bluuebunny/crossref_metadata_2025 huggingface dataset:
The ING gene family in the regulation of cell growth and tumorigenesis
Authors: Coles Andrew H. , Jones Stephen N.
Published: September 2008

The five members of the inhibitor of growth (ING) gene family have garnered significant interest due to their putative roles as tumor suppressors. However, the precise role(s) of these ING proteins in regulating cell growth and tumorigenesis remains uncertain. Biochemical and molecular biological analysis has revealed that all ING members encode a PHD finger motif proposed to bind methylated histones and phosphoinosital, and all ING proteins have been found as components of large chromatin remodeling complexes that also include histone acetyl transferase (HAT) and histone deacetylase (HDAC) enzymes, suggesting a role for ING proteins in regulating gene transcription. Additionally, the results of forced overexpression studies performed in tissue culture have indicated that several of the ING proteins can interact with the p53 tumor suppressor protein and/or the nuclear factor‐kappa B (NF‐κB) protein complex. As these ING‐associated proteins play well‐established roles in numerous cell processes, including DNA repair, cell growth and survival, inflammation, and tumor suppression, several models have been proposed that ING proteins act as key regulators of cell growth not only through their ability to modify gene transcription but also through their ability to alter p53 and NF‐κB activity. However, these models have yet to be substantiated by in vivo experimentation. This review summarizes what is currently known about the biological functions of the five ING genes based upon in vitro experiments and recent mouse modeling efforts, and will highlight the potential impact of INGs on the development of cancer. J. Cell. Physiol. 218: 45–57, 2009. © 2008 Wiley‐Liss, Inc.
Conjunctival sac fluid contains elevated levels of soluble TRAIL: Implications for the anti‐tumoral surveillance of the anterior surface of the eye
Authors: Secchiero Paola , Lamberti Giuseppe , Corallini Federica , Melloni Elisabetta , Guarnotta Carla , Sebastiani Adolfo , Zauli Giorgio
Published: September 2008

Little is known on the ability of different epithelia to release soluble TNF‐related apoptosis‐inducing ligand (TRAIL) and the relevance of TRAIL secretion by epithelial cells is still incompletely understood. On these bases, we have measured the concentration of soluble TRAIL by ELISA in the conjunctival sac fluid. It was the highest ever detected in a biological fluid (mean value of 26,800 pg/ml), being approximately 20‐fold greater than that found in human saliva and >200‐fold greater than that detected in human serum. On the other hand, osteoprotegerin, the soluble decoy receptor of TRAIL, was almost undetectable in the conjunctival sac fluid. Of note, the levels of soluble TRAIL measured in conjunctival sac fluid were in the range able to induce in vitro apoptosis of lymphoma cells. By in situ immunohistochemistry, TRAIL protein expression was predominantly detected in the corneal epithelium and, to a less extent, in the conjunctival epithelium. By flow cytometry analysis, membrane‐associated TRAIL was documented in isolated corneal epithelial cells obtained from patients undergoing photorefractive keratectomy (PRK). The key contribution provided by corneal epithelium to the production of soluble TRAIL was underscored in time‐course experiments, in which a marked decrease of the levels of soluble TRAIL in the conjunctival sac fluid was demonstrated 1 day after PRK followed by a progressive recovery at days 5–30 after PRK. Taken together, our findings strongly support a major role of soluble TRAIL in protecting cornea and conjunctiva from tumor formation and/or invasion. J. Cell. Physiol. 218: 199–204, 2009. © 2008 Wiley‐Liss, Inc.
3D and 4D sonographic imaging of amniotic band syndrome in early pregnancy
Authors: Inubashiri Eisuke , Hanaoka Uiko , Kanenishi Kenji , Yamashiro Chizu , Tanaka Hirokazu , Yanagihara Toshihiro , Hata Toshiyuki
Published: September 2008

We present a case of amniotic band syndrome diagnosed with two‐dimensional (2D), three‐dimensional (3D), and four‐dimensional (4D) sonography at 14 weeks and 5 days of gestation. Conventional 2D sonography revealed multiple amniotic bands, fetal acrania, deformed hand, gastroschisis, kyphoscoliosis, and club foot. 3D and 4D sonography revealed multiple amniotic bands swinging in the amniotic cavity with 1 of them attached to the fetal head, and the severe deformity of the fetal face. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Effects of cell‐penetrating peptides and pegylation on transfection efficiency of polyethylenimine in mouse lungs
Authors: Nguyen Juliane , Xie Xiulan , Neu Michael , Dumitrascu Rio , Reul Regina , Sitterberg Johannes , Bakowsky Udo , Schermuly Ralph , Fink Ludger , Schmehl Thomas , Gessler Tobias , Seeger Werner , Kissel Thomas
Published: September 2008

Background

Cell‐penetrating peptides (CPPs) could potentially be used as vectors for intracellular delivery of proteins, peptides and nucleic acids. The present study examined different CPPs, such as TAT‐derived and arginine rich sequences, as well as model amphiphilic peptide, with respect to transfection efficiency of pegylated polyethylenimine (PEI) in A549, Calu‐3 cells and in mice after intra‐tracheal administration.

