bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial Evaluation and Assimilation of SMAP, SMOS, and ASCAT Satellite Soil Moisture Products Over Africa Using Statistical Techniques
Authors: Mousa B. G. , Shu Hong 
Published: December 2019

AbstractThe limited number of in situ stations of surface soil moisture (SM) in Africa creates a shortage in the validation of SM satellite products. Therefore, this study investigates the performance of Soil Moisture Active Passive (SMAP), Soil Moisture and Ocean Salinity (SMOS), and the H113 product from the Advanced Scatterometer (ASCAT) on the regional scale over Africa through these goals: (1) validate of satellite SM products against in situ stations and SM data from the ERA‐Interim atmospheric reanalysis product, (2) study the spatiotemporal variability of satellite SM products on the regional scale, and (3) evaluate the regional scale error patterns and investigate regions where the assimilation of satellites SM data may add improvement to ERA‐Interim. Standard statistical metrics, hovmöller diagrams, and the Triple Collocation (TC) model were used to achieve these goals. Land cover data, Normalized Difference Vegetation Index, and precipitation data were used to interpret results. The validation results based on statistical metrics and TC indicate that over the desert and shrub, passive products showed better performance than ASCAT, while over moderate vegetation areas (grassland), SMAP had the best among SM products. Over high densely vegetated regions, ASCAT showed a high comparatively performance than passive products. The potential regions for assimilation of satellite data sets were selected to be over savannas and grassland regions for ASCAT, and over shrub and grassland regions for SMAP. In particular, SMAP and ASCAT SM data sets are considered more stable than SMOS for data assimilation and capturing the spatial distribution of SM on the regional scale over Africa.
An Explicit IMF B Dependence on Solar Wind‐Magnetosphere Coupling
Authors: Reistad J. P. , Laundal K. M. , Ohma A. , Moretto T. , Milan S. E. 
Published: December 2019

AbstractPresently, all empirical coupling functions quantifying the solar wind—magnetosphere energy—or magnetic flux conversion assume that the coupling is independent of the sign of the dawn‐dusk component (B
) of the Interplanetary Magnetic Field (IMF). In this paper we present observations strongly suggesting an explicit IMF B
effect on the solar wind‐magnetosphere coupling. When the Earth's dipole is tilted in the direction corresponding to northern winter, positive IMF B
is found to on average lead to a larger polar cap than when IMF B
is negative during otherwise similar conditions. This explicit IMF B
effect is found to reverse when the Earth's dipole is inclined in the opposite direction (northern summer) and is consistently observed from both hemispheres. We interpret the different responses of the polar cap size due to the sign of IMF B
to likely be a result of differences in the dayside reconnection rate.
Jovian UV Aurora's Response to the Solar Wind: Hisaki EXCEED and Juno Observations
Authors: Kita H. , Kimura T. , Tao C. , Tsuchiya F. , Murakami G. , Yamazaki A. , Yoshioka K. , Ebert R.W. , Wilson R.J. , Allegrini F. , Clark G. , Connerney J. E. P. , Gladstone G. R. , Yoshikawa I. , Fujimoto M. 
Published: December 2019

AbstractWe summarize Jupiter's ultraviolet (UV) auroral response to solar wind dynamic pressure variations during Juno's approach to Jupiter in 2016. The response time of Jupiter's aurora to external drivers has thus far been unknown owing to a sparsity of upstream in situ solar wind measurements. Combining the Juno solar wind observations with continuous UV aurora data obtained by Hisaki EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) and Juno UV spectrograph, the UV aurora brightenings in response to three major shock arrivals showed time lags of 10–15 hr. These time lags are longer than the time required for ballistic propagation of the shocks by the solar wind. In addition to that puzzle, while an enhancement in the UV auroral power was observed with an increase in dynamic pressure to ~0.03 nPa, no associated brightening was observed with a dynamic pressure elevation of >0.1 nPa. These imply that internal magnetospheric aspects need to be taken into consideration to fully resolve the issue.
Significantly Enhanced Aerosol CCN Activity and Number Concentrations by Nucleation‐Initiated Haze Events: A Case Study in Urban Beijing
Authors: Zhang Fang , Ren Jingye , Fan Tianyi , Chen Lu , Xu Weiqi , Sun Yele , Zhang Renyi , Liu Jieyao , Jiang Sihui , Jin Xiaoai , Wu Hao , Li Shangze , Cribb Maureen C. , Li Zhanqing 
Published: December 2019

