bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Technique for Automated Detection of Lightning in Images and Video From the International Space Station for Scientific Understanding and Validation
Authors: Schultz Christopher J. , Lang Timothy J. , Leake Skye , Runco Mario , Stefanov William 
Published: December 2020

AbstractA combination of Chiba University's METEOR camera, International Space Station Lightning Imaging Sensor (ISS LIS), Geostationary Lightning Mapper (GLM), National Lightning Detection Network (NLDN) data, and other space and ground based data sets were utilized to develop a METEOR‐derived lightning identification technique to automatically identify lightning flashes within International Space Station video and still frame imagery. Approximately 14,000 frames were used from two METEOR camera videos. Zero lightning events were missed by the technique using manual inspection of both videos, and the technique did not identify other sources of light (e.g., city lights). Three‐hundred and nine METEOR‐identified flashes were matched with 289 GLM flashes and 285 ISS LIS flashes in the METEOR field of view on May 17, 2017. On average, the flash area determined by the analysis technique developed in this study was 266 km2 smaller than the flash area observed by GLM. The primary reason for this difference in size was the spatial resolution of GLM and METEOR (>8 km vs. 260 m). When NLDN flashes were observed, there was a 200–500 km2 increase in the algorithm‐derived flash area within 100 ms of the NLDN time, indicative of return stroke processes as bright light is scattered through cloud top. Accurate reverse geolocation using lightning data alone was difficult due to the different spatial resolution, temporal resolution, and other geolocation assumptions between the camera images and comparison data. However, the use of satellite‐derived city lights aided in the geolocation process for scientific comparisons.
Estimating Submicron Aerosol Mixing State at the Global Scale With Machine Learning and Earth System Modeling
Authors: Zheng Zhonghua , Curtis Jeffrey H. , Yao Yu , Gasparik Jessica T. , Anantharaj Valentine G. , Zhao Lei , West Matthew , Riemer Nicole 
Published: December 2020

AbstractThis study integrates machine learning and particle‐resolved aerosol simulations to develop emulators that predict submicron aerosol mixing state indices from the Earth system model (ESM) simulations. The emulators predict aerosol mixing state using only quantities that are predicted by the ESM, including bulk aerosol species concentrations, which do not by themselves carry mixing state information. We used PartMC‐MOSAIC as the particle‐resolved model and NCAR's CESM as the ESM. We trained emulators for three different mixing state indices for submicron aerosol in terms of chemical species abundance (χa), the mixing of optically absorbing and nonabsorbing species (χo), and the mixing of hygroscopic and nonhygroscopic species (χh). Our global mixing state maps show considerable spatial and seasonal variability unique to each mixing state index. Seasonal averages varied spatially between 13% and 94% for χa, between 38% and 94% for χo, and between 20% and 87% for χh with global annual averages of 67%, 68%, and 56%, respectively. High values in one index can be consistent with low values in another index depending on the grouping of species and their relative abundance, meaning that each mixing state index captures different aspects of the population mixing state. Although a direct validation with observational data has not been possible yet, our results are consistent with mixing state index values derived from ambient observations. This work is a prototypical example of using machine learning emulators to add information to ESM simulations.
Magnetospheric Multiscale Statistics of High Energy Electrons Trapped in Diamagnetic Cavities
Authors: Burkholder B. L. , Nykyri K. , Ma X. 
Published: December 2020

AbstractHigh‐energy electrons observed in the magnetosheath must be accelerated by some mechanism that is as yet undetermined. We present observations of high‐energy electrons trapped in diamagnetic cavities as measured by Magnetospheric Multiscale from 2015 to 2018. The observations support the notion of local acceleration in the reconnection quasi‐potential as many of events show particles with pitch angles that are increasingly closer to 90° with increasing energy. It is suggested that these particles can end up in the loss cone and be transported to the magnetosheath. We also characterize each diamagnetic cavity as formed due to low‐ or high‐latitude reconnection based on prevailing solar wind conditions. The character of the ions in the diamagnetic cavity is only briefly mentioned as their properties warrant another stand‐alone investigation.
Nonlinear Landau Resonant Interaction Between Kinetic Alfvén Waves and Thermal Electrons: Excitation of Time Domain Structures
Authors: An Xin , Bortnik Jacob , Zhang Xiao‐Jia 
Published: December 2020

