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2010

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Articles 4711 - 4740 of 8620

Full-Text Articles in Physical Sciences and Mathematics

Oxygen Regulates The Effective Diffusion Distance Of Nitric Oxide In The Aortic Wall, Xiaoping Liu, Parthasarathy Srinivasan, Eric Collard, Paula Grajdeanu, Kevin Lok, Sarah E. Boyle, Avner Friedman, Jay L. Zweier Feb 2010

Oxygen Regulates The Effective Diffusion Distance Of Nitric Oxide In The Aortic Wall, Xiaoping Liu, Parthasarathy Srinivasan, Eric Collard, Paula Grajdeanu, Kevin Lok, Sarah E. Boyle, Avner Friedman, Jay L. Zweier

Mathematics and Statistics Faculty Publications

Endothelium-derived nitric oxide (NO) is critical in maintaining vascular tone. Accumulating evidence shows that NO bioavailability is regulated by oxygen concentration. However, it is unclear to what extent the oxygen concentration regulates NO bioavailability in the vascular wall. In this study, a recently developed experimental setup was used to measure the NO diffusion flux across the aortic wall at various oxygen concentrations. It was observed that for a constant NO concentration at the endothelial surface, the measured NO diffusion flux out of the adventitial surface at [O2] = 0 μM is around fivefold greater than at [O2] = 150 μM, …

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Ion Microprobe Analysis Of Oxygen Isotopes In Garnets Of Complex Chemistry, F. Zeb Page, Noriko T. Kita, John W. Valley Feb 2010

Ion Microprobe Analysis Of Oxygen Isotopes In Garnets Of Complex Chemistry, F. Zeb Page, Noriko T. Kita, John W. Valley

Faculty & Staff Scholarship

Accurate ion microprobe analysis of oxygen isotope ratios in garnet is possible if appropriate standards are employed to correct for instrumental bias, a component of which depends on the cation chemistry of the analyzed mineral. In this study, 26 garnet standards (including 14 new standards) that span the compositional range of pyrope, almandine, grossular, spessartine, and andradite were analyzed repeatedly by ion microprobe to develop a new method of correcting for instrumental bias in garnets. All analyses were normalized to a single master garnet standard (UWG-2) before bias from cation composition was considered. Bias due to cation composition in garnet …

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Potential Driven Deposition Of Polyelectrolytes Onto The Surface Of Cysteine Monolayers Assembled On Gold, Wesley Sanders, Mark Anderson Feb 2010

Potential Driven Deposition Of Polyelectrolytes Onto The Surface Of Cysteine Monolayers Assembled On Gold, Wesley Sanders, Mark Anderson

Mark R. Anderson

Electrochemical impedance spectroscopy and the quartz crystal microbalance measurements are used to examine the ability of potential applied to a substrate to create, in situ, conditions favorable for the electrostatic deposition of polyelectrolytes onto a gold substrate modified by the self-assembly of cysteine. Cysteine is a zwitterionic compound that, when confined to a substrate, has the ability to establish either a net positive or a net negative interfacial charge, depending on the conditions. As such, cysteine modified interfaces could possibly be used as a versatile substrate for deposition of either cationic or anionic polyelectrolytes. The potential of zero charge of …

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Synthesis And Characterization Of Allylic Dinuclear Molybdenum Complexes With Bridging Oxygen And Sulfur Containing Ligands., Mazin Shatnawi, Samer Tanash, Saleem Al-Ahmad, Paul Challen, Gerald Henkel Feb 2010

Synthesis And Characterization Of Allylic Dinuclear Molybdenum Complexes With Bridging Oxygen And Sulfur Containing Ligands., Mazin Shatnawi, Samer Tanash, Saleem Al-Ahmad, Paul Challen, Gerald Henkel

Paul R. Challen

No abstract provided.

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Electrically Switched Color With Polymer-Stabilized Blue-Phase Liquid Crystals, Shin-Ying Lu, Liang-Chy Chien Feb 2010

Electrically Switched Color With Polymer-Stabilized Blue-Phase Liquid Crystals, Shin-Ying Lu, Liang-Chy Chien

Liang-Chy Chien

We report an electrical-field switched color device using a polymer-stabilized blue-phase ( PSBP) liquid crystal in which the Bragg-reflected color of the blue phase ( BP) can be switched to reflect a second color. The phase-separated three-dimensional polymer network transcribes the cubic structure of a BP liquid crystal and restrains the deformation of cubic lattice by the external electric field. The new wide-range electric-field switched colors with PSBP may be an important step toward ecofriendly color reflective displays. (C) 2010 Optical Society of America

