bluuebunny/crossref_metadata_2025 huggingface dataset:
Pre‐Tensioned Belts Overhanging Elastic Rollers
Authors: Daxner T. , Luxner M. H. , Rammerstorfer F. G.
Published: December 2005

Subject of this paper are deformation mechanisms in pre‐tensioned elastic belts, which are wrapped around rollers carrying elastic layers that support the belts over part of their width. By means of analytical models and the finite element method the corresponding deformations of the belts are predicted. Special emphasis is put on the effects of the nonlinear (contact) boundary conditions in the vicinity of the lateral edges of the roller. The continuum finite element simulations provide reference solutions, and, furthermore, serve as an accurate means for predicting the contact stress distribution, whereas the semi‐analytical solutions allow for an inexpensive and quick investigation of several parameter combinations. The high quality of the semi‐analytical model can be judged by the excellent agreement of the obtained results with the reference finite element results. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Active control laws for aeroelasticity
Authors: Dumitrache Alexandru , Botez Ruxandra
Published: December 2005

The objective of this paper is to describe a methodology to design control laws in the context of a computational aeroelasticity environment. The technical approach involves employing a systems identification technique to develop an explicit state‐space model for control law design from the output of a computational aeroelasticity code. As a control law design techniques, the standard LQG technique is employed. The computational aeroelasticity code is modified to accept control laws and perform closed‐loop simulations. Numerical results for flutter suppression of the BACT wind‐tunnel model are given. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An Arnoldi‐Type Algorithm for Parametric Finite Element Modelling of Microwave Components
Authors: Farle O. , Hill V. , Nickel P. , Dyczij‐Edlinger R.
Published: December 2005

In this paper, we present an efficient model order reduction (MOR) technique for computing the solution of a linear equation system depending on a multivariate polynomial of scalar parameters. We propose a moment‐matching projection method based on the concept of multivariate Krylov spaces of higher order. The new method exhibits greater stability and allows to build models of higher order than previous approaches. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamical Particle Simulation with Parallel Cache‐Aware Domain Decomposition Strategies
Authors: Fleissner Florian , Eberhard Peter
Published: December 2005

The simulation of large particle systems with the Discrete Element Method can be very time consuming. This is due to the necessity for collision detection between the disordered particles. Various methods, originating from different areas such as computer science, are well established and have been used in various applications. For parallel computations the simulation domain needs to be divided into subdomains to be distributed among the different nodes or machines within a supercomputer or a computer‐cluster. The strategy for this domain decomposition has a significant influence on the performance of the calculation. In this paper we discuss some aspects of the development of a hierarchical domain decomposition algorithm that provides flexible adaption of the decomposition pattern to the changing structure of the particle system during the simulation. Thus an even load distribution among the different machines can be maintained. Moreover, the same method is also used to deal with the computational bottleneck caused by the presence of unstructured data. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal Control for non–isothermal crystallization of polymers
Authors: Götz Thomas , Pinnau Rene , Struckmeier Jens
Published: December 2005

In this paper an optimal control problem for polymer crystallization is investigated. The crystallization is described by a non–isothermal Avrami–Kolmogorov model. The boundary temperature serves as control variable. The cost functional takes the spatial variation of the crystallinity and the final degree of crystallization into account. The resulting boundary control problem for a parabolic equation coupled with two ordinary differential equations is treated by an adjoint variable approach. A steepest descent algorithm is used to solve the problem numerically. Simulations illustrate the applicability and performance of the optimization algorithm. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coupling of Systems of Hyperbolic Equations
Authors: Herty Michael
Published: December 2005

We consider the Aw‐Rascle system of hyperbolic equations which describes traffic flow phenomena on a single road. The model consists of two coupled nonlinear conservation laws in a single space dimension. We study an extension of the Aw/Rascle system to a network of roads. We derive necessary coupling conditions and introduce an obvious definition of a solution. We prove the existence of a solution to the road network problem. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computation of moment functions for parabolic PDEs with random parameters
Authors: Kandler Anne , vom Scheidt Jürgen
Published: December 2005

This paper deals with different approaches for the computation of stochastic characteristics (such as mean, variance, correlation function, …) of the solution to parabolic PDEs with random parameters, in particular with a random Neumann boundary conditions and a random initial condition. Thereby Finite‐Element discretisation of the spatial variables is used for the construction of pathwise solutions. The random influences are assumed to beε‐correlated (cp. [4]) that means the correlation functions vanish if the difference of the arguments exceeds a given correlation lengthε. So an asymptotic expansion of higher order with respect to the correlation length for the correlation function of the approximative solution is given. A second possibility is the so called explicit calculation. Examples which compare the different methods can be found in [2]. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐linear modelling and statistical anlaysis of multi‐stage high‐pressure inactivation of lactic acid bacteria
Authors: Kilimann Klaus Valentin , Hartmann Christoph , Gänzle Michael , Delgado Antonio
Published: December 2005

