The Community Land Model (CLM) is the land component of the Community Earth System Model (CESM) and is used in several global and regional modeling systems. In this paper, we introduce model ...developments included in CLM version 5 (CLM5), which is the default land component for CESM2. We assess an ensemble of simulations, including prescribed and prognostic vegetation state, multiple forcing data sets, and CLM4, CLM4.5, and CLM5, against a range of metrics including from the International Land Model Benchmarking (ILAMBv2) package. CLM5 includes new and updated processes and parameterizations: (1) dynamic land units, (2) updated parameterizations and structure for hydrology and snow (spatially explicit soil depth, dry surface layer, revised groundwater scheme, revised canopy interception and canopy snow processes, updated fresh snow density, simple firn model, and Model for Scale Adaptive River Transport), (3) plant hydraulics and hydraulic redistribution, (4) revised nitrogen cycling (flexible leaf stoichiometry, leaf N optimization for photosynthesis, and carbon costs for plant nitrogen uptake), (5) global crop model with six crop types and time‐evolving irrigated areas and fertilization rates, (6) updated urban building energy, (7) carbon isotopes, and (8) updated stomatal physiology. New optional features include demographically structured dynamic vegetation model (Functionally Assembled Terrestrial Ecosystem Simulator), ozone damage to plants, and fire trace gas emissions coupling to the atmosphere. Conclusive establishment of improvement or degradation of individual variables or metrics is challenged by forcing uncertainty, parametric uncertainty, and model structural complexity, but the multivariate metrics presented here suggest a general broad improvement from CLM4 to CLM5.
Plain Language Summary
The Community Land Model (CLM) is the land component of the widely used Community Earth System Model (CESM). Here, we introduce model developments included in CLM version 5 (CLM5), the default land component for CESM2 which will be used for the Coupled Model Intercomparison Project (CMIP6). CLM5 includes many new and updated processes including (1) hydrology and snow features such as spatially explicit soil depth, canopy snow processes, a simple firn model, and a more mechanistic river model, (2) plant hydraulics and hydraulic redistribution, (3) revised nitrogen cycling with flexible leaf stoichiometry, leaf N optimization for photosynthesis, and carbon costs for plant nitrogen uptake, (4) expansion to six crop types (global) and time‐evolving irrigated areas and fertilization rates, (5) improved urban building energy model, and (6) carbon isotopes. New optional features include a demographically structured dynamic vegetation model, ozone damage to plants, and fire trace gas emissions coupling to the atmosphere. Model performance is generally improved for most assessed variables and metrics, though clear establishment of improvement or degradation is challenging due to model complexity as well as observational data limitations. Nonetheless, CLM5 is increasingly suited for research into a broad range of societally relevant scientific questions related to the terrestrial system.
Key Points
Updated Community Land Model has more hydrological and ecological process fidelity and more comprehensive representation of land management.
The model is systematically evaluated using International Land Model Benchmarking system and shows marked improvement over prior versions.
Atmospheric humidity and soil moisture in the Amazon forest are tightly coupled to the region's water balance, or the difference between two moisture fluxes, evapotranspiration minus precipitation ...(ET-P). However, large and poorly characterized uncertainties in both fluxes, and in their difference, make it challenging to evaluate spatiotemporal variations of water balance and its dependence on ET or P. Here, we show that satellite observations of the HDO/H
O ratio of water vapor are sensitive to spatiotemporal variations of ET-P over the Amazon. When calibrated by basin-scale and mass-balance estimates of ET-P derived from terrestrial water storage and river discharge measurements, the isotopic data demonstrate that rainfall controls wet Amazon water balance variability, but ET becomes important in regulating water balance and its variability in the dry Amazon. Changes in the drivers of ET, such as above ground biomass, could therefore have a larger impact on soil moisture and humidity in the dry (southern and eastern) Amazon relative to the wet Amazon.
The long-term “Grain-to-Green Program” (GGP) on China’s Loess Plateau is a major global ecological engineering project which has significantly boosted vegetation renewal. Some studies have found that ...the rate of restoration is quite rapid during the implementation of ecological engineering, however, the influence of multi-scale climatic conditions on the performance of ecological engineering is unclear. In this study, multiple sources of remote sensing data were used to estimate the dynamics of vegetation structural and functional indicators, water-related local climatic factors, and atmospheric circulation factors. These datasets were also used to detect possible causes for vegetation restoration on the Loess Plateau over the past 20 years. The results show that widespread increases in rates of normalized difference vegetation indexes (NDVI), leaf area indexes (LAI), gross primary production (GPP), and aboveground biomass carbon (ABC) during 2000–2016 were significantly higher than before 2000. GPP was significantly correlated with rainfall and surface runoff on a monthly scale, and there were significant positive correlations between GPP and atmospheric circulation. Our results demonstrate that both vegetation structural and functional indicators rapidly increase, and ecological engineering greatly accelerated vegetation restoration after 2000. Local climatic conditions and atmospheric circulation patterns enhance vegetation growth and impact of ecological engineering.
