Improving the traits that underlie meat quality is a major challenge in the beef industry. The ob... more Improving the traits that underlie meat quality is a major challenge in the beef industry. The objective of this paper was to detect QTL linked to sensory meat quality traits in 3 French beef cattle breeds. We genotyped 1,059, 1,219, and 947 young bulls and their sires belonging to the Charolais, Limousin, and Blonde d'Aquitaine breeds, respectively, using the Illumina BovineSNP50 BeadChip (Illumina Inc., San Diego, CA). After estimating relevant genetic parameters using VCE software, we performed a linkage disequilibrium and linkage analysis on 4 meat traits: intramuscular fat content, muscle lightness, shear force, and tenderness score. Heritability coefficients largely ranged between 0.10 and 0.24; however, they reached a maximum of 0.44 and 0.50 for intramuscular fat content and tenderness score, respectively, in the Charolais breed. The 2 meat texture traits, shear force and tenderness score, were strongly genetically correlated (-0.91 in the Charolais and Limousin breed an...
We present new features of the self-ordered N/Cu(1 0 0) surface: this pre-patterned template offe... more We present new features of the self-ordered N/Cu(1 0 0) surface: this pre-patterned template offers the possibility of growing ordered square-based nanodots regular in sizes and spacings on the bare copper areas in-between the octagonal-shaped nitrogen domains at high N coverage. Furthermore, we applied another method of nitrogen adsorption on the copper (1 0 0) surface leading to a higher quality template, namely adsorption at a sample temperature of 630 K and the sample surface being not directly seen by the filament activating the nitrogen. As example, we deposited gold onto this pre-structured template N/Cu(1 0 0) surface resulting in a perfect arrangement of regular and ordered squarebased two atomic layers high gold nanodots. Ó
Hetero-epitaxial growth on a strain-relief vicinal patterned substrate has revealed unprecedented... more Hetero-epitaxial growth on a strain-relief vicinal patterned substrate has revealed unprecedented 2D long range ordered growth of uniform cobalt nanostructures. The morphology of a Co sub-monolayer deposit on a Au(111) reconstructed vicinal surface is analyzed by Variable Temperature Scanning Tunneling Microscopy (VT-STM) experiments. A rectangular array of nano-dots (3.8 nm x 7.2 nm) is found for a particularly large deposit temperature range lying from 60 K to 300 K. Although the nanodot lattice is stable at room temperature, this paper focus on the early stage of ordered nucleation and growth at temperatures between 35 K and 480 K. The atomistic mechanisms leading to the nanodots array are elucidated by comparing statistical analysis of VT-STM images with multi-scaled numerical calculations combining both Molecular Dynamics for the quantitative determination of the activation energies for the atomic motion and the Kinetic Monte Carlo method for the simulations of the mesoscopic time and scale evolution of the Co submonolayer.
CONCLUSION : Les erreurs de Pred EE-OW sont inférieures à 10 % par rapport aux références, ce qui... more CONCLUSION : Les erreurs de Pred EE-OW sont inférieures à 10 % par rapport aux références, ce qui est satisfaisant. L'application est adaptée et spécifique aux personnes en surcharge pondérale pour quantifier les activités de la vie quotidienne. Celle-ci est fonctionnelle et sera prochainement disponible pour les projets de recherche.
