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Abstract In Southeast Alaska (SE-AK), rapid ground uplift of up to 3 cm/yr has been observed associated with post-Little Ice Age glacial isostatic adjustment (GIA). Geodetic techniques such as global navigation satellite system (GNSS) and absolute gravimetry have been applied to monitor GIA since the last 1990s. Rheological parameters for SE-AK were determined from dense GNSS array data in earlier studies. However, the absolute gravity rate of change observed in SE-AK was inconsistent with the ground uplift rate, mainly because few gravity measurements from 2006 to 2008 resulted in imprecise gravity variation rates. Therefore, we collected absolute gravity data at six gravity points in SE-AK every June in 2012, 2013, and 2015, and updated the gravity variation rate by reprocessing the absolute gravity data collected from 2006 to 2015. We found that the updated gravity variation rate at the six gravity points ranged from −2.05 to −4.40 $$\upmu$$ μ Gal/yr, and its standard deviation was smaller than that reported in the earlier study by up to 88 %. We also estimated the rheological parameters under the assumption of the incompressible Earth to explain the updated gravity variation rate, and their optimal values were determined to be 55 km and $$1.2 \times 10^{19}$$ 1.2 × 10 19 Pa s for lithospheric thickness and upper mantle viscosity, respectively. These optimal values are consistent with those independently obtained from GNSS observations, and this fact indicates that absolute gravimetry can be one of the most effective methods in determining sub-surface structural parameters associated with GIA accurately. Moreover, we utilized the gravity variation rates for estimating the ratio of gravity variation to vertical ground deformation at the six gravity points in SE-AK. The viscous ratio values were obtained as −0.168 and −0.171 $$\upmu$$ μ Gal/mm from the observed data and the calculated result, respectively. These ratios are greater (in absolute) than those for other GIA regions (−0.15 to −0.16 $$\upmu$$ μ Gal/mm in Antarctica and Fennoscandia), because glaciers in SE-AK have melted more recently than in other regions. Graphical Abstract

Abstract Background The genome of human immunodeficiency virus type 1 (HIV-1) is encapsulated in a core consisting of viral capsid proteins (CA). After viral entry, the HIV-1 core dissociates and releases the viral genome into the target cell, this process is called uncoating. Uncoating of HIV-1 core is one of the critical events in viral replication and several studies show that host proteins positively or negatively regulate this process by interacting directly with the HIV-1 CA. Results Here, we show that arginyl-tRNA-protein transferase 1 (ATE1) plays an important role in the uncoating process by governing the optimal core stability. Yeast two-hybrid screening of a human cDNA library identified ATE1 as an HIV-1-CA-interacting protein and direct interaction of ATE1 with Pr55 gag and p160 gag − pol via HIV-1 CA was observed by cell-based pull-down assay. ATE1 knockdown in HIV-1 producer cells resulted in the production of less infectious viruses, which have normal amounts of the early products of the reverse transcription reaction but reduced amounts of the late products of the reverse transcription. Interestingly, ATE1 overexpression in HIV-1 producer cells also resulted in the production of poor infectious viruses. Cell-based fate-of-capsid assay, a commonly used method for evaluating uncoating by measuring core stability, showed that the amounts of pelletable cores in cells infected with the virus produced from ATE1-knockdown cells increased compared with those detected in the cells infected with the control virus. In contrast, the amounts of pelletable cores in cells infected with the virus produced from ATE1-overexpressing cells decreased compared with those detected in the cells infected with the control virus. Conclusions These results indicate that ATE1 expression levels in HIV-1 producer cells contribute to the adequate formation of a stable HIV-1 core. These findings provide insights into a novel mechanism of HIV-1 uncoating and revealed ATE1 as a new host factor regulating HIV-1 replication. Graphic abstract

Abstract An electrical resistivity model beneath Azumayama Volcano, NE Japan, is explored using magnetotelluric method to probe the magma/hydrothermal fluid distribution. Azumayama is one of the most concerning active volcanoes capable of producing a potential eruption triggered by the 2011 Tohoku-Oki Earthquake. The three-dimensional resistivity model reveals a conductive magma reservoir (

Abstract We present one of the first studies on source location determination for volcanic earthquakes and characterization of volcanic subsurfaces using data from a distributed acoustic sensing (DAS) system. Using the arrival time difference estimated from well-correlated waveforms and a dense spatial distribution of seismic amplitudes recorded along the fiber-optic cable, we determine the hypocenters of volcanic earthquakes recorded at Azuma volcano, Japan. The sources are located at a shallow depth beneath active volcanic areas with a range of approximately 1 km. Spatial distribution of the site amplification factors determined from coda waves of regional tectonic earthquakes are well correlated with old lava flow distributions and volcano topography. Since DAS observation can be performed remotely and buried fiber-optic cables are not damaged by volcanic ash or bombs during eruptions, this new observation system is suitable for monitoring of volcanoes without risk of system damage and for evaluating volcanic structures.

