Early Peer Interaction: A Research Agenda

We propose and discuss several hypotheses concerning the unique developmental status of peer relations in the first three years of life. We then suggest how these developmental differences might translate into hypotheses regarding early individual differences. The integrating questions revolve around whether individual differences in toddler and early preschool peer relations mean the same thing to young children as they do to older children, and whether they carry the same weight and serve the same functions in toddler peer groups as in peer groups among older children. Specifically, we suggest three ways that peer relations in the first three years are fundamentally different from later childhood peer relations: 1) they are likely to be more directly linked to and determined by temperament and attachment relationships; 2) limits in self and other understanding in the early years we likely to constrain both individual interaction skills and the formation of relationships with peers; 3) because emotion regulation in very young children is different from childhood emotion regulation, its role in governing peer relations will likely be different as well. Together, these proposals lead to the conclusion that individual differences in toddler peer relations must carry different meaning than in later childhood. A developmental perspective on individual differences suggests both continuities and discontinuities between toddler peer relations and childhood peer relations, and we offer several predictions.     

Tools in practice, mathematics in use

We seek to analyse the notion of structuring resources and their role in shaping mathematical activity, and more broadly to add to our understanding of mathematical epistemologies in workplace settings. Our analysis is of two nursing activities – drug administration and fluid balance monitoring – based on data collected in an in–depth study of paediatric nurses on the ward. In the first activity, we examine ways in which nurses conceptualise ratio and proportion problems, while in the second, we provide a case study of two nurses discussing conflicting strategies when monitoring the fluid balance of a patient. We discuss the ways in which the available resources give mathematical and professional meanings in these situations and draw out some implications for the design of viable didactical strategies in vocational mathematics teaching.     

小红帽

A little boy sat at his mother＇s knees, by the long western window, looking out into the garden. It was autumn, and the wind was sad, and the golden elm leaves lay scattered about among the grass, and on the gravel path. The mother was knitting a little stocking; her fingers moved the bright needles, but her eyes were fixed on the clear evening sky.     

Protective effects of photobiomodulation against resistance exercise-induced muscle damage and inflammation in rats

We investigated whether low-level laser therapy (LLLT) prior to or post resistance exercise could attenuate muscle damage and inflammation. Female Wistar rats were assigned to non-LLLT or LLLT groups. An 830-nm DMC Laser Photon III was used to irradiate their hind legs with 2J, 4J, and 8J doses. Irradiations were performed prior to or post (4J) resistance exercise bouts. Resistance exercise consisted of four maximum load climbs. The load work during a resistance exercise bout was similar between Control (non-LLLT, 225 ± 10 g), 2J (215 ± 8 g), 4J (210 ± 9 g), and 8J (226 ± 9 g) groups. Prior LLLT did not induce climbing performance improvement, but exposure to 4J irradiation resulted in lower blood lactate levels post-exercise. The 4J dose decreased creatine kinase and lactic dehydrogenase levels post-exercise regardless of the time of application. Moreover, 4-J irradiation exposure significantly attenuated tumor necrosis factor alpha, interleukin-6, interleukin-1β, cytokine-induced neutrophil chemoattractant-1, and monocyte chemoattractant protein-1. There was minor macrophage muscle infiltration in 4J-exposed rats. These data indicate that LLLT prior to or post resistance exercise can reduce muscle damage and inflammation, resulting in muscle recovery improvement. We attempted to determine an ideal LLLT dose for suitable results, wherein 4J irradiation exposure showed a significant protective role.     

Effects of inspiratory muscle training in professional women football players: a randomized sham-controlled trial

This study was conducted to determine the effects of inspiratory muscle training (IMT) on respiratory and peripheral muscles oxygenation during a maximal exercise tolerance test and on repeated-sprint ability (RSA) performance in professional women football players. Eighteen athletes were randomly assigned to one of the following groups: SHAM (n = 8) or IMT (n = 10). After a maximal incremental exercise test, all participants performed (on a different day) a time-to-exhaustion (Tlim) test. Peripheral and respiratory muscles oxygenation by near-infrared spectroscopy, breath-by-breath ventilatory and metabolic variables, and blood lactate concentration were measured. The RSA test was performed on a grass field. After a 6 week intervention, all athletes were reevaluated. Both groups showed increases in inspiratory muscles strength, exercise tolerance and RSA performance, however only the IMT group presented lower deoxyhemoglobin and total hemoglobin blood concentrations on intercostal muscles concomitantly to an increased oxyhemoglobin and total hemoglobin blood concentrations on vastus lateralis muscle during Tlim. In conclusion, these results may indicate the potential role of IMT to attenuate inspiratory muscles metaboreflex and consequently improve oxygen and blood supply to limb muscles during high-intensity exercise, with a potential impact on inspiratory muscle strength, exercise tolerance and sprints performance in professional women football players.