1,720,974 research outputs found
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
The relationship between endoglin levels and inflammatory microenvironment in colorectal cancer patients
No full textKolorektal Kanser Hastalarında Endoglin Düzeyleri ile Enflamatuvar Mikroçevre İlişkisinin Araştırılması Kolorektal kanser (CRC) dünya çapında en yaygın görülen kanserlerden biridir ve kansere bağlı ölümlerin önde gelen nedenlerindendir. Tümörlerin sıklıkla kronik enflamasyon ortamında geliştiği ve tümör biyopsi örneklerinde enflamatuvar hücrelerin mevcut olduğu gözlemine dayanarak, enflamasyon ve kanser arasındaki nedensel bağlantı öne sürülmüştür. Epidemiyolojik çalışmalar, kronik enflamasyonun farklı kanser türlerine zemin hazırladığını ortaya çıkarmıştır. Kronik enflamasyonun kanser gelişimini destekleyebildiğini ve tümör kaynaklı enflamasyonun kartopu etkisi yaratarak tümör progresyonunu sürdürdüğünü gösteren çok sayıda kanıt bulunmaktadır. Bu tez çalışmasında kolorektal kanser tanısı almış olan hastalar ile sağlıklı gönülllülerin kan plazma örneklerinde, yaygın olarak bilinen enflamasyon belirteçlerinden olan sPLA2, cPLA2, NfκB, TGF-β1 düzeyleri ELISA (enzyme-linked immunosorbent assay) yöntemi ile ölçülmüş ve elde edilen bulgular, plazma Endoglin düzeyleri ile karşılaştırılmıştır. Tez çalışması kapsamında ayrıca, hasta ve kontrol gönüllülerden alınan kan örneklerinden daha önceki çalışmalarda izole edilmiş olan RNA örnekleri kullanılmış olup, söz konusu materyal ile endoglin ve PLA2 mRNA ekspresyon düzeylerinin analizleri Real-Time PCR yöntemi ile gerçekleştirilmiştir. Çalışmamızda kolorektal kanser grubu endoglin mRNA ekspresyonu ve PLA2 mRNA ekspresyonu düzeylerinin, kontrol grubuna göre anlamlı olarak yüksek olduğu saptanmıştır. Çalışma sonuçlarına göre, kolorektal kanser grubu plazma endoglin, NfκB, TGF-β1 düzeylerinin, kontrol grubuna göre anlamlı olarak yüksek olduğu saptanırken, cPLA2 ve sPLA2 düzeyleri incelendiğinde hasta ve kontrol grupları arasında istatistiksel olarak anlamlı bir farklılık bulunmamıştır. Kolorektal kanser grubuna ait plazma endoglin düzeyleri ile TGF-β1, cPLA2, sPLA2 düzeyleri arasındaki korelasyon incelendiğinde; bu parametreler arasında istatiksel olarak anlamlı bir korelasyon bulunamamışken, plazma NFκB ile karşılaştırılması sonucunda, iki parametre arasında istatiksel olarak anlamlı pozitif korelasyon olduğu saptanmıştır. Çalışmanın sonuçları kolorektal kanserde hem plazma düzeyleri hem de gen ekspresyon düzeyleri ile ölçülen endoglin artışının enflamasyonla bağlantılı olabileceğini, dolayısıyla enflamasyon varlığının anjiyogenez ve neovaskülarizasyonu desteklediğini düşündürmektedir. Anahtar sözcükler: Endoglin, Kolorektal Kanser, NFκB, PLA2, TGF-β1The Relationship Between Endoglin Levels and Inflammatory Microenvironment in Colorectal Cancer Patients Colorectal cancer (CRC) is one of the most common cancers worldwide and is one of the leading causes of cancer-related deaths. The causal link between inflammation and cancer has been proposed based on the observation that tumors often develop in a chronic inflammatory environment and that inflammatory cells are present in tumor biopsy specimens. Epidemiological studies have revealed that chronic inflammation provides a basis for different types of cancer. There is a great deal of evidence to suggest that chronic inflammation can support cancer development and that tumor-induced inflammation maintains tumor progression by creating a snowball effect. In this study, sPLA2, cPLA2, NfκB, TGF-β1 levels were measured by ELISA (enzyme-linked immunosorbent assay) in blood plasma samples of patients with colorectal cancer and healthy volunteers and the results were compared with plasma endoglin levels. In addition, RNA samples isolated in the previous studies from blood samples of patient and control volunteers were used, and endoglin and PLA2 mRNA expression levels were analyzed by Real-Time PCR. In this study, endoglin mRNA expression and PLA2 mRNA expression levels in colorectal cancer group were found significantly higher than in the control group. According to the results of the study, plasma endoglin, NfκB, TGF-β1 levels were found significantly higher in colorectal cancer group compared to control group, while there was no statistically significant difference in plasma cPLA2 and sPLA2 levels between colorectal cancer and control groups. There was no statistically significant correlation between endoglin plasma levels and TGF-β1, cPLA2, sPLA2 plasma levels of colorectal cancer patients group, while plasma NFκB levels was found statistically significant positive correlation with endoglin plasma levels. The results of the study suggest that the increase of endoglin determined by both plasma levels and gene expression levels in colorectal cancer may be associated with inflammation, and therefore the presence of inflammation promotes angiogenesis and neovascularization. Key words: Colorectal cancer, Endoglin, NFκB, PLA2, TGF-β
