1,720,959 research outputs found
Plant homeodomain-leucine zipper transcription factors: toward the understanding of functional differences between the different members through a molecular analysis. Particular characterization of the Arabidopsis thaliana gene AtHB1
No full textFil: Capella, Matías. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina.Las proteínas HD-Zip son factores de transcripción (FT) exclusivos de plantas, que se clasifican en cuatro subfamilias. Los miembros de la subfamilia I se asocian principalmente a respuestas de estrés abiótico. La caracterización funcional de varios miembros indicó que cumplen un papel en diferentes vías de transducción de señales, aun cuando sus patrones de expresión son similares y unen la misma secuencia blanco de ADN. Un análisis bioinformático reveló la existencia de motivos conservados por fuera del dominio HD-Zip, que incluyen motivos putativos de transactivación. Demostramos que AtHB1, AtHB7, AtHB12 y AtHB13 presentan diferentes grados de actividad transcripcional en plantas y levaduras, y que el segmento proteico necesario para tal activación es distinto entre estas proteínas. Además, estos TFs interaccionan diferencialmente con TBP2 y TFIIB. Por otro lado, AtHB1 es un HD-Zip I descripto como un activador transcripcional con función desconocida, por lo que investigamos su función en el desarrollo vegetal. AtHB1 se expresa principalmente en los hipocotilos y las raíces, y en plántulas se induce en condiciones de día corto. Demostramos que este FT actuaria corriente abajo de PIF1 para regular la expresión de proteínas relacionadas al crecimiento, promoviendo de esta forma la elongación celular del hipocotilo, especialmente en respuesta a fotoperiodos de día corto. Finalmente, la región 5 no codificante regula negativamente la expresión de AtHB1 e inhibe la traducción inducida por etileno de este FT, que a su vez tendría un papel negativo en la promoción por etileno del crecimiento del hipocotilo en luz.Homeodomain-leucine zipper (HD-Zip) proteins are transcription factors (TF) unique to plants, classified in four subfamilies. Subfamily I members have been mainly associated to abiotic stress responses. The functional characterization of several members indicated that they take part in different signal transduction pathways even when their expression patterns are similar and they have high binding affinity for the same DNA sequence. A recent bioinformatic analysis revealed the existence of conserved motifs outside the HD-Zip domain, including putative transactivation motifs. We demonstrated that AtHB1, AtHB7, AtHB12 and AtHB13 exhibited activation activities in yeast and plants but with different degrees, and the protein segment necessary for such activation is different for these proteins. Furthermore, these TFs differentially interact with TBP2 and TFIIB. Their differential activation ability significantly contributes to the functional divergence presented by these HD-Zip I proteins, and together with their expression patterns, these differences could explain, at least in part, such functional divergence. Furthermore, AtHB1 is a HD-Zip I TF described as a transcriptional activator with unknown function and its role in Arabidopsis thaliana development was investigated. AtHB1 is mainly expressed in hypocotyls and roots and up-regulated in seedlings grown under a short-day photoperiod. We demonstrated that this TF would act downstream of PIF1 to regulate growth-related proteins expression, thus promoting hypocotyl cell elongation, especially in response to short-day photoperiod. Finally, a conserved 5 UTR negatively regulates AtHB1 expression and inhibits ethylene-translation induction of this TF, which in place would be playing a negative role in ethylene-promoted hypocotyl growth in light.Consejo Nacional de Investigaciones Científicas y Técnica
Plant homeodomain-leucine zipper transcription factors: toward the understanding of functional differences between the different members through a molecular analysis. Particular characterization of the Arabidopsis thaliana gene AtHB1
No full textFil: Capella, Matías. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina.Las proteínas HD-Zip son factores de transcripción (FT) exclusivos de plantas, que se clasifican en cuatro subfamilias. Los miembros de la subfamilia I se asocian principalmente a respuestas de estrés abiótico. La caracterización funcional de varios miembros indicó que cumplen un papel en diferentes vías de transducción de señales, aun cuando sus patrones de expresión son similares y unen la misma secuencia blanco de ADN. Un análisis bioinformático reveló la existencia de motivos conservados por fuera del dominio HD-Zip, que incluyen motivos putativos de transactivación. Demostramos que AtHB1, AtHB7, AtHB12 y AtHB13 presentan diferentes grados de actividad transcripcional en plantas y levaduras, y que el segmento proteico necesario para tal activación es distinto entre estas proteínas. Además, estos TFs interaccionan diferencialmente con TBP2 y TFIIB. Por otro lado, AtHB1 es un HD-Zip I descripto como un activador transcripcional con función desconocida, por lo que investigamos su función en el desarrollo vegetal. AtHB1 se expresa principalmente en los hipocotilos y las raíces, y en plántulas se induce en condiciones de día corto. Demostramos que este FT actuaria corriente abajo de PIF1 para regular la expresión de proteínas relacionadas al crecimiento, promoviendo de esta forma la elongación celular del hipocotilo, especialmente en respuesta a fotoperiodos de día corto. Finalmente, la región 5 no codificante regula negativamente la expresión de AtHB1 e inhibe la traducción inducida por etileno de este FT, que a su vez tendría un papel negativo en la promoción por etileno del crecimiento del hipocotilo en luz.Homeodomain-leucine zipper (HD-Zip) proteins are transcription factors (TF) unique to plants, classified in four subfamilies. Subfamily I members have been mainly associated to abiotic stress responses. The functional characterization of several members indicated that they take part in different signal transduction pathways even when their expression patterns are similar and they have high binding affinity for the same DNA sequence. A recent bioinformatic analysis revealed the existence of conserved motifs outside the HD-Zip domain, including putative transactivation motifs. We demonstrated that AtHB1, AtHB7, AtHB12 and AtHB13 exhibited activation activities in yeast and plants but with different degrees, and the protein segment necessary for such activation is different for these proteins. Furthermore, these TFs differentially interact with TBP2 and TFIIB. Their differential activation ability significantly contributes to the functional divergence presented by these HD-Zip I proteins, and together with their expression patterns, these differences could explain, at least in part, such functional divergence. Furthermore, AtHB1 is a HD-Zip I TF described as a transcriptional activator with unknown function and its role in Arabidopsis thaliana development was investigated. AtHB1 is mainly expressed in hypocotyls and roots and up-regulated in seedlings grown under a short-day photoperiod. We demonstrated that this TF would act downstream of PIF1 to regulate growth-related proteins expression, thus promoting hypocotyl cell elongation, especially in response to short-day photoperiod. Finally, a conserved 5 UTR negatively regulates AtHB1 expression and inhibits ethylene-translation induction of this TF, which in place would be playing a negative role in ethylene-promoted hypocotyl growth in light.Consejo Nacional de Investigaciones Científicas y Técnica
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
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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