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Data-driven models for ground and excited states for Single Atoms on Ceria

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npj Computational Materials 2022年第1期8卷 1636-1643页

作者： Julian Geiger Albert Sabadell-Rendón nathan Daelman núria López Institute of Chemical Research of Catalonia(ICIQ) The Barcelona Institute of Science and Technology(BIST)Avinguda Països Catalans 1643007TarragonaSpain Universitat Rovira i Virgili Avinguda Catalunya3543002TarragonaSpain

Ceria-based single-atom catalysts present complex electronic structures due to the dynamic electron transfer between the metal atoms and the semiconductor oxide *** these materials implies retrieving all states in these electronic ensembles,which can be limiting if done via density functional ***,we propose a data-driven approach to obtain a parsimonious model identifying the appearance of dynamic charge transfer for the single atoms(SAs).We first constructed a database of(701)electronic configurations for the group 9–11 metals on CeO_(2)(100).Feature Selection based on predictive Elastic net and Random Forest models highlights eight fundamental variables:atomic number,ionization potential,size,and metal coordination,metal–oxygen bond strengths,surface strain,and Coulomb *** these variables a Bayesian algorithm yields an expression for the adsorption energies of SAs in ground and low-lying excited *** work paves the way towards understanding electronic structure complexity in metal/oxide interfaces.

关键词： theory excited states

Late neoproterozoic to early Cambrian high-grade metamorphism from Mikir Hills(Assam-Meghalaya gneissic Complex,northeast India):Implications for eastern Gondwana assembly

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Geoscience Frontiers 2024年第5期15卷 256-282页

作者： Rahul nag H.Hrushikesh nathan Cogné n.Prabhakar Department of Earth Sciences Indian Institute of Technology BombayPowaiMumbaiMaharastra 400076India Geological Survey of India Northeastern RegionGuwahatiAssam 781005India Géosciences Rennes UMR6118CNRS Universitéde RennesFrance

Mikir Hills region,which represents the eastern segment of the Assam-Meghalaya Gneissic Complex(AMGC)in northeast India,constitutes part of the Eastern *** Mikir Hills preserves multiple metamorphic and magmatic events ranging from Early Mesoproterozoic to Early *** of these events,documenting the late neoproterozoic to early Cambrian tectonothermal events is helpful in correlating the continental blocks of Eastern *** present an integrated study involving field relations,petrology,P-T history and zircon-monazite geochronology of hitherto poorly studied pelitic and quartzo-feldspathic gneisses from the Mikir Hills *** gneisses have experienced at least three deformation events(D_(1),D_(2) and D_(3))with dominant foliation indicated by EnE-WSW striking and shallow-moderately dipping(neissic *** peak metamorphism in pelitic and quartzo-feldspathic gneisses is characterized by garnet(core)-K-feldspar-sillimanite-plagioclase-bio tite-rutile-quartz-ilmenite-melt and garnet-plagioclase-K-feldspar-biotite-quartz-ilmenite-melt assemblages,*** application of thermobarometric methods constrains the peak P-T conditions of 7.5-8.4 kbar at 674-778℃and 6.7-7.4 kbar at 601-618℃for pelitic and quartzofeldspathic gneisses,*** results are consistent with the values estimated using phase equilibria modelling and melt reintegration *** results of pseudosection modelling suggests a clockwise P-T path for pelitic gneisses involving migmatisation during peak metamorphism followed by near isothermal decompression from 8.0 to 8.6 kbar at 768-780℃to 4.0-5.0 kbar at 720-765℃.In contrast,quartzo-feldspathic gneisses preserved slightly lower peak P-T conditions at 3.8-4.6 kbar and 590-650℃.The U-Pb zircon dating of migmatised pelitic and quartzo-feldspathic gneisses yielded concordant ages of 1647±11 Ma and 1590±7 Ma,*** dates represent the inherited igneous protolith components,possibly

关键词： Gondwana Assam-Meghalaya Gneissic Complex Migmatisation neoproterozoic Geochronology P-T-t history

