56016 research outputs found
Sort by
Role of land-atmosphere interaction in the 2016 Northeast Asia heat wave: Impact of soil moisture initialization
No full textThe impact of soil moisture initialization on the 2016 Northeast Asian heat wave was explored using the Land Information System (LIS) Weather Research and Forecasting (WRF) model. To obtain advanced soil moisture estimates, various meteorological variables from the Global Data Assimilation System analysis and Integrated Multi-Satellite Retrievals for Global Precipitation Measurement observation data were used as atmospheric forcings for the offline simulation of the Noah land surface model (Noah-LSM). Based on the LIS, Soil Moisture Active Passive satellite were assimilated in the Noah LSM simulation. The assimilated soil moisture estimates revealed the drier land surface conditions over Northeast Asia compared with the product from the National Centers for Environmental Prediction Final Analysis (FNL) and were used as the initial condition of the WRF model. The WRF experiment initialized by the assimilated soil moisture product (LIS experiment) exhibited the observed surface air temperature (SAT) and 500 hPa geopotential height (500 GPH) over Northeast Asia compared with the result from the experiment initialized by the FNL (CTL experiment). At Week 1, the LIS experiment simulated warmer SAT than that from the CTL experiment, which was induced by the negative anomaly of latent heat flux over Mongolia. Then, 500 GPH became strong and spatially expanded in response to the thermal low induced by the warmer SAT, and the SAT was further increased during Weeks 2 and 3
Remarkably slow corrosion rate of high-purity Mg microalloyed with 0.05wt% Sc
No full textWe report that the corrosion resistance of Mg is significantly improved by adding 0.05wt% Sc. Corrosion rates evaluated from weight loss values after room-temperature immersion in 0.6 M NaCl solution for two weeks were 0.27 and 4.0 mm y???1 for the high-purity Mg samples with and without microalloyed 0.05wt% Sc, respectively. The beneficial effect of Sc microalloying on the corrosion resistance of Mg is discussed in connection with Sc-induced microstructural modifications
RANKL-responsive epigenetic mechanism reprograms macrophages into bone-resorbing osteoclasts
No full textMonocyte/macrophage lineage cells are highly plastic and can differentiate into various cells under different environmental stimuli. Bone-resorbing osteoclasts are derived from the monocyte/macrophage lineage in response to receptor activator of NF-kappa B ligand (RANKL). However, the epigenetic signature contributing to the fate commitment of monocyte/macrophage lineage differentiation into human osteoclasts is largely unknown. In this study, we identified RANKL-responsive human osteoclast-specific superenhancers (SEs) and SE-associated enhancer RNAs (SE-eRNAs) by integrating data obtained from ChIP-seq, ATAC-seq, nuclear RNA-seq and PRO-seq analyses. RANKL induced the formation of 200 SEs, which are large clusters of enhancers, while suppressing 148 SEs in macrophages. RANKL-responsive SEs were strongly correlated with genes in the osteoclastogenic program and were selectively increased in human osteoclasts but marginally presented in osteoblasts, CD4+ T cells, and CD34+ cells. In addition to the major transcription factors identified in osteoclasts, we found that BATF binding motifs were highly enriched in RANKL-responsive SEs. The depletion of BATF1/3 inhibited RANKL-induced osteoclast differentiation. Furthermore, we found increased chromatin accessibility in SE regions, where RNA polymerase II was significantly recruited to induce the extragenic transcription of SE-eRNAs, in human osteoclasts. Knocking down SE-eRNAs in the vicinity of the NFATc1 gene diminished the expression of NFATc1, a major regulator of osteoclasts, and osteoclast differentiation. Inhibiting BET proteins suppressed the formation of some RANKL-responsive SEs and NFATc1-associated SEs, and the expression of SE-eRNA:NFATc1. Moreover, SE-eRNA:NFATc1 was highly expressed in the synovial macrophages of rheumatoid arthritis patients exhibiting high-osteoclastogenic potential. Our genome-wide analysis revealed RANKL-inducible SEs and SE-eRNAs as osteoclast-specific signatures, which may contribute to the development of osteoclast-specific therapeutic interventions
Virtual portraits from rotating selfies
Get PDFSelfies are a popular form of photography. However, due to physical constraints, the compositions of selfies are limited. We present algorithms for creating virtual portraits with interesting compositions from a set of selfies. The selfies are taken at the same location while the user spins around. The scene is analyzed using multiple selfies to determine the locations of the camera, subject, and background. Then, a view from a virtual camera is synthesized. We present two use cases. After rearranging the distances between the camera, subject, and background, we render a virtual view from a camera with a longer focal length. Following that, changes in perspective and lens characteristics caused by new compositions and focal lengths are simulated. Second, a virtual panoramic view with a larger field of view is rendered, with the user's image placed in a preferred location. In our experiments, virtual portraits with a wide range of focal lengths were obtained using a device equipped with a lens that has only one focal length. The rendered portraits included compositions that would be photographed with actual lenses. Our proposed algorithms can provide new use cases in which selfie compositions are not limited by a camera's focal length or distance from the camera
