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Superconvergence and the Numerical Flux: a Study Using the Upwind-Biased Flux in Discontinuous Galerkin Methods

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Communications on Applied Mathematics and Computation 2020年第3期2卷 461-486页

作者： Daniel J.Frean jennifer K.ryan School of Mathematics University of East AngliaNorwichUK Applied Mathematics and Statistics Colorado School of MinesGoldenCOUSA

One of the beneficial properties of the discontinuous Galerkin method is the accurate wave propagation *** is,the semi-discrete error has dissipation errors of order 2k+1(≤Ch2k+1)and order 2k+2 for dispersion(≤Ch2k+2).Previous studies have concentrated on the order of accuracy,and neglected the important role that the error constant,C,plays in these *** this article,we show the important role of the error constant in the dispersion and dissipation error for discontinuous Galerkin approximation of polynomial degree k,where k=0,1,2,*** gives insight into why one may want a more centred flux for a piecewise constant or quadratic approximation than for a piecewise linear or cubic *** provide an explicit formula for these error *** is illustrated through one particular flux,the upwind-biased flux introduced by Meng et al.,as it is a convex combination of the upwind and downwind *** studies of wave propagation are typically done through a Fourier *** higher order Fourier information can be extracted using the smoothness-increasing accuracy-conserving(SIAC)*** SIAC filter ties the higher order Fourier information to the negative-order norm in physical *** show that both the proofs of the ability of the SIAC filter to extract extra accuracy and numerical results are unaffected by the choice of flux.

关键词： Discontinuous Galerkin Smoothness-increasing accuracy-conserving(SIAC)filtering Superconvergence

Preface to the Focused Issue in Honor of Professor Philip Roe on the Occasion of His 80th Birthday

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Communications on Applied Mathematics and Computation 2020年第3期2卷 319-320页

作者： Rémi Abgrall jennifer K.ryan Chi-Wang Shu Institüt für Mathematik Universität ZürichWinterhurerstrasse 1908057ZurichSwitzerland Department of Applied Mathematics and Statistics Colorado School of MinesGoldenCO80401USA Division of Applied Mathematics Brown UniversityProvidenceRI02912USA

On July 3-4,2018,an international workshop was organised at the University of Cambridge,by ***,to mark the 80th anniversary of a young scientist,Philip ***'s scientific achievements are numerous,and it is quite difficult to adequately address his accomplishments in a short *** began his journey at Cambridge,first for his Bachelor's degree and then obtaining his Master's degree in *** left for the Royal Aircraft Establishment(RAE)between 1962 to 1984 to work as an *** was a period of adventure,and the design of mature CFD codes for solving the Euler equations was far from being *** the Lax-Wendroff theorem was known(published in 1960),as for many novelties,it had taken some time before it became a gold *** the RAE,Phil was assigned by his manager to work in a direction that eventually led to Roe's Riemann solver and *** method is now standard in every specialised textbook,but the jump from generalizing the Murman scheme for Euler equations to what is now commonly known as the Roe flux is far from *** Roe relates this adventure,and others,in his"scientific autobiography",one of the papers of this focused issue.

关键词： eventually accomplishment assigned

Plasma angiopoietin 2 as a novel prognostic biomarker in alcohol- related cirrhosis and hepatitis

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Liver Research 2022年第1期6卷 21-29页

作者： Victoria Tatiana Kronsten Josepmaria Argemi Ada Sera Kurt Godhev Mannakat Vijay jennifer Marie ryan Ramon Bataller Debbie Lindsay Shawcross Institute of Liver Studies Department of Inflammation BiologySchool of Immunology and Microbial SciencesFaculty of Life Sciences and MedicineKing's College LondonUK Division of Gastroenterology Hepatology and NutritionPittsburgh Liver Research CenterUniversity of Pittsburgh Medical CenterPittsburghPAUSA Liver Unit.University of Navarra Clinic Hepatology Program.Center for Applied Medical Research(CIMA)Navarra Research InstitutePamplonaSpain Department of Hepatology Royal Free HospitalLondonUK

