bluuebunny/crossref_metadata_2025 huggingface dataset:
Amifostine‐Induced Fever: Case Report and Review of the Literature
Authors: Boehme Sabrina , Wilson David B.
Published: June 2004

Amifostine, also known as WR‐2721 (S‐2‐(3‐aminopropylamino)‐ethylphosphorothioic acid), is an organic thiophosphate cytoprotective agent used to reduce the frequency of severe xerostomia in patients with cancer undergoing postoperative radiation of the head and neck. A 56‐year‐old Caucasian man who received concomitant chemotherapy and radiation for head and neck cancer developed fever concurrent with the administration of amifostine. To our knowledge, this is the first case report that demonstrates the occurrence of fever with low‐dose amifostine therapy without the manifestation of accompanying rash or hypotension. Patients receiving amifostine who develop only fever should be evaluated for an adverse drug reaction, as well as for sepsis and fevers of neutropenia, and it may be necessary to discontinue the drug. Recognition of amifostine as the cause of this adverse event may prevent the cost and inconvenience of a hospital admission.
Temozolomide in Patients with Advanced Cancer: Phase I and Pharmacokinetic Study
Authors: Rudek Michelle A. , Donehower Ross C. , Statkevich Paul , Batra Vijay K. , Cutler David L. , Baker Sharyn D.
Published: June 2004

Study Objective. To determine the maximum tolerated dose, dose‐limiting toxicity, pharmacokinetics, and potential antitumor activity of temozolomide administered as a single dose every 28 days.

Design. Open label, phase I, dose‐escalation trial.

Setting. University‐affiliated cancer center.

Patients. Eleven patients aged 33–73 years with a documented solid tumor or lymphoma who failed therapy of proven efficacy for their disease or had a disease for which no conventional therapy was available.

Intervention. Temozolomide 500 mg/m2 was administered as a single oral dose every 28 days. Doses were escalated to 750 or 1000 mg/m2. No intrapatient dose escalation was allowed. At least two patients were enrolled at each dose level. Patients who did not have progressive disease and did not experience a dose‐limiting toxicity, or experienced a dose‐limiting toxicity but were eligible for dose reduction, were eligible to continue on the study.

Measurements and Main Results: Pharmacokinetic analysis was performed for temozolomide and its active metabolite, 5‐(3‐methyltriazeno)‐imidazole‐4‐carboxamide (MTIC). Neutropenia and thrombocytopenia were dose limiting at 1000 mg/m2. Temozolomide was absorbed rapidly (mean time to maximum concentration 1.4 hrs) and eliminated, with average half‐life and apparent oral systemic clearance values of 1.8 hours and 97 ml/minute/m2, respectively. Mean systemic exposure to MTIC was 3.7% of temozolomide. No objective responses were observed. The maximum tolerated dose of temozolomide was 750 mg/m2.

Conclusion. Temozolomide 750 mg/m2 administered orally every 28 days was well tolerated. Alternate temozolomide dosing schedules such as continuous daily administration may enhance antitumor activity through sustained depletion of the DNA repair protein O6‐alkylguanine DNA alkyltransferase.
Effect of Fluticasone Propionate Nasal Spray on Bioavailability of Intranasal Hydromorphone Hydrochloride in Patients with Allergic Rhinitis
Authors: Davis George A. , Rudy Anita C. , Archer Sanford M. , Wermeling Daniel P. , McNamara Patrick J.
Published: June 2004

Study Objective. To investigate the effect of the nasal corticosteroid fluticasone propionate on the bioavailability and pharmacokinetics of single‐dose intranasal hydromorphone hydrochloride in patients with allergic rhinitis.

Design. Randomized, three‐way, crossover pharmacokinetic study.

Setting. University clinical research unit.

Patients. Twelve patients with allergic rhinitis.

Intervention. Hydromorphone hydrochloride 2.0 mg was administered by intravenous infusion (treatment A), intranasal spray without allergic rhinitis treatment (treatment B), and intranasal spray after 6 days of fluticasone propionate (treatment C). Blood samples were collected serially from 0–16 hours.

Measurements and Main Results. Pharmacokinetic parameters were determined by noncompartmental methods. An analysis of variance (ANOVA) model was used for statistical analysis. Mean (% coefficient of variation) absolute bioavailability of intranasal hydromorphone was 51.9% (28.2) and 46.9% (30.3) in patients with allergic rhinitis with and without treatment with fluticasone propionate, respectively. Mean maximum concentration (Cmax) values were 3.02 and 3.56 ng/ml, respectively. No statistical differences in Cmax and area under the concentration versus time curve were detected between intranasal treatments. Bioavailability values for both intranasal treatments were lower than those in healthy volunteers (57%). Median time to Cmax (Tmax) values were significantly different (p=0.02) for treatments B and C (15 and 30 min, respectively) using rank‐transformed Tmax for ANOVA. Adverse effects were consistent with known effects of hydromorphone administered by other routes, with the exception of bad taste after intranasal administration.

