bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating Wetland and Nonwetland Soil Methane Emissions and Sinks Across the Contiguous United States Using a Land Surface Model
Authors: Shu Shijie , Jain Atul K. , Kheshgi Haroon S. 
Published: July 2020

AbstractWe estimated the distribution of CH4 emissions and sinks from wetlands (including freshwater and coastal wetlands) and nonwetland (including wet and dry soils) with a newly developed vertically resolved soil CH4 model, integrated into a global land surface model (ISAM). We calibrated and tested this integrated model with CH4 observations at test sites in the Contiguous United States (CONUS). ISAM is applied across the CONUS to estimate CH4 emissions and sinks given both recent past observed climate and wetland extent, and future climate and wetland extent driven by two scenarios, RCP4.5 and RCP8.5. Estimated net CH4 emissions for the 2000s are 13.8 TgCH4 yr−1, mostly from wetland soils. Estimated net emissions under RCP4.5 and RCP8.5 are 30% and 64% higher, respectively, in the 2090s than in the 2000s due to (1) higher temperature and seasonal wetland extent (driven by higher precipitation in the climate scenarios), which increase modeled methanogenic activity more than methanotrophic activity in soils and (2) altered transport in the soil column and exchange with the atmosphere by modeled transport processes (diffusion, ebullition, and aerenchyma transport). Nonwetland soils emit CH4 (1.4 TgCH4 yr−1) in some areas and take up CH4 (−2.9 TgCH4 yr−1) in other areas, resulting in a net estimated sink for the 2000s; the net nonwetland soil sink increases by 15% and 46% by the 2090s under RCP4.5 and RCP8.5, respectively, mainly due to drier soil conditions, which enhances methanotrophic activity and oxidation of CH4 diffused into soil from a future atmosphere with higher CH4 concentration.
Hydrologic Export Is a Major Component of Coastal Wetland Carbon Budgets
Authors: Bogard Matthew J. , Bergamaschi Brian A. , Butman David E. , Anderson Frank , Knox Sara H. , Windham‐Myers Lisamarie 
Published: July 2020

AbstractCoastal wetlands are among the most productive habitats on Earth and sequester globally significant amounts of atmospheric carbon (C). Extreme rates of soil C accumulation are widely assumed to reflect efficient C storage. Yet the fraction of wetland C lost via hydrologic export has not been directly quantified, since comprehensive budgets including direct estimates of lateral C loss are lacking. We present a complete net ecosystem C budget (NECB), demonstrating that lateral losses of C are a major component of the NECB for the largest stable brackish tidal marsh on the U.S. Pacific coast. Mean annual net ecosystem exchange of CO2 with the atmosphere (NEE = −185 g C m2 year−1, negative NEE denoting ecosystem uptake) was compared to long‐term soil C burial (87–110 g C m2 year−1), suggesting only 47–59% of fixed atmospheric C accumulates in soils. Consistently, direct monitoring in 2017–2018 showed NEE of −255 g C m−2 year−1, and hydrologic export of 105 g C m−2 year−1 (59% of NEE remaining on site). Despite their high C sequestration capacity, lateral losses from coastal wetlands are typically a larger fraction of the NECB when compared to other terrestrial ecosystems. Loss of inorganic C (the least measured NECB term) was 91% of hydrologic export and may be the most important term limiting C sequestration. The high productivity of coastal wetlands thus serves a dual function of C burial and estuarine export, and the multiple fates of fixed C must be considered when evaluating wetland capacity for C sequestration.
Advective Controls on the North Atlantic Anthropogenic Carbon Sink
Authors: Ridge S. M. , McKinley G. A. 
Published: July 2020

