bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart Damping System Based on MR Damper and Electromagnetic Induction Device for Suppressing Vibration of Stay Cable
Authors: Kim In-Ho , Jang Dong-Doo , Jung Hyung-Jo , Koo Jeong-Hoi
Published: February 2010

This paper investigates the effectiveness of a smart damping system consisting of a magnetorheological (MR) damper and an electromagnetic induction (EMI) device in reducing cable vibrations. The smart damping system incorporates an EMI device to reduce complexity of conventional MR damper based semi-active control system by eliminating external power sources. This is because the EMI part in the system generates electrical energy (i.e., induced voltage) from mechanical energy (i.e., reciprocal motions of an MR damper), which can be used as a power source for the MR damper. The primary goal of this experimental study is to evaluate the performance of the proposed smart damping system using a full-scale, 44.7 meters long, high-tension cable. To this end, free vibration responses and damping of the proposed smart damping system were compared with those of an equivalent passive control system. The experimental results show that the smart damping system shows better control performance than all the passive control cases.
A New Method for Analyzing Thick Walled Shape Memory Alloy Cylinders Subjected to Internal Pressure
Authors: Mirzaeifar Reza
Published: February 2010

In this paper, a new method is proposed for analyzing thick walled shape memory alloy cylinders subjected to internal pressure. The plane stress condition is assumed for the cylinder and three-dimensional phenomenological macroscopic SMA constitutive model presented by Boyd and Lagoudas is simplified to obtain the required two-dimensional constitutive relations. The cylinder is divided to some narrow annular regions and appropriate assumptions are made in order to find a closed-form solution for the equilibrium equation in terms of radial displacements in each region. Numerical examples are presented for demonstrating the performance of the proposed method and the results are compared with three-dimensional finite element method.
Modeling of a Displacement Amplified Magnetostrictive Actuator for Active Mounts
Authors: Chakrabarti Suryarghya , Dapino Marcelo J.
Published: February 2010

A hydraulically-amplified Terfenol-D actuator is developed to be used as a driver in active engine mounts. A measure of the actuator’s performance is obtained through electromechanical tests in mechanically-blocked and mechanically-free conditions. A nonlinear model for the actuator is presented. The Jiles-Atherton model is coupled with Maxwell’s equations in order to quantify the radial dependence of magnetization and associated dynamic losses. Magnetostriction, which is modeled as a single-valued function of magnetization, provides an input to the mechanical model describing the system vibrations. Friction at the elastomeric seals is modeled using the LuGre friction model for lubricated contacts. Results show that the model is able to accurately describe the dynamic behavior of the actuator up to 400 Hz. An order analysis on the data and modeled responses show that the model is capable of describing the higher harmonic content of the device with sufficient accuracy for control design.
Active Length Control of Shape Memory Alloy Wires Via Reinforcement Learning
Authors: Kirkpatrick Kenton , Valasek John , Lagoudas Dimitris
Published: February 2010

The ability to actively control the shape of aerospace structures has initiated research regarding the use of Shape Memory Alloy actuators. These actuators can be used for morphing or shape change by controlling their temperature, which is effectively done by applying a voltage difference across their length. The ability to characterize this temperature-strain relationship using Reinforcement Learning has been previously accomplished, but in order to control Shape Memory Alloy wires it is more beneficial to learn the voltage-position relationship. Numerical simulation using Reinforcement Learning has been used for determining the temperature-strain relationship for characterizing the major and minor hysteresis loops, and determining a limited control policy relating applied temperature to desired strain. Since Reinforcement Learning creates a non-parametric control policy, and there is not currently a general parametric model for this control policy, determining the voltage-position relationship for a Shape Memory Alloy is done separately. This paper extends earlier numerical simulation results and experimental results in temperature-strain space by applying a similar Reinforcement Learning algorithm to voltage-position space using an experimental hardware apparatus. Results presented in the paper show the ability to converge on a near-optimal control policy for Shape Memory Alloy length control by means of an improved Reinforcement Learning algorithm. These results demonstrate the power of Reinforcement Learning as a method of constructing a policy capable of controlling Shape Memory Alloy wire length.
On-Line Time-Series Damage State Estimation Using Correlation Analysis and Ultrasonic Broadband Active Sensing
Authors: Mohanty Subhasish , Wei Jun , Chattopadhyay Aditi , Peralta Pedro
Published: February 2010

This paper proposes an approach to estimate the fatigue-induced damage state of a metallic structure under biaxial cyclic load. An ultrasonic based technique for broadband active sensing is used. A novel damage index estimation technique based on dual sensor signals is developed that removes the contribution from high frequency input dependant noise. The scalar damage index at any particular damage condition is evaluated using a nonparametric system identification approach such as correlation analysis. The time series estimation of the damage indices (or damage states) shows good correlation with visual measurements of crack length. The time series 2σ error bound was also evaluated to study the effect of measurement noise on damage state estimation.
Nonlinear Parameters of Shape Memory Alloys via Strain Rate
Authors: Amini Abbas , Mehdigholi Hamid , Elahinia Mohammad
Published: February 2010

