bluuebunny/crossref_metadata_2025_split huggingface dataset:
Authigenic Ferrimagnetic Iron Sulfide Preservation Due to Nonsteady State Diagenesis: A Perspective From Perseverance Drift, Northwestern Weddell Sea
Authors: Reilly Brendan T. , McCormick Michael L. , Brachfeld Stefanie A. , Haley Brian A. 
Published: October 2020

AbstractWe document magnetic mineral diagenesis with high‐resolution magnetic susceptibility, hysteresis, isothermal remanent magnetization, and other rock magnetic measurements through a shallow sulfate‐methane transition (SMT) at Perseverance Drift—a high‐accumulation rate Holocene biosiliceous Antarctic marine sediment deposit. The structure of the SMT is defined with porewater measurements from the same core, allowing direct comparison. Dissolution of the detrital (titano)magnetite assemblage, with preferential dissolution of stochiometric magnetite, occurs in the upper SMT. Higher coercivity magnetic minerals dissolve more slowly, continuing to dissolve through the entire SMT and could be a source of ferric iron for microbial respiration following exhaustion of porewater sulfate, as suggested by accumulation of porewater ferrous iron below the SMT. Superparamagnetic ferrimagnetic mineral enrichment/depletion occurs in three phases through the SMT and is coupled tightly to the availability of dissolved ferrous iron relative to dissolved sulfide. High concentrations of authigenic remanence‐bearing iron sulfides, including greigite and hexagonal 3C pyrrhotite, which can be detected using remanence parameters but not in‐field concentration dependent parameters, accumulate in a transient horizon at the base of the SMT during this early diagenesis, where sulfide is present but limited relative to dissolved ferrous iron. Formation of this remanence‐bearing iron sulfide horizon is likely facilitated by continued iron reduction through the SMT. Nonsteady state perturbations that shift the porewater profile, such as changes in carbon flux or sedimentation rate, can lead to preservation of these transient horizons, much like well documented preservation of manganese oxide layers in marine sediments following similar shifts to porewater profiles.
Dayside Polar Cap Density Enhancements Formed During Substorms
Authors: Goodwin L. V. , Nishimura Y. , Coster A. J. , Zhang S. , Nishitani N. , Ruohoniemi J. M. , Anderson B. J. , Zhang Q.‐H. 
Published: October 2020

AbstractThe formation of polar cap density enhancements, such as tongues‐of‐ionization (TOIs), are often attributed to enhanced dayside reconnection and convection due to solar wind changes. However, ionospheric poleward moving density enhancements can also form in the absence of changes in the solar wind. This study examines how TOI and patch events that are not triggered by solar wind changes relate to magnetospheric processes, specifically substorms. Based on total electron content and Super Dual Auroral Radar Network (SuperDARN) observations, we find substorms that occur at the same time as TOIs are associated with sudden enhancements in dayside poleward flows during the substorm expansion phase. Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) observations also show enhanced field‐aligned currents (FACs) that extend into the dayside ionosphere during this period. We suggest that the global enhancement of FACs and convection during these substorms are the drivers of these TOIs by enhancing dayside convection and transporting high‐density lower‐latitude plasma into the polar cap. However, we also find that not all substorms are coincident with polar cap density enhancements. A superposed epoch study showed that the AL index for TOIs during substorms is not particularly stronger than substorms without TOIs, but epoch studies of AMPERE observations do show events with TOIs to have a higher total FAC on both the dayside and nightside. Our results show the importance of TOI formation during substorms when solar wind drivers are absent, and the importance of considering substorms in the global current system. This work also shows the need to incorporate substorms into models of high‐latitude global convection and currents.
Temperature Trends in the Northwestern Tibetan Plateau Constrained by Ice Core Water Isotopes Over the Past 7,000 Years
Authors: Pang Hongxi , Hou Shugui , Zhang Wangbin , Wu Shuangye , Jenk Theo M. , Schwikowski Margit , Jouzel Jean 
Published: October 2020