It was the aim of this work to determine the combined effects of pressure, temperature, and co‐solvents on Lactococcus lactis , and to detect correlations between culture‐dependent and culture‐independent methods for assessment of cellular viability and sublethal injury. Therefore, the pressure induced inactivation of L. lactis MG 1363 was investigated in 21 buffer systems at a pressure range of 0.1 MPa to 600 MPa and a temperature range of 5 to 50 Grad Celsius. The inactivation was characterised by viable cell counts, stress resistant cell counts, membrane integrity, metabolic activity, and LmrP activity. By using Principal Component Analysis, correlations were detected between viable cell counts and metabolic activity as well as stress resistant cell counts and LmrP activity. Based on these correlations, a fuzzy logic model was formulated. The model uses two of the five physiological states as autonomous output variables. Input variables are pressure, temperature, application time and food systems. Latter fully describe the inactivation process of L. lactis correctly. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐temperature mastication of raw natural rubber: Changes in macrostructure and mesostructure
Authors: Ehabe E.E. , Bonfils F. , Sainte‐Beuve J. , Collet A. , Schué F.
Published: December 2005

Raw natural rubber samples of different Mooney viscosity values and inherent molar mass distributions (MMD) were used to characterize changes occurring during high‐temperature mastication and to identify the structural components conditioning mastication‐induced degradation. The macrogel degraded rapidly to essentially microgel, the latter of which was also continuously degraded, and at times completely. Mastication provoked decreases in the average molar mass of polyisoprene chains and changes in their MMD. The MMDs evolved differently as mastication progressed, differences that could be linked to the inherent MMD of each rubber. The non‐viscosity stabilized grade rubber (TSR 10) of monomodal MMD was progressively degraded by mastication, whereas rubber of the same grade but with a bimodal MMD was degraded much slowly and even stagnated on prolonged mastication. The stage at which stagnation occurred was characterized by an offset of the balance between long and short polyisoprene chains due to increases in the quantity of short chains, which facilitate the sliding of the longer ones. POLYM. ENG. SCI., 46:222–227, 2006. © 2005 Society of Plastics Engineers
Effect of heat‐sealing temperature on the failure criteria of oriented polypropylene/cast polypropylene heat seal
Authors: Hashimoto Yasuo , Ishiaku U.S. , Leong Y.W. , Hamada Hiroyuki , Tsujii Tetsuya
Published: December 2005

Failure criteria of the heat‐sealed part of oriented polypropylene (OPP) and cast polypropylene (CPP) heat seals made by an impulse type heat‐sealing machine were investigated. Circular notches and precracks were introduced to direct failure to specific areas such as inside the seal, at the border, or at the unsealed part. The notched strength as a function of heat‐sealing temperature revealed that the seals were stronger in the transverse direction (TD) as compared with the machine direction (MD). Tensile failure that occurred inside the heat seal is more sensitive to sealing temperature, whereas that at the unsealed part is immune. The stress intensity factor (K1) is generally higher along the TD. At high sealing temperatures, i.e. above 150°C, orientation in the OPP film is relaxed and this results in consistently low mechanical properties at this temperature range. This morphology was revealed by studies of crystalline orientation state and FTIR imaging. POLYM. ENG. SCI., 46:205–214, 2006. © 2005 Society of Plastics Engineers
Hydrothermal effects on the thermomechanical properties of high performance epoxy/clay nanocomposites
Authors: Wang Lei , Wang Ke , Chen Ling , He Chaobin , Zhang Yongwei
Published: December 2005

The effects of hydrothermal ageing on the thermomechanical properties of high performance epoxy and its nanocomposite were studied. The epoxy–clay nanocomposite was prepared through a recently developed “slurry‐compounding” approach. The cured samples were immersed in distilled water at 60°C for different periods of time before subjecting to characterization. The storage modulus, relaxation behavior, fracture toughness, and tensile properties were investigated. It was found that the storage modulus and α‐relaxation were strongly affected by water uptake, while the fracture toughness and Young's modulus were less influenced. Dependence of tensile strength and strain at break on water uptake was found to be different in neat epoxy and epoxy–clay systems. POLYM. ENG. SCI., 46:215–221, 2006. © 2005 Society of Plastics Engineers
QoS Model of a Router with Feedback Control
Authors: Yang Zhibin , Ye Nong , Lai Ying‐Cheng
Published: December 2005

The Internet has evolved into a shared, integrated platform of a broad range of applications with different Quality‐of‐Service (QoS) requirements. Routers are an important part of the Internet and play a critical role in assuring QoS. A router is usually placed between two networks to receive data packets from one network and then transmit those data packets to another network if necessary. Data packets are the actual units of data traveling on computer networks. A data packet has two parts: header and data. The data carries messages, such as e‐mail text, from computer applications. The header carries information that is required to control and manage the transmission of the data packet on computer networks. Existing approaches for providing QoS involve prediction or estimation for traffic characterization to determine parameters required of static traffic admission control. However, prediction or estimation inaccuracy in traffic characterization can result in inappropriate parameter settings for static admission control and, in turn, compromise QoS or resource utilization. This study presents a QoS model of a router with feedback control that monitors the state of resource usage and adaptively adjusts parameters of traffic admission control to overcome prediction or estimation inaccuracy and achieve a balance between QoS and resource utilization. The QoS model of a router with feedback control is simulated to test its performance on QoS and resource utilization in both heavy and light traffic conditions. The performance of the QoS model of a router with feedback control is also compared with that of two basic QoS models of a router with static admission control using admission control parameters resulting from over‐ and under‐characterization of traffic, respectively. The simulation results show that the QoS model of a router with feedback control achieves a better balance between QoS and resource utilization than the basic QoS models with over‐ and under‐characterizations of traffic in the heavy traffic condition. This study also shows that the three models of routers demonstrate similar QoS performances and resource utilization in the light traffic condition. Copyright © 2005 John Wiley & Sons, Ltd.
Availability Demonstration Testing
Authors: Usher John S. , Taylor G. Don
Published: December 2005