Though it is clear that the North Atlantic is the site of the highest storage of anthropogenic carbon (Cant) per area, it is uncertain whether the air‐sea Cant fluxes contributing to North Atlantic Cant storage occur in the subpolar gyre or upstream in the subtropical gyre. Using data and models, we show that air‐sea Cant uptake capacity is advected into the subpolar gyre along the same subsurface pathway as nutrients. This pathway is known as the nutrient stream. On the A22 section between Woods Hole and Bermuda, nutrient stream waters are the oldest in the upper 2,000 m and contain low Cant. These northward moving waters are sufficiently depleted in Cant such that they could sustain a subpolar air‐sea Cant flux of −0.19 Pg Cant year−1. The ocean hindcast model used here indicates that despite some subtropical re‐circulation, uptake capacity is transported into the subpolar gyre where it sustains subpolar air‐sea Cant uptake. With this model, we show that high‐ and low‐end estimates of subpolar air‐sea Cant flux are reconciled by accounting for a factor of two difference in their respective study areas. If half of the observed air‐sea Cant uptake capacity transport at A22 is ventilated in the subpolar region, it can fully support high‐end estimates of the subpolar air‐sea Cant sink (−0.09±0.01 Pg Cant year−1).
Effects of Snow Grain Shape and Mixing State of Snow Impurity on Retrieval of Snow Physical Parameters From Ground‐Based Optical Instrument
Authors: Tanikawa T. , Kuchiki K. , Aoki T. , Ishimoto H. , Hachikubo A. , Niwano M. , Hosaka M. , Matoba S. , Kodama Y. , Iwata Y. , Stamnes K. 
Published: July 2020

AbstractWe proposed new snow grain model and snow impurity mixture models for the purpose of accurate retrievals of snow grain size and concentration of light‐absorbing particles (LAP) in snow from the optical remote sensing data. Two kinds of ice crystal models, irregularly shaped Voronoi columns, and Voronoi aggregates were employed. LAP can be captured by the snow through two processes: dry and wet deposition. Two different snow impurity mixture models were proposed. One is an external mixture model. We employed a coated sphere model in which soot were hydrophilic particles to represent a hygroscopic property of aerosol and assumed the hydrophilic soot particles to be externally mixed with snow particles. The other is an internal mixture model. We employed a dynamic effective medium approximation method in which soot particles were randomly located within snow particle with any size distribution and number concentration. Validation of these models is conducted using a ground‐based spectral radiometer system with in situ measurement data. For snow grain size retrievals, a Voronoi mixture model seamlessly representing a geometrical shape and an optical properties of various snow types can provide accurate retrievals. For the retrieval of LAP concentration in snow, employing different mixing state models depending on season and measurement site gives accurate results. We also discussed the uncertainty of retrieved snow parameters on the surface slope involved in the retrieval accuracy. These models are expected to be useful for advanced airborne/satellite remote sensing and climate studies via radiative transfer modeling in the atmosphere‐snow system.
Contribution of IASI to the Observation of Dust Aerosol Emissions (Morning and Nighttime) Over the Sahara Desert
Authors: Chédin A. , Capelle V. , Scott N. A. , Todd M. C. 
Published: July 2020

AbstractObserving the planet at global scale, twice a day, and measuring the whole infrared atmospheric spectrum (8,461 channels at 0.50 cm−1 resolution), Infrared Atmospheric Sounder Interferometer (IASI)/METOP can concurrently detect clouds, determine the 3‐D atmospheric structure (temperature, water vapor, ozone, etc.), surface properties (emissivity and temperature), as well as dust aerosol AOD and altitude. Observing morning (0930 hr) and nighttime (2130 hr), IASI is in relatively good phase with the most frequent times of occurrence of the main Saharan dust uplift mechanisms reported in the literature. Here we classify IASI dust observations according to both the dust loading (AOD) and the dust layer height, providing a more comprehensive picture of dust characteristics. This classification is analyzed at daily scale and its capability to detect dust uplift events is evaluated through comparisons with results from the particularly well documented June 2011 Fennec campaign. Then, a Dust Emission Index (DEI), specific to IASI, is constructed by selecting AOD‐altitude bins with largest AODs and smallest altitudes likely indicative of freshly emitted dust. Applying this to the 12‐year 2007–2018 period, we determine climatological DEI maps and comparisons are made with other equivalent existing results derived from ground‐based or other satellite observations. Results of these comparisons demonstrate the capability of IASI to document the dust distribution over the whole Earth desert areas over a long period of time. The present approach is also suitable to the processing of the at least hourly observations of the coming Infrared Sounder instrument (IRS), planned on board Meteosat Third Generation (2021).
Postseismic Deformation Following the 2015 Mw7.8 Gorkha (Nepal) Earthquake: New GPS Data, Kinematic and Dynamic Models, and the Roles of Afterslip and Viscoelastic Relaxation
Authors: Liu‐Zeng J. , Zhang Z. , Rollins C. , Gualandi A. , Avouac J.‐P. , Shi H. , Wang P. , Chen W. , Zhang R. , Zhang P. , Wang W. , Li Y. , Wang T. , Li Z. 
Published: July 2020