Large-scale climate response to regionally confined extratropical cooling: effect of ocean dynamics
Get PDFThis study investigates the effect of ocean dynamics on the tropical climate response to localized radiative cooling over three northern extratropical land regions using hierarchical model simulations that vary in the degree of ocean coupling. Without ocean dynamics, the tropical climate response is independent of the extratropical forcing location, characterized by a southward tropical precipitation shift with a high degree of zonal symmetry, a reduced zonal sea surface temperature gradient along the equatorial Pacific, and the eastward-shifted Walker circulation. When ocean dynamical adjustments are allowed, the zonal-mean tropical precipitation shift is damped primarily via Eulerian-mean ocean heat transport. The oceanic damping effect is strongest (weakest) for North Asian (American) cooling, associated with the largest (smallest) Eulerian-mean ocean heat transport across the equatorial Pacific. The cross-equatorial ocean heat transport in the Pacific is anchored to the North Pacific subtropical high, the response of which can be inferred from the corresponding slab ocean simulations. Hence, the slab ocean simulations provide useful a priori prediction for oceanic damping efficiency. Ocean dynamics also modulates the spatial pattern of climate response in a distinct manner depending on the zonal distribution of imposed forcing. North Asian forcing induces a pronounced eastern equatorial Pacific cooling extending to the western basin, accompanying the westward shifted Walker circulation. European forcing causes cooling confined to the eastern equatorial Pacific and strengthens the Walker circulation. The tropical precipitation response in these two cases exhibits large zonal variations with a high degree of equatorial symmetry, being essentially uncorrelated with the corresponding slab ocean simulations. By contrast, North American forcing induces a sufficiently strong inter-hemispheric contrast in the tropical Pacific SST response, due to the relatively weak oceanic damping effect, producing a weaker but spatially similar tropical response to that in the slab ocean simulation. This study demonstrates that the effect of ocean dynamics in modulating the tropical climate response depends on the extratropical forcing location. The results are relevant for understanding the distinct climate response induced by aerosols from different continental sites
Natural leaf-inspired solar water splitting system
No full textWe designed a monolithic artificial leaf that mimics a natural leaf; the artificial leaf has a crystalline silicon (c-Si) interdigitated back contact (collectively, c-Si IBC) structure. On the front-side of the artificial leaf, the c-Si module acts similar to chlorophyll in natural leaves, converting solar energy into photo-carriers. On the rear-side of the artificial leaf, a hydrogen and oxygen evolution catalyst converts the carriers into hydrogen; this occurs without blocking light, similar to the conversion of photo-carriers into chemical energy, which mostly occurs on the backside of natural leaves. The solar-to-hydrogen conversion efficiency of the c-Si IBC photoanode and artificial leaf was 10.1% and 8.4% respectively, which are higher than that of a natural leaf (0.1-1%)
Development of M??ller cell-based 3D biomimetic model using bioprinting technology
No full textM??ller cells are the principal glial cells for the maintenance of structural stability and metabolic homeostasis in the human retina. Although various in vitro experiments using two-dimensional (2D) monolayer cell cultures have been performed, the results provided only limited results because of the lack of 3D structural environment and different cellular morphology. We studied a M??ller cell-based 3D biomimetic model for use in experiments on the in vivo-like functions of M??ller cells within the sensory retina. Isolated primary M??ller cells were bioprinted and a 3D-aligned architecture was induced, which aligned M??ller cell structure in retinal tissue. The stereographic and functional characteristics of the biomimetic model were investigated and compared to those of the conventional 2D cultured group. The results showed the potential to generate M??ller cell-based biomimetic models with characteristic morphological features such as endfeet, soma, and microvilli. Especially, the 3D M??ller cell model under hyperglycemic conditions showed similar responses as observed in the in vivo diabetic model with retinal changes, whereas the conventional 2D cultured group showed different cytokine and growth factor secretions. These results show that our study is a first step toward providing advanced tools to investigate the in vivo function of M??ller cells and to develop complete 3D models of the vertebrate retina
MHD convective flow of Ag-TiO2 hybrid nanofluid in an inclined porous annulus with internal heat generation
