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Articular cartilage is a low-friction white connective tissue. The only cell type in articular cartilage are chondrocytes. They permit smooth articulation in cartilage. They have insufficient regenerative capacity. Response surface methodology is a very useful tool for the modelling of any processes using polynomials. This study investigated the depth-dependent chondrocyte surface area from bovine articular cartilage. Confocal microscope was utilized to image osteochondral explants. The response surface methodology was used to constitute the predictive regression model to guess chondrocyte area from confocal image of bovine articular cartilage. This methodology was employed to examine the relationships among input variables and response. The response was surface area of chondrocyte while the inputs were perimeter of chondrocyte and depth. The depth-dependent measured and calculated chondrocyte surface area was demonstrated. The response surface model was significant (p=0.001) and adequate for the prediction the chondrocyte surface area since R2 = 0.81. The chondrocyte surface area can be predicted with perimeter and depth by response surface methodology. The implementation of statistical experimental design techniques in image processing can reduce experimental runs and save experimental animals live.

Background Cortical visual prostheses often use penetrating electrode arrays to deliver microstimulation to the visual cortex. To optimize electrode placement within the cortex, the neural responses to microstimulation at different cortical depths must first be understood. Objective We investigated how the neural responses evoked by microstimulation in cortex varied with cortical depth, of both stimulation and response. Methods A 32-channel single shank electrode array was inserted into the primary visual cortex of anaesthetized rats, such that it spanned all cortical layers. Microstimulation with currents up to 14 μA (single biphasic pulse, 200 μs per phase) was applied at depths spanning 1600 μm, while simultaneously recording neural activity on all channels within a response window 2.25–11 ms. Results Stimulation elicited elevated neuronal firing rates at all depths of cortex. Compared to deep sites, superficial stimulation sites responded with higher firing rates at a given current and had lower thresholds. The laminar spread of evoked activity across cortical depth depended on stimulation depth, in line with anatomical models. Conclusion Stimulation in the superficial layers of visual cortex evokes local neural activity with the lowest thresholds, and stimulation in the deep layers evoked the most activity across the cortical column. In conjunction with perceptual reports, these data suggest that the optimal electrode placement for cortical microstimulation prostheses has electrodes positioned in layers 2/3, and at the top of layer 5.

Current study was set to determine the impact of active smoking on Achilles Tendon (AT) as soft tissue using an elastographic technique. This study comprises of 54 male individuals having sedentary lifestyle. Volunteers were categorized into two groups of smokers (n = 20) and non-smokers (n = 34). Body composition analysis was performed to evaluate the physiological changes in human body mass indexes. Ultrasound Strain Elastog-raphy (USE) technique was used to find the stiffness along with anatomical images to envisage the anomalous status of Achilles tendon. Statistical analysis of data obtained through body composition, tendon anatomy and Strain Elastography (SE) was used to scrutinize the physiological, anatomical and elasticity variations within the tendon. A reduction in Fat Free Mass Index (FFMI) was observed among smokers with a significant difference (P = 0.042). Further, an increased significant difference (P = 0.029) was found in AT Strain Ratios (SR) of smokers as compared to non-smokers. Lightening in tendon mass and dilution in tendon stiffness indicates that smoking mechanism may generate excessive apoptosis and decrease the density of tenocytes. Nicotine is the key element that inhibits the functional capacity of Tendon Stem Cells and is highly responsible for tendinopathy, eventually leading to tendon rupture and injury.

Theories of the Beaufort Gyre (BG) dynamics commonly represent the halocline as a single layer with a thickness depending on the Eulerian-mean and eddy-induced overturning. However, observations suggest that the isopycnal slope increases with depth, and a theory to explain this profile remains outstanding. Here we develop a multilayer model of the BG, including the Eulerian-mean velocity, mesoscale eddy activity, diapycnal mixing, and lateral boundary fluxes, and use it to investigate the dynamics within the Pacific Winter Water (PWW) layer. Using theoretical considerations, observational data, and idealized simulations, we demonstrate that the eddy overturning is critical in explaining the observed vertical structure. In the absence of the eddy overturning, the Ekman pumping and the relatively weak vertical mixing would displace isopycnals in a nearly parallel fashion, contrary to observations. This study finds that the observed increase of the isopycnal slope with depth in the climatological state of the gyre is consistent with a Gent–McWilliams eddy diffusivity coefficient that decreases by at least 10%–40% over the PWW layer. We further show that the depth-dependent eddy diffusivity profile can explain the relative magnitude of the correlated isopycnal depth and layer thickness fluctuations on interannual time scales. Our inference that the eddy overturning generates the isopycnal layer thickness gradients is consistent with the parameterization of eddies via a Gent–McWilliams scheme but not potential vorticity diffusion. This study implies that using a depth-independent eddy diffusivity, as is commonly done in low-resolution ocean models, may contribute to misrepresentation of the interior BG dynamics.

