Geophysical features of permafrost in the Canadian Beaufort Sea

第6回極域科学シンポジウム分野横断セッション：[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日（木）　国立極地研究所１階交流アトリウ

Clinical and Pathological Characteristics of Four Korean Patients with Limb-Girdle Muscular Dystrophy type 2B

Limb-girdle muscular dystrophy type 2B (LGMD2B), a subtype of autosomal recessive limb-girdle muscular dystrophy (ARLGMD), is characterized by a relatively late onset and slow progressive course. LGMD2B is known to be caused by the loss of the dysferlin protein at sarcolemma in muscle fibers. In this study, the clinical and pathological characteristics of Korean LGMD2B patients were investigated. Seventeen patients with ARLGMD underwent muscle biopsy and the histochemical examination was performed. For the immunocytochemistry, a set of antibodies against dystrophin, α, β, γ, δ-sarcoglycans, dysferlin, caveolin-3, and β-dystroglycan was used. Four patients (24%) showed selective loss of immunoreactivity against dysferlin at the sarcolemma on the muscle specimens. Therefore, they were classified into the LGMD2B category. The age at the onset of disease ranged from 9 yr to 33 yr, and none of the patients was wheelchair bound at the neurological examination. The serum creatine kinase (CK) was high in all the patients (4010-5310 IU/L). The pathologic examination showed mild to moderate dystrophic features. These are the first Korean LGMD2B cases with a dysferlin deficiency confirmed by immunocytochemistry. The clinical, pathological, and immunocytochemical findings of the patients with LGMD2B in this study were in accordance with those of other previous reports

Bidirectional Association Between Parkinson’s Disease and Obstructive Sleep Apnea: A Cohort Study

STUDY OBJECTIVES: Chronic intermittent hypoxia due to obstructive sleep apnea (OSA) causes oxidative stress, which may contribute to the pathophysiology of Parkinson\u27s disease (PD). However, the bidirectional relationship between PD and OSA has not been satisfactorily established. The objective of this study was to try to estimate whether there is a bidirectional relationship between PD and OSA through a retrospective cohort study in the South Korean population. METHODS: This study used data from the Korean National Health Information Database of the National Health Insurance Service, which contains data from 3.5 million individuals evenly distributed. In study 1, patients with OSA were matched in a 1:2 ratio with non-OSA controls. In study 2, patients with PD were matched in a 1:2 ratio with non-PD controls. A stratified Cox proportional hazards model was used to calculate hazard ratios. RESULTS: In study 1, which included 6,396 patients with OSA and 12,792 non-OSA controls, the incidence of PD per 10,000 person-years was 11.59 in the OSA group and 8.46 in the non-OSA group. The OSA group demonstrated a 1.54-fold higher incidence of PD than the non-OSA group (95% confidence interval, 1.14-2.07; CONCLUSIONS: This study supports a possible bidirectional relationship between PD and OSA. CITATION: Jeon S-H, Hwang YS, Oh S-Y, et al. Bidirectional association between Parkinson\u27s disease and obstructive sleep apnea: a cohort study

Moment and shear capacity of Ply-lam composed with plywood and structural timber under out-of-plane bending

The aim of this study was to investigate the moment and shear capacity of Ply-lam which is composed with plywood and structural timber. The moment and shear capacity of Ply-lam were predicted by using prediction methodologies for typical cross-laminated timber (CLT). The predicted values by the methodologies were verified by comparison with measured capacities. Fifty-eight specimens of Ply-lam (five layers) were manufactured and half of the specimens were tested for bending (span-to-depth ratio (Rsd) was 25:1). The other specimens were tested for rolling shear (Rsd)) in accordance with EN 16351. The results show that typical prediction methods for structural properties of CLT can also be used to predict those of Ply-lam, since the measured values were higher than the predicted values. In rolling shear test, 52% specimens failed by bending at the bottom layer. This indicates that the rolling shear test method in EN 16351 was not suitable for Ply-lam because the typical CLT would be reinforced by replacing the cross layer with plywood. Thus, the span-to-depth ratio needs to be reduced for hybrid CLT like Ply-lam.This project funded by Korea Forest Service (Korea Forestry Promotion Institute)

The natural history of pediatric trigger thumb

BACKGROUND: Pediatric trigger thumb is a condition of flexion deformity of the interphalangeal joint in children. Although the surgical outcome is satisfactory, the indications for nonoperative treatment for this condition are not clear. The aim of the present study was to determine the rate of resolution of untreated pediatric trigger thumb. METHODS: Data on seventy-one thumbs in fifty-three children were collected prospectively. The dates of the first visits ranged from April 1994 to March 2004. Patients were diagnosed with pediatric trigger thumb during initial outpatient department visits. During the present study, no treatment such as passive stretching or splinting was applied. The amount of flexion deformity at the thumb interphalangeal joint was measured at every six-month follow-up visit, and the duration of follow-up was at least two years after diagnosis. The end point of follow-up was when the deformity caused pain or secondary deformity or prevented normal use of the hand. The median duration of follow-up was forty-eight months. RESULTS: Of the seventy-one trigger thumbs, forty-five (63%) resolved spontaneously. The median time from the initial visit to resolution was forty-eight months. There was no significant difference in the pattern of resolution between patients with unilateral and bilateral trigger thumb. Although resolution was not observed in the remaining twenty-six thumbs, flexion deformities improved in twenty-two thumbs. For the first two years after the initial visit, the mean flexion deformity significantly decreased over the one-year intervals (p 60% of patients. Moreover, the flexion deformity can be expected to show an improving pattern in patients who do not have resolution. This information may help both parents and surgeons to make decisions regarding the treatment of pediatric trigger thumb

Imaging the P‐Wave Velocity Structure of Arctic Subsea Permafrost Using Laplace‐Domain Full‐Waveform Inversion

Climate change in the Arctic has recently become a major scientific issue, and detailed information on the degradation of subsea permafrost on continental shelves in the Arctic is critical for understanding the major cause and effects of global warming, especially the release of greenhouse gases. The subsea permafrost at shallow depths beneath the Arctic continental shelves has significantly higher P‐wave velocities than the surrounding sediments. The distribution of subsea permafrost on Arctic continental shelves has been studied since the 1970s using seismic refraction methods. With seismic refraction data, the seismic velocity and the depth of the upper boundary of subsea permafrost can be determined. However, it is difficult to identify the lower boundary and the internal shape of permafrost. Here, we present two‐dimensional P‐wave velocity models of the continental shelf in the Beaufort Sea by applying the Laplace‐domain full‐waveform inversion method to acquired multichannel seismic reflection data. With the inverted P‐wave velocity model, we identify anomalous high seismic velocities that originated from the subsea permafrost. Information on the two‐dimensional distribution of subsea permafrost on the Arctic continental shelf area, including the upper and lower bounds of subsea permafrost, are presented. Also, the two‐dimensional P‐wave velocity model allows us to estimate the thawing pattern and the shape of subsea permafrost structures. Our proposed P‐wave velocity models were verified by comparison with the previous distribution map of subsea permafrost from seismic refraction analyses, geothermal modeling, and well‐log data