bluuebunny/crossref_metadata_2025_split huggingface dataset:
Making instructional animations more effective: a cognitive load approach
Authors: Ayres Paul , Paas Fred 
Published: August 2007

AbstractThis themed issue consists of seven empirical papers, as well as an introduction and discussion, and has its genesis in three symposia, organised by the authors of this article and presented at the 2006 Annual Meeting of the American Educational Research Association (AERA) in San Francisco, California. The papers investigate a number of conditions under which instructional animations may be effective. This article uses cognitive load theory (CLT) to provide an explanation for why animated instructions have not currently produced the learning benefits expected. A brief overview of the papers with a focus on how they accommodate critical aspects of cognitive load is given. The issue finishes with a discussion on each paper and identifies some common principles and recommendations for instructional design and research into animations. Copyright © 2007 John Wiley & Sons, Ltd.
Attention cueing as a means to enhance learning from an animation
Authors: de Koning Björn B. , Tabbers Huib K. , Rikers Remy M. J. P. , Paas Fred 
Published: August 2007

AbstractThe question how animations should be designed so that learning is optimised, is still under discussion. Animations are often cognitively very demanding, resulting in decreased learning outcomes. In this study, we tried to prevent cognitive overload and foster learning by focusing the learners' attention to one element (i.e. process) of an animation using a cueing technique. Psychology students viewed an animation of the cardiovascular system and were subsequently given a comprehension test and a transfer test. One group studied the animation without a visual cue, while for another group a visual cue was added to the animation. Results indicated that cueing not only enhanced comprehension and transfer performance for cued information, but also for uncued information. It is concluded that cueing can be used as a technique to improve learning from an animation. Results are interpreted in terms of cognitive load theory (CLT). Copyright © 2007 John Wiley & Sons, Ltd.
Animated pedagogical agents: does their degree of embodiment impact learning from static or animated worked examples?
Authors: Lusk Mary Margaret , Atkinson Robert K. 
Published: August 2007

AbstractThis study examined the impact of varying an animated pedagogical agent's level of embodiment in a learning environment consisting of static or animated multimodal worked examples illustrating how to solve multi‐step proportional word problems. In the fully embodied condition, the agent was programmed to coordinate spoken instructional explanations with non‐verbal forms of communication (locomotion, gesture, and gaze) to support learning. In the minimally embodied condition, the same agent provided the spoken instructions but remained static on the screen. In the voice‐only condition, the spoken instructions were provided without an agent. Of the 174 college‐age participants, those provided with the fully embodied agent produced more conceptually accurate answers to near and far transfer items than their counterparts in the voice‐only condition. Moreover, participants that studied animated worked examples, where the problem's subgoals were presented sequentially over time, outperformed their peers provided with static examples with simultaneously‐presented subgoals on measures of transfer. Copyright © 2007 John Wiley & Sons, Ltd.
Optimising learning from animations by minimising cognitive load: cognitive and affective consequences of signalling and segmentation methods
Authors: Moreno Roxana 
Published: August 2007

AbstractProspective teachers learned about seven teaching skills either with or without (control group) an exemplar classroom video (Experiment 1) or animation (Experiment 2) showing how an expert teacher applied such skills. It was hypothesised that directing attention to relevant dynamic information with signalling (SI) and/or segmenting (SE) the video/animation into smaller chunks of information would facilitate students' learning. Across both experiments, the control group outperformed SI and SE groups on retention of the theoretical information but underperformed most video/animation groups when asked to evaluate and apply teaching skills to a classroom scenario. SE groups outperformed no‐SE groups on all learning measures and reported lower levels of cognitive load. The findings encourage segmenting instructional videos and animations into small chunks to help novice students learn from complex dynamic visualisations. Copyright © 2007 John Wiley & Sons, Ltd.
Instructional efficiency of animation: effects of interactivity through mental reconstruction of static key frames
Authors: Paas Fred , Van Gerven Pascal W. M. , Wouters Pieter 
Published: August 2007

