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Dynamics of Advantageous Mutant Spread in Spatial Death-Birth and Birth-Death Moran Models

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Communications on Applied Mathematics and Computation 2024年第1期6卷 576-604页

作者： Jasmine Foo Einar Bjarki Gunnarsson kevin Leder David Sivakoff School of Mathematics University of MinnesotaTwin CitiesMN55455USA Department of Industrial and Systems Engineering University of MinnesotaTwin CitiesMN55455USA Departments of Statistics and Mathematics The Ohio State UniversityColumbusOH43210USA

The spread of an advantageous mutation through a population is of fundamental interest in population genetics. While the classical Moran model is formulated for a well-mixed population, it has long been recognized that in real-world applications, the population usually has an explicit spatial structure which can significantly influence the dynamics. In the context of cancer initiation in epithelial tissue, several recent works have analyzed the dynamics of advantageous mutant spread on integer lattices, using the biased voter model from particle systems theory. In this spatial version of the Moran model, individuals first reproduce according to their fitness and then replace a neighboring individual. From a biological standpoint, the opposite dynamics, where individuals first die and are then replaced by a neighboring individual according to its fitness, are equally relevant. Here, we investigate this death-birth analogue of the biased voter model. We construct the process mathematically, derive the associated dual process, establish bounds on the survival probability of a single mutant, and prove that the process has an asymptotic shape. We also briefly discuss alternative birth-death and death-birth dynamics, depending on how the mutant fitness advantage affects the dynamics. We show that birth-death and death-birth formulations of the biased voter model are equivalent when fitness affects the former event of each update of the model, whereas the birth-death model is fundamentally different from the death-birth model when fitness affects the latter event.

关键词： Spatial death-birth models Spatial birth-death models Spatial evolutionary models Spatial cancer models Evolutionary graph theory Stochastic processes Biased voter model Dual process Fixation probability Shape theorem

Failure characterization of fully grouted rock bolts under triaxial testing

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 778-789页

作者： Hadi Nourizadeh Ali Mirzaghorbanali Mehdi Serati Elamin Mutaz kevin McDougall Naj Aziz Centre for Future Materials(CFM) School of EngineeringUniversity of Southern QueenslandToowoombaQLD4350Australia School of Engineering University of Southern QueenslandSpringfield CentralQLD4300Australia School of Civil Engineering University of QueenslandSt LuciaQLD4072Australia School of Surveying and Build Environment University of Southern QueenslandToowoombaQLD4350Australia School of Civil Mining&Environmental EngineeringUniversity of WollongongWollongongNSW2500Australia

Confining stresses serve as a pivotal determinant in shaping the behavior of grouted rock ***,prior investigations have oversimplified the three-dimensional stress state,primarily assuming hydrostatic stress *** these conditions,it is assumed that the intermediate principal stress(σ_(2))equals the minimum principal stress(σ_(3)).This assumption overlooks the potential variations in magnitudes of in situ stress conditions along all three directions near an underground opening where a rock bolt is *** this study,a series of push tests was meticulously conducted under triaxial *** tests involved applying non-uniform confining stresses(σ_(2)≠σ_(3))to cubic specimens,aiming to unveil the previously overlooked influence of intermediate principal stresses on the strength properties of rock *** results show that as the confining stresses increase from zero to higher levels,the pre-failure behavior changes from linear to nonlinear forms,resulting in an increase in initial stiffness from 2.08 kN/mm to 32.51 kN/*** load-displacement curves further illuminate distinct post-failure behavior at elevated levels of confining stresses,characterized by enhanced ***,the peak load capacity ranged from 27.9 kN to 46.5 kN as confining stresses advanced from σ_(2)=σ_(3)=0 to σ_(2)=20 MPa and σ_(3)=10 ***,the outcomes highlight an influence of confining stress on the lateral deformation of *** levels of confinement prompt overall dilation in lateral deformation,while higher confinements maintain a state of ***,diverse failure modes have been identified,intricately tied to the arrangement of confining *** confinements tend to induce a splitting mode of failure,whereas higher loads bring about a shift towards a pure interfacial shear-off and shear-crushed failure mechanism.

