1,720,967 research outputs found
The Three Subunits of the Polymerase and the Nucleoprotein of Influenza B Virus Are the Minimum Set of Viral Proteins Required for Expression of a Model RNA Template
No full textAbstractThe genes encoding the nucleoprotein, PB1, PB2, and PA proteins of the influenza virus strain B/Panamá/45/90 have been cloned under control of the T7 RNA polymerase promoter of plasmid pGEM-3. Transfection of the recombinant plasmids obtained into mammalian cells, which had been infected with a vaccinia virus encoding the T7 RNA polymerase, resulted in expression of the expected influenza B virus polypeptides. Moreover, it is shown that coexpression of the four recombinant core proteins in COS-1 cells reconstituted a functional polymerase capable of expressing a synthetic influenza B virus-like CAT RNA. By using the influenza B virus recombinant plasmids and a set of pGEM-derived plasmids encoding the homologous core proteins of the influenza A virus A/Victoria/3/75 (I. Menaet al.(1994).J. Gen. Virol.75, 2109–2114), the capabilities of homo- and heterotypic mixtures of the four core proteins to express synthetic type A and B CAT RNAs were analyzed. Both the influenza A and B virus polymerases were active in expressing, albeit with reduced efficiencies, the heterotypic model CAT RNAs. However, none of all possible heterotypic mixtures of the core proteins reconstituted a functional polymerase. In order to fully characterize the recombinant plasmids obtained, the nucleotide sequences of the cloned genes were determined and compared to sequences of other type B virus isolates. The results obtained from these latter analyses are discussed in terms of the conservation and evolution of the influenza B virus core genes
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
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
Epidemiología molecular de coronavirus SARS-CoV-2 en Mar del Plata y zonas aledañas.
Full text linkTesis de Maestría"La emergencia del coronavirus SARS-CoV-2 a fines de 2019 en China, y su rápida transmisión por el mundo generó una pandemia de gran impacto sanitario y económico. Su diagnóstico temprano y las medidas restrictivas de aislamiento permitieron limitar y controlar la diseminación regional, hasta el rápido desarrollo de vacunas eficaces que permitieron disminuir la gravedad de las infecciones respiratorias agudas (IRA). La secuenciación del genoma viral fue importante para el desarrollo de métodos diagnósticos moleculares sensibles y específicos, y para conocer su epidemiología molecular en tiempo real y evolución en el tiempo, así como detectar tempranamente mutaciones que pudieran afectar los métodos diagnósticos. Esta tesis se centra en la descripción de la epidemiología clásica y molecular del SARS-CoV-2 en la Región Sanitaria VIII de la provincia de Buenos Aires, Argentina, durante los dos primeros años de pandemia (marzo 2020 -diciembre 2021). Los principales objetivos fueron realizar la detección viral por RT-qPCR en pacientes con IRA para describir la frecuencia de SARS-CoV-2, y obtener secuencias del genoma viral completo o parcial del gen que codifica la proteína espícula, para conocer la diversidad viral y su dinámica en nuestra región mediante análisis de filogenia identificando linajes y variantes virales. Se analizaron muestras respiratorias obtenidas de 120421 pacientes con IRA, mediante extracción del ARN viral y posterior RT-qPCR. Los resultados se informaron al sistema Nacional SISA. La frecuencia de positividad de SARS-CoV-2 durante 2020 fue 37,4%, significativamente superior al 31,9% durante 2021 (p<0,001). Determinamos un aumento exponencial de casos positivos durante 2020 con pico en la SE37 (primera ola) seguido de un amesetamiento y disminución hacia la SE50; un rebrote de verano con pico de casos positivos en la SE2 de 2021 que descendió hacia la SE13; una segunda ola con pico en la SE20; y finalmente, un nuevo incremento de la positividad viral las últimas dos semanas de 2021. La mayoría de las muestras provenían de residentes de nuestra región, especialmente de General Pueyrredón (Mar del Plata); las muestras de viajeros representaron el 19% y 29% durante 2020 y 2021, respectivamente. Las muestras estudiadas y positivas para SARS-CoV-2 provenían mayoritariamente de adultos masculinos de 45-65 años. Se secuenciaron 22 muestras positivas del 2020 y