Methods

The conjugates were prepared by the coupling of CPPs to PEI via a heterobifunctional polyethylene glycol (PEG) linker, resulting in the bioconjugates CPP‐PEG‐PEI. Structures were successfully confirmed by 1H‐nuclear magnetic resonance and diffusion‐ordered spectroscopy. Unmodified PEI 25 kDa was compared with pegylated PEI, and aggregation tendency in cell culture medium, interaction with mucin and stability against heparin was assayed. After evaluating transfection efficiency of the polymers in two different lung cell lines, luciferase reporter gene expression was determined in mouse lungs.

Results

All conjugates showed superior transfection efficiency compared to unmodified PEI 25 kDa. The conjugates sizes were generally < 300 nm, thus enabling them to penetrate through the mucus lining of the lung and reach the target cells. Coupling of CPPs to PEG‐PEI, however, did not significantly improve transfection efficiency in A549 cells, calu‐3 cells and in mouse lungs.

Conclusions

We show that small and stable polyplex size achieved by pegylation is favourable for successful pulmonary gene delivery. Compared to PEI 25 kDa, pegylated PEI and CPP‐PEG‐PEI displayed enhanced transfection efficiency both in vitro and in vivo. Copyright © 2008 John Wiley & Sons, Ltd.
Management of spatial and temporal thermal dynamics using TLM
Authors: Koay A. L. , Wilkinson A. J. , Pulko S. H.
Published: September 2008

The design of a preliminary spatial thermal control algorithm is described. This is based on the traditional state‐space servo design and exploits the analogy between the transmission line matrix (TLM) method and state‐space. The TLM algorithm involves not only temporal dynamics but also spatial ones. The control algorithm presented here involves estimating an analogous TLM model for the process to be controlled, the states of which are then used to calculate the control signals, across space, to be employed.

The performance of the control algorithm is briefly investigated over a range of design parameter values, in order to seek a preliminary insight into parameter selection. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of supplementation of garlic powder on rumen ecology and digestibility of nutrients in ruminants
Authors: Wanapat Metha , Khejornsart Pichad , Pakdee Pawadee , Wanapat Sadudee
Published: September 2008

BACKGROUND: The present study investigated the effect of garlic powder (GAP) supplementation on rumen fermentation pattern, nutrient digestibility and intake in ruminants fed on straw as a roughage source.

RESULTS: Dry matter intake and apparent digestibility of nutrients were similar among treatments. The apparent digestibility of crude protein tended to be higher in cattle supplemented with GAP compared to those fed without GAP (P = 0.08). Ruminal populations of protozoa and bacteria were decreased, as influenced by GAP supplementation. Ruminal pH and NH3‐N were similar among treatments, while blood urea nitrogen tended to be decreased (P < 0.05). Total volatile fatty acids (VFAs) were not affected by GAP supplementation but individual VFAs were significantly different (P < 0.05), especially C3; meanwhile, C2:C3 ratio was reduced by GAP supplementation (P < 0.05). In addition, N balances were significantly increased as level of GAP supplementation increased and was highest at 120 g d−1 GAP.

CONCLUSION: Results of this study suggest that feeding of GAP at 80 g d−1 with urea‐treated rice straw could enhance ruminal propionate production and thus lower C2:C3 ratio, decreasing the protozoal population, as well as increasing N retention and absorption in ruminants. Copyright © 2008 Society of Chemical Industry
The protective effects of garlic oil on acute ethanol‐induced oxidative stress in the liver of mice
Authors: Zeng Tao , Zhang Cui‐Li , Pan Guang‐Bing , Zhao Sheng , Dou Dan‐Dan , Xin Xing , Xie Ke‐Qin
Published: September 2008

BACKGROUND: Alcoholic liver disease is so serious that no effective therapies have been developed up to now. This study was conducted to elucidate the effects of garlic oil (GO) on acute ethanol‐induced liver injury. Male Kun‐Ming mice were orally administered GO (50, 100 or 200 mg kg−1) for 30 days and then ethanol (4.8 g kg−1). At 16 h after ethanol treatment the mice were sacrificed. Subsequent serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and triglyceride (TG) levels, hepatic malondialdehyde (MDA) and glutathione (GSH) levels and antioxidant enzyme activities were measured. Histopathological examination of mouse liver sections was performed by Sudan III staining.

RESULTS: GO pretreatment significantly inhibited acute ethanol‐induced increase in ALT, AST, TG and MDA and decrease in GSH in a dose‐dependent manner. In the three GO groups the level of GSH increased by 10.3%, 15.8% (P < 0.05) and 25.5% (P < 0.01) respectively compared with that in the ethanol group. The activities of superoxide dismutase, catalase and glutathione reductase were increased markedly in the 200 mg kg−1 GO group (P < 0.01). Histopathological examination showed fewer fat droplets in liver sections of GO‐pretreated mice.

