bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Use of Monthly Mean Average for Investigating the Presence of Hysteresis and Long‐Term Trends in Ionospheric NmF2
Authors: Huang Jianping , Hao Yongqiang , Zhang Donghe , Xiao Zuo 
Published: December 2019

AbstractYearly averaging is a basic preprocessing of ionospheric data to smooth out the short‐term, cyclic variations in the observations. However, we find that the use of yearly (running) average method probably leads to a biased evaluated relation between the ionospheric parameters (e.g.,
2 peak electron density,
) and the solar extreme ultraviolet (EUV) irradiance. The bias is essentially related to the annual/seasonal variations of the ionosphere, which means that the ionospheric sensitivity to the solar EUV irradiance varies with season and the same solar input can produce different ionization levels in different months/seasons. The yearly method simply averages the observations of different seasons, leading to a biased yearly
‐EUV relation, which will further affect the estimation of the ionospheric hysteresis (different
‐EUV relation in the solar rising and declining phase). Also, the extraction of long‐term trends in the ionosphere will be more uncertain if using a regression approach based on the biased
‐EUV relation. In conclusion, we suggest to do the analysis month by month (using monthly average method) to properly deal with the annual/seasonal variations of the ionosphere, and to obtain accurate estimation of the hysteresis and long‐term trends. Though both the yearly and monthly methods were used in precedent works, the bias introduced by the yearly average method has not been fully recognized prior to this study.
Comprehensive Analysis of the Magnetic Signatures of Small‐Scale Traveling Ionospheric Disturbances,as Observed by Swarm
Authors: Yin Fan , Lühr Hermann , Park Jaeheung , Wang Ling 
Published: December 2019

AbstractBased on Swarm satellite data from 2015 through 2018, we present the mean characteristics of magnetic field fluctuations at midlatitudes and low latitudes. It is the first comprehensive study focusing on small‐scale variations (<10 km). Events are observed on about 35% of the orbits. The highest occurrence rates are detected after sunset, in the East Asian/Australian sector, and during months around June solstice. Low occurrence rates are found at low magnetic latitudes (below ±10° quasi‐dipole latitude), in the region of the South Atlantic Anomaly, and during equinox seasons. All these occurrence features compare well with those of medium‐scale traveling ionospheric disturbances. We therefore term our small‐scale events small‐scale traveling ionospheric disturbances (SSTIDs). SSTIDs exhibit high field‐aligned current (FAC) densities connected to narrow current sheets with meridional width of typically 4 km. The intense FACs of several μA/m2 flow typically between the hemispheres. Return currents are distributed over larger scales and thus have smaller amplitudes. Peak current densities get larger toward lower latitudes. There are two groups of events, around morning‐noontime and evening‐night, which are separated by demarcation lines near 04 and 15 magnetic local time. The magnetic amplitudes of the small‐scale fluctuations are larger in sunlight than in darkness, indicating larger total currents in the loops. But the FAC peak current densities are larger in darkness, inferring a stronger squeezing of the current sheet under low‐conductivity conditions. We suggest that our SSTIDs are an evolutional state of medium‐scale traveling ionospheric disturbances.
Periodic Mesoscale Eddies in the South China Sea
Authors: Chu Xiaoqing , Chen Gengxin , Qi Yiquan 
Published: December 2019

AbstractAlthough numerous mesoscale eddies are observed in the South China Sea (SCS), a comprehensive study that focuses on periodic eddies has not yet been reported. Periodic eddies are a type of eddies that occur nearly annually in fixed time frames with similar patterns and trajectories. On the basis of in situ and satellite observations, this paper reports a periodic anticyclonic eddy in the western SCS (the Western SCS Anticyclonic Eddy, WAE) and elucidates the underlying processes responsible for its generation and evolution. The WAE is a seasonal phenomenon modulated by the Asian monsoon and basin‐scale circulation. Usually, the WAE generates around 112°E, 14°N in February–March, induced by the cyclonic gyre in the northern SCS associated with the winter monsoon. The WAE occupies the western SCS for 5 months and finally dissipates in July due to the reversal of the monsoon and thus the circulation transition. The WAE shows important interannual variations associated with large‐scale climate variation, and the Niño‐3.4 index could be a potential predictor for its interannual variation. Finally, we summarize 13 periodic eddies in the SCS, including those unreported by previous studies. The period eddies in the SCS exhibit an inverse “L” shape vortex train structure along the western boundary and around the 17°N section, with an anticyclonic “phase” in summer and a cyclonic “phase” in winter. This study provides new knowledge for periodic eddies in the SCS and will benefit targeted observations of periodic eddies.
Evaporation From the Southern Ocean Estimated on the Basis of AIRS Satellite Data
Authors: Boisvert Linette , Vihma Timo , Shie Chung‐Lin 
Published: December 2019

