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Used to reduce damage from rainfall-induced landslides and establish disaster-warning systems, physically based stability models are efficient tools for evaluating spatial or temporal patterns of susceptibility to shallow landslides. Such comprehensive models can be classified as dynamic and steady hydrological models, which combine the simulation of dynamic or steady-state subsurface saturation generation with slope stability analysis. Although numerous dynamic and steady models have been proposed and validated against actual landslides, comprehensive comparisons of the performance and detection preferences for topographic characteristics (hereafter, topographic preferences) between the dynamic and steady models are lacking. Based on detailed observational data on topography at the soil–bedrock interface, this study compared numerical predictions from dynamic and steady models to a case of rainfall-induced shallow landslides in a small catchment. The dynamic model was based on time-varying generation of subsurface saturation using the three-dimensional Richards equation, and the steady model was based on the steady-state distribution of subsurface saturation. The results showed that both the dynamic and steady models could generally detect cells at risk of failure in the landslide areas. However, the precision of the dynamic model was approximately double that of the steady model. Rainfall patterns had significant impacts on the timing and locations of landslides, and the delayed rainfall peak pattern was most prone to landslides, which was reflected by the dynamic model but not the steady model. The steady model underestimated instability or the number of unstable locations relative to the dynamic model. This study revealed that the topographic preference at the soil–bedrock interface differs between the models. The dynamic model exhibited topographic preference in detecting landslides with deep soil depth and steep gradient, whereas the steady model was better for detecting landslides with large contribution areas. The elucidation of such topographic preferences for landslide types is crucial for comparing the performance of dynamic and steady models.

Physically based numerical simulation models have been developed to predict hazard area relating to debris flows. Since fine sediments are expected to behave as a part of the fluid rather than solid phase in stony debris flows, several models have recently included this process of the phase shift from solid to fluid in the context of fine sediment. However, models have not been fully tested regarding the ability to reproduce a variety of debris flow characteristics. We therefore tested (i) applicability of a numerical simulation model for describing debris flow characteristics and (ii) the effect of phase shift of fine sediment on debris flow behaviors. Herein we applied a numerical simulation model to a well-documented dataset from the Illgraben debris flow observation station in Switzerland. Based on the stony debris flow concept, we physically modeled effects of the phase shift of sediment on transport capacity and flow resistance. We successfully reproduced the observed bulk density, erosion and deposition patterns, front velocity, and erosion rate, although we had to tune the ratio of fine sediment that behaves as a fluid. Considering the effects of the phase shift of sediments, we conclude that physically based numerical simulation models can describe a variety of debris flow behaviors.

The mechanisms of efficacy in mindfulness-based interventions for depression and anxiety are not fully understood. To clarify these mechanisms, we tested the hypotheses that mind-wandering, daydreaming, cognitive fusion, and experiential avoidance will decrease through mindfulness group therapy, and this decrease will correlate with improvements in depression and anxiety. Participants self-reported depression and/or anxiety (N = 28) took part in an 8-week mindfulness group therapy program. They were assessed using self-report scales at pre- and post-intervention, and at 2-month follow-up. Results indicated that depression and trait-anxiety decreased between pre- and post-intervention with moderate effect sizes, which were maintained at follow-up. Mind-wandering and cognitive fusion also decreased between pre- and post-intervention with small to moderate effect sizes, and maintained at follow-up. The decreases in mind-wandering and cognitive fusion moderately correlated with improvements in depression and anxiety, suggesting that decreases in mind-wandering and cognitive fusion might underlie efficacious mechanisms of mindfulness group therapy.

