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Search Results: 1 - 10 of 56508 matches for " Constantino Carlos Reyes-Aldasoro "
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Whole cell tracking through the optimal control of geometric evolution laws
Konstantinos N. Blazakis,Anotida Madzvamuse,Constantino-Carlos Reyes-Aldasoro,Vanessa Styles,Chandrasekhar Venkataraman
Mathematics , 2015,
Abstract: Cell tracking algorithms which automate and systematise the analysis of time lapse image data sets of cells are an indispensable tool in the modelling and understanding of cellular phenomena. In this study we present a theoretical framework and an algorithm for whole cell tracking. Within this work we consider that "tracking" is equivalent to a dynamic reconstruction of the whole cell data (morphologies) from static image datasets. The novelty of our work is that the tracking algorithm is driven by a model for the motion of the cell. This model may be regarded as a simplification of a recently developed physically meaningful model for cell motility. The resulting problem is the optimal control of a geometric evolution law and we discuss the formulation and numerical approximation of the optimal control problem. The overall goal of this work is to design a framework for cell tracking within which the recovered data reflects the physics of the forward model. A number of numerical simulations are presented that illustrate the applicability of our approach.
PhagoSight: An Open-Source MATLAB? Package for the Analysis of Fluorescent Neutrophil and Macrophage Migration in a Zebrafish Model
Katherine M. Henry, Luke Pase, Carlos Fernando Ramos-Lopez, Graham J. Lieschke, Stephen A. Renshaw, Constantino Carlos Reyes-Aldasoro
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0072636
Abstract: Neutrophil migration in zebrafish larvae is increasingly used as a model to study the response of these leukocytes to different determinants of the cellular inflammatory response. However, it remains challenging to extract comprehensive information describing the behaviour of neutrophils from the multi-dimensional data sets acquired with widefield or confocal microscopes. Here, we describe PhagoSight, an open-source software package for the segmentation, tracking and visualisation of migrating phagocytes in three dimensions. The algorithms in PhagoSight extract a large number of measurements that summarise the behaviour of neutrophils, but that could potentially be applied to any moving fluorescent cells. To derive a useful panel of variables quantifying aspects of neutrophil migratory behaviour, and to demonstrate the utility of PhagoSight, we evaluated changes in the volume of migrating neutrophils. Cell volume increased as neutrophils migrated towards the wound region of injured zebrafish. PhagoSight is openly available as MATLAB? m-files under the GNU General Public License. Synthetic data sets and a comprehensive user manual are available from http://www.phagosight.org.
Drift-Diffusion Analysis of Neutrophil Migration during Inflammation Resolution in a Zebrafish Model
Geoffrey R. Holmes,Giles Dixon,Sean R. Anderson,Constantino Carlos Reyes-Aldasoro,Philip M. Elks,Stephen A. Billings,Moira K. B. Whyte,Visakan Kadirkamanathan,Stephen A. Renshaw
Advances in Hematology , 2012, DOI: 10.1155/2012/792163
Abstract: Neutrophils must be removed from inflammatory sites for inflammation to resolve. Recent work in zebrafish has shown neutrophils can migrate away from inflammatory sites, as well as die in situ. The signals regulating the process of reverse migration are of considerable interest, but remain unknown. We wished to study the behaviour of neutrophils during reverse migration, to see whether they moved away from inflamed sites in a directed fashion in the same way as they are recruited or whether the inherent random component of their migration was enough to account for this behaviour. Using neutrophil-driven photoconvertible Kaede protein in transgenic zebrafish larvae, we were able to specifically label neutrophils at an inflammatory site generated by tailfin transection. The locations of these neutrophils over time were observed and fitted using regression methods with two separate models: pure-diffusion and drift-diffusion equations. While a model hypothesis test (the F-test) suggested that the datapoints could be fitted by the drift-diffusion model, implying a fugetaxis process, dynamic simulation of the models suggested that migration of neutrophils away from a wound is better described by a zero-drift, “diffusion” process. This has implications for understanding the mechanisms of reverse migration and, by extension, neutrophil retention at inflammatory sites. 1. Introduction The fate of neutrophils following completion of the inflammatory programme is of critical importance for the outcome of episodes of acute inflammation and can determine whether there is prompt healing of a wound or the development of chronic inflammation and tissue injury. Neutrophils recruited to sites of inflammation may leave the site or die in situ [1]. The most widely accepted mechanism of neutrophil disposal is the programmed cell death or apoptosis, of the neutrophil followed by macrophage uptake and clearance (reviewed in [2]). Recently, other routes have been proposed; neutrophils may move away from the inflamed site into the bloodstream (“reverse transmigration” [3]), by migration through other tissues (“retrograde chemotaxis” or “reverse migration” [4–6]), or be lost into the inflammatory exudate [7, 8]. Current understanding of the process of reverse migration is reviewed elsewhere [9]. The uncertainty as to the in vivo fates of individual cells relates in part to the difficulty in following individual cells during inflammation resolution in vivo. The transgenic zebrafish model is emerging as a key model for the study of vertebrate immunity [10] and allows direct