AbstractEvaporation plays an important role in the global water and energy cycles and, hence, in climate change. Evaporation over the Southern Ocean, where the Antarctic sea ice coverage has a large annual cycle, is poorly quantified. In this study, daily evaporation is estimated for the Southern Ocean with a sea‐ice‐specific algorithm, using surface temperature and air humidity from National Aeronautics and Space Administration's Atmospheric Infrared Sounder (AIRS), and wind speeds from Modern‐Era Retrospective Analysis for Research and Applications, Version 2 (MERRA‐2), reanalysis during 2003–2016. An uncertainty of 34% was found in the evaporation product. The results indicate that annual evaporation has considerable interannual and regional variability, but with a decreasing trend during the study period over most of the Southern Ocean. There are, however, areas where evaporation has increased, specifically in the Ross Sea in winter and summer, with smaller positive trends in spring and fall. Overall, the changes in the difference between the surface specific humidity and the air specific humidity, and to a much lesser extent in the wind speed, are the main drivers for the changes in evaporation throughout the year. During spring and fall months, changes to the sea ice cover, which alter the surface specific humidity, are the main drivers for the change, but in summer and winter the main driver is the air‐specific humidity. Air masses originating from the Antarctic continent (south) are associated with cold and dry conditions, which increase evaporation, whereas air masses from lower latitudes in the Southern Ocean (north) are associated with warm and moist conditions, decreasing evaporation. Comparisons with other reanalysis evaporation products produce similar trends, although annual averages differ.
An Integrated Agriculture, Atmosphere, and Hydrology Modeling System for Ecosystem Assessments
Authors: Ran L. , Yuan Y. , Cooter E. , Benson V. , Yang D. , Pleim J. , Wang R. , Williams J. 
Published: December 2019

AbstractWe present a regional‐scale integrated modeling system (IMS) that includes Environmental Policy Integrated Climate (EPIC), Weather Research and Forecast (WRF), Community Multiscale Air Quality (CMAQ), and Soil and Water Assessment Tool (SWAT) models. The centerpiece of the IMS is the Fertilizer Emission Scenario Tool for CMAQ (FEST‐C), which includes a Java‐based interface and EPIC adapted to regional applications along with built‐in database and tools. The SWAT integration capability is a key enhanced feature in the current release of FEST‐C v1.4. For integrated modeling demonstration and evaluation, FEST‐C EPIC is simulated over three individual years with WRF/CMAQ weather and N deposition. Simulated yearly changes in water and N budgets along with yields for two major crops (corn grain and soybean) match those inferred from intuitive physical reasoning and survey data given different‐year weather conditions. Yearlong air quality simulations with an improved bidirectional ammonia flux modeling approach directly using EPIC‐simulated soil properties including NH3 content helps reduce biases of simulated gas‐phase NH3 and NH4+ wet deposition over the growing season. Integrated hydrology and water quality simulations applied to the Mississippi River Basin show that estimated monthly streamflow and dissolved N near the outlet to the Gulf of Mexico display similar seasonal patterns as observed. Limitations and issues in different parts of the integrated multimedia simulations are identified and discussed to target areas for future improvements.
Parameterizing Perennial Bioenergy Crops in Version 5 of the Community Land Model Based on Site‐Level Observations in the Central Midwestern United States
Authors: Cheng Yanyan , Huang Maoyi , Chen Min , Guan Kaiyu , Bernacchi Carl , Peng Bin , Tan Zeli 
Published: December 2019