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Self-compassion is regarded as a mediating or moderating variable in mindfulness-based interventions (MBI). However, few studies have investigated the role of self-compassion on MBI. Therefore, we conducted a randomized controlled trial to examine whether (1) MBI decreases depression and trait anxiety, while increasing trait mindfulness, trait self-compassion, self-compassionate behaviors (SC behaviors), and behaviors, along with improving mood; and (2) SC behaviors moderate the effect of mindful behaviors on mood in daily life. Participants were patients with depression and/or anxiety ( N=19) in Japan. Of the 27 participants recruited, 19 participated in the study. Using stratified randomization, we allocated 10 participants to the intervention group, with an 8-week standard MBI, and nine to the waitlist control group. Depression, trait anxiety, trait mindfulness, and trait self-compassion were assessed using questionnaires, while SC behaviors, mindful behaviors, and mood were measured using an ecological momentary assessment—a method used to repeatedly record events and behaviors in daily life. The results revealed that depression, trait anxiety, trait mindfulness, and trait self-compassion did not significantly change. However, SC behaviors, mindful behaviors, and mood significantly improved with MBI. Moreover, the interaction between SC behaviors and mindful behaviors was significantly shown in the pre-intervention, suggesting that SC behaviors moderate the effect of mindful behaviors on mood in daily life.

Observation of bedload is quite important for understanding temporal and spatial variation of sediment transport in mountainous regions. In government-owned mountain watersheds in Japan, Japanese pipe-type hydrophones (Hydrotech Co., Ltd.) have been installed as a surrogate monitoring tool since about 2009 and continuous observations have been conducted. According to positive correlation between sound pressure and bedload transport rate, observed sound pressure is used to be integrated with respect to time and its value is converted into bedload transport rate using proportionality constant. However, it remains challenging to obtain precise bedload transport rate with high accuracy, because we should consider the difference of the way to fix the hydrophone on river bed among installed sites, deformation of steel pipe due to collision of sediment particles, and the difference of initial performance and aging of microphone. Hence, we have to calibrate frequently the proportionality constant. In this study, we investigate a calibration method which is easily conducted by engineers. Because it takes time and effort to obtain time integral of sound pressure, we try to calibrate the proportionality constant with the maximum sound pressure, which can be obtained easily.

Storm-induced landslides are a common hazard, but the link between their spatial pattern and rainfall properties is poorly understood, mostly because hillslope stability is modulated by under-constrained, spatially variable topographic, hydrological and mechanical properties.Here, we use a 26 years long, high spatial resolution rainfall dataset from the Japanese radar network, to analyze the landslide pattern (1900 landslides within ~5000 km2) caused by Typhoon Talas (>1500 mm in 3 days) in 2011 in the Kii Peninsula. We show that it poorly correlates with the rainfall amount accumulated during the event over short to long timescales (1-72h), but agrees well with the rainfall anomaly (i.e., the event rainfall amount over the rainfall amount expected for a 10-year return period rainfall). Normalizing the event rainfall by mean annual or seasonal rainfall does not match as well the landslide pattern. This suggests that the variability in hillslope properties has co-evolved with the recent climate, where slopes exposed to stronger extreme rainfall have experienced higher landslide rates until their properties (e.g., regolith thickness, strength and permeability) have reached an equilibrium. In this framework, the 10-year return rainfall amount would be a proxy for hillslope properties, and we show that it allows an improved prediction of the landslide pattern when coupled with rainfall amount and slope. Finding ways to constrain the spatial variability of these parameters to test this hypothesis is an exciting challenge.Last we note that rock-types seem to respond to rainfall anomalies at various timescales, favoring specific landslide geometries, and suggesting various hydrological properties in these zones. Specifically, a coastal area underlain by highly weathered volcanic rocks yielded a high landslide density with a high proportion of debris flow, correlating with the 2h anomaly while the rest of the landslides matches best the 48h anomaly.Although such influence of lithology on hydrological behavior remains hard to predict, we propose the computation of rainfall anomalies for multiple timescales to pave the way towards operational landslide forecasts in case of large storms. More generally, regional landslide susceptibility maps may also be significantly enhanced by considering maps of past extreme rainfall.

