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This study assesses three factors that influence the quantification of children's and adolescents' physical activity (PA) using accelerometers: selection of (1) non-wear algorithm, (2) epoch length and (3) cut-points. A total of 1525 participants from MoMo wave 3 (2018–2022), aged 6–17 years, wore GT3X accelerometers (ActiGraph, LLC, Pensacola, FL, USA) during waking hours. Acceleration counts were reintegrated into lengths of 1, 5, 15, 30, and 60 s epochs. Two non-wear time algorithms and two sets of cut-points were applied to each epoch length. Differences were found in both the comparison of the non-wear time algorithms and the comparison of the cut-points when the different epoch lengths were considered. This may result in large differences in estimated sedentary behavior and PA values. We propose to pool the data by merging and combining multiple accelerometer datasets from different studies and evaluate them in a harmonized way in the future. In addition to the need for future validation studies using short epoch lengths for young children, we also propose to conduct meta-analyses. This allows the use of data from multiple studies to validate cut-points and to propose a consensual set of cut-points that can be used in different settings and projects. The high discrepancy between results when comparing different epoch lengths has to be considered when interpreting accelerometer data and is regarded a confounding variable when comparing levels of PA between studies. [ABSTRACT FROM AUTHOR]

Gobi sand is a commonly used soil material in China that can be classified as silty sand with a fines content of 30.1%. A series of laboratory tests were conducted on Gobi sand and many unique physical behaviors were found, such as a low permeability coefficient, sticky behavior after moisturization, and being located in the CL (low liquid limit clay) classification group. In addition, the critical state lines (CSL) of the Gobi silty sand in the e-lnp space decrease in parallel with decreasing initial void ratio e0, and the critical state stress ratio Mcs is not a constant but decreases with increasing confining pressure σ3 and initial void ratio e0. This is quite different from the unique CSL and Mcs observed from quartz clean sand and silty sand. Therefore, unified CSL and Mcs equations for the Gobi sand were proposed to express the unique critical state behavior affected by various pressure conditions and initial void ratios. It is believed that the composite mineral composition (containing 5 minerals) of Gobi silty sand plays a significant role in the reaction of these unique physical behaviors as well as the critical state behaviors. [ABSTRACT FROM AUTHOR]

Purpose: Increasing physical activity level is a generally effective intervention goal for patients who suffer from chronic cancer-related fatigue (CCRF). However, patients are unlikely to benefit equally from these interventions, as their behavioral starting points might vary substantially. Therefore, we explored patterns of physical behavior of participants who suffer from CCRF.Methods: Baseline data of a randomized controlled trial were used for a latent profile analysis on nine accelerometer-derived physical behavior measures, describing levels and patterns of physical activity, moderate-to-vigorous intensity physical activity (MVPA), and sedentary behavior. The relation between participant characteristics and the latent profiles was analyzed.Results: Accelerometer data of 172 participants from the Netherlands was analyzed. Three latent profiles were distinguished that differed most on physical activity level and total time spent in MVPA. Eighty-eight percent of all participants were assigned to a profile with a probability higher than 8. Age and perceiving limitations by comorbid conditions and pain were significant covariates of profile membership.Conclusions: We distinguished three physical behavior profiles. The differences between the patterns indicate that the heterogeneity of this sample requires patients to have substantially different treatment goals. Further research should test the applicability of these profiles in clinical practice. [ABSTRACT FROM AUTHOR]

Many engineering activities are confronted with the relation between shape and behavior. Modern ‘state-of-the-art’ CAD systems can support a dynamic design process with flexible and umambiguous geometric modeling of artifacts. The Finite Element (FE) method is a general method to model and simulate physical behavior. CAD and FE integration enables numerical prediction of the physical behavior of artifacts. To deal with the complexity of modern products and the dynamic character of the design process, the integration must be addressed from both a systems and a process point of view. The models must thus be flexible, scalable, and reusable. A modularized modeling approach based on four stages is proposed, and exemplified with behavior modeling of a turn-key grinding machine. [ABSTRACT FROM AUTHOR]