1,721,781 research outputs found
Open access self-archiving: An author study
No full textThis, our second author international, cross-disciplinary study on open access had 1296 respondents. Its focus was on self-archiving. Almost half (49%) of the respondent population have self-archived at least one article during the last three years. Use of institutional repositories for this purpose has doubled and usage has increased by almost 60% for subject-based repositories. Self-archiving activity is greatest amongst those who publish the largest number of papers. There is still a substantial proportion of authors unaware of the possibility of providing open access to their work by self-archiving. Of the authors who have not yet self-archived any articles, 71% remain unaware of the option. With 49% of the author population having self-archived in some way, this means that 36% of the total author population (71% of the remaining 51%), has not yet been appraised of this way of providing open access. Authors have frequently expressed reluctance to self-archive because of the perceived time required and possible technical difficulties in carrying out this activity, yet findings here show that only 20% of authors found some degree of difficulty with the first act of depositing an article in a repository, and that this dropped to 9% for subsequent deposits. Another author worry is about infringing agreed copyright agreements with publishers, yet only 10% of authors currently know of the SHERPA/RoMEO list of publisher permissions policies with respect to self-archiving, where clear guidance as to what a publisher permits is provided. Where it is not known if permission is required, however, authors are not seeking it and are self-archiving without it. Communicating their results to peers remains the primary reason for scholars publishing their work; in other words,
researchers publish to have an impact on their field. The vast majority of authors (81%) would willingly comply with a mandate from their employer or research funder to deposit copies of their articles in an institutional or subject-based repository. A further 13% would comply reluctantly; 5% would not comply with such a mandate
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
Pré-Tratamento para Amostras de Concreto, Atum, Material Refratário e Argilas para as análises de cloreto, sódio, silica e metais respectivamente
Get PDFTCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Curso de Química.Grande parte das principais metodologias empregadas em nossos estudos foram dedicadas aos métodos de pré-tratamento que transformam amostras solidas em soluções verdadeiras. Os métodos de solubilização utilizados foram conduzidos por via úmida e por via seca, dependendo da natureza e característica das amostras. Na decomposição por via seca, o ar freqüentemente, o oxigênio puro, atuou como oxidante ao lado da pirolise do material, quando esta se processou em mufla a altas temperaturas. Em determinadas situações entretanto, a dissolução total das amostras não era desejável, mas sim a dissolução seletiva de um ou outros elementos de interesse ficando o restante da amostra (fração insolúvel) no estado sólido. Por outro lado, existiram vários inconvenientes encontrados durante o pré-tratamento de amostras, bem como a perda do analito durante a etapa de dissolução da amostra e possíveis riscos de contaminação. No tratamento das amostras por via úmida, os reagentes utilizados foram geralmente ácidos concentrados. Em geral, o tratamento de amostras conduzidas por via úmida ofereceu como grande vantagem o uso de temperaturas relativamente baixas, evitando assim perdas por volatilização, e a rapidez do método em sua execução. A decomposição normalmente foi executada sob temperatura variando entre 100 a 250 °C em sistema aberto ou à pressão atmosférica ou alta pressão (com o uso de recipientes fechados — bombonas de teflon), ambos os métodos empregando-se ácidos minerais fortemente oxidantes, como o ácido nítrico (HNO3), Acido súlfurico (H2SO4) e ácido perclorico (HC104); bem como o ácido forte, porém não um agente oxidante, o ácido clorídrico (HC1) e o Acido fluoridrico (HF), sendo este ultimo utilizado somente para a solubilização de amostras contendo silica e silicatos. Após o pré-tratamento das amostras, várias foram as técnicas analíticas empregadas, objetivando-se a determinação quantitativa de um dado analito. Os métodos analíticos empregados, foram a titrimetria, gravimetria, colorimetria, turbidimetria, potenciometria com eletrodos de ions seletivo, espectrofotometria e fotometria de chama. Neste trabalho, as várias técnicas empregadas, permitiram a quantificação de parâmetros utilizados com diferentes propósitos, bem como a qualidade de Aguas disponíveis para uso doméstico ou industrial, a qualificação de areias empregadas na construção civil e qualidade dos combustíveis mediante a quantidade de água neles encontrada
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
Biosynthesis of Arcyriaflavin F from Streptomyces venezuelae ATCC 10712.
Get PDFIndolocarbazoles are natural products with broad bioactivities. A distinct feature of indolocarbazole biosynthesis is the modification of the indole and maleimide rings by regioselective tailoring enzymes. Here, we study a new indolocarbazole variant, which is encoded by the acfXODCP genes from Streptomyces venezuelae ATCC 10712. First we characterise this pathway by expressing the acfXODCP genes in Streptomyces coelicolor, which led to the production of a C-5/C-5'-dihydroxylated indolocarbazole. We assign as a new product arcyriaflavin F. Second, we demonstrate the flavin-dependent monooxygenase AcfX catalyses the C-5/C-5' dihydroxylation of the unsubstituted arcyriaflavin A into arcyriaflavin F. Interestingly, AcfX shares homology to EspX from erdasporine A biosynthesis, which instead catalyses a single C-6 indolocarbazole hydroxylation. In summary, we report a new indolocarbazole biosynthetic pathway and a regioselective C-5 indole ring tailoring enzyme AcfX
Biosynthesis of Arcyriaflavin F from Streptomyces venezuelae ATCC 10712
Get PDFIndolocarbazoles are natural products with a broad spectrum of reported bioactivities. A distinct feature of indolocarbazole biosynthesis is the modification of the indole and maleimide rings by regioselective tailoring enzymes. Here, we study a new indolocarbazole variant, which is encoded by the acfXODCP genes from Streptomyces venezuelae ATCC 10712. First, we characterise this pathway by expressing the acfXODCP genes in Streptomyces coelicolor, which led to the production of a C-5/C-5’-dihydroxylated indolocarbazole. We name this new product arcyriaflavin F. Second, we demonstrate the flavin-dependent monooxygenase AcfX catalyses the C-5/C-5’ dihydroxylation of the unsubstituted arcyriaflavin A into arcyriaflavin F. Interestingly, AcfX shares homology to EspX from erdasporine A biosynthesis, which instead catalyses a single C-6 indolocarbazole hydroxylation. In summary, we report a new indolocarbazole biosynthetic pathway and a regioselective C-5 indole ring tailoring enzyme AcfX
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