Conclusion. Hydromorphone was rapidly absorbed after nasal administration, with maximum concentrations occurring for most subjects within 30 minutes. Allergic rhinitis may affect pain management strategies for intranasal hydromorphone, with a delay in onset of action for patients treated with fluticasone propionate.
Acute and Continuation Treatment Adequacy with Venlafaxine Extended Release Compared with Fluoxetine
Authors: Yu‐Isenberg Kristina S. , Fontes Christina L. , Wan George J. , Geissler Erika C. , Harada Ann S. M.
Published: June 2004

Study Objective. To compare treatment adequacy in the management of depression during the acute and continuation phases between patients newly treated with venlafaxine extended release (XR) and those newly treated with fluoxetine.

Design. Retrospective observational analysis of pharmacy claims data.

Setting. Large California‐based managed care organization.

Patients. A total of 11,298 patients newly prescribed venlafaxine XR or fluoxetine between January 1, 2000, and February 28, 2001, and continuously enrolled throughout the study, as well as a subset of 7430 patients who continued taking venlafaxine XR or fluoxetine during the follow‐up period.

Measurements and Main Results. The Health Plan Employer Data and Information Set definition was used for continuous antidepressant treatment during the acute and continuation phases. Treatment adequacy was determined for those deemed continuous. Patients receiving within ±10% of the target dose for each drug (venlafaxine XR 75–150 mg, fluoxetine 20 mg) were defined as receiving an adequate dose. Logistic regression was used to evaluate venlafaxine XR versus fluoxetine on treatment adequacy, controlling for age, sex, physician specialty, and pharmacy benefit. The unadjusted adequacy rate for the venlafaxine XR‐only group was 79% versus 57% for the fluoxetine‐only group for 84 continuous days (p<0.0001) and 77% versus 52%, respectively, for 180 continuous days (p<0.0001). The adjusted odds ratios of achieving treatment adequacy with venlafaxine XR only versus that with fluoxetine only were 3.05 (95% confidence interval [CI] 2.65–3.52) for 84 continuous days and 3.57 (95% CI 3.00–4.24) for 180 continuous days.

Conclusion. Patients newly prescribed venlafaxine XR were at least 3 times more likely to achieve treatment adequacy for 84 and 180 days compared with those newly prescribed fluoxetine. Treatment adequacy as a proxy for optimal treatment may be an important factor to consider when selecting an antidepressant drug.
Daptomycin
Authors: Tedesco Kerry L. , Rybak Michael J.
Published: June 2004

Daptomycin, the first in a class of agents known as lipopeptides, is a novel antimicrobial agent used for the treatment of gram‐positive infections. The compound has a distinctive mechanism of action that exerts its bactericidal activity by disrupting plasma membrane function without penetrating into the cytoplasm. The agent has received much interest because of its activity against multidrug‐resistant, gram‐positive bacteria such as methicillin‐resistant Staphylococcus aureus, vancomycin‐resistant enterococci, and glycopeptide‐intermediate and ‐resistant S. aureus. Daptomycin demonstrates concentration‐dependent killing and is eliminated primarily by glomerular filtration. It was approved in September 2003 for the treatment of complicated skin and soft tissue infections. It has a safety profile similar to other agents commonly administered to treat gram‐positive infections. Daptomycin is a welcome addition to the antimicrobial armamentarium for the treatment of bacterial infections. Further clinical experience with this compound will help define its role in the treatment of resistant gram‐positive organisms.
Oritavancin and Tigecycline: Investigational Antimicrobials for Multidrug‐Resistant Bacteria
Authors: Guay David R. P.
Published: June 2004

The advent of multidrug‐resistant gram‐positive aerobes such as Staphylococcus aureus, Streptococcus pneumoniae, and the enterococci, which are resistant to β‐lactams, vancomycin, and a host of other commonly used antimicrobials, has complicated our approach to antibiotic therapy. Despite marketing of the first oxazolidinone, linezolid, and the streptogramin combination, quinupristin‐dalfopristin, an urgent need exists for more agents to combat these pathogens. Two such agents, the glycopeptide oritavancin (LY333328) and the glycylcycline tigecycline (GAR‐936), are in phase III clinical trials. These agents, which require parenteral administration, exhibit substantial in vitro activity against a variety of gram‐positive aerobes and anaerobes, including the multidrug‐resistant organisms listed previously. Only tigecycline demonstrates useful activity against gram‐negative organisms. Combination therapy of these agents with ampicillin or aminoglycosides frequently leads to synergistic in vitro activity against multidrug‐resistant staphylococci and streptococci. These agents are also active in a variety of animal models of systemic and localized infections. Few published efficacy and tolerability data are available in humans. If controlled clinical trial data verify these agents' efficacy and tolerability, both drugs should become welcome additions to the available antimicrobials. However, restricting their use to the treatment of infections caused by bacteria resistant to other antimicrobials, especially multidrug‐resistant staphylococci and streptococci, may prolong their clinical utility by retarding the development of resistance. Careful surveillance of bacterial sensitivity to these agents should be undertaken to assist clinicians in the decision whether or not to use these agents empirically to treat infections caused by suspected multidrug‐resistant gram‐positive pathogens.
Poppers: Epidemiology and Clinical Management of Inhaled Nitrite Abuse
Authors: Romanelli Frank , Smith Kelly M. , Thornton Alice C. , Pomeroy Claire
Published: June 2004

