bluuebunny/crossref_metadata_2025_split huggingface dataset:
Small Volcanic Vents of the Tharsis Volcanic Province, Mars
Authors: Richardson J. A. , Bleacher J. E. , Connor C. B. , Glaze L. S. 
Published: February 2021

AbstractDistributed‐style volcanism is an end member of terrestrial volcanism that produces clusters of small volcanoes when isolated magma bodies ascend from broad magma source regions. Volcano clusters can develop over millions of years, one volcano at a time, and can be used to infer unobserved geologic phenomena, including subsurface stresses and cracks during eruption periods. The Tharsis Volcanic Province covers approximately one‐quarter of the martian surface and hosts a large concentration of small volcanoes that formed from distributed volcanism. We present a catalog of 1,106 small volcanic vents identified within Tharsis Volcanic Province. This catalog includes morphologic measurements for each cataloged vent. Vent lengths range from 71 m to 51 km, widths range from 40 m to 3.1 km, and 90% of vents have lengths at least 1.5 times their widths. Additionally, 90% of edifices associated with vents have topographic prominences <100 m. Vents are found throughout Tharsis, though they generally form clusters near large volcanoes or among large graben sets. Older regions with volcanic eruption ages of >1 Ga are found at the Tharsis periphery in the Tempe‐Mareotis region and Syria Planum. Vents in the Tharsis interior have reported ages <500 Ma. Regional trends in vent orientation and intervent alignment are dependent on nearby central volcanoes and fossae. We use these findings to hypothesize that within the most recent 500 Ma, magma was present under and to the east of the Tharsis Montes and that some of this magma erupted and built hundreds of small volcanoes in this region.
Emulating Ocean Dynamic Sea Level by Two‐Layer Pattern Scaling
Authors: Yuan Jiacan , Kopp Robert E. 
Published: February 2021

AbstractOcean dynamic sea level (DSL) change is a key driver of relative sea level (RSL) change. Projections of DSL change are generally obtained from simulations using atmosphere‐ocean general circulation models (GCMs). Here, we develop a two‐layer climate emulator to interpolate between emission scenarios simulated with GCMs and extend projections beyond the time horizon of available simulations. This emulator captures the evolution of DSL changes in corresponding GCMs, especially over middle and low latitudes. Compared with an emulator using univariate pattern scaling, the two‐layer emulator more accurately reflects GCM behavior and captures non‐linearities and non‐stationarity in the relationship between DSL and global‐mean warming, with a reduction in global‐averaged error during 2271–2290 of 36%, 24%, and 34% in RCP2.6, RCP4.5, and RCP8.5, respectively. Using the emulator, we develop a probabilistic ensemble of DSL projections through 2300 for four scenarios: Representative Concentration Pathway (RCP) 2.6, RCP 4.5, RCP 8.5, and Shared Socioeconomic Pathway (SSP) 3–7.0. The magnitude and uncertainty of projected DSL changes decrease from the high‐to the low‐emission scenarios, indicating a reduced DSL rise hazard in low‐ and moderate‐emission scenarios (RCP2.6 and RCP4.5) compared to the high‐emission scenarios (SSP3‐7.0 and RCP8.5).
Global Monitoring of Geomagnetic Storm‐Induced Ionosphere Anomalies Using 3‐D Ionospheric Modeling With Multi‐GNSS and COSMIC Measurements
Authors: Cheng Na , Song Shuli , Jiao Guoqiang , Jin Xulei , Li Wei 
Published: February 2021

