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The form-factor for the stem surface area is directly proportional to the square root of the form-factor for the stem volume, i.e., the square root law of the form-factor. Although the square root law addresses the stems of coniferous trees, the nature of the proportional coefficient of the law has not been discussed. In this study, we demonstrated that the coefficient indicates the stem taper; therefore, it is named “Taper Index based on Form-Factor (TIFF).” We also examined the relationship between the form-factor for the culm surface area and the form-factor for the apparent culm volume of 570 culms across three bamboo species (Phyllostachys pubescensMazel ex Houz.,P.bambusoidesSieb. et Zucc., andP.nigravar.henonis). The square root law held true for all three bamboo species. The species-specific TIFF was determined to be 0.873 forP. pubescens, 0.897 forP. bambusoides, and 0.901 forP. nigra. This result implied thatP. pubescenshad a more tapering culm form compared to the other two species, while culm taper was similar betweenP. bambusoidesandP. nigra. Our findings align with empirical observations of the culm taper of the bamboo species. Intra-species variation in TIFF was considerably small, allowing us to evaluate the species-specific culm taper from a small number of samples. Therefore, we conclude that TIFF provides a simple and useful method for quantifying species-specific culm or stem taper, and facilitates the estimation of merchantable or total volume.

Stem surface area (S) plays an important role in the eco-physiological processes of trees or forests such as stem respiration, self-thinning mortality, and rainfall interception. As the direct meas...

A well‐ordered polygonal crack pattern is frequently observed on the outcrop surface of columnar joints. The crack pattern's geometry and topology result from the volume contraction of solidified lava during thermal dissipation. In this study, we conducted field measurements of columnar joints at four different sites with various lithologies in Japan to understand the influence of geography and lithological character on their geometric characteristics. Drone‐aided photography and computer‐based image analysis enabled us to examine the constituent polygons' geometric attributes and their statistics with high accuracy. This methodology revealed a relationship between the geometry and topology of the polygonal crack patterns. Moreover, we established a positive correlation between the polygon area and the number of vertices of a polygon at each study site, irrespective of lithology, or geographic position. These results are consistent with previous investigational studies, in particular starch‐based analog experiments.

The cosmological lithium problem (CLP) stems from the outstanding discrepancy between theoretical predictions and astronomical observations of primordial lithium abundances. For the radiogenic production of 7Li, 7Be plays a pivotal role in the Big Bang nucleosynthesis (BBN). Nevertheless, the data for neutron-induced 7Be destruction processes were still sparse, and especially lacked information on the contributions of transitions to the 7Li excited states. In this work, we have determined the 7BeLi, 7BeLi*, and 7BeHe reaction cross sections by means of the Trojan Horse method. The present and the previous data were analyzed together by a multichannel R-matrix fit, providing an improved uncertainty evaluation of the channel and the first-ever quantification of the contribution in the BBN-relevant energy range. We implemented the revised total reaction rate summing both the and contributions in a state-of-the-art BBN code PRIMAT. As a consequence, the present nuclear-physics data offers a reduction of the predicted 7Li abundance by about one-tenth, which would impose a stricter constraint on BBN and head us in the correct direction to the CLP solution.

We study the $3~\mu$m scattering feature of water ice detected in the outer disk of HD 142527 by performing radiative transfer simulations. We show that an ice mass abundance at the outer disk surface of HD 142527 is much lower than estimated in a previous study. It is even lower than inferred from far-infrared ice observations, implying ice disruption at the disk surface. Next, we demonstrate that a polarization fraction of disk-scattered light varies across the ice-band wavelengths depending on ice grain properties; hence, polarimetric spectra would be another tool for characterizing water-ice properties. Finally, we argue that the observed reddish disk-scattered light is due to grains with a few microns in size. To explain the presence of such grains at the disk surface, we need a mechanism that can efficiently oppose dust settling. If we assume turbulent mixing, our estimate requires $\alpha\gtrsim2\times10^{-3}$, where $\alpha$ is a non-dimensional parameter describing the vertical diffusion coefficient of grains. Future observations probing gas kinematics would be helpful to elucidate vertical grain dynamics in the outer disk of HD 142527., Comment: 21 pages, 14 figures, 1 table; Accepted for publication in ApJ

