bluuebunny/crossref_metadata_2025_split huggingface dataset:
Degree‐Depth Relation for Planetary Gravity Field Model Based on Wavelength
Authors: Deng Qingyun , Li Fei , Yan Jianguo , Ye Mao , Barriot Jean‐Pierre 
Published: May 2022

AbstractIn this paper we investigate the relation between the spherical harmonic (SH) degree of gravity field model and the corresponding depth of the source body. By investigating the gravity of a buried point mass, we find that a relationship can be found between the horizontal extent of the signal (which we assume to be indicative of the wavelength) and the depth of the source. We introduce a threshold to define the gravity anomaly wavelength of an isolated mass body. The region where the gravity anomaly of an isolated mass body is larger than the threshold defines its gravity anomaly wavelength. For an isolated point mass with fixed total mass, the wavelength is a function of the depth. The ratio between the maximum wavelength and the depth at which the maximum wavelength occurs (effective resolvable depth) is invariant provided that the mass and threshold are determined. When this maximum wavelength is larger than the minimum resolvable wavelength of n‐degree gravity field, this isolated mass body is considered as a reliable density feature. Combining the relation between maximum wavelength and effective resolvable depth of the isolated mass body and the relation between minimum resolvable wavelength and SH degree of gravity field, we derived the degree‐depth relation under the limiting resolvable condition: . This relation was validated with Gravity Recovery and Interior Laboratory gravity field data at lunar Orientale basin region, and provided insights for the planetary gravity field analysis.
Regional Geophysics of the Caribbean and Northern South America: Implications for Tectonics
Authors: Barrera‐Lopez Carol V. , Mooney Walter D. , Kaban Mikhail K. 
Published: May 2022

AbstractThe Caribbean plate is an enclosed oceanic basin whose formation and evolution are controversial. In the most commonly accepted model, the Caribbean plate is mainly composed of the Caribbean Large Igneous Province (CLIP) and the buoyant characteristic of this oceanic plateau resisted subduction and allowed an eastward migration to its present position north of South America. In this study, we integrate a broad range of geophysical and geomorphological data to define structural elements and present‐day tectonics of the Caribbean plate and the surrounding region. We present a Bouguer gravity anomaly map and a new crustal thickness map that documents large areas of normal‐thickness oceanic crust within the Venezuela and Colombia basins of the Caribbean plate. Selected cross sections of seismicity and P‐wave anomalies from a seismic tomographic model depict the present‐day geometry of subducting oceanic plates within the Caribbean region. We observe that rather than resisting subduction, as expected for the thick crust of a buoyant large igneous province, the subduction of the Caribbean plate can be traced to a depth of 600 km beneath NW South America. This, together with the crustal thickness map, implies that a significant area of the Caribbean plate, including the subducted portion, is composed of normal‐thickness oceanic crust. As proposed by the Pacific origin model, the Caribbean plate likely migrated eastward from the Pacific Ocean as an oceanic plate mostly with normal‐thickness crust and limited portions of the crust thickened by hot spot volcanism (CLIP).
Mean, Annual, and Interannual Circulation and Volume Transport in the Western Tropical North Pacific From the Western Pacific Ocean State Estimates (WPOSE)
Authors: Schönau Martha C. , Rudnick Daniel L. , Gopalakrishnan Ganesh , Cornuelle Bruce D. , Qiu Bo 
Published: May 2022

AbstractInterannual volume transport anomalies in the far western tropical North Pacific were calculated using the Western Pacific Ocean State Estimates (WPOSE; 2009–2017; 115°E−170°E, 15°S–27°N) to assess the magnitude, phase, and vertical structure of volume transport, and the relationship of interannual transport to the El Niño‐Southern Oscillation phenomena. The mean velocity and thermohaline structure for the WPOSE were verified using Argo climatology and autonomous glider observations. Transport was calculated for both an upper layer (surface‐26 kg m−3) and a lower layer (26–27.3 kg m−3). Annual volume transport anomalies were small north of 8°N but varied by 50% of the mean volume transport between the equator and 8°N. Interannual anomalies exceeded annual anomalies throughout the region. Volume transports of the North Equatorial Current, the Mindanao Current, and the South Equatorial Current/New Guinea Coastal Undercurrent increased beginning in September 2014, leading to a large increase in transport in the North Equatorial Counter Current before the mature phase of El Niño in 2015/2016. The increase in transport was related to the meridional gradient in thermocline depth centered at 5°N at the southern part of the Mindanao Dome, where extreme shoaling of the thermocline took place. Lower‐layer volume transports were not always in phase with those of the upper‐layer and made considerable contributions to total transport variability.
Effects of Lake Nam Co and Surrounding Terrain on Extreme Precipitation Over Nam Co Basin, Tibetan Plateau: A Case Study
Authors: Zhao Zhizhan , Huang Anning , Ma Weiqiang , Wu Yang , Wen Lijuan , Lazhu  , Gu Chunlei 
Published: May 2022

