Search

Your search keyword '"Caroff, M."' showing total 227 results
Start Over Author "Caroff, M."
227 results on '"Caroff, M."'

2. Probing Quantum Gravity with Cherenkov Telescopes

Author

T. Terzić, J. Bolmont, S. Caroff, M. Gaug, A. Gent, A. Jacholkowska, D. Kerszberg, C. Levy, T.T.Y. Lin, M. Martinez, L. Nogués, A.N. Otte, C. Perennes, M. Ronco, J. Strišković

Subjects
Astrophysics::High Energy Astrophysical Phenomena, gamma rays: general, methods: statistical, active galactic nuclei, gamma-ray bursts, pul-sars, quantum gravity, Lorentz invariance violation
Abstract

Cherenkov telescopes play a crucial role in testing possible consequences of Quantum Gravity (QG), such as violations or deformations of Lorentz symmetry. In both cases, the photon dispersion relation is modified, making the photon group velocity energy dependent. This tiny effect, if real, could be measured using very high energy (VHE, E > 100 GeV) gamma rays crossing cosmological distances. The so-called time of flight measurements were up to now performed on individual sources with single instruments. No deviations from the special relativistic predictions have been detected, although strong constraints have been set on modified dispersion relations. In order to increase the sensitivity of QG analyses, and to perform the most robust searches for the energy-dependent photon group velocity up to date, researchers from the three major imaging Cherenkov telescopes (IACTs) experiments (H.E.S.S., MAGIC, and VERITAS) have joined forces. It is the first attempt at merging data from different instruments for this purpose, thus creating exceptionally large statistics. Moreover, combining observations from various gamma-ray sources at different redshifts alleviates the entanglement between the effects of QG and the source intrinsic time-delays. In addition, the influence of different theoretical formalisms for distance contribution were investigated and compared for the first time. In this talk, we will describe the likelihood-based analysis method developed for this purpose, and present the results obtained from simulated data. However, this is only the first part of the anticipated work. We will introduce our plans for the continuation and future endeavours in this field, specifically, for performing our analysis on real data sets.

Published
2022

6. Structural characterization of the lipids A of three Bordetella bronchiseptica strains: variability of fatty acid substitution

Author

Zarrouk, H., Karibian, D., Bodie, S., Perry, M.B., Richards, J.C., and Caroff, M.

Subjects
Bacteria -- Research, Endotoxins -- Research, Biological sciences
Abstract

The structures of lipids A isolated from the lipopolysaccharides (LPSs) of three different pathogenic Bordetella bronchiseptica strains were investigated. The LPSs were found to contain the classical lipid A bisphosphorylated beta-(1->6)-linked D-glucosamine disaccharide with hydroxytetradecanoic acid in amide linkages. Their structures are different from that of the lipid A of Bordetella pertussis endotoxin by the replacement of hydroxydecanoic acid on the C-3 position with hydroxydodecanoic acid or dodecanoic acid and the presence of various amounts of hexadecanoic acid.

Published
1997

8. Leptospiral LPS escapes mouse TLR4 internalization and TRIF-associated antimicrobial responses through O antigen and associated lipoproteins

Author

Coburn, J, Bonhomme, D, Santecchia, I, Vernel-Pauillac, F, Caroff, M, Germon, P, Murray, G, Adler, B, Boneca, IG, Werts, C, Coburn, J, Bonhomme, D, Santecchia, I, Vernel-Pauillac, F, Caroff, M, Germon, P, Murray, G, Adler, B, Boneca, IG, and Werts, C

