University Cote Dazur

La Côte-Saint-André, France

University Cote Dazur

La Côte-Saint-André, France
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Szczepanski C.R.,University Cote dAzur | Guittard F.,University Cote dAzur | Darmanin T.,University Cote dAzur
Advances in Colloid and Interface Science | Year: 2017

Parahydrophobic surfaces are an interesting class of materials that combines both high contact angles and very strong adhesion with wetting fluids, most commonly water. This unique set of properties makes parahydrophobic surfaces attractive for a variety of applications, including water harvesting and collection, guided fluid transport, and membrane development, amongst many others. Taking inspiration from natural surfaces that display this same behavior such as rose petals and gecko feet, synthetic approaches aim to incorporate the nano- and micro-scale topography as well as the low surface energy chemistry found on these interfaces. Here, we discuss the chemical and physical factors that contribute to parahydrophobic behavior and provide a comprehensive overview on the current technologies and procedures used towards constructing surfaces that mimic this behavior already observed in nature. This includes etching processes, colloidal assemblies, deposition methods, and in situ growth of surface features. Furthermore, issues such as ease of scale-up, efficiency of technical procedures, and other current challenges associated with these methods will be discussed to provide insight as to the future directions for this growing area of research. © 2017 Elsevier B.V.


Fournier M.,University Cote dAzur | d'Arripe- Longueville F.,University Cote dAzur | Radel R.,University Cote dAzur
Psychoneuroendocrinology | Year: 2017

Instrumental learning occurs through both goal-directed and habit memory systems, which are supported by anatomically distinct brain systems. Interestingly, stress may promote habits at the expense of goal-directed performance, since stress before training in an instrumental task was found to cause individuals to carry on with the learned association in spite of a devalued outcome. These findings nevertheless left pending questions, and it has been difficult to determine which system is primarily affected by stress (an improved habit system, an impaired goal-directed system, or both) and at what point the stress acts (at the moment of learning by making more resistant habits, or after devaluation by making individuals less sensitive to change in the outcome value). The present study (N = 72 participants, 63 males and 9 females) aimed to answer these questions with (i) an instrumental task that dissociates the two memory systems and (ii) three conditions of psychosocial stress exposure (Trier Social Stress Test): stress induced before learning, before devaluation, and not induced for the control group. The study confirms that exposure to psychosocial stress leads to habitual performance. Moreover, it provides new insight into this effect by locating its origin as an impairment in the capacity of the goal-directed system rather than a reinforcement in habit learning. These results are discussed in light of recent neurobiological models of stress and memory. © 2016 Elsevier Ltd


Aristidi E.,University Cote dAzur
EAS Publications Series | Year: 2016

This paper gives an introduction to the theory of orthogonal projection of functions or signals. Several kinds of decomposition are explored: Fourier, Fourier-Legendre, Fourier-Bessel series for 1D signals, and Spherical Harmonic series for 2D signals. We show how physical conditions and/or geometry can guide the choice of the base of functions for the decomposition. The paper is illustrated with several numerical examples. © EAS, EDP Sciences, 2016.


Perbal B.,University Cote Dazur
Journal of Cell Communication and Signaling | Year: 2016

In a recent manuscript, Goff and collaborators (Metzger et al. 2016) reported data arguing for the spread of contagious cancer cells among different species of shellfish. Although horizontal transmission of cancer cells has been observed in a few cases in higher organisms, it appears to be rather frequent among molluscs. Recent evidence supports the concept of inter-species horizontal infectious transmission of cancer cells both in molluscs but also in mammals, including humans. © 2016 The International CCN Society


Ogihara M.,University Cote dAzur | Morbidelli A.,University Cote dAzur | Guillot T.,University Cote dAzur
Astronomy and Astrophysics | Year: 2015

Context. Planets less massive than Saturn tend to rapidly migrate inward in protoplanetary disks. This is the so-called type I migration. Simulations attempting to reproduce the observed properties of exoplanets show that type I migration needs to be significantly reduced over a wide region of the disk for a long time. However, the mechanism capable of suppressing type I migration over a wide region has remained elusive. The recently found turbulence-driven disk winds offer new possibilities. Aims. We investigate the effects of disk winds on the disk profile and type I migration for a range of parameters that describe the strength of disk winds. We also examine the in situ formation of close-in super-Earths in disks that evolve through disk winds. Methods. The disk profile, which is regulated by viscous diffusion and disk winds, was derived by solving the diffusion equation. We carried out a number of simulations and plot here migration maps that indicate the type I migration rate. We also performed N-body simulations of the formation of close-in super-Earths from a population of planetesimals and planetary embryos. Results. We define a key parameter, Kw, which determines the ratio of strengths between the viscous diffusion and disk winds. For a wide range of Kw, the type I migration rate is presented in migration maps. These maps show that type I migration is suppressed over the whole close-in region when the effects of disk winds are relatively strong (Kw â‰2 100). From the results of N-body simulations, we see that type I migration is significantly slowed down assuming Kw = 40. We also show that the results of N-body simulations match statistical orbital distributions of close-in super-Earths. © ESO, 2015.