This paper theoretically finds the different parameters of shape memory alloys via strain rate. Finite element formulation for temperature rate, and produced latent heat due to phase transition have been derived. Moreover, the equivalent viscous damp coefficient is provided. In addition, the Devonshire coefficient has been theoretically found by simplifications. This method helps to predict the heat and temperature change in quasi-static and dynamic studies in NiTi. Furthermore, they could be used in high nonlinear and low elastic deflection of NiTi. Then, the nonlinear vibration of smart composite involved with NiTi from any kind and percent of Ni and Ti could be handled by results.
Modeling Creep and Hysteresis in Piezoceramics Using Domain Switching Simulation
Authors: Zareian Jahromi Seyed Abdolali , Sun Qiao
Published: February 2010

Modeling nonlinear behaviour of polycrystalline piezoceramics accurately can result in an improvement in the wide range of their application, either as actuator or sensor. Two of the main nonlinear behaviours in piezoceramics are hysteresis and creep. These nonlinear and complex macroscopic behaviours of piezoceramics under an electro-mechanical loading are results of domain wall motion in the microscopic level. We developed a micromechanical model to simulate creep and hysteresis behaviour in a piezoceramic. We considered a polycrystal piezoceramic with a random structural configuration of crystals in an isothermal process. An appropriate finite element method (FEM) was used to solve mechanical and electrical governing equations. Each element in FEM represents a crystal in actual polycrystal piezoceramics. volume fractions are needed to evaluate spontaneous polarization and strain caused directly by switching of tetragonal crystal. We improved the constitutive law introduced by Huber et al. [1] in order to consider the effect of exhausted domains in switching process. We used our model to simulate the electromechanical response of a piezoelectric stack under different loading conditions. Our results show a good qualitative agreement with the published experimental results. This model can predict creep as well as hysteresis.
Adipose Tissue Macrophages: A Piece of the PAI of Metabolic Syndrome
Authors: Lumeng Carey N.
Published: February 2010

Adipose tissue macrophages may link cardiovascular disease and diabetes via the dynamic production of plasminogen activator inhibitor–1.
It’s Not My Fault, I Was Born This Way
Authors: Bremer Andrew A.
Published: February 2010

Prenatal exposure to androgens affects fetal metabolic programming and reproductive health.
Persistent Stuttering: Finding the Key to the Riddle
Authors: Hansel Donna E.
Published: February 2010

Defects in lysosomal targeting signals underlie a genetic form of stuttering in a large Pakistani family.
GEOMETRICAL DIAGNOSTICS FOR THE NEW AGEGRAPHIC DARK ENERGY MODEL WITH INTERACTION
Authors: WU YA-BO , WANG DI , ZHANG SHU-HONG , WANG LEI , QI FANG
Published: February 2010

In this paper, on the basis of Ref. 24 we will further study the new agegraphic dark energy (NADE) model with interaction term Γ = 3b2Hρc. Concretely, not only can the evolutions of some related cosmological quantities be described, but also the two geometrical diagnostic approaches are performed to this model, i.e. statefinder and Om diagnostics. By illustrating the evolutionary trajectories in r-s, r-q, w'-w and Om planes, we find that the constant n and coupling intensity b2 play very important roles in the NADE model, and the Om curves of the NADE model are more sensitive to the constants than ones of the OADE model. In addition, we also plot the LCDM horizonal lines in Om diagrams, and show the discrimination among the NADE, OADE and LCDM models.
STANDARD MODEL WITH COSMOLOGICALLY BROKEN QUANTUM SCALE INVARIANCE
Authors: JAIN PANKAJ , MITRA SUBHADIP
Published: February 2010

We consider a locally scale invariant extension of the Standard Model of particle physics and argue that it fits both the particle and cosmological observations. The model is scale invariant both classically and quantum mechanically. The scale invariance is broken (or hidden) by a mechanism which we refer to as cosmological symmetry breaking. This produces all the dimensionful parameters in the theory. The cosmological constant or dark energy is a prediction of the theory and can be calculated systematically order by order in perturbation theory. It is expected to be finite at all orders. The model does not suffer from the hierarchy problem due to the absence of scalar particles, including the Higgs, from the physical spectrum.
BRANE SOLUTIONS WITH TENSION
Authors: YUN SANGHEON
Published: February 2010

In this note, we apply a special metric ansatz to simplify the equations of motion for gravitational systems. Then we construct charged brane solutions in D = n+p+2 dimensions which have spherical symmetry of Sn and translational symmetry along p directions. They are characterized by mass density, uniform tension and electric/magnetic charges, and nonsingular only for specific tension. In particular, we find the limits and the coordinate transformations which reduce the charged brane solutions to M2- and M5-branes. We also obtain the regularity condition for an electrically charged two-brane solution which has two tensions.
SYNTHESIS AND CHARACTERIZATION OF REBaBiO4 (WHERE RE = Pr and Gd) SYSTEM
Authors: MANIGANDAN A. , ANBARASU V. , SATHIYAKUMAR S. , KALIYAPERUMAL L. K. , JAYABALAN K.
Published: February 2010

The new bismuthates in the system REBaBiO 4 (where RE = Pr and Gd ) have been prepared by solid state reaction technique. From the structural characterizations through powder XRD patterns shows the single phase of the title compounds, which crystallizes in orthorhombic structure. The lattice parameters observed for the system BaPrBiO 4 is a = 6.512(3) Å, b = 6.589(5) Å, c = 8.732(4) Å and BaGdBiO 4 is a = 6.374(4) Å, b = 6.515(4) Å, c = 8.624(4) Å. The magnetization property of both the samples exhibit paramagnetic nature at both low and room temperature conditions. The energy gap value of the compound PrBaBiO 4 was calculated as 3.6046 eV, which shows the insulating nature of the material, and GdBaBiO 4 compound has got the range of 1.6356–2.1767 eV, which shows the semi-conducting nature at room temperature condition.
GLOBAL BIFURCATIONS AND CHAOTIC DYNAMICS IN SUSPENDED CABLES
Authors: CHEN HONGKUI , ZHANG ZHAOHUA , WANG JILONG , XU QINGYU
Published: February 2010

