Evaluation and Stability Analysis of Onshore Wind Turbine Supporting Structures

This chapter shows research of stability of supporting structure of onshore wind turbine foundations based on field measurements, finite element (FE) analysis and laboratory experiment. In order to investigate the relation of action-response of tower-foundation system, long-term field measurements were carried out for two existing onshore wind turbines with/without piles for its foundations. Then, the models were built up for three-dimensional nonlinear FE analyses. The damage processes of reaching failure were examined by FE models, and limit state of foundations was individually defined by fatigue limit state of concrete. Consequently, the stress-number of cycle (S-N) diagram derived from both experiment and analysis was discussed for the assessment of existing structure

Immature male gibbons produce female-specific songs.

Gibbons are apes that are well known to produce characteristic species-specific loud calls, referred to as "songs." Of particular interest is the sex specificity of the "great calls" heard in gibbon songs. However, little is known about the development of such calls. While great calls are given by female gibbons of various ages, they have never been recorded from males. Here, we report two observations of immature male gibbons from two different species, wild Hylobates agilis and captive H. lar, which spontaneously sang female-specific great calls. Based on the video clips, we conclude that immature males also have the potential to produce great calls. Our observations led us to propose a new hypothesis for the development of sexual differentiation in the songs of gibbons, and its implications for the general issue of sex-specific behavior in primates

Correlation among Inflammatory Cytokine Expression Levels, Degree of Disk Degeneration, and Predominant Clinical Symptoms in Patients with Degenerated Intervertebral Discs

Study DesignObservational study.PurposeTo assess the correlation among inflammatory cytokine expression levels, degree of intervertebral disk (IVD) degeneration, and predominant clinical symptoms observed in degenerative disk disease (DDD).Overview of LiteratureLow back pain (LBP) is associated with inflammatory cytokine expression levels, including those of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and nerve growth factor (NGF). However, the association between cytokine expression levels and the physiological mechanisms of disk degeneration and clinical pain remain controversial.MethodsUsing the enzyme-linked immunosorbent assay, TNF-α, IL-6, and NGF expression levels were analyzed in 58 IVD samples that were harvested from patients with lumbar DDD. Patient samples were grouped according to the degree of IVD degeneration using the Pfirrmann grading system and magnetic resonance imaging, and the correlations between the disease groups and each cytokine expression level were assessed. In addition, on the basis of their predominant preoperative symptoms, the patients were assigned to either an LBP or leg pain group to determine the correlation among these disease manifestations and individual cytokine expression levels.ResultsA gradual increase in TNF-α (R=0.391) and IL-6 (R=0.388) expression levels correlated with the degree of IVD degeneration, whereas NGF (R=0.164) expression levels exhibited a minimal decrease with disease progression. Regarding the predominant clinical manifestation, only the LBP group exhibited a significant increase in TNF-α expression levels (p=0.002).ConclusionsThese results suggested that TNF-α and IL-6 play an important role in the pathophysiology of IVD degeneration at any stage, whereas NGF plays an important role during the early disease stages. Moreover, because TNF-α expression levels were significantly high in the LBP group, we propose that they are involved in LBP onset or progression

Inhibiting Vascular Endothelial Growth Factor in Injured Intervertebral Discs Attenuates Pain-Related Neuropeptide Expression in Dorsal Root Ganglia in Rats

Study DesignAn experimental animal study.PurposeTo evaluate effects of anti-vascular endothelial growth factor (VEGF) on the content and distribution of the calcitonin gene-related peptide (CGRP) in the dorsal ganglia in a rat model.Overview of LiteratureIncreased expression of VEGF in degenerative disc disease increases the levels of inflammatory cytokines and nerve ingrowth into the damaged discs. In animal models, increased levels of VEGF can persist for up to 2 weeks after an injury.MethodsThrough abdominal surgery, the dorsal root ganglia (DRG) innervating L5/L6 intervertebral disc were labeled (FluoroGold neurotracer) in 24, 8-week old Sprague Dawley rats. The rats were randomly allocated to three groups of eight rats each. The anti-VEGF group underwent L5/6 intervertebral disc puncture using a 26-gauge needle, intradiscal injection of 33.3 µg of the pegaptanib sodium, a VEGF165 aptamer. The control-puncture group underwent disc puncture and intradiscal injection of 10 µL saline solution, and the sham-surgery group underwent labeling but no disc puncture. Two rats in each group were sacrificed on postoperative days 1, 7, 14, and 28 after surgery. L1–L6 DRGs were harvested, sectioned, and immunostained to detect the content and distribution of CGRP.ResultsCompared with the control, the percentage of CGRP-positive cells was lower in the anti-VEGF group (p<0.05; 40.6% and 58.1% on postoperative day 1, 44.3% and 55.4% on day 7, and 42.4% and 59.3% on day 14). The percentage was higher in the control group compared with that of the sham group (p<0.05; sham group, 34.1%, 40.7%, and 33.7% on postoperative days 1, 7, and 14, respectively).ConclusionsDecreasing CGRP-positive cells using anti-VEGF therapy provides fundamental evidence for a possible therapeutic role of anti-VEGF in patients with discogenic lower back pain

Does Discontinuing Teriparatide Treatment and Replacing It with Bisphosphonate Maintain the Volume of the Bone Fusion Mass after Lumbar Posterolateral Fusion in Women with Postmenopausal Osteoporosis?