detectamos por análisis de filogenia 4 linajes de SARS-CoV-2: B.1.1.33 y N.3 en la SE27, luego B.1.499 que fue el predominante, y a fin de año N.5. Durante 2021 se secuenciaron 235 genomas completos y 114 regiones parciales de espícula; detectamos 5 variantes de interés epidemiológico: las VOC Alpha, Gamma, Delta y Épsilon, y la VOI Lambda; Lambda y Gamma predominaron hasta el ingreso de Delta. Los resultados de esta tesis fueron fundamentales para conocer la frecuencia de SARS-CoV-2 y determinar los linajes y variantes que fueron ingresando y se diseminaron durante los dos primeros años de pandemia en la Región Sanitaria VIII. Ayudaron a la toma de decisiones de salud pública y contribuyeron al control de la transmisión, a partir de la colaboración de grupos multidisciplinarios de los Ministerios de Salud y Ciencia, Tecnología e Innovación Argentinos."The emergence of the SARS-CoV-2 coronavirus at the end of 2019 in China, along with its rapid transmission worldwide, resulted in a pandemic with significant health and economic consequences. Early diagnosis and strict isolation measures helped limit and control regional spread. Additionally, the development of effective vaccines reduced the severity of acute respiratory infections (ARI). The sequencing of viral genome played a crucial role in creating sensitive and specific molecular diagnostic methods, as well as understanding the real-time molecular epidemiology and evolutionary changes of the virus. It also facilitated the early detection of mutations that could impact diagnostic methods. This thesis focuses on describing the classical and molecular epidemiology of SARS-CoV-2 in the VIII Health Region of Buenos Aires, Argentina, during the first two years of the pandemic (March 2020 to December 2021). The main objectives were to detect the presence of the virus using RT-qPCR in patients with ARI, determine the frequency of SARS-CoV-2, and obtain sequences of the complete or partial viral genome, specifically the gene encoding the spike protein. These sequences were analyzed to assess viral diversity and dynamics in our region through phylogenetic analysis, allowing the identification of lineages and variants. Respiratory samples obtained from 120,421 patients with ARI were subjected to viral RNA extraction and subsequent RT-qPCR analysis. The results were reported to the National SISA system. The frequency of SARS-CoV-2 positivity in 2020 was 37.4%, significantly higher than the 31.9% recorded in 2021 (p<0.001). Positive cases experienced an exponential increase during 2020, peaking in EW37 (first wave), followed by a plateau and subsequent decrease towards EW50. There was a summer outbreak with a peak in positive cases during EW2 of 2021, which decreased towards EW13. This was followed by a second wave with a peak in EW20, and finally, a new increase in viral positivity in the last two weeks of 2021. Most of the samples were from residents of our region, particularly from General Pueyrredón (Mar del Plata). Traveler samples accounted for 19% and 29% of the total in 2020 and 2021, respectively. Samples tested and positive for SARS-CoV-2 mainly came from adult males aged 45-65 years. Twenty-two positive samples from 2020 were sequenced, and phylogenetic analysis identified four SARS-CoV-2 lineages: B.1.1.33 and N.3 in EW27, followed by B.1.499 as the predominant lineage, and finally N.5 towards the end of the year. In 2021, a total of 235 complete genomes and 114 partial spike regions were sequenced. Five variants of epidemiological interest were detected: the VOC Alpha, Gamma, Delta, and Epsilon, as well as the VOI Lambda. Lambda and Gamma were predominant until the emergence of the Delta variant. The results of this thesis were crucial in determining the frequency of SARS-CoV-2 and understanding the lineages and variants that entered and spread within the VIII Health Region during the first two years of the pandemic. They contributed to public health decision-making and facilitated the control of transmission through collaboration between multidisciplinary groups from the Argentine Ministries of Health and Science, Technology, and Innovation.Fil: Cimmino, Carlos José. Universidad Nacional de San Martín. Escuela de Bio y Nanotecnologías; Buenos Aires, Argentina
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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