Monitoring of sediment transport from hillslopes to channel networks as a consequence of floods with suspended and bedload transport, hyperconcentrated flows, debris and mud flows is essential not only for scientific issues, but also for prevention and mitigation of natural disasters, i.e. for hazard assessment, land use planning and design of torrent control interventions. In steep, potentially unstable terrains, ground-based continuous monitoring of hillslope and hydrological processes is still highly localized and expensive, especially in terms of manpower. In recent years, new seismic and acoustic methods have been developed for continuous bedload monitoring in mountain rivers. Since downstream bedload transport rate is controlled by upstream sediment supply from tributary channels and bed-external sources, continuous bedload monitoring might be an effective tool for detecting the sediments mobilized by debris flow processes in the upper catchment and thus represent an indirect method to monitor slope instability processes at the catchment scale. However, there is poor information about the effects of episodic sediment supply from upstream bed-external sources on downstream bedload transport rate at a single flood time scale. We have examined the effects of sediment supply due to upstream debris flow events on downstream bedload transport rate along the Yotagiri River, central Japan. To do this, we have conducted continuous bedload observations using a hydrophone (Japanese pipe microphone) located 6.4 km downstream the lower end of a tributary affected by debris flows. Two debris flows occurred during the two-years-long observation period. As expected, bedload transport rate for a given flow depth showed to be larger after storms triggering debris flows. That is, although the magnitude of sediment supply from debris flows is not large, their effect on bedload is propagating >6 km downstream at a single flood time scale. This indicates that continuous bedload observations could be effective for detecting sediment supply as a consequence of debris flow events.

Many studies on shallow landslides have focused on seepage mechanisms. However, most of these studies assumed that the hillslope was parallel to the seepage direction and force; they did not consider how the seepage was changed by the topography during failure. To investigate the seepage mechanism, particularly the influence of the topographic change during failure, flume experiments using a 30° sandy slope were performed with artificial rainfall. The factor of safety (FS) equation, which considers the seepage direction and force, and the numerical simulation were also applied to analyze the effect of topographic change on the seepage mechanism. The experiments were divided into two stages: rainfall-induced experiment (RIE) and seepage-induced experiment (SIE) with rainfall. In the RIE with a rainfall intensity of 80 mm/h, seepage erosion occurred followed by undercutting, which resulted from seepage erosion, to upward direction of sandy slope. The analysis of FS in RIE are showing an instability when seepage direction is be a slope parallel with theoretical value, i ( Hydraulic gradient ). In the numerical model, when topographic changes of the surface of the sandy flume were applied, seepage flow concentrated from failure surface of the toe of flume to middle part of flume, which is affected by saturation. In SIE, multiple failures caused by the seepage in the vertically upward direction occurred with a high seepage force, and the failure mass then moved in the downward direction with the seepage flow. FS for SIE showed a high instability than those of RIE when seepage direction with high force already changed from vertically downward seepage flow to increasing slope parallel seepage flow. Applying changed topography (more deep from sandy flume surface) in numerical model is showing concentrated seepage flow at the bottom of failures. This is one of mechanism developing failure mass to downward direction to the toe of flume because soil moisture sensors installed near failures (25 cm-depth) show high value than porosity value, indicating soil mobilization. Therefore, the seepage direction and force play important roles in landslide mechanism, and these factors should be considered in landslide studies.

A simple method for controlling the pore structure and properties of ordered mesoporous silica (OMS) by the physisorption of organic molecules is reported. The paraffin-modified OMSs were characterized by N2 gas and water vapor adsorption isotherms, small-angle X-ray scattering, and infrared spectroscopy. We found that paraffin first adsorbed on the pore surface defects, resulting in a smooth OMS pore surface; thus, the paraffin controlled the pore structure. In addition, the surface hydrophobicity increased with increasing paraffin filling fraction.

