Exclusion Expected? Cardiac Slowing Upon Peer Exclusion Links Preschool Parent Representations to School-Age Peer Relationships

Attachment theory proposes that children’s representations of interactions with caregivers guide information-processing about others, bridging interpersonal domains. In a longitudinal study (N = 165), preschoolers (M_age = 5.19 years) completed the MacArthur Story Stem Battery to assess parent representations. At school-age (M_age = 8.42 years), children played a virtual ballgame with peers who eventually excluded them to track event-related cardiac slowing, a physiological correlate of rejection, especially when unexpected. At both ages, parents and teachers reported on peer and emotional problems. During exclusion versus inclusion-related events, cardiac slowing was associated with greater positive parent representations and fewer emerging peer problems. Cardiac slowing served as a mediator between positive parent representations and peer problems, supporting a potential psychophysiological mechanism underlying the generalization of attachment-related representations to peer relationships.     

Persistence of innovation and patterns of firm growth

In this work we exploit a long-in-time panel of Spanish manufacturing firms observed during the period 1990–2012 to examine the long-run contribution of innovation persistence to sales growth and market share dynamics. We examine two main research questions. First, do persistent innovators grow more than other firms? Second, do persistent innovators show more persistent growth patterns over time compared to other firms? We find negative answers to both questions: firms that persistently innovate over the first decade, do not grow more and do not display more persistent growth dynamics in the succeeding years, regardless of whether innovation persistence is defined in terms of R&D, patenting activity, or product or process innovation. These findings lend support to luck and random theories of firm growth, in turn challenging innovation persistence theories commonly suggesting that persistent innovators enjoy large and sustained comparative advantages.     

Venture capital and the birth of the local area networking industry

Venture capital has played an important role in funding the development of a number of US high-technology industries. Economists and business scholars utilizing models based in traditional economics have studied venture capital from the perspective of investment decision-making. These models provide significant insights, and yet they do not explain the actual operation of venture capital. This case study of the creation of LAN industry utilizes a synthesis of the dominant design and social constructionist perspectives to create a more nuanced explanation of how the practice of venture capitalists operates to create firms and industries.     

Changes in ankle work,foot work,and tibialis anterior activation throughout a long run

Background:The ankle and foot together contribute to over half of the positive and negative work performed by the lower limbs during running.Yet,little is known about how foot kinetics change throughout a run.The amount of negative foot work may decrease as tibialis anterior(TA)electromyography(EMG) changes throughout longer-duration runs.Therefore,we examined ankle and foot work as well as TA EMG changes throughout a changing-speed run.Methods:Fourteen heel-striking subjects ran on a treadmill ...     

The missing base molecules in atmospheric acid–base nucleation

Transformation of low-volatility gaseous precursors to new particles affects aerosol number concentration, cloud formation and hence the climate. The clustering of acid and base molecules is a major mechanism driving fast nucleation and initial growth of new particles in the atmosphere. However, the acid–base cluster composition, measured using state-of-the-art mass spectrometers, cannot explain the measured high formation rate of new particles. Here we present strong evidence for the existence of base molecules such as amines in the smallest atmospheric sulfuric acid clusters prior to their detection by mass spectrometers. We demonstrate that forming (H₂SO₄)₁(amine)₁ is the rate-limiting step in atmospheric H₂SO₄-amine nucleation and the uptake of (H₂SO₄)₁(amine)₁ is a major pathway for the initial growth of H₂SO₄ clusters. The proposed mechanism is very consistent with measured new particle formation in urban Beijing, in which dimethylamine is the key base for H₂SO₄ nucleation while other bases such as ammonia may contribute to the growth of larger clusters. Our findings further underline the fact that strong amines, even at low concentrations and when undetected in the smallest clusters, can be crucial to particle formation in the planetary boundary layer.     

Movement planning reflects skill level and age changes in toddlers

Kinematic measures of children's reaching were found to reflect stable differences in skill level for planning for future actions. Thirty-five toddlers (18-21 months) were engaged in building block towers (precise task) and in placing blocks into an open container (imprecise task). Sixteen children were retested on the same tasks a year later. Longer deceleration as the hand approached the block for pickup was found in the tower task compared with the imprecise task, indicating planning for the second movement. More skillful toddlers who could build high towers had a longer deceleration phase when placing blocks on the tower than toddlers who built low towers. Kinematic differences between the groups remained a year later when all children could build high towers.     

Analysis of author affiliation across four school psychology journals from 2000 to 2008: Where is the practitioner research?

Articles published between 2000 and 2008 in four major school psychology journals—School Psychology Review, Journal of School Psychology, Psychology in the Schools, and School Psychology Quarterly—were classified based on type (empirical or narrative) and on the primary and secondary authors' affiliations. Results showed that more than 90% of the primary and secondary authors were university affiliated with little difference across article type. Although more than 85% of school psychologists are practitioners, these results suggest that their contributions to these school psychology journals are limited because they account for less than 10% of the authors of articles. Discussion focuses on practitioners' involvement in the research base that is intended to inform their professional behaviors. © 2009 Wiley Periodicals, Inc.