Flow biosensing and sampling in indirect electrochemical detection

Miniaturization in biological analyses has several advantages, such as sample volume reduction and fast response time. The integration of miniaturized biosensors within lab-on-a-chip setups under flow conditions is highly desirable, not only because it simplifies process handling but also because measurements become more robust and operator-independent. In this work, we study the integration of flow amperometric biosensors within a microfluidic platform when analyte concentration is indirectly measured. As a case study, we used a platinum miniaturized glucose biosensor, where glucose is enzymatically converted to [Formula: see text] that is oxidized at the electrode. The experimental results produced are strongly coupled to a theoretical analysis of fluid dynamic conditions affecting the electrochemical response of the sensor. We verified that the choice of the inlet flow rate is a critical parameter in flow biosensors, because it affects both glucose and [Formula: see text] transport, to and from the electrode. We identify optimal flow rate conditions for accurate sensing at high time resolution. A dimensionless theoretical analysis allows the extension of the results to other sensing systems according to fluid dynamic similarity principles. Furthermore, we developed a microfluidic design that connects a sampling unit to the biosensor, in order to decouple the sampling flow rate from that of the actual measurement.     

Static analysis of programming exercises: Fairness,usefulness and a method for application

This article explores the suitability of static analysis techniques based on the abstract syntax tree (AST) for the automated assessment of early/mid degree level programming. Focus is on fairness, timeliness and consistency of grades and feedback. Following investigation into manual marking practises, including a survey of markers, the assessment of 97 student Java programming submissions is automated using static analysis rules. Initially, no correlation between human provided marks and rule violations is found. This paper investigates why, and considers several improvements to the approaches used for applying static analysis rules. New methods for application are explored and the resulting technique is applied to a second exercise with 95 submissions. The results show a stronger positive correlation with manual assessment, whilst retaining advantages in terms of time cost, pedagogic advantages and instant feedback. This study provides insight into the differences between human assessment and static analysis approaches and highlights several potential pitfalls of simplistic implementations. Finally, this paper concludes that static analysis approaches are appropriate for automated assessment; however, these approaches should be used with care.     

Navigating between an emic and an etic approach in ethnographic research. Crucial aspects and strategies when communicating critical results to participants

There is a fundamental tension in ethnographic research between trying to understand participants from within their own perspective and viewing them with greater distance. With this in mind, the aim of this article is to describe how a reflexive communication model was developed during the study of El Sistema Gothenburg, and to discuss aspects and strategies that are crucial when navigating between an emic and an etic approach. It is argued that by reflexive communication, researchers can make their results useful for participants and that reflecting upon the relationship is even more important when communicating critique. With the help of this model, communication of critical results was facilitated by the establishment of an integrative approach that combined the insiders’ and outsiders’ perspectives and was based on the formation of a strong relationship between the researchers and the participants, as well as by the participants’ own cultivation of theoretical understanding.     

Black Mathematics Educators: Researching Toward Racial Emancipation of Black Students

This article focuses on the scholarship of Black mathematics education researchers whose work focuses on Black students in P–20 mathematics spaces. We conducted a metasynthesis literature review of empirical studies by Black mathematics education researchers. The authors utilized critical theories of race and racism to aid in the synthesis of the literature. The Black researchers we reviewed challenged the perspective that failure and limited persistence in Black students who are learning and participating in mathematics is normative. As a critical defense, these scholars offer research that problematizes test score data, race and racism, opportunities to learn mathematics, identity considerations, and other constructs that produce unequal effects in mathematics learning. We found that Black mathematics education researchers strategically disrupt the deficit narrative about Black students. Black scholars select theoretical frameworks that allow them to focus on race and how racism operates in mathematics education. We present this research to incite dialogue among all mathematics educators about improving the mathematical context for Black students.     

Against the grain: science education researchers and social justice agendas

Cultural Studies of Science Education - This paper is written in response to Alberto J. Rodriguez and Deb Morrison’s article entitled, “Expanding and Enacting Transformative Meanings of...