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Background Musculoskeletal diseases are a major public health concern among older adults. There has been an increase in the number of studies on pain between men and women, such as knee and lumbar pain. However, there is a dearth of research on pain between men and women in hand disease. This study compared health-related quality of life (HRQOL) between patients with musculoskeletal disorders of the hand and those with disorders of the knee and the lumbar spine. Methods From 2014 to 2018, 5595 adult patients completed a questionnaire on HRQOL. Among these patients, we identified patients with hand disease (n = 1038), knee disease (n = 680), and lumbar spine disease (n = 2021) resulting in a total sample of 3739 patients (1749 men and 1992 women). Patients’ responses to the EuroQol (EQ-5D), the Short Form 12-item Survey (SF-12), and three visual analogue scales (VAS), as different measures of the HRQOL, were evaluated. Results It was found that the EQ-5D index was lowest in the lumbar spine patients, followed by knee and hand patients. The VAS scores were negatively affected in all groups. The EQ-5D index was significantly lower in women than in men only in the hand disease group. Multivariate analysis revealed that for the EQ-5D index, age, gender, and VAS scores for job and activities of daily living were explanatory factors in the hand disease group. Gender was not a significant predictor in the other groups. Conclusions This study demonstrated that pain negatively affected HRQOL, and gender differences in HRQOL were found only in patients with hand disease. Gender differences in HRQOL in patients with hand disease warrant appropriate clinical attention.

Sarcopenia is a complication of Chronic Obstructive Pulmonary Disease (COPD) that negatively affects physical activity and quality of life. However, the underlying mechanism by which COPD affects skeletal muscles remains to be elucidated. Therefore, we investigated the association between oxidative stress and structural alterations in muscles in elastase-induced emphysema mouse models.Twelve-week-old male C57BL/6J mice were treated with either intratracheal porcine pancreatic elastase (PPE) dissolved in saline, or saline alone. The mice were euthanized 12 weeks after treatment, and the lungs and limb muscles were used for protein analysis of oxidative stress, p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway and muscle atrophy signaling pathway related with oxidative stress. Furthermore, C57BL/6J mice treated with PPE or saline were analyzed for the effects of oral administration of astaxanthin or p38 inhibitor.The weight of the soleus muscle, proportion of type I muscle fibers, and cross-sectional areas of muscle fibers in the PPE group were lower than those in the control group. Oxidative stress marker levels in the PPE group were elevated in skeletal muscles. The p38 MAPK signaling pathway was activated in the soleus muscles, leading to the activation of the ubiquitin-proteasome system and autophagy. Astaxanthin and p38 inhibitors attenuated alterations in muscle structure through the deactivation of the p38 MAPK signaling pathway.This study provides first evidence in COPD mouse model that oxidative stress trigger a series of muscle structural changes. Our findings suggest a novel target for sarcopenia in COPD.

Several studies have used animal models to examine knee joint contracture; however, few reports detail the construction process of a knee joint contracture model in a mouse. The use of mouse models is beneficial, as genetically modified mice can be used to investigate the pathogenesis of joint contracture. Compared to others, mouse models are associated with a lower cost to evaluate therapeutic effects. Here, we describe a novel knee contracture mouse model by immobilization using external fixation.The knee joints of mice were immobilized by external fixation using a splint and tape. The passive extension range of motion (ROM), histological and immunohistochemical changes, and expression levels of fibrosis-related genes at 2 and 4 weeks were compared between the immobilized (Im group) and non-immobilized (Non-Im group) groups.The extension ROM at 4 weeks was significantly lower in the Im group than in the Non-Im group (p 0.01). At 2 and 4 weeks, the thickness and area of the joint capsule were significantly greater in the Im group than in the Non-Im group (p 0.01 in all cases). At 2 weeks, the mRNA expression levels of the fibrosis-related genes, except for theThis mouse model may serve as a useful tool to investigate the etiology of joint contracture and establish new treatment methods.

