1,598 research outputs found
Revolutionizing Stroke Recovery: Unveiling the Promise of Stem Cell Therapy
No full textLeonidas D Panos,1,2 Panagiotis Bargiotas,2 Marcel Arnold,1 Georgios Hadjigeorgiou,2 Georgios D Panos3,4 1Department of Neurology, Bern University Hospital Inselspital, Bern, Switzerland; 2Department of Neurology, School of Medicine, University of Cyprus, Nicosia, Cyprus; 3Department of Ophthalmology, Queen’s Medical Centre, Nottingham University Hospitals (NUH), Nottingham, UK; 4Division of Ophthalmology and Visual Sciences, School of Medicine, University of Nottingham, Nottingham, UKCorrespondence: Leonidas D Panos, Department of Neurology, Bern University Hospital “Inselspital”, Freiburgstrasse 16, Bern, 3010, Switzerland, Tel +41 31 632 70 00, Email [email protected] Georgios D Panos, Department of Ophthalmology, Queen’s Medical Centre, NUH, Derby Road, Lenton, Nottingham, NG7 2UH, UK, Tel +44 115 924 9924, Email [email protected]: Stem cells, renowned for their unique regenerative capabilities, present significant hope in treating stroke, a major cause of disability globally. This review offers a detailed analysis of stem cell applications in stroke (ischemic and hemorrhagic) recovery. It examines therapies based on autologous (patient-derived), allogeneic (donor-derived), and Granulocyte-Colony Stimulating Factor (G-CSF) based stem cells, focusing on cell types such as Mesenchymal Stem/Stromal Cells (MSCs), Bone Marrow Mononuclear Stem Cells (BMMSCs), and Neural Stem/Progenitor Cells (NSCs). The paper compiles clinical trial data to evaluate their effectiveness and safety and addresses the ethical concerns of these innovative treatments. By explaining the mechanisms of stem cell-induced neurological repair, this review underscores stem cells’ potential in revolutionizing stroke rehabilitation and suggests avenues for future research.Keywords: stem cell therapy, stroke, brain hemorrhage, autologous stem cells transplantation, allogeneic stem cells transplantation, granulocyte-colony stimulating facto
IMS LD Author Schemas
No full textMany XML tools encounter problems with the modular XML schemas of the IMS LD specification. Therefore non-modular XML schemas have been created for each of the levels of IMS LD. The only normative XML schemas for the IMS LD specification can be found at the IMS website
IMS LD Author Schemas
No full textMany XML tools encounter problems with the modular XML schemas of the IMS LD specification. Therefore non-modular XML schemas have been created for each of the levels of IMS LD. The only normative XML schemas for the IMS LD specification can be found at the IMS website
IMS LD Author Schemas
No full textMany XML tools encounter problems with the modular XML schemas of the IMS LD specification. Therefore non-modular XML schemas have been created for each of the levels of IMS LD. The only normative XML schemas for the IMS LD specification can be found at the IMS website
Impact of population structure, effective bottleneck time, and allele frequency on linkage disequilibrium maps
No full textGenetic maps in linkage disequilibrium (LD) units play the same role for association mapping as maps in centimorgans provide at much lower resolution for linkage mapping. Association mapping of genes determining disease susceptibility and other phenotypes is based on the theory of LD, here applied to relations with three phenomena. To test the theory, markers at high density along a 10-Mb continuous segment of chromosome 20q were studied in African-American, Asian, and Caucasian samples. Population structure, whether created by pooling samples from divergent populations or by the mating pattern in a mixed population, is accurately bioassayed from genotype frequencies. The effective bottleneck time for Eurasians is substantially less than for migration out of Africa, reflecting later bottlenecks. The classical dependence of allele frequency on mutation age does not hold for the generally shorter time span of inbreeding and LD. Limitation of the classical theory to mutation age justifies the assumption of constant time in a LD map, except for alleles that were rare at the effective bottleneck time or have arisen since. This assumption is derived from the Malecot model and verified in all samples. Tested measures of relative efficiency, support intervals, and localization error determine the operating characteristics of LD maps that are applicable to every sexually reproducing species, with implications for association mapping, high-resolution linkage maps, evolutionary inference, and identification of recombinogenic sequences
Extensión de la especificación IMS Learning Design desde la adaptación e integración de unidades de aprendizaje