CONCLUSION: GO may have protective effects against acute ethanol‐induced liver injury through restoration of the GSH level and enhancement of the activities of antioxidant enzymes. Copyright © 2008 Society of Chemical Industry
Determination of the content of fatty acid methyl esters (FAME) in biodiesel samples obtained by esterification using 1H‐NMR spectroscopy
Authors: Mello Vinicius M. , Oliveira Flavia C. C. , Fraga William G. , do Nascimento Claudia J. , Suarez Paulo A. Z.
Published: September 2008

Three different calibration curves based on 1H‐NMR spectroscopy (300 MHz) were used for quantifying the reaction yield during biodiesel synthesis by esterification of fatty acids mixtures and methanol. For this purpose, the integrated intensities of the hydrogens of the ester methoxy group (3.67 ppm) were correlated with the areas related to the various protons of the alkyl chain (olefinic hydrogens: 5.30–5.46 ppm; aliphatic: 2.67–2.78 ppm, 2.30 ppm, 1.96–2.12 ppm, 1.56–1.68 ppm, 1.22–1.42 ppm, 0.98 ppm, and 0.84–0.92 ppm). The first curve was obtained using the peaks relating the olefinic hydrogens, a second with the parafinic protons and the third curve using the integrated intensities of all the hydrogens. A total of 35 samples were examined: 25 samples to build the three different calibration curves and ten samples to serve as external validation samples. The results showed no statistical differences among the three methods, and all presented prediction errors less than 2.45% with a co‐efficient of variation (CV) of 4.66%. Copyright © 2008 John Wiley & Sons, Ltd.
Monitoring dynamic alterations in calcium homeostasis by T1‐weighted and T1‐mapping cardiac manganese‐enhanced MRI in a murine myocardial infarction model
Authors: Waghorn Ben , Edwards Tiffany , Yang Yuhui , Chuang Kai‐Hsiang , Yanasak Nathan , Hu Tom C.‐C.
Published: September 2008

Manganese has been used as a T1‐weighted MRI contrast agent in a variety of applications. Because manganese ions (Mn2+) enter viable myocardial cells via voltage‐gated Ca2+ channels, manganese‐enhanced MRI is sensitive to the viability and inotropic state of the heart. In spite of the established importance of Ca2+ regulation in the heart both before and after myocardial injury, monitoring strategies to assess Ca2+ homeostasis in affected cardiac tissues are limited. This study implements a T1‐mapping method to obtain quantitative information both dynamically and over a range of MnCl2 infusion doses. To optimize the current Mn2+ infusion protocols, we performed both dose‐dependent and temporal washout studies. A non‐linear relationship between infused MnCl2 solution dose and increase in left ventricular wall relaxation rate (ΔR1) was observed. Control mice also exhibited significant Mn2+ clearance over time, with a decrease in ΔR1 of ∼50% occurring in just 2.5 h. The complicated efflux time dependence possibly suggests multiple efflux mechanisms. With the use of the measured relationship between infused Mn2+ dose, ΔR1, and inductively coupled plasma mass spectrometry data analysis provided a means of estimating the absolute heart Mn concentration in vivo. We show that this technique has the sensitivity to observe or monitor potential alterations in Ca2+ handling in vivo because of the physiological remodeling after myocardial infarction. Left ventricular free wall ΔR1 values were significantly lower (P = 0.005) in the adjacent zone, surrounding the injured myocardial tissue, than in healthy tissue. This inferred reduction in Mn concentration can be used to estimate potentially salvageable myocardium in vivo for future treatment or evaluation of disease progression. Copyright © 2008 John Wiley & Sons, Ltd.
Analysis of a thermomechanical phase transition model
Authors: Chełmiński Krzysztof , Hömberg Dietmar , Kern Daniela
Published: September 2008

Subject of this work is a macroscopic thermomechanical model of phase transitions in steel. Effects like transformation strain and transformation plasticity induced by the phase transitions are considered and used to formulate a consistent thermomechanical model. The resulting system of state equations consists of a quasistatic momentum balance coupled with a nonlinear stress‐strain relation, a nonlinear energy balance equation and a system of ODEs for the phase volume fractions. We prove the existence of a unique weak solution using fixed‐point arguments. A key issue is a regularity analysis for the mechanical subsystem to obtain continuity of the stress tensor. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of the non‐isothermal flow in a twin‐screw extruder
Authors: Conzen Carsten , Wünsch Olaf
Published: September 2008

The paper deals with the numerical simulation and experimental validation of transport phenomena in a co‐rotating twin screw extruder. We show steady state simulations of conveying elements in a relative system and compare them with transient simulations. With the transient simulation we are able to simulate the temperature development in the twin screw extruder. The results are compared with experimental results and show good agreement. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast algorithms for PDEs in simple and complex geometries
Authors: Daripa Prabir
Published: September 2008

A brief review of our fast algorithms is given in this short paper. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nondegeneracy, from the prospect of wave‐wave regular interactions of a gasdynamic type
Authors: Dinu Liviu Florin , Dinu Marina Ileana
Published: September 2008

A parallel is considered between Burnat's “algebraic” approach [restricted to a genuine nonlinearity] and Martin's “differential” approach regarding their contribution to describing some nondegenerate one‐dimensional gasdynamic regular interaction solutions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase‐field modeling and simulations of multicomponent cell membranes
Authors: Du Qiang
Published: September 2008

In this talk, we report some of recent works with current and former colleagues at Penn State (S. Das, M. Li, C. Liu, R. Ryham, X. Wang and J. Zhang) on the phase field modeling and simulations of the vesicle membrane deformation under elastic bending energy and the interaction with background fluid flows and other external fields. We discuss the relations between the phase field model and the sharp interface limits and numerical simulations of membranes with various topology and multiple components. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of latent energy storage effects in thermoplasticity of metals
Authors: Fritzen Felix , Böhlke Thomas , Schnack Eckart
Published: September 2008

