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1. Skin-brain dialogue in auto-inflammatory diseases: A new route to biomarkers?

Author

S. Matar, S. Aractingi, R. Gaillard, and A.-C. Petit

Subjects
Autoinflammatory disease, Skin-brain axis, Psychoneuroimmunology, Neuro-immune-endocrine-cutaneous system, Biomarker, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Autoinflammatory diseases (AID) are rare systemic inflammatory disorders due to monogenic or polygenic dysfunction of innate immunity. They affect many organs including the brain and the skin. The spectrum of these diseases has been rapidly expanding recently due to newly developed diagnostic tools. The neuro-immuno-endocrine-cutaneous interactions play an important role in the pathophysiology of these diseases. The skin-brain interplay is not fully investigated in AID and evidence supporting bidirectional communication is examined. This article provides an overview of the current state of the art in the pathophysiology of AID with cutaneous and psychiatric manifestations. Elucidating the neuro-immuno-endocrine-cutaneous dysregulation underlying pathophysiology of AID is promising for determining future biomarkers and therapeutic options.

Published
2024
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2. The MUSE second-generation VLT instrument

Author

R., Bacon, M., Accardo, L., Adjali, H., Anwand, S., Bauer, I., Biswas, J., Blaizot, D., Boudon, S., Brau-Nogue, J., Brinchmann, P., Caillier, L., Capoani, M., Carollo C., T., Contini, P., Couderc, E., Daguise, S., Deiries, B., Delabre, S., Dreizler, P., Dubois J., M., Dupieux, C., Dupuy, E., Emsellem, T., Fechner, A., Fleischmann, M., Francois, G., Gallou, T., Gharsa, A., Glindemann, D., Gojak, B., Guiderdoni, G., Hansali, T., Hahn, A., Jarno, A., Kelz, C., Koehler, J., Kosmalski, F., Laurent, M., Le Floch, J., Lilly S., -L., Lizon J., M., Loupias, A., Manescau, C., Monstein, H., Nicklas, J-C, Olaya, L., Pares, L., Pasquini, A., Pecontal-Rousset, R., Pello, C., Petit, E., Popow, R., Reiss, A., Remillieux, E., Renault, M., Roth, G., Rupprecht, D., Serre, J., Schaye, G., Soucail, M., Steinmetz, O., Streicher, R., Stuik, H., Valentin, J., Vernet, P., Weilbacher, L., Wisotzki, and N, Yerle

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Multi Unit Spectroscopic Explorer (MUSE) is a second-generation VLT panoramic integral-field spectrograph currently in manufacturing, assembly and integration phase. MUSE has a field of 1x1 arcmin2 sampled at 0.2x0.2 arcsec2 and is assisted by the VLT ground layer adaptive optics ESO facility using four laser guide stars. The instrument is a large assembly of 24 identical high performance integral field units, each one composed of an advanced image slicer, a spectrograph and a 4kx4k detector. In this paper we review the progress of the manufacturing and report the performance achieved with the first integral field unit., Comment: 10 pages, 5 figures

Published
2022
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3. River incision, 10Be production and transport in a source-to-sink sediment system (Var catchment, SW Alps)

Author

C. Petit, T. Salles, V. Godard, Y. Rolland, and L. Audin

Subjects
Dynamic and structural geology, QE500-639.5
Abstract

Detrital 10Be from continental river sands or submarine sediments has been extensively used to determine the average long-term denudation rates of terrestrial catchments, based on the assumption that the rate of cosmogenic nuclide production by the interaction of source rocks with cosmic radiation balances out the loss of these nuclides by surface denudation. However, the 10Be signal recorded in sediments may be affected at the source by the response time of mountainous catchments to high-frequency forcings. In addition, transient sediment storage in piedmonts, alluvial plains and lakes or near the coast may also induce a difference between the erosive signal and its record in the sedimentary sink. Consequently, a significant part of the signal recorded in shallow-water sediments can be lost, as deep marine sediments may simultaneously record a signal coming from newly eroded source rocks along with one coming from the destabilization of previously deposited sediments. In this paper, we use the landscape evolution model Badlands to simulate erosion, deposition and detrital 10Be transfer from a source-to-sink sedimentary system (the Var River catchment, southern French Alps) over the last 100 kyr. We first compare model-based denudation rates with the ones that would be extracted from the 10Be record of local continental sediments (equivalent to river sands) and from sediments deposited offshore over time in order to examine if this record provides an accurate estimate of continental denudation rates. Then, we examine which conditions (precipitation rate, flexure, ice cover) satisfy published measured river incision rates and 10Be concentration in submarine sediments. Our results, based on the Var catchment cosmic ray exposure dating and modelling indicate that, while river sands do accurately estimate the average denudation rate of continental catchments, this is much less the case for deep submarine sediments. We find that deep-sea sediments have a different and often much smoother 10Be signature than continental ones and record a significant time lag with respect to imposed precipitation rate changes, representing the geomorphological response of the margin. A model which allows us to fit both measured 10Be concentration in marine sediments and river incision rates on land involves an increase in precipitation rates from 0.3 to 0.7 m yr−1 after 20 ka, suggesting more intense precipitation starting at the end of the Last Glacial Maximum.

Published
2023
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4. Dissipative Capture of Planets into First-order Mean-motion Resonances

Author

Konstantin Batygin and Antoine C. Petit

Subjects
Orbital resonances, Perturbation methods, Astrophysics, QB460-466
Abstract

The emergence of orbital resonances among planets is a natural consequence of the early dynamical evolution of planetary systems. While it is well established that convergent migration is necessary for mean-motion commensurabilities to emerge, recent numerical experiments have shown that the existing adiabatic theory of resonant capture provides an incomplete description of the relevant physics, leading to an erroneous mass scaling in the regime of strong dissipation. In this work, we develop a new model for resonance capture that self-consistently accounts for migration and circularization of planetary orbits, and derive an analytic criterion based upon stability analysis that describes the conditions necessary for the formation of mean-motion resonances. We subsequently test our results against numerical simulations and find satisfactory agreement. Our results elucidate the critical role played by adiabaticity and resonant stability in shaping the orbital architectures of planetary systems during the nebular epoch, and provide a valuable tool for understanding their primordial dynamical evolution.

Published
2023
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5. A new finite element approach to model microscale strain localization within olivine aggregates

Author

J. Furstoss, C. Petit, C. Ganino, M. Bernacki, and D. Pino-Muñoz

Subjects
Geology, QE1-996.5, Stratigraphy, QE640-699
Abstract

This paper presents a new mesoscopic full field approach for the modeling of microstructural evolutions and mechanical behavior of olivine aggregates. The mechanical framework is based on a reduced crystal plasticity (CP) formulation which is adapted to account for non-dislocation glide strain-accommodating mechanisms in olivine polycrystals. This mechanical description is coupled with a mixed velocity–pressure finite element (FE) formulation through a classical crystal plasticity finite element method (CPFEM) approach. The microstructural evolutions, such as grain boundary migration and dynamic recrystallization, are also computed within a FE framework using an implicit description of the polycrystal through the level-set approach. This numerical framework is used to study the strain localization, at the polycrystal scale, on different types of pre-existing shear zones for thermomechanical conditions relevant to laboratory experiments. We show that both fine-grained and crystallographic textured pre-existing bands favor strain localization at the sample scale. The combination of both processes has a large effect on strain localization, which emphasizes the importance of these two microstructural characteristics (texture and grain size) on the mechanical behavior of the aggregate. Table 1 summarizes the list of the acronyms used in the following.

