11,381 research outputs found

    Digital Tools and Instructional Rules: A study of how digital technologies become rooted in classroom procedures

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    This paper examines how a classroom culture developsadvanced strategies and procedures for handling complexdigital tools. We report from a vocational Mediaand Communication course at an Upper SecondarySchool in Oslo, Norway. Our analysis reveals how aprocedure called practical assignments has developedhistorically at the school, and how this procedure iscarried out in the classroom. Theoretically, our studyis informed by Activity Theory, which affords us toolsto analyze how social institutions and learning trajectoriesevolve over time, and how longitudinal dimensionsemerge in situ. Our findings show how teachers andlearners create a space for solving context-specific problemsinvolving sophisticated technology. A historicalanalysis is here crucial not only in understanding whydigital technologies are used in specific ways, but alsohow they evolve into classroom conventions

    Abundence indices of 19 "non-commercial" species in the Barents Sea based on groundfish surveys - the "Winter-survey" - during 1981-2003.

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    The aim of this report is to present abundance estimates of nineteen fishes/fish-groups in the Barents Sea that have small or no commercial interest. Such non-commercial species may be used as ecosystem characters. NORSK SAMMENDRAG: Formålet med å lage mengdeindekser for arter som er av liten eller ingen kommersiell interesse er å få en bedre dokumentasjon på antall og mengde av et større antall arter som er viktige i økosystemet, og hvordan forekomstene av disse har variert over tid. De ikke-kommersielle artene kan også si oss noe om endringer i miljøet de lever i, og kan fungere som såkalte bioindikatorer

    The effects of rhetorical patterns or schemata on reading comprehension in expository text of Persian

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    AbstractThis study attempts to explore the schemata or rhetorical patterns on reading comprehension of 300 state run university students of psychology and educational fields. The subjects involved were selected through stratified random sampling. This group includes two ways factorial design through random assignment. The variables of this article were investigated in three groups (100 subjects in each group). Each group was asked to recall the text and finish a multiple-choice test. The central instrument included three versions of passage with identical content but different schemata: descriptive (listing) pattern, explaining pattern and analysis pattern. Analysis of recall test indicated that subjects displayed better recall of the text with highly structured schema than the one with loosely controlled schema. The outcomes suggested that rhetorical patterns have a significant effect on written communication

    The Reduction in Right Ventricular Longitudinal Contraction Parameters Is Not Accompanied by a Reduction in General Right Ventricular Performance During Aortic Valve Replacement:An Explorative Study

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    Objective: The aim of the present study was to identify whether the decrease of longitudinal parameters after cardiothoracic surgery (ie, tricuspid annular systolic plane excursion [TAPSE] and systolic excursion velocity [S']) is accompanied by a reduction in global right ventricular (RV) performance. Design: Prospective, observational study. Setting: Single-center explorative study in a tertiary teaching hospital. Participants: The study comprised 20 patients who underwent aortic valve replacement with or without coronary artery bypass grafting. Interventions: During cardiac surgery, simultaneous measurements of RV function were performed with a pulmonary artery catheter and transesophageal echocardiography. Measurements and Main Results: TAPSE and S’ were reduced significantly directly after surgery compared with the time before surgery (TAPSE from 20.8 [16.6-23.4] mm to 9.1 [5.6-15.5] mm; p < 0.001 and S’ from 8.7 [7.9-10.7] cm/s to 7.2 [5.7-8.6] cm/s; p = 0.041). However, the reduction in TAPSE and S’ was not accompanied by a reduction in RV performance, as assessed with the TEE-derived myocardial performance index (MPI) and pulmonary artery catheter–derived RV ejection fraction (RVEF). Both remained statistically unaltered before and after the procedure (MPI from 0.52 [0.43-0.58] to 0.50 [0.42-0.88]; p = 0.278 and RVEF from 27% [22%-32%] to 26% [22%-28%]; p = 0.294). Conclusions: In the direct postoperative phase, the reduction of echocardiographic parameters of longitudinal RV contractility (TAPSE and S’) were not accompanied by a reduction in global RV performance, expressed as MPI and RVEF. Solely relying on a single RV parameter as a marker for global RV performance may not be adequate to assess the complex adaptation of the right ventricle to aortic valve replacement

    Stubborn Predictions in Primary Visual Cortex

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    Perceivers can use past experiences to make sense of ambiguous sensory signals. However, this may be inappropriate when the world changes and past experiences no longer predict what the future holds. Optimal learning models propose that observers decide whether to stick with or update their predictions by tracking the uncertainty or "precision" of their expectations. However, contrasting theories of prediction have argued that we are prone to misestimate uncertainty-leading to stubborn predictions that are difficult to dislodge. To compare these possibilities, we had participants learn novel perceptual predictions before using fMRI to record visual brain activity when predictive contingencies were disrupted-meaning that previously "expected" events become objectively improbable. Multivariate pattern analyses revealed that expected events continued to be decoded with greater fidelity from primary visual cortex, despite marked changes in the statistical structure of the environment, which rendered these expectations no longer valid. These results suggest that our perceptual systems do indeed form stubborn predictions even from short periods of learning-and more generally suggest that top-down expectations have the potential to help or hinder perceptual inference in bounded minds like ours
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