关键词： Rock bolts Bolt-grout interface Bond strength Push test Triaxial tests

Potential transformation of organic matter by microbes in cryoconite,Tibetan Plateau

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Science China Earth Sciences 2024年第6期67卷 1978-1989页

作者： Bixi GUO Yongqin LIU kevin Xu ZHONG Quan SHI Chen HE Qiang ZHENG Ruanhong CAI State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Center for the Pan-Third Pole Environment Lanzhou UniversityLanzhou 730000China Department of Earth Oceanand Atmospheric SciencesUniversity of British ColumbiaVancouverBC V6T 1Z4Canada State Key Laboratory of Heavy Oil Processing Petroleum Molecules Engineering Center(PMEC)China University of PetroleumBeijing 102249China State Key Laboratory for Marine Environmental Science Collage of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Fujian Key Laboratory of Marine Carbon Sequestration Xiamen UniversityXiamen 361005China

Microorganisms play an essential role in the glacier carbon cycle;how they transform organic matter in mountain glacial cryoconite remains to be ***,we applied ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)and deep sequencing of 16S rRNA gene,to investigate the temporal microbial transformation of dissolved organic matter(DOM)of the Tibetan Plateau *** the 60-day incubation,we found that DOM in cryoconite underwent a three-stage transformation,with decreasing bioavailability over *** microbial community did not change much in the first week while degrading DOM molecules that were associated with higher H/C_(wa)and lower O/C_(wa).During days 15-30,DOM composition remained stable while microbial diversity *** day 60,the DOM was microbially converted into a higher state of recalcitrance,with higher values of aromatic index,O/C_(wa),and lower H/C_(wa),which contained molecules containing more *** among various microbial taxa,like Cyanobacteria,Bacteroidota,Gammaproteobacteria,Firmicutes,and Actinobacteriota,drove the DOM transformation in *** study sheds light on the in-situ transformation of DOM composition meditated by microbial populations in cryoconite at a temporal scale,providing new insights into understanding the microbial roles in the glacier organic carbon transformation.

关键词： Cryoconite Dissolved organic matter Biodegradation Microbial community Temporal variation

Source of metals related to gold occurrences in Cameroon, Central African Belt

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Acta Geochimica 2024年第2期43卷 308-324页

作者： kevin Igor Azeuda Ndonfack Jinlin Zhang Yuling Xie NSamiratou Yaya Emmanuel Archelaus Afanga Basua JCHX Mining Management Co. LtdBeijing 101500People’s Republic of China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037People’s Republic of China School of Civil and Environmental Engineering University of Science and Technology BeijingBeijing 100083People’s Republic of China Department of Earth Science University of BamendaBamendaRepublic of Cameroon

Suites of granitic and metamorphic rocks form a perfect geological environment in which to investigate the source of metals related to gold *** the East Province of Cameroon,the source of metals-related gold(grade~4.6 g/t)that occurs within metamorphic and granitic rocks remains *** host rocks were subjected to XRF and ICP-MS whole-rock geochemistry and BSE/EDS mineral analyses to investigate the source(s)of metals related to gold in the ***,chalcopyrite-pyrite and magnetite-ilmenite are the main sulfi des and oxides of granites,*** low-grade metamorphic rocks are sulfi de-rich consisting of arsenopyrite,chalcopyrite,pyrite,and sphalerite,and oxides include magnetite,ilmenite,hematite,and ***,Ni,Co,Sb,Sc,and Zn concentrations depleted in high-grade metamorphic rocks and granites compared to low-grade metamorphic *** well,Bi,Cd,Co,Cu,Ni,Sb,V,W,and Zn concentrations decrease with increasing temperatures from low-grade rocks to high-grade rocks and *** suite of depleted elements in high-grade rocks and granites is almost identical to those enriched in gold *** conclude that metals(Bi,Cd,Co,Cu,Ni,Sb,and Zn)related to gold mineralization in the East Province of Cameroon likely originated from metal-rich low-grade metamorphic rocks during prograde metamorphic processes prior to partial melting.

关键词： East Province of Cameroon Metamorphic rocks Granites Oxide–sulﬁdes Metal and gold Geochemistry

Polylactic acid micro/nanoplastic-induced hepatotoxicity: Investigating food and air sources via multi-omics

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Environmental Science and Ecotechnology 2024年第5期21卷 294-308页

作者： Hua Zha Shengyi Han Ruiqi Tang Dan Cao kevin Chang Lanjuan Li State Key Laboratory for Diagnosis and Treatment of Infectious Diseases National Clinical Research Center for Infectious DiseasesNational Medical Center for Infectious DiseasesCollaborative Innovation Center for Diagnosis and Treatment of Infectious DiseasesThe First Affiliated HospitalZhejiang University School of MedicineHangzhouChina Department of Statistics The University of AucklandAucklandNew Zealand