No full textIMS Learning Design (IMS-LD) representa una corriente actual en aprendizaje online y blended que se caracteriza porque: a) Es una especificación que pretende estandarizar procesos de aprendizaje, así como reutilizarlos en diversos contextos b) Posee una expresividad pedagógica más elaborada que desarrollos anteriores o en proceso c) Mantiene una relación cordial y prometedora con Learning Management Systems (LMSs), herramientas de autoría y de ejecución d) Existe una amplia variedad de grupos de investigación y proyectos europeos trabajando sobre ella, lo que augura una sostenibilidad, al menos académica Aun así, IMS Learning Design es un producto inicial (se encuentra en su primera versión, de 2003) y mejorable en diversos aspectos, como son la expresividad pedagógica y la interoperabilidad. En concreto, en esta tesis nos centramos en el aprendizaje adaptativo o personalizado y en la integración de Unidades de Aprendizaje, como dos de los pilares que definen la especificación, y que al mismo tiempo la potencian considerablemente. El primero (aprendizaje adaptativo) hace que se puedan abordar itinerarios individuales personalizados de estudio, tanto en flujo de aprendizaje como en contenido o interfaz; el segundo (integración) permite romper el aislamiento de los paquetes de información o cursos (Unidades de Aprendizaje, UoL) y establecer un diálogo con otros sistemas (LMSs), modelos y estándares, así como una reutilización de dichas UoLs en diversos contextos. En esta tesis realizamos un estudio de la especificación desde la base, analizando su modelo de información y cómo se construyen Unidades de Aprendizaje. Desde el Nivel A al Nivel C analizamos y criticamos la estructura de la especificación basándonos en un estudio teórico y una investigación práctica fruto del modelado de Unidades de Aprendizaje reales y ejecutables que nos proporcionan una información muy útil de base, y que mayormente adjuntamos en los anexos, para no interferir en el flujo de lectura del cuerpo principal. A partir de este estudio, analizamos la integración de Unidades de Aprendizaje con otros sistemas y especificaciones, abarcando desde la integración mínima mediante un enlace directo hasta la compartición de variables y estados que permiten una comunicación en tiempo real de ambas partes. Exponemos aquí también las conclusiones de diversos casos de estudio basados en adaptación que se anexan al final de la tesis y que se vuelven un instrumento imprescindible para lograr una solución real y aplicable. Como segundo pilar de la tesis complementario a la integración de Unidades de Aprendizaje, estudiamos el aprendizaje adaptativo: Los tipos, los avances y los enfoques y restricciones de modelado dentro de IMS-LD. Por último, y como complemento de la investigación teórica, a través de diversos casos prácticos estudiamos la manera en que IMS-LD modela la perzonalización del aprendizaje y hasta qué punto. Este primer bloque de análisis (general, integración y aprendizaje adaptativo) nos permite realizar una crítica estructural de IMS-LD en dos grandes apartados: Modelado y Arquitectura. Modelado apunta cuestiones que necesitan mejora, modificación, extensión o incorporación de elementos de modelado dentro de IMS-LD, como son procesos, componentes y recursos de programación. Arquitectura engloba otras cuestiones centradas en la comunicación que realiza IMS-LD con el exterior y que apuntan directamente a capas estructurales de la especificación, más allá del modelado. Aunque se encuentra fuera del núcleo de esta tesis, también se ha realizado una revisión de aspectos relacionados con Herramientas de autoría, por ser este un aspecto que condiciona el alcance del modelado y la penetración de la especificación en los distintos públicos objetivo. Sobre Herramientas, no obstante, no realizamos ninguna propuesta de mejora. La solución desarrollada, se centra en las diversas cuestiones sobre Modelado y Arquitectura encontradas en el análisis. Esta solución se compone de un conjunto de propuestas de estructuras, nuevas o ya existentes y modificadas, a través de las que se refuerza la capacidad expresiva de la especificación y la capacidad de interacción con un entorno de trabajo ajeno. Esta investigación de tres años ha sido llevada a cabo entre 2004 y 2007, principalmente con colegas de The Open University of The Netherlands, The University of Bolton, Universitat Pompeu Fabra y del departamento Research & Innovation de ATOS Origin, y ha sido desarrollada parcialmente dentro de proyectos europeos como UNFOLD, EU4ALL y ProLearn. La conclusión principal que se extrae de esta investigación es que IMS-LD necesita una reestructuración y modificación de ciertos elementos, así como la incorporación de otros nuevos, para