Published
2021
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6. Extended embryo culture is effective for patients of an advanced maternal age

Author

R. Sainte-Rose, C. Petit, L. Dijols, C. Frapsauce, and F. Guerif

Subjects
Medicine, Science
Abstract

Abstract The aim of this study was to determine the effectiveness of extended embryo culture in advanced maternal age (AMA) patients (37–43 years). In this retrospective analysis, 21,301 normally fertilized zygotes from 4952 couples were cultured until the blastocyst stage. Blastocyst development, including kinetics and morphology, transfer rate, implantation and live birth rates, were measured. In AMA patients, the blastocyst rate was significantly decreased as compared to that in younger women. On day 5, blastocysts underwent growth retardation in AMA patients, which was highlighted by a decreased rate of full/expanded blastocysts. Organization of the cells (trophectoderm and inner cell mass) was unaffected by age. However, in AMA patients, a ‘good’ morphology blastocyst had a decreased probability to implant compared with an ‘average’ morphology blastocyst in younger women. While the rates of blastocyst transfer and useful blastocysts were similar to younger patients, in AMA patients, both implantation and live birth rates were significantly reduced. Our results support the idea that extended embryo culture is not harmful for AMA patients. However, embryo selection allowed by such culture is not powerful enough to avoid chromosomal abnormalities in the developed blastocysts and therefore cannot compensate for the effect of a woman’s age.

Published
2021
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7. Some properties of deformed $q$-numbers

Author

Lobão, Thierry C. Petit, Cardoso, Pedro G. S., Pinho, Suani T. R., and Borges, Ernesto P.

Subjects
Mathematical Physics, 16Wxx, 08A05
Abstract

Nonextensive statistical mechanics has been a source of investigation in mathematical structures such as deformed algebraic structures. In this work, we present some consequences of $q$-operations on the construction of $q$-numbers for all numerical sets. Based on such a construction, we present a new product that distributes over the $q$-sum. Finally, we present different patterns of $q$-Pascal's triangles, based on $q$-sum, whose elements are $q$-numbers., Comment: 8 pages, 1 eps figure

Published
2009

8. Denudation systematics inferred from in situ cosmogenic 10Be concentrations in fine (50–100 µm) and medium (100–250 µm) sediments of the Var River basin, southern French Alps

Author

A. Mariotti, P.-H. Blard, J. Charreau, C. Petit, S. Molliex, and the ASTER Team

Subjects
Dynamic and structural geology, QE500-639.5
Abstract

Marine sedimentary archives are well dated and often span several glacial cycles; cosmogenic 10Be concentrations in their detrital quartz grains could thus offer the opportunity to reconstruct a wealth of past denudation rates. However, these archives often comprise sediments much finer ( µm) than typically analyzed in 10Be studies, and few studies have measured 10Be concentrations in quartz grains smaller than 100 µm or assessed the impacts of mixing, grain size, and interannual variability on the 10Be concentrations of such fine-grained sediments. Here, we analyzed the in situ cosmogenic 10Be concentrations of quartz grains in the 50–100 and 100–250 µm size fractions of sediments from the Var basin (southern French Alps) to test the reliability of denudation rates derived from 10Be analyses of fine sands. The Var basin has a short transfer zone and highly variable morphology, climate, and geology, and we test the impact of these parameters on the observed 10Be concentrations. Both analyzed size fractions returned similar 10Be concentrations in downstream locations, notably at the Var's outlet, where concentrations ranged from (4.02±0.78)×104 to (4.40±0.64)×104 atoms g−1 of quartz. By comparing expected and observed 10Be concentrations at three major river junctions, we interpret that sediment mixing is efficient throughout the Var basin. We resampled four key locations 1 year later, and despite variable climatic parameters during that period, interannual 10Be concentrations were in agreement within uncertainties, except for one upper subbasin. The 10Be-derived denudation rates of Var subbasins range from 0.10±0.01 to 0.57±0.09 mm yr−1, and spatial variations are primarily controlled by the average subbasin slope. The integrated denudation rate of the entire Var basin is 0.24±0.04 mm yr−1, in agreement with other methods. Our results demonstrate that fine-grained sediments (50–250 µm) may return accurate denudation rates and are thus potentially suitable targets for future 10Be applications, such as studies of paleo-denudation rates using offshore sediments.

Published
2019
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9. Individual patient data network meta-analysis using either restricted mean survival time difference or hazard ratios: is there a difference? A case study on locoregionally advanced nasopharyngeal carcinomas

Author

C. Petit, P. Blanchard, JP. Pignon, and B. Lueza

Subjects
Hazard ratio, Survival analysis, Restricted mean survival time difference, Network meta-analysis, Nasopharyngeal carcinoma, Medicine
Abstract

Abstract Background This study aimed at applying the restricted mean survival time difference (rmstD) as an absolute outcome measure in a network meta-analysis and comparing the results with those obtained using hazard ratios (HR) from the individual patient data (IPD) network meta-analysis (NMA) on the role of chemotherapy for nasopharyngeal carcinoma (NPC) recently published by the MAC-NPC collaborative group (Meta-Analysis of Chemotherapy [CT] in NPC). Patients and methods Twenty trials (5144 patients) comparing radiotherapy (RT) with or without CT in non-metastatic NPC were included. Treatments were grouped in seven categories: RT alone (RT), induction CT followed by RT (IC-RT), RT followed by adjuvant CT (RT-AC), IC followed by RT followed by AC (IC-RT-AC), concomitant chemoradiotherapy (CRT), IC followed by CRT (IC-CRT), and CRT followed by AC (CRT-AC). The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival and locoregional control. The rmstD was estimated at t* = 10 years in each trial. Random-effect frequentist NMA models were applied. P score was used to rank treatments. Heterogeneity and inconsistency were evaluated. Results The three treatments that had the highest effect on OS with rmstD were CRT-AC, IC-CRT, and CRT (respective P scores of 92%, 72%, and 64%) compared to CRT-AC, CRT, and IC-CRT when using HR (respective P scores of 96%, 71%, and 63%). Of the 32 HR and rmstD analyzed, 5 had a different interpretation, 3 with a direction change (different direction of treatment effect) and 2 with a change in significance (same direction but a change in statistical significance). Results for secondary endpoints were overall in agreement. Conclusion The use of either HR or rmstD impacts the results of NMA. Given the sensitivity of HR to non-proportional hazards, this finding could have implications in terms of meta-analysis methodology.

