bluuebunny/crossref_metadata_2025_split huggingface dataset:
Basis set convergence of electric properties in HF and DFT calculations of nucleic acid bases
Authors: Campos C. T. , Jorge F. E. 
Published: August 2008

AbstractRecently, a hierarchical sequence of augmented basis sets of double, triple, and quadruple zeta valence quality plus polarization functions (AXZP, X = D, T, and Q) for the atoms from H to Ar were presented by Jorge et al. We report a systematic study of basis sets required to obtain accurate values of several electric properties for benzene, pyridine, the five common nucleic acid bases (uracil, cytosine, thymine, guanine, and adenine), and three related bases (fluorouracil, 5‐methylcytosine, and hypoxanthine) at their full optimized geometries. Two methods were examined: Hartree‐Fock (HF) and density functional theory (DFT). Including electron correlation decreases the magnitude of the dipole moment and increases the mean polarizability and also the polarizability anisotropy for every molecule. Calculated B3LYP/ADZP dipole moments and dipole polarizabilities show good agreement with both experimental and ab initio results based on second‐order Møller‐Plesset perturbation theory calculations. We have also showed that a basis set of double zeta quality is enough to obtain reliable and accurate electric property results for this kind of compounds. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
A new expansion of the leaky aquifer function
Authors: Pinchon Didier , Hoggan Philip E. , Harris Frank E. 
Published: August 2008

AbstractA new expansion is presented for the incomplete Bessel function also known as the leaky aquifer function, and the computational efficiency of that expansion for prespecified relative accuracy is compared with that of other evaluation methods. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Synchronization patterns in spaghetti‐like nanoclusters
Authors: Purqon Acep , Nagao Hidemi , Nishikawa Kiyoshi 
Published: August 2008

AbstractSpaghetti‐like nanoclusters concern disordered shapes and irregular shape fluctuations in few correlated biological lipids. We evaluate the shape fluctuations by introducing Symmetry‐S as a physical parameter for measuring symmetry degrees and detecting shape transitions. From numerical simulation of few correlated lipids of POPC and POPE at 300 K and 340 K by using molecular dynamics, we investigate the symmetry dynamics for each individual cluster by analyzing both spatiotemporal and frequency. From spatiotemporal analysis, we find several jump motions in S‐dynamics and non‐Gaussian distributions in S‐distribution. Interestingly, the jump motions likely contribute on the existence of transitions in the non‐Gaussian distributions. Additionally, even number of lipids show more symmetric than the odd number of lipids and the symmetry distributions shift at higher temperature, while, from three dimension of actual position of symmetry dynamics, they are not easy to configure high symmetry as well as showing certain patterns. From power spectra density analysis, each individual cluster shows nearly random fluctuation. Besides individual clusters, we also investigate mutual clusters. Surprisingly, although individual clusters show fluctuations randomly, mutual clusters show certain direction correlations. Moreover, they show certain patterns in delayed time analysis such as mutual fluctuations periodically occur for same number of lipids. It indicates that an existence of synchronization patterns occur in shape fluctuations of spaghetti‐like nanoclusters. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Two‐stage design for dose‐finding that accounts for both efficacy and safety
Authors: Dragalin Vladimir , Fedorov Valerii V. , Wu Yuehui 
Published: August 2008

AbstractWe introduce a two‐stage design for dose‐finding in the context of Phase I/II studies, where two binary correlated endpoints are available, for instance, one for efficacy and one for toxicity. The bivariate probit model is used as a working model for the dose–response relationship. Given a ‘desirable point’ for the marginal probabilities of efficacy and toxicity, the goal is to find the target dose that is ‘closest’ to the desirable point. The criterion of optimality (objective function) is the variance of the estimator for that dose. Optimal experimental design methodology is used to construct efficient dose allocation procedures that treat patients in the study at doses that are both safe and efficacious. Copyright © 2008 John Wiley & Sons, Ltd.
A comparison of regression calibration, moment reconstruction and imputation for adjusting for covariate measurement error in regression
Authors: Freedman Laurence S. , Midthune Douglas , Carroll Raymond J. , Kipnis Victor 
Published: August 2008