Background and aim:Severe alcoholic hepatitis(SAH),the most florid form of alcohol-related liver dis-ease(ALD),has a mortality rate of 16%at 28 *** angiopoietin-Tie 2 system regulates angiogenesis and inflammation,both of which are implicated in the pathogenesis of *** study examined plasma and hepatic gene expression of angiopoietin 1(ANG1)and angiopoietin 2(ANG2)in patients with SAH and ALD and investigated their roles as prognostic ***:A case-control study was performed measuring plasma levels of ANG1 and ANG2 by enzyme-linked immunosorbent assay(ELISA)from 30 patients with SAH(Maddrey's discriminant function32),32 patients with ALD cirrhosis and 15 healthy controls(HC).RNA sequencing for ANG1,ANG2,TIE1(codes for Tie1 receptor)and TEK(codes for Tie2 receptor)gene expression from a separate cohort study of 79 patients was also ***:Plasma levels of ANG1 were lower(P=0.010)and ANG2 were higher(P<0.0001)in patients with ALD/SAH compared to *** ANG2:ANG1 ratio was higher in those with ALD/SAH compared to HC(P<0.0001).ANG2 levels were the highest in patients who developed sepsis(P=0.030)and those dying within 90 days(P=0.020).ANG2 levels correlated positively with model for end-stage liver disease(MELD)score(r=0.30,P=0.020),Child-Pugh score(r=0.38,P=0.003),international normalized ratio(r=0.41,P=0.001)and white blood cell count(r=0.28,P=0.040)and inversely correlated with albumin(r=0.26,P=0.040).ANG1 gene expression from liver biopsies was higher in SAH than that in HC(P<0.0001),and greater in severe disease(P<0.0001).ANG2 gene expression trended towards being lower in SAH than that in HC(P=0.070)though was upregulated in severe disease(P=0.0003).Conclusions:Plasma ANG2 is raised in SAH and ALD and could be useful as a prognostic biomarker in this patient population.

关键词： Alcohol-related cirrhosis Alcoholic hepatitis Alcohol-related liver disease(ALD) Angiopoietin 1(ANG1) Angiopoietin 2(ANG2)

Preface to Focused Issue on Discontinuous Galerkin Methods

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Communications on Applied Mathematics and Computation 2022年第1期4卷 1-2页

作者： Jan S.Hesthaven jennifer ryan Chi-Wang Shu Jaap van der Vegt Yan Xu Qiang Zhang Zhimin Zhang Ecole Polytechnique Federale de Lausanne(EPFL) 1015 LausanneSwitzerland Department of Applied Mathematics and Statistics Colorado School of MinesGoldenCO 80401USA Division of Applied Mathematics Brown UniversityProvidenceRI 02912USA Department of Applied Mathematics University of Twente7500AE EnschedeThe Netherlands School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026AnhuiChina Department of Mathematics Nanjing UniversityNanjing 210093JiangsuChina Department of Mathematics Wayne State UniversityDetroitMI 48202USA

The discontinuous Galerkin(DG)method is a class of finite element methods using com-pletely discontinuous piecewise smooth functions(typically polynomials)as basis and test *** its inception in 1973[10],it has seen a sustained development,both in the computational mathematics community and in many scientific and engineering application *** DG methods have several advantages,such as its extreme flexibility in dealing with complex geometry and adaptive computation(both h-and p-adaptivities are easy to implement),extremely high parallel efficiency,good stability properties(energy and entropy stability has been established for DG methods in many situations),nice con-vergence and superconvergence properties,and capability to solve hyperbolic and convec-tion-dominated problems effectively.

