USV-Observed Turbulent Heat Flux Induced by Late Spring Cold Dry Air Incursion over Sub-Mesoscale Warm Regions off Sanriku, Japan.

We performed oceanic and atmospheric observations in the region off the Sanriku coast, Japan, from May 11 to 5 July 2022, using a wave-propelled unmanned surface vehicle, a Wave Glider (WG). Despite the severe weather conditions of atmospheric low-pressure system crossings, we successfully measured wind, air temperature, humidity, and sea surface temperature over the course of 55 days to calculate the turbulent heat flux. The WG observed that the atmosphere became more humid due to the southerly wind along the northwestern rim of the North Pacific subtropical high.

Investigating a tsunamigenic megathrust earthquake in the Japan Trench.

The 2011 Tohoku-oki earthquake occurred in the Japan Trench 10 years ago, where devastating earthquakes and tsunamis have repeatedly resulted from subduction of the Pacific plate. Densely instrumented seismic, geodetic, and tsunami observation networks precisely recorded the event, including seafloor observations. A large coseismic fault slip that unexpectedly extended to a shallow part of megathrust fault was documented.

Rapid mantle flow with power-law creep explains deformation after the 2011 Tohoku mega-quake.

The deformation transient following large subduction zone earthquakes is thought to originate from the interaction of viscoelastic flow in the asthenospheric mantle and slip on the megathrust that are both accelerated by the sudden coseismic stress change. Here, we show that combining insight from laboratory solid-state creep and friction experiments can successfully explain the spatial distribution of surface deformation in the first few years after the 2011 M 9.0 Tohoku-Oki earthquake.

Along-trench variation in seafloor displacements after the 2011 Tohoku earthquake.

The 2011 Tohoku-oki earthquake was the largest earthquake ever observed with seafloor geodetic techniques in and around its source region. Large crustal deformation associated with both the coseismic rupture and the rapid postseismic deformation has been reported. However, these observations are insufficient to describe the postseismic deformation processes occurring around the broad rupture area.

Seafloor observations indicate spatial separation of coseismic and postseismic slips in the 2011 Tohoku earthquake.

Large interplate earthquakes are often followed by postseismic slip that is considered to occur in areas surrounding the coseismic ruptures. Such spatial separation is expected from the difference in frictional and material properties in and around the faults. However, even though the 2011 Tohoku Earthquake ruptured a vast area on the plate interface, the estimation of high-resolution slip is usually difficult because of the lack of seafloor geodetic data.

Periodic slow slip triggers megathrust zone earthquakes in northeastern Japan.

Both aseismic and seismic slip accommodate relative motion across partially coupled plate-boundary faults. In northeastern Japan, aseismic slip occurs in the form of decelerating afterslip after large interplate earthquakes and as relatively steady slip on uncoupled areas of the subduction thrust. Here we report on a previously unrecognized quasi-periodic slow-slip behavior that is widespread in the megathrust zone.

Prevalence of viscoelastic relaxation after the 2011 Tohoku-oki earthquake.

After a large subduction earthquake, crustal deformation continues to occur, with a complex pattern of evolution. This postseismic deformation is due primarily to viscoelastic relaxation of stresses induced by the earthquake rupture and continuing slip (afterslip) or relocking of different parts of the fault. When postseismic geodetic observations are used to study Earth's rheology and fault behaviour, it is commonly assumed that short-term (a few years) deformation near the rupture zone is caused mainly by afterslip, and that viscoelasticity is important only for longer-term deformation.

Detection of lung cancer by FDG-PET cancer screening program: a nationwide Japanese survey.

Aim: The aim of this study was to analyze the lung cancer detection rate in asymptomatic individuals by the Fluorine-18 fluorodeoxyglucose-positron emission tomography FDG-PET cancer screening program in Japan.

Materials And Methods: A total of 153,775 asymptomatic individuals underwent the FDG-PET cancer screening program; the 854 cases with findings that indicated suspected lung cancer by any detection method were analyzed.

Results: Among the 854 cases, 319 were verified as lung cancer.

The current status of an FDG-PET cancer screening program in Japan, based on a 4-year (2006-2009) nationwide survey.

Objective: The aim of this study was to survey the 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) cancer screening program conducted in Japan.

Methods: The "FDG-PET cancer screening program" included both FDG-PET and positron emission tomography with computed tomography (PET/CT) with or without other combined screening tests that were performed for cancer screening in asymptomatic subjects. A total of 155,456 subjects who underwent the FDG-PET cancer screening program during 2006-2009 were analyzed.

Radiation exposure and risk-benefit analysis in cancer screening using FDG-PET: results of a Japanese nationwide survey.

Objective: The aim of this study was to estimate radiation exposure and evaluate the risks and benefits of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in cancer screening.

Methods: A nationwide survey of FDG-PET cancer screening was conducted in 2006, and the results were analyzed with a common index, "extension/shortening of the average life expectancy."

Results: The average estimated effective dose was 4.

Analysis of various malignant neoplasms detected by FDG-PET cancer screening program: based on a Japanese Nationwide Survey.

Objective: The most distinctive feature of FDG-PET cancer screening program is the ability to find various kinds of malignant neoplasms in a single test. The aim of this survey is to clarify the range and frequency of various malignant neoplasms detected by FDG-PET cancer screening performed in Japan.

Methods: "FDG-PET cancer screening" was defined as FDG-PET or positron emission tomography and computed tomography (PET/CT) scan with or without other tests performed for cancer screening of healthy subjects.

Evaluation of the risk of radiation exposure from new 18FDG PET/CT plans versus conventional X-ray plans in patients with pediatric cancers.

Objective: Unnecessary radiological examination should be avoided, particularly for children, who are more vulnerable to radiation than adults. Replacement of X-ray examination with 18F-fluoro-2-deoxy-D-glucose (18FDG) positron emission tomography/computed tomography (PET/CT) is a potential option for reduction of radiation exposure, and thus improvement in the quality of life (QOL) of patients. Therefore, this study aimed to evaluate new plans integrating 18FDG PET/CT versus current conventional imaging (CI) plans for patients with pediatric cancers.

[Risk-benefit analysis of 18FDG PET cancer screening].

The benefits of (18)F-fluorodeoxyglucose ((18)FDG) positron emission tomography (PET) cancer screening are expected to include a large population of examinees and are intended for a healthy group. Therefore, we attempted to determine the benefit/risk ratio, estimated risk of radiation exposure, and benefit of cancer detection. We used software that embodied the method of the International Commission on Radiological Protection (ICRP) to calculate the average duration of life of radiation exposure.

[Performance profile of FDG-PET and PET/CT for cancer screening based on a Japanese nationwide survey].

A total of 50,558 healthy subjects underwent an FDG-PET (including PET/CT) scan with or without combination of other tests for cancer screening in 46 PET centers during fiscal year of 2005 in Japan. Thorough examination was indicated for 9.8% of the cases due to positive findings suggesting possible cancer.

Performance profile of FDG-PET and PET/CT for cancer screening on the basis of a Japanese Nationwide Survey.

Objective: The aim of this study is to survey the situation of (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) cancer screening in Japan and to describe its performance profile.

Methods: "FDG-PET for cancer screening" was defined as FDG-PET or positron emission tomography and computed tomography (PET/CT) scan with or without other tests performed for cancer screening of healthy subjects. We sent questionnaires regarding FDG-PET cancer screening to 99 facilities in which FDG-PET tests were performed during the fiscal year 2005.