bluuebunny/crossref_metadata_2025 huggingface dataset:
B
ayesian Networks in Reliability
Authors: Langseth Helge , Jensen Finn Verner
Published: February 2008

Over the last decade, Bayesian networks (BNs) have become a popular tool for modeling many kinds of statistical problems. We have also seen a growing interest for using BNs in the reliability analysis community. This article discusses the properties of the modeling framework that are of highest importance for reliability practitioners.
Quality Control, Computing in
Authors: Noguera John
Published: February 2008

The article provides a brief survey of important advances in quality control tools that are (or should be) available to practitioners using current statistical quality software tools. The tools discussed include the use of the noncentral distribution function for power and sample size, confidence intervals in measurement systems analysis, dealing with nonnormality and autocorrelation in statistical process control, and the use of genetic algorithms in the design and analysis of experiments.
Density and Failure Rate Estimation
Authors: Müller Hans‐Georg , Wang Jane‐Ling
Published: February 2008

Density and failure rate estimation are valuable tools to assess and explore the occurrence and timing of failures in reliability and quality control. This article focuses on nonparametric approaches such as histograms, the kernel method, and other smoothing procedures. Nonparametric density and failure rate estimation is particularly valuable for exploratory data analysis and in situations where available information is insufficient to specify a parametric model, as these methods “let the data speak for themselves”, and no assumptions are needed beyond smoothness of the functions to be estimated. Issues specific for nonparametric approaches are finite bias behavior and choice of the necessary smoothing parameter. For failure rate estimation, available data are sometimes incompletely observed (censored) or available in aggregated form only, necessitating appropriate adjustments. Shape restrictions such as increasing failure rate (IFR) are also occasionally of interest in reliability.
M
onte
C
arlo Methods, Univariate and Multivariate
Authors: Walsh Cathal D.
Published: February 2008

With the prevalence of high‐powered computing, Monte Carlo methods are increasingly used in a wide range of disciplines. In this article we review some of the principles behind these methods, note the relationship with other techniques used in systems reliability, and demonstrate some methods in practice. In particular, the accept–reject algorithm, the importance sampler, the method of compositions and the specific case of Box–Muller transformation are highlighted here.
Failure Modes and Effects Analysis, Implementation of
Authors: Bowles John B.
Published: February 2008

Failure modes and effects analysis (FMEA) is potentially one of the most beneficial and productive tasks in a well structured reliability program. FMEA consists of examining the modes and causes of potential item failures and determining the product response to the failure. Steps can then be taken to change the design to eliminate the failure, mitigate its effects, or develop compensating provisions if the failure should occur. FMEA can be applied to hardware, software, material, and process related causes of failure. Functional, interface, and detailed FMEAs can be usefully employed throughout the design process from the concept stage to production and deployment.
Fault Tree Analysis for Large Systems
Authors: Andrews John D.
Published: February 2008

This article describes the binary decision diagram (BDD) technique of fault tree analysis. The BDD provides an alternative to the traditional fault tree analysis method of kinetic tree theory which is progressed in two phases. The first phase is a qualitative stage to determine the minimal cut sets. The second stage then uses the minimal cut sets together with the component failure probabilities to conduct the system quantification. For large fault trees, this process is inefficient.

While fault trees express the system failure logic in a convenient way from the engineering viewpoint, they do not lend themselves to the mathematical manipulation. BDDs express the failure logic in a disjoint form, which makes quantification very fast. The calculations require just one pass through the BDD structure. Minimal cut sets are not required as an intermediate step, although there are methods by which they can be obtained if they are of interest. Calculations are exact and do not need any form of approximation. The trade‐off for the gains in speed and accuracy is that the fault tree has to be converted to a BDD. The advantages of this are more evident on large, complex fault tree structures.
Integrating Computer and Physical Experiment Data
Authors: Williams Brian J. , Higdon David M.
Published: February 2008

The investigation of complex physical systems utilizing sophisticated computer models has become commonplace with the advent of modern computational facilities. In many applications, experimental data on the physical systems of interest is extremely expensive to obtain and hence is available in limited quantities. The mathematical systems implemented by the computer models often include parameters having uncertain values. This article provides an overview of statistical methodology for calibrating uncertain parameters to experimental data. This approach assumes that prior knowledge about such parameters is represented as a probability distribution, and the experimental data is used to refine our knowledge about these parameters, expressed as a posterior distribution. Uncertainty quantification for computer model predictions of the physical system are based fundamentally on this posterior distribution. Computer models are generally not perfect representations of reality for a variety of reasons, such as inadequacies in the physical modeling of some processes in the dynamic system. The statistical model includes components that identify and adjust for such discrepancies. A standard approach to statistical modeling of computer model output for unsampled inputs is introduced for the common situation where limited computer model runs are available. Extensions of the statistical methods to functional outputs are available and discussed briefly.
M
arkov Chain
M
onte
C
arlo, Introduction
Authors: Wiper Michael P.
Published: February 2008