AbstractWe report Global Positioning System (GPS) measurements of postseismic deformation following the 2015 Mw7.8 Gorkha (Nepal) earthquake, including previously unpublished data from 13 continuous GPS stations installed in southern Tibet shortly after the earthquake. We use variational Bayesian Independent Component Analysis (vbICA) to extract the signal of postseismic deformation from the GPS time series, revealing a broad displacement field extending >150 km northward from the rupture. Kinematic inversions and dynamic forward models show that these displacements could have been produced solely by afterslip on the Main Himalayan Thrust (MHT) but would require a broad distribution of afterslip extending similarly far north. This would require the constitutive parameter (a − b)σ to decrease northward on the MHT to ≤0.05 MPa (an extreme sensitivity of creep rate to stress change) and seems unlikely in light of the low interseismic coupling and high midcrustal temperatures beneath southern Tibet. We conclude that the northward reach of postseismic deformation more likely results from distributed viscoelastic relaxation, possibly in a midcrustal shear zone extending northward from the seismogenic MHT. Assuming a shear zone 5–20 km thick, we estimate an effective shear‐zone viscosity of ~3·1016–3·1017 Pa·s over the first 1.12 postseismic years. Near‐field deformation can be more plausibly explained by afterslip itself and implies (a − b)σ ~ 0.5–1 MPa, consistent with other afterslip studies. This near‐field afterslip by itself would have re‐increased the Coulomb stress by ≥0.05 MPa over >30% of the Gorkha rupture zone in the first postseismic year, and deformation further north would have compounded this reloading.
Anaerobic metabolism of Foraminifera thriving below the seafloor
Authors: Orsi William D , Morard Raphaël , Vuillemin Aurele , Eitel Michael , Wörheide Gert , Milucka Jana , Kucera Michal 
Published: July 2020

Abstract
Foraminifera are single-celled eukaryotes (protists) of large ecological importance, as well as environmental and paleoenvironmental indicators and biostratigraphic tools. In addition, they are capable of surviving in anoxic marine environments where they represent a major component of the benthic community. However, the cellular adaptations of Foraminifera to the anoxic environment remain poorly constrained. We sampled an oxic-anoxic transition zone in marine sediments from the Namibian shelf, where the genera Bolivina and Stainforthia dominated the Foraminifera community, and use metatranscriptomics to characterize Foraminifera metabolism across the different geochemical conditions. Relative Foraminifera gene expression in anoxic sediment increased an order of magnitude, which was confirmed in a 10-day incubation experiment where the development of anoxia coincided with a 20–40-fold increase in the relative abundance of Foraminifera protein encoding transcripts, attributed primarily to those involved in protein synthesis, intracellular protein trafficking, and modification of the cytoskeleton. This indicated that many Foraminifera were not only surviving but thriving, under the anoxic conditions. The anaerobic energy metabolism of these active Foraminifera was characterized by fermentation of sugars and amino acids, fumarate reduction, and potentially dissimilatory nitrate reduction. Moreover, the gene expression data indicate that under anoxia Foraminifera use the phosphogen creatine phosphate as an ATP store, allowing reserves of high-energy phosphate pool to be maintained for sudden demands of increased energy during anaerobic metabolism. This was co-expressed alongside genes involved in phagocytosis and clathrin-mediated endocytosis (CME). Foraminifera may use CME to utilize dissolved organic matter as a carbon and energy source, in addition to ingestion of prey cells via phagocytosis. These anaerobic metabolic mechanisms help to explain the ecological success of Foraminifera documented in the fossil record since the Cambrian period more than 500 million years ago.
Long noncoding RNA SNHG12 promotes tumour progression and sunitinib resistance by upregulating CDCA3 in renal cell carcinoma
Authors: Liu Yuenan , Cheng Gong , Huang Ziwei , Bao Lin , Liu Jingchong , Wang Cheng , Xiong Zhiyong , Zhou Lijie , Xu Tianbo , Liu Di , Yang Hongmei , Chen Ke , Zhang Xiaoping 
Published: July 2020