AbstractThe evolution of haze, involving multiple processes such as nucleation, coagulation, and condensation, may exert complex effects on aerosols' cloud condensation nuclei (CCN) activity and number concentration (NCCN). Based on field campaigns carried out in the winters of 2014 and 2016 in Beijing, we show that NCCN was significantly enhanced by the evolution of haze, substantially driven by the nucleation process (or new particle formation). The enhancement factor of NCCN by such nucleation‐initiated haze episodes, E_NCCN, defined as the ratio of NCCN after haze events to NCCN prior to haze events, ranged from 2.2 to 6.5 at a supersaturation (S) = 0.76% and from 4.2 to 17.3 at S = 0.23%, the magnitude of which partially depends on the severity of the haze event. The enhancements are much greater than those previously observed and those from model simulations of contribution from new particle formation. This suggests that CCN sources from new particle formation may be underestimated, needing reevaluation in polluted environments where the subsequent growth of newly formed particles can last 2–3 days, yielding more CCN‐sized particles. We further quantified that the changes in particle size and composition during the nucleation‐initiated evolution of haze are responsible for > 80% and 12–20%, respectively, of the enhancement in CCN activity. The changes in particle composition had a limited impact because most of the ambient particles were already hydrophilic, with hygroscopic parameters of 0.2–0.65.
Density Structure of the Rümker Region in the Northern Oceanus Procellarum: Implications for Lunar Volcanism and Landing Site Selection for the Chang'E‐5 Mission
Authors: Chisenga Chikondi , Yan Jianguo , Zhao Jiannan , Atekwana Estella A. , Steffen Rebekka 
Published: December 2019

AbstractThe Rümker region, located in the northern Oceanus Procellarum, is the candidate landing region for China's Chang'E‐5 lunar sample‐return mission. The area is geologically complex and known for its volcanic activity. To understand the volcanism of the Rümker region, we investigate the 3D crustal density structure of this region using Bouguer gravity data from the Gravity Recovery and Interior Laboratory mission. We applied derivative filters and a 3D density inversion to resolve both the shallow and deep structures in the subsurface. Results indicate that the Rümker region exhibits different modes of emplacement. The Mons Rümker volcanic complex is fed by an intrusion‐like structure at a depth of ~6–18 km and contains high‐density basaltic materials of >3,000 kg/m3. A quasi‐circular mass anomaly that was identified in a previous study with high gravity amplitude (~130 mGal) and high density (> 3,000 kg/m3) was also documented in the study region. The quasi‐circular mass anomaly feature represents deeper and thicker buried mare basalts with a bowl‐shaped geometry formed by an impact event. Based on our geophysical analysis, we propose four landing site candidates for the Chang'E‐5 mission that satisfy the geological and geophysical criteria for maximum scientific return.
Insights Into Preferential Flow Snowpack Runoff Using Random Forest
Authors: Avanzi Francesco , Johnson Ryan Curtis , Oroza Carlos A. , Hirashima Hiroyuki , Maurer Tessa , Yamaguchi Satoru 
Published: December 2019

AbstractUsing 12 seasons of data from a multicompartment snow lysimeter and a statistical learning algorithm (Random Forest), we investigated to what extent preferential flow snowpack runoff can be predicted from concurrent weather and snow conditions, as well as the relative importance of factors affecting this process. We found that preferential flow development can be partially predicted based on concurrent weather and snow conditions. In this case study where snow is generally wet and coarse, the most important predictors of standard and maximum deviation from mean spatial snowpack runoff are related to weather inputs and their interaction with the snowpack (rainfall, longwave radiation, and snow‐surface temperature) and to more season‐specific snow properties (number of macroscopic snow layers and snowfall days to date, the latter being a feature we included to account for microstructural heterogeneity developing at smaller scales than macroscopic layers). This combination between weather and season‐specific snow factors and the fact that several of these important features are correlated with other processes result in significant seasonal variability of the Random Forest algorithm's accuracy. All versions of the Random Forest algorithm underestimated seasonal peaks in preferential flow, which points to these peaks being either undersampled in our data set or caused by poorly understood redistribution processes acting at larger spatial scales than the size of our multicompartment lysimeter (e.g., dimples).
Host–microbiota interactions in rheumatoid arthritis
Authors: Maeda Yuichi , Takeda Kiyoshi 
Published: December 2019

