1,720,969 research outputs found
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
From calcium entry blockers to ryanodine receptors: a new therapeutic target in heart diseases.
No full textEven if, calcium entry blockers were introduced many years ago in the treatment of cardiovascular disorders such as hypertension, atrial arrhythmia, and angina pectoris, they still remain key drugs. At present, isoform tissue -selective L-type calcium channel (LTCC) modulators might extend their pharmacotherapeutic potential as well as their established use in cardiovascular diseases. In particular, negative inotropic selective compounds could be useful in the treatment of hypertrophic obstructive cardiomyopathy (HOCM), otherwise known as idiopathic hypertrophic subaortic stenosis. In addition, compounds that can directly modulate RyR2 (ryanodine receptor type 2) or indirectly through voltage-gated calcium channels, are claimed as a new therapeutic approach to heart failure and lethal arrhythmia. With the aim to improve and mapping the ligand site of diltiazem and benzothiazepines to the α1 pore forming subunit of L-type calcium channel, we discovered a series of thiazinoxadiazolone derivatives structurally related to diltiazem (fig. 1) with selective negative inotropic activity. Recently we have applied a multidisciplinary approach based on a virtual screening procedure to discover novel and cardioselective compounds able to bind the benzothiazepine site in the LTCCs. Three novel chemotypes were characterized as LTCC blockers: different forms of the benzosulfonamide scaffold, the 3-phenyl-4-isoxazolecarboxylate and, the 4-phenyl-thiomorpholine-3,5-dione. Compound M8, that is [(4-chlorophenyl)sulfonyl]-2-(2-thienyl)pyrrolidine (fig. 1), was considered the most interesting compound for its negative inotropic effect and vasorelaxant properties. First, M8 was studied as racemate, then the two enantiomers were separated to evaluate their own biological proprieties. As expected, the functional profile observed for the two enantiomers was significantly different. Both the enantiomers have negative inotropic activity in the guinea-pig left atria, R-(+) being twice more potent than S-(–). On the contrary, the vasorelaxing properties tested in guinea pig aortic strips 80 mM K+-depolarized, is uniquely shown by S-(–)-M8, with a potency comparable to (±)-M8. No variation in activity between the two enantiomers was found in binding studies in rat cardiomyocytes and patch-clamp experiments in isolated myocytes from rat tail artery. Such different behavior suggested us an additional mechanism of action for the S-(–)-M8 enatiomer possessing vasorelaxant effect. To verify this hypothesis we began a series of experiments on guinea-pig aortic strips. In this model both (±)-M8 and the two enantiomers did not modify the concentration-response curve to noradrenalin in guinea-pig aortic strips. Otherwise, only S-(–)-M8 inhibited the aortic strip contraction evoked by noradrenalin in absence of extracellular Ca2+. These preliminary findings confirmed that S-(–)-M8 does not interfere with adrenergic receptors and, might exploit its vasorelaxat activity through the modulation of the intracellular Ca2+ release. This latter phenomenon is probably due to the opening of RyRs in the sarcoplasmic reticulum. Voltage-clamp and Ca2+ transient experiments indicate that (±)-M8 interferes with the intracellular Ca2+ handling probably owing to its activity at LTCC level that are coupled to RyRs. As above mentioned, it is well established that RyR2 leakage in cardyomyocites is the main cause of heart failure and lethal arrhythmia, consequently the compounds able to modulate RyRs prevent the intracellular Ca2+ leak and arrhythmias
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
Modulazione delle correnti ioniche nei canali del calcio di tipo-L (CaV1.2) nativi e clonati di un analogo funzionale del Diltiazem.
No full textOBIETTIVO: il nostro gruppo di ricerca basandosi su un approccio di tipo multidisciplinare ha scoperto recentemente un nuovo calciomodulatore analogo funzionale del diltiazem con struttura fenilsulfonilpirrolidinica (M8). L’ obiettivo di questo studio è la valutazione dell’attività di M8 e dei suoi enantiomeri sulle correnti ioniche, la cinetica dei canali Cav1.2 e sugli effetti del rilascio del Ca2+ intracellulare. MATERIALI E METODI: le correnti del (ICa) o Ba2+ (IBa) nei canali Cav1.2 sono state registrate mediante patch-clamp e voltage-clamp rispettivamente in miociti di arteria caudale di ratto e cardiomiociti di topo, e in oociti di Xenopus che esprimono la variante cardiaca umana dei Cav1.2. L’attività vasorilassante, inotropa negativa e la modulazione del rilascio del Ca2+ intracellulare è stata determinata in vitro su tessuti isolati di cavia. RISULTATI: studi di binding precedenti avevano dimostrato che M8 spiazza [3H]-diltiazem dal proprio sito di legame in cardiomiociti di ratto. Studi di patch-clamp eseguiti su miociti di arteria caudale di ratto hanno evidenziato che M8 riduce la ICa e accelera la cinetica di inattivazione del canale. In cardiomiociti di topo M8 non ha effetti sulla intensità della ICa, allo stesso modo nel voltage-clamp su canali Cav1.2 cardiaci umani, M8 e diltiazem mostrano una trascurabile inibizione della IBa. In tutti gli esperimenti M8 accelera la cinetica di inattivazione del canale e perde il caratteristico use-dependence phenomenon del diltiazem. Su tessuti isolati di cavia i due enantiomeri hanno mostrato una diversa attività: solo uno di essi è responsabile dell’azione vasorilassante posseduta dal racemo mentre entrambi inibiscono la forza di contrazione cardiaca. Esperimenti condotti impiegando strips di aorta di cavia hanno mostrato che solo l’enantiomero dotato dell’attività vasorilassante inibisce il rilascio del Ca2+ dal reticolo sarcoplasmatico indotto da noradrenalina in assenza di Ca2+ extracellulare. CONCLUSIONI: gli studi di patch e voltage-clamp hanno evidenziato che questo nuovo calciomodulatore blocca i canali Cav1.2 preferenzialmente nel loro stato aperto. La perdita dello use-dependence phenomenon potrebbe essere associata alla rapida dissociazione del composto dal sito di legame delle benzotiazepine. Infine uno dei suoi enantiomeri sembra inibire il rilascio di Ca2+ intracellulare con un meccanismo imputabile al blocco del recettore della ryanodina
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
