Exposing piaget's scheme: Empirical evidence for the ontogenesis of coordination in learning a mathematical concept

The combination of two methodological resources-natural-user interfaces (NUI) and multimodal learning analytics (MMLA)-is creating opportunities for educational researchers to empirically evaluate seminal models for the hypothetical emergence of concepts from situated sensorimotor activity. 76 participants (9-14 yo) solved tablet-based non-symbolic manipulation tasks designed to foster grounded meanings for the mathematical concept of proportional equivalence. Data gathered in task-based semi-structured clinical interviews included action logging, eye-gaze tracking, and videography. Successful task performance coincided with spontaneous appearance of stable dynamical gaze-path patterns soon followed by multimodal articulation of strategy. Significantly, gaze patterns included uncued non-salient screen locations. We present cumulative results to argue that these 'attentional anchors' mediated participants' problem solving. We interpret the findings as enabling us to revisit, support, refine, and elaborate on central claims of Piaget's theory of genetic epistemology and in particular his insistence on the role of situated motor-action coordination in the process of reflective abstraction

Eye-tracking the emergence of attentional anchors in a mathematics learning tablet activity

Little is known about micro-processes by which sensorimotor interaction gives rise to conceptual development. Per embodiment theory, these micro-processes are mediated by dynamical attentional structures. Accordingly this study investigated eye-gaze behaviors during engagement in solving tablet-based bimanual manipulation tasks designed to foster proportional reasoning. Seventy-six elementary- and vocational-school students (9-15 yo) participated in individual task-based clinical interviews. Data gathered included action-logging, eye-tracking, and videography. Analyses revealed the emergence of stable eye-path gaze patterns contemporaneous with first enactments of effective manipulation and prior to verbal articulations of manipulation strategies. Characteristic gaze patterns included consistent or recurring attention to screen locations that bore non-salient stimuli or no stimuli at all yet bore invariant geometric relations to dynamical salient features. Arguably, this research validates empirically hypothetical constructs from constructivism, particularly reflective abstraction

Recent Developments in Ring-Opening Metathesis Polymerization (ROMP)

Properties and applications of newly developed homogeneous Ring-Opening Metathesis Polymerization catalysts as well as Photo-induced Ring-Opening Metathesis Polymerization catalysts are discussed. In contrast to well-defined, one-component metal-carbene catalysts, the aqueous ROMP with simple RuII salts is a chain reaction and not a living polymerization. One-component Photo-ROMP initiators were developed with good thermal latency and are either based on early-transition-metal alkyl complexes or on [Ru(arene)2]2+ complexes. Mechanistic aspects of the photochemically induced solvation of RuII complexes are presented

Students’ personal professional theories in competence-based vocational education: the construction of personal knowledge through internalisation and socialisation

Schaap, H., De Bruijn, E., Van der Schaaf, M. F., & Kirschner, P. A. (2009). Students' personal professional theories in competence-based vocational education: the construction of personal knowledge through internalisation and socialisation. Journal of Vocational Education & Training, 61(4), 481-494.Competence-based vocational education is based on a constructivist learning paradigm, where the development of students’ personal professional knowledge is emphasised. However, there is a lack of insight into how students construct their own professional knowledge and what the content and nature of personal professional knowledge is. This article elaborates the concept Personal Professional Theory (PPT): a personal knowledge base in which professional knowledge and beliefs are internalised. PPTs are built upon a combination of declarative and procedural knowledge and are stored in the long-term memory. Furthermore, knowledge in PPTs refers to compiled knowledge which can be specified and applied to different professional situations. These PPTs develop through an interrelated process of internalisation and socialisation, in which students grow into the existing body of shared knowledge and collective norms, values and beliefs of professionals of an occupational domain. It is concluded that the elaboration of PPTs can be used to stimulate and monitor personal professional knowledge development in vocational education, but further research into the content and nature of PPTs is required

Interleukin-1 as a mediator of fatigue in disease: a narrative review

Fatigue is commonly reported in a variety of illnesses, and it has major impact on quality of life. Previously, it was thought that fatigue originates in the skeletal muscles, leading to cessation of activity. However, more recently, it has become clear that the brain is the central regulator of fatigue perception. It has been suggested that pro-inflammatory cytokines, especially interleukin-1 alpha (IL-1α) and interleukin-1 beta (IL-1β), play a prominent role in the development of central fatigue, and several studies have been performed to elucidate the connection between inflammation and these central processes.In this narrative review, mechanisms of action of IL-1 are described, with special attention to its effect on the central nervous system. In addition, we present a summary of studies that (i) investigated the relationship between circulating IL-1α and IL-1β and fatigue severity and/or (ii) evaluated the effect of inhibiting IL-1 on fatigue. We aim to improve the understanding of fatigue in both inflammatory and non-inflammatory illnesses, which could help develop strategies to treat fatigue more effectively.Reviewing the studies that have been performed, it appears that there is a limited value of measuring circulating IL-1. However, inhibiting IL-1 has a positive effect on severe fatigue in most studies that have been conducte

The degree to which traditional play equipment, Parkour play elements, and Aldo van Eyck's play sculptures have an open function

The concept of open functions was introduced to capture an intended feature of van Eyck's seminal play sculptures - they do not suggest a specific action. In a recent study, Van der Schaaf, A. L., S. R. Caljouw, and R. Withagen. (2020. "Are Children Attracted to Play Elements with an Open Function?" Ecological Psychology 32: 79-94) aimed to determine the degree of openness of Parkour play elements by asking participants what behavior children will mainly perform on them. In the present study, we used this method to determine the degree of openness of traditional play elements (e.g. a slide), van Eyck's play sculptures, and Parkour play elements. In addition, we measured the time participants needed to answer the question of what action children will mainly perform on the different elements. We found that generally the Parkour elements have the highest degree of openness. Interestingly, van Eyck's play elements appeared not to be that open. Moreover, the reaction time proved to be an alternative measure for the degree of openness

Can the mean linear energy transfer of organs be directly related to patient toxicities for current head and neck cancer intensity-modulated proton therapy practice?

BACKGROUND AND PURPOSE: The relative biological effectiveness (RBE) of proton therapy is predicted to vary with the dose-weighted average linear energy transfer (LETd). However, RBE values may substantially vary for different clinical endpoints. Therefore, the aim of this study was to assess the feasibility of relating mean D⋅LETd parameters to patient toxicity for HNC patients treated with proton therapy. MATERIALS AND METHODS: The delivered physical dose (D) and the voxel-wise product of D and LETd (D⋅LETd) distributions were calculated for 100 head and neck cancer (HNC) proton therapy patients using our TPS (Raystation v6R). The means and covariance matrix of the accumulated D and D⋅LETd of all relevant organs-at-risk (OARs) were used to simulate 2.500 data sets of different sizes. For each dataset, an attempt was made to add mean D⋅LETd parameters to a multivariable NTCP model based on mean D parameters of the same OAR for xerostomia, tube feeding and dysphagia. The likelihood of creating an NTCP model with statistically significant parameters (i.e. power) was calculated as a function of the simulated sample size for various RBE models. RESULTS: The sample size required to have a power of at least 80% to show an independent effect of mean D⋅LETd parameters on toxicity is over 15000 patients for all toxicities. CONCLUSION: For current clinical practice, it is not feasible to directly model NTCP with both mean D and mean D⋅LETd of OARs. These findings should not be interpreted as a contradiction of previous evidence for the relationship between RBE and LETd