bluuebunny/crossref_metadata_2025 huggingface dataset:
Seismic Anisotropy and Mantle Flow Constrained by Shear Wave Splitting in Central Myanmar
Authors: Fan Enbo , He Yumei , Ai Yinshuang , Gao Stephen S. , Liu Kelly H. , Jiang Mingming , Hou Guangbing , Mon Chit Thet , Thant Myo , Sein Kyaing
Published: September 2021

This study represents the first campaign‐style teleseismic shear wave splitting (SWS) investigation of central Myanmar, an area that is tectonically controlled by the oblique subduction of the Indian Plate underneath the Eurasian Plate. The resulting 678 well‐defined and 247 null SWS measurements obtained from recently deployed 71 broadband seismic stations show that the Indo‐Burma Ranges (IBR) possess mostly N‐S fast orientations that are parallel to the trend of the depth contours of the subducted slab. Relative to the global average of 1.0 s, extremely large splitting times with station‐averaged values ranging from 1.28 to 2.79 s and an area‐averaged value of 2.09 ± 0.55 s are observed in the IBR. In contrast, the Central Basin (CB) and the Shan Plateau (SP) are characterized by slightly larger than normal splitting times. The fast orientations observed in the CB are mostly NE‐SW in the northern part of the study area, N‐S in the central part, and NW‐SE in the southern part. The fast orientations change from nearly N‐S along the N‐S oriented Sagaing Fault, to NW‐SE in the central and eastern portions of the SP. These observations, together with SWS measurements using local S events, crustal anisotropy measurements using P‐to‐S receiver functions, and the estimated depth of the source of anisotropy using the spatial coherency of the splitting parameters, suggest the presence of a trench‐parallel sub‐slab flow system driven by slab rollback, a trench‐perpendicular corner flow, and a trench‐parallel flow possibly entering the mantle wedge through a slab window or gap.
Seismic Velocity Structure Along and Across the Ultraslow‐Spreading Southwest Indian Ridge at 64°30′E Showcases Flipping Detachment Faults
Authors: Corbalán A. , Nedimović M. R. , Louden K. E. , Cannat M. , Grevemeyer I. , Watremez L. , Leroy S.
Published: September 2021

We present two ∼150‐km‐long orthogonal 2D P‐wave tomographic velocity models across and along the ridge axis of the ultraslow‐spreading Southwest Indian Ridge at 64°30′E. Here, detachment faults largely accommodate seafloor accretion by mantle exhumation. The velocity models are constructed by inverting first arrival traveltimes recorded by 32 ocean bottom seismometers placed on the two profiles. The velocities increase rapidly with depth, from 3 to 3.5 km/s at the seafloor to 7 km/s at depths ranging from 1.5 to 6 km below the seafloor. The vertical gradient decreases for velocities >7 km/s. We suggest that changes in velocity with depth are related to changes in the degree of serpentinization and interpret the lithosphere to be composed of highly fractured and fully serpentinized peridotites at the top with a gradual downward decrease in serpentinization and pore space to unaltered peridotites. One active and five abandoned detachment faults are identified on the ridge‐perpendicular profile. The active axial detachment fault (D1) shows the sharpest lateral change (horizontal gradient of ∼1 s–1) and highest vertical gradient (∼2 s–1) in the velocities. In the western section of the ridge‐parallel profile, the lithosphere transitions from non‐volcanic to volcanic over a distance of ∼10 km. The depth extent of serpentinization on the ridge‐perpendicular profile ranges from ∼2 to 5 km, with the deepest penetration at the D1 hanging wall. On the ridge‐parallel profile, this depth (∼2.5–4 km) varies less as the profile crosses the D1 hanging wall at ∼5–9 km south of the ridge axis.
Iron Sulfides and Anomalous Electrical Resistivity in Cratonic Environments
Authors: Saxena S. , Pommier A. , Tauber M. J.
Published: September 2021

The interpretation of low‐resistivity anomalies in the lithospheric mantle of several cratonic regions has invoked hydrogen, or connected networks of graphite with iron‐rich silicates, and/or metal sulfides. Electrical laboratory measurements are a powerful approach for exploring these alternatives. We report electrical measurements of two xenoliths (pyroxenite and dunite) from Tanzania; two metal sulfides (FeS and Fe‐S‐Ni); and several mixtures of metal sulfides (3.4–18.2 vol.%) with xenolith. A multi‐anvil press was employed to maintain a 2 GPa pressure and temperatures up to 1,627 K. The addition of 3.4 vol.% FeS to the pyroxenite or dunite matrix has little effect on bulk resistivity, particularly for T > 800 K. However, the resistivity drops dramatically–by factors of up to 1,000, depending on temperature–upon addition of 6.5 vol.% FeS in the dunite. Addition of 18.2% FeS causes a further decrease of the same magnitude relative to the 6.5% sample. Scanning electron microscope images do not reveal the formation of a connected FeS network as part of the decreased resistivity. Possible explanations for the apparently conflicting results include connections of the sulfide that are not imaged in the back‐scattered images, either because of limited resolution, or perhaps the inherent limitations of the 2‐D perspective. The complete data set (xenoliths, metal sulfides, and mixtures) was modeled with a modified version of Archie's law, and we find satisfactory agreement over a truncated temperature range. We conclude that the low‐resistivity anomalies in Tanzania, Kaapvaal, and Gawler cratons can be explained by the presence of a few vol.% of solid sulfide.
Cyclostationary EOF Modes of Antarctic Sea Ice and Their Application in Prediction
Authors: Pei Yuhua
Published: September 2021

