1,721,022 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
Preclinical evaluation of CHF3381 as a novel antiepileptic agent
CHF3381 [n-(2-indanyl)-glycinamide hydrochloride] has been selected on the basis of a screening program as the compound displaying the highest anticonvulsant activity in the maximal electroshock seizure (MES) test and the best therapeutic index with reference to the rotarod test in mice and rats. In this study, the antiepileptic activity and the behavioural toxicity of CHF3381 were characterised in multiple model systems. CHF3381 effectively prevented MES-induced convulsions when administered i.p. (ED50, 24 mg/kg and 7.5 mg/kg) or p.o. (ED50, 21 mg/kg and 21 mg/kg) in both mice and rats, respectively. The time course of oral anti-MES activity in the rat was related to the brain concentration profile of unchanged CHF3381. Interestingly, the brain drug levels were about 4-5 times higher than in plasma. CHF3381 was very effective in mice against picrotoxin-, and i.c.v. N-methyl-D-aspartate (NMDA)-induced hind limb tonic extension (ED50 ≅ 10 mg/kg), but was a weaker antagonist of 4-amynopy..
Neuroprotective activity of CHF3381, a putative N-methyl-D-aspartate receptor antagonist
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Strain difference in protein expression in lungs of mice after cigarette smoke exposure
Cigarette smoke (CS) is the most prominent factor determining the increased prevalence of the emphysema. However, little is known why only a susceptible minority (8% – 16%) of heavy tobacco smokers develop a clinically significant disease. This suggests that genetic factors may modulate each individual’s risk. We recently reported strain differences in the response to CS in mice characterized by different levels of serum alpha1-proteinase inhibitor and sensitivity to oxidants. When exposed to CS, C57Bl and DBA/2 mice develop emphysema, while ICR mice do not show any parenchymal changes. In order to have some information on individual factors underlying this suscep- tibility, we examined the global change of lung protein expression in response to CS in these strains. With a classical proteomic approach, 2D electrophoresis and mass spectrometry, several proteins have been found significantly up- and down-regulated in the different strains of mice. In particular, we identified 6 up-regulated and 8 down-regulated proteins in C57Bl mice as well as 4 up- regulated and 6 down-regulated proteins in DBA/2 mice. On the other hand, in insensitive ICR mice we found only down-regulated proteins. These proteins belong to cytoskeleton proteins or various functional protein groups involved in antioxidant and detoxification processes, glucose metabolism or stress response. The distribution of some of these proteins in the lung has been analysed by immunohistochemistry. A series of qualitative and quantitative protein variations have been found among mouse strains with a different susceptibility to develop smoke-induced pulmonary lesion
Characterization of the effect of ganstigmine (CHF2819) on amyloid precursor protein metabolism in SH-SY5Y neuroblastoma cells
Biochemical and neurobehavioral profile of CHF2819, a novel orally active acethylcholinesterase inhibitor for Alzheimer’s disease
1,2,3,3a,8,8a-Hexahydro-1,3a,8-trimethylpyrrolo¿2,3-bĭndol-5-ol 2-ethylphenylcarbamate N-oxide hydrochloride (3aS-cis) (CHF2819) is a novel acetylcholinesterase inhibitor that produces central cholinergic stimulation after oral administration in rats. In vivo studies show that CHF2819 (0.5, 1.5, and 4.5 mg/kg p.o.) significantly increases acetylcholine levels in young adult rat hippocampus in a dose-dependent manner. Moreover, aged animals, which show a significant decrease in basal acetylcholine levels with respect to young adult rats, also exhibit a marked increase in the hippocampal concentrations of this neurotransmitter after the administration of CHF2819. This compound (1.5 mg/kg p.o.) significantly attenuates scopolamine-induced amnesia in a passive avoidance task. Furthermore, CHF2819 induces a significant decrease in dopamine levels and a significant elevation of extracellular concentrations of 5-hydroxytryptamine, whereas it does not modify norepinephrine and gamma-aminobutyric acid levels in the hippocampus of young adult rats. Functional observational battery screening demonstrates that CHF2819 (1.5 and 4.5 mg/kg p.o.) does not affect activity, excitability, autonomic, neuromuscular, and sensorimotor domains, as well as physiological end points (body weight and temperature). However, this compound induces involuntary motor movements (ranging from mild tremors to myoclonic jerks) in a dose-dependent manner. These findings suggest that the anti-amnestic properties of CHF2819, together with its stimulatory effect on cholinergic and serotonergic functions, might have a therapeutic potential mainly for the symptomatic treatment of Alzheimer's disease patients in which the cognitive impairment is accompanied by a depressive syndrome
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