bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced, Climate‐Driven Sedimentation on Salt Marshes
Authors: FitzGerald D. M. , Hughes Z. J. , Georgiou I. Y. , Black S. , Novak A. 
Published: April 2020

AbstractWith Arctic amplification (enhanced polar warming) possibly increasing periods of intense winter freezing and global warming producing more powerful extratropical storms, winter sedimentation on northern salt marshes may likely increase in the future. Here, we show that a large ice‐rafting event in northern Massachusetts delivered the equivalent of 15 years of mineral deposition to the marsh surface in a single storm. During an intense extratropical cyclone in January 2018, sediment‐laden ice was rafted onto the Great Marsh, Massachusetts, by an ~1‐m storm surge coinciding with high astronomical tides. The muddy sand content combined with abundant shells indicates that the sediment originated from proximal bays and tidal flats. Sediment layers delivered by individual ice rafts averaged 3.19 cm in thickness, 12 times the combined organic and inorganic yearly vertical accretion rate on high marshes. This previously underappreciated vector for sediment deposition is likely to help marsh resiliency to sea‐level rise.
Dynamics of the Gibraltar Arc System: A Complex Interaction Between Plate Convergence, Slab Pull, and Mantle Flow
Authors: Civiero Chiara , Custódio Susana , Duarte João C. , Mendes Virgilio B. , Faccenna Claudio 
Published: April 2020

AbstractIn typical subduction systems, plate convergence is subperpendicular to the trench. The Gibraltar Arc System is exceptional, with its narrow subduction arc oriented N‐S and laterally “squeezed” by the NNW‐SSE tectonic convergence between Nubia and Iberia. The extent to which the slab is still coupled to the surface and how it interacts actively with the surrounding mantle is a matter of ongoing debate. Here, we analyze new densely spaced GPS data, together with crustal and mantle observations, to better understand the slab kinematics, plate dynamics, and mantle flow. In light of previous and current research, we find that subduction below the Gibraltar Arc is currently in the middle of a disruption process, with parts of it already detached and others yet coupled to the surface. In particular, the slab seems to be detached to the north of the Gibraltar Strait, with a small portion still attached to the surface or in the process of detaching below the western Betics. South of Gibraltar, the slab is still coupled to the overriding plate, although the subduction seems to be very slow or stopped. Flow of mantle material around the detached portions of the slab causes most of the surface uplift and a positive residual topography anomaly. Our findings show that the interplay between slab dynamics, mantle flow, and plate convergence explains much of the observed residual topography, surface motion, seismicity, and mantle structure.
Challenges in Applying Machine Learning Models for Hydrological Inference: A Case Study for Flooding Events Across Germany
Authors: Schmidt Lennart , Heße Falk , Attinger Sabine , Kumar Rohini 
Published: April 2020

AbstractMachine learning (ML) algorithms are being increasingly used in Earth and Environmental modeling studies owing to the ever‐increasing availability of diverse data sets and computational resources as well as advancement in ML algorithms. Despite advances in their predictive accuracy, the usefulness of ML algorithms for inference remains elusive. In this study, we employ two popular ML algorithms, artificial neural networks and random forest, to analyze a large data set of flood events across Germany with the goals to analyze their predictive accuracy and their usability to provide insights to hydrologic system functioning. The results of the ML algorithms are contrasted against a parametric approach based on multiple linear regression. For analysis, we employ a model‐agnostic framework named Permuted Feature Importance to derive the influence of models' predictors. This allows us to compare the results of different algorithms for the first time in the context of hydrology. Our main findings are that (1) the ML models achieve higher prediction accuracy than linear regression, (2) the results reflect basic hydrological principles, but (3) further inference is hindered by the heterogeneity of results across algorithms. Thus, we conclude that the problem of equifinality as known from classical hydrological modeling also exists for ML and severely hampers its potential for inference. To account for the observed problems, we propose that when employing ML for inference, this should be made by using multiple algorithms and multiple methods, of which the latter should be embedded in a cross‐validation routine.
A New Unsupervised Learning Method to Assess Clusters of Temporal Distribution of Rainfall and Their Coherence with Flood Types
Authors: Oppel Henning , Fischer Svenja 
Published: April 2020