mejorar una expresividad pedagógica y una capacidad de integración con otros sistemas de aprendizaje y estándares eLearning, si se pretenden alcanzar dos de los objetivos principales establecidos de base en la definición de esta especificación: La personalización del proceso de aprendizaje y la interoperabilidad real. Aun así, es cierto que la implantación de la especificación se vería claramente mejorada si existieran unas herramientas de más alto nivel (preferiblemente con planteamiento visual) que permitieran un modelado sencillo por parte de los usuarios finales reales de este tipo de especificaciones, como son los profesores, los creadores de contenido y los pedagogos-didactas que diseñan la experienicia de aprendizaje. Este punto, no obstante, es ajeno a la especificación y afecta a la interpretación que de la misma realizan los grupos de investigación y compañías que desarrollan soluciones de autoría. _____________________________________________IMS Learning Design (IMS-LD) is a current asset in eLearning and blended learning, due
to several reasons:
a) It is a specification that points to standardization and modeling of learning processes,
and not just content; at the same time, it is focused on the re-use of the information
packages in several contexts;
b) It shows a deeper pedagogical expressiveness than other specifications, already
delivered or in due process
c) It is integrated at different levels into well-known Learning Management Systems
(LMSs)
d) There are a huge amount of European research projects and groups working with it,
which aims at sustainability (in academia, at least)
Nevertheless, IMS-LD is roughly an initial outcome (be aware that we are still working
with the same release, dated on 2003). Therefore, it can and must be improved in
several aspects, i.e., pedagogical expressiveness and interoperability. In this thesis, we
concentrate on Adaptive Learning (or Personalised Learning) and on the Integration of
Units of Learning (UoLs). They both are core aspects which the specification is built upon.
They also can improve it significantly. Adaptation makes personalised learning itineraries,
adapted to every role, to every user involved in the process, and focus on several
aspects, i.e., flow, content and interface. Integration fosters the re-use of IMS-LD
information packages in different contexts and connects both-ways UoLs with other
specifications, models and LMSs. In order to achive these goals we carry out a threephase
analysis. First, analysis of IMS-LD in several steps: foundations, information
model, construction of UoLs. From Level A to Level C, we analyse and review the
specification structure. We lean on a theoretical frameword, along with a practical
approach, coming from the actual modeling of real UoLs which give an important report
back. Out of this analysis we get a report on the general structure of IMS-LD.
Second, analysis and review of the integration of UoLs with several LMSs, models and
specifications: we analyse three different types of integration: a) minimal integration,
with a simple link between parts; b) embedded integration, with a marriage of both parts
in a single information package; and d) full integration, sharing variables and states
between parts. In this step, we also show different case studies and report our partial
conclusions.
And third, analysis and review of how IMS-LD models adaptive learning: we define,
classify and explain several types of adaptation and we approach them with the specificacion. A key part of this step is the actual modeling of UoLs showing adaptive
learning processes. We highlight pros and cons and stress drawbacks and weak points
that could be improved in IMS-LD to support adaptation, but also general learning
processes
Out of this three-step analysis carried out so far (namely general, integration,
adaptation) we focus our review of the IMS-LD structure and information model on two
blocks: Modeling and Architecture. Modeling is focused on process, components and
programming resources of IMS-LD. Architecture is focused on the communication that
IMS-LD establishes outside, both ways, and it deals with upper layers of the specification,
beyong modeling issues. Modeling and Architecture issues need to be addressed in order
to improve the pedagogical expressiveness and the integration of IMS-LD. Furthermore,
we provide an orchestrated solution which meets these goals. We develop a structured
and organized group of modifications and extensions of IMS-LD, which match the
different reported problems issues. We suggest modifications, extensions and addition of
different elements, aiming at the strength of the specification on adaptation and
integration, along with general interest issues.