AbstractWith projected expansion of biofuel production at a global scale, there is a pressing need to develop adequate representation of bioenergy crops in land surface models to help effectively quantify the biogeophysical and biogeochemical effects of its associated land use changes. This study implements two new perennial bioenergy crops, Miscanthus and switchgrass, into the Community Land Model Version 5 based on site‐level observations from the midwestern United States by modifying parameters associated with photosynthesis, phenology, allocation, decomposition, and carbon cost of nitrogen uptake and integrating concomitantly land management practices. Sensitivity analyses indicate that carbon and energy fluxes of the perennial crops are most sensitive to photosynthesis and phenology parameters. Validation of simulated fluxes against site‐level measurements demonstrates that the model is capable of capturing the overall patterns of energy and carbon fluxes, as well as physiological transitions from leaf emergence to senescence. Compared to annual crops, perennial crops feature longer growing season, greater leaf areas, and higher productivity, leading to increased transpiration, lower annual runoff, and larger carbon uptake. The model simulations suggest that with higher CO2 assimilation rates and lower demands for nutrients and water, high‐yielding perennial crops are promising alternatives of bioenergy feedstocks compared to traditional annual crops not only for mitigating climate change but also for environmental conservation purposes by reducing fertilizer application and therefore alleviating surface‐ and ground‐water contaminations. Although the local‐scale simulations shed light on potential benefits of using perennial grasses as bioenergy feedstocks, quantifying consequences of their plantations at larger scales warrants additional investigation.
Mathematical Reconstruction of Land Carbon Models From Their Numerical Output: Computing Soil Radiocarbon From C Dynamics
Authors: Metzler Holger , Zhu Qing , Riley William , Hoyt Alison , Müller Markus , Sierra Carlos A. 
Published: December 2019

AbstractRadiocarbon (14C) is a powerful tracer of the global carbon cycle that is commonly used to assess carbon cycling rates in various Earth system reservoirs and as a benchmark to assess model performance. Therefore, it has been recommended that Earth System Models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 report predicted radiocarbon values for relevant carbon pools. However, a detailed representation of radiocarbon dynamics may be an impractical burden on model developers. Here, we present an alternative approach to compute radiocarbon values from the numerical output of an ESM that does not explicitly represent these dynamics. The approach requires computed 12C stocks and fluxes among all carbon pools for a particular simulation of the model. From this output, a time‐dependent linear compartmental system is computed with its respective state‐transition matrix. Using transient atmospheric 14C values as inputs, the state‐transition matrix is then applied to compute radiocarbon values for each pool, the average value for the entire system, and component fluxes. We demonstrate the approach with ELMv1‐ECA, the land component of an ESM model that explicitly represents 12C, and 14C in 7 soil pools and 10 vertical layers. Results from our proposed method are highly accurate (relative error <0.01%) compared with the ELMv1‐ECA 12C and 14C predictions, demonstrating the potential to use this approach in CMIP6 and other model simulations that do not explicitly represent 14C.
Upscaling Reactive Transport Under Hydrodynamic Slip Conditions in Homogeneous Porous Media
Authors: Valdés‐Parada Francisco J. , Lasseux Didier , Whitaker Stephen 
Published: December 2019

AbstractReactive transport of a dilute species in a Newtonian fluid saturating a homogeneous porous medium for slip flow is analyzed in this work. Incompressible Newtonian flow with a first‐order (Navier) slip boundary condition is considered together with a first‐order heterogeneous reaction. Kinetic numbers range up to unity while Knudsen numbers, characteristic of slip‐flow, are smaller than approximately 0.1. The pore‐scale problem is upscaled, using the volume averaging method, to obtain a macroscopic transport equation (referred to as the complete upscaled model) operating at the Darcy scale. Using order of magnitude estimates and an expansion in terms of the Kinetic number, simplifications in the expressions of the effective coefficients are explored. The conditions under which the effective convective velocity and the total dispersion tensor are independent of reaction are derived. Under such conditions, a simplified version of the macroscopic transport equation is obtained. This is referred to as the simplified model. Numerical results for a simple structure indicate that the longitudinal dispersion coefficient decreases with decreasing Knudsen number, while the opposite holds for the transverse component of the total dispersion tensor, the effective convective velocity, and the effective reaction rate coefficient. These effects are more evident when the Péclet number increases (i.e., in the convective‐favored regime) and when slip effects are more pronounced. Results predicted by the simplified and the complete versions of the upscaled model are validated with direct numerical simulations of the pore‐scale problem on a two‐dimensional model structure.
DKC1 enhances angiogenesis by promoting HIF-1α transcription and facilitates metastasis in colorectal cancer
Authors: Hou Pingfu , Shi Peicong , Jiang Tao , Yin Hang , Chu Sufang , Shi Meilin , Bai Jin , Song Jun 
Published: December 2019