AbstractRegression calibration (RC) is a popular method for estimating regression coefficients when one or more continuous explanatory variables, X, are measured with an error. In this method, the mismeasured covariate, W, is substituted by the expectation E(X|W), based on the assumption that the error in the measurement of X is non‐differential. Using simulations, we compare three versions of RC with two other ‘substitution’ methods, moment reconstruction (MR) and imputation (IM), neither of which rely on the non‐differential error assumption. We investigate studies that have an internal calibration sub‐study. For RC, we consider (i) the usual version of RC, (ii) RC applied only to the ‘marker’ information in the calibration study, and (iii) an ‘efficient’ version (ERC) in which the estimators (i) and (ii) are combined. Our results show that ERC is preferable when there is non‐differential measurement error. Under this condition, there are cases where ERC is less efficient than MR or IM, but they rarely occur in epidemiology. We show that the efficiency gain of usual RC and ERC over the other methods can sometimes be dramatic. The usual version of RC carries similar efficiency gains to ERC over MR and IM, but becomes unstable as measurement error becomes large, leading to bias and poor precision. When differential measurement error does pertain, then MR and IM have considerably less bias than RC, but can have much larger variance. We demonstrate our findings with an analysis of dietary fat intake and mortality in a large cohort study. Copyright © 2008 John Wiley & Sons, Ltd.
What is the difference? Evidence on the distribution of wealth, health, life expectancy, and health insurance coverage
Authors: Kennickell Arthur B. 
Published: August 2008

AbstractThere is a literature of long standing that considers the relationship between income and differentials in mortality and morbidity, but information on differentials over the distribution of accumulated wealth have been far more scarce and subject to measurement problems. This paper provides evidence from the Survey of Consumer Finances, which is designed as a survey of wealth, on the distribution of wealth and income and how those distributions have shifted in recent years. Particular attention is paid to the distribution of wealth across minority groups and across age groups. The paper also examines the relationship between wealth and health status, life expectancy, and health insurance coverage. Copyright © 2008 John Wiley & Sons, Ltd.
A random change point model for assessing variability in repeated measures of cognitive function
Authors: Dominicus Annica , Ripatti Samuli , Pedersen Nancy L. , Palmgren Juni 
Published: August 2008

AbstractSome cognitive functions undergo transitions in old age, which motivates the use of a change point model for the individual trajectory. The age when the change occurs varies between individuals and is treated as random. We illustrate the properties of a random change point model and use it for data from a Swedish study of change in cognitive function in old age. Variance estimates are obtained from Markov chain Monte Carlo simulation using Gibbs sampling. The random change point model is compared with models within the family of linear random effects models. The focus is on the ability to capture variability in measures of cognitive function. The models make different assumptions about the variance over the age span, and we demonstrate that the random change point model has the most reasonable structure. Copyright © 2008 John Wiley & Sons, Ltd.
Direct estimation of the area under the receiver operating characteristic curve in the presence of verification bias
Authors: He Hua , Lyness Jeffrey M. , McDermott Michael P. 
Published: August 2008

AbstractThe area under a receiver operating characteristic (ROC) curve (AUC) is a commonly used index for summarizing the ability of a continuous diagnostic test to discriminate between healthy and diseased subjects. If all subjects have their true disease status verified, one can directly estimate the AUC nonparametrically using the Wilcoxon statistic. In some studies, verification of the true disease status is performed only for a subset of subjects, possibly depending on the result of the diagnostic test and other characteristics of the subjects. Because estimators of the AUC based only on verified subjects are typically biased, it is common to estimate the AUC from a bias‐corrected ROC curve. The variance of the estimator, however, does not have a closed‐form expression and thus resampling techniques are used to obtain an estimate. In this paper, we develop a new method for directly estimating the AUC in the setting of verification bias based on U‐statistics and inverse probability weighting (IPW). Closed‐form expressions for the estimator and its variance are derived. We also show that the new estimator is equivalent to the empirical AUC derived from the bias‐corrected ROC curve arising from the IPW approach. Copyright © 2008 John Wiley & Sons, Ltd.
Negative cognitions in emotional problems following romantic relationship break‐ups
Authors: Boelen Paul A. , Reijntjes Albert 
Published: August 2008

