Cognitive Variables in Problem Solving: A Nonlinear Approach

We employ tools of complexity theory to examine the effect of cognitive variables, such as working-memory capacity, degree of field dependence–independence, developmental level and the mobility–fixity dimension. The nonlinear method correlates the subjects rank-order achievement scores with each cognitive variable. From the achievement scores in organic-synthesis problems of various mental demands, rank-order sequences of the subjects, according to their scores, were generated, and in the place of each subject, his/her score was replaced by the value of the corresponding cognitive variable. Then each sequence was mapped onto a one-dimensional random walk, and when treated as a dynamic flow, was found to possess fractal geometry, with characteristics depending on the complexity of the problem. The findings were interpreted using concepts from complexity theory, such as order, correlation exponents, and entropy. The method provides meaningful results and adds to the understanding of information processing and the role of cognitive variables within the frame of predictive models in problem solving. Although the method is applied to a particular kind of problems (chemical, organic-synthesis problems), it can be generalized to other problems, not only in chemistry, but also in other sciences and in mathematics. Finally, the educational implications are discussed.     

Teaching Air Pollution in an Authentic Context

This paper describes a teaching-learning sequence (TLS) about air pollution and the findings resulting from its implementation by pre-service elementary teachers (PET) currently undergraduate students of the Department of Primary Education in the National and Kapodistrian University of Athens, Greece. The TLS focused on the relation of air pollution with wind and topography in local conditions. An authentic context was provided to the students based on daily up-to-date meteorological data via the Internet in order to estimate air pollution. The results are encouraging given that PET can correlate wind and concentration of air pollutants through reading specialized angular diagrams and weather maps, can recognize the correlation of topography in the concentration of air pollutants, and can describe temperature inversion. However, the PET demonstrated clear difficulties in ability of orientation, in wind naming, and in interpretation of symbols on weather map. Finally, the implications on teaching air pollution are discussed.     

Academic Intrinsic Motivation and Perceived Academic Competence in Greek Elementary Students with and without Learning Disabilities

The aim of this study was to examine differences in intrinsic motivation and perceived academic competence as well as in their association between 5th‐ and 6th‐grade students with learning disabilities (LD) (n= 40) and their typically achieving peers. Participants were 980 Greek elementary students from the metropolitan area of Athens. As predicted, students with LD showed lower intrinsic motivation and perceived academic competence than students without LD almost across all subscales. Exceptions were noticed in intrinsic motivation concerning curiosity/interest and history subscales as well as perceptions of academic competence in the subjects of history and science. Support was found that among typically achieving students intrinsic motivation was positively and significantly related at a moderate level to perceived academic competence across all subscales, as opposed to students with LD, for whom few correlations were found.     

希腊体育法规制下的体育责任和体育行为

体育涉及到经济利益最大化的人类活动的广泛领域,经常决定着体育行为和体育项目的结果。法律确保体育组织顺利且有秩序组织体育行为和体育赛事,确保自然人和法人公平参与到体育活动中。文章从侵权对责任的区别、体育中的侵权行为等视角对希腊体育法规制下的体育责任和体育行为兴奋进行阐述,认为在发生体育活动侵权、追究责任时应当考虑在保护运动理念、运动原则及运动一般方面存在疏忽或故意。在体育活动中追究责任,应当先考虑行为违法的环境因素、条件和原因。     

