This study assesses the added value of using emerging maps of soil properties to improve surface soil moisture simulations using the HydroBlocks land surface model with different soil hydraulic ...parameterization schemes. Simulations were run at an hourly 30‐m resolution between 2012 and 2019 and evaluated against U.S. Climate Reference Network measurements. The results show that state‐of‐the‐art soil properties maps (POLARIS and SoilGrids250m V2.0) improve the accuracy of simulated surface soil moisture when compared to the STATSGO‐derived CONUS‐SOIL map. Contemporary pedotransfer functions (multi‐linear regression and Artificial Neural Networks‐based) also improve model performance in comparison to the lookup table‐derived soil parameterization schemes. The addition of vertical heterogeneity to the soil properties further improves the mean Kling‐Gupta efficiency by 0.04 and lowers the mean Root mean square error by 0.003 over the CONUS. This study demonstrates that land surface modeling can be improved by using state‐of‐the‐art maps of soil properties, accounting for the vertical heterogeneity of soils, and advancing the use of contemporary pedotransfer functions.
Plain Language Summary
This work studied if advanced soil properties maps can improve soil moisture modeling using a Land Surface Model. The model was run over 7 years and was compared to site measurements. The results showed that using contemporary soil properties maps and pedotransfer functions to estimate soil properties improved model performance, especially for soils with different layers. This study demonstrated that improving hydraulic modeling is possible by using soil properties maps and contemporary pedotransfer functions in the setting of different vertical layers.
Key Points
State‐of‐the‐art digital soil maps improve the agreement between soil moisture modeling and observations
Including vertical soil heterogeneity improves the accuracy of simulated soil moisture
Simulating soil moisture using soil hydraulic properties computed from contemporary pedotransfer functions generally outperforms classic lookup tables
The liver circulatory system comprises two blood supply vascular trees (the hepatic artery and portal venous networks), microcirculation through the hepatic capillaries (the sinusoids), and a blood ...drainage vascular tree (the hepatic vein network). Vasculature changes due to fibrosis -located predominantly at the microcirculation level- lead to a marked increase in resistance to flow causing an increase in portal pressure (portal hypertension). Here, we present a liver fibrosis/cirrhosis model. We build on our 1D model of the healthy hepatic circulation, which considers the elasticity of the vessels walls and the pulsatile character of blood flow and pressure, and recreate the deteriorated liver vasculature due to fibrosis. We emulate altered sinusoids by fibrous tissue (stiffened, compressed and splitting) and propose boundary conditions to investigate the impact of fibrosis on hemodynamic variables within the organ. We obtain that the sinusoids stiffness leads to changes in the amplitude and shape of the blood flow and pressure waveforms but not in their mean value. For the compressed and splitting sinusoids, we observe significant increases in the mean value and amplitude of the pressure waveform in the altered sinusoids and in the portal venous network. In other words, we obtain the portal hypertension clinically observed in fibrotic/cirrhotic patients. We also study the extent of the spreading fibrosis by performing the structural fibrotic changes in an increasingly number of sinusoids. Finally, we calculate the portal pressure gradient (PPG) in the model and obtain values in agreement with those reported in the literature for fibrotic/cirrhotic patients.
Abstract
Lactation is a critical period during which maternal nutritional and environmental challenges affect milk composition and, therefore, organ differentiation, structure, and function in ...offspring during the early postnatal period. Evidence to date shows that lactation is a vulnerable time during which transient insults can have lasting effects, resulting in altered health outcomes in offspring in adult life. Despite the importance of the developmental programming that occurs during this plastic period of neonatal life, there are few comprehensive reviews of the multiple challenges—especially to the dam—during lactation. This review presents milk data from rodent studies involving maternal nutritional challenges and offspring outcome data from studies involving maternal manipulations during lactation. Among the topics addressed are maternal nutritional challenges and the effects of litter size and artificial rearing on offspring metabolism and neural and endocrine outcomes. The lactation period is an opportunity to correct certain functional deficits resulting from prenatal challenges to the fetus, but, if not personalized, can also lead to undesirable outcomes related to catch up-growth and overnutrition.
One of the persistent challenges of Land Surface Models (LSMs) is to determine a realistic yet efficient sub‐grid representation of heterogeneous landscapes. This is particularly important in ...emulating the fine‐scale and nonlinear interactions between water, energy, and biogeochemical fluxes at the land surface. In LSMs, landscape heterogeneity can be represented using sub‐grid tiling techniques, which partition macroscale grid cells (e.g., 1°) into smaller units or “tiles.” However, there is currently no formal procedure to define the number of tiles required to adequately represent the heterogeneity of hydrologic processes within a macroscale grid cell, and across spatial scales. To address these challenges, a new approach is presented to diagnose sub‐grid process heterogeneity formally and to infer an optimal number of tiles per macroscale grid cell. The approach is demonstrated using the HydroBlocks modeling framework coupled to Noah‐MP LSM implemented over a 1.0‐degree domain in Western Colorado in the United States. Our results show that (a) a surrogate model can accurately infer the spatial structure of the LSM's time‐averaged hydrological fields, with over 95% overall R2 performance in the validation stage; (b) the optimal configurations for a target level of complexity can be determined using a multi‐objective Pareto efficiency analysis, which includes the simultaneous representation of the multi‐scale heterogeneity of several processes; (c) the use of ∼100 tiles effectively reproduces a quasi‐fully distributed LSM setup (i.e., 83,000 tiles) with approximately 1% of the computational expense. This method provides a path forward to efficiently determine the optimal tile configurations for LSMs while simultaneously considering the spatial heterogeneity and spatial accuracy of hydrologic processes.
