bluuebunny/crossref_metadata_2025_split huggingface dataset:
Roles of Sea Surface Temperature Warming and Loss of Arctic Sea Ice in the Enhanced Summer Wetting Trend Over Northeastern Siberia During Recent Decades
Authors: Sun Cheng , Liu Yusen , Zhang Jing 
Published: August 2020

AbstractThe water cycle over middle‐ to high‐latitude regions has experienced rapid changes in recent decades. The sea surface temperature (SST) and Arctic sea ice influence the water cycle over these regions, but the relative roles of SST warming and the loss of Arctic sea ice remain unclear. We identify an enhanced change in the summer (June–August) water cycle over northeastern Siberia (55–70°N, 100–170°E) during the last three decades. The driving force of this enhanced wetting trend is investigated using both observations and model simulations. An increasing trend of low‐level southerly winds and a decrease in sea‐level pressure are observed over northeastern Siberia during summer, leading to stronger lower tropospheric moisture convergence and ascending motion, which favor an increase in precipitation. The wetting trend and the associated atmospheric features are successfully reproduced by an atmospheric model driven by the observed Arctic sea ice concentrations and SSTs, whereas the model driven solely by the Arctic sea ice concentrations simulates a negligible increase in precipitation. This is primarily due to the absence of the stronger southerly winds that transport moisture from the Pacific Ocean. The modeling evidence suggests that SST changes in recent decades have a stronger influence on the intensified precipitation than does sea ice. An atmospheric bridge mechanism links the strengthened southerly winds to an upper‐level Rossby wave train originating from the North Atlantic. Another atmospheric simulation forced only by Atlantic SST warming recreates the observed enhanced wetting trend in northeastern Siberia and supports the hypothesized atmospheric bridge mechanism.
Assessing Underground Water Exchange Between Regions Using GRACE Data
Authors: Yin Wenjie , Hu Litang , Zheng Wei , Jiao Jiu Jimmy , Han Shin‐Chan , Zhang Menglin 
Published: August 2020

AbstractQuantifying the underground water exchange between adjacent regions is a common question in field investigations and groundwater flow models. This paper proposes an innovative approach to assess underground water exchange patterns based on Gravity Recovery and Climate Experiment (GRACE) observations, the water balance method, and Darcy's law. The dynamic patterns of flux changes are investigated over four boundaries of an arid plain. Moreover, the causes of anthropogenic and climate factors are evaluated using the entropy method and the partial least squares regression (PLSR) model. The results indicate that terrestrial water storage (TWS) in the study area shows a decreasing trend at a rate of −1.77 ± 0.21 mm/yr from 2003 to 2015. The water resources recharging the study area from its southern boundary show a noticeable increasing trend, which is mainly attributed to the warming climate and increasing precipitation on the Qilian Mountains. The Ecological Water Diversion Project and the imbalance between precipitation and evapotranspiration are the main factors inducing the decline of flux changes for the northern, western, and eastern boundaries. Under the constrains of empirical values of hydrogeological parameters, GRACE‐based methods find that increment of the flux changes in the southern boundary may account for approximately 0.43% of the investigated flux in 2000, and the decrement of flux changes in the eastern boundary may be about 0.01% to the previous measured results. Anthropogenic activities are the dominant driving force for the changes in water resources, with the weight of 88.70%. The presented method can provide insights into the patterns of flux change in data‐poor areas.
High‐Resolution Mg/Ca and δ18O Patterns in Modern Neogloboquadrina pachyderma From the Fram Strait and Irminger Sea
Authors: Livsey Caitlin M. , Kozdon Reinhard , Bauch Dorothea , Brummer Geert‐Jan A. , Jonkers Lukas , Orland Ian , Hill Tessa M. , Spero Howard J. 
Published: August 2020