AbstractThe reasons for the Holocene temperature conundrum, known as the inconsistency between the reconstructed cooling and the inferred warming simulations during the Holocene, remain unclear. Temperature reconstructions from the Tibetan Plateau (TP) provide important insights for understanding the Holocene temperature conundrum due to enhanced sensitivity to climate at high altitudes. Given the significant positive correlation between air temperature and δ18O in precipitation over the northern TP, the stable isotopic records of ice cores recovered from this area are widely used for paleotemperature reconstruction. Here we present a new high‐resolution δ18O record from the Chongce ice cores to bedrock, dated back to 7 ka BP by the accelerator mass spectrometry (AMS) 14C dating technique. Our reconstructed temperature record shows a long‐term warming trend until ~2 ka BP, followed by an abrupt change to a relatively cool period until the start of the industrial‐era warming. This record challenges the widely recognized Holocene reconstruction from the neighboring Guliya ice core. It is also different from many previous temperature reconstructions, most of which have summer biases and show a long‐term cooling trend over the past two millennia. In addition, our record shows that temperatures during the recent decades are almost the highest during the past 7 ka BP, highlighting the unusual warming forced by anthropogenic greenhouse gases.
SUV39H1 regulates the progression of MLL-AF9-induced acute myeloid leukemia
Authors: Chu Yajing , Chen Yangpeng , Guo Huidong , Li Mengke , Wang Bichen , Shi Deyang , Cheng Xuelian , Guan Jinxia , Wang Xiaomin , Xue Chenghai , Cheng Tao , Shi Jun , Yuan Weiping 
Published: October 2020

AbstractEpigenetic regulations play crucial roles in leukemogenesis and leukemia progression. SUV39H1 is the dominant H3K9 methyltransferase in the hematopoietic system, and its expression declines with aging. However, the role of SUV39H1 via its-mediated repressive modification H3K9me3 in leukemogenesis/leukemia progression remains to be explored. We found that SUV39H1 was down-regulated in a variety of leukemias, including MLL-r AML, as compared with normal individuals. Decreased levels of Suv39h1 expression and genomic H3K9me3 occupancy were observed in LSCs from MLL-r-induced AML mouse models in comparison with that of hematopoietic stem/progenitor cells. Suv39h1 overexpression increased leukemia latency and decreased the frequency of LSCs in MLL-r AML mouse models, while Suv39h1 knockdown accelerated disease progression with increased number of LSCs. Increased Suv39h1 expression led to the inactivation of Hoxb13 and Six1, as well as reversion of Hoxa9/Meis1 downstream target genes, which in turn decelerated leukemia progression. Interestingly, Hoxb13 expression is up-regulated in MLL-AF9-induced AML cells, while knockdown of Hoxb13 in MLL-AF9 leukemic cells significantly prolonged the survival of leukemic mice with reduced LSC frequencies. Our data revealed that SUV39H1 functions as a tumor suppressor in MLL-AF9-induced AML progression. These findings provide the direct link of SUV39H1 to AML development and progression.
SARS-CoV-2 triggers inflammatory responses and cell death through caspase-8 activation
Authors: Li Shufen , Zhang Yulan , Guan Zhenqiong , Li Huiling , Ye Meidi , Chen Xi , Shen Jun , Zhou Yiwu , Shi Zheng-Li , Zhou Peng , Peng Ke 
Published: October 2020

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to respiratory illness and multi-organ failure in critically ill patients. Although the virus-induced lung damage and inflammatory cytokine storm are believed to be directly associated with coronavirus disease 2019 (COVID-19) clinical manifestations, the underlying mechanisms of virus-triggered inflammatory responses are currently unknown. Here we report that SARS-CoV-2 infection activates caspase-8 to trigger cell apoptosis and inflammatory cytokine processing in the lung epithelial cells. The processed inflammatory cytokines are released through the virus-induced necroptosis pathway. Virus-induced apoptosis, necroptosis, and inflammation activation were also observed in the lung sections of SARS-CoV-2-infected HFH4-hACE2 transgenic mouse model, a valid model for studying SARS-CoV-2 pathogenesis. Furthermore, analysis of the postmortem lung sections of fatal COVID-19 patients revealed not only apoptosis and necroptosis but also massive inflammatory cell infiltration, necrotic cell debris, and pulmonary interstitial fibrosis, typical of immune pathogenesis in the lung. The SARS-CoV-2 infection triggered a dual mode of cell death pathways and caspase-8-dependent inflammatory responses may lead to the lung damage in the COVID-19 patients. These discoveries might assist the development of therapeutic strategies to treat COVID-19.
Modulation of cognition and neuronal plasticity in gain- and loss-of-function mouse models of the schizophrenia risk gene Tcf4
Authors: Badowska D. M. , Brzózka M. M. , Kannaiyan N. , Thomas C. , Dibaj P. , Chowdhury A. , Steffens H. , Turck C. W. , Falkai P. , Schmitt A. , Papiol S. , Scheuss V. , Willig K. I. , Martins-de-Souza D. , Rhee J. S. , Malzahn D. , Rossner M. J. 
Published: October 2020

