SODA-IIoT4Factory: Blockchain to keep the A.I. of your Intrusion Detection System up-to-date

International audienceCo-designed with FPC Ingénierie, SODA-IIoT4Factory offers a secure way to update CyPRES rule engines & cyber security/attack models.CyPRES is an intelligent IDS that strengthens industrial information systems. It learns then verifies the operation and behaviour of the system to the lowest level of detail. It detects the first signs of attacks before damage is incurred

Ironing out Fe residence time in the dynamic upper ocean

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Black, E. E., Kienast, S. S., Lemaitre, N., Lam, P. J., Anderson, R. F., Planquette, H., Planchon, F., & Buesseler, K. O. Ironing out Fe residence time in the dynamic upper ocean. Global Biogeochemical Cycles, 34(9), (2020): e2020GB006592, doi:10.1029/2020GB006592.Although iron availability has been shown to limit ocean productivity and influence marine carbon cycling, the rates of processes driving iron's removal and retention in the upper ocean are poorly constrained. Using 234Th‐ and sediment‐trap data, most of which were collected through international GEOTRACES efforts, we perform an unprecedented observation‐based assessment of iron export from and residence time in the upper ocean. The majority of these new residence time estimates for total iron in the surface ocean (0–250 m) fall between 10 and 100 days. The upper ocean residence time of dissolved iron, on the other hand, varies and cycles on sub‐annual to annual timescales. Collectively, these residence times are shorter than previously thought, and the rates and timescales presented here will contribute to ongoing efforts to integrate iron into global biogeochemical models predicting climate and carbon dioxide sequestration in the ocean in the 21st century and beyond.We would like to thank S. Albani for providing the dust model results (Community Atmosphere Model, C4fn) and the three anonymous reviewers for their constructive comments. The U.S. GEOTRACES work was supported by the National Science Foundation (OCE‐1232669 and OCE‐1518110) and E. Black was also funded by a NASA Earth and Space Science Graduate Fellowship (NNX13AP31H) and the Ocean Frontier Institute. The GEOVIDE work was funded by the Flanders Research Foundation (G071512N), the Vrije Universiteit Brussel (SRP‐2), the French ANR Blanc GEOVIDE (ANR‐13‐BS06‐0014), ANR RPDOC BITMAP (ANR‐12‐PDOC‐0025‐01), IFREMER, CNRS‐INSU (programme LEFE), INSU OPTIMISP, and Labex‐Mer (ANR‐10‐LABX‐19)

Contamination pathways of spore-forming bacteria in a vegetable cannery

International audienceSpoilage of low-acid canned food during prolonged storage at high temperatures is caused by heat resistant thermophilic spores of strict or facultative bacteria. Here, we performed a bacterial survey over two consecutive years on the processing line of a French company manufacturing canned mixed green peas and carrots. In total, 341 samples were collected, including raw vegetables, green peas and carrots at different steps of processing, cover brine, and process environment samples. Thermophilic and highly-heat-resistant thermophilic spores growing anaerobically were counted. During vegetable preparation, anaerobic spore counts were significantly decreased, and tended to remain unchanged further downstream in the process. Large variation of spore levels in products immediately before the sterilization process could be explained by occasionally high spore levels on surfaces and in debris of vegetable combined with long residence times in conditions suitable for growth and sporulation. Vegetable processing was also associated with an increase in the prevalence of highly-heat-resistant species, probably due to cross-contamination of peas via blanching water. Geobacillus stearothermophilus M13-PCR genotypic profiling on 112 isolates determined 23 profile-types and confirmed process-driven cross-contamination. Taken together, these findings clarify the scheme of contamination pathway by thermophilic spore-forming bacteria in a vegetable cannery

The biogeochemical cycle of dissolved cobalt in the Atlantic and the Southern Ocean south off the coast of South Africa

The spatial distribution, biogeochemical cycle and external sources of dissolved cobalt (DCo) were investigated in the southeastern Atlantic and the Southern Ocean between 33°58′S and 57°33′S along the Greenwich Meridian during the austral summer 2008 in the framework of the International Polar Year. DCo concentrations were measured by flow-injection analysis and chemiluminescence detection in filtered (0.2 μm), acidified and UV-digested samples at 12 deep stations in order to resolve the several biogeochemical provinces of the Antarctic Circumpolar Current and to assess the vertical and frontal structures in the Atlantic sector of the Southern Ocean. We measured DCo ranging from 5.73 ± 1.15 pM to 72.9 ± 4.51 pM. The distribution of DCo was nutrient-like in surface waters of the subtropical domain with low concentrations in the euphotic layer due to biological uptake. The biological utilization of dissolved cobalt was proportional to that of phosphate in the subtropical domain with a DCo:HPO42− depletion ratio of ~ 44 μM M−1. In deeper waters the distribution indicated remineralization of DCo and inputs from the margins of South Africa with lateral advection of enriched intermediate and deep waters to the southeastern Atlantic Ocean. In contrast the vertical distribution of DCo changed southward, from a nutrient-like distribution in the subtropical domain to scavenged-type behavior in the domain of the Antarctic Circumpolar Current and conservative distribution in the Weddell Gyre. There the cycle of DCo featured low biological removal by Antarctic diatoms with input to surface waters by snow, removal in oxygenated surface waters, and dissolution and stabilization in the low-oxygenated Upper Circumpolar Deep Waters. DCo distributions and physical hydro-dynamics features also suggest inputs from the Drake Passage and the southwestern Atlantic to the 0° meridian along the eastward flow of the Antarctic Circumpolar Current. Bottom enrichment of DCo in the Antarctic Bottom Waters was also evident, together with increasing water-mass pathway and aging, possibly due to sediment resuspension and/or mixing with North Atlantic Deep waters in the Cape Basin. Overall atmospheric input of soluble Co by dry aerosols to the surface waters was low but higher in the ACC domain than in the northern part of the section. At the highest latitudes, it is possible that snowfall could be a source of DCo to surface waters. Tentative budgets for DCo in the mixed layer of the subtropical and the ACC domains have been constructed for each biogeochemical region encountered during the cruise. The estimated DCo uptake flux was found to be the dominant cobalt flux along the section. This flux decreases southward, which is consistent with the observations that DCo shows a southward transition from nutrient-like towards conservative distribution in the mixed layer