Key Points
A surrogate model can accurately predict the spatial structure of Land Surface Model's (LSM) hydrological output fields
For a target level of complexity, the optimal LSM tile configuration was determined using a multi‐objective Pareto efficiency analysis
Approximately 100 tiles can effectively reproduce a quasi‐fully distributed LSM setup with 1% of the computational cost
The liver plays a key role in the metabolic homeostasis of the whole organism. To carry out its functions, it is endowed with a peculiar circulatory system, made of three main dendritic flow ...structures and lobules. Understanding the vascular anatomy of the liver is clinically relevant since various liver pathologies are related to vascular disorders. Here, we develop a novel liver circulation model with a deterministic architecture based on the constructal law of design over the entire scale range (from macrocirculation to microcirculation). In this framework, the liver vascular structure is a combination of superimposed tree-shaped networks and porous system, where the main geometrical features of the dendritic fluid networks and the permeability of the porous medium, are defined from the constructal viewpoint. With this model, we are able to emulate physiological scenarios and to predict changes in blood pressure and flow rates throughout the hepatic vasculature due to resection or thrombosis in certain portions of the organ, simulated as deliberate blockages in the blood supply to these sections. This work sheds light on the critical impact of the vascular network on mechanics-related processes occurring in hepatic diseases, healing and regeneration that involve blood flow redistribution and are at the core of liver resilience.
The efficient use of water worldwide is of overriding importance due to its vital role in life. Recently, several countries have suffered water scarcity mainly due to population increase and problems ...associated to climate change such as the change in the precipitation patterns in the world. In this project, a mathematical programming model for the efficient and sustainable use of water under parametric uncertainty is proposed. The model considers rainwater harvesting (which includes catchment, storage and distribution) as alternative water source; it also considers sustainability aspects from the economic and environmental points of view, maximizing the revenue from the sales of water minus the cost of production and treatment, while maintaining desirable levels of water in the natural reservoirs. The uncertainty is a result of the change in the precipitation patterns. The proposed model is applied to a case study for the city of Morelia, Michoacán in Mexico, considering a time horizon of 5 years. Results show the optimal schedule for water storage and distribution to different sectors of the society (public, agricultural and industrial users). It was found that the use of alternative water sources such as harvested rainwater, along with an appropriate planning schedule of storage and distribution might help reduce the pressure over natural reservoirs even under conditions of uncertainty in the precipitation, while satisfying the water demands in a city.
•Optimization of macroscopic water systems under parametric uncertainty is presented.•Multi annual scheduling of water storage and distribution in a city is considered.•Parametric uncertainty for the precipitation is considered.•Results of a case study of Mexico show that the solutions are robust to uncertainty.•Solutions improve the sustainability by reducing the pressure over natural bodies.
Soil moisture (SM) spatiotemporal variability critically influences water resources, agriculture, and climate. However, besides site‐specific studies, little is known about how SM varies locally ...(1–100‐m scale). Consequently, quantifying the SM variability and its impact on the Earth system remains a long‐standing challenge in hydrology. We reveal the striking variability of local‐scale SM across the United States using SMAP‐HydroBlocks — a novel satellite‐based surface SM data set at 30‐m resolution. Results show how the complex interplay of SM with landscape characteristics and hydroclimate is primarily driven by local variations in soil properties. This local‐scale complexity yields a remarkable and unique multi‐scale behavior at each location. However, very little of this complexity persists across spatial scales. Experiments reveal that on average 48% and up to 80% of the SM spatial information is lost at the 1‐km resolution, with complete loss expected at the scale of current state‐of‐the‐art SM monitoring and modeling systems (1–25 km resolution).