In this article, we introduce the basic ideas of Markov chain Monte Carlo simulation. We start by briefly commenting on the main ideas of Monte Carlo sampling and then by reviewing the theory of Markov chains, concentrating in particular on the conditions required for the existence of a stationary distribution. We then introduce the Metropolis–Hastings algorithm and show that this generates a Markov chain with a specific stationary distribution. We next introduce some specific ways of implementing the Metropolis–Hastings algorithm,
via
the independence sampler, the Metropolis sampler and the Gibbs sampler among others. Finally, we comment on how the convergence of a Markov chain to equilibrium can be assessed in practice and we finish with an example.
Laplace Approximations inBayesian Lifetime Analysis
Authors: Onar Arzu
Published: February 2008

We provide some background on Laplace approximations based on the work by Tierney and Kadane and illustrate the method's use in obtaining posterior distributions as well as the associated parameter estimates in Bayesian lifetime analysis. The advantages and the disadvantages of using this approach compared to other numerical alternatives are also discussed. Finally, a few examples from the relevant literature where the approximation has been successfully employed are provided.
Neural Networks in Statistical Process Control
Authors: Hwarng H. Brian
Published: February 2008

The tremendous interest and wide applicability of neural computing theories and technology motivate researchers to explore how this class of modeling tools can be effectively applied to statistical process control (SPC). The basic principle of SPC is to signal an out‐of‐control state when the behavior of critical quality variables in a process is considered statistically abnormal, but also to leave the process intact when no evidence of statistical abnormality is present. Two primary categories of problems are the detection of shifts and the recognition of unnatural patterns from the process monitored. The article focuses on models appropriate in the SPC context and the general modeling approach employing various neural network algorithms. We illustrate the use of the approach with data generated from a bivariate autocorrelated process. While the neural network approach is flexible, adaptable, and capable of learning, it is limited by a lack of analytical robustness and the need for intensive data. Nevertheless, the approach enhances process‐troubleshooting capabilities and serves as a powerful alternative to the traditional SPC approaches in handling data collected from a dynamic and complex environment.
Decision Search via Simulation
Authors: De Iorio Maria
Published: February 2008

This entry provides an overview of simulation‐based methods in decision theory and optimal design problems. We consider decision problems defined by a utility function and an underlying probability model for all unknowns. The search for the optimal design requires the maximization of the expected utility with respect to some design parameter, where the expectation is taken with respect to all the unknowns. In many applications the solution to the optimal design problem is not analytically tractable, as neither the maximization nor the integration have a closed‐form solution requiring approximation and/or simulation‐based methods. We present four related simulation‐based strategies: prior simulations, curve fitting of Monte Carlo experiments, Markov chain Monte Carlo simulations in an augmented probability model, and inhomogeneous Markov chain simulations.
Lifetime Distributions, Optimization Methods for
Authors: Hayes Kevin , Barry Don
Published: February 2008

This article introduces the likelihood function as the main tool for parameter estimation and statistical inference with lifetime distributions. When the likelihood function cannot be maximized directly, numerical optimization is required. Approaches based on the Newton–Raphson algorithm are discussed and modifications used to ensure properties such as convergence to maxima rather than minima or saddle points, calculation of nonnegative parameter estimates, and invertibility of the Fisher information matrix are considered. The variability of parameter estimates, generalized linear models, and stochastic search routines are also briefly mentioned.
Bootstrap and Jackknife, Overview
Authors: Martin Michael A. , Roberts Steven
Published: February 2008

A quarter of a century ago, the advent of fast, cheap computing saw the emergence of computationally intensive methods that sought to exploit the data itself as a resource for information rather than relying on restrictive classical distributional assumptions that often failed to hold in practice. Methods such as permutation procedures and the whimsically named jackknife and bootstrap have found wide use among practitioners in a variety of contexts. In this article, the basic uses of resampling techniques are described, with particular attention to bias and variance estimation, and confidence interval construction.
Resampling for Lifetime Distributions
Authors: Belyaev Yuri K.
Published: February 2008

In many applications, data sets contain lifetimes of occurred events, e.g., times of failures, diagnoses, censorings, and so on. If we want to use an estimator of a lifetime characteristic of interest, then it is necessary to evaluate the accuracy of this estimator. Resampling methods can be efficiently used to evaluate the accuracy of many estimators if the size of the data with lifetimes is sufficiently large. They are feasible for realization on personal computers. Correctly applied resampling methods give asymptotically consistent evaluation of the accuracy of estimators under certain assumptions as the size
n
of the data unboundedly grows. The basic tools of mathematical statistics, the likelihood and the central limit resampling theorem, are used to justify resampling methods.
Life Distributions, Simulation of
Authors: Marseguerra Marzio , Zio Enrico
Published: February 2008

This chapter introduces the principles underlying the simulation of the probability distributions that typically characterize the life or failure processes of engineered components and systems. The basic procedures for sampling random numbers are reviewed and examples are provided with reference to the uniform, exponential, and Weibull distributions, which are among the most commonly used probability distributions in reliability, availability, and safety analysis.
Simulation of the Beta‐Stacy Process
Authors: De Blasi Pierpaolo
Published: February 2008