Commonly referred to as “poppers,” inhaled nitrites have a long history of abuse. Poppers are rapid‐onset, short‐acting potent vasodilators that produce a rush characterized by warm sensations and feelings of dizziness. Poppers sometimes are used to facilitate anal intercourse because of their actions on the anal sphincter. Epidemiologically, the frequent use of nitrites by men who have sex with men has led some experts to implicate these chemicals in the pathogenesis of Kaposi's sarcoma and acquired immunodeficiency syndrome. Controlled clinical trials to examine this potential correlation have not been conducted, and the use of nitrites simply may be a marker for other high‐risk behaviors such as unprotected sex. Although regulated in the United States, many nitrite compounds and isomers are sold at various venues including bars, bookstores, and over the Internet. Adverse effects associated with these products vary from mild allergic reactions to life‐threatening methemo‐globinemia. The potential for drug‐drug interactions and a propensity toward unsafe sex also exist. Clinicians should be familiar with the populations most likely to abuse these agents and with the clinical effects and management guidelines for acute ingestions.
Nonhormonal Alternatives for the Treatment of Hot Flashes
Authors: Sicat Brigitte L. , Brokaw Deborah K.
Published: June 2004

Objective. To review the literature on clonidine, venlafaxine, selective serotonin reuptake inhibitors, and gabapentin for the treatment of hot flashes.

Data Sources. A MEDLINE search (January 1966‐July 2003) was conducted to identify English‐language literature available on the treatment of hot flashes that focused on clonidine, venlafaxine, selective serotonin reuptake inhibitors, and gabapentin. These articles, relevant abstracts, and additional references listed in articles were used to collect pertinent data.

Study Selection. All controlled and uncontrolled trials were reviewed.

Data Synthesis. In women unable or unwilling to take hormonal therapies, several nonhormonal alternatives have been evaluated in small controlled and uncontrolled trials. Oral and transdermal formulations of clonidine are moderately effective in reducing hot flashes. Results of studies evaluating venlafaxine, paroxetine, and gabapentin suggest greater reductions in hot‐flash frequency and severity compared with those of clonidine. Fluoxetine appears to display a modest benefit compared with paroxetine, although no comparative trials have been conducted. Most women studied in these trials had a history of breast cancer, and many were taking concurrent tamoxifen. All of these agents were fairly well tolerated.

Conclusions. Clonidine, venlafaxine, paroxetine, fluoxetine, and gabapentin are nonhormonal agents that have demonstrated efficacy in small controlled and uncontrolled trials in reducing hot flashes and should be considered in patients unwilling or unable to take hormonal therapies.
Pharmacodynamics of Meropenem and Imipenem Against Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa
Authors: Kuti Joseph L. , Florea Naomi R. , Nightingale Charles H. , Nicolau David P.
Published: June 2004

Study Objective. To compare the pharmacodynamics of meropenem and imipenem, both administered as 500 mg every 6 hours, against populations of Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa.

Design. Ten thousand–subject Monte Carlo simulation.

Intervention. Variability in total body clearance (ClT), volume of distribution as calculated by the terminal elimination rate (Vdβ), and minimum inhibitory concentration (MIC) distributions (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, A. baumannii, P. aeruginosa) were derived from the literature for both meropenem and imipenem. For the free drug concentrations, the percentage of the dosing interval that the drug concentrations remain above the MIC (%T>MIC) for each carbapenem‐bacteria combination was calculated for 10,000 iterations, substituting a different ClT, Vdβ, fraction of unbound drug, and MIC into the equation each time based on the probability distribution for each parameter. Probabilities of attaining targets of 30%, 50%, and 100% T>MIC were calculated.

Measurements and Main Results. Meropenem free drug %T>MIC exposure was significantly greater than that of imipenem against Enterobacteriaceae and P. aeruginosa, whereas imipenem exposure was greater for A. baumannii. For both agents, free drug %T>MIC exposure was greatest against Enterobacteriaceae and less for A. baumannii and P. aeruginosa. Probabilities of target attainment for 30% and 50% T>MIC were similar between drugs for most bacteria. At 100% T>MIC, meropenem target attainments were greater than those of imipenem against Enterobacteriaceae and P. aeruginosa, and imipenem attainment was higher for A. baumannii.

Conclusion. The probability of attaining lower pharmacodynamic targets for most gram‐negative bacteria is similar for these carbapenems; however, differences become apparent as the pharmacodynamic requirement increases. Further study of the benefits of achieving this pharmacodynamic breakpoint with a higher probability of attaining targets is necessary.
Evaluation of Carvedilol for the Treatment of Portal Hypertension
Authors: Hemstreet Brian A.
Published: June 2004

