Statistical learning and dyslexia: a systematic review

The existing literature on developmental dyslexia (hereafter: dyslexia) often focuses on isolating cognitive skills which differ across dyslexic and control participants. Among potential correlates, previous research has studied group differences between dyslexic and control participants in performance on statistical learning tasks. A statistical learning deficit has been proposed to be a potential cause and/or a marker effect for early detection of dyslexia. It is therefore of practical importance to evaluate the evidence for a group difference. From a theoretical perspective, such a group difference would provide information about the causal chain from statistical learning to reading acquisition. We provide a systematic review of the literature on such a group difference. We conclude that there is insufficient high-quality data to draw conclusions about the presence or absence of an effect.     

Nearest neighbor search in metric spaces through Content-Addressable Networks

Most of the peer-to-peer search techniques proposed in the recent years have focused on the single-key retrieval. However, similarity search in metric spaces represents an important paradigm for content-based retrieval in many applications. In this paper we introduce an extension of the well-known Content-Addressable Network paradigm to support storage and retrieval of more generic metric space objects. In particular we address the problem of executing the nearest neighbors queries, and propose three different algorithms of query propagation. An extensive experimental study on real-life data sets explores the performance characteristics of the proposed algorithms by showing their advantages and disadvantages.     

The influence of core affect on cyclo-ergometer endurance performance: Effects on performance outcomes and perceived exertion

BackgroundCore affect is defined as the most general affective construct consciously accessible that is experienced constantly. It can be experienced as free-floating (mood) or related to prototypical emotional episodes. The aim of this study was to examine the influence of pleasant and unpleasant core affect on cyclo-ergometer endurance performance. Specifically, we considered the influence of pleasant and unpleasant core affect on performance outcomes (i.e., time to task completion) and rate of perceived exertion (RPE; Borg Scale, category ratio-10) collected during the task.MethodsThirty-one participants aged 20–28 years were recruited. Core affect was randomly elicited by 2 sets of pleasant and unpleasant pictures chosen from the international affective picture system. Pictures were displayed to participants during a cyclo-ergometer performance in 2 days in a counterbalanced order. RPE was collected every minute to detect volunteers’ exhaustion.ResultsThe study sample was split into 2 groups. Group 1 comprised participants who performed better with pleasant core affect, whereas Group 2 included participants who performed better with unpleasant core affect. Mixed between-within subjects analysis of variance revealed a significant 2 (group) × 2 (condition) × 5 (isotime) interaction (p = 0.002, η_p² = 0.158). Post hoc comparisons showed that participants who obtained better performance with pleasant core affect (pleasant pictures; Group 1) reported lower RPE values at 75% of time to exhaustion in a pleasant core affect condition compared to an unpleasant core affect condition. On the other hand, participants who obtained better performance with unpleasant core affect (unpleasant pictures; Group 2) reported lower RPE values at 75% and 100% of time to exhaustion in an unpleasant core affect condition.ConclusionFindings suggest differential effects of pleasant and unpleasant core affect on performance. Moreover, core affect was found to influence perceived exertion and performance according to participants’ preferences for pleasant or unpleasant core affect.     

Thermo-formation process of plastic shells for winter sport boots for improved comfort

We have performed a study on the thermo-formation process of plastic shells of boots for winter sports. The aim of the work has been to determine how the process parameters can improve the ergonomic and thermal comfort for athletes and winter sports participants. We have found that the initial deformation and memory effect are strongly influenced by the type of thermoplastic material used, heating time and cooling procedure. We have also found that the ovens currently used for this process are not correctly designed to obtain an efficient heat transfer and, therefore, a heating time of at least 12 min is necessary to achieve an average deformation of more than 2 mm. The measure of the boot flexural stiffness has shown that there are no changes in the load–deflection behavior after the thermo-formation process of a ski boot made of thermoplastic polyurethane. We have also found that the thermo-formation process decreases the pressure on skier’s feet of more than five times and, therefore, improves the comfort of the skier.     