Published
2019
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10. Design of an instrumented microwave multimode cavity for sintering of nuclear ceramics

Author

J. Croquesel, C. Meunier, C. Petit, F. Valdivieso, S. Pillon, A.C. Robisson, J. Martinez, and F. Lemont

Subjects
Microwave sintering, Nuclear fuel, Finite elements, Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract

This paper describes the development of an innovative instrumented and automated 2.45GHz multimode microwave cavity for sintering of uranium oxide based nuclear fuels (UO2, (U,Pu)O2, (U,Am)O2 …). The cavity and the sintering cell were designed using Finite Element simulation and the expertise acquired over years on microwave heating. This original setup allows for hybrid and homogeneous heating of nuclear fuels. Reliable in situ monitoring of the samples' shrinkage and temperature is performed with an optical dilatometer and infrared pyrometers calibrated with a specific protocol. A dedicated software including a Proportional-Integral-Derivative (PID) controller was developed to precisely control the sintering cycles like under conventional heating. The setup is also designed for operating in a glovebox under reducing sintering atmosphere.A stable and homogeneous heating with controlled sintering cycles is reached to successfully sinter UO2 crack free pellets to high density. This is a key point of innovation compared to previous studies in the literature on microwave sintering of nuclear ceramics. The pellets' final densities are equivalent to those obtained under conventional sintering, but with a significant decrease in the total duration of the sintering cycle.

Published
2021
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11. The network of concepts in written texts

Author

Caldeira, Silvia M. G., Lobao, Thierry C. Petit, Andrade, R. F. S., Neme, Alexis, and Miranda, J. G. V.

Subjects
Physics - Data Analysis, Statistics and Probability
Abstract

Complex network theory is used to investigate the structure of meaningful concepts in written texts of individual authors. Networks have been constructed after a two phase filtering, where words with less meaning contents are eliminated, and all remaining words are set to their canonical form, without any number, gender or time flexion. Each sentence in the text is added to the network as a clique. A large number of written texts have been scrutinized, and its found that texts have small-world as well as scale-free structures. The growth process of these networks has also been investigated, and a universal evolution of network quantifiers have been found among the set of texts written by distinct authors. Further analyzes, based on shufling procedures taken either on the texts or on the constructed networks, provide hints on the role played by the word frequency and sentence length distributions to the network structure. Since the meaningful words are related to concepts in the author's mind, results for text networks may uncover patterns in communication and language processes that occur in the mind.

Published
2005
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13. Magnetic particles with perpendicular anisotropy for mechanical cancer cell destruction

Author

Rhodri Mansell, Tarun Vemulkar, Dorothée C. M. C. Petit, Yu Cheng, Jason Murphy, Maciej S. Lesniak, and Russell P. Cowburn

Subjects
Medicine, Science
Abstract

Abstract We demonstrate the effectiveness of out-of-plane magnetized magnetic microdiscs for cancer treatment through mechanical cell disruption under an applied rotating magnetic field. The magnetic particles are synthetic antiferromagnets formed from a repeated motif of ultrathin CoFeB/Pt layers. In-vitro studies on glioma cells are used to compare the efficiency of the CoFeB/Pt microdiscs with Py vortex microdiscs. It is found that the CoFeB/Pt microdiscs are able to damage 62 ± 3% of cancer cells compared with 12 ± 2% after applying a 10 kOe rotating field for one minute. The torques applied by each type of particle are measured and are shown to match values predicted by a simple Stoner-Wohlfarth anisotropy model, giving maximum values of 20 fNm for the CoFeB/Pt and 75 fNm for the Py vortex particles. The symmetry of the anisotropy is argued to be more important than the magnitude of the torque in causing effective cell destruction in these experiments. This work shows how future magnetic particles can be successfully designed for applications requiring control of applied torques.

Published
2017
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14. Plasma Induced Damage on AlGaN/GaN Heterostructure During Gate Opening for Power Devices

Author

O. Fesiienko, C. Petit-Etienne, M. Darnon, A. Soltani, H. Maher, E. Pargon, Institut Interdisciplinaire d'Innovation Technologique [Sherbrooke] (3IT), Université de Sherbrooke (UdeS), Laboratoire Nanotechnologies et Nanosystèmes [Sherbrooke] (LN2), Université de Sherbrooke (UdeS)-École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire des technologies de la microélectronique (LTM ), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Plasma etching, [SPI]Engineering Sciences [physics], HEMT - High Electronic Mobility Transistor, III-V SEMICONDUCTORS, Plasma etching of III-V materials, Surfaces and Interfaces, Condensed Matter Physics, Surfaces, Coatings and Films
Abstract

During the fabrication of metal oxide semiconductor high electron mobility transistor based on AlGaN/GaN heterostructure, gate patterning is recognized as the most critical step that can lead to electrical degradation of the transistor. In this work, we performed the SiN cap layer plasma etching processes by two fluorine-based plasma processes (SF6/Ar and CHF3/CF4/Ar) with low (≈15 eV) and high (≈260 eV) ion energies. Moreover, we investigate the postetching treatment using a KOH solution in order to restore the quality of the AlGaN barrier surface after etching. The objective of this article is to evaluate the AlGaN barrier surface damage after the listed plasma etching processes and postetching strategies by using quasi- in situ angle-resolved x-ray photoelectron spectroscopy, transmission electron microscopy, and atomic force microscope. Accordingly, it is found that both high ion energy plasma processes lead to a significant stoichiometric change and modification of the AlGaN barrier layer into a 1.5 nm F-rich AlGaNFx subsurface reactive layer. The decrease in ionic energy leads to a decrease in the SiN etch rate and a significant improvement in the SiN/AlGaN etch selectivity (which becomes infinite) for both plasma chemistries. Moreover, the decrease in ion energy decreases the depth of the modification (about 0.5 nm) and reduces the stochiometric change of the AlGaN barrier layer. However, both low and high ion energy SF6/Ar plasma lead to 0.8 eV Fermi level shift toward the valence band. Furthermore, the KOH postetching treatment demonstrates complete and effective removal of the AlGaNFx subsurface reactive layer and restoration of the surface properties of the AlGaN layer. However, this removal leads to AlGaN recesses that are correlated to the thickness of the reactive layer formed during the etching.

Published
2023
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15. Comparison of complex networks and tree-based methods of phylogenetic analysis and proposal of a bootstrap method

Author

Aristóteles Góes-Neto, Marcelo V.C. Diniz, Daniel S. Carvalho, Gilberto C. Bomfim, Angelo A. Duarte, Jerzy A. Brzozowski, Thierry C. Petit Lobão, Suani T.R. Pinho, Charbel N. El-Hani, and Roberto F.S. Andrade

Subjects
Complex networks, Community detection, Phylogenetic methods, Statistical support, Basidiomycota, Chitin synthases, Medicine, Biology (General), QH301-705.5
Abstract

Complex networks have been successfully applied to the characterization and modeling of complex systems in several distinct areas of Biological Sciences. Nevertheless, their utilization in phylogenetic analysis still needs to be widely tested, using different molecular data sets and taxonomic groups, and, also, by comparing complex networks approach to current methods in phylogenetic analysis. In this work, we compare all the four main methods of phylogenetic analysis (distance, maximum parsimony, maximum likelihood, and Bayesian) with a complex networks method that has been used to provide a phylogenetic classification based on a large number of protein sequences as those related to the chitin metabolic pathway and ATP-synthase subunits. In order to perform a close comparison to these methods, we selected Basidiomycota fungi as the taxonomic group and used a high-quality, manually curated and characterized database of chitin synthase sequences. This enzymatic protein plays a key role in the synthesis of one of the exclusive features of the fungal cell wall: the presence of chitin. The communities (modules) detected by the complex network method corresponded exactly to the groups retrieved by the phylogenetic inference methods. Additionally, we propose a bootstrap method for the complex network approach. The statistical results we have obtained with this method were also close to those obtained using traditional bootstrap methods.