AbstractPhase space holes, double layers and other solitary electric field structures, referred to as time domain structures (TDSs), often occur around dipolarization fronts in the Earth's inner magnetosphere. They are considered to be important because of their role in the dissipation of the injection energy and their potential for significant particle scattering and acceleration. Kinetic Alfvén waves are observed to be excited during energetic particle injections, and are typically present in conjunction with TDS observations. Despite the availability of a large number of spacecraft observations, the origin of TDSs and their relation to kinetic Alfvén waves remains poorly understood to date. Part of the difficulty arises from the vast scale separations between kinetic Alfvén waves and TDSs. Here, we demonstrate that TDSs can be excited by electrons in nonlinear Landau resonance with kinetic Alfvén waves. These electrons get trapped by the parallel electric field of kinetic Alfvén waves, form localized beam distributions, and subsequently generate TDSs through beam instabilities. A big picture emerges as follows: macroscale dipolarization fronts first transfer the ion flow (kinetic) energy to kinetic Alfvén waves at intermediate scale, which further channel the energy to TDSs at the microscale and eventually deposit the energy to the thermal electrons in the form of heating. In this way, the ion flow energy associated with dipolarization fronts is effectively dissipated in a cascade from large to small scales in the inner magnetosphere.
Inner Magnetospheric Response to the Interplanetary Magnetic Field By Component: Van Allen Probes and Arase Observations
Authors: Case N. A. , Hartley D. P. , Grocott A. , Miyoshi Y. , Matsuoka A. , Imajo S. , Kurita S. , Shinohara I. , Teramoto M. 
Published: December 2020

AbstractWe utilize 17 years of combined Van Allen Probes and Arase data to statistically analyze the response of the inner magnetosphere to the orientation of the interplanetary magnetic field (IMF) By component. Past studies have demonstrated that the IMF By component introduces a similarly oriented By component into the magnetosphere. However, these studies have tended to focus on field lines in the magnetotail only reaching as close to the Earth as the geosynchronous orbit. By exploiting data from these inner magnetospheric spacecraft, we have been able to investigate the response at radial distances of <7RE. When subtracting the background magnetic field values, provided by the T01 and IGRF magnetic field models, we find that the IMF By component does affect the configuration of the magnetic field lines in the inner magnetosphere. This control is observed throughout the inner magnetosphere, across both hemispheres, all radial distances, and all magnetic local time sectors. The ratio of IMF By to the observed By residual, also known as the “penetration efficiency,” is found to be ∼0.33. The IMF Bz component is found to increase, or inhibit, this control depending upon its orientation.
Factors Controlling Terminus Position of Hansbreen, a Tidewater Glacier in Svalbard
Authors: Błaszczyk Małgorzata , Jania Jacek A. , Ciepły Michał , Grabiec Mariusz , Ignatiuk Dariusz , Kolondra Leszek , Kruss Aleksandra , Luks Bartłomiej , Moskalik Mateusz , Pastusiak Tadeusz , Strzelewicz Agnieszka , Walczowski Waldemar , Wawrzyniak Tomasz 
Published: December 2020

AbstractThe mechanism of glacier recession and its climatic controls are complex processes that differ across the Arctic region. Here, we investigate factors influencing front variations of Hansbreen, a glacier terminated in Hornsund fjord (SW Svalbard). We apply remote sensing data to observe glacier front fluctuations between 1992 and 2015 and compare them to atmospheric and oceanographic data, sea water depth at the terminus and surface velocity. Rate of subglacial meltwater discharge approximated by the seasonal positive degree‐day index (PDD) together with sea thermal conditions appear to be the main factors responsible for the fluctuations of the front of Hansbreen, while water depth at the front plays a secondary role. Taking into account ocean and air thermal conditions, the studied period has been divided into warm, cold and moderate years. The glacier retreated considerably throughout a bedrock overdeepening in the very warm period 2012–2014. This recession coincided with a slower ice flow due to intense subglacial runoff and increased submarine melting. The long‐term retreat was interrupted by glacier advances in colder years, regardless of water depth at the front. The slower recession rate was the combined effect of decreased subglacial melting and increased glacier movement associated with lower subglacial runoff. Although the seasonal PDD is a good indicator of the front fluctuations, the duration of the retreat and advance periods are strongly correlated with the sea surface temperature. Expected climate warming and an increase of water temperature in the West Spitsbergen Current will stimulate further recession of Hansbreen in future.
A Mountain‐Front Recharge Component Characterization Approach Combining Groundwater Age Distributions, Noble Gas Thermometry, and Fluid and Energy Transport Modeling
Authors: Markovich Katherine H. , Condon Laura E. , Carroll Kenneth C. , Purtschert Roland , McIntosh Jennifer C. 
Published: December 2020