AbstractThe transcription factor TCF4 was confirmed in several large genome-wide association studies as one of the most significant schizophrenia (SZ) susceptibility genes. Transgenic mice moderately overexpressing Tcf4 in forebrain (Tcf4tg) display deficits in fear memory and sensorimotor gating. As second hit, we exposed Tcf4tg animals to isolation rearing (IR), chronic social defeat (SD), enriched environment (EE), or handling control (HC) conditions and examined mice with heterozygous deletion of the exon 4 (Tcf4Ex4δ+/−) to unravel gene-dosage effects. We applied multivariate statistics for behavioral profiling and demonstrate that IR and SD cause strong cognitive deficits of Tcf4tg mice, whereas EE masked the genetic vulnerability. We observed enhanced long-term depression in Tcf4tg mice and enhanced long-term potentiation in Tcf4Ex4δ+/− mice indicating specific gene-dosage effects. Tcf4tg mice showed higher density of immature spines during development as assessed by STED nanoscopy and proteomic analyses of synaptosomes revealed concurrently increased levels of proteins involved in synaptic function and metabolic pathways. We conclude that environmental stress and Tcf4 misexpression precipitate cognitive deficits in 2-hit mouse models of relevance for schizophrenia.
N6-methyladenosine-dependent pri-miR-17-92 maturation suppresses PTEN/TMEM127 and promotes sensitivity to everolimus in gastric cancer
Authors: Sun Yiting , Li Song , Yu Wenbin , Zhao Zeyi , Gao Jing , Chen Cheng , Wei Meng , Liu Teng , Li Lanbo , Liu Lian 
Published: October 2020

AbstractN6-methyladenosine (m6A) is the most common epigenetic RNA modification with essential roles in cancer progression. However, roles of m6A and its regulator METTL3 on non-coding RNA in gastric cancer are unknown. In this study, we found elevated levels of m6A and METTL3 in gastric cancer. Increased METTL3 expression indicated poor outcomes of patients and high malignancy in vitro and in vivo. Mechanically, m6A facilitated processing of pri-miR-17-92 into the miR-17-92 cluster through an m6A/DGCR8-dependent mechanism. The m6A modification that mediated this process occurred on the A879 locus of pri-miR-17-92. The miR-17-92 cluster activated the AKT/mTOR pathway by targeting PTEN or TMEM127. Compared with those with low levels of METTL3, METTL3-high tumors showed preferred sensitivity to an mTOR inhibitor, everolimus. These results reveal a perspective on epigenetic regulations of non-coding RNA in gastric cancer progression and provide a theoretical rationale for use of everolimus in the treatment of m6A/METTL3-high gastric cancer.
Reconstructing the maize leaf regulatory network using ChIP-seq data of 104 transcription factors
Authors: Tu Xiaoyu , Mejía-Guerra María Katherine , Valdes Franco Jose A. , Tzeng David , Chu Po-Yu , Shen Wei , Wei Yingying , Dai Xiuru , Li Pinghua , Buckler Edward S. , Zhong Silin 
Published: October 2020

AbstractThe transcription regulatory network inside a eukaryotic cell is defined by the combinatorial actions of transcription factors (TFs). However, TF binding studies in plants are too few in number to produce a general picture of this complex network. In this study, we use large-scale ChIP-seq to reconstruct it in the maize leaf, and train machine-learning models to predict TF binding and co-localization. The resulting network covers 77% of the expressed genes, and shows a scale-free topology and functional modularity like a real-world network. TF binding sequence preferences are conserved within family, while co-binding could be key for their binding specificity. Cross-species comparison shows that core network nodes at the top of the transmission of information being more conserved than those at the bottom. This study reveals the complex and redundant nature of the plant transcription regulatory network, and sheds light on its architecture, organizing principle and evolutionary trajectory.
Ethnic and biological differences in the association between physical activity and survival after breast cancer
Authors: Cao Yunfeng , Baumgartner Kathy B. , Visvanathan Kala , Boone Stephanie D. , Baumgartner Richard N. , Connor Avonne E. 
Published: October 2020