Abstract

Leptospirosis is a worldwide re-emerging zoonosis caused by pathogenic Leptospira spp. All vertebrate species can be infected; humans are sensitive hosts whereas other species, such as rodents, may become long-term renal carrier reservoirs. Upon infection, innate immune responses are initiated by recognition of Microbial Associated Molecular Patterns (MAMPs) by Pattern Recognition Receptors (PRRs). Among MAMPs, the lipopolysaccharide (LPS) is recognized by the Toll-Like-Receptor 4 (TLR4) and activates both the MyD88-dependent pathway at the plasma membrane and the TRIF-dependent pathway after TLR4 internalization. We previously showed that leptospiral LPS is not recognized by the human-TLR4, whereas it signals through mouse-TLR4 (mTLR4), which mediates mouse resistance to acute leptospirosis. However, although resistant, mice are known to be chronically infected by leptospires. Interestingly, the leptospiral LPS has low endotoxicity in mouse cells and is an agonist of TLR2, the sensor for bacterial lipoproteins. Here, we investigated the signaling properties of the leptospiral LPS in mouse macrophages. Using confocal microscopy and flow cytometry, we showed that the LPS of L. interrogans did not induce internalization of mTLR4, unlike the LPS of Escherichia coli. Consequently, the LPS failed to induce the production of the TRIF-dependent nitric oxide and RANTES, both important antimicrobial responses. Using shorter LPS and LPS devoid of TLR2 activity, we further found this mTLR4-TRIF escape to be dependent on both the co-purifying lipoproteins and the full-length O antigen. Furthermore, our data suggest that the O antigen could alter the binding of the leptospiral LPS to the co-receptor CD14 that is essential for TLR4-TRIF activation. Overall, we describe here a novel leptospiral immune escape mechanism from mouse macrophages and hypothesize that the LPS altered signaling could contribute to the stealthiness and chronicity of the leptospires in mice.

Published
2020

10. Structural characterization of the lipid A of Bordetella pertussis 1414 endotoxin

Author

Caroff, M., Deprun, C., Richards, J.C., and Karibian, D.

Subjects
Endotoxins -- Research, Bordetella pertussis -- Research, Biological sciences
Abstract

Fast atom bombardment mass spectrometry, plasma desorption mass spectrometry and chemical analysis of the lipid A structure in Bordetella pertussis 1414 endotoxin reveal two principal molecular groups with large and small signals. The molecular ion, which consists of two phosphate, two glucosamine, one tetradecanoic acid, three hydroxytetradecanoic acid and one hydroxy decanoic acid residues, is responsible for a large signal, while a lighter ion molecule causes the smaller signal. The C-6' and C-4 hydroxyl groups of the backbone disaccharide remain unsubstituted.

Published
1994

11. Comparison of lipids A of several Salmonella and Escherichia strains by 252Cf plasma desorption mass spectrometry

Author

Karibian, D., Deprun, C., and Caroff, M.

Subjects
Lipids -- Analysis, Salmonella -- Physiological aspects, Escherichia coli -- Physiological aspects, Biological sciences
Abstract

Plasma desorption mass spectrometry was used to compare structures in lipid A preparations from several Salmonella and Escherichia strains. Considerable variation in degree of heterogeneity was observed. Molecular species associated with Salmonella lipid A were found in preparations from Escherichia coli. Moreover, preparations from three different batches of lipid A from S. minnesota R595 showed significant differences in composition.

Published
1993

14. Basophil responses to microbial stimulation

Author

Alkan, M., Dietrich, C., Sayes, F., Ramadan, A., Machavoine, F., Fioramonti, Jean, Caroff, M., Cavaillon, J. M., Dy, M., Thieblemont, N., Institut Cochin (IC UM3 (UMR 8104 / U1016)), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Paris Descartes - Paris 5 (UPD5), CHU Necker - Enfants Malades [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), ToxAlim (ToxAlim), Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Ecole d'Ingénieurs de Purpan (INP - PURPAN), Université de Toulouse (UT)-Université de Toulouse (UT), Université Paris-Sud - Paris 11 (UP11), Institut Pasteur [Paris] (IP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Vétérinaire de Toulouse (ENVT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole d'Ingénieurs de Purpan (INPT - EI Purpan), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Recherche Agronomique (INRA), Institut Pasteur [Paris], Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Vétérinaire de Toulouse (ENVT), Université Fédérale Toulouse Midi-Pyrénées-Ecole d'Ingénieurs de Purpan (INPT - EI Purpan), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, and ProdInra, Migration

