Fluidite de l’huile produite par des arbres du second cycle de selection reccurente reciproque chez le palmier a huile (Elaeis guineensis Jacq)

L’étude de la fluidité de l’huile du Palmier à huile (Elaeis guineensis) présente de nombreux intérêts, en particulier pour l’identification des arbres élites qui seront utilisés dans le programme d’amélioration soit par clonage, soit par croisement en vue d’augmenter la fraction d’huile fluide dans le fruit. Dans cette perspective, les indices d’iode des huiles extraites à partir des régimes produits par des arbres du second cycle de sélection récurrente réciproque ont été évalués et comparés à ceux des huiles extraites à partir d’arbres du premier cycle. Les résultats obtenus indiquent que le matériel végétal Deli x La Mé issu du premier cycle de sélection récurrente réciproque possède un indice d’iode moyen de 55. Les indices d’iode des matériels issus du second cycle de sélection récurrente réciproque, laissent apparaître globalement une amélioration de 2 points pour les arbres des croisements réalisés avec des parents femelles DA5D x DA3D et DA 115D AF (Indice d’Iode moyen = 57) et de 3 points pour ceux issus des croisements ayant pour parent femelle DA3D AF (Indice d’Iode moyen = 58). La fluidité de l’huile des arbres témoins ayant pour parent femelle DA115D AF pris comme référence dans les essais comparatifs, demeure stable du premier au second cycle de sélection récurrente réciproque avec un indice d’iode moyen de 54. L’amélioration sensible obtenue au niveau de la fluidité de l’huile du matériel de second cycle, serait essentiellement due aux meilleures recombinaisons des génotypes du premier cycle de sélection récurrente réciproque.Mots clés : Fluidité, huile, indice d’iode, palmier à huile, Elaeis guineensisFUIDITY OF OIL PRODUCED BY TREES FROM THE SECOND CYCLE OF RECIPROCAL RECURRENT BREEDING (RRS) OF OIL PALM (Elaeis guineensis JACQ)Research on Palm oil’s fluidity has several interests, especially for the identification of elite trees used in breeding program for the improvement of the quantity of fluid oil in the fruit. In this prospective, iodine indices of oil produced by bunches of palm trees derived from second cycle of reciprocal recurrent breeding (RRS) are measured and compared to those of trees from first cycle of reciprocal recurrent breeding. Obtained results indicate that Deli x La Mé Plant material from the first cycle of RRS displays an iodine index of 55. The values of oil iodine indices of trees from the second cycle of RRS showan improvement of 2 points for trees derived from crosses using DA5D x DA3D and DA115D AF as female parents (mean iodine index = 57). The oil iodine index increases by 3 points for bunches harvested on trees derived from DA3D AF as female parent (mean iodine index = 58). Fluidity of the oil from DA115D x LM2T used as control in the comparative trials remains steady from the first to the second cycle of RRS with a mean value of 54. The significant rise in fluidity of the palm oil from the second cycle of RRS, would be essentially due to better recombinations of the genotypes of the first cycle of RRS.Keywords : Fluidity, oil, iodine index, oil Palm, Elaeis guineensis

A transgenic Camelina sativa seed oil effectively replaces fish oil as a dietary source of eicosapentaenoic acid in mice

Background: Fish currently supplies only 40% of the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) required to allow all individuals globally to meet the minimum intake recommendation of 500 mg/d. Therefore, alternative sustainable sources are needed. Objective: The main objective was to investigate the ability of genetically engineered Camelina sativa (20% EPA) oil (CO) to enrich tissue EPA and DHA relative to an EPA-rich fish oil (FO) in mammals. Methods: Six-week-old male C57BL/6J mice were fed for 10 wk either a palm oil–containing control (C) diet or diets supplemented with EPA-CO or FO, with the C, low-EPA CO (COL), high-EPA CO (COH), low-EPA FO (FOL), and high-EPA FO (FOH) diets providing 0, 0.4, 3.4, 0.3, and 2.9 g EPA/kg diet, respectively. Liver, muscle, and brain were collected for fatty acid analysis, and blood glucose and serum lipids were quantified. The expression of selected hepatic genes involved in EPA and DHA biosynthesis and in modulating their cellular impact was determined. Results: The oils were well tolerated, with significantly greater weight gain in the COH and FOH groups relative to the C group (P < 0.001). Significantly lower (36–38%) blood glucose concentrations were evident in the FOH and COH mice relative to C mice (P < 0.01). Hepatic EPA concentrations were higher in all EPA groups relative to the C group (P < 0.001), with concentrations of 0.0, 0.4, 2.9, 0.2, and 3.6 g/100 g liver total lipids in the C, COL, COH, FOL, and FOH groups, respectively. Comparable dose-independent enrichments of liver DHA were observed in mice fed CO and FO diets (P < 0.001). Relative to the C group, lower fatty acid desaturase 1 (Fads1) expression (P < 0.005) was observed in the COH and FOH groups. Higher fatty acid desaturase 2 (Fads2), peroxisome proliferator–activated receptor α (Ppara), and peroxisome proliferator–activated receptor γ (Pparg) (P < 0.005) expressions were induced by CO. No impact of treatment on liver X receptor α (Lxra) or sterol regulatory element-binding protein 1c (Srebp1c) was evident. Conclusions: Oil from transgenic Camelina is a bioavailable source of EPA in mice. These data provide support for the future assessment of this oil in a human feeding trial