The hallmarks of cancer include dysregulated metabolism and immune evasion. As a basic way of metabolism, lipid metabolism is reprogrammed for the rapid energy and nutrient supply in the occurrence ...and development of tumors. Lipid metabolism alterations that occur in the tumor microenvironment (TME) affect the antitumor responses of immune cells and cause immune evasion. Therefore, targeting lipid metabolism in the TME for enhancing the antitumor effect of immune cells is a promising direction for cancer treatment. Cancer nanomedicine has great potential in regulating tumor metabolism and tumor immunity. This review summarizes the nanotechnology-based strategies for lipid metabolism regulation in the TME for enhanced anticancer immune responses.
While the long‐term drought effect on tropical forests has been observed in ground‐based and remote sensing measurements, the feedback of reduced forest biomass on subsequent rainfall is not well ...understood. We evaluate the impact of slow forest recovery after the 2005 Amazonian drought on local evapotranspiration (ET) and wet season onset (WSO) using remotely sensed precipitation, deuterium retrievals, reanalysis data, and a new ET product. A comparison to the 2009 rainy season, which exhibits similar large‐scale moisture flux convergence, shows that 2006 experienced a 25% ET reduction and 20 days of postponed WSO in the dry‐to‐wet transition. Our results imply that ET reduction due to drought‐driven legacy effect on the Amazon rainforest could be a crucial factor triggering WSO delay in the transitional season following drought events.
Plain Language Summary
Drought legacy effect, observed as reduced growth and incomplete forest recovery after severe drought events, impacts the carbon and water cycles of Amazonia. Satellite observations showed a reduction of canopy carbon during and after the 2005 Amazonian drought. To understand the impact of local evapotranspiration (ET) changes associated with this canopy carbon reduction on the timing of wet season onset (WSO) over southern Amazonia, we study the precipitation and ET changes in the 2006 dry‐to‐wet transition by using space‐based remote sensing of precipitation, deuterium retrievals, reanalysis data, and a new ET product. A comparison to the 2009 rainy season, which has a similar large‐scale moisture flux convergence amount, shows a 25% reduction in ET and 20 days of postponed WSO during the dry‐to‐wet transition of 2006. Our results indicate that drought legacy effects could be a crucial factor triggering WSO delay following drought events and imply the importance of accurately representing biogeochemical processes and land‐atmosphere feedbacks when predicting precipitation over Amazon in Earth system models.
Key Points
Precipitation observations from TRMM show a postponed wet season onset in southern Amazonia in 2006
Both deuterium retrievals from TES and a new evapotranspiration (ET) product suggest an ET reduction during the late transition of 2006
ET reduction due to 2005 Amazonian drought legacy effect on forest delays the wet season onset in 2006
The spread of coronavirus disease 2019 (COVID-19) throughout the world has resulted in stressful healthcare burdens and global health crises. Developing an effective measure to protect people from ...infection is an urgent need. The blockage of interaction between angiotensin-converting enzyme 2 (ACE2) and S protein is considered an essential target for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) drugs. A full-length ACE2 protein could be a potential drug to block early entry of SARS-CoV-2 into host cells. In this study, a therapeutic strategy was developed by using extracellular vesicles (EVs) with decoy receptor ACE2 for neutralization of SARS-CoV-2. The EVs embedded with engineered ACE2 (EVs-ACE2) were prepared; the EVs-ACE2 were derived from an engineered cell line with stable ACE2 expression. The potential effect of the EVs-ACE2 on anti-SARS-CoV-2 was demonstrated by both in vitro and in vivo neutralization experiments using the pseudovirus with the S protein (S-pseudovirus). EVs-ACE2 can inhibit the infection of S-pseudovirus in various cells, and importantly, the mice treated with intranasal administration of EVs-ACE2 can suppress the entry of S-pseudovirus into the mucosal epithelium. Therefore, the intranasal EVs-ACE2 could be a preventive medicine to protect from SARS-CoV-2 infection. This EVs-based strategy offers a potential route to COVID-19 drug development.
Extracellular vesicles (EVs) embedded with engineered ACE2 can inhibit the transfection of S-pseudovirus in the host cells by serving as decoy receptors and competitively binding with the virus. Display omitted
There is a close connection between epigenetic regulation, cancer metabolism, and immunology. The combination of epigenetic therapy and immunotherapy provides a promising avenue for cancer ...management. As an epigenetic regulator of histone acetylation, panobinostat can induce histone acetylation and inhibit tumor cell proliferation, as well as regulate aerobic glycolysis and reprogram intratumoral immune cells. JQ1 is a BRD4 inhibitor that can suppress PD-L1 expression. Herein, we proposed a chemo-free, epigenetic-based combination therapy of panobinostat/JQ1 for metastatic colorectal cancer. A novel targeted binary-drug liposome was developed based on lactoferrin-mediated binding with the LRP-1 receptor. It was found that the tumor-targeted delivery was further enhanced by in situ formation of albumin corona. The lactoferrin modification and endogenous albumin adsorption contribute a dual-targeting effect on the receptors of both LRP-1 and SPARC that were overexpressed in tumor cells and immune cells (e.g., tumor-associated macrophages). The targeted liposomal therapy was effective to suppress the crosstalk between tumor metabolism and immune evasion via glycolysis inhibition and immune normalization. Consequently, lactic acid production was reduced and angiogenesis inhibited; TAM switched to an anti-tumor phenotype, and the anti-tumor function of the effector CD8+ T cells was reinforced. The strategy provides a potential method for remodeling the tumor immune microenvironment (TIME).