The Neutrophil's Eye-View: Inference and Visualisation of the Chemoattractant Field Driving Cell Chemotaxis In Vivo
Visakan Kadirkamanathan, Sean R. Anderson, Stephen A. Billings, Xiliang Zhang, Geoffrey R. Holmes, Constantino C. Reyes-Aldasoro, Philip M. Elks, Stephen A. Renshaw
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0035182
Abstract: As we begin to understand the signals that drive chemotaxis in vivo, it is becoming clear that there is a complex interplay of chemotactic factors, which changes over time as the inflammatory response evolves. New animal models such as transgenic lines of zebrafish, which are near transparent and where the neutrophils express a green fluorescent protein, have the potential to greatly increase our understanding of the chemotactic process under conditions of wounding and infection from video microscopy data. Measurement of the chemoattractants over space (and their evolution over time) is a key objective for understanding the signals driving neutrophil chemotaxis. However, it is not possible to measure and visualise the most important contributors to in vivo chemotaxis, and in fact the understanding of the main contributors at any particular time is incomplete. The key insight that we make in this investigation is that the neutrophils themselves are sensing the underlying field that is driving their action and we can use the observations of neutrophil movement to infer the hidden net chemoattractant field by use of a novel computational framework. We apply the methodology to multiple in vivo neutrophil recruitment data sets to demonstrate this new technique and find that the method provides consistent estimates of the chemoattractant field across the majority of experiments. The framework that we derive represents an important new methodology for cell biologists investigating the signalling processes driving cell chemotaxis, which we label the neutrophils eye-view of the chemoattractant field.
Anatomy, Morphology, and Cladistic Analysis of Monsonia L. (Geraniaceae).
Aedo, Carlos,Vargas, Pablo,Navarro, Carmen,Aldasoro, Juan Jose
Anales del Jardín Botánico de Madrid , 2001,
Abstract: Phylogenetip relationships among the 25 species of the old-world genus Monsonia are explored by means of a cladistic analysis. After a detailed revision, 20 morphological and anatomical characters were selected, including some new ones from nectaries, androecium, and mericarps. Phylogenetic analysis yielded 9 most parsimonious trees. The strict consensus tree showed two major clades: one is formed by the 9 species of Monsonia sect. Monsonia, characterised by plumose awns, plus Sarcocaulon; and a second with the 16 species of Monsonia sect. Olopetalum which share the type of mericarp detaching, consistency of columella and the thick mericarp walls. Consequently, some doubts about the monophyly of Monsonia exists. However, the current infrageneric classification of Monsonia is supported after transferring M. longipes and M. speciosa to sect. Olopetalum. Several characters of the mericarp are related to zoochory, which seems to be a derived syndrome in Monsonia, as in the other Geraniaceae. Se exploran mediante un an41isis cladístico las relaciones filogenéticas entre las 25 especies incluidas en el genero Monsonia. Tras una detallada revisi6n se seleccionan 20 caracteres morfológicos y anatómicos, entre ellos algunos previamente no descritos sobre los nectarios, el androceo y los mericarpos. El análisis filogenético produjo nueve árboles más parsimoniosos. El árbol de consenso estricto muestra dos clados principales: uno, formado por las nueve especies de Monsonia sect. Monsonia, caracterizadas por las aristas plumosas y las tres de Sarcocaulon que se usaron como grupo externo; y el segundo, formado por las 16 especies de Monsonia sect. Olopetalum, que comparten el tipo de separación del mericarpo, la consistencia de la columela y las paredes gruesas en el mericarpo. Como consecuencia surgen nuevas dudas sobre la monofilia de Monsonia. Sin embargo, nuestros datos apoyan la clasificación subgenérica actual de Monsonia si se incluyen M. tongipes y M. speciosa en la sect. Olopetalum. Numerosos caracteres del mericarpo estan relacionados con el tipo de zoocoria, lo cual parece derivado en Monsonia al igual que en otras geraniáceas.
La evaluación del impacto sobre la salud: una herramienta para incorporar la salud en las intervenciones no sanitarias
Bacigalupe,Amaia; Esnaola,Santiago; Calderón,Carlos; Zuazagoitia,Juan; Aldasoro,Elena;
Gaceta Sanitaria , 2009, DOI: 10.1590/S0213-91112009000100013
Abstract: interventions implemented by governments are very frequently related to the determinants of health. health impact assessment (hia) is used as a predictive tool to include health in nonhealth policymaking. this paper defines hia, describes its methods, procedures and applications, and discusses opportunities and challenges associated with hia. doing a hia implies studying the intervention, profiling the target population, and estimating its impacts on health by means of combining quantitative and qualitative evidence. hia has been used in different kinds of policies (transports, urban regeneration, culture, energy development etc.), at different levels (local, national, european) and in many countries. despite its scarce use in spain, hia allows to consider health in sectorial policymaking, taking into account social inequalities in health, so that healthier public policies can be designed. on the other hand, hia is a tool under methodological development which use is hindered due to the existing narrow biomedical perspective on the determinants of health, and to the difficulties in working in public policy-making with multisectorial and participative perspectives.
