1,720,968 research outputs found
Role of GpNMB on microglia and Aß plaque formation in a mouse model of Alzheimer's disease
No full textLa enfermedad de Alzheimer, principal causa de demencia, sufre un aumento de casos en la sociedad occidental actual. La pérdida de memoria, el deterioro cognitivo y las dificultad para orientarse son solo algunos de los graves síntomas que sufren los pacientes de esta enfermedad. Se trata de un trastorno neurodegenerativo que se caracteriza por la formación de cúmulos de péptido tóxico amiloide (Aß) en forma de placas seniles, la acumulación de proteína Tau en forma de ovillos, la neuroinflamación y deterioro neuronal.
En este trabajo nos hemos centrado en el estudio de la glicoproteína no metastática B (GpNMB), de la cual ya existen indicios de posibles efectos paliativos en la interacción con la enfermedad de Alzheimer. Con el fin de conocer el impacto de la glicoproteína en la enfermedad, se ha llevado a cabo una caracterización de un modelo preclínico, en ratones, de esta enfermedad.
Primero, estudiamos uno de los marcadores de la enfermedad más significativo, la cantidad de placas amiloides depositadas en los distintos modelos de ratón generados. Por otra parte, estudiaremos la activación de la microglía mediante una cuantificación de glía activa en el cerebro de los ratones. La investigación sobre el efecto de la glicoproteína en el cerebro se realiza con una comparativa de los datos obtenidos en ambos experimentos.
Existe una disminución en el número de formación de placas en los animales con sobreexpresión de GpNMB, aunque no se observan diferencias significativas en la relación entre la intensidad y el área de las placas Aß. La activación microglial en los animales con EA y sobreexpresión de GpNMB es menor que en los animales con EA podría tener un papel neuroprotector en el cerebro.
ABSTRACT
Alzheimer's disease, the leading cause of dementia, is on the rise in today's western society. Memory loss, cognitive impairment and difficulty in finding one's way around are just some of the serious symptoms suffered by Alzheimer's patients. It is a neurodegenerative disorder characterized by the formation of clusters of toxic amyloid peptide (Aß) in the form of senile plaques, the accumulation of Tau protein in the form of tangles, neuroinflammation and neuronal deterioration.
In this work we have focused on the study of non-metastatic glycoprotein B (NMPBG), for which there are already indications of possible palliative effects in the interaction with Alzheimer's disease. In order to understand the impact of the glycoprotein on the disease, we have characterized a preclinical mouse model of the disease. First, we studied one of the most significant markers of the disease, the number of amyloid plaques deposited in the different mouse models generated. On the other hand, we will study the activation of microglia by quantifying active glia in the brains of mice. The investigation of the effect of glycoprotein in the brain is carried out by comparing the data obtained in both experiments.
There is a decrease in the number of plaque formation in the GpNMB-overexpressing animals, although no significant differences in the relationship between the intensity and area of Aß plaques are observed. Microglial activation in AD animals with AD and GpNMB overexpression is lower than in animals with AD alone. The positive results suggest that GpNMB may have a neuroprotective role in the brain
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
Dispelling 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
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
Electrophysiological characterisation of the classical TRP channel TRPC5
No full textKlassische TRP-Kanäle (TRPC) sind Ca(2+)-permeable, unselektive Kationenkanäle, die durch PLC-abhängige Signalwege intrazellulär aktiviert werden. Obwohl die ersten Mitglieder dieser Subfamilie bereits vor über 15 Jahren kloniert wurden, sind sie auf funktioneller Ebene bisher nur unvollständig untersucht. Das Ziel dieser Arbeit bestand darin, die biophysikalischen Eigenschaften von TRPC5 im heterologen Expressionssystem mit Hilfe von molekularbiologischen und elektrophysiologischen Methoden im Detail zu studieren und mit denen anderer Vertreter der TRPC-Subfamilie zu vergleichen.
TRPC5 wurde in der vorliegenden Arbeit als ein spannungsabhängig gesteuerter Kationenkanal herausgestellt, dessen Aktivität durch ein breites Spektrum an extrazellulären, positiv geladenen Elementarionen direkt moduliert werden kann. Die Permeation von mono- und divalenten Kationen durch TRPC5 ist unselektiv und wird durch Aminosäuren im Bereich zwischen der 5. und 6. Transmembrandomäne determiniert.Classical TRP channels (TRPC) are Ca(2+)-permeable, unselective cation channels that are activated by PLC-dependent intracellular pathways. Although most members of this subfamily were cloned at least 10 years ago, functional data on some of their biophysical properties are still not available. The main aim of this study was to investigate the properties of TRPC5, and to compare them with those of other members of the TRPC subfamily.
In the present study, TRPC5 was characterised to be a voltage-dependent channel that can be modulated directly by a multiplicity of extracellular elementary cations. The permeation of mono- or divalent cations through TRPC5 is unselective and determined by amino acids between the 5th and 6th transmembrane domain
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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