bluuebunny/crossref_metadata_2025_split huggingface dataset:
Significance of 4DVAR Radar Data Assimilation in Weather Research and Forecast Model‐Based Nowcasting System
Authors: Thiruvengadam P. , Indu J. , Ghosh Subimal 
Published: April 2020

AbstractAccurate nowcasting of short‐lived extreme weather events is essential for saving millions of lives and property. Traditional methods of nowcasting are majorly focused on extrapolation of precipitation derived from radar reflectivity data, which often fail to capture the initiation and decay of weather systems. Earlier studies have shown the ability of high‐resolution Numerical Weather Prediction (NWP) models to better capture the structure and lifecycle of storms compared to data‐driven methods. However, the initial value problem of NWP makes it more challenging to be implemented for nowcasting applications. To handle such uncertainty from initial conditions, we have designed an NWP nowcasting system based on variational approach using WRF model. One of the major challenges of the variational methods in the nowcasting system is the choice of control variables used for generating background error statistics. Thus, we have investigated the impact of control variable options on improving the skill of variational‐based NWP nowcasting system. The proposed nowcasting system was tested for a heavy rainfall event that occurred over the Chennai city, India, on 1 December 2015, by assimilating Doppler Weather Radar data using different control variable options in Weather Research and Forecast—three‐dimensional (3DVAR)‐ and four‐dimensional variational data assimilation (4DVAR)‐based nowcasting system. Results show that control variables choices have a positive impact on 4DVAR analysis, particularly on radial velocity. Our results also indicate that assimilation of Doppler Weather Radar data with zonal and meridional momentum control variable in a 4DVAR system shows more than 30% improvement in precipitation forecast skill compared to the 3DVAR system.
Electron Mixing and Isotropization in the Exhaust of Asymmetric Magnetic Reconnection With a Guide Field
Authors: Tang B.‐B. , Li W. Y. , Le A. , Graham D. B. , Wu Y.‐F. , Wang C. , Khotyaintsev Yu. V. , Egedal J. , Tao X. , Gershman D. J. , Giles B. L. , Lindqvist P.‐A. , Ergun R. E. , Russell C. T. , Burch J. L. 
Published: April 2020

AbstractWe investigate an exhaust crossing of asymmetric guide field reconnection observed by Magnetospheric Multiscale (MMS) mission at Earth's dayside magnetopause. One MMS spacecraft (MMS 4) observes multicomponent electron distributions, including two counterstreaming electron beams, while the other three MMS spacecraft, with a separation of ∼30 km, record nearly isotropic electron distributions. As counterstreaming electrons are unstable for the electron two‐stream instability, our observations suggest that the electrostatic waves generated by the fast‐growing electron two‐stream instability can contribute to the rapid isotropization of electron distributions in the reconnection exhaust, indicating that wave‐particle interactions play an important role in electron dynamics.
Sparse Ambient Resonance Measurements Reveal Dynamic Properties of Freestanding Rock Arches
Authors: Geimer Paul R. , Finnegan Riley , Moore Jeffrey R. 
Published: April 2020

AbstractThe dynamic properties of freestanding rock landforms are a function of fundamental material and mechanical parameters, facilitating noninvasive vibration‐based structural assessment. Characterization of resonant frequencies, mode shapes, and damping ratios, however, can be challenging at culturally sensitive geologic features, such as rock arches, where physical access is limited. Using sparse ambient vibration measurements, we describe three resonant modes between 1 and 40 Hz for 17 natural arches in Utah spanning a range of lengths from 3–88 m. Modal polarization data are evaluated to combine field observations with 3‐D numerical models. We find outcrop‐scale elastic moduli vary from 0.8 to 8.0 GPa, correlated with diagenetic processes and identify low damping at all sites. Correlation of dense‐array measurements from one arch validates predictions of simple bending modes and fixed boundary conditions. Our results establish use of sparse ambient resonance measurements for structural assessment and monitoring of arches and similar freestanding geologic features worldwide.
River Inflow Dominates Methane Emissions in an Arctic Coastal System
Authors: Manning Cara C. , Preston Victoria L. , Jones Samantha F. , Michel Anna P. M. , Nicholson David P. , Duke Patrick J. , Ahmed Mohamed M. M. , Manganini Kevin , Else Brent G. T. , Tortell Philippe D. 
Published: April 2020

