2,593 research outputs found
Learnersā confusion: faulty prior knowledge or a metacognitive monitoring error?
Research often treats confusion as a turning point of the learnersā cognitive-affective dynamics in digital environments (e.g. DāMello, Grasser and colleagues). The origin of confusion, however, is a topic of a debate. Could inaccurate prior knowledge serve as a source of confusion, or does confusion relate to metacognitive processes? In this paper we are attempting to address this question by employing case study analysis with fourteen participants who worked through simulated learning problems with feedback in a digital environment. Physiological and self-reported data were combined to examine problem-solving patterns. Preliminary findings highlighted the role of metacognitive monitoring in confusion development and its interrelation with inaccurate prior knowledge.5 page(s
Investigating the factors that influence the use of digital learning resources in the K-12 educational context
Australian and New Zealand governments have made a significant investment in the establishment of an on-line repository that will make digital learning resources, also called learning objects, available to teachers in the K-12 sector. The focus of this, and similar learning object initiatives around the world, has been on content development and delivery. Much of the current learning object research has been concerned with resolving the technical issues to support these processes, with little attention paid to pedagogical and practical issues that might influence learning object use. This paper argues for research to address this gap and reports on a study investigating the factors that influence the use of digital learning resources in the K-12 educational context. The findings of the study are relevant to understanding how learning object approaches can be best conceived of and supported
Isolation and characterization of the full-length cDNA encoding a member of a novel cytochrome p450 family (CYP320A1) from the tropical freshwater snail, Biomphalaria glabrata, intermediate host for Schistosoma mansoni
Cytochrome p450s (cyp450s) are a family of structurally related proteins, with diverse functions, including steroid synthesis and breakdown of toxins. This paper reports the full-length sequence of a novel cyp450 gene, the first to be isolated from the tropical freshwater snail Biomphalaria glabrata, an important intermediate host of Schistosoma mansoni. The nucleotide sequence is 2291 bp with a predicted amino acid sequence of 584aa. The sequence demonstrates conserved cyp450 structural motifs, but is sufficiently different from previously reported cyp450 sequences to be given a new classification, CYP320A1. Initially identified as down-regulated in partially resistant snails in response to S. mansoni infection, amplification of this gene using RT-PCR in both totally resistant or susceptible snail lines when exposed to infection, and all tissues examined, suggests ubiquitous expression. Characterization of the first cyp450 from B. glabrata is significant in understanding the evolution of these metabolically important proteins
Musculoskeletal education: a curriculum evaluation at one university
<p>Abstract</p> <p>Background</p> <p>The increasing burden of illness related to musculoskeletal diseases makes it essential that attention be paid to musculoskeletal education in medical schools. This case study examines the undergraduate musculoskeletal curriculum at one medical school.</p> <p>Methods</p> <p>A case study research methodology used quantitative and qualitative approaches to systematically examine the undergraduate musculoskeletal course at the University of Calgary (Alberta, Canada) Faculty of Medicine. The aim of the study was to understand the strengths and weaknesses of the curriculum guided by four questions: (1) Was the course structured according to standard principles for curriculum design as described in the Kern framework? (2) How did students and faculty perceive the course? (3) Was the assessment of the students valid and reliable? (4) Were the course evaluations completed by student and faculty valid and reliable?</p> <p><b>Results</b></p> <p>The analysis showed that the structure of the musculoskeletal course mapped to many components of Kern's framework in course design. The course had a high level of commitment by teachers, included a valid and reliable final examination, and valid evaluation questionnaires that provided relevant information to assess curriculum function. The curricular review identified several weaknesses in the course: the apparent absence of a formalized needs assessment, course objectives that were not specific or measurable, poor development of clinical presentations, small group sessions that exceeded normal 'small group' sizes, and poor alignment between the course objectives, examination blueprint and the examination. Both students and faculty members perceived the same strengths and weaknesses in the curriculum. Course evaluation data provided information that was consistent with the findings from the interviews with the key stakeholders.</p> <p>Conclusions</p> <p>The case study approach using the Kern framework and selected questions provided a robust way to assess a curriculum, identify its strengths and weaknesses and guide improvements.</p
Differential spatial repositioning of activated genes in Biomphalaria glabrata snails infected with Schistosoma mansoni
Copyright @ 2014 Arican-Goktas et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Schistosomiasis is an infectious disease infecting mammals as the definitive host and fresh water snails as the intermediate host. Understanding the molecular and biochemical relationship between the causative schistosome parasite and its hosts will be key to understanding and ultimately treating and/or eradicating the disease. There is increasing evidence that pathogens that have co-evolved with their hosts can manipulate their hosts' behaviour at various levels to augment an infection. Bacteria, for example, can induce beneficial chromatin remodelling of the host genome. We have previously shown in vitro that Biomphalaria glabrata embryonic cells co-cultured with schistosome miracidia display genes changing their nuclear location and becoming up-regulated. This also happens in vivo in live intact snails, where early exposure to miracidia also elicits non-random repositioning of genes. We reveal differences in the nuclear repositioning between the response of parasite susceptible snails as compared to resistant snails and with normal or live, attenuated parasites. Interestingly, the stress response gene heat shock protein (Hsp) 70 is only repositioned and then up-regulated in susceptible snails with the normal parasite. This movement and change in gene expression seems to be controlled by the parasite. Other differences in the behaviour of genes support the view that some genes are responding to tissue damage, for example the ferritin genes move and are up-regulated whether the snails are either susceptible or resistant and upon exposure to either normal or attenuated parasite. This is the first time host genome reorganisation has been seen in a parasitic host and only the second time for any pathogen. We believe that the parasite elicits a spatio-epigenetic reorganisation of the host genome to induce favourable gene expression for itself and this might represent a fundamental mechanism present in the human host infected with schistosome cercariae as well as in other host-pathogen relationships.NIH and Sandler Borroughs Wellcome Travel Fellowshi
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APOLIPOPROTEIN E (epsilon) genotype has a greater impact on apoB-48 than apoB-100 responses to dietary fat manipulation- insights from the SATgenĪµ study
SCOPE:
To determine the contribution of intestinally and liver-derived lipoproteins to the postprandial plasma triacylglycerol (TAG) response in APOE3/E3 and E3/E4 individuals following chronic dietary fat manipulation.