Subjects
[SDV] Life Sciences [q-bio], [SDV]Life Sciences [q-bio]
Published
2016

15. The Aun cluster probe in SIMS analysis of bacterial lipid A

Author

Novikov, A., Caroff, M., Pautrat, M., Fallavier, M., Della Negra, S., Girod, Dominique, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
[PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-ATM-PH] Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus]
Published
2011

17. Origin of Tore-Josephine seamounts from U-Pb ages, geochemistry and Pb isotopes

Author

Merle, R., Caroff, M., Girardeau, J., Cotten, Joseph, Guivel, C., Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2005

18. Age progression along the Society hotspot chain (French Polynesia) based on new unspiked K-Ar

Author

Guillou, H., Maury, René, Cotten, Joseph, Legendre, C., Caroff, M., Blais, S., Guille, G., Domaines Océaniques (LDO), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography
Published
2005

19. Evolution géologique et pétrologique de l’île de Huahine (archipel de la Société, Polynésie française) : un cas original de déstabilisation de volcan-bouclier intraocéanique

Author

Legendre, C., Maury, R.C., Guillou, Herve, Cotten, J., Chauvel, C., Caroff, M., Blais, S., Guille, G., Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Paléocéanographie (PALEOCEAN), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2003

20. Les marquises (Polynésie Françaises) : un archipel intraocéanique atypique

Author

Guille, G., Legendre, C., Maury, René, Caroff, M., Munschy, G., Blais, S., Chauvel, C., Cotten, Joseph, Guillou, H., Domaines Océaniques (LDO), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology
Published
2002

21. Structure of the lipid A of Bordetella hinzii ATCC 51730: Rapid Commun.Mass Spectrom

Author

Aussel, L., Brisson, J., Perry, Malcolm, and Caroff, M.

Subjects
liquid chromatography/mass spectrometry, endotoxin, chemical, isolation & purification, magnetic, Bordetella, electrophoresis, polyacrylamide gel, Lipopolysaccharide, desorption mass spectrometry, Bordetella bronchiseptica, chemistry, fatty acids, Bordetella pertussis, methods, esters, lipid, carbohydrate conformation, component, spectrum analysis, mass, acylation, models, molecular, molecular, structure, lipid A, comparative study, plasma, mass spectrometry, silicon dioxide, Support, Non-U. S. Gov't, amide, magnetic resonance spectroscopy, mass fragmentography, Parapertussis, NMR, laser, nuclear, species specificity, linkages, chromatography, thin layer, glucosamine, lipids (amino acids, peptides, and proteins), acid, chromatography, gel, disaccharide, spectrometry, mass, matrix-assisted laser desorption-ionization
Abstract

Bordetella hinzii has recently been isolated from immunocompromised human hosts. The structure of the lipid A of its endotoxin was investigated using chemical analyses, nuclear magnetic resonnance (NMR), gas liquid chromatography/mass spectrometry (GC/MS), plasma desorption mass spectrometry (PDMS) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The lipid A contains the classical bisphosphorylated beta-(1-->6)-linked D-glucosamine disaccharide with hydroxytetradecanoic acid (C14OH) in amide linkages. The lipid A components of B. pertussis, B. bronchiseptica, and B. parapertussis all differ in their acylation pattern but share a residue of tetradecanoyl-3-hydroxytetradecanoic acid in amide linkage at the C-2' position. However, in the B. hinzii species, the tetradecanoic acid (C14) is stoichiometrically replaced by a 2-hydroxytetradecanoic acid (2-C14OH). In the few reported examples of a hydroxylated fatty acid in this position, the substitutions were only partial. The B. hinzii lipid A differs from that of B. pertussis also by replacement of the hydroxydecanoic acid (C10OH) by hydroxydodecanoic acid (C12OH) and by the presence of a hexadecanoic acid (C16) to give a sixth fatty acid. The lipid A was heterogeneous, being composed of three major molecular species: tetra-, penta- and hexaacylated. The fatty acids in ester linkage were localized by PDMS of the native and alkali-treated lipid A. The lipid A components isolated from the O-chain-linked lipopolysaccharides (LPSs) were shown to be more acylated than those from the O-chain-free LPSs

