Advances in the application of information technology to sport performance

This paper overviews the diverse information technologies that are used to provide athletes with relevant feedback. Examples taken from various sports are used to illustrate selected applications of technology-based feedback. Several feedback systems are discussed, including vision, audition and proprioception. Each technology described here is based on the assumption that feedback would eventually enhance skill acquisition and sport performance and, as such, its usefulness to athletes and coaches in training is critically evaluated.     

Passengers information in public transport and privacy: Can anonymous tickets prevent tracking?

Modern public transportation companies often record large amounts of information. Privacy can be safeguarded by discarding nominal tickets, or introducing anonymization techniques. But is anonymity at all possible when everything is recorded? In this paper we discuss travel information management in the public transport scenario and we present a revealing case study (relative to the city of Cesena, Italy), showing that even anonymous 10-ride bus tickets may betray a user's privacy expectations. We also propose a number of recommendations for the design and management of public transport information systems, aimed at preserving the users’ privacy, while retaining the useful analysis features enabled by the e-ticketing technology.     

Assessment of muscle fatigue after an ultra-endurance triathlon using tensiomyography (TMG)

In this study, we used tensiomyography (TMG) to assess muscle status immediately after an ultra-endurance triathlon. Maximal radial displacement or deformation of the muscle belly, contraction time, delay time, sustain time, and relaxation time were measured for both legs, and dependent t-tests were used to compare means between the beginning and end of the race. The 19 men assessed (age 37.9 ± 7.1 years; height 177.5 ± 4.6 cm; weight: 73.6 ± 6.5 kg) participated in the 2009 edition of the Lanzarote Ironman. Deterioration in the neural response was observed for contraction time (P = 0.008) and relaxation time (P = 0.011), with a moderate decrease in the response time (sustain time) and a loss in muscle stiffness (deformation of the muscle belly). The effect of muscle fatigue on the rectus femoris and biceps femoris was different. Barely any changes in contraction time, relaxation time, sustain time, and deformation of the muscle belly were observed, while only the contraction response time decreased to a significant extent (reduction in delay time; P = 0.003). The considerable loss in contractile capacity induced by a long-distance race was reflected in changes in the neuromuscular response and fluctuations in the contractile capacity of the muscle. These modifications, derived from a prolonged, exhausting effort, can be assessed in a simple, non-aggressive, non-invasive way using tensiomyography.     

The anti-Lagrangian equations: A missing network description

The explicit topological formulation of dynamic equations in terms of scalar functions for RM (M-memristor) networks, called the anti-Lagrangian equations, is introduced. In general, two scalar functions are needed to set the anti-Lagrangian equations. The differential operators acting on these functions bear a certain anti-symmetry relationship with respect to the operators occuring in the standard Lagrangian equations for LC networks. The well-known stationary principles for pure R networks, as well as new quasi-stationary principles for pure M networks are shown to emerge naturally from anti-Lagrangian equations. The form of transformation of variables leaving the form of equations invariant is also studied.     

Using growth models to monitor school performance: comparing the effect of the metric and the assessment

This paper investigates whether inferences about school performance based on longitudinal models are consistent when different assessments and metrics are used as the basis for analysis. Using norm-referenced (NRT) and standards-based (SBT) assessment results from panel data of a large heterogeneous school district, we examine inferences based on vertically equated scale scores, normal curve equivalents (NCEs), and nonvertically equated scale scores. The results indicate that the effect of the metric depends upon the evaluation objective. NCEs significantly underestimate absolute individual growth, but NCEs and scale scores yield highly correlated (r >.90) school-level results based on mean initial status and growth estimates. SBT and NRT results are highly correlated for status but only moderately correlated for growth. We also find that as few as 30 students per school provide consistent results and that mobility tends to affect inferences based on status but not growth – irrespective of the assessment or metric used.     

Development of Math Attitudes and Math Self-Concepts: Gender Differences,Implicit–Explicit Dissociations,and Relations to Math Achievement

Three hundred and ninety-one children (195 girls; M_age = 9.56 years) attending Grades 1 and 5 completed implicit and explicit measures of math attitudes and math self-concepts. Math grades were obtained. Multilevel analyses showed that first-grade girls held a strong negative implicit attitude about math, despite no gender differences in math grades or self-reported (explicit) positivity about math. The explicit measures significantly predicted math grades, and implicit attitudes accounted for additional variance in boys. The contrast between the implicit (negativity for girls) and explicit (positivity for girls and boys) effects suggest implicit–explicit dissociations in children, which have also been observed in adults. Early-emerging implicit attitudes may be a foundation for the later development of explicit attitudes and beliefs about math.     

The Structuring of Invisibility Among the Hidden Homeless: The Politics of Space,Stigma, and Identity Construction

This ethnographic portrayal relies on participant observations at two supplemental support programs for youth without homes, narratives collected through in-depth interviews with educators and case managers, and focus group interviews with youth participants to explore the discursive (re)production of invisibility among youth without homes. Structuration theory is used to frame macro and micro forces coalescing to enable and constrain processes of invisibility among the hidden homeless. Analysis reveals how invisibility shapes (and is shaped by) processes of stigmatization, “street smarts” as enacted by youth, and “Mayberry” and “not in my backyard” community discourses, and how the disappearance of youth without homes simultaneously serves and undermines various stakeholders.