METHODS AND RESULTS:
In sequential order, participants (n = 12 E3/E3, n = 11 E3/E4) followed low fat (LF); high-fat, high-saturated fat (HSF); and HSF with 3.45 g/day docosahexaenoic acid (HSF-DHA) diets, each for 8 weeks. After each dietary period, an acute test meal with a macronutrient profile representative of the dietary intervention was consumed. Apolipoprotein (apo)B isoforms were determined in isolated TAG-rich lipoprotein fractions (Sf >400, Sf 60-400 and Sf 20-60) by specific ELISA. A genotype*meal/diet interaction for the Sf >400 fraction apoB-48 response (P400 particles. Fasting Sf 60-400 and 20-60 apoB-48 concentrations were also significantly higher in E4 carriers. No impact of genotype on the apoB-100 responses was evident.
CONCLUSION:
Our study revealed marked effects of dietary fat composition on the Sf >400 apoB-48 response and particle TAG content in E4 carriers relative to the 'wild-type' E3/E3 genotype, which suggest APOE genotype is a potential modulator of chylomicron particle synthesis. This article is protected by copyright. All rights reserved
Enabling High-Power SmallSats with Advanced Thermal Management
High-power Small Satellites have the potential to provide new and advanced capabilities; however, significant challenges prevent wide-spread use. Of these, thermal management of high-heat loads is significant. Although advances in thermal acquisition, transport, and storage are available; thermal dissipation technologies for high-power systems are lacking. Several design concepts are presented focused on high-efficiency, lightweight deployable radiating technologies. Analysis showed that realistic deployable radiator designs offer 220% more thermal dissipation than body-mounted radiator designs, which directly correlates to the same amount of increase in feasible total bus power. Using deployable radiators, a nominal 6U Small Satellite can realistically dissipate around 200 W
The nuclear receptors of Biomphalaria glabrata and Lottia gigantea: Implications for developing new model organisms
Ā© 2015 Kaur et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedNuclear receptors (NRs) are transcription regulators involved in an array of diverse physiological functions including key roles in endocrine and metabolic function. The aim of this study was to identify nuclear receptors in the fully sequenced genome of the gastropod snail, Biomphalaria glabrata, intermediate host for Schistosoma mansoni and compare these to known vertebrate NRs, with a view to assessing the snail's potential as a invertebrate model organism for endocrine function, both as a prospective new test organism and to elucidate the fundamental genetic and mechanistic causes of disease. For comparative purposes, the genome of a second gastropod, the owl limpet, Lottia gigantea was also investigated for nuclear receptors. Thirty-nine and thirty-three putative NRs were identified from the B. glabrata and L. gigantea genomes respectively, based on the presence of a conserved DNA-binding domain and/or ligand-binding domain. Nuclear receptor transcript expression was confirmed and sequences were subjected to a comparative phylogenetic analysis, which demonstrated that these molluscs have representatives of all the major NR subfamilies (1-6). Many of the identified NRs are conserved between vertebrates and invertebrates, however differences exist, most notably, the absence of receptors of Group 3C, which includes some of the vertebrate endocrine hormone targets. The mollusc genomes also contain NR homologues that are present in insects and nematodes but not in vertebrates, such as Group 1J (HR48/DAF12/HR96). The identification of many shared receptors between humans and molluscs indicates the potential for molluscs as model organisms; however the absence of several steroid hormone receptors indicates snail endocrine systems are fundamentally different.The National Centre for the Replacement, Refinement and Reduction of Animals in Research, Grant Ref:G0900802 to CSJ, LRN, SJ & EJR [www.nc3rs.org.uk]
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