Hydrogen evolution reaction (HER) on Cu and Ag electrodes in neutral and alkaline media (but not in acidic media) is significantly accelerated by the addition of 4,4′-bipyridine (BiPy). The mechanism of the HER acceleration is discussed at a molecular level by using surface-enhanced infrared absorption spectroscopy (SEIRAS) coupled with electrochemical techniques and density functional theory (DFT) calculations. Simultaneous SEIRAS and cyclic voltammetry measurements reveal that the onset potential of the accelerated HER coincides with the 1e − + 1H + reduction potential of adsorbed BiPy to yield monohydro BiPy radical (BiPy-H ). Tafel plot analysis and DFT calculations suggest that BiPy-H is further reduced to N , C(3) -dihydro BiPy via a subsequent 1e − + 1H + step and finally H 2 is evolved by the combination of two H atoms on N and C(3) atoms (BiPy-H 2 → BiPy + H 2 ). Since adsorbed BiPy is readily reduced again to BiPy-H in the potential range of HER, the reaction process is catalytically cycled. The enhanced HER is not observed on Au electrodes due to the desoption of BiPy from the surface. Also the enhanced HER is not observed on Pt electrodes despite strong adsorption on Pt because the redox potential of adsorbed BiPy, the first step of the HER, is more negative than the onset of HER on bare Pt surface.

Electrochemical hydrogen evolution reaction (HER) on silver is significantly accelerated by adding 4,4 ′ -bipyridine (BiPy) into neutral or alkaline aqueous solution (T. Uchida et al. J. Am. Chem. Soc. , 130 (2008) 10826). The mechanism of the accelerated HER by BiPy is studied by the first-principles molecular dynamics simulation with the constant Fermi energy scheme of the effective screening medium (ESM) method. The simulation shows that H 2 is evolved through the following three steps: First, BiPy adsorbed on the electrode via one N-end directing another N-end toward the solution is reduced to N -hydro BiPy radical (BiPy-H⋅), in which H is bonded to N atom of the solution side. BiPy-H⋅ is further reduced to N , C (3)-dihydro BiPy with an activation free energy of 0.5 eV by the second proton-coupled electron transfer. Finally, H 2 is released from the two H atoms on N and C(3) of N , C (3)-dihydro BiPy by the assist of H 2 O or OH − . BiPy is reproduced by the H 2 evolution and the processes are catalytic-cycled.

Cyclic voltammetry (CV) and in-situ Surface-Enhanced Infrared Absorption Spectroscopy (SEIRAS) are used to study the adsorption behavior of an electroplating additive, 3,3 thiobis-(1-propanesulfonic acid sodium salt) (TBPS), on a polycrystalline Au(111) surface. The effects of the applied potentials on the adsorption behavior of TBPS are investigated and compared to that obtained by in-situ scanning tunneling microscopy (STM) in a previous work. The results show that TBPS molecules can adsorb on the Au surface at 0.05 V (RHE) and approach an equilibrium state after ca. 200 sec. For the IR spectrum detected in the air, the most pronounced peaks of TBPS are symmetric S O (ss-SO) and asymmetric S O (as-SO) stretching modes. Upon adsorption on the Au surface, the ss-SO peak still keeps a sharp and intense shape, while the as-SO peaks appear as a broad peak with much lower intensity. Since the ss-SO vibration mode is parallel to the long molecular axis, these results imply that the TBPS molecules mainly adsorb with a lift-up conformation at 0.05 V. With the increase in electrode potential, the ss-SO peak intensities first increase slightly due to further adsorption of the TBPS, and then, decrease steadily, ascribing to a conformation change of adsorbed TBPS molecules from an upright to a lie-down orientation. On the contrary, the as-SO band intensity first stays constant, and then, increases with increasing potential, consistent with the inference of the conformation change. Accompanying the adsorption and conformation change in the TBPS molecules, the peak corresponding to the bending mode of the adsorbed water δ(HOH) reflects that water molecules move away from the surface when TBPS molecules are adsorbed at low potentials, but will become closer again as the molecular conformation shifts to a lie-down orientation. The adsorption behavior of TBPS with respect to the potential change is reversible.