The global bifurcations and chaotic dynamics of parametrically and externally excited suspended cables are investigated in this paper. The governing equations are obtained to describe the nonlinear transverse vibrations of suspended cables. The Galerkin procedure is introduced to simplify the governing equations of motion to ordinary differential equations with two-degrees-of-freedom. The case of one-to-one internal resonance between the modes of suspended cables, primary and principal parametric resonance of suspended cables is considered. With the method of multiple scales, parametrically and externally excited system is transformed to the averaged equation, based on which, the recently developed global bifurcation method is employed to detect the presence of orbits which are homoclinic to certain invariant sets for the resonant case. The analysis of the global bifurcations indicates that there exist the generalized Šhilnikov type multipulse homoclinic orbits in the averaged equation of suspended cables. The results obtained here mean that chaotic motions can occur in suspended cables. Numerical simulations also verify the analytical predictions. It is found, according to the results of numerical simulations, that the Šhilnikov type multipulse homoclinic orbits exist in the nonlinear motion of the cables.
TWO-DIMENSIONAL DYNAMICAL SYSTEMS WITH PERIODIC COEFFICIENTS
Authors: ROSSETTO BRUNO , ZHANG YING
Published: February 2010

This paper is devoted to the properties conferred on phase space by a vector field of generic second order autonomous dynamical systems with periodic coefficients, called parametric autonomous dynamical systems (PADS).

At first, an associated periodical parametric linear equation (APPLE) is defined at every point of the phase plane. The exact value of the Floquet–Liapunov exponent of the APPLE is computed using a fast algorithm, without integration. The role of Floquet–Liapunov exponents is known to establish the stability of periodic solutions. In this work, it is pointed out that, under certain conditions, they bring information on local characteristics of PADS solutions according to their location in the phase plane, such as sensitivity to initial conditions, oscillation frequency, period doubling, parametric resonance, funneling.

Then, an invariant manifold of an associated constant coefficients equivalent system (ACCES) is defined. It is shown that this manifold is periodically crossed by solutions of the PADS. This manifold crossing property contributes to the structure of the PADS solutions in phase plane.

The implementation of this method is shown on a Van der Pol equation with a periodic coefficient in order to illustrate all kinds of solution patterns near the manifold in the phase plane according to the Floquet–Liapunov exponent local value. The manifold crossing property can be observed in all cases.

Then, a parametric Duffing equation is processed. A numerical study shows some chaos routes, their bifurcation diagram and the top Liapunov exponent variations. The ACCES of the Duffing equation does not have any slow manifold. However, the Floquet–Liapunov exponent computation allows to specify the locus in the phase plane where the curvature of the trajectories changes, giving rise to chaos.
TOPOLOGICAL ENTROPY IN THE SYNCHRONIZATION OF PIECEWISE LINEAR AND MONOTONE MAPS: COUPLED DUFFING OSCILLATORS
Authors: CANECO ACILINA , ROCHA J. LEONEL , GRÁCIO CLARA
Published: February 2010

In this paper is presented a relationship between the synchronization and the topological entropy. We obtain the values for the coupling parameter, in terms of the topological entropy, to achieve synchronization of two unidirectional and bidirectional coupled piecewise linear maps. In addition, we prove a result that relates the synchronizability of two m-modal maps with the synchronizability of two conjugated piecewise linear maps. An application to the unidirectional and bidirectional coupled identical chaotic Duffing equations is given. We discuss the complete synchronization of two identical double-well Duffing oscillators, from the point of view of symbolic dynamics. Working with Poincaré cross-sections and the return maps associated, the synchronization of the two oscillators, in terms of the coupling strength, is characterized.
ON PERTURBATIONS OF CONTINUOUS STRUCTURES
Authors: YAACOV ITAÏ BEN
Published: February 2010

We give a general framework for the treatment of perturbations of types and structures in continuous logic, allowing to specify which parts of the logic may be perturbed. We prove that separable, elementarily equivalent structures which are approximately ℵ0-saturated up to arbitrarily small perturbations are isomorphic up to arbitrarily small perturbations (where the notion of perturbation is part of the data). As a corollary, we obtain a Ryll–Nardzewski style characterization of complete theories all of whose separable models are isomorphic up to arbitrarily small perturbations.
AN INCENTIVE MECHANISM FOR AD-HOC WIRELESS CONTENT SERVICE: CONTEXTUALIZED MICRO PRICING
Authors: YUAN SOE-TYSR , TSAO JOAN
Published: February 2010