The depth dependent UV-light absorption profile of GaN nanorods with different lattice arrays and filling factors was studied using finite-difference time-domain (FDTD) methods. By comparing to the results from Lambert-Beer's law with Maxwell-Garnett effective medium theory, we identified the quantitative contribution from nano-scattering effect on the light absorption in the nanorod arrays. The FDTD study of graphical 3D profile of light absorption and electric field intensity was parallelly conducted to investigate the origin of the nano-scattering. We found that the coupled electric field in the gap regions led to the larger absorption cross-section of the nanorod arrays, which is attributed to the distorted depth profile of the light absorption.

Defects at the bulk grain boundaries and heterojunction interfaces could dictate the power losses of perovskite solar cells (PSCs) during the operation process, which are regarded as major roadblocks towards further development of this emerging photovoltaic technology. The common modulation strategies reported for the state-of-the-art cells cannot concurrently heal the defects located at the grain boundaries and interfaces. Herein, a depth-dependent manipulation strategy is demonstrated to concurrently modulate the bulk and interfacial defects in the perovskite films. According to the distinct penetrability of the employed binary modulators within the polycrystalline perovskite film, one of the modulators can penetrate through the bulk to the buried interface, accompanied by bulk and buried interface defect healing, while the other remains to anchor atop the surface along with the surface defect modulation, assuring simultaneous defect management from the interfaces to the bulk. As a result, the mitigated non-radiative losses and the improved charge transport of the modulated perovskite film boost the efficiency of PSCs from 21.79% to 24.36%. This universally effective depth-dependent manipulation strategy provides new insights into spatial defect modulation, which would open up a promising way for defect modulator design for highly efficient perovskite optoelectronic devices.

This study is to analyze geotechnical properties and biological status of undisturbed municipal solid waste (MSW) associated with depth by using a large-diameter borehole sampling method. Through the method, a 28 m-borehole with 0.8 m of the diameter was drilled into the MSW body consisting of ten-lift layers of waste placed over 4000 days in an operating landfill. MSW sample cuttings were collected from the field site, weighted, and transferred to a laboratory for additional experiments to measure various properties such as moisture content, constituent characterization, unit weights, specific gravity, decomposition state, saturation, and compression rates with regard to waste depth. Also, the methane production obtained from MSW decomposition tests indicated that waste mass was relatively consistent throughout the depth of borehole and had not reached the accelerated production phase of methane. The wet and dry unit weights of the MSW sample with different depths produced excellent trends of the first-order rate with vertical stress. First Oder Rate Equation (FORE) analysis indicated that the maximum total and dry unit weight of MSW (

A new reference attenuation model for calculating local magnitude (ML) for New Zealand earthquakes is derived. An earlier reference model, denoted NZ16, was developed in 2016 as a possible alternative to the classical reference model used by GeoNet for earthquakes located by the SeisComP processing system since January 2012. It aimed to provide a logA0 attenuation relation of the amplitude with the hypocentral distance applicable to the New Zealand region and to make ML more consistent with moment magnitude (Mw). For the present update, denoted NZ20, a much larger set of regional moment tensor solutions and corresponding station amplitudes is available. Residual analysis is used to screen the individual station amplitude readings and then to exclude observations from periods of time when the station residuals were consistently anomalous. Effects of other possible sources of bias on the attenuation relation are also examined, including unreliable locations of earthquakes with large azimuthal gaps and the saturation of ML in large earthquakes. An extra explanatory variable is added to the attenuation relation to account for dependence on hypocentral depth, so the updated local magnitude is consistent with Mw across the full range of depths at which earthquakes occur in New Zealand. Furthermore, to counteract possible sources of bias, the data set for analysis is restricted. Earthquakes above the approximate amplitude saturation threshold of Mw 6.6, as well as those with azimuthal gaps greater than 270°, are excluded.

Cell counts decrease with sediment depth. Typical explanations consider limiting factors such as water availability and chemistry, carbon source, nutrients, energy and temperature, and overlook the role of pore size. Our analyses consider sediment self-compaction, the evolution of pore size with depth, and the probability of pores larger than the microbial size to compute the volume fraction of life-compatible pores. We evaluate cell counts vs. depth profiles gathered at 116 sites worldwide. Results confirm the critical role of pore size on cell counts in the subsurface and explain much of the data spread (from ~ 9 orders of magnitude range in cell counts to ~ 2 orders). Cells colonize pores often forming dense biofilms, thus, cell counts in pores are orders of magnitude higher than in the water column. Similar arguments apply to rocks.

