Poly(vinyl alcohol)-heparin biosynthetic microspheres produced by microfluidics and ultraviolet photopolymerisation

Biosynthetic microspheres have the potential to address some of the limitations in cell microencapsulation; however, the generation of biosynthetic hydrogel microspheres has not been investigated or applied to cell encapsulation. Droplet microfluidics has the potential to produce more uniform microspheres under conditions compatible with cell encapsulation. Therefore, the aim of this study was to understand the effect of process parameters on biosynthetic microsphere formation, size, and morphology with a co-flow microfluidic method. Poly(vinyl alcohol) (PVA), a synthetic hydrogel and heparin, a glycosaminoglycan were chosen as the hydrogels for this study. A capillary-based microfluidic droplet generation device was used, and by varying the flow rates of both the polymer and oil phases, the viscosity of the continuous oil phase, and the interfacial surface tension, monodisperse spheres were produced from ∼200 to 800 μm. The size and morphology were unaffected by the addition of heparin. The modulus of spheres was 397 and 335 kPa for PVA and PVA/heparin, respectively, and this was not different from the bulk gel modulus (312 and 365 for PVA and PVA/heparin, respectively). Mammalian cells encapsulated in the spheres had over 90% viability after 24 h in both PVA and PVA/heparin microspheres. After 28 days, viability was still over 90% for PVA-heparin spheres and was significantly higher than in PVA only spheres. The use of biosynthetic hydrogels with microfluidic and UV polymerisation methods offers an improved approach to long-term cell encapsulation.     

Influence of Participation Motivation on Success and Satisfaction in Team Performance

Abstract

The present study determined the effect of affiliation and task motivation on the success and satisfaction of college intramural basketball teams. Over 1,200 male college students, members of 144 basketball teams, responded to a pre- and post-season questionnaire which assessed affiliation and task motivation as well as team satisfaction. Teams were categorized into low, moderate, and high levels for both affiliation and task motivation. The number of games won determined success. An Affiliation Motivation × Task Motivation (3 × 3) factorial design was used. The multivariate ANOVA for the affiliation hypothesis was significant, indicating that high affiliation-motivated teams in contrast to moderate- and low-affiliation-motivated teams were less successful but more satisfied. High task-motivated teams, on the other hand, were more successful and more satisfied than moderate or low task-motivated teams. No significant interaction between task and affiliation motivation was found.     

Coaction Effects on a Muscular Endurance Task

Abstract

The effect of one and three coactors on an individual's performance of a muscular endurance task was determined for 8-, 13-, and 18-year-old males. Subjects extended the dominant leg in a horizontal position for as long as possible under one of three conditions: alone, in pairs, and in groups of four. Results showed that individuals in quadrads performed significantly better than individuals in dyads and alone. No significant difference was found between individuals performing alone and in dyads. Eight-year-olds were found to be superior to the two older age groups, but the age factor was independent of the coaction effect.     

Competence,persistence, and success: The positive psychology of behavioral skill instruction

Early school failure is a critical factor in the development of peer rejection and antisocial behavior in children. This paper describes three sets of instructional strategies that have been shown to promote high levels of academic competence by arranging frequent opportunities for correct skill practice: (a) teaching children at their instructional level and monitoring progress, (b) teaching children differently as their skills improve, and (c) rewarding success and setting goals. Research is reviewed showing that practicing skills to high levels of fluency leads to retention and endurance, the emergence of new forms of a skill, and creative problem solving. The motivation of children to complete academic tasks through the strategic use of reinforcement is discussed, as are the implications of these strategies for encouraging children to be persistent, self‐motivated, life‐long learners. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 19–30, 2004.     

Issues of access and usability in designing digital resources for children

The way children's cognitive states affect how they function in digital interfaces is examined through articles published between 1989 and 2010. Children have developmental limitations, such as underdeveloped motor skills, difficulties with spelling, and trouble understanding hierarchies, classification schemes, and metadata, that make it difficult for them to find information, and challenging for adult designers to accommodate their needs. From icons to metadata to hierarchies, the best research in designing digital resources for children, (OPACs such as Pejtersen's Book House, online public libraries such as the Internet Public Library, and online collections of books such as the International Children's Digital Library), places the child user at the center, and takes an interdisciplinary and intergenerational approach. The literature indicates that research in designing for children is valuable, not only because it seeks to improve children's experience with digital resources, but also because such research translates to other marginalized users and special needs populations.     

Executive functioning, metacognition, and self-perceived competence in elementary school children: an explorative study on their interrelations and their role for school achievement

In the present study, associations between executive functioning, metacognition, and self-perceived competence in the context of early academic outcomes were examined. A total of 209 children attending first grade were initially assessed in terms of their executive functioning and academic self-concept. One year later, children??s executive functioning, academic self-concept, metacognitive monitoring and control, as well as their achievement in mathematics and literacy were evaluated. Structural equation modeling revealed that executive functioning was significantly related to metacognitive control, both cross-sectionally and longitudinally, and that self-concept was substantially associated with metacognitive monitoring, both cross-sectionally and longitudinally. Individual differences in executive functioning and metacognitive control were significantly related to academic outcomes, with metacognitive control appearing to yield a more circumscribed influence on academic outcomes (only literacy) compared to executive functioning (literacy and mathematics).     

Professional role and identity of Icelandic preschool teachers: effects of stakeholders’ views

In this article, we explore the reality of Icelandic preschool teachers who are, as in most other countries, predominantly female. The gendered nature of the role and the current identity adopted by preschool teachers appear to impact on their perceived status and professionalism. In this process, stakeholders in early childhood education (ECE), as well as the preschool teachers themselves, play important parts. The question that underlies the paper is: ‘How do the views of preschool teachers and stakeholders in ECE affect the preschool teachers’ professional identity?’ The data used to answer the question are from focus group research carried out with preschool teachers and stakeholders in ECE in one community in Iceland. These stakeholders, besides preschool teachers and staff within the preschools, were parents, professionals at the municipal preschool office and politicians. The theoretical perspective informing the methodology of the research was ‘symbolic interactionism’ and the concept of ‘democratic professionalism’ was used as an aspirational framework to analyse the data. The findings reveal connections between the ideology relating to the preschool teachers’ educational role, their limited leadership and the gendered views of stakeholders. At the end of the paper, implications and recommendations for preschool teachers are suggested.