AbstractSeveral factors have an impact on the generation of floods, for example, antecedent moisture conditions and the shape of the catchment. A very important factor is the event rainfall, especially its temporal distribution. However, the categorization of temporal distributions is riddled with uncertainty, due to a priori assumptions on distribution types. Here, we propose a new clustering approach based on unsupervised learning, using dimensionless mass curves to describe the temporal distributions. The purpose of the proposed method is the identification of reoccurring temporal distributions of precipitation events. Additionally, the correlation of the resulting clusters of temporal distribution with rainfall‐induced flood types is investigated. The application to several catchments in Germany showed the existence of spatial patterns of six different clusters for the temporal distribution and a significant coherence with the flood types. It was found that the temporal distribution of rainfall intensities shifts from early peaked to more uniformly distributed when shifting the flood type from short floods with high peaks to long‐duration floods, often with several peaks.
Time‐Lapse Imaging of Coseismic Ruptures for the 2019 Ridgecrest Earthquakes Using Multiazimuth Backprojection With Regional Seismic Data and a 3‐D Crustal Velocity Model
Authors: Yang Jidong , Zhu Hejun , Lumley David 
Published: April 2020

AbstractUsing regional seismic data and a 3‐D crustal velocity model, we develop a novel multiazimuth backprojection approach and apply it to image time‐lapse coseismic ruptures for the 2019 Ridgecrest earthquakes. The time‐integrated images for theMw6.4 foreshock andMw7.1 mainshock agree with the fault geometry delineated by the aftershock distributions. Backprojection images at different times illustrate the detailed rupture processes for these two events. For instance, theMw6.4 foreshock initialized close to the hypocenter, then the rupture propagated along a northwest trending fault with an average velocity of 1.0 km/s, and finally jumped to a southwest trending fault and propagated about 20 km with a velocity about 1.5 km/s. In contrast, theMw7.1 mainshock initialized near the hypocenter, then propagated to the northwest upon reaching the Coso volcanic field with an average velocity of 1.4 km/s, and later turned to the southeast and propagated along the main fault zone with a complex bilateral process and a velocity about 0.6 km/s.
Monitoring of Dust Devil Tracks Around the InSight Landing Site, Mars, and Comparison With In Situ Atmospheric Data
Authors: Perrin C. , Rodriguez S. , Jacob A. , Lucas A. , Spiga A. , Murdoch N. , Lorenz R. , Daubar I. J. , Pan L. , Kawamura T. , Lognonné P. , Banfield D. , Banks M. E. , Garcia R. F. , Newman C. E. , Ohja L. , Widmer-Schnidrig R. , McEwen A. S. , Banerdt W. B. 
Published: April 2020

AbstractThe NASA InSight mission on Mars is a unique opportunity to study atmospheric processes both from orbit and in situ observations. We use post‐landing high‐resolution satellite images to monitor dust devil activity during the first 8 months of the mission. We perform mapping and semiautomatic detection of newly formed dust devil tracks and analyze their characteristics (sizes, azimuths, distances, and directions of motion). We find a large number of tracks appearing shortly after landing, followed by a significant decrease of activity during late winter, then a progressive increase during early spring. New tracks are characterized by dark linear, to slightly curvilinear, traces ranging from a few to more than 10 m wide. Tracks are oriented in the ambient wind direction, according to measurements made by InSight's meteorological sensors. The systematic analysis of dust devil tracks is useful to have a better understanding of atmospheric and aeolian activity around InSight.
Nitric Oxide Abundance in the Martian Thermosphere and Its Diurnal Variation
Authors: Cui J. , Fu M.‐H. , Ren Z.‐P. , Gu H. , Guo J.‐H. , Wu X.‐S. , Wu Z.‐P. , Lai H.‐R. , Wei Y. 
Published: April 2020

AbstractAs an important species of the Martian thermosphere, NO is chemically and radiatively active. However, its abundance is poorly constrained due to difficulties in both remote sensing and in situ measurements. In this study, we use the Neutral Gas and Ion Mass Spectrometer measurements made onboard the Mars Atmosphere and Volatile Evolution to derive the N(4S), N(2D), and NO abundances in the Martian thermosphere based on time‐dependent odd N chemistry. At a reference altitude of 160 km, our calculations suggest that the NO abundance is maximized in the afternoon whereas the N(4S) and N(2D) abundances maximized in the morning, both driven by the variation of the ambient N2 mixing ratio. The difference in chemical loss time scale implies a strong diurnal variation for NO and N(2D) but a weak variation for N(4S).
Reprogramming of lipid metabolism in cancer-associated fibroblasts potentiates migration of colorectal cancer cells
Authors: Gong Jin , Lin Yiyun , Zhang Huaqin , Liu Chunqi , Cheng Zhong , Yang Xiaowei , Zhang Jiamei , Xiao Yuanyuan , Sang Na , Qian Xinying , Wang Liang , Cen Xiaobo , Du Xiao , Zhao Yinglan 
Published: April 2020

