bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Temporal Variability of High‐Altitude Reflection Potential Structures (HARPS)
Authors: Glocer Alex , Collinson Glyn A. , Conway Rachel , Barjatya Aroh , Michell Robert , Xu Shaosui , Mitchell David , Robertson Ellen , Chornay Dennis , Khazanov George 
Published: November 2024

AbstractHigh Altitude Reflection Potential Structures (HARPS) with typical magnitudes of a few tens of volts have been frequently detected above Earth's sunlit polar cap. They are thought to be electrostatic structures forming between 1 to several Earth radii in altitude. Previous satellite studies have been unable to probe the temporal variability of their magnitude owing to their fast motion through the region of observation. In this study, we present a 10 min time series of observations of HARPS from NASA's Endurance sounding rocket. These observations were made from a spatially localized region, enabling the first experimental investigation of the temporal variability of HARPS. The magnitude of the potential drop was found to vary unexpectedly rapidly between 15.5 and 23.7 V on a time cadence of s. We additionally find an inverse correlation between polar rain precipitating flux and reflection potential magnitude, consistent with predictions from prior theoretical work.
Effects of a Solar Flare on Global Propagation of Extremely Low Frequency Waves
Authors: Ostrowski M. , Gołkowski M. , Kubisz J. , Nieckarz Z. , Michalec A. , Mlynarczyk J. , Lichtenberger J. , Maxworth A. 
Published: December 2024

AbstractSolar flares have profound impacts on the lower ionosphere and long‐distance radio propagation. Extremely low frequency (ELF: 3–3,000 Hz) waves are challenging to observe and experience unique interactions with the lower ionosphere. The primary natural sources of ELF waves are thunderstorm lightnings across the globe. Using a newly developed azimuth determination technique and improved observation hardware we show that ELF attenuation in the Earth‐Ionosphere spherical cavity decreases and propagation velocity increases under the influence of an M‐class solar flare. Using a two‐parameter model of the lower ionosphere, the observations are shown to be consistent with increased electron density and sharper gradients in the D‐region resulting from X‐ray radiation. The sharper electron density gradient is primarily responsible for the propagation velocity increase, suggesting a unique capability that ELF observations can bring to global remote sensing of the lower ionosphere under space weather perturbations.
Investigating the Spatiotemporal Development of Substorm Expansion Phase Aurora: Successive Onsets or Poleward Boundary Intensifications?
Authors: Yadav Sneha , Lyons Larry R. , Nishimura Yukitoshi , Liu Jiang , Tian Sheng , Zou Ying , Donovan Eric F. 
Published: December 2024

AbstractFollowing the auroral substorm onset, the active aurora undergoes expansion, which can vary in spatial and temporal extent. The spatiotemporal development of the expansion phase active aurora is controlled by new auroral intensifications that often follow the initial onset. Using seven examples, we investigate the nature of these new auroral intensifications and address a question: are they new auroral onsets, that is, “successive onsets” or poleward‐boundary intensifications (PBIs) and ensuing auroral streamers? We observed events that included both types of auroral features—successive onsets and PBIs—and their combinations. For multiple‐onset substorms, successive onsets may occur eastward, westward, and poleward of the initial onset, resulting in a diverse range of expansion phase spatial extent and durations. Single‐onset substorms show only one auroral onset, but their spatiotemporal development can resemble that of multiple‐onset substorms. However, the additional activations are mainly PBIs and subsequent streamers. In some cases, PBIs undergo explosion, leading to a rapid poleward and azimuthal expansion of the aurora, resembling the auroral substorm onset. A prolonged sequence of PBIs and its longitudinal extension can contribute significantly to the spatiotemporal development of substorms expansion phase. Results suggest that post‐onset flow channels drive the spatiotemporal development of the substorm expansion phase by (a) triggering successive onsets and (b) inducing bursts of PBIs and their prolonged sequence. We speculate that post‐onset flow channels likely originate from the polar cap, but more evaluation is required. Our findings highlight the significance of examining imager data before solely relying on magnetometers to identify substorm onsets.
Categorization of Electron Isotropy Boundary Patterns: ELFIN and POES Observations
Authors: Artemyev A. V. , Sergeev V. A. , Angelopoulos V. , Zhang X.‐J. , Wilkins C. 
Published: November 2024

