1,722 research outputs found
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
A TSHr-LH/CGr Chimera that Measures Functional TSAb in Graves' Disease.
No full textContext: Stimulating thyrotropin receptor (TSHr) autoantibodies (TSAb) are the cause of hyperthyroidism in Graves' disease. In a patient's serum, TSAb can coexist with antagonist TSHr autoantibodies that block TSAb stimulatory activity (TSBAb); both can vary in amount and time. Objective: The objective of the study was to create a functional assay that detects only TSAb, thus having an increased accuracy for diagnosing Graves' disease. Design: A TSHr chimera (Mc4) that retains an agonist-sensitive TSAb epitope but replaces a TSBAb epitope was stably transfected in cells to establish the Mc4 assay. Setting: The study was conducted at the Chieti University (Outpatient Endocrine Clinic) and the University of Pisa (the Department of Endocrinology). Patients: The assay was validated using sera from 170 individuals with Graves' disease, Hashimoto's thyroiditis, and nonautoimmune hyperthyroidism and normal subjects from Chieti University. A second blinded study evaluated sera from 175 patients with autoimmune thyroid disease (mainly Graves' disease) from the University of Pisa. Interventions: Interventions included the assessment of patients' sera using human wild-type TSHr (WT-TSHr), Mc4 chimera, and binding (TRAb) assays. Main Outcome Measures: The Mc4 assay has the best accuracy for diagnosing Graves' disease. Results: The Mc4 assay has a better diagnostic accuracy than WT-TSHr and second-generation TRAb assays. Indeed, the sensitivity of the WT-TSHr, TRAb, and Mc4 assays was 97.3, 86.5, and 100%, respectively, whereas the specificity was 93.1, 97, and 98.5%, respectively. Conclusion: The Mc4 assay is a functional assay with improved sensitivity and specificity for the detection of TSAb and is clinically useful in diagnosing Graves' disease
Transcriptional regulation of major histocompatibility complex class I gene by insulin and IGF-I in FRTL-5 thyroid cells.
No full textIncreased major histocompatibility complex (MHC) class I gene expression in nonimmune cell ‘target tissues’ involved in organ-specific diseases may be important in the pathogenesis of autoimmune diseases. This possibility in part evolves from studies of cultured thyrocytes where properties appear relevant to the development of thyroid autoimmune disease. In FRTL-5 rat thyroid cells in continuous culture, hormones and growth factors that regulate cell growth and function specifically decrease MHC class I gene expression. We hypothesized that this could reflect a mechanism to preserve self-tolerance and prevent autoimmune disease. The mechanisms of action of some of these hormones, namely TSH and hydrocortisone, have been already characterized. In this report, we show that IGF-I transcriptionally downregulates MHC class I gene expression and that its action is similar to that of insulin. The two hormones have a complex effect on the promoter of the MHC class I gene, PD1. In fact, they decrease the full promoter activity, but upregulate the activity of deleted mutants that have lost an upstream, tissue-specific regulatory region but still retain the enhancer A region. We show that insulin/IGF-I promotes the interactions of the p50/p65 subunits of NF-κB and AP-1 family members with these two regions, and that the tissue-specific region acts as a dominant silencer element on insulin/IGF-I regulation of promoter activity. These observations may be important to understand how MHC class I gene transcription is regulated in the cells
Acute inflammatory demyelinating polyradiculoneuropathy associated with perforin-deficient familial haemophagocytic lymphohistiocytosis.
No full textJaundice in critical illness: promoting factors of a concealed reality
No full textAbstract Objective: In critical
illness, liver dysfunction (LD) is
associated with a poor outcome
independently of other organ dysfunctions. Since strategies to support liver function are not available,
a timely and accurate identification
of factors promoting LD may lead
to prevention or attenuation of its
consequences. The aim of this study
was to assess risk factors for LD
in critically ill patients. Design:
Prospective, observational study.
Setting: A multidisciplinary intensive
care unit (ICU) of a university
hospital. Patients: All patients
consecutively admitted over a 6-
month period. Intervention: None.
Measurements and results: LD was
defined as serum bilirubin levels
≥ 2 mg/dl and lasting for at least 48 h. Out of 283 patients, 141 matched
inclusion criteria. Forty-four patients
(31.2%) showed LD (LD group),
while 97 (68.8%) were included in
control group (C group). A binomial
analysis showed that LD occurrence
was associated with moderate (odds
ratio [OR] 3.11; p = 0.04) and severe
shock (OR 3.46; p = 0.05), sepsis
(OR 3.03; p = 0.04), PEEP ventilation
(OR 4.25; p = 0.006), major
surgery (OR 4.03; p = 0.03), and
gram-negative infections (OR 3.94;
p = 0.002). In stepwise multivariate
analysis, the single independent predictive factors of LD resulted in
severe shock (p = 0.002), sepsis
(p = 0.03), PEEP ventilation
(p = 0.04), and major surgery
(p = 0.05). Conclusions: In critically
ill patients jaundice is common,
and severe shock states, sepsis, mechanical ventilation with PEEP and
major surgery are critical risk factors
for its onset. Since there is no specific
treatment, prompt resuscitation,
treatment of sepsis and meticulous
supportive care will likely reduce its
incidence and severity
Extensión de la especificación IMS Learning Design desde la adaptación e integración de unidades de aprendizaje
Get PDFIMS 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
Get PDFCurrently, 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
Assessment of the Different Types of Failure on Anterior Cantilever Resin-Bonded Fixed Dental Prostheses Fabricated with Three Different Materials: An In Vitro Study
Get PDFbackground: resin-bonded fixed dental prosthesis (RBFDP) represents a highly aesthetic and conservative treatment option to replace a single tooth in a younger patient. The purpose of this in vitro study was to compare the fracture strength and the different types of failure on anterior cantilever RBFDPs fabricated using zirconia (ZR), lithium disilicate (LD), and PMMA-based material with ceramic fillers (PM) by the same standard tessellation language (STL) file. Methods: sixty extracted bovine mandibular incisives were embedded resin block; scanned to design one master model of RBFDP with a cantilevered single-retainer. Twenty cantilevered single-retainer RBFDPs were fabricated using ZR; LD; and PM. Static loading was performed using a universal testing machine. Results: the mean fracture strength for the RBFDPs was: 292.5 Newton (Standard Deviation (SD) 36.6) for ZR; 210 N (SD 37.6) for LD; and 133 N (SD 16.3) for PM. All the failures of RBFDPs in ZR were a fracture of the abutment tooth; instead; the 80% of failures of RBFDPs in LD and PM were a fracture of the connector. Conclusion: within the limitations of this in vitro study, we can conclude that the zirconia RBFDPs presented load resistance higher than the maximum anterior bite force reported in literature (270 N) and failure type analysis showed some trends among the group
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