This study examines the modes of sea ice concentration (SIC) in the Southern Ocean from a new perspective using the cyclostationary empirical orthogonal function (CSEOF) method, which decomposes a space‐time field into a combination of modulating variability on phase‐locked annual cycles. The first CSEOF mode of SIC (72.55% of total variance) represents the normal annual cycle modulated by a low‐frequency oscillation. The second mode of SIC (3.39%) represents the trend pattern, which reveals that the SIC increases in most regions of the Southern Ocean except for those adjacent to the Antarctic Peninsula, wherein the decreasing SIC trend is evident in austral warm seasons. This trend mode also explains that the sea ice in the Weddell Sea is increasing in austral summer and decreasing in austral winter. The Principal Component (PC) of this model is negatively corrected with the Southern Annular Mode index with a correlation coefficient of about −0.5. The third mode of SIC (2.48%) represents a wavenumber‐2 Antarctic Circumpolar Wave mode that is linked to ENSO. As the CSEOF method decomposes the space‐time SIC field into low‐frequency modulations of phase‐locked annual cycles, it can be used for SIC prediction, by taking the spatial modes as the basis functions and predicting their PCs from the autoregressive models. However, this CSEOF‐based SIC prediction model exhibits unsatisfactory forecast skills, even with optimized model parameters. Therefore, it is still necessary to study more SIC prediction models and evaluate their forecast skills in the future.
An Extension of the Guided Wave M‐Component Model Taking Into Account the Presence of a Tall Strike Object
Authors: Li Quanxin , Rachidi Farhad , Rubinstein Marcos , Wang Jianguo , Azadifar Mohammad , Cai Li , Wang Junlin , Zhou Mi , Fan Yadong
Published: September 2021

We present in this paper an extension of the guided‐wave M‐component model of Rakov et al. considering the presence of a vertically elevated strike object. The tall object is represented as a lossless, uniform transmission line. Expressions for the current distribution along the channel and along the strike object are derived. Simulation results for the electric field at close (100 m), intermediate (15 km), and far (100 km) distance ranges are presented, considering fast and slow M‐component currents. The results show that, for very tall structures and fast M‐component waves, the presence of a tall strike object can result in a sharp peak superimposed on the M‐component electric field at intermediate and far distance ranges (e.g., 15 and 100 km). At close distances, the electric field of a fast M‐component is characterized by an initial negative excursion followed by a polarity change. It is shown that the presence of the tower results in a decrease of the negative initial excursion of the field. For slow M‐component waveforms or for moderately tall structures, the presence of the tall strike object can be disregarded in the M‐component field calculations. A discussion on the influence of the M‐wave channel height and velocity on the electric fields for fast M‐component currents is also presented. The study suggests a noticeable effect of the M‐wave velocity on the electric fields at all distance ranges. The variations of the wave velocity and channel length affect the time of appearance of the superimposed sharp peak on the electric fields. However, the sharp peak magnitude, which is due to the presence of the tower, is independent of the channel length and wave velocity. It is determined by the injected current and the reflection coefficients from the ground and tower top.
Recognition of Inter‐Cloud Versus Intra‐Cloud Controls on Droplet Dispersion With Applications to Microphysics Parameterization
Authors: Hu Arthur Z. , Igel Adele L. , Chuang Patrick Y. , Witte Mikael K.
Published: September 2021

Aerosols in the atmosphere can have a large impact on weather and climate. One of its lesser‐known impacts is the aerosol‐dispersion effect, which refers to the feedback between the aerosol (or cloud droplet) concentration and the relative dispersion of the droplet size distribution. This study attempts to reconcile the inconsistent sign of the correlation between aerosol number and droplet dispersion found in past studies by distinguishing local correlation from cloud‐mean correlation. We find that while the cloud‐mean correlation between aerosol concentration and droplet size relative dispersion is largely nonexistent, in‐cloud regions with high relative dispersion are typically associated with low local droplet concentration. Even stronger correlation is found with respect to the local activation fraction (the ratio of droplet concentration to total droplet and aerosol concentration). Based on this local correlation, we propose a new equation to diagnose the shape parameter in marine stratocumulus clouds for double moment bulk schemes in cloud‐resolving or large‐eddy simulations. This new equation is more physically realistic than many existing ones that are based on the weak cloud‐mean correlation.
Cloud‐Radiation Interactions and Their Contributions to Convective Self‐Aggregation
Authors: Pope Kieran N. , Holloway Christopher E. , Jones Todd R. , Stein Thorwald H. M.
Published: September 2021

This study investigates the direct radiative‐convective processes that drive and maintain aggregation within convection‐permitting elongated channel (and smaller square) simulations of the UK Met Office Unified Model. Our simulations are configured using three fixed sea surface temperatures (SSTs) following the Radiative‐Convective Equilibrium Model Intercomparison Project (RCEMIP) protocol. By defining cloud types based on the profile of condensed water, we study the importance of radiative interactions with each cloud type to aggregation. We eliminate the SST dependence of the vertically integrated frozen moist static energy (FMSE) variance budget framework by normalizing FMSE between hypothetical upper and lower limits based on SST. The elongated channel simulations reach similar degrees of aggregation across SSTs, despite shortwave and longwave interactions with FMSE contributing less to aggregation as SST increases. High‐cloud longwave interactions are the main drivers and maintainers of aggregation. Their influence decreases with SST as high clouds become less abundant. This SST dependence is consistent with changes in grid spacing and the critical humidity threshold for condensation (RHcrit). However, the domain‐mean longwave‐FMSE feedback would likely decrease as grid spacing and RHcrit are reduced by lowering the condensed water path and cloud top height of high‐cloud, and altering the distribution of different cloud types. Shortwave interactions with water vapor are key maintainers of aggregation and are dependent on SST and the degree of aggregation itself. The analysis method used provides a new framework to compare the effects of radiative‐convective processes on self‐aggregation across different SSTs and model configurations to help improve our understanding of self‐aggregation.
Development and Validation of Precipitation Enhanced Densities for the Empirical Canadian High Arctic Ionospheric Model
Authors: Watson C. , Themens D. R. , Jayachandran P. T.
Published: September 2021