No full textThe current article deals with the computational study of buoyant convection and heat dissipation processes of hybrid nanoliquid saturated in an inclined porous annulus. The fluid flow movement in the porous annular region is modeled using Darcy???Brinkman???Forchheimer model. The vertical boundaries of the cylinder are subjected to uniform but different heating profiles and horizontal surfaces are maintained adiabatic. In the current investigation, for the conservation laws which govern the considered physical process, numerical simulations have been performed using the time-splitting ADI (Alternating Direction Implicit) and line over-relaxation methods. Computations have been performed for broad range of physical and geometric parameters, such as Hartmann number (), geometric inclination angle (), Darcy number (), aspect ratio () and internal heat generation () to address their impacts on hybrid nanofluid movement and associated heat dissipation rate in the annulus. In addition, heat transfer rate has also been estimated by considering the impact of concentration of each nanoparticle present in the hybrid nanofluid pair. The outcome of numerical computations reveal that an increment in Darcy number enhances the average Nusselt number. Additionally, it has been noticed that the geometric tilt angle of 30?? results in dissipating maximum amount of thermal energy in the system. Through this investigation, it is also noticed that shallow annular enclosure exhibits greater amount of heat transport compared to other aspect ratios. Also, significant impact of magnetic field on fluid flow and thermal transport rate has been noticed from the detailed numerical simulations. Further, an enhancement in internal heat generation deteriorates the heat transfer rate and this reduction becomes more steep as the internal heat generation increases
Lactate oxidase/catalase-displaying nanoparticles efficiently consume lactate in the tumor microenvironment to effectively suppress tumor growth
Get PDF<jats:title>Abstract</jats:title><jats:p>The aggressive proliferation of tumor cells often requires increased glucose uptake and excessive anaerobic glycolysis, leading to the massive production and secretion of lactate to form a unique tumor microenvironment (TME). Therefore, regulating appropriate lactate levels in the TME would be a promising approach to control tumor cell proliferation and immune suppression. To effectively consume lactate in the TME, lactate oxidase (LOX) and catalase (CAT) were displayed onto <jats:italic>Aquifex aeolicus</jats:italic> lumazine synthase protein nanoparticles (AaLS) to form either AaLS/LOX or AaLS/LOX/CAT. These complexes successfully consumed lactate produced by CT26 murine colon carcinoma cells under both normoxic and hypoxic conditions. Specifically, AaLS/LOX generated a large amount of H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> with complete lactate consumption to induce drastic necrotic cell death regardless of culture condition. However, AaLS/LOX/CAT generated residual H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>, leading to necrotic cell death only under hypoxic condition similar to the TME. While the local administration of AaLS/LOX to the tumor site resulted in mice death, that of AaLS/LOX/CAT significantly suppressed tumor growth without any severe side effects. AaLS/LOX/CAT effectively consumed lactate to produce adequate amounts of H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> which sufficiently suppress tumor growth and adequately modulate the TME, transforming environments that are favorable to tumor suppressive neutrophils but adverse to tumor-supportive tumor-associated macrophages. Collectively, these findings showed that the modular functionalization of protein nanoparticles with multiple metabolic enzymes may offer the opportunity to develop new enzyme complex-based therapeutic tools that can modulate the TME by controlling cancer metabolism.</jats:p>
<jats:p><jats:bold>Graphical Abstract</jats:bold></jats:p>
Improved Tropical Cyclone Track Simulation over the Western North Pacific using the WRF Model and a Machine Learning Method
No full textAccurate tropical cyclone (TC) track simulations are required to mitigate property damage and casualties. Previous studies have generally simulated TC tracks using numerical models, which tend to experience systematic errors due to model imperfections, although the model accuracy has improved over time. Recently, machine-learning methods have been applied to correct such errors. In this study, we used an artificial neural network (ANN) to correct TC tracks hindcasted by the Weather Research and Forecasting (WRF) model from 2006 to 2018 over the western North Pacific. TC categories that are stronger than tropical depressions (i.e., tropical storms, severe tropical storms, and typhoons) were selected from June to November, and a bias correction was made to target TC positions at 72 h. The WRF-simulated tracks were used as input variables for training and testing the ANN using the best track and reanalysis data. To obtain a reliable corrected result, the number of neurons in the ANN structure was optimized for TCs during 2006???2015, and the optimized ANN was verified for TCs from 2016???2018. Because the performance of the numerical model differed according to the TC track, the ANN was assessed by cluster analysis. The results of the ANN were analyzed using k-means clustering to classify TCs into eight clusters. Overall, ANN with post-processing improved the WRF performance by 4.34%. The WRF error was corrected by 8.81% for clusters where the ANN was most applicable