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To stimulate the intellectual curiosity of elementary school students, we conducted a workshop in distance education aimed at exploring the microscopic world inside a cell. In this workshop, elementary school students motivated to learn more on the subject of science analyzed movies of the Brownian motion of micrometer-sized particles suspended in water, using the open-source software Tracker. These students then performed two-dimensional (2D) random walk experiments using a dice game sheet to examine the physical mechanism of Brownian motion. After the workshop, we conducted a questionnaire-based survey. Many participants answered that the contents were difficult but interesting, suggesting that our workshop was very efficient in stimulating the curiosity of motivated students.

The Icosahedral Nonhydrostatic (ICON) general circulation model with upper atmosphere extension (UA-ICON) in the configuration with the physics package for numerical weather prediction (NWP) is presented with optimized parameter settings for the non-orographic and orographic gravity wave drag parameterizations (GWD). In this paper, we present UA-ICON(NWP) (version: ua-icon-2.1) in which we implemented optimized parameter settings for the GWD parameterizations to achieve more realistic MLT temperatures and zonal winds. The parameter optimization is based on perpetual January simulations targeting the thermal and dynamic state of the MLT and the Northern Hemisphere stratosphere. The climatology and variability of the Northern Hemisphere stratospheric winter circulation widely improve when applying UA-ICON with the NWP physics package compared to UA-ICON with ECHAM physics. Likewise improves the thermal and dynamic state of the MLT of the re-tuned UA-ICON(NWP) compared with the UA-ICON(NWP) using default settings. For UA-ICON(NWP), a statistical evaluation reveals a slight improvement in the stratosphere/mesosphere coupling compared to UA-ICON(ECHAM). The cold summer mesopause, the warm winter stratopause, and the related wind reversals are reasonably simulated. The GWD parameter optimization further significantly improves the frequency of major sudden stratospheric warmings (SSWs). However, the seasonal distribution needs improvement and the relative frequency of split vortex SSWs is underestimated compared to reanalyses, as is the zonal wavenumber 2 preconditioning of SSWs. This indicates that zonal wavenumber 2 forcing in UA-ICON(NWP) is underrepresented. The analysis of migrating diurnal and semidiurnal tides in temperature shows a good agreement of UA-ICON(NWP) with SABER-derived tides and the enhancement of the migrating semidiurnal tide during SSWs is well represented in UA-ICON(NWP). [ABSTRACT FROM AUTHOR]

Despite ensuring the integrity of bogie frames for railway vehicles via nondestructive inspections during periodic maintenance, the possibility of fatigue cracks occurring at locations other than the predetermined inspection points cannot be dismissed. Therefore, fatigue cracks can be prevented more efficiently by assessing the overall degree of fatigue damage to the entire bogie frame and determining the results via nondestructive inspections. In this study, dynamic stresses in the bogie frame during running were estimated via finite element dynamic analysis by using the axle box acceleration as input, and the degree of fatigue damage and life were calculated from the waveform of the estimated stresses. Furthermore, we developed a bogie frame fatigue prediction system based on a high‐speed and high‐precision stress calculation method. The developed system visualized the overall relative life. [ABSTRACT FROM AUTHOR]

As one of the most successful techniques in experimental mechanics, digital image correlation (DIC) has been widely used to measure the motion and deformation of solid materials, especially in situations where non-contact measurement is required. This study describes and provides a comprehensive overview of the application of DIC using the open-source platform Ncorr on orthotropic materials. Orthotropic materials are a subset of anisotropic materials; their properties depend on the direction in which they are measured. Deformation displacement and in-plane strain in two directions are extracted from digital image correlation using a reference image recorded during the experiment. Tests are carried out on Laminated Veneer Lumber timber specimens according to the ASTM standard to determine the mechanical properties of materials under compression. DIC has proven to be a reliable, consistent, and cost-effective non-contact deformation measurement method that can assist in the extraction of mechanical properties of orthotropic materials. This study also showed that DIC analysis with a natural timber grain can be used to measure the displacement and strain fields of the material.