AbstractThis study used cognitive load theory to investigate whether an animation about the cardiovascular system can become a more effective educational tool by designing it with sensitivity to the capacity limitations of working memory. To manage the high extraneous cognitive load imposed by the need to process series of successive and transient information elements, a sequence of static key frames from the animation was presented to learners directly after the animation. Two interactive instructional conditions, which required learners either to construct or reconstruct the sequence of key frames, were compared to a non‐interactive condition. It was hypothesised that the interactive activities would lead to more efficient transfer performance. The results confirmed the hypothesis, indicating that the interactive conditions required less mental effort to attain the same performance as the non‐interactive condition. Instructional design implications for learning from animations are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Creating retroactive and proactive interference in multimedia learning
Authors: Mayer Richard E. , DeLeeuw Krista E. , Ayres Paul 
Published: August 2007

AbstractWhen students learn how a physical system works, does it help if they also learn how similar systems work? Some college students (concise group) studied a multimedia lesson that explained how hydraulic brakes work, consisting of narrated animation or annotated illustrations. Others (expanded group) received the same lesson along with multimedia explanations of caliper brakes and air brakes presented either after (Experiment 1) or before (Experiment 2) the explanation of hydraulic brakes. Across the combined experiments, students performed worse on retention (d = 0.37) and transfer tests (d = 0.30) concerning hydraulic brakes if the lesson also contained lessons on caliper and air brakes; within each experiment, the effects were statistically significant in Experiment 1 (d = 0.57 and 0.53, respectively) but not in Experiment 2 (d = 0.23 and 0.17, respectively). Students performed similarly with narrated animations and annotated illustrations. These results suggest that if students are expected to learn about a specific system, using examples about related systems can depress learning, particularly in the form of retroactive interference (in Experiment 1). These results extend the coherence principle, that is, the idea that adding extra material to an explanation can interfere with learning. There was no evidence to support converting static graphics into animation. Copyright © 2007 John Wiley & Sons, Ltd.
Non‐Hydrothermal Synthesis of 1D Nanostructured Manganese‐Based Oxides: Effect of Cation Substitution on the Electrochemical Performance of Nanowires
Authors: Park D. H. , Lee S.‐H. , Kim T. W. , Lim S. T. , Hwang S.‐J. , Yoon Y. S. , Lee Y.‐H. , Choy J.‐H. 
Published: August 2007

AbstractThe synthesis of cation‐substituted 1D manganese oxide nanowires is achieved via a non‐hydrothermal oxidation reaction using a solid‐state precursor and conventional glassware. By changing the reaction conditions and precursor composition, it is possible to control the crystal structure and chemical composition of the resulting 1D nanostructured materials. The nanowires are found to exhibit promising electrochemical properties as cathode materials in lithium secondary batteries; moreover, the electrochemical properties of the nanowires can be improved by the partial replacement of Mn with Cr3+ cations. The measurements strongly suggest that the cation composition of the nanostructured metal oxides is very important for optimizing their electrode performance. The non‐hydrothermal solution synthesis method presented here provides an effective composition‐tailored approach for the fabrication of large quantities of 1D manganese oxide nanowires.
A Molecular Glass for Deep‐Blue Organic Light‐Emitting Diodes Comprising a 9,9′‐Spirobifluorene Core and Peripheral Carbazole Groups
Authors: Tang S. , Liu M. R. , Lu P. , Xia H. , Li M. , Xie Z. Q. , Shen F. Z. , Gu C. , Wang H. P. , Yang B. , Ma Y. G. 
Published: August 2007