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A Note On Empirical Sample Distribution Of Journal Impact Factors In Major Discipline Groups, Sudhanshu K. Mishra Feb 2010

A Note On Empirical Sample Distribution Of Journal Impact Factors In Major Discipline Groups, Sudhanshu K. Mishra

Sudhanshu K Mishra

What type of statistical distribution do the Journal Impact Factors follow? In the past, researchers have hypothesized various types of statistical distributions underlying the generation mechanism of journal impact factors. These are: lognormal, normal, approximately normal, Weibull, negative exponential, combination of exponentials, Poisson, Generalized inverse Gaussian-Poisson, negative binomial, generalized Waring, gamma, etc. It is pertinent to note that the major characteristics of JIF data lay in the asymmetry and non-mesokurticity. The present study, frequently encounters Burr-XII, inverse Burr-III (Dagum), Johnson SU, and a few other distributions closely related to Burr distributions to best fit the JIF data in subject groups …

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Evaluation And Development Of Selection Criteria To Guide Organizational Selection Of A Project Management Maturity Model, Diane Zandin Feb 2010

Evaluation And Development Of Selection Criteria To Guide Organizational Selection Of A Project Management Maturity Model, Diane Zandin

Regis University Student Publications (comprehensive collection)

Organizations wishing to measurably and continuously improve processes often look towards maturity models, such as OPM3 and CMMI, as their panacea. However, selecting the wrong model for the organizations goals and resources can result in project failure. This study, focusing on OPM3 and CMMI, proposes a guidance tool that can help organizations select the right maturity model. The study is framed in the state government context due to the complexity and relative insularity of that environment. In addition to being a limited based, state governments have several limiters that factor into project selection, namely budget and taxpayer transparency. Using several …

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The Power Of The Weak: Recognition Of Ion Pairs In Water Using A Simple Array Sensor, Yuan-Li Liu, Manuel A. Palacios, Pavel Anzenbacher Feb 2010

The Power Of The Weak: Recognition Of Ion Pairs In Water Using A Simple Array Sensor, Yuan-Li Liu, Manuel A. Palacios, Pavel Anzenbacher

Pavel Anzenbacher

An array sensor comprising six off-the-shelf indicators doped in a poly(ether-urethane) recognizes five cations, seven anions and thirty-five ion pairs at pH 5-9 in water. Such a discrimination capacity and recognition efficiency (6:35) with >= 93% accuracy is rare. Low cost and wide availability of various polymers and indicators could make this approach useful in numerous applications.

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Organization, Structure, And Assembly Of Alpha-Carboxysomes Determined By Electron Cryotomography Of Intact Cells, Cristina V. Iancu, Dylan M. Morris, Zhicheng Dou, Sabine Heinhorst, Gordon C. Cannon, Grant J. Jensen Feb 2010

Organization, Structure, And Assembly Of Alpha-Carboxysomes Determined By Electron Cryotomography Of Intact Cells, Cristina V. Iancu, Dylan M. Morris, Zhicheng Dou, Sabine Heinhorst, Gordon C. Cannon, Grant J. Jensen

Faculty Publications

Carboxysomes are polyhedral inclusion bodies that play a key role in autotrophic metabolism in many bacteria. Using electron cryotomography, we examined carboxysomes in their native states within intact cells of three chemolithoautotrophic bacteria. We found that carboxysomes generally cluster into distinct groups within the cytoplasm, often in the immediate vicinity of polyphosphate granules, and a regular lattice of density frequently connects granules to nearby carboxysomes. Small granular bodies were also seen within carboxysomes. These observations suggest a functional relationship between carboxysomes and polyphosphate granules. Carboxysomes exhibited greater size, shape, and compositional variability in cells than in purified preparations. Finally, we …

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Phenotypic Variance Predicts Symbiont Population Densities In Corals: A Modeling Approach, Robert Van Woesik, Kazuyo Shiroma, Semen Koksal Feb 2010

Phenotypic Variance Predicts Symbiont Population Densities In Corals: A Modeling Approach, Robert Van Woesik, Kazuyo Shiroma, Semen Koksal

Ocean Engineering and Marine Sciences Faculty Publications

We test whether the phenotypic variance of symbionts (Symbiodinium) in corals is closely related with the capacity of corals to acclimatize to increasing seawater temperatures. Moreover, we assess whether more specialist symbionts will increase within coral hosts under ocean warming. The present study is only applicable to those corals that naturally have the capacity to support more than one type of Symbiodinium within the lifetime of a colony; for example, Montastraea annularis and Montastraea faveolata. Methodology/Principal Findings: The population dynamics of competing Symbiodinium symbiont populations were projected through time in coral hosts using a novel, discrete time optimal-resource model. Models …