Sophisticated mobile wireless, net-connected devices are allowing people who do not know each other to cluster temporarily around information of mutual interest. Rheingold characterized the sociology of this brave new world of social medium as a world of "ad-hocracy". This paper aims to explore a force that can drive context-sensitive companionable relationships or activities in the "ad-hocracy" world of wireless ad-hoc networks and presents a contextualized micro-pricing mechanism for content services operating in the environment of wireless ad-hoc networks. This is a novel effective pricing mechanism that involves both value-based pricing and contextualized consideration of perishability (in terms of time, location, and urgency). This mechanism is the first attempt in adding the contextual element into pricing and is believed to encourage further exploration of pricing methods in the "ad-hocracy" world. The notion of contextualized micro-pricing is believed not only to improve mobile peers' willingness to furnish differentiated services but also to enhance the distribution of the service resources on the social medium of the wireless ad-hoc network environments.
FROM CHOICE OF PROCUREMENT STRATEGY TO SUPPLY NETWORK CONFIGURATION: AN EVOLUTIONARY APPROACH
Authors: ZHANG YIFENG , BHATTACHARYYA SIDDHARTHA , LI XIAOMING
Published: February 2010

This study examines the complex and evolutionary nature of supply network configuration. Taking a bottom-up approach, we examine how supply network configuration at the macro-level evolves as a result of individual retailers' dynamic choice of procurement strategies at the micro-level. Employing agent-based modeling, we focus on the effects of switch cost and distributors' ordering policy on the evolution of supply network configuration. Our results show that (1) supply networks tend to evolve into a set of separate supply chains when switch cost is high and into an integrated network when switch cost is low, (2) a responsive ordering policy adopted by distributors is more conducive to the integrated network configuration than a non-responsive policy, and (3) lack of coordination among retailers in their dynamic choice of procurement strategies hurts not only the overall system performance, but also retailers themselves. More importantly, our study demonstrates the capabilities of agent-based modeling as a methodology for researching complex supply network issues.
JUDGMENT NUMBER REDUCTION: AN ISSUE IN THE ANALYTIC HIERARCHY PROCESS
Authors: WU LONG-TING , CUI XIA , DAI RU-WEI
Published: February 2010

The Analytic Hierarchy Process (AHP) uses pairwise comparison to evaluate alternatives' advantages to a certain criterion. For decision-making problem with many different criteria and alternatives, pairwise comparison causes a prolonged decision-making period and rises fatigue in decision-makers' mentality. A question of practical value is if there exists a way to reduce judgment number and what influence the reduction will have on the overall evaluation of alternative ratings. To answer this question, we introduce scale error and judgment error into AHP judgment matrix. By expanding the scales defined in the AHP, scale error is eliminated. Taking judgment error as random variable, a new estimator to calculate priority vector is presented. In the end, an example is proved to show lowering judgment number will increase the probability of larger errors appearing in priority vector computation.
A UAV MODEL PARAMETER IDENTIFICATION METHOD: A SIMULATION STUDY
Authors: HATAMLEH K. S. , MA O. , PAZ R.
Published: February 2010

Dynamics modeling of Unmanned Aerial Vehicles (UAVs) is an essential step for design and evaluation of an UAV system. Many advanced control strategies for nonlinear dynamical or robotic systems which are applicable to UAVs depend upon known dynamics models. The accuracy of a model depends not only on the mathematical formulae or computational algorithm of the model but also on the values of model parameters. Many model parameters are very difficult to measure for a given UAV. This paper presents the results of a simulation based study of an in-flight model parameter identification method. Assuming the motion state of a flying UAV is directly or indirectly measureable, the method can identify the unknown inertia parameters of the UAV. Using the recursive least-square technique, the method is capable of updating the model parameters of the UAV while the vehicle is in flight. A scheme of estimating an upper bound of the identification error in terms of the input data errors (or sensor errors) is also discussed.
Upregulation of Salmonella-Induced IL-6 Production in Caco-2 Cells by PJ-34, PARP-1 Inhibitor: Involvement of PI3K, p38 MAPK, ERK, JNK, and NF-κB
Authors: Huang Fu-Chen
Published: February 2010

FollowingSalmonellainvasion, intestinal epithelial cells release a distinct array of proinflammatory cytokines. Interleukin (IL)-6 produced by enterocytes may have anti-inflammatory and cell-protective effects, and may counteract some of the injurious effects of sepsis and endotoxemia. Recent studies in a variety of rodent models of experimental colitis by using PJ-34, a potent poly (ADP-ribose) polymerase-1 (PARP-1) inhibitor, support the concept that the marked beneficial effect of PJ-34 can be exploited to treat human inflammatory diseases. The present study was to investigate the effect of PJ-34 onSalmonella-induced enterocyte IL-6 production and its mechanisms. We found that PJ-34 enhanced Salmonella-induced IL-6 production in Caco-2 cells, either secreted protein or mRNA expression. PJ-34 treatment enhanced the activity of NF-κB inSalmonella-infected Caco-2 cells. Besides, the involvement of PJ-34 in up-regulating IL-6 production in S. typhimurium-infected Caco-2 cells might be also through the ERK but not p38 MAPK, JNK or PI3K/Akt pathways, as demonstrated by Western blot of phosphorylated ERK, p38, JNK and Akt proteins. It suggests that PJ-34 may exert its protective effect on intestinal epithelial cells against invasive Salmonella infection by up-regulating IL-6 production through ERK and NF-κB but not P38 MAPK, JNK or PI3K/Akt signal pathways.
Global Expression Patterns of ThreeFestucaSpecies Exposed to Different Doses of Glyphosate Using the Affymetrix GeneChip Wheat Genome Array
Authors: Cebeci Ozge , Budak Hikmet
Published: February 2010