AbstractThis study examined the role of negative cognitions in emotional problems following relationship dissolution. Seventy‐nine undergraduate students who experienced a relationship break‐up completed measures of break‐up related complicated grief, depression and anxiety, together with an adjusted version of the Grief Cognitions Questionnaire (GCQ) that assesses four types of global negative beliefs, negative cognitions about self‐blame and the responses of others, and three types of negative interpretations of one's own grief reactions. Results showed that all cognitive variables tapped by the GCQ were significantly associated with complicated grief, and—except for global beliefs about life—with depression and anxiety. Most of these associations remained significant when controlling for the influence of initiator status, variables linked with the ended relationship (e.g. duration) and personality factors (e.g. attachment anxiety, neuroticism). Catastrophic misinterpretations about one's own reactions, global negative beliefs about the self and cognitions reflecting self‐blame were the strongest cognitive correlates of break‐up related emotional problems. Overall, the findings are in keeping with cognitive models of trauma and loss, and suggest that changing negative cognitions could be a useful intervention for those who fail to recover from a relationship break‐up. Copyright © 2008 John Wiley & Sons, Ltd.
Organizational responses to environmental demands: opening the black box
Authors: Delmas Magali A. , Toffel Michael W. 
Published: August 2008

AbstractThis article combines new and old institutionalism to explain differences in organizational strategies. We propose that differences in the influence of corporate departments lead their facilities to prioritize different external pressures and thus adopt different management practices. Specifically, we argue that external constituents—including customers, regulators, legislators, local communities, and environmental activist organizations—who interact with influential corporate departments are more likely to affect facility managers' decisions. As a result, managers of facilities that are subjected to comparable institutional pressures adopt distinct sets of management practices that appease different external constituents. We test our framework in the context of the adoption of environmental management practices using an original survey and archival data obtained for nearly 500 facilities. We find support for these hypotheses. Copyright © 2008 John Wiley & Sons, Ltd.
Mesoporous Silica Nanoparticles as a Delivery System of Gadolinium for Effective Human Stem Cell Tracking
Authors: Hsiao Jong‐Kai , Tsai Chih‐Pin , Chung Tsai‐Hua , Hung Yann , Yao Ming , Liu Hon‐Man , Mou Chung‐Yuan , Yang Chung‐Shi , Chen Yao‐Chang , Huang Dong‐Ming 
Published: August 2008

AbstractThe progress of using gadolinium (Gd)‐based nanoparticles in cellular tracking lags behind that of superparamagnetic iron oxide (SPIO) nanoparticles in magnetic resonance imaging (MRI). Here, dual functional Gd‐fluorescein isothiocyanate mesoporous silica nanoparticles (Gd‐Dye@MSN) that possess green fluorescence and paramagnetism are developed in order to evaluate their potential as effective T1‐enhancing trackers for human mesenchymal stem cells (hMSCs). hMSCs are labeled efficiently with Gd‐Dye@MSN via endocytosis. Labeled hMSCs are unaffected in their viability, proliferation, and differentiation capacities into adipocytes, osteocytes, and chondrocytes, which can still be readily MRI detected. Imaging, with a clinical 1.5‐T MRI system and a low incubation dosage of Gd, low detection cell numbers, and short incubation times is demonstrated on both loaded cells and hMSC‐injected mouse brains. This study shows that the advantages of biocompatibility, durability, high internalizing efficiency, and pore architecture make MSNs an ideal vector of T1‐agent for stem‐cell tracking with MRI.
EPR Spectroscopy Reveals Nanoinhomogeneities in the Structure and Reactivity of Thermoresponsive Hydrogels
Authors: Junk Matthias J. N. , Jonas Ulrich , Hinderberger Dariush 
Published: August 2008

