Lunar laser ranging in infrfared at hte Grasse laser station

For many years, lunar laser ranging (LLR) observations using a green wavelength have suffered an inhomogeneity problem both temporally and spatially. This paper reports on the implementation of a new infrared detection at the Grasse LLR station and describes how infrared telemetry improves this situation. Our first results show that infrared detection permits us to densify the observations and allows measurements during the new and the full Moon periods. The link budget improvement leads to homogeneous telemetric measurements on each lunar retro-reflector. Finally, a surprising result is obtained on the Lunokhod 2 array which attains the same efficiency as Lunokhod 1 with an infrared laser link, although those two targets exhibit a differential efficiency of six with a green laser link

Multiple metabolomics of uropathogenic E. coli reveal different information content in terms of metabolic potential compared to virulence factors.

No single analytical method can cover the whole metabolome and the choice of which platform to use may inadvertently introduce chemical selectivity. In order to investigate this we analysed a collection of uropathogenic Escherichia coli. The selected strains had previously undergone extensive characterisation using classical microbiological methods for a variety of metabolic tests and virulence factors. These bacteria were analysed using Fourier transform infrared (FT-IR) spectroscopy; gas chromatography mass spectrometry (GC-MS) after derivatisation of polar non-volatile analytes; as well as reversed-phase liquid chromatography mass spectrometry in both positive (LC-MS(+ve)) and negative (LC-MS(-ve)) electrospray ionisation modes. A comparison of the discriminatory ability of these four methods with the metabolic test and virulence factors was made using Procrustes transformations to ascertain which methods produce congruent results. We found that FT-IR and LC-MS(-ve), but not LC-MS(+ve), were comparable with each other and gave highly similar clustering compared with the virulence factors tests. By contrast, FT-IR and LC-MS(-ve) were not comparable to the metabolic tests, and we found that the GC-MS profiles were significantly more congruent with the metabolic tests than the virulence determinants. We conclude that metabolomics investigations may be biased to the analytical platform that is used and reflects the chemistry employed by the methods. We therefore consider that multiple platforms should be employed where possible and that the analyst should consider that there is a danger of false correlations between the analytical data and the biological characteristics of interest if the full metabolome has not been measured

Discriminant Analysis of Raman Spectra for Body Fluid Identification for Forensic Purposes

Detection and identification of blood, semen and saliva stains, the most common body fluids encountered at a crime scene, are very important aspects of forensic science today. This study targets the development of a nondestructive, confirmatory method for body fluid identification based on Raman spectroscopy coupled with advanced statistical analysis. Dry traces of blood, semen and saliva obtained from multiple donors were probed using a confocal Raman microscope with a 785-nm excitation wavelength under controlled laboratory conditions. Results demonstrated the capability of Raman spectroscopy to identify an unknown substance to be semen, blood or saliva with high confidence

Fingerprinting microbiomes towards screening for microbial antibiotic resistance

There is an increasing need to investigate microbiomes in their entirety in a variety of contexts ranging from environmental to human health scenarios. This requirement is becoming increasingly important with emergence of antibiotic resistance. In general, more conventional approaches are too expensive and/or time-consuming and often predicated on prior knowledge of the microorganisms one wishes to study. Herein, we propose the use of biospectroscopy tools as relatively high-throughput, non-destructive approaches to profile microbiomes under study. Fourier-transform infrared (FTIR) or Raman spectroscopy both generate fingerprint spectra of biological material and such spectra can readily be subsequently classed according to biochemical changes in the microbiota, such as emergence of antibiotic resistance. FTIR spectroscopy techniques generally can only be applied to desiccated material whereas Raman approaches can be applied to more hydrated samples. The ability to readily fingerprint microbiomes could lend itself to new approaches in determining microbial behaviours and emergence of antibiotic resistance

Rapid Etiological Classification of Meningitis by NMR Spectroscopy Based on Metabolite Profiles and Host Response

Bacterial meningitis is an acute disease with high mortality that is reduced by early treatment. Identification of the causative microorganism by culture is sensitive but slow. Large volumes of cerebrospinal fluid (CSF) are required to maximise sensitivity and establish a provisional diagnosis. We have utilised nuclear magnetic resonance (NMR) spectroscopy to rapidly characterise the biochemical profile of CSF from normal rats and animals with pneumococcal or cryptococcal meningitis. Use of a miniaturised capillary NMR system overcame limitations caused by small CSF volumes and low metabolite concentrations. The analysis of the complex NMR spectroscopic data by a supervised statistical classification strategy included major, minor and unidentified metabolites. Reproducible spectral profiles were generated within less than three minutes, and revealed differences in the relative amounts of glucose, lactate, citrate, amino acid residues, acetate and polyols in the three groups. Contributions from microbial metabolism and inflammatory cells were evident. The computerised statistical classification strategy is based on both major metabolites and minor, partially unidentified metabolites. This data analysis proved highly specific for diagnosis (100% specificity in the final validation set), provided those with visible blood contamination were excluded from analysis; 6-8% of samples were classified as indeterminate. This proof of principle study suggests that a rapid etiologic diagnosis of meningitis is possible without prior culture. The method can be fully automated and avoids delays due to processing and selective identification of specific pathogens that are inherent in DNA-based techniques

A large topographic feature on the surface of the trans-Neptunian object (307261) 2002 MS4_4 measured from stellar occultations

This work aims at constraining the size, shape, and geometric albedo of the dwarf planet candidate 2002 MS4 through the analysis of nine stellar occultation events. Using multichord detection, we also studied the object's topography by analyzing the obtained limb and the residuals between observed chords and the best-fitted ellipse. We predicted and organized the observational campaigns of nine stellar occultations by 2002 MS4 between 2019 and 2022, resulting in two single-chord events, four double-chord detections, and three events with three to up to sixty-one positive chords. Using 13 selected chords from the 8 August 2020 event, we determined the global elliptical limb of 2002 MS4. The best-fitted ellipse, combined with the object's rotational information from the literature, constrains the object's size, shape, and albedo. Additionally, we developed a new method to characterize topography features on the object's limb. The global limb has a semi-major axis of 412 $\pm$ 10 km, a semi-minor axis of 385 $\pm$ 17 km, and the position angle of the minor axis is 121 $^\circ$ $\pm$ 16$^\circ$. From this instantaneous limb, we obtained 2002 MS4's geometric albedo and the projected area-equivalent diameter. Significant deviations from the fitted ellipse in the northernmost limb are detected from multiple sites highlighting three distinct topographic features: one 11 km depth depression followed by a 25$^{+4}_{-5}$ km height elevation next to a crater-like depression with an extension of 322 $\pm$ 39 km and 45.1 $\pm$ 1.5 km deep. Our results present an object that is $\approx$138 km smaller in diameter than derived from thermal data, possibly indicating the presence of a so-far unknown satellite. However, within the error bars, the geometric albedo in the V-band agrees with the results published in the literature, even with the radiometric-derived albedo

Chapitre 11. Approche historique et kinesthésique au sujet de la présence de l’œuvre de Kenny Hunter sur la place Degeyter à Fives (Lille)

Introduction Dans ce chapitre, nous abordons l’analyse de la place Degeyter dans le quartier de Fives à Lille. Nous portons plus précisément notre attention sur la présence de l’œuvre d’art réalisée par Kenny Hunter, la Demoiselle de Fives, en considérant toute œuvre comme une présence agissante et l’espace public comme un lieu public pouvant, potentiellement, accueillir des actions reliées par un horizon commun, politique ou pré-politique (dans le sens de la polis grecque). Pour ce faire, no..

Caractérisation de la flore sulfato / thiosulfato réductrice par spectroscopie infrarouge à transformée de fourier (IRTF)

La présence de certaines bactéries au sein d'un biofilm peut soit accélérer un processus de corrosion déjà établi, soit créer des conditions favorables à son élaboration. Les souches principalement décrites comme étant les plus agressives vis-à-vis des matériaux métalliques sont les Bactéries Sulfato/Thiosulfato Réductrices (BSR et BTR). Il paraît donc important de les détecter rapidement lorsqu'elles colonisent un milieu afin de pouvoir diagnostiquer les problèmes et déployer les moyens de lutte appropriés. Malheureusement les techniques actuelles d'identification sont coûteuses et/ou peu rapides. Nous avons donc tenté de caractériser plusieurs souches de BSR/BTR provenant de la collection DSMZ par spectroscopie infrarouge àtransformée de Fourier. Les résultats de la classification hiérarchique des spectres infrarouge sur les fenêtres spectrales 3100-2800 cm-1 et 1500-700 cm-1 ont permis de séparer en deux groupes bien distincts les BSR et la BTR étudiées, mais aussi de différencier les BSR au niveau espèce. L'introduction de spectres de bactéries de contamination fécale dans l'analyse scinde le dendrogramme, les BSR/BTR restant groupées entre elles. La spectroscopie IRTF différencie avec succès les BSR et la BTR étudiées et devrait permettre, après enrichissement de la bibliothèque en spectres de nouvelles espèces, une caractérisation des souches sulfurogènes à partir d'échantillons prélevés en eau de mer

Application of magnetic iron oxide nanoparticles prepared from microemulsions for protein purification

International audienceBACKGROUND: Magnetic nanoparticles are of immense interest for their applications in biotechnology. This paper reports the synthesis of magnetic iron oxide nanoparticles from two different water-in-oil microemulsion systems (ME-MIONs), their characterization and also their use in purification of coagulant protein. RESULTS: ME-MIONs have demonstrated to be an efficient binder in the purification of Moringa oleifera protein when compared with the superparamagnetic iron oxide nanoparticles prepared from coprecipitation in aqueous media. The size and morphology of the ME-MIONs were studied by transmission electron microscopy (TEM) while the structural characteristics were studied by X-ray diffraction (XRD). The microemulsion magnetic iron oxide nanoparticles (ME 1-MION and ME 2-MION) obtained have a size range 7-10 nm. The protein and ME-MIONs interaction was investigated by Fourier transform infrared spectroscopy (FT-IR); the presence of three peaks at 2970, 2910 and 2870 cm(-1) respectively, confirms the binding of the protein. The purification and molecular weight of the coagulant protein was 6.5 kDa as analyzed by SDS-PAGE. CONCLUSION: The ME-MIONs have the advantage of being easily tailored in size, are highly efficient as well as magnetic, cost effective and versatile; they are, thus, very suitable for use in a novel purification technique for protein or biomolecules that possess similar characteristics to the Moringa oleifera coagulant protein. (C) 2011 Society of Chemical Industr