This paper presents a procedure for conducting an availability demonstration test (ADT) under the assumption that time to failure and time to repair are both exponentially distributed. The procedure yields a test plan consisting of the required number of failures that must be observed, and the required ratio of total observed repair time to total observed failure time. The test is designed to meet stated levels of producer and consumer risk. Solutions require the use of numerical integration, but can easily be implemented using mathematics software or spreadsheets. The approach should be useful to both producers and consumers who want to define a system test for which availability is the primary performance measure of interest. Copyright © 2005 John Wiley & Sons, Ltd.
Performance Measures for ―X Charts with Asymmetric Control Limits
Authors: Marcellus Richard L.
Published: December 2005

Theoretical and empirical justification is given for using asymmetric control limits for certain types of production processes. The following are also discussed: the sensitivity of the performance measures to the process and control parameters, the advantages and disadvantages of using asymmetric control limits, and the construction of tradeoff curves to characterize performance. The justification is given in terms of a collection of quantitative performance measures for ―X charts with asymmetric control limits. The performance measures quantify the false‐alarm frequency, the sensitivity to out‐of‐control conditions, and the resources required for sampling. Copyright © 2005 John Wiley & Sons, Ltd.
Parameter Selection for a Robust Tracking Signal
Authors: Brence John R. , Mastrangelo Christina M.
Published: December 2005

Tracking signals use past forecast errors to monitor and control a forecasting process. In this study, the cumulative‐sum tracking signal and the smoothed‐error tracking signal are evaluated on their ability to aid in shift (process upset) detection. The moving‐centerline EWMA control chart technique is coupled with these tracking signals to enhance the monitoring of autocorrelated processes. The analysis characterizes two prevalent time series models: AR(1) and ARMA(1,1). The goal of this paper is to explore the capabilities of the tracking signals and the moving‐centerline EWMA when the smoothing constants are varied and a shift is introduced into the process. The tracking signals are evaluated based on average run length (ARL) and false alarm rate (FA). Copyright © 2005 John Wiley & Sons, Ltd.
Temperature dependence of the mean autodetachment lifetime of the p‐benzoquinone molecular radical anion
Authors: Pshenichnyuk S. A. , Lomakin G. S. , Fokin A. I. , Pshenichnyuk I. A. , Asfandiarov N. L.
Published: December 2005

Experimental data previously published from this laboratory (Asfandiarov NL, Pshenichnyuk SA, Fokin AI, Nafikova EP. Chem. Phys. 2004; 298: 263), on the temperature dependence of the mean autodetachment lifetime of the p‐benzoquinone molecular radical anion, were analyzed in the framework of a simple statistical model. This model is a simplification of the well‐known semiempirical approach elaborated by Christophorou et al. (Christophorou LG, Hadjiantoniou A, Carter JG. J. Chem. Soc., Faraday Trans. II 1973; 69: 1722). Evaluation of the vibrational energy storage of the target molecule and anion was made in a quantum approximation following a published procedure (Matejčik Š, Märk TD, Španěl P, Smith D, Jaffke T, Illenberger E. J. Chem. Phys. 1994; 102: 2516). The results obtained are in reasonable agreement with the experimental data. Copyright © 2005 John Wiley & Sons, Ltd.
Desorption electrospray ionization mass spectrometry for the analysis of pharmaceuticals and metabolites
Authors: Kauppila Tiina J. , Wiseman Justin M. , Ketola Raimo A. , Kotiaho Tapio , Cooks R. Graham , Kostiainen Risto
Published: December 2005

The performance of desorption electrospray ionization (DESI) in the analysis of a group of pharmaceuticals and their glucuronic acid conjugates is reported. The suitability of different sprayer solvents and different surfaces was examined. In the positive ion mode, water/methanol/trifluoroacetic acid performed best, whereas, in the negative ion mode, water/methanol/ammonium hydroxide was found to be the most suitable spray solvent. Of the surfaces investigated, polymethylmethacrylate (PMMA) was found to give the best performance in terms of sensitivity. Spray solution flow rate and the distance of the sprayer tip from the surface were also found to have significant effects on the signal intensity. Analytes with basic groups efficiently formed the corresponding protonated molecules in the positive ion mode, whereas acidic analytes, such as the glucuronic acid conjugates, formed intense signals due to the deprotonated molecules in the negative ion mode. Ionization of neutral compounds was less efficient and in many cases it was achieved through adduct formation with simple anions or cations. Copyright © 2005 John Wiley & Sons, Ltd.
An ion‐pairing liquid chromatography/tandem mass spectrometric method for the determination of ethephon residues in vegetables
Authors: Marín José M. , Pozo Óscar J. , Beltrán Joaquín , Hernández Félix
Published: December 2005