The objective of this study was to evaluate the validity of total energy expenditure (TEE) provid... more The objective of this study was to evaluate the validity of total energy expenditure (TEE) provided by Actiheart ® and Armband ® . Normal-weight adult volunteers wore both devices either for 17 hours in a calorimetric chamber (CC, n = 49) or for 10 days in free-living conditions (FLC) outside the laboratory (n = 41). The two devices and indirect calorimetry or doubly labelled water, respectively, were used to estimate TEE in the CC group and FLC group. In the CC, the relative value of TEE error was not significant (p > 0.05) for Actiheart ® but significantly different from zero for Armband ® , showing TEE underestimation (−4.9%, p < 0.0001). However, the mean absolute values of errors were significantly different between Actiheart ® and Armband ® : 8.6% and 6.7%, respectively (p = 0.05). Armband ® was more accurate for estimating TEE during sleeping, rest, recovery periods and sitting-standing. Actiheart ® provided better estimation during step and walking. In FLC, no significant error in relative value was detected. Nevertheless, Armband ® produced smaller errors in absolute value than Actiheart ® (8.6% vs. 12.8%). The distributions of differences were more scattered around the means, suggesting a higher inter-individual variability in TEE estimated by Actiheart ® than by Armband ® . Our results show that both monitors are appropriate for estimating TEE. Armband ® is more effective than Actiheart ® at the individual level for daily light-intensity activities.
Many potential applications of graphene require either the possibility of tuning its electronic s... more Many potential applications of graphene require either the possibility of tuning its electronic structure or the addition of reactive sites on its chemically inert basal plane. Among the various strategies proposed to reach these objectives, nitrogen doping, i.e., the incorporation of nitrogen atoms in the carbon lattice, leads in most cases to a globally n-doped material and to the presence of various types of point defects. In this context, the interactions between chemical dopants in graphene have important consequences on the electronic properties of the systems and cannot be neglected when interpreting spectroscopic data or setting up devices. In this report, the structural and electronic properties of complex doping sites in nitrogendoped graphene have been investigated by means of scanning tunneling microscopy and spectroscopy, supported by density functional theory and tight-binding calculations. In particular, based on combined experimental and simulation works, we have systematically studied the electronic fingerprints of complex doping configurations made of pairs of substitutional nitrogen atoms. Localized bonding states are observed between the Dirac point and the Fermi level in contrast with the unoccupied state associated with single substitutional N atoms. For pyridinic nitrogen sites (i.e., the combination of N atoms with vacancies), a resonant state is observed close to the Dirac energy. This insight into the modifications of electronic structure induced by nitrogen doping in graphene provides us with a fair understanding of complex doping configurations in graphene, as it appears in real samples.
ABSTRACT The present scanning tunneling microscopy study reports on the growth processes of Co va... more ABSTRACT The present scanning tunneling microscopy study reports on the growth processes of Co vapor-deposited on a dodecanethiol (DDT) self-assembled monolayer (SAM)/Au(111). We observe strongly modified surface and depth diffusions of Co adatoms depending on the growth temperature. Co deposited at 300 K shows an extremely incomplete regime of condensation on the organic layer. Besides, Co penetrates the DDT monolayer and resides at the DDT/Au(111) interface as 2D clusters. This phenomenon takes place through defects in the SAM which are transient channels. In contrast, Co deposited at 50 K shows a complete condensation and nucleates on defects of the SAM layer as 3D islands sitting most likely on top of the DDTs. These results are of interest in the growing field of organic spintronics where the quality of the organic/ferromagnetic interface is a key issue.
Nitrogen-doped epitaxial graphene grown on SiC(0001) was prepared by exposing the surface to an a... more Nitrogen-doped epitaxial graphene grown on SiC(0001) was prepared by exposing the surface to an atomic nitrogen flux. Using Scanning Tunneling Microscopy (STM) and Spectroscopy (STS), supported by Density Functional Theory (DFT) calculations, the simple substitution of carbon by nitrogen atoms has been identified as the most common doping configuration. High-resolution images reveal a reduction of local charge density on top of the nitrogen atoms, indicating a charge transfer to the neighboring carbon atoms. For the first time, local STS spectra clearly evidenced the energy levels associated with the chemical doping by nitrogen, localized in the conduction band. Various other nitrogen-related defects have been observed. The bias dependence of their topographic signatures demonstrates the presence of structural configurations more complex than substitution as well as hole-doping.
