Search

Following drastic changes in geoenvironmental components by coseismic landslides in mountainous watersheds, more gradual changes can be observed in the elements, including bare-land surface conditions, sediment connectivity, and vegetation recovery on sloping terrains. Such geoenvironmental changes may continue for years to decades, with complex interrelationships among various geomorphological and ecological factors. Their assessments are also crucial for local to regional environmental management. After the occurrence of numerous coseismic landslides triggered by the 2018 Hokkaido Eastern Iburi Earthquake in northern Japan, geomorphological and geoecological changes were explored using optical and laser sensors on uncrewed aerial systems. Morphological characteristics of the landslide-affected slopes in the watersheds were assessed with structure-from-motion multi-view stereo photogrammetry and light detection and ranging topographic datasets, while vegetation recovery on the slopes was examined with visible-light and near-infrared images. Although spatial relationships among morphological developments, sediment mobility, and vegetation recovery were not clearly observed, their general temporal trends may be correspondent. Dominant processes affecting the morphological developments are supposed to be frost heave in the cold climate and non-frequent high-intensity rainfalls, and these can be conditioning vegetation growth. Such local changes will be further examined on a wider, regional scale.

Astrophysical reactions involving radioactive isotopes (RI) often play an important role in high-temperature stellar environments. The experimental studies on the reaction rates for those are still limited mainly due to the technical difficulties in producing high-quality RI beams. A direct measurement of those reactions would be still challenging in many cases, however, we can make a reliable evaluation of the reaction rates by an indirect method or by studying the resonance prorerties. Here we ntroduce recent examples of experimental studies on such RI-involving astrophysical reactions, performed at Center for Nuclear Study, the University of Tokyo, using the low-energy RI beam separator CRIB. One is for the neutron-induced destruction reactions of 7Be in the Big-Bang nucleosynthesis, and the other is the study on the 22Mg(α, p) reaction relevant in X-ray bursts, which was performed with the resonant scattering method from the inverse reaction channel.

Geomorphological knowledge is critical in understanding watershed scale surface processes, including steep mountainous areas and flat lowlands, particularly if the mid- and downstream areas are densely populated and hazard assessments are highly required. However, our knowledge about such surface processes has relatively been limited in some areas in South Asia due likely to the lack of comprehensive studies of geomorphology and related fields. This article undertakes an overview of the geomorphological processes of the disaster-prone deltaic landscape of the Ganges–Brahmaputra–Meghna (GBM), particularly focusing on fluvial processes. The area locates in the downstream of the watershed system including Himalayan Mountains and highly connected with the upper basin morphodynamics, hydrology, and sediment flux. The previous studies are summarized at different geomorphic settings concerning hillslopes, fluvial plains, and coastal areas to provide clarity about the geomorphic processes linking erosion-prone upstream source areas to deposition-dominated downstream areas. The review found that most of the geomorphic researches in Bangladesh are exploring landslide inventory and susceptibility mapping in hilly areas; river channel or riverbank shifting, riverbank erosion and accretion in fluvial environments; watershed morphometric analysis and geomorphic unit identification in plain land; and coastline shifting or coastal erosion and accretion in coastal environments at a small scale. Then, we discuss the fluvial dynamics and sediment transport of the GBM river system to address the knowledge gap in the context of deltaic plain land in Bangladesh, where upstream fluvial sedimentation processes impact the geomorphic connectivity from Himalayan to the Bay of Bengal. Although some studies on the fluvial dynamics and sediment dispersal in the upstream GBM river basin are present, the fluvial processes in the downstream domain of Bangladesh are not fully understood with a limited number of research with field-based approaches. Some future perspectives of geomorphic research in Bangladesh are then mentioned to understand better the complex geomorphological settings in the entire GBM watershed and to strengthen the existing research capacity. This review will also develop a holistic understanding of fluvial geomorphic processes of the GBM River to the policymakers and may be helpful to improve the transboundary river basin management policies or strategies.