Phylofloristics:an example from the Lesser Antilles

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Journal of Plant Ecology 2014年第2期7卷 166-175页

作者： nathan G.Swenson María n.Umaña Department of Plant Biology Michigan State UniversityEast LansingMichigan 48824USA

Aims The last decade has seen many plant ecologists integrating phylogenetic analysis into ecology to explain patterns of species cooccurrence and compositional similarity across *** the advances in this area,there are still some challenges that need to be *** challenge is that most of the phylogenetic studies of plant assemblages have focused only on a small proportion of all of the vascular plants that co-occur(*** plants),while much of the remaining co-occurring flora has been *** Here we introduce an analytical approach that we term phylofloristics that analyzes the compositional similarity of floras in relation to spatial and environmental gradients to understand their *** an illustration,we assembled a large phylogenetic tree for the flora of the Lesser Antilles and evaluated the patterns of floristic and phylofloristic similarity among the island-specific *** analyzed the relationship of these similarities with spatial and environmental distance and compared the results for non-endemic and endemic *** Findings The results show a major influence of environmental heterogeneity on the assembly of island floras and far less evidence for the importance of dispersal limitation of lineages and *** study highlights the importance of incorporating broader taxonomic sampling to improve our understanding of assembly processes in *** expect future phylofloristic studies will improve the approach we have taken by generating more refined phylogenetic trees and by incorporating phylogeographic information.

关键词： biogeography Caribbean flora phylogeny plant geography

Capacity of Old Trees to Respond to Environmental Change

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Journal of Integrative Plant Biology 2008年第11期50卷 1355-1364页

作者： nathan G.Phillips Thomas n.Buckley David T.Tissue Centre for Plant and Food Science University of Western Sydney Department of Geography and Environment Boston University Department of Biology Sonoma State University School of Biological Earth and Environmental SciencesUniversity of New South Wales Bushfire Cooperative Research Centre

Atmospheric carbon dioxide [CO2] has increased dramatically within the current life spans of long-lived trees and old forests. Consider that a 500-year-old tree in the early twenty-first century has spent 70% of its life growing under preindustrial levels of [CO2], which were 30% lower than current levels. Here we address the question of whether old trees have already responded to the rapid rise in [CO2] occurring over the past 150 years. In spite of limited data, aging trees have been shown to possess a substantial capacity for increased net growth after a period of post-maturity growth decline. Observations of renewed growth and physiological function in old trees have, in some instances, coincided with Industrial Age increases in key environmental resources, including [CO2], suggesting the potential for continued growth in old trees as a function of continued global climate change.

关键词： carbon dioxide hydraulic limitation old growth stomata tree rings.

Dynamic Patterns of Gene Expression Additivity and Regulatory Variation throughout Maize Development

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Molecular Plant 2019年第3期12卷 410-425页

作者： Peng Zhou Candice n.Hirsch Steven P.Briggs nathan M.Springer Department of Plant and Microbial Biology University of MinnesotaSaint PaulMN 55108USA Department of Agronomy and Plant Genetics University of MinnesotaSaint PaulMN 55108USA Division of Biological Sciences University of CaliforniaSanDiegoLaJollaCA92093USA

Gene expression variation is a key component underlying phenotypic variation and heterosis. Transcriptome profiling was performed on 23 different tissues or developmental stages of two maize inbreds, B73 and Mo17, as well as their hybrid. The obtained large-scale datasets provided opportunities to monitor the developmental dynamics of differential expression, additivity for gene expression, and regulatory variation. The transcriptome can be divided into .30 000 genes that are expressed in at least one tissue of one in bred and an additional ~10 000 “silent” genes that are not expressed in any tissue of any genotype, 90% of which are non-syntenic relative to other grasses. Many (.74%) of the expressed genes exhibit differential expression in at least one tissue. However, the majority of genes with differential expression do not exhibit consistent differential expression in different tissues. These genes often exhibit tissue-specific differential expression with equivalent expression in other tissues, and in many cases they switch the directionality of differential expression in different tissues. This suggests widespread variation for tissue-specific regulation of gene expression between the two maize inbreds B73 and Mo17. nearly 5000 genes are expressed in only one parent in at least one tissue (single parent expression) and 97% of these genes are expressed at mid-parent levels or higher in the hybrid, providing extensive opportunities for hybrid complementation in heterosis. In general, additive expression patterns are much more common than non-additive patterns, and this trend is more pronounced for genes with strong differential expression or single pare nt expressi on. There is relatively little evidence for non-additive expression patterns that are maintained in multiple tissues. The analysis of allele-specific expression allowed classification of cis. and trans-regulatory variation. Genes with c/s-regulatory variation often exhibit additive expression and tend

