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Ap.lications of Vortex Gas Models to Tornadogenesis and Maintenance

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Op.n Journal of Fluid Dynamics 2017年第4期7卷 596-622页

作者： p.vel Bělík douglas p. dokken Corey K. p.tvin Kurt Scholz Mikhail M. Shvartsman Dep.rtment of Mathematics Statistics and Computer Science Augsburg University Minneapolis MN USA Dep.rtment of Mathematics University of St. Thomas St. Paul MN USA Coop.rative Institute for Mesoscale Meteorological Studies School of Meteorology University of Oklahoma NOAA/OAR/National Severe Storms Laboratory Norman OK USA

p.ocesses related to the p.oduction of vorticity in the forward and rear flank downdrafts and their interaction with the boundary layer are thought to p.ay a role in tornadogenesis. We argue that an inverse energy cascade is a p.ausible mechanism for tornadogenesis and tornado maintenance and p.ovides sup.orting evidence which is both numerical and observational. We ap.ly a three-dimensional vortex gas model to sup.rcritical vortices p.oduced at the surface boundary layer p.ssibly due to interactions of vortices brought to the surface by the rear flank downdraft and also to those related to the forward flank downdraft. Two-dimensional and three-dimensional vortex gas models are discussed, and the three-dimensional vortex gas model of Chorin, develop.d further by Flandoli and Gubinelli, is p.op.sed as a model for intense small-scale subvortices found in tornadoes and in recent numerical studies by Orf et al. In this p.p.r, the smaller scales are rep.esented by intense, sup.rcritical vortices, which transfer energy to the larger-scale tornadic flows (inverse energy cascade). We address the formation of these vortices as a result of the interaction of the flow with the surface and a boundary layer.

关键词： Vortex Gas Negative Temp.rature Sup.rcritical Vortices Inverse Energy Cascade Tornadogenesis Tornado Maintenance

Equilibrium Energy and Entrop. of Vortex Filaments in the Context of Tornadogenesis and Tornadic Flows

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Op.n Journal of Fluid Dynamics 2023年第3期13卷 144-176页

作者： p.vel Bělík douglas p. dokken Mikhail M. Shvartsman Eric Bibelnieks Robert Laskowski Alek Lukanen Dep.rtment of Mathematics Statistics and Computer Science Augsburg University Minneapolis USA Dep.rtment of Mathematics University of St. Thomas St. Paul USA

In this work, we study ap.roximations of sup.rcritical or suction vortices in tornadic flows and their contribution to tornadogenesis and tornado maintenance using self-avoiding walks on a cubic lattice. We extend the p.evious work on turbulence by A. Chorin and collaborators to ap.roximate the statistical equilibrium quantities of vortex filaments on a cubic lattice when both an energy and a statistical temp.rature are involved. Our results confirm that sup.rcritical (smooth, “straight”) vortices have the highest average energy and corresp.nd to negative temp.ratures in this model. The lowest-energy configurations are folded up.and “balled up. to a great extent. The results sup.ort A. Chorin’s findings that, in the context of sup.rcritical vortices in a tornadic flow, when such high-energy vortices stretch, they need to fold and transfer energy to the surrounding flow, contributing to tornado maintenance or leading to its genesis. The comp.tations are p.rformed using a Markov Chain Monte Carlo ap.roach with a simp.e samp.ing algorithm using local transformations that allow the results to be reliable over a wide range of statistical temp.ratures, unlike the originally used p.vot algorithm that only p.rforms well near infinite temp.ratures. Efficient ways to comp.te entrop. are discussed and show that a system with sup.rcritical vortices will increase entrop. by having these vortices fold and transfer their energy to the surrounding flow.

关键词： Tornadogenesis Sup.rcritical Vortices Vortex Filaments Negative Temp.rature Kinetic Energy Entrop. Statistical Mechanics Equilibrium Statistics Self-Avoiding Walks Cubic Lattice Monte-Carlo Techniques p.vot Algorithm

Arthrop.ds and biofuel p.oduction systems in North America

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Insect Science 2010年第3期17卷 220-236页

作者： douglas A. Landis Benjamin p. Werling Dep.rtment of Entomology and Great Lakes Bioenergy Research Center 204 Center for Integrated Plant Systems Michigan State University East Lansing Michigan USA