AbstractNeogloboquadrina pachyderma is the dominant species of planktonic foraminifera found in polar waters and is therefore invaluable for paleoceanographic studies of the high latitudes. However, the geochemistry of this species is complicated due to the development of a thick calcite crust in its final growth stage and at greater depths within the water column. We analyzed the in situ Mg/Ca and δ18O in discrete calcite zones using laser ablation‐inductively coupled plasma‐mass spectrometry, electron probe microanalysis, and secondary ion mass spectrometry within modern N. pachyderma shells from the highly dynamic Fram Strait and the seasonally isothermal/isohaline Irminger Sea. Here we compare shell geochemistry to the measured temperature, salinity, and δ18Osw in which the shells calcified to better understand the controls on N. pachyderma geochemical heterogeneity. We present a relationship between Mg/Ca and temperature in N. pachyderma lamellar calcite that is significantly different than published equations for shells that contained both crust and lamellar calcite. We also document highly variable secondary ion mass spectrometry δ18O results (up to a 3.3‰ range in single shells) on plankton tow samples which we hypothesize is due to the granular texture of shell walls. Finally, we document that the δ18O of the crust and lamellar calcite of N. pachyderma from an isothermal/isohaline environment are indistinguishable from each other, indicating that shifts in N. pachyderma δ18O are primarily controlled by changes in environmental temperature and/or salinity rather than differences in the sensitivities of the two calcite types to environmental conditions.
Modeling brain, symptom, and behavior in the winds of change
Authors: Lydon-Staley David M. , Cornblath Eli J. , Blevins Ann Sizemore , Bassett Danielle S. 
Published: August 2020

AbstractNeuropsychopharmacology addresses pressing questions in the study of three intertwined complex systems: the brain, human behavior, and symptoms of illness. The field seeks to understand the perturbations that impinge upon those systems, either driving greater health or illness. In the pursuit of this aim, investigators often perform analyses that make certain assumptions about the nature of the systems that are being perturbed. Those assumptions can be encoded in powerful computational models that serve to bridge the wide gulf between a descriptive analysis and a formal theory of a system’s response. Here we review a set of three such models along a continuum of complexity, moving from a local treatment to a network treatment: one commonly applied form of the general linear model, impulse response models, and network control models. For each, we describe the model’s basic form, review its use in the field, and provide a frank assessment of its relative strengths and weaknesses. The discussion naturally motivates future efforts to interlink data analysis, computational modeling, and formal theory. Our goal is to inspire practitioners to consider the assumptions implicit in their analytical approach, align those assumptions to the complexity of the systems under study, and take advantage of exciting recent advances in modeling the relations between perturbations and system function.
GSK3β inhibition restores cortical gamma oscillation and cognitive behavior in a mouse model of NMDA receptor hypofunction relevant to schizophrenia
Authors: Nakao Kazuhito , Singh Mahendra , Sapkota Kiran , Hagler Bailey C. , Hunter Robert N. , Raman Chander , Hablitz John J. , Nakazawa Kazu 
Published: August 2020

AbstractCortical gamma oscillations are believed to be involved in mental processes which are disturbed in schizophrenia. For example, the magnitudes of sensory-evoked oscillations, as measured by auditory steady-state responses (ASSRs) at 40 Hz, are robustly diminished, whereas the baseline gamma power is enhanced in schizophrenia. Such dual gamma oscillation abnormalities are also present in a mouse model of N-methyl-D-aspartate receptor hypofunction (Ppp1r2cre/Grin1 knockout mice). However, it is unclear whether the abnormal gamma oscillations are associated with dysfunction in schizophrenia. We found that glycogen synthase kinase-3 (GSK3) is overactivated in corticolimbic parvalbumin-positive GABAergic interneurons in Grin1 mutant mice. Here we addressed whether GSK3β inhibition reverses both abnormal gamma oscillations and behavioral deficits with high correlation by pharmacological and genetic approach. We demonstrated that the paralog selective-GSK3β inhibitor, but not GSK3α inhibitor, normalizes the diminished ASSRs, excessive baseline gamma power, and deficits in spatial working memory and prepulse inhibition (PPI) of acoustic startle in Grin1 mutant mice. Cell-type specific GSK3B knockdown, but not GSK3A knockdown, also reversed abnormal gamma oscillations and behavioral deficits. Moreover, GSK3B knockdown, but not GSK3A knockdown, reverses the mutants’ in vivo spike synchrony deficits. Finally, ex vivo patch-clamp recording from pairs of neighboring cortical pyramidal neurons showed a reduction of synchronous spontaneous inhibitory-postsynaptic-current events in mutants, which was reversed by GSK3β inhibition genetically and pharmacologically. Together, GSK3β inhibition in corticolimbic interneurons ameliorates the deficits in spatial working memory and PPI, presumably by restoration of synchronous GABA release, synchronous spike firing, and evoked-gamma power increase with lowered baseline power.
Quantum-assisted photoelectric gain effects in perovskite solar cells
Authors: Wang Ying-Chiao , Huang Shao-Ku , Nakamura Toshihiro , Kao Yu-Ting , Chiang Chun-Hao , Wang Di-Yan , Chang Yuan Jay , Koshida Nobuyoshi , Shimada Toshikazu , Liu Shihao , Chen Chun-Wei , Tsukagoshi Kazuhito 
Published: August 2020