Abstract
Background
Dyskeratosis congenita 1 (DKC1) is dysregulated in several cancers. However, the expression and function of DKC1 in colorectal cancer (CRC) is rarely reported.

Methods
Tissue microarrays (TAMs) including 411 cases of CRC tissues and corresponding paracancerous tissues were used to examine the DKC1 expression. The correlations between the DKC1 expression and clinicopathological or survival characters were further analysed. The functions and molecular mechanism of DKC1 in CRC were investigated through a series of in vitro and in vivo experiments.

Results
The result showed that DKC1 expression was increased in CRC tissues. Increased DKC1 expression was associated with high grade of TNM stage, additional lymph node metastasis, and poor prognosis of patients with CRC. Multivariate COX analysis indicated that DKC1 can act as an independent prognostic factor for patients with CRC. DKC1 also facilitated the CRC angiogenesis and metastasis by increasing HIF-1α and VEGF expression levels. Chromatin immunoprecipitation assay demonstrated that DKC1 facilitated HIF-1α expression by regulating HIF-1α promoter activity.

Conclusion
DKC1 appears to regulate CRC angiogenesis and metastasis through directly activating HIF-1α transcription. DKC1 can serve as an accurate indicator in predicting the prognosis of patients with CRC and act as a potential therapeutic target for CRC.
Paclitaxel induces lymphatic endothelial cells autophagy to promote metastasis
Authors: Zamora Audrey , Alves Melinda , Chollet Charlotte , Therville Nicole , Fougeray Tiffany , Tatin Florence , Franchet Camille , Gomez-Brouchet Anne , Vaysse Charlotte , Martinez Laurent O. , Najib Souad , Guillermet-Guibert Julie , Lacazette Eric , Prats Anne-Catherine , Garmy-Susini Barbara 
Published: December 2019

AbstractCytotoxic therapy for breast cancer inhibits the growth of primary tumors, but promotes metastasis to the sentinel lymph nodes through the lymphatic system. However, the effect of first-line chemotherapy on the lymphatic endothelium has been poorly investigated. In this study, we determined that paclitaxel, the anti-cancer drug approved for the treatment of metastatic or locally advanced breast cancer, induces lymphatic endothelial cell (LEC) autophagy to increase metastases. While paclitaxel treatment was largely efficacious in inhibiting LEC adhesion, it had no effect on cell survival. Paclitaxel inhibited LEC migration and branch point formation by inducing an autophagy mechanism independent of Akt phosphorylation. In vivo, paclitaxel mediated a higher permeability of lymphatic endothelium to tumor cells and this effect was reversed by chloroquine, an autophagy-lysosome inhibitor. Despite a strong effect on reducing tumor size, paclitaxel significantly increased metastasis to the sentinel lymph nodes. This effect was restricted to a lymphatic dissemination, as chemotherapy did not affect the blood endothelium. Taken together, our findings suggest that the lymphatic system resists to chemotherapy through an autophagy mechanism to promote malignant progression and metastatic lesions. This study paves the way for new combinative therapies aimed at reducing the number of metastases.
Retinoid acid induced 16 deficiency aggravates colitis and colitis-associated tumorigenesis in mice
Authors: Xu Yu-Lin , Ding Cui-Ling , Qian Chun-Lin , Qi Zhong-Tian , Wang Wen 
Published: December 2019

