bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated Identification of Current Sheets—A New Tool to Study Turbulence and Intermittency in the Solar Wind
Authors: Khabarova Olga , Sagitov Timothy , Kislov Roman , Li Gang 
Published: July 2021

AbstractWe propose a new method of the automated identification of current sheets (CSs) that represents a formalization of the visual inspection approach employed in case studies. CSs are often identified by eye via the analysis of characteristic changes in the interplanetary magnetic field (IMF) and plasma parameters. Known visual and semi‐automated empirical methods of CS identification are exact but do not allow a comprehensive statistical analysis of CS properties. Existing automated methods partially solve this problem. Meanwhile, these methods suggest an analysis of variations of the IMF and its direction only. In our three‐parameter empirical method, we employ both the solar wind plasma and IMF parameters to identify CSs of various types. Derivatives of the IMF strength, the plasma beta and the ratio of the Alfvén speed VA to the solar wind speed V taken with the one‐second cadence are used. We find that the CS daily rate R correlates with the solar wind temperature T rather than with V and is proportional to the sum of the kinetic and thermal energy density ∼V2(N+5N′)+10T(N + N′), where N′ = 2 cm−3 is the background level of the solar wind density N. Maxima of R are associated with stream/corotating interaction regions and interplanetary mass ejection sheaths. A multiyear list of CSs identified at 1 AU can be found at https://csdb.izmiran.ru.
Rationalizing the Differences Among Hydraulic Relationships Using a Process‐Based Model
Authors: Xu Fan , Coco Giovanni , Townend Ian , Guo Leicheng , He Qing , Zhao Kun , Zhou Zeng 
Published: July 2021

AbstractThe use of power law forms to describe hydraulic geometry is a classic subject with a history of over 70 years. Two distinct forms of power laws have been proposed: at‐a‐station hydraulic geometry (AHG) and downstream hydraulic geometry (DHG). Although the utility of these semiempirical expressions is widely recognized, they remain poorly understood in terms of the mechanisms underlying the differences between AHG and DHG, as well as the variability among different systems. In this study, we attempt to address these basic issues. Two hypotheses are proposed: (a) the different geomorphic relationships represented by AHG and DHG result from the control of lateral adjustment of the bank and flow turbulence over short and long timescales, respectively; and (b) the systematic variability of the AHG and DHG exponents is related to the description of the frictional resistance. These two hypotheses are embedded in our theoretical models and lead to explicit functional forms for AHG and DHG. The verification of our hypotheses is based on a large data set consisting of over 550 b‐f‐m exponents and 120 power law hydraulic relations. The analysis highlights the role of uncertainties in data acquisition and theoretical/statistical explanations. In addition, the theoretical expressions of AHG also provide an explanation of at‐many‐stations hydraulic geometry (AMHG) in a physical sense. Overall, our work provides new insights into the fundamental theory of power laws and hydraulic geometry.
Global Survey of Electron Precipitation due to Hiss Waves in the Earth’s Plasmasphere and Plumes
Authors: Ma Q. , Li W. , Zhang X. ‐J. , Bortnik J. , Shen X. ‐C. , Connor H. K. , Boyd A. J. , Kurth W. S. , Hospodarsky G. B. , Claudepierre S. G. , Reeves G. D. , Spence H. E. 
Published: July 2021

AbstractWe present a global survey of energetic electron precipitation from the equatorial magnetosphere due to hiss waves in the plasmasphere and plumes. Using Van Allen Probes measurements, we calculate the pitch angle diffusion coefficients at the bounce loss cone, and evaluate the energy spectrum of precipitating electron flux. Our ∼6.5‐year survey shows that, during disturbed times, hiss inside the plasmasphere primarily causes the electron precipitation at L > 4 over 8 h < MLT < 18 h, and hiss waves in plumes cause the precipitation at L > 5 over 8 h < MLT < 14 h and L > 4 over 14 h < MLT < 20 h. The precipitating energy flux increases with increasing geomagnetic activity, and is typically higher in the plasmaspheric plume than the plasmasphere. The characteristic energy of precipitation increases from ∼20 keV at L = 6–∼100 keV at L = 3, potentially causing the loss of electrons at several hundred keV.
Episodicity and Migration of Low Frequency Earthquakes Modeled With Fast Fluid Pressure Transients in the Permeable Subduction Interface
Authors: Farge Gaspard , Jaupart Claude , Shapiro Nikolai M. 
Published: July 2021

