Adults' past-day recall of sedentary time: reliability, validity and responsiveness

Purpose: Past-day recall rather than recall of past week or a usual/typical day may improve the validity of self-reported sedentary time measures. This study examined the test-retest reliability, criterion validity, and responsiveness of the seven-item questionnaire, Past-day Adults' Sedentary Time (PAST). Methods: Participants (breast cancer survivors, n = 90, age = 33-75 yr, body mass index = 25-40 kg.m(-2)) in a 6-month randomized controlled trial of a lifestyle-based weight loss intervention completed the interviewer-administered PAST questionnaire about time spent sitting/lying on the previous day for work, transport, television viewing, nonwork computer use, reading, hobbies, and other purposes (summed for total sedentary time). The instrument was administered at baseline, 7 d later for test-retest reliability (n = 86), and at follow-up. ActivPAL3-assessed sit/lie time in bouts of >= 5 min during waking hours on the recall day was used as the validity criterion measure at both baseline (n = 72) and follow-up (n = 68). Analyses included intraclass correlation coefficients, Pearson's correlations (r), and Bland-Altman plots and responsiveness index. Results: The PAST had fair to good test-retest reliability (intraclass correlation coefficient = 0.50, 95% confidence interval [CI] = 0.32-0.64). At baseline, the correlation between PAST and activPAL sit/lie time was r = 0.57 (95% CI = 0.39-0.71). The mean difference between PAST at baseline and retest was -25 min (5.2%), 95% limits of agreement = -5.9 to 5.0 h, and the activPAL sit/lie time was -9 min (1.8%), 95% limits of agreement = -4.9 to 4.6 h. The PAST showed small but significant responsiveness (-0.44, 95% CI = -0.92 to -0.04); responsiveness of activPAL sit/lie time was not significant. Conclusion: The PAST questionnaire provided an easy-to-administer measure of sedentary time in this sample. Validity and reliability findings compare favorably with other sedentary time questionnaires. Past-day recall of sedentary time shows promise for use in future health behavior, epidemiological, and population surveillance studies

Measuring older adults' sedentary time: Reliability, validity, and responsiveness

GARDINER, P. A., B. K. CLARK, G. N. HEALY, E. G. EAKIN, E. A. H. WINKLER, and N. OWEN. Measuring Older Adults' Sedentary Time: Reliability, Validity, and Responsiveness. Med. Sci. Sports Exerc., Vol. 43, No. 11, pp. 2127-2133, 2011. Purpose: With evidence that prolonged sitting has deleterious health consequences, decreasing sedentary time is a potentially important preventive health target. High-quality measures, particularly for use with older adults, who are the most sedentary population group, are needed to evaluate the effect of sedentary behavior interventions. We examined the reliability, validity, and responsiveness to change of a self-report sedentary behavior questionnaire that assessed time spent in behaviors common among older adults: watching television, computer use, reading, socializing, transport and hobbies, and a summary measure (total sedentary time). Methods: In the context of a sedentary behavior intervention, nonworking older adults (n = 48, age = 73 +/- 8 yr (mean +/- SD)) completed the questionnaire on three occasions during a 2-wk period (7 d between administrations) and wore an accelerometer (ActiGraph model GT1M) for two periods of 6 d. Test-retest reliability (for the individual items and the summary measure) and validity (self-reported total sedentary time compared with accelerometer-derived sedentary time) were assessed during the 1-wk preintervention period, using Spearman (rho) correlations and 95% confidence intervals (CI). Responsiveness to change after the intervention was assessed using the responsiveness statistic (RS). Results: Test-retest reliability was excellent for television viewing time (rho (95% CI) = 0.78 (0.63-0.89)), computer use (rho (95% CI) = 0.90 (0.83-0.94)), and reading (rho (95% CI) = 0.77 (0.62-0.86)); acceptable for hobbies (rho (95% CI) = 0.61 (0.39-0.76)); and poor for socializing and transport (rho < 0.45). Total sedentary time had acceptable test-retest reliability (rho (95% CI) = 0.52 (0.27-0.70)) and validity (rho (95% CI) = 0.30 (0.02-0.54)). Self-report total sedentary time was similarly responsive to change (RS = 0.47) as accelerometer-derived sedentary time (RS = 0.39). Conclusions: The summary measure of total sedentary time has good repeatability and modest validity and is sufficiently responsive to change suggesting that it is suitable for use in interventions with older adults