A rapid, sensitive and selective method has been developed for the direct determination of ethephon residues in vegetables (apple, cherry and tomato). Given the anionic character of ethephon, the use of ion‐pairing liquid chromatography (LC) in combination with tandem mass spectrometry (MS/MS, triple quadrupole) allowed its direct determination in these matrices avoiding a derivatisation step and favouring the automation of the method. Samples were extracted with a mixture of dichloromethane/aqueous formic acid (pH 3) (1:1). Then, tetrabutylammonium acetate (TBA) was added as an ion‐pairing reagent, and an aliquot of the aqueous extract was directly injected into the LC/MS/MS system. Quantification was performed with matrix‐matched standards prepared from blank sample extracts. MS/MS measurements were made in the selected reaction monitoring (SRM) mode, using the most sensitive transition (m/z 107 > 79) for quantification, and up to four additional transitions for confirmation. Quantitative recoveries were obtained for all matrices (between 83% and 96%) at two concentration levels tested (0.05 and 0.5 mg/kg), with relative standard deviations lower than 9% in all cases. The addition of TBA directly into the sample extract contained in the injection vial was found sufficient to obtain satisfactory LC retention for the analyte. Under these conditions, the absence of ion‐pairing reagent in the mobile phase minimised the ionisation suppression for ethephon in the MS source, leading to an increase in the sensitivity of the method and reaching limits of detection of 0.02 mg/kg for all matrices investigated. The acquisition of five specific MS/MS transitions for ethephon allowed the simultaneous and reliable quantification and confirmation of the analyte in the samples. Copyright © 2006 John Wiley & Sons, Ltd.
Changes in pool size in response to a reduction in discharge: a flume experiment
Authors: Thompson Douglas M.
Published: December 2005

Management of river systems can create a reduction in flow with associated potential impacts on channel morphology. A total of 30 flume runs were conducted with two different sediment sizes to determine the effect of a reduction in flow on pool size and depth in confined channels. The experiments were conducted in a 6 m long, 0.5 m wide recirculating flume. Pools were scoured adjacent to a triangular‐shaped obstruction to flow from an initially flat bed. After 3 h of high flow, bed topography was measured and the flow was changed to a level of 50, 67, 80, 85 or 100% of the original flow. Changes in bed topography were then measured after 3 h under the modified flow regime. Results indicate that a reduction in flow creates smaller volume pools. With well sorted, fine‐sand substrate, changes in pool volume, volume of deep habitat and depth were significant for both 50 and 80% reductions in flow level. However, development of an armor level in experiments with poorly sorted, very coarse sand limited sedimentation at lower flows. Consequently, no changes in pool size were statistically significant with this sediment. The results suggest that data on the dimensions of pools are needed prior to any flow modifications in order to detect degradation of the physical pool habitat. Monitoring programs initiated after flow regulation may only identify changes in a limited number of cases where sediments are mobile at low flows and the reduction in flow level is severe. Copyright © 2005 John Wiley & Sons, Ltd.
On smoothed analysis in dense graphs and formulas
Authors: Krivelevich Michael , Sudakov Benny , Tetali Prasad
Published: December 2005

We study a model of random graphs, where a random instance is obtained by adding random edges to a large graph of a given density. The research on this model has been started by Bohman and colleagues (Random Struct Algor22 (2003), 33‐42; Random Struct Algor24 (2004), 105‐117). Here we obtain a sharp threshold for the appearance of a fixed subgraph and for certain Ramsey properties. We also consider a related model of randomk‐SAT formulas, where an instance is obtained by adding randomk‐clauses to a fixed formula with a given number of clauses, and derive tight bounds for the non‐satisfiability of the thus‐obtained random formula. © 2006 Wiley Periodicals, Inc. Random Struct. Alg., 2006
An analysis of viewpoint dependency in three‐dimensional object recognition using support vector machines
Authors: Hayasaka Taichi , Nakauchi Shigeki , Usui Shiro
Published: December 2005

Conflicting results in terms of the recognition rate and response times of humans for 3‐dimensional object recognition have been obtained on the basis of experiments conducted under various conditions; while some results suggest that these variables vary depending on the viewpoint of an object (viewpoint dependency), others suggest there is no such variation (viewpoint invariance). In this research we have analyzed the issue of viewpoint dependency in object recognition results using support vector machines, a type of machine learning algorithm, based on the belief that 3‐dimensional objects are represented in the brain by sets of 2‐dimensional data consisting of images of the object from a range of viewpoints. From this perspective it is suggested that the information contained in images of a 3‐dimensional object from a range of viewpoints plays a significant role that ties together apparently conflicting results seen in psychophysical experiments regarding the issue of viewpoint dependency or invariance. © 2005 Wiley Periodicals, Inc. Syst Comp Jpn, 37(1): 105–115, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10265
Adjustment of sampling locations in rail‐geometry datasets: Using dynamic programming and nonlinear filtering
Authors: Kamiyama Masako , Higuchi Tomoyuki
Published: December 2005

