Multiple representations in web-based learning of chemistry concepts

A new chemistry curriculum for secondary schools is currently under construction in the Netherlands, in which chemical knowledge will be embedded in contexts that show applications of chemistry in the society. Several research groups develop such modules and a committee appointed by the Dutch Ministry of Education advises about the chemical content and concepts.\ud A central issue in chemistry education is the relation between the real, molecular and symbolic world. Skilled chemists switch easily between these worlds, but beginning students do not. They could get better results and will be more able to solve problems if they would make better connections between the three chemical worlds. The University of Twente has developed a series of lessons about the particle model. Included in this instruction material are animations of chemical processes at the molecular level. In the lessons students are supported and stimulated to make connections between the three chemical worlds. Students are shown the importance of new chemical knowledge in society. The mental images and the knowledge schemata of the students are investigated in this research. The students were interviewed before they received instruction, and after they received about half of the instruction. At the end of the instruction they were asked to make a concept map.\ud It appeared that the links between the real, molecular and symbolic world are not strengthened after the instruction. The students make more links between the real and symbolic world, but hardly connect these world to the molecular world or vice versa. There is still a gap between the students’ mental models and scientifically accepted models as represented in animations and illustrations in the instruction. Most students liked the animations in the instruction and mentioned them as strong point. It is therefore surprising that some students could not remember the animations when they were interviewed, whilst others their representations were about the same as the animations. Clearly, the effectiveness of the animations must be enhanced and more research is needed for this

Assessing teachers’ beliefs to facilitate the transition to a new chemistry curriculum: what do the teachers want?

In this article, we describe the results of a study of chemistry high school teachers’ beliefs (N = 7) of the chemistry curriculum and their roles, their beliefs on the teacher as developer of materials, and their beliefs about professional development. Teachers’ beliefs influence the implementation of a curriculum. We view the use of a new curriculum as a learning process, which should start at teachers’ prior knowledge and beliefs. The results reveal that it is possible to develop a new curriculum in which teachers’ beliefs are taken as a starting point. Promising approaches to prepare teachers for a new curriculum is to let them (co)develop and use curriculum materials: It creates ownership, and strengthens and develops teachers’ pedagogical content knowledge (PCK)

The effects of the design and development of a chemistry curriculum reform on teachers’ professional growth: a case study

A curriculum innovation requires new learning material for students and a preparation program for teachers, in which teacher learning is a key ingredient. In this paper we describe how three experienced teachers, involved in the development and subsequent classroom enactment of student learning material for context-based chemistry education, professionalized. For data collection a questionnaire, three interviews and discussion transcripts were used. Our results show that: (a) teachers, cooperating in a network under supervision of an expert, can develop innovative learning material; (b) the development of learning material can be seen as a powerful program to prepare teachers for an innovation; and (c) teachers’ knowledge increased in all five pedagogical content knowledge domains during the development and class enactment phases

Renewable sustainable biocatalyzed electricity production in a photosynthetic algal microbial fuel cell (PAMFC)

Electricity production via solar energy capturing by living higher plants and microalgae in combination with microbial fuel cells are attractive because these systems promise to generate useful energy in a renewable, sustainable, and efficient manner. This study describes the proof of principle of a photosynthetic algal microbial fuel cell (PAMFC) based on naturally selected algae and electrochemically active microorganisms in an open system and without addition of instable or toxic mediators. The developed solarpowered PAMFC produced continuously over 100 days renewable biocatalyzed electricity. The sustainable performance of the PAMFC resulted in a maximum current density of 539 mA/m2 projected anode surface area and a maximum power production of 110 mW/m2 surface area photobioreactor. The energy recovery of the PAMFC can be increased by optimization of the photobioreactor, by reducing the competition from non-electrochemically active microorganisms, by increasing the electrode surface and establishment of a further-enriched biofilm. Since the objective is to produce net renewable energy with algae, future research should also focus on the development of low energy input PAMFCs. This is because current algae production systems have energy inputs similar to the energy present in the outcoming valuable products

Role of TRPV4 in Astrocyte Extracellular Matrix Production

Traumatic Brain Injury (TBI) is an alteration of brain pathology following damage of the central nervous system (CNS) by an external force. In the CNS, glial scar formation often occurs following TBI, and astrocytes are widely believed to contribute to this scar formation. While the role of astrocytes in extracellular matrix (ECM) production is known, the exact mechanism(s) for this event remain unclear. One possible method is the activation of transient receptor potential vanilloid 4 (TRPV4). TRPV4 is a channel protein found in the astrocyte membrane which has been shown to generate intracellular calcium ions following mechanical stimulation. Previous research has shown activation of TRPV4 to increase collagen content in chondrocytes. This research compared mouse astrocyte matrix composition following TRPV4 biochemical activation/inactivation through rheological analysis techniques. Sample storage modulus values were shown to significantly increase following TRPV4 activation possibly due to an increase in astrocyte ECM production

The role of boundary objects in health innovation:design for alignment

This thesis investigated and explored if and how boundary objects and their perspective can contribute to the meaningful design of innovation for the healthcare sector. The concept of boundary objects has found its way into healthcare and health contexts. Boundary object scan have many forms and can trigger different learning mechanisms: identification, coordination, relfection, and transformation. The reflection and transformation mechanisms are underrepresented in existing literature, but pursuing the reflective mechanism in design, development, and implementation projects is beneficial for a fluid and smooth integration of innovation into practice. Our case studies show that it is significant to trigger the reflective mechanism during the design and innovation process. By applying methods and prototypes as boundary objects and by approaching interventions to be developed as boundary objects, we see good effects in terms of acceptance, adoption, and creating (co-)ownership of the innovation, whit an inclusive design as outcome. The boundary object focus and perspective adds value to existing change and innovation frameworks by not pursuing consensus but harmony in differences. Results of this thesis are useful for both the growing design discipline in health as for policymakers in healthcare who have to come up with innovative strategies to meet the challenges healthcare faces today. Future work should focus on a more unambiguous use of the concept in healthcare, a pursuit to trigger the reflective mechanism in innovative processes in health, and adopt more 'designerly ways of knowing’ in health by applying design research in complex healthcare issues