Using organic materials in spintronic devices raises a lot of expectation for future applications... more Using organic materials in spintronic devices raises a lot of expectation for future applications due to their flexibility, low cost, long spin lifetime, and easy functionalization. However, the interfacial hybridization and spin polarization between the organic layer and the ferromagnetic electrodes still has to be understood at the molecular scale. Coupling state-of-the-art spinpolarized scanning tunneling spectroscopy and spin-resolved ab initio calculations, we give the first experimental evidence of the spin splitting of a molecular orbital on a single non magnetic C 60 molecule in contact with a magnetic material, namely, the Cr(001) surface. This hybridized molecular state is responsible for an inversion of sign of the tunneling magnetoresistance depending on energy. This result opens the way to spin filtering through molecular orbitals.
We study the growth of submonolayer coverage of cobalt on the Au(788) vicinal surface. Due to a l... more We study the growth of submonolayer coverage of cobalt on the Au(788) vicinal surface. Due to a large unit cell reconstruction, this surface is spontaneously patterned in two dimensions at a nanometer scale. We show that the cobalt growth on this substrate displays a long-range ordered nanodots array in a wide temperature range. The atomic processes responsible for such an organized growth are discussed using STM images with atomic resolution and chemical contrast. # (S. Rousset).
Self-ordering on crystal surfaces has been the subject of intense efforts during the last ten yea... more Self-ordering on crystal surfaces has been the subject of intense efforts during the last ten years. It has been recognized as a promising way for growing uniform nanostructures with regular sizes and spacings. Continuum models have been proposed where long-range elastic repulsive interactions are responsible for the periodic domain spontaneous formation. Vicinal surfaces unstable towards faceting lead to a one dimensional (1D) periodic morphology. Au(111) vicinals self-ordering provides a unique opportunity to point out the interplay between atomic and mesoscopic order. 2D ordering has been investigated in the complex case of atomic nitrogen adsorbed on Cu(100). Using scanning tunneling microscopy (STM) at elevated temperature, we have followed the ordered arrays of N square-shaped domains spontaneous formation. Observations are discussed in the light of previous continuum models for self-ordering. The question of understanding self-ordering is not only of fundamental but also of technological interest since it is a fruitful way of growing regularly spaced nanostructures in the 1 Á/100 nm range. This will be illustrated by two examples: (i) selfordered substrates can serve as templates for growing 2D square lattice of regular nanostructures; (ii) magnetic domains of an ultrathin film can be tailored by using self-ordered substrates. #
Self-ordering at crystal surfaces has been the subject of intense efforts during the last ten yea... more Self-ordering at crystal surfaces has been the subject of intense efforts during the last ten years, since it has been recognized as a promising way for growing uniform nanostructures with regular sizes and spacings in the 1-100 nm range. In this article we give an overview of the self-organized nanostructures growth on spontaneously nano-patterned templates. A great variety of surfaces exhibits a nano-scale order at thermal equilibrium, including adsorbate-induced reconstruction, surface dislocations networks, vicinal surfaces or more complex systems. Continuum models have been proposed where long-range elastic interactions are responsible for spontaneous periodic domain formation. Today the comparison between experiments such as Grazing Incidence X-Ray Diffraction experiments and calculations has lead to a great improvement of our fundamental understanding of the physics of self-ordering at crystal surfaces. Then, epitaxial growth on self-ordered surfaces leads to nanostructures organized growth. The present knowledge of modelization of such an heterogeneous growth using multi-scaled calculations is discussed. Such a high quality of both long-range and local ordered growth opens up the possibility of making measurements of physical properties of such nanostructures by macroscopic integration techniques. To cite this article: S. Rousset et al., C. R. Physique 6 (2005). 2004 Académie des sciences. Published by Elsevier SAS. All rights reserved.
The surface topography of a kinked vicinal surface of Au(111) is characterized by in situ grazing... more The surface topography of a kinked vicinal surface of Au(111) is characterized by in situ grazing incidence small-angle x-ray scattering and scanning tunneling microscopy. The step edges exhibit a long range ordering of kinks which is attributed to the repulsive interaction between the ...