AbstractThe dynamic and chemical behavior of solute molecules inside new thermoresponsive hydrogels (photocrosslinked poly(N‐isopropylacrylamide) (pNiPAAm) copolymers) is studied by continuous‐wave electron paramagnetic resonance spectroscopy. Via addition of paramagnetic tracer molecules (so‐called spin probes) a picture is obtained of the thermally induced collapse on the molecular scale, which proceeds over a substantially broader temperature range than indicated by the sharp macroscopic volume transition. The sampling of hydrophilic and hydrophobic environments suggests a discontinuous collapse mechanism with a coexistence of collapsed and expanded network regions. These structural inhomogeneities on the nanoscale also lead to an inhomogeneity in chemical reactivity. The hydrophilic regions form nanoreactors, which strongly accelerate the reaction while the hydrophobic regions act as nanoshelters, in which enclosed spin probes are protected from the decay. The results show that the system consisting of a statistical binary or tertiary copolymer displays remarkably complex behavior that mimics spatial and chemical inhomogeneities observed in functional biopolymers such as enzymes.
An Investigation into the Interactions Between Self‐Assembled Adenine Molecules and a Au(111) Surface
Authors: Kelly Ross E. A. , Xu Wei , Lukas Maya , Otero Roberto , Mura Manuela , Lee Young‐Joo , Lægsgaard Erik , Stensgaard Ivan , Kantorovich Lev N. , Besenbacher Flemming 
Published: August 2008

AbstractTwo molecular phases of the DNA base adenine (A) on a Au(111) surface are observed by using STM under ultrahigh‐vacuum conditions. One of these phases is reported for the first time. A systematic approach that considers all possible gas‐phase two‐dimensional arrangements of A molecules connected by double hydrogen bonds with each other and subsequent ab initio DFT calculations are used to characterize and identify the two phases. The influence of the gold surface on the structure of A assemblies is also discussed. DFT is found to predict a smooth corrugation potential of the gold surface that will enable A molecules to move freely across the surface at room temperature. This conclusion remains unchanged if van der Waals interaction between A and gold is also approximately taken into account. DFT calculations of the A pairs on the Au(111) surface show its negligible effect on the hydrogen bonding between the molecules. These results justify the gas‐phase analysis of possible assemblies on flat metal surfaces. Nevertheless, the fact that it is not the most stable gas‐phase monolayer that is actually observed on the gold surface indicates that the surface still plays a subtle role, which needs to be properly addressed.
An AFM/Rotaxane Molecular Reading Head for Sequence‐Dependent DNA Structures
Authors: Ashcroft Brian A. , Spadola Quinn , Qamar Shahid , Zhang Peiming , Kada Gerald , Bension Rouvain , Lindsay Stuart 
Published: August 2008

AbstractDNA secondary structure may prove to be a significant obstacle both for enzymes that process DNA through an orifice and for the passage of DNA through nanopores proposed for some novel sequencing schemes. A nanomechanical molecular “tape reader” is assembled by threading a nanopore over DNA and pulling it using an atomic force microscope. Its formation is confirmed by studying the force required to open hairpins under that geometry. Unfolding induced by this 0.7‐nm‐diameter aperture requires 40 times more force than that reported for pulling on the ends of the DNA. Kinetic analysis shows that much less strain is required to destabilize the double helix in this geometry. Consequently, much more force is required to provide the free energy needed for opening.
Coalition analysis in the graph model for conflict resolution
Authors: Inohara Takehiro , Hipel Keith W. 
Published: August 2008