A track inspection car, which measures the shape of railway tracks (hereafter, rail geometry) while it is running on rails, discretizes the measurement results at nearly fixed spatial intervals. However, the distance between the discretized locations (spatial sampling intervals) may shorten or lengthen locally due to slipping or sliding of the car wheel, and this prevents the sampling locations from aligning with those of a dataset obtained with another measuring run. The authors developed an algorithm for approximately aligning the sampling locations of the measurement datasets obtained with different runs. First, they considered this problem as the selection of the series of data corresponding to each supervised data from a training dataset, which was constructed by interpolation in order to minimize the evaluation function of a number sequence representing data points. Next, they used the maximum likelihood method to identify the unknown parameters contained in the evaluation function. This problem uses two features of the evaluation function. The first is that the evaluation function is minimized by dynamic programming, and the obtained optimum sequence is equivalent to a maximum a posteriori (MAP) estimate in the Bayesian framework. The second is that by converting the evaluation function to a general state space representation, the log likelihood of the model that includes the parameters is obtained by a nonlinear filtering method. Also, to simplify the search for the identification, they devised a parameter search procedure for the parameters in the autoregressive (AR) model. © 2005 Wiley Periodicals, Inc. Syst Comp Jpn, 37(1): 61–70, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20313
A survey of medical applications of 3D image analysis and computer graphics
Authors: Muraki Shigeru , Kita Yasuyo
Published: December 2005

This paper is a survey of visualization and analysis techniques for medical 3D images for researchers and students in computer science. Publications from this decade with internationally high evaluation are reviewed, focusing on medical applications of new mathematical techniques and computer hardware, mostly from the viewpoint of the authors' specialty, namely, volume graphics and computer vision. © 2005 Wiley Periodicals, Inc. Syst Comp Jpn, 37(1): 13–46, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20393
Focus measurement and all in‐focus image synthesis for light‐field rendering
Authors: Takahashi Keita , Kubota Akira , Naemura Takeshi
Published: December 2005

Light field rendering is a fundamental method of image‐based rendering that synthesizes free‐viewpoint images from a set of multiviewpoint images. It is known that this method causes focus‐like effects on synthesized images. A problem is that the range of the “focused” depth is too limited in most practical cases. In this paper, we propose a new measure for stably evaluating the “focus” on synthesized images by light‐field rendering. We also describe a method of synthesizing an all in‐focus image that is clear and sharp throughout the entire scene: First, we synthesize multiple images with different “focused” depths, and then integrate the in‐focus parts of those images that can be detected with the “focus measure” we propose. We conducted experiments to demonstrate that our method effectively enhances the quality of the final synthetic images. © 2005 Wiley Periodicals, Inc. Syst Comp Jpn, 37(1): 1–12, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20512
On the application of the von Mises distribution and angular regression methods to investigate the seasonality of disease onset
Authors: Gao Fei , Chia Kee‐Seng , Krantz Ingela , Nordin Per , Machin David
Published: December 2005

This paper describes an approach to summarize the data arising from studies investigating the pattern of disease onset within a calendar year. Such data have been traditionally summarized into monthly counts summated over the complete years studied and patterns often examined by use of Pearson's χ2 tests with 11 degrees of freedom. This test and others commonly used in practice are reviewed. As an alternative, we suggest that by first representing the date of onset for an individual as a point on a unit circle that the von Mises distribution with a single peak may provide a useful description of such data. Further an extension to angular regression including covariates, analogous to that used routinely in other areas of clinical research, potentially allows a more systematic and detailed investigation of possible seasonal patterns in patient subgroups. The methodology is applied to examples from the date of onset of primary angle‐closure glaucoma and date of diagnosis of acute lymphoblastic leukaemia and examines in both situations how the peak onset varies with covariates. Difficulties associated with convergence to the maximum likelihood estimates of the associated parameters are described. Finally, we emphasize the need for individualized (rather than grouped) patient data to be available for study, a clear specification of the particular ‘onset’ time studied, and suggest that further case studies are required to evaluate the approach. Copyright © 2005 John Wiley & Sons, Ltd.
The sigmoidally transformed cosine curve: a mathematical model for circadian rhythms with symmetric non‐sinusoidal shapes
Authors: Marler Matthew R. , Gehrman Philip , Martin Jennifer L. , Ancoli‐Israel Sonia
Published: December 2005

We introduce a family of non‐linear transformations of the traditional cosine curve used in the modelling of biological rhythms. The non‐linear transformation is the sigmoidal family, represented here by three family members: the Hill function, the anti‐logistic function, and the arctangent function. These transforms add two additional parameters that must be estimated, in addition to the acrophase, MESOR, and amplitude (and period in some applications), but the estimated curves have shapes requiring many more than two additional harmonics to achieve the same fit when modelled by harmonic regression. Particular values of the additional parameters can yield rectangular waves, narrow pulses, wide pulses, and for rectangular waves (representing alternating ‘on’ and ‘off’ states) the times of onset and offset (hence duration, as when modelling the duration of the large night‐time melatonin secretory epoch). We illustrate the sigmoidally transformed cosine curves, and compare them to harmonic regression modelling, in a sample of eight activity recordings made on patients in a nursing home. Copyright © 2006 John Wiley & Sons, Ltd.
The behavior of SATB1, a MAR‐binding protein, in response to apoptosis stimulation
Authors: Sun Yujie , Wang Ting , Su Yongqian , Yin Yongmei , Xu Shan , Ma Changyan , Han Xiao
Published: December 2005