The Empirical Canadian High Artic Ionospheric Model (E‐CHAIM) provides the four‐dimensional ionosphere electron density at northern high latitudes (>50° geomagnetic latitude). Despite its emergence as the most reliable model for high‐latitude ionosphere density, there remain significant deficiencies in E‐CHAIM's representation of the lower ionosphere (below ∼200 km) due to a sparsity of reliable measurements at these altitudes, particularly during energetic particle precipitation events. To address this deficiency, we have developed a precipitation component for E‐CHAIM to be driven by satellite‐based far‐ultraviolet (FUV) imager data. Satellite observations of FUV emissions may be used to infer the characteristics of energetic particle precipitation and subsequently calculate the precipitation‐enhanced ionization rates and ionosphere densities. In order to demonstrate the improvement of E‐CHAIM's ionosphere density representation with the addition of a precipitation component, this paper presents comparisons of E‐CHAIM precipitation‐enhanced densities with ionosphere density measurements of three auroral region incoherent scatter radars (ISRs) and one polar cap ISR. Calculations for 29,038 satellite imager and ISR conjunctions during the years 2005–2019 revealed that the root‐mean‐square difference between E‐CHAIM and ISR measurements decreased by up to 2.9 × 1010 ele/m3 (altitude dependent) after inclusion of the precipitation component at auroral sites, and by 2.6 × 109 ele/m3 in the polar cap. Improvements were most substantial in the winter season and during active auroral conditions. The sensitivity of precipitation‐enhanced densities to uncertainties inherent to the calculation method was also examined, with the bulk of the errors due to uncertainties in FUV imager data and choice of distribution function for precipitation energy spectra.
An Adjoint Sensitivity Model for Radionuclide Transport in Heterogeneous Discrete Fractured Porous Formation in Steady‐State Regime
Authors: Hayek Mohamed , RamaRao Banda S. , Lavenue Marsh
Published: September 2021

The development of the adjoint state method for the system of partial differential equations (PDEs) describing radionuclide transport in heterogeneous discrete fractured porous media in steady‐state regime is presented in this study for both continuous and discrete adjoint approaches. The continuous adjoint approach has its own advantage in the sense that the adjoint system can be derived in terms of PDEs which can be solved analytically for specific performance measures. These PDEs can then be used to obtain a physical interpretation of the adjoint state functions. The discrete adjoint approach permits a simpler mathematical treatment based on the use of the same matrix (or its transpose) of the linear system of the discretized transport equations referring to from hereon as the forward problem. Analytical solutions for both the forward problem and its associated adjoint problem have been derived for radionuclide transport in layered formations including a fracture using an analytical inversion of tridiagonal matrices. A set of 14 formulas of sensitivity coefficients with respect to pertinent system parameters has been derived and presented in integral forms. Analytical results have been compared with numerical results and have shown excellent agreements. The discrete adjoint approach has been coupled with the differential sensitivity analysis method and applied to a real field case involving the performance assessment of a site currently being considered for underground nuclear storage in northern Switzerland, Zürich Nordost. The results show that when a fracture is present in the vicinity of waste repository, the state parameter controlling flow through the fracture, referred to herein as fracture transmissivity, is among the important parameters which should be considered in sensitivity analysis studies.
Liproxstatin-1 attenuates unilateral ureteral obstruction-induced renal fibrosis by inhibiting renal tubular epithelial cells ferroptosis
Authors: Zhang Bo , Chen Xiang , Ru Feng , Gan Yu , Li Bingsheng , Xia Weiping , Dai Guoyu , He Yao , Chen Zhi
Published: September 2021

Renal fibrosis is a common pathological process that occurs with diverse etiologies in chronic kidney disease. However, its regulatory mechanisms have not yet been fully elucidated. Ferroptosis is a form of non-apoptotic regulated cell death driven by iron-dependent lipid peroxidation. It is currently unknown whether ferroptosis is initiated during unilateral ureteral obstruction (UUO)-induced renal fibrosis and its role has not been determined. In this study, we demonstrated that ureteral obstruction induced ferroptosis in renal tubular epithelial cells (TECs) in vivo. The ferroptosis inhibitor liproxstatin-1 (Lip-1) reduced iron deposition, cell death, lipid peroxidation, and inhibited the downregulation of GPX4 expression induced by UUO, ultimately inhibiting ferroptosis in TECs. We found that Lip-1 significantly attenuated UUO-induced morphological and pathological changes and collagen deposition of renal fibrosis in mice. In addition, Lip-1 attenuated the expression of profibrotic factors in the UUO model. In vitro, we used RSL3 treatment and knocked down of GPX4 level by RNAi in HK2 cells to induce ferroptosis. Our results indicated HK2 cells secreted various profibrotic factors during ferroptosis. Lip-1 was able to inhibit ferroptosis and thereby inhibit the secretion of the profibrotic factors during the process. Incubation of kidney fibroblasts with culture medium from RSL3-induced HK2 cells promoted fibroblast proliferation and activation, whereas Lip-1 impeded the profibrotic effects. Our study found that Lip-1 may relieve renal fibrosis by inhibiting ferroptosis in TECs. Mechanistically, Lip-1 could reduce the activation of surrounding fibroblasts by inhibiting the paracrine of profibrotic factors in HK2 cells. Lip-1 may potentially be used as a therapeutic approach for the treatment of UUO-induced renal fibrosis.
EMP3 negatively modulates breast cancer cell DNA replication, DNA damage repair, and stem-like properties
Authors: Zhou Kailing , Sun Yu , Dong Dan , Zhao Chenghai , Wang Wei
Published: September 2021