AbstractMetabolic interaction between cancer-associated fibroblasts (CAFs) and colorectal cancer (CRC) cells plays a major role in CRC progression. However, little is known about lipid alternations in CAFs and how these metabolic reprogramming affect CRC cells metastasis. Here, we uncover CAFs conditioned medium (CM) promote the migration of CRC cells compared with normal fibroblasts CM. CAFs undergo a lipidomic reprogramming, and accumulate more fatty acids and phospholipids. CAFs CM after protein deprivation still increase the CRC cells migration, which suggests small molecular metabolites in CAFs CM are responsible for CRC cells migration. Then, we confirm that CRC cells take up the lipids metabolites that are secreted from CAFs. Fatty acids synthase (FASN), a crucial enzyme in fatty acids synthesis, is significantly increased in CAFs. CAF-induced CRC cell migration is abolished by knockdown of FASN by siRNA or reducing the uptake of fatty acids by CRC cells by sulfo-N-succinimidyloleate sodium in vitro and CD36 monoclonal antibody in vivo. To conclude, our results provide a new insight into the mechanism of CRC metastasis and suggest FASN of CAFs or CD36 of CRC cells may be potential targets for anti-metastasis treatment in the future.
RETRACTED ARTICLE: Circ_0002770, acting as a competitive endogenous RNA, promotes proliferation and invasion by targeting miR-331-3p in melanoma
Authors: Qian Peng , Linbo Liu , Xiaomei Zhai , Hui Pei 
Published: April 2020

AbstractMelanoma is a kind of tumor that originates from melanocytes and is characterized by chemoresistance and distant metastasis. Although the complete pathogenesis of melanoma remains unclear, increasing evidence suggests that circular RNAs (circRNAs) may be involved. In the present study, we identified a circular RNA, circ_0002770, which is produced from the well-known oncogene MDM2, and was sharply increased in melanoma and correlated with a poor prognosis. Knockdown of circ_0002770 suppressed melanoma cell invasion, migration and proliferation. Mechanistically, circ_0002770 acted as a sponge of miR-331-3p and could indirectly regulate DUSP5 and TGFBR1. Inhibition of miR-331-3p reversed the inhibitory effect of si-circ_0002770 on melanoma cell proliferation and invasion. In vivo evidence further confirmed that silencing circ_0002770 inhibited melanoma tumor formation. In conclusion, circ_0002770 facilitated melanoma cell proliferation, invasion and migration by sponging miR-331-3p and modulating DUSP5 and TGFBR1.
RETRACTED ARTICLE: ERK1/2-Nanog signaling pathway enhances CD44(+) cancer stem-like cell phenotypes and epithelial-to-mesenchymal transition in head and neck squamous cell carcinomas
Authors: Huang Chuang , Yoon Changhwan , Zhou Xiao-Hong , Zhou Ying-Chun , Zhou Wen-Wen , Liu Hong , Yang Xin , Lu Jun , Lee Sei Young , Huang Kun 
Published: April 2020

Abstract
Head and neck squamous cell carcinomas (HNSCCs) harbor a subset of cells that are CD44(+) and present with malignancy and radiotherapy resistance. As a key regulator of self-renewal, Nanog expression not only determines cell fate in pluripotent cells but also mediates tumorigenesis in cancer cells; thus, we examined the role of Nanog in CD44(+) HNSCC. Three HNSCC cell lines, tumor xenografts, and patient tumors were examined. Nanog levels were significantly higher in CD44(+) HNSCC spheroids than in CD44(−) spheroids, and further increased when grown as spheroids to enrich for CSCs. CD44(+) spheroids showed a 3.4–7.5-fold increase in migration and invasion compared with CD44(−) spheroids and were resistant to radiation therapy, which was reversed by inhibiting Nanog. Nanog knockdown also decreased spheroid formation by 66.5–68.8%. Moreover, a phosphokinase array identified upregulated ERK1/2 signaling in CD44(+) HNSCC cells compared with that in CD44(−) cells. ERK1/2 signaling was found to regulate Nanog expression, aiding tumor progression, metastasis, and radiotherapy resistance. In xenograft models, the combination of radiation and Nanog or ERK1/2 inhibition inhibited tumor growth by 75.6% and 79.1%, respectively. In lung metastasis models, CD44(+) cells injected into the tail vein of mice led to significantly more lung metastases and higher Nanog expression level compared with that by ERK1/2-knockdown CD44(+) cells. Finally, in tumor tissues, CD44 and Nanog expression levels were correlated with tumorigenesis in HNSCC patients. Thus, targeting Nanog and the ERK1/2 signaling pathway may prevent or reverse CSC phenotypes and epithelial–mesenchymal transition that drive tumor progression, metastasis, and radiotherapy resistance in HNSCC.
Robust autoactivation for apoptosis by BAK but not BAX highlights BAK as an important therapeutic target
Authors: Iyer Sweta , Uren Rachel T. , Dengler Michael A. , Shi Melissa X. , Uno Etsuko , Adams Jerry M. , Dewson Grant , Kluck Ruth M. 
Published: April 2020

