bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microphysics of Summer Precipitation Over Yangtze‐Huai River Valley Region in China Revealed by GPM DPR Observation
Authors: Hu Xiong , Ai Weihua , Qiao Junqi , Hu Shensen , Han Ding , Yan Wei 
Published: December 2021

AbstractUtilizing the measurements and retrievals from the Global Precipitation Measurement dual‐frequency precipitation radar data during the summer of 2014–2020, this study analyzes the precipitation microphysics for summer rainfall over the Yangtze‐Huai River Valley (YHRV) region in China with respect to the precipitation efficiency index (PEI). The results show that the mean near‐surface rain rate and PEI for convective precipitation are generally larger than that for stratiform precipitation. There are larger raindrops in near‐surface rainfall for convective precipitation than that for stratiform precipitation. The High PEI precipitation is characterized by the larger ratio of convective precipitation samples compared to that for the other two categories of precipitation. The mean mass‐weighted mean diameter (Dm) of the near‐surface raindrops increase along with the precipitation top height (PTH) in Moderate PEI precipitation for convective and stratiform precipitating clouds. The larger PEI indicates the larger occurrence of the heavy raindrops and strong radar echoes near the ground. The growth process of raindrops falling below the melting layer in the High PEI precipitation is dominated by collision‐coalescence while the collisional break up is the dominant process below the melting layer in Low PEI precipitation. It is further verified that the microphysical characteristics and mechanisms of summer rainfall over the YHRV region are similar to that of precipitation derived from tropical cyclones over the ocean during the monsoon period.
Evolution of Thermal Electron Distributions in the Magnetotail: Convective Heating and Scattering‐Induced Losses
Authors: Shustov P. I. , Lukin A. S. , Zhang X.‐J. , Artemyev A. V. , Petrukovich A. A. , Angelopoulos V. 
Published: December 2021

AbstractEarth's magnetotail is filled with solar wind and ionospheric electrons, whose initial energies are significantly lower than the typical energies (temperatures) of plasmasheet electrons. One of the most common mechanisms responsible for heating of solar wind and ionospheric electrons in Earth's magnetotail is adiabatic heating caused by earthward convection of these electrons from the deep tail (i.e., from the region of a weak magnetic field) toward the region of stronger magnetic fields closer to Earth. This heating is moderated by electron losses into the ionosphere due to local wave scattering. In this study, we compare electron spectra from simultaneous observations of The Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft at different radial distances with spectra obtained from a simple model that includes adiabatic heating and losses. Our comparison shows that the model heating significantly overestimates the increase in energetic ( keV) electron fluxes, indicating that losses are essential for accurate modeling of the observed spectra. The required electron losses are similar to or even greater than the losses in the strong diffusion limit (when the loss cone is full). The latter can be interpreted as loss cone widening by field‐aligned electron acceleration.
Compositional Variation in the Crust of Peninsular Ranges and Surrounding Regions, Southern California, Revealed by Full‐Wave Seismic and Gravity Joint Inversion
Authors: Bao Xueyang , Guo Lianghui , Shen Yang 
Published: December 2021

AbstractDetailed three‐dimensional models of crustal compositional variations are essential for better understanding crustal evolution and dynamics. High‐resolution wave speed and density models of the crust provide one of the most important constraints on crustal compositional variations, particularly at depths beyond direct rock sampling. Here we present a three‐dimensional density and wave speed model of Southern California obtained by jointly inverting gravity anomalies and seismic component‐differential phase delays with full‐wave sensitivity kernels, which provide a link between wave speed and density. Thus, unlike previous joint seismic and gravity inversions, the new model does not depend on an empirical relationship between wave speed and density. The resulting density and compressional‐to‐shear wave‐speed ratio (Vp/Vs) reveal detailed features of compositional variations in the upper and middle crust in the study area, such as the three‐dimensional geometry of the boundary between the western and eastern portions of the Peninsular Ranges batholith, the gabbro‐ and metavolcanics‐rich locations within the Western Peninsular Ranges batholith, the variation of sedimentary basin thickness beneath the Coachella Valley, and a likely intermediate‐to‐mafic batholith beneath the Coachella Valley and the Eastern Peninsular Ranges. The jointly inverted density and Vp/Vs values also suggest a lithological control on seismic activities off the major fault zones.
Seasonal Transformation and Spatial Variability of Water Masses Within MacKenzie Polynya, Prydz Bay
Authors: Portela Esther , Rintoul Stephen R. , Bestley Sophie , Herraiz‐Borreguero Laura , van Wijk Esmee , McMahon Clive R. , Roquet Fabien , Hindell Mark 
Published: December 2021