Nanospray desorption electrospray ionization (nano-DESI) has been utilized in direct sampling mass spectrometry (MS) that requires highly spatially resolved sampling with minimal sample destruction. In this study, we explored the applicability of nano-DESI MS for the forensic chemical analysis of ink directly from handwriting on paper. Nano-DESI readily ionizes dyes, including the polyanionic ones, with minimal fragmentation and produces chemical fingerprints of ballpoint pens directly from a paper surface. Further, we specifically focused on how the potential of nano-DESI that changes the mass spectral profiles over time could reflect the differential distribution of analytes in a vertical direction because mildly extracted analytes are immediately transferred and analyzed in real time. To test this, we wrote the character "X" with various combinations of two different pens and analyzed the crosspoints by nano-DESI MS. As a result, the time-course changes in the chemical fingerprints of the ink, which were consistent with the order of the pen strokes, were successfully obtained by nano-DESI MS in most cases. After confirming the capability of the depth-dependent analysis of nano-DESI MS, we analyzed a simulated forgery in which the original and forged writings were made before and after affixing a seal and clearly distinguished the two portions based on the time-dependent changes in the profile of the ink compound.

Summary Objective To assess the potential of using ΔT2 as an indirect index of cartilage strain by quantifying the relationship between local in situ compressive strain and ΔT2 through the full depth of human tibial and femoral articular cartilage. Design Osteochondral samples (n = 4) of human tibial and femoral cartilage were harvested from cadavers and imaged in a Bruker 7T research MRI scanner under increasing displacement-controlled compressive strains. T2 was calculated for 3D double echo steady state (DESS) image volumes at each strain level. A decaying exponential model estimated local, depth-dependent strains. Strained image volumes were non-linearly warped back to their unloaded configurations and ΔT2 was calculated by image subtraction. Linear modeling assessed local relationships between strain and ΔT2. Results Bulk average tibial T2 was 13.2 ms for unstrained cartilage and ranged from 13.0 to 13.1 ms under strain; femoral T2 was 14.0 ms for unstrained cartilage and ranged from 13.5 to 14.8 ms under strain. Local ΔT2 in strained cartilage varied with depth. Linear modeling revealed significant correlations between in situ strain and ΔT2 for both tibial and femoral cartilage; correlation coefficients were higher for tibial cartilage. Conclusions Changes in bulk average T2 are unsuitable as a quantitative surrogate measure of cartilage strain because bulk averaging masks important local variations. High-resolution measures of local ΔT2 have potential value as a surrogate for strain; however, their value is limited until we fully understand the influence of factors like age, joint surface and degeneration on the strain vs T2 relationship.

Thiol-organosilica nanoparticles that are internally functionalized with IR-820 (thiol-OS/IR820) were prepared via a one-pot process for near-infrared (NIR) fluorescence in vivo imaging. Thiol-OS/I...

Further developed methods based on an indenter penetration into a material allow generalised quantitative statements on the composition, the depth-dependent mechanical properties and the delamination behaviour of multilayer polymer films, which is demonstrated on gelatine-coated polyethylene terephthalate and polyethylene films. These highly sensitive polymer testing methods, include the recording microindentation test and the recording adhesion test, describe the material behaviour multi-parametrically and are fast (raw data acquisition within several minutes) and relatively simple, requiring a minimum 1 gram sample depending on the film thickness. Based on the Vickers hardness under load approach, the hardness–depth diagrams calculated from the recording microindentation test provide information about the structure, the thickness and the coating hardness and the substrates. The tangential load vs. tangential path length diagrams from recording adhesion test can detect different scratch processes such as continuous scratching or non-continuous stick-slip layer delamination. Furthermore, they form the basis to quantitatively analyze adhesion, i.e. to determine the critical tangential load and the critical tangential delamination work. Both are highly dependent on the substrate type and treatment.

