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Bitki moleküler filogenisinde kullanılan bazı gen ve yöntemlerin karşılaştırılması
No full textCanlıların sınıflandırılması ve canlı birliklerinin sınırlarının çizilmesi gözleme ve deneye dayalı sistemli bilgi üretmeye başlanmasıyla birlikte karşılaşılan en karmaşık problemlerden biri olmuştur. Bu amaçla araştırmacılar birçok kuram ve metot geliştirerek var olan canlı çeşitliliğini saptamaya çalışmışlardır. Bu çeşitliliği ortaya koyan moleküler sistematik çalışmaları özellikle son 20 yıldır hızla gelişmektedir. Bu gelişme süreci içinde dizi analizlerinin kullanımı ve yeni filogenetik analiz metotlarının bulunması moleküler sistematiğe de katkı sağlamaya başlamıştır. Filogenetik bilgi açısından morfolojik karakterlerin yetersiz olduğu fosil kaynaklarının bulunmadığı durumlarda dizi analizleri filogenetik analizler için çok faydalı olmaktadır. Bu çalışmada, filogenetik çalışmalarda etkin olarak kullanılabilecek gen, gen bölgesi, gen sayısı, genin hücresel lokasyonu (kloroplast, nükleus), gen veya genler için hizalama yöntemleri (alignment) ve hizalama yöntemleri ile hizalanmış veriler yaygın filogenetik analiz yöntemleri ve programları kullanılarak değerlendirilmiştir. Çalışmada dört farklı alignment programı (CLUSTAL W, T-COFFEE, MAFFT, MUSCLE) ve bu programlarda bulunan iki farklı algoritma kullanılmıştır.Filogenetik yöntemlerin karşılaştırılması için uzunluk (?Distance?), Maksimum Olası (Maksimum Liklelihood, ML), Maksimum Parsimoni (Maximum Parsimony, MP) ve Bayes-MCMC (BI) yöntemleri iki farklı veri seti kullanılarak karşılaştırılmıştır. Veri setlerinden birincisi 44 pamuk (Gossypium) türünden oluşturulmuş olup burada ITS1, ITS2, ITS1-ITS2 nüklear ribozomal RNA'ya ait DNA dizileri, ikinci veri seti ise çalı, ağaçsı, otsu, monokotiledon ve dikotiledondan oluşan toplam 60 taksondan ve 5 farklı lokustan (matK, trnH-psbA, accD, rpoC1, rpoB) oluşturulmuştur. Çalışmamız sonucunda yaptığımız analizlere dayanarak kullanılan alignment (hizalama) programlarından olan MAFFT'ın mevcut sekans verilerimizi en uygun bir şekilde hizalayarak doğru Gossypium ağaç topolojisini vermiştir. Aynı zamanda filogenetik metodları analiz etmek için mevcut veriye en uygun subtitüsyon modeli olarak GTR ve TN93 modeli önerilmiştir. Çalışmada kullanılan atmış bitki taksonu için ise bitki gruplarını yüksek posterior probability değerleri ayırt ettiğinden matK, ve trnH-psbA ilgili bitki grubu için markır geni olarak belirlenmiştir
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
Genetic characterization and virulence of Fusarium spp. isolated from chickpea
No full textAbstract: Fusarium wilt causing yield losses in chickpea is one of the most important diseases, and occurs due to some fungi especially F. oxysporum and F. solani. Molecular studies are important in revealing the genetic characterization and virulence of the pathogen. In this study ten Fusarium genotypes isolated from chickpea plants showing symptoms of wilting were used. The ITS region was amplifed by using the thermal cycler and genetic similarities and di?erences among species were revealed by performing sequence analysis of ITS region. Samples except for two of Fusarium genotypes; N1, N2, N3, N4, N5, N7, N9 and N10 genotypes showed a close relative to F. oxysporum. However, the N8 genotyped was found to be similar to F. solani, and interestingly the N6 genotype showed an equal relationship with F. solani and F. oxysporum so, it could not be fully identifed. According to the phylogenetic tree, F. oxysporum, N2, N4 and N10 were determined in a separate group and F. oxysporum N5, N7 and N9 formed separate another group which showed a close relationship to each other. The severity of disease caused by isolates on ILC-482 chickpea variety varied between 1.25 and 3.50. The close relationship was found between F. oxysporum, N2, N4, N5, N7, N9 and N10 isolates was confrmed the result of the pathogenicity test of same isolates. The results revealed that N7 isolate prevented the emergence of plants by causing disease on chickpea seeds and it also indicated the high virulence
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
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