This article reviews simulation methods for the beta‐Stacy process, which belongs to the family of neutral‐to‐the‐right (NTR) processes used in Bayesian nonparametric inference on survival distributions. The definition and properties of the NTR processes are recalled, with a view to represent the continuous component of the process at the integrated hazard levelviathe Lévy measure. The conditional distribution of the prior process, given right‐censored data, is described; this represents the key ingredient for devising sampling schemes. Four methods aiming at the generation of increments or trajectories of the hazard rate process are revised. We explain the ideas behind each of them and sketch the correspondent algorithms for the posterior beta‐Stacy process.
Dirichlet Process, Simulation of
Authors: Laud Purushottam W. , Pajewski Nicholas M.
Published: February 2008

We describe the Dirichlet process and its basic implementation in Bayesian hierarchical modeling. In particular, we discuss Dirichlet process mixture models with emphasis on computational strategies for both conjugate and nonconjugate forms of these models in the context of Markov chain Monte Carlo simulation.
Convergence and Mixing in Markov Chain Monte Carlo
Authors: Mira Antonietta
Published: February 2008

We survey possible strategies to improve the performance of Markov chain Monte Carlo methods either by reducing the asymptotic variance of the resulting estimators or by increasing the speed of convergence to stationarity.
Optimal Reliability Design‐Modeling
Authors: Kuo Way , Wan Rui
Published: February 2008

Reliability has become a greater concern in recent years because high‐tech industrial processes with ever increasing levels of sophistication comprise most engineering systems today. To keep pace with this rapidly developing field, this chapter provides a broad overview of recent research on reliability optimization problems. In particular, we address issues related to:

UGF‐based optimal multistate system (MSS) design;

percentile life employed as a system performance measure;

multiobjective optimization of reliability systems, especially with uncertain component reliability estimations;

innovation and improvement in traditional reliability optimization problems, such as fault‐tolerance mechanism and cold‐standby redundancy involved system design.

The chapter concludes with a discussion of future challenges related to reliability optimization.
Expectation Maximization Algorithm
Authors: Gormley Isobel C. , Murphy Thomas B.
Published: February 2008

The expectation maximization (EM) algorithm is a powerful tool for finding maximum‐likelihood estimates in problems where the data are incomplete. Missing data may be an intrinsic feature of the problem or may be artificially imputed to ease estimation. The EM algorithm is an iterative algorithm that consists of two steps—an expectation step (E‐step) and a maximization step (M‐step). The output is a sequence of parameter estimates that converge to a maximum‐likelihood estimate. The implementation of the EM algorithm is illustrated using a finite mixture of exponential densities.
Data Mining, Evaluation Techniques in
Authors: Gür Ali Özden F.
Published: February 2008

In this article, we focus on evaluation techniques for data mining models after feature selection and parameter estimation have already been performed. Though performance evaluation techniques for data mining models are typically independent of the data mining task, goodness measures
are
task specific. We discuss the rationale, and the pros and cons of different goodness measures by data mining task, using illustrative examples to explain the concepts. We cover the following data mining tasks: classification, regression, rank prediction, clustering, and market basket analysis tasks. We provide detailed discussions for accuracy measures such as misclassification rate, confusion matrix, misclassification cost, quadratic and informational loss, ROC curve and lift chart, RMSE, MAD, AIC, BIC, Spearman's ρ, and Kendall's τ, within and between cluster distance. The following performance estimation techniques are discussed: resubstitution, holdout,
v
‐fold cross‐validation, leave‐one‐out/jackknife, and bootstrap. Further, we cover statistical hypothesis testing for comparing performance of two algorithms for the same data mining task. Also, references for further reading on the topics covered in this article are provided.
Applications of Extreme Statistics in Science and Engineering
Authors: Teugels Jozef L.
Published: February 2008

We offer a large number of typical applications of extremal thinking to risk in the widest sense of the word. A comprehensive list of references is included.
Polya Trees and Their Use in Reliability and Survival Analysis
Authors: Hanson Timothy E.
Published: February 2008

The nonparametric Polya tree prior generalizes traditional parametric models such as the Weibull family. Relative to other well‐known priors, such as Dirichlet, gamma, and beta processes, Polya trees have seen more limited use. However, the Polya tree prior has several attractive features, including the existence of survival densities and the ability to be incorporated in different semiparametric models.
K
ano Analysis
Authors: Shenk Debra
Published: February 2008

In the early 1980s, Dr. Noriaki Kano of Tokyo Rika University introduced several concepts aimed at a better understanding of quality as the customer defines it. He described a continuum over which a customer assigns a valuation to a particular feature or attribute of a product or service. These concepts include the “attractive quality” and “must‐be quality”. When properly implemented, an understanding of these methods can lead companies to define sets of features that will fulfill customer needs and grow market share.
Change Management, Stakeholder Assessment in
Authors: Trabert Thomas F.
Published: February 2008

In managing organizational changes, a stakeholder assessment tool is used to increase the chances of a successful outcome. The benefit of a stakeholder assessment is to understand a stakeholder's level of support for a particular change initiative by first, determining his level of involvement in and commitment to the change and then assessing his ability to impact that change through his influence, authority, and control in the organization. The results of these two assessments of each stakeholder are summarized in a matrix showing the relationship of each stakeholder with the others. For stakeholders who support the change, a plan is created to increase their level of influence throughout. For those who are not supportive of the change, a plan is created to either gain their support or decrease their influence.
Optimal Reliability Design–Algorithms and Comparisons
Authors: Kuo Way , Wan Rui
Published: February 2008