Enhanced DNA damage repair capacity attenuates cell killing of DNA-damaging chemotherapeutic agents. In silico analysis showed that epithelial membrane protein 3 (EMP3) is associated with favorable survival, and negatively regulates cell cycle S-phase. Consistently, loss and gain of function studies demonstrated that EMP3 inhibits breast cancer cell S-phage entry, DNA replication, DNA damage repair, and stem-like properties. Moreover, EMP3 blocks Akt-mTOR signaling activation and induces autophagy. EMP3 negatively modulates BRCA1 and RAD51 expression, indicating EMP3 suppresses homologous recombination repair of DNA double-strand breaks. Accordingly, EMP3 sensitizes breast cancer cells to the DNA-damaging drug Adriamycin. EMP3 downregulates YTHDC1, a RNA-binding protein involved in m6a modification, which at least in part mediates the effects of EMP3 on breast cancer cells. Taken together, these data indicate that EMP3 is a putative tumor suppressor in breast cancer, and EMP3 downregulation may be responsible for breast cancer chemoresistance.
Adipocytes disrupt the translational programme of acute lymphoblastic leukaemia to favour tumour survival and persistence
Authors: Heydt Q. , Xintaropoulou C. , Clear A. , Austin M. , Pislariu I. , Miraki-Moud F. , Cutillas P. , Korfi K. , Calaminici M. , Cawthorn W. , Suchacki K. , Nagano A. , Gribben J. G. , Smith M. , Cavenagh J. D. , Oakervee H. , Castleton A. , Taussig D. , Peck B. , Wilczynska A. , McNaughton L. , Bonnet D. , Mardakheh F. , Patel B.
Published: September 2021

The specific niche adaptations that facilitate primary disease and Acute Lymphoblastic Leukaemia (ALL) survival after induction chemotherapy remain unclear. Here, we show that Bone Marrow (BM) adipocytes dynamically evolve during ALL pathogenesis and therapy, transitioning from cellular depletion in the primary leukaemia niche to a fully reconstituted state upon remission induction. Functionally, adipocyte niches elicit a fate switch in ALL cells towards slow-proliferation and cellular quiescence, highlighting the critical contribution of the adipocyte dynamic to disease establishment and chemotherapy resistance. Mechanistically, adipocyte niche interaction targets posttranscriptional networks and suppresses protein biosynthesis in ALL cells. Treatment with general control nonderepressible 2 inhibitor (GCN2ib) alleviates adipocyte-mediated translational repression and rescues ALL cell quiescence thereby significantly reducing the cytoprotective effect of adipocytes against chemotherapy and other extrinsic stressors. These data establish how adipocyte driven restrictions of the ALL proteome benefit ALL tumours, preventing their elimination, and suggest ways to manipulate adipocyte-mediated ALL resistance.
A physicochemical orthophosphate cycle via a kinetically stable thermodynamically activated intermediate enables mild prebiotic phosphorylations
Authors: Maguire Oliver R. , Smokers Iris B. A. , Huck Wilhelm T. S.
Published: September 2021

The incorporation of orthophosphate from scarce geochemical sources into the organic compounds essential for life under mild conditions is a fundamental challenge for prebiotic chemistry. Here we report a prebiotic system capable of overcoming this challenge by taking inspiration from extant life’s recycling of orthophosphate via its conversion into kinetically stable thermodynamically activated (KSTA) nucleotide triphosphates (e.g. ATP). We separate the activation of orthophosphate from its transfer to organic compounds by, crucially, first accumulating a KSTA phosphoramidate. We use cyanate to activate orthophosphate in aqueous solution under mild conditions and then react it with imidazole to accumulate the KSTA imidazole phosphate. In a paste, imidazole phosphate phosphorylates all the essential building blocks of life. Integration of this chemistry into a wet/dry cycle enables the continuous recycling of orthophosphate and the accretion of phosphorylated compounds. This system functions even at low reagent concentrations due to solutes concentrating during evaporation. Our system demonstrates a general strategy for how to maximise the usage of scarce resources based upon cycles which accumulate and then release activated intermediates.
A CRISPR/Cas9 genetically engineered organoid biobank reveals essential host factors for coronaviruses
Authors: Beumer Joep , Geurts Maarten H. , Lamers Mart M. , Puschhof Jens , Zhang Jingshu , van der Vaart Jelte , Mykytyn Anna Z. , Breugem Tim I. , Riesebosch Samra , Schipper Debby , van den Doel Petra B. , de Lau Wim , Pleguezuelos-Manzano Cayetano , Busslinger Georg , Haagmans Bart L. , Clevers Hans
Published: September 2021

