136,399 research outputs found
Y. Delatour, D. Jennepin, M. Léon-Dufour, A. Mattle, B. Teyssier, 350 exercices de grammaire, Paris, Hachette, 1987
No full textRiegel Martin. Y. Delatour, D. Jennepin, M. Léon-Dufour, A. Mattle, B. Teyssier, 350 exercices de grammaire, Paris, Hachette, 1987. In: L'Information Grammaticale, N. 36, 1988. pp. 46-47
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Analysis of DNA methylation levels in wild and cultivated tomato species
No full textTomato plants are used as a model system to study fruit development and quality. Tomato fruit development can be divided into three main phases: cell division, cell elongation and fruit ripening. All these phases are associated with deep changes at the gene expression as well as at the epigenetic level. Cytosine methylation is an epigenetic mark associated with genetic inactivity and heterochromatin state in higher eukaryotes, including plants. In plants cytosines are mainly methylated at CG and CXG contexts and, at low levels, at CXX. These methylated sequences are widespread in the whole genome, but are present at higher density at LTR-retrotransposons.
Using genomic DNA methylation assays, we analysed the global and locus specific variations of CG and CXG methylation patterns to understand the potential role of epigenetic mechanisms during the development of tomato plants. The analysis showed changes in the cytosine methylation pattern at CG and CXG sites in fruits of the cultivated tomato Ailsa Craig (Teyssier et al., 2008, Planta 228: 391-9).
Domesticated and wild tomato species do show remarkable differences in terms of shape, colour, timing and development of fruits, therefore it is very interesting to compare these species also in terms of epigenetic variations.
The preliminary comparative analysis of DNA methylation in wild and cultivated tomato species indicated contrasting situations, characterized by different patterns of DNA methylation at repetitive loci such as the 5S rDNA, various retrotransposons and at single loci.
Furthermore, the analysis of the abundance of retrotransposons between species revealed differences in distribution and amount between wild and cultivated tomato species. A specific transposon-related case will be described, suggesting that the domestication process of tomato cultivated species might have been associated with DNA epigenetic variations
Analysis of DNA methylation levels in wild and cultivated tomato species
No full textTomato plants are used as a model system to study fruit development and quality. Tomato fruit development can be divided into three main phases: cell division, cell elongation and fruit ripening. All these phases are associated with deep changes at the gene expression as well as at the epigenetic level. Cytosine methylation is an epigenetic mark associated with genetic inactivity and heterochromatin state in higher eukaryotes, including plants. In plants cytosines are mainly methylated at CG and CXG contexts and, at low levels, at CXX. These methylated sequences are widespread in the whole genome, but are present at higher density at LTR-retrotransposons.
Using genomic DNA methylation assays, we analysed the global and locus specific variations of CG and CXG methylation patterns to understand the potential role of epigenetic mechanisms during the development of tomato plants. The analysis showed changes in the cytosine methylation pattern at CG and CXG sites in fruits of the cultivated tomato Ailsa Craig (Teyssier et al., 2008, Planta 228: 391-9).
Domesticated and wild tomato species do show remarkable differences in terms of shape, colour, timing and development of fruits, therefore it is very interesting to compare these species also in terms of epigenetic variations.
The preliminary comparative analysis of DNA methylation in wild and cultivated tomato species indicated contrasting situations, characterized by different patterns of DNA methylation at repetitive loci such as the 5S rDNA, various retrotransposons and at single loci.
Furthermore, the analysis of the abundance of retrotransposons between species revealed differences in distribution and amount between wild and cultivated tomato species. A specific transposon-related case will be described, suggesting that the domestication process of tomato cultivated species might have been associated with DNA epigenetic variations
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
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