Published
2000

23. $^{Cf}$252-plasma desorption mass spectrometry of unmodified lipid A:Fragmentation patterns and localization of fatty acids

Author

Karibian, D., Brunelle, A., Aussel, L., Caroff, M., Institut de Physique Nucléaire d'Orsay (IPNO), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]
Abstract

The fragmentation patterns of synthetic Escherichia coli-type lipid A in plasma desorption mass spectrometry (PDMS) in both negative- and positive-ion modes were determined. Negative-ion spectra gave signals for the main diphosphorylated (intact) molecular species in their native proportions. Intact and alkaline-treated lipid A in this mode gave, for the glucosamine I moiety, easily identified signals that have not been previously reported in PDMS, These spectra gave enough information to localize the fatty acids. The procedure was verified with relatively homogeneous lipids A prepared from Salmonella minnesota R595 and Neisseria meningitidis lipopolysaccharides, and then applied to the previously unstudied Yersinia entercolitica O:11,24 lipid A to obtain the localization of its fatty acids. The possibility of obtaining this much information from two negative-ion spectra was attributed to the method, described earlier, of preparing the samples.In the positive-ion mode, about half of the E. coli ions containing diglucosamine appeared as monodephosphorylated species and/or as Na adducts. The intact glucosamine II moiety and its fragment ions gave signals none of which were Na adducts. With lipids A prepared from S. minnesota, N. meningitidis, and Y. enterocolitica, similar fragmentation patterns were observed, For lipid A structure determination, the positive-ion mode could play a confirmatory role, The above results and some of those reported by others were compared.

Published
1999

24. Géochimie des basaltes de l'île de Ua Huka (archipel des Marquises) : variation du taux de fusion partielle et hétérogénéité de la source mantellique

Author

Ielsch, G., Caroff, M., Barsczus, Hans Gustave, Maury, R.C., Guillou, H., and Guille, G.

Subjects
GEOCHIMIE, PETROLOGIE, DIFFERENTIATION MAGMATIQUE, MAGMA BASIQUE, BASALTE
Abstract

L'île de Ua Huka (archipel des Marquises) comporte un volcan-bouclier principal, édifié entre 3,2 et 2,4 Ma, puis immédiatement affecté par un double effondrement caldeirique. Après un arrêt de l'activité volcanique pendant 0,9 Ma, deux petits volcans se sont mis en place au sud-ouest de l'île entre 1,5 et 0,75 Ma. Les différents types de basaltes constituant ces édifices (tholéiites à olivine, basaltes alcalins et basanites) résulteraient de la fusion partielle d'une source chimiquement hétérogène, dont le taux aurait diminué au cours du temps. La variation temporelle de la composition de la source mantellique est tout à fait originale par rapport à l'évolution généralement observée aux Marquises. Elle implique en effet une contribution de plus en plus importante d'un composant de type manteau appauvri (DMM), probablement lithosphérique, dans la genèse des termes basanitiques les plus tardifs. (Résumé d'auteur)

Published
1998

27. Matrix Implanted Laser Desorption Ionization (MILDI) Combined with Ion Mobility-Mass Spectrometry for Bio-Surface Analysis

Author

Tempez, A., primary, Ugarov, M., additional, Egan, T., additional, Schultz, J. A., additional, Novikov, A., additional, Della-Negra, S., additional, Lebeyec, Y., additional, Pautrat, M., additional, Caroff, M., additional, Smentkowski, V. S., additional, Wang, H-Y. J., additional, Jackson, S. N., additional, and Woods, A. S., additional

Published
2005
Full Text
View/download PDF

28. Orthogonal time-of-flight secondary ion mass spectrometric analysis of peptides using large gold clusters as primary ions

Author

Tempez, Agnès, primary, Schultz, J. A., additional, Della-Negra, S., additional, Depauw, J., additional, Jacquet, D., additional, Novikov, A., additional, Lebeyec, Y., additional, Pautrat, M., additional, Caroff, M., additional, Ugarov, M., additional, Bensaoula, H., additional, Gonin, M., additional, Fuhrer, K., additional, and Woods, Amina, additional

Published
2004
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results