L’application de la géophysique marine au diagnostic subaquatique

Les surfaces des diagnostics subaquatiques prescrits peuvent très vite frôler le gigantisme, ce qui rend inadéquate la méthode traditionnelle de prospection de la totalité des fonds avec des plongeurs. La recherche d’artefacts, tant en milieu maritime que fluvial, nécessite le recours aux outils acoustiques et magnétométriques. A la création du service des activités subaquatiques de l’Inrap en 2011, une réflexion a été menée afin de transposer les protocoles d’acquisition de données géophysiques issues de l’industrie et de la Marine aux opérations de diagnostics préventifs. Trois catégories de systèmes sont identifiables : ceux qui permettent d’« observer » le fond (sonar latéral ou sidescan sonar) voire de le topographier (sondeurs multifaisceaux ou SMF), ceux qui mesurent le champ magnétique et ceux qui pénètrent le sédiment en profondeur (sondeur de sédiments ou subbotom profiler).The size of the areas that need to be surveyed underwater can quickly get out of hand, which means that traditional survey methods of total survey of the seabed by divers are not up appropriate. Acoustic and magnetometric tools are necessary to detect features in both marine and river environments. When an underwater section was set up by Inrap in 2011, we assessed how the geophysical data-capture protocols that industry and the Navy use could be adapted for archaeological evaluations. Three systems are relevant here: those that allow us to “observe” the seabed (lateral sonar or sidescan sonar) or map it (multi-probe array), those that measure the magnetic field, and those that penetrate the sediments in depth (sediment corers or sub-bottom profilers).Las superficies de los diagnósticos subacuáticos prescritos pueden alcanzar rápidamente tamaños insospechados, por lo que recurrir al método tradicional de prospección de los fondos con buzos resulta totalmente inadecuado. Además, la búsqueda de artefactos en los medios marino o fluvial requiere el uso de herramientas acústicas y magnetométricas. En 2011, tras la creación del servicio de actividades subacuáticas del Inrap, se inició una reflexión destinada a transponer los protocolos de adquisición de datos geofísicos obtenidos a partir de la industria y de la Marina a las operaciones de diagnósticos preventivas. Así, es posible distinguir tres categorías de sistemas: los que permiten «observar» el fondo (sonar lateral o side scan sonar), e incluso de topografiarlo (sonda multihaz o SMF); aquellos que miden el campo magnético; y los que penetran el sedimento en profundidad (sonda de sedimentos o sub-botom profiler)

Bioluminescent Imaging of Trypanosoma brucei Shows Preferential Testis Dissemination Which May Hamper Drug Efficacy in Sleeping Sickness

Monitoring Trypanosoma spread using real-time imaging in vivo provides a fast method to evaluate parasite distribution especially in immunoprivileged locations. Here, we generated monomorphic and pleomorphic recombinant Trypanosoma brucei expressing the Renilla luciferase. In vitro luciferase activity measurements confirmed the uptake of the coelenterazine substrate by live parasites and light emission. We further validated the use of Renilla luciferase-tagged trypanosomes for real-time bioluminescent in vivo analysis. Interestingly, a preferential testis tropism was observed with both the monomorphic and pleomorphic recombinants. This is of importance when considering trypanocidal drug development, since parasites might be protected from many drugs by the blood-testis barrier. This hypothesis was supported by our final study of the efficacy of treatment with trypanocidal drugs in T. brucei-infected mice. We showed that parasites located in the testis, as compared to those located in the abdominal cavity, were not readily cleared by the drugs

Continuous cultivation of photosynthetic microorganisms: approaches, applications and future trends

The possibility of using photosynthetic microorganisms, such as cyanobacteria and microalgae, for converting light and carbon dioxide into valuable biochemical products has raised the need for new cost-efficient processes ensuring a constant product quality. Food, feed, biofuels, cosmetics and pharmaceutics are among the sectors that can profit from the application of photosynthetic microorganisms. Biomass growth in a photobioreactor is a complex process influenced by multiple parameters, such as photosynthetic light capture and attenuation, nutrient uptake, photobioreactor hydrodynamics and gas-liquid mass transfer. In order to optimize productivity while keeping a standard product quality, a permanent control of the main cultivation parameters is necessary, where the continuous cultivation has shown to be the best option. However it is of utmost importance to recognize the singularity of continuous cultivation of cyanobacteria and microalgae due to their dependence on light availability and intensity. In this sense, this review provides comprehensive information on recent breakthroughs and possible future trends regarding technological and process improvements in continuous cultivation systems of microalgae and cyanobacteria, that will directly affect cost-effectiveness and product quality standardization. An overview of the various applications, techniques and equipment (with special emphasis on photobioreactors) in continuous cultivation of microalgae and cyanobacteria are presented. Additionally, mathematical modelling, feasibility, economics as well as the applicability of continuous cultivation into large-scale operation, are discussed.This research work was supported by the grant SFRH/BPD/98694/2013 (Bruno Fernandes) from Fundacao para a Ciencia e a Tecnologia (Portugal). The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013. The authors also thank the Project "BioInd Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028" Co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDE

Operating a full tungsten actively cooled tokamak: overview of WEST first phase of operation

WEST is an MA class superconducting, actively cooled, full tungsten (W) tokamak, designed to operate in long pulses up to 1000 s. In support of ITER operation and DEMO conceptual activities, key missions of WEST are: (i) qualification of high heat flux plasma-facing components in integrating both technological and physics aspects in relevant heat and particle exhaust conditions, particularly for the tungsten monoblocks foreseen in ITER divertor; (ii) integrated steady-state operation at high confinement, with a focus on power exhaust issues. During the phase 1 of operation (2017–2020), a set of actively cooled ITER-grade plasma facing unit prototypes was integrated into the inertially cooled W coated startup lower divertor. Up to 8.8 MW of RF power has been coupled to the plasma and divertor heat flux of up to 6 MW m−2 were reached. Long pulse operation was started, using the upper actively cooled divertor, with a discharge of about 1 min achieved. This paper gives an overview of the results achieved in phase 1. Perspectives for phase 2, operating with the full capability of the device with the complete ITER-grade actively cooled lower divertor, are also described