The microscopic structure of a new infrared-driven amorphous white-light-generating material was explored by X-ray diffraction, EXAFS and Reverse Monte Carlo simulation. In this material, structural disorder appears to be prerequisite for this nonlinear optical effect. The results are consistent with quantum chemical predictions, but it is also found that the molecular cores are distorted, which is identified as a crystallization inhibitor. Sulfur atoms thereby form a uniform vibrational network, which may be responsible for the high capability of the material to absorb infrared radiation., 5 pages, 5 figures, 1 table

Fluctuations in sediment storage arising from sediment discharge and recharge in headwater channels are an important factor influencing changes in landforms in mountainous areas, but the frequency of surveys is limited because of access difficulties and complex topography. Although unmanned aerial vehicle-based structure-from-motion photogrammetry (UAV-SfM) may be effective for topographic measurement, its utilization in headwater channels has not been fully examined. We assessed the accuracy and reproducibility of a digital elevation model acquired via UAV-SfM (DEMSfM) in a headwater channel within the Ohya landslide area, Japan, using a DEM acquired via terrestrial laser scanning (DEMTLS). The results indicate that differences in the measured elevation between DEMSfM and DEMTLS in the vicinity of the channel bed ranged from about 0.4 to −0.4 m, with a median of 0.06 m. Hence, the profiles acquired via DEMSfM coincide well with those acquired via DEMTLS, and the spatial distributions and histograms of the measured surface slope were nearly the same for UAV-SfM and TLS. However, part of the DEMSfM indicates low elevation compared with DEMTLS, probably because of topical distortion arising from technical problems in UAV-SfM. The positive and negative differences in volume between DEMSfM and DEMTLS were approximately 200 and −30 m3, respectively. To remedy this bias, an alignment of the UAV-SfM point cloud using the TLS point cloud in the hillslope sections was conducted, based on an iterative closest point (ICP) algorithm. Consequently, the median of the elevation differences decreased to −0.002 m, resulting in the positive and negative differences becoming approximately 100 m3. This demonstrates that ICP-based alignment can lead to a reduction of the deviation of differences in the estimated volume. In terms of eliminating biases due to topical distortion in elevation, this approach would be valid for the estimation of volumetric changes using UAV-SfM.

Experimental studies on astrophysical reactions involving radioactive isotopes (RI) often accompany technical challenges. Studies on such nuclear reactions have been conducted at the low-energy RI beam separator CRIB, operated by Center for Nuclear Study, the University of Tokyo. We discuss two cases of astrophysical reaction studies at CRIB; one is for the 7Be+n reactions which may affect the primordial 7Li abundance in the Big-Bang nucleosynthesis, and the other is for the 22Mg(α, p) reaction relevantin X-raybursts.

We report the first (in)elastic scattering measurement of ^{25}Al+p with the capability to select and measure in a broad energy range the proton resonances in ^{26}Si contributing to the ^{22}Mg(α,p) reaction at type I x-ray burst energies. We measured spin-parities of four resonances above the α threshold of ^{26}Si that are found to strongly impact the ^{22}Mg(α,p) rate. The new rate advances a state-of-the-art model to remarkably reproduce light curves of the GS 1826-24 clocked burster with mean deviation

The $$^{27}\hbox {Al}(\hbox {p},\alpha )^{24}\hbox {Mg}$$ 27 Al ( p , α ) 24 Mg reaction, which drives the destruction of $$^{27}$$ 27 Al and the production of $$^{24}\hbox {Mg}$$ 24 Mg in stellar hydrogen burning, has been investigated via the Trojan Horse Method (THM), by measuring the $$^2\hbox {H}(^{27}\hbox {Al},\alpha ^{24}\hbox {Mg})\hbox {n}$$ 2 H ( 27 Al , α 24 Mg ) n three-body reaction. The experiment covered a broad energy range ($$E_\mathrm{c.m.}\le \,1.5\,\hbox {MeV}$$ E c . m . ≤ 1.5 MeV ), aiming to investigate those of interest for astrophysics. The results confirm the THM as a valuable technique for the experimental study of fusion reactions at very low energies and suggest the presence of a rich pattern of resonances in the energy region close to the Gamow window of stellar hydrogen burning (70–120 keV), with potential impact on astrophysics. To estimate such an impact a second run of the experiment is needed, since the background due the three-body reaction hampered to collect enough data to resolve the resonant structures and extract the reaction rate.

