bluuebunny/crossref_metadata_2025 huggingface dataset:
Coracoid process anatomy: Implications in radiographic imaging and surgery
Authors: Bhatia Deepak N. , de Beer Joe F. , du Toit Donald F.
Published: August 2007

The coracoid process forms an important part of scapular‐glenoid construct and is involved in many surgical procedures on the glenohumeral joint. The unique three‐dimensional orientation of each coracoid pillar makes radiographic imaging difficult. Congenital variations and minimal traumatic/iatrogenic changes in this orientation can predispose to subcoracoid impingement. We performed a quantitative and statistical analysis of the osseous anatomy of the coracoid process in 101 scapulae; the purpose was to determine the anatomical variations and gender‐specific differences in the length, breadth, thickness, vertical and horizontal projections, and triplane angulations of each individual coracoid pillar. All parameters were measured in reference to the glenoid plane to ensure surgical and radiological applicability. The mean dimensions of the inferior coracoid pillar were 31.1 × 16.6 × 9.9 mm and that of the superior coracoid pillar were 41.7 × 14.2 × 8.4 mm (medial)/6.6 mm (lateral). The mean maximal harvestable coracoid length measured 19.0 mm. The mean angular orientation of the inferior coracoid pillar, with reference to the glenoid, measured 51.2° (axial), 126.1° (sagittal), and 134.6° (coronal), and that of the superior coracoid pillar measured 146.1° (axial) with an interpillar angulation of 84.9° (axial). A statistically significant gender difference (P < 0.05) was found in the lengths, breadths, and projections of each coracoid pillar. We used data from this study to devise two new radiographic views (for imaging individual coracoid pillars), to calculate dimensions and orientation of internal fixation/prosthetic hardware during surgery, and conceptualize a geometric model to explain the role of measured parameters in coracoid impingement syndrome. Clin. Anat. 20:774–784, 2007. © 2007 Wiley‐Liss, Inc.
Unexpected motor axons in the distal superficial radial and posterior interosseous nerves: A cadaver study
Authors: Okwueze Martina I. , Cardwell Nancy L. , Wolfort Sean L. , Nanney Lillian B.
Published: August 2007

The prevalence of motor variations in the nerves supplying muscles of the first web space was evaluated by a visual dissection and immunohistochemical analysis from 56 cadaver hands. By microscopic visualization, 30% of the superficial radial nerves (SRNs) sent branches into muscles of the first web space. Since these unexpected penetrating branches were expected to be sensory or proprioceptive, markers of sensory and motor axons were used for confirmation. Positive identifications of motor axons (as identified by positive immunostaining for choline acetyltransferase) were made in 30% of SRNs and in 28.5% of posterior interosseous nerves. Classical teachings that the SRNs and PINs are exclusively sensory have been brought into question. Our data are in agreement with the rare clinical finding that motor function occasionally persists following devastating injury to both the ulnar and median nerves. Anatomic prevalence for this variation appears much higher than previous descriptions have indicated. Clin. Anat. 20:790–794, 2007. © 2007 Wiley‐Liss, Inc.
An investigation into medical students' approaches to anatomy learning in a systems‐based prosection course
Authors: Smith Claire France , Mathias Haydn
Published: August 2007

Students' approaches to learning anatomy are driven by many factors and perceptions, e.g., the curriculum, assessment, previous educational experience, and the influence of staff and fellow students. However, there has been remarkably little research into characterizing how students approach their anatomy learning. What is known, based on a sample of 243 students, is that students studying medicine at the University of Southampton adopt primarily a “deep” approach to learning. Medical students at Southampton learn anatomy in a systems‐based curriculum through prosections. Analysis of data from an Approaches to Study Inventory (ASSIST) revealed that students preferred using a deep approach over a strategic or surface approach (P < 0.001 and P < 0.001, respectively). They also adopted an increasingly strategic approach as they moved through the medical curriculum. There was a relationship between anatomy examination results and approach to learning. Students who adopted a strategic approach performed better (R = 0.266, P < 0.001). It is argued that curriculum design, including the form of assessment, is the key to promote effective anatomy education and the goal of deep and meaningful learning in preparation for professional practice. Clin. Anat. 20:843–848, 2007. © 2007 Wiley‐Liss, Inc.
Styryl‐Based Compounds as Potential in vivo Imaging Agents for β‐Amyloid Plaques
Authors: Li Qian , Min Jaeki , Ahn Young‐Hoon , Namm Joshua , Kim Eun Min , Lui Rowena , Kim Hye Yun , Ji Yong , Wu Hueizhi , Wisniewski Thomas , Chang Young‐Tae
Published: August 2007