Fracture-related infections (FRIs) are challenging for orthopedic surgeons, as conventional surgical treatment and systemic antimicrobial therapy cannot completely control local infections. Continuous local antibiotic perfusion (CLAP) is a novel and innovative therapy for bone and soft-tissue infections, and is expected to eradicate biofilms by maintaining a sustained high concentration of antimicrobial agents at the infected site. If CLAP therapy can eradicate infection even in cases with implants while preserving the implants, it would be an ideal and effective treatment for local refractory infections. This study aimed to evaluate the usefulness of novel CLAP therapy for FRIs.Nine patients treated with CLAP therapy were retrospectively analyzed. The mean age was 65.9 (43-82) years, and the mean follow-up period was 14.9 (6-45) months. In all cases, the infected sites were related to the lower extremities (tibia, n = 6; fibula, n = 1; hip joint, n = 1; foot, n = 1). All patients underwent similar procedures for this therapy combined with negative-pressure wound therapy after thorough irrigation and debridement of infected tissues.The pathogens identified were Staphylococcus aureus (methicillin-resistant S. aureus, n = 5; methicillin-susceptible S. aureus, n = 1), Pseudomonas aeruginosa (n = 3), Enterococcus faecalis (n = 2), Corynebacterium (n = 1), and Enterobacter (n = 1); pathogens were not detected in one case. The mean duration of CLAP was 17.0 (7-35) days. In all cases, implants were preserved until bone union was achieved. Five cases relapsed; however, infection was finally suppressed in all cases by repeating this method. No side effects were observed.This novel case series presents treatment outcomes using CLAP therapy for FRIs. This method has the potential to control the infection without removing the implants, because of the sustained high concentration of antimicrobial agents at the infected site, and could be a valuable treatment option for refractory FRIs with implants, in which bone union has not been achieved.

Background Carpal tunnel steroid injection is a nonoperative intervention for the treatment for idiopathic carpal tunnel syndrome (CTS). The antifibrotic, anti-inflammatory, and antiedematous properties of steroids account for their therapeutic effects in the context of CTS; however, their relative contribution has not been clarified. Methods Fibroblasts from subsynovial connective tissues (SSCT) were intraoperatively collected from patients with idiopathic CTS and were incubated with or without the steroid triamcinolone acetonide (TA) for 1, 3, and 7 days; the expression of fibrosis-related genes and inflammatory cytokines was evaluated using quantitative reverse transcription-polymerase chain reaction. A clinical prospective study was conducted with patients who received carpal tunnel TA injections. We performed clinical and electrophysiological evaluations before and 1, 3, and 5 months after TA injection; and we compared the median nerve, flexor tendon, and SSCT areas and the median nerve flattening ratio before and 1 month after TA injection using 3-T magnetic resonance imaging (MRI). Results TA induced downregulation of the fibrosis-related genes Col1A1 (collagen type I alpha 1 chain), Col1A2, and Col3A1 but not the inflammation-related genes. The nerve flattening ratio did not change after TA injection according to the MRI-based observation of the median nerve, flexor tendon, and SSCT areas. Conclusions The therapeutic effects of injected TA are apparently mediated by its antifibrotic rather than its anti-inflammatory and antiedematous properties. TA probably alters the properties but not the morphology of SSCT. Level of evidence Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Wind tunnel simulation is a very important approach to studying snow drifting and predicting drift snow loads on roofs. A complete simulation of the full process of wind-induced snow accumulation on a roof should include snow drifting both during snowfall and after snowfall. However, in most of the previous studies, snow drifting phenomenon was only simulated without concurrence of snowfall. We herein describe simulations of snow drifting on a flat roof during snowfall, which were carried out in a cryogenic wind tunnel using artificial snow particles. Based on the results, we demonstrate the differences and similarities between snow drifting during snowfall and that without concurrent snowfall. The developments of snow transport before saturated state apparently follow the same rule, no matter whether there is concurrent snowfall or not. However, it seems that the required fetch distance for a saturated saltation state can be reduced by snowfall. A formula is proposed to more reasonably describe the development of snow transport rate. Based on test results and deductions, some discussions on similarity requirements for modelling snow drifting on roofs during snowfall will be presented. Finally, a prediction of the prototype fetch distances under different wind and snowfall conditions will also be presented, which can provide a guide for further research and engineering application.

Aeolian transport of particles occurs in many geophysical contexts such as wind-blown sand or snow drift and is governed by a myriad of physical mechanisms. Most of drifting particles are transported within a saltation layer and has been largely studied for cohesionless particles whether for snow or for sand. Thus, the theoretical description of aeolian transport has been greatly improved for the last decades. In contrast cohesive particles-air system have received much less attention and there remain many important physical issues to be addressed. In the present study, the characteristics of drifting cohesive snow phenomena is investigated experimentally. Several wind tunnel experiments were carried out in the Cryopsheric Environment simulator at Shinjo (Sato et al., 2001). Spatial distribution of wind velocity and the mass flux of drifting snow were measured simultaneously by an ultrasonic anemometer and a snow particle counter. Compacted snow was sifted on the floor and left for a determined duration time to become cohesive by sintering. Two kinds of snow beds with different compression hardness were used (“hard snow” with a compression hardness of about 60 kPa and “semi hard snow” with a compression hardness of about 30 kPa). Wind tunnel velocity varied from 7 m/s to 15 m/s. Moreover steady snow drifting can be produced by seeding snow particles at a constant rate at the upwind of the test section.It was shown that :- on hard snow cover, aerodynamic entrainment does not occur and saltating particles from the seeder just rebounded without splashing particles composing the snow surface (Kosugi et al.,2004). At a given transport rate, the characteristic decay length lν,which can be seen as an estimation of the height of the saltating layer, exhibits a quadratic dependence with the air friction speed, u*. It is in agreement with results obtained by Ho (2011) with saltating sand on non-erodible bed. More surprisingly, lν increases with snow particles diameter, which means that restitution coefficient over hard snow cover also increases with snow particles diameters. - On loose snow cover, without seeder, data analysis from Sugiura et al. (1998), shows that lv is proportional to u* to the power 1.4. This results therefore supports the idea that cohesionless snow doesn’t exist: on erodible sand bed configuration, the decay length is invariant (Ho, 2012).-on semi hard snow cover, without seeder, the inter-particle cohesion makes the transport unsteady and spatially inhomogeneous. lv is proportional to u* to the power 1.6. It is therefore an intermediate case between “loose” and “hard “snow. Restitution coefficient on semi-hard snow is higher than on loose snow cover but smaller than on hard snow cover. Particles are mainly lifted through aerodynamic entrainment so that saturation length is not obtained in the wind-tunnel : the transport rate is two orders of magnitude lower than the maximum transport rate observed for loose snow.-on semi hard snow cover, with seeder, the drifting snow flux dramatically increases, even for low wind speed, leading sometimes to snow cover vanish. Experimental results provide evidence that impacting particles are efficient to lift cohesive snow particles : the transport rate increases to nearly 10.

Background Implants made from bioabsorbable unsintered hydroxyapatite and poly-L-lactate composites (u-HA/PLLA) are widely used in the oral, maxillofacial, and orthopedic fields. This study assess the long-term (> 5 years) outcomes of patients with metacarpal fractures who were surgically treated using bioabsorbable plates and screws (Super-Fixsorb MX40 mesh; Teijin Medical Technology, Osaka, Japan). Methods A retrospective analysis of six patients with eight metacarpal fractures treated with bioabsorbable plates was done. All patients were followed for more than 5 years post-surgery. The clinical outcomes were evaluated using Q-DASH scores and the grip strength (GS): opposite side ratio. The resorption status of implants was assessed on plain computed tomography (CT) scans at final follow-up appointments. Results The mean age of the patients at the time of surgery was 29.5 years (16–54), and the median follow-up period was 81.8 months (68–101). All fractures united without displacement after an average of 3.5 months, and there were no implant specific complications associated with the use of absorbable plates. The mean grip strength ratio was 85.1% (56.8–104.5). The mean Q-DASH scores of 11.36 points (0–34.09) was good in all but two patients. We also observed that it took more than 8 years for the plates to be absorbed completely. Conclusions This study demonstrates that the process of bioabsorption in metacarpal fractures might be completed in about 8 years, and the absorption speeds were different inside and outside of the bone. The bioabsorbable plates are more cost-effective than metallic implants. The potential for bioabsorbable plates to be used in various clinical procedures is promising.

Background Scaphoid excision and four-corner arthrodesis is an acceptable salvage procedure for the treatment of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrists, since first popularized in the 1980s. We investigated the potential application of novel bioabsorbable plates and screws made of un-sintered hydroxyapatite/poly-L-lactide composite for the treatment of metacarpal fractures. We used this material for the fixation of four-corner fusions for SLAC or SNAC wrists commencing from April 2009. The purpose of this study was to clarify the controversy in the literature regarding the use of these plates. Methods The surgical procedures and clinical outcomes of four-corner fusions using a bioabsorbable (poly-L-lactic acid and hydroxyapatite) plate were reported. Ten patients (mean age, 59.2 years) with SLAC or SNAC wrists underwent fusions between April 2009 and June 2016. The primary diseases were scapholunate ligament injury, Preiser disease, and scaphoid pseudarthrosis. The mean postoperative follow-up period was 45.9 months (range, 12–86). Results In all patients, bone union was achieved without dislocation or pain. The mean wrist flexion and extension arc improved from 78.5 degrees before surgery to 90.5 degrees after surgery. Mean grip strength improved from 51 to 69% after surgery, and the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score improved from 53.5 to 14.3. No complications such as infection, avascular swelling, or tendon adhesion were observed. This implant requires no removal of internal fixation devices, produces stable outcomes, and is an effective fusion technique. Conclusions We summarized the outcomes of four-corner arthrodesis using bioabsorbable plates. Satisfactory clinical results were shown, with no obvious complications. This novel plate also serves as a good alternative for patients who are allergic to metals. Furthermore, bioabsorbable plates are advantageous as they do not require removal.