AbstractThousands of lakes and complex topography on Tibetan Plateau (TP) have important impacts on the local weather and climate, especially extreme weather events. In this study, the Weather Research and Forecasting model was adopted to quantify the impacts of Lake Nam Co (LNC) and surrounding topography on the extreme snowfall event over Nam Co basin on 24 October 2006 based on numerical experiments. The accumulated precipitation of 12 hr in this event is characterized by a maximum precipitation center with an intensity exceeding 20 mm over eastern LNC and downwind regions. Results show that the precipitation regionally averaged over eastern LNC and downstream regions can be reduced by 53%, 26%, and 68% when LNC, surrounding terrain, and both of them are absent, respectively, suggesting that LNC plays a dominant role in the formation of this event while the surrounding mountains further amplify the lake effect precipitation/snow over the downwind of LNC. Mechanism analysis indicates that the low‐level convective instability and water vapor convergence induced by LNC are essential for the formation of this extreme snowfall event, while the wind deflection and topographic lifting further strengthen the precipitation over the downwind of LNC and shift the snow belt distribution. This study is not only important to deepen the understanding of the complex interactions between the lake and orography and their combined influences on regional extreme precipitation, but also helpful for further improving the refined forecasting of the extreme precipitation induced by the lake and surrounding terrain in other regions over TP.
Seasonal Variations of Gravity Wave Induced Thermal and Constituent Diffusivities in the Mesopause Region Above Ft. Collins, CO (40.6°N, 105.1°W)
Authors: Gardner Chester S. , She Chiao‐Yao , Yan Zhao‐Ai 
Published: May 2022

AbstractQuasi‐random vertical displacement fluctuations, caused by the spectrum of non‐breaking gravity waves, mix the atmosphere, similar to turbulence, which induces significant vertical transport of heat and constituents in the upper atmosphere. Multi‐decade observations of temperature, made between 85 and 100 km with a Na lidar at Colorado State University (CSU, 40.6°N, 105.1°W), are used to derive the seasonal variations of the wave‐induced thermal (KH) and constituent (KWave) diffusivities. Both show strong annual oscillations with maxima in winter, which increase with increasing altitude. KH and KWave exhibit summer minima of ∼40 and ∼70 m2s−1, respectively, that are approximately constant with altitude. In winter, KH varies from ∼50 at 85 to ∼180 m2s−1 at 100 km, while KWave varies from ∼110 at 85 to ∼340 m2s−1 at 100 km. These values are much larger than the eddy diffusivity (Kzz ∼ 35 m2s−1) predicted for this site by the Whole Atmosphere Community Climate Model. The CSU diffusivities are comparable to similar measurements made at other mid‐latitude mountain sites in both hemispheres, and derived from global observations of atomic O. However, the seasonal variations differ from the O observations, which may reflect differences in wave sources at these sites and the different approaches employed to derive the wave diffusivities. Even so, the CSU results demonstrate that heat and constituent transport by unresolved, non‐breaking gravity waves are important processes that need to be incorporated in global chemistry models to properly characterize the thermal and constituent structure of the upper atmosphere.
Marine Ecosystem Changepoints Spread Under Ocean Warming in an Earth System Model
Authors: Cael B. B. , Begouen Demeaux Charlotte , Henson Stephanie , Stock Charles A. , Taboada Fernando González , John Jasmin G. , Barton Andrew D. 
Published: May 2022