AbstractFurther boosting the power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) without excessively increasing production expenses is critical for practical applications. Here, we introduce silicon quantum dots (SiQDs) to enable perovskites to harvest additional sunlight without changing PSC processes. These SiQDs can convert shorter wavelength excitation light (300–530 nm) into visible region light and reflect longer wavelength perovskite-unabsorbed visible light (550–800 nm), leading to broadband light absorption enhancement in PSCs. As a result, the SiQD-based photocurrent gain can improve the external quantum efficiencies of PSCs over a wide wavelength range of 360–760 nm, yielding relatively enhanced short-circuit current density (+1.66 mA/cm2) and PCE (+1.4%). Surprisingly, even the PSC with a low-purity perovskite layer shows an ultrahigh PCE improvement of 5.6%. Our findings demonstrate QD-assisted effects based on earth-abundant and environmentally friendly silicon, leading to effective optical management that remarkably promotes the performance of PSCs and enables the balance of costs to be substantially addressed.
A leap in quantum efficiency through light harvesting in photoreceptor UVR8
Authors: Li Xiankun , Ren Haisheng , Kundu Mainak , Liu Zheyun , Zhong Frank W. , Wang Lijuan , Gao Jiali , Zhong Dongping 
Published: August 2020

AbstractPlants utilize a UV-B (280 to 315 nm) photoreceptor UVR8 (UV RESISTANCE LOCUS 8) to sense environmental UV levels and regulate gene expression to avoid harmful UV effects. Uniquely, UVR8 uses intrinsic tryptophan for UV-B perception with a homodimer structure containing 26 structural tryptophan residues. However, besides 8 tryptophans at the dimer interface to form two critical pyramid perception centers, the other 18 tryptophans’ functional role is unknown. Here, using ultrafast fluorescence spectroscopy, computational methods and extensive mutations, we find that all 18 tryptophans form light-harvesting networks and funnel their excitation energy to the pyramid centers to enhance light-perception efficiency. We determine the timescales of all elementary tryptophan-to-tryptophan energy-transfer steps in picoseconds to nanoseconds, in excellent agreement with quantum computational calculations, and finally reveal a significant leap in light-perception quantum efficiency from 35% to 73%. This photoreceptor is the first system discovered so far, to be best of our knowledge, using natural amino-acid tryptophans to form networks for both light harvesting and light perception.
Genetically controlled membrane synthesis in liposomes
Authors: Blanken Duco , Foschepoth David , Serrão Adriana Calaça , Danelon Christophe 
Published: August 2020

AbstractLipid membranes, nucleic acids, proteins, and metabolism are essential for modern cellular life. Synthetic systems emulating the fundamental properties of living cells must therefore be built upon these functional elements. In this work, phospholipid-producing enzymes encoded in a synthetic minigenome are cell-free expressed within liposome compartments. The de novo synthesized metabolic pathway converts precursors into a variety of lipids, including the constituents of the parental liposome. Balanced production of phosphatidylethanolamine and phosphatidylglycerol is realized, owing to transcriptional regulation of the activity of specific genes combined with a metabolic feedback mechanism. Fluorescence-based methods are developed to image the synthesis and membrane incorporation of phosphatidylserine at the single liposome level. Our results provide experimental evidence for DNA-programmed membrane synthesis in a minimal cell model. Strategies are discussed to alleviate current limitations toward effective liposome growth and self-reproduction.
High force catch bond mechanism of bacterial adhesion in the human gut
Authors: Liu Zhaowei , Liu Haipei , Vera Andrés M. , Bernardi Rafael C. , Tinnefeld Philip , Nash Michael A. 
Published: August 2020