This study aimed to clarify whether novel cotton-like composite made of β-tricalcium phosphate (β-TCP) and poly(Dl-lactide-co-glycolide) (PDLGA) has a different effect on in vivo bone regeneration after bone defect than that of granular β-TCP. Five male Beagle dogs served as subjects. Cortical and medullary bone defect as non-through holes were made at the diaphysis of the bilateral femurs. One side was implanted with β-TCP/PDLGA (β-TCP/PDLGA group) and the other side was implanted with granular β-TCP (β-TCP group). At 4 weeks after implantation, we found no significant differences in the percentages of newly formed bone area and fibrous tissue area in the bone defect between the two groups. The β-TCP/PDLGA group showed more uniform filling on the surface and earlier disappearance of the material in the medullary region, and there were fewer inflammatory cells and osteoclasts in the bone defect in the β-TCP/PDLGA group. In conclusion, β-TCP/PDLGA performs better at filling the bone defect uniformly and disappears earlier at the cortical and medullary regions while causing less inflammation and bone resorption. Although bone formation activity of the β-TCP/PDLGA group in the cortical region was lower, the newly formed bone volume in bone defect of the β-TCP/PDLGA group was equal to that of the β-TCP group., Highlights • Novel cotton-like composite made of β-TCP/PDLGA was compared with granular β-TCP. • Cotton-like β-TCP/PDLGA performed better at filling the bone defect uniformly. • Cotton-like β-TCP/PDLGA disappeared earlier at the implanted bone regions. • β-TCP/PDLGA caused less inflammation and bone resorption in the bone defect. • The newly formed bone volume in bone defect was equal between the two materials.

Calcium balance is important in bone homeostasis. The transient receptor potential vanilloid (TRPV) channel is a nonselective cation channel permeable to calcium and is activated by various physiological and pharmacological stimuli. TRPV1 and TRPV4, in particular, have important roles in intracellular Ca2+ signaling and extracellular calcium homeostasis in bone cells. TRPV1 and TRPV4 separately mediate osteoclast and osteoblast differentiation, and deficiency in any of these channels leads to increased bone mass. However, it remains unknown whether bone mass increases in the absence of both TRPV1 and TRPV4. In this study, we used TRPV1 and TRPV4 double knockout (DKO) mice to evaluate their bone mass in vivo, and osteoclast and osteoblast differentiation in vitro. Our results showed that DKO mice and wild type (WT) mice had no significant difference in body weight and femur length. However, the results of dual-energy X-ray absorption, microcomputed tomography, and bone histomorphometry clearly showed that DKO mice had higher bone mass than WT mice. Furthermore, DKO mice had less multinucleated osteoclasts and had lower bone resorption. In addition, the results of cell culture using flushed bone marrow from mouse femurs and tibias showed that osteoclast differentiation was suppressed, whereas osteoblast differentiation was promoted in DKO mice. In conclusion, our results suggest that the increase in bone mass in DKO mice was induced not only by the suppression of osteoclast differentiation and activity but also by the augmentation of osteoblast differentiation and activity. Our findings reveal that both the single deficiency of TRPVs and the concurrent deficiency of TRPVs result in an increase in bone mass. Furthermore, our data showed that DKO mice and single KO mice had varying approaches to osteoclast and osteoblast differentiation in vitro, and therefore, it is important to conduct further studies on TRPVs regarding the increase in bone mass to explore not only individual but also a combination of TRPVs., Highlights • Knockout of either TRPV1 or TRPV4 results in increased bone mass in mice. • This study evaluates the effects of TRPV1 and TRPV4 double knockout (DKO) in mice. • Concurrent TRPV1 and TRPV4 deficiency increases mouse bone mass. • TRPV1 and TRPV4 DKO suppresses osteoclast differentiation and activity. • TRPV1 and TRPV4 DKO enhances osteoblast differentiation and activity.