The modeling of coupled thermo‐plasticity includes the consideration of self‐heating which produces significant effects in many metal‐forming applications. While it has become given practice to use a constant fraction of the plastic power as heat production term in computations, experiments show considerably varying Taylor‐Quinney factors. The presented micromechanically motivated model describes non‐constant and non‐uniform latent energy storage effects. The Taylor‐Quinney factor has been computed for different isotropic hardening laws for illustration. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Uncertainty modeling in autonomous robust spacecraft system design
Authors: Fuchs Martin , Neumaier Arnold , Girimonte Daniela
Published: September 2008

In the last few years, much research has been dedicated to the development of decisions support systems for the space system engineers or even of completely automated design methods capturing the reasoning of the system experts. However, the problem of taking into account the uncertainties of the variables and models to determine an optimal and robust spacecraft design has not been tackled effectively yet. Based on the clouds formalism we propose a novel approach to process the uncertainty information provided by expert designers and incorporate it into the automated search for a robust optimal design. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical solution of the time‐dependent incompressible Navier‐Stokes equations in the stream function and vorticity formulation
Authors: Ghadi Fattehallah , Ruas Vitoriano , Wakrim Mohamed
Published: September 2008

In this work we study the time‐dependent incompressible Navier‐Stokes problem. We introduce a suitable technique based on the splitting of the vorticity into two components. Then we discretize in space the resulting uncoupled system by means of continuous Lagrange finite elements. This is achieved by first performing the semi‐discretization in time of these equations by a classical characteristics method for the advective term. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SDP approximability of relative robust QP
Authors: Hauser Raphael , Tütüncü Reha
Published: September 2008

We consider a relative robust quadratic optimization problem with ellipsoidal uncertainty. This problem is generally NP‐hard, but we show how it can often be well approximated via a conic programming model. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bayesian signal restoration and Mumford‐Shah functional
Authors: Helin Tapio , Lassas Matti
Published: September 2008

We introduce a Bayesian signal restoration method which extracts jumps from a periodical signal. The maximum a posterior estimate of the model problem equals to a minimiser of a functional that Γ‐converges to the Mumford‐Shah functional. Furthermore, the behaviour of the approximative model in the infinite‐dimensional limit is discussed in more detail. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical analysis and algorithms in control and state constrained optimization with PDEs
Authors: Deckelnick Klaus , Günther Andreas , Hinze Michael
Published: September 2008

We consider an elliptic optimal control problem with control and pointwise state constraints. The cost functional is approximated by a sequence of functionals which are obtained by discretizing the state equation with the help of linear finite elements and enforcing the state constraints in the nodes of the triangulation. The control variable is not discretized. A general error bound for control and state is obtained which forms the starting point for optimal error estimates in both in two and three space dimensions. For the numerical implementation of the discrete concept fix‐point iterations or generalized Newton methods are proposed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generalized sensitivity analysis in a delay system
Authors: Kappel F.
Published: September 2008

It is shown that abstract formulations of state dependent delay equations are useful for numerical computations of sensitivities and generalized sensitivities for such equations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling wave propagation phenomena in time domain by using the symmetric Galerkin BEM and the Convolution Quadrature Method
Authors: Kielhorn Lars , Schanz Martin
Published: September 2008

The boundary element method (BEM) is known to be well suited to treat wave propagation phenomena. Here, a 3‐d elastodynamic body is under consideration. For a numerical treatment of the underlying boundary integral equations appropriate time and spatial discretizations have to be introduced. The time discretization is done via the Convolution Quadrature Method (CQM) as proposed by Lubich while a symmetric Galerkin scheme is applied in space.

Unfortunately, the symmetric Galerkin boundary element method (SGBEM) requires the use of the second boundary integral equation involving a hypersingular kernel. Therefore, an appropriate regularization of the hypersingular bilinear form has to be established.

Finally, a numerical study show that the presented approach yields good convergence rates as well as good numerical stability properties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interactions between compressibility and heat release in turbulent mixing layers
Authors: Mahle Inga , Friedrich Rainer
Published: September 2008

Reduced turbulence activity and growth rate of a compressible mixing layer when the convective Mach number increases, are well‐known phenomena. Heat release due to combustion has similar effects and important implications for applications such as scramjet engines the efficiency of which depends on a proper mixing of oxidizer and fuel. To understand the underlying mechanisms, highly resolved DNS of inert and reacting, temporally evolving mixing layers at different convective Mach numbers and Reynolds numbers ensuring a self‐similar state are performed and analyzed with a particular focus on the pressure‐strain correlations in the Reynolds‐stress transport equations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mathematical issues concerning the Boussinesq approximation for thermally coupled viscous flows
Authors: Díaz J. Ildefonso , Rakotoson Jean‐Michel , Schmidt Paul G.
Published: September 2008

The flow of a viscous fluid driven by buoyancy forces is governed by balance equations for momentum, mass, and internal energy. Frequently, the Boussinesq approximation is employed to simplify the system, even in situations where dissipative heating cannot be neglected. The resulting equations violate the principle of conservation of total energy, which causes significant mathematical problems. We discuss these problems and possible remedies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A two‐scale homogenization procedure for the meso‐macro‐modeling of electro‐mechanically coupled problems
Authors: Schröder Jörg
Published: September 2008