AbstractMagnetic field‐line curvature scattering (FLCS) of energetic particles in the equatorial magnetotail results in isotropization of pitch‐angle distributions, loss‐cone filling, and precipitation above a minimum energy at a given latitude. At a fixed energy, the lowest latitude of isotropization is the isotropy boundary (IB) for that energy. Nominally, the IB (latitude) exhibits a characteristic energy dependence due to the monotonic variation of the equatorial magnetic field intensity with radial distance. Deviations from this nominal IB dispersion can occur if the radial variation (spatial or temporal) is non‐mononotic and/or if other precipitation mechanisms prevail. With its sensitive and detailed measurements of electron spectra up to relativistic energies, ELFIN's recent observations reveal a variety of electron IBe patterns near magnetic midnight which are repeatable enough to warrant classification. This study aims to categorize the various IBe patterns observed by ELFIN's high‐fidelity but short lived dataset (a few months), compare them with simultaneous nearby POES observations, which are made with a limited energy coverage and resolution but last for decades, and discuss their possible interpretation. The general agreement between ELFIN and POES IB observations indicate a relatively large‐scale nature of IBe patterns. Surprisingly, there exists a large number (up to 2/3 of all events) of non‐monotonic‐or steep/multiple‐IB patterns. This suggest an abundance of non‐trivial tail current sheet structures or a mixed contribution of two mechanisms in the vicinity of IBe in these cases.
Contribution of Anthropogenic and Lithogenic Aerosol Fe in the East China Sea
Authors: Hsieh Chih‐Chiang , Ho Tung‐Yuan 
Published: December 2024

AbstractAerosol deposition is one of the major processes providing bioavailable Fe to the surface ocean. However, the quantification of aerosol Fe flux in the surface ocean is highly challenging operationally. In this study, we measured both Fe isotopic composition and specific elemental ratios in 5 size‐fraction aerosols collected over the East China Sea (ECS) to quantify the relative contribution of lithogenic and anthropogenic aerosol Fe. Both the isotopic and elemental ratios indicate that anthropogenic aerosol Fe mainly originates from high‐temperature combustion activities with the end member of the δ56Fe to be −4.5‰. We found that the Cd/Ti ratio is a much more reliable proxy to quantify the contribution of anthropogenic aerosol Fe in coarse aerosols than δ56Fe in the ECS. Attributed to extremely high deposition velocities and high total Fe concentrations for large size aerosols, lithogenic aerosols are still the dominant dissolved aerosol Fe source in the ECS.
Influence of the Southern Hemisphere Supergyre on Antarctic Intermediate Water Properties in CMIP6 Models
Authors: Meuriot Ophélie , Lique Camille , Plancherel Yves 
Published: December 2024

AbstractThe supergyre in the Southern Hemisphere is thought to connect the Atlantic, Indian, and Pacific subtropical gyres together. The aim of the study is to investigate whether the supergyre is identifiable in the Coupled Model Intercomparison Project Phase 6 (CMIP6) models and in the Estimating the Circulation and Climate of the Ocean (ECCO) reanalysis and to evaluate the influence of the supergyre on the properties of Antarctic Intermediate Water (AAIW), the dominant water mass at intermediate depths in the Southern Hemisphere. CMIP6 models and ECCO are in agreement at the surface with supergyres connected across all basins but present some differences at depth in both position and strength. AAIW core properties (temperature and salinity) present a high degree of similarity across basins within the supergyre but not outside of it. By the end of the century, the supergyre reduces in size and intensifies at intermediate depths, and the AAIW core depth warms in all basins and freshens in the Pacific although no clear trend in salinity can be found in the Atlantic and Indian basins in the SSP5‐8.5 scenario. The high degree of similarity across basins within the supergyre is maintained in the future scenario. The results suggest that by connecting the basins together at intermediate depth, the supergyre plays a key role in circulating and homogenizing the AAIW core properties. Our results emphasize the role of the supergyre in circulating water masses at the surface and intermediate depths in CMIP6 models and hence its importance to the global circulation.
Prolonged Fluvial Activity Revealed by Mapping and Analyses of Valley Networks in the Northwestern Hellas Region, Mars
Authors: Xia Miaosen , Zhao Jiannan , Shi Yutong , Lan Qin , Wueller Lukas , Hiesinger Harald , Xiao Long 
Published: November 2024