Background: The Li 6 ( p , γ ) Be 7 cross section influences a variety of astrophysical scenarios, including big-bang and stellar nucleosynthesis. In recent years, conflicting results of direct measurements have been published, reporting contradictory low-energy trends. Purpose: To shed light on the contradiction between the existing data sets, the reaction was studied using the asymptotic normalization coefficient (ANC) technique which was up-to-now never used for this reaction. Methods: To derive the ANC, the Li 6 ( He 3 , d ) Be 7 transfer reaction, studied at the Department of Physics and Astronomy of the University of Catania and at the John. D. Fox Superconducting Accelerator Laboratory at Florida State University, was re-analyzed, focusing on the proton transfer mechanism [the α transfer process is discussed by Kiss et al. [Phys. Lett. B 807, 135606 (2020)]. The energy of the He 3 beam impinging on a Li 6 target was E lab = 3 MeV and E lab = 5 MeV. The yield of the emitted deuterons was measured with high precision by using silicon Δ E - E telescopes. Results: From the DWBA analysis of the angular distributions of the emitted deuterons populating the ground ( E * = 0.0 MeV; 3 2 − ) and the first excited ( E * = 0.429 MeV ; 1 2 − ) states of Be 7 , the ANCs for the Li 6 + p → Be 7 system were deduced. Furthermore, the recently measured Li 6 ( p , γ ) Be 7 reaction cross sections [Piatti , Phys. Rev. C 102, 052802 (2020)] were also analyzed within this theoretical framework. Excellent agreement was found between ANC values derived indirectly and those determined from the direct data, which strengthens the conclusion of the present work. The astrophysical S factor—at energies characterizing the Sun—for the Li 6 ( p , γ ) Be 7 reaction was calculated using the weighted mean of the experimentally derived ANC values. Conclusions: The result of the present comprehensive study supports the extrapolation of Piatti [Phys. Rev. C 102, 052802 (2020)], Dong [J. Phys. G Nucl. Partic. 44, 045201 (2017)], and Gnech and Marcucci [Nucl. Phys. A 987, 1 (2019)], and thus disfavors the conclusions drawn by He [Phys. Lett. B 725, 287 (2013)] and Xu [Nucl. Phys. A 918, 61 (2013)].

The characteristics of debris flows (e.g., velocity, discharge, kinematic energy) are highly dependent on surges incurring abrupt changes to flow height, velocity, and boulder concentration. Therefore, understanding the initiation and runout characteristics of surges is essential when planning debris flow mitigation. Monitoring performed using 10 time-lapse cameras (TLCs) in Ohya landslide, central Japan, where debris flows occur frequently due to mobilization of storage (i.e., talus cone and channel deposits), allowed us to obtain data on a series of surge processes, from initiation to termination, which occurred during each debris flow event. We also analyzed temporal changes in the spatial distribution of storage in the debris flow initiation zone, associated with sediment supply from hillslopes and evacuation of sediment by the occurrence of debris flows, through periodic measurements of topography using unmanned aerial vehicles (UAVs). Debris flow surges were mainly induced by repetitive mass movement of storage through the erosion of channel deposits by overland flow, sliding of channel deposits, and sediment and water supply from channel banks and tributaries. Development of a spontaneous wave on the flow surface was not an important formation process of surges in the Ohya landslide. Many debris flow surges initiated at channel sections with deep storage (>2 m in depth), located

The $^{9}\mathrm{Be}(^{3}\mathrm{He},\ensuremath{\alpha})^{8}\mathrm{Be}^{*}(p)^{7}\mathrm{Li}$ reaction was studied at ${E}_{\mathrm{lab}}{(}^{3}\mathrm{He})=30$ MeV to deduce the branching ratios of ${\mathrm{\ensuremath{\Gamma}}}_{p1}$/${\mathrm{\ensuremath{\Gamma}}}_{p0}$ of resonant states at 18.91--20.1MeV in $^{8}\mathrm{Be}$, which are necessary to extract the $^{7}\mathrm{Be}(n,{p}_{1})^{7}\mathrm{Li}^{*}$ reaction rate relevant to the $^{7}\mathrm{Be}$ destruction in the big bang nucleosynthesis, from the $^{7}\mathrm{Li}(p,{n}_{0})^{7}\mathrm{Be}$ reaction cross section. The decay protons from $^{8}\mathrm{Be}^{*}$ to the ground and first excited states in $^{7}\mathrm{Li}$ were well-separately measured. The ${\mathrm{\ensuremath{\Gamma}}}_{p1}$/${\mathrm{\ensuremath{\Gamma}}}_{p0}$ ratio of the 19.235-MeV state was deduced to be $3.4\ifmmode\pm\else\textpm\fi{}1.9$ %. The 19.86- and 20.1-MeV states were found to decay dominantly into the first excited and ground states of $^{7}\mathrm{Li}$, respectively.