The challenge in the field of ferroelectric ceramics is the modeling of complicated interactions between electrical and mechanical properties of the material on the macro‐scale, caused by switching processes on the meso‐scale. This paper presents a two‐scale homogenization framework for the description of polycrystalline material behavior of ferroelectric ceramics, that takes into account the effects occurring on the meso‐scale. The macroscopic variables of the underlying field equations are expressed in terms of mesoscopic boundary integrals and appropriate boundary conditions on the meso‐scale are derived. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient numerical schemes for singularly perturbed parabolic initial‐boundary‐value problems
Authors: Natesan Srinivasan , Deb Rajdeep
Published: September 2008

In this article, we propose two efficient numerical schemes for singularly perturbed parabolic reaction‐diffusion initialboundary‐value problems. The spatial derivative is replaced by a hybrid scheme, which is a combination of the cubic spline and the classical central difference scheme in both the methods. In the first method, the time derivative is replaced by the Crank‐Nicolson scheme, whereas in the second method the time derivative is replaced by the extended‐trapezoidal scheme. These schemes are applied on the layer resolving piecewise‐uniform Shishkin mesh. Numerical examples show ε ‐uniform convergence results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐phase field systems with anisotropic surface energies
Authors: Stinner Björn
Published: September 2008

The dynamics of phase boundaries in multi‐phase systems has been studied with a focus on interfacial energy contributions. A diffuse interface model based on the phase field methodology has been derived which, in the sharp interface limit, is related to a classical description with moving hypersurfaces modeling the phase boundaries. A nontrivial task in the case of multiple phases is to let the surface energies enter the equations of the diffuse interface model in the right way. A gradient potential and a multi‐well potential of obstacle type are presented that allow for a wide class of surface anisotropies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of microcracks in ferroelectric materials by application of a grain‐boundary‐motivated cohesive law
Authors: Utzinger J. , Menzel A. , Steinmann P.
Published: September 2008

Ferroelectric materials exhibit a huge potential for engineering applications – ranging from electrical actuators (inverse piezoelectric effect) to sensor technology (direct piezoelectric effect). To give an example, lead zirconate titanate (PZT) is a typical perovskite ion crystal possessing ferroelectric properties. In this contribution, we are particularly interested in the modelling of microcracking effects in ferroelectric materials.

In view of Finite‐Element‐based simulations, the geometry of a natural grain structure, as observed on the so‐called micro‐level, is represented by an appropriate mesh. While the response on the grains themselves is approximated by coupled continuum elements, grain boundaries are numerically incorporated via so‐called cohesive‐type elements. For the sake of simplicity, switching effects in the bulk material will be neglected. The behaviour of the grain boundaries is modelled by means of cohesive‐type laws. Identifying grain boundaries as potential failure zones leading to microcracking, cohesive‐type elements consequently offer a great potential for numerical simulations. As an advantage, in the case of failure they do not a priori result in ill‐conditioned systems of equations as compared with the application of standard continuum elements to localised deformations. Finally, representative constitutive relations for both the bulk material and the grain boundaries, enable two‐dimensional studies of low‐cycle‐fatigue motivated benchmark boundary value problems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Estimation of the optimal shift for the discrete Helmholtz operator preconditioned with a shifted Laplacian
Authors: Gijzen M.B. van , Erlangga Y.A. , Vuik C.
Published: September 2008

Shifted Laplace preconditioners have attracted considerable attention as a technique to speed up convergence of iterative solution methods for the Helmholtz equation. In this paper we present an approach to determine a near‐optimal value for the shift. We illustrate our results with a geophysical test problem. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the inertial subrange of symmetry‐preserving regularization models for turbulent flow
Authors: Verstappen Roel
Published: September 2008

Foias et al. [1] have proven the existence of the inertial subrange for the (incompressible) Navier‐Stokes equations. In this paper, we proof the same result for any skew‐symmetric regularization of the nonlinearity in the Navier‐Stokes equations. A simple dimensional analysis gives then Kolmogorov's ‐5/3 spectrum. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A proof of MIKOTA's conjecture
Authors: Weber Wolfgang , Anders Bernd
Published: September 2008

Coming from MIKOTA's conjecture [1] a proof is given by examinating the properties of the occuring matrices M, K and M–1K and deducing the natural frequencies of the chain structured mass‐spring vibration system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analyzing securitization processes using simulation methods
Authors: Radoslaw Pytlak , Marcin Wierzbicki
Published: September 2008

The aim of this paper is to present an analysis of securitization processes using simulation and optimization methods. We discuss the main risk factors that may affect profitability of the process. These risk factors are interest rates and mortgage prepayments. We combine latest risk factor models to create a consistent framework to analyze and improve securitization processes. We then show that making ad hoc securitization decisions may be far less efficient than by solving optimization problems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Collective coordinates and the mechanism for conformational transitions of complex molecules
Authors: Yanao Tomohiro , Koon Wang S. , Marsden Jerrold E. , Kevrekidis Ioannis G.
Published: September 2008

