Paper-based colorimetric enzyme linked immunosorbent assay fabricated by laser induced forward transfer

We report the Laser Induced Forward Transfer (LIFT) of antibodies from a liquid donor film onto paper receivers for application as point-of-care diagnostic sensors. To minimise the loss of functionality of the active biomolecules during transfer, a dynamic release layer was employed to shield the biomaterial from direct exposure to the pulsed laser source. Cellulose paper was chosen as the ideal receiver because of its inherent bio-compatibility, liquid transport properties, wide availability and low cost, all of which make it an efficient and suitable platform for point-of-care diagnostic sensors. Both enzyme-tagged and untagged IgG antibodies were LIFT-printed and their functionality was confirmed via a colorimetric enzyme-linked immunosorbent assay. Localisation of the printed antibodies was exhibited, which can allow the creation of complex 2-d patterns such as QR codes or letters for use in a final working device. Finally, a calibration curve was determined that related the intensity of the colour obtained to the concentration of active antibodies to enable quantitative assessment of the device performance. The motivation for this work was to implement a laser-based procedure for manufacturing low-cost, point-of-care diagnostic devices on paper.     

How Have Concepts of Informal Learning Developed Over Time?

Although the current interest in informal learning seems recent, performance improvement professionals have long had an interest in informal learning‐the ways that people learn outside of formal structures. The earliest forms of learning for work were informal, including de facto and formal apprenticeship programs and the “school of life.” Contemporary interest began in the 1960s and 1970s with the rise of self‐directed learning. In the 1970s and 1980s, focus shifted to adult learning theory and human performance technology, both of which explore the roles of interventions other than classroom learning. The early 1990s brought two practical applications—electronic performance support systems and edutainment—followed by a third in the late 1990s—knowledge management. Discussions of informal learning arose in the 2000s. Each movement offers practical lessons for designing informal learning today.     

How Designers Make Decisions: A Descriptive Model of Instructional Design for Informal Learning in Museums

In response to a call for theories of instructional design that are grounded in practice, I conducted a naturalistic study of the instructional design process for three permanent museum exhibits. An analysis of the data indicated that design involves a series of decisions, each of which has 4 components: • Design goals: principles to be achieved through the decision process and that must be realized before the choice is considered complete. • Design resources: the materials–both physical and intellectual–available to present information. • Design techniques: the strategies for achieving the goals using the design resources available. • Constraints: outside influences such as budget and schedule that limit the use of resources and techniques to achieve a goal. Each phase in the design process is characterized by certain types of decisions in which one of the four components dominates. Design team members participate to different extents in design decisions based on their roles. In theory, the model should transfer from museum exhibition design to instructional design. Further study would indicate the extent as well as which design decisions are guided by research, theory, or instinct, so we might understand and ultimately improve decisions about instructional programs.     

Learning and Metamemory Failures Despite Extensive Experience

A number of studies has shown excellent recognition memory for pictures when participants are asked to remember what has been presented. This study explored unpractised memory for the English 5 note-an everyday item containing a great deal of pictorial information. Forty participants were asked to study a copy of the etching of the Rocket locomotive from the reverse side of the note. Of the participants 75% claimed never to have seen the image before, and were confident in their judgements. Further, participants were confident that experimenter claims about bank-note details were wrong. Results point to both dramatic memory failure, and to misrepresentations in memory. They provide a vivid demonstration of the failure of passive learning to encode information reliably, and the need for active learner engagement for effective recall.