1,720,990 research outputs found
El rol del guadalupanismo en la guerra de Independencia de México
No full textEl gudalupanismo en Nueva España , a diferencia de lo que sucedió en otras colonias latinoamericanas, tuvo el rol de cohesión y unión nacionales , todavía antes de que México fuera una nación idependiente
BETA-ARRESTIN DEPENDENT REGULATION OF CYTOSKELETON DYNAMICS AND SIGNALLING OF CHEMOKINE RECEPTOR ACKR2
No full textChemokines promote leukocyte migration through the activation of dedicated G-protein coupled receptors. Beyond conventional chemokine receptors, which directly induce cell migration through heterotrimeric Gαi-mediated signalling events, a set of atypical chemokine receptors (ACKRs) have been described. ACKRs do not activate Gαi-mediated signalling activity, but they are mainly involved in shaping the chemokine gradient. The best characterized member of this family is ACKR2.
ACKR2, previously referred to as D6, is a scavenger receptor that binds with high affinity to 13 inflammatory CC chemokines. The scavenging activity of ACKR2 relies on its intracellular traffic properties. Under homeostatic conditions, ACKR2 is mainly localized in intracellular stores associated with both early Rab4/5-positive and recycling Rab11-positive endosomes. At increasing levels of chemokines, ACKR2 increases plasma membrane abundance through an acceleration in the rate of Rab11-depedent recycling pathway, in order to optimize its chemokine scavenging activity. Here, I demonstrated that the intracellular distribution of ACKR2 is maintained by cytoskeletal dynamics. After chemokine engagement, ACKR2 activate a G-protein-independent and β-arrestin-dependent Rac1-PAK1-LIMK1 signalling cascade to finely regulate the actin cytoskeletal and the microtubules network reorganization, to promote receptor up-regulation and scavenging function. ACKR2 is able to recruit and associates both β-arrestins in basal condition, at membrane and intracellular levels, but only β-arrestin1 is recruited after active ligand stimulation, in order to promote a β-arrestin1-dependent signalling pathway, required for supporting the myosin Vb-dependent ACKR2 up-regulation and scavenging properties
Detection of Epstein-Barr virus and human herpesvirus-8 DNA from Kaposi‚s sarcoma in patients with AIDS
No full textThis note reports the finding of both Epstein-Barr virus (EBV) and human herpesvirus 8 (HHV-8) genomic sequences in the skin and visceral sections from Kaposi‚s sarcoma (KS) in two patients with AIDS. To our knowledge, this is the first description of an HHV-8-positive KS associated with EBV in patients with AIDS
Atypical chemokine receptors : from silence to sound
Full text linkACRs (atypical chemokine receptors) were initially referred to as 'silent' receptors on the basis of a lack of signalling and functional activities that are typically observed with conventional chemokine receptors. Although ACRs do not directly induce cell migration, they indirectly control leucocyte recruitment by shaping chemokine gradients in tissues through degradation, transcytosis or local concentration of their cognate ligands. Recent evidence also suggests that these biological activities are supported by G-protein-independent, beta-arrestin-dependent signalling events. In the present article, we review current knowledge on structural and signalling properties of ACRs that are changing our view on this entire class of receptors from silent to endogenous beta-arrestin-biased signalling receptors
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
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