Glyphosate has been shown to act as an inhibitor of an aromatic amino acid biosynthetic pathway, while other pathways that may be affected by glyphosate are not known. Cross species hybridizations can provide a tool for elucidating biological pathways conserved among organisms. Comparative genome analyses have indicated a high level of colinearity among grass species and Festuca, on which we focus here, and showed rearrangements common to the Pooideae family. Based on sequence conservation among grass species, we selected the Affymetrix GeneChip Wheat Genome Array as a tool for the analysis of expression profiles of three Festuca (fescue) species with distinctly different tolerances to varying levels of glyphosate. Differences in transcript expression were recorded upon foliar glyphosate application at 1.58 mM and 6.32 mM, representing 5% and 20%, respectively, of the recommended rate. Differences highlighted categories of general metabolic processes, such as photosynthesis, protein synthesis, stress responses, and a larger number of transcripts responded to 20% glyphosate application. Differential expression of genes encoding proteins involved in the shikimic acid pathway could not be identified by cross hybridization. Microarray data were confirmed by RT-PCR and qRT-PCR analyses. This is the first report to analyze the potential of cross species hybridization in Fescue species and the data and analyses will help extend our knowledge on the cellular processes affected by glyphosate.
Maintained Smoking Cessation for 6 Months Equilibrates the Percentage of SputumCD8+Lymphocyte Cells with That of Nonsmokers
Authors: Bouloukaki Izolde , Tsoumakidou Maria , Vardavas Constantine I. , Mitrouska Ioanna , Koutala Eleni , Siafakas Nikolaos M. , Schiza Sophia E. , Tzanakis Nikos
Published: February 2010

Little is known about the longitudinal effects of smoking cessation on sputum inflammatory cells. We aimed to investigate the changes in sputum inflammatory cells and T-lymphocyte subpopulations after 6 and 12 months smoking cessation. Induced sputum was obtained from 68 healthy smokers before and after 6 months (n=21) and 1 year (n=14) smoking cessation and from ten healthy never-smokers. Inflammatory cells were identified by morphology and T-lymphocyte subpopulations by flow cytometry. Sputum macrophages were decreased after 12 months of smoking cessation in comparison to baseline, while neutrophils increased. Moreover,CD8+T-cells were decreased in smokers before smoking cessation compared to never-smokers and increased in smokers after 6 months of smoking cessation in comparison to baseline; result that was maintained after 1 year of smoking cessation. These novel findings indicate that smoking cessation can equilibrate certain inflammatory cells of smokers with those of nonsmokers, within 6 months of smoking cessation.
The First Galaxies and the Likely Discovery of Their Fossils in the Local Group
Authors: Ricotti Massimo
Published: February 2010

The lower bound for the mass of a galaxy is unknown, as are the typical luminosity of the smallest galaxies and their numbers. The answers depend on the extent to which star formation in the first population of small mass halos may be suppressed by radiative feedback loops. If early populations of dwarf galaxies did form in significant number before reionization, their “fossils” should be found today in the Local Group. This paper reviews our ongoing efforts to simulate and identify fossil dwarfs in the Local Group. It is widely believed that reionization stopped star formation in fossil dwarfs. However, here we dispute this idea and discuss a physical mechanism whereby recent episodes of star formation would be produced in some fossil dwarfs that, hence, may characterized by a bimodal star formation history. The same mechanism could turn dark halos that failed to form stars before reionization into gas‐rich “dark galaxies”. We believe that current observational data supports the thesis that a fraction of the new ultra‐faint dwarfs discovered in the Local Group are fossil dwarfs and we predict the existence of a population of ultra‐faint dwarfs with lower surface brightness than currently observed.
Convergence Theorems on a New Iteration Process for Two Asymptotically Nonexpansive Nonself‐Mappings with Errors in Banach Spaces
Authors: Ozdemir Murat , Akbulut Sezgin , Kiziltunc Hukmi
Published: February 2010

We introduce a new two‐step iterative scheme for two asymptotically nonexpansive nonself‐mappings in a uniformly convex Banach space. Weak and strong convergence theorems are established for this iterative scheme in a uniformly convex Banach space. The results presented extend and improve the corresponding results of Chidume et al. (2003), Wang (2006), Shahzad (2005), and Thianwan (2008).
Modulation of Dendritic Cell Responses by Parasites: A Common Strategy to Survive
Authors: Terrazas César A. , Terrazas Luis I. , Gómez-García Lorena
Published: February 2010

Parasitic infections are one of the most important causes of morbidity and mortality in our planet and the immune responses triggered by these organisms are critical to determine their outcome. Dendritic cells are key elements for the development of immunity against parasites; they control the responses required to eliminate these pathogens while maintaining host homeostasis. However, there is evidence showing that parasites can influence and regulate dendritic cell function in order to promote a more permissive environment for their survival. In this review we will focus on the strategies protozoan and helminth parasites have developed to interfere with dendritic cell activities as well as in the possible mechanisms involved.
Quo Vadis, Artificial Intelligence?
Authors: Berrar Daniel , Sato Naoyuki , Schuster Alfons
Published: February 2010