Agricultural soil emissions are a balance between sinks and sources of greenhouse gases (GHGs). The fluxes of GHGs from soils are complex and spatially and temporally heterogenous. While the soil surface is the exchange site with the atmosphere and is commonly where GHG fluxes are measured, it is important to consider processes occurring throughout the soil profile. To reduce emissions and improve agricultural sustainability we need to better understand the drivers and dynamics (production, consumption, diffusion) of these gases within the soil profile. Due to the heterogeneous nature of GHG processes at small to large scales, it is important to test how these processes differ with depth in different systems. In this study, we measured in situ CO2, N2O and CH4 concentration gradients as a function of soil depth over subsequent maize and wheat growing seasons with active gas samplers inserted into an arable field at 10, 20, 30 and 50 cm depths. We found N2O and CH4 concentrations increased with depth, but only CO2 concentrations differed with depth between growing seasons due likely to differences in soil diffusivity driven by soil conditions. Using the concentration gradient method (GM), the CO2 fluxes at each depth and their contribution to the surface flux were calculated and validated against a chamber method (CM) measured surface flux. We found the GM estimated surface CO2 flux was only 6 % different in the wheat, but 28 % lower than the surface measured flux in the maize growing season, due to drought conditions reducing the accuracy of the GM. Finally, we measured fluxes of CO2, N2O and CH4 in ambient and highly concentrated headspaces in laboratory mesocosms over a 72 h incubation period. We provide evidence of depth dependent CH4 oxidation and N2O consumption and possibly CO2 fixation. In conclusion, our study provides valuable information on the applicability of the GM and further evidence of the GHG production, consumption and diffusion mechanisms that occur deeper in the soil in a temperate arable context.

Previously we introduced a concise dose-response model for the heat-induced withdrawal reflex caused by millimeter wave radiation. The model predicts the occurrence of withdrawal reflex from the given spatial temperature profile. It was formulated on the assumption that the density of nociceptors in skin is uniform, independent of the depth. The model has only two parameters: the activation temperature of heat-sensitive nociceptors and the critical threshold on the activated volume for triggering withdrawal reflex. In this study, we consider the case of depth-dependent nociceptor density in skin. We use a general parametric form with a scaling parameter in the depth direction to represent the nociceptor density. We analyze system behaviors for four density types of this form. Based on the theoretical results, we develop a methodology for 1) identifying from test data the density form of nociceptors distribution, 2) finding from test data the scaling parameter in the density form, and 3) determining from test data the activation temperature of nociceptors.

The inverse problem of electrical impedance tomography is severely ill-posed. In particular, the resolution of images produced by impedance tomography deteriorates as the distance from the measurement boundary increases. Such depth dependence can be quantified by the concept of distinguishability of inclusions. This paper considers the distinguishability of perfectly conducting ball inclusions inside a unit ball domain, extending and improving known two-dimensional results to an arbitrary dimension $d \geq 2$ with the help of Kelvin transformations. The obtained depth-dependent distinguishability bounds are also proven to be optimal., 20 pages, 2 figures

Depth-dependent geoacoustic properties are inferred from wide-angle frequency-domain reflection-coefficient data at two sites with different mud-layer thicknesses on the New England Mud Patch. A trans-dimensional Bayesian inversion is employed to estimate geoacoustic properties and uncertainties from these data using the viscous grain shearing sediment model and spherical-wave reflection-coefficient predictions. Results near the thick-mud (SWAMI) site show a nearly uniform sound velocity over the upper approximately 9.2 m, followed by a transition layer with velocity increasing nonlinearly by $\sim$ 280 m/s over 1.8 m. At the thin-sediment (VC31-2) site, the velocity profile exhibits a similar transition layer. Estimates of intrinsic velocity and attenuation dispersion are also obtained. Over the measurement band of about 400–1300 Hz, the velocity in the fine-grained sediments (mud) at both sites varies by only a few meters per second, i.e., velocity is nearly independent of frequency. The attenuation of the fine-grained sediments at both sites follows a nearly linear frequency dependence. The geoacoustic inferences compare reasonably closely with independent measurements including core measurements, chirp-reflection data, and angle of intromission data.

Depth patterns of soil microbial distribution have not been well characterized and little is known about the balance between stochastic and deterministic processes in shaping microbial community th...

Technological advancements in fMRI have afforded the opportunity to conduct submillimeter investigations into human brain function. The ability to do cortical depth dependent (or layer-specific) fMRI could allow probing intrinsic neuronal organizations and inter-connections, including the directionality of interregional information flow, while ultimately shedding light on uniquely human behaviors. The methodological development and applications of cortical depth dependent fMRI has been ongoing for nearly a decade, yet a consensus on protocols, analysis pipelines and interpretations of data has yet to be reached. In this article we discuss the current status and understandings of high resolution fMRI data and methods. In particular, the spatial signal characteristics of the BOLD contrast are examined in relation to the intra-cortical vasculature and associated underlying contrast mechanisms for three pulse sequences used in laminar fMRI: gradient echo (GE), spin echo (SE) and 3D-GRASE. We conclude with a short overview of factors to be taken into account when designing a specific study, including the choice of pulse sequence, experimental design, and data analysis strategy.

