The SOPHIE search for northern extrasolar planets XIV. A temperate (Teq ~ 300 K) super-earth around the nearby star Gliese 411

Periodic radial velocity variations in the nearby M-dwarf star Gl 411 are reported, based on measurements with the SOPHIE spectrograph. Current data do not allow us to distinguish between a 12.95-day period and its one-day alias at 1.08 days, but favour the former slightly. The velocity variation has an amplitude of 1.6 m s−1, making this the lowest-amplitude signal detected with SOPHIE up to now. We have performed a detailed analysis of the significance of the signal and its origin, including extensive simulations with both uncorrelated and correlated noise, representing the signal induced by stellar activity. The signal is significantly detected, and the results from all tests point to its planetary origin. Additionally, the presence of an additional acceleration in the velocity time series is suggested by the current data. On the other hand, a previously reported signal with a period of 9.9 days, detected in HIRES velocities of this star, is not recovered in the SOPHIE data. An independent analysis of the HIRES dataset also fails to unveil the 9.9-day signal. If the 12.95-day period is the real one, the amplitude of the signal detected with SOPHIE implies the presence of a planet, called Gl 411 b, with a minimum mass of around three Earth masses, orbiting its star at a distance of 0.079 AU. The planet receives about 3.5 times the insolation received by Earth, which implies an equilibrium temperature between 256 and 350 K, and makes it too hot to be in the habitable zone. At a distance of only 2.5 pc, Gl 411 b, is the third closest low-mass planet detected to date. Its proximity to Earth will permit probing its atmosphere with a combination of high-contrast imaging and high-dispersion spectroscopy in the next decade

Concentration des éléments de transition divalents par les gels silicatés. Interprétation thermodynamique de quelques données expérimentales

Distribution equilibria of two divalent transition elements (A,B) between silicate gels p(SiO₂) — (A,B)O — nH₂ and aqueous solutions A²⁺, B²⁺ (А, В = Mg, Mn, Ni, Co, Cu,Zn) were investigated. It was found that the standard molar free enthalpy of exchange reactions is given by the simplified relation ΔG°(experimental) = K(p) ΔG°(calculated) where K(p) is a coefficient which depends only on the silica content of the gel, and ΔG°(calculated) = (G° (A(OH)2)> — G°(B(OH)2))hydrox — (G°(A)²⁺— G°(B)²⁺)(sol). This law indicates that the selectivity of the exchange reactions decreases when the silica content of the gels (p) increases. The behaviour of any divalent element can be predicted for any p value. These ion exchange mechanisms can play an important role in the genesis of residual silicate deposits, especially nickel and copper.On étudie les équilibres de distribution de deux éléments de transition divalents A, В entre gels silicatés de formule pSiO₂ — (A,B)O — nH₂O et solution aqueuse A²⁺, B²⁺. (A, В = Mg, Mn, Ni, Co, Cu,Zn). On montre que l'enthalpie libre molaire standard des réactions d'échange est donnée par la relation simplifiée ΔG0(expérimental) = K(p) ΔG°(calculé), où K(p) est un coefficient qui ne dépend que de la teneur en silice du gel, et ΔG°(calculé) = (G°(A(OH)2) — G°(B(OH)2)>)hydrox — (G°(A²⁺) — G °(B²⁺)so1. Cette loi montre que la sélectivité des réactions d'échange diminue lorsque la teneur en silice des gels (définie par p) augmente. Elle permet de prévoir le comportement d'un quelconque élément divalent quel que soit p. Les mécanismes d'échange d'ions étudiés doivent jouer un rôle important dans la genèse des gîtes silicatés résiduels, en particulier de cuivre et de nickel.Perruchot Alain, Delbove François. Concentration des éléments de transition divalents par les gels silicatés. Interprétation thermodynamique de quelques données expérimentales. In: Sciences Géologiques. Bulletin, tome 35, n°1-2, 1982. Géochimie de la silice. pp. 55-69

Étude de l'extraction sélective du nickel d'un minerai garniéritique pauvre par sulfuration par le soufre suivie de recuit en tube scellé

The effect of sulphur, in a vacuum-sealed tube at 700 °C, on a Ni-poor garnieritic ore, leads to a selective sulphidation of nickel ; however, the extremely small grain-size of the sulphides prevents use of physical means (flotation) for their recovery. In order to improve the grain-size of the sulphides, samples were submitted, after sulphidation, to annealing in various conditions : — A single annealing, at 1 000 °C, increases the grain-size slightly, but the recovery of the sulphides remains difficult. It leads however to an important lowering of the sulphidation-ratio of iron and, so, to a sharp improvement of the chemical selectivity of the procedure. — An annealing with 3 % NaCl allows the grain-size to be increased appreciably and the selectivity to be improved simultaneously. Granulometries are obtained (D₈₀ about 10 to 20 µm) which make possible the use of physical means of recovery. The sulphides consists of Mss when the annealing is followed by a quench, and of varying sulphide phase assemblages in the case of a slow cooling, while the silicates recrystallize as orthopyroxenes.L'action du soufre, en tube scellé à 700 °C, sur un minerai garniéritique pauvre, conduit à une sulfuration sélective du nickel ; cependant, l'extrême finesse des sulfures obtenus est un obstacle à leur récupération par voie physique (flottation). Dans le but d'améliorer la taille des grains de sulfures, on a soumis un minerai ainsi sulfuré à l'action de divers recuits : — Un simple recuit à 1 000 °C donne lieu à une augmentation limitée de la taille des grains qui restent encore difficilement séparables. La baisse importante du taux de sulfuration du fer conduit cependant à une nette amélioration en ce qui concerne la sélectivité de l'opération. — Un recuit en présence de 3 % de NaCl permet d'accroître sensiblement la taille des grains tout en améliorant également la sélectivité. Les granulométries obtenues (D₈₀ compris entre 10 et 20 µm) rendent possible une séparation par voie physique. Les sulfures sont constitués de Mss lorsque le recuit est suivi d'une trempe, et d'assemblages de phases sulfurées diverses lorsque le refroidissement est lent, tandis que les silicates recristallisent en orthopyroxènes.Gruget Olivier, Delbove François, Perruchot Alain. Étude de l'extraction sélective du nickel d'un minerai garniéritique pauvre par sulfuration par le soufre suivie de recuit en tube scellé. In: Bulletin de Minéralogie, volume 103, 6, 1980. pp. 603-612

