1,721,026 research outputs found
Effects of C/EBP alpha and C/EBP beta in BCR/ABL-expressing cells - Differences and similarities
No full textC/EBP alpha and C/EBP beta, two transcription factors of the C/EBP family play important roles in the proliferation and differentiation of various cell types including myeloid progenitors. Expression of C/EBP alpha and C/EBP beta is repressed in myeloid blast crisis of Chronic Myelogenous Leukemia by mechanisms that involve translation repression which depends on the interaction of RNA-binding proteins with conserved binding sites in the 5'UTR of c/ebp alpha and c/ebp beta mRNA. Ectopic expression of C/EBP alpha and C/EBP beta in myeloid progenitors expressing the BCR/ABL oncogene inhibits proliferation, induces differentiation and suppresses leukemogenesis in mice, but C/EBP a is markedly more effective than C/EBP beta. The more potent effects of C/EBP a probably depends on protein-protein interaction with cell-cycle regulatory proteins, but the pattern of genes modulated by C/EBP alpha and C/EBP beta is not completely overlapping. This suggests that transcription-dependent and -independent effects are both involved and support the therapeutic potential of reactivating C/EBP alpha and C/EBP beta expression in leukemic cells
P2X purinoceptors in postmortem human cerebral arteries
No full textPharmacological studies have demonstrated that various purinoceptors are involved in the control of the cerebral vascular tone in many species. In this study, the existence of P2X purinoceptors in the postmortem human cerebral arteries was investigated with organ-bath pharmacology, autoradiography, and immunohistochemistry. Specimens were obtained from the M2 region of the middle cerebral arteries from human cadavers with an age range of 53-91 years and postmortem time of 37-54 h. Application of α,β- methylene adenosine triphosphate (ATP) produced concentration-dependent contraction in the arterial ring, whereas transmural nerve stimulation and noradrenaline did not elicit contraction. Autoradiography using [3H]α,β- methylene ATP (a radioligand for P2X purinoceptors) showed specific [3H]α,β-methylene ATP binding sites in the smooth-muscle cells of the postmortem human cerebral arteries. Immunohistochemistry with specific P2X1 purinoceptor antibodies revealed positive staining exclusively in the smooth muscle of the same specimens. All these results demonstrate the existence of P2X purinoceptors in human cerebral arteries, which were still functionally active despite the long postmortem time. The results from this study suggest that the postmortem human cerebral arteries can be useful specimens for studying the P2X purinoceptor-mediated responses
Nematode and microarthropod communities: comparative use of soil quality bioindicators in covered dump and natural soils.
No full textReclaimed waste disposal sites usually have problems regarding soil quality. Their topsoil is generally affected by physical, biological and sometimes chemical degradation. These conditions in turn affect both site plant and animal communities and, in a more general sense, the effectiveness of the restoration process itself. The site’s fauna, either inherited with the soil or established after its introduction, has a community complexity defined by the structure of the soil: generally the more structured the soil, the more complex the community. There exists a relevant number of fauna bioindicators that can be used to evaluate soil quality and monitor the restoration process. We have used two bioindicators to compare our research results: the Maturity Index (MI), based on the nematode population and the Soil Biology Quality (QBS-ar) index, based on soil microarthropods. These indicators were applied to the topsoil of a reclaimed waste disposal site and to wild grassland and wood soils
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
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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