关键词： discontinuous stability piecewise

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卡梅伦尝试重振英国制造业

商业周刊（中文版） 2011年第10期 12-13页

作者： jennifer ryan Stanley Reed

作为他演讲的开始，马克·斯泰因（Mark Stein）——通用汽车位于伦敦以北29英里的卢顿镇的Vauxhall厢型货车工厂的经理——展示了一张摄于1965年的该厂航拍照。

关键词：制造业英国斯泰因马克经理

Evaluation of cardiolipin nanodisks as lipid replacement therapy for Barth syndrome

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The Journal of Biomedical Research 2018年第2期32卷 107-112页

作者： Nikita Ikon Fong-Fu Hsu jennifer Shearer Trudy M.Forte Robert O.ryan Children's Hospital Oakland Research Institute Oakland CA 94609 USA Department of Medicine School of Medicine Washington University St. Louis MO 63110 USA Department of Biochemistry University of Nevada Reno NV 89557 USA.

Barth syndrome（BTHS） is a mitochondrial disorder characterized by cardiomyopathy and skeletal muscle weakness. Disease results from mutations in the tafazzin（TAZ） gene, encoding a phospholipid transacylase. Defective tafazzin activity results in an aberrant cardiolipin（CL） profile. The feasibility of restoring the intracellular CL profile was tested by in vivo administration of exogenous CL in nanodisk（ND） delivery particles. Ninety mg/kg CL（as ND）was administered to doxycycline-inducible taz shRNA knockdown（KD） mice once a week. After 10 weeks of CLND treatment, the mice were sacrificed and tissues harvested. Liquid chromatography-mass spectrometry of extracted lipids revealed that CL-ND administration failed to alter the CL profile of taz KD or WT mice. Thus, although CL-ND were previously shown to be an effective means of delivering CL to cultured cells, this effect does not extend to an in vivo setting. We conclude that CL-ND administration is not a suitable therapy option for BTHS.

关键词： mitochondria cardiomyopathy nanoparticles drug delivery

Metal Fabrication by Additive Manufacturing Using Laser and Electron Beam Melting Technologies

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Journal of Materials Science & Technology 2012年第1期28卷 1-14页

作者： Lawrence E. Murr Sara M. Gaytan Diana A. Ramirez Edwin Martinez jennifer Hernandez Krista N. Amato Patrick W. Shindo Francisco R. Medina ryan B. Wicker Department of Metallurgical and Materials Engineering The University of Texas at El PasoEl Paso TX 79968 USA W.M. Keck Center for 3D Innovation The University of Texas at El PasoEl Paso TX 79968 USA

Lawrence E. Murr is Mr.J Mrs. Macintosh Murehison Professor and Chairman of the Department of Metallurgical and Materials Engineering and Ph.D. Program Director in the Materials Research Technology Institute at The University of Texas at El Paso. Dr. Murr received his ***. in physical science from Albright College, and his B.S.E.E. in electronics, his M.S. in engineering mechanics, and his Ph.D. in solidstate science, all from the Pennsylvania State University. Dr. Murr has published 20 books, over 750 scientific and technical articles in a wide range of research areas in materials science and engineering, environmental science and engineering, manufacturing science and engineering （especially rapid prototype/layered manufacturing）,

关键词： Selective laser melting Electron beam melting Additive manufacturing Microstructures Microstructural architecture

Habitual sedentary time and stationary time are inversely related to aerobic fitness

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Sports Medicine and Health Science 2022年第4期4卷 260-266页

作者： Myles W.O'Brien Madeline E.Shivgulam jennifer L.Petterson Yanlin Wua ryan J.Frayne Said Mekari Derek S.Kimmerly Division of Kinesiology School of Health and Human PerformanceFaculty of HealthDalhousie UniversityHalifaxNova ScotiaCanada Department of Family Medicine Universitéde SherbrookeSherbrookeQuebecCanada