Rapid identification of host genes essential for virus replication may expedite the generation of therapeutic interventions. Genetic screens are often performed in transformed cell lines that poorly represent viral target cells in vivo, leading to discoveries that may not be translated to the clinic. Intestinal organoids are increasingly used to model human disease and are amenable to genetic engineering. To discern which host factors are reliable anti-coronavirus therapeutic targets, we generate mutant clonal IOs for 19 host genes previously implicated in coronavirus biology. We verify ACE2 and DPP4 as entry receptors for SARS-CoV/SARS-CoV-2 and MERS-CoV respectively. SARS-CoV-2 replication in IOs does not require the endosomal Cathepsin B/L proteases, but specifically depends on the cell surface protease TMPRSS2. Other TMPRSS family members were not essential. The newly emerging coronavirus variant B.1.1.7, as well as SARS-CoV and MERS-CoV similarly depended on TMPRSS2. These findings underscore the relevance of non-transformed human models for coronavirus research, identify TMPRSS2 as an attractive pan-coronavirus therapeutic target, and demonstrate that an organoid knockout biobank is a valuable tool to investigate the biology of current and future emerging coronaviruses.
Structure of human cytomegalovirus virion reveals host tRNA binding to capsid-associated tegument protein pp150
Authors: Liu Yun-Tao , Strugatsky David , Liu Wei , Zhou Z. Hong
Published: September 2021

Under the Baltimore nucleic acid-based virus classification scheme, the herpesvirus human cytomegalovirus (HCMV) is a Class I virus, meaning that it contains a double-stranded DNA genome—and no RNA. Here, we report sub-particle cryoEM reconstructions of HCMV virions at 2.9 Å resolution revealing structures resembling non-coding transfer RNAs (tRNAs) associated with the virion’s capsid-bound tegument protein, pp150. Through deep sequencing, we show that these RNA sequences match human tRNAs, and we built atomic models using the most abundant tRNA species. Based on our models, tRNA recruitment is mediated by the electrostatic interactions between tRNA phosphate groups and the helix-loop-helix motif of HCMV pp150. The specificity of these interactions may explain the absence of such tRNA densities in murine cytomegalovirus and other human herpesviruses.
Structural insight into the mechanism of energy transfer in cyanobacterial phycobilisomes
Authors: Zheng Lvqin , Zheng Zhenggao , Li Xiying , Wang Guopeng , Zhang Kun , Wei Peijun , Zhao Jindong , Gao Ning
Published: September 2021

Phycobilisomes (PBS) are the major light-harvesting machineries for photosynthesis in cyanobacteria and red algae and they have a hierarchical structure of a core and peripheral rods, with both consisting of phycobiliproteins and linker proteins. Here we report the cryo-EM structures of PBS from two cyanobacterial species, Anabaena 7120 and Synechococcus 7002. Both PBS are hemidiscoidal in shape and share a common triangular core structure. While the Anabaena PBS has two additional hexamers in the core linked by the 4th linker domain of ApcE (LCM). The PBS structures predict that, compared with the PBS from red algae, the cyanobacterial PBS could have more direct routes for energy transfer to ApcD. Structure-based systematic mutagenesis analysis of the chromophore environment of ApcD and ApcF subunits reveals that aromatic residues are critical to excitation energy transfer (EET). The structures also suggest that the linker protein could actively participate in the process of EET in both rods and the cores. These results provide insights into the organization of chromophores and the mechanisms of EET within cyanobacterial PBS.
Atomic-scale imaging of CH3NH3PbI3 structure and its decomposition pathway
Authors: Chen Shulin , Wu Changwei , Han Bo , Liu Zhetong , Mi Zhou , Hao Weizhong , Zhao Jinjin , Wang Xiao , Zhang Qing , Liu Kaihui , Qi Junlei , Cao Jian , Feng Jicai , Yu Dapeng , Li Jiangyu , Gao Peng
Published: September 2021

Understanding the atomic structure and structural instability of organic-inorganic hybrid perovskites is the key to appreciate their remarkable photoelectric properties and understand failure mechanism. Here, using low-dose imaging technique by direct-detection electron-counting camera in a transmission electron microscope, we investigate the atomic structure and decomposition pathway of CH3NH3PbI3 (MAPbI3) at the atomic scale. We successfully image the atomic structure of perovskite in real space under ultra-low electron dose condition, and observe a two-step decomposition process, i.e., initial loss of MA+ followed by the collapse of perovskite structure into 6H-PbI2 with their critical threshold doses also determined. Interestingly, an intermediate phase (MA0.5PbI3) with locally ordered vacancies can robustly exist before perovskite collapses, enlightening strategies for prevention and recovery of perovskite structure during the degradation. Associated with the structure evolution, the bandgap gradually increases from ~1.6 eV to ~2.1 eV. In addition, it is found that C-N bonds can be readily destroyed under irradiation, releasing NH3 and HI and leaving hydrocarbons. These findings enhance our understanding of the photoelectric properties and failure mechanism of MAPbI3, providing potential strategies into material optimization.
Argininosuccinate lyase is a metabolic vulnerability in breast development and cancer
Authors: Karvelsson Sigurdur Trausti , Wang Qiong , Hilmarsdottir Bylgja , Sigurdsson Arnar , Moestue Siver Andreas , Mælandsmo Gunhild Mari , Halldorsson Skarphedinn , Gudmundsson Steinn , Rolfsson Ottar
Published: September 2021