Quasi 16‐day waves (Q16DWs) are a prominent and recurrent phenomenon in the middle atmosphere, typically observed over winter mid and high latitudes. This study investigates the intense Q16DW event during the 2018–2019 Northern Hemisphere (NH) winter, and explores its propagation in the middle atmosphere and its notable influence on the E‐region ionosphere. Long‐term geopotential height estimates of Aura Microwave Limb Sounder (MLS) reveal that the wave activity under consideration exhibited the largest amplitudes in the mesosphere for past 16 years. An analysis of wind data obtained from medium frequency (MF) and meteor radars, as well as from Modern‐Era Retrospective analysis for Research and Applications, Version 2 (MERRA‐2) reanalysis, reveals the presence of a westward‐propagating Q16DW with zonal wavenumber 1 exhibiting notable asymmetry about the equator, with the majority of the wave activity being confined to the NH. The prominently large amplitudes and vertical wavelengths of the wave suggest potential for the wave propagation to extend deep into the E‐region ionosphere. Swarm satellite observations reveal concurrent ∼16‐day oscillations in the eastward component of the geomagnetic field at low latitudes. These oscillations can be attributed to the periodic variations in interhemispheric field‐aligned currents (IHFACs). The ∼16‐day oscillations in the IHFACs are likely a consequence of asymmetric wind‐dynamo action, which is directly or indirectly associated with the Q16DW. These findings suggest that planetary waves originating in the middle atmosphere can cause interhemispheric coupling in the ionosphere. Plain Language Summary: This study examines the strong quasi‐16‐day wave activity that occurred during the winter of 2018–2019 over mid‐to‐high latitudes. A data set consisting of medium frequency (MF) and meteor radar winds, reanalysis data, Aura Microwave Limb Sounder (MLS) and Swarm geomagnetic field measurements is utilized to characterize the wave. The simultaneous occurrence of wave signatures in the middle atmosphere and the ionosphere suggests some atmosphere‐ionosphere coupling. The wave signatures observed in the eastward component of the geomagnetic field are attributed to interhemispheric field‐aligned currents. Key Points: Strong quasi‐16‐day wave signatures in middle atmospheric temperatures and winds during the northern hemispheric winter of 2018–2019Simultaneous occurrence of the wave in the eastward component of the geomagnetic fieldPlanetary wave oscillations of ∼16‐day period observed in the interhemispheric field aligned currents [ABSTRACT FROM AUTHOR]

Plants have unique responses to fluctuating light conditions. One such response involves chloroplast photorelocation movement, which optimizes photosynthesis under weak light by the accumulation of chloroplasts along the periclinal side of the cell, which prevents photodamage under strong light by avoiding chloroplast positioning toward the anticlinal side of the cell. This light-responsive chloroplast movement relies on the reorganization of chloroplast actin (cp-actin) filaments. Previous studies have suggested that CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1) is essential for chloroplast photorelocation movement as a regulator of cp-actin filaments. In this study, we conducted comprehensive analyses to understand CHUP1 function. Functional, fluorescently tagged CHUP1 colocalized with and was coordinately reorganized with cp-actin filaments on the chloroplast outer envelope during chloroplast movement in Arabidopsis thaliana. CHUP1 distribution was reversibly regulated in a blue light- and phototropin-dependent manner. X-ray crystallography revealed that the CHUP1-C-terminal domain shares structural homology with the formin homology 2 (FH2) domain, despite lacking sequence similarity. Furthermore, the CHUP1-C-terminal domain promoted actin polymerization in the presence of profilin in vitro. Taken together, our findings indicate that CHUP1 is a plant-specific actin polymerization factor that has convergently evolved to assemble cp-actin filaments and enables chloroplast photorelocation movement. CHLOROPLAST UNUSUAL POSITIONING 1 is an actin polymerization factor that is unique to plants and essential for chloroplast movement in response to high-light stress. [ABSTRACT FROM AUTHOR]

This paper describes a simple method for characterizing global-scale waves in the mesosphere and lower thermosphere (MLT), such as tides and traveling planetary waves, using uniformly gridded two-dimensional longitude–time data. The technique involves two steps. In the first step, the Fourier transform is performed in space (longitude), and then the time series of the space Fourier coefficients are derived. In the second step, the wavelet transform is performed on these time series, and wavelet coefficients are derived. A Fourier–wavelet spectrum can be obtained from these wavelet coefficients, which gives the amplitude and phase of the wave as a function of time and wave period. It can be used to identify wave activity that is localized in time, similar to a wavelet spectrum, but the Fourier–wavelet spectrum can be obtained separately for eastward- and westward-propagating components and for different zonal wavenumbers. The Fourier–wavelet analysis can be easily implemented using existing Fourier and wavelet software. MATLAB and Python scripts are created and made available at https://igit.iap-kborn.de/yamazaki/fourierwavelet (last access: 18 August 2023) that compute Fourier–wavelet spectra using the wavelet software provided by. Some application examples are presented using MLT data from atmospheric models. [ABSTRACT FROM AUTHOR]

The combined Fourier-wavelet (CFW) transform is a useful technique to characterize planetary-scale waves, such as tides and traveling planetary waves in the Earth's atmosphere. A CFW spectrum, presented in a time versus period diagram, can be used to identify wave activity that is localized in time, similar to a wavelet spectrum. A CFW spectrum can be obtained for each of eastward- and westward-propagating wave components with different zonal wavenumbers. This paper introduces an easy-to-implement method to derive CFW spectra in two steps. In the first step, the Fourier transform is performed in space (longitude), and time series of the space Fourier coefficients are derived. In the second step, the wavelet transform is performed on these time series, and wavelet coefficients are derived. It is shown that the CFW transform can be easily derived from these wavelet coefficients. The results suggest that existing Fourier and wavelet software can be utilized to derive CFW spectra. Matlab and Python scripts are created and made available at https://igit.iap-kborn.de/yy01/cfw that compute CFW spectra using the wavelet software provided by Torrence and Compo (1998). Some application examples are presented using longitude-time data from atmospheric and geomagnetic-field models. [ABSTRACT FROM AUTHOR]