The trabecular architecture of the superior articular process of the lumbar spine (L2-S1)

The role of the facet joint in low back pain has gained public attention lately. The objective of our study was to investigate whether there is any difference in the adaptation of the cancellous bone in the superior articular process depending on the specific stress condition in different levels of the spine. Therefore, the trabecular structure of the superior articular processes of L2 and S1 of 15 cadavers (aged 63-100years) were studied using μCT (micro-computer tomography). Each sample was divided into five sections, each of which containing 20% of the slices. The following structure parameters were compared between L2 and S1 as well as within each process; bone-volume-fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), structure-model-index (SMI) and degree of anisotropy (DA). Statistically significant differences were observed between L2 and S1 for the BV/TV, SMI, Tb.Th and Tb.N in superior 2 sections. BV/TV, Tb.Th and Tb.N were higher in S1 than in L2. The SMI is lower, and even negative in S1 compared to L2, showing a more plate-like structure. Within the articular process all structure parameters show a similar distribution in L2 and S1. BV/TV, Tb.N and DA decreased from cranial to caudal while Tb.Th was highest in the most cranial and caudal sections, with the lowest value in the middle. The SMI, on the other hand, increased from cranial to caudal displaying more rod-like structures. These results can be explained by the different stress the processes of the different spinal levels are exposed to as well as the specific motion patterns of the facet joint. The processes of the os sacrum are exposed to a higher axial and ventral load due to their location and the lumbosacral flexion. In addition the upper sections of each process experience higher stress peaks than the lower ones. Therefore, this study shows the material distribution within the cancellous bone adapts to these specific stress conditions the facet joints are exposed t

A Report on Overseas Teaching Practicum by Graduate Students in Elementary/Secondary Schools in the United States（Ⅹ）

This short paper reports on the 10th overseas teaching practicum in the United States by 8 graduate students of Hiroshima University， Japan， partly organized by Hiroshima University Global Partnership School Center (GPSC). This year marks the 10-year anniversary of this project since its start. This year’s participants were students of Graduate School of Education and Graduate School for International Development and Cooperation (IDEC). They observed and conducted lessons in English in four local public schools in North Carolina. This project had the following three aims: 1) to self-develop practical instructional competence by teaching pupils with different cultural backgrounds; 2) to enhance the abilities in developing teaching materials through hands-on teaching experiences in English; and 3) to acquire the abilities to design， implement and evaluate programs for promoting global partnership. Like previous years， their teachings were very positively covered by the local newspapers and websites. Later， the project was followed by cross-cultural field study visits to NC State Capitol， Raleigh and the U.S. Capitol， Washington， D.C. It is hoped that this intensive experience will raise the prospective teachers’ global awareness and confidence in teaching

Body measurement of riding horses with a versatile tablet-type 3D scanning device

The measurement of various body dimensions of horses plays a significant role in quality improvement, genetic breeding, health, and soundness. There has been significant advancement in the technology for acquiring stereoscopic images with a three-dimensional (3D) scanner. This study aimed to validate the accuracy of body measurements obtained from stereoscopic images taken with a 3D scanner. We manually took the following body measurements for 8 riding horses: height at the withers, height at the back, height at the croup, chest depth, width of the chest, width of the croup, width of the waist, girth circumference, cannon circumference, and body length. Using a versatile tablet-type 3D scanning device, we captured a 3D image of each horse. Relative errors varied from −1.37% to 6.25%. The correlation coefficient between manual and 3D measurements was significant for all body measurements (P<0.01) except for width of the waist and cannon circumference. The low accuracy of cannon circumference (r=0.248) was due to effect of hair. A simple regression analysis of all body measurements revealed a strong correlation (P<0.001, R2=0.9994, root-mean-square error [RMSE]=1.522). Notable advantages of this methodology include high accuracy, good operability, non-contact, high versatility, and low cost. Further studies are required for the establishment of an accurate measurement methodology that can scan the whole body in a shorter time