AbstractValley networks (VNs) on Mars are crucial for understanding the Martian hydrologic and climatic history. However, the limited resolution of remote sensing data hindered the complete identification of Martian VNs, affecting our understanding of the formation and duration of VNs as well as their climatic significance. In this study, we utilized high‐resolution imaging and topographic data to conduct detailed mapping and investigations of the VNs around the northwestern margin of the Hellas basin, the largest impact basin and major sedimentary sink in the Martian southern highlands. We identified a total of 911 VNs with a cumulative length of 32,086.3 km, more than twice that of previous mapping results. Additionally, we analyzed the morphological parameters of VNs, including stream order, sinuosity, junction angle, stream slope, etc., investigated their geomorphologic characteristics, and determined their formation ages. We propose that occasional precipitation and regional groundwater fostered the formation of well‐developed VNs and a “Hellas Ocean” in the Noachian Period. The main fluvial activity occurred during ∼3.9–3.2 Ga. Subsequently, the climate transitioned from warm and semiarid to cold and arid during the Noachian‐Hesperian transition, leading to the evaporation of the “Hellas Ocean.” In the Amazonian, some small simple valleys formed during ∼2.1–1.0 Ga with the supply of meltwater associated with obliquity‐controlled glacial processes. These results reveal prolonged fluvial activity in the northwestern Hellas region with diverse water sources under changing climatic conditions, which make the region a very promising candidate for future in situ exploration missions.
Universal Coherence of Elements in River‐Fed Earth‐Human Systems
Authors: Wang Yidi , Zhang Qian , Sun Weiling , Shan Yingchun , Wang Ting , Zheng Tong , Gao Yuan , Li Bin , Borthwick Alistair G. L. , Ni Jinren 
Published: November 2024

AbstractElements are the indelible imprint left by the Earth on rivers and life entities. Here, we unveil the evident inheritance of persistent elements, from the Earth's upper continental crust, through the Yellow River, to the associated life entities along a 5,200 km continuum of the Mother River of the Chinese nation. In particular, we confirm the coherence of “metal community” composed of more than 60 detected metallic elements throughout water, suspended particulate matter, and sediment in the river, and further extend such elemental correlations to fish species and even the tissues in human body. Our study also reveals an interesting fact that media‐specific metal abundance occurs in a persistent inverse order with metal toxicity, and microbial cells in the river tend to establish their own self‐defense systems against toxic metals through hosting higher‐level resistance genes. These findings not only stress the human needs for integrated trace element provision, but also highlight the fundamental importance of elemental coherence in the river‐coordinated Earth‐life systems for establishing drinking water and dietary standards that benefit ecological and human health.
Validation of Soil Detachment Rate Equations on Spring Thaw Period Slopes: Insights From Sediment Concentration and Transport Capacity
Authors: Zhang Kai , Zhang Chengcheng , Wang Zhidan , Wang Xuan , Sheng Siyuan 
Published: December 2024

AbstractSoil detachment plays a central role in the formulation of soil erosion models, particularly for the simulation and prediction of erosion in cold climates during the thaw period. This research attempts to elucidate the mechanisms of soil detachment on spring thaw period slopes through comprehensive flume experiments, coupled with the application of rare earth element (REE) tracer, investigating the relationships between soil detachment rates, sediment concentration and sediment transport capacity. Observations indicate a nuanced response of soil detachment rate and sediment concentration to scour duration, characterized by an initial increase, subsequent decrease and eventual equilibrium. As thaw depth increases, the primary source of eroded sediment gradually shifts from the upper slope to the mid‐slope. Soil detachment rate was affected by sediment concentration, flow discharge, slope gradient, thawing depth, and slope positions. Furthermore, our analysis reveals a power function relationship (R2 = 0.846) between soil detachment rate, effective shear stress, and sediment transport rate and capacity. These results provide valuable insights into the modeling and prediction of soil erosion processes on brown soil slopes subjected to spring thaw period cycles.
Cytokine-overexpressing dendritic cells for cancer immunotherapy
Authors: Han Joonsu , Wang Hua 
Published: December 2024