Development of bleeding gastroesophageal varices is a serious consequence of portal hypertension secondary to cirrhosis. Nonselective β‐blockers have been used to reduce portal pressures and prevent primary and secondary bleeding episodes. However, up to two thirds of patients may not respond appropriately to these agents. Nonselective β‐blockers combined with vasodilatory drugs result in enhanced lowering of portal pressures by targeting several mechanisms involved in this process. Unfortunately, this practice is associated with increased adverse effects, such as hypotension, and minimal reductions in mortality. Carvedilol possesses both nonselective β‐antagonist and α1‐receptor antagonist activity. Given its combined mechanism of action, carvedilol presents a potential option for lowering portal pressures. Its effects on lowering portal pressures and its role in therapy are undefined. Using MEDLINE (1966–2003) and International Pharmaceutical Abstracts (1970–2003), the English‐language literature was searched to identify human studies assessing carvedilol's effects on lowering portal pressure. In general, carvedilol therapy was associated with mean reductions of 16–43% in portal pressure, assessed by the hepatic venous pressure gradient (HVPG) after single and multiple doses. Studies comparing carvedilol with propranolol revealed equal or enhanced efficacy in lowering HVPG. Large percentages of patients had significant HVPG reductions to levels that prevent variceal bleeding. Carvedilol also was associated with substantial symptomatic hypotension, especially in patients with ascites or Child‐Pugh class B or C cirrhosis. Efficacy and adverse effects generally seem to be dose related. Carvedilol appears to be a potentially viable option for treating portal hypertension. Further multiple‐dose trials comparing carvedilol with standard therapy are needed to assess the agent's long‐term safety and effectiveness in preventing variceal bleeding.
Chronic Obstructive Pulmonary Disease
Authors: MacIntyre Neil R.
Published: June 2004

Chronic obstructive pulmonary disease (COPD) is characterized primarily by irreversible lung damage resulting in reduced airflow. Approximately 16 million Americans have the disease, which is the fourth leading cause of death in the United States. Current practice is guided by staging guidelines for both diagnosis and treatment. Pharmacotherapy particularly with the brochodilators ipratropium and β2‐agonists, remains the cornerstone of treatment. Corticosteroids are recommended for patients who experience frequent acute exacerbations accompanied by reversible symptoms. Noninvasive ventilation therapy may be used for patients experiencing acute exacerbations of COPD. Oxygen therapy should be started in patients with hypoxemia. For qualified candidates with very severe COPD, lung volume reduction surgery may be appropriate. Pulmonary rehabilitation therapy of varying levels is recommended for all patients with COPD. Patient education is an important component of any rehabilitation program, particularly instruction on drug management. Several treatment strategies that may dramatically affect the management of COPD are in development. Prevention remains the most powerful approach in reversing climbing prevalence rates.
Focus on Inhaled β2‐Agonists: Efficacy, Safety, and Patient Preference
Authors: Pleasants Roy A.
Published: June 2004

Inhaled β2‐agonists are a standard therapy for patients with obstructive lung diseases. Clinical efficacy, safety, and patient preference are important reasons that these agents have become so widely used. In addition to significant bronchodilatory effects, β2‐agonists have potentially clinically important effects on the lungs including promotion of mucociliary clearance and effects on inflammation. Albuterol, levalbuterol, and salmeterol are the most frequently used agents in the United States. In the acute care setting, short‐acting β2‐agonists are standard therapy for obstructive lung disease whereas the use of long‐acting β2‐agonists in this setting is less clear. Potential clinical issues regarding the use of β2‐agonists in the acute care setting include type of inhalational delivery method used, such as metered‐dose inhaler versus nebulization, use of heliox instead of oxygen, safety issues, and selection of agent. The role of the more recently available β2‐agonists—levalbuterol (the R‐isomer of albuterol) and formoterol—are evolving. Levalbuterol may have clinical and economic advantages in the emergency department setting, however, additional research is necessary to validate this observation.
Cover Picture: Expanding and Shrinking Porous Modulation Based on Pillared‐Layer Coordination Polymers Showing Selective Guest Adsorption (Angew. Chem. Int. Ed. 25/2004)
Authors: Maji Tapas Kumar , Uemura Kazuhiro , Chang Ho‐Chol , Matsuda Ryotaro , Kitagawa Susumu
Published: June 2004

To expand or shrink are properties of the new pillared‐layer porous coordination polymers shown in the cover picture. These features show that coordination polymers are much softer than generally believed. The adsorption selectivity exhibited by these new zeolite‐like materials arises from a simple change in the organic‐pillar module, and may find applications in molecular separation techniques. For more information see the Communication by S. Kitagawa et al. on page 3269 ff.
An improved study of real‐time fluid simulation on GPU
Authors: Wu Enhua , Liu Youquan , Liu Xuehui
Published: June 2004

Taking advantage of the parallelism and programmability of GPU, we solve the fluid dynamics problem completely on GPU. Different from previous methods, the whole computation is accelerated in our method by packing the scalar and vector variables into four channels of texels. In order to be adaptive to the arbitrary boundary conditions, we group the grid nodes into different types according to their positions relative to obstacles and search the node that determines the value of the current node. Then we compute the texture coordinates offsets according to the type of the boundary condition of each node to determine the corresponding variables and achieve the interaction of flows with obstacles set freely by users. The test results prove the efficiency of our method and exhibit the potential of GPU for general‐purpose computations. Copyright © 2004 John Wiley & Sons, Ltd.
Controlling fluid animation with geometric potential
Authors: Hong Jeong‐mo , Kim Chang‐hun
Published: June 2004

