350 research outputs found

    Observational learning from animated models: effects of studying-practicing alternation and illusion of control on transfer

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    Wouters, P. J. M., Paas, F., & Van Merriënboer, J. J. G. (2010). Observational learning from animated models: effects of studying-practicing alternation and illusion of control on transfer. Instructional Science, 38(1), 89-104. doi:10.1007/s11251-008-9079-0Animated models explicating how a problem is solved and why a particular method is chosen are expected to be effective learning tools for novices, especially when abstract cognitive processes or concepts are involved. Cognitive load theory was used to investigate how learners could be stimulated to engage in genuine learning activities. It was hypothesized that illusion of control would impede transfer performance compared to a condition without illusion of control. Moreover, we hypothesized that learners who first studied an animated model and then solved the same problem would perform better on transfer than learners who studied the same animated model twice or who first solved the problem and then studied the animated models. In a 2 x 3 factorial experiment (N = 90) with the factors illusion of control (yes vs. no) and instruction method (study-practice, practice-study, study-study) only the first hypothesis was confirmed. Implications for the design of animated models are discussed

    Interactivity in video-based models

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    In this review we argue that interactivity can be effective in video-based models to engage learners in relevant cognitive processes. We do not treat modeling as an isolated instructional method but adopted the social cognitive model of sequential skill acquisition in which learners start with observation and finish with independent, self-regulated performance. Moreover, we concur with the notion that interactivity should emphasize the cognitive processes that learners engage in when they interact with the learning environment. The four-component instructional design (4C/ID) model is used to define a set of cognitive processes: Elaboration and induction enable learners to construct schemas, whereas compilation and strengthening enable learners to automate these schemas. Pacing, cues, control over appearance, prediction, working in dyads, personalized task selection, and reflection prompts are identified as guidelines that might support learners to interactively construct schemas. Personalized task selection with part-task practice helps learners to interactively automate schemas

    Thermotolerance of an inactivated rabies vaccine for dogs

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    This study provides the first robust data that the antibody response of dogs vaccinated with Nobivac® Rabies vaccine stored for several months at high temperatures (up to 30 °C) is not inferior to that of dogs vaccinated with vaccine stored under recommended cold-chain conditions (2–8 °C). A controlled and randomized non-inferiority study was carried out comparing the four-week post vaccination serological responses of Tanzanian village dogs inoculated with vaccine which had been stored at elevated temperatures for different periods of time with those of dogs vaccinated with the same product stored according to label recommendations. Specifically, the neutralizing antibody response following the use of vaccine which had been stored for up to six months at 25 °C or for three months at 30 °C was not inferior to that following the use of cold-chain stored vaccine. These findings provide reassurance that the vaccine is likely to remain efficacious even if exposed to elevated temperatures for limited periods of time and, under these circumstances, it can safely be used and not necessarily destroyed or discarded. The availability of thermotolerant vaccines has been an important factor in the success of several disease control and elimination programs and could greatly increase the capacity of rabies vaccination campaigns to access hard to reach communities in Africa and Asia. We have not confirmed a 3-year duration of immunity for the high temperature stored vaccine, however because annual re-vaccination is usually practiced for dogs presented for vaccination during campaigns in Africa and Asia this should not be a cause for concern. These findings will provide confidence that, for rabies control and elimination programs using this vaccine in low-income settings, more flexible delivery models could be explored, including those that involve limited periods of transportation and storage at temperatures higher than that currently recommended

    Collaborative mental health care in the bureaucratic field of post-apartheid South Africa

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    South Africa's long and arduous journey from colonial and apartheid-era care for people with mental illness to more comprehensive, equitable mental health care is well-described. Deeper engagement with the structural power dynamics involved in providing collaborative mental health services are less-well described, especially in its post-apartheid era. This conceptual article positions state and non-state mental health service providers - along with their relationships and conflicts - within Bourdieu's bureaucratic field. It is suggested that key internecine struggles in South Africa's post-apartheid socio-political arena have influenced the ways in which collaborative mental health care is provided. Drawing from two recent examples of conflict within the bureaucratic field, the article illustrates the ways in which neoliberal forces play out in contemporary South Africa's mental health service delivery. Struggles between the state and private healthcare in the Life Esidimeni tragedy receive focus, as well as the shifting of responsibility onto civil society. A court case between the state and a coalition of non-profit organisations provides further evidence that neoliberal rationalities significantly influences the position and power of non-state service providers. Unless serious consideration is given to these dynamics, collaborative mental health care in South Africa will remain out of reach

    Morphological MR imaging of the articular cartilage of the knee at 3 T : comparison of standard and novel 3D sequences

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    Objectives: This study sought to compare various 3D cartilage sequences and to evaluate the usefulness of ultrashort TE (UTE) imaging, a new technique to isolate signal from the osteochondral junction. Methods: Twenty knees were examined at 3 T with 3D spoiled GRE (FLASH), double-echo steady-state (DESS), balanced SSFP, 3D turbo spin-echo (TSE), and a prototype UTE sequence. Two radiologists independently evaluated all images. Consensus readings of all sequences were the reference standard. Statistical analysis included Friedman and pairwise Wilcoxon tests. Retrospective analysis of UTE morphology of osteochondral tissue in normal and abnormal cartilage seen at conventional MR was also performed. Results: Three-dimensional TSE was superior to other sequences for detecting cartilage lesions. FLASH and DESS performed best in the subjective quality analysis. On UTE images, normal cartilage exhibited a high-intensity linear signal near the osteochondral junction. Retrospective analysis revealed abnormal UTE morphology of the osteochondral junction in 50 % of cartilage lesions diagnosed at conventional MR. Conclusions: Cartilage imaging of the knee at 3 T can be reliably performed using 3D TSE, showing high accuracy when compared to standard sequences. Although UTE depicts signal from the deep cartilage layer, further studies are needed to establish its role for assessment of cartilage
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