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Dynamics Of A Liquid-Crystal Variable Optical Prism Based On Pancharatnam Phase, Lei Shi, Paul F. Mcmanamon, Douglas Bryant, Ke Zhang, Philip J. Bos Feb 2010

Dynamics Of A Liquid-Crystal Variable Optical Prism Based On Pancharatnam Phase, Lei Shi, Paul F. Mcmanamon, Douglas Bryant, Ke Zhang, Philip J. Bos

Philip J. Bos

We consider the dynamics of a variable optical prism based on Pancharatnam phase. The device basics, using liquid crystals (LCs) as the electro-optical material, have been previously proposed. In this paper, we study the dynamics of discrete changes in the phase profile, and also continuous changes in the phase profile through acquired data and numerical modeling. We show that a design based on LCs whose dielectric anisotropy can change sign (as a function of frequency) allows continuous tuning with reasonable response times.

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Bio-Creep In Non-Inferiority Clinical Trials, Siobhan P. Everson-Stewart, Scott S. Emerson Feb 2010

Bio-Creep In Non-Inferiority Clinical Trials, Siobhan P. Everson-Stewart, Scott S. Emerson

UW Biostatistics Working Paper Series

After a non-inferiority clinical trial, a new therapy may be accepted as effective, even if its treatment effect is slightly smaller than the current standard. It is therefore possible that, after a series of trials where the new therapy is slightly worse than the preceding drugs, an ineffective or harmful therapy might be incorrectly declared efficacious; this is known as “bio-creep.” Several factors may influence the rate at which bio-creep occurs, including the distribution of the effects of the new agents being tested and how that changes over time, the choice of active comparator, the method used to model the …

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Designing Successful Online Courses - Part 2, Kathleen P. King Feb 2010

Designing Successful Online Courses - Part 2, Kathleen P. King

Kathleen P King

Once again, our major goal is to provide faculty with consistent guidance through the many instructional decisions and design steps they need to pursue in this process. This process is a fantastic opportunity to craft a virtual learning space in which people can engaging in learning beyond the constraints of time and space.

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On Type Of Periodicity And Ergodicity To A Class Of Fractional Order Differential Equations, Ravi P. Agarwal, Bruno D. Andrade, Claudio Cuevas Feb 2010

On Type Of Periodicity And Ergodicity To A Class Of Fractional Order Differential Equations, Ravi P. Agarwal, Bruno D. Andrade, Claudio Cuevas

Mathematics and System Engineering Faculty Publications

We study several types of periodicity to a class of fractional order differential equations.

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Open Notebook Science Challenge Solubilities Of Organic Compounds In Organic Solvents, Andrew Lang, Jean-Claude Bradley, Cameron Neylon, Rajarshi Guha, Antony J. Williams, Bill Hooker, Brent Friesen Feb 2010

Open Notebook Science Challenge Solubilities Of Organic Compounds In Organic Solvents, Andrew Lang, Jean-Claude Bradley, Cameron Neylon, Rajarshi Guha, Antony J. Williams, Bill Hooker, Brent Friesen

College of Science and Engineering Faculty Research and Scholarship

The Open Notebook Science Solubility Challenge Solubility is an important consideration for many chemistry applications. Synthetic chemists usually use a solvent to perform reactions and knowledge of the solubility of the starting materials or products can be very useful to pick an appropriate solvent. Analytical chemists can use solubility to design separation techniques and factor in dynamic range considerations. Physical chemists can create and evaluate their models of how molecules interact in the solubilization and precipitation processes. Solubility data can be obtained from a variety of online and offline sources. As with all chemical data, it can be a challenge …

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Designing Successful Online Courses - Part 2, Kathleen P. King Feb 2010

Designing Successful Online Courses - Part 2, Kathleen P. King

Leadership, Counseling, Adult, Career and Higher Education Faculty Publications

Once again, our major goal is to provide faculty with consistent guidance through the many instructional decisions and design steps they need to pursue in this process. This process is a fantastic opportunity to craft a virtual learning space in which people can engaging in learning beyond the constraints of time and space.