Improving the traits that underlie meat quality is a major challenge in the beef industry. The ob... more Improving the traits that underlie meat quality is a major challenge in the beef industry. The objective of this paper was to detect QTL linked to sensory meat quality traits in 3 French beef cattle breeds. We genotyped 1,059, 1,219, and 947 young bulls and their sires belonging to the Charolais, Limousin, and Blonde d'Aquitaine breeds, respectively, using the Illumina BovineSNP50 BeadChip (Illumina Inc., San Diego, CA). After estimating relevant genetic parameters using VCE software, we performed a linkage disequilibrium and linkage analysis on 4 meat traits: intramuscular fat content, muscle lightness, shear force, and tenderness score. Heritability coefficients largely ranged between 0.10 and 0.24; however, they reached a maximum of 0.44 and 0.50 for intramuscular fat content and tenderness score, respectively, in the Charolais breed. The 2 meat texture traits, shear force and tenderness score, were strongly genetically correlated (-0.91 in the Charolais and Limousin breed an...
We present new features of the self-ordered N/Cu(1 0 0) surface: this pre-patterned template offe... more We present new features of the self-ordered N/Cu(1 0 0) surface: this pre-patterned template offers the possibility of growing ordered square-based nanodots regular in sizes and spacings on the bare copper areas in-between the octagonal-shaped nitrogen domains at high N coverage. Furthermore, we applied another method of nitrogen adsorption on the copper (1 0 0) surface leading to a higher quality template, namely adsorption at a sample temperature of 630 K and the sample surface being not directly seen by the filament activating the nitrogen. As example, we deposited gold onto this pre-structured template N/Cu(1 0 0) surface resulting in a perfect arrangement of regular and ordered squarebased two atomic layers high gold nanodots. Ó
Hetero-epitaxial growth on a strain-relief vicinal patterned substrate has revealed unprecedented... more Hetero-epitaxial growth on a strain-relief vicinal patterned substrate has revealed unprecedented 2D long range ordered growth of uniform cobalt nanostructures. The morphology of a Co sub-monolayer deposit on a Au(111) reconstructed vicinal surface is analyzed by Variable Temperature Scanning Tunneling Microscopy (VT-STM) experiments. A rectangular array of nano-dots (3.8 nm x 7.2 nm) is found for a particularly large deposit temperature range lying from 60 K to 300 K. Although the nanodot lattice is stable at room temperature, this paper focus on the early stage of ordered nucleation and growth at temperatures between 35 K and 480 K. The atomistic mechanisms leading to the nanodots array are elucidated by comparing statistical analysis of VT-STM images with multi-scaled numerical calculations combining both Molecular Dynamics for the quantitative determination of the activation energies for the atomic motion and the Kinetic Monte Carlo method for the simulations of the mesoscopic time and scale evolution of the Co submonolayer.
CONCLUSION : Les erreurs de Pred EE-OW sont inférieures à 10 % par rapport aux références, ce qui... more CONCLUSION : Les erreurs de Pred EE-OW sont inférieures à 10 % par rapport aux références, ce qui est satisfaisant. L'application est adaptée et spécifique aux personnes en surcharge pondérale pour quantifier les activités de la vie quotidienne. Celle-ci est fonctionnelle et sera prochainement disponible pour les projets de recherche.
