1,720,975 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    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

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    “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

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    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

    Dispelling the Myths Behind First-author Citation Counts

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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

    Survival with first-line bosentan in patients with primary pulmonary hypertension.

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    The efficacy and safety of combining bosentan, an orally active dual endothelin receptor antagonist and epoprostenol, a continuously infused prostaglandin, in the treatment of pulmonary arterial hypertension (PAH) was investigated. In this double-blind, placebo-controlled prospective study, 33 patients with PAH started epoprostenol treatment (2 ng.kg(-1)min(-1) starting dose, up to 14+/-2 ng.kg(-1)min(-1) at week 16) and were randomised for 16 weeks in a 2:1 ratio to bosentan (62.5 mg b.i.d for 4 weeks then 125 mg b.i.d) or placebo. Haemodynamics, exercise capacity and functional class improved in both groups at week 16. In the combination treatment group, there was a trend for a greater (although nonsignificant) improvement in all measured haemodynamic parameters. There were four withdrawals in the bosentan/epoprostenol group (two deaths due to cardiopulmonary failure, one clinical worsening, and one adverse event) and one withdrawal in the placebo/epoprostenol group (adverse event). This study showed a trend but no statistical significance towards haemodynamics or clinical improvement due to the combination of bosentan and epoprostenol therapy in patients with pulmonary arterial hypertension. Several cases of early and late major complications were reported. Additional information is needed to evaluate the risk/benefit ratio of combined bosentan-epoprostenol therapy in pulmonary arterial hypertension

    Survival in patients with class III idiopathic pulmonary arterial hypertension treated with first line oral bosentan compared with an historical cohort of patients started on intravenous epoprostenol.

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    BACKGROUND: The oral dual endothelin receptor antagonist bosentan improves exercise capacity and delays clinical worsening in patients with pulmonary arterial hypertension, but its use could delay starting intravenous epoprostenol, a life saving treatment. METHODS: Survival in patients with functional class III idiopathic pulmonary arterial hypertension (PAH) treated with bosentan in clinical trials was compared with historical data from similar patients treated with epoprostenol in the clinic. Statistical methods were used to adjust for possible underlying differences between the two groups. RESULTS: Baseline factors for the 139 patients treated with bosentan and the 346 treated with epoprostenol suggested that the epoprostenol cohort had more severe disease-that is, a lower cardiac index (2.01 v 2.39 l/min/m2) and higher pressures and resistance. Kaplan-Meier survival estimates after 1 and 2 years were 97% and 91%, respectively, in the bosentan cohort and 91% and 84% in the epoprostenol cohort. Cox regression analyses adjusting for differences in baseline factors showed a greater probability of death in the epoprostenol cohort (hazard ratio 2.2 (95% confidence interval 1.2 to 4.0) in the model adjusted for haemodynamics). Alternative regression analyses and analyses to adjust for different data collection dates gave consistently similar results. When matched cohorts of 83 patients each were selected, survival estimates were similar. In the bosentan cohort 87% and 75% of patients followed for 1 and 2 years, respectively, remained on monotherapy. CONCLUSIONS: No evidence was found to suggest that initial treatment with oral bosentan, followed by or with the addition of other treatment if needed, adversely affected the long term outcome compared with initial intravenous epoprostenol in patients with class III idiopathic PAH

    [Treatment goals of pulmonary hypertension].