Background Ratcheting strain is produced due to the repeated accumulation of compressive strain in cartilage and may be a precursor to osteoarthritis. The aim of this study was to investigate the ratcheting behaviors of young and adult articular cartilages under cyclic compression by experiments and theoretical predictions. Methods A series of uniaxial cyclic compression tests were conducted for young and adult cartilage, and the effects of different loading conditions on their ratcheting behaviors were probed. A theoretical ratcheting model was constructed and applied to predict the ratcheting strains of young and adult cartilages with different loading conditions. Results Ratcheting strains of young and adult cartilages rapidly increased at the initial stage, followed by a slower increase in subsequent stages. The strain accumulation value and its rate for young cartilage were greater than them for adult cartilage. The ratcheting strains of the two groups of cartilage samples decreased with increasing stress rate, while they increased with increasing stress amplitude. As the stress amplitude increased, the gap between the ratcheting strains of young and adult cartilages increased gradually. The ratcheting strains of young and adult cartilages decreased along the cartilage depth from the surface to the deep layer. The ratcheting strains of different layers increased with the compressive cycle, and the difference among the three layers was noticeable. Additionally, the theoretical predictions agreed with the experimental data. Conclusions Overall, the ratcheting behavior of articular cartilage is affected by the degree of articular cartilage maturation.

Cold-water corals are highly sensitive to changes in water temperature, as it is an important determinant of their distribution. In recent years, several heatwave events have occurred in multiple marine ecosystems , including the northeast Pacific Ocean. However, the effects of elevated ocean temperatures on cold-water corals are largely unknown. Determining the upper thermal limits of cold-water octocorals is an important first step in identifying if warm-water events pose a potential threat. Temperature data were obtained from loggers placed in the Channel Islands National Marine Sanctuary (CINMS) at 20, 50, 100, and 200 m prior to the 2015–2016 El Nino Southern Oscillation (ENSO) event and used to characterize warm-water anomalies. Live colonies of the common gorgonian octocoral, Adelogorgia phyllosclera, were collected from the CINMS using a remotely operated vehicle (ROV) and transported to laboratory aquaria where they were maintained. A laboratory study was conducted to investigate the upper thermal limit of A. phyllosclera during a series of temperature assays using coenenchyme health scores, polyp activity, and estimated survival. Results of in-situ temperature analyses indicated that warm-water anomalies occurred frequently at 50 and 100 m, with most of these anomalies occurring during strong ENSO months. Based on the laboratory temperature assays, the upper thermal limit of A. phyllosclera was estimated to be 20 °C, with a time to effect of 96 hours. During the 2015–2016 ENSO event, this upper thermal limit was exceeded (21.1 °C) by warm-water anomalies at 20 m that lasted up to 14.1 hours, and approached (18.3 °C) by warm-water anomalies at 50 m that lasted up to 52.7 hours. Projections for future warm-water events suggest that the upper thermal limit of A. phyllosclera and other cold-water corals will likely be reached more frequently in the coming years. Thus, understanding the responses of cold-water corals to thermal stress will help predict the resilience of these species to future ocean warming.

Megathrust earthquakes exhibit a ubiquitous seismic radiation style: low-frequency (LF) seismic energy is efficiently emitted from the shallowest portion of the fault, whereas high-frequency (HF) s...

Bivalve sclerochronological records with annually resolved growth bands are applicable proxies in reconstructing features of the hydro-climate system. Here we evaluate the relationship between growth indices of A. islandica, previously collected at approximately 82 m depth in the North Atlantic, and seasonal subsurface temperature at various depths for the 1900–2005 period. Correlations with sea surface temperature at the collection site are not significant during winter and weak for the remaining seasons. The strongest in-phase correlations persist for summer and autumn below 56 m water depth, whereas weaker correlations are lagged by one or two years. We also observe similarities with distant water bodies in the North Atlantic sector, and a corresponding large-scale oceanographic pattern that increases significantly with water depth along the trajectory of the North Atlantic Current. We suggest that by investigating the relationship with the temperature signal at various depths locally and at large-scale increases the reliability and application of bivalve shells as marine archives.

