Separation and enrichment of sodium-motile bacteria using cost-effective microfluidics

Many motile bacteria are propelled by the rotation of flagellar filaments. This rotation is driven by a membrane protein known as the stator-complex, which drives the rotor of the bacterial flagellar motor. Torque generation is powered in most cases by proton transit through membrane protein complexes known as stators, with the next most common ionic power source being sodium. Sodium-powered stators can be studied through the use of synthetic chimeric stators that combine parts of sodium- and proton-powered stator proteins. The most well studied example is the use of the sodium-powered PomA-PotB chimeric stator unit in the naturally proton-powered Escherichia coli. Here we designed a fluidics system at low cost for rapid prototyping to separate motile and non-motile populations of bacteria while varying the ionic composition of the media and thus the sodium-motive force available to drive this chimeric flagellar motor. We measured separation efficiencies at varying ionic concentrations and confirmed using fluorescence that our device delivered eightfold enrichment of the motile proportion of a mixed population. Furthermore, our results showed that we could select bacteria from reservoirs where sodium was not initially present. Overall, this technique can be used to implement the selection of highly motile fractions from mixed liquid cultures, with applications in directed evolution to investigate the adaptation of motility in bacterial ecosystems.     

Bandpass sorting of heterogeneous cells using a single surface acoustic wave transducer pair

Separation and sorting of biological entities (viruses, bacteria, and cells) is a critical step in any microfluidic lab-on-a-chip device. Acoustofluidics platforms have demonstrated their ability to use physical characteristics of cells to perform label-free separation. Bandpass-type sorting methods of medium-sized entities from a mixture have been presented using acoustic techniques; however, they require multiple transducers, lack support for various target populations, can be sensitive to flow variations, or have not been verified for continuous flow sorting of biological cells. To our knowledge, this paper presents the first acoustic bandpass method that overcomes all these limitations and presents an inherently reconfigurable technique with a single transducer pair for stable continuous flow sorting of blood cells. The sorting method is first demonstrated for polystyrene particles of sizes 6, 10, and 14.5 μm in diameter with measured purity and efficiency coefficients above 75 ± 6% and 85 ± 9%, respectively. The sorting strategy was further validated in the separation of red blood cells from white blood cells and 1 μm polystyrene particles with 78 ± 8% efficiency and 74 ± 6% purity, respectively, at a flow rate of at least 1 μl/min, enabling to process finger prick blood samples within minutes.     

Decentralising the patent system

Modern patent systems are slow, inefficient, expensive, and may result in outcomes that actively harm technological progress. This paper proposes a substantive re-think of these systems and lays a foundation upon which practical solutions can be built. Many solutions proposed in the past, such as prior-art bounties, outsourced examination, and dynamic fee setting, have gone unheeded due to the cost of administering them and the rigidity of the patent system. We explore how distributed ledger technologies (DLTs) enable these major changes by altering the way stakeholders are able to interact with the patent records system. We find that transitioning to a DLT-based patent records system can enable many previously suggested improvements to current patent systems in a flexible, scalable, and transparent manner. The case for such a transition is strengthened when jointly considering the complex but common roots of problems facing modern patent systems, rather than a balkanised set of technical solutions to address each issue independently. Noting that a DLT-based system is not a panacea, we also provide comment on the political, legal, and organisational challenges that must be overcome for such changes to be implemented at scale.     

Implementation of the flipped classroom and its longitudinal impact on improving academic performance

Educational technology research and development - The objective has been to know the impact of the flipped classroom methodology on the academic performance of students during their training...     

Correction to: The State of Current Reading Intervention Research for English Learners in Grades K–2: a Best-Evidence Synthesis

Educational Psychology Review -     

Fostering parents-professional collaboration for facilitating the school inclusion of students with ASD: design of the “ToGather” web-based prototype

Educational technology research and development - In recent years, many psycho-educational technologies were studied to address the school-related difficulties encountered by students with autism...     

Errors of programming and ownership of the robot concept made by trainee kindergarten teachers during an induction training

Education and Information Technologies - Computational thinking in the educational environment has awaken a rising interest, having been included as part of the curricula from the very beginnings...     

Novice teacher vertical professional development? Exploring teachers’ and coaches’ beliefs throughout a two-year induction program

Learning Environments Research - The pedagogical beliefs of novice teachers and their coaches throughout a two-year induction program and how those beliefs impact their induction experiences were...     

Development and preliminary validation of the moral authorship questionnaire

Learning Environments Research - Background When novice teachers start working in a school, it is vital that they are aware of the moral aspects of the work environment and can use their moral...