AbstractIonosphere is a signiﬁcant component of the solar‐terrestrial space environment. Geomagnetic storm induces global ionospheric disturbances, severely affect radio communications and human space activities, e.g., earth observation, deep space exploration, and space weather monitoring and prediction. Monitoring ionospheric anomalies are critical to improve the performance of Global Navigation Satellite System (GNSS) positioning, navigation and timing (PNT) and provide early‐warning of disaster service during the extreme space weather event. The spatial and temporal variation of ionospheric electron density (IED) is utilized to characterize the ionospheric anomalies respond to storm. Thus, the global‐scale three‐dimensional (3‐D) ionospheric model is constructed by computerized ionospheric omography (CIT) technique combine multi‐GNSS(GPS/GLONASS/BDS/Galileo) and Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation (RO) measurements. As ground‐based multi‐GNSS and space‐based Low Earth Orbit (LEO)/GNSS observation networks expand gradually, massive measurements are employed in ionospheric inversion in high temporal‐spatial resolution. Hence, the Open Multi‐Processing (OpenMP) parallel computing method is applied to improve the efﬁciency of imaging 3‐D ionosphere. The processing time reduces to within 10 mins, thus 3‐D ionospheric model updates in near real‐time is achievable. Moreover, the 3‐D IED model is applied to monitor the ionosphere dynamically during storms and the storm‐induced ionospheric anomalies are observed. This contribution suggests our reconstructed 3‐D model is capable of reﬂecting the ionospheric anomalies during storm in global‐scale, also it reveals the characteristics of the ionosphere respond to the storm and its evolution.
Optimizing Forward‐Looking Missile‐Borne BSAR Imaging With Convolutional Neural Network
Authors: Shi Hongyin , Yang Yupeng , Lv Chunyang , Zhang Jing , Guo Jianwen 
Published: February 2021

AbstractDuring the guidance of the missile, the target needs to be positioned in real time. The detonating missile will look forward to the target area during the flight, and the imaging distance becomes closer as the missile approaches the target. The image quality of forward‐looking missile‐borne bistatic synthetic aperture radar (FM‐BSAR) deteriorates rapidly when the detonator enters a rapid dive stage. One of the most serious problem is the azimuth defocusing, the more deviated from the center of the imaging aperture, the more defocusing. In this paper, a method of using convolutional neural network (CNN) to accomplish image focusing is proposed to improve the image quality of BSAR. The advantage of this method is to focus the image accurately with inaccurate imaging parameters. The experimental results show that the proposed method can accurately locate and focus the defocusing points, which has practical significance for improving the BSAR close‐range imaging effect of high‐maneuvering platform.
Proterozoic Basin Evolution and Tectonic Geography of Madagascar: Implications for an East Africa Connection During the Paleoproterozoic
Authors: Armistead Sheree E. , Collins Alan S. , Schmitt Renata S. , Costa Raisa L. , De Waele Bert , Razakamanana Théodore , Payne Justin L. , Foden John D. 
Published: February 2021

AbstractMadagascar hosts several Paleoproterozoic sedimentary sequences that are key to unraveling the geodynamic evolution of past supercontinents on Earth. New detrital zircon U–Pb and Hf data, and a substantial new database of ∼15,000 analyses are used here to compare and contrast sedimentary sequences in Madagascar, Africa, and India. The Itremo Group in central Madagascar, the Sahantaha Group in northern Madagascar, the Maha Group in eastern Madagascar, and the Ambatolampy Group in central Madagascar have indistinguishable age and isotopic characteristics. These samples have maximum depositional ages >1700 Ma, with major zircon age peaks at c. 2500 Ma, c. 2000 Ma, and c. 1850 Ma. We name this the Greater Itremo Basin, which covered a vast area of Madagascar in the late Paleoproterozoic. These samples are also compared with those from the Tanzania and the Congo cratons of Africa, and the Dharwar Craton and Southern Granulite Terrane of India. We show that the Greater Itremo Basin and sedimentary sequences in the Tanzania Craton of Africa are correlatives. These also tentatively correlate with sedimentary protoliths in the Southern Granulite Terrane of India, which together formed a major intra‐Nuna/Columbia sedimentary basin that we name the Itremo‐Muva‐Pandyan Basin. A new Paleoproterozoic plate tectonic configuration is proposed where central Madagascar is contiguous with the Tanzania Craton to the west and the Southern Granulite Terrane to the east. This model strongly supports an ancient Proterozoic origin for central Madagascar and a position adjacent to the Tanzania Craton of East Africa.
Tectonics of the Isua Supracrustal Belt 2: Microstructures Reveal Distributed Strain in the Absence of Major Fault Structures
Authors: Zuo Jiawei , Webb A. Alexander G. , Piazolo Sandra , Wang Qin , Müller Thomas , Ramírez‐Salazar Anthony , Haproff Peter J. 
Published: February 2021