AbstractStability definitions for use in coalition analysis are developed within the framework of the Graph Model for Conflict Resolution. Specifically, based on the concept of joint movement by members of a coalition, the noncooperative stability definitions of Nash, general metarational, symmetric metarational, and sequential stability are extended for employment in coalition analysis. To demonstrate how the coalition stability definitions can be conveniently applied to an actual conflict, they are used to investigate a dispute arising over the pollution of an aquifer by a chemical plant located in Elmira, Ontario, Canada, and thereby obtain valuable strategic insight regarding cooperative behavior. © 2008 Wiley Periodicals, Inc. Syst Eng
An obsolescence management framework for system baseline evolution—Perspectives through the system life cycle
Authors: Herald Tom , Verma Dinesh , Lubert Caroline , Cloutier Robert 
Published: August 2008

AbstractIn military, civil, and commercial systems there exists a need to affordably manage the operational effectiveness of the system of interest through the acquisition and operational stages of its life cycle. Once a system design is baselined and instantiated, then the challenge during development, production, and utilization life cycle stages is to maintain the currency of the physical system baseline to facilitate affordable system support. In essence, the system must adapt to potentially frequent asynchronous obsolescence of its constituent elements, requirements growth (driven by the operational environmental and external constraints such as funding, schedule or risk), and external environment changes. This paper specifically addresses the impact that system element obsolescence has on a system baseline during the various system life cycle phases and provides a framework for affordable system evolution. Literature search and consolidation has articulated six integral components that comprise a comprehensive evolution framework through bottoms‐up obsolescence management of constituent system elements. Each of the obsolescence management components is tangibly addressed in terms of each system life cycle phase and the available tools and methods. Additionally, each of the obsolescence management framework components is analyzed for life cycle phase applicability and then extended further with the criticality and type of analysis to be done for that life cycle phase. In this way, a project can determine which studies to perform, while in a specific life cycle phase, that maximizes the insight of impending obsolescence for a particular system. © 2008 Wiley Periodicals, Inc. Syst Eng
Should you manage ethics or corruption?
Authors: Unruh Gregory 
Published: August 2008

AbstractCorruption is truly a global scourge. Ethical scandals are recurring theater on the business stage, coming most often in the wake of financial booms that feed individual greed and lead managers to make decisions that favor personal gain over organizational good. The recurring cycle of scandalreform‐scandal, however, demonstrates the challenges of ethics management. Some companies are discovering a better way to confront the challenge and managing not just ethics, but corruption as well. The advantage of a corruption perspective lies in its focus on systems instead of a personal philosophy. Taking a corruption management perspective doesn't ignore the individual but sees the individual in a larger systemic context. Taking a corruption management approach requires fusing the insights of managerial ethics with the tactics used to fight systemic corruption. When successful it creates something simple and elegant: integrity. © 2008 Wiley Periodicals, Inc.
An interview with Eric M. Pillmore: Hitting the CSR bull's‐eye in a shifting corporate environment
Authors: Staczek John J. 
Published: August 2008

AbstractEric M. Pillmore served as the senior vice president of corporate governance for Tyco International Ltd. from 2002 to 2007. Working with the board of directors and the Tyco leadership team, Pillmore helped transform Tyco from an image of poor governance to a role as a leader in corporate governance. These efforts resulted in Tyco being named by GMI as the most improved U.S. company in the governance area from 2002 to 2005.Prior to Tyco, he served as senior vice president and CFO for Multilink Technology. Pillmore worked for General Instrument Corp (GI) from 1996 to 2000 and served as senior vice president and CFO from December 1997 to January 2000, leading up to the sale of GI to Motorola. In addition, he served for 17 years in a variety of senior finance roles for General Electric from 1979 to 1996, including roles as CFO for GE Plastics Americas and GE Medical Systems Asia. He also served as a US Navy officer from 1975 to 1979, aboard the USS Robison in the western Pacific, and as an auditor with the Naval Audit Service in Washington, D.C.Pillmore has a master's in business administration from the Villanova School of Business and a bachelor's degree in business administration from the Anderson School of Business at the University of New Mexico. He currently serves on the boards of the CEO Forum, Focus on the Family, the Ken Blanchard School of Business, the Anderson Schools of Management, and the Pillmore Family Foundation. © 2008 Wiley Periodicals, Inc.