Epithelial-to-mesenchymal transition (EMT) is fundamental to both normal tissue development and cancer progression. We hypothesized that EMT plasticity defines a range of metabolic phenotypes and that individual breast epithelial metabolic phenotypes are likely to fall within this phenotypic landscape. To determine EMT metabolic phenotypes, the metabolism of EMT was described within genome-scale metabolic models (GSMMs) using either transcriptomic or proteomic data from the breast epithelial EMT cell culture model D492. The ability of the different data types to describe breast epithelial metabolism was assessed using constraint-based modeling which was subsequently verified using 13C isotope tracer analysis. The application of proteomic data to GSMMs provided relatively higher accuracy in flux predictions compared to the transcriptomic data. Furthermore, the proteomic GSMMs predicted altered cholesterol metabolism and increased dependency on argininosuccinate lyase (ASL) following EMT which were confirmed in vitro using drug assays and siRNA knockdown experiments. The successful verification of the proteomic GSMMs afforded iBreast2886, a breast GSMM that encompasses the metabolic plasticity of EMT as defined by the D492 EMT cell culture model. Analysis of breast tumor proteomic data using iBreast2886 identified vulnerabilities within arginine metabolism that allowed prognostic discrimination of breast cancer patients on a subtype-specific level. Taken together, we demonstrate that the metabolic reconstruction iBreast2886 formalizes the metabolism of breast epithelial cell development and can be utilized as a tool for the functional interpretation of high throughput clinical data.
Long-term warming and nitrogen fertilization affect C-, N- and P-acquiring hydrolase and oxidase activities in winter wheat monocropping soil
Authors: Zhang Chuang , Dong Wenxu , Manevski Kiril , Hu Wenpei , Timilsina Arbindra , Chen Xiaoru , Zhang Xinyuan , Hu Chunsheng
Published: September 2021

The enzymatic activities and ratios are critical indicators for organic matter decomposition and provide potentially positive feedback to carbon (C) loss under global warming. For agricultural soils under climate change, the effect of long-term warming on the activities of oxidases and hydrolases targeting C, nitrogen (N) and phosphorus (P) and their ratios is unclear, as well as whether and to what extend the response is modulated by long-term fertilization. A 9-year field experiment in the North China Plain, including an untreated control, warming, N fertilization, and combined (WN) treatment plots, compared the factorial effect of warming and fertilization. Long-term warming interacted with fertilization to stimulate the highest activities of C, N, and P hydrolases. Activities of C and P hydrolase increased from 8 to 69% by N fertilization, 9 to 53% by warming, and 28 to 130% by WN treatment compared to control, whereas the activities of oxidase increased from 4 to 16% in the WN soils. Both the warming and the WN treatments significantly increased the enzymatic C:N ratio from 0.06 to 0.16 and the vector length from 0.04 to 0.12 compared to the control soil, indicating higher energy and resource limitation for the soil microorganisms. Compared to WN, the warming induced similar ratio of oxidase to C hydrolase, showing a comparable ability of different microbial communities to utilize lignin substrates. The relationship analyses showed mineralization of organic N to mediate the decomposition of lignin and enzyme ratio in the long-term warming soil, while N and P hydrolases cooperatively benefited to induce more oxidase productions in the soil subject to both warming and N fertilization. We conclude that coupled resource limitations induced microbial acclimation to long-term warming in the agricultural soils experiencing high N fertilizer inputs.
Influence of atmospheric deposition on surface water quality and DBP formation potential as well as control technology of rainwater DBPs: a review
Authors: Shi Minghao , Geng Bing , Zhao Tiantao , Wang Feifei
Published: September 2021

This manuscript mainly conducted a literature review of the contribution of atmospheric dry and wet deposition to surface water quality and DBP formation potential.
Synergetic contribution of fluorinated azide for high EQE and operational stability of top-illuminated, semitransparent, photomultiplication-type organic photodiodes
Authors: Kim Juhee , Joo Chul Woong , Hassan Syed Zahid , Yu Seong Hoon , Kang Mingyun , Pi Jae-Eun , Kang Seung-Youl , Park Young-Sam , Chung Dae Sung
Published: September 2021

A fluorinated azide can improve the EQE and long-term stability of photomultiplication-type organic photodiodes (PM-OPDs). The resulting top-illuminated, semitransparent, stable, and high-EQE PM-OPD is successfully applied to a fingerprint sensor.
Influence of sample momentum space features on scanning tunnelling microscope measurements
Authors: West Maxwell T. , Usman Muhammad
Published: September 2021

Scanning tunnelling microscopy (STM) images are shown to depend on the momentum space features of sample electronic states, with important implications for material design and characterisation, and applications in quantum computing, quantum sensing and photonics.
Copper-catalysed low-temperature water–gas shift reaction for selective deuteration of aryl halides
Authors: Li Wu , Qu Ruiyang , Liu Weiping , Bourriquen Florian , Bartling Stephan , Rockstroh Nils , Junge Kathrin , Beller Matthias
Published: September 2021

A practical and stable heterogeneous copper catalyst has been developed for dehalogenative deuteration via water–gas shift reaction at low temperature, allowing deuteration of diverse (hetero)aryl halides with good functional group tolerance.
The solvation structure, transport properties and reduction behavior of carbonate-based electrolytes of lithium-ion batteries
Authors: Hou Tingzheng , Fong Kara D. , Wang Jingyang , Persson Kristin A.
Published: September 2021

The different roles of the anion, cyclic and linear carbonates, and additive in mixed-carbonate electrolytes are revealed. The anion–solvent exchange mechanism and factors influencing the solid electrolyte interphase (SEI) formation are deciphered.
Octavinyl polyhedral oligomeric silsesquioxane on tailoring the DC electrical characteristics of polypropylene
Authors: Lin Xiaosi , Siew Wah Hoon , Liggat John , Given Martin , He Jinliang
Published: September 2021

This work reports the effect of octavinyl polyhedral oligomeric silsesquioxane (OvPOSS) on tuning the electrical performance of polypropylene (PP). OvPOSS with different content are introduced into PP using the solution method. The microstructural morphology, crystallinity behaviour, breakdown strength, DC conductivity, space charge formation, and trapping level distribution are measured. The results indicate that the OvPOSS nanofiller can be dispersed uniformly with a doping content of 2.0 phr or less. The DC conductivity is decreased, and the breakdown strength of OvPOSS/PP nanocomposites is significantly increased. The space charge accumulation of the OvPOSS/PP nanocomposites is significantly suppressed due to the introduction of deeper traps by the OvPOSS nanofiller. Finally, the experimental results demonstrate that the OvPOSS nanofiller can greatly increase the electrical performance of the base PP and the OvPOSS/PP nanocomposites have much potential for HVDC applications. They further demonstrate that the PP is environmental‐friendly due to its thermo‐plastic property, which can be recycled after the manufacture.
Learning compact ConvNets through filter pruning based on the saliency of a feature map
Authors: Liu Zhoufeng , Liu Xiaohui , Li Chunlei , Ding Shumin , Liao Liang
Published: September 2021