Abstract Breast cancer diagnosis has been mostly accomplished through imaging. These methods have great advantages in being able to detect the presence and location of breast cancer. However, it is difficult to distinguish between a benign and malignant tumor located in a deep position because both tumor types look similar. In this paper, tissue including the tumor from skin was vibrated using a compression cylinder, to analyze the frequency difference for distinguishing tissue type. Before distinguishing between a benign and malignant tumor, it is necessary to validate that the difference between normal tissue and tumor can be distinguished. The objective of the study is to validate the feasibility to emphasize the frequency differences in a 10.0 mm or greater deep tumors during vibration by pushing a cylinder towards the deep tumor. A phantom model and finite element analysis model were constructed to simulate the breast. In the experiment, air was injected into the phantom and the displacement was measured. The frequency response for distinction of tissue types was analyzed and it was found that the displacement difference rate was over 50% at a frequency of 130 Hz when the cylinder was pushed into the sample as opposed to when not pushed in. Changes in displacement were measured according to the distance between the tumor and vibration point using finite element analysis. When the measurement and vibration points were on the center of the tumor, the difference in the resonance point was at its largest (5.5 Hz). Results show that the position of a tumor could be easily and rapidly detected by vibrations from a cylinder pushed into the diagnostic site.

The Okama Crater Lake is located in the highly active Zao Volcano on the boundary of Miyagi and Yamagata Prefectures, Japan. At present, the lake stays relatively calm with neither bubbling, steaming nor gas smell at a pH of 3.2–3.4, though the lake did change color with steaming from the water surface in 1939 as the result of one of Zao’s volcanic activities. In order to clarify the geothermal effect on Okama and the groundwater flow system below or around Okama, field observations were performed in 2019 and 2020. Groundwater inflow and outflow in Okama were separately evaluated by estimating the hydrological and chemical budgets of the lake, based on the hydrometeorology, water temperature and river inflow measured in the field. The average groundwater inflow and outflow were estimated at 0.012 m3/s and 0.039 m3/s during the non-rainfall periods of 2020, respectively. A surplus of groundwater outflow makes the lake level consistently decrease during non-rainfall periods or the completely ice-covered season. In the completely ice-covered periods, the water temperature consistently increased at 0–15 m above the lake bottom, which is probably due to thermal leakage from a hydrothermal reservoir below the lake bottom. The heat fluxes averaged over December 2019–April 2020 and December 2020–March 2021 were calculated at 2.5 and 2.9 W/m2, respectively. A coupling between the estimated groundwater inflow and the calculated geothermal heat flux was used to evaluate the temperature of inflowing groundwater.

This paper presents a method to inspect the interior of a winding small gas pipe using a hollow guide wire. There is no conventional method to insert an endoscope into an 8-bend 25-mm-diameter gas pipe within 2 hours. In medical practice, a guide wire inserted in advance enables insertion of a catheter into a vessel. However, it is impossible to insert a normal guide wire into a gas pipe because the wire buckles in the pipe. Thus, we designed a hollow guide wire with a small front diameter and large rear diameter, making the front soft and the rear stiff. This guide wire can be inserted without buckling or meandering. First, we measured mechanical properties such as the torsional spring constant and damping coefficient of the wire and the frictional coefficient between the pipe and wire. Second, we conducted an experiment inserting guide wires with various tip pitches, front lengths, front outer diameters, and rear outer diameters. Third, we analyzed the insertion distance by simulating guide wire insertion using the Lagrange method, and optimized the guide wire shape via the response surface method. Finally, the optimized guide wires were tested experimentally to validate the analysis. As a result, an optimized guide wire and an endoscope can both be inserted into a gas pipe and removed within just 3 minutes.

Abstract We report an experimental demonstration of controlling plasma flow direction with a magnetic nozzle consisting of multiple coils. Four coils are controlled separately to form an asymmetric magnetic field to change the direction of laser-produced plasma flow. The ablation plasma deforms the topology of the external magnetic field, forming a magnetic cavity inside and compressing the field outside. The compressed magnetic field pushes the plasma via the Lorentz force on a diamagnetic current: j × B in a certain direction, depending on the magnetic field configuration. Plasma and magnetic field structure formations depending on the initial magnetic field were simultaneously measured with a self-emission gated optical imager and B-dot probe, respectively, and the probe measurement clearly shows the difference of plasma expansion direction between symmetric and asymmetric initial magnetic fields. The combination of two-dimensional radiation hydrodynamic and three-dimensional hybrid simulations shows the control of the deflection angle with different number of coils, forming a plasma structure similar to that observed in the experiment.

