A requirement for filopodia extension toward Slit during Robo-mediated axon repulsion

Axons navigate long distances through complex 3D environments to interconnect the nervous system during development. Although the precise spatiotemporal effects of most axon guidance cues remain poorly characterized, a prevailing model posits that attractive guidance cues stimulate actin polymerization in neuronal growth cones whereas repulsive cues induce actin disassembly. Contrary to this model, we find that the repulsive guidance cue Slit stimulates the formation and elongation of actin-based filopodia from mouse dorsal root ganglion growth cones. Surprisingly, filopodia form and elongate toward sources of Slit, a response that we find is required for subsequent axonal repulsion away from Slit. Mechanistically, Slit evokes changes in filopodium dynamics by increasing direct binding of its receptor, Robo, to members of the actin-regulatory Ena/VASP family. Perturbing filopodium dynamics pharmacologically or genetically disrupts Slit-mediated repulsion and produces severe axon guidance defects in vivo. Thus, Slit locally stimulates directional filopodial extension, a process that is required for subsequent axonal repulsion downstream of the Robo receptor.National Institutes of Health (U.S.) (Grant F32-CA165700)National Institutes of Health (U.S.) (Grant R01-GM068678)National Institutes of Health (U.S.) (Grant P30-CA014051

A produção sobre aprendizagem informal nas organizações no Brasil: mapeando o terreno e rastreando possibilidades futuras

A aprendizagem informal é entendida como aquela baseada na experiência intencional, mas não formalmente estruturada; induzida por um processo de reflexão crítica, ação, pró-atividade e criatividade; incrustada no contexto organizacional e nas práticas cotidianas. Pode ser planejada ou não, embora envolva algum grau de consciência de quem aprende. Sua relevância para o ambiente de trabalho tem sido atestada por vários autores. Este trabalho tem como objetivo identificar, descrever e analisar a produção a respeito dessa temática no Brasil, no período de 2006 a 2012. O conjunto de 21 artigos selecionados para fazer parte desta revisão reúne estudos teóricos e empíricos publicados em periódicos nacionais da área de Administração e avaliados com conceito B2 ou superior pelo WebQualis da CAPES. O estudo envolveu duas etapas. Numa primeira etapa definiram-se as fontes de dados e amostra a ser trabalhada. Uma segunda etapa consistiu na análise dos artigos a partir das seguintes dimensões: foco dos estudos (origem, tema e objetivos), nível de aprendizagem, autores referenciados, perspectivas teóricas, posicionamentos epistemológicos, tipos de pesquisa, dados de contexto da produção e principais achados. Os resultados mostram uma produção dispersa que ainda precisa ser aprimorada em relação aos arcabouços teóricos tomados como referência para o aprofundamento do tema

Formal vs. informal coach education

The training of coaches is considered central to sustaining and improving the quality of sports coaching and the ongoing process of professionalisation. Sports coaches participate in a range of learning opportunities (informal to formal) that contribute to their development to varying degrees. In this article, we present our collective understanding on the varying types of learning opportunities and their contribution to coach accreditation and development. The authors presented these views (from a sports pedagogy perspective) as part of a workshop entitled "Formal vs. Informal Coach Education" at the 2007 International Council of Coach Education Master Class in Beijing. These reflections seek to stimulate the on-going, and often sterile, debate about formal versus informal coach education/learning in order to progress scholarship in coaching

Visualising the invisible: a network approach to reveal the informal social side of student learning

World-wide, universities in health sciences have transformed their curriculum to include collaborative learning and facilitate the students’ learning process. Interaction has been acknowledged to be the synergistic element in this learning context. However, students spend the majority of their time outside their classroom and interaction does not stop outside the classroom. Therefore we studied how informal social interaction influences student learning. Moreover, to explore what really matters in the students learning process, a model was tested how the generally known important constructs—prior performance, motivation and social integration—relate to informal social interaction and student learning. 301 undergraduate medical students participated in this cross-sectional quantitative study. Informal social interaction was assessed using self-reported surveys following the network approach. Students’ individual motivation, social integration and prior performance were assessed by the Academic Motivation Scale, the College Adaption Questionnaire and students’ GPA respectively. A factual knowledge test represented student’ learning. All social networks were positively associated with student learning significantly: friendships (β = 0.11), providing information to other students (β = 0.16), receiving information from other students (β = 0.25). Structural equation modelling revealed a model in which social networks increased student learning (r = 0.43), followed by prior performance (r = 0.31). In contrast to prior literature, students’ academic motivation and social integration were not associated with students’ learning. Students’ informal social interaction is strongly associated with students’ learning. These findings underline the need to change our focus from the formal context (classroom) to the informal context to optimize student learning and deliver modern medics

Vocational teachers and workplace learning: integrative, complementary and implicit accounts of boundary crossing

Where young people’s upper-secondary education spans work and institutional domains, questions arise about learning across both spheres and its guidance. Theoretical accounts of ‘boundary crossing’ have explored how vocational teachers can integrate learning across domains by drawing on extended concepts and theoretical knowledge to solve workplace problems; whilst empirical accounts have validated the role of vocational educators by describing the workplace and schools as equally valid, complementary spheres. Different understandings, described here as ‘integrative’, ‘complementary’ and ‘implicit’, appear to reflect different national patterns of vocational education. The paper reports a qualitative study conducted around two case studies, located in Germany and England, of the way vocational teachers’ understandings of facilitating learning across domains are constructed. Vocational teachers working in Germany’s ‘dual training’ claimed to provide advanced knowledge that they compared to practical work skills, reflecting ‘implicit’ or ‘complementary’ approaches to learning across domains. Teachers in England, where workplace learning elements are more unevenly developed and lack institutional foundations, nevertheless described colleges and workplaces as distinctive, little-connected spheres. These differences suggest that teachers’ approaches are less shaped by the potential or necessity for ‘integrative’ approaches than by the way different systems enable or constrain their conceptualisation of ‘possible futures’.N/

Advancing a Conceptual Model of Evidence-Based Practice Implementation in Public Service Sectors

Implementation science is a quickly growing discipline. Lessons learned from business and medical settings are being applied but it is unclear how well they translate to settings with different historical origins and customs (e.g., public mental health, social service, alcohol/drug sectors). The purpose of this paper is to propose a multi-level, four phase model of the implementation process (i.e., Exploration, Adoption/Preparation, Implementation, Sustainment), derived from extant literature, and apply it to public sector services. We highlight features of the model likely to be particularly important in each phase, while considering the outer and inner contexts (i.e., levels) of public sector service systems

Learning / becoming / organizing

In this paper we rethink and reframe organizational learning in terms of organizational becoming. We see these concepts as two mutually implicating ways of exploring and simultaneously constituting the phenomena of organization. Bearing in mind that the understanding of organization is simultaneously a question of the organization of understanding, we reflect on the complex interrelation between thinking and organizing. In order to connect the processes of learning and becoming, we consider the concept of organization as space in between order and chaos. We propose a perspective that sees learning not as something that is done to organizations, or as something that an organization does; rather, learning and organizing are seen as mutually constitutive and unstable, yet pragmatic, constructs that might enable a dynamic appreciation of organizational life. Further, we argue that the becoming that is in organizing implies a permanent non-rational movement such that organization can never be rationally defined. copyright © 2005 sage