Reduction of dimensionality is crucial for the deeper understanding of the mechanism for large‐amplitude conformational transitions of complex molecules. By taking up a six‐atomcluster as an illustrative example, we present a general methodology to understand conformational transitions of molecules in terms of the low‐dimensional dynamics of molecular gyration radii. The dynamics of gyration radii is generally governed by the interplay between the ordinary potential force and a dynamical force called the internal centrifugal force. We show that the internal centrifugal force can be more important than the original potential barrier and gives rise to a new dynamical barrier that truly dominates the conformational transitions of the system. This kind of dynamical effect should be crucially important in a wide class of molecular reaction dynamics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Neonatal Apnea: What's New?
Authors: Abu‐Shaweesh Jalal M. , Martin Richard J.
Published: September 2008

Apnea of prematurity (AOP) remains a major clinical problem in present day neonatology that warrants frequent evaluations and imposes challenges in therapeutic strategies. Although the pathogenesis of AOP is poorly understood, it is probably a manifestation of physiologic immaturity of breathing control rather than a pathologic disorder. Immature breathing responses to hypoxia, hypercapnia and exaggerated inhibitory pulmonary reflexes in preterm infants might also contribute to the occurrence or severity of AOP. Recent data suggest a role for genetic predisposition. Although typically resolve with maturation, the role of bradycardia and desaturation episodes associated with AOP in the development of sleep disorder breathing and neurodevelopmental delay needs further clarification. Pharmacological treatment with methylxanthines and CPAP remain the mainstay for treatment of AOP. However, recent studies have implicated central inhibitory neuromodulators including prostaglandins, GABA and adenosine in its pathogenesis, the fact that might provide future specific targets for treatment. This review will summarize new insights involving these issues as well as others involving the pathogenesis, treatment strategies and consequences of apnea in premature infants. Pediatr Pulmonol. 2008; 43:937–944. © 2008 Wiley‐Liss, Inc.
Safety of bronchoalveolar lavage in young children with cystic fibrosis
Authors: Wainwright Claire E. , Grimwood Keith , Carlin John B. , Vidmar Suzanna , Cooper Peter J. , Francis Paul W. , Byrnes Catherine A. , Whitehead Bruce F. , Martin A. James , Robertson Ian F. , Cooper David M. , Dakin Carolyn J. , Masters Ian. B. , Massie R. John , Robinson Philip J. , Ranganathan Sarath , Armstrong David S. , Patterson Lyndall K. , Robertson Colin F.
Published: September 2008

Objective:

Our aim was to determine the safety of BAL in young children <6 years with CF.

Methods:

As part of a multi‐center study of BAL‐directed therapy, children with CF < 6 years had one or more BALs between September 1999 and December 2005. Adverse events were recorded intraoperatively and for 24 hr thereafter. Clinical characteristics before BAL, findings at bronchoscopy and BAL results were assessed as risk factors for adverse events.

Results:

333 BALs were conducted in 107 (56 males) children, median age 23.5 (range 1.6–67.5) months, including 170 (51%) for pulmonary exacerbation. 29 BALs (8.7%) were followed by fever ≥38.5°C and 10 (3%) had clinically significant episodes (five intraoperative hemoglobin desaturations to <90% requiring intervention, one tachyarrhythmia, two needing post‐operative supplemental oxygen, one hospitalization for stridor). Two contaminated bronchoscopes were detected. 180 minor adverse events were recorded in 174 (52%) BAL procedures (137 altered cough, 41 fever <38.5°C). Low percentage BAL return (P = 0.002) and focal bronchitis (P = 0.02) were associated with clinically significant deterioration. Multivariable analysis identified Streptococcus pneumoniae (OR 22.3; 95% confidence interval (CI); 6.9,72), Pseudomonas aeruginosa (OR 2.4; 95% CI 1.0, 5.8), respiratory signs (OR 5.0; 95% CI 1.7, 14.6) and focal bronchitis (OR 5.9; 95% CI 1.2, 29.8) as independent risk factors for post‐bronchoscopy fever ≥38.5°C.

Conclusions:

Adverse events are common with BAL in young CF children, but are usually transient and well tolerated. Parents should be counseled that signs of a pre‐existing lower respiratory infection are associated with increased risk of post‐BAL fever. Pediatr Pulmonol. 2008; 43:965–972. © 2008 Wiley‐Liss, Inc.
The SRD5A2 V89L polymorphism is associated with severity of disease in men with early onset prostate cancer
Authors: Scariano John K. , Treat Eric , Alba Frances , Nelson Harold , Ness Scott A. , Smith Anthony Y.
Published: September 2008

BACKGROUND

Emerging evidence indicates that testosterone (T), and not dihydrotestosterone (DHT), is the most relevant androgen that promotes carcinogenesis in the prostate. Steroid 5‐alpha reductase type II (SRD5A2) catalyzes the irreversible conversion of T to DHT in male reproductive organs. Because the SRD5A2 gene is highly polymorphic at codon 89, two SRD5A2 isoforms are expressed that differ in Km and Vmax values. The more common and rapid catalytic isoform contains a valine residue at position 89; the slower‐catalytic variant contains leucine at this position.

METHODS

Thirty‐three men with early onset prostate cancer (PCa) were genotyped for the SRD5A2 V89L substitution and other polymorphisms in genes encoding receptors or enzymes that play important roles in pathways of steroid metabolism to ascertain if they were associated with standard clinical measures of disease progression at the time of diagnosis.

RESULTS

The expression of at least one SRD5A2 leucine allele in young men with PCa was associated with more significant disease at the time of presentation, as was defined by pretreatment PSA level, clinical staging and Gleason score when compared with affected subjects harboring the more common SRD5A2 valine variant. A dosage effect of a single leucine allele was evident in heterozygotes, as values of their clinical and pathological variables were consistently situated between the extremes of the homozygous V or L phenotypes.

