1,721,108 research outputs found
Spatial and substrate relationships of the functional redundancy in Mediterranean lichen communities.
No full textRidondanza funzionale nelle comunità licheniche in ambienti Mediterranei: relazioni spaziali e importanza del substrato.
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Colour blindness (CB) distribution in the male population of Albanian and Croatian communities of Molise, Italy (with a review of the published Caucasoid CB gene frequencies).
No full textAll the secondary school students of the Albanian and Croatian communities of Molise were tested for colour vision. Percent frequencies of red-green colour blindness were 5.91 +/- 1.73 and 7.02 +/- 3.38. These figures are in agreement with those found for Central Italy thus confirming the similarity of these communities with the rest of Italy as described for several other autosomal polymorphisms. The distribution of red-green CB genes in Europe shows that they are slightly more frequent in Northern Europe than in Southern Europe and Northern Africa
Charge patch attraction and reentrant condensation in DNA-liposome complexes
Full text linkWe investigated the formation of complexes between cationic liposomes built up by DOTAP and three linear anionic polyions, with different charge density and flexibility, such as a single-stranded ssDNA, a double-stranded dsDNA and the polyacrylate sodium salt [NaPAA] of three different molecular weights. Our aim is to gain further insight into the formation mechanism of polyion-liposome aggregates of different sizes (lipoplexes), by comparing the behavior of DNA with a model polyelectrolyte, such as NaPAA, with approximately the same charge density but with a higher flexibility. We employed dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements, in order to explore both the hydrodynamic and structural properties of the aggregates resulting from polyion-liposome interaction and to present a comprehensive picture of the complexation process. The phenomenology can be summarized in a charge ratio-dependent scenario, where the main feature is the formation of large equilibrium clusters due to the aggregation of intact polyion-coated vesicles. At increasing polyion-liposome ratio, the size of the clusters continuously increases, reaching a maximum at a welldefined value of this ratio, and then decreases ("reentrant" condensation). The aggregation mechanism and the role of the polyion charge density in the complex formation are discussed in the light of the recent theories on the correlated adsorption of polyelectrolytes at charged interfaces. Within this framework, the phenomena of charge inversion and the reentrant condensation, peaked at the isoelectric point, finds a simple explanation. (c) 2005 Elsevier B.V All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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