We propose a new fluid control technique that uses a geometrically induced potential field. Instead of optimizing the control forces exerted at each frame, as was done in previous work, a potential is added as an extra dimension to the simulation space which coerces the fluid inside this space to form the target shape. This type of shape control requires practically no additional computing by the Navier‐Stokes solver at run‐time, and adds little overhead to implementation. The confinement potentials are induced from geometric information given by animators, and so the control forces that take fluids to a lower potential can be decided in a preprocessing step. We show that a slightly generalized Navier‐Stokes equation for fluids in potential fields can be simulated without changing the solver itself. A harmonic potential function can be quickly found with the Poisson solver which is already implemented as a part of the Navier‐Stokes solver. 2 and 3 dimensional flows designed by common methods such as hand drawing, traditional shape modeling and key‐framing, can be animated efficiently with our control technique. Copyright © 2004 John Wiley & Sons, Ltd.
Interaction of fluids with deformable solids
Authors: Müller Matthias , Schirm Simon , Teschner Matthias , Heidelberger Bruno , Gross Markus
Published: June 2004

In this paper, we present a method for simulating the interaction of fluids with deformable solids. The method is designed for the use in interactive systems such as virtual surgery simulators where the real‐time interplay of liquids and surrounding tissue is important. In computer graphics, a variety of techniques have been proposed to model liquids and deformable objects at interactive rates. As important as the plausible animation of these substances is the fast and stable modeling of their interaction. The method we describe in this paper models the exchange of momentum between Lagrangian particle‐based fluid models and solids represented by polygonal meshes. To model the solid‐fluid interaction we use virtual boundary particles. They are placed on the surface of the solid objects according to Gaussian quadrature rules allowing the computation of smooth interaction potentials that yield stable simulations. We demonstrate our approach in an interactive simulation environment for fluids and deformable solids. Copyright © 2004 John Wiley & Sons, Ltd.
Inviscid and incompressible fluid simulation on triangle meshes
Authors: Shi Lin , Yu Yizhou
Published: June 2004

Simulating fluid motion on manifold surfaces is an interesting but rarely explored area because of the difficulty of establishing plausible physical models. In this paper, we introduce a novel method for inviscid fluid simulation over meshes. It can enforce incompressibility on closed surfaces by utilizing a discrete vector field decomposition algorithm. It also includes effective implementations of semi‐Lagrangian tracing and velocity interpolation schemes. Different from previous work, our method performs simulations directly on triangle meshes and thus eliminates parametrization distortions. Our implementation can produce convincing fluid motion on surfaces and has interactive performance for meshes with tens of thousands of faces. Copyright © 2004 John Wiley & Sons, Ltd.
Modeling and rendering viscous liquids
Authors: Steele Kevin , Cline David , Egbert Parris K. , Dinerstein Jonathan
Published: June 2004

We present a particle‐based algorithm for modeling highly viscous liquids. Using a numerical time‐integration of particle acceleration and velocity, we apply external forces to particles and use a convenient organization, the adhesion matrix, to represent forces between different types of liquids and objects. Viscosity is handled by performing a momentum exchange between particle pairs such that momentum is conserved. Volume is maintained by iteratively adjusting particle positions after each time step. We use a two‐tiered approach to time stepping that allows particle positions to be updated many times per frame while expensive operations, such as calculating viscosity and adhesion, are done only a few times per frame. The liquid is rendered using an implicit surface polygonization algorithm, and we present an implicit function that convolves the liquid surface with a Gaussian function, yielding a smooth liquid skin. Copyright © 2004 John Wiley & Sons, Ltd.
HapticFlow: PDE‐based mesh editing with haptics
Authors: Duan Ye , Hua Jing , Qin Hong
Published: June 2004

This paper presents HapticFlow, a haptics‐based direct mesh editing system founded upon the concept of PDE‐based geometric surface flow. The proposed flow‐based approach for direct geometric manipulation offers a unified design paradigm that can seamlessly integrate implicit, distance‐field based shape modeling with dynamic, physics‐based shape design. HapticFlow provides an intuitive haptic interface and allows users to directly manipulate 3D polygonal objects with ease. To demonstrate the effectiveness of our new approach, we developed a variety of haptics‐based mesh editing operations such as embossing, engraving, sketching as well as force‐based shape manipulation operations. Copyright © 2004 John Wiley & Sons, Ltd.
Robust morphing of point‐sampled geometry
Authors: Xiao Chunxia , Zheng Wenting , Peng Qunsheng , Forrest A. R.
Published: June 2004

We propose a novel morphing algorithm for objects represented by point‐sampled geometry. The fundamental problem of point‐sampled geometry morphing is how to set the correspondence between points of the two objects which are usually of different size. The two objects are first parameterized by projecting the sample points onto a common parametric domain. As both objects are densely sampled, we present a novel accelerated parameterization algorithm employing the technique of LOD. The common parameter domain is then split recursively into clusters. The correspondence between sample points of the two objects is established by performing a local mapping in each cluster. As for complex geometries, the establishment of correspondence is facilitated by decomposing the geometry into patches using geodesic decomposition curves.