Micro/nanoplastics(MNPs)are detected in human liver,and pose significant risks to human *** exposure to MNPs derived from non-biodegradable plastics can induce toxicity in mouse ***,nasal exposure to non-biodegradable plastics can cause airway dysbiosis in ***,the hepatotoxicity induced by foodborne and airborne biodegradable MNPs remains poorly *** we show the hepatotoxic effects of biodegradable polylactic acid(PLA)MNPs through multi-omics analysis of various biological samples from mice,including gut,fecal,nasal,lung,liver,and blood *** results show that both foodborne and airborne PLA MNPs compromise liver function,disrupt serum antioxidant activity,and cause liver ***,foodborne MNPs lead to gut microbial dysbiosis,metabolic alterations in the gut and serum,and liver transcriptomic *** MNPs affect nasal and lung microbiota,alter lung and serum metabolites,and disrupt liver *** gut Lachnospiraceae_NK4A136_group is a potential biomarker for foodborne PLA MNP exposure,while nasal unclassified_Muribaculaceae and lung Klebsiella are potential biomarkers for airborne PLA MNP *** relevant results suggest that foodborne PLA MNPs could affect the“gut microbiota-gutliver”axis and induce hepatoxicity,while airborne PLA MNPs could disrupt the“airway microbiota-lungliver”axis and cause *** findings have implications for diagnosing PLA MNPs-induced hepatotoxicity and managing biodegradable materials in the *** current study could be a starting point for biodegradable MNPs-induced *** research is needed to verify and inhibit the pathways that are crucial to MNPs-induced hepatotoxicity.

关键词： Micro/nanoplastics Hepatotoxicity Microbiota dysbiosis Metabolic disruption Transcriptomic dysregulation

Speed and surface steepness affect internal tibial loading during running

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Journal of Sport and Health Science 2024年第1期13卷 118-124页

作者： Hannah Rice Markus Kurz Patrick Mai Leon Robertz kevin Bill Timothy R.Derrick Steffen Willwacher Department of Physical Performance Norwegian School of Sport SciencesOslo 0806Norway Sports Tech Research Centre Mid Sweden UniversityÖstersund SE-83125Sweden Department of Mechanical and Process Engineering Offenburg University of Applied SciencesOffenburg 77652Germany Institute of Biomechanics and Orthopaedics German Sport University CologneCologne 50933Germany Department of Kinesiology Iowa State UniversityAmesIA 50011USA

Background:Internal tibial loading is influenced by modifiable factors with implications for the risk of stress *** encounter varied surface steepness(gradients)when running outdoors and may adapt their speed according to the *** study aimed to quantify tibial bending moments and stress at the anterior and posterior peripheries when running at different speeds on surfaces of different ***:Twenty recreational runners ran on a treadmill at 3 different speeds(2.5 m/s,3.0 m/s,and 3.5 m/s)and gradients(level:0%;uphill:+5%,+10%,and+15%;downhill:-5%,-10%,and-15%).Force and marker data were collected synchronously *** moments were estimated at the distal third centroid of the tibia about the medial-lateral axis by ensuring static equilibrium at each 1%of *** was derived from bending moments at the anterior and posterior peripheries by modeling the tibia as a hollow ***-way repeated-measures analysis of variance were conducted using both functional and discrete statistical ***:There were significant main effects for running speed and gradient on peak bending moments and peak anterior and posterior *** running speeds resulted in greater tibial *** uphill at+10%and+15%resulted in greater tibial loading than level *** downhill at-10%and-15%resulted in reduced tibial loading compared to level *** was no difference between+5%or-5%and level ***:Running at faster speeds and uphill on gradients≥+10%increased internal tibial loading,whereas slower running and downhill running on gradients≥-10%reduced internal *** running speed according to the gradient could be a protective mechanism,providing runners with a strategy to minimize the risk of tibial stress injuries.

关键词： Bending moments Gradient Musculoskeletal modeling Overuse injury Tibial stress Training factors

Microfacies and diagenetic alteration in a semi-deep to deep lacustrine shale: The Yanchang Formation in the Ordos Basin, China

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Petroleum Science 2024年第3期21卷 1524-1538页

作者： Bin Bai Jing-Yue Hao Ling Fu Yu-Xi Liu Jian-Peng Wang Lan Wang kevin GTaylor Lin Ma PetroChina Research Institute of Petroleum Exploration and Development Beijing100083China Department of Earth and Environmental Sciences University of ManchesterM139PLUK College of Earth Sciences Jilin UniversityChangchun130061jilinChina Department of Chemical Engineering University of ManchesterM139PLUK