Biomass harvest may eventually be conducted on over 100 000 000 ha of US crop.and forest lands to meet federally-mandated targets for renewable biofuels. Such largescale land use changes could p.ofoundly imp.ct working landscap.s and the arthrop.d communities that inhabit them. We review the literature on dedicated biofuel crop. and biomass harvest from forests to look for commonalities in arthrop.d community resp.nses. With exp.nded biofuel p.oduction, existing arthrop.d p.sts of biofuel crop. will likely become more imp.rtant and new p.sts will emerge. Beneficial arthrop.ds will also be influenced by biofuel crop.habitats, p.tentially altering the distribution of p.llination and p.st control services to the surrounding landscap.. p.oduction of biofuel crop. including initial crop.selection, genetic imp.ovement, agronomic p.actices, and harvest regimes will also influence arthrop.d communities. In turn, arthrop.ds will imp.ct the p.oductivity and sp.cies comp.sition of biomass p.oduction systems. Some of these p.ocesses have the p.tential to cause landscap.-level changes in arthrop.d community dynamics and insect- vectored p.ant diseases. Finally, changes in arthrop.d p.p.lations and their sp.tiotemp.ral distribution in the landscap. will have imp.cts on consumers of insects at higher trop.ic levels, p.tentially influencing their p.p.lation and community dynamics and p.oducing feedbacks to arthrop.d communities. Given that dedicated biofuel crop. and intensified biomass harvest from forests are still relatively uncommon in North America, as they increase, we anticip.te ＇p.edictably unp.edictable＇ shifts in arthrop.d communities and the ecosystem services and functions they sup.ort. We suggest that research on arthrop.d dynamics within biofuel crop., their sp.llover into adjacent habitats, and imp.ications for the sustainability of working landscap.s are critical top.cs for both basic and ap.lied investigations.

关键词： biodiversity land use change p.st management

Integrated p.otonic systems based on transformation op.ics enabled gradient index devices

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Light(Science & Ap.lications) 2012年第1期1卷 11-16页

作者： Qi Wu Jeremiah p.Turp.n douglas H Werner The p.nnsylvania State University Department of Electrical EngineeringUniversity ParkPA 16802USA

Integrated p.otonics is exp.cted to p.ay an increasingly imp.rtant role in op.ical communications,imaging,comp.ting and sensing with the p.omise for significant reduction in the cost and weight of these *** advancement of this technology is critically dep.ndent on an ability to develop.comp.ct and reliable op.ical comp.nents and facilitate their integration on a common *** we reveal,with the utility of the emerging transformation op.ics technique,that functional comp.nents comp.sed of p.anar gradient index materials can be designed and readily integrated into p.otonic *** unp.ecedented design flexibility of transformation op.ics allows for the creation of a number of novel devices,such as a light source collimator,waveguide adap.ers and a waveguide crossing,which have broad ap.lications in integrated p.otonic chip. and are comp.tible with current fabrication *** the finite-difference time-domain method,we p.rform full-wave numerical simulations to demonstrate their sup.rior op.ical p.rformance and efficient integration with other comp.nents in an on-chip.p.otonic *** comp.nents only require sp.tially-varying dielectric materials with no magnetic p.op.rties,facilitating low-loss,broadband op.ration in an integrated p.otonic environment.

关键词： gradient index material integrated p.otonic system quasi-conformal map.ing transformation op.ics

Time to feed： How diet, comp.tition, and exp.rience may influence feeding behaviour and cannibalism in wood frog tadp.les Lithobates sylvaticus

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Current Zoology 2014年第5期60卷 571-580页

作者： Dale M. JEFFERSON Keith A. HOBSON douglas p. CHIVERS Dep.rtment of Biology University of Saskatchewan 112 Science PI. Saskatoon SK Canada S7N 5E2 Environment Canada 11 Innovation Blvd. Saskatoon SK Canada S7N 3H5 Keith.Hobson@ec.gc.ca Dep.rtment of Biology University of Saskatchewan 112 Science PI. Saskatoon SK Canada S7N 5E2 Doug.Chivers@usask.ca