AbstractSudden shifts in marine plankton communities in response to environmental changes are of special concern because of their low predictability and high potential impacts on ocean ecosystems. We explored how anthropogenic climate change influences the spatial extent and frequency of changepoints in plankton populations by comparing the behavior of a plankton community in a coupled Earth system model under pre‐industrial, historical 20th century, and projected 21st century forcing. The ocean areas where surface ocean temperature, nutrient concentrations, and different plankton types exhibited changepoints expanded over time. In contrast, regional hotspots where changepoints occur frequently largely disappeared. Heterotrophy and larger organism sizes were associated with more changepoints. In the pre‐industrial and 20th century, plankton changepoints were associated with shifts in physical fronts, and more often with changepoints for iron and silicate than for nitrate and phosphate. In the 21st century, climate change disrupts these interannual‐variability‐driven changepoint patterns. Together, our results suggest anthropogenic climate change may drive less frequent but more widespread changepoints simultaneously affecting several components of pelagic food webs.
Modelling M(3000)F2 at an African Equatorial Location for Better IRI‐Model Prediction
Authors: Adebesin B. O. , Adeniyi J. O. , Afolabi P. A. , Ikubanni S. O. , Adebiyi S. J. 
Published: May 2022

AbstractThe F2‐layer propagation factor M(3000)F2 is important to ionospheric studies owning to its use in high High frequency radio communication/ionospheric modeling. This study focused on reducing the shortcomings in the use of M(3000)F2 IRI‐model for obtaining hmF2, especially in the African equatorial region, by obtaining an empirical “constructed model” (M(3000)F2CM) using the Korhogo (geomag. lat. 1.26°S, long. 67.38°E, dip. −0.67°S) data (M(3000)F2KOR). The data spans 8 years (1993–2000) under magnetically quiet conditions (Ap < 20 nT). The Regression method technique was used in obtaining the M(3000)F2CM. The regression coefficient (R2) for the M(3000)F2KOR versus F10.7 relationship was stronger during the solstices. The associated diurnal equations obtained for all seasons from the regression plot of the M(3000)F2KOR‐F10.7 relationship were used to obtained the constructed model equation given by M(3000)F2CM(m)i = ai(m) ∗ (F10.7) + bi(m), which allows the prediction of diurnal, seasonal and solar cycle variation of the M(3000)F2 parameter. M(3000)F2CM predicted well when tested at different solar activities. Generally, M(3000)F2CM performed reasonably well in comparison with the IRI model (M(3000)F2IRI) when validated with Ouagadougou (lat. 0.59°S, long. 71.46°E) observed data ‐ M(3000)F2OUA. The percentage deviation of M(3000)F2CM versus M(3000)F2OUA during high solar activity and low solar activity ranges from −10.8–5.3/−7.6–15.8 for solstices/equinoxes; whereas percentage deviation of M(3000)F2IRI versus M(3000)F2OUA spans −15.5–9.2 and −9.7–17.7 in similar order of seasons. The characteristic diurnal post‐sunset drop in M(3000)F2, a prominent feature of the equatorial ionosphere is well captured by the empirical model. These results suggest that the new model has a measure of potential for its use in the equatorial African region.
A Two‐Part Model for Wave‐Sea Ice Interaction: Attenuation and Break‐Up
Authors: Kousal J. , Voermans J. J. , Liu Q. , Heil P. , Babanin A. V. 
Published: May 2022

AbstractWaves and sea ice form a closely coupled system: waves govern sea ice through stress, floe break‐up, and wave‐induced currents, while sea ice affects waves through attenuation and reflection. Wave‐induced sea ice break‐up is particularly important as it can regulate air‐sea interaction and consequently also regulate the growth and melt of sea ice. This coupled nature is complex and generally, especially at the large scale, neglected in modeling of the polar climate system. Here, we explore a novel way of coupling through wave‐induced ice break‐up, and conduct a case study for the Antarctic summer of 2019/2020. Our modeling approach builds upon previous investigations as follows: (a) sea ice takes a binary form, either “broken” or ”unbroken,” (b) waves may break sea ice, transitioning it from unbroken to broken, (c) a threshold separating breaking and nonbreaking wave fields is used to identify when this occurs, (c) two modes of attenuation for waves in ice (dependent upon the ice state), representing the observed on/off switch in wave attenuation. By characterizing wave attenuation and sea ice break‐up as described above, we achieve two‐way wave‐sea ice coupling, thereby allowing wave‐sea ice feedbacks. This model is limited to the ice‐melt season as refreeze is not represented here. We demonstrate that our model can simulate both the wavefield in and the evolution of the Marginal Ice Zone. Our results show the validity of empirically derived wave‐induced sea ice break‐up threshold, and substantiate that waves have a critical influence on the morphology of the Marginal Ice Zone.
Wnt/beta-catenin signaling confers ferroptosis resistance by targeting GPX4 in gastric cancer
Authors: Wang Yue , Zheng Lixin , Shang Wenjing , Yang Zongcheng , Li Tongyu , Liu Fen , Shao Wei , Lv Lin , Chai Li , Qu Lingxin , Xu Qing , Du Jie , Liang Xiuming , Zeng Jiping , Jia Jihui 
Published: May 2022