To preserve the features during morphing, a process of features assignment is incorporated. By re‐sampling the in‐between object dynamically and adaptively, the cracks that would occasionally occur during morphing are successfully eliminated. Experiment results show that our algorithms are fast, stable and easy to implement. High‐quality morphing is produced. Copyright © 2004 John Wiley & Sons, Ltd.
Mesh‐free deformations
Authors: Chang Jian , Zhang Jian J.
Published: June 2004

Existing physically based deformation techniques, such as the finite element method (FEM) and the mass‐spring systems (MSS), require the deformed object to be properly meshed. This is arguably the most expensive manual intervention process. In this paper, we propose a mesh‐free deformation technique where only unconnected points are involved. The idea is to develop an approximate analytical solution using the Kelvin solution. Due to the fact that no mesh is involved, deforming a complex shape is as straightforward as deforming a simple one. Furthermore, the trade‐off between efficiency and accuracy is easy to achieve by redistributing the points concerned. Experiments show that this method is fast and offers similar accuracy to the FEM. Copyright © 2004 John Wiley & Sons, Ltd.
A hybrid condensed finite element model with GPU acceleration for interactive 3D soft tissue cutting
Authors: Wu Wen , Heng Pheng Ann
Published: June 2004

To meet the requirement of computer‐aided medical operations, apart from the real‐time deformation, it is also necessary in the design to simulate the tissue cutting and suturing in a surgery simulation. In this paper, we present a model on topology change and deformation of soft tissue, referred to as the hybrid condensed finite element model, based on the volumetric finite element method. The most important advantage of our model is its ability to achieve an interactive frame rate for the topology change in surgical simulation on standard PC platform. This is achieved through two innovations. One is to apply the condensation technique, by fully calculating the volumetric deformation in the operation part while only calculating the surface nodes in the non‐operation part. Secondly, the major calculation work in the Conjugate Gradient solver for cutting and deformation is migrated from the CPU to the contemporary GPU to promote the calculation. Test examples have been given to show the feasibility and efficiency of the model. Copyright © 2004 John Wiley & Sons, Ltd.
Geometry‐driven physical interaction between avatars and virtual environments
Authors: Schmidl Harald , Lin Ming C.
Published: June 2004

We present an interactive technique on virtual contact handling for avatars in virtual environments using geometry‐driven physics. If a contact has occurred between an articulated avatar and a virtual environment, the global penetration depth and contact points are estimated based on a fast local penetration depth computation for decomposed convex pieces. The penetration depth and contact information are then used to resolve overlap between the avatar and the virtual environment. If applicable, joint angles for an articulated body are computed using an inverse kinematics approach based on cyclic coordinate descent. Resulting dynamic response with friction is modeled with impulse‐based dynamics under the Coulomb friction law. We demonstrate the algorithm on a modestly complex virtual environment. The resulting system is able to maintain an interactive frame rate of 30–60 Hz. Copyright © 2004 John Wiley & Sons, Ltd.
Physically‐based simulation of plant leaf growth
Authors: Wang Iris R. , Wan Justin W. L. , Baranoski Gladimir V. G.
Published: June 2004

A mathematical model is presented to simulate the growth of a plant leaf. The tissue in the leaf has been regarded as a viscous, incompressible fluid whose 2D expansion comes from the non‐zero specific growth rate in area. The resulting system of equations are composed of the modified Navier‐Stokes equations. The level set method is used to capture the expanding leaf front. Numerical simulations indicate that different portions of the leaf expand at different rates, which is consistent with the biological observations in the growth of a plant leaf. Numerical results for the case of the Xanthium leaf growth are also presented. A standard ray tracing technique is applied to produce an animation simulating the leaf growth process of three days. The key results with their physical and practical implications are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Example‐based motion cloning
Authors: Park Min Je , Shin Sung Yong
Published: June 2004

In this paper, we pose a motion cloning problem of retargeting the motion of a source character to a target character with a different structure. Based on scattered data interpolation, an example‐based approach to motion cloning is proposed. Provided with a set of example motions, our method automatically extracts a small number of representative postures called source key‐postures. The animator then creates the corresponding key‐postures of the target character, breathing his/her imagination and creativity into the output animation. Exploiting this correspondence, each input posture is cloned frame by frame to the target character to produce an initial animation, which is further adjusted in space and time for retargeting and timewarping and then finalized with some interactive fine tuning. With rich animation data available, our motion cloning method aims at rapid prototyping of an animation to verify an animator's concept at an early stage. Copyright © 2004 John Wiley & Sons, Ltd.
Modeling human affective postures: an information theoretic characterization of posture features
Authors: De Silva P. Ravindra , Bianchi‐Berthouze Nadia
Published: June 2004

One of the challenging issues in affective computing is to give a machine the ability to recognize the mood of a person. Efforts in that direction have mainly focused on facial and oral cues. Gestures have been recently considered as well, but with less success. Our aim is to fill this gap by identifying and measuring the saliency of posture features that play a role in affective expression. As a case study, we collected affective gestures from human subjects using a motion capture system. We first described these gestures with spatial features, as suggested in studies on dance. Through standard statistical techniques, we verified that there was a statistically significant correlation between the emotion intended by the acting subjects, and the emotion perceived by the observers. We used Discriminant Analysis to build affective posture predictive models and to measure the saliency of the proposed set of posture features in discriminating between 4 basic emotional states: angry, fear, happy, and sad. An information theoretic characterization of the models shows that the set of features discriminates well between emotions, and also that the models built over‐perform the human observers. Copyright © 2004 John Wiley & Sons, Ltd.
A measure for mesh compression of time‐variant geometry
Authors: Mathur Prasun , Upadhyay Chhavi , Chaudhuri Parag , Kalra Prem
Published: June 2004

