Academic Functioning and Peer Influences: A Short‐Term Longitudinal Study of Network–Behavior Dynamics in Middle Adolescence

In this study, the associations between peer effects and academic functioning in middle adolescence (N = 342; 14–15 years old; 48% male) were investigated longitudinally. Similarity in achievement (grade point averages) and unexplained absences (truancy) was explained by both peer selection and peer influence, net of acceptance, and connectedness. Friendships were formed and maintained when adolescents had low levels of achievement or high levels of truancy. Friends influenced one another to increase rather than decrease in achievement and truancy. Moreover, friends’ popularity moderated peer influences in truancy in reciprocal friendships but not in unilateral friendships, whereas friends’ acceptance moderated peer influences in achievement in both unilateral and reciprocal friendships. The findings illustrate the dynamic interplay between peer effects and academic functioning.     

What was out of the frame? A dialogic look at youth media production in a cultural diversity and educational context in Chile

This article accounts for an experience of digital storytelling workshops with indigenous adolescents in Chile, and proposes a theoretical and methodological approach to analyze digital creations with a dialogic and ethnographic point of view. Based on this, it discusses the possibilities of digital media production as a strategy for the self-expression of children and adolescents, particularly immersed in unequal and ethnically diverse educational contexts. The specific case of two Mapuche girls reveals complex ways of organizing and positioning their voices, where ‘girl power’ and ‘post-girl power’ discourses are relevant, but not so their ethnicity. The results show that television, with its main audiovisual genres, styles and stereotypes, appears clearly on the teenagers’ creations, while the absence of Mapuche signs along the creation process and also into the digital stories seems to be related with two important features of the Chilean educational system: ethnic inequalities and its fierce attachment to neoliberalism.     

A static method for obtaining a calibration factor for SRM bicycle power cranks

Many scientists and coaches are interested in mechanical power produced during cycling, and use Schoberer Rad Me\technik (SRM) bicycle power cranks to obtain this data. However, it has been expensive and difficult to calibrate SRM cranks, causing much of the collected data to be unreliable. We present a static method, derived from first principles, for obtaining a calibration factor for SRM cranks. A known mass and lever arm (chainring of a known diameter) are used to apply a known torque load to the instrument in four positions, and the output frequencies are used to calculate the calibration factor in Hz/Nm. The reproducibility of this method is ±0.01 Hz/Nm, which is acceptable for the application of the instrument, which is measurement of mechanical power application by cyclists at the crank. The method is reliable, inexpensive, and easy to set up, and will allow higher confidence in data collected using SRM power cranks. We recommend calibration of the power meter once every six months because of the measured drift of the calibration factor over time.     

“Inhabitants of the Earth”: Reasoning About Folkbiological Concepts in Wichi Children and Adults

Across the world, people form folkbiological categories to capture their commonsense organization of the natural world. Structured in accordance with universal principles, folkbiological categories are also shaped by experience. Here we provide new evidence from the Wichi—an understudied indigenous community who live in the Chaco rainforest and speak their heritage language. A total of 44 Wichi (6- to 8-year-olds, 9- to 12-year-olds, adults) participated in an induction task designed to identify how broadly they attribute an invisible biological property (e.g., an internal organ) from 1 individual (either a human, nonhuman animal, or plant) to other humans, nonhuman animals, plants, natural kinds, and artifacts. Research Findings: These results (a) clarify the content of the Wichi’s categories and the words they use to describe them, (b) showcase the power of covert (unnamed) categories, and (c) fortify the view that human-centered reasoning is not a universal starting point for reasoning about nature. Practice or Policy: Implications of these findings for early science education are discussed. In particular, we discuss (a) how the Wichi’s construal of the natural world may be best integrated when they reach the (Western science–inspired) classroom and (b) how the current results bear on central issues in early science education more broadly.     