AbstractThe gut microbiota has been proposed to be an important environmental factor in the development of rheumatoid arthritis (RA). Here, we review a growing body of evidence from human and animal studies that supports the hypothesis that intestinal microbiota play a role in RA. Previous studies from we and others showed an altered composition of the microbiota in early RA patients. A recent study demonstrated that Prevotella species are dominant in the intestine of patients in the preclinical stages of RA. In addition, Prevotella-dominated microbiota isolated from RA patients contributes to the development of Th17 cell-dependent arthritis in SKG mice. Moreover, it was reported that periodontal bacteria correlates with the pathogenesis of RA. In this review, we discuss the link between oral bacteria and the development of arthritis. However, many questions remain to be elucidated in terms of molecular mechanisms for the involvement of intestinal and oral microbiota in RA pathogenesis.
TGIF2 promotes the progression of lung adenocarcinoma by bridging EGFR/RAS/ERK signaling to cancer cell stemness
Authors: Du Renle , Shen Wenzhi , Liu Yi , Gao Wenjuan , Zhou Wei , Li Jun , Zhao Shuangtao , Chen Chong , Chen Yanan , Liu Yanhua , Sun Peiqing , Xiang Rong , Shi Yi , Luo Yunping 
Published: December 2019

AbstractTGF-β-induced factor homeobox 2 (TGIF2) is a transcription regulator that plays essential roles in the regulation of development and cell fate decisions. Aberrant expression of TGIF family proteins has been observed in several cancers, including ovarian, esophageal, and colorectal cancers. Here, we report that TGIF2 mediates the EGFR–RAS–ERK signaling pathway to enhance the stemness of lung adenocarcinoma (LUAD) cells and, therefore, promote the progression and metastasis of LUAD. We found that high TGIF2 expression was closely correlated with tumor growth, lymph node metastasis, and survival of patients with LUAD. Mice bearing TGIF2-silenced H1299 xenografts developed smaller tumors and fewer lung metastases. Importantly, silencing TGIF2 decreased the cancer stem cell (CSC)-like properties in A549 and H1299 cells. Furthermore, we identified that TGIF2 binding to the OCT4 promoter promotes its expression. In both LUAD cells and in vivo LUAD mouse models, we revealed that EGFR–RAS–ERK signaling phosphorylated TGIF2 and increased its stability, which was important for TGIF2-promoted LUAD stemness since phosphorylation-deficient TGIF2 mutants lost these functions. Thus, our study revealed that an important factor, TGIF2, bridges EGFR signaling to the CSC characteristics of LUAD cells, which can be utilized as an effective target for LUAD therapy.
KAT6B-related disorder in a patient with a novel frameshift variant (c.3925dup)
Authors: Hamaguchi Yo , Aoki Mikihiro , Watanabe Satoshi , Mishima Hiroyuki , Yoshiura Koh-ichiro , Moriuchi Hiroyuki , Dateki Sumito 
Published: December 2019

AbstractHeterozygous pathogenic variants in the KAT6B gene, which encodes lysine acetyltransferase 6B, have been identified in patients with congenital rare disorders, including genitopatellar syndrome and Say-Barber-Biesecker-Young-Simpson syndrome. Herein, we report another Japanese patient with a KAT6B-related disorder and a novel de novo heterozygous variant in exon 18 of KAT6B [c.3925dup, p.(Glu1309fs*33)], providing further evidence that truncating variants in exon 17 and in the proximal region of exon 18 are associated with genitopatellar syndrome-like phenotypes.
Rap1 regulates hematopoietic stem cell survival and affects oncogenesis and response to chemotherapy
Authors: Khattar Ekta , Maung Kyaw Ze Ya , Chew Chen Li , Ghosh Arkasubhra , Mok Michelle Meng Huang , Lee Pei , Zhang Jun , Chor Wei Hong Jeff , Cildir Gökhan , Wang Chelsia Qiuxia , Mohd-Ismail Nur Khairiah , Chin Desmond Wai Loon , Lee Soo Chin , Yang Henry , Shin Yong-Jae , Nam Do-Hyun , Chen Liming , Kumar Alan Prem , Deng Lih Wen , Ikawa Masahito , Gunaratne Jayantha , Osato Motomi , Tergaonkar Vinay 
Published: December 2019