AbstractPhysical activity is recommended for most cancer patients as a nonpharmacological therapy to improve prognosis. Few studies have investigated the association between physical activity and breast cancer prognosis by ethnicity, biological, and modifiable risk factors for mortality. We investigated the association between physical activity and long-term survival among breast cancer survivors. A total of 397 survivors (96 Hispanic and 301 non-Hispanic White (NHW)) from the New Mexico HEAL study contributed baseline and biological data approximately 6 months after diagnosis. Study outcomes included all-cause, breast cancer-specific, and non-breast cancer mortality. The exposure was self-reported physical activity within the past month. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox Proportional Hazards regression. A total of 133 deaths (53 breast cancer-specific deaths) were observed after a median follow-up time of 13 years. Engaging in >6.9 metabolic equivalent hours/week (MET-h/week) of moderate to vigorous physical activity (active) was inversely associated with all-cause mortality among all women (HR 0.66, 95% CI 0.43–0.99) and NHWs (HR 0.58, 95% CI 0.36–0.94). Active NHW women also had a reduced risk of non-breast cancer mortality (HR 0.56, 95% CI 0.31–0.99), compared to inactive women (0 MET-h/week). In subgroups, we observed the inverse associations with all-cause mortality among women >58 years old (p-interaction= 0.03) and with localized stage (p-interaction = 0.046). Our results confirm the protective association between physical activity and mortality after breast cancer diagnosis, and demonstrate that this association significantly differs by age and cancer stage. Larger studies are warranted to substantiate our findings.
Pragmatic trial on inhaled corticosteroid withdrawal in patients with COPD in general practice
Authors: van den Bemt Lisette , van den Nieuwenhof Lotte , Rutjes Anne , van der Meer Victor , Stege Gerben , Wensing Michel , Teichert Martina , Schermer Tjard 
Published: October 2020

AbstractThe therapeutic value of inhaled corticosteroids (ICSs) for COPD is limited. In published RCTs, ICS could be withdrawn in COPD patients without increasing exacerbation risk when bronchodilator treatment is optimized. Here we report on the feasibility and risks of ICS withdrawal in Dutch general practice for COPD patients without an indication for ICSs. In our pragmatic trial, general practitioners decided autonomously which of their COPD patients on ICS treatment could stop this, how this was done, and whether additional bronchodilator therapy was needed. We recruited 62 COPD patients (58 analysed) who were eligible for ICS withdrawal in 79 practices. In 32 patients (55.2%, 95% CI: 42.5–67.3%) ICS was withdrawn successfully, 19 (32.8%, 95% CI: 22.1–45.6%) restarted ICS treatment within six months, 12 patients (20.7%, 95% CI: 12.3–32.8%) had a moderate exacerbation, and one patient had a severe exacerbation. ICS withdrawal was successful in just over half of the patients with COPD without an indication for ICS.
Myoelectric digit action decoding with multi-output, multi-class classification: an offline analysis
Authors: Krasoulis Agamemnon , Nazarpour Kianoush 
Published: October 2020

AbstractThe ultimate goal of machine learning-based myoelectric control is simultaneous and independent control of multiple degrees of freedom (DOFs), including wrist and digit artificial joints. For prosthetic finger control, regression-based methods are typically used to reconstruct position/velocity trajectories from surface electromyogram (EMG) signals. Unfortunately, such methods have thus far met with limited success. In this work, we propose action decoding, a paradigm-shifting approach for independent, multi-digit movement intent prediction based on multi-output, multi-class classification. At each moment in time, our algorithm decodes movement intent for each available DOF into one of three classes: open, close, or stall (i.e., no movement). Despite using a classifier as the decoder, arbitrary hand postures are possible with our approach. We analyse a public dataset previously recorded and published by us, comprising measurements from 10 able-bodied and two transradial amputee participants. We demonstrate the feasibility of using our proposed action decoding paradigm to predict movement action for all five digits as well as rotation of the thumb. We perform a systematic offline analysis by investigating the effect of various algorithmic parameters on decoding performance, such as feature selection and choice of classification algorithm and multi-output strategy. The outcomes of the offline analysis presented in this study will be used to inform the real-time implementation of our algorithm. In the future, we will further evaluate its efficacy with real-time control experiments involving upper-limb amputees.
Habitat segregation and migration in tropical anguillid eels, Anguilla bengalensis bengalensis and A. bicolor bicolor
Authors: Arai Takaomi , Chai Inn-Ju , Iizuka Yoshiyuki , Chang Chih-Wei 
Published: October 2020