Palladium nanoparticles in catalytic carbon nanoreactors: the effect of confinement on Suzuki-Miyaura reactions

We explore the construction and performance of a range of catalytic nanoreactors based on palladium nanoparticles encapsulated in hollow graphitised nanofibres. The optimum catalytic material, with small palladium nanoparticles located almost exclusively at the graphitic step-edges within nanoreactors, exhibits attractive catalytic properties in Suzuki-Miyaura cross-coupling reactions. Confinement of nanoparticles at the step-edges facilitates retention of catalytic centres and recycling of catalytic nanoreactors without any significant loss of activity or selectivity over multiple catalytic cycles. Furthermore, careful comparison of the catalytic properties of palladium nanoparticles either on or in nanoreactors reveals that nanoscale confinement of catalysts fundamentally affects the pathways of the Suzuki-Miyaura reaction, with the yield and selectivity for the cross-coupled product critically dependent on the steric properties of the aryl iodide reactant, whereas no effects of confinement are observed for aryl boronic acid reactants possessing substituents in different positions. These results indicate that the oxidative addition step of the Suzuki-Miyaura reaction occurs at the step-edge of nanofibres, where the mechanisms and kinetics of chemical reactions are known to be sensitive to nanoscale confinement, and thus the extent of confinement in carbon nanoreactors can be discretely controlled by careful selection of the aryl iodide reactant

The Effect of Quantum Dot Shell Structure on Fluorescence Quenching By Acridine Ligand

The current strategy for the development of advanced methods of tumor treatment focuses on targeted drug delivery to tumor cells. Quantum dot (QD) - semiconductor fluorescent nanocrystal, conjugated with a pharmacological ligand, such as acridine, ensures real-time tracking of the delivery process of the active substance. However, the problem of QD fluorescence quenching caused by charge transfer can arise in the case when acridine is bound to the QD. We found that QD shell structure has a defining role on photoinduced electron transfer from QD on acridine ligand which leads to quenching of QD photoluminescence. We have found that multishell CdSe/ZnS/CdS/ZnS QD structure provides minimal reduction of photoluminescence quantum yield at minimal shell thickness compared to classical thin ZnS or “giant” shells. Thus, CdSe/ZnS/CdS/ZnS core/multishell QD could be an optimal choice for engineering of small-sized acridine-based fluorescent labels for tumor diagnosis and treatment systems. Keywords: Quantum dot, photoluminescence quenching, DNA ligand, acridine derivative

Horizontal rotation signals detected by "G-Pisa" ring laser for the Mw=9.0, March 2011, Japan earthquake

We report the observation of the ground rotation induced by the Mw=9.0, 11th of March 2011, Japan earthquake. The rotation measurements have been conducted with a ring laser gyroscope operating in a vertical plane, thus detecting rotations around the horizontal axis. Comparison of ground rotations with vertical accelerations from a co-located force-balance accelerometer shows excellent ring laser coupling at periods longer than 100s. Under the plane wave assumption, we derive a theoretical relationship between horizontal rotation and vertical acceleration for Rayleigh waves. Due to the oblique mounting of the gyroscope with respect to the wave direction-of-arrival, apparent velocities derived from the acceleration / rotation rate ratio are expected to be always larger than, or equal to the true wave propagation velocity. This hypothesis is confirmed through comparison with fundamental-mode, Rayleigh wave phase velocities predicted for a standard Earth model.Comment: Accepted for publication in Journal of Seismolog

The magnetic field of the B3V star 16 Pegasi

The Slowly Pulsating B3V star 16 Pegasi was discovered by Hubrig (2006) to be magnetic, based on low-resolution spectropolarimetric observations with FORS1 at the VLT. We have confirmed the presence of a magnetic field with new measurements with the spectropolarimeters Narval at TBL, France and Espadons at CFHT, Hawaii during 2007. The most likely period is about 1.44 d for the modulation of the field, but this could not be firmly established with the available data set. No variability has been found in the UV stellar wind lines. Although the star was reported once to show H alpha in emission, there exists at present no confirmation that the star is a Be star.Comment: 2 pages, 4 figures, contrubuted poster at IAU Symposium 259 "Cosmic Magnetic Fields: from Planets, to Stars and Galaxies", Tenerife, Spain, November 3-7, 200