AbstractIncreased levels and non-telomeric roles have been reported for shelterin proteins, including RAP1 in cancers. Herein using Rap1 null mice, we provide the genetic evidence that mammalian Rap1 plays a major role in hematopoietic stem cell survival, oncogenesis and response to chemotherapy. Strikingly, this function of RAP1 is independent of its association with the telomere or with its known partner TRF2. We show that RAP1 interacts with many members of the DNA damage response (DDR) pathway. RAP1 depleted cells show reduced interaction between XRCC4/DNA Ligase IV and DNA-PK, and are impaired in DNA Ligase IV recruitment to damaged chromatin for efficient repair. Consistent with its role in DNA damage repair, RAP1 loss decreases double-strand break repair via NHEJ in vivo, and consequently reduces B cell class switch recombination. Finally, we discover that RAP1 levels are predictive of the success of chemotherapy in breast and colon cancer.
An unexpected N-dependence in the viscosity reduction in all-polymer nanocomposite
Authors: Chen Tao , Zhao Huan-Yu , Shi Rui , Lin Wen-Feng , Jia Xiang-Meng , Qian Hu-Jun , Lu Zhong-Yuan , Zhang Xing-Xing , Li Yan-Kai , Sun Zhao-Yan 
Published: December 2019

AbstractAdding small nanoparticles (NPs) into polymer melt can lead to a non-Einstein-like decrease in viscosity. However, the underlying mechanism remains a long-standing unsolved puzzle. Here, for an all-polymer nanocomposite formed by linear polystyrene (PS) chains and PS single-chain nanoparticles (SCNPs), we perform large-scale molecular dynamics simulations and experimental rheology measurements. We show that with a fixed (small) loading of the SCNP, viscosity reduction (VR) effect can be largely amplified with an increase in matrix chain length$$N$$N, and that the system with longer polymer chains will have a larger VR. We demonstrate that such$$N$$N-dependent VR can be attributed to the friction reduction experienced by polymer segment blobs which have similar size and interact directly with these SCNPs. A theoretical model is proposed based on the tube model. We demonstrate that it can well describe the friction reduction experienced by melt polymers and the VR effect in these composite systems.
LRRK2 kinase activity regulates lysosomal glucocerebrosidase in neurons derived from Parkinson’s disease patients
Authors: Ysselstein Daniel , Nguyen Maria , Young Tiffany J. , Severino Alex , Schwake Michael , Merchant Kalpana , Krainc Dimitri 
Published: December 2019

AbstractMutations in LRRK2 and GBA1 are common genetic risk factors for Parkinson’s disease (PD) and major efforts are underway to develop new therapeutics that target LRRK2 or glucocerebrosidase (GCase). Here we describe a mechanistic and therapeutic convergence of LRRK2 and GCase in neurons derived from patients with PD. We find that GCase activity was reduced in dopaminergic (DA) neurons derived from PD patients with LRRK2 mutations. Inhibition of LRRK2 kinase activity results in increased GCase activity in DA neurons with either LRRK2 or GBA1 mutations. This increase is sufficient to partially rescue accumulation of oxidized dopamine and alpha-synuclein in PD patient neurons. We have identified the LRRK2 substrate Rab10 as a key mediator of LRRK2 regulation of GCase activity. Together, these results suggest an important role of mutant LRRK2 as a negative regulator of lysosomal GCase activity.
Global urban expansion offsets climate-driven increases in terrestrial net primary productivity
Authors: Liu Xiaoping , Pei Fengsong , Wen Youyue , Li Xia , Wang Shaojian , Wu Changjiang , Cai Yiling , Wu Jianguo , Chen Jun , Feng Kuishuang , Liu Junguo , Hubacek Klaus , Davis Steven J. , Yuan Wenping , Yu Le , Liu Zhu 
Published: December 2019

AbstractThe global urbanization rate is accelerating; however, data limitations have far prevented robust estimations of either global urban expansion or its effects on terrestrial net primary productivity (NPP). Here, using a high resolution dataset of global land use/cover (GlobeLand30), we show that global urban areas expanded by an average of 5694 km2 per year between 2000 and 2010. The rapid urban expansion in the past decade has in turn reduced global terrestrial NPP, with a net loss of 22.4 Tg Carbon per year (Tg C year−1). Although small compared to total terrestrial NPP and fossil fuel carbon emissions worldwide, the urbanization-induced decrease in NPP offset 30% of the climate-driven increase (73.6 Tg C year−1) over the same period. Our findings highlight the urgent need for global strategies to address urban expansion, enhance natural carbon sinks, and increase agricultural productivity.
New isotope constraints on the Mg oceanic budget point to cryptic modern dolomite formation
Authors: Shalev Netta , Bontognali Tomaso R. R. , Wheat C. Geoffrey , Vance Derek 
Published: December 2019

