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Spon's Landscape and External Works Price Book 2005: Free CdrOM (Spons Price Books) 24

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Approximation of the Mean Escape Time for a Tilted Periodic Potential

2004年

作者： davis Langdon

来源：畅想之星图书光盘版（南... 评论

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Communications in Computational Physics 2019年第1期25卷 1-40页

作者： Tamra Heberling Lisa davis Tomas Gedeon Los Alamos National Laboratory XTD-SSLos AlamosNM87545USA Department of Mathematical Sciences Montana State UniversityBozemanMT59717-2400USA

We present a formula approximating the mean escape time(MST)of a particle from a tilted multi-periodic potential *** potential function consists of a weighted sum of a finite number of component functions,each of which is *** this particular case,the least period of the potential function is a common period amongst all of its component *** approximation of the MST for the potential function is derived,and this approximation takes the form of a product of the MSTs for each of the individual periodic component *** first example illustrates the computational advantages of using the approximation for model validation and parameter tuning in the context of the biological application of DNA *** also use this formula to approximate the MST for an arbitrary tilted periodic potential by the product of MSTs of a finite number of its Fourier *** examples using truncated Fourier series are presented and analyzed.

关键词： Brownian Ratchet multi-periodic potential tilted periodic potential Fokker-Plank equation

Focal therapy for localized prostate cancer:is there a “middle ground” between active surveillance and definitive treatment?

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Asian Journal of Andrology 2019年第1期21卷 37-44页

作者： Cihan H Demirel Muammer Altok John W davis Department of Urology The University of Texas MD Anderson Cancer CenterHoustonTexas 77030USA.

In recent years,it has come a long way in the diagnosis,treatment,and follow-up of prostate *** this,it was argued that definitive treatments could cause overtreatment,particularly in the very low,low,and favorable risk *** alternative treatment and follow-up methods are being considered for this group of patients,active surveillance is seen as a good alternative for patients with very low and low-risk groups in this ***,it has become necessary to find other alternatives for patients in the favorable risk group or patients who cannot adopt active *** the light of technological developments,the concept of focal therapy was introduced with the intensification of research to treat only the lesioned area instead of treating the entire organ for prostate lesions though there are not many publications about many of them *** to the initial results,it was understood that the results could be good if the appropriate focal therapy technique was applied to the appropriate ***,focal therapies have begun to find their"middle ground"place between definitive therapies and active follow-up.

关键词： focal therapy multiparametric magnetic resonance imaging prostate biopsy prostate cancer prostatic neoplasms

COMPUTATIONAL ISSUES IN SENSITIVITY ANALYSIS FOR 1-D INTERFACE PROBLEMS

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Journal of Computational Mathematics 2011年第1期29卷 108-130页

作者： Lisa G. davis John R. Singler Montana State University Department of Mathematical Sciences PO Box 172400 Bozeman MT 59717-2400 USA Missouri University of Science and Technology Department of Mathematics and Statistics 300 W. 12th St. Rolla MO 65409 0020 USA

This paper is concerned with the construction of accurate and efficient computational algorithms for the numerical approximation of sensitivities with respect to a parameter dependent interface location. Motivated by sensitivity analysis with respect to piezoelectric actuator placement on an Euler-Bernonlli beam, this work illustrates the key concepts related to sensitivity equation formulation for interface problems where the parameter of interest determines the location of the interface. A fourth order model problem is considered, and a homogenization procedure for sensitivity computation is constructed using standard finite clement methods. Numerical results show that proper formulation and approximation of the sensitivity interface conditions is critical to obtaining convergent numerical sensitivity approximations. A second order elliptic interface model problem is also mentioned, and the homogenization procedure is outlined briefly for this model.

关键词： Finite element method Interface Problems Sensitivity Equation.

Comparison of aerosol optical depth of UV-B Monitoring and Research Program （UVMRP）, AERONET and MODIS over continental United States

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Frontiers of Earth Science 2013年第2期7卷 129-140页

作者： Hongzhao TANG Maosi CHEN John davis Wei GAO USDA UV-B Monitoring and Research Program Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80521 USA Department of Ecosystem Science and Sustainability Colorado State University Fort Collins C-O 80521 USA

The concern about the role of aerosols as to their effect in the Earth-Atmosphere system requires observation at multiple temporal and spatial scales. The Moderate Resolution Imaging Spectroradiameters （MODIS） is the main aerosol optical depth （AOD） monitoring satellite instrument, and its accuracy and uncertainty need to be validated against ground based measurements routinely. The comparison between two ground AOD measurement programs, the United States Department of Agriculture （USDA） Ultmviolet-B Monitoring and Research Program （UVMRP） and the Aerosol Robotic Network （AERONET） program, confirms the consistency between them. The intercomparison between the MODIS AOD, the AERONET AOD, and the UVMRP AOD suggests that the UVMRP AOD measurements are suited to be an alternative ground-based validation source for satellite AOD products. The experiments show that the spatial-temporal dependency between the MODIS AOD and the UVMRP AOD is positive in the sense that the MODIS AOD compare more favorably with the UVMRP AOD as the spatial and temporal intervals are increased. However, the analysis shows that the optimal spatial interval for all time windows is defined by an angular subtense of around 1° to 1.25°, while the optimal time window is around 423 to 483 minutes at most spatial intervals. The spatial-temporal approach around 1.25° ＆ 423 minutes shows better agreement than the prevalent strategy of 0.25° ＆ 60 minutes found in other similar investigations.