Flow Cytometry Approach to Quantify the Viability of Milk Somatic Cell Counts after Various Physico-Chemical Treatments.

Flow cytometry has been used as a routine method to count somatic cells in milk, and to ascertain udder health and milk quality. However, few studies investigate the viability of somatic cells and even fewer at a subpopulation level to follow up how the cells can resist to various stresses that can be encountered during technological processes. To address this issue, a flow cytometry approach was used to simultaneously identify cell types of bovine milk using cell-specific antibodies and to measure the cell viability among the identified subpopulations by using a live/dead cell viability kit. Confirmation of the cell viability was performed by using conventional microscopy. Different physico-chemical treatments were carried out on standardized cell samples, such as heat treatment, various centrifugation rates and storage in milk or in PBS pH 7.4 for three days. Cytometry gating strategy was developed by using blood cell samples stored at 4°C in PBS and milk cell samples heat-treated at 80°C for 30 min as a control for the maximum (95.9%) and minimum (0.7%) values of cell viability respectively. Cell viability in the initial samples was 39.5% for all cells and varied for each cell population from 26.7% for PMNs, to 32.6% for macrophages, and 58.3% for lymphocytes. Regarding the physico-chemical treatments applied, somatic cells did not sustain heat treatment at 60°C and 80°C in contrast to changes in centrifugation rates, for which only the higher level, i.e. 5000×g led to a cell viability decrease, down to 9.4%, but no significant changes within the cell subpopulation distribution were observed. Finally, the somatic cells were better preserved in milk after 72h storage, in particular PMNs, that maintained a viability of 34.0 ± 2.9% compared to 4.9±1.9% in PBS, while there was almost no changes for macrophages (41.7 ± 5.7% in milk vs 31.2 ± 2.4% in PBS) and lymphocytes (25.3 ± 3.0% in milk vs 11.4 ± 3.1% in PBS). This study provides a new array to better understand milk cell biology and to establish the relationship between the cell viability and the release of their endogenous enzymes in dairy matrix

Intervalence Charge Transfer in Mixed Valence Compound Modified by the Formation of a Supramolecular Complex.

International audienc

Flow cytometry identification of differential somatic cell count and simultaneous their quantification of all cells and each cell type.

<p>(A)(B)(C) fresh blood cell suspension, (D)(E)(F) milk cell suspension after 80°C × 30 min and (G)(H)(I)milk cell suspension conserved at 4°C in PBS pH 7.4. The cell subpopulations of each sample were shown in APC/FITC dotplot (A)(D)(G), the viable and non-viable population of all cells and each subpopulation were shown in histogram-Vioblue scatter (B)(E)(H) and (C)(F)(I), respectively.</p

Summary of the experimental design of the somatic cell preparation and the various treatments applied, i.e. storage in milk or PBS for 72 h, variation of the centrifugation rates and heat treatment.

<p>Summary of the experimental design of the somatic cell preparation and the various treatments applied, i.e. storage in milk or PBS for 72 h, variation of the centrifugation rates and heat treatment.</p

Flow cytometry scatter pattern for the identification of differential somatic cells in blood-milk mix cell suspension (1/1, v/v) and corresponding isotype control sample, respectively.

<p>(A) FSC/SSC dotplot of cell suspension. All somatic cells (in yellow) in cell suspension (B) were identified by CD45/PerCp+. The subpopulation of cell suspension in APC/FITC dotplot (C), macrophages (red), PMNs (blue) and lymphocytes (green) are identified by CD14/APC+ gate in APC/SSC plot (D), CH138A/FITC+ gate in FITC/SSC plot (E), and FSC/SSC size/granularity gate (F), respectively.</p

Cell viability with various centrifugation rates (400, 1500, 3000, 5000×<i>g</i> during 10 min at 4°C) comparing to the reference milk cell suspension without supplementary centrifugation (Ref).

<p>(A) Boxplot and whiskers of flow cytometry results with milk somatic cell suspensions incubated with specific antibodies and vioblue live/dead kit (n = 4); (B) Cell viability of each type cell for 400×<i>g</i> (white bars), 1500×<i>g</i> (hatched bars), 3000×<i>g</i> (grey bars), 5000×<i>g</i> (dark bars) centrifugations by flow cytometry; (C) Mean proportion of macrophages (dark sectors), PMNs (grey sectors) and lymphocytes (white sectors) in cell samples under various centrifugation with different gravitational velocities. Means with different superscripts (a-d) differ significantly (<i>P</i><0.05).</p

Specificities of linear Si QD arrays integration and characterization

International audienceThe low temperature operation of quantum computing devices implies developing characterization protocols, from extensive statistical tests to targeted device screening at cryogenic temperature. This paper reviews major integration constraints arising in linear Si quantum dots arrays and their implication on both the device operation and electrical characterization