1,720,968 research outputs found
NEUROPEPTIDES ANALYSIS OF OCTOPUS VULGARIS TRANSCRIPTOME: OCT-PEDAL PEPTIDE EXPRESSION IN CNS LOBES INVOLVED IN MOTOR COORDINATION
No full textThe discovery of novel peptides and hormones from the phylum Mollusca, enabled by the availability of whole genomes, transcriptomes and peptidomes, gives now ample tools for studying the structural evolution of peptides and hormones, and for redefining the phylogenetic relationships of key families of peptide and hormones across ecdysozoans, lophotrochozoans and chordates. In this frame, the genome sequence of the limpet Lottia gigantea (Veenstra, 2010) and the initiated large-scale molluscan transcriptome and genome projects (Moroz et al., 2011; De Lisa et al., 2011; Di Cosmo and Polese, 2012) offer an excellent opportunity to look at the neuropetides and neurohormone genes. Mollusks have several genes coding pedal peptides (PP), three in Lottia and four in Aplysia (Veenstra, 2010). Neuropeptides are the fastest evolving intercellular signals; in particular, cephalopods developed a number of specific innovations in their repertoire of secretory molecules that might supp ort their unique features (Moroz, 2011). Using neuronal transcriptome from Octopus vulgaris, we developed a specific probe to analyze expression of Oct-PP in O. vulgaris brain in horizontal sections throughout the suboesophageal and supraoesophageal masses, including optic lobes. Performing ISH analysis we found the expression of Oct-PP mRNA confined in the anterior suboesophageal mass, in the prebrachial lobe and in the middle suboesophageal mass, in all pedal lobes. The prebrachial lobe is involved in reflex coordination. The middle suboesophageal mass, representative of the pedal ganglionated cord of early mollusks, is involved in all actions in Octopus (Young, 1971). Our findings support the involvement of Oct-PP in reflex and motor coordination in Octopus
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Molecular organization of Octopus brains: First insights into unique memory center signaling
No full textCephalopod molluscs (Octopus, cuttlefish, squid, Nautilus) have independently evolved neural circuitry that controls stereotyped and learned behaviors whose complexity rivals that of many mammals. The Vertical Lobe (VL), a functional analog to the mammalian hippocampus, is unique to cephalopods and mediates spatial memory and visual discrimination. We used RNA-seq/transcriptome profiling, and anatomical validation using in-situ hybridization to identify and map candidate cephalopod memory molecules. We identified 17,841 transcripts in the VL and found 12,379 (69.4%) appear to be cephalopod-specific, while many memory related signal molecules were not identified in the VL transcriptome. These data suggest that cephalopods used a distinct subset of genes and signaling molecules (SM) to form memory circuits. Previously, we identified the neuropeptide complement in the Aplysia genome, and found 22 homologs in Octopus VL. We mapped the expression of 17 of these conserved neuropeptides and two of them, TkP and WhP, localize to the VL circuit. WhP is expressed in the cell bodies of the MSF, where the afferent tract to the VL begins, and TkP localizes to cell bodies of each VL gyrus. Next, we used computational predictions and manual annotation to identify putative SM in the VL. We identified four cephalopod-specific abundant transcripts, one of which (IRP) maps to cell bodies in the VL. Two others are highly expressed in Octopus brain, but absent in the ancestrally branching Nautilus CNS. This expansion of novel SM in the VL circuit is likely a key feature of cephalopod memory systems, implying extensive parallel evolution of cephalopod brains. Supported by NSF, NIH & NAS
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Molecular characterization of fragile X mental retardation protein and the diversity of RNA binding proteins in the CNS of Aplysia Californica.
No full textProg. N. 553.11
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