The objective of this study was to evaluate the validity of total energy expenditure (TEE) provid... more The objective of this study was to evaluate the validity of total energy expenditure (TEE) provided by Actiheart ® and Armband ® . Normal-weight adult volunteers wore both devices either for 17 hours in a calorimetric chamber (CC, n = 49) or for 10 days in free-living conditions (FLC) outside the laboratory (n = 41). The two devices and indirect calorimetry or doubly labelled water, respectively, were used to estimate TEE in the CC group and FLC group. In the CC, the relative value of TEE error was not significant (p > 0.05) for Actiheart ® but significantly different from zero for Armband ® , showing TEE underestimation (−4.9%, p < 0.0001). However, the mean absolute values of errors were significantly different between Actiheart ® and Armband ® : 8.6% and 6.7%, respectively (p = 0.05). Armband ® was more accurate for estimating TEE during sleeping, rest, recovery periods and sitting-standing. Actiheart ® provided better estimation during step and walking. In FLC, no significant error in relative value was detected. Nevertheless, Armband ® produced smaller errors in absolute value than Actiheart ® (8.6% vs. 12.8%). The distributions of differences were more scattered around the means, suggesting a higher inter-individual variability in TEE estimated by Actiheart ® than by Armband ® . Our results show that both monitors are appropriate for estimating TEE. Armband ® is more effective than Actiheart ® at the individual level for daily light-intensity activities.
Many potential applications of graphene require either the possibility of tuning its electronic s... more Many potential applications of graphene require either the possibility of tuning its electronic structure or the addition of reactive sites on its chemically inert basal plane. Among the various strategies proposed to reach these objectives, nitrogen doping, i.e., the incorporation of nitrogen atoms in the carbon lattice, leads in most cases to a globally n-doped material and to the presence of various types of point defects. In this context, the interactions between chemical dopants in graphene have important consequences on the electronic properties of the systems and cannot be neglected when interpreting spectroscopic data or setting up devices. In this report, the structural and electronic properties of complex doping sites in nitrogendoped graphene have been investigated by means of scanning tunneling microscopy and spectroscopy, supported by density functional theory and tight-binding calculations. In particular, based on combined experimental and simulation works, we have systematically studied the electronic fingerprints of complex doping configurations made of pairs of substitutional nitrogen atoms. Localized bonding states are observed between the Dirac point and the Fermi level in contrast with the unoccupied state associated with single substitutional N atoms. For pyridinic nitrogen sites (i.e., the combination of N atoms with vacancies), a resonant state is observed close to the Dirac energy. This insight into the modifications of electronic structure induced by nitrogen doping in graphene provides us with a fair understanding of complex doping configurations in graphene, as it appears in real samples.
ABSTRACT The present scanning tunneling microscopy study reports on the growth processes of Co va... more ABSTRACT The present scanning tunneling microscopy study reports on the growth processes of Co vapor-deposited on a dodecanethiol (DDT) self-assembled monolayer (SAM)/Au(111). We observe strongly modified surface and depth diffusions of Co adatoms depending on the growth temperature. Co deposited at 300 K shows an extremely incomplete regime of condensation on the organic layer. Besides, Co penetrates the DDT monolayer and resides at the DDT/Au(111) interface as 2D clusters. This phenomenon takes place through defects in the SAM which are transient channels. In contrast, Co deposited at 50 K shows a complete condensation and nucleates on defects of the SAM layer as 3D islands sitting most likely on top of the DDTs. These results are of interest in the growing field of organic spintronics where the quality of the organic/ferromagnetic interface is a key issue.
Nitrogen-doped epitaxial graphene grown on SiC(0001) was prepared by exposing the surface to an a... more Nitrogen-doped epitaxial graphene grown on SiC(0001) was prepared by exposing the surface to an atomic nitrogen flux. Using Scanning Tunneling Microscopy (STM) and Spectroscopy (STS), supported by Density Functional Theory (DFT) calculations, the simple substitution of carbon by nitrogen atoms has been identified as the most common doping configuration. High-resolution images reveal a reduction of local charge density on top of the nitrogen atoms, indicating a charge transfer to the neighboring carbon atoms. For the first time, local STS spectra clearly evidenced the energy levels associated with the chemical doping by nitrogen, localized in the conduction band. Various other nitrogen-related defects have been observed. The bias dependence of their topographic signatures demonstrates the presence of structural configurations more complex than substitution as well as hole-doping.