Postseismic slip of the 2011 Tohoku earthquake in Japan has occurred on the plate interface, but quantifying the slip has been difficult due to a lack of seafloor data. Here, the authors use seafloor and terrestrial data and show that areas of co- and postseismic slip are spatially separated.

A fall can result in fractures, sequelae, or even death in the worst-case scenario. Falls often occur because people misjudge step height and do not lift their feet sufficiently. One strategy to combat this issue is the use of vertical stripes to make stairs appear taller than they really are, which can thus prevent underestimation of the real height. However, the appropriate size of the space between the stripes is different for everyone. This study demonstrates how the intensity of an illusion can influence the height of foot clearance when ascending stairs. We validate the feasibility of using a model for determining the striping that can be used to adapt the pattern to individual differences. We constructed the model based on a contrast-sensitivity function using a Gaussian model. In an experiment, we measured the location of the toe via motion capture as participants climbed stairs. As a result, the relationship between foot-clearance and the spatial frequency approximated the function described by the CSF, Contrast Sensitive Function. The coefficients of determination exceeded 0.9 for one participant, 0.8 for two participant and 0.6 for other two participants. We concluded that the model presented CSF would fit the foot clearance with striped stairs for any individual.

In this study, we propose a novel endoscopic manipulation system that is controlled by a surgeon's eye movements. The optical axis direction of the endoscopic manipulator is altered intuitively based on the surgeon's pupil movements. A graphical user interface was developed by dividing the monitor screen into several areas with shape boundaries, so that the movement direction of the endoscope can be identified by the area gazed at by the operator. We used a probabilistic neural network (PNN) to decide the regional distribution proportion to recognize the direction in which the operator would want the endoscopic manipulator to move. The PNN model was trained by individual calibration data. We hypothesized that PNN model training could be completed immediately after calibration, which also determines the boundary of the regional distribution portion (RDP). We designed an experiment and recorded the path of direction change to verify the PNN's effectiveness in our proposed system. All participants, including four who wore glasses, completed the requested task. Moreover, wearing glasses had no significant effect on the performance of the proposed system. Furthermore, the PNN training duration only took 2% of the entire time of the procedure to handle individual differences. We conclude that our method can handle individual differences in operators' eyes through machine learning of personal calibration data over a short time frame, which will not take significant extra preoperative setup time.

Hemiplegic patients often have reduced typing speed due to finger paralysis. Our motivation is to develop a keyboard that enables their typing speed to increase. For this purpose, we have developed a three-dimensional keyboard that reduces the distance that fingers move while typing. In this paper, our objective was to construct the finger model that combines the motion speed and muscle fatigue for design of keyboard that can be typed with fast motion speed and low muscle fatigue. In experiment, we measured the finger position using a magnetic 3D motion device and EMG when the participant pressed the proposed key. The experiment was carried out in a variety of the finger postures. We qualified the motion speed and muscle fatigue at each joint angle. Then, we weighted and combined two of the objective functions. We found out the Pareto solution and get an effective keyboard design straight. In the future, we verify the typing speed and finger muscle fatigue during typing the three-dimensional keyboard that is designed based on our finger model.

In recent years, development of the automated driving system is aggressively promoted for the purpose of reducing burden of drivers and for the enhanced safety. Transferring the intention of the driver to the automobile control, such as to stop on the way or to change destinations, is essential even if a direct control from the driver is no longer necessary. Therefore, an in-car interface to conduct intention of the driver promptly and accurately to the automobile control is needed. In this paper, we proposed an interface which recognizes the intended target of the driver using gestures and speech recognition. The speech recognition technology was previously developed. Hence, we developed an interface to recognize the direction in which the driver is pointing toward from the gesture. We hypothesize that we can estimate the direction in which the driver is pointing toward from the fingertip and eye position. Verification using three-dimensional motion analysis system showed that it is possible to recognize the direction of the object with a maximum error of 5.5° and an average error of 1.2°. After verifying the hypothesis, a position measurement device that integrates Leap Motion® and KINECT®, the non-contact sensor, was developed to recognize gestures of the driver in the automobiles. The maximum error of the angle recognition in accordance with the present device was 16.1°. However, the value of the error exists only in a certain interval. For this reason, by taking into account the movement of the eye position, and provide adequate tuning for each driver, proposed interface is sufficiently usable.