623 research outputs found

    Monitoring Conceptual Development: Design Considerations of a Formative Feedback tool

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    This paper presents the design considerations of a tool aiming at providing formative feedback. The tool uses Latent Semantic Analysis, to automatically generate reference models and provide learners a means to compare their conceptual development against these models. The design of the tool considers a theoretical background which combines research on expertise development, knowledge creation, and conceptual development assessment. The paper also illustrates how the tool will work using a problem and solution scenario, and presents initial validations results. Finally the paper draws conclusions and future work

    Effective utilization of oral hypoglycemic agents to achieve individualized HbA1c targets in patients with type 2 diabetes mellitus

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    YesType 2 diabetes is a progressive condition that may require the combination of three oral treatments to achieve optimal glycemic management to prevent microvascular and macrovascular complications whilst minimizing the risk of acute complications and side effects or adverse reactions to treatments. With the widening availability of treatment options and increasing importance of individualized treatment pathways, including personalized HbA1c targets, this article will explore the mode of action of currently available oral treatments, factors to consider when individualizing HbA1c targets, the relevance of estimated glomerular filtration rate assessment, and the importance of reviewing the clinical impact of all treatment decisions

    The taxophysiological paradox: changes in the intestinal microbiota of the xylophagous cockroach Cryptocercus punctulatus depending on the physiological state of the host

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    The phylogenetic relationships of symbiotic bacteria from the xylophagous cockroach Cryptocercus (Cryptocercidae, Blattaria) were compared to those described in previous reports in lower termites. The 16S rDNA bacterial genes were PCR-amplified from DNA isolated from the entire hindgut using Bacteria-selective primers, and the 16S rDNA amplicons were cloned into Escherichia coli. The changes in the gut microbiota of Cryptocercus under three physiological conditions, “active,” “fasting,” and “dead,” were studied. Analysis of the active-clone library revealed 45 new phylotypes (clones sharing > 97% sequence identity were grouped into the same phylotype) from 54 analyzed clones. The clones were affiliated with the phyla Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, Spirochaetes, Synergistetes, Verrucomicrobia, and candidate phylum Termite Group 1 (TG1). Clones belonging to Spirochaetes, Bacteroidetes, and TG1 phyla clustered with previously reported sequences obtained from the guts of several termites, suggesting that these clones are common constituents of the intestinal microbiota of lower termites and Cryptocercus. In the fasting-clone library, 19 new phylotypes, from 49 clones studied, were distinguished. The new phylotypes were affiliated with the phyla Bacteroidetes, Firmicutes, Actinobacteria, Proteobacteria, Spirochaetes, Synergistetes, and the candidate phylum TM7. Finally, in the dead-clone library, 24 new phylotypes from 50 studied clones were found. The new phylotypes were affiliated with the phyla Firmicutes, Actinobacteria, and Proteobacteria. Thus, from active, to fasting, to dead physiological states, a decrease in the number of phyla present in the whole microbial gut was evident. However, in the dead physiological state, each phylum conserved contained more new phylotypes. This poses a taxophysiological paradox, because a stable, active physiological state of Cryptocercus—due to a continuous input of wood—supports a higher diversity of bacterial phyla, probably necessary to maintain a sharp O2–H2 gradient in the gut. By contrast, in the dead state, nutrient input is limited to the residual gut microbiota that is killed by the newly oxic environment, thus providing a food source for other, aerobic or facultative anaerobic bacteria. This results in an increase in the internal diversity of the few remaining phyla. [Int Microbiol 2009; 12(4):227-236

    Coevolution of symbiotic spirochete diversity in lower termites

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    The phylogenetic relationships of symbiotic spirochetes from five dry-wood feeding lower termites (Cryptotermes cavifrons, Heterotermes tenuis, Kalotermes flavicollis, Neotermes mona, and Reticulitermes grassei) was compared to those described in previous reports. The 16S rDNA bacterial genes were PCR-amplified from DNA isolated from intestinal samples using a spirochete-selective primer, and the 16S amplicons were cloned into Escherichia coli. Sequences of the cloned inserts were then used to determine closest relatives by comparison with published sequences. Clones sharing more than 97% sequence identity were grouped into the same phylotype. Forty-three new phylotypes were identified. These termite whole-gut-spirochetes fell into two previous defined clusters, designated as Treponema Clusters I and II, and one new Cluster III. Thirty-seven phylotypes were grouped in Cluster I. Cluster II comprised three phylotypes, two from Reticulitermes grassei (LJ029 and LJ012) and one from Heterotermes tenuis (LQ016). Three phylotypes, LK057, LK050 and LK028, were affiliated to Cluster III. Members of Cluster I showed the following characteristics: (i) spirochete phylotypes from a particular species of termite were more closely related to each other than to phylotypes of other termite species; (ii) spirochetes obtained from different genera of the same family, such as Cryptotermes sp., Kalotermes sp., and Neotermes sp., all from the family Kalotermitidae, were also related to each other. It was therefore concluded that spirochetes are specific symbionts that have coevolved with their respective species of termites, are stably harbored, and are closely related to members of the same termite family. [Int Microbiol 2007; 10(2):133-139

    A Proposal to Define Adaptive Learning Designs

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    Abstract. This paper outlines a framework to describe adaptive learning designs where definitions as the instructional design method, the type of tests, the learning style approach, and the adaptive rules are not prescribed. Standardized metadata based on IMS is used to guarantee the reusability and interoperability of the elements. The framework proposes, also, to adjust the learning design taking into account the student knowledge and the learning style of both the learner and the learning activities by means of adaptive rule definitions. These rules are defined using a set of elements (based on IMS LD) and they describe adaptive statements, techniques and students’ stereotypes

    Comparison of the gut microbiota from soldier and worker castes of the termite Reticulitermes grassei

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     The bacterial microbiota from the whole gut of soldier and worker castes of the termite Reticulitermes grassei was isolated and studied. In addition, the 16S rDNA bacterial genes from gut DNA were PCR-amplified using Bacteria-selective primers, and the 16S rDNA amplicons subsequently cloned into Escherichia coli. Sequences of the cloned inserts were then used to determine closest relatives by comparison with published sequences and with sequences from our previous work. The clones were found to be affiliated with the phyla Spirochaetes, Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Synergistetes, Verrucomicrobia, and candidate phyla Termite Group 1 (TG1) and Termite Group 2 (TG2). No significant differences were observed with respect to the relative bacterial abundances between soldier and worker phylotypes. The phylotypes obtained in this study were compared with reported sequences from other termites, especially those of phylotypes related to Spirochaetes, Wolbachia (an Alphaproteobacteria), Actinobacteria, and TG1. Many of the clone phylotypes detected in soldiers grouped with those of workers. Moreover, clones CRgS91 (soldiers) and CRgW68 (workers), both affiliated with 'Endomicrobia', were the same phylotype. Soldiers and workers also seemed to have similar relative protist abundances. Heterotrophic, poly-β-hydroxyalkanoate-accumulating bacteria were isolated from the gut of soldiers and shown to be affiliated with Actinobacteria and Gammaproteobacteria. We noted that Wolbachia was detected in soldiers but not in workers.Overall, the maintenance by soldiers and workers of comparable axial and radial redox gradients in the gut is consistent with the similarities in the prokaryotes and protists comprising their microbiota
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