Published
2018
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18. Contributors

Author

G. Ares, S. Ballay, N. Bellissimo, D. Blumenthal, M. Cadoret, P. Courcoux, C. Dehlholm, Julien Delarue, L. Demonteil, P. Faye, C.J. Findlay, M.B. Frøst, G. Gazano, A. Gere, D. Giacalone, L.M. Hamilton, A. Harizi, J.E. Hayes, N. Herbeth, S.R. Jaeger, J. Lahne, J.B. Lawlor, E. Loescher, S. Lê, T.M. Lê, I. Maitre, H.L. Meiselman, H. Moskowitz, S. Nicklaus, C. Petit, N. Pineau, B. Piqueras-Fiszman, P.H. Punter, E.M. Qannari, K.K. Rasmussen, D. Roberts, M. Rogeaux, P. Schlich, H. Stone, C. Sulmont-Rossé, R. Symoneaux, E. Teillet, A. Thomas, D.M.H. Thomson, B. Veinand, T. Worch, and R. van Bommel

Published
2023
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19. Influence of the Cl$_2$ etching on the Al$_2$O$_3$ /GaN metal–oxide–semiconductor interface

Author

T. Meyer, S. Boubenia, C. Petit-Etienne, B. Salem, E. Pargon, Laboratoire des technologies de la microélectronique (LTM ), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
[SPI]Engineering Sciences [physics], Process Chemistry and Technology, Materials Chemistry, Electrical and Electronic Engineering, Instrumentation, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials
Abstract

Controlling the plasma etching step involved in metal-oxide-semiconductor high-electron-mobility-transistor (MOSHEMT) GaN fabrication is essential for device performance and reliability. In particular, understanding the impact of GaN etching conditions on dielectric/GaN interface chemical properties is critically important. In this work, we investigate the impact of the carrier wafers (Si, photoresist, SiO2, and Si3N4) used during the etching of GaN in chlorine plasma on the electrical behavior of Al2O3/n-GaN metal–oxide–semiconductor (MOS) capacitors. X-ray Photoelectron spectroscopy (XPS) analyses show that the Al2O3/GaN interface layer contains contaminants from the etching process after the Al2O3 deposition. Their chemical nature depends on the plasma chemistry used as well as the chemical nature of the carrier wafer. Typically, Cl and C are trapped at the interface for all substrates. In the particular case of Si carrier wafer, a significant amount of SiOx is present at the Al2O3/GaN interface. The capacitance–voltage (C–V) characteristics of the MOS capacitors indicate that the presence of Si residues at the interface shifts the flat band voltage to negative values, while the presence of Cl or C at the interface increases the hysteresis. We demonstrate that introducing an in situ plasma cleaning treatment based on N2/H2 gas, before the atomic layer deposition, allows the removal of most of the residues except silicon and suppresses the hysteresis.

Published
2022
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20. Post-conjunction detection of β Pictoris b with VLT/SPHERE

Author

A.-M. Lagrange, A. Boccaletti, M. Langlois, G. Chauvin, R. Gratton, H. Beust, S. Desidera, J. Milli, M. Bonnefoy, A. Cheetham, M. Feldt, M. Meyer, A. Vigan, B. Biller, M. Bonavita, J.-L. Baudino, F. Cantalloube, M. Cudel, S. Daemgen, P. Delorme, V. D’Orazi, J. Girard, C. Fontanive, J. Hagelberg, M. Janson, M. Keppler, T. Koypitova, R. Galicher, J. Lannier, H. Le Coroller, R. Ligi, A.-L. Maire, D. Mesa, S. Messina, A. Müeller, S. Peretti, C. Perrot, D. Rouan, G. Salter, M. Samland, T. Schmidt, E. Sissa, A. Zurlo, J.-L. Beuzit, D. Mouillet, C. Dominik, T. Henning, E. Lagadec, F. Ménard, H.-M. Schmid, M. Turatto, S. Udry, A. J. Bohn, B. Charnay, C. A. Gomez Gonzales, C. Gry, M. Kenworthy, Q. Kral, C. Mordasini, C. Moutou, G. van der Plas, J. E. Schlieder, L. Abe, J. Antichi, A. Baruffolo, P. Baudoz, J. Baudrand, P. Blanchard, A. Bazzon, T. Buey, M. Carbillet, M. Carle, J. Charton, E. Cascone, R. Claudi, A. Costille, A. Deboulbe, V. De Caprio, K. Dohlen, D. Fantinel, P. Feautrier, T. Fusco, P. Gigan, E. Giro, D. Gisler, L. Gluck, N. Hubin, E. Hugot, M. Jaquet, M. Kasper, F. Madec, Y. Magnard, P. Martinez, D. Maurel, D. Le Mignant, O. Möller-Nilsson, M. Llored, T. Moulin, A. Origné, A. Pavlov, D. Perret, C. Petit, J. Pragt, J. Szulagyi, and F. Wildi

Subjects
Astronomy, Astrophysics
Abstract

Context. With an orbital distance comparable to that of Saturn in the solar system, β Pictoris b is the closest (semi-major axis ≃9 au) exoplanet that has been imaged to orbit a star. Thus it offers unique opportunities for detailed studies of its orbital, physical, and atmospheric properties, and of disk-planet interactions. With the exception of the discovery observations in 2003 with NaCo at the Very Large Telescope (VLT), all following astrometric measurements relative to β Pictoris have been obtained in the southwestern part of the orbit, which severely limits the determination of the planet’s orbital parameters. Aims. We aimed at further constraining β Pictoris b orbital properties using more data, and, in particular, data taken in the northeastern part of the orbit. Methods. We used SPHERE at the VLT to precisely monitor the orbital motion of beta β Pictoris b since first light of the instrument in 2014. Results. We were able to monitor the planet until November 2016, when its angular separation became too small (125 mas, i.e., 1.6 au) and prevented further detection. We redetected β Pictoris b on the northeast side of the disk at a separation of 139 mas and a PA of 30° in September 2018. The planetary orbit is now well constrained. With a semi-major axis (sma) of a = 9.0 ± 0.5 au (1σ), it definitely excludes previously reported possible long orbital periods, and excludes β Pictoris b as the origin of photometric variations that took place in 1981. We also refine the eccentricity and inclination of the planet. From an instrumental point of view, these data demonstrate that it is possible to detect, if they exist, young massive Jupiters that orbit at less than 2 au from a star that is 20 pc away.