关键词： maize gene expression heterosis differential expression non-additive expression allele-specific expression

Spectral square moments of a resonance sum for Maass forms

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Frontiers of Mathematics in China 2017年第5期12卷 1183-1200页

作者： nathan SALAZAR Yangbo YE Department of Mathematics The University of Iowa Iowa City Iowa 52242-1419 USA

Let f be a Maass cusp form for Г0（n） with Fourier coefficients 1 k2. λf（n） and Laplace eigenvalue 1/4 ＋k2 For real α≠0 and β 〉 0, consider the sum Sx（f; α,β） = ∑n λf（n）e（αnβ）φ（n/X）, where φ is a smooth function of compact support. We prove bounds for the second spectral moment of Sx （f;α, β）, with the eigenvalue tending towards infinity. When the eigenvalue is sufficiently large, we obtain an average bound for this sum in terms of X. This implies that if f has its eigenvalue beyond X1/2＋ε, the standard resonance main term for Sx（f; ±2√q 1/2）, q ∈Z＋, cannot appear in general. The method is adopted from proofs of subconvexity bounds for Rankin-Selberg L-functions for GL（2） × GL（2）. It contains in particular a proof of an asymptotic expansion of a well-known oscillatory integral with an enlarged range of Kε≤ L≤ K1-ε. The same bounds can be proved in a similar way for holomorphie cusp forms.

关键词： Cusp form Maass form Fourier coefficient of cusp form Kuznetsovtrace formula resonance sum first derivative test weighted stationary phase

REDOX IMAGInG OF THE p53-DEPEnDEnT MITOCHOnDRIAL REDOX STATE In COLOn CAnCER EX VIVO

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Journal of Innovative Optical Health Sciences 2013年第3期6卷 1-10页

作者： HE n.XU MIn FEnG LILY MOOn nathan DOLLOFF WAFIKEL-DEIRY LIn Z.LI Department of Radiology University of Pennsylvania PhiladelphiaPAUSA Britton Chance Laboratory of Redox Imaging Johnson Research Foundation Department of Biochemistry and Biophysics Perelman School of Medicine University of Pennsylvania PhiladelphiaPAUSA Department of Medicine Penn State Hershey Medical Center and Penn State College of MedicineHersheyPAUSA Hematology/Oncology Penn State Hershey Medical Center HersheyPAUSA Abramson Cancer Center University of Pennsylvania PhiladelphiaPAUSA Institute of Translational Medicine and Therapeutics University of Pennsylvania PhiladelphiaPAUSA