AbstractNovel fluorene‐based compounds, TCPC‐6 and TCPC‐4, with rigid central spirobifluorene cores and peripheral carbazole groups are synthesized using the Suzuki coupling reaction. The optical, electrochemical, and thermal properties of these compounds are characterized. The compounds show strong deep‐blue emission both in solution and as thin films. Both TCPC‐6 and TCPC‐4 exhibit amorphous morphologies in the solid state with high glass transition temperatures (Tg) of 108 and 143 °C, respectively. Atomic force microscopy (AFM) measurements indicate that high‐quality amorphous films of these novel compounds can be prepared by spin‐coating. The oxidation potentials of TCPC‐6 and TCPC‐4 are significant lower than that of model compounds without peripheral carbazole groups, which suggests that these compounds have relatively high highest occupied molecular orbital (HOMO) energy levels and better hole‐injection capabilities. Light‐emitting devices fabricated by spin‐coating films of these molecules exhibit deep‐blue emission with Commission Internationale de l'Eclairage (CIE) chromaticity coordinates (x, y) of (0.16, 0.05); the devices fabricated using spin‐coated TCPC‐6 and TCPC‐4 layers exhibit high luminance efficiencies of 1.35 and 0.90 cd A–1 (with external quantum efficiencies of 3.72 and 2.47 %), respectively.
Mineral Deposition and Crystal Growth in the Continuously Forming Teeth of Sea Urchins
Authors: Ma Y. R. , Weiner S. , Addadi L. 
Published: August 2007

AbstractThe early stages of formation of the crystalline elements in the continuously forming sea urchin teeth were studied using polarized light microscopy, SEM, TEM and calcite overgrowth. Transient amorphous calcium carbonate (ACC) is initially deposited in the needles and subsequently transforms into a single crystal of calcite. ACC exists in the center of both the primary plates and the needles, even though the surfaces are already well crystallized. TEM images and electron diffraction patterns, as well as calcite crystal overgrowth shows that the highly convoluted primary plate‐lamellar needle complex grows into a single crystal of calcite. The calcite crystal c axis is approximately parallel to the slightly curved surface of the primary plate. The needles grow along the unusual [102] direction of calcite. This study demonstrates that highly complex shaped single crystals are produced using a transient amorphous precursor phase. The beneficial properties of the single crystals are then combined with those of a polycrystalline matrix to yield a sophisticated composite functional material. This strategy could conceivably be applied to the production of synthetic materials.
Neuropathy as a presenting feature in fragile X‐associated tremor/ataxia syndrome
Authors: Hagerman Randi J. , Coffey Sarah M. , Maselli Ricardo , Soontarapornchai Kultida , Brunberg James A. , Leehey Maureen A. , Zhang Lin , Gane Louise W. , Fenton‐Farrell Grace , Tassone Flora , Hagerman Paul J. 
Published: August 2007

AbstractPeripheral neuropathy is common among patients with fragile X‐associated tremor ataxia syndrome (FXTAS). Four patients with FXTAS are described with neuropathy as the presenting feature, two having received a prior diagnosis of Charcot‐Marie‐Tooth (CMT) disease. A fifth is described with neuropathy as the only clinical feature. A functional connection between FXTAS and neuropathy has been suggested by the presence of lamin A/C in the intranuclear, neuronal and astrocytic inclusions of FXTAS, since mutations in lamin A/C are known to give rise to an axonal form of CMT. © 2007 Wiley‐Liss, Inc.
Neuronal LR11/sorLA expression is reduced in mild cognitive impairment
Authors: Sager Kristen L. , Wuu Joanne , Leurgans Susan E. , Rees Howard D. , Gearing Marla , Mufson Elliott J. , Levey Allan I. , Lah James J. 
Published: August 2007