Published
2019
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21. Experimental assessment of various optical communication chains for high-capacity optical feeder links

Author

A. Maho, S. Levêque, A. Le Kernec, B. Benazet, A. Montmerle Bonnefois, J.-M. Conan, C.B. Lim, J. Montri, P. Perrault, C. Petit, B. Sorrente, L. Paillier, N. Védrenne, D. Matter, L. Pommarel, H. Lindberg, L. Francou, and M. Sotom

Abstract

Optical feeder links (OFL) are expected to become part of future Very High Throughput Satellite (VHTS) systems in response to the growing demand for higher capacity and lower costs. H2020 VERTIGO (Very High Throughput Satellite Ground Optical Link) project was set to prove key optical communication technologies and to address: 1) Throughput increase with high spectral and power efficiencies. 2) Higher optical power generation and delivery. 3) Atmospheric turbulence mitigation by optical and digital processing.

Published
2022
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22. FEELINGS, ONERA's optical ground terminal for AO pre-compensated GEO Feeder links demonstration

Author

A. Montmerle Bonnefois, C. Petit, J.-M. Conan, A. Durecu, F. Gustave, C. B. Lim, J. Montri, L. Paillier, P. Perrault, M.-T. Velluet, J.-B. Volatier, and N. Vedrenne

Subjects
optical ground station, GEO feeder links, adaptive optics
Abstract

These last years have seen a raising interest for ground to GEO satellites optical very high throughput links, i.e. GEO-feeder links, or GEO-FL. However, despite their potential, these applications have to overcome atmospheric turbulence, which requires the development of mitigation techniques, such as adaptive optics (AO). In the case of GEO-FL, AO performance is limited by the Point-Ahead Angle (PAA) induced anisoplanatism. We describe here how our feedback on our field experiments helped us to design ONERA’s AO-compensated ground station, FEELINGS, and the status of said ground station in the fall of 2022.

Published
2022
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25. A low accretion efficiency of planetesimals formed at planetary gap edges

Author

Linn E. J. Eriksson, Thomas Ronnet, Anders Johansen, Ravit Helled, Claudio Valletta, Antoine C. Petit, and University of Zurich

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), 1912 Space and Planetary Science, 530 Physics, Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, 10231 Institute for Computational Science, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, 3103 Astronomy and Astrophysics, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

Observations and models of giant planets indicate that such objects are enriched in heavy elements compared to solar abundances. The prevailing view is that giant planets accreted multiple Earth masses of heavy elements after the end of core formation. Such late solid enrichment is commonly explained by the accretion of planetesimals. Planetesimals are expected to form at the edges of planetary gaps, and here we address the question of whether these planetesimals can be accreted in large enough amounts to explain the inferred high heavy element contents of giant planets. We perform a series of N-body simulations of the dynamics of planetesimals and planets during the planetary growth phase, taking into account gas drag as well as the enhanced collision cross-section caused by the extended envelopes. We consider the growth of Jupiter and Saturn via gas accretion after reaching the pebble isolation mass and we include their migration in an evolving disk. We find that the accretion efficiency of planetesimals formed at planetary gap edges is very low: less than 10% of the formed planetesimals are accreted even in the most favorable cases, which in our model corresponds to a few Earth-masses. When planetesimals are assumed to form beyond the feeding zone of the planets, extending to a few Hill radii from a planet, accretion becomes negligible. Furthermore, we find that the accretion efficiency increases when the planetary migration distance is increased and that the efficiency does not increase when the planetesimal radii are decreased. Based on these results we conclude that it is difficult to explain the large heavy element content of giant planets with planetesimal accretion during the gas accretion phase. Alternative processes most likely are required, e.g. accretion of vapor deposited by drifting pebbles., Accepted for publication in A&A

Published
2022
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27. Controlling domain wall nucleation and injection through focussed ion beam irradiation in perpendicularly magnetized nanowires

Author

A. Beguivin, D. C. M. C. Petit, R. Mansell, and R. P. Cowburn

Subjects
Physics, QC1-999
Abstract

Using Ga+ focussed ion beam irradiation of Ta/Pt/CoFeB/Pt perpendicularly magnetized nanowires, the nucleation and injection fields of domain walls into the nanowires is controlled. The nucleation and injection fields can be varied as a function of dose, however, the range of injection fields is found to be limited by the creation of a step in anisotropy between the irradiated and unirradiated regions. This can be altered by defocussing the beam, which allows the injection fields to be further reduced. The ability to define an arbitrary dose profile allows domain walls to be injected at different fields either side of an asymmetrically irradiated area, which could form the initial stage of a logic device. The effect of the thickness of the magnetic layer and the thickness of a Ta underlayer on the dose required to remove the perpendicular anisotropy is also studied and is seen that for similar Ta underlayers the dose is determined by the thickness of the magnetic layer rather than its anisotropy. This finding is supported by some transport of ions in matter simulations.

Published
2017
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29. Signs of late infall and possible planet formation around DR Tau using VLT/SPHERE and LBTI/LMIRCam

