Providing Undergraduates with Opportunities to Explicitly Reflect on How News Articles Promote the Public (Mis)understanding of Science

Science & Education - A well-informed populace is vitally important for the proper functioning of democracy. Media news articles constitute an essential means by which the public comes into...     

The Use of Analogies in Science Communication: Effectiveness of an Activity in Initial Primary Science Teacher Education

International Journal of Science and Mathematics Education - This article presents a study focused on analysing the effectiveness of an activity about the use of analogies in science communication....     

Robust stability analysis of formation control in local frames under time-varying delays and actuator faults

This paper investigates the robust stability of a multiagent system moving to a desired rigid formation in presence of unknown time-varying communication delays and actuator faults. Each agent uses relative position measurements to implement the proposed control method, which does not require common coordinate references. However, the presence of time delays in the measurements, which is inherent to the communication links between agents, has a negative impact in the control system performance leading, in some cases, to instability. Furthermore, the robust stability analysis becomes more complex if failures on actuators are taken into account. In addition, delays may be subject to time variations, depending on network load, availability of communication resources, dynamic routing protocols, or other environmental conditions. To cope with these problems, a sufficient condition based on Linear Matrix Inequalities (LMI) is provided to ensure the robust asymptotic convergence of the agents to the desired formation. This condition is valid for any arbitrarily fast time-varying delays and actuator faults, given a worst-case point-to-point delay. Finally, simulation results show the performance of the proposed approach.     

User-centred versus system-centred evaluation of a personalization system

Some of the most popular measures to evaluate information filtering systems are usually independent of the users because they are based in relevance judgments obtained from experts. On the other hand, the user-centred evaluation allows showing the different impressions that the users have perceived about the system running. This work is focused on discussing the problem of user-centred versus system-centred evaluation of a Web content personalization system where the personalization is based on a user model that stores long term (section, categories and keywords) and short term interests (adapted from user provided feedback). The user-centred evaluation is based on questionnaires filled in by the users before and after using the system and the system-centred evaluation is based on the comparison between ranking of documents, obtained from the application of a multi-tier selection process, and binary relevance judgments collected previously from real users. The user-centred and system-centred evaluations performed with 106 users during 14 working days have provided valuable data concerning the behaviour of the users with respect to issues such as document relevance or the relative importance attributed to different ways of personalization. The results obtained shows general satisfaction on both the personalization processes (selection, adaptation and presentation) and the system as a whole.     

Effects of mat characteristics on plantar pressure patterns and perceived mat properties during landing in gymnastics

Shock absorption and stability during landings is provided by both, gymnast ability and mat properties. The aims of this study were to determine the influence of different mat constructions on their energy absorption and stability capabilities, and to analyse how these properties affect gymnast's plantar pressures as well as subjective mat perception during landing. Six mats were tested using a standard mechanical drop test. In addition, plantar pressures and subjective perception during landing were obtained from 15 expert gymnasts. The different mats influenced plantar pressures and gymnasts' subjective perception during landing of gymnasts. Significant correlations between plantar pressures at the medial metatarsal and lateral metatarsal zones of the gymnasts' feet with the different shock absorption characteristics of the mats were found. However, subjective perception tests were not able to discriminate mat functionality between the six mats as no significant correlations between the mechanical mat properties with the subjective perception of these properties were found. This study demonstrated that plantar pressures are a useful tool for discriminating different landing mats. Using similar approaches, ideally including kinematics as well, could help us in our understanding about the influences of different mats upon gymnast-mat interaction.     

From Inquiry-Based Science Education to the Approach Based on Scientific Practices

Science & Education - For years, inquiry-based learning has been conceived of and promoted as one of the best approaches to learning science. However, there is currently a movement within the...     