With the performance increase of convolutional neural network (CNN), the disadvantages of CNN's high storage and high power consumption are followed. Among the methods mentioned in various literature, filter pruning is a crucial method for constructing lightweight networks. However, the current filter pruning method is still challenged by complicated processes and training inefficiency. This paper proposes an effective filter pruning method, which uses the saliency of the feature map (SFM), i.e. information entropy, as a theoretical guide for whether the filter is essential. The pruning principle use here is that the filter with a weak saliency feature map in the early stage will not significantly improve the final accuracy. Thus, one can efficiently prune the non‐salient feature map with a smaller information entropy and the corresponding filter. Besides, an over‐parameterized convolution method is employed to improve the pruned model's accuracy without increasing parameter at inference time. Experimental results show that without introducing any additional constraints, the effectiveness of this method in FLOPs and parameters reduction with similar accuracy has advanced the state‐of‐the‐art. For example, on CIFAR‐10, the pruned VGG‐16 achieves only a small loss of 0.39% in Top‐1 accuracy with a factor of 83.3% parameters, and 66.7% FLOPs reductions. On ImageNet‐100, the pruned ResNet‐50 achieves only a small accuracy degradation of 0.76% in Top‐1 accuracy with a factor of 61.19% parameters, and 62.98% FLOPs reductions.
The BER performance of a FSO system with polar codes under weak turbulence
Authors: Mohan Nithin , Ghassemlooy Zabih , Li Emma , Abadi Mojtaba Mansour , Zvanovec Stanislav , Hudson Ralph , Htay Zun
Published: September 2021

The key challenge in free space optical (FSO) communications is combating turbulence‐induced fading. As the channel fading in FSO is quasi‐static, the transmission parameters such as the code rates, transmit power and modulation schemes can be modified with respect to the channel state information transmitted via the feedback path. As a result, adaptive channel coding is considered as one of the practical approaches to improve the FSO link performance. In this study, the FSO system with polar codes is investigated and its performance is analysed by determining the optimum code‐rate required to achieve a bit error rate of 10−9 under weak turbulence. It is shown that, using Monte‐Carlo simulations for the scintillation indices of 0.12 and 0.2, the successive cancelation list (SCL) decoder offers coding gains of 2.5 and 0.3 dB, respectively, as compared with SC decoder, and for the scintillation index of 0.31, the SC decoder offers a coding gain of 2.5 dB compared to that of the SCL decoder for the code rate.
Comparative analysis of the effect of Ca and Mg-Al modification on the composite inclusions in S50C Die steel
Authors: Cao Chen-wei , Wang Gao-feng , Li Jie , Tian Qian-ren , Zhu Qiang-bin , Ai Ke-nan , Fu Jian-xun
Published: September 2021

At present, the effective ways to improve the cleanliness of S50C die steel are Ca or Mg-Al treatment processes. In order to explore the effect difference of two kinds of modification process of S50C killed steel, evaluate the industrial application prospect of the two processes, and clarify the modification mechanism. In this paper, the advantages of Mg-Al modification are demonstrated from the aspects of theoretical basis and actual sample modification effect. The thermodynamics and kinetics of inclusion precipitation, composition, morphology, and distribution are analyzed. The results show that: the precipitation temperature of MnS in S50C die steel is 1686 K, the corresponding solid-phase rate is 0.98. In Mg-Al modification, when the Al content is 332 ppm, the Mg content should be controlled below 14.1 ppm. When the Al content is higher than 0.02%, the Ca content should be controlled below 28.7 ppm. Kinetic calculations show that the equilibrium shape size of MnS is in the range of 0.3‑1.4 µm. Both modifications increase the nucleation rate of inclusions and control the shape and size of inclusions by pre-precipitation. Ca treatment is preventing the formation of large inclusions by forming calcium aluminate. Mg can provide more uniform nucleation sites and form smaller inclusions.
Near-room temperature ferromagnetic behavior of single-atom-thick 2D iron in nanolaminated ternary MAX phases
Authors: Li Youbing , Liang Jinghua , Ding Haoming , Lu Jun , Mu Xulin , Yan Pengfei , Zhang Xiao , Chen Ke , Li Mian , Persson Per O. Å. , Hultman Lars , Eklund Per , Du Shiyu , Yang Hongxin , Chai Zhifang , Huang Qing
Published: September 2021