AbstractObjectiveLR11 (aka sorLA) is a multifunctional neuronal receptor that binds apolipoprotein E and interacts with amyloid precursor protein to regulate amyloidogenesis. Reduced expression of LR11, as occurs in the brains of individuals with Alzheimer's disease (AD), increases amyloidogenesis, and variants in the gene that encodes LR11, SORL1, have recently been linked to risk for late‐onset AD. In this study, we sought to determine whether reduced expression of LR11 occurs early in the disease process and whether protein levels in cortical neurons are associated with clinical and pathological changes in mild cognitive impairment (MCI), a condition that may represent prodromal AD.MethodsA novel quantitative immunohistochemical approach was used to measure LR11 levels in brain tissue collected from subjects diagnosed antemortem with either no cognitive impairment, MCI, or AD from the Rush University Religious Orders Study.ResultsLR11 levels in MCI were intermediate between no cognitive impairment and AD. LR11 expression was heterogeneous in MCI, forming low‐ and high‐level LR11 subgroups. MCI subjects with low LR11 were significantly more cognitively impaired than the high LR11 subjects. We also found a significant correlation between cognitive performance and LR11 levels across all clinical groups examined. There was no association between LR11 and plaque and tangle pathology.InterpretationNeuronal LR11 levels are reduced in prodomal AD. The correlation between LR11 expression and cognitive performance indicates that reduced LR11 levels reflect disease severity and may predict progression to AD in a subgroup of individuals with MCI. Ann Neurol 2007
Design guidelines for using distillation simulation software in the field
Authors: Kolmetz Karl , Mardikar Asit , Gulati Harpreet , Kiong Ng Wai , Yee (Ron) Lim Tau , Cheah Phaik Sim 
Published: August 2007

AbstractProcess simulation is a powerful chemical engineering tool that has widespread use in the chemical processing industry. If used correctly, it can help design, optimize and troubleshoot process units, when you follow the guidelines developed from the fundamental basics of chemical engineering. It is important to remember that computer hardware advancements have only improved the speed of the calculation. Despite rapid progress in computational speed and user‐friendly interfaces, understanding the rules and limitations of simulation tools is still a prerequisite to obtain simulated results close to those measured in the field. The engineer must supply the correct input data, interpret errors that occurred and make critical judgment on the results. Mastering these techniques often requires substantial field experience and practice.Accumulating such knowledge in the form of design guidelines helps young engineers to ramp up their learning curves. Working steps like correct selection of actual field efficiencies, choosing appropriate vapor and liquid equilibrium (VLE) methods, feed characterization and analysis of actual hydraulic behavior, have a strong influence on the accuracy of the model's results. Developing guidelines for each of these steps is very important to a practicing engineer. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
FTIR study of ageing epoxy resin reinforced by reactive graphitic nanofibers
Authors: Jana Soumen , Zhong Wei‐Hong 
Published: August 2007

AbstractWe previously developed a novel modified epoxy matrix for macrocomposites using reactive graphitic nanofibers (r‐GNFs), which showed improved mechanical properties. This article is devoted to study the efficacy of the r‐GNFs against the damage due to exposition of the matrix to hygrothermal environment and UV radiation. Moisture sorption characteristics of the pure epoxy and nanoepoxy were investigated and all kinds of matrices showed similar absorption behavior. Both diffusion and relaxation processes in sorption were observed. DSC curves of nonaged specimens of all concentrations confirmed that samples were not fully cured and r‐GNFs lowered the curing degree. The effects of ageing were studied through the changes of molecular conformation by Fourier Transform infrared spectroscopy (FTIR). The results show that UV radiation assists in post‐curing of the matrices. Hydroxyl unit, carbonyl unit, and epoxide unit were chosen to study the degradation. It is observed that the degradation due to UV radiation is more severe compared with that due to hygrothermal expose. It also reveals that r‐GNFs resist the degradation of the epoxy resin; particularly, the nanoepoxy with 0.3 wt % of r‐GNFs has the highest ageing resistance, which is in agreement with our previously tested results of mechanical properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Directed evolution of novel protein functions
Authors: Zhao Huimin 
Published: August 2007

AbstractDirected evolution has been successfully used to engineer proteins for basic and applied biological research. However, engineering of novel protein functions by directed evolution remains an overwhelming challenge. This challenge may come from the fact that multiple simultaneously or synergistic mutations are required for the creation of a novel protein function. Here we review the key developments in engineering of novel protein functions by using either directed evolution or a combined directed evolution and rational or computational design approach. Specific attention will be paid to a molecular evolution model for generation of novel proteins. The engineered novel proteins should not only broaden the range of applications of proteins but also provide new insights into protein structure–function relationship and protein evolution. Biotechnol. Bioeng. 2007;98: 313–317. © 2007 Wiley Periodicals, Inc.
Inferential non‐centred principal curve analysis of time‐intensity curves in sensory analysis: the methodology and its application to beer astringency evaluation
Authors: François Nancy , Govaerts Bernadette , Guyot‐Declerck C. 
Published: August 2007