The mitochondrial redox state and its heterogeneity of colon cancer at tissue level have not been previously *** has how p53 regulates mitochondial respi ration been measured at(deep)tissue level,presumably due to the unavailability of the technology that has sufficient spatial resolution and tissue penetration *** prior work demonstrated that the mito-chondrial redox state and its intnatumor heterogeneity is associated with cancer aggressiveness in human melanoma and breast cancer in mouse models,with the more metastatic tumons exhi-bit ing localized negions of more oxidized redox *** the Chance redox scanner with an in-plane spatial resolution of 200 pm,we imaged the mitochondrial redox state of the wild-type p53 colon tumors(HCT116 p53 ut)and the p5-deleted colon tumors(HCT116 p53-/-)by cllcting the fuorescence si gnals of nicotinamide adenine dimucleotide(nA DH)and oxidized flavoproteins [Fp,including favin adenine dinucleotide(FAD)]from the mouse xenogmafts snap frozen at low *** results show that:(1)both tumor lines have significant degree of intratumor heterogeneity of the redox state,typically exhibiting a distinct bi modal distribution that either correlates with the spatial core-rim pattern or the“hot/oold”oxida tion-roduction patches;.(2)the p531-group is significantly more beterogencous in the mitochondrial redox state and has a more oxidized turmor core compared to the p53 wt group when the tunor sizes of the two groups are matched;(3)the tumor size dependence of the redox indices(such as Fp and Fp redox ratio)is significant in the p531-group with the larger ones being more oxidized and more hetero-geneous in their redox state,particularly more oxidized in the tumor central regions;(4)the H&E staining images of tumor soctions grossly correlate with the redox *** present work is the first to reveal at the submillimeter scale the intratumor heterogeneity pattem of the mitochon-drial redox state in colon cancer and

关键词： nADH favoprotein intratumor heterogeneity HCT116 p53 null necrotic

Environmental cues determine the fate of astrocytes after spinal cord injury

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neural Regeneration Research 2017年第12期12卷 1964-1970页

作者： Fatima M.nathan Shuxin Li Shriners Hospitals Pediatric Research Center Department of Anatomy and Cell Biology Lewis Katz School of Medicine at Temple UniversityPhiladelphia PA USA

Reactive astrogliosis occurs after central nervous system（CnS） injuries whereby resident astrocytes form rapid responses along a graded continuum. Following CnS lesions, na？ve astrocytes are converted into reactive astrocytes and eventually into scar-forming astrocytes that block axon regeneration and neural repair. It has been known for decades that scarring development and its related extracellular matrix molecules interfere with regeneration of injured axons after CnS injury, but the cellular and molecular mechanisms for controlling astrocytic scar formation and maintenance are not well known. Recent use of various genetic tools has made tremendous progress in better understanding genesis of reactive astrogliosis. Especially, the latest experiments demonstrate environment-dependent plasticity of reactive astrogliosis because reactive astrocytes isolated from injured spinal cord form scarring astrocytes when transplanted into injured spinal cord, but revert in retrograde to naive astrocytes when transplanted into naive spinal cord. The interactions between upregulated type I collagen and its receptor integrin β1 and the n-cadherin-mediated cell adhesion appear to play major roles for local astrogliosis around the lesion. This review centers on the environment-dependent plasticity of reactive astrogliosis after spinal cord injury and its potential as a therapeutic target.

关键词： astrogliosis astrocyte fate scar formation spinal cord injury axon regeneration environmentcue collagen I integrin β1

Validating neural networks for spectroscopic classification on a universal synthetic dataset

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npj Computational Materials 2023年第1期9卷 1325-1336页

作者： Jan Schuetzke nathan J.Szymanski Markus Reischl Institute for Automation and Applied Informatics Karlsruhe Institute of TechnologyKarlsruhe 76131Germany Department of Materials Science&Engineering Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Department of Materials Science&Engineering UC BerkeleyBerkeleyCA 94720USA

To aid the development of machine learning models for automated spectroscopic data classification,we created a universal synthetic dataset for the validation of their *** dataset mimics the characteristic appearance of experimental measurements from techniques such as X-ray diffraction,nuclear magnetic resonance,and Raman spectroscopy among *** applied eight neural network architectures to classify artificial spectra,evaluating their ability to handle common experimental *** all models achieved over 98%accuracy on the synthetic dataset,misclassifications occurred when spectra had overlapping peaks or *** found that non-linear activation functions,specifically ReLU in the fully-connected layers,were crucial for distinguishing between these classes,while adding more sophisticated components,such as residual blocks or normalization layers,provided no performance *** on these findings,we summarize key design principles for neural networks in spectroscopic data classification and publicly share all scripts used in this study.

关键词： spectroscopic adding classify