Mn+1AXn (MAX) phases' nanolaminated ternary carbides or nitrides possess a unique crystal structure in which single-atom-thick “A” sublayers are interleaved by alternative stacking of a “Mn+1Xn” sublayer; these materials have been investigated as promising high-safety structural materials for industrial applications because of their laminated structure and metal and ceramic properties. However, limited of A-site elements in the definition of Mn+1AXn phases, it is a huge challenge for designing nanolaminated ferromagnetic materials with single-atom-thick two-dimensional iron layers occupying the A layers in the Mn+1AXn phases. Here, we report three new ternary magnetic Mn+1AXn phases (Ta2FeC, Ti2FeN, and Nb2FeC) with A sublayers of single-atom-thick two-dimensional iron through an isomorphous replacement reaction of Mn+1AXn precursors (Ta2AlC, Ti2AlN, and Nb2AlC) with a Lewis acid salts (FeCl2). All these Mn+1AXn phases exhibit ferromagnetic behavior. The Curie temperatures of the Ta2FeC and Nb2FeC Mn+1AXn phases are 281 and 291 K, respectively, i.e., close to room temperature. The saturation magnetization of these ternary magnetic MAX phases is almost two orders of magnitude higher than V2(Sn,Fe)C, whose A-site is partially substituted by Fe. Theoretical calculations on magnetic orderings of spin moments of Fe atoms in these nanolaminated magnetic Mn+1AXn phases reveal that the magnetism can be mainly ascribed to an intralayer exchange interaction of the two-dimensional Fe atomic layers. Owing to the richness in composition of Mn+1AXn phases, our work provides a large imaginary space for constructing functional single-atom-thick two-dimensional layers in materials using these nanolaminated templates.
A Comparison of Bats and Birds as Pollinators of Banksia integrifolia in Northern New South Wales, Australia.
Authors: Woodside D.P. , Pyke G.H.
Published: September 2021

We captured Queensland Blossom Bats (Syconycteris australis) feeding at the flowers of Banksia integrifolia during the night and several honeyeater species feeding at the same flowers during the day. Nearby were flowering Melaleuca quinquenervia and various forested areas including littoral rainforest. Honeyeaters appear to be more frequent visitors to the Banksia flowers than Blossom Bats but less effective at transporting pollen. When they are feeding at Banksia flowers both birds and bats carry pollen on the parts of their bodies that contact successive inflorescences. Hence, both honeyeaters and bats are likely to be pollinators of B. integrifolia in our study area. However, the flowers produce nectar and dehisce pollen primarily at night, suggesting that Blossom Bats are more important than honeyeaters as pollinators of this plant. Banksia pollen was the most common item in the diet of the Blossom Bats during our study and the bats were able to digest the contents of this pollen. Interestingly, the diet of these animals also included relatively small amounts of Melaleuca pollen, fruit and arthropods. The spatial and temporal patterns of capture of the Blossom Bats suggested that Blossom Bats prefer to forage at Banksia flowers that are near to the forested areas and that adult bats may influence where and when younger bats feed. Banksia integrifolia appears to produce nectar mostly during the night and/or early morning in two different locations, one coastal and one on the tablelands, but shows different daily patterns of pollen anthesis in these locations.
Hybridisation Between Black (Pteropods alecto) and Grey- Headed (P. poliocephalus) Flying-Foxes (Megachiroptera: Pteropodidae).
Authors: Webb N.J. , Tidemann C.R.
Published: September 2021

The range of the black flying-fox (Pteropus alecto) in Australia overlaps with two morphologically very similar congenerics: the grey-headed flying-fox (P. poliocephalus) and the spectacled flying-fox (P. conspecillatus). Protein electrophoresis was used to examine cases of apparent hybridisation between P. alecto and these other species. Two loci with fixed allelic differences were identified between P. alecto and P. poliocephalus and were used to confirm three cases of interspecific hybridisation, one of which probably occurred in the wild, and one of backcrossing. Hybrid individuals possessed external characteristics that were intermediate between the parental species. Pteropus alecto and P. conspecillatus showed very little genetic differentiation and only one out of 23 scorable loci showed a fixed allelic difference. A reported interspecific hybrid, and two other flying-foxes, considered to be possible P. alecto/P. conspecillatus hybrids, failed to show the expected heterozygous condition at this locus. Further diagnostic loci need to be sought before a definite conclusion can be made concerning the hybrid status of these individuals. The very close morphological similarity of P. alecto and P. conspecillatus, combined with their genetic similarity, suggests that more discriminating DNA based techniques would be necessary to fully describe the relationships between these closely related species.
Systematic Revision Within the Phalanger ornatus Complex (Phalangeridae: Marsupialia), With Description of a New Species and Subspecies.
Authors: Flannery T.F. , Boeadi
Published: September 2021

The Phalanger ornatus species complex includes three species (P. omatus, P. rothschildi, and P. alexandrae n. sp.), which have allopatric distributions on the islands of the North Moluccas, Indonesia. They are unique in the genus in sharing a plesiomorphic condition (a diastema between C1 and I3) (Flannery et al. 1987). There is considerable geographic variation within Phalanger omatus, and two subspecies (P. o. ornatus from Batjan, Halmahera and possibly Morotai; and P.o. matabiru from Temate and Tidore) are recognised here.
Genetic Analysis of a Female Macropodid Hybrid (Macropus agilis X M. rufogriseus) and Her Backcross Offspring.
Authors: Lowry P.S. , Eldridge M.D.B. , Johnston P.G.
Published: September 2021

NA
Tail Fat Storage in Arid Zone Bandicoots.
Authors: Gordon G. , Hall L.S.
Published: September 2021

NA
Current Literature
Authors: Calaby J.H.
Published: September 2021

NA
Observation of Three Dingoes Killing A Large Lace Monitor (Varanus varius).
Authors: Webb J.K.
Published: September 2021

NA
The Home Range and Habitat Utilisation of Cercartetus nanus (Marsupialia: Burramyidae) In Coastal Heathland, Anglesea, Victoria.
Authors: Laidlaw W.S. , Wilson B A.
Published: September 2021

NA
Australian Mammalogy Reviews: Mammals of Victoria: Distribution, Ecology and Conservation.
Authors: Mckay M.
Published: September 2021

NA
Foreword: Oraparinna In Perspective.
Authors: Close R.L.
Published: September 2021

NA