AbstractIn many subduction zones, the plate interface hosts intermittent, low‐frequency, low‐magnitude seismic tremor and low‐frequency earthquakes (LFEs). Seismic activity clusters in episodic bursts that migrate along the fault zone in complex ways. Geological structures in fossil tremor source regions testify to large and pervasive variations of fluid pressure and permeability. Here, we explore the potential of fluid pressure transients in a permeable subduction interface to trigger seismic sources and induce interactions between them. We show how variations of pore pressure and permeability can act in tandem to generate tremor‐like patterns. The core feature of the model is that low‐permeability plugs behave as elementary fault‐valves. In a mechanism akin to erosive bursts and deposition events documented in porous media, valve permeability opens and closes in response to the local fluid pressure distribution. The rapid pressure release and/or mechanical fracturing associated with valve opening acts as the source of an LFE‐like event. Valves interact constructively, leading to realistic, tremor‐like patterns: cascades, synchronized bursts, and migrations of activity along the channel, on both short and long time and space scales. Our model predicts that the input fluid flux is a key control on activity occurrence and behavior. Depending on its value, the subduction interface can be seismically quiescent or active, and seismicity can be strongly time‐clustered, quasi‐periodic or almost random in time. This model allows new interpretations of low frequency seismic activity in terms of effective fluid flux and fault‐zone permeability.
Compact Lightning Strokes in Winter Thunderstorms
Authors: Wu Ting , Wang Daohong , Takagi Nobuyuki 
Published: July 2021

AbstractWith the observation of a 14‐site Fast Antenna Lightning Mapping Array in the Hokuriku region of Japan, we identified a special type of lightning stroke called “compact stroke” in winter thunderstorms. A compact stroke starts with a fast downward negative leader followed by a “compact return stroke.” Compact strokes have the following characteristics that are not seen in normal lightning strokes: (a) Durations of preceding discharges (defined as the time difference between the return stroke and the start of the flash) are generally smaller than 200 μs. (b) Most compact strokes are inferred to be produced in small gaps between mountain tops and negative charge regions in winter thunderstorms. (c) Channel lengths of compact strokes are estimated to be shorter than 600 m with an average of about 300 m. (d) Characteristics of electric field change waveforms of compact return strokes are closely related with durations of preceding discharges. (e) Peak currents of compact return strokes increase with increasing channel lengths. It seems that elevations of mountain surfaces where compact strokes occur are comparable to the altitude of the lower positive charge region, so we speculate that the mountain surface and the near‐surface space carry positive charges when a storm is overhead and are virtually the lower positive charge region of a normal tripole structure. As a result, compact strokes are confined between the main negative and lower positive charge regions, and small pulses with short durations preceding compact return strokes are produced by downward negative leaders corresponding to the preliminary breakdown stage.
Strain Partitioning and Interseismic Fault Behavior Along the Caribbean‐South American Transform Plate Boundary
Authors: Higgins M. , La Femina P. C. , Weber J. C. , Geirsson H. , Ryan G. A. , Wauthier C. 
Published: July 2021

AbstractWe combine Global Positioning System and Interferometric Synthetic Aperture Radar (InSAR) data to characterize the interseismic behavior (i.e., locked or creeping), and strain partitioning for the faults along the Caribbean‐South American transform plate boundary. Interseismic strain is distributed mainly on three faults, the San Sebastian, El Pilar, and Central Range faults, but partitioning occurs across multiple faults in the west (San Sebastian and La Victoria faults) and east (Sub‐Tobago Terrane, Central Range, and South Coast faults). In northern Venezuela, slip is partitioned on the San Sebastian (16.4 ± 1.7 mm/yr) and La Victoria (4.3 ± 0.9 mm/yr) faults. In north‐eastern Venezuela, the El Pilar fault accommodates slip at a rate of 18.6 ± 1.8 mm/yr. In Trinidad and Tobago, slip is partitioned between the Sub‐Tobago Terrane (3.0 ± 0.1 mm/yr), Central Range (14.5 ± 2.0 mm/yr), and South Coast (3.0 ± 0.1 mm/yr) faults. The La Victoria, San Sebastian, the western El Pilar segment, and Sub‐Tobago Terrane faults are locked to depths of 16.2 ± 4.0 km, 7.7 ± 5.2 km, 6.7 ± 2.8 km, and 8.0 ± 0.2 km, respectively. The eastern segment of the El Pilar, the Central Range, and the South Coast faults all creep. Our new InSAR results indicate that the entire Central Range Fault is creeping. The locked western segment of this transform plate boundary is capable of producing a Mw 8 earthquake, which is a significant finding regarding seismic hazard and risk.
Correlative optical photothermal infrared and X-ray fluorescence for chemical imaging of trace elements and relevant molecular structures directly in neurons
Authors: Gustavsson Nadja , Paulus Agnes , Martinsson Isak , Engdahl Anders , Medjoubi Kadda , Klementiev Konstantin , Somogyi Andrea , Deierborg Tomas , Borondics Ferenc , Gouras Gunnar K. , Klementieva Oxana 
Published: July 2021