A one metabolic-equivalent-of-task increase in peak aerobic fitness(peak MET)is associated with a clinically relevant improvement in survival risk and all-cause *** co-dependent impact of free-living physical behaviours on aerobic fitness are poorly *** purpose of this study was to investigate the impact of theoretically re-allocating time spent in physical behaviours on aerobic *** hypothesized that substituting sedentary time with any physical activity(at any intensity)would be associated with a predicted improvement in aerobic *** volume rate of oxygen uptake(VO_(2)peak)was assessed via indirect calorimetry during a progressive,maximal cycle ergometer protocol in 103 adults(52 females;[38±21]years;[25.0±3.8]kg/m^(2);VO_(2)peak:[35.4±11.5]ml⋅kg^(-1)⋅min^(-1)).Habitual sedentary time,standing time,light-(LPA),moderate-(MPA),and vigorous-physical activity(VPA)were assessed 24-h/day via thigh-worn inclinometry for up to one week(average:[6.3±0.9]days).Isotemporal substitution modelling examined the impact of replacing one physical behaviour with *** time(β=0.8,95%CI:[-1.3,-0.2])and standing time(β=0.9,95%CI:[-1.6,-0.2])were negatively associated with VO_(2)peak,whereas VPA was positively associated with relative VO_(2)peak(β=9.2,95%CI:[0.9,17.6]).Substituting 30-min/day of VPA with any other behaviour was associated with a 2.4–3.4 higher peak *** standing time was associated with a lower aerobic *** little as 10-min/day of VPA predicted a clinically relevant 0.8–1.1 peak MET ***,replacing any time with relatively small amounts of VPA is associated with improvements in aerobic fitness.

关键词： Physical activity intensity Cardiorespiratory fitness Objective activity monitoring Sedentary activity Isotemporal substitution modelling

Preliminary evaluation of the VIsion PERformance(VIPER) simulator

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Military Medical Research 2020年第3期7卷 312-323页

作者： Denise S.ryan Rose K.Sia jennifer B.Eaddy Lorie A.Logan Jide O.Familoni Hind Beydoun Samantha B.Rodgers Bruce A.Rivers Warfighter Refractive Eye Surgery Program and Research Center Fort Belvoir Community HospitalFort BelvoirVA 22060USA Night Vision and Electronic Sensors Directorate Fort BelvoirVA 22060USA Department of Research Programs Fort Belvoir Community HospitalFort BelvoirVA 22060USA

Background:This study evaluated the VIsion PERformance(VIPER)simulator’s ability to assess the functional visual performance in warfighters conducting civilian and military ***:Thirty service members,aged 25–35 years old with a best corrected distance visual acuity(VA)better than or equal to 20/20 or logarithm of the minimum angle of resolution(logMAR)0.00,were randomized to locate and identify road signs and mock improvised explosive devices(IEDs)under either daytime conditions or with infrared imagery,with(cc)and without(sc)wearing their habitual *** also underwent binocular uncorrected(UDVA)and corrected(CDVA)visual assessment,refraction,contrast sensitivity testing and wavefront ***:The mean age was 28.47 *** manifest spherical equivalent was–3.16±1.75 diopters(D),the UDVA in both eyes(OU)was logMAR 0.83±0.47,and the CDVA OU was–0.11±*** VIPER,the mean difference in the detection distance(DD)for road signs ccDD *** was(76.7±52.8)m(P<0.001).The average difference in identification distance(ID)ccID *** was(13.9±6.3)m(P<0.001).The mean accuracies were 83.5%and 27.9%for cc and sc,respectively(P<0.001).The regression analysis indicated that a 1.6 m change in the distance accounts for a 1%change in the accuracy(P=0.002).Without correction,a 4.1 m change accounts for a 1%change in the accuracy(P<0.001).The average IED ccDD was(29.9±8.2)m,and that for scDD was(13.2±13.6)m(P<0.001).The average IED ccID was(32.2±6.2)m and that for the scID was(7.4±10.3)m(P<0.001).The mean IED identification accuracy was 46.7 and 11.4%for cc and sc,respectively(P<0.001).Conclusions:The preliminary results reflect VIPER’s ability to assess functional visual performance when detecting and identifying signs and ***,VIPER is able to detect performance changes with and without correction.

关键词： Functional visual performance Military task performance