As a MAR‐binding protein, SATB1 regulates genes by folding chromatin into a loop domain. Apoptosis is known to be accompanied by a collapse of nuclear architecture and cleavage of condensing chromatin into oligonucleosomal fragments. To further understand the functional role of MAR‐binding proteins during apoptosis we investigated the relationship of the behavior of SATB1 and the collapse of nuclear architecture in Jurkat cells with immunostaining and Western blot analysis. We demonstrated that SATB1 formed special three‐dimensional network distributions during early apoptosis. The distribution change of SATB1 was associated with cleavage of the protein and accompanied by the nuclear architecture collapse. Cleavage of SATB1 was mediated by caspase‐3 and was apoptosis specific. Our observations further support the notion that early proteolysis of MAR‐binding proteins might represent a universal mechanism that renders these DNA sites vulnerable to endonucleolysis.
Cytotoxicity, haematotoxicity and genotoxicity of high molecular mass arborescent polyoxyethylene polymers with polyglycidol‐block‐containing shells
Authors: Klajnert Barbara , Walach Wojciech , Bryszewska Maria , Dworak Andrzej , Shcharbin Dzmitry
Published: December 2005

We have examined the impact on biological systems of some newly synthesised polyoxyethylene polymers using in vitro assays. Toxicity was tested by the 3‐[4,5‐dimethylthiazole‐2‐yl]‐2,5 diphenyltetrazolium bromide (MTT) assay, haemolysis was assessed, and an ethidium bromide (EB) assay was used to study interactions between the polymers and DNA. All the assay data showed that the polymers are biocompatible. No differences were found between generations (i.e. macromolecule sizes). The results encourage continuing studies on the clinical use of these molecules as drug carriers.
Improved Taxol production by combination of inducing factors in suspension cell culture of Taxus baccata
Authors: Khosroushahi A. Yari , Valizadeh M. , Ghasempour A. , Khosrowshahli M. , Naghdibadi H. , Dadpour M.R. , Omidi Y.
Published: December 2005

To date enormous attempts have been devoted to improve Taxol production exploiting various methodologies from bioprocess engineering to biotechnological and synthetic approaches. We have developed a 2‐stage suspension cell culture of Taxus baccata L. using modified B5 medium in order to improve cell growth as well as productivity. After callus induction and cell line selection, B5 medium was supplemented with vanadyl sulfate (0.1 mg/l), silver nitrate (0.3 mg/l) and cobalt chloride (0.25 mg/l) at the first day of stage I culture to maximize cell growth. This medium was further supplemented with sucrose (1%) and ammonium citrate (50 mg/l) on day 10 and sucrose (1%) and phenylalanine (0.1 mM) on day 20 (i.e., biomass growth medium). At stage II (day 25), two different concentrations of several elicitors such as methyl jasmonate (10 or 20 mg/l), salicylic acid (50 or 100 mg/l) and fungal elicitor (25 or 50 mg/l) were added to the biomass growth medium with the aim of improving cellular productivity.

For morphological analysis, microscopic inspection was carried out during cultivation. Cell‐associated and extracellular amount of Taxol were detected and measured using HPLC methodology. At stage I, overall Taxol amount of biomass growth medium was 13.75 mg/l (i.e., 5.6‐fold higher than that of untreated B5 control). At stage II, treated cells with methyl jasmonate (10 mg/l), salicylic acid (100 mg/l) and fungal elicitor (25 mg/l) produced the highest amount of Taxol (39.5 mg/l), which is 16‐fold higher than that of untreated B5 control (2.45 mg/l). Microscopic analyses of Taxus cells in suspension cultures showed various positional auto‐fluorescence showing direct correlation with Taxol production. Our studies revealed that intervallic supplementation of B5 medium with combination of biomass growth factors at stage I and mixture of elicitors at stage II could significantly increase Taxol production. Thus, we suggest that the exploitation of this methodology may improve the production of Taxol since demands for Taxol pharmaceuticals are increasingly growing and resource paucities have limited its direct harvesting from Taxus trees.
Overexpressed LEF‐1 proteins display different nuclear localization patterns of β‐catenin in normal versus tumor cells
Authors: Ki Hyunkyoung , Jung Ho‐Chul , Park Jae‐Hyo , Kim Jin‐Sook , Lee Kwang Youl , Kim Tae Sung , Kim Kwonseop
Published: December 2005

β‐Catenin not only plays a role in cadherin‐dependent cell adhesion, but also interacts with T‐cell factor (TCF)/lymphoid enhancer factor‐1 (LEF‐1) to affect gene expression. In this report, we describe the effects of exogenous LEF‐1 and of treatment with leptomycin B (LMB), a specific inhibitor of CRM1‐medicated nuclear export, on the nuclear localization and export of β‐catenin. Normal epithelial cells overexpressing LEF‐1 accumulate nuclear β‐catenin in a LEF‐1 concentration‐dependent manner. Nuclear β‐catenin, once imported from the cytoplasm, is rapidly removed from the nucleus. Treatment with LMB results in dramatic retention of nuclear β‐catenin in normal epithelial cells transfected with LEF‐1, and this effect is intensified by treatment of N‐Acetyl‐leucyl‐leucyl‐norleucinal together with LMB. Colon carcinoma cells containing an adenomatous polyposis coli mutation retain significant amounts of LEF‐1 induced nuclear β‐catenin considerably after the time‐point when β‐catenin disappears from the nuclei of LEF‐1 transfected normal epithelial cells. β‐Catenin binds directly to CRM1, and overexpression of CRM1 reduces nuclear β‐catenin‐mediated transactivation function.
The 2-year stability of neurological soft signs after a first episode of non-affective psychosis
Authors: Boks Marco P.M. , Selten Jean-Paul , Leask Stuart , Van den Bosch Robert J.
Published: December 2005