Hollow-section columns are one of the mechanically superior structures with high buckling resistance and high bending stiffness. The mechanical properties of the column are strongly influenced by the cross-sectional shape. Therefore, when evaluating the stability of a column against external forces, it is necessary to accurately reproduce the cross-sectional shape. In this study, we propose a mathematical method to describe a polygonal section with rounded edges and vertices. This mathematical model would be quite useful for analyzing the mechanical properties of plants and designing plant-mimicking functional structures, since the cross-sections of the actual plant culms and stems often show rounded polygons., 9 pages, 8 figures

Bamboo forests are likely to be subjected to self-thinning due to their rapid growth rate. In fully stocked bamboo forests, the stand density (ρ) was suggested to be inversely proportional to the square of mean diameter at breast height (D) (ρ ∝ D−2), differing from the conventional power-law for trees, i.e., Reineke equation (ρ ∝ D−1.6). Nevertheless, the validity and mechanism of the inverse-square law remained unclear, despite its significance for managing bamboo forests. In this study, we derived an allometric model that predicts the slope of the maximum size-density relationship (MSDR) between D and ρ on double logarithmic coordinates based on well-known ecological laws. The model indicates that the slope of −2 for bamboo is theoretically valid, with the difference in the slope between bamboo and trees being caused by their differences in inner-culm (or inner-stem) structure. We also determined the MSDR empirically by compiling data of 415 Phyllostachys pubescens Mazel ex Houz. pure stands across Japan. The obtained MSDR describes the upper boundary of the D-ρ relationship well, with a slope of −1.996 that is very close to − 2. We further established a stand density management diagram of P. pubescens stands based on the MSDR. This diagram allows forest managers to regulate ρ depending on D as well as management purposes (production of bamboo shoot, bamboo charcoal and culm wood).

The hollow cylindrical culm is one of the most remarkable morphological characters of most bamboo species. In relation to its hollow structure, there are two different attributes of the culm volume in bamboo: the apparent culm volume (va: the total culm volume including the hollow portion) and the woody culm volume (vw: the volume of the woody walls of the culm). The ratio of vw to va is defined as the reduction factor for culm volume (fv). The quantity fv is useful to quantify the biomass resources of bamboo culms as well as to evaluate the carbon stock of bamboo forests. However, the direct measurement of fv requires destructive sampling, which consumes time and labor. Hence, an alternative method for obtaining fv is desired. In this study, we examined fv in five species of the genus Phyllostachys and proposed alternative methods to estimate fv. Our data showed that fv varied by species, some of which exhibited a dependency of fv on culm sizes. These findings indicate that the intraspecific and interspecific variation in fv should be considered carefully when converting va into vw by fv. Based on our results, we propose here six approaches for predicting fv and we discuss their advantages and disadvantages. Our results are intended to facilitate evaluation of the carbon sequestration capacity of bamboo forests and the commercial utilization of bamboo culms.

Fibrodysplasia ossificans progressiva (FOP) is an extremely rare genetic condition characterized by congenital malformation and progressive heterotopic ossification (HO) caused by a recurrent single nucleotide substitution at position 617 in the ACVR1 gene. As the condition progresses, HO leads to joint ankylosis, breathing difficulties, and mouth-opening restriction, and it can shorten the patient's lifespan. This report describes 3 cases of FOP confirmed by genetic testing in patients with restricted mouth opening. Each patient presented a different onset and degree of jaw movement restriction. The anatomic ossification site of the mandibular joint was examined in each patient using reconstructed computed tomographic (CT) images and 3-dimensional reconstructed CT (3D-CT) images. A 29-year-old woman complained of jaw movement restriction since 13 years of age. 3D-CT image of the mandibular joint showed an osseous bridge, formed by the mandibular depressors that open the mouth, between the hyoid bone and the mentum of the mandible. A 39-year-old man presented with jaw movement restriction that developed at 3 years of age after a mouth injury. 3D-CT image of the jaw showed ankylosis of the jaw from ossification of the mandibular depressors that was worse than in patient 1. CT images showed no HO findings of the masticatory muscles. To the authors' knowledge, these are the first 2 case descriptions of the anatomic site of ankylosis involving HO of the mandibular depressors in the jaw resulting from FOP. In contrast, a 62-year-old bedridden woman with an interincisal distance longer than 10 mm (onset, 39 years of age) had no HO of the mandibular depressors and slight HO of the medial pterygoid muscle on the right and left sides. These findings suggest that restricted mouth opening varies according to the presence or absence of HO of the mandibular depressors.

