Bidirectional microwave and optical signal dissemination

Abstract not availablePhilip S. Light, Ashby P. Hilton, Richard T. White, Christopher Perrella, James D. Anstie, John G. Hartnett, Giorgio Santarelli and Andre N. Luite

Moderate drinking before the unit: medicine and life assurance in Britain and the US c.1860–1930

This article describes the way in which “Anstie’s Limit” – a particular definition of moderate drinking first defined in Britain in the 1860s by the physician Francis Edmund Anstie (1833–1874) – became established as a useful measure of moderate alcohol consumption. Becoming fairly well-established in mainstream Anglophone medicine by 1900, it was also communicated to the public in Britain, North America and New Zealand through newspaper reports. However, the limit also travelled to less familiar places, including life assurance offices, where a number of different strategies for separating moderate from excessive drinkers emerged from the dialogue between medicine and life assurance. Whilst these ideas of moderation seem to have disappeared into the background for much of the twentieth century, re-emerging as the “J-shaped” curve, these early developments anticipate many of the questions surrounding uses of the “unit” to quantify moderate alcohol consumption in Britain today. The article will therefore conclude by exploring some of the lessons of this story for contemporary discussions of moderation, suggesting that we should pay more attention to whether these metrics work, where they work and why

Accurate optical number density measurement of 12CO2 and 13CO2 with direct frequency comb spectroscopy

We report on the use of direct frequency comb spectroscopy to accurately measure the concentrations of ¹²C¹⁶O₂ and ¹³C¹⁶O₂ isotopologs in a gas sample. We demonstrate an accuracy of 0.5% and 12% for concentration measurements of ¹²C¹⁶O₂ and ¹³C¹⁶O₂, respectively, with the measured isotopic ratio in excellent agreement with that expected from their natural abundances. The precision of the concentration measurements is also high, at 0.03% and 1.24% for ¹²C¹⁶O₂ and ¹³C¹⁶O₂, respectively. The measurement technique is verified to be highly linear for concentrations ranging over 3 orders of magnitude. Direct frequency comb spectroscopy can be applied to numerous molecular species, and is therefore a promising technique for measurements in environmental monitoring and biomedical sciences.Sarah K. Scholten, Christopher Perrella, James D. Anstie, Richard T. White, and Andre N. Luite

A quantitative mode-resolved frequency comb spectrometer

Abstract not availableNicolas Bourbeau H'ebert, Sarah K. Scholten, Richard T. White, Jérôme Genest, Andre N. Luiten, and James D. Ansti

Number-density measurements of CO(2) in real time with an optical frequency comb for high accuracy and precision

Published 29 May 2018Real-time and accurate measurements of gas properties are highly desirable for numerous real-world applications. Here, we use an optical-frequency comb to demonstrate absolute number-density and temperature measurements of a sample gas with state-of-the-art precision and accuracy. The technique is demonstrated by measuring the number density of ¹²C¹⁶O₂ with an accuracy of better than 1% and a precision of 0.04% in a measurement and analysis cycle of less than 1 s. This technique is transferable to numerous molecular species, thus offering an avenue for near-universal gas concentration measurements.Sarah K. Scholten, Christopher Perrella, James D. Anstie, Richard T. White, Waddah Al-Ashwal, Nicolas Bourbeau Hébert, Jérôme Genest, and Andre N. Luite

Handheld probe for quantitative micro-elastography

16 pags., 7 figs., 1 tab.Optical coherence elastography (OCE) has been proposed for a range of clinical applications. However, the majority of these studies have been performed using bulky, lab-based imaging systems. A compact, handheld imaging probe would accelerate clinical translation, however, to date, this had been inhibited by the slow scan rates of compact devices and the motion artifact induced by the user’s hand. In this paper, we present a proof-of-concept, handheld quantitative micro-elastography (QME) probe capable of scanning a 6 × 6 × 1 mm volume of tissue in 3.4 seconds. This handheld probe is enabled by a novel QME acquisition protocol that incorporates a custom bidirectional scan pattern driving a microelectromechanical system (MEMS) scanner, synchronized with the sample deformation induced by an annular PZT actuator. The custom scan pattern reduces the total acquisition time and the time difference between B-scans used to generate displacement maps, minimizing the impact of motion artifact. We test the feasibility of the handheld QME probe on a tissue-mimicking silicone phantom, demonstrating comparable image quality to a bench-mounted setup. In addition, we present the first handheld QME scans performed on human breast tissue specimens. For each specimen, quantitative micro-elastograms are co-registered with, and validated by, histology, demonstrating the ability to distinguish stiff cancerous tissue from surrounding soft benign tissue.Australian Research Council (ARC); Department of Health, Western Australia; Cancer Council, Western Australia; OncoRes Medical