Since its conception in the mid 1950s, artificial intelligence with its great ambition to understand and emulate intelligence in natural and artificial environments alike is now a truly multidisciplinary field that reaches out and is inspired by a great diversity of other fields. Rapid advances in research and technology in various fields have created environments into which artificial intelligence could embed itself naturally and comfortably. Neuroscience with its desire to understand nervous systems of biological organisms and systems biology with its longing to comprehend, holistically, the multitude of complex interactions in biological systems are two such fields. They target ideals artificial intelligence has dreamt about for a long time including the computer simulation of an entire biological brain or the creation of new life forms from manipulations of cellular and genetic information in the laboratory. The scope for artificial intelligence in neuroscience and systems biology is extremely wide. This article investigates the standing of artificial intelligence in relation to neuroscience and systems biology and provides an outlook at new and exciting challenges for artificial intelligence in these fields. These challenges include, but are not necessarily limited to, the ability to learn from other projects and to be inventive, to understand the potential and exploit novel computing paradigms and environments, to specify and adhere to stringent standards and robust statistical frameworks, to be integrative, and to embrace openness principles.
Large Carpenter Bees as Agricultural Pollinators
Authors: Keasar Tamar
Published: February 2010

Large carpenter bees (genusXylocopa) are wood-nesting generalist pollinators of broad geographical distribution that exhibit varying levels of sociality. Their foraging is characterized by a wide range of food plants, long season of activity, tolerance of high temperatures, and activity under low illumination levels. These traits make them attractive candidates for agricultural pollination in hot climates, particularly in greenhouses, and of night-blooming crops. Carpenter bees have demonstrated efficient pollination service in passionflower, blueberries, greenhouse tomatoes and greenhouse melons. Current challenges to the commercialization of these attempts lie in the difficulties of mass-rearingXylocopa, and in the high levels of nectar robbing exhibited by the bees.
Cyclooxygenase-2 and Cancer Treatment: Understanding the Risk Should Be Worth the Reward
Authors: Menter David G. , Schilsky Richard L. , DuBois Raymond N.
Published: February 2010

Targeting the prostaglandin (PG) pathway is potentially a critical intervention for the prevention and treatment of cancer. Central to PG biosynthesis are two isoforms of cyclooxygenase (COX 1 and 2), which produce prostaglandin H2 (PGH2) from plasma membrane stores of fatty acids. COX-1 is constitutively expressed, whereas COX-2 is an inducible isoform upregulated in many cancers. Differences between COX-1 and COX-2 catalytic sites enabled development of selective inhibitors. Downstream of the COX enzymes, prostaglandin E2 synthase converts available PGH2 to prostaglandin E2 (PGE2), which can stimulate cancer progression. Significant research efforts are helping identify more selective targets and fully elucidate the downstream targets of prostaglandin E2-mediated oncogenesis. Nonetheless, as a key rate-limiting control point of PG biosynthesis, COX-2 continues to be an important anticancer target. As we embark upon a new era of individualized medicine, a better understanding of the individual risk and/or benefit involved in COX-2 selective targeting is rapidly evolving. This review endeavors to summarize developments in our understanding of COX-2 and its downstream targets as vital areas of anticancer research and to provide the current status of an exciting aspect of molecular medicine. Clin Cancer Res; 16(5); 1384–90
Lapatinib, a Dual EGFR and HER2 Kinase Inhibitor, Selectively Inhibits HER2-Amplified Human Gastric Cancer Cells and is Synergistic with Trastuzumab In vitro and In vivo
Authors: Wainberg Zev A. , Anghel Adrian , Desai Amrita J. , Ayala Raul , Luo Tong , Safran Brent , Fejzo Marlena S. , Hecht J. Randolph , Slamon Dennis J. , Finn Richard S.
Published: February 2010

Purpose: HER2 amplification occurs in 18% to 27% of gastric and gastroesophageal junction cancers. Lapatinib, a potent ATP-competitive inhibitor simultaneously inhibits both EGFR and HER2. To explore the role of HER family biology in upper gastrointestinal cancers, we evaluated the effect of lapatinib, erlotinib, and trastuzumab in a panel of molecularly characterized human upper gastrointestinal cancer cell lines and xenografts.

Experimental Design: EGFR and HER2 protein expression were determined in a panel of 14 human upper gastrointestinal cancer cell lines and HER2 status was assessed by fluorescent in situ hybridization. Dose-response curves were generated to determine sensitivity to lapatinib, erlotinib, and trastuzumab. In HER2-amplified cells, the combination of trastuzumab and lapatinib was evaluated using the median effects principal. The efficacy of lapatinib, trastuzumab, or the combination was examined in HER2-amplified xenograft models.

Results: Lapatinib had concentration-dependent antiproliferative activity across the panel with the greatest effects in HER2-amplified cells. There was no association between EGFR protein expression and sensitivity to any of the HER-targeted agents. Cell cycle analysis revealed that lapatinib induced G1 arrest in sensitive lines and phosphorylated AKT and phosphorylated ERK were decreased in response to lapatinib as well. The combination of lapatinib and trastuzumab was highly synergistic in inhibiting cell growth with a combination index of <1. The combination also induced greater decreases in AKT and ERK activation, G0-G1 cell cycle arrest, and increased rates of apoptosis. In vivo studies showed that the combination of lapatinib and trastuzumab had greater antitumor efficacy than either drug alone.