New developments in optimization techniques are emphasized in this paper. Specially, the methods of ant colony optimization and hybrid optimization deserve more attention in the literature. We suggest that those interested in the field read this paper in conjunction withOptimal Reliability Design‐Modeling.
Bias in Modeling and Monitoring Health Outcomes
Authors: Grigg Olivia A. J.
Published: February 2008

The issue of bias is discussed in relation to the combined activities of both modelling health outcomes and monitoring them. As a motivating example, six‐monthly infection rates over the period April 2001 to September 2005 of MRSA in a UK NHS Trust are considered. Given a signal in the interval October 2003 to March 2004 of a potential increase in the underlying infection rate, it is described and discussed in detail how one might go about re‐estimating the rate of infection and perhaps adjusting it for bias.
Repair Data, Sets of: How to Graph, Analyze, and Compare
Authors: Nelson Wayne B.
Published: February 2008

Many products accumulate repeated repairs and repair costs over time. Analysis of such recurrence data requires special statistical models and methods not covered in basic reliability books. This article presents a simple and informative model and plot for analyzing data on numbers or costs of repeated repairs of a random sample of units. The plot is illustrated with transmission repair data from preproduction cars on a track test. This article also presents a method for comparing two such datasets, illustrated with automatic and manual transmissions. Computer programs that calculate and make the plots and comparisons with confidence limits are surveyed.
Contingency Table, Square
Authors: Lipsitz Stuart R.
Published: February 2008

This article discusses the analysis of contingency tables for which the number of rows equals the number of columns. Three types of models for such tables are discussed: marginal models for comparing margins of the table, log linear models for describing the joint distribution and the association patterns, and conditional models that consider the distribution of one of the categorical variables conditional on the outcome for the other one. Other topics discussed include testing marginal homogeneity and symmetry, the models of quasisymmetry and quasi‐independence, and modeling agreement.
Contingency Table
Authors: Altham P.M.E.
Published: February 2008

Contingency tables give counts for cross classifications of categorical variables. This article illustrates two‐dimensional tables (two variables). It then discusses the hypothesis of independence and presents χ
2
tests. An example of quasi‐independence is presented, and small‐sample tests are mentioned. Extensions to multiway contingency tables and the relevant hypotheses for such tables are also discussed. Loglinear models describe the hypotheses, and there are corresponding logistic regression models when one of the variables is a binary response variable.
Brainstorming
Authors: Plsek Paul E.
Published: February 2008

Brainstorming is a group process for generating ideas on a selected topic. It can be used in a variety of applications in quality and reliability work whenever a diverse set of original ideas, approaches, theories, or points of view is desired. Brainstorming builds on classic research into the traits of highly creative groups by providing practical rules and a model for use in organizational group settings.
Laboratory Maintenance of Neisseria gonorrhoeae
Authors: Spence Janice M. , Wright Lori , Clark Virginia L.
Published: February 2008

Neisseria gonorrhoeae is a human pathogen of mucosal surfaces, thus laboratory manipulations must include appropriate safety measures. The growth requirements and behavior of the gonococcus are significantly different from many bacteria, necessitating modifications of common laboratory techniques. A fastidious organism, N. gonorrhoeae requires enriched media in a CO2 atmosphere at 35° to 37°C for growth. In addition, N. gonorrhoeae expresses potent autolysins whose activity increases following glucose depletion during stationary phase, leading to cell death. Long believed to be an obligate aerobe, the gonococcus is capable of anaerobic growth when provided with a suitable electron acceptor. This unit provides information for both aerobic and anaerobic growth, basic long‐term and daily maintenance of gonococcal cultures, as well as safety considerations for laboratory studies. Curr. Protoc. Microbiol. 8:4A.1.1‐4A.1.26. © 2008 by John Wiley & Sons, Inc.
Lymphocytic Choriomeningitis Virus (LCMV): Propagation, Quantitation, and Storage
Authors: Welsh Raymond M. , Seedhom Mina O.
Published: February 2008

Lymphocytic choriomeningitis virus (LCMV) is an enveloped, ambisense RNA virus and the prototypic virus of the arenavirus group. It can cause viral meningitis and other ailments in humans, but its natural host is the mouse. The LCMV/mouse model has been useful for examining mechanisms of viral persistence and the basic concepts of virus‐induced immunity and immunopathology. This unit discusses strain differences and biosafety containment issues for LCMV. Recommendations are made for techniques for propagating LCMV to high titers to quantify it by plaque assay and PCR techniques and to preserve its infectivity by appropriate storage. Curr. Protoc. Microbiol. 8:15A.1.1‐15A.1.11. © 2008 by John Wiley & Sons, Inc.
Application of hydrophilic starch‐based coatings on polyethylene surfaces
Authors: Patil Damodar R. , Fanta George F. , Felker Frederick C. , Salch John H.
Published: February 2008