We present a novel measure for compression of time‐variant geometry. Compression of time‐variant geometry has become increasingly relevant as transmission of high quality geometry streams is severely limited by network bandwidth. Some work has been done on such compression schemes, but none of them give a measure for prioritizing the loss of information from the geometry stream while doing a lossy compression. In this paper we introduce a cost function which assigns a cost to the removal of particular geometric primitives during compression, based upon their importance in preserving the complete animation. We demonstrate that the use of this measure visibly enhances the performance of existing compression schemes. Copyright © 2004 John Wiley & Sons, Ltd.
Expressive audio‐visual speech
Authors: Bevacqua Elisabetta , Pelachaud Catherine
Published: June 2004

We aim at the realization of an Embodied Conversational Agent able to interact naturally and emotionally with user. In particular, the agent should behave expressively. Specifying for a given emotion, its corresponding facial expression will not produce the sensation of expressivity. To do so, one needs to specify parameters such as intensity, tension, movement property. Moreover, emotion affects also lip shapes during speech. Simply adding the facial expression of emotion to the lip shape does not produce lip readable movement. In this paper we present a model based on real data from a speaker on which was applied passive markers. The real data covers natural speech as well as emotional speech. We present an algorithm that determines the appropriate viseme and applies coarticulation and correlation rules to consider the vocalic and the consonantal contexts as well as muscular phenomena such as lip compression and lip stretching. Expressive qualifiers are then used to modulate the expressivity of lip movement. Our model of lip movement is applied on a 3D facial model compliant with MPEG‐4 standard. Copyright © 2004 John Wiley & Sons, Ltd.
The role of image size in the recognition of conversational facial expressions
Authors: Cunningham Douglas W. , Nusseck Manfred , Wallraven Christian , Bülthoff Heinrich H.
Published: June 2004

Facial expressions can be used to direct the flow of a conversation as well as to improve the clarity of communication. The critical physical differences between expressions can, however, be small and subtle. Clear presentation of facial expressions in applied settings, then, would seem to require a large conversational agent. Given that visual displays are generally limited in size, the usage of a large conversational agent would reduce the amount of space available for the display of other information. Here, we examine the role of image size in the recognition of facial expressions. The results show that conversational facial expressions can be easily recognized at surprisingly small image sizes. Copyright © 2004 John Wiley & Sons, Ltd.
An artificial life environment for autonomous virtual agents with multi‐sensorial and multi‐perceptive features
Authors: Conde Toni , Thalmann Daniel
Published: June 2004

Our approach is based on the multi‐sensory integration of the standard theory of neuroscience, where signals of a single object coming from distinct sensory systems are combined. The acquisition steps of signals, filtering, selection and simplification intervening before proprioception, active and predictive perception are integrated into virtual sensors and a virtual environment. We will focus on two aspects: 1) the assignment problem: determining which sensory stimuli belong to the same virtual object and (2) the sensory recoding problem: recoding signals in a common format before combining them. We have developed three novel methodologies to map the information coming from the virtual sensors of vision, audition and touch as well as that of the virtual environment in the form of a ‘cognitive map’. Copyright © 2004 John Wiley & Sons, Ltd.
Behavioral programming of autonomous characters based on probabilistic automata and personality
Authors: Chittaro Luca , Serra Milena
Published: June 2004

This paper presents a system for realistic behavioral programming of virtual characters, based on personality and probabilistic automata. We describe personality by using the Five‐Factor Model and achieve autonomy through a goal‐oriented approach. Each character perceives the surrounding world, decides how to behave and acts on the environment according to its personality and to its goals. The chief idea explored by the proposed approach is that personality has a probabilistic influence on behavior selection instead of a deterministic one. Different behavior sequences available to achieve a goal are modeled using probabilistic automata and making probability dependent on character personality. This leads to non‐repetitive behaviors, whose evolution is not foreseeable. The paper first motivates the approach in the context of cybertherapy. Then, it summarizes related work and illustrates in detail the proposed approach. Finally, it presents obtained results and discusses the main limitations of the implemented system. Copyright © 2004 John Wiley & Sons, Ltd.
Affection for cohabitant toy dolls
Authors: Matsumoto Naoko , Tokosumi Akifumi , Hirai Yoko
Published: June 2004

In an unprecedented phenomenon characterizing a new kind of relationship between humans and artifacts, a craze within middle‐aged people for a toy doll is analyzed. In this paper, we deal with a talking toy doll. Specifically, 51 fan letters and 271 web site postings spontaneously sent to the toy company are analyzed in terms of their communicative functions and affective‐cognitive contents. The results indicate that (a) the doll is simultaneously seen as both an artifact and a cohabitant (b) the doll owners attribute positive feelings in terms of both mental and physical states to the doll, (c) the doll owners believe that the utterances of the doll facilitate interaction with family members and with friends, and that (d) affections are evoked through owner actions toward the artifact. Based on these results, we propose a cognitive model of cognitive activity with artifacts. Copyright © 2004 John Wiley & Sons, Ltd.
Toward anthropometrics simulation of face rejuvenation and skin cosmetic
Authors: Bastanfard A. , Bastanfard O. , Takahashi H. , Nakajima M.
Published: June 2004