Conclusion: Together, these data suggest that lapatinib has activity in HER2-amplified upper gastrointestinal cancer and supports the ongoing clinical investigation of lapatinib in patients with HER2-amplified disease. Clin Cancer Res; 16(5); 1509–19
Testing Clonal Relatedness of Tumors Using Array Comparative Genomic Hybridization: A Statistical Challenge
Authors: Ostrovnaya Irina , Begg Colin B.
Published: February 2010

In recent years several investigative groups have sought to use array technologies that characterize somatic alterations in tumors, such as array comparative genomic hybridization (ACGH), to classify pairs of tumors from the same patients as either independent primary cancers or metastases. A wide variety of strategies have been proposed. Several groups have endeavored to use hierarchical clustering for this purpose. This technique was popularized in genomics as a means of finding clusters of patients with similar gene expression patterns with a view to finding subcategories of tumors with distinct clinical characteristics. Unfortunately, this method is not well suited to the problem of classifying individual pairs of tumors as either clonal or independent. In this article we show why hierarchical clustering is unsuitable for this purpose, and why this method has the paradoxical property of producing a declining probability that clonal tumor pairs will be correctly identified as more information is accrued (i.e., more patients). We discuss alternative strategies that have been proposed, which are based on more conventional conceptual formulations for statistical testing and diagnosis, and point to the remaining challenges in constructing valid and robust techniques for this problem. Clin Cancer Res; 16(5); 1358–67
Implications of LINE1 Methylation for Bladder Cancer Risk in Women
Authors: Wilhelm Charlotte S. , Kelsey Karl T. , Butler Rondi , Plaza Silvia , Gagne Luc , Zens M. Scot , Andrew Angeline S. , Morris Steven , Nelson Heather H. , Schned Alan R. , Karagas Margaret R. , Marsit Carmen J.
Published: February 2010

Purpose: Epigenetic alterations including changes to cellular DNA methylation levels contribute to carcinogenesis and may serve as powerful biomarkers of the disease. This investigation sought to determine whether hypomethylation at the long interspersed nuclear elements (LINE1), reflective of the level of global DNA methylation, in peripheral blood–derived DNA is associated with increased risk of bladder cancer.

Experimental Design: LINE1 methylation was measured from blood-derived DNA obtained from participants of a population-based incident case-control study of bladder cancer in New Hampshire. Bisulfite-modified DNA was pyrosequenced to determine LINE1 methylation status; a total of 285 cases and 465 controls were evaluated for methylation.

Results: Being in the lowest LINE1 methylation decile was associated with a 1.8-fold increased risk of bladder cancer [95% confidence interval (95% CI), 1.12-2.90] in models controlling for gender, age, and smoking, and the association was stronger in women than in men (odds ratio, 2.48; 95% CI, 1.19-5.17 in women; and odds ratio, 1.47; 95% CI, 0.79-2.74 in men). Among controls, women were more likely to have lower LINE1 methylation than men (P = 0.04), and levels of arsenic in the 90th percentile were associated with reduced LINE1 methylation (P = 0.04).

Conclusions: LINE1 hypomethylation may be an important biomarker of bladder cancer risk, especially among women. Clin Cancer Res; 16(5); 1682–9
Finasteride Modifies the Relation between Serum C-Peptide and Prostate Cancer Risk: Results from the Prostate Cancer Prevention Trial
Authors: Neuhouser Marian L. , Till Cathee , Kristal Alan , Goodman Phyllis , Hoque Ashraful , Platz Elizabeth A. , Hsing Ann W. , Albanes Demetrius , Parnes Howard L. , Pollak Michael
Published: February 2010

Hyperinsulinemia and obesity-related metabolic disturbances are common and have been associated with increased cancer risk and poor prognosis. To investigate this issue in relation to prostate cancer, we conducted a nested case-control study within the Prostate Cancer Prevention Trial (PCPT), a randomized, placebo-controlled trial testing finasteride versus placebo for primary prevention of prostate cancer. Cases (n = 1,803) and controls (n = 1,797) were matched on age, PCPT treatment arm, and family history of prostate cancer; controls included all eligible non-whites. Baseline bloods were assayed for serum C-peptide (marker of insulin secretion) and leptin (an adipokine) using ELISA. All outcomes were biopsy determined. Logistic regression calculated odds ratios (OR) for total prostate cancer and polytomous logistic regression calculated ORs for low-grade (Gleason <7) and high-grade (Gleason >7) disease. Results were stratified by PCPT treatment arm for C-peptide. For men on placebo, higher versus lower serum C-peptide was associated with a nearly 2-fold increased risk of high-grade prostate cancer (Gleason >7; multivariate-adjusted OR, 1.88; 95% confidence interval, 1.19–2.97; Ptrend = 0.004). When C-peptide was modeled as a continuous variable, every unit increase in log(C-peptide) resulted in a 39% increased risk of high-grade disease (P = 0.01). In contrast, there was no significant relationship between C-peptide and high-grade prostate cancer among men receiving finasteride. Leptin was not independently associated with high-grade prostate cancer. In conclusion, these results support findings from other observational studies that high serum C-peptide and insulin resistance, but not leptin, are associated with increased risk of high-grade prostate cancer. Our novel finding is that the C-peptide–associated risk was attenuated by use of finasteride. Cancer Prev Res; 3(3); 279–89
Effects of Cigarette Smoke on the Human Oral Mucosal Transcriptome
Authors: Boyle Jay O. , Gümüş Zeynep H. , Kacker Ashutosh , Choksi Vishal L. , Bocker Jennifer M. , Zhou Xi Kathy , Yantiss Rhonda K. , Hughes Duncan B. , Du Baoheng , Judson Benjamin L. , Subbaramaiah Kotha , Dannenberg Andrew J.
Published: February 2010