AbstractArchean geological records are increasingly interpreted to indicate a ≤3.2 Ga initiation of plate tectonics on Earth. This hypothesis contrasts with dominant plate tectonic interpretations for the Eoarchean (ca. 4.0–3.6 Ga) Isua supracrustal belt (southwest Greenland). Alternatively, recent work shows the belt could have formed via heat‐pipe tectonics. Predicted strain distributions across the belt vary between models. Plate tectonic models predict a dominant unidirectional shear sense, corresponding to subduction vergence, and strain localization within ∼10‐m‐scale shear zones. In contrast, the proposed heat‐pipe model predicts two opposing shear senses, corresponding to opposite limbs of 0.1‐m to km‐scale a‐type folds (i.e., sheath and curtain folds), with relatively equal strain distributed across the belt. Here, we present the first microstructure study using thin‐section petrography and electron backscatter diffraction analysis on quartz of oriented samples from throughout the Isua supracrustal belt. Key findings are: (1) the Eoarchean Isua supracrustal belt was deformed at ∼500°C–650°C, with potential postdeformational recovery at similar or lower temperatures, (2) the spatial distribution of the two opposing shear senses which dominate the belt (top‐to‐southeast and top‐to‐northwest) appears to be random, and (3) the strain intensity across the belt appears to be quasiuniform as evidenced by the uniformly low (mostly <0.1) M‐indexes of quartz fabrics, such that no ≤ 100 ‐m‐scale shear zones can be detected. Our findings are only consistent with the predictions of the heat‐pipe model and do not require plate tectonics, so the geology of the belt is compatible with a ≤3.2 Ga initiation of plate tectonics.
Tectonics of the Isua Supracrustal Belt 1: P‐T‐X‐d Constraints of a Poly‐Metamorphic Terrane
Authors: Ramírez‐Salazar Anthony , Müller Thomas , Piazolo Sandra , Webb A. Alexander G. , Hauzenberger Christoph , Zuo Jiawei , Haproff Peter , Harvey Jason , Wong Tsz Kin , Charlton Callum 
Published: February 2021

AbstractThe Eoarchean Isua supracrustal belt (ISB) has been interpreted as one of the earliest records of subduction processes, leading to the conclusion that a plate tectonic geodynamic system was likely operating since the early Archean. However, proposed tectonic models remain difficult to evaluate as our understanding of the metamorphic and structural evolution remains fragmentary. Here, we present a metamorphic study of the supracrustal rocks of the ISB. We used petrographic and microstructural observations, phase equilibria, isopleth geothermobarometry, and conventional thermometry to explore the prograde, peak, and retrograde metamorphic evolution of the northeastern ISB. Our results show that the ISB records a syn‐tectonic, amphibolite facies metamorphic event (M1) with peak conditions of 550°C–600°C and 0.5–0.7 GPa. M1 was followed by a static, lower amphibolite facies metamorphic event (M2; <540°C and <0.5 GPa). Published constraints suggest that M1 and M2 occurred in the late Eoarchean (>3.5 Ga) and the Neoarchean (<2.9 Ga), respectively. These events are partially overprinted by late low temperature (<500°C) retrogression (M3) that is most intensely developed in the northeastern part of the belt; it typically overprints some peak mineral phases while preserving the peak fabric. Our findings are consistent with spatially homogeneous syn‐tectonic amphibolite facies metamorphism and macroscale folding. Such features are predicted by a heat‐pipe tectonic model. Therefore, our findings permit the interpretation of the ISB as a record of early nonuniformitarian tectonic processes.
Experimental Methods and Imaging for Enzymatically Induced Calcite Precipitation in a Microfluidic Cell
Authors: Weinhardt Felix , Class Holger , Vahid Dastjerdi Samaneh , Karadimitriou Nikolaos , Lee Dongwon , Steeb Holger 
Published: February 2021