AbstractBacterial colonization of the human intestine requires firm adhesion of bacteria to insoluble substrates under hydrodynamic flow. Here we report the molecular mechanism behind an ultrastable protein complex responsible for resisting shear forces and adhering bacteria to cellulose fibers in the human gut. Using single-molecule force spectroscopy (SMFS), single-molecule FRET (smFRET), and molecular dynamics (MD) simulations, we resolve two binding modes and three unbinding reaction pathways of a mechanically ultrastable R. champanellensis (Rc) Dockerin:Cohesin (Doc:Coh) complex. The complex assembles in two discrete binding modes with significantly different mechanical properties, with one breaking at ~500 pN and the other at ~200 pN at loading rates from 1-100 nN s−1. A neighboring X-module domain allosterically regulates the binding interaction and inhibits one of the low-force pathways at high loading rates, giving rise to a catch bonding mechanism that manifests under force ramp protocols. Multi-state Monte Carlo simulations show strong agreement with experimental results, validating the proposed kinetic scheme. These results explain mechanistically how gut microbes regulate cell adhesion strength at high shear stress through intricate molecular mechanisms including dual-binding modes, mechanical allostery and catch bonds.
Complete chemical structures of human mitochondrial tRNAs
Authors: Suzuki Takeo , Yashiro Yuka , Kikuchi Ittoku , Ishigami Yuma , Saito Hironori , Matsuzawa Ikuya , Okada Shunpei , Mito Mari , Iwasaki Shintaro , Ma Ding , Zhao Xuewei , Asano Kana , Lin Huan , Kirino Yohei , Sakaguchi Yuriko , Suzuki Tsutomu 
Published: August 2020

AbstractMitochondria generate most cellular energy via oxidative phosphorylation. Twenty-two species of mitochondrial (mt-)tRNAs encoded in mtDNA translate essential subunits of the respiratory chain complexes. mt-tRNAs contain post-transcriptional modifications introduced by nuclear-encoded tRNA-modifying enzymes. They are required for deciphering genetic code accurately, as well as stabilizing tRNA. Loss of tRNA modifications frequently results in severe pathological consequences. Here, we perform a comprehensive analysis of post-transcriptional modifications of all human mt-tRNAs, including 14 previously-uncharacterized species. In total, we find 18 kinds of RNA modifications at 137 positions (8.7% in 1575 nucleobases) in 22 species of human mt-tRNAs. An up-to-date list of 34 genes responsible for mt-tRNA modifications are provided. We identify two genes required for queuosine (Q) formation in mt-tRNAs. Our results provide insight into the molecular mechanisms underlying the decoding system and could help to elucidate the molecular pathogenesis of human mitochondrial diseases caused by aberrant tRNA modifications.
Cyst growth in ADPKD is prevented by pharmacological and genetic inhibition of TMEM16A in vivo
Authors: Cabrita Ines , Kraus Andre , Scholz Julia Katharina , Skoczynski Kathrin , Schreiber Rainer , Kunzelmann Karl , Buchholz Björn 
Published: August 2020

AbstractIn autosomal dominant polycystic kidney disease (ADPKD) multiple bilateral renal cysts gradually enlarge, leading to a decline in renal function. Transepithelial chloride secretion through cystic fibrosis transmembrane conductance regulator (CFTR) and TMEM16A (anoctamin 1) are known to drive cyst enlargement. Here we demonstrate that loss of Pkd1 increased expression of TMEM16A and CFTR and Cl− secretion in murine kidneys, with TMEM16A essentially contributing to cyst growth. Upregulated TMEM16A enhanced intracellular Ca2+ signaling and proliferation of Pkd1-deficient renal epithelial cells. In contrast, increase in Ca2+ signaling, cell proliferation and CFTR expression was not observed in Pkd1/Tmem16a double knockout mice. Knockout of Tmem16a or inhibition of TMEM16A in vivo by the FDA-approved drugs niclosamide and benzbromarone, as well as the TMEM16A-specific inhibitor Ani9 largely reduced cyst enlargement and abnormal cyst cell proliferation. The present data establish a therapeutic concept for the treatment of ADPKD.
Selective flexible packaging pathways of the segmented genome of influenza A virus
Authors: Haralampiev Ivan , Prisner Simon , Nitzan Mor , Schade Matthias , Jolmes Fabian , Schreiber Max , Loidolt-Krüger Maria , Jongen Kalle , Chamiolo Jasmine , Nilson Niklaas , Winter Franziska , Friedman Nir , Seitz Oliver , Wolff Thorsten , Herrmann Andreas 
Published: August 2020

AbstractThe genome of influenza A viruses (IAV) is encoded in eight distinct viral ribonucleoproteins (vRNPs) that consist of negative sense viral RNA (vRNA) covered by the IAV nucleoprotein. Previous studies strongly support a selective packaging model by which vRNP segments are bundling to an octameric complex, which is integrated into budding virions. However, the pathway(s) generating a complete genome bundle is not known. We here use a multiplexed FISH assay to monitor all eight vRNAs in parallel in human lung epithelial cells. Analysis of 3.9 × 105 spots of colocalizing vRNAs provides quantitative insights into segment composition of vRNP complexes and, thus, implications for bundling routes. The complexes rarely contain multiple copies of a specific segment. The data suggest a selective packaging mechanism with limited flexibility by which vRNPs assemble into a complete IAV genome. We surmise that this flexibility forms an essential basis for the development of reassortant viruses with pandemic potential.
Connexin-46/50 in a dynamic lipid environment resolved by CryoEM at 1.9 Å
Authors: Flores Jonathan A. , Haddad Bassam G. , Dolan Kimberly A. , Myers Janette B. , Yoshioka Craig C. , Copperman Jeremy , Zuckerman Daniel M. , Reichow Steve L. 
Published: August 2020

