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Even without breaking or wind influence, ocean surface waves are observed to produce turbulence in the water, possibly influencing ocean surface dynamics and air–sea interactions. Based on the water-side free-surface simulations, recent studies suggest that such turbulence is produced through the interaction between the waves and the near-surface Eulerian current associated with the viscous attenuation of waves. To clarify the dynamical role of the air–water interface in the turbulence production, the attenuating interfacial gravity waves were simulated directly using a newly developed two-phase wave-resolving numerical model. The air–water coupling enhanced the wave energy dissipation through the formation of a strong shear at the air-side viscous boundary layer. This led to an enhancement of the wave-to-current momentum transfer and the formation of the down-wave Eulerian mean sheared current, which is favourable for the CL2 instability responsible for the production of Langmuir circulations. As a result, the water-side turbulence grew stronger compared with the corresponding free surface (water-only) wave-resolving simulation. The evolution of the wave-averaged field was well reproduced with the Craik–Leibovich equation with the upper boundary condition provided with the virtual wave stress based on linear theory. The wave energy dissipation by air–water coupling plays a significant role in the quantitative understanding of the wave-induced turbulence at the laboratory and field scales. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective multicenter cohort study Objectives: We aimed to clarify the efficacy of multimodal intraoperative neuromonitoring (IONM), especially in transcranial electrical stimulation of motor-evoked potentials (TES-MEPs) with spinal cord-evoked potentials after transcranial stimulation of the brain (D-wave) in the detection of reversible spinal cord injury in high-risk spinal surgery. Methods: We reviewed 1310 patients who underwent TES-MEPs during spinal surgery at 14 spine centers. We compared the monitoring results of TES-MEPs with D-wave vs TES-MEPs without D-wave in high-risk spinal surgery. Results: There were 40 cases that used TES-MEPs with D-wave and 1270 cases that used TES-MEPs without D-wave. Before patients were matched, there were significant differences between groups in terms of sex and spinal disease category. Although there was no significant difference in the rescue rate between TES-MEPs with D-wave (2.0%) and TES-MEPs (2.5%), the false-positivity rate was significantly lower (0%) in the TES-MEPs-with-D-wave group. Using a one-to-one propensity score-matched analysis, 40 pairs of patients from the two groups were selected. Baseline characteristics did not significantly differ between the matched groups. In the score-matched analysis, one case (2.5%) in both groups was a case of rescue (P = 1), five (12.5%) cases in the TES-MEPs group were false positives, and there were no false positives in the TES-MEPs-with-D-wave group (P =.02). Conclusions: TES-MEPs with D-wave in high-risk spine surgeries did not affect rescue case rates. However, it helped reduce the false-positivity rate. [ABSTRACT FROM AUTHOR]

In this study, it is executed to obtain Zr 2 - x Ti x WP 2 O 12 (x = 0. 0 5 , 0.10, 0.15, 0.20) ceramics with high relative density, 0–0.9 wt% MgO was added as a sintering aid. The influence of MgO amount and relative density on the coefficient of thermal expansion for Zr 2 - x Ti x WP 2 O 12 was also investigated. Pure and monophase of Zr 1. 8 Ti 0. 2 WP2O 1 2 with MgO has been obtained and MgO used sintering aid was doped in the crystal. The coefficients of thermal expansion of the 0.9 wt% MgO-doped sample and MgO-free sample were − 2. 2 4 ppm/K and − 2. 2 5 ppm/K, respectively. This result suggests that doping of MgO does not have an influence on the coefficient of thermal expansion. In other words, adding MgO increases sintering properties without change in the coefficient of thermal expansion. [ABSTRACT FROM AUTHOR]

Study Design: Multicenter prospective study. Objectives: Although intramedullary spinal cord tumor (IMSCT) and extramedullary SCT (EMSCT) surgeries carry high risk of intraoperative motor deficits (MDs), the benefits of transcranial motor evoked potential (TcMEP) monitoring are well-accepted; however, comparisons have not yet been conducted. This study aimed to clarify the efficacy of TcMEP monitoring during IMSCT and EMSCT resection surgeries. Methods: We prospectively reviewed TcMEP monitoring data of 81 consecutive IMSCT and 347 EMSCT patients. We compared the efficacy of interventions based on TcMEP alerts in the IMSCT and EMSCT groups. We defined our alert point as a TcMEP amplitude reduction of ≥70% from baseline. Results: In the IMSCT group, TcMEP monitoring revealed 20 true-positive (25%), 8 rescue (10%; rescue rate 29%), 10 false-positive, a false-negative, and 41 true-negative patients, resulting in a sensitivity of 95% and a specificity of 80%. In the EMSCT group, TcMEP monitoring revealed 20 true-positive (6%), 24 rescue (7%; rescue rate 55%), 29 false-positive, 2 false-negative, and 263 true-negative patients, resulting in a sensitivity of 91% and specificity of 90%. The most common TcMEP alert timing was during tumor resection (96% vs. 91%), and suspension surgeries with or without intravenous steroid administration were performed as intervention techniques. Conclusions: Postoperative MD rates in IMSCT and EMSCT surgeries using TcMEP monitoring were 25% and 6%, and rescue rates were 29% and 55%. We believe that the usage of TcMEP monitoring and appropriate intervention techniques during SCT surgeries might have predicted and prevented the occurrence of intraoperative MDs. [ABSTRACT FROM AUTHOR]