CONCLUSION

The SRD5A2 leucine isoform appears to be acting in a dose‐dependent manner as a significant disease‐modifying factor in young men diagnosed with PCa. Prostate © 2008 Wiley‐Liss, Inc.
Prolonged androgen receptor loading onto chromatin and the efficient recruitment of p160 coactivators contribute to androgen‐independent growth of prostate cancer cells
Authors: Shi Xu‐Bao , Xue Lingru , Zou June X. , Gandour‐Edwards Regina , Chen Hongwu , deVere White Ralph W.
Published: September 2008

BACKGROUND

Growth of most ablation‐resistant prostate cancers (CaPs) is dependent on androgen receptor (AR) activity in chromatin, but cancer cells in these tumors have acquired altered AR activation. It is unclear how the aberrantly activated AR loads onto regulatory regions of AR‐targeted genes. The purpose of this study was to assess the AR chromatin loading in an androgen‐depleted environment.

METHODS

The expression of PSA in androgen‐resistant CaP cells was determined using RT‐PCR and Western blot analysis. In order to investigate the binding of the AR to the PSA gene regulatory regions, chromatin immunoprecipitation (ChIP) was performed in the androgen‐independent cds2 cell line in the presence or absence of androgens. In addition, we examined the involvement of p160 coactivators in the chromatin loading of the AR.

RESULTS

It was found that constitutive activation of PSA expression was the result of sustained occupancy by the AR at the regulatory region of this gene. This stable AR loading was not blocked by the AR antagonist bicalutamide. Furthermore, androgen‐resistant CaP cells highly expressed both AR and the p160 coactivators and the AR was able to recruit TIF2. Downregulation of TIF2 using short hairpin RNA disrupted the AR loading to the PSA enhancer and subsequently inhibited AR activity.

CONCLUSION

Prolonged AR localization to the regulatory regions of AR targeted genes and the recruitment of p160 coactivators are a potential mechanism leading to androgen‐independent activation of the AR. Disruption of AR chromatin loading could therefore become an important therapeutic target for this disease. Prostate © 2008 Wiley‐Liss, Inc.
Computerized whole slide quantification shows increased microvascular density in pT2 prostate cancer as compared to normal prostate tissue
Authors: van Niekerk Cornelis G. , van der Laak Jeroen A.W.M. , Börger M. Elisa , Huisman Henk‐Jan , Witjes J. Alfred , Barentsz Jelle O. , Hulsbergen‐van de Kaa Christina A.
Published: September 2008

BACKGROUND

Contrast enhanced imaging enables powerful, non‐invasive diagnostics, important for detection and staging of early prostate cancer. The uptake of contrast agent is increased in prostate cancer as compared to normal prostate tissue. To reveal the underlying physiological mechanisms, quantification of tissue components in pathology specimens may yield important information. Aim of this study was to investigate whether microvascularity is increased in prostate confined cancer (pT2).

METHODS

Radical prostatectomy specimens of 26 patients were selected for organ confined peripheral zone tumors which were restricted to one side of the prostate. Microvessels were visualized by immunohistochemistry against CD31. Specimens were scanned using a computer controlled microscope and scanning stage and vessels were recognized automatically. Pseudocolor mappings were produced showing number of vascular profiles (MVD), vascular area (MVA) and perimeter (MVP) in an overview of the entire prostate transection. MVD is a common measure for vascularity, whereas MVA represents the 3D vascular volume and MVP the perfused surface area. Mean, coefficient of variation and 75th percentile of these parameters were calculated automatically in manually indicated areas, consisting of the entire tumor area and the corresponding normal area in the contra lateral side of the prostate.

RESULTS

The mappings clearly indicate areas of increased vascularity in prostate transections. In tumor tissue an increase was found compared to normal tissue of 81%, 49%, and 62% for mean MVD, mean MVA and mean MVP, respectively (P < 0.001 for all comparisons). In contrast, the heterogeneity in tumor vasculature was significantly decreased as compared to normal prostate (P < 0.001).

CONCLUSIONS

Characteristics of microvasculature deviated significantly in pT2 prostate tumor as compared to normal tissue. Prostate 69: 62–69, 2009. © 2008 Wiley–Liss, Inc.
InGaAsP/InGaAs tandem cells for a solar cell configuration with more than three junctions
Authors: Szabó N. , Sağol B. E. , Seidel U. , Schwarzburg K. , Hannappel T.
Published: September 2008

Currently, triple‐junction solar cells realized from III–V semiconductor compounds hold the solar energy conversion efficiency world record. To improve the efficiency significantly, it is necessary to increase the number of junctions and to involve a sub‐cell with an absorber layer in the band gap range of 1 eV. For the realization of a stacked four‐junction device with optimised band gaps, we have grown InGaAsP/InGaAs tandem cells lattice matched to InP substrates, and investigated properties of the absorber bulk material. Time‐resolved photoluminescence of the low band gap In0.53Ga0.47As absorber embedded between InP barriers was measured. The InGaAs/GaAsSb tunnel diode structure used in the tandem has been processed into a separate device andI–Vcurves were measured. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Monolithically integrated organic waveguide photodiode
Authors: Lamprecht B. , Ditlbacher H. , Jakopic G. , Krenn J. R.
Published: September 2008

