Ecology and chemical ecology of plant-insect interactions in rice: implications for pest management

Induced resistance to the rice water weevil, Lissorhoptrus oryzophilus, was assessed in greenhouse and field experiments. The fall armyworm,Spodoptera frugiperda, and an elicitor, jasmonic acid, were used to induce resistance. The effect of these treatments on rice resistance to oviposition varied between cultivar used, but significantly fewer larvae were found on plants exposed to S. frugiperda and jasmonic acid on both cultivars tested. Application of jasmonic acid significantly reduced the number of L. oryzophilus larvae per plant, and represents the first example of elicitor-induced resistance in rice in field experiments. Oviposition by the sugarcane borer, Diatraea saccharalis, induced resistance to further oviposition by D. saccharalis in several cultivars. Plants with egg masses present received 33- 50% fewer egg masses when exposed to gravid D. saccharalis. However, D. saccharalis oviposition on cultivar M202 rendered plants more susceptible to subsequent oviposition. M202 plants with egg masses present received 2-3 fold more egg masses when subsequently exposed to D. saccharalis. The rice stink bug, Oebalus pugnax, was reared on rice (Oryza sativa), barnyardgrass (Echinochloa crus-galli) and amazon sprangletop (Leptochloa panicoides) and the metathoracic gland (MTG) contents were analyzed using GC/MS. Quantities of three compounds ((E)-2- decenal, (E)-2-hexenyl acetate and n-dodecane) are significantly influenced by host-plant. Crude metathoracic gland extracts attracted O. pugnax at low concentrations, and attraction decreased as the concentration increased, suggesting a bifunctional role of metathoracic gland compounds. Field experiments using a synthetic mixture of the four most abundant MTG chemicals significantly reduced O. pugnax in plots sprayed with this mixture. In addition, the host-plant on which O. pugnax was reared was found to significantly alter the ratio of four MTG chemicals, as well as influence development time and adult weights. The biological activity of four common phenolic compounds in rice (ferulic, p-coumaric, cinnamic and caffeic acids) were evaluated for their effects on the growth rate of D. saccharalis and S. frugiperda larvae. Levels of these compounds were quantified and then incorporated into diet bioassays. Despite minor structural differences, these compounds were found to have widely divergent effects on the larval weights of D. saccharalis and S. frugiperda

Inventory and First Assessment of Oil and Gas Wells Conversion for Geothermal Heat Recovery in France

International audienceThe repurposing of oil and gas wells for geothermal energy production and resource assessment can provide sustainable solutions to meet the objectives of renewable energy balance targeted within 2030 by the French Parliament in the "energy transition law for a green growth" promulgated in August 2015. Approximately 12 500 wells have been drilled in France since the 19th century for hydrocarbon reservoir exploration and exploitation. Most of them are closed and abandoned or nearing the end of production due to the planned end of exploitation of hydrocarbons in France by 2040. Several sustainable cases of conversion for geothermal energy production have been reported in France and abroad, demonstrating the possibility of using former wells for heat extraction from aquifers or coaxial heat exchangers. This paper presents an overview of the wells drilled in France and the methodology proposed to identify and rank them according to the a priori feasibility of open and closed loop conversion. To this purpose, wells data, geological and hydrothermal information acquired by the BRGM (geometry and dynamic aquifer properties from models) and land occupation have been cross-referenced. The quantitative overview should be followed by a detailed analysis of selected wells to assess their conversion potential for geothermal energy production (possible use at surface, well drilling and abandonment reports, hydrodynamic properties of the reservoir, technology to be implemented, etc.)