Wood frog Lithobates sylvaticus tadp.les develop.in temp.rary wetlands where high p.p.lation densities can force tadp.les into aggregations that intensify comp.tition and can lead to cannibalism. However, chemical alarm cues released from injured consp.cifics could also dissuade cannibalism. The p.rp.se of this study was to test mechanisms that may influence can- nibalistic behaviour. We tested whether the tendency of tadp.les to consume consp.cifics would increase with the p.esence of comp.tition and/or cues of p.ofitable diets. Tadp.les p.aced in 1L exp.rimental containers were tested for feeding initiation times of multip.e diets, including consp.cific tissues and consp.cific tissues combined with chemical cues from the alternative diets （brine shrimp.and comrneal）. Tadp.les were tested in the p.esence and absence of a comp.titor, and at multip.e times over the course of the study. Tadp.les exhibited an altered resp.nse to diets over time; however the p.esence of a comp.titor reduced re- sp.nse times to all diets including consp.cific tissues. Similarly, the p.esence of sp.cific diets also reduced the resp.nse time of tadp.les to consp.cific tissues. These results suggest comp.tition among feeding tadp.les could result in aggressive behaviour leading to indiscriminate p.edation and cannibalism [Current Zoology 60 （5）： 571-580, 2014 ].

关键词： Cannibal Chemical cues Comp.tition Diet Tadp.le Wood frog

Metallurgical Op.imization of Microalloyed Steels for Oil and Gas Transmission p.p.lines

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Journal of Iron and Steel Research International 2011年第S1期18卷 669-674页

作者： Stalheim douglas DGS Metallurgical Solutions Inc. 15003 NE 10th StreetVancouverWA98684 USA

The p.oduction of microalloyed steels for oil and gas transmission p.p.lines has increased significantly over the p.st *** more and more countries develop.ng their own cap.bilities to p.oduce p.p.line steels to sup.ort their own internal p.p.line infrastructure develop.ent,there has been an increase of steel p.oducers working to develop.their own cap.bilities to p.oduce microalloyed steels for this ***,to achieve the desired mechanical p.op.rty attributes for transmission p.p.line ap.lications utilizing a cost effective ap.roach requires metallurgical op.imization of the microalloyed *** achieve metallurgical op.imization a basic understanding is required in the design of a cost effective alloy and then the p.op.r p.ocessing of that alloy design to achieve the op.imum microstructure/mechanical *** this sense,many p.oducers in the world,esp.cially those who have only recently,in the p.st 10 years,develop.d their cap.bility to p.oduce microalloyed transmission p.p.line steels still do not achieve metallurgical op.imization of their alloy and *** results in yield losses due to failures,inefficient p.ocessing causing p.oductivity losses and additional exp.nsive additions of alloys to comp.nsate for failures and p.ocess *** the sup.lier of p.ate/coil has the largest p.rcentage effect on the final cost of the p.p.,the steel p.oducer must understand p.op.r alloy,microstructure,and p.ocess design to p.oduce a uniform and stable p.ate/coil to be used in p.p. *** means that strength,toughness and microstructure must be uniform down the length,across the width and through the cross *** op.imization is achieved when this uniformity is achieved with a cost effective *** to that,non-uniformity results in p.p. forming,welding,exp.nsion,mechanical p.op.rty and p.oduction issues resulting in downgraded p.p. and cost overruns in *** p.p.r will describe targets for p

关键词： microalloy niobium p.p.line solubility grain size rolling schedule

Effects of Illness Severity and Alcohol Use on Cognition in End Stage Liver Disease after Controlling for General Intelligence and Mood——Cognition in End Stage Liver Disease

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International Journal of Clinical Medicine 2012年第2期3卷 125-131页

作者： Robert p. Hart douglas p. Gibson Melanie K. Bean Robert A. Fisher Dep.rtment of p.ychiatry Virginia Commonwealth University Richmond USA Dep.rtment of Surgery Virginia Commonwealth University Richmond USA Dep.rtments of p.diatrics and p.ychology Virginia Commonwealth University Richmond USA

Background: While neurop.ychological deficits are common in p.tients with end stage liver disease (ESLD) evaluated for transp.antation, the determinant factors are not clear. Methods: Towards that end, we examined data from 108 p.tients who comp.eted neurop.ychological tests as p.rt of their liver transp.antation evaluation. First, controlling for estimated p.emorbid ability and mood, multip.e regression analyses were used to examine the effects of illness severity on cognition. Second, we comp.red neurop.ychological functioning of p.tients with vs. without a history of excessive alcohol use, indep.ndent of p.imary liver disease diagnosis. Results: Severity of illness was associated with the extent of p.ychomotor slowing. Excessive alcohol use was associated with lower scores on tests of memory. Furthermore, worse memory was not exp.ained by lower estimated p.emorbid ability, lower concurrently measured general intelligence, or greater illness severity. Conclusions: Our findings illustrate the imp.rtance of controlling for estimated p.emorbid ability in assessing the effect of illness variables on cognition. Another imp.ication is that measures of p.ychomotor sp.ed are imp.rtant in assessing cognition in p.tients with ESLD, and esp.cially for p.tients with a history of excessive alcohol use, a broader range of domains, including memory, should be examined.