The evaluation of anticancer efficiency of piroxicam in human prostate cancer cells
No full textKanser ve inflamasyon arasındaki ilişki yıllardır bilinmekle birlikte prostat kanseri ile inflamasyon ve inflamatuvar ajanlar arasındaki ilişki son zamanlarda yapılan çalışmalarla ortaya konulmuştur. Araştırmalar, inflamasyon tedavisinde etkin olan nonsteroidal antiinflamatuvar ilaçların (NSAİ), prostaglandin sentezini ya siklooksijenaz aktivitesini inhibe etme yetenekleri sayesinde ya da bu mekanizmalardan bağımsız olarak, bazı kanser türlerinde de tedaviye yardımcı olabileceğini göstermiştir. Bununla birlikte son yıllarda yapılan çalışmlar, bazı NSAİ'lerin düzenli kullanımla prostat kanseri riskini azalttığı ya da önlediğini ortaya koymuştur. Bu tez çalışmasında, NSAİ grubundan bir ilaç olan piroksikamın, insan prostat kanser hücreleri üzerindeki antikanser etkinliğinin değerlendirilmesi amaçlanmış ve bu kapsamda, androjen bağımsız PC-3 insan prostat kanser hücreleri üzerinde çalışılmıştır. Çalışmada, piroksikamın hücreler üzerindeki sitotoksik etkisi 3-(4,5-dimetiltriazol-2-il).2,5-difeniltetrazolium bromür (MTT) testi ile saptanmıştır. Sitotoksik etkinin gözlendiği konsantrasyonlarda, söz konusu hücrelerde, hücre döngüsü ve çeşitli apoptotik etki mekanizmalarının değerlendirimesi çalışmaları gerçekleştirilmiştir. Hücreler üzerinde yapılan MTT testi sonucunda, piroksikamın PC-3 hücrelerinde 48. saatte sitotoksik etki gösterdiği saptanmış ve tespit edilen konsantrasyonlarla yapılan hücre döngüsü analiziyle, hücre döngüsünü S evresinde durdurduğu tespit edilmiştir. Piroksikamın söz konusu hücreler üzerindeki apoptotik etkisinin tespiti amacıyla Annexin V bağlanma testi yapılmış ve kontrol grubuna kıyasla elde edilen verilerde erken apoptotik hücre popülasyonunda istatistiksel olarak anlamlı artış tespit edilmiştir. Piroksikamın PC-3 hücrelerinde apoptotik etkisinin saptanmasının ardından apoptotik etkinin detaylandırılabilmesi amacı ile hücrelerdeki kaspaz düzeyleri ve mitokondriyel potansiyel değişiklikleri tayin edilmiştir. Piroksikamın bahsi geçen hücreler üzerinde total kaspaz düzeylerini ve mitokondri membran depolarizasyonunu anlamlı olarak arttırdığı sonuçları elde edilmiştir. Çalışmanın sonuçları, bir nonsteroidal antiinflamatuvar bileşik olan piroksikamın, PC-3 hücrelerinde sitotostik ve apoptotik etki gösterdiğini ve prostat kanserinde umut vadedici bir bileşik olabileceğini ortaya koymaktadır.Although the relationship between cancer and inflammation has been known since decades, this relationship has been discovered with recent studies. Studies have shown that nonsteroidal antiinflammatory drugs (NSAIDs) can assist chemotherapy in certain cancer types, with or without affecting prostaglandin biosynthesis or cyclooxygenase activity. Additionally, recent studies have proven that regular usage of some NSAIDs may prevent prostate cancer or decrease the risk. In this thesis study, the purpose mainly consists of the assessment the anticancer activity of piroxicam, a member of NSAIDs, against human prostate cancer cells. In this context, androgen-independent PC-3 human prostate cancer cells were used. 3-(4,5-dimethyltriazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test was implemented to determine cytotoxic activity of piroxicam. At these cells, evaluations of cell cycle and various apoptotic mechanisms were conducted at cytotoxic concentrations. As a result of MTT analysis on cells, cytotoxic activity of piroxicam in PC-3 cells was determined after 48 hours. Via cell cycle analysis at certain detected concentrations, it has been proven that this compound halts cell cycle at S phase. To determine apoptotic activity of this compound against this cell line, Annexin V test was used. According to the data collected by comparing to the control group, a statistically significant increase has been found. After evidencing apoptotic activity of piroxicam in PC-3 cells, to add further detail on this activity, caspase levels and mitochondrial potential changes have been analyzed. As a result of these tests, a significant increase of total caspase levels and mitochondrial membran depolarization has been found. The results of this study shows that piroxicam, which is a nonsteroidal antiinflammatory drug exhibits cytotoxic and apoptotic activity in PC-3 cells and may be a promising drug against prostate cancer
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
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
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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