Nitric oxide (NO) is synthesised not only from l-arginine by NO synthases (NOSs), but also from its inert metabolites, nitrite and nitrate. Green leafy vegetables are abundant in nitrate, but whether or not a deficiency in dietary nitrite/nitrate spontaneously causes disease remains to be clarified. In this study, we tested our hypothesis that long-term dietary nitrite/nitrate deficiency would induce the metabolic syndrome in mice. To this end, we prepared a low-nitrite/nitrate diet (LND) consisting of an amino acid-based low-nitrite/nitrate chow, in which the contents of l-arginine, fat, carbohydrates, protein and energy were identical with a regular chow, and potable ultrapure water. Nitrite and nitrate were undetectable in both the chow and the water. Three months of the LND did not affect food or water intake in wild-type C57BL/6J mice compared with a regular diet (RD). However, in comparison with the RD, 3 months of the LND significantly elicited visceral adiposity, dyslipidaemia and glucose intolerance. Eighteen months of the LND significantly provoked increased body weight, hypertension, insulin resistance and impaired endothelium-dependent relaxations to acetylcholine, while 22 months of the LND significantly led to death mainly due to cardiovascular disease, including acute myocardial infarction. These abnormalities were reversed by simultaneous treatment with sodium nitrate, and were significantly associated with endothelial NOS downregulation, adiponectin insufficiency and dysbiosis of the gut microbiota. These results provide the first evidence that long-term dietary nitrite/nitrate deficiency gives rise to the metabolic syndrome, endothelial dysfunction and cardiovascular death in mice, indicating a novel pathogenetic role of the exogenous NO production system in the metabolic syndrome and its vascular complications.

Background Mindfulness-based interventions are increasingly being implemented worldwide for problems with depression and anxiety, and they have shown evidence of efficacy. However, few studies have examined the effects of a mindfulness-based group therapy based on standard programs for depression and anxiety until follow-up in Japan. This study addresses that gap. Furthermore, this study explored the mechanisms of action, focusing on mindfulness, mind wandering, self-compassion, and the behavioral inhibition and behavioral activation systems (BIS/BAS) as possible mediators. Methods We examined 16 people who suffered from depression and/or anxiety in an 8-week mindfulness group therapy. Measurements were conducted using questionnaires on depression and trait-anxiety (outcome variables), mindfulness, mind wandering, self-compassion, and the BIS/BAS (process variables) at pre- and post-intervention and 2-month follow-up. Changes in the outcome and process variables were tested, and the correlations among the changes in those variables were explored. Results Depression and anxiety decreased significantly, with moderate to large effect sizes, from pre- to post-intervention and follow-up. In process variables, the observing and nonreactivity facets of mindfulness significantly increased from pre- to post-intervention and follow-up. The nonjudging facet of mindfulness and self-compassion significantly increased from pre-intervention to follow-up. Other facets of mindfulness, mind wandering, and the BIS/BAS did not significantly change. Improvements in some facets of mindfulness and self-compassion and reductions in BIS were significantly correlated with decreases in depression and anxiety. Conclusions An 8-week mindfulness group therapy program may be effective for people suffering from depression and anxiety in Japan. Mindfulness and self-compassion may be important mediators of the effects of the mindfulness group therapy. Future studies should confirm these findings by using a control group. Trial registration University Hospital Medical Information Network (UMIN CTR) UMIN000022966. Registered July 1, 2016, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000026425

Shallow landslides are affected by various conditions, including soil depth and subsurface flow via an increase in the pore water pressure. In this study, we evaluate the effect of soil depth and subsurface flow on shallow landslide prediction using the shallow landslide stability (SHALSTAB) model. Three detailed soil depth data—the average soil depth, weathered soil depth, and bedrock soil depth—were collected using a knocking pole test at a small hillslope site composed of granite in the Republic of Korea. The SHALSTAB model was applied to a ground surface topographic digital elevation model (DEM) using the three soil depths and upslope contributing area (SCA) assuming subsurface flow calculated from four DEMs: a ground surface topography (GSTO) DEM, weathered soil topography (WSTO) DEM, bedrock topography (BSTO) DEM, and low-level bedrock topography (EBSTO) DEM. The model performance was measured using a receiver operating characteristic (ROC) analysis. While evaluating the effect of the soil depth with SCA using GSTO DEM, it was found that the bedrock soil depth had higher prediction accuracy compared to that of the average soil depth or weathered soil depth. To evaluate the saturated subsurface flow between the soil and bedrock, SCAs calculated using WSTO and BSTO DEMs were applied. From these simulations, we found that SCA from BSTO DEM and the bedrock soil depth affect the shallow landslide prediction; however, these prediction effects are not significantly increased by large differences in the elevation (between the lowest and highest elevation values). Therefore, we considered the influence of the bedrock depression and SCA from EBSTO DEM. In applying SCA from EBSTO, the prediction accuracy was significantly increased compared to the other predictions. Our results demonstrate that the influence of the bedrock topography on the prediction of shallow landslides may be particularly significant at the scale of a hillslope.