Influence of Culture Period on Osteoblast Differentiation of Tissue-Engineered Bone Constructed by Apatite-Fiber Scaffolds Using Radial-Flow Bioreactor

With the limitation of autografts, the development of alternative treatments for bone diseases to alleviate autograft-related complications is highly demanded. In this study, a tissue-engineered bone was formed by culturing rat bone marrow cells (RBMCs) onto porous apatite-fiber scaffolds (AFSs) with three-dimensional (3D) interconnected pores using a radial-flow bioreactor (RFB). Using the optimized flow rate, the effect of different culturing periods on the development of tissue-engineered bone was investigated. The 3D cell culture using RFB was performed for 0, 1 or 2 weeks in a standard medium followed by 0, 1 or 2 weeks in a differentiation medium. Osteoblast differentiation in the tissue-engineered bone was examined by alkaline phosphatase (ALP) and osteocalcin (OC) assays. Furthermore, the tissue-engineered bone was histologically examined by hematoxylin and eosin and alizarin red S stains. We found that the ALP activity and OC content of calcified cells tended to increase with the culture period, and the differentiation of tissue-engineered bone could be controlled by varying the culture period. In addition, the employment of RFB and AFSs provided a favorable 3D environment for cell growth and differentiation. Overall, these results provide valuable insights into the design of tissue-engineered bone for clinical applications

Spin glass behavior and magnetic boson peak in a structural glass of a magnetic ionic liquid

Abstract Glassy magnetic behavior has been observed in a wide range of crystalline magnetic materials called spin glass. Here, we report spin glass behavior in a structural glass of a magnetic ionic liquid, C4mimFeCl4. Magnetization measurements demonstrate that an antiferromagnetic ordering occurs at T N = 2.3 K in the crystalline state, while a spin glass transition occurs at T SG = 0.4 K in the structural glass state. In addition, localized magnetic excitations were found in the spin glass state by inelastic neutron scattering, in contrast to spin-wave excitations in the ordered phase of the crystalline sample. The localized excitation was scaled by the Bose population factor below T SG and gradually disappeared above T SG. This feature is highly reminiscent of boson peaks commonly observed in structural glasses. We suggest the “magnetic” boson peak to be one of the inherent dynamics of a spin glass state

Scaling relations between trabecular bone volume fraction and microstructure at different skeletal sites

In this study, we investigated the scaling relations between trabecular bone volume fraction (BV/TV) and parameters of the trabecular microstructure at different skeletal sites. Cylindrical bone samples with a diameter of 8mm were harvested from different skeletal sites of 154 human donors in vitro: 87 from the distal radius, 59/69 from the thoracic/lumbar spine, 51 from the femoral neck, and 83 from the greater trochanter. μCT images were obtained with an isotropic spatial resolution of 26μm. BV/TV and trabecular microstructure parameters (TbN, TbTh, TbSp, scaling indices ( and σ of α and αz), and Minkowski Functionals (Surface, Curvature, Euler)) were computed for each sample. The regression coefficient β was determined for each skeletal site as the slope of a linear fit in the double-logarithmic representations of the correlations of BV/TV versus the respective microstructure parameter. Statistically significant correlation coefficients ranging from r=0.36 to r=0.97 were observed for BV/TV versus microstructure parameters, except for Curvature and Euler. The regression coefficients β were 0.19 to 0.23 (TbN), 0.21 to 0.30 (TbTh), −0.28 to −0.24 (TbSp), 0.58 to 0.71 (Surface) and 0.12 to 0.16 (), 0.07 to 0.11 (), −0.44 to −0.30 (σ(α)), and −0.39 to −0.14 (σ(αz)) at the different skeletal sites. The 95% confidence intervals of β overlapped for almost all microstructure parameters at the different skeletal sites. The scaling relations were independent of vertebral fracture status and similar for subjects aged 60–69, 70–79, and >79years. In conclusion, the bone volume fraction–microstructure scaling relations showed a rather universal character