Coatings were applied to polyethylene (PE) film surfaces by spraying formulations prepared from a jet cooked dispersion of waxy cornstarch, a water‐born epoxy resin, a wax emulsion, and a fluorinated surfactant. The air‐dried coatings were comprised of discontinuous areas of polymer that adhered tightly to the PE surface. Although the starch component separated rapidly from the coating when the film was placed in water at room temperature, heating the coated film for 24 h at 80°C increased the adhesion of starch and produced a surface coating that remained uniformly wet when the film was placed in water. Most of the starch, however, could be still be removed by gently rubbing the wet surface. If melamine‐formaldehyde resin was added to the formulation as a crosslinking agent for starch, and the coated film was then heated for 24 h at 80°C, most of the starch remained bonded to the wet coating, even after the surface was gently rubbed. Identification of successful spray application techniques and formulations will allow the development of commercial production methods for starch‐coated PE films and similar products. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Response of benthic cave invertebrates to organic pollution events
Authors: Wood P. J. , Gunn J. , Rundle S. D.
Published: February 2008

Even though the fragility and vulnerability of subterranean ecosystems (caves, groundwater and hyporheic habitats) is widely acknowledged, the impacts of human disturbances have been poorly quantified when compared with surface waters. In particular, limited data exist regarding the impact of organic pollution upon aquatic cave invertebrate communities.

The Peak–Speedwell Cavern system (Derbyshire, UK) was affected by two organic pollution events, during a 7‐year study (1997–2003), originating from the same source in the surface catchment but resulting in markedly different ecological responses. The first event led to the elimination of most taxa from affected sites while the second resulted in an increase in abundance of organisms within the cave associated with the increased availability of trophic resources. The second event also coincided with the invasion of the stygophilic amphipod, Gammarus pulex, at a site where it had not previously been recorded.

Recovery of the invertebrate community following both organic pollution events occurred within 12 months. Recolonization of the affected sites was facilitated by annual flooding of the cave and by the presence of refugia on unaffected subterranean tributaries.

The data highlight the problems associated with the conservation and management of subterranean ecosystems where impacts in distant surface catchments may have unseen repercussions for the subterranean environment. Aquatic subterranean habitats are not widely monitored and the impacts of pollution/disturbance may not be detected in surface waters for some time, if at all, owing to dilution effects. Caves supporting obligate subterranean organisms (stygobites) are particularly vulnerable to these pressures and require clear management strategies to protect both the subterranean and surface catchments which support them.

Copyright © 2008 John Wiley & Sons, Ltd.
Comparison of three types of adhesives in attaching coral transplants to clam shell substrates
Authors: Dizon Romeo M. , Edwards Alasdair J. , Gomez Edgardo D.
Published: February 2008

Nubbins from 12 coral species were transplanted onto dead giant clam shells at three sites in a lagoon near Bolinao, north‐western Philippines. Transplants were attached using three types of adhesives: cyanoacrylate glue (SG), epoxy putty (EP) and marine epoxy (ME) and were monitored over five months for detachment, in situ mortality and natural self‐attachment by tissue growth.

Corals attached with SG showed a significantly higher rate of detachment (logrank test) than those attached with either EP or ME (P<0.001 in each case). Also, those attached with EP showed a higher rate of detachment than corals attached with ME (logrank=6.46, P<0.05).

ANOVA (P>0.05) and survival analysis (logrank=2.85, P>0.05) showed no among‐adhesives differences in in situ mortality. Among the species used, Porites cylindrica, Pavona frondifera, Heliopora coerulea and Porites rus had the highest survivorship with 82%, 80%, 76% and 73%, respectively, of nubbins alive at the end of the experiment and also displayed the highest cumulative rates of self‐attachment. Species with the lowest survival rates included Acropora muricata and four pocilloporids.

Although there was no significant difference in the number of self‐attaching transplants among the adhesives, corals transplanted using ME and EP self‐attached earlier than those transplanted using SG (logrank=11.19, P<0.01).

Results from this study highlight the importance of selecting the appropriate means of attaching corals to substrates and carefully considering species‐specific traits of candidate corals for transplantation.

Copyright © 2008 John Wiley & Sons, Ltd.
Die neue Traunbrücke in Siegsdorf. Entwurf und Konstruktion einer vorgespannten integralen Zweifeldbrücke
Authors: Fuchs Maximilian , Dannhorn Thomas
Published: February 2008

Im Zuge der Neugestaltung des zentralen innerörtlichen Verkehrsknotens in Siegsdorf/Oberbayern wurde die alte Brücke über die Weiße Traun durch einen Neubau ersetzt. Aufgrund der komplexen Randbedingungen aus verkehrlichen und wasserwirtschaftlichen Vorgaben wurde ein innovatives Tragwerkskonzept für das Brückenbauwerk erforderlich. Nach einer umfangreichen Entwurfsphase mit Grenzfallbetrachtungen und einer Optimierung der Bauteilabmessungen kam eine vorgespannte integrale Zweifeldbrücke mit Plattenquerschnitt und starker einseitiger Aufweitung als technisch und wirtschaftlich sinnvolle sowie gestalterisch sehr ansprechende Lösung zur Ausführung.
Neubau der Saalebrücke Jena Süd. Technik einer außergewöhnlichen Taktschiebebrücke
Authors: Becker Manfred , Kinkel Horst , Martin Rainer , Neuser Jens U.
Published: February 2008