We examined the 2-year stability of neurological soft signs (NSS) in 29 patients after a first episode of psychosis. The numbers of NSS at inclusion and at 2 years follow-up were similar, but there was a significant increase in the numbers of NSS in the sub-group of patients whose dosage of antipsychotic medication had increased over time.
Impact of cognitive-psychoeducational interventions in bipolar patients and their relatives
Authors: Bernhard Britta , Schaub Annette , Kümmler Petra , Dittmann Sandra , Severus Emanuel , Seemüller Florian , Born Christoph , Forsthoff Anna , Licht Rasmus W. , Grunze Heinz
Published: December 2005

Background.

In recent years, several controlled studies could show that psychoeducational interventions have been effective for relapse prevention in bipolar disorders. We therefore established a cognitive-psychoeducational group intervention with 14 sessions providing information about the illness, early warning signs, cognitive and behavioural strategies for stress management and social rhythm. Additionally we offered a group intervention for the patients' relatives. The objective of this study was to describe the outcome associated with our psychoeducational intervention in bipolar patients and their relatives.

Methods.

Sixty-two bipolar patients attended 14 sessions (à 90 min) of cognitive-psychoeducational group therapy. Patients' knowledge of bipolar disorder and their satisfaction with the treatment were assessed using self-developed questionnaires before and after the group intervention. Additionally, 49 relatives of bipolar patients received two psychoeducational workshops of 4 hours each. We assessed demographic variables, burden, high expressed emotion and depressive symptoms of the relatives before and after the two workshops and at 1-year follow-up.

Results.

Patients significantly improved their knowledge of bipolar disorder. They also have benefited from the discussions and the exchange of useful coping strategies. Burden and high expressed emotions showed no significant reductions at post-assessment, however they were significantly reduced at 1-year follow-up. Relatives also felt significantly better informed about the illness.

Conclusions.

These findings show that psychoeducational interventions in bipolar patients and their relatives improve patients' and their relatives' knowledge of the illness and the burden of the disorder as well as high expressed emotions are reduced in relatives at 1-year follow-up.
Meta-analysis of drop-out rates in randomised clinical trials, comparing typical and atypical antipsychotics in the treatment of schizophrenia
Authors: Martin José Luis R. , Pérez Víctor , Sacristán Montse , Rodríguez-Artalejo Fernando , Martínez Cristóbal , Álvarez Enric
Published: December 2005

Objective

To assess antipsychotic medication in the treatment of schizophrenia, based on trial drop-out rates.

Methods

The studies included were randomised controlled trials that compared any of the four clinically best-established atypical antipsychotics (quetiapine, olanzapine, risperidone or clozapine) against either of two typical antipsychotics regarded as the gold standard (haloperidol or chlorpromazine).

Results

Meta-analysis indicated less risk of all-cause patient withdrawal from atypical medication trials where dosage was flexible, in both the short, relative risk (RR) 0.70 (95% CI 0.64–0.76),P< 0.00001, and long term, RR 0.72 (0.65–0.80),P< 0.00001. Similar results were observed for withdrawal due to adverse events, RR: 0.54 (0.41–0.72),P< 0.0001. Nevertheless, the favourable effects of atypical medication disappeared in trials relying on fixed dosage.

Conclusions

We detected a significant positive effect in terms of the outcome of treatment discontinuation for atypical versus typical medication, though only where the use of flexible rather than fixed doses (closer to an experimental control situation) was possible.
Predicting protein interaction sites from residue spatial sequence profile and evolution rate
Authors: Wang Bing , Chen Peng , Huang De-Shuang , Li Jing-jing , Lok Tat-Ming , Lyu Michael R.
Published: December 2005

This paper proposes a novel method that can predict protein interaction sites in heterocomplexes using residue spatial sequence profile and evolution rate approaches. The former represents the information of multiple sequence alignments while the latter corresponds to a residue's evolutionary conservation score based on a phylogenetic tree. Three predictors using a support vector machines algorithm are constructed to predict whether a surface residue is a part of a protein–protein interface. The efficiency and the effectiveness of our proposed approach is verified by its better prediction performance compared with other models. The study is based on a non‐redundant data set of heterodimers consisting of 69 protein chains.
In vivo tracing of canonical Wnt signaling in Xenopus tadpoles by means of an inducible transgenic reporter tool
Authors: Denayer Tinneke , Van Roy Frans , Vleminckx Kris
Published: December 2005