AbstractImproving technologies and better understanding of sensory phenomena have lead sensory analysts to develop statistical methods to assess sensations that endure over time (e.g. the bitterness or astringency of a beer) dynamically. The data produced by this type of experiment is classically a time‐intensity (TI) curve, and their analysis remains an active research topic. The classical approach, widely used in this context, starts by extracting some significant parameters from the initial curves (maximum intensity, area under the curve (AUC), etc.). Descriptive data analysis or statistical modelling is then applied to get information from these summary parameters. This paper presents a different method, called inferential non‐centred principal curve analysis (INCPCA), for the analysis of TI curves. It combines multivariate analysis (to visualise the curves in a space of smaller dimensions) with statistical modelling (aimed at enhancing the significance of factor effects). Non‐centred principal curves (NCPCs) are first extracted from the curves matrix. They decompose the TI curves into different interpretable components. Score plots are used to represent the projection of the initial curves in the space of the first principal curves and allow factors and judge effects to be visualised. Mixed modelling is then applied to test the significance of these effects using PCA scores as model responses. The classical and INCPCA methods are illustrated on a TI experiment exploring the relation between beer astringency and three factors of interest: pH, O2 content and aging. Eight beers arranged in a 23 factorial design were tested in triplicate by eight trained judges. Copyright © 2007 John Wiley & Sons, Ltd.
Geometry and a priori estimates for free boundary problems of the Euler's equation
Authors: Shatah Jalal , Zeng Chongchun 
Published: August 2007

AbstractIn this paper we derive estimates to the free boundary problem for the Euler equation with surface tension, and without surface tension provided the Rayleigh‐Taylor sign condition holds. We prove that as the surface tension tends to 0, when the Rayleigh‐Taylor condition is satisfied, solutions converge to the Euler flow with zero surface tension. © 2007 Wiley Periodicals, Inc.
High‐level distribution for the rapid production of robust telecoms software: comparing C++ and ERLANG
Authors: Nyström J. H. , Trinder P. W. , King D. J. 
Published: August 2007

AbstractCurrently most distributed telecoms software is engineered using low‐ and mid‐level distributed technologies, but there is a drive to use high‐level distribution. This paper reports the first systematic comparison of a high‐level distributed programming language in the context of substantial commercial products. Our research strategy is to reengineer some C++/CORBA telecoms applications in ERLANG, a high‐level distributed language, and make comparative measurements. Investigating the potential advantages of the high‐level ERLANG technology shows that two significant benefits are realized. Firstly, robust configurable systems are easily developed using the high‐level constructs for fault tolerance and distribution. The ERLANG code exhibits resilience: sustaining throughput at extreme loads and automatically recovering when load drops; availability: remaining available despite repeated and multiple failures; dynamic reconfigurability: with throughput scaling near‐linearly when resources are added or removed. Secondly, ERLANG delivers significant productivity and maintainability benefits: the ERLANG components are less than one‐third of the size of their C++ counterparts. The productivity gains are attributed to specific language features, for example, high‐level communication saves 22%, and automatic memory management saves 11%—compared with the C++ implementation. Investigating the feasibility of the high‐level ERLANG technology demonstrates that it fulfils several essential requirements. The requisite distributed functionality is readily specified, even although control of low‐level distributed coordination aspects is abrogated to the ERLANG implementation. At the expense of additional memory residency, excellent time performance is achieved, e.g. three times faster than the C++ implementation, due to ERLANG's lightweight processes. ERLANG interoperates at low cost with conventional technologies, allowing incremental reengineering of large distributed systems. The technology is available on the required hardware/operating system platforms, and is well supported. Copyright © 2007 John Wiley & Sons, Ltd.