AbstractWe present a year‐round time series of dissolved methane (CH4), along with targeted observations during ice melt of CH4 and carbon dioxide (CO2) in a river and estuary adjacent to Cambridge Bay, Nunavut, Canada. During the freshet, CH4 concentrations in the river and ice‐covered estuary were up to 240,000% saturation and 19,000% saturation, respectively, but quickly dropped by >100‐fold following ice melt. Observations with a robotic kayak revealed that river‐derived CH4 and CO2 were transported to the estuary and rapidly ventilated to the atmosphere once ice cover retreated. We estimate that river discharge accounts for >95% of annual CH4 sea‐to‐air emissions from the estuary. These results demonstrate the importance of resolving seasonal dynamics in order to estimate greenhouse gas emissions from polar systems.
Repeated Near‐Collapse of the Pliocene Sea Surface Temperature Gradient in the North Atlantic
Authors: Naafs B. D. A. , Voelker A. H. L. , Karas C. , Andersen N. , Sierro F. J. 
Published: April 2020

AbstractSea surface temperature (SST) is used to infer past changes in the state of the climate system. Here we use a combination of newly generated and published organic paleothermometer records, together with novel high‐resolution benthic foraminiferal δ18O stratigraphy, from four sites in the midlatitude North Atlantic (41–58°N) to reconstruct the long‐term evolution of the latitudinal SST gradient during the Pliocene and early Pleistocene (4.0 to 2.4 Myr), the last time atmospheric CO2reached concentrations above 400 ppmv. We demonstrate that the latitudinal SST gradient in the North Atlantic nearly collapsed twice during this period. We conclude that the latitudinal SST gradient in the midlatitude North Atlantic has two end‐members: a maximum as existing at present and a minimum that existed during certain periods of the (late) Pliocene. Our results suggest that the 400‐ppmv Pliocene world was more dynamic than currently thought.
RAGE acts as an oncogenic role and promotes the metastasis of human lung cancer
Authors: Chen Mei-Chih , Chen Kun-Chieh , Chang Gee-Chen , Lin Ho , Wu Chun-Chi , Kao Wei-Hsiang , Teng Chieh-Lin Jerry , Hsu Shih-Lan , Yang Tsung-Ying 
Published: April 2020

AbstractRAGE (receptor for advanced glycation end-product) is thought to be associated with metastasis and poor prognosis of various types of cancer. However, RAGE is constitutively expressed in the normal lung and down-regulated in cancerous lung, while the opposite evidence shows that RAGE-mediated signaling contributes to the tumorigenesis of lung cancer. Therefore, the role of RAGE in lung cancer progression is still unclear to be further investigated. In this study, RAGE-overexpressed stable clones of human lung cancer A549 cells and two local lung adenocarcinoma cell lines CL1-0 and CL1-5 were utilized to verify the effect of RAGE on lung cancer cells while the in vivo xenograft animal model was further performed to evaluate the role of RAGE in the progression of lung cancer. The growth of A549 cells was inhibited by RAGE overexpression. p53-dependent p21CIP1 expression contributed to RAGE-induced growth inhibition by suppressing CDK2 kinase activity and retinoblastoma protein (RB) phosphorylation in vitro. On the other hand, RAGE overexpression promoted migration, invasion, and mesenchymal features of lung adenocarcinoma cells through ERK signaling. Furthermore, an in vivo xenograft experiment indicated that RAGE promoted the metastasis of lung cancer cells with p21CIP1 up-regulation, ERK activation, and the changes of EMT markers. Regarding to the involvement of tumor-associated macrophage (TAM) in the microenvironment, we monitored the expressions of TAM markers including CD68 and CD163 as well as angiogenesis marker CD31 in xenograft slice. The data showed that RAGE might induce the accumulation of TAM in lung cancer cells and further accelerate the in vivo tumor growth. In summary, our study provides evidence indicating the distinct in vitro and in vivo effects of RAGE and related mechanisms on tumor growth and metastasis, which shed light on the oncogenic role of RAGE in lung cancer.
SK channel-mediated metabolic escape to glycolysis inhibits ferroptosis and supports stress resistance in C. elegans
Authors: Krabbendam Inge E. , Honrath Birgit , Dilberger Benjamin , Iannetti Eligio F. , Branicky Robyn S. , Meyer Tammo , Evers Bernard , Dekker Frank J. , Koopman Werner J. H. , Beyrath Julien , Bano Daniele , Schmidt Martina , Bakker Barbara M. , Hekimi Siegfried , Culmsee Carsten , Eckert Gunter P. , Dolga Amalia M. 
Published: April 2020