International audience; Mixing tree species is a forest management strategy put forward to increase and stabilize primary productivity. Yet, little is known about soil organic carbon (SOC) storage in mixed species forests, particularly under water shortage. In this study, we used a tree diversity experiment in southwestern France to assess the interactive effects of water availability (via irrigation) and mixing tree species (monocultures of pine (Pinus pinaster) and birch (Betula pendula) versus mixed plots of pine-birch and pine-birch-oak (Quercus robur)) on SOC stocks in the forest floor and across five mineral soil layers (0-5, 5-15, 15-30, 30-60 and 60-90 cm deep). We found that SOC stocks were negatively affected by irrigation in the forest floor due to an increase in decomposition rates. However, SOC stocks were positively influenced by both the mixing of tree species and irrigation in the mineral soil, particularly at the 15-30-cm soil depth. This is because root niche partitioning in mixed plots and an increase in tree biomass in irrigated plots may have resulted in greater organic matter inputs through rhizodeposition and the incorporation of microbially-derived compounds. These preliminary results indicate that SOC dynamics and its response to biotic and abiotic factors are strongly dependent on soil depth. Our data further highlight that the positive effect of mixing trees on SOC stocks was higher in irrigated plots, thereby contradicting the idea that tree mixture effects are expected to be greater when environmental conditions are harsher. We conclude that mixing tree species can increase SOC stocks in the short term in temperate forests, even if the exact mechanisms remain to be identified.

Functional magnetic resonance imaging (fMRI) using a blood-oxygenation-level-dependent (BOLD) contrast is a common method for studying human brain function non-invasively. Gradient-echo (GRE) BOLD is highly sensitive to the blood oxygenation change in blood vessels; however, the spatial signal specificity can be degraded due to signal leakage from activated lower layers to superficial layers in depth-dependent (also called laminar or layer-specific) fMRI. Alternatively, physiological variables such as cerebral blood volume using the VAscular-Space-Occupancy (VASO) contrast have shown higher spatial specificity compared to BOLD. To better understand the physiological mechanisms such as blood volume and oxygenation changes and to interpret the measured depth-dependent responses, models are needed which reflect vascular properties at this scale. For this purpose, we extended and modified the “cortical vascular model” previously developed to predict layer-specific BOLD signal changes in human primary visual cortex to also predict a layer-specific VASO response. To evaluate the model, we compared the predictions with experimental results of simultaneous VASO and BOLD measurements in a group of healthy participants. Fitting the model to our experimental data provided an estimate of CBV change in different vascular compartments upon neural activity. We found that stimulus-evoked CBV change mainly occurs in small arterioles, capillaries and intracortical arteries, and that the contribution from venules and ICVs is small. Our results confirm that VASO is less susceptible to large vessel effects compared to BOLD, as blood volume changes in intracortical arteries did not substantially affect the resulting depth-dependent VASO profiles, whereas depth-dependent BOLD profiles showed a bias towards signal contributions from intracortical veins.

Dynamic rupture simulation of an earthquake mostly aims at a characteristic event, which may rupture the entire seismogenic zone of a fault system, perhaps reaching the ground surface. However, hazardous earthquakes sometimes occur along a part of the depths of a fault. Many questions arise why only this particular depth does rupture and whether the surrounding part remains hazardous. Previously, Aochi (GJI, 2018) has considered a depth-dependent stress accumulation for emphasizing the difference of reverse and normal faults under the hypothesis that stress is sufficiently and uniformly charged at all depths. We probably need to revise this hypothesis and the partially charged fault along depth would be more suitable for explaining the given question. By developing the previous simulations by Aochi (GJI, 2018), we carry out numerical simulations for demonstrating the importance of the depth-dependent stress accumulation.

An open ocean often has a wind driven shear-current near the surface that is able to significantly change the properties of surface waves. This work aims to investigate the effects of a vertically sheared background flow on weakly nonlinear waves with both a statistical study for irregular random waves and a deterministic study for a wave group.We first extended the theory by Dalzell (1999) to allow for the effects of a horizontal background flow with arbitrary depth dependence. The extended theory is valid up to second order in wave steepness and is applicable for directional-spread waves of a broad bandwidth. The Direct Integration Method (Li & Ellingsen 2019) is used for the linear dispersion relation.Using the theory, we examine the effects of an opposing and assisting shear, respectively, on the nonlinear properties of a short wave group on deep-water through comparisons to cases without a shear flow. A shear flow leads to wave crests (troughs) being either steepened or flattened, depending mainly on the direction of a shear relative to the propagation direction of the group and the strength of the depth-integrated velocity of a shear relative to the group velocity. We, furthermore, investigated skewness and kurtosis of a time record of the wave elevation for irregular waves in a background sheared flow, compared to a linear Gaussian random sea for surface waves only. We obtained the probability density function and exceedance probability for wave crests. Relevance for rogue wave formation is discussed.Key words: waves/free-surface flow, ocean surface waves, wave-current interaction ReferencesDalzell, J. F. "A note on finite depth second-order wave–wave interactions." Applied Ocean Research 21, no. 3 (1999): 105-111.Li, Y., and Ellingsen, S. Å. "A framework for modeling linear surface waves on shear currents in slowly varying waters." Journal of Geophysical Research: Oceans 124, no. 4 (2019): 2527-2545.