The main conclusion out of this research is that IMS-LD needs a re-structure and a
modification of some elements. It also needs to incorporate new ones. Both actions
(modification and extension) are the key to improve the pedagogical expressiveness and
the integration with other specifications and eLearning systems. Both actions aim at two
clear objectives in the definition of IMS-LD: the personalisation of learning processes,
and a real interoperability. It is fair to highlight the welcome help of high-level visual
authoring tools. They can support a smoother modeling process that could focus on
pedagogical issues and not on technical ones, so that a broad target group made of
teachers, learning designers, content creators and pedagogues could make use of the
specification in a simpler way. However, this criticism is outside the specification, so
outside the core of this thesis too.
This three-year research (2004-2007) has been carried out along with colleagues from
The Open University of The Netherlands, The University of Bolton, Universitat Pompeu
Fabra and from the Department of Research & Innovation of ATOS Origin. In addition, a
few European projects, like UNFOLD, EU4ALL and ProLearn, have partially supported it
Comparative analysis of adaptation in adaptive educational hypermedia and IMS-learning design
No full textCurrently, Adaptive Educational Hypermedia (AEH) and IMS Learning Design (IMS-LD) are separate research areas, with little shared knowledge between them. Their goal, however, is the same: to design, author and implement the best possible learning experience for the learner. This paper addresses the issue of differences and similarities between AEH and IMS-LD with regard to knowledge representation and adaptation and investigates, generically, as well as for the specific case of the Layered AHS Authoring-Model and Operators (LAOS) framework, how these paradigms can benefit from each other
The impact of SNP density on fine-scale patterns of linkage disequilibrium
No full textLinkage disequilibrium (LD) is a measure of the degree of association between alleles in a population. The detection of disease-causing variants by association with neighbouring single nucleotide polymorphisms (SNPs) depends on the existence of strong LD between them. Previous studies have indicated that the extent of LD is highly variable in different chromosome regions and different populations, demonstrating the importance of genome-wide accurate measurement of LD at high resolution throughout the human genome. A uniform feature of these studies has been the inability to detect LD in regions of low marker density. To investigate the dependence of LD patterns on marker selection we performed a high-resolution study in African-American, Asian and UK Caucasian populations. We selected over 5000 SNPs with an average spacing of 1 SNP per 2 kb after validating ca 12 000 SNPs derived from a dense SNP collection (1 SNP per 0.3 kb on average). Applications of different statistical methods of LD assessment highlight similar areas of high and low LD. However, at high resolution, features such as overall sequence coverage in LD blocks and block boundaries vary substantially with respect to marker density. Model-based linkage disequilibrium unit (LDU) maps appear robust to marker density and consistently influenced by marker allele frequency. The results suggest that very dense marker sets will be required to yield stable views of fine-scale LD in the human genome
Mahalanobis distances from each Federalist Paper of disputed authorship to each author centroid.
No full text<p>The texts with the closest distance to each author centroid are highlighted in bold. The longest distance (LD) between an undisputed authorship text and its author centroid is given in the table header.</p
Genome-wide association study identifies susceptibility loci for dengue shock syndrome at MICB and PLCE1.
No full textHypovolemic shock (dengue shock syndrome (DSS)) is the most common life-threatening complication of dengue. We conducted a genome-wide association study of 2,008 pediatric cases treated for DSS and 2,018 controls from Vietnam. Replication of the most significantly associated markers was carried out in an independent Vietnamese sample of 1,737 cases and 2,934 controls. SNPs at two loci showed genome-wide significant association with DSS. We identified a susceptibility locus at MICB (major histocompatibility complex (MHC) class I polypeptide-related sequence B), which was within the broad MHC region on chromosome 6 but outside the class I and class II HLA loci (rs3132468, P(meta) = 4.41 × 10(-11), per-allele odds ratio (OR) = 1.34 (95% confidence interval: 1.23-1.46)). We identified associated variants within PLCE1 (phospholipase C, epsilon 1) on chromosome 10 (rs3765524, P(meta) = 3.08 × 10(-10), per-allele OR = 0.80 (95% confidence interval: 0.75-0.86)). We identify two loci associated with susceptibility to DSS in people with dengue, suggesting possible mechanisms for this severe complication of dengue
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