A group of styryl‐based neutral compounds has been synthesized in this study for potential use as in vivo imaging agents for β‐amyloid plaques. Of 56 candidates, 14 compounds were found to label β‐amyloid plaques well on Alzheimer's disease (AD) human brain sections in vitro. The binding affinity to β‐amyloid fibrils was then determined by measuring the change in fluorescence intensity. Interestingly, we found that a class of quinaldine‐styryl scaffold compounds displays specific binding to β‐amyloid fibrils. A representative compound, STB‐8, was used in ex vivo and in vivo imaging experiments on an AD transgenic mouse model and demonstrated excellent blood–brain barrier (BBB) permeability and specific staining of the AD β‐amyloid plaques.
Keratanase II‐Catalyzed Synthesis of Keratan Sulfate Oligomers by Using Sugar Oxazolines as Transition‐State Analogue Substrate Monomers: A Novel Insight into the Enzymatic Catalysis Mechanism
Authors: Ohmae Masashi , Sakaguchi Kazuya , Kaneto Taihei , Fujikawa Shun‐ichi , Kobayashi Shiro
Published: August 2007

Keratan sulfate (KS) oligomers with well‐defined structures were synthesized by keratanase II (KSase II)‐catalyzed transglycosylation. N‐Acetyllactosamine [Galβ(1→4)GlcNAc; LacNAc] oxazoline derivatives with sulfate groups at the C‐6 (1 a) and both the C‐6 and the C‐6′ (1 b) were prepared as transition‐state analogue substrate monomers for KSase II. Monomer 1 a was effectively oligomerized by the enzyme under weak alkaline conditions, to give alternating 6‐sulfated KS oligomers (2 a) in good yields, and with total control of regioselectivity and stereochemistry. KSase II also recognized 1 b, which provided fully 6‐sulfated KS oligomers (2 b) in good yields under similar conditions. Nonsulfated LacNAc oxazoline was difficult to oligomerize enzymatically. These results imply that the catalysis mechanism of KSase II involves a sugar oxazolinium ion that requires the 6‐sulfate group in the GlcNAc residue not only in hydrolysis of KS chains, but also in oligomerization of oxazoline monomers. This is the first report of KSase II‐catalyzed transglycosylation to form β(1→3)‐glycosidic bond through a substrate‐assisted mechanism.
Differential Selectivity of Natural and Synthetic Aminoglycosides towards the Eukaryotic and Prokaryotic Decoding A Sites
Authors: Kondo Jiro , Hainrichson Mariana , Nudelman Igor , Shallom‐Shezifi Dalia , Barbieri Christopher M. , Pilch Daniel S. , Westhof Eric , Baasov Timor
Published: August 2007

The lack of absolute prokaryotic selectivity of natural antibiotics is widespread and is a significant clinical problem. The use of this disadvantage of aminoglycoside antibiotics for the possible treatment of human genetic diseases is extremely challenging. Here, we have used a combination of biochemical and structural analysis to compare and contrast the molecular mechanisms of action and the structure–activity relationships of a new synthetic aminoglycoside, NB33, and a structurally similar natural aminoglycoside apramycin. The data presented herein demonstrate the general molecular principles that determine the decreased selectivity of apramycin for the prokaryotic decoding site, and the increased selectivity of NB33 for the eukaryotic decoding site. These results are therefore extremely beneficial for further research on both the design of new aminoglycoside‐based antibiotics with diminished deleterious effects on humans, as well as the design of new aminoglycoside‐based structures that selectively target the eukaryotic ribosome.
The Unexpected Versatility of P4S3 as a Building Block in Polymeric Copper Halide Networks: 2,3‐P, 1,2,3‐P and all‐P Coordination
Authors: Biegerl Andreas , Brunner Eike , Gröger Christian , Scheer Manfred , Wachter Joachim , Zabel Manfred
Published: August 2007