Understanding the complex seismic, thermal, hydraulic and mechanical processes active during the hydraulic stimulation or continuous operation of Enhanced Geothermal Systems (EGS) requires an accurate description of the pre-existing fractures and faults. However, the three-dimensional characterization of the fracture network is challenging, as direct observation of the discontinuity network at great depth is limited. Fracture image logs and continuous core, which provide line samples through the fracture network, are most valuable in this regard as they provide the most precise option to place constraints on network attributes in stochastic realizations of the fractured rock mass. Among various geometrical attributes, the spatial clustering of fractures plays a critical role on the rock mass properties. Here, we analyzed the spatial distribution of fractures derived from image log runs in six deep boreholes in crystalline basement rock. In one well, the fracture distribution from continuous core was also available. The wells were drilled to depths between 2-5 km, and were all located in the same tectonic setting of the Upper Rhine Graben, which is recognized for its high geothermal potential. The normalized correlation integral method was employed to define the scaling relationships of fracture patterns. This methodology is demonstrated to be less affected by the finite size effects, delivering reliable estimates of scaling laws.Detailed analyses of image log datasets revealed fractal scaling with similar fractal dimensions (between 0.85 and 0.96), prevailed over almost two orders of magnitude of scale. The same was true for the fracture distribution derived from the continuous core, although this distribution was found to be more clustered than that derived from image logs in the same well (i.e. the fractal dimension was lower, which may be due to the partial fracture sampling of image logs which have a coarser resolution than continuous core analyses). Analysis of fractures in sub-sections of the core dataset from progressively increasing depths revealed no systematic depth-dependency for the fractal dimension, although a local variation at a scale of hundreds of meters was identified.

Predicting the magnitude of the impact force that snow avalanches can exert on structures still remains a challenging question.In fast flow regimes, the impact pressure is mainly driven by the kinetic energy of the flow: it scales as one-half the product of the flow density and the square of the avalanche speed, and the effect of the shape of the structure is encapsulated in the so-called drag coefficient. Recent measurements on well-documented snow avalanches that have impacted different types of structures have confirmed the existence of another impact force regime at lower speed for which the pressure exerted on the obstacle is independent of the avalanche speed but rather controlled by the lithostatic pressure associated with the typical flow thickness. These measurements have also shown that the depth-dependent force could reach values that are many times greater than the lithostatic force.The present paper proposes a general analytic form for the impact force of dense avalanches on structures. The approach is based on the application of mass and momentum conservation equations, in their depth-averaged forms, to a control-volume which surrounds the influence zone of the obstacle. A criterion to distinguish between the depth-dependent force regime and the velocity-square force regime can be derived. It is demonstrated that the size of the influence zone of the obstacle, relative to the dimension of the obstacle and/or the avalanche thickness, is a key ingredient (in addition to the traditional Froude number) to demarcate the depth-dependent impact forces from the velocity-square impact forces. Further developments are needed to unravel the size and shape of the influence zone (of any kind obstacle for any type of flowing snow), and then to be able to hone the proposed criterion. However, the present study takes a step forward for a better characterization of avalanche impact forces on structures.

The inversion of rift-related faults on passive margins through kinematic reactivation is documented globally. Such structures form an integral part in petroleum systems, provide essential constraints on the kinematic and structural evolution of rifts and passive margins, and can be used as global markers for far-field stresses. Despite the importance of inverted normal faults, the controls on their kinematic evolution, as well as existence and interactions within fault populations are often poorly constrained. Here, we present new structural interpretation and kinematic modelling of an inverted relay ramp structure located offshore Nova Scotia, Canada. This structure is imaged on the Penobscot 3D seismic reflection survey down to ~3.5 s TWTT, and is constrained by two exploration wells. We map two major normal faults that display evidence for inversion in their lower portions (reverse faulting and low-amplitude folding), below ~2.5 s TWTT, though retain a normal offset in upper sections. The wider fault population is dominated by ~ENE-WSW striking normal faults that dip both north and south, while both of the two major faults dip approximately south and are associated with antithetic and synthetic faults. This kinematic dichotomy along the major faults is important as inversion such as this may go unrecognised if seismic data does not image the full depth of a structure. To accommodate such depth-dependent inversion, if both horizons co-existed during inversion, a reduction in volume of the sedimentary package is required between the normal and reverse segments of the fault. In this study, we explore possible kinematic mechanisms to explain inversion structure and the mechanisms accommodating the volumetric changes/ or mass movements required using fault restoration and strain modelling. Our results favour a poly-phase deformation history that can be reconciled with other inversion structures on related passive-margin segments, suggesting these could be widespread processes.