AbstractInflammatory bowel disease (IBD) and colitis-associated colorectal cancer (CAC) is a serious health issue, but etiopathological factors remain unclear. Although some studies reported the roles of Retinoid acid induced 16 (RAI16) in the tumorigenesis of hepatocellular carcinoma and PKA signaling, the roles of RAI16 in IBD and CRC are undressed. RAI16−/− mice were generated and the roles of RAI16 were addressed in dextran sodium sulfate (DSS) or azoxymethane (AOM)-DSS induced IBD or CAC mouse models, respectively. At first, RAI16−/− mice were viable, fertile with no apparent defects. Then, it was found that RAI16−/− mice were more susceptibility to colitis induced by DSS than wild type (WT) littermates, which was evaluated by disease activity index and histological score. Furthermore, the expressions of tissues repair associated molecules Cox2, Ereg and MMP-10 were significantly decreased in RAI16−/− colon under DSS treatment. Gut barrier related genes including antimicrobial peptides Reg3b and Reg3g and intestinal mucus genes Muc4, Muc6 and Muc20 were reduced in RAI16−/− colon. These findings indicated that RAI16 may function to affect genes involved in intestinal barrier function and immunoprotective inflammation. Accordingly, RAI16−/− mice displayed significantly increased tumor burden compared with WT mice assessed in CAC model induced by AOM/DSS. Much more Ki67 + nuclei were observed in RAI16−/− tumors suggesting RAI16 to be critical in colonic cell proliferation during tumorigenesis. Conclusively, we demonstrate the roles of RAI16 in colonic inflammation and inflammation-associated tumorigenesis by using a novel RAI16−/− mouse model for the first time.
W–Cu composites with submicron- and nanostructures: progress and challenges
Authors: Hou Chao , Song Xiaoyan , Tang Fawei , Li Yurong , Cao Lijun , Wang Jie , Nie Zuoren 
Published: December 2019

AbstractW–Cu composite materials are widely used in civilian industries and aerospace fields owing to their integrated properties of high hardness, wear and arc resistance, electrical and thermal conductivities, and low coefficient of thermal expansion. The recently developed submicron- and nanostructured W–Cu composites exhibit superior performance compared to their conventional coarse-grained counterparts and are expected to further expand applications of this group of materials. This review is focused on recent important progress in the preparation, characterization, and mechanical and physical properties of W–Cu composites with refined structures. We summarize the technologies that are capable of refining component structures and evaluate their advantages and limitations. Furthermore, the effects of component refinement and additives such as alloying elements and dispersed particles on the comprehensive performance of W–Cu composites are demonstrated. At the end of the review, we propose potential research issues and directions worthy of attention for the future development of W–Cu composites.
Quantum Griffiths singularities in TiO superconducting thin films with insulating normal states
Authors: Zhang Chao , Fan Yunjie , Chen Qiaoling , Wang Tianyi , Liu Xiang , Li Qi , Yin Yuewei , Li Xiaoguang 
Published: December 2019

AbstractA superconductor–metal transition (SMT) with an unconventional diverging dynamic critical exponent was recently discovered, and it drew tremendous attention because this signature of a quantum Griffiths singularity (QGS) was thought to be a common characteristic of low-disorder crystalline superconductors. However, because the QGS was observed only in limited materials with metallic normal states, the question of whether the QGS exists in other superconducting systems is still unanswered. In this paper, a superconductor–insulator transition (SIT) is observed in TiO thin films with insulating normal states, which offers a more universal platform for investigating the QGS. A thickness-tuned SIT is obtained when the magnetic field is zero. Importantly, a magnetic field-tuned SIT with a diverging dynamic critical exponent, which is direct evidence of a QGS, is observed in TiO thin films with different thicknesses. By constructing a comprehensive phase diagram, it is demonstrated that the critical magnetic field Hc tends to saturate as the temperature approaches 0 K, which is different from the upturn trend of Hc observed in SMT systems and probably due to the weaker Josephson coupling of the locally ordered superconducting islands (rare regions) in a weakly insulating normal state background. The results extend the QGS scenario from only SMT systems to SIT systems, and they provide vital evidence that QGSs are common in crystalline superconducting thin films, which has possible applications in quantum-computing devices.