Facial rejuvenation is the process of reversing the aging effects on the human face digitally. This paper generalizes a new approach for facial rejuvenation in adults image. Applications of facial rejuvenation are widespread. They include face recognition, education, entertainment, telecommunications, Psychology, criminal objects, Cosmetic arts and it can be used as an aid for medical cosmetics surgery and the reconstruction of the face. This paper proposes a novel facial rejuvenation modeling algorithm with two techniques. These techniques discuss the facial deformation based on the face anthropometrics theory and remove wrinkles based on what we called wrinkles inpainting. For example if we have been given a few different faces, we need to be able to compare the difference between the facial characteristics of the youth and the aged, then from there onwards, define a set of outlines which are going to be the basis of the simulation of Face Rejuvenation. The first is the geometric deformation details like skin texture, which differs between the aged and the youth. The second is anthropometrics data change. It was developed in the face anthropometrics measurement theory. Then together with warping technique we map the characteristics to any other particular persons' face in order to generate more expressive and convincing facial rejuvenation. The original contribution and advantage of this paper are that, the proposed methods are simple to implement, reliable, in which they required only one source image without needing to collect a lot of images and their computation are fast for interactive environment. Copyright © 2004 John Wiley & Sons, Ltd.
Virtual investigation of pulmonary airways in volumetric computed tomography
Authors: Perchet Diane , Fetita Catalin I. , Vial Laurence , Prêteux Françoise , Caillibotte George , Sbiêrlea‐Apiou Gabriela , Thiriet Marc
Published: June 2004

This paper addresses the issue of non‐invasive investigation and functional assessment of pulmonary airways reconstructed from multi detector computed tomography clinical acquisitions. Such an analysis combines accurate 3D meshing of the inner bronchial wall surface and navigation and interactivity tools based on a robust central axis representation. A reliable endoluminal investigation of airways via virtual bronchoscopy is possible regardless of their anatomical/pathological specificity (small caliber bronchi, severe stenoses, …). Computational fluid dynamics simulations on real airway geometries allow to assess functional modifications induced by physiopathological changes. Copyright © 2004 John Wiley & Sons, Ltd.
Motion capture and visualization of the hip joint with dynamic MRI and optical systems
Authors: Yahia‐Cherif Lydia , Gilles Benjamin , Molet Tom , Magnenat‐Thalmann Nadia
Published: June 2004

We present a methodology for motion tracking and visualization of the hip joint by combining MR images and optical motion capture systems. MRI is typically used to capture the subject's anatomy while optical systems are used to capture and analyse the relative movement between adjacent bones of the joint. Reflective markers are attached to the subject's skin and their trajectories are tracked and processed. However, the skin surface deforms while in motion due to muscle contraction leading to significant errors in the estimation of trajectories. In order to reduce these errors, we use MR images to capture both the anatomy and the trajectories of the bone. Prior to the scanning, we attach skin markers to the subject in order to analyse the markers displacements relative to the bone. We reconstruct the anatomical models of the subject and we compute the markers trajectories from the images. Using these calculated trajectories, we select the best markers configuration based on the criteria of markers displacements. The optimized configuration is used for recording external movements with the optical motion capture system. The resulting animation is mapped onto the virtual body of the subject including internal bones and the joint motion is visualized. Copyright © 2004 John Wiley & Sons, Ltd.
Video metamorphosis using dense flow fields
Authors: Yu Yizhou , Wu Qing
Published: June 2004

When we perform video metamorphosis, it would be desirable to make smooth morphing transitions simultaneously along with the original motion in the image sequences. In this paper, we present a novel semi‐automatic video morphing technique that exhibits this behavior. Our technique effectively exploits temporal coherence and automatic image matching. One‐to‐one dense mappings between pairs of corresponding frames are obtained by applying a compositing procedure and a hierarchical image matching technique. These dense mappings can be initialized with sparse frame‐to‐frame feature correspondences obtained semi‐automatically by integrating a friendly user interface with a robust feature tracking algorithm. Experimental results show that our approach to video metamorphosis can produce superior results. Copyright © 2004 John Wiley & Sons, Ltd.
Automated markerless extraction of walking people using deformable contour models
Authors: Wagg David K. , Nixon Mark S.
Published: June 2004

We develop a new automated markerless motion capture system for the analysis of walking people. We employ global evidence gathering techniques guided by biomechanical analysis to robustly extract articulated motion. This forms a basis for new deformable contour models, using local image cues to capture shape and motion at a more detailed level. We extend the greedy snake formulation to include temporal constraints and occlusion modelling, increasing the capability of this technique when dealing with cluttered and self‐occluding extraction targets.

This approach is evaluated on a large database of indoor and outdoor video data, demonstrating fast and autonomous motion capture for walking people. Copyright © 2004 John Wiley & Sons, Ltd.