AbstractWe provide a detailed description of the spatial distribution, seasonality and transformation of the main water masses within MacKenzie Polynya (MP) in Prydz Bay, East Antarctica, using data from instrumented southern elephant seals. Dense Shelf Water (DSW) formation in MP shows large spatial variability that is related to the (a) local bathymetry, (b) water column preconditioning from the presence/absence of different water masses, and (c) proximity to the Amery Ice Shelf meltwater outflow. MP exhibits sustained sea ice production and brine rejection (thus, salinity increase) from April to October. However, new DSW is only formed from June onward, when the mixed layer deepens and convection is strong enough to break the stratification set by Antarctic Surface Water above and Ice Shelf Water below. We found no evidence of DSW export from MP to Darnley polynya, as previously suggested. Rather, our observations suggest some DSW formed in Darnley Polynya may drain toward the western Prydz Bay. Then, DSW is exported offshore from Prydz Bay through the Prydz Channel. The interplay between sea ice formation, meltwater input, and sea floor topography is likely to explain why some coastal polynyas form more DSW than others, as well as the temporal variability in DSW formation within a particular polynya.
Discovery of Quasi‐Stationary Equatorial Waves Trapped in Stratospheric QBO Westerly and Easterly Jets
Authors: Sakazaki Takatoshi , Hamilton Kevin 
Published: December 2021

AbstractQuasi‐stationary planetary Rossby waves forced in the extratropical troposphere propagate upwards into the stratospheric vortex and can also be refracted toward the equator. To the extent that such waves penetrate the low latitudes they will be observable as quasi‐stationary zonal eddies in the equatorial middle stratosphere. These eddies should be strongly modulated by the phase of the Quasi‐Biennial Oscillation (QBO) of the mean zonal wind. In this project we used global reanalysis data to examine the quasi‐stationary waves in the monthly mean wind and geopotential fields near the equator and their relation to the QBO mean winds and the extratropical planetary waves. We discovered quasi‐stationary mid‐stratospheric eddy circulations near the equator that often take the form of equatorial planetary modes. Notably a quasi‐stationary equatorial Rossby mode structure can develop during westerly QBO phases, especially when the westerly mean jet is almost symmetric about the equator and deep in the vertical (often in November). More surprisingly, during the easterly QBO phase (EQBO), a modest amplitude quasi‐stationary equatorial Kelvin mode structure develops. Stationary equatorial waves forced in the troposphere will encounter critical surfaces at one or more levels below the mid‐stratosphere, and so presumably cannot account for our findings. A linear, steady model in an equatorial channel that was forced by observed fields specified at extratropical lateral boundaries also cannot fully reproduce the equatorial mode structures, especially for the Kelvin wave during EQBO. Other factors such as transient wave‐mean flow interaction or some dynamic instability might be responsible.
Identifying Global‐Scale Patterns of Vegetation Change During the Last Deglaciation From Paleoclimate Networks
Authors: Adam Moritz , Weitzel Nils , Rehfeld Kira 
Published: December 2021