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Differential Cross Section And Recoil Polarization Measurements For The Γp→K+Λ Reaction Using Clas At Jefferson Lab, M. E. Mccracken, Gerard P. Gilfoyle, Et. Al. Feb 2010

Differential Cross Section And Recoil Polarization Measurements For The Γp→K+Λ Reaction Using Clas At Jefferson Lab, M. E. Mccracken, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

We present measurements of the differential cross section and 'B; recoil polarization for the γp → K+Λ reaction made using the CLAS detector at Jefferson Lab. These measurements cover the center-of-mass energy range from 1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles. Independent analyses were performed using the K+pπ− and K+p (missing π−) final-state topologies; results from these analyses were found to exhibit good agreement. These differential-cross-section measurements show excellent agreement with previous CLAS and LEPS results and offer increased precision and a 300-MeV increase …

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Dual-Action Hygienic Coatings: Benefits Of Hydrophobicity And Silver Ion Release And Surface Analysis, Niall Stobie, Brendan Duffy, John Colreavy, Patrick Mchale, Steven Hinder, Declan Mccormack Feb 2010

Dual-Action Hygienic Coatings: Benefits Of Hydrophobicity And Silver Ion Release And Surface Analysis, Niall Stobie, Brendan Duffy, John Colreavy, Patrick Mchale, Steven Hinder, Declan Mccormack

Articles

Coatings that demonstrate reduced attachment of crystalline precipitates and the medical device colonising Staphylococcus epidermidis were prepared by the immobilisation of silver doped perfluoropolyether–urethane siloxane thin films on glass substrates. The presence of stratified hydrophobic perfluoropolyether groups protects the coating surface from the attachment of crystalline hydrophilic species such as chlorides and phosphates, whilst silver ion release inhibited attachment of S. epidermidis and subsequent biofilm formation in vitro. The release of silver ions protects the perfluoro groups from the hydrophobic interactions of S. epidermidis cells, which can reduce the hydrophobicity of the protective coating. These coatings also exhibited significant antibacterial …

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Analysis Of An All-Optical Sbs Avalanche Detector, D. Walker, M. Steiner, Armen Gulian Feb 2010

Analysis Of An All-Optical Sbs Avalanche Detector, D. Walker, M. Steiner, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

Seeding Brillouin scattering with a sufficiently efficient source of coherent phonons has the potential to produce energy-sensitive photon detectors. Based on this idea, we propose and analyze some possible designs for such a detector.

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An Examination Of Factors Influencing The Thermodynamics Of Correlation-Gas Chromatography As Applied To Large Molecules And Chiral Separations, Dmitry Lipkind, James S. Chickos Feb 2010

An Examination Of Factors Influencing The Thermodynamics Of Correlation-Gas Chromatography As Applied To Large Molecules And Chiral Separations, Dmitry Lipkind, James S. Chickos

James Chickos

No abstract provided.

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High-Excitation Emission Lines Near Eta Carinae, And Its Likely Companion Star, Andrea Mehner, Kris Davidson, Gary J. Ferland, Roberta M. Humphreys Feb 2010

High-Excitation Emission Lines Near Eta Carinae, And Its Likely Companion Star, Andrea Mehner, Kris Davidson, Gary J. Ferland, Roberta M. Humphreys

Physics and Astronomy Faculty Publications

In order to study the distribution of gas and ionizing radiation around η Car and their implications for its likely companion star, we have examined high-excitation emission lines of [Ne III], [Fe III], etc., in spectra obtained with the Hubble Space Telescope/Space Telescope Imaging Spectrograph instrument during 1998-2004. Our principal results, some of them unexpected, are as follows. (1) The high-excitation fluxes varied systematically and non-trivially throughout η Car's 5.5 year spectroscopic cycle. Instead of rising to a plateau after the 1998 ''event,'' they changed continuously with a maximum in mid-cycle. (2) At one significant location a brief, strong …

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Hyperbranched Conjugated Polymers: Postfunctionalization, C Kub, J Tolosa, Aj Zucchero, Pl Mcgrier, C Subramani, A Khorasani, Vm Rotello, Uhf Bunz Feb 2010

Hyperbranched Conjugated Polymers: Postfunctionalization, C Kub, J Tolosa, Aj Zucchero, Pl Mcgrier, C Subramani, A Khorasani, Vm Rotello, Uhf Bunz

Vincent Rotello

Out on a limb: Sonogashira coupling of a suitable AB(2) monomer containing two iodine and one alkyne group forms a hyperbranched conjugated polymer that is studded with iodine end groups (see picture: I purple). These iodine groups are a perfect handle for convenient, efficient, and high-yielding post-functionalization to access hyperbranched, fluorescent poly(phenyleneethynylene)s.

