1,721,017 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
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
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
The investigation of the possible effects of resveratrol on human coronary artery endothelial cell damage induced by in vitro hydrogen peroxide
No full textGiriş: Oksidatif stres, reaktif oksijen ürünlerinin oluşumu ve yıkılımı arasındaki bir dengesizlik olarak tanımlanmaktadır. Vasküler ve enflamatuvar hücrelerden kaynaklanan hidrojen peroksit, oksidatif stresi indükleyerek endotelde fonksiyon kaybına neden olmaktadır. Bu da koroner arter hastalığı, kalp yetmezliği, hipertansiyon, periferal arter hastalığı ve diyabet gibi hastalıklarda önemlidir. Enzimatik antioksidan savunma kaynakları süperoksit dismutaz, glutatyon peroksidaz ve katalazı kapsamaktadır. Enzimatik olmayan antioksidanlar askorbik asit, ?-tokoferol, glutatyon, karotenoidler, flavonoidler, stilbenler ve diğerleridir. Resveratrolæ stilbenlerin alt grubu olup, üzüm ve kırmızı şarapta bulunan polifenolik bir bileşiktir. Antienflamatuvar, antioksidan, antikanser, sitoprotektif ve kardioprotektif etkilere sahiptir. Amaç: Literatürde resveratrolün hidrojen peroksit hasarı ile indüklenen endotel hücresi üzerine in vitro etkisinin araştırıldığı bir çalışmaya rastlanmamıştır. Bu çalışmanın amacı, resveratrolün in vitro insan koroner arter endotel hücresini hidrojen peroksit hasarına karşı koruyucu etki gösterip göstermediğini araştırmaktır. Bu amaçla hücre sitotoksisitesi, reaktif oksijen ürünleri oluşumu, ?-glutamil sistein sentetaz, glutatyon redüktaz ve glutatyon peroksidaz enzimlerinin protein ekspresyonları ve glutatyon düzeyi incelenmiştir. Gereç ve Yöntem: Bu çalışmadaæ in vitro insan koroner endotel hücrelerinde resveratrolün değişik konsantrasyonları ve preinkübasyon sürelerinde hidrojen peroksit'in indüklediği hücre sitotoksisitesi üzerine etkileri araştırıldı. Resveratrolün hücre hasarındaki etkisi hücre sitotoksisite değerlendirme testi olan laktat dehidrogenaz ile incelendi. Hasar modelinde resveratrolün değişik konsantrasyonlarının çeşitli preinkübasyon sürelerinde ve zaman dilimlerinde reaktif oksijen ürünleri oluşumuna etkisi oksidan duyarlı bir fluoresans prob olan hidroksifenil floresin kullanılarak değerlendirildi. Resveratrolün antioksidan etkileri ?-glutamil sistein sentetaz, glutatyon redüktaz ve glutatyon peroksidaz enzimlerinin protein ekspresyonları Western blot yöntemi ile değerlendirildi. İn vitro insan koroner endotel hücrelerinde resveratrolün glutatyon düzeyine etkisi de yüksek performanslı sıvı kromatografisinde değerlendirilmiştir. Bulgular: Resveratrolün 10 ve 50 ?M konsantrasyonlarının 1, 12 ve 24 saat preinkübasyon sürelerinde 1 saat, 750 ?M hidrojen peroksit'in oluşturduğu sitotoksisiteyi istatistiksel olarak anlamlı azalttığı saptanmıştır (p Sonuç: Tüm bulgular birbirlerini destekleyici özellikte olup, araştırma koşullarında resveratrolün çeşitli yönlerden insan koroner arter endotel hücre hasarına koruyucu etki gösterdiğine işaret etmektedir. Bu araştırmanın sonuçlarının kardiyovasküler hastalıklarda oluşan oksidatif stresin geri döndürülmesinde kullanılabilecek yeni terapötik yaklaşımlara ışık tutabileceği düşünülmektedir. Anahtar Kelimeler: Resveratrol, İnsan Koroner Arter Endotel Hücresi, Oksidatif Hasar Introduction: Oxidative stress is defined as an imbalance between the production and destruction of reactive oxygen species. Hydrogen peroxide resulting from vascular and inflammatory cells causes endothelial dysfunction by inducing oxidative stress, which is of importance in coronary artery disease, cardiac failure, hypertension, peripheral artery disease and diabetes. Defense sources of enzymatic antioxidant include superoxide dismutase, glutathione peroxidase and glutathione catalase. Non-enzymatic antioxidants are ascorbic acid, ?-tocopherol, glutathione, carotenoids, flavonoids, stilbenes and others. Resveratrol, a subclass of stilbenes family, is a polyphenolic compound found in grapes and red wine. It has anti-inflammatory, anti-oxidant, anti-apoptotic, cytoprotective, anti-cancer and cardio-protective effects. Aim: No research conducted on in vitro effects of resveratrol on endothelial cells induced by hydrogen peroxide damage have been found in the literature. The purpose of this study is to investigate whether resveratrol can protect in vitro human endothelial cells against hydrogen peroxide damage. Therefore, cell cytotoxicity, production of reactive oxygen species, expressions of ?-glutamylcysteine synthetase, glutathione reductase and glutathione peroxidase enzymes and glutathione levels were investigated. Materials and methods: In this study, various concentrations of resveratrol found in in vitro human coronary endothelial cells and the effects of resveratrol on cell cytotoxicity induced by hydrogen peroxide during pre-incubation periods were investigated. The effect of resveratrol on cell damage was investigated with the lactate dehydrogenase test, a test used for the evaluation of cell cytotoxicity. The effects of various concentrations of resveratrol on the production of reactive oxygen species during various pre-incubation periods and time slices were evaluated by using hydroxyphenyl fluorescein, an oxidant-sensitive fluorescent probe. Anti-oxidant effects of resveratrol, protein expressions of ?-glutamylcysteine synthetase, glutathione peroxidase and glutathione reductase enzymes were evaluated with the Western blot method. The effects of resveratrol on the glutathione level in vitro human coronary endothelial cells were evaluated with high performance liquid chromatography. Results: It was determined that 10 and 50 ?M concentrations of resveratrol statistically significantly decreased the cytotoxicity induced by 750 ?M hydrogen peroxide during 1, 12 and 24-hour pre-icubation periods for one hour (p Conclusion: All the data support each other and suggest that resveratrol has a protective effect on the human coronary artery endothelial cell damage. It is thought that the findings obtained in this study can light the way to the new therapeutic approaches to be used for the reversal of oxidative stress which develops in cardiovascular diseases. Key words: Resveratrol, human coronary artery endothelial cell, oxidative damag
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
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