关键词： aerosol optical depth (AOD) United States Department of Agriculture (USDA) UV-B Monitoring andresearch Program (UVMRP) Aerosol Robotic Network (AERONET) Moderate Resolution Imaging Spectmradiameters (MODIS) validation spatial-temporal approach

A Variable Stiffness Soft Gripper Using Granular Jamming and Biologically Inspired Pneumatic Muscles

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Journal of Bionic Engineering 2018年第2期15卷 236-246页

作者： Loai AI Abeach Samia Nefti-Meziani Theo Theodoridis Steve davis Autonomous Systems and Robotics Research Centre University of Salford Salford M5 4WT UK Computer Engineering Department College of Engineering Basra University Basra 61004 Iraq

As the domains, in which robots operate change the objects a robot may be required to grasp and manipulate, are likely to vary sig- nificantly and often. Furthermore there is increasing likelihood that in the future robots will work collaboratively alongside people. There has therefore been interest in the development of biologically inspired robot designs which take inspiration from nature. This paper pre- sents the design and testing of a variable stiffness, three fingered soft gripper, which uses pneumatic muscles to actuate the fingers and granular jamming to vary their stiffness. This gripper is able to adjust its stiffness depending upon how fragile/deformable the object being grasped is. It is also lightweight and low inertia, making it better suited to operation near people. Each finger is formed from a cylindrical rubber bladder filled with a granular material. It is shown how decreasing the pressure inside the finger increases the jamming effect and raises finger stiffness. The paper shows experimentally how the finger stiffness can be increased from 21 N·m^-1 to 71 N·m^-1. The paper also describes the kinematics of the fingers and demonstrates how they can be position-controlled at a range of different stiffness values.

关键词： biologically inspired robots variable stiffness actuation soft robotics soft grippers pneumatic muscles

Effect of TiN Particles and Grain Size on the Charpy Impact Transition Temperature in Steels

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Journal of Materials Science & Technology 2012年第10期28卷 878-888页

作者： J.Du M.Strangwood C.L.davis School of Metallurgy and Materials University of Birmingham

The toughness of ferritic steels is influenced by the grain size distribution, second phase, precipitates and coarse inclusions. In this work an examination of the effect of coarse TiN particles （〉0.5 μm） and ferrite grain size on the Charpy impact transition temperature in high strength low alloyed steels has been carried out. Steels with high Ti content （up to 0.045 wt%）, have been heat-treated and furnace cooled to obtain a ferrite-pearlite microstructure with different ferrite grain sizes. Coarse TiN particle size and ferrite grain size distributions have been measured and Charpy impact testing has been carried out. Scanning electron microscopy （SEM） analysis has been used to measure the grain boundary carbide thickness and to determine if the coarse TiN particles are acting as cleavage initiation sites by fractographic analysis. The Charpy ductile-brittle transition temperatures （DBTT） have been predicted using standard literature equations, and compared to the measured values. The relationship between the ferrite grain size and coarse TiN particle size and number density in terms of whether the coarse TiN particles act as effective cleavage initiation sites is discussed in this paper.

关键词： TiN particles Grain size Charpy impact test Ductile-brittle transitiontemperatures (DBTT) Steels

Appetite control： why we fail to stop eating even when we are full？

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Frontiers in Biology 2014年第3期9卷 169-174页

作者： Kristen davis Young-Jai YOU Department of Biochemistry and Molecular Biology Virginia Commonwealth University Richmond VA 23298 USA

We often eat more than our body needs. We live in an environment where high calorie food is abundant and physical activities are limited. Living in this environment, maintaining healthy bodyweight becomes challenging and obesity becomes a social burden. Why do we continue to eat even after the metabolic needs are satisfied？ Feeding is an ancient behavior essential to survive. Thus the mechanisms to regulate appetite, energy expenditure, and energy storage are well conserved throughout animals. Based on this conservation, we study why we fail to control appetite using a simple genetic model system C. elegans. We have discovered certain genetic components that when misregulated have animals eat more and store more fat. In this review we discuss how these genes work in the appetite control circuit to ultimately understand overall appetite control behavior. We will also briefly discuss how social influence affects feeding regardless of the metabolic status of an animal.

关键词： cGMP TGFI3 C. elegans satiety appetite obesity

Stem cell-derived extracellular vesicles as potential mechanism for repair of microvascular damage within and outside of the central nervous system in amyotrophic lateral sclerosis:perspective schema

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Neural Regeneration Research 2021年第4期16卷 680-681页

作者： Svitlana Garbuzova-davis Cesario V.Borlongan Center of Excellence for Aging&Brain Repair Department of Neurosurgery and Brain RepairUniversity of South FloridaMorsani College of MedicineTampaFLUSA Department of Molecular Pharmacology and Physiology Department of Pathology and Cell BiologyUniversity of South FloridaMorsani College of MedicineTampaFLUSA

Microvascular alterations within and outside the central nervous system(CNS)in amyotrophic lateral sclerosis(ALS):ALS is a fatal neurodegenerative disease leading to paralysis and eventual death within 3 to 5 years of diagnosis due to respiratory *** pathogenic intrinsic and extrinsic effectors are involved in the diffuse motor neuron ***,impairment of neurovascular unit components in the brain and spinal cord in ALS patients and in animal models of disease was noted and points to vascular pathology being a key factor in the recognition of ALS as a neurovascular disease(Garbuzova-davis et al.,2011).

关键词： damage alterations diagnosis