Using organic materials in spintronic devices raises a lot of expectation for future applications... more Using organic materials in spintronic devices raises a lot of expectation for future applications due to their flexibility, low cost, long spin lifetime, and easy functionalization. However, the interfacial hybridization and spin polarization between the organic layer and the ferromagnetic electrodes still has to be understood at the molecular scale. Coupling state-of-the-art spinpolarized scanning tunneling spectroscopy and spin-resolved ab initio calculations, we give the first experimental evidence of the spin splitting of a molecular orbital on a single non magnetic C 60 molecule in contact with a magnetic material, namely, the Cr(001) surface. This hybridized molecular state is responsible for an inversion of sign of the tunneling magnetoresistance depending on energy. This result opens the way to spin filtering through molecular orbitals.
We study the growth of submonolayer coverage of cobalt on the Au(788) vicinal surface. Due to a l... more We study the growth of submonolayer coverage of cobalt on the Au(788) vicinal surface. Due to a large unit cell reconstruction, this surface is spontaneously patterned in two dimensions at a nanometer scale. We show that the cobalt growth on this substrate displays a long-range ordered nanodots array in a wide temperature range. The atomic processes responsible for such an organized growth are discussed using STM images with atomic resolution and chemical contrast. # (S. Rousset).
Self-ordering on crystal surfaces has been the subject of intense efforts during the last ten yea... more Self-ordering on crystal surfaces has been the subject of intense efforts during the last ten years. It has been recognized as a promising way for growing uniform nanostructures with regular sizes and spacings. Continuum models have been proposed where long-range elastic repulsive interactions are responsible for the periodic domain spontaneous formation. Vicinal surfaces unstable towards faceting lead to a one dimensional (1D) periodic morphology. Au(111) vicinals self-ordering provides a unique opportunity to point out the interplay between atomic and mesoscopic order. 2D ordering has been investigated in the complex case of atomic nitrogen adsorbed on Cu(100). Using scanning tunneling microscopy (STM) at elevated temperature, we have followed the ordered arrays of N square-shaped domains spontaneous formation. Observations are discussed in the light of previous continuum models for self-ordering. The question of understanding self-ordering is not only of fundamental but also of technological interest since it is a fruitful way of growing regularly spaced nanostructures in the 1 Á/100 nm range. This will be illustrated by two examples: (i) selfordered substrates can serve as templates for growing 2D square lattice of regular nanostructures; (ii) magnetic domains of an ultrathin film can be tailored by using self-ordered substrates. #
Self-ordering at crystal surfaces has been the subject of intense efforts during the last ten yea... more Self-ordering at crystal surfaces has been the subject of intense efforts during the last ten years, since it has been recognized as a promising way for growing uniform nanostructures with regular sizes and spacings in the 1-100 nm range. In this article we give an overview of the self-organized nanostructures growth on spontaneously nano-patterned templates. A great variety of surfaces exhibits a nano-scale order at thermal equilibrium, including adsorbate-induced reconstruction, surface dislocations networks, vicinal surfaces or more complex systems. Continuum models have been proposed where long-range elastic interactions are responsible for spontaneous periodic domain formation. Today the comparison between experiments such as Grazing Incidence X-Ray Diffraction experiments and calculations has lead to a great improvement of our fundamental understanding of the physics of self-ordering at crystal surfaces. Then, epitaxial growth on self-ordered surfaces leads to nanostructures organized growth. The present knowledge of modelization of such an heterogeneous growth using multi-scaled calculations is discussed. Such a high quality of both long-range and local ordered growth opens up the possibility of making measurements of physical properties of such nanostructures by macroscopic integration techniques. To cite this article: S. Rousset et al., C. R. Physique 6 (2005). 2004 Académie des sciences. Published by Elsevier SAS. All rights reserved.
The surface topography of a kinked vicinal surface of Au(111) is characterized by in situ grazing... more The surface topography of a kinked vicinal surface of Au(111) is characterized by in situ grazing incidence small-angle x-ray scattering and scanning tunneling microscopy. The step edges exhibit a long range ordering of kinks which is attributed to the repulsive interaction between the ...
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Papers by Sylvie Rousset