Sensitivity to change of the Neck Pain and Disability Scale

The Neck Pain and Disability Scale (NPAD) is a 20-item instrument to measure neck pain and related disability. The aim of this study was to assess sensitivity to change of the NPAD. A total of 411 participants from 15 general practices in the middle of Germany completed a multidimensional questionnaire including the German version of the NPAD and self-reported demographic and clinical information. Sensitivity to change was analysed by linear regression analysis of the NPAD at follow-up and educational level, age class, depression, anxiety, and deficits in social support, respectively, and by Pearson’s correlation analyses between mean change in NPAD at follow-up and mean change in prognostic markers. Those having more than basic education (regression coefficient −7.2, p < 0.001) and/or being in a younger age class (−2.9, p = 0.020) consistently reported significantly lower average NPAD scores at follow-up compared to those with basic education and/or a older age class. In contrast, those who were classified to be depressed (regression coefficient 2.1, p < 0.001), anxious (1.9, p < 0.001), or having deficits in social support (5.5, p = 0.004) reported significantly higher NPAD scores. Change in depression, anxiety, and social support scale between baseline and follow-up was significantly correlated with change in the NPAD score. Hence, these data are in the direction anticipated across all baseline factors investigated. In conclusion, the NPAD seems to be a sensitive measure for use in clinical practice and future studies of neck pain and related disability

Formulation Pre-screening of Inhalation Powders Using Computational Atom–Atom Systematic Search Method

The synthonic modeling approach provides a molecule-centered understanding of the surface properties of crystals. It has been applied extensively to understand crystallization processes. This study aimed to investigate the functional relevance of synthonic modeling to the formulation of inhalation powders by assessing cohesivity of three active pharmaceutical ingredients (APIs, fluticasone propionate (FP), budesonide (Bud), and salbutamol base (SB)) and the commonly used excipient, α-lactose monohydrate (LMH). It is found that FP (−11.5 kcal/mol) has a higher cohesive strength than Bud (−9.9 kcal/mol) or SB (−7.8 kcal/mol). The prediction correlated directly to cohesive strength measurements using laser diffraction, where the airflow pressure required for complete dispersion (CPP) was 3.5, 2.0, and 1.0 bar for FP, Bud, and SB, respectively. The highest cohesive strength was predicted for LMH (−15.9 kcal/mol), which did not correlate with the CPP value of 2.0 bar (i.e., ranking lower than FP). High FP–LMH adhesive forces (−11.7 kcal/mol) were predicted. However, aerosolization studies revealed that the FP–LMH blends consisted of agglomerated FP particles with a large median diameter (∼4–5 μm) that were not disrupted by LMH. Modeling of the crystal and surface chemistry of LMH identified high electrostatic and H-bond components of its cohesive energy due to the presence of water and hydroxyl groups in lactose, unlike the APIs. A direct comparison of the predicted and measured cohesive balance of LMH with APIs will require a more in-depth understanding of highly hydrogen-bonded systems with respect to the synthonic engineering modeling tool, as well as the influence of agglomerate structure on surface–surface contact geometry. Overall, this research has demonstrated the possible application and relevance of synthonic engineering tools for rapid pre-screening in drug formulation and design

Study of the main geochemical characteristics of Phobos' regolith using laser time-of-flight mass spectrometry

The peculiarities of the airborne LAZMA instrument applied for the measurement of the isotopic and elemental composition of Phobos’ regolith by the method of laser time-of-flight mass spectrometry are discussed. These measurements may confirm the assumptions that the material of Phobos is an initial substance with a composition close to carbonaceous chondrites, from which the Earth was formed. The results of the measurements may also confirm the original mechanism of the formation of the anomalous absorption of Phobos’ regolith suggested in this study. The obtained results regarding the elemental composition of the regolith may contain information about the conditions of the formation of Phobos, as well as provide information about it age. The scientific tasks of individual experiments and ways for their realization are considered in the paper. A detailed description of the airborne instrument and the principle of its operation is presented. The analytical and technical characteristics of the instrument and the peculiarities of constructive decisions are given. Data on the most important functional assemblies of the instrument, the development and transmission of scientific information to the Earth, are considered. The mass spectra presented in the paper were obtained by airborne instruments during the course of their laboratory test and the selection of the operating regime. It is demonstrated that the LAZMA instrument is the first version of the original next-generation airborne instrument constructed at the Space Research Institute and patented in Russia

Fast synthesis of n-type half-heusler TiNiSn thermoelectric material

The n-type half-Heusler TiNiSn is very promising for thermoelectric applications in the medium temperature range. However, the synthesis of TiNiSn often involves long annealing times (up to several weeks) to obtain a single phase, which is a major barrier to scaling-up. In this work, TiNiSn was synthesized by a combination of arc-melting, ball-milling and spark plasma sintering. The obtained samples with diameters up to 30 mm had high-purity, high-density and fine-grains. Without the need for an annealing step, the total synthesis time was significantly shortened. Addition of Cu was used to optimize the thermoelectric properties of TiNiSn, and a maximum figure of merit of 0.6 was achieved at 773 K. The fast and scalable synthesis of TiNiSn with good thermoelectric performance presented in this work opens up the possibility of industrial scaling-up