Layering solutions of P4S3 in CH2Cl2 with solutions of CuCl or CuI in CH3CN gives the coordination polymers (P4S3)3(CuCl)7 (1), (P4S3)2(CuCl)3 (2), (P4S3)(CuI) (3) and (P4S3)(CuI)3 (4), respectively, after slow diffusion. The yellow compounds were characterised by elemental analysis, 31P magic‐angle spinning (MAS) NMR spectroscopy and single‐crystal X‐ray crystallography. The solid‐state structures demonstrate the unexpected ligand versatility of the P4S3 molecule, which interacts through two, three, or even all of the phosphorus atoms with copper according to the nature of the copper halide. Compound 1 has a three‐dimensional network in which linear and cylindrical infinite CuCl subunits coexist with diatomic CuCl building blocks. For the first time, all four P atoms of the P4S3 cage are involved in coordination with metal atoms. The 3D structure of 2 contains stacks of P4S3 that are interconnected by slightly undulated and planar [CuCl]n ribbons. Compound 3 is a one‐dimensional polymer composed of alternating (CuI)2 rings and P4S3 bridges. The structure of 4 consists of undulated [CuI]n layers in which the P4S3 cage functions as a bridge within the layer, as well as a spacer between the layers. The 31P MAS NMR spectra obtained are in good agreement with the solid‐state structures obtained crystallographically. Thus, analytically pure 3 and 4 show singlet peaks that correspond to uncoordinated P and quartets owing to coupling with 63Cu and 65Cu, respectively, whereas that of 1 contains quartets according to all‐P coordination. The spectrum of 2 was obtained from a sample that still contained 40 % of 1.
An Ionically Driven Molecular IMPLICATION Gate Operating in Fluorescence Mode
Authors: Rurack Knut , Trieflinger Christian , Koval'chuck Anton , Daub Jörg
Published: August 2007

An asymmetrically core‐extended boron–dipyrromethene (BDP) dye was equipped with two electron‐donating macrocyclic binding units with different metal ion preferences to operate as an ionically driven molecular IMPLICATION gate. A Na+‐responsive tetraoxa‐aza crown ether (R2) was integrated into the extended π system of the BDP chromophore to trigger strong intramolecular charge transfer (ICT2) fluorescence and guarantee cation‐induced spectral shifts in absorption. A dithia‐oxa‐aza crown (R1) that responds to Ag+ was attached to the meso position of BDP in an electronically decoupled fashion to independently control a second ICT1 process of a quenching nature. The bifunctional molecule is designed in such a way that in the absence of both inputs, ICT1 does not compete with ICT2 and a high fluorescence output is obtained (InA=InB=0→Out=1). Accordingly, binding of only Ag+ at R1 (InA=1, InB=0) as well as complexation of both receptors (InA=InB=1) also yields Out=1. Only for the case in which Na+ is bound at R2 and R1 is in its free state does quenching occur, which is the distinguishing characteristic for the InA=0 and InB=1→Out=0 state that is required for a logic IMPLICATION gate and Boolean operations such as IF‐THEN or NOT.
Going to Extremes: “Super” Armed Glycosyl Donors in Glycosylation Chemistry
Authors: Jensen Henrik H. , Pedersen Christian Marcus , Bols Mikael
Published: August 2007

This concept article gives an overview of stereoelectronic effects in monosaccharide systems and how these can be used to dramatically enhance the reactivity of glycosyl donors in oligosaccharide synthesis.
Multicomponent Dynamic Covalent Assembly of a Rhombicuboctahedral Nanocapsule
Authors: Liu Yong , Liu Xuejun , Warmuth Ralf
Published: August 2007