Aeolian transport of particles occurs in many geophysical contexts such as wind-blown sand or snow drift and is governed by a myriad of physical mechanisms. Most of drifting particle are transported within de saltation layer and has been largely studied for cohesionless particles whether for snow or for sand. Thus, the theoretical description of aeolian transport has been greatly improved for the last decades. In contrast cohesive particles-air system have received much less attention and there remain many important physical issues to be addressed. In the present study, the characteristics of drifting cohesive snow phenomena is investigated experimentally Several wind tunnel experiments were carried out in the Cryopsheric Environment simulator at Shinjo (Sato et al., 2001). Spatial distribution of wind velocity and the mass flux of drifting snow were measured simultaneously by an ultrasonic anemometer and a snow particle counter. The SPC measures the size of each particle passing through a sampling area. The size is classified into 32 classes between 50 and 500µm. Compacted snow was sifted on the floor. Then snow bed is left for a determined duration time to become cohesive by sintering.Two kinds of snow beds with different compression hardness were used (“hard snow” with a compression hardness of about 60 kPa and “semi hard snow” with a compression hardness of about 30 kPa). Wind tunnel velocity varied from 7 m/s to 15 m/s. Moreover steady snow drifting can be produced by seeding snow particles at a constant rate at the upwind of the test section. The results are compared with those obtained for loose surfaces. It was shown that :- on hard snow cover, aerodynamic entrainment does not occur and saltating particles from the seeder just rebounded without splashing particles composing the snow surface (Kosugi et al.,2004). b, the inverse of the gradient of the mass flux decay with height is proportional to the friction velocity. The mass flux profiles exhibit a focus point. It is also confirmed (Kosugi et al., 2008) that the saltation height increased with increasing particle diameter throughout the full range of investigated wind tunnel velocity. Such characteristics are not observed for cohesionless snow particles (Sugiura et al.,1998)-on semi hard snow cover, the inter-particle cohesion makes the transport unsteady and spatially inhomogeneous. A steady state is never obtained. It makes experimental protocol and experiments repeatability tricky. Without seeder, the same trends are observed compared to the previous experiments on hard snow. With seeder, the drifting snow flux dramatically increases, even for low wind speed, leading to snow cover vanish.

Owing to the controllability and reliability, wind tunnel experiment is considered as a powerful and effective approach for the investigation of snow drifting. Most of the previous experimental studies were mainly concerned with snow drifting on roofs without snowfall, in which a layer of particles was uniformly paved on the roof surface to model the initial snow cover. Hence, a cryogenic wind tunnel experiment using artificial snow particles was conducted to investigate snow drifting on flat roofs during snowfall. The similarity requirement related to snowfall intensity is derived according to the similarities of snow distribution pattern and the development of snow transport. Based on the results of snow distributions and transport rates for different roof spans and snowfall intensities, the features of snow drifting under snowfall conditions are analyzed in detail. The concurrence of snowfall is further revealed to greatly affect the development of snow drifting on flat roofs and thereby result in a reduction in the required fetch for reaching the saturated state. And the typical distribution patterns for snow drifting on flat roofs with and without snowfall are also summarized. Besides, the snow transport rate is found to increase along the roof surface before the achievement of the saturated state, whereas a slight decrease in the degree of snow erosion with roof span is observed. But the location of the crest formed near the windward edge is nearly unaffected by roof span as well as snowfall intensity. The results also indicate obvious linear characteristics in the relationship between the degree of erosion on the roof surface and snowfall intensity. And the normalized development process of snow transport before reaching the saturated state is nearly independent of snowfall intensity, although both the saturated transport rate and the required fetch for saturated drifting are strongly affected in the meantime.

Aldehyde dehydrogenase 2 (ALDH2) is the enzyme that oxidizes the acetaldehyde produced by alcohol metabolism. This variant not only affects the response to alcohol but is also associated with several diseases, such as esophageal cancer, myocardial infarction, and particularly osteoporosis. In our previous study, we reported that compared to wild-type (WT) mice, Aldh2 knockout (KO) mice naturally have a strong bone formation ability, and high expression of parathyroid hormone receptor (PTHR1) in osteocytes. The effect of the Aldh2 gene on bone metabolism in response to intermittent PTH treatment is unknown. The purpose of this study was to clarify the effect of the Aldh2 gene on the bone anabolic response to intermittent PTH treatment in ovariectomized mice. Female KO and WT mice were ovariectomized at 8 weeks of age. At 14 weeks of age, the KO and WT mice were divided into vehicle-treated (Veh) and PTH-treated (PTH) groups (i.e., the WT-Veh, WT-PTH, KO-Veh and KO-PTH groups). PTH (1–34) and vehicle were subcutaneously administered to each group at a dose of 40 μg/kg body weight (BW) five times per week for 4 weeks. Micro-CT showed that the bone volume (BV), trabecular number (Tb.N), connectivity density (Conn.D), and cortical thickness (Ct.Th) values in the KO-PTH mice were significantly higher than those in the KO-Veh mice. Histomorphometric analysis showed that the BV, Tb.N, and mineral apposition rate (MAR) values in the KO-PTH group were significantly higher than those in the KO-Veh group. The mRNA expression level of PTHR1 in the KO-PTH group was significantly increased and that of p21 in the KO-PTH group was significantly decreased compared with the levels in the KO-Veh group. The expression of PTHR in osteocytes from the KO-PTH group was also significantly increased compared with that in osteocytes from the KO-Veh group. Furthermore, cell cultures revealed that the ALP+CFU-f/total CFU-f percentage was significantly higher in the KO-PTH group than in the KO-Veh group. We concluded that in ovariectomized Aldh2 KO mice, the bone anabolic response to intermittent PTH treatment was significantly enhanced compared to that in WT mice, which may be mediated by the high expression level of PTHR1.