AbstractAlzheimer’s disease (AD) is the most common cause of dementia, costing about 1% of the global economy. Failures of clinical trials targeting amyloid-β protein (Aβ), a key trigger of AD, have been explained by drug inefficiency regardless of the mechanisms of amyloid neurotoxicity, which are very difficult to address by available technologies. Here, we combine two imaging modalities that stand at opposite ends of the electromagnetic spectrum, and therefore, can be used as complementary tools to assess structural and chemical information directly in a single neuron. Combining label-free super-resolution microspectroscopy for sub-cellular imaging based on novel optical photothermal infrared (O-PTIR) and synchrotron-based X-ray fluorescence (S-XRF) nano-imaging techniques, we capture elemental distribution and fibrillary forms of amyloid-β proteins in the same neurons at an unprecedented resolution. Our results reveal that in primary AD-like neurons, iron clusters co-localize with elevated amyloid β-sheet structures and oxidized lipids. Overall, our O-PTIR/S-XRF results motivate using high-resolution multimodal microspectroscopic approaches to understand the role of molecular structures and trace elements within a single neuronal cell.
New transitional fossil from late Jurassic of Chile sheds light on the origin of modern crocodiles
Authors: Novas Fernando E. , Agnolin Federico L. , Lio Gabriel L. , Rozadilla Sebastián , Suárez Manuel , de la Cruz Rita , de Souza Carvalho Ismar , Rubilar-Rogers David , Isasi Marcelo P. 
Published: July 2021

AbstractWe describe the basal mesoeucrocodylianBurkesuchus mallingrandensisnov. gen. et sp.,from the Upper Jurassic (Tithonian) Toqui Formation of southern Chile. The new taxon constitutes one of the few records of non-pelagic Jurassic crocodyliforms for the entire South American continent.Burkesuchuswas found on the same levels that yielded titanosauriform and diplodocoid sauropods and the herbivore theropodChilesaurus diegosuarezi, thus expanding the taxonomic composition of currently poorly known Jurassic reptilian faunas from Patagonia.Burkesuchuswas a small-sized crocodyliform (estimated length 70 cm), with a cranium that is dorsoventrally depressed and transversely wide posteriorly and distinguished by a posteroventrally flexed wing-like squamosal. A well-defined longitudinal groove runs along the lateral edge of the postorbital and squamosal, indicative of a anteroposteriorly extensive upper earlid. Phylogenetic analysis supportsBurkesuchusas a basal member of Mesoeucrocodylia. This new discovery expands the meagre record of non-pelagic representatives of this clade for the Jurassic Period, and together withBatrachomimus, from Upper Jurassic beds of Brazil, supports the idea that South America represented a cradle for the evolution of derived crocodyliforms during the Late Jurassic.
Generation and first characterization of TRDC-knockout pigs lacking γδ T cells
Authors: Petersen Bjoern , Kammerer Robert , Frenzel Antje , Hassel Petra , Dau Tung Huy , Becker Roswitha , Breithaupt Angele , Ulrich Reiner Georg , Lucas-Hahn Andrea , Meyers Gregor 
Published: July 2021