The cosmological lithium problem (CLP) stems from the outstanding discrepancy between theoretical predictions and astronomical observations of primordial lithium abundances. For the radiogenic production of 7Li, 7Be plays a pivotal role in the Big Bang nucleosynthesis (BBN). Nevertheless, the data for neutron-induced 7Be destruction processes were still sparse, and especially lacked information on the contributions of transitions to the 7Li excited states. In this work, we have determined the 7BeLi, 7BeLi*, and 7BeHe reaction cross sections by means of the Trojan Horse method. The present and the previous data were analyzed together by a multichannel R-matrix fit, providing an improved uncertainty evaluation of the channel and the first-ever quantification of the contribution in the BBN-relevant energy range. We implemented the revised total reaction rate summing both the and contributions in a state-of-the-art BBN code PRIMAT. As a consequence, the present nuclear-physics data offers a reduction of the predicted 7Li abundance by about one-tenth, which would impose a stricter constraint on BBN and head us in the correct direction to the CLP solution.

The mechanism of reactions with weakly-bound proton-rich nuclei at energies near the Coulomb barrier is a long-standing open question owing to the paucity of experimental data. In this study, a complete kinematics measurement was performed for the proton drip-line nucleus 17F interacting with 58Ni at four energies near the Coulomb barrier. Thanks to the powerful performance of the detector array, exhaustive information on the reaction channels, such as the differential cross sections for quasielastic scattering, exclusive and inclusive breakup, as well as for fusion-evaporation protons and alphas, was derived for the first time. The angular distributions of quasielastic scattering and exclusive breakup can be described reasonably well by the continuum-discretized coupled-channels calculations. The inclusive breakup was investigated using the three-body model proposed by Ichimura, Austern, and Vincent, and results indicate the non-elastic breakup is the dominant component. The total fusion cross sections were determined by the fusion-evaporation protons and alphas. Based on the measured exclusive breakup data, the analysis of the classical dynamical simulation code PLATYPUS demonstrates that the incomplete fusion plays a minor role. Moreover, compared with 16O+58Ni, both the reaction and total fusion cross sections of 17F+58Ni exhibit an enhancement in the sub-barrier energy region, which mainly arises from couplings to the continuum states. This work indicates that the information of full reaction channels is crucially important to comprehensively understand the reaction mechanisms of weakly bound nuclear systems.

Measuring three-dimensional morphological changes in rocky coasts is essential in evaluating the sediment dynamics in coastal areas. We carried out repeated surveys using terrestrial laser scanning (TLS) and unmanned aerial vehicle (UAV)-based structure-from-motion (SfM) photogrammetry to obtain time series of detailed topographic data of a coastal island which has been rapidly eroded. The resultant 3D point clouds were compared and differential point cloud was converted into 3D polygons showing the changed mass volume. The use of TLS enhances the accuracy of the alignment of different time datasets by UAV-SfM up to a several centimeters scale. The measured short-term erosion rates are generally lower than the reported long-term rates but are supposedly high enough to force the coastal island totally eroded within several decades.