Plain Language Summary
Soil moisture (SM) widely varies in space and time. This variability critically influences freshwater availability, agriculture, ecosystem dynamics, climate and land‐atmosphere interactions, and it can also trigger hazards such as droughts, floods, landslides, and aggravate wildfires. Limited SM observational data constrained our understanding of this variability and its impact on the Earth system. Here, we present the first continental assessment of how SM varies at the local scales using SMAP‐HydroBlocks – the first 30‐m surface SM data set over the United States. This study maps the SM spatial variability, characterizes the landscape drivers, and quantifies how this variability persists across larger spatial scales. Results revealed striking SM spatial variability across the United States, mainly driven by local spatial variations in soil properties and less so by vegetation and topography. However, this SM variability does not persist at coarser spatial scales resulting in extensive information loss. This information loss implicates inaccuracies when predicting non‐linear SM‐dependent hydrological, ecological, and biogeochemical processes using coarse‐scale models and satellite estimates. By mapping the SM spatial variability locally and its scaling behavior, we provide a pathway toward understanding SM‐dependent hydrological, biogeochemical, and ecological processes at local (and so far unresolved) spatial scales.
Key Points
30‐m soil moisture (SM) data shows striking and complex spatial variability driven mainly by climate and local variations in soil properties
This variability yields a remarkable and unique multi‐scale behavior at each location that cannot be generalized across the diverse US
Up to 80% of SM information is lost at the 1‐km scale, with complete loss at the scale of state‐of‐the‐art SM observation/monitoring systems
For the last years, there has been growing interest in the band gap study of 2D heterostructures due to high expectations of developing a new generation of electronic devices. In this work, using ...density functional theory the structural and electronic properties of several bi, tri, tetra and pentalayers of 2D graphene/hexagonal boron nitride (G/hBN) vertical heterostructures have been studied. We compared the results with the bulk (graphite, hBN) and monolayer structures (graphene, hBN). It is found that the graphene band gap can be changed from 0 to 114 meV and is sensitive to the number and configuration of graphene and hBN layers. We attribute the band gap opening in 2D heterostructures G/hBN to the decrease of the overlap for the pz orbitals in graphene, due to the Pauli repulsion.
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•Several 2D G/hBN vertical heterostructures for bi to pentalayer in one single study.•2D G/hBN band gap changes with configuration and number of layers of G and hBN.•Maximum band gap that can be obtained for any 2D G/hBN heterostructures is 114 meV.•Band gap is 0 eV for 2D G/hBN heterostructures from 3 consecutive graphene layers.
Rationale
The jumbo squid Dosidicus gigas is a fishery resource of considerable economic and ecological importance in the Mexican Pacific. Studies on its habitat preferences are needed to understand ...recent fluctuations in the abundance and availability of the species. Stable isotope analysis allows us to infer ecological aspects such as spatial distribution and trophic preferences.
Methods
We used an isotope ratio mass spectrometer, automated for carbonate analysis, and coupled to an elemental analyzer, to determine the isotopic composition of statoliths (δ18O and δ13C values) and beaks (δ13C and δ15N values) from 219 individuals caught over two fishing seasons (2007 and 2009) off the coast of Santa Rosalía, in the central Gulf of California. We used these isotopic ratios to assess variation in spatial and trophic preferences by sex, size, and fishing season.
Results
In the 2009 group, we observed significant differences in statolith δ13C values and beak δ13C and δ15N values between males and females. Between size groups, we observed significant differences in statolith δ18O and δ13C values in 2007 and in beak δ13C and δ15N values during both seasons. Both seasons were characterized by high overlap in δ18O and δ13C values between sexes and in 2009 between size groups. We observed low trophic overlap between sexes in 2009 and between size groups during both seasons.
Conclusions
The isotopic ratios from statoliths and beaks indicate that D. gigas has changed its spatial and trophic preferences, a shift that is probably related to changes in the species' diet. This intraspecific variation in preferences could be related to characteristics such as size, which may influence squid distribution preferences.
Our understanding of the trophic transfer of pollutants in marine subtropical ecosystems remains limited due to the complexity of their food webs. Thus, we aimed to evaluate Cd, Cu, Mn, Pb, and Zn ...sources, incorporation, and trophodynamics throughout the food web of the southeastern Gulf of California by stomach content analysis, stable isotope analysis, isotope mixing models, and trace element analysis in biological and environmental matrices. The food web comprised three main trophic guilds (TG1, TG2, and TG3). The bioaccumulation of Cd and Zn from seawater was efficient (> 1000) in TG2 and TG3. Bioaccumulation factor from sediment (BSAF >1) evidenced of Cd in all trophic guilds. In addition, non-trophic Cd relationships were identified in the food web. Based on the trophic magnification factor (TMF), Mn and Pb showed biodilution (TMFMn = 0.38; TMFPb = 0.16), while Cu and Zn exhibited biomagnification (TMFCu = 2.08; TMFZn = 3.31).
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•Trophodynamics of Cd, Cu, Mb, Pb, and Zn were investigated in the Gulf of California•Efficient bioaccumulation of Cd and Zn from seawater was observed in TG2 and TG3•Cd bioaccumulation from the sediment to organisms was evident across all trophic guilds.•Notable biodilution was observed for Mn and Pb throughout the food web.•Cu and Zn exhibited significant biomagnification within the Gulf of California's food web.
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