From the Olive Flower to the Drupe: Flower Types, Pollination, Self and Inter-Compatibility and Fruit Set

Automotive technology & trade

Measurement of the ortho-positronium confinement energy in mesoporous thin films

In this paper, we present measurements of the ortho-positronium emission energy in vacuum from mesoporous films using the time of flight technique. We show evidence of quantum mechanical confinement in the mesopores that defines the minimal energy of the emitted Ps. Two samples with different effective pore sizes, measured with positron annihilation lifetime spectroscopy, are compared for the data collected in the temperature range 50-400 K. The sample with smaller pore size exhibits a higher minimal energy ($73\pm$5 meV), compared to the sample with bigger pores ($48\pm$5 meV), due to the stronger confinement. The dependence of the emission energy with the temperature of the target is modeled as ortho-positronium being confined in rectangular boxes in thermodynamic equilibrium with the sample. We also measured that the yield of positronium emitted in vacuum is not affected by the temperature of the target.Comment: 8 pages, 9 figures *Added references. * Corrected typos and Fig. 3 label. * Revised argument in section IV B abd C, results unchanged

L’impact du drainage agricole souterrain sur la morphologie des petits cours d’eau dans la région de Cookshire, Québec

Le drainage agricole souterrain a des effets sur l'hydrologie des bassins versants, ce qui, selon toute vraisemblance, se répercute sur la morphologie des cours d'eau. Cette note montre que, pour une même superficie de drainage, les petits cours d'eau des bassins versants où il y a drainage souterrain sont plus larges et de plus grande dimension que ceux sans drainage souterrain. Bien que le lien entre cet effet et les changements du régime hydrologique n'ait pu être établi directement, les résultats laissent croire à une augmentation des débits de pointe par suite de l'implantation des drains souterrains.Land drainage induces hydrological changes which should effect stream channel morphology. This paper shows that, for a similar drainage area, small stream channels of watersheds with land drainage are larger in width and size than those without land drainage. Despite the fact that a direct link between this morphological effect and changes in the hydrological regime has not been established, these results suggest an increase in peak discharge following the introduction of land drainage

Does a visual reference help ballet dancers turn more successfully?

In dance, performing multiple rotations around the longitudinal axis is a complex task that can only be accomplished proficiently by highly skilled dancers. However, this extraordinary skill has been investigated sparsely. The few studies to date have focused on the biomechanical analysis of ballet rotations. However, none have investigated the influence of visual information on continuous rotations, such as Fouettés or à la Seconde turns. Therefore, the present study aims to examine the role of a visual reference on balance control and the dance-specific head coordination - spotting - during turning performance of highly skilled ballet dancers. To this end, 12 participants performed 12 Fouettés (females) or à la Seconde turns (males) with and without a visual reference. As dependent measures, we analysed balance control (i.e., supporting foot path length), spotting duration, head isolation, and orientation (i.e., deviation of pelvis from the front). A linear mixed model was performed to analyse the influence of the visual conditions overall and over the continued performance of 12 consecutive rotations. The results revealed that overall, path length was significantly smaller in the condition without a visual reference. Spotting duration and head isolation did not differ significantly between conditions. Moreover, dancers oriented themselves better towards the front in the condition with a visual reference. When looking closer into the progression of performance over each consecutive rotation, highly skilled ballet dancers significantly decreased the supporting foot path length, and improved orientation when turning with a visual reference. On the other hand, without a visual reference, the dancers increased the spotting duration over time. Additionally, dancers increased head isolation towards the end of the turns in both conditions. These findings suggest that a visual reference helps ballet dancers sustain performance of consecutive rotations, mainly in optimising balance control and orientation. Thus, the more rotations a ballet dancer must turn, the more relevant a visual reference becomes for sustaining successful performance

Automatic differential analysis of NMR experiments in complex samples

Liquid state NMR is a powerful tool for the analysis of complex mixtures of unknown molecules. This capacity has been used in many analytical approaches: metabolomics, identification of active compounds in natural extracts, characterization of species, and such studies require the acquisition of many diverse NMR measurements on series of samples. While acquisition can easily be performed automatically, the number of NMR experiments involved in these studies increases very rapidly and this data avalanche requires to resort to automatic processing and analysis. We present here a program that allows the autonomous, unsupervised processing of a large corpus of 1D, 2D and DOSY experiments from a series of samples acquired in different conditions. The program provides all the signal processing steps, as well as peak-picking and bucketing of 1D and 2D spectra, the program and its components are fully available. In an experiment mimicking the search of an active species in natural extract, we use it for the automatic detection of small amounts of artemisin added to a series of plant extracts, and for the generation of the spectral fingerprint of this molecules. This program called Plasmodesma is a novel tool which should be useful to decipher complex mixtures, particularly in the discovery of biologically active natural products from plants extracts, but can also in drug discovery or metabolomics studies.Comment: 35 pages, 36 figures, 26 reference