AbstractDuring the last deglaciation (∼19–11 ka before present), the global mean temperature increased by 3–8 K. The concurrent hydroclimate and land cover changes are not well constrained. Here, we use a pollen database to quantify global‐scale vegetation changes during this transitional period at orbital (∼104 years) and millennial timescales (∼103 years). We focus on the proportion of tree and shrub pollen, the arboreal pollen (AP) fraction. Temporal similarities over long distances are identified by a paleoclimate network approach. At the orbital scale, we find coherent AP variations in the low and mid‐latitudes which we attribute to the global climate forcing. While AP fractions predominantly increased through the deglaciation, we identify regions where AP fractions decreased. For millennial timescales, we do not observe spatially coherent similarity structures. We compare our results with networks computed from three deglacial climate simulations with the CCSM3, HadCM3, and LOVECLIM models. Networks based on simulated precipitation patterns reproduce the characteristics of the AP network. Sensitivity experiments with statistical emulators indicate that, indeed, precipitation variations explain the diagnosed patterns of vegetation change better than temperature and CO2 variations. Our findings support previous interpretations of deglacial forest evolution in the mid‐latitudes being the result of atmospheric circulation changes. The network analysis identifies differences in the vegetation‐climate‐CO2 relationship simulated by CCSM3 and HadCM3. We conclude that network analyses are a promising tool to benchmark transient climate simulations with dynamical vegetation changes. This may result in stronger constraints of future hydroclimate and land cover changes.
Improved Neutral Density Predictions Through Machine Learning Enabled Exospheric Temperature Model
Authors: Licata Richard J. , Mehta Piyush M. , Weimer Daniel R. , Tobiska W. Kent 
Published: December 2021

AbstractThe community has leveraged satellite accelerometer data sets in previous years to estimate neutral mass density and exospheric temperatures. We utilize derived temperature data and optimize a nonlinear machine‐learned (ML) regression model to improve upon the performance of the linear EXospheric TEMPeratures on a PoLyhedrAl gRid (EXTEMPLAR) model. The newly developed EXTEMPLAR‐ML model allows for exospheric temperature predictions at any location with one model and provides performance improvements over its predecessor. We achieve reductions in mean absolute error of 2 K on an independent test set while providing similar error standard deviation values. Comparing the performance of both EXTEMPLAR models and the Naval Research Laboratory Mass Spectrometer and Incoherent Scatter radar Extended model (NRLMSISE‐00) across different solar and geomagnetic activity levels shows that EXTEMPLAR‐ML has the lowest mean absolute error across 80% of conditions tested. A study for spatial errors demonstrated that at all grid locations, EXTEMPLAR‐ML has the lowest mean absolute error for over 60% of the polyhedral grid cells on the test set. Like EXTEMPLAR, our model's outputs can be utilized by NRLMSISE‐00 (exclusively) to more closely match satellite accelerometer‐derived densities. We conducted 10 case studies where we compare the accelerometer‐derived temperature and density estimates from four satellites to NRLMSISE‐00, EXTEMPLAR, and EXTEMPALR‐ML during major storm periods. These comparisons show that EXTEMPLAR‐ML generally has the best performance of the three models during storms. We use principal component analysis on EXTEMPLAR‐ML outputs to verify the physical response of the model to its drivers.
Erosion Mechanisms of Debris Flow on the Sediment Bed
Authors: Zheng Hongchao , Shi Zhenming , Yu Songbo , Fan Xuanmei , Hanley Kevin J. , Feng Shijin 
Published: December 2021

AbstractDebris flows are common geological hazards in mountainous regions worldwide. The scale of debris flows can be significantly enhanced by basal erosion and bank collapse in the transportation process, resulting in an increase in casualties and property losses. However, the mechanisms of this growth are largely unclear. Here, we conduct a series of experiments to investigate the erosion of two different bed sediments (coarse‐grained and widely graded) by released flows with three different densities and two different volumes. The erosion mechanisms of bed sediments are revealed by comparing detailed sensor data for flow level, pore pressure and total normal stress. A flow nose develops on the coarse‐grained bed sediment, resulting in a high flow depth and low velocity, while a tabular flow develops on the widely graded bed sediment, leading to a low flow depth and high velocity. The mean erosion rates of the coarse‐grained bed sediment are generally higher than those of the widely graded bed sediment due to significant pore pressure developed in coarse‐grained bed sediment. The feedback effect of bed sediment on the erosion process strongly influences the flow depth and velocity, which in turn affects the mean erosion rate of bed sediment. The interaction between the overlying flow and sediment bed controls the erosion pattern: coarse‐grained bed sediment is eroded by a layer of mass movement whereas widely graded bed sediment is progressively scoured. The interaction between debris flow and bed sediment during erosion is principally attributed to pore‐pressure transmission.
Touchable cell biophysics property recognition platforms enable multifunctional blood smart health care
Authors: Chen Longfei , Liu Yantong , Xu Hongshan , Ma Linlu , Wang Yifan , Le Yu  , Wang Fang , Zhu Jiaomeng , Hu Xuejia , Yi Kezhen , Yang Yi , Shen Hui , Zhou Fuling , Gao Xiaoqi , Cheng Yanxiang , Bai Long , Duan Yongwei , Wang Fubing , Zhu Yimin 
Published: December 2021