Molecular container compounds have a range of potential applications in chemical and biological sciences, most notably as nanoreactors, drug delivery devices, and storage materials. We report a highly efficient dynamic covalent chemistry approach for the synthesis of covalent rhombicuboctahedral nanocapsule 1 from 14 square‐ and triangular‐shaped molecular components. The nanocapsule is obtained in a one‐pot reaction in high yield and high purity, and has a solvodynamic diameter of 3.9 nm. In our approach, six formyl cavitands and eight 1,3,5‐tris(p‐aminophenyl)benzene molecules are assembled into a molecular rhombicuboctahedron through twenty four newly formed dynamic imine bonds. Binding studies show that 1 encapsulates tetraalkylammonium salts in toluene. We also discuss the growth mechanism of this nanocapsule.
New method for specifying color‐rendering properties of light sources based on feeling of contrast
Authors: Hashimoto Kenjiro , Yano Tadashi , Shimizu Masanori , Nayatani Yoshinobu
Published: August 2007

“Visual clarity” or “feeling of contrast” of object colors under illumination is affected significantly by changing color‐rendering property of light source used. Though the feeling of contrast is considered one of the most important characteristics on color‐rendering properties of light sources, it cannot be estimated adequately by using the present Ra method. The new index FCI is proposed for estimating the effect of feeling of contrast quantitatively under any light sources. The FCI is derived using a simple transformation of the gamut area, which is constituted by a specially selected four‐color combination in CIE LAB color space. The FCI correlates well with the illuminance ratio for equal feeling of contrast (or equal visual clarity) on various light sources reported so far. Using the FCI together with the present CIE Ra, the color‐rendering capability of a light source can be well clarified. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 361–371, 2007
Complexity of the color appearance of objects with nonuniform illumination
Authors: Nayatani Yoshinobu , Sakai Hideki
Published: August 2007

An inversion relationship is clarified between lightness and brightness, and also between chroma and colorfulness under nonuniform illumination with different illuminance levels (high and low) within the same visual field. Brightness (or colorfulness) of object color with low lightness (or chroma) under high illuminance level is perceived higher than that of another object color with high lightness (or chroma) under low illuminance level. Two color images are given for showing the inversion phenomena on brightness–lightness and colorfulness–chroma between object colors under different illuminance levels. These color images are useful for making researchers on color understand the differences in concept between brightness and lightness, and also between colorfulness and chroma. In particular, the concept of colorfulness is important, but difficult to understand. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 372–377, 2007
Image‐based spectral reflectance reconstruction using the matrix R method
Authors: Zhao Yonghui , Berns Roy S.
Published: August 2007

The ultimate goal of spectral imaging is to achieve high spectral accuracy, so that the spectral information can be used to calculate colorimetrically accurate images for any combination of illuminant and observer. A new spectral reconstruction method, called the matrix R method, was developed to reconstruct spectral reflectance factor accurately while simultaneously achieving high colorimetric performance for a defined illuminant and observer. The method combines the benefits of both colorimetric and spectral transformations. Tristimulus values were predicted by a colorimetric transformation from multi‐channel camera signals, while spectral reflectance factor was estimated by a spectral transformation from the same signals. The method reconstructed reflectance factor by combining the fundamental stimulus from the predicted tristimulus values with the metameric black from the estimated spectral reflectance, based on the Wyszecki hypothesis. The experimental results verified the new method as a promising technique for building a spectral image database. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 343–351, 2007
Generic device color gamut description
Authors: Zhao Xianfeng
Published: August 2007

This article describes two methods for N‐dimensional device color gamut representation: one is for gamut surface description, the other for gamut volume description. Both methods combine analytical and geometrical approaches. These methods can be applied to any colorant spaces such as 3‐Dimensional RGB or CMY, 4‐Dimensional CMYK, 6‐Dimensional Hexachrome® (CMYKOG), as well as the 14‐Dimensional PANTONE MATCHING SYSTEM®. The N‐Dimensional gamut surface description method divides the gamut surface into many subsurfaces with only two‐colorant variables. The gamut volume description first divides the whole gamut volume into 3D cubes without overlaps; then an analytical, geometrical, or interpolation method can be applied to each cube. Finally, all subgamuts are united to create the whole gamut. The analytical approach or interpolation technology is applied into these methods to predict unknown colors. The result is highly accurate with an average error less than 0.11 ΔEin CIEDE2000 for CMYK space and less than 0.56 ΔEin CIEDE2000 for higher dimensions. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 394–408, 2007
Faithful representation of colours on a CRT monitor
Authors: Yoonessi Ali , Kingdom Frederick A. A.
Published: August 2007