AbstractRenal cell carcinoma (RCC) is one of the most frequently observed malignant tumours in the urinary system and targeted drug resistance is quite common in RCC. Long noncoding RNA SNHG12 (lncRNA SNHG12) has emerged as a key molecule in numerous human cancers, but its functions in renal cell carcinoma (RCC) sunitinib resistance remain unclear. In this study, we found SNHG12 was highly expressed in RCC tissues and in sunitinib-resistant RCC cells and was associated with a poor clinical prognosis. SNHG12 promoted RCC proliferation, migration, invasion and sunitinib resistance via CDCA3 in vitro. Mechanically, SNHG12 bound to SP1 and prevented the ubiquitylation-dependent proteolysis of SP1. Stabilised SP1 bound to a specific region in the promoter of CDCA3 and increased CDCA3 expression. Furthermore, in vivo experiments showed that SNHG12 increased tumour growth and that knocking down SNHG12 could reverse RCC sunitinib resistance. Our study revealed that the lncRNA SNHG12/SP1/CDCA3 axis promoted RCC progression and sunitinib resistance, which could provide a new therapeutic target for sunitinib-resistant RCC.
Oxidized ATM promotes breast cancer stem cell enrichment through energy metabolism reprogram-mediated acetyl-CoA accumulation
Authors: Yang Dan , Peng Meixi , Hou Yixuan , Qin Yilu , Wan Xueying , Zhu Pengpeng , Liu Shuiqing , Yang Liping , Zeng Huan , Jin Ting , Qiu Yuxiang , Li Qiao , Liu Manran 
Published: July 2020

AbstractCancer stem cell (CSC) is a challenge in the therapy of triple-negative breast cancer (TNBC). Intratumoral hypoxia is a common feature of solid tumor. Hypoxia may contribute to the maintenance of CSC, resulting in a poor efficacy of traditional treatment and recurrence of TNBC cases. However, the underlying molecular mechanism involved in hypoxia-induced CSC stemness maintenance remains unclear. Here, we report that hypoxia stimulated DNA double-strand breaks independent of ATM kinase activation (called oxidized ATM in this paper) play a crucial role in TNBC mammosphere formation and stemness maintenance by governing a specific energy metabolism reprogramming (EMR). Oxidized ATM up-regulates GLUT1, PKM2, and PDHa expressions to enhance the uptake of glucose and production of pyruvate rather than lactate products, which facilitates glycolytic flux to mitochondrial pyruvate and citrate, thus resulting in accumulation of cytoplasmic acetyl-CoA instead of the tricarboxylic acid (TCA) cycle by regulating ATP-citrate lyase (ACLY) activity. Our findings unravel a novel model of TNBC-CSC glucose metabolism and its functional role in maintenance of hypoxic TNBC-CSC stemness. This work may help us to develop new therapeutic strategies for TNBC treatment.
Opposing biological functions of the cytoplasm and nucleus DAXX modified by SUMO-2/3 in gastric cancer
Authors: Chen Chenbin , Sun Xiangwei , Xie Wangkai , Chen Sian , Hu Yuanbo , Xing Dong , Xu Jianfeng , Chen Xiaodong , Zhao Zhiguang , Han Zheng , Xue Xiangyang , Shen Xian , Lin Kezhi 
Published: July 2020

AbstractDeath domain-associated protein (DAXX) is a complex biological multifunctional protein and is involved in the tumorigenesis and progression of multiple cancers. The accumulation of DAXX in the nucleus is a common phenomenon in tumor cells. However, altering the subcellular localizations of DAXX results in different biological functions, and we also found that its nuclear/cytoplasmic ratio (NCR) was associated with poor prognosis in gastric cancer (GC). In this study, we investigated the effect of cytoplasmic and nuclear DAXX (cDAXX and nDAXX) in GC and the underlying mechanisms. Immunohistochemical detection performed in 323 GC tissues reveled that cDAXX was associated with a better survival, while high nDAXX expression suggested a poorer prognosis outcome. Upregulation of DAXX in the cytoplasm inhibited cell proliferation and promoted apoptosis, whereas downregulation of DAXX in the nucleus displayed opposite effects. Moreover, Transwell assays revealed that DAXX enhanced GC cell migration and invasion. Analysis from the Gene Expression Profile Interactive Analysis (GEPIA) database showed that the expression of DAXX was significantly associated with SUMO-2/3 in GC tissues. Co-immunoprecipitation combined with immunofluorescence analysis indicated that DAXX interacted directly with SUMO-2/3. Subsequently, down-regulating the expression of SUMO-2/3 resulted in altered subcellular localization of DAXX. Bioinformatics analysis showed that RanBP2 may act as SUMO E3 ligase to promote nuclear-plasma transport via combining with RanGAP1. Taken together, our results indicated that DAXX plays opposing roles in GC and suggest a new model whereby cDAXX, nDAXX, and SUMO-2/3 form a molecular network that regulates the subcellular localization of DAXX and thereby modulates its opposing biological effects. Thus, our findings provide a foundation for future studies of DAXX as a novel therapeutic target for patients with GC.
SARS-CoV-2 is transmitted via contact and via the air between ferrets
Authors: Richard Mathilde , Kok Adinda , de Meulder Dennis , Bestebroer Theo M. , Lamers Mart M. , Okba Nisreen M. A. , Fentener van Vlissingen Martje , Rockx Barry , Haagmans Bart L. , Koopmans Marion P. G. , Fouchier Ron A. M. , Herfst Sander 
Published: July 2020