AbstractAs a crucial biophysical property, red blood cell (RBC) deformability is pathologically altered in numerous disease states, and biochemical and structural changes occur over time in stored samples of otherwise normal RBCs. However, there is still a gap in applying it further to point-of-care blood devices due to the large external equipment (high-resolution microscope and microfluidic pump), associated operational difficulties, and professional analysis. Herein, we revolutionarily propose a smart optofluidic system to provide a differential diagnosis for blood testing via precise cell biophysics property recognition both mechanically and morphologically. Deformation of the RBC population is caused by pressing the hydrogel via an integrated mechanical transfer device. The biophysical properties of the cell population are obtained by the designed smartphone algorithm. Artificial intelligence-based modeling of cell biophysics properties related to blood diseases and quality was developed for online testing. We currently achieve 100% diagnostic accuracy for five typical clinical blood diseases (90 megaloblastic anemia, 78 myelofibrosis, 84 iron deficiency anemia, 48 thrombotic thrombocytopenic purpura, and 48 thalassemias) via real-world prospective implementation; furthermore, personalized blood quality (for transfusion in cardiac surgery) monitoring is achieved with an accuracy of 96.9%. This work suggests a potential basis for next-generation blood smart health care devices.
Pyroglutamate Aβ cascade as drug target in Alzheimer’s disease
Authors: Bayer Thomas A. 
Published: December 2021

AbstractOne of the central aims in Alzheimer’s disease (AD) research is the identification of clinically relevant drug targets. A plethora of potential molecular targets work very well in preclinical model systems both in vitro and in vivo in AD mouse models. However, the lack of translation into clinical settings in the AD field is a challenging endeavor. Although it is long known that N-terminally truncated and pyroglutamate-modified Abeta (AβpE3) peptides are abundantly present in the brain of AD patients, form stable and soluble low-molecular weight oligomers, and induce neurodegeneration in AD mouse models, their potential as drug target has not been generally accepted in the past. This situation has dramatically changed with the report that passive immunization with donanemab, an AβpE3-specific antibody, cleared aymloid plaques and stabilized cognitive deficits in a group of patients with mild AD in a phase II trial. This review summarizes the current knowledge on the molecular mechanisms of generation of AβpE, its biochemical properties, and the intervention points as a drug target in AD.
Role of the flagellar hook in the structural development and antibiotic tolerance of Pseudomonas aeruginosa biofilms
Authors: Valentin Jules D P , Straub Hervé , Pietsch Franziska , Lemare Marion , Ahrens Christian H , Schreiber Frank , Webb Jeremy S , van der Mei Henny C , Ren Qun 
Published: December 2021

Abstract
Pseudomonas aeruginosa biofilms exhibit an intrinsic resistance to antibiotics and constitute a considerable clinical threat. In cystic fibrosis, a common feature of biofilms formed by P. aeruginosa in the airway is the occurrence of mutants deficient in flagellar motility. This study investigates the impact of flagellum deletion on the structure and antibiotic tolerance of P. aeruginosa biofilms, and highlights a role for the flagellum in adaptation and cell survival during biofilm development. Mutations in the flagellar hook protein FlgE influence greatly P. aeruginosa biofilm structuring and antibiotic tolerance. Phenotypic analysis of the flgE knockout mutant compared to the wild type (WT) reveal increased fitness under planktonic conditions, reduced initial adhesion but enhanced formation of microcolony aggregates in a microfluidic environment, and decreased expression of genes involved in exopolysaccharide formation. Biofilm cells of the flgE knock-out mutant display enhanced tolerance towards multiple antibiotics, whereas its planktonic cells show similar resistance to the WT. Confocal microscopy of biofilms demonstrates that gentamicin does not affect the viability of cells located in the inner part of the flgE knock-out mutant biofilms due to reduced penetration. These findings suggest that deficiency in flagellar proteins like FlgE in biofilms and in cystic fibrosis infections represent phenotypic and evolutionary adaptations that alter the structure of P. aeruginosa biofilms conferring increased antibiotic tolerance.
Cerebrospinal fluid abnormalities in first- and multi-episode schizophrenia-spectrum disorders: impact of clinical and demographical variables
Authors: Oviedo-Salcedo Tatiana , Wagner Elias , Campana Mattia , Gagsteiger Anna , Strube Wolfgang , Eichhorn Peter , Louiset Marie-Luise , Luykx Jurjen , de Witte Lot D. , Kahn René S. , Benros Michael E. , Falkai Peter , Hasan Alkomiet 
Published: December 2021