In the large caldera of Mt. Aso, Japan, artificial grasslands were converted into forests of different species due to the decline of the livestock industry in this region. These changes in species composition are thought to have changed not only the transpiration rates (E), but also the responses in E to variations in environmental conditions. For three introduced forest types, we monitored E using sap flux sensors and computed E with a multilayer model parameterized by independently obtained leaf-scale ecophysiological traits. Modeled E replicated the time series of measured E reasonably well, but did not reproduce a decrease in E lasting 20 days after a short rainless period in conifer plantation. Mean leaf-scale stomatal conductance of two deciduous broadleaved tree species was as low as that of trees under dry conditions in other studies, possibly an adaptation for the avoidance of excessive E during rainless periods. These results suggest that land use change influenced E and its response to the rainfall patterns of the region and that drought plays an important role in influencing species-specific E characteristics in this rainy region. The multilayer model in combination with sap flux measurements was found to be a useful tool not only for the extrapolation of E, but also for the detection of the unexpected events, as long as the measured parameter values capture the species-specific seasonality in leaf ecophysiological traits.

Node distribution along the mature culm of three Phyllostachys species is governed by a hidden universal law and can be determined at the bamboo shoot stage by its base diameter. Bamboo exhibits unique structural properties that distinguish it from most other woody plants. One of the most remarkable properties is that the long hollow culm is separated into many small chambers by a sequence of nodes. The node distribution along the culm is, in general, sparse at the mid-culm and dense near the ends of the culm. In this study, we examined the intraspecific and interspecific variation in the node distribution of three species of the genus Phyllostachys (Phyllostachys pubescens Mazel ex Houz., Phyllostachys nigra var. henonis and Phyllostachys nigra Munro) with different culm sizes. The node distribution followed a single fitting curve via the normalization procedure, indicating the existence of a hidden universal law that governs the node distribution of the three species, despite their different appearances. Our findings also suggest that the node distribution along the mature culm could be determined at the stage of bamboo shoot by its base diameter.

We compared several methods for quantifying the culm surface area (S) of one of the most common bamboos in Japan, Phyllostachys pubescens Mazel ex Houz. Nine sample culms of P. pubescens were felled, and the true S was determined by the fine resolution analysis of the culm form (S FRA). The S was then calculated independently with the sectional measurement method from the successive diameters measured at equal intervals of one-twentieth (S 20), one-tenth (S 10), one-fifth (S 5) and one-half (S 2) of the total culm length. The S was also quantified geometrically from the total culm length and the diameter at breast height or at base by assuming that the culm form could be approximated by a cone (S DBH and S DAB). The S FRA was compared with each of the computed S values. For S 10, S 5 and S 2, both the mean relative bias (%BIAS) and relative root mean square error (%RMSE) decreased with an increase in the number of measured diameters. The %BIAS and %RMSE of the S 10 were, respectively, comparable and smaller compared to those of S 20. The bias of the S DBH and S DAB suggested that the cone assumption of the culm form was violated. In conclusion, we recommend that the S should be quantified from the successive diameters measured at equal intervals of one-tenth of the total culm length using the sectional measurement method.

To establish evidence-based therapy for motor rehabilitation of the upper limbs, we developed a desktop simple exercise machine for upper limbs (D-SEMUL) as a low-cost and high-quality rehabilitation robot. However, the psychological effects of the visual feedback (VF) after the training have not yet been assessed. We investigated the relationship between brain activations and VFs after training in this study. For this purpose, we developed a maze program for the D-SEMUL. Here, the function of the target score (visualized target) was measured as a motivating intervention. We recruited 10 subjects each for a control and an experimental group. Electroencephalogram (EEG) readings from the participants, while they were exposed to the VF after the training, were measured and analyzed to check for the presence of significant differences between two different VFs. Although the results demonstrated no significant differences in the scores among the two groups, the frontal regions of the brain demonstrated a significantly greater degree of activation for VF with target value than without it.