AbstractMountain‐front recharge (MFR), or all inflow to a basin‐fill aquifer with its source in the mountain block, is an important component of recharge to basin‐fill aquifer systems. Distinguishing and quantifying the surface from subsurface components of MFR is necessary for water resource planning and management, particularly as climate change may impact these components in distinct ways. This study tests the hypothesis that MFR components can be distinguished in long‐screened, basin‐fill production wells by (1) groundwater age and (2) the median elevation of recharge. We developed an MFR characterization approach by combining age distributions in six wells using tritium, krypton‐85, argon‐39, and radiocarbon, and median recharge elevations from noble gas thermometry combined with numerical experiments to determine recharge temperature lapse rates using flow and energy transport modeling. We found that groundwater age distributions provided valuable information for characterizing the dominant flow system behavior captured by the basin‐fill production wells. Tracers indicated the presence of old (i.e., no detectable tritium) water in a well completed in weathered bedrock located close to the mountain front. Two production wells exhibited age distributions of binary mixing between modern and a small fraction of old water, whereas the remaining wells captured predominantly modern flow paths. Noble gas thermometry provided important complementary information to the age distributions; however, assuming constant recharge temperature lapse rates produced improbable recharge elevations. Numerical experiments suggest that surface MFR, if derived from snowmelt, can locally suppress water table temperatures in the basin‐fill aquifer, with implications for recharge elevations estimated from noble gas thermometry.
Peroxiredoxin 4 protects against ovarian ageing by ameliorating d-galactose-induced oxidative damage in mice
Authors: Liang Xiuru , Yan Zhengjie , Ma Weiwei , Qian Yi , Zou Xiaofei , Cui Yugui , Liu Jiayin , Meng Yan 
Published: December 2020

AbstractPeroxiredoxin 4 (Prdx4), a member of the Prdx family, is a vital ER-resident antioxidant in cells. As revealed in our previous study, Prdx4 expression was detected in ovarian granulosa cells and was closely related to ovarian function. This research aimed to explore the effect and underlying molecular mechanism of the protective role of Prdx4 against d-gal-induced ovarian ageing in mice. The d-gal-induced ovarian ageing model has been extensively used to study the mechanisms of premature ovarian failure (POF). In this study, adult Prdx4−/− and wild-type mice were intraperitoneally injected with d-gal (150 mg/kg/day) daily for 6 weeks. Ovarian function, granulosa cell apoptosis, oxidative damage and ER stress in the ovaries were evaluated in the two groups. Ovarian weight was significantly lower, the HPO axis was more strongly disrupted, and the numbers of atretic follicles and apoptotic granulosa cells were obviously higher in Prdx4−/− mice. In addition, Prdx4−/− mice showed increased expression of oxidative damage-related factors and the ovarian senescence-related protein P16. Moreover, the levels of the proapoptotic factors CHOP and activated caspase-12 protein, which are involved in the ER stress pathway, and the level of the apoptosis-related BAX protein were elevated in the ovaries of Prdx4−/− mice. Thus, d-gal-induced ovarian ageing is accelerated in Prdx4−/− mice due to granulosa cell apoptosis via oxidative damage and ER stress-related pathways, suggesting that Prdx4 is a protective agent against POF.
Automated calculation and convergence of defect transport tensors
Authors: Swinburne Thomas D. , Perez Danny 
Published: December 2020

