Antonio Robles

Serum leptin levels correlate with hepatic steatosis in chronic hepatitis C

OBJECTIVES:Hepatic steatosis (HS) has been related to obesity and fibrosis in chronic hepatitis C (CHC). The aim of this study was to determine the role of leptin system in HS development.METHODS:Patients (n = 131) with biopsy-proven CHC, positive HCV RNA, and raised ALT were enrolled. Body mass index, percentage of body fat by skin fold measurement, and bioelectrical impedance analysis was calculated and serum leptin concentration measured. Intrahepatic HCV RNA, HS, necroinflammatory activity, and fibrosis were determined in liver biopsy tissue.RESULTS:HS was present in 63 patients (48.1%). Steatosis was evident in 32 of 91 patients (35.2%) infected with genotype 1 and in 22 of 27 patients (81.5%) with genotype 3a (p < 0.001). In patients infected by genotype 3a, HS correlated significantly with intrahepatic HCV RNA load (r= 0.78; p < 0.001). However, in genotype 1, HS was associated with host factors such as leptin, body mass index, percentage of body fat, and visceral obesity. Multivariate analysis showed genotype (OR = 11.54, 95% CI = 1.13–117.14, p = 0.038), leptin levels (OR = 1.09, 95% CI = 1.03–1.17, p = 0.008) and fibrosis (OR = 9.86, 95% CI = 2.11–5.86, p = 0.03) as independent variables of HS development.CONCLUSIONS:Hepatic steatosis was related to genotype, fibrosis degree, and serum leptin levels. Genotype 3 seems to have a viral specific steatogenic effect. Leptin seems to be a link between obesity and steatosis development in CHC genotype 1–infected patients.

On the Use of Extended TAM to Assess Students' Acceptance and Intent to Use Third-Generation Learning Management Systems.

Service-oriented e-learning platforms can be considered as a third generation of learning management systems ( LMSs). As opposed to the previous generations, consisting of ad hoc solutions and traditional LMS, this new technology contemplates e-learning systems as services that can be integrated into different learning scenarios. This paper shows that the flexibility of these systems allows building personal learning environments and proposes the use of an extended technology acceptance model ( TAM) to assess the acceptance and intention to use a third generation of LMS. To fit and validate the service-oriented e-learning platforms acceptance model, structural equation modeling and path analysis have been implemented. The results point out that the intention to use this third-generation LMS is determined by the gadgets and container design, both of which are structural elements of this technology. Finally, it is also shown that previous experience does not determine the use intention of this technology. [ABSTRACT FROM AUTHOR]

Online laboratories as a cloud service developed by students

On-line laboratories (virtual or remote) are widely used in experimental engineering subjects as part of the learning process. In order to develop these laboratories, a development framework called RELATED (Remote Laboratories exTendED) is used by the Communications and Control System Department of the Spanish University for Distance Education of Spain (UNED). This framework defines a structured and methodological development procedure, allowing the students the generation of their own laboratories. Once the laboratory is developed (based in its components), students have to configure their own computing resources in order to make their labs available. However, several problems must be faced by students in the “deployment” of their labs: network configuration, hardware availability, and so on. So, in order to solve these problems, an automatic system based on cloud providers is defined to allow students having their own cloud network/resources for their developed labs. This system simplifies the lab deployment and avoids common errors/mistakes in the development of laboratories with RELATED.

Middleware solutions for service-oriented remote laboratories: A review

The evolution of Web 3.0 and consequently eLearning 3.0 have demanded a major change of the way learning objects are provided and implemented. It is foreseen that learning objects in eLearning 3.0 should be interoperable and easily discovered, and will represent any kind of virtual or physical object. Several approaches attempted to implement remote Laboratories as a Service (LaaS) in order to achieve such interoperability and to allow their integration into heterogeneous educational systems for pedagogical purposes and for more convenience, as well as, their coupling and mashing up with other learning objects in order to yield a scaffold and rich educational environment. This paper provides a broad study on the available middleware solutions for service-oriented remote laboratories implementation, emphasizing the pros and cons of each and the upcoming challenges in developing service-oriented remote laboratories.

Integration of management services for remote/virtual laboratories

Development of virtual/remote laboratories is a common task involved in the design of courses assessments (in engineering disciplines). The deployment of these laboratories must manage several aspects related to the real use of them, as users authorization and access, tracking of usage information, loading/saving data from experiments and so on. These features must be implemented by developers in a particular way for each laboratory. This paper shows how these services can be used automatically, with no development, using the RELATED management services. The deployment task consists of making a connector to the RELATED framework in order to consume these services. A full example is shown, describing the steps followed to integrate a previously developed low cost laboratory (based on a Lego system).