1,720,993 research outputs found
A comparison of the behavioral effects of minaprine, amphetamine and stress.
No full textDifferent types of clinically effective antidepressants prevent the behavioral effects of experimental stress, and some of these treatments affect mesolimbic dopamine (DA) functioning. Animal studies have demonstrated that repeated psychostimulant administration and repeated or chronic stressful experiences also affect mesolimbic DA functioning. These results could suggest homologies among stress, psychostimulants and antidepressants. The present experiments show that either repeated stress (120 min restraint daily for 10 consecutive days) or subchronic treatment with the antidepressant minaprine (5 mg/kg daily for 10 consecutive days) significantly reduced the inhibitory effect of 120 min of restraint on climbing, a behavioral response dependent on mesolimbic DA functioning. However, the antidepressant did not induce the altered sensitivity of presynaptic DA receptors promoted by repeated stress. Chronic stressful experience (13 days of food restriction) and repeated amphetamine (2.5 mg/kg daily for 10 consecutive days) were as effective as subchronic minaprine in reducing immobility in the Porsolt's swimming test. However, whilst both stress and amphetamine enhanced struggling, minaprine promoted swimming. Finally, chronically stressed mice and mice pretreated with amphetamine showed enhanced sensitivity to amphetamine-induced locomotion, whilst this effect was absent in animals pretreated with the antidepressant. These results indicate that although chronic and repeated stress as well as amphetamine have some antidepressant-like behavioral effects, their mode of action could be different from that of clinically active substances
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
The flattening of globular clusters : internal rotation or velocity anisotropy?
No full textInternal rotation is considered to play a major role in determining the structure and dynamics of some globular clusters. We present a dynamical analysis of the photometry and three-dimensional kinematics of 47 Tuc and ω
Cen, by means of a new family of self-consistent axisymmetric rotating models. The combined use of line-of-sight velocities and
proper motions allows us to obtain a global description of the internal dynamical structure of the objects together with an estimate of their dynamical distances. The well-relaxed cluster 47 Tuc is very well interpreted by our dynamical models; in particular, internal rotation is found to explain the observed morphology. For the partially relaxed cluster ω Cen, the selected model provides a good representation of its complex three-dimensional kinematics, in general qualitative agreement with the observed anisotropy profile, which is characterized by tangential anisotropy in the outer parts; discrepancies are found between the observed
and the expected ellipticity profile and are ascribed to the presence of a high degree of radial anisotropy in the intermediate region and to its interplay with rotation
Il territorio di Leptis Magna: ricognizioni tra Ras el-Mergheb e Ras el-Hammam (2007)
No full textI primi dati di una nuova indagine di superficie condotta nel territorio a sud di Leptis Magna
Strain-dependent effects of cocaine on memory storage improvement induced by post-training physostigmine.
No full textPost-training administration of the inhibitor of cholinesterase enzymes, physostigmine, dose-dependently (0.025-0.4 mg/kg) improved retention of an inhibitory avoidance response in C57BL/6 (C57) as well as in DBA/2 (DBA) mice, the latter being more responsive than C57 mice. The effects on retention performance induced by physostigmine in C57 and DBA mice appeared to be due to an effect on memory consolidation. In fact, they were observed when drugs were given at short, but not long, periods of time after training, which is when the memory trace is susceptible to modulation. Moreover, these effects are not to be ascribed to a rewarding or non-specific action of the drugs on retention performance, as the latencies during the retention test of those mice that had not received a footshock during the training were not affected by the post-training drug administration. Post-training administration of cocaine (1-5 mg/kg) dose-dependently improved retention of an inhibitory avoidance response in C57 mice, while impairing it in the DBA strain, thus confirming previous results (Puglisi-Allegra et al. 1994b). Pretreatment with cocaine at ineffective doses as well as at an effective one potentiated the effects of an ineffective as well as of an effective dose of physostigmine in C57 mice, while it antagonized the effects of the inhibitor of cholinesterase enzymes on memory consolidation in DBA mice. The present results indicate that the indirect DA receptor agonist cocaine affects physostigmine action on memory consolidation in an opposite manner in the two inbred strains, pointing to genotype-dependent interaction between cholinergic and dopaminergic activity in memory consolidation
Combattere a Leptis Magna: archeologia della Guerra di Libia
No full textFighting at Lepcis Magna: Libyan War Archaeology. Just 100 years ago, declaring war on Turkey for the conquest of the Ottoman provinces of Tripolitania and Cyrenaica, Italy started one of the last great colonial wars (the last should have been Mussolini’s war against Ethiopia in 1935-1936). During this conflict, the outskirts of the small village of Lebda were the location of bloody battles. The Italian troops landed at Khoms on the 21st of October 1911 and conquered the dominant hill of Ras el-Mergheb on the 27th of February 1912, but bloody fights occurred again on the 5th-6th of March, when Arab-Turks came back in order to recover the strategic position. After the Italian occupation of the ruins of Lebda (Lepcis Magna) on the 2nd of May, the opposing troops clashed on the ancient agger of Monticelli on the 12th of June. The location of Italian strongholds and the lines of Arab-Turkish attacks were roughly known through the contemporary military accounts. The more precise locations of the battlefields were accidentally recorded in one of the samples of the multi-period archaeological survey which the University of Roma Tre has conducted in the territory of Lepcis Magna since 1995. Classical and medieval archaeologists have had to examine the military evidence for more modern conflict archaeology. The discovery of elements of the munitions supplied to the two armies made it possible to identify their positions in the field. Surface finds included cartridge cases and bullets of the Italian guns Vetterli Vitali mod. 1870/87 and Carcano mod. 1891, of which there were also brass stripper clips, and the Turkish Mauser M1887. Fragments of shells and numerous shrapnel lead balls testify to the widespread use of artillery
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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