We quantified the differences in growth responses between Cryptomeria japonica and Chamaecyparis obtusa trees in approximately 0.1-ha group selection openings in southern Japan. We measured the position, height (H), and diameter at ground level (D) of 6- and 13-year-old C. japonica and C. obtusa trees that were planted in two respective openings. The annual H and D growth of C. japonica increased until trees were 10 and 8 m, respectively, distant from the nearest edge of the opening. For C. obtusa, the annual H and D growth increased slightly until the trees were 6 m distant from the nearest edge, but they did not significantly differ between 6 and 18 m distant from the nearest edge. While the shortest distance from the edge explained 63% and 50% of the variationsal H and D growth, respectively, of C. obtusa. Our result demonstrates that C. obtusa is less sensitive to edge effects than C. japonica. We conclude that C. obtusa is likely to be more suitable than C. japonica for planting within 0.1-ha...

We observed the rainfall interception (Ic) in an intensively managed low density Phyllostachys pubescens Mazel ex Houz. stand. The stand had been managed to maintain 2,000 culms ha–1 by felling old culms and harvesting bamboo shoots. Gross rainfall (Rf), throughfall (Tf) and culm flow (Cf) were monitored over a 10-month period, and Ic was quantified by a water balance method. Rf, Tf and Cf during the experimental period were 2,100, 1,786 and 102 mm, respectively, which resulted in an Ic of 212 mm. The proportions of Tf, Cf and Ic to Rf (i.e. Tf/Rf, Cf/Rf and Ic/Rf, respectively) were 85%, 5% and 10%, respectively. The observed interception ratio, Ic/Rf, in our site was comparable to those reported in other unmanaged P. pubescens stands with higher densities (around 4,000–7,000 culms ha–1). Ic/Rf in both managed and unmanaged P. pubescens stands was generally lower than that in other coniferous and broad-leaved stands in Japan. These findings substantially extend the application range of previous results for Ic/Rf in unmanaged P. pubescens stands. The rainfall partitioning (i.e. Tf/Rf and Cf/Rf) in P. pubescens stands was influenced not only by stand density and culm size but also by the age distribution of culms. Our results stress the importance of considering the culm age distribution when quantifying Ic in P. pubescens stands with the water balance method.

Although stemflow (SF) had been regarded as a small portion of the gross rainfall (GR), recent studies have revealed that, depending on the forest stand structure, the SF/GR ratio should not be neglected. This study derived SF/GR estimation models using common forest inventory data. A set of SF/GR ratio and forest inventory data (stand density (SD), total basal area (BA), mean diameter at breast height ( D B H ¯ ), mean tree height ( H ¯ ), canopy cover (CC), and leaf area index (LAI)) was collected from previous studies of Japanese cedar and cypress plantations. To further investigate the relation between SF/GR ratio and forest stand structures, we examined additional stand-structure variables (mean basal area ( B A ¯ ), mean stem surface area ( S A ¯ ), and total stem surface area (SA)) derived from the inventory data, and the stand-scale funneling ratio (FRstand) evaluating the efficiency of funneling rainwater. Among all the stand-structure variables, SD exclusively determined the SF/GR ratio, providing the best-fitting positive single linear regression equation as a density-based SF/GR model with a root mean square error (RMSE) of 2.4%. Although this model is useful for practical forest water management because it requires only SD which is the most basic forest inventory data, it has a weak point in meticulous forest water management because it cannot reflect the effect of tree growth on SF/GR ratio. Thus, we developed a size-based SF/GR model (RMSE = 2.0%) based on the strong relationship between the FRstand and D B H ¯ . This model is applicable to meticulous forest water management because it reflects the effects of not only SD but also tree growth by DBH on SF/GR ratio. These models derived from the common forest inventory data are potentially applicable to the evaluation and control of SF in forest water management.