AbstractMetabolic flexibility is an essential characteristic of eukaryotic cells in order to adapt to physiological and environmental changes. Especially in mammalian cells, the metabolic switch from mitochondrial respiration to aerobic glycolysis provides flexibility to sustain cellular energy in pathophysiological conditions. For example, attenuation of mitochondrial respiration and/or metabolic shifts to glycolysis result in a metabolic rewiring that provide beneficial effects in neurodegenerative processes. Ferroptosis, a non-apoptotic form of cell death triggered by an impaired redox balance is gaining attention in the field of neurodegeneration. We showed recently that activation of small-conductance calcium-activated K+ (SK) channels modulated mitochondrial respiration and protected neuronal cells from oxidative death. Here, we investigated whether SK channel activation with CyPPA induces a glycolytic shift thereby increasing resilience of neuronal cells against ferroptosis, induced by erastin in vitro and in the nematode C. elegans exposed to mitochondrial poisons in vivo. High-resolution respirometry and extracellular flux analysis revealed that CyPPA, a positive modulator of SK channels, slightly reduced mitochondrial complex I activity, while increasing glycolysis and lactate production. Concomitantly, CyPPA rescued the neuronal cells from ferroptosis, while scavenging mitochondrial ROS and inhibiting glycolysis reduced its protection. Furthermore, SK channel activation increased survival of C. elegans challenged with mitochondrial toxins. Our findings shed light on metabolic mechanisms promoted through SK channel activation through mitohormesis, which enhances neuronal resilience against ferroptosis in vitro and promotes longevity in vivo.
MicroRNA-4476 promotes glioma progression through a miR-4476/APC/β-catenin/c-Jun positive feedback loop
Authors: Lin Jie , Ding Shengfeng , Xie Cheng , Yi Renhui , Wu Zhiyong , Luo Jie , Huang Tengyue , Zeng Yu , Wang Xizhao , Xu Anqi , Xiao Jianqi , Song Ye , Zhang Xian 
Published: April 2020

AbstractGlioma has been a major healthcare burden; however, the specific molecular regulatory mechanism underlying its initiation and progression remains to be elucidated. Although it is known that many miRNAs are involved in the regulation of malignant phenotypes of glioma, the role of miR-4476 has not been reported yet. In the present study, we identify miR-4476 as an upregulated microRNA, which promotes cell proliferation, migration, and invasion in glioma. Further mechanistic analyses indicate that the adenomatous polyposis coli (APC), a negative regulator of the Wnt/β-catenin signaling pathway, is a direct target of miR-4476 and mediates the oncogenic effects of miR-4476 in glioma. C-Jun, a downstream effector of the Wnt/β-catenin signaling, is upregulated by miR-4476 overexpression. In turn, c-Jun could positively regulate miR-4476 expression by binding to the upstream of its transcription start site (TSS). Furthermore, in our clinical samples, increased miR-4476 is an unfavorable prognostic factor, and its expression positively correlates with c-Jun expression but negatively correlates with that of APC. In conclusion, our study demonstrates that miR-4476 acts as a tumor enhancer, directly targeting APC to stimulate its own expression and promoting the malignant phenotypes of glioma.
Discovery of superionic conductors by ensemble-scope descriptor
Authors: Kajita Seiji , Ohba Nobuko , Suzumura Akitoshi , Tajima Shin , Asahi Ryoji 
Published: April 2020

AbstractMachine learning accelerates virtual screening in which material candidates are selected from existing databases, facilitating materials discovery in a broad chemical search space. Machine learning models quickly predict a target property from explanatory material features called descriptors. However, a major bottleneck of the machine learning model is an insufficient amount of training data in materials science, especially data with non-equilibrium properties. Here, we develop an alternative virtual-screening process via ensemble-based machine learning with one handcrafted and two generic descriptors to maximize the inference ability even using a small training dataset. A joint representation with the three descriptors translates the physical and chemical properties of a material as well as its underlying short- and long-range atomic structures to describe a multifaceted perspective of the material. As an application, the ensemble-scope descriptor learning model was trained with only 29 entries in the training dataset, and it selected potential oxygen-ion conductors from 13,384 oxides in the inorganic crystal structure database. The experiments confirmed that we successfully discovered five compounds that have not been reported, to the best of our knowledge, as oxygen-ion conductors.
Development of a wearable infrared shield based on a polyurethane–antimony tin oxide composite fiber
Authors: Jeong Sang-Mi , Ahn Jihun , Choi Yong Kyu , Lim Taekyung , Seo Keumyoung , Hong Taekuk , Choi Gwang Hwi , Kim Heesoo , Lee Bo Wha , Park Sang Yoon , Ju Sanghyun 
Published: April 2020