A method is described to display faithfully on a CRT monitor the colours of images taken by a calibrated digital camera. A multicoloured “input” image, displayed on a monitor, was photographed with the camera. After correcting the digital image to take into account the gammas of both camera and monitor, the image was redisplayed as an “output” image on the same monitor. An iterative procedure found the linear matrix transformation that minimized the difference between the input and output image RGB values. We compared the efficacy of this method with two conventional methods for displaying photographed images on CRTs: the method of displaying the raw untransformed image, and the method whereby the image is transformed via the CIE common frame of reference. The results of the comparisons suggest that the iterative method produces the most faithful representation of the colours of the original image. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 388–393, 2007
Provenance trails in the Wings/Pegasus system
Authors: Kim Jihie , Deelman Ewa , Gil Yolanda , Mehta Gaurang , Ratnakar Varun
Published: August 2007

Our research focuses on creating and executing large‐scale scientific workflows that often involve thousands of computations over distributed, shared resources. We describe an approach to workflow creation and refinement that uses semantic representations to (1) describe complex scientific applications in a data‐independent manner, (2) automatically generate workflows of computations for given data sets, and (3) map the workflows to available computing resources for efficient execution. Our approach is implemented in the Wings/Pegasus workflow system and has been demonstrated in a variety of scientific application domains. This paper illustrates the application‐level provenance information generated Wings during workflow creation and the refinement provenance by the Pegasus mapping
system for execution over grid computing environments. We show how this information is used in answering the queries of the First Provenance Challenge. Copyright © 2007 John Wiley & Sons, Ltd.
Addressing the provenance challenge using ZOOM
Authors: Cohen‐Boulakia Sarah , Biton Olivier , Cohen Shirley , Davidson Susan
Published: August 2007

ZOOM* UserViews presents a model of provenance for scientific workflows that is simple, generic, and yet sufficiently expressive to answer questions of data and step provenance that have been encountered in a large variety of scientific case studies. In addition, ZOOM builds on the concept of composite step‐classes—or sub‐workflows—which is present in many scientific workflow systems to develop a notion of user views. This paper discusses the design and implementation of ZOOM in the context of the queries posed by the provenance challenge, and shows how user views affect the level of granularity at which provenance information can be seen and reasoned about. Copyright © 2007 John Wiley & Sons, Ltd.
A Semantic Web approach to the provenance challenge
Authors: Golbeck Jennifer , Hendler James
Published: August 2007

Provenance is critically important for scientific workflow systems, as it allows users to verify data, repeat experiments, and discover dependencies. The Semantic Web is a natural fit for representing provenance, as it contains explicit support for representing and inferring connections between data and processes, as well as for adding annotations to data. In this article, we present a Semantic Web approach to the Provenance Challenge (Concurrency Computat.: Pract. Exper. 2007; DOI: 10.1002/cpe.1233). We use web services, ontologies, OWL reasoners, triple stores, and the SPARQL query language to implement the workflow, represent the data and the connections within it, and execute queries. We successfully implemented and answered all of the challenge queries. The flexibility of the Semantic Web also makes it quite easy to convert different provenance systems' data representation to a form we can work with. We illustrate this by integrating data from the PASS approach into our system, and successfully executing all of the challenge queries on it as well. Copyright © 2007 John Wiley & Sons, Ltd.
A frequency‐domain approach to the analysis of stability and bifurcations in nonlinear systems described by differential‐algebraic equations
Authors: Traversa F. L. , Bonani F. , Guerrieri S. Donati
Published: August 2007

