Plus grandes, plus fortes, plus loin… Les performances des firmes exportatrices françaises

This article examines the performances of French exporting firms. Using a highly detailed database, we confirm that exporting firms are much bigger, more productive and more profitable than domestic ones. This difference is particularly strong for firms exporting to non-EU markets, and for small businesses. For large businesses, the discrepancy between exporters and domestic firms is fairly small, and non-significant in some industries and for firms that only export to EU destinations. Our results suggest that export-enhancing public policies should target small businesses and firms attempting to export to remote countries.Exporting firms, Productivity, Competitiveness.

Phosphoribulokinase abundance is not limiting the Calvin-Benson-Bassham cycle in Chlamydomonas reinhardtii

Improving photosynthetic efficiency in plants and microalgae is of utmost importance to support the growing world population and to enable the bioproduction of energy and chemicals. Limitations in photosynthetic light conversion efficiency can be directly attributed to kinetic bottlenecks within the Calvin-Benson-Bassham cycle (CBBC) responsible for carbon fixation. A better understanding of these bottlenecks in vivo is crucial to overcome these limiting factors through bio-engineering. The present study is focused on the analysis of phosphoribulokinase ( PRK) in the unicellular green alga Chlamydomonas reinhardtii. We have characterized a PRK knock-out mutant strain and showed that in the absence of PRK, Chlamydomonas cannot grow photoautotrophically while functional complementation with a synthetic construct allowed restoration of photoautotrophy. Nevertheless, using standard genetic elements, the expression of PRK was limited to 40% of the reference level in complemented strains and could not restore normal growth in photoautotrophic conditions suggesting that the CBBC is limited. We were subsequently able to overcome this initial limitation by improving the design of the transcriptional unit expressing PRK using diverse combinations of DNA parts including PRK endogenous promoter and introns. This enabled us to obtain strains with PRK levels comparable to the reference strain and even overexpressing strains. A collection of strains with PRK levels between 16% and 250% of WT PRK levels was generated and characterized. Immunoblot and growth assays revealed that a PRK content of approximate to 86% is sufficient to fully restore photoautotrophic growth. This result suggests that PRK is present in moderate excess in Chlamydomonas. Consistently, the overexpression of PRK did not increase photosynthetic growth indicating that that the endogenous level of PRK in Chlamydomonas is not limiting the Calvin-Benson-Bassham cycle under optimal conditions

Artificially decreasing cortical tension generates aneuploidy in mouse oocytes

Human and mouse oocytes’ developmental potential can be predicted by their mechanical properties. Their development into blastocysts requires a specific stiffness window. In this study, we combine live-cell and computational imaging, laser ablation, and biophysical measurements to investigate how deregulation of cortex tension in the oocyte contributes to early developmental failure. We focus on extra-soft cells, the most common defect in a natural population. Using two independent tools to artificially decrease cortical tension, we show that chromosome alignment is impaired in extra-soft mouse oocytes, despite normal spindle morphogenesis and dynamics, inducing aneuploidy. The main cause is a cytoplasmic increase in myosin-II activity that could sterically hinder chromosome capture. We describe here an original mode of generation of aneuploidies that could be very common in oocytes and could contribute to the high aneuploidy rate observed during female meiosis, a leading cause of infertility and congenital disorders

Preparation and certification of 243Am spike reference material: IRMM-0243 : Certified reference material for the amount content of 243Am and n(241Am)7n(243Am) isotope amount ratio