The mineralogical development and diagenetic sequence of lacustrine shales in the Chang 7 Member of the Yanchang Formation in the Ordos Basin are detailed studied.A model of their depositional system and a diagenetic diagram are proposed in this *** detailed petrographic,mineralogical,and elemental analyses,four distinct shale types are identified:argillaceous shale,siliceous shale,calcareous shale,and carbonate,clay,and silt-bearing *** main diagenetic process in argillaceous shale is the transformation of illite to smectite,negatively impacting shale *** shale undergoes carbonate cementation and quartz dissolution,contributing to increased porosity,particularly in *** shale experiences diagenesis characterised by carbonate formation and dissolution,with a prevalence of *** carbonate,clay,and silt-bearing shale,the dissolution of K-feldspar contributes to illitization of *** shale,characterised by more clay minerals and lower mesopore volume,is identified as a potential hydrocarbon *** shale,with the highest pore volume and abundant inter-mineral pores,emerges as a promising shale oil *** findings contribute to a comprehensive understanding of shale properties,aiding in the prediction of shale oil exploration potential in the studied area.

关键词： Ordos Basin Yanchang Formation Chang 7 Member Diagenesis Microfacies

Batch Active Learning for Multispectral and Hyperspectral Image Segmentation Using Similarity Graphs

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1013-1033页

作者： Bohan Chen kevin Miller Andrea L.Bertozzi Jon Schwenk Department of Mathematics University of CaliforniaLos Angeles520 Portola PlazaLosAngeles90095CAUSA Oden Institute for Computational Engineering and Sciences University of Texas at Austin201 E 24th StAustin 78712TXUSA Los Alamos National Laboratory Los AlamosNM 87545USA

Graph learning,when used as a semi-supervised learning(SSL)method,performs well for classification tasks with a low label *** provide a graph-based batch active learning pipeline for pixel/patch neighborhood multi-or hyperspectral image *** batch active learning approach selects a collection of unlabeled pixels that satisfy a graph local maximum constraint for the active learning acquisition function that determines the relative importance of each pixel to the *** work builds on recent advances in the design of novel active learning acquisition functions(e.g.,the Model Change approach in arXiv:2110.07739)while adding important further developments including patch-neighborhood image analysis and batch active learning methods to further increase the accuracy and greatly increase the computational efficiency of these *** addition to improvements in the accuracy,our approach can greatly reduce the number of labeled pixels needed to achieve the same level of the accuracy based on randomly selected labeled pixels.

关键词： Image segmentation Graph learning Batch active learning Hyperspectral image

Rational Design and Construction of a CdS QDs/InVO4 Atomic-Layer（110）/（110） Facet S-Scheme Heterojunction for Highly Efficient Photocatalytic Degradation of C2H4

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Energy & Environmental Materials 2024年第3期7卷 215-222页

作者： Yuanpeng Dong Peizhu Ji Xinyue Xu Rong Li Yin Wang kevin Peter Homewood Xiaohong Xia Yun Gao Xuxing Chen Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials School of Materials Science&Engineering Hubei University Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices Hubei University of Arts and Science State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences United Water (Xianning) Company Limited

Exploring high efficiency S-scheme heterojunction photocatalysts with strong redox ability for removing volatile organic compounds from the air is of great interest and ***,how to predict and regulate the transport of photogenerated carriers in heterojunctions is a great ***,density functional theory calculations were first used to successfully predict the formation of a CdS quantum dots/InVO4atomic-layer （110）/（110） facet S-scheme ***,a CdS quantum dots/InVO4atomic-layer was synthesized by in-situ loading of CdS quantum dots with （110） facets onto the（110） facets of *** a result of the deliberately constructed built-in electric field between the adjoining facets,we obtain a remarkably enhanced photocatalytic degradation rate for *** rate is 13.8 times that of pure CdS and 13.2 times that of pure ***-situ irradiated X-ray photoelectron spectroscopy,photoluminescence and time-resolved photoluminescence measurements were carried *** experiments validate that the built-in electric field enhanced the dissociation of photoexcited excitons and the separation of free charge carriers,and results in the formation of S-scheme charge transfer *** reaction mechanism of the photocatalytic C2H4oxidation is investigated by in-situ electron paramagnetic *** work provides a mechanistic insight into the construction and optimization of semiconductor heterojunction photocatalysts for application to environmental remediation.

关键词： CdS QDs InVO4 atomic-layer photocatalysis S-scheme volatile organic compounds