AbstractThe TRDC-locus encodes the T cell receptor delta constant region, one component of the γδ T cell receptor which is essential for development of γδ T cells. In contrast to peptide recognition by αβ T cells, antigens activating γδ T cells are mostly MHC independent and not well characterized. Therefore, the function of γδ T cells and their contribution to protection against infections is still unclear. Higher numbers of circulating γδ T cells compared to mice, render the pig a suitable animal model to study γδ T cells. Knocking-out the porcine TRDC-locus by intracytoplasmic microinjection and somatic cell nuclear transfer resulted in healthy living γδ T cell deficient offspring. Flow cytometric analysis revealed that TRDC-KO pigs lack γδ T cells in peripheral blood mononuclear cells (PBMC) and spleen cells. The composition of the remaining leucocyte subpopulations was not affected by the depletion of γδ T cells. Genome-wide transcriptome analyses in PBMC revealed a pattern of changes reflecting the impairment of known or expected γδ T cell dependent pathways. Histopathology did not reveal developmental abnormalities of secondary lymphoid tissues. However, in a vaccination experiment the KO pigs stayed healthy but had a significantly lower neutralizing antibody titer as the syngenic controls.
CRISPR/Cas-9 mediated knock-in by homology dependent repair in the West Nile Virus vector Culex quinquefasciatus Say
Authors: Purusothaman Deepak-Kumar , Shackleford Lewis , Anderson Michelle A. E. , Harvey-Samuel Tim , Alphey Luke 
Published: July 2021

AbstractCulex quinquefasciatusSay is a mosquito distributed in both tropical and subtropical regions of the world. It is a night-active, opportunistic blood-feeder and vectors many animal and human diseases, including West Nile Virus and avian malaria. Current vector control methods (e.g. physical/chemical) are increasingly ineffective; use of insecticides also imposes hazards to both human and ecosystem health. Advances in genome editing have allowed the development of genetic insect control methods, which are species-specific and, theoretically, highly effective. CRISPR/Cas9 is a bacteria-derived programmable gene editing tool that is functional in a range of species. We describe the first successful germline gene knock-in by homology dependent repair inC. quinquefasciatus. Using CRISPR/Cas9, we integrated an sgRNA expression cassette and marker gene encoding a fluorescent protein fluorophore (Hr5/IE1-DsRed, Cq7SK-sgRNA) into the kynurenine 3-monooxygenase (kmo) gene. We achieved a minimum transformation rate of 2.8%, similar to rates in other mosquito species. Precise knock-in at the intended locus was confirmed. Insertion homozygotes displayed a white eye phenotype in early-mid larvae and a recessive lethal phenotype by pupation. This work provides an efficient method for engineeringC. quinquefasciatus, providing a new tool for developing genetic control tools for this vector.
Pelagic organisms avoid white, blue, and red artificial light from scientific instruments
Authors: Geoffroy Maxime , Langbehn Tom , Priou Pierre , Varpe Øystein , Johnsen Geir , Le Bris Arnault , Fisher Jonathan A. D. , Daase Malin , McKee David , Cohen Jonathan , Berge Jørgen 
Published: July 2021

AbstractIn situ observations of pelagic fish and zooplankton with optical instruments usually rely on external light sources. However, artificial light may attract or repulse marine organisms, which results in biased measurements. It is often assumed that most pelagic organisms do not perceive the red part of the visible spectrum and that red light can be used for underwater optical measurements of biological processes. Using hull-mounted echosounders above an acoustic probe or a baited video camera, each equipped with light sources of different colours (white, blue and red), we demonstrate that pelagic organisms in Arctic and temperate regions strongly avoid artificial light, including visible red light (575–700 nm), from instruments lowered in the water column. The density of organisms decreased by up to 99% when exposed to artificial light and the distance of avoidance varied from 23 to 94 m from the light source, depending on colours, irradiance levels and, possibly, species communities. We conclude that observations from optical and acoustic instruments, including baited cameras, using light sources with broad spectral composition in the 400–700 nm wavelengths do not capture the real state of the ecosystem and that they cannot be used alone for reliable abundance estimates or behavioural studies.
Autoantibody profiles and clinical association in Thai patients with autoimmune retinopathy
Authors: Pawestri Aulia Rahmi , Arjkongharn Niracha , Suvannaboon Ragkit , Tuekprakhon Aekkachai , Srimuninnimit Vichien , Udompunthurak Suthipol , Atchaneeyasakul La-ongsri , Koolvisoot Ajchara , Trinavarat Adisak 
Published: July 2021