Author

D. Mesa, C. Ginski, R. Gratton, S. Ertel, K. Wagner, M. Bonavita, D. Fedele, M. Meyer, T. Henning, M. Langlois, A. Garufi, S. Antoniucci, R. Claudi, D. Defrère, S. Desidera, M. Janson, N. Pawellek, E. Rigliaco, V. Squicciarini, A. Zurlo, A. Boccaletti, M. Bonnefoy, F. Cantalloube, G. Chauvin, M. Feldt, J. Hagelberg, E. Hugot, A.-M. Lagrange, C. Lazzoni, D. Maurel, C. Perrot, C. Petit, D. Rouan, A. Vigan, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Large Binocular Telescope Observatory [Tucson] (LBTO), Steward Observatory, University of Arizona, University of Edinburgh, Scottish Universities Physics Alliance (SUPA), INAF - Osservatorio Astrofisico di Arcetri (OAA), University of Michigan [Ann Arbor], University of Michigan System, Institute for Particle Physics and Astrophysics [ETH Zürich] (IPA), Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Roma (OAR), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Stockholm University, Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), University of Cambridge [UK] (CAM), Universidad Diego Portales [Santiago] (UDP), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Geneva Observatory, Université de Genève = University of Geneva (UNIGE), Universidad de Valparaiso [Chile], DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, This work has made use of the SPHERE Data Center, jointly operated by OSUG/IPAG (Grenoble), PYTHEAS/LAM/CeSAM (Marseille), OCA/Lagrange (Nice) and Observatoire de Paris/LESIA (Paris). This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work was supported by the PRIN-INAF 2019 Planetary Systems At Early Ages (PLATEA). This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. D.M., R.G., S.D., A.Z. acknowledge support from the 'Progetti Premiali' funding scheme of the Italian Ministry of Education, University, and Research. A.Z. acknowledges support from the CONICYT + PAI/Convocatoria nacional subvención a la instalación en la academia, convocatoria 2017 + Folio PAI77170087. A.M. acknowledges the support of the DFG priority program SPP 1992 'Exploring the Diversity of Extrasolar Planets' (MU 4172/1-1). C.P. acknowledges financial support from Fondecyt (grant 3 190 691) and financial support from the ICM (Iniciativa Científica Milenio) via the Núcleo Milenio de Formación Planetaria grant, from the Universidad de Valparaíso. T.H. acknowledges support from the European Research Council under the Horizon 2020 Framework Program via the ERC Advanced Grant Origins 83 24 28. SPHERE is an instrument designed and built by a consortium consisting of IPAG (Grenoble, France), MPIA (Heidelberg, Germany), LAM (Marseille, France), LESIA (Paris, France), Laboratoire Lagrange (Nice, France), INAF-Osservatorio di Padova (Italy), Observatoire de Genève (Switzerland), ETH Zurich (Switzerland), NOVA (Netherlands), ONERA (France) and ASTRON (Netherlands), in collaboration with ESO. SPHERE was funded by ESO, with additional contributions from CNRS (France), MPIA (Germany), INAF (Italy), FINES (Switzerland) and NOVA (Netherlands). SPHERE also received funding from the European Commission Sixth and Seventh Framework Programmes as part of the Optical Infrared Coordination Network for Astronomy (OPTICON) under grant number RII3-Ct-2004-001566 for FP6 (2004–2008), grant number 226604 for FP7 (2009–2012) and grant number 312430 for FP7 (2013–2016). The LBT is an international collaboration among institutions in the United States, Italy and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona Board of Regents, Istituto Nazionale di Astrofisica, Italy, LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, The Leibniz Institute for Astrophysics Potsdam, and Heidelberg University, The Ohio State University, representing OSU, University of Notre Dame, University of Minnesota and University of Virginia. The results reported herein benefited from collaborations and/or information exchange within NASA’s Nexus for Exoplanet System Science (NExSS) research coordination network sponsored by NASA’s Science Mission Directorate. K.W. acknowledges support from NASA through the NASA Hubble Fellowship grant HST-HF2-51472.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26 555., European Project: 832428, Department of Biochemistry and Molecular Biology, Mayo Clinic, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Laboratoire d'interaction du rayonnement X avec la matière (LIXAM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Computer Science::Digital Libraries, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Adaptive optics -instrumentation, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Imaging spectroscopy, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Physics::Space Physics, Data analysis - methods, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract

Context. Protoplanetary disks around young stars often contain substructures like rings, gaps, and spirals that could be caused by interactions between the disk and forming planets. Aims. We aim to study the young (1-3 Myr) star DR Tau in the near-infrared and characterize its disk, which was previously resolved through sub-millimeter interferometry with ALMA, and to search for possible sub-stellar companions embedded into it. Methods. We observed DR Tau with VLT/SPHERE both in polarized light (H broad band) and total intensity (in Y, J, H, and K spectral bands). We also performed L' band observations with LBTI/LMIRCam on the Large Binocular Telescope (LBT). Results. We found two previously undetected spirals extending north-east and south of the star, respectively. We further detected an arc-like structure north of the star. Finally a bright, compact and elongated structure was detected at separation of 303 +/- 10 mas and position angle 21.2 +/- 3.7 degrees, just at the root of the north-east spiral arm. Since this feature is visible both in polarized light and in total intensity and has a flat spectrum it is likely caused by stellar light scattered by dust. Conclusions. The two spiral arms are at different separation from the star, have very different pitch angles, and are separated by an apparent discontinuity, suggesting they might have a different origin. The very open southern spiral arm might be caused by infalling material from late encounters with cloudlets into the formation environment of the star itself. The compact feature could be caused by interaction with a planet in formation still embedded in its dust envelope and it could be responsible for launching the north-east spiral. We estimate a mass of the putative embedded object of the order of few M_Jup ., 13 pages, 11 Figures. Accepted for publications on A&A

Published
2022
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32. High Brightness programmable source of frequency-bin qubits

Author

M. Clementi, F. A. Sabattoli, H. El Dirani, N. Bergamasco, L. Gianini, L. Youssef, C. Petit-Etienne, E. Pargon, M. Liscidini, C. Sciancalepore, M. Galli, and D. Bajoni

Abstract

A high brightness silicon integrated source of entangled frequency-bins is presented. We experimentally demonstrate programmable emission of both computational basis states and Bell states.

Published
2022
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33. Mean motion resonance capture in the context of type-I migration

Author

Kaltrina Kajtazi, Antoine C. Petit, and Anders Johansen

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Space and Planetary Science, Celestial mechanics, FOS: Physical sciences, Astronomy and Astrophysics, dynamical evolution and stability [Planets and satellites], formation [Planets and satellites], Planet-disk interactions, Astrophysics - Earth and Planetary Astrophysics
Abstract

Capture into mean motion resonance (MMR) is an important dynamical mechanism as it shapes the final architecture of a planetary system. We simulate systems of two or three planets undergoing migration with varied initial parameters such as planetary mass and disk surface density and analyse the resulting resonant chains. In contrast to previous studies, our results show that the disk properties have the dominant impact on capture into mean motion resonance, while the total planetary mass barely affects the final system configuration as long as the planet does not open a gap in the disk. We confirm that the adiabatic resonant capture is the correct framework to understand the conditions leading to MMR formation, since its predictions are qualitatively similar to the numerical results. However, we find that the eccentricity damping can facilitate the capture in a given resonance. We find that under typical disk conditions, planets tend to be captured into 2:1 or 3:2 MMRs, which agrees well with the observed exoplanet MMRs. Our results predict two categories of systems: those that have uniform chains of wide resonances (2:1 or 3:2 MMRs) and those that have a more compact inner pair than the outer pair such as 4:3:2 chains. Both categories of resonant chains are present in observed exoplanet systems. On the other hand, chains with a wider inner pair than the outer one are very rare and emerge from stochastic capture. Our work here can be used to link current configuration of exoplanetary systems to the formation conditions within protoplanetary disks., Comment: Accepted in A&A

Published
2022
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34. Synthesis of Ni-doped ceria nanoparticles and their unusual surface reduction in hydrogen

Author

M. Barreau, D. Chen, J. Zhang, V. Papaefthimiou, C. Petit, D. Salusso, E. Borfecchia, S. Turczyniak-Surdacka, K. Sobczak, S. Mauri, L. Braglia, P. Torelli, S. Zafeiratos, Barreau, M, Chen, D, Zhang, J, Papaefthimiou, V, Petit, C, Salusso, D, Borfecchia, E, Turczyniak-Surdacka, S, Sobczak, K, Mauri, S, Braglia, L, Torelli, P, and Zafeiratos, S

Subjects
Biomaterials, NEXAFS, X-ray absorption spectroscopy, Operando analysis, In situ DRIFT, Square -planar symmetry, Colloid and Surface Chemistry, Polymers and Plastics, Operando analysi, Materials Chemistry, Catalysis, Electronic, Optical and Magnetic Materials
Abstract