We demonstrate the monolithic integration of a microstructured organic photodiode with a planar optical stripe waveguide. The manufacturing of this waveguide‐integrated organic photodiode is based on an UV photolithography process. The integration of photodiodes with optical waveguides represents an essential building block in the field of optoelectronic‐photonic integrated circuits.

magnified image

(© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure of GaN(0001)‐2 × 2 thin films grown by PAMBE
Authors: Gutt R. , Lorenz P. , Tonisch K. , Himmerlich M. , Schaefer J. A. , Krischok S.
Published: September 2008

Gallium nitride thin films were grown on silicon carbide (0001) by plasma‐assisted molecular beam epitaxy (PAMBE). The samples were cooled down in nitrogen plasma and characterized in situ by reflection high energy electron diffraction (RHEED), photoelectron spectroscopy (XPS/UPS), and atomic force microscopy (AFM) revealing stoichiometric and smooth GaN films virtually free of contaminations. We present valence band data obtained by UPS with strong emission from surface states inside the fundamental band gap. These states and the observed 2 × 2 surface reconstruction are highly sensitive towards residual molecules. Once these surface states have disappeared the original state could not be recovered by surface preparation methods underlining the necessity of in situ investigations on as‐grown surfaces. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
‘Big‐eyed frog’ sign on spatiotemporal image correlation (STIC) in the antenatal diagnosis of transposition of the great arteries
Authors: Shih J. C. , Shyu M. K. , Su Y. N. , Chiang Y. C. , Lin C. H. , Lee C. N.
Published: September 2008

Objective

To determine the value of simultaneous visualization of the cross‐sectional view of both atrioventricular (AV) valves, the pulmonary artery and the aorta (en‐face view of the AV valves and great vessels) in the identification of fetuses with transposition of the great arteries (TGA).

Methods

This was a retrospective analysis of volume datasets obtained with the spatiotemporal image correlation (STIC) technique from 56 fetuses with and 30 fetuses without congenital heart defects. Volume datasets were reviewed offline to compare the en‐face view of the AV valves and great vessels between fetuses with normal echocardiography and those with TGA.

Results

The en‐face view of both AV valves and great vessels in fetuses with TGA displayed the main pulmonary artery situated side‐by‐side with the aorta (‘big‐eyed frog’ sign). In contrast, fetuses with normal hearts did not have this characteristic sonographic sign. This novel sonographic sign also helped to identify additional cases of TGA in 17 fetuses with complex heart defects.

Conclusion

The big‐eyed frog sign may prove helpful in the prenatal diagnosis of TGA. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Efficient convolution with the Newton potential in d dimensions
Authors: Hackbusch W.
Published: September 2008

The paper is concerned with the evaluation of the convolution integral $${\int_{\mathbb{R}^d}\frac{1}{\left\Vert x-y\right\Vert} f(y){\rm d}y}$$ in d dimensions (usually d = 3), when f is given as piecewise polynomial of possibly large degree, i.e., f may be considered as an hp-finite element function. The underlying grid is locally refined using various levels of dyadically organised grids. The result of the convolution is approximated in the same kind of mesh. If f is given in tensor product form, the d-dimensional convolution can be reduced to one-dimensional convolutions. Although the details are given for the kernel $${{1 / \left \Vert x \right\Vert,}}$$ the basis techniques can be generalised to homogeneous kernels, e.g., the fundamental solution $${{const\cdot\left\Vert x\right\Vert ^{2-d}}}$$ of the d-dimensional Poisson equation.
Difference in seasonal activity pattern between non‐native and native ants in subtropical forest of Okinawa Island, Japan
Authors: Suwabe Mayuko , Ohnishi Hitoshi , Kikuchi Tomonori , Kawara Kengo , Tsuji Kazuki
Published: September 2008

Biological invasions by non‐native tramp ants are reported throughout the world, particularly in island ecosystems. In Okinawa Island, a subtropical island in south‐western Japan, many tramp ants including the invasive ant, Anoplolepis gracilipes, already occur. In this study activity patterns of the ground‐foraging tramp and native ants were investigated for one year by using food bait traps at the forest edges where both categories of ants coexist. On a seasonal time scale, activity patterns were different between exotic and native ants. Native ants are active and seemingly more dominant from spring to summer whereas tramp ants become more dominant from autumn to winter. These results suggest there might be temporal niche partitioning between tramp and native ants, and native ants might be able to dominate tramp ants in their suitable seasons.
A New Concurrent Calibration Method for Nonequivalent Group Design under Nonrandom Assignment
Authors: Miyazaki Kei , Hoshino Takahiro , Mayekawa Shin-ichi , Shigemasu Kazuo
Published: September 2008

This study proposes a new item parameter linking method for the common-item nonequivalent groups design in item response theory (IRT). Previous studies assumed that examinees are randomly assigned to either test form. However, examinees can frequently select their own test forms and tests often differ according to examinees’ abilities. In such cases, concurrent calibration or multiple group IRT modeling without modeling test form selection behavior can yield severely biased results. We proposed a model wherein test form selection behavior depends on test scores and used a Monte Carlo expectation maximization (MCEM) algorithm. This method provided adequate estimates of testing parameters.