Fibrosis of the subsynovial connective tissue (SSCT) is a characteristic finding in patients with idiopathic carpal tunnel syndrome (CTS). Idiopathic CTS frequently occurs in postmenopausal women; therefore, female steroid hormones, especially estrogens, may be involved in its development. In this study, we evaluated the effect of the estradiol on the expression of genes and proteins related to fibrosis of SSCT fibroblasts from patients with idiopathic CTS. This study included 10 postmenopausal women (mean age 76 years). Fibroblasts derived from SSCT were treated with estradiol (10-4 -10-12 M), and the expression levels of TGF-β-responsive genes were evaluated. The relationships between the expression of untreated estrogen receptor α (ERα) and ERβ and changes in gene expression due to estradiol treatment were examined by quantitative real-time polymerase chain reaction. The effects of 10-4 M estradiol on collagen type I (Col1) and collagen type III (Col3) protein expression levels were also evaluated by fluorescent staining. The relationships between ERα/β and Col1/3 expression were evaluated by immunohistochemical staining. The reduction in Col1A1 mRNA expression due to estradiol treatment was positively correlated with ERα expression (r = 0.903, p

Aldehyde dehydrogenase 2 (ALDH2) is the enzyme that degrades and detoxifies the acetaldehyde produced by alcohol metabolism. In our previous study, we found that compared with wild-type mice (WT), climbing exercises did not increase trabecular bone mass in Aldh2 knockout mice (KO). The purpose of this study was to clarify the effect of the Aldh2 gene on cortical bone structure and on the dynamics of skeletal unloading. Eight-week-old male KO and WT were divided into ground control (GC) or tail suspension (TS) groups for one week (i.e., the KOGC, KOTS, WTGC and WTTS groups). We measured the bone mineral density (BMD) of the femur using dual-energy X-ray absorptiometry. We assessed the femoral morphometry using peripheral quantitative computed tomography (pQCT) and evaluated the femoral cortex histomorphometry, and cortical mRNA using quantitative RT-PCR and cortical bone immunohistostaining. No significant differences were found between the femoral BMD of WTGC and that of WTTS, but the BMD in KOTS was significantly lower than that of KOGC. The pQCT results revealed that the cortical BMD of the femoral diaphysis in KOTS was significantly lower than that of KOGC. Furthermore, the cortical bone area and cortical thickness were significantly lower in KOTS than in the other three groups. Cortical histomorphometric analysis revealed that the endosteal and periosteal bone formation parameters were significantly lower in KOTS than in KOGC. Bone formation signals such as parathyroid hormone receptor (PTHR) were significantly decreased in KOTS compared with the levels in KOGC. Cortical bone immunohistostaining revealed a significantly decreased expression of PTHR in the osteocytes of KOTS compared with the expression level in KOGC. Thus, we concluded that when the Aldh2 gene is disrupted, skeletal unloading suppresses bone formation to decrease cortical bone mass, which may be mediated by a decreased expression of PTH receptors in osteocytes.

Wind-tunnel and numerical experiments were performed to investigate the effects of snowfall on the wind profile and the development of drifting snow. Wind profiles and mass-flux profiles of drifting snow were measured with and without artificial snowfall over a snow surface within the tunnel. Wind and shear-stress profiles and the impact speeds of the snowflakes during snowfall were also investigated numerically. During snowfall, snowflakes transfer part of their horizontal momentum to the air, which increases the stress close to the snow surface; however, the resultant modifications of the wind profiles are small. Because snowflakes have large momentum, the decomposed snow crystals that result from their collision with a surface can form a saltation layer, even over a hard snow surface where entrainment of the grains from the surface does not occur. Additionally, during snowfall, the threshold friction velocity can be lower than the impact threshold because snowflake fragmentation facilitates snow drifting. The broken crystals contribute to the increase in the number of drifting snow grains, even below the impact threshold.

Link to publishers version: 10.1016/j.coldregions.2016.03.012 Icing load and icing rate are necessary feedback variables for an intelligent anti/de-icing systemtowork effectively in harsh cold environment of high north. These parametersmay be measured by axial loadings or by rotational loadings, as a function of current demand. However the former may not necessarily be dynamic, whereas the later necessarily be rotational. Sufficiently at a fixed rpm, a mathematical model between additional polar moment of inertia vs electrical demand of the sensor can be established to analytically shape the icing load and icing rate adequately as hypothesized in Cost 727. This paper aims to develop such model and is validated using experimental data from a case study conducted by Atmospheric Icing Research Team of Narvik University College at Cryospheric Environmental Simulator, Snow and Ice Research Center, (NIED) Japan.

