1,720,994 research outputs found
Role of the parafascicular thalamic nucleus and N-methyl-D-aspartate transmission in the D-1-dependent control of in vivo acetylcholine release in rat striatum
No full textWe investigated the involvement of glutamatergic neurotransmission in the modulation of D-1 receptor-mediated stimulation of acetylcholine outflow in dorsal striatum in freely moving rats, and the relative roles of the thalamostriatal and corticostriatal pathways in this regulation using in vivo microdialysis. The selective n-methyl-D-aspartate non-competitive antagonist dizocilpine maleate (0.1 mg/kg i.p.), but not the kainate/quisqualate receptor antagonist, 6,7-dinitroquinoxaline-2,3-dione (3 mu g per side i.c.v.), completely prevented the rise in striatal extracellular acetylcholine elicited by maximal effective doses of the full D-1 agonist SKF 82958 (3 mg/kg s.c.) and of the dopamine releaser d-amphetamine (2 mg/kg s.c.). Acute bilateral electrolytic lesions of the parafascicular nucleus of the thalamus prevented the stimulation of striatal acetylcholine output by SKF 82958 and d-amphetamine but only slightly reduced basal acetylcholine release. In contrast acute interruption of the corticostriatal pathway did not alter the effect of the two dopaminergic drugs although it markedly reduced basal striatal acetylcholine release. Lesions of the parafascicular thalamic nucleus, or a low dose of dizocilpine maleate (0.1 mg/kg i.p.), also prevented the acetylcholine-increasing effect of the neuroleptic remoxipride (10 mg/kg s.c.), an effect known to be D-1 receptor dependent. The results suggest that striatal projections arising from the parafascicular thalamic nucleus and utilizing N-methyl-D-aspartate receptors play a critical role in the D-1-mediated stimulation of acetylcholine release in dorsal striata
Morphoanatomic evolution and ecdysteroid variation during the metamorphosis of Neodiprion sertifer
No full textPrevious studies have emphasized that, in sawfly metamorphosis, most of morphogenesis and hormonal activity occurs during the pronymphal phase in the prepupal stage. The titres of ecdysteroids in haemolymph and ovaries were measured in selected stages of development of the sawfly Neodiprion sertifer (Hymenoptera Diprionidae), during the metamorphosis and in the adult. The hormonal levels detected were compared with the main morphological and anatomical differentiations observed. The last larval instar showed a peak of ecdysteroid secretion about two days before the apolysis. During the prepupal stage there were two peaks of ecdysteroid secretion with the second much higher. At the pupal stage a sudden increase of the hormone titre was found. The sawfly therefore showed a variation of the molting hormone titre comparable with that observed for other holometabolous insects. Moreover an intense secretive activity of the ovaries from the late pupal stage to the adult stage was clearly detected. The doseresponse hypothesis of ecdysteroid action is discussed
Giardini romani. Forme reali e fittizie dell’arredo vegetale
No full textThe paper continues the long series of studies on Roman painted gardens to propose a renewed discussion on the relationship between figurative representation and material reality and between the use and value of vegetal decoration
within domestic space, with particular attention to how the image was constructed and perceived according to a wellcoded visual language
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Some factors influencing oviposition in an artificial host by the pupal parasitoid Brachymeria intermedia (Nees)
No full textAttempts to identify factors capable of inducing Brachymeria intermedia to oviposit in an artificial host are reported. The development of an artificial substrate for in vitro egg laying of this hymenopterous parasitoid is also described. When presented with a choice between pupae of the factitious host Galleria mellonella and a blank cell in a Y tube olfactometer the females did not show a significant olfactory preference for the pupae. The response of B. intermedia females to G. mellonella pupae washed in hexane or untreated was also not significantly different. The role of kairomonal cues in the cuticle of G. mellonella pupae in attracting B. intermedia females was therefore not clear. Cylindrical host shape, on the other hand, was apparently important in inducing parasitoid oviposition. In fact, the females were observed to probe cylinder-shaped artificial substrates with their ovipositors even in the absence of chemical cue. When cylinder-shaped and purposefully flattened G. mellonella cuticles were exposed to parasitoid females oviposition holes were recorded only in the former and none in the latter. Cylinder-shaped artificial hosts composed of an agar-water suspension and G. mellonella haemolymph encapsulated in Parafilm were hence prepared and exposed to B. intermedia females. Some eggs were recorded in artificial pupae containing 50% or 25% haemolymph. No eggs were found in the pupae containing agar-water suspension alone, or 75% or 100% haemolymph. These results suggest that G. mellonella haemolymph contains ovipositional kairomones, an excess of which, however, prevents B. intermedia females from ovipositing
Il mosaico delle Bestie ferite (Aquileia, UD): aggiornamenti e nuovi studi
No full textRecent excavations in the Casa delle Bestie ferite (Aquileia, UD), in the area of the well-known namesake mosaic, allowed to update its photographic documentation, to refine its chronology and to find a new coin which is unusual for Aquileia. Along with previous campaigns’results, these new elements deepen the understanding of the domus and make possible to realize new reconstruction of the mosaic’s decorative scheme and plan
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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