Information-governing dynamics of attacker–defender interactions in youth rugby union

Abstract

Previous work on dynamics of interpersonal interactions in 1 vs. 1 sub-phases of basketball has identified changes in interpersonal distance between an attacker and defender as a potential control parameter for influencing organizational states of attacker–defender dyads. Other studies have reported the constraining effect of relative velocity between an attacker and defender in 1 vs. 1 dyads. To evaluate the relationship between these candidate control parameters, we compared the impact of both interpersonal distance and relative velocity on the pattern-forming dynamics of attacker–defender dyads in the sport of rugby union. Results revealed that when interpersonal distance achieved a critical value of less than 4 m, and relative velocity values increased or were maintained above 1 m · s^?1, a successful outcome (i.e. clean attempt) for an attacker was predicted. Alternatively, when values of relative velocity suddenly decreased below this threshold, at the same critical value of interpersonal distance, a successful outcome for the defender was predicted. Data demonstrated how the coupling of these two potential, nested control parameters moved the dyadic system to phase transitions, characterized as a try or a tackle. Observations suggested that relative velocity increased its influence on the organization of attacker–defender dyads in rugby union over time as spatial proximity to the try line increased.     

The Developmental Sequence and Relations Between Gesture and Spoken Language in Toddlers With Autism Spectrum Disorder

In typical development, gestures precede and predict language development. This study examines the developmental sequence of expressive communication and relations between specific gestural and language milestones in toddlers with autism spectrum disorder (ASD), who demonstrate marked difficulty with gesture production and language. Communication skills across five stages (gestures, word approximations, first words, gesture-word combinations, and two-word combinations) were assessed monthly by blind raters for toddlers with ASD participating in an randomized control trial of parent-mediated treatment (N = 42, 12–30 months). Findings revealed that toddlers acquired skills following a reliable (vs. idiosyncratic) sequence and the majority of toddlers combined gestures with words before combining words in speech, but in contrast to the pattern observed in typical development, a significant subset acquired pointing after first words.     

Designing minimal computer manuals from scratch

We designed from scratch a minimal manual of the kind proposed by Carroll (1990) for Unix e-mail. The design process involved acquiring from a set of experts information about e-mail use that would be helpful to novices, and acquiring from novices information that guided subsequent versions of the manual. The seventh version of the minimal manual was tested against a commercial manual, in a comparative performance experiment, with 30 naive subjects. It had approximately 13% of the pages of the commercial manual; it resulted in 30% faster learning and more effective use of the e-mail system overall, and significantly better performance on individual subtasks; including the recovery from errors. Significantly more users were satisfied with it than with the conventional manual. Carroll's general principles of manual design for minimal manuals were found to be a good basis for design, and we suggest these guidelines are suitable for the design of such manuals from scratch.     

“‘I Was Gonna Go Off,but My Best Friend is White.”: Hispanic Students’ Co-Cultural Reasoning in a Hispanic Serving Institution

The researchers engaged in a qualitative analysis (using journaling and focus group methodology) of the communicative behaviors of Hispanic students with White institutional members at a medium-sized, Southwest HSI. Utilizing Co-Cultural Theory and Elaborative Coding analysis, the authors mapped how Hispanic students narrated their co-cultural communication and reasoning (i.e., why they engage in one strategy rather than another). The findings show that, although Hispanic students used almost all co-cultural strategies, their responses were clustered primarily around assimilationist strategies – indicating that they engage in a high degree of self-monitoring and self-censorship when interacting with White institutional members in an HSI. These results suggest that even when Hispanic students constitute a large or majority part of the institution’s population, they still feel the need to engage in behaviors that navigate White norms. The study concludes by examining the findings for co-cultural theorizing as well as providing insights for instructors who wish to engage in inclusive teaching practices.     

Validation of the elementary social behaviour assessment: teacher ratings of students’ social skills adapted to Norwegian,grades 1–6

This study investigated the psychometric properties of the Elementary Social Behaviour Assessment (ESBA), a teacher-report measure of students’ social skills and academic engagement adapted for use in Norwegian schools. At two times, 8 weeks apart, 151 teachers rated 793 students in Grades 1–6 on the ESBA and the Social Skills Rating System Teacher’s form (SSRS-T). Exploratory factor analysis with the first assessment suggested one or possibly two factors. Confirmatory factor analysis with the second assessment confirmed the one- or two-factor models but did not offer strong evidence for one over the other. The ESBA demonstrated good to excellent reliability. Strong concurrent and predictive correlations with the SSRS-T established criterion validity. The school and teacher levels explained only a limited amount of the total variance in ESBA scores, suggesting that teachers rate students quite similarly. The Norwegian-adapted ESBA paralleled the reliability and validity evidence from US samples.     

Gravity-oriented microfluidic device for uniform and massive cell spheroid formation

We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours.     

Size-dependent trajectories of DNA macromolecules due to insulative dielectrophoresis in submicrometer-deep fluidic channels

In this paper, we demonstrate for the first time that insulative dielectrophoresis can induce size-dependent trajectories of DNA macromolecules. We experimentally use λ (48.5 kbp) and T4GT7 (165.6 kbp) DNA molecules flowing continuously around a sharp corner inside fluidic channels with a depth of 0.4 μm. Numerical simulation of the electrokinetic force distribution inside the channels is in qualitative agreement with our experimentally observed trajectories. We discuss a possible physical mechanism for the DNA polarization and dielectrophoresis inside confining channels, based on the observed dielectrophoresis responses due to different DNA sizes and various electric fields applied between the inlet and the outlet. The proposed physical mechanism indicates that further extensive investigations, both theoretically and experimentally, would be very useful to better elucidate the forces involved at DNA dielectrophoresis. When applied for size-based sorting of DNA molecules, our sorting method offers two major advantages compared to earlier attempts with insulative dielectrophoresis: Its continuous operation allows for high-throughput analysis, and it only requires electric field strengths as low as ∼10 V∕cm.     

Supervision and evaluation: The Wyoming perspective

The intent of this study was to assess the perceptions and actions of Wyoming principals concerning their role in supervising and evaluating teachers. A survey was sent to all 286 principals in the state of Wyoming, of which, 143 returned surveys, a response rate of 50%. Findings suggested that principals utilized supervisory behaviors more often than evaluative behaviors. Elementary principals perceived their evaluative practices as significantly more prevalent than secondary principals. Furthermore, principals indicated that their greatest frustrations in supervising teachers were time, the evaluation instrument, and teachers’ unwillingness to change. Additionally, findings suggested that Wyoming principals utilized classroom walkthroughs because they provided a snapshot of teaching and provided a medium for providing feedback. In regards to developmental supervision, principals indicated that novice teachers received much more supervision than veteran teachers. However, their reported use of differentiated supervision only applied to teacher autonomy concerning professional development goals. Principals reported that teachers had little input concerning the methods by which they were supervised. Finally, a majority of the Wyoming principals felt that improvement plans were effective at changing mediocre teaching behaviors, but 40% were speculative that such plans truly remediated poor teachers.