The canonical Wnt pathway is recurrently used during embryogenesis and adult life. To track the cellular output of Wnt signaling in a living organism, we designed a hormone‐inducible Wnt responsive system, capable to dynamically and specifically report Wnt pathway activities through eGFP expression. In contrast to previous in vivo reporters, our system essentially avoids interference of consecutive signals by remaining dormant until addition of hormone, which makes it a valuable tool to map canonical Wnt signaling in post‐embryonic stages. Transgenic Xenopus laevis embryos were analyzed revealing at tadpole stage in specific tissues and organs cell populations with high Wnt pathway activity.
Hirsutenone inhibits phorbol ester‐induced upregulation of COX‐2 and MMP‐9 in cultured human mammary epithelial cells: NF‐κB as a potential molecular target
Authors: Kim Jung-Hwan , Lee Ki Won , Lee Min-Won , Lee Hyong Joo , Kim Sung-Hoon , Surh Young-Joon
Published: December 2005

Inappropriate upregulation of cyclooxygenase‐2 (COX‐2) and matrix metalloproteinases (MMPs) has been implicated in the pathogenesis of various types of cancer. In the present study, we investigated the effects of hirsutenone, a diarylheptanoid isolated from the medicinal plant Alnus hirsuta var. sibirica, on the expression of COX‐2 and MMP‐9 induced by the tumor promoter 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) in MCF10A human breast epithelial cells. Treatment of MCF10A cells with TPA led to the expression of COX‐2 and MMP‐9. Hirsutenone at 12 μM inhibited the TPA‐induced COX‐2 expression at both the transcriptional and posttranscriptional levels. Hirsutenone also suppressed the synthesis of prostaglandin E2, one of the major products of COX‐2, and its catalytic activity. The upregulation of MMP‐9 by TPA was also significantly reduced by hirsutenone. Likewise, hirsutenone attenuated the invasiveness and motility of MCF10A cells stimulated with TPA. Hirsutenone blocked the TPA‐induced DNA binding of nuclear factor kappa B (NF‐κB) and translocation of p65, the functionally active NF‐κB subunit, to the nucleus. The luciferase reporter gene assay revealed that hirsutenone abrogated the transcriptional activity of NF‐κB. Treatment of MCF10A cells with N‐alpha‐Tosyl‐l‐phenylalanine chloromethyl ketone, a specific inhibitor of NF‐κB, reduced the TPA‐induced expression of COX‐2 and MMP‐9. In summary, hirsutenone inhibits the TPA‐induced upregulation of COX‐2 and MMP‐9 in human breast epithelial cells, possibly by targeting NF‐κB, which may contribute to its chemopreventive effects.
Microarray analysis of gene expression in adult retinal ganglion cells
Authors: Ivanov Dmitry , Dvoriantchikova Galina , Nathanson Lubov , McKinnon Stuart J. , Shestopalov Valery I.
Published: December 2005

Retinal ganglion cells (RGCs) transfer visual information to the brain and are known to be susceptible to selective degeneration in various neuropathies such as glaucoma. This selective vulnerability suggests that these highly specialized neurons possess a distinct gene expression profile that becomes altered by neuropathy‐associated stresses, which lead to the RGC death. In this study, to identify genes expressed predominantly in adult RGCs, a global transcriptional profile of purified primary RGCs has been compared to that of the whole retina. To avoid alterations of the original gene expression profile by cell culture conditions, we isolated RNA directly from adult RGCs purified by immunopanning without prior sub‐cultivation. Genes expressed predominantly in RGCs included: Nrg1, Rgn, 14‐3‐3 family (Ywhah, Ywhaz, Ywhab), Nrn1, Gap43, Vsnl1, Rgs4. Some of these genes may serve as novel markers for these neurons. Our analysis revealed enrichment in genes controlling the pro‐survival pathways in RGCs as compared to other retinal cells.
Thr199 phosphorylation targets nucleophosmin to nuclear speckles and represses pre‐mRNA processing
Authors: Tarapore Pheruza , Shinmura Kazuya , Suzuki Hitoshi , Tokuyama Yukari , Kim Song-Hee , Mayeda Akila , Fukasawa Kenji
Published: December 2005

Nucleophosmin (NPM) is a multifunctional phosphoprotein, being involved in ribosome assembly, pre‐ribosomal RNA processing, DNA duplication, nucleocytoplasmic protein trafficking, and centrosome duplication. NPM is phosphorylated by several kinases, including nuclear kinase II, casein kinase 2, Polo‐like kinase 1 and cyclin‐dependent kinases (CDK1 and 2), and these phosphorylations modulate the activity and function of NPM. We have previously identified Thr199 as the major phosphorylation site of NPM mediated by CDK2/cyclin E (and A), and this phosphorylation is involved in the regulation of centrosome duplication. In this study, we further examined the effect of CDK2‐mediated phosphorylation of NPM by using the antibody that specifically recognizes NPM phosphorylated on Thr199. We found that the phospho‐Thr199 NPM localized to dynamic sub‐nuclear structures known as nuclear speckles, which are believed to be the sites of storage and/or assembly of pre‐mRNA splicing factors. Phosphorylation on Thr199 by CDK2/cyclin E (and A) targets NPM to nuclear speckles, and enhances the RNA‐binding activity of NPM. Moreover, phospho‐Thr199 NPM, but not unphosphorylated NPM, effectively represses pre‐mRNA splicing. These findings indicate the involvement of NPM in the regulation of pre‐mRNA processing, and its activity is controlled by CDK2‐mediated phosphorylation on Thr199.