Currently, preoperative chemotherapy is usually done for advanced esophageal cancer according to guidelines. It is still difficult to predict the effect of chemotherapy before the chemotherapy. If the effect would be poor, the patient may miss the possibility of treatment. We have been examining the possibility of predicting the chemotherapy effect based on test results before and during chemotherapy. In this study we used artificial intelligence to predict the effect of chemotherapy. Methods 80 patients who underwent preoperative chemotherapy for esophageal cancer in our department from 2012 to 2019. We predict the chemotherapy effect according to age, sex, type of chemotherapy (FP/DCF), number of chemotherapy, T, M, N, blood examination results before chemotherapy as WBC, neutrophil count, lymphocyte count, hemoglobin, platelets, total protein, Albumin, CRP, IgG, IgA, IgM, IL6, creatinine, lowest WBC, neutrophil and lymphocyte count, during chemotherapy. The effect of chemotherapy was classified: CR, PR, and PD. Prediction were performed using MatLab R2019b classification learner and Neural Net Pattern Recognition. Results The actual effect was CR/PR/SD/PD = 0/33/42/5 cases. The correct answer rate was 66.3% for the optimized tree model, 66.3% for the optimized Naïve Bayesian model, 67.5% for the optimized SVM model, and 56.3% for the optimized ensemble model. With optimized SVM, the sensitivity to predict PD was 20%, specificity was 94.5%, and AUC was 0.83. Moreover, the sensitivity to predict PR was 75.8%, and the specificity was 76.6%. With Neural Net Pattern Recognition, the correct answer rate was 90%, and the sensitivity to predict PD was 20%, specificity was 94.7%. Conclusion In this study, Neural Net Pattern Recognition as a deep learning model could predict the effect of preoperative chemotherapy more accurately than that of classification learner. The poor prediction of PD was due to the small number of teacher models, and the prediction of PR with many teacher models was more accurate. We will add more teacher models, and establish a prediction model that can be used clinically for both sensitivity and specificity.

Albumin and globulin make up the majority of serum proteins and are strongly involved in inflammation. In recent years, reports on cancer and inflammation have been scattered, and there are reports indicating that the albumin / globulin ratio (A/G ratio) may be a predictor of prognosis in patients with cancer. Here, we examined the A/G ratio and clinicopathological factors in curative cases of esophageal cancer. Methods A retrospective study was conducted on 122 patients who underwent radical surgery for esophageal cancer in our department from January 2013 to December 2017. We analyzed the correlation between A/G ratio and blood biochemical test values, and the relationship between postoperative complications and prognosis. With respect to prognosis, the cut-off value was set to 1.6 from the ROC curve, and divided into a high-value group and a low-value group, and comparatively examined. Results There were 106 males and 16 females. The median age at surgery was 69 years. Neoadjuvant chemotherapy was performed in 65 patients. A negative correlation was found between the A/G ratio and inflammatory markers. On the other hand, a positive correlation was observed between the A/G ratio and the value of a marker for nutritional indicators. In the prognostic study, the low-value group had a significantly worse prognosis than the high-value group. The group with an A/G ratio of less than 1.6 after chemotherapy had a poor prognosis. The A/G ratio was lower in the group with pneumonia after surgery. Conclusion The A/G ratio reflects the preoperative inflammatory response and nutritional status, suggesting that it is a useful factor for predicting postoperative complications and prognosis in patients with curative esophageal cancer.

We report the first (in)elastic scattering measurement of ^{25}Al+p with the capability to select and measure in a broad energy range the proton resonances in ^{26}Si contributing to the ^{22}Mg(α,p) reaction at type I x-ray burst energies. We measured spin-parities of four resonances above the α threshold of ^{26}Si that are found to strongly impact the ^{22}Mg(α,p) rate. The new rate advances a state-of-the-art model to remarkably reproduce light curves of the GS 1826-24 clocked burster with mean deviation9% and permits us to discover a strong correlation between the He abundance in the accreting envelope of the photospheric radius expansion burster and the dominance of ^{22}Mg(α,p) branch.

