1,720,992 research outputs found
S100B protein interacts with and activates Src kinase in astrocytes thereby regulating cell shape and migration: implications for astrocyte development, activation and tumor growth.
No full textSlow radioactive saliva transit through the esophagus mimicking a mediastinal thyroid mass in a patient with myasthenia gravis
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Exploring the Role of Hamiltonian Expressibility in Ansatz Selection for Variational Quantum Algorithms
Get PDFA key challenge in Variational Quantum Algorithms (VQAs) consists in designing effective parametric quantum circuits, or ansatzes, that account for both the specific problem and the limitations of quantum hardware. While Machine Learning-based methods for circuit construction have been developed, selecting the appropriate metrics to include in the cost function to ensure the circuit has the desired properties remains a non-trivial task. Hamiltonian expressibility has been proposed as a metric to quantify a circuit ability to explore the problem energy landscape. However, its potential to enhance the likelihood of obtaining high-quality solutions remains underexplored. In this work, we investigate the correlation between an ansatz Hamiltonian expressibility and the quality of solutions found using the Variational Quantum Eigensolver (VQE), aiming to determine whether such metric could enhance Machine Learning methods for ansatz design. Specifically, we propose a protocol to estimate the Hamiltonian expressibility of a given ansatz and Hamiltonian, and employ VQE to solve the associated optimization problem. By conducting a correlation analysis, we assess the relationship between Hamiltonian expressibility and solution quality. Our results suggest that Hamiltonian expressibility could serve as a valuable metric to enhance Machine Learning techniques used for ansatz design
S100B-induced increase in proliferation and decrease in NGF sensitivity of PC12 cells depends on PI3-K/Akt (PKB) activation
No full textS100B increases proliferation in PC12 neuronal cells and reduces their responsiveness to NGF via Akt activation
No full textS100B is a Ca2+-modulated protein of the EF-hand type expressed in high abundance in a restricted set of cell types including certain neuronal populations. S100B has been suggested to participate in cell cycle progression, and S100B levels are high in tumor cells, compared with normal parental cells. We expressed S100B in the neuronal cell line PC12, which normally does not express the protein, by the Tet-Off technique, and found the following: (i) proliferation was higher in S100B+ PC12 cells than in S100B- PC12 cells; (ii) nerve growth factor (NGF), which decreased the proliferation of S100B- PC12 cells, was less effective in the case of S100B+ PC12 cells; (iii) expression of S100B made PC12 cells resistant to the differentiating effect of NGF; and (iv) interruption of S100B expression did not result in an immediate restoration of PC12 cell sensitivity to the differentiating effect of NGF. Expression of S100B in PC12 cells resulted in activation of Akt; increased levels of p21WAF1, an inhibitor of cyclin-dependent kinase (cdk) 2 and a positive regulator of cdk4; increased p21WAF1-cyclin D1 complex formation; and increased phosphorylation of the retinoblastoma suppressor protein, Rb. These S100B-induced effects, as well as the reduced ability of S100B+ PC12 cells to respond to NGF, were dependent on Akt activation because they were remarkably reduced or abrogated in the presence of LY294002, an inhibitor of the Akt upstream kinase phosphatidylinositol 3-kinase. Thus, S100B might promote cell proliferation and interfere with NGF-induced PC12 cell differentiation by stimulating a p21WAF1/cyclin D1/cdk4/Rb/E2F pathway in an Akt-mediated manner
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
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