AbstractDefect diffusion is a key process in materials science and catalysis, but as migration mechanisms are often too complex to enumerate a priori, calculation of transport tensors typically have no measure of convergence and require significant end-user intervention. These two bottlenecks prevent high-throughput implementations essential to propagate model-form uncertainty from interatomic interactions to predictive simulations. In order to address these issues, we extend a massively parallel accelerated sampling scheme, autonomously controlled by Bayesian estimators of statewide sampling completeness, to build atomistic kinetic Monte Carlo models on a state-space irreducible under exchange and space group symmetries. Focusing on isolated defects, we derive analytic expressions for drift and diffusion coefficients, providing a convergence metric by calculating the Kullback–Leibler divergence across the ensemble of diffusion processes consistent with the sampling uncertainty. The autonomy and efficacy of the method is demonstrated on surface trimers in tungsten and Hexa-interstitials in magnesium oxide, both of which exhibit complex, correlated migration mechanisms.
Species-specific bioaccumulation of trace metals among fish species from Xincun Lagoon, South China Sea
Authors: Feng Weihua , Wang Zhifu , Xu Hengtao , Zhang Dongrong , Zhang Haifeng , Zhu Wenzhuo 
Published: December 2020

AbstractXincun Lagoon is an important fishing area in northern Hainan Island, China. It has long been exposed to pollutants from local sewage, breeding cages and fishing boats, resulting in serious pollution threats to the survival of fish. In this study, we examined the concentrations of seven trace metals (Cu, Pb, Zn, Cd, Hg, As and Cr) in sixteen economic fish species collected from Xincun Lagoon and their exposed environment (water and sediment). The concentrations of Pb and Zn in the water column were higher than the safety threshold stipulated by Chinese legislation, while the contents of all examined metals in the sediment and fish species were lower than the legislative thresholds set by China and international organizations. The contents of trace metals in the fish species in high trophic levels or those that prefer to live in/on the sediment layer were significantly higher than those in other trophic levels and pelagic/subbenthic fish, these species had homogeneous anthropogenic pollution sources for Cu, Zn, Cd, Hg and As. Our results show that the trace metal contents in fish were mainly affected by trophic level and habitat preference. The contribution of metal exposure from the sediment to metal accumulation in fish was lower than that in water, especially for the Cd and Hg in the sediment. These results provide valuable information for further understanding the species-specific patterns of metal accumulation in fish and the development of targeted conservation measures for the environment and fish consumers.
Sonodynamic therapy in combination with photodynamic therapy shows enhanced long-term cure of brain tumor
Authors: Borah Ballav M. , Cacaccio Joseph , Durrani Farukh A. , Bshara Wiam , Turowski Steven G. , Spernyak Joseph A. , Pandey Ravindra K. 
Published: December 2020

AbstractThis article presents the construction of a multimodality platform that can be used for efficient destruction of brain tumor by a combination of photodynamic and sonodynamic therapy. For in vivo studies, U87 patient-derived xenograft tumors were implanted subcutaneously in SCID mice. For the first time, it has been shown that the cell-death mechanism by both treatment modalities follows two different pathways. For example, exposing the U87 cells after 24 h incubation with HPPH [3-(1′-hexyloxy)ethyl-3-devinyl-pyropheophorbide-a) by ultrasound participate in an electron-transfer process with the surrounding biological substrates to form radicals and radical ions (Type I reaction); whereas in photodynamic therapy, the tumor destruction is mainly caused by highly reactive singlet oxygen (Type II reaction). The combination of photodynamic therapy and sonodynamic therapy both in vitro and in vivo have shown an improved cell kill/tumor response, that could be attributed to an additive and/or synergetic effect(s). Our results also indicate that the delivery of the HPPH to tumors can further be enhanced by using cationic polyacrylamide nanoparticles as a delivery vehicle. Exposing the nano-formulation with ultrasound also triggered the release of photosensitizer. The combination of photodynamic therapy and sonodynamic therapy strongly affects tumor vasculature as determined by dynamic contrast enhanced imaging using HSA-Gd(III)DTPA.
Controlling biodiversity impacts of future global hydropower reservoirs by strategic site selection
Authors: Dorber Martin , Arvesen Anders , Gernaat David , Verones Francesca 
Published: December 2020