Study DesignRetrospective case series.PurposeThe purpose of this study was to determine whether discontinuing teriparatide treatment and replacing it with bisphosphonate treatment maintains the volume of the fusion mass after posterolateral fusion (PLF) in women with postmenopausal osteoporosis.Overview of LiteratureClinical data support the efficacy of parathyroid hormone (PTH) for lumbar PLF. However, the use of PTH is limited to 2 years.MethodsWe treated 19 women diagnosed with osteoporosis and degenerative spondylolisthesis with teriparatide (20 µg daily subcutaneously). All patients underwent one-level instrumented PLF. Teriparatide was used during 2 months prior to surgery and more than 8 months after surgery. After discontinuing teriparatide treatment, all patients used bisphosphonate (17.5 mg risedronate weekly, oral administration). Area of the fusion mass across the transverse processes at one segment was determined on an anteroposterior radiograph at 1, 2, and 3 years after surgery.ResultsWe followed 19 patients for 3 years. The average duration of teriparatide treatment was 11.5 months. The bone union rate was 95%. The average area of the bone fusion mass was not significantly different between the right and left sides at 1, 2, or 3 years after surgery (p>0.05).ConclusionsThis study showed that replacing teriparatide treatment with bisphosphonate maintained the bone fusion mass volume after PLF in women with postmenopausal osteoporosis

Change of Lumbar Ligamentum Flavum after Indirect Decompression Using Anterior Lumbar Interbody Fusion

Study DesignRetrospective case series.PurposeThe purpose of this study was to examine changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a 10-year follow-up.Overview of LiteratureExtreme lateral interbody fusion provides minimally invasive treatment of the lumbar spine; this anterior fusion without direct posterior decompression, so-called indirect decompression, can achieve pain relief. Anterior fusion may restore disc height, stretch the flexure of the ligamentum flavum, and increase the spinal canal diameter. However, changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a long follow-up have not yet been reported.MethodsWe evaluated 10 patients with L4 spondylolisthesis who underwent stand-alone anterior interbody fusion using the iliac crest bone. Magnetic resonance imaging was performed 10 years after surgery. The cross-sectional area (CSA) of the dural sac and the ligamentum flavum at L1–2 to L5–S1 was calculated using a Picture Archiving and Communication System.ResultsSpinal fusion with correction loss (average, 4.75 mm anterior slip) was achieved in all patients 10 years postsurgery. The average CSAs of the dural sac and the ligamentum flavum at L1–2 to L5–S1 were 150 mm2 and 78 mm2, respectively. The average CSA of the ligamentum flavum at L4–5 (30 mm2) (fusion level) was significantly less than that at L1–2 to L3–4 or L5–S1. Although patients had an average anterior slip of 4.75 mm, the average CSA of the dural sac at L4–5 was significantly larger than at the other levels.ConclusionsSpinal stability induced a lumbar ligamentum flavum change and a sustained remodeling of the spinal canal, which may explain the long-term pain relief after indirect decompression fusion surgery

Freeze-Dried Human Platelet-Rich Plasma Retains Activation and Growth Factor Expression after an Eight-Week Preservation Period

Study DesignControlled laboratory study.PurposeThis study aimed to evaluate the efficacy of platelet-rich plasma (PRP) stored at room temperature (RT), frozen, or after freeze-drying.Overview of LiteraturePRP enriches tissue repair and regeneration, and is a novel treatment option for musculoskeletal pathologies. However, whether biological activity is preserved during PRP storage remains uncertain.MethodsPRP was prepared from blood of 12 healthy human volunteers (200 mL/person) and stored using three methods: PRP was stored at RT with shaking, PRP was frozen and stored at −80℃, or PRP was freeze-dried and stored at RT. Platelet counts and growth factor content were examined immediately after preparation, as well as 2, 4, and 8 weeks after storage. Platelet activation rate was quantified by flow cytometry.ResultsPlatelet counts were impossible to determine in many RT samples after 2 weeks, but they remained at constant levels in frozen and freeze-dried samples, even after 8 weeks of storage. Flow cytometry showed approximately 80% activation of the platelets regardless of storage conditions. Almost no growth factors were detected in the RT samples after 8 weeks, while low but significant expression was detected in the frozen and freeze-dried PRP. Over time, the mean relative concentrations of various growth factors decreased significantly or disappeared in the RT group. In the frozen group, levels were maintained for 4 weeks, but decreased significantly by 8 weeks (p <0.05). The freeze-dried group maintained baseline levels of growth factors for the entire 8-week duration.ConclusionsFreeze-drying enables PRP storage while maintaining bioactivity and efficacy for extended periods

The Hyper Suprime-Cam SSP survey: Overview and survey design

Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg2 in five broad bands (grizy), with a 5 σ point-source depth of r ≈ 26. The Deep layer covers a total of 26 deg2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey