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3-D geochemical interpolation guided by geophysical inversion models

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Geoscience Frontiers 2021年第3期12卷 132-145页

作者： Tom Horrocks Eun-Jung holden Daniel Wedge ChrisWijns Centre for Exploration Targeting.School of Earth Sciences University of Western AustraliaCrawleyWA 6009Australia

3-D geochemical subsurface models,as constructed by spatial interpolation of drill-core assays,are valuable assets across multiple stages of the mineral industry's ***,the accuracy of such models is limited by the spatial sparsity of the underlying drill-core,which samples only a small fraction of the *** limitation can be alleviated by integrating collocated 3-D models into the interpolation process,such as the 3-D rock property models produced by modern geophysical inversion procedures,provided that they are sufficiently resolved and correlated with the interpolation *** standard machine learning algorithms are capable of predicting the target property given these data,incorporating spatial autocorrelation and anisotropy in these models is often not *** propose a Gaussian process regression model for 3-D geochemical interpolation,where custom kernels are introduced to integrate collocated 3-D rock property models while addressing the trade-off between the spatial proximity of drill-cores and the similarities in their collocated rock properties,as well as the relative degree to which each supporting 3-D model contributes to *** proposed model was evaluated for 3-D modelling of Mg content in the Kevitsa Ni-Cu-PGE deposit based on drill-core analyses and four 3-D geophysical inversion *** the inversion models improved the regression model's likelihood(relative to a purely spatial Gaussian process regression model)when evaluated at held-out test holes,but only for moderate spatial scales(100 m).

关键词： Machine learning Gaussian process regression Kriging Geophysical inversion Interpolation

cGMP signaling:a potential therapeutic target for neurodegeneration in glaucoma?

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Neural Regeneration Research 2023年第6期18卷 1267-1268页

作者： Joseph M.holden Lauren K.Wareham Vanderbilt Eye Institute Vanderbilt University Medical CenterNashvilleTNUSA

Neurodegeneration of the central nervous system(CNS)underscores many of humanity’s most debilitating diseases,including Alzheimer’s disease,Parkinson’s disease,and multiple ***,the nitric oxide-guanylate cyclase-cyclic guanosine monophosphate(NOGC-cGMP)signaling pathway has gained traction as a neuroprotective pathway in the *** an extension of the CNS,the retina is also susceptible to neurodegeneration with *** most prevalent optic neuropathy is glaucoma,the world’s leading cause of irreversible blindness,predicted to affect more than 112 million people worldwide by 2040(Calkins,2021).In glaucoma,vision loss occurs due to the progressive degeneration of retinal ganglion cells(RGCs),the output neurons of the retina,along with their axons which form the optic nerve(Wareham et al.,2022).Degeneration of RGCs leads to a characteristic pattern of scotopic visual field deficiencies that spread from one retinotopic sector to the next(Elze et al.,2015).Visual deficits are linked to increasing age and the sensitivity of RGCs to intraocular pressure(Calkins,2021).

关键词： glaucoma degeneration protective

Predicting phosphorus sorption isotherm parameters in soil using data of routine laboratory tests

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Pedosphere 2021年第5期31卷 694-704页

作者： Kathleen S.DUNNE Nicholas M.holden Karen DALY Teagasc Johnstown CastleEnvironmental Research CentreCo.Wexford Y35TC97(Ireland) UCD School of Biosystems and Food Engineering University College DublinBelfieldDublin 4 D04VIW8(Ireland)

Knowledge of phosphorus(P)sorption dynamics across different soil types could direct agronomic and environmental management of *** objective of this study was to predict P isotherm parameters for a national soil population using data of routine laboratory *** and Freundlich sorption parameters were calculated from two different ranges(0-25 and 0-50 mg P L^(-1))using an archive of representative agricultural soil types from *** linear regression(MLR)identified labile forms of aluminium(Al)and iron(Fe),organic matter(OM),cation exchange capacity(CEC),and clay as significant *** and Freundlich sorption capacities,Freundlich affinity constant,and Langmuir buffer capacity were predicted reliably,with R^(2) of independent validation>*** isotherm parameters were predicted from P sorbed at a single concentration of 50 mg P L^(-1)(S_(50)).An MLR prediction of P sorption maximum in the 0-50 mg P L-1 range was achieved,to an accurate standard,using S_(50),OM,and Mehlich-3 Fe(R^(2) of independent calibration and validation being 0.91 and 0.95,respectively).Using Giles’four shapes of isotherms(C,L,H,and S),L non-strict-and C-shaped isotherm curves accounted for 64% and 27% of the soils,*** clustering identified a separation of isotherm curves influenced by two ranges of Mehlich-3 *** with a low range of Mehlich-3 Al(2.5-698 mg kg^(-1))had no incidence of rapid sorption(C shape).Single point indices,Al,or available soil data make the regression approach a feasible way of predicting Langmuir parameters that could be included with standard agronomic soil P testing.

关键词： available phosphorus binding fertilizer soil test sorption maximum

STRONG COMPACTNESS OF APPROXIMATE SOLUTIONS TO DEGENERATE ELLIPTIC-HYPERBOLIC EQUATIONS WITH DISCONTINUOUS FLUX FUNCTION

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Acta Mathematica Scientia 2009年第6期29卷 1573-1612页

作者： Helge holden Kenneth H. Karlsen Darko Mitrovic Evgueni Yu. Panov Department of Mathematical Sciences Norwegian University of Science and TechnologyNO–7491 Trondheim Norway Centre of Mathematics for Applications University of Oslo P.O. Box 1053 BlindernNO–0316 Oslo Norway Centre of Mathematics for Applications University of OsloP.O. Box 1053 Blindern N–0316 Oslo Norway Faculty of Mathematics University of Montenegro 81000 Podgorica Montenegro Mathematical Analysis Department Novgorod State Universityul. B. St. Peterburgskaya 41 173003 Veliky Novgorod Russia

Under a non-degeneracy condition on the nonlinearities we show that sequences of approximate entropy solutions of mixed elliptic-hyperbolic equations are strongly precompact in the general case of a Caratheodory flux vector. The proofs are based on deriving localization principles for H-measures associated to sequences of measurevalued functions. This main result implies existence of solutions to degenerate parabolic convection-diffusion equations with discontinuous flux. Moreover, it provides a framework in which one can prove convergence of various types of approximate solutions, such as those generated by the vanishing viscosity method and numerical schemes.

关键词： degenerate hyperbolic-elliptic equation degenerate convection-diffusion equation conservation law discontinuous flux approximate solutions compactness

Chinese physicists set to unveil conceptual designs for the globe's most advanced circular collider

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Science Bulletin 2015年第1期60卷 146-148页

作者： Kevin holden Beijing China

The leaders of China＇ s high energy physics sector will soon unveil initial designs for the world＇s most technologically advanced circular collider, set to stage near-speed-of-light particle collisions aimed at recr... 详细信息

关键词：概念设计对撞机物理学家循环中国设置高能物理粒子碰撞

A study of different fluid droplets impacting on a liquid film

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Petroleum Science 2008年第1期5卷 62-66页

作者： Huang Qiyu Zhang holden Petroleum Engineering Department The University of Tulsa Tulsa OK 74104 USA Beijing Key Laboratory of Urban Oil and Gas Distribution Technology China University of Petroleum Beijing 102249China

Knowledge of droplet dynamics provides the basis of predicting pressure drops, holdups and corrosion inhibitor distribution in multiphase flow. Droplet size and its distribution also determine the separation efficiency between different phases. Experimental observations were conducted for droplet impingements with different fluids, droplet sizes and velocities, and film thicknesses. The observed transition boundaries were compared with the models developed by different authors. For impingement on a deep pool surface, the Marengo and Tropea correlation for splashing does not agree with the experimental results in this study. The Bai and Gosman critical Weber number for bouncing agrees with the water results but not the oil results. Three new correlations for transition boundaries between bouncing, coalescence, jetting and splashing were proposed and compared with the experimental observations.

关键词： Droplet liquid film transition boundary high-speed video

Recurrent missense mutation of GDF5 (p.R438L) causes proximal symphalangism in a British family

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World Journal of Orthopedics 2016年第12期7卷 839-842页

作者： Andreas Leonidou Melita Irving Simon holden Marcos Katchburian Department of Traumaand Orthopaedic Surgery Maidstone and Tunbridge Wells NHSTrust Department of Clinical Genetics Guy’s and St Thomas’ NHS Foundation Trust Department of Clinical Genetics Addenbrookes Hospital

Proximal symphalangism(SYM1B)(OMIM 615298) is an autosomal dominant developmental disorder affecting joint fusion. It is characterized by variable fusions of the proximal interphalangeal joints of the hands,typically of the ring and little finger,with the thumb typically being spared. SYM1 is frequently associated with coalition of tarsal bones and conductive hearing loss. Molecular studies have identified two possible genetic aetiologies for this syndrome,NOG and GDF5. We herein present a British caucasian family with SYM1 B caused by a mutation of the GDF5 gene. A mother and her three children presented to the orthopaedic outpatient department predominantly for feet related problems. All patients had multiple tarsal coalitions and hand involvement in the form of either brachydactyly or symphalangism of the proximal and middle phalanx of the little fingers. Genetic testing in the eldest child and his mother identified a heterozygous missense mutation in GDF5 c.1313G>T(p.R438L),thereby establishing SYM1 B as the cause of the orthopaedic problems in this family. There were no mutations identified in the NOG gene. This report highlights the importance of thorough history taking,including a three generation family history,and detailed clinical examination of children with fixed planovalgus feet and other family members to detect rare skeletal dysplasia conditions causing pain and deformity,and provides details of the spectrum of problems associated with SYM1 B.

关键词： Proximal symphalangism GDF5

Incorporating conceptual and interpretation uncertainty to mineral prospectivity modelling

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Geoscience Frontiers 2019年第4期10卷 1383-1396页

作者： J.N.Burkin M.D.Lindsay S.A.Occhipinti E.-J.holden Centre for Exploration Targeting School of Earth SciencesThe University of Western Australia

Prospectivity analyses are used to reduce the exploration search space for locating areas prospective for mineral *** scale of a study and the type of mineral system associated with the deposit control the evidence layers used as proxies that represent critical ore genesis *** particular,knowledge-driven approaches(fuzzy logic)use a conceptual mineral systems model from which data proxies represent the critical *** typically vary based on the scale of study and the type of mineral system being *** analyses utilising interpreted data to represent proxies for a mineral system model inherit the subjectivity of the interpretations and the uncertainties of the evidence layers used in the *** the case study presented,the prospectivity for remobilised nickel sulphide(NiS)in the west Kimberley,Western Australia,is assessed with two novel techniques that objectively grade interpretations and accommodate alternative mineralisation *** targets are then identified and supplied with a robustness assessment that reflects the variability of prospectivity value for each location when all models are *** first technique grades the strength of structural interpretations on an individual line-segment *** are obtained from an objective measure of feature evidence,which is the quantification of specific patterns in geophysical data that are considered to reveal underlying *** structures are weighted in the prospectivity model with grading values correlated to their feature *** technique allows interpreted features to contribute prospectivity proportional to their strength in feature evidence and indicates the level of associated stochastic *** second technique aims to embrace the systemic uncertainty of modelling complex mineral *** this approach,multiple prospectivity maps are each generated with different combinations of confidence values applied

关键词： Prospectivity Confidence Uncertainty Multiple models Mineral exploration Nickel

Nanobiotechnology： 1D nanomaterial building blocks for cellular interfaces and hybrid tissues

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Nano Research 2018年第10期11卷 5372-5399页

作者： Haitao Liu Bilal Haider holden R. Fried Jie Ju Olurotimi Bolonduro Vineeth Raghuram Brian P. Timko Department of Biomedical Engineering Tufts University Medford Massachusetts 02755 USA School of Materials Science and Technology China University ofGeosciences Beijing 100083 China

Solid-state nanomaterials exhibit complementary interactions with biological systems because of their biologically-relevant size scales and rationally tunable electrical, chemical and mechanical properties. In this review, we focus specifically on one-dimensional （1D） nanomaterials such as silicon or gold nanowires or carbon nanotubes. We discuss the nature of the nanomaterial-cell interface, and how that interface may be engineered to enhance or modulate cellular function. We then describe how those unique interfaces may be exploited in three-dimensional （3D） tissue culture to recapitulate the extracellular matrix and promote or complement morphogenesis. Finall~ we describe how 1D nanomaterials may be elucidated as nanoelectronic devices that monitor the chemical or electrical environment of cells or tissue with exquisite spatial and temporal resolution. We discuss prospects for entirely new classes of engineered, hybrid tissues with rationally-designed biological function and two-way, closed-loop electronic communication.

关键词： nanomaterial neuron cardiomyocyte nanoelectronics bioelectronics hybrid tissue