AbstractDendritic cells (DCs), the main type of antigen-presenting cells in the body, act as key mediators of adaptive immunity by sampling antigens from diseased cells for the subsequent priming of antigen-specific T and B cells. While DCs can secrete a diverse array of cytokines that profoundly shape the immune milieu, exogenous cytokines are often needed to maintain the survival, proliferation, and differentiation of DCs, T cells, and B cells. However, conventional cytokine therapies for cancer treatment are limited by their low therapeutic benefit and severe side effects. The overexpression of cytokines in DCs, followed by paracrine release or membrane display, has emerged as a viable approach for controlling the exposure of cytokines to interacting DCs and T/B cells. This approach can potentially reduce the necessary dose of cytokines and associated side effects to achieve comparable or enhanced antitumor efficacy. Various strategies have been developed to enable the overexpression or chemical conjugation of cytokines on DCs for the subsequent modulation of DC–T/B-cell interactions. This review provides a brief overview of strategies that enable the overexpression of cytokines in or on DCs via genetic engineering or chemical modification methods and discusses the promise of cytokine-overexpressing DCs for the development of new-generation cancer immunotherapy.
A stearate-rich diet and oleate restriction directly inhibit tumor growth via the unfolded protein response
Authors: Ogura Jumpei , Yamanoi Koji , Ishida Kentaro , Nakamura Eijiro , Ito Shinji , Aoyama Naoki , Nakanishi Yuki , Menju Toshi , Kawaguchi Kosuke , Hosoe Yuko , Taki Mana , Murakami Ryusuke , Yamaguchi Ken , Hamanishi Junzo , Mandai Masaki 
Published: December 2024

AbstractFatty acids are known to have significant effects on the properties of cancer cells. Therefore, these compounds have been incorporated into therapeutic strategies. However, few studies have examined the effects of individual fatty acids and their interactions in depth. This study analyzed the effects of various fatty acids on cancer cells and revealed that stearic acid, an abundant saturated fatty acid, had a stronger inhibitory effect on cell growth than did palmitic acid, which is also an abundant saturated fatty acid, by inducing DNA damage and apoptosis through the unfolded protein response (UPR) pathway. Intriguingly, the negative effects of stearate were reduced by the presence of oleate, a different type of abundant fatty acid. We combined a stearate-rich diet with the inhibition of stearoyl-CoA desaturase-1 to explore the impact of diet on tumor growth. This intervention significantly reduced tumor growth in both ovarian cancer models and patient-derived xenografts (PDXs), including those with chemotherapy resistance, notably by increasing stearate levels while reducing oleate levels within the tumors. Conversely, the negative effects of a stearate-rich diet were mitigated by an oleate-rich diet. This study revealed that dietary stearate can directly inhibit tumor growth through mechanisms involving DNA damage and apoptosis mediated by the UPR pathway. These results suggest that dietary interventions, which increase stearic acid levels while decreasing oleic acid levels, may be promising therapeutic strategies for cancer treatment. These results could lead to the development of new cancer treatment strategies.
ErbB4 precludes the occurrence of PTSD-like fear responses by supporting the bimodal activity of the central amygdala
Authors: Sung Kibong , Jeong Min-Jae , Yoo Taesik , Jung Jung Hoon , Kang Sumin , Yoo Jong-Yeon , Kim Hyun Jin , Park Kyunghyun , Pyo Jung Hyun , Lee Hyun-Yong , Koo Noah , Choi Soo-Hee , Kim Joung-Hun 
Published: December 2024