Ethical issues in learning analytics: a review of the field

Learning analytics (LA) collects, analyses, and reports big data about learners to optimise learning. LA ethics is an interdisciplinary field of study that addresses moral, legal, and social issues; therefore, institutions are responsible for implementing frameworks that integrate these topics. Many of the ethical issues raised apply equally to educational data sets of any size. However, in this study, we focus on big data that increases the scale and granularity of data gathered. The purpose of this study is twofold: (a) to critically review the published (2011–2018) scientific literature on LA ethics issues and (b) to identify current trends and answer research questions in the field. This study’s research questions are as follows: what is essential in LA ethics for key educational stakeholders, and what should a proposed checklist for LA ethics include for specific educational stakeholders? After systematically searching online bibliographic databases, journals, and conferences, a literature review identified 53 articles from a sample of 562. The selected articles, based on critical and qualitative content analysis, were exhaustively analysed. The findings demonstrate the shortage of empirical evidence-based guidelines on LA ethics and highlight the need to establish codes of practices to monitor and evaluate LA ethics policies. Finally, this work proposes a useful checklist as an instructional design model for scholars, policymakers, and instructional designers, so that trusted partners may use LA responsibly to improve teaching and learning.

     

Rapid magnetic heating treatment by highly charged maghemite nanoparticles on Wistar rats exocranial glioma tumors at microliter volume

One of the most significant challenges implementing colloidal magnetic nanoparticles in medicine is the efficient heating of microliter quantities by applying a low frequency alternating magnetic field. The ultimate goal is to accomplish nonsurgically the treatment of millimeter size tumors. Here, we demonstrate the synthesis, characterization, and the in vitro as well as in vivo efficiency of a dextran coated maghemite (γ-Fe₂O₃) ferrofluid with an exceptional response to magnetic heating. The difference to previous synthetic attempts is the high charge of the dextran coating, which according to our study maintains the colloidal stability and good dispersion of the ferrofluid during the magnetic heating stage. Specifically, in vitro 2 μl of the ferrofluid gives an outstanding temperature rise of 33 °C within 10 min, while in vivo treatment, by infusing 150 μl of the ferrofluid in animal model (rat) glioma tumors, causes an impressive cancer tissue dissolution.     

Music search engines: Specifications and challenges

Nowadays we have a proliferation of music data available over the Web. One of the imperative challenges is how to search these vast, global-scale musical resources to find preferred music. Recent research has envisaged the notion of music search engines (MSEs) that allow for searching preferred music over the Web. In this paper, we examine the growing research topic of MSEs, and provide potential specifications to follow and challenges to face.     

嵌入学习管理系统的基于词汇表的概念图应用程序

概念构图作为一种有价值的教学活动,有着非常稳固的理论框架作为支持,其在教育教学中的作用不容置疑.本文介绍了一个软件工具的开发,在该工具中,概念构图被当作一种重要的教学活动予以支持.该工具以课程词汇表为基础,被集成到一个学习管理系统中.该工具允许在词汇表中概念的详细描述和认知结构的知识表示之间切换.论文介绍了该应用程序的开发动机、合理性、特色及其应用.     

Anatomy Learning from Prosected Cadaveric Specimens Versus Plastic Models: A Comparative Study of Upper Limb Anatomy

Human cadaveric prosections are a traditional, effective, and highly appreciated modality of anatomy learning. Plastic models are an alternative teaching modality, though few studies examine their effectiveness in learning of upper limb musculoskeletal anatomy. The purpose of this study is to investigate which modality is associated with a better outcome, as assessed by students' performance on examinations. Overall, 60 undergraduate medical students without previous knowledge of anatomy participated in the study. Students were assigned into two groups. Group 1 attended lectures and studied from cadaveric prosections (n = 30) and Group 2 attended lectures and used plastic models in the laboratory (n = 30). A knowledge assessment, including examination with tag questions (spot test) and written multiple-choice questions, was held after the end of the study. Students' perceptions were also investigated via an anonymous questionnaire. No significant difference in students' performance was observed between the group using prosections and the group using plastic models (32.2 ± 14.7 vs 35.0 ± 14.8, respectively; P = 0.477). Similarly, no statistically significant difference was found regarding students' satisfaction from using each learning modality (P = 0.441). Plastic models may be a valuable supplementary modality in learning upper limb musculoskeletal anatomy, despite their limitations. Easy to use and with no need for maintaining facilities, they are highly appreciated by students and can be useful when preparing for the use of cadaveric specimens.