We present our analysis of the LyC emission and escape fraction of 111 spectroscopically verified galaxies with and without AGN from $2.26, Comment: 36 pages, 17 figures, 5 tables. Accepted for publication in The Astrophysical Journal. v1 abstract latex errors corrected, minor changes to table 5, orcid ID corrected for one author

We performed indirect measurements of the neutron-induced reactions \(^{7}\)Be(n,p)\(^{7}\)Li and \(^{7}\)Be(n,\(\mathsf \alpha \))\(^{4}\)He simultaneously by the Trojan Horse method relevant to the cosmological \(^7\)Li problem. Preliminary excitation functions for \((n,p_0)\) and \((n,\alpha )\) are basically consistent with the previous studies, and new information about the \((n,p_1)\) contribution suggests possible enhancement of the total reaction rate.

This paper proposed a tread-surface swing mechanism for lower limbs strength training devices. In the standing position and the training for lower limbs, if the tread-surface angle is inappropriate, then the posture of the knee joints will be affected, and knee adduction/valgus moments, which result to knee stress, will be generated. The target trainings are the front-back crossing and the right-left spread exercises. Regarding the swing of the tread-surface, it is necessary to realize a pitch/yaw rotation and a roll/yaw rotation for the former and the latter exercises, respectively. The mechanism we proposed has a further differential mechanism that utilizes the difference between pulley diameters. The translational movement force of the tread-part is transmitted as the torque of the swing motion for pitch, roll, and yaw by the effect of the differential mechanism. The rate of the swing angle can be changed by adjusting the pulley diameter. Rehabilitation and strength training that result in small knee joint stresses and that generate large muscle load cab pose great demand from people suffering from knee joint failure.

This paper reports the development of the ERIK isokinetic exercise device for the lower limbs, which provided a resistant force laterally to a sliding led during a type of single- limb squat exercise. The muscles of the stance leg during the single leg squat was strongly loaded by the translational load on the sliding leg in the closed kinetic chain style. The training device effectively applied loads to the gluteal muscles, which contribute to decreasing the knee valgus moment, which easily beings anterior cruciate ligament injuries. The four training modes of the ERIK were tested experimentally. ERIK’s performance was confirmed by comparing results with the results from a conventional exercise device. The isokinetic exercise mode was especially superior to the others. While a high resistance was created within the wide motion area and the provision of isokinetic training was achieved by controlling the leg velocity, ERIK had the advantage of safety because of the passive resistive function.

Upper-limb rehabilitation training for hemiplegic patients has been primarily conducted by human therapists, and, hence, their use of training methods and conditions strongly depends on their expertise. The force control and motion sensing functions of rehabilitation robots are expected to be used for the qualitative training/assessment in the next-generation computerized rehabilitation. In this study, we developed a desktop rehabilitation robot for upper limbs (D-SEMUL). In addition, we also assessed the usability of its user interface and the affinity (acceptance) of the training program with a questionnaire for elderly hemiplegic/non-hemiplegic participants (nine hemiplegic, five males and four females and seven non-hemiplegic, two males and five females). The results indicated that the touchscreen is acceptable for the user interface, and the background music used significantly affects the affinity of the program.

The relationship between stem surface area and stand density was analyzed using a large data set collected from 14 districts for Japanese cedar (Cryptomeria japonica D. Don) and 11 districts for Japanese cypress (Chamaecyparis obtusa Endl.) stands across Japan. The results demonstrated that the mean stem surface area in overcrowded stands was inversely proportional to the stand density for both species and all districts. The inverse relationship indicates that the total stem surface area in overcrowded stands becomes a maximum constant independent of stand density, which is termed the ‘conservation rule of stem surface area.’ Since the stem surface area is proportional to the amount of cambium cells in the stem, the conservation rule suggests that there is an upper limit to the total amount of cambium per unit area, i.e., conservation rule of cambium. The conservation rule of stem surface area was linked to the 3/2 power law of self-thinning by an allometric power exponent between stem surface area and volume. Since the allometric power exponent was approximately equal to 3/2, the self-thinning exponent would vary within a relatively narrow band around −3/2. In conclusion, we hypothesized that the conservation rule of stem surface area, or the conservation rule of cambium, may be an alternative starting point for understanding self-thinning in overcrowded tree populations.

