1,720,987 research outputs found
The Evolution of Extracellular Hemoglobins of Annelids, Vestimentiferans, and Pogonophorans.
No full textThe evolution of extracellular hemoglobins of annelids, vestimentiferans, and pogonophorans was investigated by applying cladistic and distance-based approaches to reconstruct the phylogenetic relationships of this group of respiratory pigments. We performed this study using the aligned sequences of globin and linker chains that are the constituents of these complex molecules. Three novel globin and two novel linker chains of Sabella spallanzanii described in an accompanying paper (Pallavicini, A., Negrisolo, E., Barbato, R., Dewilde, S., Ghiretti-Magaldi, A., Moens, L., and Lanfranchi, G. (2001) J. Biol. Chem. 276, 26384--26390) were also included. Our results allowed us to test previous hypotheses on the evolutionary pathways of these proteins and to formulate a new most parsimonious model of molecular evolution. According to this novel model, the genes coding for the polypeptides forming these composite molecules were already present in the common ancestor of annelids, vestimentiferans, and pogonophorans
Molecular Relationships and Genetic Diversity Analysis of Venetian Radicchio (Leaf Chicory, Cichorium intybus subsp. intybus var. sylvestre, 2n = 2x = 18) Biotypes
Full text linkChicory (Cichorium intybus L., 2n = 2x = 18) is naturalized and grows wild in many parts of Europe, South and Central Asia and N. Africa; moreover, this plant is an important leafy vegetable cultivated worldwide. In Italy, this horticultural crop is known as radicchio, and different bio-types of this crop are cultivated, especially in the north‐eastern part of the Italian Peninsula. Known to be introduced in and cultivated since the 17th century in the Venice area, the original biotype, still cultivated and named “Late Red of Treviso”, differentiated over the centuries, and it was also hybridized with endive (C. endivia), giving origin to many other biotypes. Several studies, based on morphological characterizations and historical reports, describe the relationships between the most popular cultivated local varieties of this species, but this work, focused on the use of molecular marker information obtained through DNA fingerprinting, presents validations and new insights into the genetic relatedness and diversity of these biotypes. By means of random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) molecular markers, this study provides insights into the genetic relationship that intercourses among the five most important local biotypes historically cultivated in the Veneto region, which is also the geographic centre of differentiation of this cultivated leafy vegetable. Through the construction of a maximum-likelihood dendrogram and the reconstruction of the genetic structure of a core collection, consisting of 652 samples belonging to five biotypes of radicchio divided into 22 old farmer populations, original data on their genetic origin, distinctiveness, relatedness and differentiation are reported and discussed
Phylogenetic analysis of the tribe Salicornieae based on matK and trnL-F chloroplast DNA sequences
No full textMorphological and molecular characterization of Crassicauda boopis (Nematoda; Spirurida) from Mediterranean fin whales: preliminary results
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Macrostructural Evolution of the Mitogenome of Butterflies (Lepidoptera, Papilionoidea)
No full textThe mitogenome of the species belonging to the Papilionodea (Lepidoptera) is a double stranded circular molecule containing the 37 genes shared by Metazoa. Eight mitochondrial gene orders are known in the Papilionoidea. MIQGO is the plesiomorphic gene order for this superfamily, while other mitochondrial arrangements have a very limited distribution. 2S1GO gene order is an exception and is present in several Lycaenidae and one species of Hesperiidae. We studied the macrostructural changes generating the gene orders of butterflies by analysing a large data set (611 taxa) containing 5 new mitochondrial sequences/assemblies and 87 de novo annotated mitogenomes. Our analysis supports a possible origin of the intergenic spacer trnQ-nad2, characterising MIQGO, from trnM. We showed that the homoplasious gene order IMQGO, shared by butterflies, species of ants, beetles and aphids, evolved through different transformational pathways. We identify a complicated evolutionary scenario for 2S1GO in Lycaenidae, characterised by multiple events of duplication/loss and change in anticodon of trnS1. We show that the gene orders ES1GO and S1NGO originated through a tandem duplication random loss mechanism. We describe two novel gene orders. Ampittia subvittatus (Hesperiidae) exhibits the gene order 2FFGO, characterised by two copies of trnF, one located in the canonical position and a second placed in the opposite strand between trnR and trnN. Bhutanitis thaidina (Papilionidae) exhibits the gene order 4QGO, characterised by the quadruplication of trnQ
Comparative analysis of r genes in solanaceae family. Atti 51° Convegno Annuale Siga Riva del Garda 23-26 settembre; 1 09 (2007).
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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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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