Application of COMPOCHIP Microarray to Investigate the Bacterial Communities of Different Composts

A microarray spotted with 369 different 16S rRNA gene probes specific to microorganisms involved in the degradation process of organic waste during composting was developed. The microarray was tested with pure cultures, and of the 30,258 individual probe-target hybridization reactions performed, there were only 188 false positive (0.62%) and 22 false negative signals (0.07%). Labeled target DNA was prepared by polymerase chain reaction amplification of 16S rRNA genes using a Cy5-labeled universal bacterial forward primer and a universal reverse primer. The COMPOCHIP microarray was applied to three different compost types (green compost, manure mix compost, and anaerobic digestate compost) of different maturity (2, 8, and 16 weeks), and differences in the microorganisms in the three compost types and maturity stages were observed. Multivariate analysis showed that the bacterial composition of the three composts was different at the beginning of the composting process and became more similar upon maturation. Certain probes (targeting Sphingobacterium, Actinomyces, Xylella/Xanthomonas/ Stenotrophomonas, Microbacterium, Verrucomicrobia, Planctomycetes, Low G + C and Alphaproteobacteria) were more influential in discriminating between different composts. Results from denaturing gradient gel electrophoresis supported those of microarray analysis. This study showed that the COMPOCHIP array is a suitable tool to study bacterial communities in composts

Échange scientifique avec la France. Épisodes significatifs

Note portant sur l’auteur Les traits caractéristiques essentiels qui ont marqué mes quarante ans de collaboration avec la France ont été, sans aucun doute, le fruit de mes années de formation post-universitaire au laboratoire Curie à Paris. Ayant achevé mes études de chimie à ce qui était alors l’Université du Brésil, je suis arrivé à Paris en 1948. Quelques mois plus tard, j’étais accepté par le couple Irène et Frédéric Joliot-Curie, comme stagiaire au Laboratoire Curie de l’Institut du radi..

Magnetic properties of lamellar tetrataenite in Toluca iron meteorite

Magnetic studies were conducted using lamellar tetrataenite extracted from the Toluca octahedrite by a diluted HCl etching technique. Natural remanent magnetization (NRM) in the lamellae is very stable against AF demagnetization and is quite intense, ranging from 2.58 to 37.42×(10)^ Am^2/kg. This NRM is completely demagnetized at about 550℃ of temperature. The most characteristic change in magnetic properties on heating up to about 550℃ is a significant decrease in magnetic coercivity. This observation is consistent with the results obtained from chondrites. The paramagnetic component in lamellar tetrataenite, which is estimated by Mossbauer spectrum analyses, was not detected by conventional magnetic studies

Magnetic properties of tetrataenite-rich meteorites II

Magnetic hysteresis and thermomagnetic characteristics of St. Severin (LL6), Appley Bridge (LL6) and Tuxtuac (LL5) chondrites, which contain tetrataenite in their metallic components, are measured and analyzed in comparison with another tetrataenite-rich chondrite, Yamato-74160 (LL7). The magnetic properties of tetrataenite-rich meteorites are characterized by (a) high magnetic coercive force (H_C) which amounts to 520 Oe for St. Severin and 160 Oe for Appley Bridge, (b) essential flatness up to about 500℃ and then a sharp irreversible drop down to Curie point of the first-run heating thermomagnetic curve. Both characteristic features are broken down to the ordinary features of disordered taenite by a breakdown of tetrataenite structure at elevated temperatures beyond the orderdisorder transition temperature. The natural remanent magnetization (NRM) of tetrataenite-rich meteorites is extremely stable against AF-demagnetization and other magnetic disturbances because of the high magnetic coercivity of tetrataenite. The breakdown processes of ordered tetrataenite structure by heat treatments are experimentally pursued to understand the formation process of tetrataenite phase in meteorites

Magnetic properties of Ni-rich iron meteorites

6 Ni-rich ataxites (25.6-35.5 wt% in Ni-content) are magnetically analyzed. These Ni-rich ataxites can be classified into 3 groups on the basis of the structure consisting of the major Fe-Ni phases; i. e., (1) ordinary taenite phase (ferromagnetic and paramagnetic γ-phases) only, (Yamato-791694 and the Lime Creek), (2) γ-phase plus tetrataenite (γ\u27-phase), (the Santa Catharina), and (3) γ-phase plus γ\u27-phase plus martensitic Fe-Ni metal (α_2-phase), (the Twin City and the San Cristobal). The Tishomingo Ni-rich ataxite has an anomalous structure, which may belong to either group (2) or group (3). Taenite lamellae of 2 octahedrites (the Toluca and the Itutinga) are also magnetically analyzed. These taenite lamellae have the structure of group (2)

Anti-Endothelial Antibodies and Neuropsychiatric Systemic Lupus Erythematosus

The pathogenesis of neuropsychiatric systemic lupus erythematosus (NPSLE) has been attributed to autoantibody-mediated neural dysfunction, vasculopathy, and coagulopathy. Several autoantibodies specificities have been reported in serum and cerebrospinal fluid of NPSLE patients (i.e., antineuronal, antiribosomal P proteins, antiglial fibrillary acidic proteins, antiphospholipid, and anti-endothelial antibodies). We have recently demonstrated an association between serum anti-endothelial antibodies and psychosis or depression in patients with SLE. Subsequently, by screening a cDNA library from human umbilical artery endothelial cells with serum from a SLE patient with psychosis, one positive strongly reactive clone was identified encoding the C-terminal region (C-ter) of Nedd5, an intracytoplasmatic protein of the septin family. Anti-Nedd5 antibodies have been found significantly associated with psychiatric manifestations in SLE patients, strengthening the view of a possible implication of autoantibodies in the development of psychiatric disorders. © 2006 New York Academy of Sciences