Martinez P.,University Cote dAzur | Janin-Potiron P.,University Cote dAzur
Astronomy and Astrophysics | Year: 2016

Context. Segmented primary mirrors are indispensable to master the steady increase in spatial resolution. Phasing optics systems must reduce segment misalignments to guarantee the high optical quality required for astronomical science programs. Aims. Modern telescopes routinely use adaptive optics systems to compensate for the atmosphere and use laser-guide-stars to create artificial stars as bright references in the field of observation. Because multiple laser-guide-star adaptive optics are being implemented in all major observatories, we propose to use man-made stars not only for adaptive optics, but for phasing optics. Methods. We propose a method called the doublet-wavelength coherence technique (DWCT), exploiting the D lines of sodium in the mesosphere using laser guide-stars. The signal coherence properties are then used. Results. The DWCT capture range exceeds current abilities by a factor of 100. It represents a change in paradigm by improving the phasing optics capture range from micrometric to millimetric. It thereby potentially eliminates the need of a man-made mechanical pre-phasing step. Conclusions. Extremely large telescopes require hundreds of segments, several of which need to be substituted on a daily basis to be recoated. The DWCT relaxes mechanical integration requirements and speeds up integration and re-integration process. © ESO, 2016.


Millour F.,University Cote dAzur | Lagadec E.,University Cote dAzur
EAS Publications Series | Year: 2015

Olivier Chesneau founded a brand new field of observational astrophysics with his attempts to resolve the novae expanding fireball from the very first days of the explosion. With the images he could get, he showed that novae do indeed explode in an aspherical way, leading to a change of paradigm for the physics of these yet-poorly understood catastrophic systems. He also set the stage for a new way of estimating novae distances, by directly measuring the sky-size of the fireball and comparing it with spectroscopic scales, taking into account the tremendous effects of the fireball geometry. © 2015 EAS, EDP Sciences.


Millour F.,University Cote dAzur
EAS Publications Series | Year: 2015

Olivier Chesneau challenged several fields of observational stellar astrophysics with bright ideas and an impressive amount of work to make them real in the span of his career, from his first paper on P Cygni in 2000, up to his last one on V838 Mon in 2014. He was using all the so-called high-angular resolution techniques since it helped his science to be made, namely study in details the inner structure of the environments around stars, be it small mass (AGBs), more massive (supergiant stars), or explosives (Novae). I will focus here on his work on massive stars. © 2015 EAS, EDP Sciences.


PubMed | University of Nice Sophia Antipolis, Aix - Marseille University, French National Center for Scientific Research, EDHEC Business School and University Cote dAzur
Type: | Journal: International journal of legal medicine | Year: 2017

This experimental study examined the lesions produced by a hatchet on human bones (tibiae). A total of 30 lesions were produced and examined macroscopically (naked eye) and by stereomicroscopy. 13 of them were also analyzed using scanning electron microscopy. The general shape of the lesion, both edges, both walls, the kerf floor and the extremities were described. The length and maximum width of the lesions were also recorded. The microscopic analysis of the lesions led to the description of a sharp-blunt mechanism. Specific criteria were identified (lateral pushing back, fragmentation of the upraising, fossa dug laterally to the edge and vertical striae) enabling the forensic expert to conclude that a hacking instrument was used. These criteria are easily identifiable using scanning electron microscopy, but can also be observed with stereomicroscopy. Overall, lateral pushing back and vertical striae visible using stereomicroscopy and scanning electron microscopy signal the use of a hacking tool.


PubMed | University Cote dAzur
Type: | Journal: Psychoneuroendocrinology | Year: 2017

Instrumental learning occurs through both goal-directed and habit memory systems, which are supported by anatomically distinct brain systems. Interestingly, stress may promote habits at the expense of goal-directed performance, since stress before training in an instrumental task was found to cause individuals to carry on with the learned association in spite of a devalued outcome. These findings nevertheless left pending questions, and it has been difficult to determine which system is primarily affected by stress (an improved habit system, an impaired goal-directed system, or both) and at what point the stress acts (at the moment of learning by making more resistant habits, or after devaluation by making individuals less sensitive to change in the outcome value). The present study (N=72 participants, 63 males and 9 females) aimed to answer these questions with (i) an instrumental task that dissociates the two memory systems and (ii) three conditions of psychosocial stress exposure (Trier Social Stress Test): stress induced before learning, before devaluation, and not induced for the control group. The study confirms that exposure to psychosocial stress leads to habitual performance. Moreover, it provides new insight into this effect by locating its origin as an impairment in the capacity of the goal-directed system rather than a reinforcement in habit learning. These results are discussed in light of recent neurobiological models of stress and memory.

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