Summary Understanding the discharge capacity of channels and changes in hydraulic properties during large storms is essential for prediction of flash floods. However, such information is limited for steep mountain channels because of their complex nature and the lack of measured data. Thus, we obtained detailed water-level and surface-velocity data during large floods of a steep mountain channel, and documented how complex channel morphology affected water flow during large storms. We installed water-level and surface-velocity sensors at a cascade and at a pool that was 10 m downstream at the Aono Research Forest of the Arboricultural Research Institute of the University of Tokyo Forests in Japan. We successfully obtained 1-min interval data for a major storm with total precipitation of 288 mm that fell over 59 h and a maximum rainfall intensity of 25 mm/h. During the storm, height of the water surface from the deepest point of each cross section ranged from 0.35 to 1.57 m and surface velocity ranged from 0.35 to 4.15 m/s. As expected, the changes in flow depth, surface velocity, and velocity profiles were complex and differed even between the cascade and adjacent pool cross sections. Dramatic changes in flow conditions first occurred at the cascade when discharge increased to a certain point, when water suddenly stagnated at the foot of the cascade and submerged flow might have occurred. Thereafter, the water level increased remarkably but surface velocity and the velocity profile stayed almost constant at the cascade cross section. At the downstream pool, where most rocks were submerged at a mean water depth of 0.7 m, surface velocity suddenly increased dramatically and the velocity profile changed as very slow flow developed in the lower portion of the profile, while water levels increased only slightly. When the rainfall diminished, first, the surface velocity markedly declined, then the velocity profile returned to its original state at the pool, and then submerged flow at the bottom of the cascade ceased. These temporally and spatially detailed flow measurements effectively document and characterize flow conditions during a large flood in a steep mountain channel. These field data confirm the long held hypothesis that marked changes in flow conditions occur when steps become submerged.

We present a new, seismologically consistent expression for the total area and volume of populations of earthquake-triggered landslides. This model builds on a set of scaling relationships between key parameters, such as landslide spatial density, seismic ground acceleration, fault length, earthquake source depth, and seismic moment. To assess the model we have assembled and normalized a catalog of landslide inventories for 40 shallow, continental earthquakes. Low landscape steepness causes systematic overprediction of the total area and volume of landslides. When this effect is accounted for, the model predicts the total landslide volume of 63% of 40 cases to within a factor 2 of the volume estimated from observations (R2=0.76). The prediction of total landslide area is also sensitive to the landscape steepness, but less so than the total volume, and it appears to be sensitive to controls on the landslide size-frequency distribution, and possibly the shaking duration. Some outliers are likely associated with exceptionally strong rock mass in the epicentral area, while others may be related to seismic source complexities ignored by the model. However, the close match between prediction and estimate for about two thirds of cases in our database suggests that rock mass strength is similar in many cases and that our simple seismic model is often adequate, despite the variety of lithologies and tectonic settings covered. This makes our expression suitable for integration into landscape evolution models and application to the anticipation or rapid assessment of secondary hazards associated with earthquakes.

Structural changes with temperature of CCl4 confined in a 1.1 nm slit-shaped carbon nanospace were investigated by neutron diffraction (ND) measurements and radial distribution function fdrdf analy...