AbstractSARS-CoV-2, a coronavirus that emerged in late 2019, has spread rapidly worldwide, and information about the modes of transmission of SARS-CoV-2 among humans is critical to apply appropriate infection control measures and to slow its spread. Here we show that SARS-CoV-2 is transmitted efficiently via direct contact and via the air (via respiratory droplets and/or aerosols) between ferrets, 1 to 3 days and 3 to 7 days after exposure respectively. The pattern of virus shedding in the direct contact and indirect recipient ferrets is similar to that of the inoculated ferrets and infectious virus is isolated from all positive animals, showing that ferrets are productively infected via either route. This study provides experimental evidence of robust transmission of SARS-CoV-2 via the air, supporting the implementation of community-level social distancing measures currently applied in many countries in the world and informing decisions on infection control measures in healthcare settings.
COVID-19 outbreak response, a dataset to assess mobility changes in Italy following national lockdown
Authors: Pepe Emanuele , Bajardi Paolo , Gauvin Laetitia , Privitera Filippo , Lake Brennan , Cattuto Ciro , Tizzoni Michele 
Published: July 2020

AbstractItaly has been severely affected by the COVID-19 pandemic, reporting the highest death toll in Europe as of April 2020. Following the identification of the first infections, on February 21, 2020, national authorities have put in place an increasing number of restrictions aimed at containing the outbreak and delaying the epidemic peak. On March 12, the government imposed a national lockdown. To aid the evaluation of the impact of interventions, we present daily time-series of three different aggregated mobility metrics: the origin-destination movements between Italian provinces, the radius of gyration, and the average degree of a spatial proximity network. All metrics were computed by processing a large-scale dataset of anonymously shared positions of about 170,000 de-identified smartphone users before and during the outbreak, at the sub-national scale. This dataset can help to monitor the impact of the lockdown on the epidemic trajectory and inform future public health decision making.
Chromatin accessibility and transcriptome landscapes of Monomorium pharaonis brain
Authors: Wang Mingyue , Liu Yang , Wen Tinggang , Liu Weiwei , Gao Qionghua , Zhao Jie , Xiong Zijun , Wang Zhifeng , Jiang Wei , Yu Yeya , Wu Liang , Yuan Yue , Wei Xiaoyu , Xu Jiangshan , Cheng Mengnan , Zhang Pei , Li Panyi , Hou Yong , Yang Huanming , Zhang Guojie , Li Qiye , Liu Chuanyu , Liu Longqi 
Published: July 2020

AbstractThe emergence of social organization (eusociality) is a major event in insect evolution. Although previous studies have investigated the mechanisms underlying caste differentiation and social behavior of eusocial insects including ants and honeybees, the molecular circuits governing sociality in these insects remain obscure. In this study, we profiled the transcriptome and chromatin accessibility of brain tissues in three Monomorium pharaonis ant castes: queens (including mature and un-mated queens), males and workers. We provide a comprehensive dataset including 16 RNA-sequencing and 16 assay for transposase accessible chromatin (ATAC)-sequencing profiles. We also demonstrate strong reproducibility of the datasets and have identified specific genes and open chromatin regions in the genome that may be associated with the social function of these castes. Our data will be a valuable resource for further studies of insect behaviour, particularly the role of brain in the control of eusociality.