Novel model reference adaptive control laws for improved transient dynamics and guaranteed saturation constraints

In classical model reference adaptive control (MRAC), the adaptive rates must be tuned to meet multiple competing objectives. Large adaptive rates guarantee rapid convergence of the trajectory tracking error to zero. However, large adaptive rates may also induce saturation of the actuators and excessive overshoots of the closed-loop system’s trajectory tracking error. Conversely, low adaptive rates may produce unsatisfactory trajectory tracking performances. To overcome these limitations, in the classical MRAC framework, the adaptive rates must be tuned through an iterative process. Alternative approaches require to modify the plant’s reference model or the reference command input. This paper presents the first MRAC laws for nonlinear dynamical systems affected by matched and parametric uncertainties that constrain both the closed-loop system’s trajectory tracking error and the control input at all times within user-defined bounds, and enforce a user-defined rate of convergence on the trajectory tracking error. By applying the proposed MRAC laws, the adaptive rates can be set arbitrarily large and both the plant’s reference model and the reference command input can be chosen arbitrarily. The user-defined rate of convergence of the closed-loop plant’s trajectory is enforced by introducing a user-defined auxiliary reference model, which converges to the trajectory tracking error obtained by applying the classical MRAC laws before its transient dynamics has decayed, and steering the trajectory tracking error to the auxiliary reference model at a rate of convergence that is higher than the rate of convergence of the plant’s reference model. The ability of the proposed MRAC laws to prescribe the performance of the closed-loop system’s trajectory tracking error and control input is guaranteed by barrier Lyapunov functions. Numerical simulations illustrate both the applicability of our theoretical results and their effectiveness compared to other techniques such as prescribed performance control, which allows to constrain both the rate of convergence and the maximum overshoot on the trajectory tracking error of uncertain systems.     

英国大学专利技术转移研究及其借鉴意义

英国大学不仅在研究水平方面而且在与产业界的合作方面均处于全球领先的地位.本文以英国大学专利技术转移活动为研究对象,首先介绍了英国大学专利技术转移活动在许可合同数量和收入两个方面的情况,继而提出英国大学的大学技术转移中心和国家大学技术转移协会是大学专利技术转移活动的重要组织保障,优秀的研究成果和商业化、国际化意识的培养是大学专利技术转移活动的先决条件,政府法律法规的设立和政府项目的支持是大学专利技术转移活动的指导因素.最后,提出了英国大学专利技术转移对我国大学专利技术转移活动的借鉴意义.     

青少年运动缺乏症研究的10大问题

摘要：运动缺乏症（EDD）是一种儿科疾病,特点是中高强度体力活动（MVPA）下降,低于目前的推荐量,也与积极的健康结果（health outcomes）不一致。目前,大多数儿童和青少年符合EDD的诊断标准,因为他们没有达到日常MVPA的最低要求。本文的目的是强调10个与青少年EDD有关的重要研究问题。需要进行重要的研究来更好的定义EDD的临床表现,包括评估体力活动行以确定开始出现EDD的年龄或发育阶段;包括运动技巧和体能的运动起源（kinesiogenesis）的检测;以及对影响青少年MVPA的生活方式因素的评估。关于治疗EDD的干预措施和政策的研究问题,包括评估对卫生保健从业者进行运动医学重要性的教育和训练;确定在临床上识别和治疗EDD青少年的方法的有效性;开发敏感的、特效的、经济的方法以诊断青少年EDD;以及定制方法以促进本病诊疗的医疗保险赔付。如果未来研究不能优化EDD青少年的识别、治疗和管理方案,具有重大影响的生物医学、心理、经济和政治的新的卫生保健问题将会不断出现。     

Infant Attachment Security and Early Childhood Behavioral Inhibition Interact to Predict Adolescent Social Anxiety Symptoms

Insecure attachment and behavioral inhibition (BI) increase risk for internalizing problems, but few longitudinal studies have examined their interaction in predicting adolescent anxiety. This study included 165 adolescents (ages 14–17 years) selected based on their reactivity to novelty at 4 months. Infant attachment was assessed with the Strange Situation. Multimethod BI assessments were conducted across childhood. Adolescents and their parents independently reported on anxiety. The interaction of attachment and BI significantly predicted adolescent anxiety symptoms, such that BI and anxiety were only associated among adolescents with histories of insecure attachment. Exploratory analyses revealed that this effect was driven by insecure‐resistant attachment and that the association between BI and social anxiety was significant only for insecure males. Clinical implications are discussed.     

From Awareness to Action: College Students’ Skill Development in Intergroup Dialogue

A central goal of intergroup dialogue (IGD) is to strengthen individual and collective capacities to foster social justice commitments by supporting new ways of thinking about oneself, others, and the social structures in which we live. Relatedly, IGD assists individuals with building multicultural competencies and skill sets that support peoples’ capacities to take action and work towards social change. The following qualitative study contributes to current research by describing the types of skills undergraduate students report learning as a result of their IGD experience and the challenges they encounter as they develop communication, cognitive, and affective skills.