1,720,955 research outputs found
Efecto del sulfonato de perfluorohexano en la viabilidad, la comunicación intercelular ovocito - células del cumulus, la función mitocondrial y el daño al DNA en células del cumulus durante la maduración in vitro de ovocitos porcinos
Get PDF
“ASOCIACION ENTRE EL DEFICIT COLINERGICO, LAS DISFUNCIONES DE LA MEMORIA Y EL METABOLISMO ENERGETICO EN UN MODELO DE RATA”
No full textAsociación entre el déficit colinérgico, las disfunciones de la memoria y el metabolismo energético en un modelo de rata
Get PDFEl aumento en la expectativa de vida ha tenido implicaciones importantes para los sistemas de salud en el ámbito mundial. Con ello se han incrementado las enfermedades asociadas con la edad, entre las que el deterioro cognitivo representa una condición que afecta de manera directa la calidad de vida de la población adulta de la tercera edad. Adicionalmente, el deterioro cognitivo sin demencia constituye una condición de alto riesgo para la aparición de demencias, como la enfermedad de Alzheimer. Asimismo, algunas enfermedades crónicas como la diabetes mellitus, han mostrado una fuerte relación con el desarrollo de la enfermedad de Alzheimer, por sus efectos directos o indirectos en el cerebro. La funcionalidad de ciertas enzimas puede verse afectada bajo condiciones patologícas, tal como sucede en la enfermedad de Alzheimer y en la diabetes mellitus. Este es el caso de las colinesterasas. Así, por ejemplo, se ha detectado una elevada actividad colinesterásica en las placas neuríticas y en las marañas neurofibrilares características de pacientes con la enfermedad de Alzheimer, que podrían relacionarse con la agregación amiloide. Se ha reportado que la actividad de las colinesterasas, también aumenta en pacientes diabéticos, en cuyo caso, estas enzimas podrían participar modificando factores de riesgo como la resistencia a la insulina. Además, se han postulado una gran variedad de mecanismos que pueden tener un papel fisiopatogénico común en el desarrollo de desórdenes metabólicos y trastornos cognitivos, pudiendo ser las colinesterasas un vínculo entre ambas condiciones. El objetivo de este trabajo fue establecer la asociación entre el déficit colinérgico, las disfunciones de la memoria y el metabolismo energético, generando un modelo que simulara deterioro cognitivo. Los animales de estudio fueron alimentados con una dieta normal o alta en grasas, según el caso, y se evalúo la capacidad cognitiva, parámetros bioquímicos tales como el perfil lipídico y la actividad de transaminasas, así como la actividad y glicosilación de las colinesterasas. Los resultados obtenidos evidencian que la lesión colinérgica generada en el hipocampo de ratas, por administración de la colinotoxina AF64A, modifica el metabolismo de la glucosa, induce un deterioro en el aprendizaje y la memoria y es capaz de alterar la actividad y glicosilación de las colinesterasas. Asimismo, el consumo de una dieta alta en grasas acelera el deterioro cognitivo y afecta los patrones de glicosilación de AChE y BChE
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
- …