This work presents an original approach to preparing pure and Ni-doped CeO2 nanoparticles (NPs) that can be directly drop-casted on a substrate or calcined to form powders. The reduction of the NPs in H-2 is very different than the one usually anticipated for supported Ni-CeO2 catalysts. In situ soft X-ray absorption and infrared spectroscopies revealed that the reduction of Ce4+ into Ce3+ in H-2 proceeds via simultaneous oxidation of Ni2+ ions into Ni delta+(2

Published
2022

35. A Reconfigurable Source of Entangled Frequency bins

Author

M. Clementi, F. A. Sabattoli, H. El Dirani, N. Bergamasco, L. Gianini, L. Youssef, C. Petit-Etienne, E. Pargon, M. Liscidini, C. Sciancalepore, M. Galli, and D. Bajoni

Abstract

We present a highly-efficient integrated reconfigurable source of entangled frequency bins. Leveraging the flexibility offered by the silicon photonics platform, we demonstrate the on-chip generation of all the main two-qubit quantum states.

Published
2022
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36. Generation of Photon Pairs in Linearly Uncoupled Resonators Employing a Reconfigurable Mach-Zehnder Interferometer

Author

L. Gianini, F. A. Sabattoli, H. El Dirani, L. Youssef, F. Garrisi, L. Zatti, C. Petit-Etienne, E. Pargon, M. Liscidini, C. Sciancalepore, D. Bajoni, and M. Galli

Abstract

We demonstrate spontaneous four-wave mixing in two linearly uncoupled resonators employing a Mach-Zehnder interferometer capable of wide band (>150 nm) operation and a fourfold improvement in the generation rate with respect to previous configurations.

Published
2022
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37. Structural transitions in jammed asymmetric bidisperse granular packings

Author

Juan C. Petit and Matthias Sperl

Subjects
Statistical Mechanics (cond-mat.stat-mech), granular packing, Mechanics of Materials, General Physics and Astronomy, Soft Condensed Matter (cond-mat.soft), FOS: Physical sciences, General Materials Science, Disordered Systems and Neural Networks (cond-mat.dis-nn), Condensed Matter - Soft Condensed Matter, Condensed Matter - Disordered Systems and Neural Networks, singularity, Condensed Matter - Statistical Mechanics
Abstract

We study the local structural changes along the jamming transitions in asymmetric bidisperse granu\-lar packings. The local structure of the packing is assessed by the contact orientational order, $\tilde{Q}_{\ell}$, that quantifies the contribution of each contact configuration (Large-Large, Small-Small, Large-Small, Small-Large) in the jammed structure. The partial values of $\tilde{Q}_{\ell}$ are calculated with respect to known ordered lattices that are fixed by the size ratio, $\delta$, of the particles. We find that the packing undergoes a structural transition at $\phi_J$, manifested by a sudden jump in the partial $\tilde{Q}_{\ell}$. Each contact configuration contributes to the jammed structure in a different way, changing with $\delta$ and concentration of small particles, $X_{\mathrm{S}}$. The results show not only that the packing undergoes a structural change upon jamming, but also that bidisperse packings exhibit local HCP and FCC structures also found in monodisperse packings. This suggests that the jammed structure of bidisperse systems is inherently endowed with local structural order. These results are relevant in understanding how the arrangement of particles determines the strength of bidisperse granular packings., Comment: 13 pages, 14 figures. Submitted to Granular Matter

Published
2022
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42. Macrolides et statines

Author

E. Jean-Bart, B. Falquet, E. Cartet, Jean-Baptiste Pace, C. Petit, M. Bourdelin, J. Coutet, B. Leroy, Emmanuelle Pont, H. Bontemps, F. Foltz, and C. Renzullo

Subjects
Pharmacology (medical)
Published
2020
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43. An algorithm for periodicity and almost periodicity of uniform substitution sequences and its implications on aperiodic spin models

Author

M.S.P. Muniz, Suani Tavares Rubim de Pinho, V.A.G.O. de Meneses, and T. C. Petit Lobão

Subjects
Pure mathematics, Character (mathematics), Hardware and Architecture, Homogeneous, Aperiodic graph, Substitution (logic), General Physics and Astronomy, SIMPLE algorithm, Spin-½, Mathematics
Abstract

Substitution sequences are sequences generated by successive applications of deterministic substitution rules on n letters that are, in general, neither regular nor disordered. We propose a simple algorithm for classifying uniform substitutions sequences concerning periodicity and/or almost periodicity, based only on the substitution rules, whose implementation was recently registered. That classification is based on two theorems – that are also proved – about almost periodicity (extended for non-uniform substitutions) and periodicity, respectively. It recognizes automatically the character of the sequences concerning the periodicity and almost periodicity: purely periodic, ultimately periodic, weakly non periodic, and strongly non-periodic. That recognization selects the non-periodic sequences; among them, it also selects automatically the ones that promote relevance of geometrical fluctuations on the critical behavior of spin models in relation to the homogeneous system .

Published
2019
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44. Substitutions in the Conserved C2C Domain of Otoferlin Cause DFNB9, a Form of Nonsyndromic Autosomal Recessive Deafness

Author

F. Mirghomizadeh, M. Pfister, F. Apaydin, C. Petit, S. Kupka, C.M. Pusch, H.P. Zenner, and N. Blin

Subjects
Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

DFNB, the nonsyndromic hearing loss with an autosomal recessive mode of inheritance constitutes the majority of severe to profound prelingual forms of hearing impairment, usually leading to inability of speech acquisition. We analyzed a consanguineous family with autosomal recessive deafness which has been shown to segregate within chromosomal region 2p23.1 (DFNB9; MIM 601071). By SSCP analysis and DNA sequencing of the 48 exons of the DFNB9 gene, coding for otoferlin, previously reported mutations in OTOF were excluded. Next to a frequent T > C single nucleotide polymorphism in exon 8, two novel mutations linked in exon 15 of the OTOF long splice form were identified comprising substitutions at positions 490 (Pro > Gln) and 515 (Ile > Thr), both located in the conserved Ca2+ binding C2C domain of this peptide. Comparisons of homology using human and mice otoferlins and closely related peptides and computer simulation analyses suggest that changes in the mutated segment's secondary structure affect the Ca2+ binding capacity of the C2C domain in otoferlin.

