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AP-1 signaling in skeletal muscle differentiation
Get PDFHeart failure is the final common pathway of most of the primary cardiovascular diseases, including hypertension, diabetes, cardiomyopathy, and valvular and congenital malfunctions. Most treatments slow the course of these primary diseases, but do not abolish them. Despite the significant progress in prevention and therapy of heart disease, treating patients with heart failure after myocardial infraction remains a major therapeutic challenge.
Adult cardiomyocytes cannot regenerate after injury. One of the most fascinating and potentially beneficial goals in the field of gene therapy for cardiovascular disease would be genetic manipulation leading to regeneration of myocytes after myocardial infraction. A potential strategy is to repopulate infracted areas of the myocardium with skeletal myocytes, which have been genetically engineered to reproliferate. In muscle cells, as in other cell types, the decision to divide or differentiate is determined by a balance of opposing cellular signals. During skeletal muscle differentiation (myogenesis), mononucleated proliferating myoblasts stop dividing, coordinately activate muscle specific gene expression and fuse into multinucleated myotubes.
It has been shown that during hypertrophy the activation of a fetal gene called skeletal alpha- actin (SkA) is associated with the AP-1 induction (Paradis et al., 1996). The AP-1 transcriptional factor is composed of dimers between Jun and Fos proteins. Thus characterization of the function of AP-1 in muscle differentiation may help to develop a new gene therapy technique for cardiovascular diseases.
Our hypothesis is that the AP-1 activity plays an important role in directing skeletal muscle cells to remain in a proliferative state. As a first step towards this goal, we engineered two different cell lines (C2C12 and SOLS) to generate the AP-1 reporter cell lines. The engineered cell lines are called C2/3XTRE and SOL8/3XTRE. The AP-1 activity during both proliferation and differentiation was measured in these engineered cell lines. We then used a dominant negative c-Jun molecule to down-regulate the AP-1 activity in the engineered cell lines and in HeLa cells (as a control of the results obtained by using the SOL8/3XTRE and C2/3XTRE). The results of this study can be summarized as follows:
1. AP-1 activity decreases as the growth factors in the growth medium decreases.
2. Expression of a dominant negative c-Jun (A169-cjun) induces myoblast differentiation in high serum.
3. AP-1 activity is a necessary signaling component directing myoblasts to remain in a proliferative state.
4. The AP-1 transcription factor is a promising target for gene therapy in muscle cells.
Suggested future work is the generation of a stable AP-1 reporter cell line, which should help to analyze both the AP-1 function and its components in a detailed manner. This will allow controlled expression of the gene of interest
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
MICRORNA-MEDIATED REGULATION OF SMAD1 IN THE VASCULAR ENDOTHELIUM PROMOTES CELL GROWTH ARREST
No full textkoamabayili/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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