AbstractFurther reservoir-based hydropower development can contribute to the United Nations’ sustainable development goals (SDGs) on affordable and clean energy, and climate action. However, hydropower reservoir operation can lead to biodiversity impacts, thus interfering with the SDGs on clean water and life on land. We combine a high-resolution, location-specific, technical assessment with newly developed life cycle impact assessment models, to assess potential biodiversity impacts of possible future hydropower reservoirs, resulting from land occupation, water consumption and methane emissions. We show that careful selection of hydropower reservoirs has a large potential to limit biodiversity impacts, as for example, 0.3% of the global hydropower potential accounts for 25% of the terrestrial biodiversity impact. Local variations, e.g. species richness, are the dominant explanatory factors of the variance in the quantified biodiversity impact and not the mere amount of water consumed, or land occupied per kWh. The biodiversity impacts are mainly caused by land occupation and water consumption, with methane emissions being much less important. Further, we indicate a trade-off risk between terrestrial and aquatic biodiversity impacts, as due to the weak correlation between terrestrial and aquatic impacts, reservoirs with small aquatic biodiversity impacts tend to have larger terrestrial impacts and vice versa.
Prognostic value of neutrophil/lymphocyte ratio and mean platelet volume/platelet ratio for 1-year mortality in critically ill patients
Authors: Ham Sung Yeon , Yoon Hei Jin , Nam Sang Beom , Yun Byung Hwan , Eum Darhae , Shin Cheung Soo 
Published: December 2020

AbstractSeveral studies have reported that the neutrophil to lymphocyte ratio (NLR) and mean platelet volume (MPV) are associated with poor prognosis. This study investigated whether NLR and/or the MPV/platelet ratio could function as predictive markers of mortality in critically ill patients. We retrospectively reviewed 1,154 patients admitted to the intensive care unit (ICU) between January 2017 and December 2017. Patients were divided into 2 groups according to 1-year mortality. We compared the NLR and MPV/platelet ratio on each day of ICU admission. Patients were classified into tertiles based on their NLR and MPV/platelet ratios, and the incidence of 1-year mortality was compared. Kaplan–Meier survival curves were plotted to evaluate their potential as prognostic factors for 1-year mortality. The NLR and MPV/platelet ratio were higher in the non-survivor group than in the survivor group. The incidence of 1-year mortality was the highest in the third tertile for both the NLR and MPV/platelet ratio. The MPV/platelet ratio was an independent predictor for 1-year mortality based on the Kaplan–Meier survival analysis. Our data showed that the MPV/platelet ratio is a predictive factor for 1-year mortality in critically ill patients.
YY1 directly interacts with myocardin to repress the triad myocardin/SRF/CArG box-mediated smooth muscle gene transcription during smooth muscle phenotypic modulation
Authors: Zheng Jian-Pu , He Xiangqin , Liu Fang , Yin Shuping , Wu Shichao , Yang Maozhou , Zhao Jiawei , Dai Xiaohua , Jiang Hong , Yu Luyi , Yin Qin , Ju Donghong , Li Claire , Lipovich Leonard , Xie Youming , Zhang Kezhong , Li Hui J. , Zhou Jiliang , Li Li 
Published: December 2020

AbstractYin Yang 1 (YY1) regulates gene transcription in a variety of biological processes. In this study, we aim to determine the role of YY1 in vascular smooth muscle cell (VSMC) phenotypic modulation both in vivo and in vitro. Here we show that vascular injury in rodent carotid arteries induces YY1 expression along with reduced expression of smooth muscle differentiation markers in the carotids. Consistent with this finding, YY1 expression is induced in differentiated VSMCs in response to serum stimulation. To determine the underlying molecular mechanisms, we found that YY1 suppresses the transcription of CArG box-dependent SMC-specific genes including SM22α, SMα-actin and SMMHC. Interestingly, YY1 suppresses the transcriptional activity of the SM22α promoter by hindering the binding of serum response factor (SRF) to the proximal CArG box. YY1 also suppresses the transcription and the transactivation of myocardin (MYOCD), a master regulator for SMC-specific gene transcription by binding to SRF to form the MYOCD/SRF/CArG box triad (known as the ternary complex). Mechanistically, YY1 directly interacts with MYOCD to competitively displace MYOCD from SRF. This is the first evidence showing that YY1 inhibits SMC differentiation by directly targeting MYOCD. These findings provide new mechanistic insights into the regulatory mechanisms that govern SMC phenotypic modulation in the pathogenesis of vascular diseases.