AbstractMultiple lines of evidence indicate that immunological and inflammatory alterations contribute at least in a subgroup to the pathophysiology of schizophrenia. In this retrospective chart review, we investigated whether clinical factors contribute to altered cerebrospinal fluid (CSF) findings in schizophrenia-spectrum disorders. Clinical data from electronic medical records of patients with psychotic disorders (ICD-10: F20-F29) who received routine CSF diagnostics at the Department of Psychiatry and Psychotherapy, LMU Munich, Germany, were included. Chi² tests for dichotomous outcomes and independent t tests for continuous outcomes were used to compare differences between groups. A total of 331 patients were included in the analyses (43.2% female and 56.8% male). The mean age was 37.67 years (±15.58). The mean duration of illness was 71.96 months (±102.59). In all, 40% (128/320) were first-episode psychosis (FEP) patients and 60% (192/320) were multi-episode psychosis (MEP) patients. Elevated CSF protein levels were found in 19.8% and elevated CSF/serum albumin ratios (QAlb) in 29.4% of the cases. Pleocytosis was found in 6.1% of patients. MEP patients showed significantly higher mean QAlb compared with FEP patients (t(304.57) = −2.75, p = 0.006), which did not remain significant after correcting for age. QAlb elevation occurred more frequently in men (X2(1) = 14.76, p = <0.001). For treatment resistance, family history, and cMRI alterations, no significant differences in CSF-related outcomes were detected. Our work extends other retrospective cohorts confirming a relevant degree of CSF alterations in schizophrenia-spectrum disorders and shows the difficulty to relate these alterations to clinical and disease course trajectories. More research is needed to develop treatment response predictors from CSF analyses.
Oncogenic microRNA-181d binding to OGT contributes to resistance of ovarian cancer cells to cisplatin
Authors: Huang Wei , Chen Ling , Zhu Kean , Wang Donglian 
Published: December 2021

AbstractOvarian cancer (OC), a common gynecological cancer, is characterized by a high malignant potential. MicroRNAs (miRNAs or miRs) have been associated with the chemo- or radiotherapeutic resistance of human malignancies. Herein, the current study set out to explore the regulatory mechanism of miR-181d involved in the cisplatin (DDP) resistance of OC cells. Firstly, in-situ hybridization method was performed to identify miR-181d expression in ovarian tissues of DDP-resistant or DDP-sensitive patients. In addition, miR-181d expression in A2780 cells and A2780/DDP cell lines was determined by RT-qPCR. Gain- and loss-of-function experiments were then performed to characterize the effect of miR-181d on OC cell behaviors. We probed the miR-181d affinity to OGT, as well as the downstream glycosylation of KEAP1 and ubiquitination of NRF2. Further, in vivo experiments were performed to define the role of miR-181d in tumor resistance to DDP. miR-181d was highly expressed in the ovarian tissues of DDP-resistant patients and the A2780/DDP cell line. Ectopic expression of miR-181d augmented DDP resistance in OC cells. In addition, miR-181d was found to target the 3′UTR of OGT mRNA, and negatively regulate the OGT expression. Mechanistic results indicated that OGT repressed NRF2 expression through glycosylation of KEAP1, thereby inhibiting the DDP resistance of OC cells. Furthermore, miR-181d negatively orchestrated the OGT/KEAP1/NRF2 axis to enhance the OC resistance to DDP in vivo. Overall, these findings suggest that miR-181d-mediated OGT inhibition restricts the glycosylation of KEAP1, and then reduces the ubiquitination and degradation of NRF2, leading to DDP resistance of OC. This study provides new insights for prevention and control of OC.