118,887 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
In situ analysis of pH gradients in mosquito larvae using non-invasive, self-referencing, pH-sensitive microelectrodes
No full textThe alkaline environment, pH approximately 11, in the anterior midgut lumen of mosquito larvae is essential for normal nutrition and development. The mechanism of alkalization is, however, unknown. Although evidence from immunohistochemistry, electron microscopy and electrophysiology suggests that a V-ATPase is present in the basal membranes of the epithelial cells, its physiological role in the alkalization process has not been demonstrated. To investigate a possible role of the V-ATPase in lumen alkalization, pH gradients emanating from the hemolymph side of the midgut in semi-intact mosquito larvae were measured using non-invasive, self-referencing, ion-selective microelectrodes (SERIS). Large H+ concentration gradients, with highest concentrations close to the basal membrane (outward [H+] gradients), were found in the anterior midgut, whereas much smaller gradients, with concentrations lowest close to this membrane (inward [H+] gradients), were found in the gastric caeca and posterior midgut. Similar region-specific pH gradients, with consistent anterior-to-posterior profiles, were observed in individuals of two Aedes species, Aedes aegypti from semi-tropical Florida and Aedes canadensis from north-temperate Massachusetts. The gradients remained in a steady state for up to 6 h, the maximum duration of the recordings. Bafilomycin A1 (10(-5), 10(-7 )mol x l(-1)) on the hemolymph side greatly diminished the [H+] gradients in the anterior midgut but had no effect on the gradients in the gastric caecum and posterior midgut. These physiological data are consistent with the previous findings noted above. Together, they support the hypothesis that a basal, electrogenic H+ V-ATPase energizes luminal alkalization in the anterior midgut of larval mosquitoes
Groundstate asymptotics for a class of singularly perturbed p-Laplacian problems in RN
No full textWe study the asymptotic behaviour of positive groundstate solutions to the quasilinear elliptic equation [Figure not available: see fulltext.]where 1 < p< N, p< q< l< + ∞ and ε> 0 is a small parameter. For ε→ 0 , we give a characterization of asymptotic regimes as a function of the parameters q, l and N. In particular, we show that the behaviour of the groundstates is sensitive to whether q is less than, equal to, or greater than the critical Sobolev exponent p∗:=pNN-p
Spectral features of 21 Lutetia, target of Rosetta mission
No full textThe International Rosetta Mission, successfully
launched on March 2nd 2004, will encounter
comet 67P/Churyumov-
Gerasimenko, the principal target of the
mission, in 2014. During its long journey
Rosetta will fly-by also two asteroids: 2867
Steins (September 2008) at a distance of
about 1700 km and at a relatively low speed
of about 9 kilometers per second and 21 Lutetia
(July 2010) at about 3000 km at a speed
of 15 kilometers per second.
Rosetta will try to answer to the main questions
related to the origin and evolution of the
Solar System as minor bodies contains the
record of the chemical, physical and dynamical
primordial processes of the formation of
our planetary system.
In this work we present the analysis of two
visible spectra of Lutetia taken at NTT-ESO,
Chile, in order to confirm the presence of
absorption bands previously determined on
other spectra of the asteroid (Lazzarin et al.,
A&A, 2004).In particular, we investigated the spectral region
where these bands were detected by using
a higher spectral resolution. We confirm
a broad complex feature between 0.45
and 0.55 micron and two narrower features
around 0.47 and 0.52 micron which possible
origin will be discussed.
A more precise knowledge of the surface
composition of Lutetia is particularly
important for the definition of the observational
strategy of the Rosetta mission
Characterization of novel cytoplasmic PARP in the brain of Octopus vulgaris
No full textIl sistema nervoso centrale di Octopus vulgaris e' caratterizzato da una PARP citoplasmatica (vPARP, 193 kDa), in grado di regolare la polimerizzazione dell'actina mediante poli-ADPribosilazion
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
New copper(II) 1D polymer containing dimethyl(phenylsulfonyl)amidophosphate: Synthesis, crystal structure and magnetic properties
No full textThe reaction of sodium dimethyl(phenylsulfonyl)amidophosphate NaL (HL=C(6)H(5)SO(2)NHP(O)(OCH(3))(2)) with Cu(NO(3))(2) center dot 6H(2)O and o-bpe (1,2-bis(pyridine-2-yl)ethane) in appropriate ratios, afford the formation of 1D coordination polymer [Cu(L)(2) center dot o-bpe](n) in good yield. The crystal structures of HL (1) and [Cu(L)(2) center dot o-bpe](n) (2) are reported. In the crystal package the molecules of 1 are linked by intermolecular hydrogen bonds formed by the phosphoryl oxygen atoms which serve as acceptors and nitrogen atoms of amide groups as donors. The crystal structure of 2 indicates the presence of unsaturated Cu(L)(2) unit bridged by o-bpe ligand in the one-dimensional polymeric chain. The Cu(II) atoms have distorted 4 + 2 octahedral CuO(4)N(2) environment formed by the oxygen atoms belonging to the sulfonyl and phosphoryl groups of two deprotonated chelate ligands and nitrogen atoms of the bridging o-bpe ligands. The magnetic study of 2 has revealed the presence of a weak intrachain antiferromagnetic exchange interaction between copper ions. (C) 2009 Elsevier Ltd. All rights reserved.Fundamental Researches State Fund of Ukraine [F25/193 - 2008
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
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