AbstractGap junctions establish direct pathways for cells to transfer metabolic and electrical messages. The local lipid environment is known to affect the structure, stability and intercellular channel activity of gap junctions; however, the molecular basis for these effects remains unknown. Here, we incorporate native connexin-46/50 (Cx46/50) intercellular channels into a dual lipid nanodisc system, mimicking a native cell-to-cell junction. Structural characterization by CryoEM reveals a lipid-induced stabilization to the channel, resulting in a 3D reconstruction at 1.9 Å resolution. Together with all-atom molecular dynamics simulations, it is shown that Cx46/50 in turn imparts long-range stabilization to the dynamic local lipid environment that is specific to the extracellular lipid leaflet. In addition, ~400 water molecules are resolved in the CryoEM map, localized throughout the intercellular permeation pathway and contributing to the channel architecture. These results illustrate how the aqueous-lipid environment is integrated with the architectural stability, structure and function of gap junction communication channels.
Fluxing of mantle carbon as a physical agent for metallogenic fertilization of the crust
Authors: Blanks Daryl E. , Holwell David A. , Fiorentini Marco L. , Moroni Marilena , Giuliani Andrea , Tassara Santiago , González-Jiménez José M. , Boyce Adrian J. , Ferrari Elena 
Published: August 2020

AbstractMagmatic systems play a crucial role in enriching the crust with volatiles and elements that reside primarily within the Earth’s mantle, including economically important metals like nickel, copper and platinum-group elements. However, transport of these metals within silicate magmas primarily occurs within dense sulfide liquids, which tend to coalesce, settle and not be efficiently transported in ascending magmas. Here we show textural observations, backed up with carbon and oxygen isotope data, which indicate an intimate association between mantle-derived carbonates and sulfides in some mafic-ultramafic magmatic systems emplaced at the base of the continental crust. We propose that carbon, as a buoyant supercritical CO2 fluid, might be a covert agent aiding and promoting the physical transport of sulfides across the mantle-crust transition. This may be a common but cryptic mechanism that facilitates cycling of volatiles and metals from the mantle to the lower-to-mid continental crust, which leaves little footprint behind by the time magmas reach the Earth’s surface.
Dynamic remodelling of the human host cell proteome and phosphoproteome upon enterovirus infection
Authors: Giansanti Piero , Strating Jeroen R. P. M. , Defourny Kyra A. Y. , Cesonyte Ieva , Bottino Alexia M. S. , Post Harm , Viktorova Ekaterina G. , Ho Vien Quang Tri , Langereis Martijn A. , Belov George A. , Nolte-‘t Hoen Esther N. M. , Heck Albert J. R. , van Kuppeveld Frank J. M. 
Published: August 2020

AbstractThe group of enteroviruses contains many important pathogens for humans, including poliovirus, coxsackievirus, rhinovirus, as well as newly emerging global health threats such as EV-A71 and EV-D68. Here, we describe an unbiased, system-wide and time-resolved analysis of the proteome and phosphoproteome of human cells infected with coxsackievirus B3. Of the ~3,200 proteins quantified throughout the time course, a large amount (~25%) shows a significant change, with the majority being downregulated. We find ~85% of the detected phosphosites to be significantly regulated, implying that most changes occur at the post-translational level. Kinase-motif analysis reveals temporal activation patterns of certain protein kinases, with several CDKs/MAPKs immediately active upon the infection, and basophilic kinases, ATM, and ATR engaging later. Through bioinformatics analysis and dedicated experiments, we identify mTORC1 signalling as a major regulation network during enterovirus infection. We demonstrate that inhibition of mTORC1 activates TFEB, which increases expression of lysosomal and autophagosomal genes, and that TFEB activation facilitates the release of virions in extracellular vesicles via secretory autophagy. Our study provides a rich framework for a system-level understanding of enterovirus-induced perturbations at the protein and signalling pathway levels, forming a base for the development of pharmacological inhibitors to treat enterovirus infections.