104 was tolerant to the combined low-pH/Al treatment. The sensitivity of the als5 and als3 mutants to the Al stress was similar. The Al-induced decrease in H+ influx at the distal elongation zone (DEZ) and Al-induced H+ efflux at the mature zone (MZ) were higher in the Al-sensitive mutants (als3 and als5) than in the wild type and the alr104 mutant. Under combined low-pH/Al treatment, alr104 and the wild type had depolarized plasma membranes for the entire 30 min measurement period, whereas in the Al-sensitive mutants (als3 and als5), initial depolarization to around –60 mV became hyperpolarization at –110 mV after 20 min. At the DEZ, the Em changes corresponded to the changes in K+ flux: K+ efflux was higher in alr104 and the wild type than in the als3 and als5 mutants. In conclusion, Al tolerance in the alr104 mutant correlated with Em depolarization, higher K+ efflux, and higher H+ influx, which led to a more alkaline rhizosphere under the combined low-pH/Al stress. Low-pH tolerance (als5) was linked to higher H+ uptake under low-pH stress, which was abolished by Al exposure

Metabolic status rather than cell cycle signals control quiescence entry and exit

The use of new candidate markers for yeast quiescence reveals that quiescence entry and exit primarily rely on cellular metabolic status and can be uncoupled from the cell cycle

Prediction of coating thickness for polyelectrolyte multilayers via machine learning

Layer-by-layer (LbL) deposition method of polyelectrolytes is a versatile way of developing functional nanoscale coatings. Even though the mechanisms of LbL film development are well-established, currently there are no predictive models that can link film components with their final properties. The current health crisis has shown the importance of accelerated development of biomedical solutions such as antiviral coatings, and the implementation of machine learning methodologies for coating development can enable achieving this. In this work, using literature data and newly generated experimental results, we first analyzed the relative impact of 23 coating parameters on the coating thickness. Next, a predictive model has been developed using aforementioned parameters and molecular descriptors of polymers from the DeepChem library. Model performance was limited because of insufficient number of data points in the training set, due to the scarce availability of data in the literature. Despite this limitation, we demonstrate, for the first time, utilization of machine learning for prediction of LbL coating properties. It can decrease the time necessary to obtain functional coating with desired properties, as well as decrease experimental costs and enable the fast first response to crisis situations (such as pandemics) where coatings can positively contribute. Besides coating thickness, which was selected as an output value in this study, machine learning approach can be potentially used to predict functional properties of multilayer coatings, e.g. biocompatibility, cell adhesive, antibacterial, antiviral or anti-inflammatory properties