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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
Microangiopathy—A Potential Contributing Factor to Idiopathic Polyneuropathy: A Mini Review
No full textChronic idiopathic axonal polyneuropathy (CIAP) is a slowly progressive predominantly sensory axonal polyneuropathy. The prevalence of CIAP increases with age. The pathogenic cause of CIAP is unknown although there are several prevailing etiological hypotheses. In this mini review, we focus on the hypothesis of disturbed microcirculation in the vasa nervorum of peripheral nerves as a pathogenic cause of CIAP. There is an association between CIAP and metabolic risk factors. Furthermore, the phenotype of CIAP resembles diabetic neuropathy both clinically and electrophysiologically. In sural nerve biopsies from patients with diabetes mellitus, structural abnormalities indicating microangiopathy in the endoneurial microvessels are well documented. Similarly, sural microvessel abnormalities have been shown in patients with atherosclerotic non-diabetic peripheral vascular disease. However, the reported histopathological alterations of microvasculature in sural nerves of CIAP patients are inconsistent. Two studies report microangiopathic changes in CIAP sural nerves comparable with those found in patients with diabetic neuropathy. Conversely, another recent study showed no significant differences in the microangiopathic parameters in the endoneurial microvessels in the sural nerve biopsies from CIAP patients compared to controls without polyneuropathy. However, this CIAP patient group was younger compared to the patient groups in the other two studies. A general limitation with the published morphological studies are that different methods have been used in the assessment of microangiopathy, and there is also a risk of subjectivity in the results. Immunohistochemistry studies of sural nerves with verification of microangiopathy using specific biomarkers would be of great interest to develop
Microangiopathy—A Potential Contributing Factor to Idiopathic Polyneuropathy: A Mini Review
No full textDispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Microangiopathy—A Potential Contributing Factor to Idiopathic Polyneuropathy: A Mini Review
No full textImmunopathogenesis of Guillain-Barré syndrome and chronic inflammatory demyelinating polyradoculoneuropathy
No full textGuillain-Barre syndrome (GBS) is an inflammatory polyradiculoneuropathy with acute onset and usually a spontaneous recovery. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic progressive inflammatory neuropathy. GBS and CIDP are associated with high morbidity despite treatment with immunomodulatory drugs. Both conditions are associated with inflammation of spinal nerve roots and/or distal nerves of the peripheral nervous system (PNS). GBS is assumed to be induced by infection + abnormal autoimmunity, whereas the immunopathogenesis of CIDP remains obscure.Previous studies have shown up-regulation of myelin-reactive T cells, and of levels of blood cytokines, indicative of T cell auto-reactivity in GBS. Few studies have addressed the balance between Th1 and Th2 cytokines over the course of GBS. GBS, but not CIDP, is associated with anti-GM1 and anti-GD1a anti-ganglioside serum antibodies (abs), but the temporal profile of anti-ganglioside abs over the course of GBS is not known. Despite the presumed importance of the role of prior infections in GBS pathogenesis, the nature of the antigen-presenting cells involved in this putative process is unclear. Dendritic cells (DC) are believed to play an important role in the induction of adaptive and innate immune responses. The myeloid subset of DC activates T and B cells, and the plasmacytoid subset of DC may induce tolerance. The role of DC has not been examined in GBS and CIDP.The aims of the study were to explore the roles of cytokine-secreting cells, anti-ganglioside abs and DC in blood, CSF and PNS over the course of GBS and CIDP, in relation to clinical parameters and immuno-modulatory treatment.Patients examined in the acute phase of GBS prior to treatment with intravenous high dose immunoglobulin (IvIg), had elevated levels of IL-10, but not of IFN-gamma secreting blood mononuclear cells (MNC). Pre-treatment levels of IL-10 secreting MNC correlated with neurophysiological signs of axonal damage and with levels of anti-ganglioside serum IgM abs.The highest titers of anti-GM1 serum IgG abs were observed in GBS patients examined 40 days after onset of GBS, while peak anti-GD1a IgM antibody titers were measured in the recovery phase, i.e. 90 days after onset of GBS. Patients developing steadily increasing levels of serum anti-GM1 IgG- and anti- GD1a IgM abs over the course of GBS, followed by a drop in levels of abs (i.e. patients developing peak ab titers) had a worse clinical outcome.Patients examined in the acute phase of GBS prior to lvIg treatment had also high levels of IL-6 secreting blood MNC. Patients examined in the recovery phase of GBS had lower levels of TNF-alpha secreting MNC vs. controls. Levels of IL-12p70 secreting blood MNC were not altered.Percentages of freshly isolated blood DC expressing cell surface molecules CD1a (involved in antigen-presentation), CD80 and CD86 (co-stimulatory molecules), CD54 (adhesion molecule), CD11c (marker of myeloid DC) and CD 123 (marker of plasmacytoid DC) as well as the chemokine receptors CCR1, CCR2, CCR5, and CXCR4 were not altered in patients with GBS and CIDP compared to controls. In contrast, levels of CD11c+ DC were elevated in cerebrospinal fluid (CSF) of CIDP patients, and of CD123+ DC in CSF of GBS patients prior to immunomodulatory treatment. Small numbers of immature myeloid CD11 c+CD14-CD16- DC were detected in the perineurium of sural nerve biopsies of patients with CIDP as well as in controls.Chemokines released by nerve tissue or in CSF are assumed to be responsible for recruiting DC to sites of inflammation. The CSF levels of chemokines MCP-1 and IP-10 were elevated in GBS patients and of IP-10 and MIP-3 beta in CIDP prior to treatment.The absence of a clear systemic Th 1 cytokine secretion profile in GBS, as well as presence in CSF of plasmacytoid DC, may be one of the explanations for the self-limited course of the auto-aggressive attack against PNS in GBS. Myeloid DC, which may enter the CSF due to elevated levels of MCP-1, may be retained by MIP-3 beta and thus contribute to sustained PNS inflammation in CIDP. DC in the CSF and in peripheral nerves, may be responsible for uptake of antigen released from the inflamed PNS, whereby antigen may be presented to T and B cells locally and/or in draining lymph nodes. Further studies of the cause of differential recruitment of DC subsets to CSF as well as the role of CSF chemokines in GBS vs. CIDP are warranted.List of scientific papersI. Press R, Deretzi G, Zou LP, Zhu J, Fredman P, Lycke J, Link H (2001). IL-10 and IFN-gamma in Guillain-Barre syndrome. J Neuroimmunol. 112(1-2): 129-38. https://pubmed.ncbi.nlm.nih.gov/11108941II. Press R, Mata S, Lolli F, Zhu J, Andersson T, Link H (2001). Temporal profile of anti-ganglioside antibodies and their relation to clinical parameters and treatment in Guillain-Barre syndrome. J Neurol Sci. 190(1-2): 41-7. https://pubmed.ncbi.nlm.nih.gov/11574105III. Press R, Ozenci V, Kouwenhoven M, Link H (2002). Non-T(H)1 cytokines are augmented systematically early in Guillain-Barre syndrome. Neurology. 58(3): 476-8. https://pubmed.ncbi.nlm.nih.gov/11839856IV. Press R, Pashenkov M, Nennesmo I, Kouwenhoven M, Huang YM, Link H (2002). Dendritic cells in cerebrospinal fluid and peripheral nerves in Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. [Manuscript]V. Press R, Pashenkov M, Jin JP, Link H (2002). Aberrated levels of cerebrospinal fluid chemokines in Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. [Submitted]</p
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