AbstractEnzymatically induced calcite precipitation (EICP) in porous media can be used as an engineering option to achieve precipitation in the pore space, for example, aiming at a targeted sealing of existing flow paths. This is accomplished through a porosity and consequent permeability alteration. A major source of uncertainty in modeling EICP is in the quantitative description of permeability alteration due to precipitation. This report presents methods for investigating experimentally the time‐resolved effects of growing precipitates on porosity and permeability on the pore scale, in a poly‐di‐methyl‐siloxane microfluidic flow cell. These methods include the design and production of the microfluidic cells, the preparation and usage of the chemical solutions, the injection strategy, and the monitoring of pressure drops for given fluxes for the determination of permeability. EICP imaging methods are explained, including optical microscopy and X‐ray microcomputed tomography (XRCT), and the corresponding image processing and analysis. We present and discuss a new experimental procedure using a microfluidic cell, as well as the general perspectives for further experimental and numerical simulation studies on induced calcite precipitation. The results of this study show the enormous benefits and insights achieved by combining both light microscopy and XRCT with hydraulic measurements in microfluidic chips. This allows for a quantitative analysis of the evolution of precipitates with respect to their size and shape, while monitoring their influence on permeability. We consider this to be an improvement of the existing methods in the literature regarding the interpretation of recorded data (pressure, flux, and visualization) during pore morphology alteration.
Role of ABCB1 in mediating chemoresistance of triple-negative breast cancers
Authors: Abd El-Aziz Yomna S. , Spillane Andrew J. , Jansson Patric J. , Sahni Sumit 
Published: February 2021

Abstract
Triple-negative breast cancer (TNBC) is a group of breast cancers which neither express hormonal receptors nor human epidermal growth factor receptor. Hence, there is a lack of currently known targeted therapies and the only available line of systemic treatment option is chemotherapy or more recently immune therapy. However, in patients with relapsed disease after adjuvant or neoadjuvant therapy, resistance to chemotherapeutic agents has often developed, which results in poor treatment response. Multidrug resistance (MDR) has emerged as an important mechanism by which TNBCs mediate drug resistance and occurs primarily due to overexpression of ATP-binding cassette (ABC) transporter proteins such as P-glycoprotein (Pgp). Pgp overexpression had been linked to poor outcome, reduced survival rates and chemoresistance in patients. The aim of this mini-review is to provide a topical overview of the recent studies and to generate further interest in this critical research area, with the aim to develop an effective and safe approach for overcoming Pgp-mediated chemoresistance in TNBC.
ACE2 and energy metabolism: the connection between COVID-19 and chronic metabolic disorders
Authors: Cao Xi , Song Li-Ni , Yang Jin-Kui 
Published: February 2021

AbstractThe renin–angiotensin system (RAS) has currently attracted increasing attention due to its potential function in regulating energy homeostasis, other than the actions on cellular growth, blood pressure, fluid, and electrolyte balance. The existence of RAS is well established in metabolic organs, including pancreas, liver, skeletal muscle, and adipose tissue, where activation of angiotensin-converting enzyme (ACE) – angiotensin II pathway contributes to the impairment of insulin secretion, glucose transport, fat distribution, and adipokines production. However, the activation of angiotensin-converting enzyme 2 (ACE2) – angiotensin (1–7) pathway, a novel branch of the RAS, plays an opposite role in the ACE pathway, which could reverse these consequences by improving local microcirculation, inflammation, stress state, structure remolding, and insulin signaling pathway. In addition, new studies indicate the protective RAS arm possesses extraordinary ability to enhance brown adipose tissue (BAT) activity and induces browning of white adipose tissue, and consequently, it leads to increased energy expenditure in the form of heat instead of ATP synthesis. Interestingly, ACE2 is the receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is threating public health worldwide. The main complications of SARS-CoV-2 infected death patients include many energy metabolism-related chronic diseases, such as diabetes. The specific mechanism leading to this phenomenon is largely unknown. Here, we summarize the latest pharmacological and genetic tools on regulating ACE/ACE2 balance and highlight the beneficial effects of the ACE2 pathway axis hyperactivity on glycolipid metabolism, as well as the thermogenic modulation.
An efficient data collection framework in the sky: An affine transformation approach based on Internet of unmanned aerial vehicles
Authors: Sun Bing , Yu Mingxing , Wu Yi , Qi Yuanhang , Nie Xin , Xi Shan 
Published: February 2021

