1,721,049 research outputs found
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
Establishment of subcellular fractionation techniques to monitor the intracellular fate of polymer therapeutics II. Identification of endosomal and lysosomal compartments in HepG2 cells combining single-step subcellular fractionation with fluorescent imaging
No full textAs they are often designed for lysosomotropic, endosomotropic and/or transcellular delivery, an understanding of intracellular trafficking pathways is essential to enable optimised design of novel polymer therapeutics. Here, we describe a single-step density gradient subcellular fractionation method combined with fluorescent detection analysis that provides a new tool for characterisation of endocytic traffic of polymer therapeutics. Hepatoma (HepG2) cells were used as a model and cell breakage was optimised using a cell cracker to ensure assay of the whole cell population. After removal of unbroken cells and nuclei, the cell lysate as a post-nuclear supernatant (PNS) was layered onto an iodixanol (OptiPrepTM) density gradient optimised to 5-20%. Early endosomes, late endosomes and lysosomes were identified from gradient fractions by immunoblotting for marker proteins early endosome antigen 1 (EEA 1) and lysosomal associated membrane protein 1 (LAMP 1) using horseradish peroxidase or fluorescently-labelled secondary antibodies. Lysosomes were also detected using N-acetyl-β-glucosamindase (Hex A) activity. In addition, cells were incubated with Texas-red labelled transferrin (TxR-Tf) for 5 min to specifically label early endosomes and this was directly detected from SDS-PAGE gels. Internalised macromolecules and colloidal particles can potentially alter vesicle buoyant density. To see if typical macromolecules of interest would alter vesicle density or perturb vesicle traffic, HepG2 cells were incubated with dextran or a polyethyleneglycol (PEG)-polyester dendron G4 (1 mg/ml for 24 h). The PEG-polyester dendron G4 caused a slight redistribution of endocytic structures to lower density fractions but immunofluorescence microscopy showed no obvious dendron effects. In conclusion, the combined subcellular fractionation with fluorescent imaging approach described here can be used as a tool for both fundamental cell biology research and/or the quantitative localisation of polymer therapeutics in the endocytic pathway
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
DENSITY-DEPENDENT RESPONSIVENESS TO AUTOCRINE GROWTH-FACTORS OF EPSTEIN-BARR-VIRUS TRANSFORMED HUMAN LYMPHOCYTES-B
No full textAnalysis of the growth requirements of Epstein-Barr virus (EBV)-transformed B lymphocytes shows that interleukin 1 and thioredoxin, a disulfide reducing enzyme, are able to induce a marked increase in DNA synthesis in the early phases of in vitro culture. By contrast, interleukin 6 induces a steady increase in DNA synthesis comparable to that observed with crude conditioned supernatant. Furthermore, EBV-transformed B cells exhibit a density-dependent responsiveness to autocrine growth factors, thus suggesting that growth regulation of EBV-transformed B cells might result from the interplay between different self-stimulating soluble factors and from the competence of the cells to respond to autocrine growth factors
On the Exploitation of the Extended Minimum Cost Flow (EMCF) Phase Unwrapping Algorithm for the Generation of Deformation Time-Series
No full textL’interferometria SAR differenziale per il monitoraggio delle deformazioni della superficie terrestre: il caso della provincia di Cagliari
No full textAppropriate 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
Analysis of a subsidence phenomenon via DInSAR data and geotechnical criteria
Full text linkThe paper discusses, using geotechnical criteria, the potentialities offered by the Small BAseline Subset (SBAS) Differential Synthetic Aperture Radar Interferometry (DInSAR) technique to investigate a subsidence phenomenon affecting the urban area of Sarno town (Campania Region, Italy). To this aim, low- and full-resolution data, acquired by ERS-1/2 and Envisat satellites in the period from 1992 to 2004, have been used. In particular, low-resolution DInSAR data, once validated via a comparison with ground levelling data, are analyzed in order to detect the most subsidence-affected areas where damages to buildings were recorded during past surveys. Interesting correlation between the ground deformation gradient vectors and some damage characteristics, such as the direction of building rotation axes, are shown. Then, a preliminary analysis at “building scale” by means of full-resolution DInSAR data is presented in order to study the response of some buildings to ground movements, also deriving the maximum values attained by some relevant parameters to be used in damage criteria. Finally, the usefulness of low- and full-resolution analyses for monitoring of urbanized areas is highlighted by stressing the role that the geotechnical approach can play in DInSAR data validation process as well as in pointing out all the issues to improve the reliability of the obtained results in at “building scale” studies
The Extended SBAS Technique For Generating Long Term Full Resolution Ers/Envisat Deformation Time-Series
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