885 research outputs found
Vitis vinifera - a chemotaxonomic approach: Anthocyanins in the skin
The gaining of new knowledge about varietal differences in grapevines can be useful for the designing of genetic improvement programs. More and more, chemical methods complement ampelographic ones in the study of variability in grapevines. This work is aimed at the anthocyanin profiling of red-coloured grapes, of which ca. 120 cultivars were sampled; among these there were a high number of old Italian vines and 30 Vitis vinifera ssp. silvestris originating from different areas of Italy. Anthocyanins were HPLC separated and quantified with the aid of an inverse phase microbore column and a photodiode detector. Grapevines were numerically separated in groups using as indexes the percentage of the 5 monoglucosides present, the summations of: acetic esters; malvidin-3-monoglucoside-caffeoate plus all 5 p-coumaric esters; as well as a series of relations correlated to certain enzymatic activities necessary for the esterification of glucosides, hydroxylation and methylation in the biosynthesis of several anthocyanins. Data derived from the study of indexes of varietal enzymatic activity enable us to qualify differences between grapevines linked to the synthesis of anthocyanins. The stability of anthocyanic profiles within the same grape variety enables the use of this technique for taxonomic purposes. This research study discusses the use of this technique for classification and analysis of grape phylogenesis. An in-depth look into the relations between cultivated and wild varieties is given
Asymmetric Hybrids: Dialogues for Computational Concept Combination
When people combine concepts these are often characterised as âhybridâ, âimpossibleâ, or âhumorousâ. However, when simply considering them in terms of extensional logic, the novel concepts understood as a conjunctive concept will often lack meaning having an empty extension (consider âa tooth that is a chairâ, âa pet flowerâ, etc.). Still, people use different strategies to produce new non-empty concepts: additive or integrative combination of features, alignment of features, instantiation, etc. All these strategies involve the ability to deal with conflicting attributes and the creation of new (combinations of) properties. We here consider in particular the case where a Head concept has superior âasymmetricâ control over steering the resulting concept combination (or hybridisation) with a Modifier concept. Specifically, we propose a dialogical approach to concept combination and discuss an implementation based on axiom weakening, which models the cognitive
and logical mechanics of this asymmetric form of hybridisation
Services surround you:physical-virtual linkage with contextual bookmarks
Our daily life is pervaded by digital information and devices, not least the common mobile phone. However, a seamless connection between our physical world, such as a movie trailer on a screen in the main rail station and its digital counterparts, such as an online ticket service, remains difficult. In this paper, we present contextual bookmarks that enable users to capture information of interest with a mobile camera phone. Depending on the userâs context, the snapshot is mapped to a digital service such as ordering tickets for a movie theater close by or a link to the upcoming movieâs Web page
On the importance of hydrodynamic interactions in polyelectrolyte electrophoresis
The effect of hydrodynamic interactions on the free-solution electrophoresis
of polyelectrolytes is investigated with coarse-grained molecular dynamics
simulations. By comparing the results to simulations with switched-off
hydrodynamic interactions, we demonstrate their importance in modelling the
experimentally observed behaviour. In order to quantify the hydrodynamic
interactions between the polyelectrolyte and the solution, we present a novel
way to estimate its effective charge. We obtain an effective friction that is
different from the hydrodynamic friction obtained from diffusion measurements.
This effective friction is used to explain the constant electrophoretic
mobility for longer chains. To further emphasize the importance of hydrodynamic
interactions, we apply the model to end-labeled free-solution electrophoresis.Comment: 15 pages, 7 figures; accepted for publication in J. Phys.: Condens.
Matte
The structure of gravel-bed flow with intermediate submergence: a laboratory study
The paper reports an experimental study of the flow structure over an immobile gravel bed in open channel at intermediate submergence, with particular focus on the near-bed region. The experiments consisted of velocity measurements using three-component (stereoscopic) Particle Image Velocimetry (PIV) in near-bed horizontal plane and two-component PIV in three vertical planes that covered three distinctly different hydraulic scenarios where the ratio of flow depth to roughness height (i.e., relative submergence) changes from 7.5 to 10.8. Detailed velocity measurements were supplemented with fine-scale bed elevation data obtained with a laser scanner. The data revealed longitudinal low-momentum and high-momentum "strips'' in the time-averaged velocity field, likely induced by secondary currents. This depth-scale pattern was superimposed with particle-scale patches of flow heterogeneity induced by gravel particle protrusions. A similar picture emerged when considering second-order velocity moments. The interaction between the flow field and gravel-bed protrusions is assessed using cross correlations of velocity components and bed elevations in a horizontal plane just above gravel particle crests. The cross correlations suggest that upward and downward fluid motions are mainly associated with upstream-facing and lee sides of particles, respectively. Results also show that the relative submergence affects the turbulence intensity profiles for vertical velocity over the whole flow depth, while only a weak effect, limited to the near-bed region, is noticed for streamwise velocity component. The approximation of mean velocity profiles with a logarithmic formula reveals that log-profile parameters depend on relative submergence, highlighting inapplicability of a conventional "universal'' logarithmic law for gravel-bed flows with intermediate submergence
Vitis vinifera - a chemotaxonomic approach: Seed storage proteins
The IEF pattern of the constituent peptides for the storage protein from Viris vinifera endosperm is used for the construction of a dendrogram relating 74 seed specimens
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