Offshore geoengineering requires reliable sediment parameters for analysis and design. This study proposes a robust framework for effective stress-dependent geotechnical and geoacoustic pro...

Deep low-frequency earthquakes (LFEs) in Northeast Japan occur beneath active volcanoes at depths of 20-40 km. LFEs radiate low-frequency seismic waves, with most energy at 2-8 Hz, despite their lo...

Recent laminar-fMRI studies have substantially improved understanding of theevokedcortical responses in multiple sub-systems; in contrast, the laminar component ofresting-state networksspread over the whole brain has been less studied due to technical limitations. Animal research strongly suggests that the supragranular layers of the cortex play a critical role in maintaining communication within the default mode network (DMN); however, whether this is true in this and other human cortical networks remains unclear. Here, we used EPIK, which offers unprecedented coverage at sub-millimeter resolution, to investigate cortical broad resting-state dynamics with depth specificity in healthy volunteers. Our results suggest that human DMN connectivity is primarily supported by intermediate and superficial layers of the cortex, and furthermore, the preferred cortical depth used for communication can vary from one network to another. This has major implications for the characterization of network-related diseases and should occupy future high-resolution studies. In addition, the laminar connectivity profile of some networks showed a tendency to change upon engagement in a motor task. In line with these connectivity changes, we observed that the amplitude of the low-frequency-fluctuations (ALFF), as well as the regional homogeneity (ReHo), exhibited a different laminar slope when subjects were either performing a task or were in a resting state (less variation among laminae, i.e., lower slope, during task performance compared to rest). The varied laminar profiles concerning network connectivity, ALFF, and ReHo, observed across two brain states (task vs. rest) suggest the potential diagnostic value of laminar fMRI in psychiatric diseases, e.g., to differentiate the cortical dynamics associated with disease stages linked, or not linked, to behavioral changes. The evaluation of laminar-fMRI across the brain encompasses computational challenges; nonetheless, it enables the investigation of a new dimension of the human neocortex, which may be key to understanding neurological disorders from a novel perspective.

PURPOSE To determine the impact of corneal crosslinking (CXL) performed over the laser in situ keratomileusis (LASIK) flap using the Standard CXL (S-CXL) protocol or under the flap after flap lift (flap-CXL) on regional corneal stiffness using Brillouin microscopy. SETTING University of Southern California Keck School of Medicine, Los Angeles, California, and Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA. DESIGN Laboratory ex vivo experiment. METHODS After epithelium debridement, LASIK flaps were created on intact fresh porcine eyes with a mechanical microkeratome. Then, S-CXL (riboflavin applied to the corneal surface followed by 3 mW/cm ultraviolet exposure with the flap in place for 30 minutes) or flap-CXL (riboflavin applied to the stromal bed after reflecting the flap followed by the same ultraviolet A exposure with the flap replaced) was performed. Depth profile of stiffness variation and averaged elastic modulus of anterior, middle, and posterior stroma were determined by analyzing Brillouin maps. Each eye served as its own control. RESULTS The study was performed on 24 fresh porcine eyes. S-CXL had maximal stiffening impact in the anterior most corneal stroma within the LASIK flap (8.40 ± 0.04 GHz), whereas flap-CXL had lower maximal stiffening impact (8.22 ± 0.03 GHz) (P < .001) that occurred 249 ± 34 μm under the corneal surface. S-CXL increased longitudinal modulus by 6.69% (anterior), 0.48% (middle), and -0.91% (posterior) as compared with flap-CXL, which increased longitudinal modulus by 3.43% (anterior, P < .001), 1.23% (middle, P < .1), and -0.78% (posterior, P = .68). CONCLUSIONS The S-CXL technique generated significantly greater stiffening effect in the anterior cornea than a modified protocol with riboflavin administration under the flap (flap-CXL). Minimal stiffening occurred in the middle or posterior cornea with either protocol.

A previous analysis of 1977 passive acoustic recordings in the Indian Ocean focused on sound pressure levels (SPLs) and showed that SPLs were slightly depth dependent and highly influenced by shipping activities [Wagstaff and Aitkenhead, IEEE J. Ocean. Eng. 30(2), 295–302 (2005)]. Consequently, SPL alone does not provide a consistent comprehensive metric to compare among sites or with contemporary recordings in the same region. Therefore, a source separation analysis was devised and applied to identify the major sound source contributions at three Indian Ocean locations. Shipping noise was a major sound contributor in all sites, while the site with the most diverse number of sources was in the central Arabian Sea.