1,720,977 research outputs found
Astrocytic tumors: role of antiapoptotic proteins
No full textApoptosis is a fundamental anti-neoplastic
AQ1
mechanism to prevent tumorigenesis. Nearly all neoplastic
changes during the development of a normal
cell to a cancer cell, such as DNA-damage, oncogene
activation or cell cycle deregulation, are potent inducers
of the programmed cell death pathway. Therefore,
overcoming the apoptotic failsafe is a key mechanism
in the genesis and progression of tumors. In
astrocytic brain tumors, the apoptotic failure has been
documented and involves both the intrinsic or mitochondrial
and extrinsic or receptor pathways of apoptosis.
This breakdown may be caused by an imbalance
of pro- and antiapoptotic members of the Bcl-2 protein
family, inhibition of the activity of caspases by
specific factors, changes in the p53 system. Detailed
molecular knowledge of the anti-apoptotic mechanisms
of astrocytic tumor cells is essential for the
improvement of conventional chemotherapies and the
development of new potent targeted therapies. In this
chapter, authors describe the multiple antiapoptotic
signals that have been demonstrated to be active in
astrocytomas
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
Role of inflammation and oxidative stress mediators in gliomas
Full text linkGliomas are the most common primary brain tumors of the central nervous
system. Despite relevant progress in conventional treatments, the prognosis of such tumors
remains almost invariably dismal. The genesis of gliomas is a complex, multistep process
that includes cellular neoplastic transformation, resistance to apoptosis, loss of control of
the cell cycle, angiogenesis, and the acquisition of invasive properties. Among a number of
different biomolecular events, the existence of molecular connections between
inflammation and oxidative stress pathways and the development of this cancer has been
demonstrated. In particular, the tumor microenvironment, which is largely orchestrated by
inflammatory molecules, is an indispensable participant in the neoplastic process,
promoting proliferation, survival and migration of such tumors. Proinflammatory
cytokines, such as tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma, as
well as chemokines and prostaglandins, are synthesized by resident brain cells and
lymphocytes invading the affected brain tissue. Key mediators of cancer progression
include nuclear factor-kappaB, reactive oxygen and nitrogen species, and specific
microRNAs. The collective activity of these mediators is largely responsible for a
pro-tumorigenic response through changes in cell proliferation, cell death, cellular
senescence, DNA mutation rates, DNA methylation and angiogenesis. We provide a
general overview of the connection between specific inflammation and oxidative stress
pathway molecules and gliomas. The elucidation of specific effects and interactions of
these factors may provide the opportunity for the identification of new target molecules
leading to improved diagnosis and treatment
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
Dispelling 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
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