AbstractPost-traumatic stress disorder (PTSD) often arises after exposure to traumatic events and is characterized by dysregulated fear responses. Although the associations of erb-b2 receptor tyrosine kinase 4 (ErbB4) with various neuropsychiatric diseases, including schizophrenia and bipolar disorder, have been widely examined, the physiological roles of ErbB4 in PTSD and fear responses remain unclear. Using Cre-dependent ErbB4 knockout (KO) mice, we observed that PTSD-like fear behaviors emerged in ErbB4-deficient mice, particularly in inhibitory neurons. Specifically, the loss of ErbB4 in somatostatin-expressing (SST+) neurons was sufficient to induce PTSD-like fear responses. We also adopted the CRISPR/Cas9 system for region-specific KO of ErbB4, which revealed that ErbB4 deletion in SST+ neurons of the lateral division of the amygdala (CeL) caused elevated anxiety and PTSD-like fear generalization. Consistent with its physiological role, ErbB4 expression was diminished in CeLSST neurons from mice that exhibited PTSD-like phenotypes. While fear On and Off cells identified in the CeL displayed distinct responses to conditioned and novel cues, as previously shown, the selectivity of those On and Off cells was compromised in SSTErbB4-/- and stressed mice, which displayed strong fear generalization. Therefore, the bimodal activity that CeL On/Off cells display is likely required for proper discrimination of fearful stimuli from ambient stimuli, which should be sustained by the presence of ErbB4. Taken together, our data substantiate the correlation between PTSD-like fear responses and ErbB4 expression in CeLSST neurons and further underscore the functional effects of ErbB4 in CeLSST neurons, supporting the bimodal responses of CeL neurons.
SurVIndel2: improving copy number variant calling from next-generation sequencing using hidden split reads
Authors: Rajaby Ramesh , Sung Wing-Kin 
Published: December 2024

AbstractDeletions and tandem duplications (commonly called CNVs) represent the majority of structural variations in a human genome. They can be identified using short reads, but because they frequently occur in repetitive regions, existing methods fail to detect most of them. This is because CNVs in repetitive regions often do not produce the evidence needed by existing short reads-based callers (split reads, discordant pairs or read depth change). Here, we introduce a new CNV short reads-based caller named SurVIndel2. SurVindel2 builds on statistical techniques we previously developed, but also employs a novel type of evidence, hidden split reads, that can uncover many CNVs missed by existing algorithms. We use public benchmarks to show that SurVIndel2 outperforms other popular callers, both on human and non-human datasets. Then, we demonstrate the practical utility of the method by generating a catalogue of CNVs for the 1000 Genomes Project that contains hundreds of thousands of CNVs missing from the most recent public catalogue. We also show that SurVIndel2 is able to complement small indels predicted by Google DeepVariant, and the two software used in tandem produce a remarkably complete catalogue of variants in an individual. Finally, we characterise how the limitations of current sequencing technologies contribute significantly to the missing CNVs.
Image-guided optogenetic spatiotemporal tissue patterning using μPatternScope
Authors: Kumar Sant , Beyer Hannes M. , Chen Mingzhe , Zurbriggen Matias D. , Khammash Mustafa 
Published: December 2024

AbstractIn the field of tissue engineering, achieving precise spatiotemporal control over engineered cells is critical for sculpting functional 2D cell cultures into intricate morphological shapes. In this study, we engineer light-responsive mammalian cells and target them with dynamic light patterns to realize 2D cell culture patterning control. To achieve this, we developedμPatternScope (μPS), a modular framework for software-controlled projection of high-resolution light patterns onto microscope samples.μPS comprises hardware and software suite governing pattern projection and microscope maneuvers. Together with a 2D culture of the engineered cells, we utilizeμPS for controlled spatiotemporal induction of apoptosis to generate desired 2D shapes. Furthermore, we introduce interactive closed-loop patterning, enabling a dynamic feedback mechanism between the measured cell culture patterns and the light illumination profiles to achieve the desired target patterning trends. Our work offers innovative tools for advanced tissue engineering applications through seamless fusion of optogenetics, optical engineering, and cybernetics.