Study Design: A retrospective cohort study., Purpose: We aimed to investigate the surgical results of foramen magnum decompression (FMD) to identify the potential factors associated with syrinx reduction in Chiari malformation type I (CMI)., Overview of Literature: The predictive value of preoperative factors for syrinx reduction in patients with CMI remains debatable., Methods: We enrolled patients who underwent microscopic FMD with outer dural layer resection for CMI. The distance from the tip of the cerebellar tonsil to the C2 vertebral endplate on sagittal magnetic resonance imaging (MRI) was defined as the tonsillar distance (TD). Patients who showed a >20% syrinx diameter reduction on the 1-year follow-up MRI were defined as the syrinx reduction group while the others were categorized in the syrinx nonreduction group. Patients with syringomyelia were categorized into the clinically improved and unimproved groups using the Chicago Chiari Outcome Scale. The imaging and clinical parameters were evaluated pre- and postoperatively., Results: This study included 25 patients of whom 19 (76.0%) had syringomyelia. At the 1-year follow-up, the syrinx diameter had decreased in 11 patients (57.8%). The increased TD significantly differed between the syrinx reduction and nonreduction groups. At the 1-year follow-up, 12 and seven patients with syringomyelia were categorized into the clinically improved and unimproved groups, respectively. The clinically improved and unimproved groups showed significant differences in the mean age and increased TD., Conclusions: Postoperative syrinx reduction was significantly correlated with the upward shifting of the cerebellar tonsil in patients with CMI. Our quantitative evaluation of the alterations in hindbrain position after FMD was easily performed and reflects the clinical outcomes.

Waves in the Marginal Ice Zone in the Okhotsk Sea are less studied compared to the Antarctic and Arctic. In February 2020, wave observations were conducted for the first time in the Okhotsk Sea, during the observational program by Patrol Vessel Soya. A wave buoy was deployed on the ice, and in situ wave observations were made by a ship-borne stereo imaging system and Inertial Measurement Unit. Sea ice was observed visually and by aerial photographs by drone, while satellite synthetic aperture radar provided basin-wide spatial distribution. On 12 February, a swell system propagating from east northeast was detected by both the stereo imaging system and the buoy-on-ice. The wave system attenuated from 0.34 m significant wave height to 0.25 m in about 90 km, while the wave period increased from 10 s to 15-17 s. This anomalous spectral downshifting was not reproduced by numerical hindcast and by applying conventional frequency-dependent exponential attenuation to the incoming frequency spectrum. The estimated rate of spectral downshifting, defined as a ratio of momentum and energy losses, was close to that of uni-directional wave evolution accompanied by breaking dissipation: this indicates that dissipation-driven nonlinear downshifting may be at work for waves propagating in ice. This article is part of the theme issue 'Theory, modelling and observations of marginal ice zone dynamics: multidisciplinary perspectives and outlooks'.

Introduction: Although intraoperative spinal neuromonitoring (IONM) is recommended for spine surgeries, there are no guidelines regarding its use in Japan, and its usage is mainly based on the surgeon's preferences. Therefore, this study aimed to provide an overview of the current trends in IONM usage in Japan., Methods: In this web-based survey, expert spine surgeons belonging to the Japanese Society for Spine Surgery and Related Research were asked to respond to a questionnaire regarding IONM management. The questionnaire covered various aspects of IONM usage, including the preferred modality, operation of IONM, details regarding muscle-evoked potential after electrical stimulation of the brain (Br(E)-MsEP), and need for consistent use of IONM in major spine surgeries., Results: Responses were received from 134 of 186 expert spine surgeons (response rate, 72%). Of these, 124 respondents used IONM routinely. Medical staff rarely performed IONM without a medical doctor. Br(E)-MsEP was predominantly used for IONM. One-third of the respondents reported complications, such as bite injuries caused by Br(E)-MsEP. Interestingly, two-thirds of the respondents did not plan responses to alarm points. Intramedullary spinal cord tumor, scoliosis (idiopathic, congenital, or neuromuscular in pediatric), and thoracic ossification of the posterior longitudinal ligament were representative diseases that require IONM., Conclusions: IONM has become an essential tool in Japan, and Br(E)-MsEP is a predominant modality for IONM at present. Although we investigated spine surgeries for which consistent use of IONM is supported, a cost-benefit analysis may be required., Competing Interests: Conflicts of Interest: The authors declare that there are no relevant conflicts of interest., (Copyright © 2023 The Japanese Society for Spine Surgery and Related Research.)