Measuring what matters to older persons for active living: part I content development for the OPAL measure across four countries.

AIMS: Many older persons do not think of themselves as "patients" but as persons wishing to live as actively as possible for as long as possible. However, most health-related quality of life (HRQL) measures were developed for use with clinical populations. The aim of this project was to fill that gap and to develop, for international use, a measure of what matters to older persons as they age and seek to remain as active as possible, Older Persons for Active Living (OPAL). METHODS: For content development, interviews about active living were conducted with older persons from Canada, USA, UK, and the Netherlands in English, French, Spanish and Dutch, respectively with subsequent thematic analysis and harmonization. RESULTS: Analyses of transcripts from 148 older persons revealed that active living was a "way of being" and not merely doing activities. Saturation was reached and a total of 59 content areas were identified. After grouping similar "ways" together and after conducting a consensus rating of importance, 19 unique and important "ways" remained. In some languages, formulating was challenging for three of the 19, resulting in changes to two English words and dropping two other words, yielding a final list of 17 "ways of being" with harmonized wording in 4 languages. CONCLUSION: This study underscores the significance of listening to older adults and highlights the importance of considering linguistic and cultural nuances in measure development.

The making of measurement: Editors' introduction.

This special issue consists of selected papers arising from the interdisciplinary conference "The Making of Measurement" held at the University of Cambridge on 23-24 July 2015. In this introduction, we seek ways to further productive interactions among historical, philosophical, and sociological approaches to the study of measurement without attempting to lay out a prescriptive program for a field of "measurement studies." We ask where science studies has led us, and answer: from the function to the making of measurement. We discuss whether there is anything privileged or exemplary about physical measurement, and alight upon models and metrology, two particular focuses of enquiry that emerge from our selection of papers. Those papers with a historical dimension complement an already well-developed body of historiography applied to measurement and metrology.

Calibration: Modelling the measurement process.

Calibration procedures establish a reliable relation between the final states ('indications') of a measurement process and features of the objects being measured ('outcomes'). This article analyzes the inferential structure of calibration procedures. I show that calibration is a modelling activity, namely the activity of constructing, deriving predictions from, and testing theoretical and statistical models of a measurement process. Measurement outcomes are parameter value ranges that maximize the predictive accuracy and mutual coherence of such models, among other desiderata. This model-based view of calibration clarifies the source of objectivity of measurement outcomes, the nature of measurement accuracy, and the close relationship between measurement and prediction. Contrary to commonly held views, I argue that measurement standards are not necessary for calibration, although they are useful in maintaining coherence across large networks of measurement procedures.

Improving the efficiency of an optical parametric oscillator by tailoring the pump pulse shape.

The conversion efficiency of an optical parametric oscillator is reduced by energy consumption during build-up of signal and idler intensities and due to back-conversion effects. By tailoring the pump pulse temporal shape, we are able to improve the conversion efficiency by minimizing build-up time and back-conversion. Simulations predict a significant improvement in 1064 nm to 4000 nm idler conversion by using a double-rectangular temporal shape rather than using a simple Gaussian pulse. Experimental results qualitatively verify the effect resulting in a 20% improvement of a rectangular pulse over a Gaussian pulse.

The 3D structure of the tectorial membrane determined by second-harmonic imaging microscopy.

The tectorial membrane (TM) is a highly hydrated non-cellular matrix situated over the sensory cells of the cochlea. It is widely accepted that the mechanical coupling, between the TM and outer hair cells stereocilia bundles, plays an important role in the cochlea energy transduction mechanism. Recently, we provided supporting evidence for the existence of mechanical coupling by demonstrating that the mechanical properties of the TM change along its longitudinal direction. Since the biochemical composition of the TM is similar throughout its entire length, it is likely that structural differences induce the observed material properties changes. Presently, however, the structure of the TM under physiological environments remains unknown. In this work, the 3D structure of native TM samples is shown by using two-photon second-harmonic imaging microscopy. We find that the collagen fibers at the basal region are arranged in a parallel orientation while being tilted in an angle with respect to the plane of the TM surface at the apical region. Moreover, we find an intensified marginal band at the basal OHC zone which forms a shell-like structure which engulfs the stereocilium imprints surface of the TM. In supports of our previous mechanical characterization, the analysis presented here provides a structural basis for the changes in TM's mechanical properties.

Improved depth resolution in video-rate line-scanning multiphoton microscopy using temporal focusing.

By introducing spatiotemporal pulse shaping techniques to multiphoton microscopy it is possible to obtain video-rate images with depth resolution similar to point-by-point scanning multiphoton microscopy while mechanically scanning in only one dimension. This is achieved by temporal focusing of the illumination pulse: The pulsed excitation field is compressed as it propagates through the sample, reaching its shortest duration (and highest peak intensity) at the focal plane before stretching again beyond it. This method is applied to produce, in a simple and scalable setup, video-rate two-photon excitation fluorescence images of Drosophila egg chambers with nearly 100,000 effective pixels and 1.5 microm depth resolution.

Scanningless depth-resolved microscopy.

The ability to perform optical sectioning is one of the great advantages of laser-scanning microscopy. This introduces, however, a number of difficulties due to the scanning process, such as lower frame rates due to the serial acquisition process. Here we show that by introducing spatiotemporal pulse shaping techniques to multiphoton microscopy it is possible to obtain full-frame depth resolved imaging completely without scanning. Our method relies on temporal focusing of the illumination pulse. The pulsed excitation field is compressed as it propagates through the sample, reaching its shortest duration at the focal plane, before stretching again beyond it. This method is applied to obtain depth-resolved twophoton excitation fluorescence (TPEF) images of drosophila egg-chambers with nearly 105 effective pixels using a standard Ti:Sapphire laser oscillator.

Depth-resolved structural imaging by third-harmonic generation microscopy.

Third harmonic generation microscopy is shown to be a robust method for obtaining structural information on a variety of biological specimens. Its nature allows depth-resolved imaging of inhomogeneities with virtually no background from surrounding homogeneous media. With an appropriate illumination geometry, third harmonic generation microscopy is shown to be particularly suitable for imaging of biogenic crystals, enabling extraction of the crystal orientation.

Depth-resolved multiphoton polarization microscopy by third-harmonic generation.

We achieve depth-resolved polarization microscopy by measuring third-harmonic generation induced by a tightly focused circularly polarized beam. In crystals exhibiting strong birefringence this signal is dominated by positively phase-matched third-harmonic generation. This process occurs in only optically anisotropic media, in which the birefringence compensates for the phase mismatch between the fundamental and the third harmonic induced by dispersion. Both the intensity and the polarization of the emitted signal provide information on the local optical anisotropy. We demonstrate the technique by imaging biogenic crystals in sea urchin larval spicules.