Search results for "Centro"
showing 10 items of 643 documents
Testing abnormality in the spatial arrangement of cells in the corneal endothelium using spatial point processes
2001
The study of central corneal endothelium morphology is important in Ophthalmology. Some of the pathologies that could compromise endothelial cell morphology are trauma, cataract, surgery, use of contact lenses, corneal dystrophies or degenerations. The quantitative analysis of cell shape and cellular pattern is more sensitive in detecting subtle changes in endothelial morphology than cell density measurement or cell area analysis. In this paper, the morphology of the central cornea, the most important area from the point of view of vision, is studied through an associated bivariate spatial point pattern: the centroids of the cells and the triple points, that is, the points where three diffe…
Prokaryotic symbiotic consortia and the origin of nucleated cells: A critical review of Lynn Margulis hypothesis.
2021
The publication in the late 1960s of Lynn Margulis endosymbiotic proposal is a scientific milestone that brought to the fore of evolutionary discussions the issue of the origin of nucleated cells. Although it is true that the times were ripe, the timely publication of Lynn Margulis' original paper was the product of an intellectually bold 29-years old scientist, who based on the critical analysis of the available scientific information produced an all-encompassing, sophisticated narrative scheme on the origin of eukaryotic cells as a result of the evolution of prokaryotic consortia and, in bold intellectual stroke, put it all in the context of planetary evolution. A critical historical reas…
Clustering of spatial point patterns
2006
Spatial point patterns arise as the natural sampling information in many problems. An ophthalmologic problem gave rise to the problem of detecting clusters of point patterns. A set of human corneal endothelium images is given. Each image is described by using a point pattern, the cell centroids. The main problem is to find groups of images corresponding with groups of spatial point patterns. This is interesting from a descriptive point of view and for clinical purposes. A new image can be compared with prototypes of each group and finally evaluated by the physician. Usual descriptors of spatial point patterns such as the empty-space function, the nearest distribution function or Ripley's K-…
Crystallization and preliminary X-ray studies of mouse centrin1.
2005
The expression, purification, crystallization and preliminary X-ray diffraction studies of mouse centrin1 are reported. Centrins belong to a family of Ca{sup 2+}-binding EF-hand proteins that play a fundamental role in centrosome duplication and the function of cilia. To shed light on the structure–function relationship of these proteins, mouse centrin1 has been crystallized. The mouse centrin1 has been expressed in Escherichia coli as a GST-centrin fusion protein containing a thrombin protease cleavage site between the fusion partners. Two constructs with different linking-sequence lengths were expressed and purified. Thrombin cleavage yielded functional centrin1 and N-terminally extended …
Spatio-Temporal Assessment of the European Hake (Merluccius merluccius) Recruits in the Northern Iberian Peninsula
2021
14 pages, 9 figures, 3 tables.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
Strategie di difesa in risposta a stress in embrioni di riccio di mare: L'embrione di riccio di Paracentrotus lividus come modello sperimentale per l…
2013
Negli ultimi decenni, grazie alle nuove tecnologie e alla maggiore disponibilità di strumenti di ricerca, il campo riguardante lo studio delle strategie di difesa attivate nella risposta a stress, compresi i meccanismi di apoptosi e autofagia, è divenuto molto ampio ed è in continua espansione. Sin dagli albori della Biologia, gli studi condotti sul modello sperimentale di riccio di mare hanno permesso di ottenere conoscenze di base, spesso applicabili ad altri modelli biologici. I dati riportati nel presente libro dovrebbero aiutare a far luce sui meccanismi di difesa che le cellule sono in grado di attivare, in caso di necessità, se esposte a sfavorevoli condizioni ambientali. Le osservaz…
Studies on sea urchin oocytes. II. Synthesis of RNA during oogenesis.
1972
Abstract Isolated oocytes of the sea urchin Paracentrotus lividus actively incorporate 3H-uridine into RNA. Labeled RNA was analysed by sucrose gradient and acrylamide gel electrophoresis following cell fractionation. Much of the radioactivity is incorporated at the nucleolar level in the form of rRNA precursors. The kinetics of maturation of these latter suggests that this occurs at a slower rate than during embryogenesis. Other non-nucleolar RNA classes are also actively labelled and retained in the nucleus for many hours. These results are confirmed by an autoradiographic investigation.
La “uberización” de los centros escolares: reorganización del trabajo pedagógico mediante las plataformas digitales de contenidos
2018
El presente trabajo se inscribe en el marco de un proyecto de investigación de I+D que estudia los cambios producidos en los centros de Primaria por la progresiva sustitución de los libros de texto por los materiales digitales. Uno de esos cambios observados es que los materiales digitales se hacen operativos mediante plataformas digitales que, además, se hacen extensibles a otras muchas tareas de centro. A partir de esta constatación nos ocupamos aquí del estudio de la 'uberización' o reestructuración organizativa del trabajo en los centros que operan con estas plataformas. Para alcanzar tal objetivo hemos recurrido a una metodología de corte cualitativo, tanto para el análisis de la prese…
Profesorado y coordinador TIC : dinámicas y cambios en un Centro Educativo Inteligente
2013
La presente comunicación analiza las percepciones del profesorado y del coordinador TIC de un centro educativo sobre las interacciones que se producen entre ellos como consecuencia de la participación en el programa de Centros Educativos Inteligentes (CEI) de la Comunidad Valenciana. Iniciativa de integración de las TIC, desarrollada en esta comunidad autónoma, al no suscribir el convenio de colaboración para la implantación del programa Escuela 2.0. Los resultados que aquí presentamos forman parte de un Trabajo Fin de Máster que tiene por objeto investigar y analizar las funciones y tareas del coordinador TIC , en tanto que es el agente clave para el desarrollo del programa CEI. Si el prog…