305,174 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
A repeated chromosomal DNA sequence is amplified as a circular extrachromosomal molecule in rice (Oryza sativa L.)
No full textThe plasmid pE10 is a pBR322-derived plasmid carrying a 4.5 kb rice (Oryza sativa L.) repeated DNA sequence. The cloned sequence has been shown to be amplified in cultured rice cells. The analysis of practically intact chromosomal rice DNA molecules by pulsed field gel electrophoresis has now shown that the amplification is associated with the appearance of extrachromosomal molecules. In fact, pE10 hybridizes exclusively with unfractionated DNA from leaf protoplasts, while it recognizes predominantly an extrachromosomal DNA molecule (ECD) of about 45 kb and its multiples in the case of protoplasts from cultured cells. Insensitivity to the action of the exonuclease Bal31 suggests that the molecule is circular. Analysis of restriction endonuclease products with both standard horizontal and pulsed field gel electrophoresis suggest that the extrachromosomal DNA, and its chromosomal counterpart, is composed of tandemly repeated units of about 7 kb. Thus, the smaller extrachromosomal circle should contain 6–7 repeats, while the sequence cloned in pE10 is a subset of this repeat. The extrachromosomal DNA represents about 1 % of total rice DNA and its level of amplification is not affected by the different phases of growth in culture
A repeated chromosomal DNA sequence is amplified as a circular extrachromosomal molecule in rice (Oryza sativa L.)
No full textThe plasmid pE10 is a pBR322-derived plasmid carrying a 4.5 kb rice (Oryza sativa L.) repeated DNA sequence. The cloned sequence has been shown to be amplified in cultured rice cells. The analysis of practically intact chromosomal rice DNA molecules by pulsed field gel electrophoresis has now shown that the amplification is associated with the appearance of extrachromosomal molecules. In fact, pE10 hybridizes exclusively with unfractionated DNA from leaf protoplasts, while it recognizes predominantly an extrachromosomal DNA molecule (ECD) of about 45 kb and its multiples in the case of protoplasts from cultured cells. Insensitivity to the action of the exonuclease Bal31 suggests that the molecule is circular. Analysis of restriction endonuclease products with both standard horizontal and pulsed field gel electrophoresis suggest that the extrachromosomal DNA, and its chromosomal counterpart, is composed of tandemly repeated units of about 7 kb. Thus, the smaller extrachromosomal circle should contain 6-7 repeats, while the sequence cloned in pE10 is a subset of this repeat. The extrachromosomal DNA represents about 1% of total rice DNA and its level of amplification is not affected by the different phases of growth in culture
Circadian rhythmicity of serum lipids concentrations in elderly and young people: a particulare methodological approach of serum lipids evaluation.
No full textComunic. al “30° Congresso Nazionale della Società Italiana di Biochimica Clinica e Biologia Molecolare Clinica (SIBioC)”, Venezia 6-9 Ottobre 1998
Biotecnologie vegetali: strategie nell'ingegneria genetica per le specie ortofrutticole.
No full textDispelling 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
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
Get PDFThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
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