AbstractAutoimmune retinopathy (AIR) is a rare immune-mediated inflammation of the retina. The autoantibodies against retinal proteins and glycolytic enzymes were reported to be involved in the pathogenesis. This retrospective cohort study assessed the antiretinal autoantibody profiles and their association with clinical outcomes of AIR patients in Thailand. We included 44 patients, 75% were females, with the overall median age of onset of 48 (17–74, IQR 40–55.5) years. Common clinical presentations were nyctalopia (65.9%), blurred vision (52.3%), constricted visual field (43.2%), and nonrecordable electroretinography (65.9%). Underlying malignancy and autoimmune diseases were found in 2 and 12 female patients, respectively. We found 41 autoantibodies, with anti-α-enolase (65.9%) showing the highest prevalence, followed by anti-CAII (43.2%), anti-aldolase (40.9%), and anti-GAPDH (36.4%). Anti-aldolase was associated with male gender (P = 0.012, OR 7.11, 95% CI 1.54–32.91). Anti-CAII showed significant association with age of onset (P = 0.025, 95% CI − 17.28 to − 1.24), while anti-α-enolase (P = 0.002, OR 4.37, 95% CI 1.83–10.37) and anti-GAPDH (P = 0.001, OR 1.87, 95% CI 1.32–2.64) were significantly associated with nonrecordable electroretinography. Association between the antibody profiles and clinical outcomes may be used to direct and adjust the treatment plans and provide insights in the pathogenesis of AIR.
Conversion from epithelial to partial-EMT phenotype by Fusobacterium nucleatum infection promotes invasion of oral cancer cells
Authors: Shao Wenhua , Fujiwara Natsumi , Mouri Yasuhiro , Kisoda Satoru , Yoshida Kayo , Yoshida Kaya , Yumoto Hiromichi , Ozaki Kazumi , Ishimaru Naozumi , Kudo Yasusei 
Published: July 2021

Abstract
The ability of cancer cells to undergo partial-epithelial mesenchymal transition (p-EMT), rather than complete EMT, poses a higher metastatic risk. Although Fusobacterium nucleatum mainly inhabits in oral cavity, attention has been focused on the F. nucleatum involvement in colorectal cancer development. Here we examined the p-EMT regulation by F. nucleatum in oral squamous cell carcinoma (OSCC) cells. We cultured OSCC cells with epithelial, p-EMT or EMT phenotype with live or heat-inactivated F. nucleatum. Expression of the genes involved in epithelial differentiation, p-EMT and EMT were examined in OSCC cells after co-culture with F. nucleatum by qPCR. Cell growth and invasion of OSCC cells were also examined. Both live and heat-inactivated F. nucleatum upregulated the expression of p-EMT-related genes in OSCC cells with epithelial phenotype, but not with p-EMT or EMT phenotype. Moreover, F. nucleatum promoted invasion of OSCC cells with epithelial phenotype. Co-culture with other strains of bacteria other than Porphyromonas gingivalis did not alter p-EMT-related genes in OSCC cells with epithelial phenotype. F. nucleatum infection may convert epithelial to p-EMT phenotype via altering gene expression in OSCC. Oral hygiene managements against F. nucleatum infection may contribute to reduce the risk for an increase in metastatic ability of OSCC.
Role of MCP-1 and IL-8 in viral anterior uveitis, and contractility and fibrogenic activity of trabecular meshwork cells
Authors: Lee Jiyoung , Choi Jin A. , Ju Hyun-hee , Kim Ju-Eun , Paik Soon-Young , Rao Ponugoti Vasantha 
Published: July 2021

AbstractThe inflammatory chemokines, monocyte chemoattractant protein (MCP)-1 and IL-8, are produced by normal trabecular meshwork cells (TM) and elevated in the aqueous humor of primary open angle glaucoma (POAG) and hypertensive anterior uveitis associated with viral infection. However, their role in TM cells and aqueous humor outflow remains unclear. Here, we explored the possible involvement of MCP-1 and IL-8 in the physiology of TM cells in the context of aqueous outflow, and the viral anterior uveitis. We found that the stimulation of human TM cells with MCP-1 and IL-8 induced significant increase in the formation of actin stress fibers and focal adhesions, myosin light chain phosphorylation, and the contraction of TM cells. MCP-1 and IL-8 also demonstrated elevation of extracellular matrix proteins, and the migration of TM cells. When TM cells were infected with HSV-1 and CMV virus, there was a significant increase in cytoskeletal contraction and Rho-GTPase activation. Viral infection of TM cells revealed significantly increased expression of MCP-1 and IL-8. Taken together, these results indicate that MCP-1 and IL-8 induce TM cell contractibility, fibrogenic activity, and plasticity, which are presumed to increase resistance to aqueous outflow in viral anterior uveitis and POAG.