The effect of long term ageing on the autogenous welding of dissimilar austenitic stainless steels

Austenitic stainless steels are used extensively throughout power stations in high temperature applications such as superheater tubes and fuel rod guides. For these applications, welding is often required to join sections of components or pipes/tubes due to their large sizes and lengths. In this paper, samples of a cast niobium stabilised stainless steel welded to a wrought 321 stainless steel were investigated. The sections were joined together using an autogenous Tungsten Inert Gas (TIG) weld. The effects of long term ageing at 750°C for up to 4000 hours have been studied. The ageing treatments were conducted in an inert atmosphere. Compositional changes and precipitates have been investigated using SEM with EDX and EBSD analysis. Niobium dissolved completely into the weld melt however it is observed to precipitate back out during long term ageing. Titanium carbonitrides however remained intact during the welding process, creating agglomerated particles throughout the weld bead. Ageing above 100 hours causes further Nb rich MX precipitates to form, which coarsen with longer ageing times up to 4000 hours

A new syndrome of the Charolais neonatal calf : paralysis in gastroenteritis. Il. Virulence markers CS31A and col V in Escherichia coli isolated from feces

Un syndrome diarrhéique associé à des troubles nerveux (gastro-entérites paralysantes = GEP) a été décrit antérieurement chez des veaux Charoláis d’environ 10 jours. L’étude comparative des colibacilles de la flore fécale de 15 veaux malades et de 9 veaux témoins en bonne santé, a montré que le syndrome GEP est significativement associé à la présence d’une flore fécale colibacillaire où dominent des E. coli pouvant coloniser fortement l’intestin (plasmides p CS31 A, p col V, p K99). Une hypothèse étiopathogé- nique est proposée selon laquelle une bactériémie colibacillaire d’origine digestive avec endotoxémie pourrait expliquer certaines manifestations clini ques des GEP.A diarrheic syndrome associated with nervous troubles (paralysing gastroenteritis) was previously described in 10 days old Charolais calves. Comparative studies of E. coli from fecal flora of 15 ill calves and 9 control healthy calves indicated that PGE was significantly associated with a dominating E. coli fecal flora able to highly colonize the gut (p CS31A, p col V or p K99 plasmids). An etiopathogenic hypothesis is proposed. E. coli bacteriemia with a digestive origin associated with endotoxemia could explain a part of clinical signs in PGE

Inflammatory Bowel Diseases Phenotype, C. difficile and NOD2 Genotype Are Associated with Shifts in Human Ileum Associated Microbial Composition

We tested the hypothesis that Crohn’s disease (CD)-related genetic polymorphisms involved in host innate immunity are associated with shifts in human ileum–associated microbial composition in a cross-sectional analysis of human ileal samples. Sanger sequencing of the bacterial 16S ribosomal RNA (rRNA) gene and 454 sequencing of 16S rRNA gene hypervariable regions (V1–V3 and V3–V5), were conducted on macroscopically disease-unaffected ileal biopsies collected from 52 ileal CD, 58 ulcerative colitis and 60 control patients without inflammatory bowel diseases (IBD) undergoing initial surgical resection. These subjects also were genotyped for the three major NOD2 risk alleles (Leu1007fs, R708W, G908R) and the ATG16L1 risk allele (T300A). The samples were linked to clinical metadata, including body mass index, smoking status and Clostridia difficile infection. The sequences were classified into seven phyla/subphyla categories using the Naïve Bayesian Classifier of the Ribosome Database Project. Centered log ratio transformation of six predominant categories was included as the dependent variable in the permutation based MANCOVA for the overall composition with stepwise variable selection. Polymerase chain reaction (PCR) assays were conducted to measure the relative frequencies of the Clostridium coccoides – Eubacterium rectales group and the Faecalibacterium prausnitzii spp. Empiric logit transformations of the relative frequencies of these two microbial groups were included in permutation-based ANCOVA. Regardless of sequencing method, IBD phenotype, Clostridia difficile and NOD2 genotype were selected as associated (FDR ≤0.05) with shifts in overall microbial composition. IBD phenotype and NOD2 genotype were also selected as associated with shifts in the relative frequency of the C. coccoides – E. rectales group. IBD phenotype, smoking and IBD medications were selected as associated with shifts in the relative frequency of F. prausnitzii spp. These results indicate that the effects of genetic and environmental factors on IBD are mediated at least in part by the enteric microbiota