This report describes the preparation and certification of IRMM-0243, a 243Am spike reference material. It is certified for the amount content of 243Am and the isotope amount ratios of n(241Am)/n(243Am) and n(242mAm)/n(243Am). Furthermore, the material is certified for the amount contents of 241Am and total Am, the mass fractions of 243Am, 241Am and total Am, the isotope amount and mass fractions (e.g. isotopic composition) and the molar mass of Am. The material was produced in compliance with ISO/IEC 17034:2016 and certified in accordance with ISO Guide 35:2006. The material was prepared by dilution of an americium starting solution in nitric acid and dispensing of the solution into glass ampoules. In total 587 units were produced. Between-unit homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The characterisation of the amount content of 243Am was performed by Isotope Dilution Mass Spectrometry (IDMS) using a 241Am spike, produced from highly enriched 241Pu material. The isotope amount ratios of n(241Am)/n(243Am) and n(242mAm)/n(243Am) were measured by Thermal Ionisation Mass Spectrometry (TIMS). The certified values were verified by alpha particle spectrometry, alpha particle counting at a defined solid angle (DSA) and high-resolution gamma-ray spectrometry as independent verification methods. The uncertainties of the certified values were estimated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) [ ] and include uncertainties related to possible inhomogeneity, instability and characterisation. The main purpose of this material is for use as a spike isotopic reference material for the quantification of americium by IDMS in unknown samples. A unit of IRMM-0243 consists of a glass ampoule with a screw cap containing about 3.5 mL nitric acid solution (c = 1 mol/L) with an americium mass fraction of about 1.5 μg/g solution. The material is a true solution; therefore there is no recommended minimum sample intake to be taken into account.JRC.G.2-Standards for Nuclear Safety, Security and Safeguard

Radiological characterisation in view of nuclear reactor decommissioning: On-site benchmarking exercise of a biological shield

Nearly all decommissioning and dismantling (D&D) projects are steered by the characterisation of the plant being dismantled. This radiological characterisation is a complex process that is updated and modified during the course of the D&D. One of the tools for carrying out this characterisation is the performance of in-situ measurements. There is a wide variety of equipment and methodologies used to carry out on-site measurements, depending on the environment in which they are to be carried out and also on the specific objectives of the measurements and the financial and personnel resources available. The extent to which measurements carried out with different types of equipment or methodologies providing comparable results can be crucial in view of the D&D strategy development and the decision-making process. This paper concerns an on-site benchmarking exercise carried out at the activated biological shield of Belgian Reactor 3 (BR3). This activity allows comparison and validation of characterisation methodologies and different equipment used as well as future interpretation of final results in terms of uncertainties and sensitivities. This paper describes the measurements and results from the analysis of this exercise. Other aspects of this exercise will be reported in separate papers. This paper provides an overview of the on-site benchmarking exercise, outlines the participating organisations and the measurement equipment used for total gamma, dose rate and gamma spectrometry measurements and finally, results obtained and their interpretations are discussed for each type of measurement as a function of detector type. Regarding the dose measurements, results obtained by using a large variety of equipment are very consistent. In view of mapping the inner surface of the biological shield the most appropriate equipment tested might be the organic scintillator, the BGO or even the ionisation chamber. In addition, for mapping this surface, the most appropriate total gamma equipment tested might be the LaBr$_{3}$(Ce), the thick organic scintillator or the BGO. These measurements can only be used as a secondary parameter in a relative way. Results for the gamma spectrometry are very consistent for all the equipment used and the main parameters to be determined