Der Bau der Saalebrücke Jena Süd stellte aufgrund eines außergewöhnlichen Entwurfs und komplizierten Randbedingungen hohe Anforderungen an die beteiligten Firmen. Durch innovative Baubehelfe sowie konsequente Planung und Arbeitsvorbereitung konnte diese schwierige Bauaufgabe termin‐ und qualitätsgerecht gelöst werden.
Terpenoids and Sterols from Saussurea cauloptera
Authors: Wang Xiu‐Ran , Wu Quan‐Xiang , Shi Yan‐Ping
Published: February 2008

A total of 27 natural products were isolated from Saussurea cauloptera, including two new eudesmane‐type sesquiterpenoids, the gerin derivatives 2 and 3, and one new ent‐labdane diterpenoid, compound 9. The known compounds included six sesquiterpenoids, eleven triterpenoids, six sterols, and one lignan. Their structures were elucidated on the basis of extensive spectroscopic and mass‐spectrometric analyses, as well as by X‐ray crystallography in the case of gerin (1). The structurally related compounds 1–4 were found to exhibit strong inhibitory activities against human gastric carcinoma (SGC‐7901) cells.
Terpenoid Compositions, and Antioxidant and Antimicrobial Properties of the Rhizome Essential Oils of Different Hedychium Species
Authors: Joshi Sushil , Chanotiya Chandan Singh , Agarwal Garima , Prakash Om , Pant Anil K. , Mathela Chandra S.
Published: February 2008

A phytochemical study of the rhizome essential oils of four different Hedychium species was performed by means of GC and GC/MS analyses. H. ellipticum mainly contained 1,8‐cineole, sabinene, and terpin‐4‐ol, while H. aurantiacum possessed terpin‐4‐ol, para‐cymene, and bornyl acetate as the major entities. Similarly, trans‐meta‐mentha‐2,8‐diene and linalool were noticed in H. coronarium. Three different collections (I–III) of H. spicatum showed amazing differences in the relative contents of their essential oils, 1,8‐cineole and 10‐epi‐γ‐eudesmol being identified as markers for samples I and II, terpin‐4‐ol and sabinene being the major compounds in sample III. The rhizome essential oils of the above species were studied for their antioxidant activities by different methods, including their effect on the chelating properties of Fe2+, DPPH radical‐scavenging activity, and reducing power. Antimicrobial screenings of the oils by the paper‐disc method were performed against Staphylococcus aureus, Shigella flexneri, Pasteurella multocida, Escherichia coli, and Salmonella enterica enterica, and the respective minimum‐inhibitory‐concentration (MIC) values were determined. The rhizome essential oils from all Hedychium species exhibited moderate‐to‐good Fe2+ chelating activity. H. spicatum from collection site III showed a completely different DPPH radical‐scavenging profile than the samples from the other collection sites.
Fungal Transformation of Dydrogesterone and Inhibitory Effect of Its Metabolites on the Respiratory Burst in Human Neutrophils
Authors: Choudhary M. Iqbal , Azizuddin  , Jalil Saima , Musharraf Syed Ghulam , Atta‐ur‐Rahman
Published: February 2008

The biotransformation of the synthetic hormone dydrogesterone (1) by a number of fungal strains – including Cephalosporium aphidicola, Rhizopus stolonifer, Cunninghamella elegans, and Fusarium lini – afforded ten different metabolites, compounds 2–11. From a structural point of view, these transformations involved a combination of hydroxylation, oxidation, reduction, and/or epoxidation. The pregnane‐based metabolites 10 and 11 are new compounds. All the known compounds were obtained for the first time from 1 by fungal transformation. The metabolites 3, 5, and 8 showed more‐potent respiratory‐burst inhibitory activity than the substrate 1 in a neutrophil‐based cellular assay (Table 3).
Phytochemical and Biological Investigation of Hymenocallis littoralisSalisb.
Authors: Abou‐Donia Amina H. , Toaima Soad M. , Hammoda Hala M. , Shawky Eman , Kinoshita Eri , Takayama Hiromitsu
Published: February 2008

A phytochemical investigation of the bulbs and flowers of Hymenocallis littoralis Salisb., cultivated in Egypt, was carried out, which resulted in the isolation of four alkaloids, lycorine (1), hippeastrine (2), 11‐hydroxyvittatine (3), and (+)‐8‐O‐demethylmaritidine (4), and of two flavonoids, quercetin 3′‐O‐glucoside (5), and rutin (6). The volatile constituents of the plant flowers were analyzed for the first time by GC/MS, which led to the identification of 26 known compounds (Table 1). Finally, the antimicrobial activity of the petroleum ether extract of the flowers of H. littoralis was investigated.
Larvicidal Effects of Fungal Meroterpenoids in the Control of Aedes aegypti L., the Main Vector of Dengue and Yellow Fever
Authors: Geris Regina , Rodrigues‐Fo Edson , Garcia da Silva Heloísa Helena , Garcia da Silva Ionizete
Published: February 2008