The cosmological 7Li problem has been one of the big issues left in the standard Big-Bang nucleosynthesis (BBN) model. In order to determine the radiogenic 7Li abundance by the BBN, it is important to know the production and the destruction rate of 7Be rather than 7Li itself. We performed indirect measurements of the relevant neutron-induced reactions 7Be(n, p)7Li and 7Be(n, α)4He simultaneously by the Trojan Horse Method (THM) via the three-body reactions 7Be(d,7Lip)1H and 7Be(d, αα)1H. A 7Be radioactive-isotope (RI) beam at 3.16 MeV/u was produced at Center-for-Nuclear-Study RI Beam (CRIB) separator. The Q-value spectra shows the evidence of the three-body channels of interest. We confirmed that the THM was applicable to the present measurements by the momentum distributions of the spectator proton. Preliminary excitation functions are roughly consistent with the previous studies, moreover providing new data in the BBN energy range, and suggesting that new information about the 7Be(n, p1)7Li* contribution may be obtained by carrying out a further data analysis.

Princess Kaguya is a heroine of a famous folk tale, as every Japanese knows. She was assumed to be confined in a bamboo cavity with cylindrical shape, and then fortuitously discovered by an elderly man in the forest. Here, we pose a question as to how long she could have survived in an enclosed space such as the bamboo chamber, which had no external oxygen supply at all. We demonstrate that the survival time should be determined by three geometric quantities: the inner volume of the bamboo chamber, the volumetric size of her body, and her body's total surface area that governs the rate of oxygen consumption in the body. We also emphasize that this geometric problem shed light on an interesting scaling relation between biological quantities for living organisms., Comment: 6 pages, 5 figures. Shortened version was submitted to FORMA (http://www.scipress.org/journals/forma/)

Particle sedimentation is one of the main issues affecting magnetorheological fluids (MRF). Though short-term testing methods are useful for their development, such methods have not looked into the effect of sedimentation. In this study, we use an ordinary angle rotor as a centrifugal accelerator, and experimentally compare the sedimentation ratio achieved by it with ratios obtained under gravity. The Stokes' viscosity model was used to discuss the differences between the two. We also found that the parameter that relates the viscosity of a solvent was several tens of times larger in the centrifugal acceleration condition than for the gravity condition. We also investigated the effect of the sedimentation in the mechanical properties of the MRFs. The yield stresses of a MRF are decreased by 30 % after the sedimentation.

Upper limb rehabilitation training for Hemiplegie patients has been conducted mainly by human therapists. Training methods and conditions depend strongly on their experience because of the wide range of individual differences between patients. The force control and sensing functions of rehabilitation robots are expected to be used for the qualitative assessment of next-generation computational rehabilitation. In this study, we developed a simple exercise machine for upper limbs (SEMUL) using an electro-rheological fluid brake, as a safe brake-type robotic rehabilitation system. We also developed a new upper limb training/assessment program, called "WIPE," for the SEMUL. Furthermore, we conducted clinical tests on twelve subjects (six each for the SEMUL training and for general training). We adopted the ABA design methodology for the clinical research tests. The motor functions of upper limbs were assessed using five clinical scores: Fugl-Meyer Assessment (FMA), Brunnstrome recovery stage, Simple Test for Evaluating Hand Function (STEF), Stroke Impairment Assessment Set (SIAS), and Motor Activity Log. Improvements of the FMA, STEF, and SIAS in the SEMUL training groups were found to be higher than those in the general training groups.

Acetaldehyde emissions from particleboard, fiberboard, and plywood were studied using the small chamber method and high-performance liquid chromatography analysis. The chamber tests were conducted for 1 month to examine the time dependence of acetaldehyde emission. Effects of temperature and relative humidity were also examined. Acetaldehyde emissions from these wood-based materials decreased rapidly and their behavior could be described by an exponential function or by the sum of two exponential functions. This result suggests that in an adequately ventilated atmosphere, the acetaldehyde emission factor decreases quickly following the board’s production. Under fixed absolute humidity conditions, the initial acetaldehyde emission factor was larger under higher temperature conditions, but tended to show almost the same value after 14 days. This suggests that higher temperatures promote higher initial concentrations and a faster decline of acetaldehyde. A semi-empirical linear equation was obtained for the early stage relationship between the emission factor and temperature. Under fixed temperature conditions, higher relative humidity caused a larger acetaldehyde emission factor throughout the testing period, and it did not result in a significantly faster decline in emissions. The relationship between acetaldehyde emission and relative humidity can be described using an exponential function.