1,720,967 research outputs found
Proliferation and autophagic degradation of peroxisomes in Hansenula polymorpha
Een karakteristieke eigenschap van eukaryote cellen is de aanwezigheid van cel organellen. Gisten zijn geschikte modelorganismen voor onderzoek aan fundamentele celbiologische processen zoals organel vorming en afbraak. Deze ééncellige eukaryoten hebben een groot aantal experimentele voordelen, waaronder het gemak waarmee genetische modificaties kunnen worden aangebracht.
Het onderzoek dat beschreven staat in dit proefschrift richt zich op de vorming en afbraak van peroxisomen in de gist Hansenula polymorpha.
Met behulp van transcriptoom-analyse werd gekeken welke genen tot expressie komen wanneer de proliferatie van peroxisomen wordt geïnduceerd. Kort na inductie van peroxisoom proliferatie was de hoeveelheid transcript van de transcriptiefactor Mpp1 bijna 400 keer verhoogd. PEX genen betrokken bij peroxisoom-vorming werden echter nauwelijks geïnduceerd.
Pex14 en Pex3, twee peroxisomale membraan eiwitten die een rol spelen in peroxisoom vorming, zijn ook betrokken bij de afbraak van het organel.
Pex14 is een eiwit van een groter eiwit complex dat betrokken is bij de import van matrix eiwitten het peroxisoom in. Studies naar de rol van de andere eiwitten in dit complex in peroxisoom afbraak wezen uit dat alleen Pex14 betrokken is bij dit proces.
Pex3 wordt van het organel verwijderd tijdens de initiële stadia van peroxisoom afbraak. Onderzocht werd of artificiële Pex3-verwijdering afbraak van peroxisomen teweegbracht. Dit bleek inderdaad het geval te zijn. De morfologische kenmerken van peroxisoom afbraak verschilden echter van de bekende peroxisoom afbraak mechanismen. Een soortgelijk proces werd ook waargenomen wanneer peroxisomen blootgesteld werden aan oxidatieve stress. Dit suggereert dat beschadiging van peroxisomen, afbraak van de organellen kan induceren.
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
We 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
We 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.
Author-wise bibliometric analysis based on entropy.</p
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