The development of new methods for estimating precise forest structure parameters is essential for the quantitative evaluation of forest resources. Conventional use of satellite image data, increasing use of terrestrial laser scanning (TLS), and emerging trends in the use of unmanned aerial systems (UASs) highlight the importance of modern technologies in the realm of forest observation. Each technology has different advantages, and this work seeks to incorporate multiple satellite, TLS- and UAS-based remote sensing data sets to improve the ability to estimate forest structure parameters. In this paper, two regression analysis approaches are considered for the estimation: random forest regression (RFR) and support vector regression (SVR). To collect the dependent variable, in situ measurements of individual tree parameters (tree height and diameter at breast height (DBH)) were taken in a Japanese cypress forest using the nondestructive TLS method, which scans the forest to obtain dense and accurate point clouds under the tree canopy. Based on the TLS data, the stem volume was then computed and treated as ground truth information. Topographic and UAS information was then used to calculate various remotely sensed explanatory variables, such as canopy size, canopy cover, and tree height. Canopy cover and canopy shapes were computed via the orthoimages derived from the UAS and watershed segmentation method, respectively. Tree height was computed by combining the digital surface model (DSM) from the UAS and the digital terrain model (DTM) from the TLS data. Topographic variables were computed from the DTM. The backscattering intensity in the satellite imagery was obtained based on L-band (Advanced Land Observing Satellite-2 (ALOS-2) Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2)) and C-band (Sentinel-1) synthetic aperture radar (SAR). All satellite (10–25 m resolution), TLS (3.4 mm resolution) and UAS (2.3–4.6 cm resolution) data were then combined, and RFR and SVR were trained; the resulting predictive powers were then compared. The RFR method yielded fitting R2 up to 0.665 and RMSE up to 66.87 m3/ha (rRMSE = 11.95%) depending on the input variables (best result with canopy height, canopy size, canopy cover, and Sentinel-1 data), and the SVR method showed fitting R2 up to 0.519 and RMSE up to 80.12 m3/ha (rRMSE = 12.67%). The RFR outperformed the SVR method, which could delineate the relationship between the variables for better model accuracy. This work has demonstrated that incorporating various remote sensing data to satellite data, especially adding finer resolution data, can provide good estimates of forest parameters at a plot level (10 by 10 m), potentially allowing advancements in precision forestry.

Measuring three-dimensional morphological changes in rocky coasts is essential in protecting the coastal areas and evaluating the sediment dynamics therein. In this study, we carried out repeated measurements of the three-dimensional morphology of a small rocky island using terrestrial laser scanning (TLS) and unmanned aerial vehicle (UAV)-based structure-from-motion (SfM) photogrammetry for 5 years. The TLS-derived point cloud data is used to align the UAV-SfM point cloud with a better accuracy at a centimeters scale, for which iterative closest point (ICP) method was applied. Aligned UAV-derived point clouds were then compared each other to extract changed mass for each time period. The extracted point cloud of changed mass was converted to 3D mesh polygons, by which the total volume of eroded mass was calculated.The temporal analysis of the point cloud revealed spatially variable rockfalls and wave cuts. The eroded mass volume for each period varied from 10.6 to 527.7 m3, which is equivalent to the horizontal erosion rates of 0.03 to 0.63 m/y. The temporal changes in the eroded volume is roughly associated with that in the frequency of high tidal waves (higher than 3 m) observed in this area. However, less correlation was found with the frequency of large ground shakes by earthquakes. The modern erosion rate is lower than the previously reported cliff retreat rates, but this suggests that the small island will disappear in decades. Three-dimensional structural analysis will also help understand the dynamic processes of the erosion of the bedrock cliffs in the island.

The 3D models creating by SfM (Structure-from-Motion) photogrammetry became one of the important and convenient methods for any kinds of objects on geomorphology, geoheritage, or geoarchaeological fields. These objects are landforms, monuments, buildings, relics and so on. In order to evaluate these objects, it is necessary to collect morphological characteristics, and then proceeding to decide investigating points or areas of these materials.The progress of this methods developed significantly, however, there have been still remained difficulties depending on the objects. For example, it is difficult to create 3D models that the object is too flat, too dark, and/or any restricts of combination of target size and focusing distances. The present study attempts to these difficulties by targeting to narrow and dark underground space. The investigating object is an archaeological man-made cave, called Taya Cave, in central Japan. It was excavated in 13 century originally and used as study areas for Buddhists by making Buddhism bas-reliefs. The cave has a total length of 570 m underground passage with a three-layer structure. The cave also has several domes connected by narrow paths. The present study tried to make a 3D model of this complicated, dark and narrow cave by SfM photogrammetry. In order to concur to make 3D models for the whole area of the cave, it is useful making chunks; separating several areas of simple morphology and then compiled. When facing narrow path, it is better to take photographs not by perpendicularly but by inclinedly. Furthermore, it is important to use strong light with attach to camera. After obtained the image data of the whole cave, the accuracy of the created model was evaluated. The results were that the accuracy of horizontal distances are higher than that of vertical distances.