Large-scale sediment supply events (LSEs) cause not only a sudden increase in sediment discharge immediately after their occurrence, but also a long-term condition of elevated sediment yield. In Japan, many LSEs, triggered by heavy rainfall or earthquakes have created high risks for sediment-related disaster. However, the difference between sediment dynamics following a LSE triggered by rainfall and one triggered by an earthquake is unclear, as the sediment dynamics due to rainfall and those due to earthquakes have not been compared using consistent methodology. In this study, we estimated the volume of sediment supply VL (m3), time series of the volume of sediment yield VY (m3year−1) and the non-dimensional parameter NVY as estimated by dividing VL by the catchment area and annual maximum 3-day rainfall amount using the same methodology for 16 events in eight study basins in Japan. We used annual maximum 3-day rainfall amounts as a surrogate for discharge. Using these parameters, we estimated the period over which the effect of a LSE continues (PLS); sediment retention time (residence time, Tr1), and time for active sediment yield to recover to the background level (recovery time, Tr2a). In addition, we estimated the recovery time (Tr2b) based on when the maximum of NVY immediately after the LSE decreased to a certain extent. This calculation allowed us to estimate the recovery time even when background level was unknown. Both residence and recovery times ranged from

Rainfall-induced landslides are a common and significant source of damage and fatality worldwide. Still, we have very little understanding of the quantity and properties of landsliding that can be expected for a given storm and a given landscape, mostly because we have very few datasets of rainfall-induced landslides. Here we present six new comprehensive landslide inventories associated to well identified rainfall events. Combining these datasets, with two previously published datasets, we study their statistical properties and their relations to topographic slope distribution and storm properties. Landslide metrics (such as total landsliding, peak landslide density or landslide distribution area) vary across 2 to 3 order of magnitudes but strongly correlate with the storm total rainfall, varying over almost 2 orders of magnitude for these events. Correlation increases when we apply a normalization on the landslide runout distances. The non-linear scaling with total rainfall should be further constrained with additional cases and incorporation of landscape properties such as regolith depth, typical strength or permeability estimates. We also observe that, for storm with longer duration, landslides do not occur preferentially on the steepest slopes of the landscape, contrarily to observations from earthquake-induced landslides, suggesting preferential failures of larger drainage area patches with intermediate slopes. The database could be used for further comparison with spatially resolved rainfall estimates and with empirical or mechanistic landslide event modeling.

Earthquakes impart an impressive force on epicentral landscapes, with immediate catastrophic hillslope response. However, their legacy on geomorphic process rates remains poorly constrained. We have determined the evolution of landslide rates in the epicentral areas of four intermediate to large earthquakes (M w , 6.6–7.6). In each area, landsliding correlates with the cumulative precipitation during a given interval. Normalizing for this meteorological forcing, landslide rates have been found to peak after an earthquake and decay to background values in 1–4 yr, with the decay time scale probably proportional to the earthquake magnitude. The transient pulse of landsliding is not related to external forcing such as rainfall or aftershocks, and we tentatively attribute it to the reduction and subsequent recovery of ground strength. Observed geomorphic trends are not linked with groundwater level changes or root system damage, both of which could affect substrate strength. We propose that they are caused by reversible damage of rock mass and/or loosening of regolith. Qualitative accounts of ground cracking due to strong ground motion abound, and our observations are circumstantial evidence of its potential importance in setting landscape sensitivity to meteorological forcing after large earthquakes.

Recent epidemiological studies have demonstrated that coffee drinking is associated with reduced mortality of cardiovascular disease. However, its precise mechanisms remain to be clarified. In this study, we examined whether single ingestion of caffeine contained in a cup of coffee improves microvascular function in healthy subjects.A double-blind, placebo-controlled, crossover study was performed in 27 healthy volunteers. A cup of either caffeinated or decaffeinated coffee was drunk by the subjects, and reactive hyperemia of finger blood flow was assessed by laser Doppler flowmetry. In an interval of more than 2 days, the same experimental protocol was repeated with another coffee in a crossover manner. Caffeinated coffee intake slightly but significantly elevated blood pressure and decreased finger blood flow as compared with decaffeinated coffee intake. There was no significant difference in heart rate between caffeinated and decaffeinated coffee intake. Importantly, caffeinated coffee intake significantly enhanced post-occlusive reactive hyperemia of finger blood flow, an index of microvascular endothelial function, compared with decaffeinated coffee intake.These results provide the first evidence that caffeine contained in a cup of coffee enhances microvascular function in healthy individuals.