The lactoferrin-modified and albumin-adsorbed liposome for targeting tumor microenvironment was designed for epigenetic-based combination therapy. This tumor-targeting liposome can activate anti-tumor immunity responses, inhibit aerobic glycolysis and angiogenesis, and restrict tumor growth and metastasis via epigenetic regulation. Display omitted
Rapid global changes are altering regional hydrothermal conditions, especially in ecologically vulnerable areas such as coastal regions, subsequently influencing the dynamics of vegetation growth. ...However, there is limited research investigating the response of vegetation in these regions to extreme climates and the associated time lag-accumulation relationships. This study utilized a combined approach of gradual and abrupt analysis to examine the spatiotemporal patterns of vegetation dynamics in the coastal provinces of China from 2000 to 2019. Additionally, we evaluated the time lag-accumulation response of vegetation to extreme climate events. The results showed that (1) extreme high temperatures and extreme precipitation had increased over the past two decades, with greater warming observed in high latitudes and concentrated precipitation increases in water-rich southern regions; (2) both gradual and abrupt analyses indicate significant vegetation improvement in coastal provinces; (3) significant lag-accumulation relationships were observed between vegetation and extreme climate in the coastal regions of China, and the time-accumulation effects were stronger than the time lag effects. The accumulation time of extreme temperatures was typically less than one month, and the accumulation time of extreme precipitation was 2–3 months. These findings are important for predicting the growth trend of coastal vegetation, understanding environmental changes, and anticipating ecosystem evolution.
The coronavirus disease 2019 (COVID-19) pandemic has so far damaged the health of millions and has made the treatment of cancer patients more complicated, and so did acute myeloid leukemia (AML). The ...current problem is the lack of understanding of their interactions and suggestions of evidence-based guidelines or historical experience for the treatment of such patients. Here, we first identified the COVID-19-related differentially expressed genes (C-DEGs) in AML patients by analyzing RNA-seq from public databases and explored their enrichment pathways and candidate drugs. A total of 76 C-DEGs associated with the progress of AML and COVID-19 infection were ultimately identified, and the functional analysis suggested that there are some shared links between them. Their protein–protein interactions (PPIs) and protein–drug interactions were then recognized by multiple bioinformatics algorithms. Moreover, a COVID-19 gene-associated prognostic model (C-GPM) with riskScore was constructed, patients with a high riskScore had poor survival and apparently immune-activated phenotypes, such as stronger monocyte and neutrophil cell infiltrations and higher immunosuppressants targeting expressions, meaning which may be one of the common denominators between COVID-19 and AML and the reason what complicates the treatment of the latter. Among the study’s drawbacks is that these results relied heavily on publicly available datasets rather than being clinically confirmed. Yet, these findings visualized those C-DEGs’ enrichment pathways and inner associations, and the C-GPM based on them could accurately predict survival outcomes in AML patients, which will be helpful for further optimizing therapies for AML patients with COVID-19 infections.
Future projections of land carbon uptake in Earth System Models are affected by land surface model responses to both CO2 and nitrogen fertilization. The Community Land Model, Version 5 (CLM5), ...contains a suite of modifications to carbon and nitrogen cycle representation. Globally, the CLM5 has a larger CO2 response and smaller nitrogen response than its predecessors. To improve our understanding of the controls over the fertilization responses of the new model, we assess sensitivity to eight parameters pertinent to the cycling of carbon and nitrogen by vegetation, both under present‐day conditions and with CO2 and nitrogen fertilization. The impact of fertilization varies with both model parameters and with the balance of limiting factors (water, temperature, nutrients, and light) in the pre‐fertilization model state. The model parameters that impact the pre‐fertilization state are in general not the same as those that control fertilization responses, meaning that goodness of fit to present‐day conditions does not necessarily imply a constraint on future transient projections. Where pre‐fertilization state has low leaf area, fertilization‐induced increases in leaf production amplify the model response to the initial fertilization via further increases in photosynthesis. Model responses to CO2 and N fertilization are strongly impacted by how much plant communities can increase their rates of nitrogen fixation and also directly affected by costs of N extraction from soil and stoichiometric flexibility. Illustration of how parametric flexibility impacts model outputs should help inform the interpretation of carbon‐climate feedbacks estimated by in fully coupled Earth system model simulations.
Key Points
The Community Land Model, Version 5, contains numerous modifications to representations of the vegetation carbon and nitrogen cycles
The control state, and responses to CO2 and nitrogen, are sensitive to parameter choice, and to baseline water and nitrogen limitation
Parameters controlling nitrogen fixation rates dominate fertilization responses, highlighting a need for greater scrutiny of this process
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