Development of an efficient search filter to retrieve systematic reviews from PubMed

Objective:Locating systematic reviews is essential for clinicians and researchers when creating or updating reviews and for decision-making in health care. This study aimed to develop a search filter for retrieving systematic reviews that improves upon the performance of the PubMed systematic review search filter.Methods:Search terms were identified from abstracts of reviews published in Cochrane Database of Systematic Reviews and the titles of articles indexed as systematic reviews in PubMed. Both the precision of the candidate terms and the number of systematic reviews retrieved from PubMed were evaluated after excluding the subset of articles retrieved by the PubMed systematic review filter. Terms that achieved a precision greater than 70% and relevant publication types indexed with MeSH terms were included in the filter search strategy.Results:The search strategy used in our filter added specific terms not included in PubMed''s systematic review filter and achieved a 61.3% increase in the number of retrieved articles that are potential systematic reviews. Moreover, it achieved an average precision that is likely greater than 80%.Conclusions:The developed search filter will enable users to identify more systematic reviews from PubMed than the PubMed systematic review filter with high precision.     

The volleyball athlete’s shoulder: biomechanical adaptations and injury associations

In volleyball, the dominant shoulder of the athlete undergoes biomechanical and morphological adaptations; however, definitive conclusions about their exact nature, aetiology, purpose and associations with shoulder injury have not been reached. We present a systematic review of the existing literature describing biomechanical adaptations in the dominant shoulders of volleyball players and factors that may predispose to shoulder pain/injury. A thorough literature search via Medline, EMBASE and SCOPUS was conducted for original studies of volleyball players and 15 eligible articles were identified. Assessment of study quality was performed using the STROBE statement. The reviewed literature supports the existence of a glenohumeral internal rotation deficit (GIRD) and a possible (and less pronounced) external rotation gain in the dominant vs. the non-dominant shoulder of volleyball athletes. Unlike other overhead sports, the GIRD in volleyball athletes appears to be anatomical as a response to the repetitive overhead movements and not to be associated with shoulder pain/injury. Additionally, the dominant shoulder exhibits muscular imbalance, which appears to be a significant risk factor for shoulder pain. Strengthening of the external rotators should be used alongside shoulder stretching and joint mobilisations, core strengthening and optimisation of spike technique as part of injury management and prevention programmes.     

Analysis of elbow muscle strength parameters in Brazilian jiu-jitsu practitioners

Upper-body dynamic and isometric maximum strength are essential components for success in Brazilian jiu-jitsu (BJJ). This study was aimed at analysing strength parameters in the elbow flexor and extensor muscles of BJJ practitioners. Participants (n = 28) performed maximum isometric contractions of elbow flexors and extensors to determine peak torque (PT), rate of force development (RFD), and the torque–angle (T–A) relationship at elbow angles of 45°, 60°, 75°, 90°, 105°, and 120°. Additionally, concentric and eccentric PTs were measured at 1.04 rad·s^-1. Student t-test and ANOVA were performed using α = 0.05. Elbow flexors were stronger isometrically (P < 0.001, ES = 1.23) but weaker concentrically (P < 0.05, ES = 0.54) than extensor muscles, possibly because of the extensive grip disputes and pushing of opponents in BJJ. The T–A relationship had an inverted “U”-shape. Torque differences across elbow angles were moderate (ES = 0.62) for the extensor and large (ES = 0.92) for the flexor muscles. Isometric torque was greatest for elbow angles of 105° and 75° and smallest for 45° and 120° for extensor and flexor muscles, respectively. Elbow flexors had a greater RFD than extensors, regardless of elbow angle. The present study provides comprehensive results for elbow muscle strength in BJJ practitioners.     

Cultural heritage interactive 3D models on the web: An approach using open source and free software

Cultural heritage sites and artefacts get a significant added value from high-resolution 3D models. These models are increasingly available due to improvements in technology and to higher integration of survey techniques such as laser scanning and photogrammetry. In this paper we present a case study on the development of a web-based application for user access and interactive exploration of three-dimensional models by providing integrated geometrical and non-geometrical information into an intuitive interface. The main feature of this interactive system is to provide the user with a completely new visit experience based on a free interactive exploration interface of the object (i.e., not constrained by any predefined pathway) and on the opportunity to get more detailed information on specific parts of interest. A parallel aim achieved was to use, in data processing and in the architecture, open source tools and free software, thus providing full transparency on adopted methodology and data processing methods, and a cost effective solution both for server and client. Furthermore, the aspect of data size has been considered using a segmentation and simplification scheme and server-side data management to keep transmission size to a minimum, thus improving access speed.