Avanzando en la evaluación del impacto en la salud: análisis de las políticas públicas sectoriales del Gobierno Vasco como paso previo a la fase de cribado sistemático
Aldasoro,Elena; Sanz,Elvira; Bacigalupe,Amaia; Esnaola,Santiago; Calderón,Carlos; Cambra,Koldo; Zuazagoitia,Juan;
Gaceta Sanitaria , 2012, DOI: 10.1590/S0213-91112012000100016
Abstract: health not only depends on biologic or lifestyle factors but also on other economic, social, political, and environmental factors that shape the way people live and become ill. thus, health policies are not the only policies affecting health, and consequently governments are increasingly interested in identifying the effect of other non-health policies on health. health impact assessment is a prospective methodology that aims to predict the health impacts of policies before their implementation so that modifications can be suggested to maximize positive effects and avoid unexpected negative repercussions on health. the first stage in this process is screening, which can be used to select the interventions that could benefit from complete health impact assessment. since resources are limited and not all government interventions can be assessed, tools that allow prioritization are essential. as a first stage in the validation of a systematic screening tool for health impact assessment in spain, this article presents the process of compiling and classifying the non-health public policies of the eighth term of office of the basque government. of the 97 policies analyzed, 76% were related to structural determinants of health inequalities, 79% were tactical or operational, 67% were aimed at specific population groups, and 66% were already implemented. the technical staff of other participating departments perceived the entire process of this initiative and its rationale positively. this initial experience allowed the planning of non-health policies in the basque country to be determined in detail as a means to move forward in incorporating impact on health in all policies.
La investigación cualitativa en la evaluación del impacto en la salud: La experiencia de un plan de reforma en un barrio de Bilbao
Calderón G,Carlos; Bacigalupe H,Amaia; Esnaola S,Santiago; Zuazagoitia,Jon; Aldasoro U,Elena;
Revista Facultad Nacional de Salud Pública , 2009,
Abstract: objective: to know the perceived effects on health of a neighborhood of bilbao reform plan from the perspective of the neighbors and stakeholders, and identify those areas for possible improvement. methodology: qualitative study. obtaining information through participant observation, four discussion groups (three neighbors and another one with health professionals and social workers), and four interviews with key informants. the analysis was designed on the model of sociological analysis of the speech. results: the findings set three areas related to socio-historical context of the neighborhood, the dynamic nature of the intervention and perceived impact on health in eight specific areas (urban accessibility, water and draining, recreation areas, power lines burial, parking place and road traffic, the small works, to feel as citizens, and social cohesion). conclusions: qualitative methods enabled deepen the significance of these findings in the direction of their interrelations, which enabled a better understanding of the impact on the health plan. it also points out some major methodological challenges for the development of future impact assessments on health.
CONOCER: UNA VISIóN EPISTéMICA
SARMIENTO REYES,JUAN CARLOS;
Acta Colombiana de Psicología , 2011,
Abstract: this article examines an epistemic notion of knowledge as opposed to other epistemic visions. for that purpose, it starts by rethinking chisholm's proposal (1977/1982) and highlights the language difficulty to differentiate between to know (that/how) and knowing. it analyzes other notions such as justification, certainty and evidence, and reviews the adjustments proposed by this author to the traditional definition of knowledge. then, it examines luis villoro's approach (1982) in order to study the difference he tries to establish between knowledge and knowing, including the grounds and reasons, the relationship of knowledge with practice and some ethical issues about the justification of beliefs. it emphasizes the need to tackle the problem of the border issue between believing, knowledge and knowing in a different way. the problem of grading the evidence, some issues related to the criterion of truth and other matters are also stressed. finally, concerning the many ethical implications that human knowledge currently has, the need for a social theory of knowledge along with an anthropological support for the same is highlighted.
CONOCER: UNA VISIóN EPISTéMICA
Sarmiento Reyes, Juan Carlos
Acta Colombiana de Psicología , 2011,
Abstract: This article examines an epistemic notion of knowledge as opposed to other epistemic visions. For that purpose, it starts by rethinking Chisholm's proposal (1977/1982) and highlights the language difficulty to differentiate between to know (that/how) and knowing. It analyzes other notions such as justification, certainty and evidence, and reviews the adjustments proposed by this author to the traditional definition of Knowledge. Then, it examines Luis Villoro's approach (1982) in order to study the difference he tries to establish between knowledge and knowing, including the grounds and reasons, the relationship of knowledge with practice and some ethical issues about the justification of beliefs. It emphasizes the need to tackle the problem of the border issue between believing, knowledge and knowing in a different way. The problem of grading the evidence, some issues related to the criterion of truth and other matters are also stressed. Finally, concerning the many ethical implications that human knowledge currently has, the need for a social theory of knowledge along with an anthropological support for the same is highlighted.
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