AbstractThe development of chemotherapy resistance is the most vital obstacle to clinical efficacy in gastric cancer (GC). The dysregulation of the Wnt/beta-catenin signaling pathway is critically associated with GC development and chemotherapy resistance. Ferroptosis is a form of regulated cell death, induced by an iron-dependent accumulation of lipid peroxides during chemotherapy. However, whether the Wnt/beta-catenin signaling directly controls resistance to cell death, remains unclear. Here, we show that the activation of the Wnt/beta-catenin signaling attenuates cellular lipid ROS production and subsequently inhibits ferroptosis in GC cells. The beta-catenin/TCF4 transcription complex directly binds to the promoter region of GPX4 and induces its expression, resulting in the suppression of ferroptotic cell death. Concordantly, TCF4 deficiency promotes cisplatin-induced ferroptosis in vitro and in vivo. Thus, we demonstrate that the aberrant activation of the Wnt/beta-catenin signaling confers ferroptosis resistance and suggests a potential therapeutic strategy to enhance chemo-sensitivity for advanced GC patients.
Characterisation of a novel OPA1 splice variant resulting in cryptic splice site activation and mitochondrial dysfunction
Authors: Harvey Joshua Paul , Yu-Wai-Man Patrick , Cheetham Michael Edward 
Published: May 2022

AbstractAutosomal dominant optic atrophy (DOA) is an inherited optic neuropathy that results in progressive, bilateral visual acuity loss and field defects. OPA1 is the causative gene in around 60% of cases of DOA. The majority of patients have a pure ocular phenotype, but 20% have extra-ocular features (DOA +). We report on a patient with DOA + manifesting as bilateral optic atrophy, spastic paraparesis, urinary incontinence and white matter changes in the central nervous system associated with a novel heterozygous splice variant NM_015560.2(OPA1):c.2356-1 G > T. Further characterisation, which was performed using fibroblasts obtained from a skin biopsy, demonstrated that this variant altered mRNA splicing of the OPA1 transcript, specifically a 21 base pair deletion at the start of exon 24, NM_015560.2(OPA1):p.Cys786_Lys792del. The majority of variant transcripts were shown to escape nonsense-mediated decay and modelling of the predicted protein structure suggests that the in-frame 7 amino acid deletion may affect OPA1 oligomerisation. Fibroblasts carrying the c.2356-1 G > T variant demonstrated impaired mitochondrial bioenergetics, membrane potential, increased cell death, and disrupted and fragmented mitochondrial networks in comparison to WT cells. This study suggests that the c.2356-1 G > T OPA1 splice site variant leads to a cryptic splice site activation and may manifest in a dominant-negative manner, which could account for the patient’s severe syndromic phenotype.
Structural complexity in ramp-compressed sodium to 480 GPa
Authors: Polsin Danae N. , Lazicki Amy , Gong Xuchen , Burns Stephen J. , Coppari Federica , Hansen Linda E. , Henderson Brian J. , Huff Margaret F. , McMahon Malcolm I. , Millot Marius , Paul Reetam , Smith Raymond F. , Eggert Jon H. , Collins Gilbert W. , Rygg J. Ryan 
Published: May 2022