Seismic response assessment and protection of statues and busts

Recent post-earthquake surveys carried out in Europe have shown that earthquake actions pose an immense threat to museums and their contents. For example, during the earthquake on 21 July 2017 in the island of Kos (Greece), severe and widespread damage on the city’s archaeological museum was reported (Figure 1). The earthquake extensively damaged the sculpture exhibition, where many pieces were dislocated, leaned against the walls, or overturned. Fortunately, the earthquake occurred when human visitors were not in the museum, since the damage to the exhibits varied from very light (minor fracturing) to severe (complete overturning and fracture of artefacts). In the case of heavy and slender sculptures, the overturning mechanism, apart from damaging the sculptures themselves, is a serious threat to other standing exhibits in the gallery and the visitors. It is, therefore, of paramount importance to have at our disposal methods and tools for characterising the seismic risk of museum artefacts and, where necessary, proposing cost-efficient protective measures. The study of the seismic vulnerability of museum artefacts, especially of slender, human-formed statues, is related to the research on the dynamic response of rocking rigid blocks. The dynamic characteristics of the hosting structures are also important. This is evident from the fact that, on many occasions, damage to the structure was reported leaving the exhibits intact and vice-versa. Although the problem is coupled, it can be studied looking separately at the structure and its contents, provided that the contents are not attached to the building. The seismic response of building contents is a topic of growing interest, since it is directly related to seismic loss assessment and earthquake community resilience. Building contents can be either attached to the structure, or may consist of objects that are simply standing. Museum exhibits belong to the latter category, while free-standing components are often studied as rocking objects and hence their response is sensitive to acceleration and velocity-based quantities and also to their geometry. Today, there is lack of standards, while the existing approaches are general in concept and do not sufficiently address the variety of rocking objects. The problem becomes more complicated when it comes to priceless objects such as museum artefacts where more refined and targeted studies are required for understanding their seismic response and also for proposing rapid tools for assessing their seismic risk. The paper presents an extensive experimental campaign on the seismic response of artefacts, with emphasis on statues and busts. The tests took place in the framework of SEREME project (Seismic Resilience of Museum Contents) at the AZALEE seismic simulator of CEA in Saclay, Paris under the auspices of the SERA project. The aim is to understand the seismic response of statues and busts and then develop novel and cost-effective risk mitigation schemes for improving the seismic resilience of museum valuable contents. The study is focused on the investigation of the seismic response of two real-scale marble roman statues and three busts of three roman emperors standing on pedestals of different types and size. Both isolated and non-isolated artefacts are considered, while two new and highly efficient base isolation systems, tailored to art objects, will be tested. The first isolator is a pendulum-based system, while the second utilizes Shape Memory Alloy wires. Furthermore, the paper examines the importance of the hosting building, i.e. building type and story. Specifically tailored, numerical models of varying complexity, for single and two-block rocking systems, were developed for the needs of this study and are also assessed against the experimental results

Anti-PrP antibodies block PrPSc replication in prion-infected cell cultures by accelerating PrPC degradation.

manuscript received October 15, 2003; revised manuscript received December 15, 2003; accepted December 16, 2003. We thanks P. Rondard, O Bischof, J.-L. Laplanche and J.-P. Pin for their fruitful discussions. we are grateful to S. barrère for her assistance in the statistical analysis of the data and H. McMahon for her assistance in reading the manuscript

Public Health

OBJECTIVE: The objective of this review was to analyse how researchers conducting studies about mobile health applications (MHApps) effectiveness assess the conditions of this effectiveness. STUDY DESIGN: A scoping review according to PRIMSA-ScR checklist. METHODS: We conducted a scoping review of efficacy/effectiveness conditions in high internal validity studies assessing the efficacy of MHApps in changing physical activity behaviours and eating habits. We used the PubMed, Web of Science, SPORTDiscus and PsycINFO databases and processed the review according to the O'Malley and PRISMA-ScR recommendations. We selected studies with high internal validity methodologies (randomised controlled trials, quasi-experimental studies, systematic reviews and meta-analyses), dealing with dietary and/or physical activity behaviours; covering primary, secondary or tertiary prevention and dealing with behaviour change (uptake, maintenance). We excluded articles on MHApps relating to high-level sport and telemedicine. The process for selecting studies followed a set protocol with two authors who independently appraised the studies. RESULTS: Twenty-two articles were finally selected and analysed. We noted that the mechanisms and techniques to support behaviour changes were poorly reported and studied. There was no explanation of how these MHApps work and how they could be transferred or not. Indeed, the main efficacy conditions reported by authors refer to practical aspects of the tools. Moreover, the issue of social inequalities was essentially reduced to access to the technology (the shrinking access divide), and literacy was poorly studied, even though it is an important consideration in digital prevention. All in all, even when they dealt with behaviours, the evaluations were tool-focused rather than intervention-focused and did not allow a comprehensive assessment of MHApps. CONCLUSION: To understand the added value of MHApps in supporting behaviour changes, it seems important to draw on the paradigms relating to health technology assessment considering the characteristics of the technologies and on the evaluation of complex interventions considering the characteristics of prevention. This combined approach may help to clarify how these patient-focused MHApps work and is a condition for improved assessment of MHApps in terms of effectiveness, transferability and scalability