AbstractBAK and BAX, which drive commitment to apoptosis, are activated principally by certain BH3-only proteins that bind them and trigger major rearrangements. One crucial conformation change is exposure of their BH3 domain which allows BAK or BAX to form homodimers, and potentially to autoactivate other BAK and BAX molecules to ensure robust pore formation and cell death. Here, we test whether full-length BAK or mitochondrial BAX that are specifically activated by antibodies can then activate other BAK or BAX molecules. We found that antibody-activated BAK efficiently activated BAK as well as mitochondrial or cytosolic BAX, but antibody-activated BAX unexpectedly proved a poor activator. Notably, autoactivation by BAK involved transient interactions, as BAK and BAX molecules it activated could dissociate and homodimerize. The results suggest that BAK-driven autoactivation may play a substantial role in apoptosis, including recruitment of BAX to the mitochondria. Hence, directly targeting BAK rather than BAX may prove particularly effective in inhibiting unwanted apoptosis, or alternatively, inducing apoptosis in cancer cells.
Premature failure of an additively manufactured material
Authors: Wang Zhi , Xie Meishen , Li Yuanyuan , Zhang Weiwen , Yang Chao , Kollo Lauri , Eckert Jürgen , Prashanth Konda Gokuldoss 
Published: April 2020

AbstractAdditively manufactured metallic materials exhibit excellent mechanical strength. However, they often fail prematurely owing to external defects (pores and unmelted particles) that act as sites for crack initiation. Cracks then propagate through grain boundaries and/or cellular boundaries that contain continuous brittle second phases. In this work, the premature failure mechanisms in selective laser melted (SLM) materials were studied. A submicron structure was introduced in a SLM Ag–Cu–Ge alloy that showed semicoherent precipitates distributed in a discontinuous but periodic fashion along the cellular boundaries. This structure led to a remarkable strength of 410 ± 3 MPa with 16 ± 0.5% uniform elongation, well surpassing the strength-ductility combination of their cast and annealed counterparts. The hierarchical SLM microstructure with a periodic arrangement of precipitates and a high density of internal defects led to a high strain hardening rate and strong strengthening, as evidenced by the fact that the precipitates were twinned and encircled by a high density of internal defects, such as dislocations, stacking faults and twins. However, the samples fractured before necking owing to the crack acceleration along the external defects. This work provides an approach for additively manufacturing materials with an ultrahigh strength combined with a high ductility provided that premature failure is alleviated.
Long-term isolation of European steppe outposts boosts the biome’s conservation value
Authors: Kirschner Philipp , Záveská Eliška , Gamisch Alexander , Hilpold Andreas , Trucchi Emiliano , Paun Ovidiu , Sanmartín Isabel , Schlick-Steiner Birgit C. , Frajman Božo , Arthofer Wolfgang ,   The STEPPE Consortium, Arthofer Wolfgang , Frajman Božo , Gamisch Alexander , Hilpold Andreas , Kirschner Philipp , Paun Ovidiu , Sanmartín Isabel , Schlick-Steiner Birgit C. , Schönswetter Peter , Steiner Florian M. , Trucchi Emiliano , Záveská Eliška , Steiner Florian M. , Schönswetter Peter 
Published: April 2020

AbstractThe European steppes and their biota have been hypothesized to be either young remnants of the Pleistocene steppe belt or, alternatively, to represent relicts of long-term persisting populations; both scenarios directly bear on nature conservation priorities. Here, we evaluate the conservation value of threatened disjunct steppic grassland habitats in Europe in the context of the Eurasian steppe biome. We use genomic data and ecological niche modelling to assess pre-defined, biome-specific criteria for three plant and three arthropod species. We show that the evolutionary history of Eurasian steppe biota is strikingly congruent across species. The biota of European steppe outposts were long-term isolated from the Asian steppes, and European steppes emerged as disproportionally conservation relevant, harbouring regionally endemic genetic lineages, large genetic diversity, and a mosaic of stable refugia. We emphasize that conserving what is left of Europe’s steppes is crucial for conserving the biological diversity of the entire Eurasian steppe biome.
Single-cell bacterial transcription measurements reveal the importance of dimethylsulfoniopropionate (DMSP) hotspots in ocean sulfur cycling
Authors: Gao Cherry , Fernandez Vicente I. , Lee Kang Soo , Fenizia Simona , Pohnert Georg , Seymour Justin R. , Raina Jean-Baptiste , Stocker Roman 
Published: April 2020