AbstractDue to a large amount of time‐series data (e.g. precipitation, temperature, humidity) in the air, reliable and fast data collection is a challenging issue. Using an unmanned aerial vehicle (UAV) as a data collector to collect time‐series data is an effective method. However, due to the limited storage capacity of the UAV, the UAV must access the sensor multiple times to collect time‐series data from the deployed sensors and dump the data to the data centre, which leads to significantly increased time and cost for data collection mission. To address this challenge, an efficient time‐series data collection framework is proposed based on the Internet of UAVs. In this system, a min‐maximum data processing strategy is adopted based on data value to store the collected time‐series data. Specifically, efficient data compression storage is achieved with minimal loss of precision by extracting the dominant dataset with maximum value. Furthermore, an efficient affine transformation method is proposed to improve the efficiency of the system. Extensive case studies on some real‐world datasets demonstrate that the proposed framework can achieve efficient data management and compressed storage.
Mobile target localization and tracking techniques in harsh environment utilizing adaptive multi‐modal data fusion
Authors: Mai Zhenzhen , Xiong Hailiang , Yang Gangqiang , Zhu Weihong , He Fen , Bian Ruochen , Li Yujun 
Published: February 2021

AbstractMulti‐source cooperative positioning systems relying on federated filtering have become attractive development directions of navigation strategy in real‐time localization and tracking under challenging urban environment. However, local Kalman filters of traditional federated filtering may result in divergence when the system model or the measurements is inaccurate, and the fixed information distribution coefficient in federated filter cannot adaptively reflect the performance of each local filter. To improve the precision and robustness of the integrated navigation system, a novel adaptive federated strong tracking Kalman filter with dynamic fading factor mechanism for multi‐sensor information fusion is proposed. Through iterative computation of the fading factor and updating the adaptive weight coefficients, strong tracking filter becomes robust to the uncertainty of system model. Meanwhile, an effective adaptive information distribution estimation algorithm based on the predicted residuals is constructed to balance the contributions of the kinematic model information and measurements on the state estimates. To ensure the stability of filtering, a simplified fusion strategy is established to solve the singular problem of the global covariance matrix of estimation error. Theoretical analysis and simulation results demonstrate the validity of the proposed approach in improving the accuracy and robustness of the integrated navigation and positioning systems. The proposed integrated multi‐modal cooperative navigation and positioning algorithm will be of great significance to the implementation of real‐time mobile target localization and tracking in harsh environment or dead zone.
Exploiting user preferences to reduce bandwidth requirements for VoD services with client caching
Authors: Pinto Felipe Alex , Fernández Evelio Martín García , Pedroso Carlos Marcelo 
Published: February 2021

AbstractInternet traffic is already dominated by video streaming applications. The quality of transmitted videos and the number of content available online is expected to increase in the upcoming years, which will further pressure the available network infrastructures. In this scenario, Video‐on‐Demand services require that distribution mechanisms improve the efficiency of video transmission, which impacts the network performance and system scalability. The efficiency of distribution is strongly related to the operating costs of the providers of such services. The most efficient methods available for Video‐on‐Demand distribution use strategies that combine multicast transmission and the storage capacity of the user's equipment. This paper presents a new method for Video‐on‐Demand distribution that explores the client storage capabilities by modelling the users' preferences with a Hidden Markov Model. The efficiency of the proposed method is demonstrated through computational simulations of different scenarios, including a sample of real users' activity. Our results indicate that the proposed scheme substantially outperforms the current Video‐on‐Demand distribution mechanisms in terms of network bandwidth consumption, significantly reducing operation costs by improving the system scalability.
A fault location and detection technique for STATCOM compensated transmission lines using game theory
Authors: Khalili Mehrdad , Namdari Farhad , Rokrok Esmaeel 
Published: February 2021

AbstractThis study aims at proposing an original single‐end protection scheme for the compensated transmission line using traveling waves and game theory. To this end, this paper initially investigates the effects of static synchronous compensator (STATCOM) on traveling waves passing through STATCOM installation point. Furthermore, based on the traveling wave theory, it evaluates the impacts of STATCOM's harmonic on conventional protections. A single‐end method will be proposed in the next stage for fault protection on the compensated transmission lines with STATCOM. The extracted traveling waves in this study will be discriminated using the game theory, and discrete wavelet transform will be utilized to process the signals and assess the sensitivity of the proposed scheme considering the extraction techniques of the traveling wave. According to the obtained results, the proposed protection scheme is a reliable and accurate method for all possible faults type on compensated transmission lines at the various locations of the line and with different fault inception angles.