AbstractHere, we investigate a wearable-based IR and thermal stealth structure that effectively blocks IR and thermal radiation from a human body or device using a polyurethane–antimony tin oxide (PU–ATO) composite fiber. The aging time of the ATO sol prepared by a sol–gel method, and the concentration of ATO with respect to that of the PU matrix were optimized to prepare PU–ATO composite fibers that simultaneously have an appropriate mechanical strength (strength of ~4 MPa and strain of ~340%) and IR- and thermal radiation-shielding properties with ~98% IR light, as determined by Fourier transform IR spectroscopic studies. The fabricated PU–ATO composite fiber showed stable IR- and thermal radiation-shielding properties even when exposed to ten cycles of repeated temperature changes of −20 and +80 °C and long-term temperature changes for 30 days. In addition, the surface of the PU–ATO composite fiber was rendered hydrophobic to prevent the distortion of the IR and thermal radiation due to the wetting of the PU–ATO composite fiber with absorbed water. The PU–ATO composite fiber-based textile proposed herein can be applied in wearable IR- and thermal radiation-shielding technologies to shield IR signals generated by objects of diverse and complex shapes.
Sex chromosome evolution in parasitic nematodes of humans
Authors: Foster Jeremy M. , Grote Alexandra , Mattick John , Tracey Alan , Tsai Yu-Chih , Chung Matthew , Cotton James A. , Clark Tyson A. , Geber Adam , Holroyd Nancy , Korlach Jonas , Li Yichao , Libro Silvia , Lustigman Sara , Michalski Michelle L. , Paulini Michael , Rogers Matthew B. , Teigen Laura , Twaddle Alan , Welch Lonnie , Berriman Matthew , Dunning Hotopp Julie C. , Ghedin Elodie 
Published: April 2020

AbstractSex determination mechanisms often differ even between related species yet the evolution of sex chromosomes remains poorly understood in all but a few model organisms. Some nematodes such as Caenorhabditis elegans have an XO sex determination system while others, such as the filarial parasite Brugia malayi, have an XY mechanism. We present a complete B. malayi genome assembly and define Nigon elements shared with C. elegans, which we then map to the genomes of other filarial species and more distantly related nematodes. We find a remarkable plasticity in sex chromosome evolution with several distinct cases of neo-X and neo-Y formation, X-added regions, and conversion of autosomes to sex chromosomes from which we propose a model of chromosome evolution across different nematode clades. The phylum Nematoda offers a new and innovative system for gaining a deeper understanding of sex chromosome evolution.
Functional and molecular heterogeneity of D2R neurons along dorsal ventral axis in the striatum
Authors: Puighermanal Emma , Castell Laia , Esteve-Codina Anna , Melser Su , Kaganovsky Konstantin , Zussy Charleine , Boubaker-Vitre Jihane , Gut Marta , Rialle Stephanie , Kellendonk Christoph , Sanz Elisenda , Quintana Albert , Marsicano Giovanni , Martin Miquel , Rubinstein Marcelo , Girault Jean-Antoine , Ding Jun B. , Valjent Emmanuel 
Published: April 2020

AbstractAction control is a key brain function determining the survival of animals in their environment. In mammals, neurons expressing dopamine D2 receptors (D2R) in the dorsal striatum (DS) and the nucleus accumbens (Acb) jointly but differentially contribute to the fine regulation of movement. However, their region-specific molecular features are presently unknown. By combining RNAseq of striatal D2R neurons and histological analyses, we identified hundreds of novel region-specific molecular markers, which may serve as tools to target selective subpopulations. As a proof of concept, we characterized the molecular identity of a subcircuit defined by WFS1 neurons and evaluated multiple behavioral tasks after its temporally-controlled deletion of D2R. Consequently, conditional D2R knockout mice displayed a significant reduction in digging behavior and an exacerbated hyperlocomotor response to amphetamine. Thus, targeted molecular analyses reveal an unforeseen heterogeneity in D2R-expressing striatal neuronal populations, underlying specific D2R’s functional features in the control of specific motor behaviors.
Direct structural evidence of Indian continental subduction beneath Myanmar
Authors: Zheng Tianyu , He Yumei , Ding Lin , Jiang Mingming , Ai Yinshuang , Mon Chit Thet , Hou Guangbing , Sein Kyaing , Thant Myo 
Published: April 2020

