Lessons learned from the use of the SlideWiki OpenCourseWare platform in different learning contexts

A major obstacle to increasing the efficiency, effectiveness and quality of education is the lack of widely available, accessible, multilingual, timely, engaging and high-quality educational material, i.e. OpenCourseWare (OCW). The creation of comprehensive OCW is often a tedious, time-consuming and expensive process, with the effect that courseware employed by educators and trainers can be incomplete and outdated, as well as inaccessible to those with disabilities. With the open-source and open-access SlideWiki platform, the effort of creation, translation and evolution of highly-structured remixable OCW can be widely shared. Similarly to Wikipedia for encyclopaedic content, SlideWiki allows to collaboratively create comprehensive OCW (curricula, slide presentations, self-assessment tests, illustrations etc.) online in a crowdsourcing manner. SlideWiki has won the OpenCourseWare Consortium’s Excellence Award and is used by hundreds of educators and thousands of learners. Several hundred comprehensive course materials are available on SlideWiki in different languages. The SlideWiki large-scale trial project is further maturing the SlideWiki platform by improving its usability and accessibility. The SlideWiki project is performing a wide range of trials covering different levels of education (i.e. from secondary to higher education) and different types of learning (i.e. formal learning, informal learning, vocational learning). Each of these large-scale trials is carried out with hundreds of educators and thousands of learners in different countries across Europe. A particular focus of the technology development and testing in the trials is the suitability for academics, teachers and learners with disabilities. This paper will present the lessons learned from piloting the SlideWiki platform in different learning contexts and scenarios. In particular, we will describe the learning scenarios considered in each pilot and how these scenarios have been implemented with the use of SlideWiki. We will then describe the methodology followed in each pilot, in terms of the authoring, teaching and learning activities performed by educators and learners using SlideWiki. Finally, the lessons learned from each pilot will be discussed, focusing on the challenges faced in each pilot, how these challenges have been addressed, as well as the best practices that have emerged from the pilots regarding the collaborative authoring and sharing of OCW

Molecular phylogenetics of the genus Gerbillus (Rodentia, Gerbillinae): Implications for systematics, taxonomy and chromosomal evolution

Although gerbils forms an important component of the mammalian fauna of arid and semi-arid area, the taxonomic and phylogenetic relationship within the species of the genus Gerbillus are still ambiguous. The present paper introduces findings based on the whole cytochrome b (1140 bp) mitochondrial genes of seven species (Gerbillus campestris, G. latastei, G. nanus, G. tarabuli, G. gerbillus, G. simoni and G. nigeriae) SIX of which are present in Tunisia. Our results show that all the Gerbillus species are monophyletic. Moreover, molecular phylogeny rejects the genus rank for the taxon Dipodillus. Gebillus nanus, a species belonging to the subgenus Hendecapleura, early diverged from the other species which are divided into two clades: the subgenus Dipodillus, including G. campestris and G. simoni and the subgenus Gerbillus including G. gerbillus, G. nigeriae, G. tarabuli and G. latastei. These results are congruent with morphological and karyological evidences. According to molecular clock, the appearance of the genus Gerbillus coincides with the Miocene-Pliocene expansion of African arid biomes. Extensive intraspecific chromosomal changes evolved in a relatively narrow lapse of time, like in the case of G. latastei, allowing the fixations of different chromosomal variants due to pericentric inversion. (C) 2010 Elsevier Inc. All rights reserved

Electrogram fractionation during sinus rhythm occurs in normal voltage atrial tissue in patients with atrial fibrillation

Introduction Electrogram (EGM) fractionation is often associated with diseased atrial tissue; however, mechanisms for fractionation occurring above an established threshold of 0.5 mV have never been characterized. We sought to investigate during sinus rhythm (SR) the mechanisms underlying bipolar EGM fractionation with high-density mapping in patients with atrial fibrillation (AF). Methods Forty-five patients undergoing AF ablation (73% paroxysmal, 27% persistent) were mapped at high density (18562 +/- 2551 points) during SR (Rhythmia). Only bipolar EGMs with voltages above 0.5 mV were considered for analysis. When fractionation (> 40 ms and >4 deflections) was detected, we classified the mechanisms as slow conduction, wave-front collision, or a pivot point. The relationship between EGM duration and amplitude, and tissue anisotropy and slow conduction, was then studied using a computational model. Results Of the 45 left atria analyzed, 133 sites of EGM fragmentation were identified with voltages above 0.5 mV. The most frequent mechanism (64%) was slow conduction (velocity 0.45 m/s +/- 0.2) with mean EGM voltage of 1.1 +/- 0.5 mV and duration of 54.9 +/- 9.4 ms. Wavefront collision was the second most frequent (19%), characterized by higher voltage (1.6 +/- 0.9 mV) and shorter duration (51.3 +/- 11.3 ms). Pivot points (9%) were associated with the highest degree of fractionation with 70.7 +/- 6.6 ms and 1.8 +/- 1 mV. In 10 sites (8%) fractionation was unexplained. The EGM duration was significantly different among the 3 mechanisms (p = .0351). Conclusion In patients with a history of AF, EGM fractionation can occur at amplitudes > 0.5 mV when in SR in areas often considered not to be diseased tissue. The main mechanism of EGM fractionation is slow conduction, followed by wavefront collision and pivot sites