Fatty acid isotopic fractionation in the diatom Chaetoceros muelleri

Carbon isotopic fractionation was studied during the development of the diatom Chaetoceros muelleri grown in batch culture with 13C-depleted CO2 addition. Cellular and growth parameters and isotopic composition of dissolved inorganic carbon and particulate organic carbon were monitored every two days, while the content and isotopic composition of individual fatty acid in polar lipid and neutral lipid were measured on the 5th day (end of exponential phase), 10th and 14th days (stationary phase). Continuous addition of petrochemical CO2 to the algae led to a rapid and strong modification of dissolved inorganic carbon isotopic composition with cascading effects on particulate organic carbon and fatty acid isotopic compositions. Carbon isotope fractionation in Chaetoceros muelleri ranged from 17‰ to 25‰ and changed according to culture ages. Isotopic fractionation into fatty acids, overall, was similar between polar and neutral lipids, and was systematically higher than in particulate organic carbon. At the end of the exponential growth phase, the isotopic composition of individual fatty acids varied from −51.3‰ to −58.4‰. At this culture age, large differences in the isotopic compositions between fatty acids were observed. Polyunsaturated fatty acids such as 16:3n-4, 18:4n-3, and 20:5n-3 were more strongly 13C-depleted than other fatty acids such as 14:0, 16:0, 16:1n-7 or 18:1n-9. These results showed how isotopic effects occur during the desaturation and elongation phases. Such isotopic effects were also supported by the lower δ13C of averaged δ13C of saturated fatty acids and monounsaturated fatty acids as compared to those of polyunsaturated fatty acids. However, during the stationary phase, fatty acid isotopic compositions were less variable and closer to particulate organic carbon, while saturated and monounsaturated fatty acids were more depleted than polyunsaturated fatty acids. Our study underlined the importance of consideration of phytoplankton physiological status when conducting ecological and biogeochemical studies as they appeared to strongly control phytoplankton carbon isotopic composition

A 13CO2 Enrichment Experiment to Study the Synthesis Pathways of Polyunsaturated Fatty Acids of the Haptophyte Tisochrysis lutea

The production of polyunsaturated fatty acids (PUFA) in Tisochrysis lutea was studied using the gradual incorporation of a 13C-enriched isotopic marker, 13CO2, for 24 h during the exponential growth of the algae. The 13C enrichment of eleven fatty acids was followed to understand the synthetic pathways the most likely to form the essential polyunsaturated fatty acids 20:5n-3 (EPA) and 22:6n-3 (DHA) in T. lutea. The fatty acids 16:0, 18:1n-9 + 18:3n-3, 18:2n-6, and 22:5n-6 were the most enriched in 13C. On the contrary, 18:4n-3 and 18:5n-3 were the least enriched in 13C after long chain polyunsaturated fatty acids such as 20:5n-3 or 22:5n-3. The algae appeared to use different routes in parallel to form its polyunsaturated fatty acids. The use of the PKS pathway was hypothesized for polyunsaturated fatty acids with n-6 configuration (such as 22:5n-6) but might also exist for n-3 PUFA (especially 20:5n-3). With regard to the conventional n-3 PUFA pathway, Δ6 desaturation of 18:3n-3 appeared to be the most limiting step for T. lutea, “stopping” at the synthesis of 18:4n-3 and 18:5n-3. These two fatty acids were hypothesized to not undergo any further reaction of elongation and desaturation after being formed and were therefore considered “end-products”. To circumvent this limiting synthetic route, Tisochrysis lutea seemed to have developed an alternative route via Δ8 desaturation to produce longer chain fatty acids such as 20:5n-3 and 22:5n-3. 22:6n-3 presented a lower enrichment and appeared to be produced by a combination of different pathways: the conventional n-3 PUFA pathway by desaturation of 22:5n-3, the alternative route of ω-3 desaturase using 22:5n-6 as precursor, and possibly the PKS pathway. In this study, PKS synthesis looked particularly effective for producing long chain polyunsaturated fatty acids. The rate of enrichment of these compounds hypothetically synthesized by PKS is remarkably fast, making undetectable the 13C incorporation into their precursors. Finally, we identified a protein cluster gathering PKS sequences of proteins that are hypothesized allowing n-3 PUFA synthesis