Published
2002
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45. Intérêt de la toxine botulinique A dans le traitement des troubles pelvi-périnéaux de la personne âgée

Author

C. Thuillier, P. Manceau, Pierre Marès, Gérard Amarenco, X. Gamé, C. Jeandel, B. Peyronnet, Claire Hentzen, G. Robain, Rebecca Haddad, Camille Chesnel, J. Kerdraon, Nicolas Turmel, A.-C. Petit, A. Charlanes, S. Campagne, Grégoire Capon, M. Mezzadri, Brigitte Fatton, Xavier Biardeau, X. Deffieux, and J M Soler

Subjects
Gynecology, 03 medical and health sciences, medicine.medical_specialty, 0302 clinical medicine, business.industry, Urology, 030232 urology & nephrology, Medicine, business, 3. Good health, Botulinum toxin a
Abstract

Resume Introduction Le present article constitue le rapport de la reunion de travail multi-disciplinaire organisee par le GRAPPPA (groupe de recherche appliquee a la pathologie pelvi-perineale des personnes âgees). L’objectif est de dresser une synthese de l’utilisation de la toxine botulinique A (TBA) dans la prise en charge des troubles pelvi-perineaux du sujet âge. Methodes Le present article a ete construit comme une revue comprehensive de la litterature, associant donnees issues de la litterature scientifique et avis d’experts. La revue systematique de la litterature a ete menee a partir de la base de donnees bibliographique MedLine (National Library of Medicine). Concernant les injections intra-detrusoriennes de TBA, seuls les articles rapportant des resultats specifiques chez les sujets âges (> 65 ans) etaient inclus. Concernant les autres localisations, compte-tenu du nombre restreint de donnees, tous les articles rapportant les resultats de la TBA etaient systematiquement inclus, quelle que soient la population etudiee. En cas de donnees manquantes ou insuffisantes, des avis d’expert etaient formules. Resultats Bien que les donnees issues de cette population specifique soient limitees, il semble que la TBA pourrait etre proposee chez le sujet âge sans critere de fragilite dans la prise en charge de l’HAV, avec taux de succes comparable aux patients jeunes a 3 mois (88,9 % vs 91,2 %), 6 mois (49,4 % vs 52,1 %) et 12 mois (23,1 % vs 22,3 %), et une diminution significative du nombre de mictions quotidiennes (11,4 vs 5,29 p Conclusion La TBA presente un interet dans la prise en charge de divers troubles pelvi-perineaux du sujet âge, et ses differentes applications devraient etre mieux evaluees au sein de cette population specifique tant en termes de securite que d’efficacite.

Published
2019
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47. Novel donors of nitric oxide derived of S-nitrosocysteine possessing antioxidant activities

Author

C. Petit, V. Bernardes-Genisson, P. Hoffmann, J.-P. Souchard, and S. Labidalle

Subjects
nitric oxide, S-nitrosothiols (thionitrites), antioxidant, peroxynitrite, Medicine (General), R5-920, Biology (General), QH301-705.5
Abstract

Novel S-nitrosothiols possessing a phenolic function were investigated as nitric oxide (NO) donors. A study of NO release from these derivatives was carried out by electron spin resonance (ESR). All compounds gave rise to a characteristic three-line ESR signal in the presence of the complex [Fe(II)(MGD)2], revealing the formation of the complex [Fe(II)(MGD)2(NO)]. Furthermore, tests based on cytochrome c reduction were performed in order to study the ability of each phenolic disulfide, the final organic decomposition product of S-nitrosothiols, to trap superoxide radical anion (O2-). This study revealed a high reactivity of 1b and 3b towards O2-. For these two compounds, the respective inhibitory concentration (IC) 50 values were 92 µM and 43 µM.

Published
1999
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50. High angular resolution polarimetric imaging of the nucleus of NGC 1068: Disentangling the polarising mechanisms

Author

Damien Gratadour, Yves Magnard, C. Petit, Frédéric Marin, Eric Lagadec, M. Montargès, Johannes Pragt, S. Hunziker, Lucas Grosset, M. Carle, Daniel Rouan, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), NASA Ames Research Center (ARC), Océan du Large et Variabilité Climatique (OLVAC), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay [Palaiseau], ONERA-Université Paris-Saclay, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Archéologies et Sciences de l'Antiquité (ArScAn), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Archéologies environnementales, and Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS)-Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Seyfert, Galaxies: individual: NGC 1068, Techniques: high angular resolution, Techniques: polarimetric, Methods: numerical, Methods: observational [Galaxies], DUST, Astrophysics, Dichroic glass, 01 natural sciences, UV POLARIZATION, galaxies, Radiative transfer, OUTFLOW, individual, 010303 astronomy & astrophysics, MOLECULAR TORUS, Physics, DISKS, Astrophysics::Instrumentation and Methods for Astrophysics, galaxies: Seyfert, Wavelength, NGC 1068, Physical Sciences, methods: observational, SPECTROPOLARIMETRY, high angular resolution, GRAINS, Active galactic nucleus, Astrophysics::High Energy Astrophysical Phenomena, MODELS, Polarimetry, FOS: Physical sciences, Context (language use), Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, Computer Science::Digital Libraries, methods, methods: numerical, numerical, galaxies: individual: NGC 1068, 0103 physical sciences, Angular resolution, observational, Astrophysics::Galaxy Astrophysics, Science & Technology, 010308 nuclear & particles physics, Scattering, techniques: high angular resolution, Astronomy and Astrophysics, ACTIVE GALACTIC NUCLEUS, Astrophysics - Astrophysics of Galaxies, Physics::History of Physics, techniques: polarimetric, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), techniques, polarimetric, EMISSION, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Context Polarisation is a decisive method to study the inner region of active galactic nuclei (AGNs) since, unlike classical imaging, it is not affected by contrast issues. When coupled with high angular resolution (HAR), polarisation can help to disentangle the location of the different polarising mechanisms and then give insight into the physics taking place in the core of AGNs. Aims We obtained a new data set of HAR polarimetric images of the archetypal Seyfert 2 nucleus of NGC 1068 observed with SPHERE/VLT. We aim in this paper to present the polarisation maps and to spatially separate the location of the polarising mechanisms, thereby deriving constraints on the organisation of the dust material in the inner region of this AGN. Methods With four new narrow-band images between the visible and the near-infrared combined with older broad-band observations, we studied the wavelength dependence of the polarisation properties from 0.7 to 2.2 μm of three selected regions within the inner 2″ surrounding the central engine. We then compared these measurements to radiative transfer simulations of scattering and dichroic absorption processes, using the Monte Carlo code MontAGN. Results We establish a detailed table of the relative importance of the polarising mechanism as a function of aperture and wavelength. We are able to separate the dominant polarising mechanisms in the three regions of the ionisation cone, the extended envelope of the torus, and the very central bright source of the AGN. Thus, we estimate the contribution of the different polarisation mechanisms to the observed polarisation flux in these regions. Dichroic absorption is estimated to be responsible for about 99% of the polarised flux coming from the photo-centre. However, this contribution would only be restricted to this location because the double-scattering process would be the most important contributor to polarisation in the equatorial plane of the AGN and single scattering is dominant in the polar outflow bi-cone. Conclusions Even though results are in good agreement with larger apertures measurements, the variety of situations with different mechanisms at play highlights the importance of spatial resolution for the interpretation of polarisation measurements. We also refine the estimation of the integrated optical depth in the visible of the obscuring structure to a range of 20−100, constraining the geometry of the inner region of this AGN., Astronomy & Astrophysics, 648, ISSN:0004-6361, ISSN:1432-0746

Published
2021
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