AbstractThe properties of all materials at one atmosphere of pressure are controlled by the configurations of their valence electrons. At extreme pressures, neighboring atoms approach so close that core-electron orbitals overlap, and theory predicts the emergence of unusual quantum behavior. We ramp-compress monovalent elemental sodium, a prototypical metal at ambient conditions, to nearly 500 GPa (5 million atmospheres). The 7-fold increase of density brings the interatomic distance to 1.74 Å well within the initial 2.03 Å of the Na+ ionic diameter, and squeezes the valence electrons into the interstitial voids suggesting the formation of an electride phase. The laser-driven compression results in pressure-driven melting and recrystallization in a billionth of a second. In situ x-ray diffraction reveals a series of unexpected phase transitions upon recrystallization, and optical reflectivity measurements show a precipitous decrease throughout the liquid and solid phases, where the liquid is predicted to have electronic localization. These data reveal the presence of a rich, temperature-driven polymorphism where core electron overlap is thought to stabilize the formation of peculiar electride states.
An ultrastrongly coupled single terahertz meta-atom
Authors: Rajabali Shima , Markmann Sergej , Jöchl Elsa , Beck Mattias , Lehner Christian A. , Wegscheider Werner , Faist Jérôme , Scalari Giacomo 
Published: May 2022

AbstractFree-space coupling to subwavelength individual optical elements is a central theme in quantum optics, as it allows the control over individual quantum systems. Here we show that, by combining an asymmetric immersion lens setup and a complementary resonating metasurface we are able to perform terahertz time-domain spectroscopy of an individual, strongly subwavelength meta-atom. We unravel the linewidth dependence as a function of the meta-atom number indicating quenching of the superradiant coupling. On these grounds, we investigate ultrastrongly coupled Landau polaritons at the single resonator level, measuring a normalized coupling ratio $$\frac{{{\Omega }}}{\omega }=0.6$$

Ω

ω

=
0.6
. Similar measurements on a lower density two dimensional electron gas yield a coupling ratio $$\frac{{{\Omega }}}{\omega }=0.33$$

Ω

ω

=
0.33
with a cooperativity C = 94. Our findings pave the way towards the control of ultrastrong light-matter interaction at the single electron/ resonator level. The proposed technique is way more general and can be useful to characterize the complex conductivity of micron-sized samples in the terahertz domain.
Plasma membrane phosphatidylinositol (4,5)-bisphosphate is critical for determination of epithelial characteristics
Authors: Kanemaru Kaori , Shimozawa Makoto , Kitamata Manabu , Furuishi Rikuto , Kayano Hinako , Sukawa Yui , Chiba Yuuki , Fukuyama Takatsugu , Hasegawa Junya , Nakanishi Hiroki , Kishimoto Takuma , Tsujita Kazuya , Tanaka Kazuma , Itoh Toshiki , Sasaki Junko , Sasaki Takehiko , Fukami Kiyoko , Nakamura Yoshikazu 
Published: May 2022

AbstractEpithelial cells provide cell-cell adhesion that is essential to maintain the integrity of multicellular organisms. Epithelial cell-characterizing proteins, such as epithelial junctional proteins and transcription factors are well defined. However, the role of lipids in epithelial characterization remains poorly understood. Here we show that the phospholipid phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] is enriched in the plasma membrane (PM) of epithelial cells. Epithelial cells lose their characteristics upon depletion of PM PI(4,5)P2, and synthesis of PI(4,5)P2 in the PM results in the development of epithelial-like morphology in osteosarcoma cells. PM localization of PARD3 is impaired by depletion of PM PI(4,5)P2 in epithelial cells, whereas expression of the PM-targeting exocyst-docking region of PARD3 induces osteosarcoma cells to show epithelial-like morphological changes, suggesting that PI(4,5)P2 regulates epithelial characteristics by recruiting PARD3 to the PM. These results indicate that a high level of PM PI(4,5)P2 plays a crucial role in the maintenance of epithelial characteristics.
Moisture adsorption-desorption full cycle power generation
Authors: Wang Haiyan , He Tiancheng , Hao Xuanzhang , Huang Yaxin , Yao Houze , Liu Feng , Cheng Huhu , Qu Liangti 
Published: May 2022

AbstractEnvironment-adaptive power generation can play an important role in next-generation energy conversion. Herein, we propose a moisture adsorption-desorption power generator (MADG) based on porous ionizable assembly, which spontaneously adsorbs moisture at high RH and desorbs moisture at low RH, thus leading to cyclic electric output. A MADG unit can generate a high voltage of ~0.5 V and a current of 100 μA at 100% relative humidity (RH), delivers an electric output (~0.5 V and ~50 μA) at 15 ± 5% RH, and offers a maximum output power density approaching to 120 mW m−2. Such MADG devices could conduct enough power to illuminate a road lamp in outdoor application and directly drive electrochemical process. This work affords a closed-loop pathway for versatile moisture-based energy conversion.