1,720,981 research outputs found
Contribution à l’étude des anticorps dirigés contre le peptide Aβ et de leur implication dans l’angiopathie amyloïde cérébrale
No full textThe β-amyloïd peptide (Aβ) accumulates in the brain parenchyma in Alzheimer’s Disease, and in brain blood vessels during cerebral amyloid angiopathy (CAA), which manifests itself by hemorrhages (CAA-he) or vascular inflammation (CAA-ri). In CAA, experimental and clinical arguments suggest the presence of anti-Aβ antibodies in the CSF of patients during acute phase of CAA-ri. However, their presence and relevance in the serum of healthy subjects and CAA patients in poorly described.We designed an ELISA-based method to analyze several anti-Aβ antibodies features (reactivity toward different antigens, isotypes, concentrations, avidity), and studied these antibodies in animal and human. Our results suggest that these antibodies are present spontaneously in mice and humans, as part of natural antibodies, and their elevation with ageing. We showed the existence of specific though complex serological profiles in a cohort of 105 participants, either healthy or with CAA-he or CAA-ri. The administration of high avidity anti-Aβ IgG in APP23 mouse apparently leads to astrocytosis, however without elevation of CAA severity or microbleeding. This contribution to the study of anti-Aβ antibodies allows to better understand physiological and pathological variations of these antibodies, and suggests that their analysis can lead to biomarkers for CAA and its manifestations.Le peptide β-amyloïde (ou Aβ) s’accumule dans le parenchyme cérébral au cours de la maladie d’Alzheimer (MA), et dans les vaisseaux cérébraux dans l’angiopathie amyloïde cérébrale (AAC), qui se manifeste notamment par des présentations hémorragiques (AAC-he), ou inflammatoires (AAC-ri). Dans l’AAC, des arguments expérimentaux et cliniques suggèrent la présence d’anticorps anti-Aβ dans le liquide céphalo-rachidien en phase aiguë d’AAC-ri, mais leur présence et leur importance dans le sérum des sujets sains ou atteints d’AAC demeure mal connue. Nous avons mis au point d’une technique dérivée de l’ELISA pour l’analyse de différentes caractéristiques des anticorps anti-Aβ sériques (réactivité vis-à-vis de différentes antigènes, isotypes, concentrations, avidité), et étudié les anticorps anti-Aβ sériques chez l’animal et chez l’homme. Nos résultats suggèrent la présence spontanée de ces anticorps chez la souris et chez l’homme en tant que part des anticorps naturels, ainsi que leur augmentation avec l’âge. Nous avons montré l’existence de profils sérologiques spécifiques complexes sur une cohorte de 105 participants sains ou présentant une AAC-he ou une AAC-ri. Enfin, l’administration d’IgG anti-Aβ de forte affinité chez la souris APP23 semble provoquer une forte réaction astrocytaire, cependant sans augmentation de l’Aβ vasculaire, ni augmentation des microsaignements. Cette contribution à l’étude des anticorps anti-Aβ permet de mieux comprendre les variations physiologiques et pathologiques de ces anticorps, et suggère que leur analyse comme potentiel biomarqueur de l’AAC, et de ses manifestations hémorragiques ou inflammatoires
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Contribution to the study of antibodies reactive to the β-amyloid peptide and their implication in cerebral amyloid angiopathy
No full textLe peptide β-amyloïde (ou Aβ) s’accumule dans le parenchyme cérébral au cours de la maladie d’Alzheimer (MA), et dans les vaisseaux cérébraux dans l’angiopathie amyloïde cérébrale (AAC), qui se manifeste notamment par des présentations hémorragiques (AAC-he), ou inflammatoires (AAC-ri). Dans l’AAC, des arguments expérimentaux et cliniques suggèrent la présence d’anticorps anti-Aβ dans le liquide céphalo-rachidien en phase aiguë d’AAC-ri, mais leur présence et leur importance dans le sérum des sujets sains ou atteints d’AAC demeure mal connue. Nous avons mis au point d’une technique dérivée de l’ELISA pour l’analyse de différentes caractéristiques des anticorps anti-Aβ sériques (réactivité vis-à-vis de différentes antigènes, isotypes, concentrations, avidité), et étudié les anticorps anti-Aβ sériques chez l’animal et chez l’homme. Nos résultats suggèrent la présence spontanée de ces anticorps chez la souris et chez l’homme en tant que part des anticorps naturels, ainsi que leur augmentation avec l’âge. Nous avons montré l’existence de profils sérologiques spécifiques complexes sur une cohorte de 105 participants sains ou présentant une AAC-he ou une AAC-ri. Enfin, l’administration d’IgG anti-Aβ de forte affinité chez la souris APP23 semble provoquer une forte réaction astrocytaire, cependant sans augmentation de l’Aβ vasculaire, ni augmentation des microsaignements. Cette contribution à l’étude des anticorps anti-Aβ permet de mieux comprendre les variations physiologiques et pathologiques de ces anticorps, et suggère que leur analyse comme potentiel biomarqueur de l’AAC, et de ses manifestations hémorragiques ou inflammatoires.The β-amyloïd peptide (Aβ) accumulates in the brain parenchyma in Alzheimer’s Disease, and in brain blood vessels during cerebral amyloid angiopathy (CAA), which manifests itself by hemorrhages (CAA-he) or vascular inflammation (CAA-ri). In CAA, experimental and clinical arguments suggest the presence of anti-Aβ antibodies in the CSF of patients during acute phase of CAA-ri. However, their presence and relevance in the serum of healthy subjects and CAA patients in poorly described.We designed an ELISA-based method to analyze several anti-Aβ antibodies features (reactivity toward different antigens, isotypes, concentrations, avidity), and studied these antibodies in animal and human. Our results suggest that these antibodies are present spontaneously in mice and humans, as part of natural antibodies, and their elevation with ageing. We showed the existence of specific though complex serological profiles in a cohort of 105 participants, either healthy or with CAA-he or CAA-ri. The administration of high avidity anti-Aβ IgG in APP23 mouse apparently leads to astrocytosis, however without elevation of CAA severity or microbleeding. This contribution to the study of anti-Aβ antibodies allows to better understand physiological and pathological variations of these antibodies, and suggests that their analysis can lead to biomarkers for CAA and its manifestations
Variations on the Author
No full text“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
No full textWe 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
No full textWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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