Arctic shipping : future polar express seaways? : shipowners’ opinion

Since about 1995, climate change has begun to mark Arctic region. The first and strongest signs of global-scale climate change exist in the high latitudes of the planet. The Earth is indeed facing what is now known as Global Warming. With the world economy continuing to grow rapidly, driven in particular by fast economic take-off in countries such as China, Brazil and India, these climate changes are likely to rush the Arctic's development and usher in a new phase of globalization. Meanwhile, demand for energy (oil and gas) and raw materials (iron, nickel, zinc, etc.) is increasing. As the reserves of some important resources such as oil run out, and assuming that diversification of supply sources has been seen as the key to energy security, energy companies scour the globe in search of promising new fields, and now in inhospitable regions which until recently aroused little interest given the importance of costs of such exploration projects

Réalisation d’un Contrat d’Etudes Prospectives des secteurs du transport: Rapport final

Le CEP a pour objectif de réaliser un état des lieux du secteur, de conduire une analyse prospective qualitative et quantitative de l’évolution des métiers et des besoins de compétences du transport et de préconiser un plan d’actions pour les transports routiers, maritimes et fluviaux. A l’issue des travaux d’étude, le rapport final a été remis aux membres du Comité de pilotage (Ministère de l’emploi - DGEFP, Représentants des branches des transports, l’OPCA Transports et Services, Pôle Emploi, Ministère de l’écologie et du développement durable, des transport et du logement)

LRCH Proteins: A Novel Family of Cytoskeletal Regulators

Background: Comparative genomics has revealed an unexpected level of conservation for gene products across the evolution of animal species. However, the molecular function of only a few proteins has been investigated experimentally, and the role of many animal proteins still remains unknown. Here we report the characterization of a novel family of evolutionary conserved proteins, which display specific features of cytoskeletal scaffolding proteins, referred to as LRCHs. Principal Findings: Taking advantage of the existence of a single LRCH gene in flies, dLRCH, we explored its function in cultured cells, and show that dLRCH act to stabilize the cell cortex during cell division. dLRCH depletion leads to ectopic cortical blebs and alters positioning of the mitotic spindle. We further examined the consequences of dLRCH deletion throughout development and adult life. Although dLRCH is not essential for cell division in vivo, flies lacking dLRCH display a reduced fertility and fitness, particularly when raised at extreme temperatures. Conclusion/Significance: These results support the idea that some cytoskeletal regulators are important to buffer environmental variations and ensure the proper execution of basic cellular processes, such as the control of cell shape

Rapid response to the M_w 4.9 earthquake of November 11, 2019 in Le Teil, Lower Rhône Valley, France

On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower Rhône Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude, and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations), geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional Cévenne fault system in a context of present-day compressional tectonics

Reconstruction and simulation of neocortical microcircuitry

We present a first-draft digital reconstruction of the microcircuitry of somatosensory cortex of juvenile rat. The reconstruction uses cellular and synaptic organizing principles to algorithmically reconstruct detailed anatomy and physiology from sparse experimental data. An objective anatomical method defines a neocortical volume of 0.29 ± 0.01 mm3 containing ∼31,000 neurons, and patch-clamp studies identify 55 layer-specific morphological and 207 morpho-electrical neuron subtypes. When digitally reconstructed neurons are positioned in the volume and synapse formation is restricted to biological bouton densities and numbers of synapses per connection, their overlapping arbors form ∼8 million connections with ∼37 million synapses. Simulations reproduce an array of in vitro and in vivo experiments without parameter tuning. Additionally, we find a spectrum of network states with a sharp transition from synchronous to asynchronous activity, modulated by physiological mechanisms. The spectrum of network states, dynamically reconfigured around this transition, supports diverse information processing strategies

Hybrid Representation and Visualization Methods Applied to Neuronal Microcircuits

For the past twenty years, scientific visualization has assisted simulation-based research to explore problems of organized complexity. Environmental research, social sciences, astronomy, and modern physics have exploited the increasing power of computer graphics to interactively visualize three-dimensional models. Of late, neuroscience has witnessed the use of large-scale simulation with biologically detailed neuron models, and aspires to benefit from scientific visualization too. This thesis is the result of a close collaboration with the Blue Brain Project, a neuroscience endeavor working on biologically detailed large-scale simulation of the brain, and tries to answer the following question: How can scientific visualization improve neuroscience insights in the context of simulation-based research? Scientific visualization of a model typically preserves its spatial layout. In continuity with this axiom, we identified in more depth the requirements for a scientific visualization solution in neuroscience. Thus, the preservation of the domain specificity, the hybrid visualization, the validation, and the adaptation to the limitations of the human-visual perception enhance the readability of the generated results. We applied these requirements to elaborate an hybrid representation of neuronal structures, and proposed a unified framework of visualization methods which preserves the domain specificities of neuroscience. This framework was finally assessed in case studies, where neuroscientific investigations about structure, composition, and dynamics of neuronal microcircuit challenge the developed visualization solutions to derive insight. We believe that these representations and visualization methods form a solid ground for the elaboration of virtual instruments dedicated to a new approach of neuroscience, where in silico landscapes of the brain are complementary to the classical in vitro and in vivo investigations

Polar super seaways? : maritime transport in the Arctic : an analysis of shipowners’ intentions

The seasonal melting of sea ice in the Arctic Ocean, which has been confirmed for several summers in a row and is widely documented, has become a hot topic in the media. It is fuelling many speculative scenarios about the purported renewal of a “cold war”, or even an actual armed conflict, in the Arctic, for the control of both its natural resources and its sea routes. The melting sea ice is indeed giving a second wind to projects, abandoned in the 19th century, to find shorter sea routes between Europe and Asia. A look at the map shows the savings in distance that can be achieved with the Arctic routes: for example, a trip between London and Yokohama through the Northwest Passage is 15,700 km and 13,841 km through the Northeast Passage, which is significantly shorter than the route through Suez (21,200 km) or Panama (23,300 km).2 These findings fuel the idea that these Arctic routes, because they are shorter, are bound to attract abundant through traffic, and consequently will become a major political issue. Amid the media widespread image of a future maritime highway across Arctic seas, even some scientists yield to the popular image and assert, without proof, that Arctic traffic is set to increase rapidly.3 Beyond the seemingly decisive advantage of Arctic routes, however, there remain many obstacles to navigation (Lasserre, 2010d). In addition, these scenarios for the development of marine traffic in the Arctic remain highly speculative and are not based on an analysis of shipowners’ perceptions, which is the goal of this paper. This article will thus present the results of an empirical survey conducted among shipping companies to determine their interest in developing activities in the Arctic. Besides examining the potential development of shipping in Arctic routes, this research must be replaced in the context of intense competition between shippers, competition that makes both service reliability and costs of transport paramount. In this competition structure, the benefits of established routes between major hubs seems to prevail, so that new routes have difficulty being established

Contribution à l' étude mathématique et numérique des solutions à support compact pour les modèles de turbulence compressible

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF