MALDI-FTICR MS Imaging as a Powerful Tool to Identify Paenibacillus Antibiotics Involved in the Inhibition of Plant Pathogens

in Journal of the American Society for Mass Spectrometry (in press)

Nowadays, microorganisms are more and more often used as biocontrol agents for crop protection against diseases. Among them, bacteria of Bacillus and Paenibacillus genders are already used as commercial ... [more ▼]

Nowadays, microorganisms are more and more often used as biocontrol agents for crop protection against diseases. Among them, bacteria of Bacillus and Paenibacillus genders are already used as commercial biocontrol agents. Their mode of action is supposed to be related to their production of antibiotics, such as cyclic lipopeptides, which exhibit great antimicrobial activities. We chose to work with a Paenibacillus polymyxa strain (Pp56) very resistant to various microorganisms. The bacteria were grown simultaneously with Fusarium oxysporum and we applied matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance (MALDI-FTICR) mass spectrometry to identify the antibiotics compounds present in the fungus growth inhibition area. We, therefore, identified fusaricidins A, B, and C and numerous members of the LI-F antibiotics family. MALDIFTICR mass spectrometry imaging was then used to follow the diffusion of lipopeptides involved in the inhibitory activity over time. We analyzed the molecular content of the inhibitory area at different Pp56 and Fusarium incubation durations and concluded that some lipopeptides such as fusaricidin B and a mixture of LI-F05b/06b/08a were mainly involved in the defense mechanism of Pp56. Our study confirms that MALDI imaging may be a powerful tool to quickly determine which molecular species is involved in an antagonism with another microorganism, avoiding time-consuming steps of extraction, purification, and activity tests, which are still commonly used in microbiology. [less ▲]

Carte géologique de Wallonie (Belgique) 1/10.000, 48/8 Clavier

Cartographic material (in press)

New geological map of Wallonia published at the scale of 1/25.000, based on a new field work and using previous scientific data produced since the previous edition in 1902 (at 1/40.000, by Lohest, Forir ... [more ▼]

New geological map of Wallonia published at the scale of 1/25.000, based on a new field work and using previous scientific data produced since the previous edition in 1902 (at 1/40.000, by Lohest, Forir and Mourlon). [less ▲]

In vivo PET/CT in a human glioblastoma chicken chorioallantoic membrane model: A new tool for oncology and radiotracer development.

in Journal of Nuclear Medicine : Official Publication, Society of Nuclear Medicine (in press)

For many years the laboratory mouse has been used as the standard model for in vivo oncology research, particularly in the development of novel PET tracers, but the growth of tumors on chicken ... [more ▼]

For many years the laboratory mouse has been used as the standard model for in vivo oncology research, particularly in the development of novel PET tracers, but the growth of tumors on chicken chorioallantoic membrane (CAM) provides a more rapid, low cost and ethically sustainable alternative. For the first time, we demonstrate the feasibility of in vivo PET and CT imaging in a U87 glioblastoma tumor model on chicken chorioallantoic membrane (CAM), with the aim of applying this model for screening of novel PET tracers. Methods: U87 glioblastoma cells were implanted on the CAM at day 11 post-fertilization and imaged at day 18. A small animal imaging cell was used to maintain incubation and allow anesthesia using isoflurane. Radiotracers were injected directly into the exposed CAM vasculature. Sodium [18F]fluoride was used to validate the imaging protocol, demonstrating that image-degrading motion can be removed with anesthesia. Tumor glucose metabolism was imaged using [18F]fluorodeoxyglucose and tumor protein synthesis was imaged using 2-[18F]fluoro-L-tyrosine. Anatomical images were obtained by contrast enhanced CT, facilitating clear delineation of the tumor, delineation of tracer uptake in tumor versus embryo and accurate volume measurements. Results: PET imaging of tumor glucose metabolism and protein synthesis was successfully demonstrated in the CAM U87 glioblastoma model. Catheterization of CAM blood vessels facilitated dynamic imaging of glucose metabolism with [18F]fluorodeoxyglucose and demonstrated the ability to study PET tracer uptake over time in individual tumors, while CT imaging improved the accuracy of tumor volume measurements. Conclusion: In summary, we describe the novel application of PET/CT in the CAM tumor model, with optimization of typical imaging protocols. PET imaging in this valuable tumor model could prove particularly useful for rapid, high-throughput screening of novel radiotracers. [less ▲]

Le virus Schmallenberg ou l’émergence du premier Orthobunyavirus du sérogroupe Simbu en Europe

in Annales de Médecine Vétérinaire (in press)

Turbulent flows in straight compound open-channel with a transverse embankment on the floodplain

in Journal of Hydraulic Research (in press)

Diet of harbor porpoises along the Dutch coast: a combined stable isotope and stomach contents approach

in Marine Mammal Science (in press)

High stranding frequency of porpoises, Phocoena phocoena, along the Dutch coast since 2006 has led to increased interest in the ecology of porpoises in the North Sea. Stranded porpoises were collected ... [more ▼]

High stranding frequency of porpoises, Phocoena phocoena, along the Dutch coast since 2006 has led to increased interest in the ecology of porpoises in the North Sea. Stranded porpoises were collected along the Dutch coast (2006–2008) and their diet was assessed through stomach content and stable isotope analysis (d13C and d15N) of porpoise muscle and prey. Stable isotope analysis (SIAR) was used to estimate the con- tribution of prey species to the porpoises’ diet. This was compared to prey composi- tion from stomach contents, to analyze differences between long- and short-term diet. According to stomach contents, 90.5% of the diet consisted of gobies, whiting, lesser sandeel, herring, cod, and sprat. Stable isotope analysis revealed that 70-83% of the diet consisted of poor cod, mackerel, greater sandeel, lesser sandeel, sprat, and gobies, highlighting a higher importance of pelagic, schooling species in the porpoises’ diet compared to stomach contents. This could be due to prey distribution as well as differ- ences in behavior of porpoises and prey between the coastal zone and offshore waters. This study supports the need for multi-method approaches. Future ecological and fishery impact assessment studies and management decisions for porpoise conservation should acknowledge this difference between the long- and short-term diet. [less ▲]

Manuel de Science politique

Book published by De Boeck (in press)

Macroporous poly(ionic liquid)s and poly(acrylamide)s monoliths from CO2-in-water emulsion templates stabilized by sugar-based surfactants

in Journal of Materials Chemistry A: Materials for energy and sustainability (in press)

Highly interconnected poly(acrylamide) (PAM) and poly(vinylimidazolium) (PVIm) porous monoliths were templated by carbon 10 dioxide-in-water (CO2/W) high internal phase emulsions (HIPEs), a toxic-solvent ... [more ▼]

Highly interconnected poly(acrylamide) (PAM) and poly(vinylimidazolium) (PVIm) porous monoliths were templated by carbon 10 dioxide-in-water (CO2/W) high internal phase emulsions (HIPEs), a toxic-solvent free process. A range of sugar-based fluorinated surfactants prepared by chemoenzymatic synthesis were used as emulsifiers. Both the concentration and the structure of the surfactants, especially the length of their CO2-philic part and of their spacer between the sugar head and the tail, were found to strongly affect the cellular structure and morphology of the PAM polyHIPEs, i.e. the size of pores and cells. A mannose derivative bearing a chain ranging from 6 to 10 perfluorinated carbons and a long spacer emerged as the best stabilizer, leading to a porous monolith with average pores and 15 cells sizes (about 2.6 1m and 5-10 1m, respectively) among the lowest reported for polyHIPEs produced from CO2/W emulsions. The same template then served for the preparation of the first macroporous poly(ionic liquid)s (PILs) polyHIPE by using 1-vinyl-3- ethylimidazolium bromide as monomer. Shrinkage of the final material was prevented by adjusting the divinylimidazolium crosslinker content. The resulting low density polyHIPE exhibits small spherical cells (~5 1m) connected by numerous small pores (~2 1m), confirming that the CO2/W HIPE templating methodology based on fluorinated glycosurfactants is a technique of choice for the 20 preparation of macroporous PILs. [less ▲]

Brain metabolic dysfunction in Capgras delusion during Alzheimer’s disease: a positron emission tomography study

in American Journal of Alzheimer's Disease & Other Dementias (in press)

Capgras delusion is characterized by the misidentification of people and by the delusional belief that the misidentified persons have been replaced by impostors, generally perceived as persecutors. Since ... [more ▼]

Capgras delusion is characterized by the misidentification of people and by the delusional belief that the misidentified persons have been replaced by impostors, generally perceived as persecutors. Since little is known regarding the neural correlates of Capgras syndrome, the cerebral metabolic pattern of a patient with probable Alzheimer’s disease (AD) and Capgras syndrome was compared with those of 24 healthy elderly subjects and 26 AD patients without delusional syndrome. Compared to the healthy and AD groups, the patient had significant hypometabolism in frontal and posterior midline structures. In light of current neural models of face perception, our patient’s Capgras syndrome may be related to impaired recognition of a familiar face, subserved by the posterior cingulate/precuneus cortex, and impaired reflection about personally relevant knowledge related to a face, subserved by the dorsomedial prefrontal cortex. [less ▲]

"How very un-Dominican of him" ou la merveilleuse masculinité d’Oscar Wao

in Banoun, Bernard; Tomiche, Anne; Zapata, Mónica (Eds.) Fictions au masculin (in press)

Dans le cadre de la littérature de l’exil, il a souvent été question de subjectivités entre-deux, de sujets in-between, et de réflexions entre un « ici » aliénant et un « là-bas » idéalisé. En réaction à ... [more ▼]

Dans le cadre de la littérature de l’exil, il a souvent été question de subjectivités entre-deux, de sujets in-between, et de réflexions entre un « ici » aliénant et un « là-bas » idéalisé. En réaction à cette pensée binaire et suite aux réflexions postcoloniales, les mouvements migratoires sont aujourd’hui célébrés et associés aux figures d’identités composées . Par ailleurs, notre compréhension des migrations a fortement évolué depuis une quinzaine d’années, on ne parle donc plus aujourd’hui de relocalisations unidirectionnelles et permanentes mais plutôt de communauté transnationale et de cultures globalisées selon un agencement postcolonial . C’est dans cette optique que j’observerai quelles sont les différentes masculinités issues de la diaspora dominicaine en confrontation dans le roman de Junot Díaz La Brève et Merveilleuse Vie d’Oscar Wao, et, face à ces tensions de genre, de quelle manière la subjectivité masculine d’Oscar Wao est singulière. [less ▲]