Analysis of the distances covered and technical actions performed by professional tennis players during official matches

The purpose of this study was to analyse the physical and technical performances of professional tennis players during official matches. The trajectories of eight players were obtained during matches, using an automatic tracking method. The distances covered and technical performances were analysed for the first and second sets. The athletes covered (mean ± standard deviation) a total of 1702.4 ± 448.2 m in the first set, 1457.6 ± 678.1 m in the second set and 3160.0 ± 880.1 in the entire match. No differences were found between the sets for the physical variables (lateral and forward displacements, distance covered per rally, per game and per set, and the percentage of time spent in each range of velocity). However, the distances covered by the athletes during the rallies in which they were serving (median = 5.2; interquartile range (IQR) = 6.7 m) were statistically smaller than when they were returning (median = 6.2; IQR = 7.7 m). Forehand ground stroke proficiency decreased from the first (mean ± standard deviation: 75.2 ± 4.11%) to the second set (mean ± standard deviation = 65.5 ± 14.3%). In conclusion, tennis players did not present reduced physical performance from the first to the second set.     

Functional impact of emotions on athletic performance: comparing the IZOF model and the directional perception approach

The aim of this study was to examine the impact of emotions on athletic performance within the frameworks of the Individual Zones of Optimal Functioning (IZOF) model and the directional perception approach. Intensity, functional impact, and hedonic tone of trait and state anxiety, self-confidence, idiosyncratic emotions, and bodily symptoms were assessed in high-level Italian swimmers and track and field athletes (N = 56). Three standards of performance (poor, average, and good), derived from retrospective self-ratings across one to three competitions (a total of 90 observations), were used as independent variables in the analysis of variance of intensity, intra-individual, and direction scores of anxiety, self-confidence, idiosyncratic emotions, and bodily symptoms. Subsequently, intra-individual scores were categorized as near to or distant from optimal/dysfunctional zones and entered as the independent variable in the analysis of direction scores. The results provided support for the predictions stemming from both the IZOF model and the directional approach, as well as help in interpreting direction of anxiety and other idiosyncratic emotions within the IZOF framework. Athletes tended to perceive emotional levels approximating an individual's optimal zone as facilitative-pleasant, and emotional levels approximating an individual's dysfunctional zone as debilitative-unpleasant.     

Exercise interventions for older adults: A systematic review of meta-analyses

Background:The evidence concerning which physical exercise characteristics are most effective for older adults is fragmented.We aimed to characterize the extent of this diversity and inconsistency and identify future directions for research by undertaking a systematic review of metaanalyses of exercise interventions in older adults.Methods:We searched the Cochrane Database of Systematic Reviews,PsycInfo,MEDLINE,Embase,CINAHL,AMED,SPORTDiscus,and Web of Science for articles that met the following criteria:(1)meta-analyses that synthesized measures of improvement(e.g.,effect sizes)on any outcome identified in studies of exercise interventions;(2)participants in the studies meta-analyzed were adults aged 65+or had a mean age of 70+;(3)meta-analyses that included studies of any type of exercise,including its duration,frequency,intensity,and mode of delivery;(4)interventions that included multiple components(e.g.,exercise and cognitive stimulation),with effect sizes that were computed separately for the exercise component;and(5)meta-analyses that were published in any year or language.The characteristics of the reviews,of the interventions,and of the parameters improved through exercise were reported through narrative synthesis.Identification of the interventions linked to the largest improvements was carried out by identifying the highest values for improvement recorded across the reviews.The study included 56 meta-analyses that were heterogeneous in relation to population,sample size,settings,outcomes,and intervention characteristics.Results:The largest effect sizes for improvement were found for resistance training,meditative movement interventions,and exercise-based active videogames.Conclusion:The review identified important gaps in research,including a lack of studies investigating the benefits of group interventions,the characteristics of professionals delivering the interventions associated with better outcomes,and the impact of motivational strategies and of significant others(e.g.,carers)on intervention delivery and outcomes.