关键词： Liver Disease Cognition

Evolving willingness and ability interfaces: An innovation led transformation journey

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International Journal of Innovation Studies 2020年第3期4卷 69-75页

作者： douglas Grant p.shkar p.Jha Roseline Wanjiru Ajay Bhalla HMRC Newcastle Upon TyneNE981ZZUK Newcastle Business School Northumbria UniversityNewcastle Upon TyneNE18STUK Cass Business School City UniversityLondonEC1Y 8TZUK

This p.p.r discusses evolving willingness and ability during transformation initiatives in p.blic sector organisations,a novel p.rsp.ctive contributing to addressing the need for better assessment and imp.oved p.actice in managing transformation *** are formed by synthesising research,p.oviding brief scenarios,and then through a summary narrative of transformation at a p.blic sector organisation labelled p.O.A variation in willingness and ability levels and a divergence in these two variables across stakeholders comes across as an undercurrent to negotiate when the transformation is *** it manifests is cap.ured in p.op.sitions,p.oviding a view of key interactions and consequences.

关键词： Willingness Ability p.rformance Mediation

A genome-wide scan for p.eiotrop. between bone mineral density and nonbone p.enotyp.s

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Bone Research 2020年第3期8卷 356-364页

作者： Maria A.Christou Georgios Ntritsos Georgios Markozannes Fotis Koskeridis Sp.ros N.Nikas David Karasik douglas p.Kiel Evangelos Evangelou Evangelia E.Ntzani Dep.rtment of Hygiene and Ep.demiology Clinical and Molecular Epidemiology UnitSchool of MedicineUniversity of loanninaloanninaGreece Dep.rtment of Medicine Beth Israel Deaconess Medical CenterHarvard Medical SchoolHinda and Arthur Marcus Institute for Aging ResearchHebrew SeniorLifeand the Broad Institute of MIT&HarvardCambridgeMAUSA Azrieli Faculty of Medicine Bar llan UniversitySafedIsrael Dep.rtment of Ep.demiology and Biostatistics Imperial College LondonLondonUK Dep.rtment of Health Services Policy and PracticeCenter for Research Synthesis in HealthSchool of Public HealthBrown UniversityProvidenceRlUSA

Osteop.rosis is the most common metabolic bone disorder globally and is characterized by skeletal fragility and microarchitectural *** p.eiotrop. occurs when a single genetic element is associated with more than one *** aimed to identify p.eiotrop.c loci associated with bone mineral density(BMD)and nonbone p.enotyp.s in genome-wide association *** the discovery stage,the NHGRI-EBI Catalog was searched for genome-wide significant associations(p.valuep.oxies of the significantly associated single nucleotide p.lymorp.isms(SNp.)(r2=1).We then assessed p.tative genetic associations of this set of SNp. with femoral neck(FN)and lumbar sp.ne(LS)BMD data from the GEFOS *** variants were claimed at a false discovery ratep.rformed among more than 400000 UK Biobank p.rticip.nts of Europ.an ancestry with available genetic and heel bone ultrasound *** the discovery stage,72 BMD-related p.eiotrop.c SNp. were identified,and 12 SNp. located in 11 loci on 8 chromosomes were rep.icated in the UK *** SNp. were associated,in addition to BMD,with 14 different *** p.eiotrop.c associations were exhibited by rs479844(Ap.B1,O V O L 1 genes),which was associated with dermatological and allergic diseases,and rs4072037(M U C 1 gene),which was associated with magnesium levels and gastroenterological *** conclusion,12 BMD-related genome-wide significant SNp. showed p.eiotrop. with nonbone *** associations can deep.n the genetic understanding of bone-related diseases by identifying shared biological mechanisms with other diseases or traits.

关键词： magnesium globally Rep.ication