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Southern Nevada Children’S Outdoor Bill Of Rights Initiative, Public Lands Institute Feb 2010

Southern Nevada Children’S Outdoor Bill Of Rights Initiative, Public Lands Institute

Our Places to Tell Stories

To encourage Southern Nevada’s children to participate in outdoor recreational activities, engage in lifelong learning adventures, and become stewards of the environment.

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Asian Spread Option Pricing Models And Computation, Sijin Chen Feb 2010

Asian Spread Option Pricing Models And Computation, Sijin Chen

Theses and Dissertations

In the commodity and energy markets, there are two kinds of risk that traders and analysts are concerned a lot about: multiple underlying risk and average price risk. Spread options, swaps and swaptions are widely used to hedge multiple underlying risks and Asian (average price) options can deal with average price risk. But when those two risks are combined together, then we need to consider Asian spread options and Asian-European spread options for hedging purposes. For an Asian or Asian-European spread call option, its payoff depends on the difference of two underlyings' average price or of one average price and …

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Five Strategies For Successful Writing Of Reports And Essays, Kathleen P. King Feb 2010

Five Strategies For Successful Writing Of Reports And Essays, Kathleen P. King

Kathleen P King

Many people cannot get started with their literary projects because they do not know where to start. In this brief article, I share insight from years of teaching students and professionals of all ages how to prepare professional work.

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Methods And Kit For Determination Of Prostacyclin In Plasma, Sylvia Daunert, Michael Poon, Urvee Desai, Sapna K. Deo Feb 2010

Methods And Kit For Determination Of Prostacyclin In Plasma, Sylvia Daunert, Michael Poon, Urvee Desai, Sapna K. Deo

Chemistry Faculty Patents

A solid-phase immunoassay for 6-keto-Prostaglandin F1α, the stable hydrolysis product of prostacyclin (Prostaglandin I2) is disclosed. Prostacyclin, a potent vasodilator with anti-platelet and anti-proliferative properties is an effective treatment for primary pulmonary hypertension and pulmonary arterial hypertension associated with scleroderma and scleroderma-like syndrome. Levels of 6-keto-Prostaglandin F1α can be directly correlated with levels of prostacyclin. Therefore, 6-keto-Prostaglandin F1α has become the indicator of choice to measure prostacyclin levels. The single step immunoassay for 6-keto-Prostaglandin F1α uses the bioluminescent protein, aequorin as a label. Analyte-label conjugates were constructed by linking the carboxyl group of …

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Five Strategies For Successful Writing Of Reports And Essays, Kathleen P. King Feb 2010

Five Strategies For Successful Writing Of Reports And Essays, Kathleen P. King

Leadership, Counseling, Adult, Career and Higher Education Faculty Publications

Many people cannot get started with their literary projects because they do not know where to start. In this brief article, I share insight from years of teaching students and professionals of all ages how to prepare professional work.

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Studying The Performance Of Wireless Mesh Networks Using The Hxh Transport Control Protocol, Timothy Scott Larsen Feb 2010

Studying The Performance Of Wireless Mesh Networks Using The Hxh Transport Control Protocol, Timothy Scott Larsen

Theses and Dissertations

As the need to remain connected increases, more and more people are turning to wireless mesh networks because they reduce the need for network infrastructure. Unfortunately, TCP does not perform well in such networks. HxH, an alternate protocol, has shown great promise in simulations, but since it relies on exploiting passive feedback, real measurements are needed to determine how effective the protocol really is. This thesis uses a measurement study on a wireless mesh network to characterize the performance of the HxH protocol in real-world networks. Several aspects of the HxH protocol do in fact perform well on real networks, …

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No Surprise People Ignore Copyright, Rebecca Giblin Feb 2010

No Surprise People Ignore Copyright, Rebecca Giblin

Dr Rebecca Giblin

No abstract provided.

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Modeling And Visualization Of Cardiovascular Systems, Thomas Wischgoll Feb 2010

Modeling And Visualization Of Cardiovascular Systems, Thomas Wischgoll

Computer Science and Engineering Faculty Publications

Modeling complex organs, such as the human heart, requires a detailed understanding of the geometric and mechanical properties of that organ. Similarly, the model is only as accurate as the precision of the underlying properties allow. Hence, it is of great importance that accurate measurements of the geometric configuration are available. This paper describes the different steps that are necessary for creating and visualizing such a vascular model, ranging from determining a basic geometric model, gathering statistical data necessary to extend an existing model up to the visualization of the resulting large-scale vascular models.

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