1,720,961 research outputs found
Studio di una putativa proteasi nucleare essenziale per la cellula di lievito e conservata dagli archebatteri all'uomo
No full textIn questo lavoro analizziamo alcune caratteristiche della proteina Kae1 di Saccharomyces cerevisiae. Essa è codificata da un gene essenziale ed è classificata come metallo-proteasi in base all’omologia di sequenza con una O-Sialo-Glico-Endo-Peptidasi di Pasteurella haemolytica. Kae1, che è localizzata prevalentemente nel nucleo, fa parte di un complesso multi proteico al quale appartiene anche la proteina piD261/Bud32. Quest’ultima è una Ser-Thr protein chinasi appartenente ad una sub famiglia, molto conservata, originatasi prima della divergenza tra Archebatteri ed Eucarioti. Il suo ruolo nel lievito è essenziale per la normale crescita cellulare e anche l’omologo umano, PRPK, è probabilmente coinvolto nel controllo della crescita cellulare, dal momento che è in grado di fosforilare p53 in corrispondenza di Ser-15, evento che porta al blocco del ciclo cellulare in seguito a danni al DNA. Anche la sequenza di Kae1 è molto conservata ed il suo omolog umano è chiamato OSGEP.
Qui mostreremo come PRPK e OSGEP siano omologhi funzionali delle corrispondenti proteine di lievito, grazie a saggi di complementazione fenotipica e anche che le due proteine PRPK e OSGEP sono in grado di interagire tra loro a supporto di un rilevante significato fisiologico di tale interazione. Dimostreremo inoltre che il mantenimento del motivo di legame al metallo HCIGH in Kae1 e OSGEP è correlato all’attività di tali proteine, dato che la sostituzione delle due istidine causa un fenotipo letale indistinguibile dalla delezione genica. Il nostro interesse è rivolto anche alla caratterizzazione del legame del metallo, data la particolarità della presenza inusuale di una cisteina nel motivo.
L’aspettativa è quella di dimostrare l’attività catalitica in vitro della putativa proteasi Kae1 isolata da lievito e di confermare il legame dello ione metallico, definendo i residui coinvolti in tale legame, attraverso saggi di assorbimento atomico sulle proteine, di tipo selvatico e mutanti, espresse in E. coli
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
In-depth study of two genes out af a six-pack: a protein kinase and a hemoglobin characterised by unusual structures.
No full textDispelling 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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