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    Özet– Pulmoner hipertansiyon alanındaki önemli gelişmelerden sonra, en önemli görevlerden biri uzun dönem sonuçlarla ilişkili kinik tedavi hedeflerini belirleme gereksinimidir. Modifiye New York Kalp Cemiyeti fonksiyonel sınıf I veya II, 380 metreden fazla 6 dakika yürüme mesafesine ulaşma, ekokardiyografide sağ ventrikül boyutunun ve fonksiyonunun normalleşmesi, B-tip natriüretik peptit düzeyinin azalması ya da normalleşmesi ve sağ atriyal basıncının 8 mmHg’den düşük ve kardiyak indeksin 2,5 L/dk/m2 ’den büyük olması güncel hedeflerdir. Bununla birlikte, egzersiz kapasitesi ve sağ kalp fonksiyonu gibi uzun dönem sonuçlarla daha fazla ilişkili olan parametreleri hedefleyen daha güçlü ve net sınırlarla çizen “eşiğin” daha yüksek tutulması gerektiği açık hale gelmektedir; Özellikle, manyetik rezonans görüntüleme ve BNP/N-terminal pro B tip natriüretik peptit gibi doğru ve noninvaziv olarak sağ ventrikül fonksiyonunu belirleyen testler, temel belirleyiciler ve tedavi hedefleri olarak hizmet etmek için umut verici göstergeler olarak ortaya çıkmaktadır. Ayrıca, sonuçlar üzerine odaklı çalışmalar tek başına hiçbir testin güvenilir bir şekilde uzun vadeli prognostik belirteç olarak kullanılamayacağını ve birleşik tedavi hedeflerinin uzun dönem sonuçlarının daha iyi öngördüreceğini gösterdi. Yeniden düzenlenen tedavi hedeflerinin şunlar olduğu ileri sürülmüştür: Modifiye New York Kalp Cemiyeti fonksiyonel sınıf I veya II, ≥380 ve 440 m arasındaki 6 dakika yürüme mesafesi, kardiyopulmoner egzersiz testi-15 ml/d/kg’dan fazla tepe oksijen tüketim ölçümü ve 45 l/dak’dan az karbondioksit için solunum eşdeğeri, normale yakın BNP değeri, ile normal/normale yakın sağ ventrikül boyut ve fonksiyonlarını gösteren ekokardiyografi ve/veya kardiyak manyetik rezonans görüntüleme ve 8 mmHg’den az sağ atriyal basınçla ve 2,5-3 l/dak/m2’den fazla kardiyak indeksle birlikte sağ ventrikül fonksiyonunun normalleştiğini gösteren hemodinamik parametreler. (J Am Coll Cardiol 2013;62:D73–81)With significant therapeutic advances in the field of pulmonary arterial hypertension, the need to identify clinically relevant treatment goals that correlate with long-term outcome has emerged as 1 of the most critical tasks. Current goals include achieving modified New York Heart Association functional class I or II, 6-min walk distance >380 m, normalization of right ventricular size and function on echocardiograph, a decreasing or normalization of B-type natriuretic peptide (BNP), and hemodynamics with right atrial pressure <8 mm Hg and cardiac index >2.5 L/dk/m2. However, to more effectively prognosticate in the current era of complex treatments, it is becoming clear that the "bar" needs to be set higher, with more robust and clearer delineations aimed at parameters that correlate with long-term outcome; namely, exercise capacity and right heart function. Specifically, tests that accurately and noninvasively determine right ventricular function, such as cardiac magnetic resonance imaging and BNP/N-terminal pro-B-type natriuretic peptide, are emerging as promising indicators to serve as baseline predictors and treatment targets. Furthermore, studies focusing on outcomes have shown that no single test can reliably serve as a long-term prognostic marker and that composite treatment goals are more predictive of long-term outcome. It has been proposed that treatment goals be revised to include the following: modified New York Heart Association functional class I or II, 6-min walk distance 380 to 440 m, cardiopulmonary exercise test-measured peak oxygen consumption >15 ml/min/kg and ventilatory equivalent for carbon dioxide <45 l/min/l/min, BNP level toward "normal," echocardiograph and/or cardiac magnetic resonance imaging demonstrating normal/near-normal right ventricular size and function, and hemodynamics showing normalization of right ventricular function with right atrial pressure <8 mm Hg and cardiac index >2.5 to 3.0 l/min/m2. (J Am Coll Cardiol 2013;62:D73-81) ©2013 by the American College of Cardiology Foundation
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