Use of tobacco is responsible for ∼30% of all cancer-related deaths in the United States, including cancers of the upper aerodigestive tract. In the current study, 40 current and 40 age- and gender-matched never smokers underwent buccal biopsies to evaluate the effects of smoking on the transcriptome. Microarray analyses were carried out using Affymetrix HGU133 Plus 2 arrays. Smoking altered the expression of numerous genes: 32 genes showed increased expression and 9 genes showed reduced expression in the oral mucosa of smokers versus never smokers. Increases were found in genes involved in xenobiotic metabolism, oxidant stress, eicosanoid synthesis, nicotine signaling, and cell adhesion. Increased numbers of Langerhans cells were found in the oral mucosa of smokers. Interestingly, smoking caused greater induction of aldo-keto reductases, enzymes linked to polycyclic aromatic hydrocarbon–induced genotoxicity, in the oral mucosa of women than men. Striking similarities in expression changes were found in oral compared with the bronchial mucosa. The observed changes in gene expression were compared with known chemical signatures using the Connectivity Map database and suggested that geldanamycin, a heat shock protein 90 inhibitor, might be an antimimetic of tobacco smoke. Consistent with this prediction, geldanamycin caused dose-dependent suppression of tobacco smoke extract–mediated induction of CYP1A1 and CYP1B1 in vitro. Collectively, these results provide new insights into the carcinogenic effects of tobacco smoke, support the potential use of oral epithelium as a surrogate tissue in future lung cancer chemoprevention trials, and illustrate the potential of computational biology to identify chemopreventive agents. Cancer Prev Res; 3(3); 266–78
Obesity, Endogenous Hormone Metabolism, and Prostate Cancer Risk: A Conundrum of “Highs” and “Lows”
Authors: Kaaks Rudolf , Stattin Pär
Published: February 2010

This perspective on the report by Neuhouser et al. (beginning on page 279 in this issue of the journal) examines the associations that have been observed between body mass index, serum insulin, preexisting diabetes, androgen metabolism, and prostate cancer risk. Based on data of the Prostate Cancer Prevention Trial, the observations by Neuhouser et al. plus findings from other studies suggest a complex mix of higher and lower risks for high- and low-grade cancer in association with obesity and endogenous hormone metabolism. Cancer Prev Res; 3(3); 259–62
Patient Satisfaction and Its Relationship With Clinical Quality and Inpatient Mortality in Acute Myocardial Infarction
Authors: Glickman Seth W. , Boulding William , Manary Matthew , Staelin Richard , Roe Matthew T. , Wolosin Robert J. , Ohman E. Magnus , Peterson Eric D. , Schulman Kevin A.
Published: February 2010

Background—

Hospitals use patient satisfaction surveys to assess their quality of care. A key question is whether these data provide valid information about the medically related quality of hospital care. The objective of this study was to determine whether patient satisfaction is associated with adherence to practice guidelines and outcomes for acute myocardial infarction and to identify the key drivers of patient satisfaction.

Methods and Results—

We examined clinical data on 6467 patients with acute myocardial infarction treated at 25 US hospitals participating in the CRUSADE initiative from 2001 to 2006. Press Ganey patient satisfaction surveys for cardiac admissions were also available from 3562 patients treated at these same 25 centers over this period. Patient satisfaction was positively correlated with 13 of 14 acute myocardial infarction performance measures. After controlling for a hospital’s overall guideline adherence score, higher patient satisfaction scores were associated with lower risk-adjusted inpatient mortality (
P
=0.025). One-quartile changes in both patient satisfaction and guideline adherence scores produced similar changes in predicted survival. For example, a 1-quartile change (75th to 100th) in either the patient satisfaction score or the guideline adherence score yielded the same change in predicted survival (odds ratio, 1.24; 95% CI, 1.02 to 1.49; and odds ratio, 1.24; 95% CI, 1.08 to 1.41, respectively). Satisfaction with nursing care was the most important determinant of overall patient satisfaction (
P
<0.001).

Conclusions—

Higher patient satisfaction is associated with improved guideline adherence and lower inpatient mortality rates, suggesting that patients are good discriminators of the type of care they receive. Thus, patients’ satisfaction with their care provides important incremental information on the quality of acute myocardial infarction care.
Rac1 targeting suppresses p53 deficiency–mediated lymphomagenesis
Authors: Bosco Emily E. , Ni Wenjun , Wang Lei , Guo Fukun , Johnson James F. , Zheng Yi
Published: February 2010

Mutation of the p53 tumor suppressor is associated with disease progression, therapeutic resistance, and poor prognosis in patients with lymphoid malignancies and can occur in approximately 50% of Burkitt lymphomas. Thus, new therapies are needed to specifically target p53-deficient lymphomas with increased efficacy. In the current study, the specific impact of inhibition of the small GTPase Rac1 on p53-deficient B- and T-lymphoma cells was investigated. p53 deficiency resulted in increased Rac1 activity in both B-cell and T-cell lines, and its suppression was able to abrogate p53 deficiency–mediated lymphoma cell proliferation. Further, Rac targeting resulted in increased apoptosis via a p53-independent mechanism. By probing multiple signaling axes and performing rescue studies, we show that the antiproliferative effect of Rac1 targeting in lymphoma cells may involve the PAK and Akt signaling pathway, but not the mitogen-activated protein (MAP) kinase pathway. The effects of inhibition of Rac1 were extended in vivo where Rac1 targeting was able to specifically impair p53-deficient lymphoma cell growth in mouse xenografts and postpone lymphomagenesis onset in murine transplantation models. Because the Rac1 signaling axis is a critical determinant of apoptosis and tumorigenesis, it may represent an important basis for therapy in the treatment of p53-deficient lymphomas.