The mosquito Aedes aegypti is an increasing problem of public health, being the vector responsible for dengue and Yellow Fever in tropical and subtropical regions. The aim of this work was to determine the potential larvicidal activity of a series of meroterpenoids, compounds 1–7, previously obtained fungal secondary metabolites from Penicillium sp., against the third‐instar larvae of A. aegypti. The lethal concentrations (LC50 and LC90) of 1–7 were evaluated 24 h after exposure. Dehydroaustin (4) was the most active meroterpenoid in the series, with an LC50 value of 2.9 ppm, making it an attractive natural insecticide.
Aldose‐Reductase‐ and Protein‐Glycation‐Inhibitory Principles from the Whole Plant ofDuchesnea chrysantha
Authors: Kim Jong Min , Jang Dae Sik , Lee Yun Mi , Yoo Jeong Lim , Kim Young Sook , Kim Joo‐Hwan , Kim Jin Sook
Published: February 2008

Ellagic acid (1), 3,3′‐di‐O‐methylellagic acid (2), 3,3′,4‐tri‐O‐methylellagic acid (3), isovitexin (4), kaempferol 3‐O‐β‐D‐glucuronide methyl ester (5), quercetin 3‐O‐α‐L‐arabinopyranosyl‐(1→6)‐β‐D‐galactopyranoside (6), ursolic acid, pomolic acid, tormentic acid, euscaphic acid, euscaphic acid 28‐O‐β‐D‐glucopyranoside, and maslinic acid were isolated from the AcOEt‐ and BuOH‐soluble MeOH extract ofDuchesnea chrysantha(whole plant). The isolates were subjected toin vitrobioassays to evaluate their inhibitory activity on rat‐lens aldose reductase (RLAR) and formation of advanced glycation end products (AGEs). The ellagic acids and flavonoids, compounds1–6, exhibited moderate inhibitory effects on RLAR. However, compounds1and4–6showed excellent inhibitory activities towards the formation of AGEs. This is the first report that4and6exhibit inhibitory activity towards AR and AGEs formation.
Site‐Specific Protein Modification on Living Cells Catalyzed by Sortase
Authors: Tanaka Tsutomu , Yamamoto Teruyasu , Tsukiji Shinya , Nagamune Teruyuki
Published: February 2008

The use of enzymes is a promising approach for site‐specific protein modification on living cells owing to their substrate specificity. Herein we describe a general strategy for the site‐specific modification of cell surface proteins with synthetic molecules by using Sortase, a transpeptidase from Staphylococcus aureus. The short peptide tag LPETGG is genetically introduced to the C terminus of the target protein, expressed on the cell surface. Subsequent addition of Sortase and an N‐terminal triglycine‐containing probe results in the site‐specific labeling of the tagged protein. We were successful in the C‐terminal‐specific labeling of osteoclast differentiation factor (ODF) with a biotin‐ or fluorophore‐containing short peptide on the living cell surface. The labeling reaction occurred efficiently in serum‐containing medium, as well as serum‐free medium or PBS. The labeled products were detected after incubation for 5 min. In addition, site‐specific protein–protein conjugation was successfully demonstrated on a living cell surface by the Sortase‐catalyzed reaction. This strategy provides a powerful tool for cell biology and cell surface engineering.
Modelling Amphetamine/Receptor Interactions: A Gas‐Phase Study of Complexes Formed between Amphetamine and Some Chiral Amido[4]resorcinarenes
Authors: Botta Bruno , Tafi Andrea , Caporuscio Fabiana , Botta Maurizio , Nevola Laura , D'Acquarica Ilaria , Fraschetti Caterina , Speranza Maurizio
Published: February 2008

Diastereomeric proton‐bound complexes formed between (R)‐ and (S)‐amphetamine and some chiral amido[4]resorcinarene receptors display significant enantioselectivities when reacting with the enantiomers of 2‐aminobutane in the gas phase. The origins of the measured enantioselectivities are discussed in the light of molecular mechanics calculations and molecular dynamics simulations and are ascribed to a combination of structural and dynamic factors, including the lengths and the isomeric structures of the host asymmetric pendants and the frequencies and amplitudes of their motion, as well as those of the proton‐bonded amphetamine guests. The emerging picture may represent a starting point for deeper comprehension of the factors determining the different affinities of (R)‐ and (S)‐amphetamine towards various chiral receptors, their selective binding to the monoamine transporters, and their sensitivity to specific inorganic ions.
Synthesis and Photoinduced Electron‐Transfer Properties of Phthalocyanine–[60]Fullerene Conjugates
Authors: Quintiliani Maurizio , Kahnt Axel , Wölfle Thorsten , Hieringer Wolfgang , Vázquez Purificación , Görling Andreas , Guldi Dirk M. , Torres Tomás
Published: February 2008