Here we have conducted an integral study using site observations and a model with detailed snow dynamics, to examine the capability of the model for deriving a simple relationship between the density and thermal conductivity of the snowpack within different climatic zones used in large-scale climate modeling. Snow and meteorological observations were conducted at multiple sites in different climatic regions (two in Interior Alaska, two in Japan). A series of thermal conductivity measurements in snow pit observations done in Alaska provided useful information for constructing the relationship. The one-dimensional snow dynamics model, SNOWPACK, simulated the evolution of the snowpack and compared observations between all sites. Overall, model simulations tended to underestimate the density and overestimate the thermal conductivity, and failed to foster the relationship evident in the observations from the current and previous research. The causes for the deficiency were analyzed and discussed, regarding a low density of the new snow layer and a slow compaction rate. Our working relationships were compared to the equations derived by previous investigators. Discrepancy from the regression for the melting season observations in Alaska was found in common. © 2012 Elsevier B.V. and NIPR.

The Snow Disaster Forecasting System (SDFS) was constructed by the Snow and Ice Research Center at the National Research Institute for Earth Science and Disaster Prevention (SIRC/NIED). It has the capability to predict avalanche potential, visibility in blowing snow, and snow conditions on roads. New schemes, such as the dry snow metamorphism factor (DSM factor) describing snow grain evolution and the ejection factor for blowing snow particles were introduced and incorporated into the SDFS. Differences between the modeled and observed vertical profiles of snowfall intensity were found by radar observations. The SDFS has experimentally provided predictions to registered users in real-time for three winters. A questionnaire survey of the users showed that the SDFS has the potential to provide useful predictions for decision making, although improved accuracy and usability are required. To improve the prediction, it is important to clarify the microphysical processes of snowfall systems, blowing snow, and snowpack by quantitative field observations and well-controlled laboratory experiments.

AbstarctThere are some reports on the measurement of the charge-to-mass ratio of blowing-snow particles, but there are few studies concerned with individual snow-particle charge. We measured the charge-to-mass ratios using snow particles selected according to size, and discussed individual charges. Experiments were conducted in a cryogenic wind tunnel. Charge-to-mass ratios measured in our experiment were all negative and their absolute values tended to increase with a decrease in particle diameter. Individual snow-particle charges were calculated from the average of particle diameter distributions. The charges were all approximated by the power function of diameter at each temperature. Assuming that the coefficient of these approximations is a function of air temperature, we could easily predict the individual snow-particle charge.

Under strong wind conditions, snowflakes break upon collision with a snow surface, and their fragments are blown away; this leads to the development of drifting snow. If these fragments accumulate, the density of the deposited snow would exceed that of new snow deposited under calm conditions. In this study, experiments on the processes of fracture and accumulation of snowflakes were conducted in a cold wind tunnel and field observations were also carried out. The experimental results obtained by using artificial snowflakes are as follows: snowflakes do not break if U1 The observational results for natural snowflake collisions almost agreed with the experimental results. These findings can be used in a model of drifting snow to explicitly describe the effect of snowfall on drifting snow and they will be useful in understanding the wind speed dependence of the new snow density.

平成18年豪雪における積雪の地域特性を明らかにすることを目的として,日本各地の雪氷研究者の協力を得て広域―斉積雪断面観測を2006年2月(上旬及び下旬)に2回実施した.観測地点数は,2月上旬の観測では北海道から中国地方にいたる46地点,2月下旬の観測では北海道から北陸地方にいたる26地点である.観測の結果,平成18年豪雪では,全国的にみた場合,融解凍結が関与するざらめ雪化の進行度合に雪質の地域的差異が最も明瞭に表れており,ざらめ率(積雪深に対するざらめ雪層の厚さの割合)は緯度と標高に強く依存して変化していた.また,積雪全層の平均密度と平均硬度には,2月上旬では低緯度ほど大きい傾向があったが,2月下旬になると平均硬度には顕著な南北差は認められなかった.豪雪地域(山間部)の住民から「今年は雪が硬い」という声が多数聞かれたことに対し,新潟県十日町市におけるラム硬度の観測データを用いて検証した結果,2006年2月上旬と下旬の十日町市の平均ラム硬度は1987年以降では群を抜いて大きいことが分かった.過去の豪雪年のラム硬度との比較から,平成18年豪雪における新潟県山間部の積雪硬度の著しい増加は,豪雪年の特徴であると考えられる.

To investigate the snow accumulation on flat roofs, daily observations of snowfall and snow cover on three kinds of buildings and ground surface were carried out for 5 winters in Shinjo, northern part of Japan. At first, to find relationship between wind speed over each roof and that over the ground surface, the maximum instantaneous wind speed and mean wind speed during 10 minutes at 1.5 m height on each roof were measured simultaneously together with those at 10 m height on the ground surface. We defined the snow accumulation factor (SAF) as the ratio of the weight of daily snowfall on a roof divided to that on the ground surface on the same day. SAF decreases with the wind speed on the roofs, and becomes 0 when the wind speed exceeds a critical value. The critical wind speeds for different temperatures obtained by the method of least squares shows obvious temperature dependence. The critical wind speed increases with temperature, especially near the melting point of snow.