AbstractThe oceanic magnesium budget is important to our understanding of Earth’s carbon cycle, because similar processes control both (e.g., weathering, volcanism, and carbonate precipitation). However, dolomite sedimentation and low-temperature hydrothermal circulation remain enigmatic oceanic Mg sinks. In recent years, magnesium isotopes (δ26Mg) have provided new constraints on the Mg cycle, but the lack of data for the low-temperature hydrothermal isotope fractionation has hindered this approach. Here we present new δ26Mg data for low-temperature hydrothermal fluids, demonstrating preferential 26Mg incorporation into the oceanic crust, on average by εsolid-fluid ≈ 1.6‰. These new data, along with the constant seawater δ26Mg over the past ~20 Myr, require a significant dolomitic sink (estimated to be 1.5–2.9 Tmol yr−1; 40–60% of the oceanic Mg outputs). This estimate argues strongly against the conventional view that dolomite formation has been negligible in the Neogene and points to the existence of significant hidden dolomite formation.
Combining tubercidin and cordycepin scaffolds results in highly active candidates to treat late-stage sleeping sickness
Authors: Hulpia Fabian , Mabille Dorien , Campagnaro Gustavo D. , Schumann Gabriela , Maes Louis , Roditi Isabel , Hofer Anders , de Koning Harry P. , Caljon Guy , Van Calenbergh Serge 
Published: December 2019

AbstractAfrican trypanosomiasis is a disease caused by Trypanosoma brucei parasites with limited treatment options. Trypanosoma is unable to synthesize purines de novo and relies solely on their uptake and interconversion from the host, constituting purine nucleoside analogues a potential source of antitrypanosomal agents. Here we combine structural elements from known trypanocidal nucleoside analogues to develop a series of 3’-deoxy-7-deazaadenosine nucleosides, and investigate their effects against African trypanosomes. 3’-Deoxytubercidin is a highly potent trypanocide in vitro and displays curative activity in animal models of acute and CNS-stage disease, even at low doses and oral administration. Whole-genome RNAi screening reveals that the P2 nucleoside transporter and adenosine kinase are involved in the uptake and activation, respectively, of this analogue. This is confirmed by P1 and P2 transporter assays and nucleotide pool analysis. 3’-Deoxytubercidin is a promising lead to treat late-stage sleeping sickness.
Biogenesis and functions of aminocarboxypropyluridine in tRNA
Authors: Takakura Mayuko , Ishiguro Kensuke , Akichika Shinichiro , Miyauchi Kenjyo , Suzuki Tsutomu 
Published: December 2019

AbstractTransfer (t)RNAs contain a wide variety of post-transcriptional modifications, which play critical roles in tRNA stability and functions. 3-(3-amino-3-carboxypropyl)uridine (acp3U) is a highly conserved modification found in variable- and D-loops of tRNAs. Biogenesis and functions of acp3U have not been extensively investigated. Using a reverse-genetic approach supported by comparative genomics, we find here that the Escherichia coli yfiP gene, which we rename tapT (tRNA aminocarboxypropyltransferase), is responsible for acp3U formation in tRNA. Recombinant TapT synthesizes acp3U at position 47 of tRNAs in the presence of S-adenosylmethionine. Biochemical experiments reveal that acp3U47 confers thermal stability on tRNA. Curiously, the ΔtapT strain exhibits genome instability under continuous heat stress. We also find that the human homologs of tapT, DTWD1 and DTWD2, are responsible for acp3U formation at positions 20 and 20a of tRNAs, respectively. Double knockout cells of DTWD1 and DTWD2 exhibit growth retardation, indicating that acp3U is physiologically important in mammals.
Stereodivergent assembly of tetrahydro-γ-carbolines via synergistic catalytic asymmetric cascade reaction
Authors: Xu Shi-Ming , Wei Liang , Shen Chong , Xiao Lu , Tao Hai-Yan , Wang Chun-Jiang 
Published: December 2019

AbstractEnantiomerically enriched indole-containing heterocycles play a vital role in bioscience, medicine, and chemistry. As one of the most attractive subtypes of indole alkaloids, highly substituted tetrahydro-γ-carbolines are the basic structural unit in many natural products and pharmaceuticals. However, the syntheses of tetrahydro-γ-carbolines with high functionalities from readily available reagents are significant challenging. In particular, the stereodivergent syntheses of tetrahydro-γ-carbolines containing multi-stereogenic centers remain quite difficult. Herein, we report an expedient and stereodivergent assembly of tetrahydro-γ-carbolines with remarkably high levels of stereoselective control in an efficient cascade process from aldimine esters and indolyl allylic carbonates via a synergistic Cu/Ir catalyst system. Control experiments-guided optimization of synergistic catalysts and mechanistic investigations reveal that a stereodivergent allylation reaction and a subsequent highly stereoselective iso-Pictet-Spengler cyclization are the key elements to success.