Implementation of drift velocities and currents in SOLEDGE2D-EIRENE

International audienceIn order to improve cross-field transport description, drifts and currents have been implemented in SOLEDGE2D-EIRENE. The derivation of an equation for the electric potential is recalled. The resolution of current equation is tested in a simple slab case. WEST divertor simulations in forward-B and reverse-B fields are also discussed. A significant increase of ExB shear is observed in the forward-B configuration that could explain a favorable L-H transition in this case

Modelling of epithelial growth, fission and lumen formation during embryonic thyroid development : a combination of computational and experimental approaches

Organogenesis is the phase of embryonic development leading to the formation of fully functional organs. In the case of the thyroid, organogenesis starts from the endoderm and generates a multitude of closely packed independent spherical follicular units surrounded by a dense network of capillaries. Follicular organisation is unique and essential for thyroid function, i.e. thyroid hormone production. Previous in vivo studies showed that, besides their nutritive function, endothelial cells play a central role during thyroid gland morphogenesis. However, the precise mechanisms and biological parameters controlling the transformation of the multi-layered thyroid epithelial primordium into a multitude of single-layered follicles are mostly unknown. Animal studies used to improve understanding of organogenesis are costly and time-consuming, with recognised limitations. Here, we developed and used a 2-D vertex model of thyroid growth, angiogenesis and folliculogenesis, within the open-source Chaste framework. Our in silico model, based on in vivo images, correctly simulates the differential growth and proliferation of central and peripheral epithelial cells, as well as the morphogen-driven migration of endothelial cells, consistently with our experimental data. Our simulations further showed that reduced epithelial cell adhesion was critical to allow endothelial invasion and fission of the multi-layered epithelial mass. Finally, our model also allowed epithelial cell polarisation and follicular lumen formation by endothelial cell abundance and proximity. Our study illustrates how constant discussion between theoretical and experimental approaches can help us to better understand the roles of cellular movement, adhesion and polarisation during thyroid embryonic development. We anticipate that the use of in silico models like the one we describe can push forward the fields of developmental biology and regenerative medicine

Managing Mediterranean nurse plants-mediated effects on soil microbial functions to improve rock phosphate solubilization processes and early growth of Cupressus atlantica G

a b s t r a c t The main objective was to evaluate the impact of nurse plant species commonly found in Mediterranean areas (Lavandula dentata and Thymus satureoides) on microbial soil functions, on the native inoculum potential of AM fungi involved in the rock phosphate weathering and to measure the potential benefits to the growth of Atlas Cypress (Cupressus atlantica G.), an endemic Cupressacea of Morocco. Soils collected from an old C. atlantica forest and pre-cultivated with each of the target plant species (L. dentata and T. satureoides). After 5 months of cultivation, they were uprooted and the treated substrate was amended or not with Khouribga Rock Phosphate (KRP). Then pots were filled with the soil mixtures and planted with one pre-germinated seed of C. atlantica. The results show that pre-cultivation step with native mycotrophic plant species improves the mycorrhizal soil infectivity, modifies soil microbial functionalities and increases the impact of rock phosphate amendment on the C. atlantica growth. This low cost cultivation practice by improving forest plant development and cultural soil quality constitutes a promising ecological engineering tool to improve the performances of ecosystem restoration

Survival probability of mutually killing Brownian motions and the O'Connell process

Recently O'Connell introduced an interacting diffusive particle system in order to study a directed polymer model in 1+1 dimensions. The infinitesimal generator of the process is a harmonic transform of the quantum Toda-lattice Hamiltonian by the Whittaker function. As a physical interpretation of this construction, we show that the O'Connell process without drift is realized as a system of mutually killing Brownian motions conditioned that all particles survive forever. When the characteristic length of interaction killing other particles goes to zero, the process is reduced to the noncolliding Brownian motion (the Dyson model).Comment: v2: AMS-LaTeX, 20 pages, 2 figures, minor corrections made for publication in J. Stat. Phy

Integrated Proteomic and Transcriptomic Investigation of the Acetaminophen Toxicity in Liver Microfluidic Biochip

Microfluidic bioartificial organs allow the reproduction of in vivo-like properties such as cell culture in a 3D dynamical micro environment. In this work, we established a method and a protocol for performing a toxicogenomic analysis of HepG2/C3A cultivated in a microfluidic biochip. Transcriptomic and proteomic analyses have shown the induction of the NRF2 pathway and the related drug metabolism pathways when the HepG2/C3A cells were cultivated in the biochip. The induction of those pathways in the biochip enhanced the metabolism of the N-acetyl-p-aminophenol drug (acetaminophen-APAP) when compared to Petri cultures. Thus, we observed 50% growth inhibition of cell proliferation at 1 mM in the biochip, which appeared similar to human plasmatic toxic concentrations reported at 2 mM. The metabolic signature of APAP toxicity in the biochip showed similar biomarkers as those reported in vivo, such as the calcium homeostasis, lipid metabolism and reorganization of the cytoskeleton, at the transcriptome and proteome levels (which was not the case in Petri dishes). These results demonstrate a specific molecular signature for acetaminophen at transcriptomic and proteomic levels closed to situations found in vivo. Interestingly, a common component of the signature of the APAP molecule was identified in Petri and biochip cultures via the perturbations of the DNA replication and cell cycle. These findings provide an important insight into the use of microfluidic biochips as new tools in biomarker research in pharmaceutical drug studies and predictive toxicity investigations

Reporting on the Seminar - Risk interpretation and action (RIA): Decision making under conditions of uncertainty

The paper reports on the World Social Science (WSS) Fellows seminar on Risk Interpretation and Action (RIA), undertaken in New Zealand in December, 2013. This seminar was coordinated by the WSS Fellows program of the International Social Science Council (ISSC), the RIA working group of the Integrated Research on Disaster Risk (IRDR) program, the IRDR International Center of Excellence Taipei, the International START Secretariat and the Royal Society of New Zealand. Twenty-five early career researchers from around the world were selected to review the RIA framework under the theme of \u27decision-making under conditions of uncertainty\u27, and develop novel theoretical approaches to respond to and improve this framework. Six working groups emerged during the seminar: 1. the assessment of water-related risks in megacities; 2. rethinking risk communication; 3. the embodiment of uncertainty; 4. communication in resettlement and reconstruction phases; 5. the integration of indigenous knowledge in disaster risk reduction; and 6. multi-scale policy implementation for natural hazard risk reduction. This article documents the seminar and initial outcomes from the six groups organized; and concludes with the collective views of the participants on the RIA framework

An international survey on the pragmatic management of epistaxis

Epistaxis is one of the most common ear, nose and throat emergencies. The management of epistaxis has evolved significantly in recent years, including the use of nasal cautery and packs. However, a correct treatment requires the knowledge of nasal anatomy, potential risks, and complications of treatment. Epistaxis is often a simple and readily treatable condition, even though a significant bleed may have potentially severe consequences. At present, there are very few guidelines concerning this topic. The current Survey explored the pragmatic approach in managing epistaxis. A questionnaire, including 7 practical questions has been used. The current International Survey on epistaxis management reported a relevant prevalence (21.7%), mainly during childhood and senescence, an important hospitalization rate (11.8%), the common use of anterior packing and electrocoagulation, and the popular prescription of a vitamin supplement and intranasal creams