AbstractDimethylsulfoniopropionate (DMSP) is a pivotal compound in marine biogeochemical cycles and a key chemical currency in microbial interactions. Marine bacteria transform DMSP via two competing pathways with considerably different biogeochemical implications: demethylation channels sulfur into the microbial food web, whereas cleavage releases sulfur into the atmosphere. Here, we present single-cell measurements of the expression of these two pathways using engineered fluorescent reporter strains of Ruegeria pomeroyi DSS-3, and find that external DMSP concentration dictates the relative expression of the two pathways. DMSP induces an upregulation of both pathways, but only at high concentrations (>1 μM for demethylation; >35 nM for cleavage), characteristic of microscale hotspots such as the vicinity of phytoplankton cells. Co-incubations between DMSP-producing microalgae and bacteria revealed an increase in cleavage pathway expression close to the microalgae’s surface. These results indicate that bacterial utilization of microscale DMSP hotspots is an important determinant of the fate of sulfur in the ocean.
Protective role of renal proximal tubular alpha-synuclein in the pathogenesis of kidney fibrosis
Authors: Bozic Milica , Caus Maite , Rodrigues-Diez Raul R. , Pedraza Neus , Ruiz-Ortega Marta , Garí Eloi , Gallel Pilar , Panadés Maria José , Martinez Ana , Fernández Elvira , Valdivielso José Manuel 
Published: April 2020

AbstractKidney fibrosis is a highly deleterious process and a final manifestation of chronic kidney disease. Alpha-(α)-synuclein (SNCA) is an actin-binding neuronal protein with various functions within the brain; however, its role in other tissues is unknown. Here, we describe the expression of SNCA in renal epithelial cells and demonstrate its decrease in renal tubules of murine and human fibrotic kidneys, as well as its downregulation in renal proximal tubular epithelial cells (RPTECs) after TGF-β1 treatment. shRNA-mediated knockdown of SNCA in RPTECs results in de novo expression of vimentin and α-SMA, while SNCA overexpression represses TGF-β1-induced mesenchymal markers. Conditional gene silencing of SNCA in RPTECs leads to an exacerbated tubulointerstitial fibrosis (TIF) in two unrelated in vivo fibrotic models, which is associated with an increased activation of MAPK-p38 and PI3K-Akt pathways. Our study provides an evidence that disruption of SNCA signaling in RPTECs contributes to the pathogenesis of renal TIF by facilitating partial epithelial-to-mesenchymal transition and extracellular matrix accumulation.
Deletion of Topoisomerase 1 in excitatory neurons causes genomic instability and early onset neurodegeneration
Authors: Fragola Giulia , Mabb Angela M. , Taylor-Blake Bonnie , Niehaus Jesse K. , Chronister William D. , Mao Hanqian , Simon Jeremy M. , Yuan Hong , Li Zibo , McConnell Michael J. , Zylka Mark J. 
Published: April 2020

AbstractTopoisomerase 1 (TOP1) relieves torsional stress in DNA during transcription and facilitates the expression of long (>100 kb) genes, many of which are important for neuronal functions. To evaluate how loss of Top1 affected neurons in vivo, we conditionally deleted (cKO) Top1 in postmitotic excitatory neurons in the mouse cerebral cortex and hippocampus. Top1 cKO neurons develop properly, but then show biased transcriptional downregulation of long genes, signs of DNA damage, neuroinflammation, increased poly(ADP-ribose) polymerase-1 (PARP1) activity, single-cell somatic mutations, and ultimately degeneration. Supplementation of nicotinamide adenine dinucleotide (NAD+) with nicotinamide riboside partially blocked neurodegeneration, and increased the lifespan of Top1 cKO mice by 30%. A reduction of p53 also partially rescued cortical neuron loss. While neurodegeneration was partially rescued, behavioral decline was not prevented. These data indicate that reducing neuronal loss is not sufficient to limit behavioral decline when TOP1 function is disrupted.