AbstractAnguillid eels of the genus Anguilla, which have a unique catadromous life history, are widely distributed across many parts of the world. However, little research has been conducted on the behavioural mechanisms of habitat segregation between sympatric species in tropical anguillid eels. To understand the ecological and behavioural mechanisms involved in the life history and migration of tropical anguillid eels, strontium (Sr):calcium (Ca) ratios were examined in otoliths of A. bengalensis bengalensis (41 specimens) and A. bicolor bicolor (130 specimens) collected from ten rivers in northwestern Peninsular Malaysia. The otolith Sr:Ca ratios revealed different habitat use between the two species. The broad range of otolith Sr:Ca ratios and habitat shift found in A. bicolor bicolor suggested that its habitat utilization was opportunistic in environments of varying salinity. A. bicolor bicolor prefers to live in the midstream to downstream areas with tidal influences. A. bengalensis bengalensis, however, was found to only reside in freshwater environments throughout their continental growth. A. bengalensis bengalensis tends to live in upstream area with no tidal influence. Their habitat use, migratory history, and habitat distribution indicate that habitat segregation occurs between the two species, leading to the different habitat preferences in tropical river systems.
Long-term potentiation of glycinergic synapses by semi-natural stimulation patterns during tonotopic map refinement
Authors: Bach Eva C. , Kandler Karl 
Published: October 2020

AbstractBefore the onset of hearing, cochlea-generated patterns of spontaneous spike activity drive the maturation of central auditory circuits. In the glycinergic sound localization pathway from the medial nucleus of the trapezoid body (MNTB) to the lateral superior olive (LSO) this spontaneous activity guides the strengthening and silencing of synapses which underlies tonotopic map refinement. However, the mechanisms by which patterned activity regulates synaptic refinement in the MNTB-LSO pathway are still poorly understood. To address this question, we recorded from LSO neurons in slices from prehearing mice while stimulating MNTB afferents with stimulation patterns that mimicked those present in vivo. We found that these semi-natural stimulation patterns reliably elicited a novel form of long-term potentiation (LTP) of MNTB-LSO synapses. Stimulation patterns that lacked the characteristic high-frequency (200 Hz) component of prehearing spike activity failed to elicit potentiation. LTP was calcium dependent, required the activation of both g-protein coupled GABABand metabotropic glutamate receptors and involved an increase in postsynaptic glycine receptor-mediated currents. Our results provide a possible mechanism linking spontaneous spike bursts to tonotopic map refinement and further highlight the importance of the co-release of GABA and glutamate from immature glycinergic MNTB terminals.
Robust deep learning classification of adamantinomatous craniopharyngioma from limited preoperative radiographic images
Authors: Prince Eric W. , Whelan Ros , Mirsky David M. , Stence Nicholas , Staulcup Susan , Klimo Paul , Anderson Richard C. E. , Niazi Toba N. , Grant Gerald , Souweidane Mark , Johnston James M. , Jackson Eric M. , Limbrick David D. , Smith Amy , Drapeau Annie , Chern Joshua J. , Kilburn Lindsay , Ginn Kevin , Naftel Robert , Dudley Roy , Tyler-Kabara Elizabeth , Jallo George , Handler Michael H. , Jones Kenneth , Donson Andrew M. , Foreman Nicholas K. , Hankinson Todd C. 
Published: October 2020

AbstractDeep learning (DL) is a widely applied mathematical modeling technique. Classically, DL models utilize large volumes of training data, which are not available in many healthcare contexts. For patients with brain tumors, non-invasive diagnosis would represent a substantial clinical advance, potentially sparing patients from the risks associated with surgical intervention on the brain. Such an approach will depend upon highly accurate models built using the limited datasets that are available. Herein, we present a novel genetic algorithm (GA) that identifies optimal architecture parameters using feature embeddings from state-of-the-art image classification networks to identify the pediatric brain tumor, adamantinomatous craniopharyngioma (ACP). We optimized classification models for preoperative Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and combined CT and MRI datasets with demonstrated test accuracies of 85.3%, 83.3%, and 87.8%, respectively. Notably, our GA improved baseline model performance by up to 38%. This work advances DL and its applications within healthcare by identifying optimized networks in small-scale data contexts. The proposed system is easily implementable and scalable for non-invasive computer-aided diagnosis, even for uncommon diseases.