Sub-nanomolar detection of thrombin activity on a microfluidic chip

Bioluminescence resonance energy transfer (BRET) is a form of Förster resonance energy transfer. BRET has been shown to support lower limits of detection than fluorescence resonance energy transfer (FRET) but, unlike FRET, has not been widely implemented on microfluidic devices for bioanalytical sensing. We recently reported a microscope-based microfluidic system for BRET-based biosensing, using a hybrid, high quantum-efficiency, form of BRET chemistry. This paper reports the first optical fiber-based system for BRET detection on a microfluidic chip, capable of quantifying photon emissions from the low quantum-efficiency BRET² system. We investigated the effects of varying core diameter and numerical aperture of optical fibers, as well as varying microfluidic channel design and measurement conditions. We optimized the set-up in order to maximize photon counts and minimize the response time. The optimized conditions supported measurement of thrombin activity, with a limit of detection of 20 pM, which is lower than the microscope-based system and more than 20 times lower than concentrations reported to occur in plasma clots.     

Resilience of anthropometric data assembly strategies to imposed error

The aim of this study was to examine strategies for selecting a criterion value during anthropometric data assembly and their resilience to imposed error. Sixty-seven women aged 16-60 years were subjected to three separate series of measurements, which included six skinfolds and three girths. A random error term was added to the first of the three series of measurements to produce a pseudo-series containing error, termed the 'erroneous replicated series'. Five strategies were then used to determine the criterion value of each of the replication series: the first measurement, the mean of the first two measurements, the mean of all three measurements, the mean of the closest two measurements and the median of the three measurements. The technical error between the criterion values of the true and the flawed replication series for each of the selection strategies was calculated. We found that, for five of the skinfolds and all of the girths, the median value provided the smallest technical error of measurement between the criterion values for the true and erroneous replication series. We conclude that the strategy of selecting the median of three measurements is the most resilient to imposed error.     

Parents’ Metacognitive Knowledge: Influences on Parent–Child Interactions in a Science Museum Setting

Despite science learning in settings such as science museums being recognized as important and given increasing attention in science education circles, the investigation of parents’ and their children’s metacognition in such settings is still in its infancy. This is despite an individual’s metacognition being acknowledged as an important influence on their learning within and across contexts. This research investigated parents’ metacognitive procedural and conditional knowledge, a key element of their metacognition, related to (a) what they knew about how they and their children thought and learned, and (b) whether this metacognitive knowledge influenced their interactions with their children during their interaction with a moderately complex simulation in a science museum. Parents reported metacognitive procedural and conditional knowledge regarding their own and their children’s thinking and learning processes. Further, parents were aware that this metacognitive knowledge influenced their interactions with their children, seeing this as appropriate pedagogical action for them within the context of the particular exhibit and its task requirements at the science museum, and for the child involved. These findings have implications for exhibit and activity development within science museum settings.     

Edinburgh University,schools and the civil service in the early twentieth century

This article is a case study of the relation between urban schooling and university education, using two main sources. Data on the schools attended by history students at Edinburgh University between 1899 and 1933 illustrate the diversity and social ranking of schools in the city. New higher grade schools had a key role in increasing access to university education for both men and women, especially for prospective teachers; the significance of the Education (Scotland) Act of 1918 for Catholic schools, and the continuing importance of small private schools for girls, are also shown. The second source analyses the school origins of successful Edinburgh candidates in civil service examinations between 1896 and 1944, supplemented for other parts of Scotland by the report of the Royal Commission on the Civil Service of 1912. This elite career drew mainly from older schools, and contemporary claims for equality of opportunity in Scotland need to be treated with reserve.     

Methodology in Sports History: Learning from Legal Scholarship?

The brief note aims to illustrate how historical context has contributed to my writing on modern sports law and principally through two pieces of work – the first relating to the historical, sui generis origins of the legality of combat or fighting sports, which continues to stretch the boundaries of core principles of criminal law, such as reasonable consent to bodily harm, to their utmost; and second, and more generally, the ‘historicalegal’ influences on the development of modern sport in mid-nineteenth-century Britain. Before that is done, it is best to give some account of research methodologies in legal scholarship and principally as they apply to legal history.     

Novel model reference adaptive control laws for improved transient dynamics and guaranteed saturation constraints

In classical model reference adaptive control (MRAC), the adaptive rates must be tuned to meet multiple competing objectives. Large adaptive rates guarantee rapid convergence of the trajectory tracking error to zero. However, large adaptive rates may also induce saturation of the actuators and excessive overshoots of the closed-loop system’s trajectory tracking error. Conversely, low adaptive rates may produce unsatisfactory trajectory tracking performances. To overcome these limitations, in the classical MRAC framework, the adaptive rates must be tuned through an iterative process. Alternative approaches require to modify the plant’s reference model or the reference command input. This paper presents the first MRAC laws for nonlinear dynamical systems affected by matched and parametric uncertainties that constrain both the closed-loop system’s trajectory tracking error and the control input at all times within user-defined bounds, and enforce a user-defined rate of convergence on the trajectory tracking error. By applying the proposed MRAC laws, the adaptive rates can be set arbitrarily large and both the plant’s reference model and the reference command input can be chosen arbitrarily. The user-defined rate of convergence of the closed-loop plant’s trajectory is enforced by introducing a user-defined auxiliary reference model, which converges to the trajectory tracking error obtained by applying the classical MRAC laws before its transient dynamics has decayed, and steering the trajectory tracking error to the auxiliary reference model at a rate of convergence that is higher than the rate of convergence of the plant’s reference model. The ability of the proposed MRAC laws to prescribe the performance of the closed-loop system’s trajectory tracking error and control input is guaranteed by barrier Lyapunov functions. Numerical simulations illustrate both the applicability of our theoretical results and their effectiveness compared to other techniques such as prescribed performance control, which allows to constrain both the rate of convergence and the maximum overshoot on the trajectory tracking error of uncertain systems.