AbstractIndian continental subduction can explain Cenozoic crustal deformation, magmatic activity and uplift of the Tibetan Plateau following the India-Asia collision. In the western Himalayan syntaxis and central Himalaya, subduction or underthrusting of the Indian Plate beneath the Eurasian Plate is well known from seismological studies. However, because information on the deep structure of the eastern Himalayan syntaxis is lacking, the nature of the Indian subduction slab beneath Myanmar and the related tectonic regime remain unclear. Here, we use receiver function common conversion point imaging from a densely spaced seismic array to detect direct structural evidence of present-day Indian continental subduction beneath Asia. The entire subducting Indian crust has an average crustal thickness of ~30 km, dips at an angle of ~19°, and extends to a depth of 100 km under central Myanmar. These results reveal a unique continental subduction regime as a result of Indian-Eurasian continental collision and lateral extrusion.
Feature-specific neural reactivation during episodic memory
Authors: Bone Michael B. , Ahmad Fahad , Buchsbaum Bradley R. 
Published: April 2020

AbstractWe present a multi-voxel analytical approach, feature-specific informational connectivity (FSIC), that leverages hierarchical representations from a neural network to decode neural reactivation infMRI data collected while participants performed an episodic visual recall task. We show that neural reactivation associated with low-level (e.g. edges), high-level (e.g. facial features), and semantic (e.g. “terrier”) features occur throughout the dorsal and ventral visual streams and extend into the frontal cortex. Moreover, we show that reactivation of both low- and high-level features correlate with the vividness of the memory, whereas only reactivation of low-level features correlates with recognition accuracy when the lure and target images are semantically similar. In addition to demonstrating the utility of FSIC for mapping feature-specific reactivation, these findings resolve the contributions of low- and high-level features to the vividness of visual memories and challenge a strict interpretation the posterior-to-anterior visual hierarchy.
Noninvasive electromagnetic source imaging of spatiotemporally distributed epileptogenic brain sources
Authors: Sohrabpour Abbas , Cai Zhengxiang , Ye Shuai , Brinkmann Benjamin , Worrell Gregory , He Bin 
Published: April 2020

AbstractBrain networks are spatiotemporal phenomena that dynamically vary over time. Functional imaging approaches strive to noninvasively estimate these underlying processes. Here, we propose a novel source imaging approach that uses high-density EEG recordings to map brain networks. This approach objectively addresses the long-standing limitations of conventional source imaging techniques, namely, difficulty in objectively estimating the spatial extent, as well as the temporal evolution of underlying brain sources. We validate our approach by directly comparing source imaging results with the intracranial EEG (iEEG) findings and surgical resection outcomes in a cohort of 36 patients with focal epilepsy. To this end, we analyzed a total of 1,027 spikes and 86 seizures. We demonstrate the capability of our approach in imaging both the location and spatial extent of brain networks from noninvasive electrophysiological measurements, specifically for ictal and interictal brain networks. Our approach is a powerful tool for noninvasively investigating large-scale dynamic brain networks.
Solar photovoltaic interventions have reduced rural poverty in China
Authors: Zhang Huiming , Wu Kai , Qiu Yueming , Chan Gabriel , Wang Shouyang , Zhou Dequn , Ren Xianqiang 
Published: April 2020

AbstractSince 2013, China has implemented a large-scale initiative to systematically deploy solar photovoltaic (PV) projects to alleviate poverty in rural areas. To provide new understanding of China’s targeted poverty alleviation strategy, we use a panel dataset of 211 pilot counties that received targeted PV investments from 2013 to 2016, and find that the PV poverty alleviation pilot policy increases per-capita disposable income in a county by approximately 7%-8%. The effect of PV investment is positive and significant in the year of policy implementation and the effect is more than twice as high in the subsequent two to three years. The PV poverty alleviation effect is stronger in poorer regions, particularly in Eastern China. Our results are robust to alternative specifications and variable definitions. We propose several policy recommendations to sustain progress in China’s efforts to deploy PV for poverty alleviation.