A series of three novel ZnPc–C60 conjugates (Pc=phthalocyanine) 1 a–c bearing different spacers (single, double, and triple bond) between the two electroactive moieties was synthesized and compared to that of ZnPc–C60 conjugate 2, in which the two electroactive moieties are linked directly. The synthetic strategy— towards the preparation of 1 a–c— involved palladium‐catalyzed cross‐coupling reactions over a monoiodophthalocyanine precursor 4 to introduce the corresponding spacer, and subsequent dipolar cycloaddition reaction to C60. Detailed photophysical investigations of 1 a–c and 2 prompted an intramolecular electron transfer that evolves from the photoexcited ZnPc to the electron‐accepting C60. In particular, with the help of femtosecond laser photolysis charge separation was indeed confirmed as the major deactivation channel. Complementary time‐dependent density functional calculations supported the spectral assignment, namely, the spectral identity of the ZnPc.+ radical cation and the C60.− radical anion as seen in the differential absorption spectra. The lifetimes of the correspondingly formed radical ion‐pair states depend markedly on the solvent polarity: they increase as polarity decreases. Similarly, although to a lesser extent, the nature of the linker impacts the lifetime of the radical ion‐pair states. In general, the lifetimes of these states tend to be shortest in the system that lacks any spacer at all (2), whereas the longest lifetimes were found in the system that carries the triple‐bond spacer (1 a).
A General Synthesis of Diarylketones by Means of a Three‐Component Cross‐Coupling of Aryl and Heteroaryl Bromides, Carbon Monoxide, and Boronic acids
Authors: Neumann Helfried , Brennführer Anne , Beller Matthias
Published: February 2008

Pd(OAc)2/di‐1‐adamantyl‐n‐butylphosphine (cataCXium A) is highly active in the three‐component Suzuki carbonylation and represents the most general catalyst system reported up to now. A broad range of aryl/heteroaryl bromides and aryl boronic acids can be coupled to the corresponding diarylketones at low catalyst loadings.
Estimation of optoelectronic conversion functions of imaging devices without using gray samples
Authors: Shen Hui‐Liang , Xin John H. , Yang Dong‐Xiao , Lou Dong‐Wu
Published: February 2008

In the colorimetric or spectral characterization of imaging devices such as digital cameras and scanners, the optoelectronic conversion functions (OECFs) are traditionally obtained from standard gray samples. However, these gray samples are sometimes unavailable when conducting color characterization. We propose an efficient method for recovering OECFs by using nongray samples, based on the finite‐dimensional modeling of spectral reflectance and the second‐order polynomial fitting of OECFs. Experimental results indicate that the accuracy of the estimated OECFs are close to those obtained from gray samples, with the correlation coefficients R2larger than 0.995. The proposed method should be useful in colorimetric and spectral characterization of imaging devices by using custom‐made color samples in textile or other industries, when standard gray samples are not available and not easily made. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 135–141, 2008
NIST 0:45 reflectometer
Authors: Nadal Maria E. , Early Edward A. , Weber Will , Bousquet Robert
Published: February 2008

The NIST 0:45 reflectometer measures the spectral reflectance factor at an influx angle of 0° and an efflux angle of 45° of colored, nonfluorescent specimens at room temperature, with widths ranging from 3 to 10 cm and heights from 3 to 20 cm and with an uncertainty of less than 0.5 in color difference units. Published in 2008 by John Wiley & Sons, Inc. Col Res Appl, 33, 94–99, 2008
Color analysis of natural colorant‐dyed fabrics
Authors: Yi Eunjou , Cho Ju‐Yeon
Published: February 2008

Colors from naturally dyed fabrics recently have attracted both consumers and manufacturers in fashion markets. Even though color attributes of the fabrics have been partially observed in some literature, a data base of colors for natural colorants in fabrics needs to be established and the colors to be characterized according to systematic color notations and tones in order to relate the traditional natural colors to contemporary color communication systems. Therefore, a study was performed to investigate color characteristics for a given large set of natural colorants‐dyed fabrics based on the Munsell color notations, to analyze their tones with relation to the notation such as hue, value, and chroma, and finally to identify the effects of mordanting, an important coloring auxiliary, on the colorimetric properties of the fabrics. As a result, the dominant hue for a total of 350 naturally dyed fabrics was yellowish families followed by reddish and purplish ones in the Munsell notation owing to the use of leaves and plant as usual natural dyestuff, which confirms the limit of color hues of the fabrics. Color value for most of naturally dyed fabrics was generally higher whereas the chroma was lower, which means that most of colors for naturally dyed fabrics tended to be bright and weak shaded. Grayish, light grayish, and soft tones were the main tones of natural colorant‐dyed fabrics. All of hue, value, and chroma were found as being influenced by mordanting in that more particularly; iron mordanting was likely to cause the decrease of both value and chroma for most of naturally dyed fabrics. These results could provide a systematic color data for naturally dyed fashion fabrics and suggest a future direction of color development for them. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 148–157, 2008
The representation of colors in spherical space
Authors: Leonov Yurii P. , Sokolov Evgenii N.
Published: February 2008

Color scaling experiments have established that perceived colors are distributed on the surface of a hypersphere in spherical space. A formal mathematical model of the color space is defined. Color differences as estimated by an observer are equal to the chord distance between corresponding points on the surface in spherical space. In one mathematical model are united: brightness, saturation, and hue as expressed in the empirical Munsell and NCS systems; complementary colors; large color differences; and contrast effects that are not represented in other models. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 113–124, 2008.