This paper describes the indoor snowfall simulation chamber and its application for evaluating visibility performance of vision-based sensors affected by environmental conditions. First, vision-based safety sensors are introduced and outdoor environmental requirements for these sensors are discussed. And also, the relationship between the visibility and the performance of vision based sensors is discussed and the current problems for evaluating visibility performance are described. Next, the indoor snowfall simulation method using expanded polystyrene beads (EPB) is explained and the spectral transmission measurement equipment for evaluating the visibility reduction is presented. Finally, the visibility reduction caused by simulated and artificial snowfall are measured for verifying the proposed indoor snowfall simulation chamber. Preliminary experiments are also carried out in both snowfall systems in order to evaluate various kinds of vision-based safety sensors for personal care robots.

Four automatic weather stations (AWS) were installed on the slopes and foot areas of the Tianshan and Kunlun Mountains along a longitude of 80 degrees east: (1) Taglak 2400 m a.s.l., (2) Aksu 1000 m, (3) Kartash 2800 m, and (4) Qira 1700 m. These two slopes face the Taklimakan Desert. Tagliak lies on the southern slope of Tianshan, and Kartash on the northern slope of Kunlun. The meteorological characteristics of the mountainous regions were investigated using surface data obtained during an intensive observation period (IOP) in spring 2002. It was found that visibility on the slopes decreases in the daytime, and there is no relationship between visibility and wind speed in the mountainous areas. Two snow layers containing dust particles were observed in the snow cover in Taglak during the IOP in spring 2003. These results suggest that a warm air parcel containing aeolian dust climbs over the slopes of the mountainous areas, and dust particles in the mountainous areas are transported from the foot areas.

To observe aeolian dust in high mountainous areas, two sets of automatic weather station including visibility meters have been installed on the slopes of the Tianshan Mountains and the Kunlun Mountains. The two observation sites are at a height of about 2500 m above sea level, and those slopes face to the Taklimakan Desert. The aeolian dust climbs the slopes with anabatic wind in daytime. Horizontal mass transportation of dust over the slopes on a fine day was estimated using the data set of visibility and wind speed, and its daily and seasonal variations were analyzed. Before this analysis, visibility was converted to dust concentration via a relationship determined by visibility meter and an optical panicle counter in a laboratory. It has been recognized that the mass transportation over the slopes reflects activity of the dust outbreak at the foot areas.

回転楕円体および角柱でモデル化した飛雪粒子がランダムに方位していると仮定して,スノー・パーティクル・カウンター(SPC)で測定される飛雪流量と真の飛雪流量の比を理論的に求めた.また,粒子形状の異なる雪を使用してSPCとネット式吹雪計による飛雪流量の比較実験を行った.理論的検討より,粒子形状が回転楕円体の場合は非球形度が増すほど,角柱の場合は薄く板状に近づくほど,あるいは細長くなるほど,SPCで測定される飛雪流量はより過大に評価されることが明らかになった.比較実験の結果は理論的検討の結果と整合するものであった.すなわち,飛雪粒子が樹枝状結晶(人工雪)の破壊されたものからなる時は,SPCによる飛雪流量はネット式吹雪計によるものよりかなり大きくなるが,飛雪粒子が粒状の時は両者はほぼ一致する.Sato et al.(1993)による野外におけるSPCとネット式吹雪計の比較観測の結果について,本研究の結果に基づき再検討し,雪面が硬く削剥が生じないような特殊な場合を除けばSPCによる飛雪流量の測定が概ね正確であることを示した.

Drifting snow experiments were conducted in a cold wind tunnel at a constant temperature of −15 °C to investigate saltation lengths of snow particles over loose and hard snow surfaces. Vertical mass flux of falling snow particles to the snow surface was measured by a box-type snow collector, which was composed of ten metallic boxes, set at the downwind end of the test section. Saltation lengths were calculated from the distributions of the falling mass flux along the snow collector. Mean saltation length over loose snow surfaces increased from 8 to 15 cm with increasing wind velocity from 6 to 15 m s−1. Mean saltation length over hard snow surfaces increased from 40 to 140 cm with increasing wind velocity from 5.5 to 8 m s−1. Mean saltation length over hard snow surfaces was several times as large as that over loose snow surfaces for the same wind velocity. Saltation length distributions were also obtained from analyses of the falling mass flux distributions. Saltation length distributions were shown as exponential functions of length in previous studies for loose snow surfaces. Present results showed that saltation length distributions over hard snow surfaces were well approximated by log-normal distributions.