A general numerical technique is proposed for the assessment of the stability of periodic solutions and the determination of bifurcations for limit cycles in autonomous nonlinear systems represented by ordinary differential equations in the differential‐algebraic form. The method is based on the harmonic balance (HB) technique, and exploits the same Jacobian matrix of the nonlinear system used in the Newton iterative numerical solution of the HB equations for the determination of the periodic steady state. To demonstrate the approach, it is applied to the determination of the bifurcation curves in the parameters' space of Chua's circuit with cubic nonlinearity, and to the study of the dynamics of the limit cycle of a Colpitts oscillator. Copyright © 2007 John Wiley & Sons, Ltd.
A time‐delay technique to improve GBW on negative feedback amplifiers
Authors: Alves Luis Nero , Aguiar Rui L.
Published: August 2007

This paper presents a new method to improve the GBW (gain‐bandwidth product) on negative feedback amplifiers. The proposed method is based on the introduction of time‐delay elements in the feedback loop, which can be exploited to retrieve significant bandwidth enhancements. This delayed feedback concept is analyzed, and considerations are presented for first‐order amplifiers, based on theoretical analysis. The concept is simulated and further demonstrated in a practical example using a series‐shunt feedback amplifier with a TL081 operational amplifier (OA) and a 36‐m‐long coaxial cable as a delay element. Measured experimental results show a maximum bandwidth improvement of almost 90%, from a theoretical maximum of 141%. Copyright © 2007 John Wiley & Sons, Ltd.
The CCII+ and the ICCII as basic building blocks in low‐pass filter realizations
Authors: Soliman Ahmed M.
Published: August 2007

Three new grounded capacitor current mode low‐pass filters using two inverting second‐generation current conveyor (ICCII) or one double output ICCII are given. The circuits employ the minimum number of passive circuit components, namely two resistors and two capacitors. The circuits are generated from three new voltage mode low‐pass filters realized with the ICCII. A new grounded capacitor CCII+ current mode low‐pass filter is generated from one of the new voltage mode low‐pass filters employing two ICCII−. A new grounded passive component low‐pass filter with independent control on Q and using three ICCII+ is also introduced. Spice simulation results based on using the 0.5 µm CMOS model are included to support the theoretical analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis, Characterisation and Ligand Properties of Novel Bi‐1,2,3‐triazole Ligands
Authors: Monkowius Uwe , Ritter Stefan , König Burkhard , Zabel Manfred , Yersin Hartmut
Published: August 2007

Three 1,1′‐disubstituted 4,4′‐bi‐1H‐1,2,3‐triazols [R‐bta; R = Bn (1), Ph (2), CH2COOH (3)] have been synthesised as bidentate, nitrogen‐based ligands by a CuI‐catalysed “click” reaction between 1,3‐butadiyne and organic azides. Their ligand properties were investigated by preparation of the complexes [RuII(R‐bta)3]Cl2 [R = Bn (4), Ph (5), CH2COOH (6)], [(Bn‐bta)CuI(DPEPhos)] (7) [DPEPhos = bis{2‐(diphenylphosphanyl)phenyl} ether] and [(Bn‐bta)ReI(CO)3Cl] (8) following standard reaction procedures. All compounds were analysed by elemental analysis, mass spectrometry and NMR, IR, UV/Vis and luminescence spectroscopy. In addition, the molecular structures of 1–4, 7, and 8 have been determined by X‐ray crystallography. In all complexes the Bn‐bta acts as a bidentate ligand with structural features comparable to the analogous 2,2′‐bipyridine complexes. In their electronic absorption spectra the RuII and ReI complexes exhibit a lowest energy band at around 300 nm, which is substantially higher in energy than in analogous complexes with bpy ligands. All R‐bta ligands yield complexes that are not luminescent in solution or in the solid state, which makes these ligands particularly suited for use as spectator ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Impedance of flexible suction caissons
Authors: Liingaard Morten , Andersen Lars , Ibsen Lars Bo
Published: August 2007

The dynamic response of offshore wind turbines is affected by the properties of the foundation and the subsoil. The aim of this paper is to evaluate the dynamic soil–structure interaction of suction caissons for offshore wind turbines. The investigations include evaluation of the vertical and coupled sliding–rocking vibrations, influence of the foundation geometry and examination on the properties of the surrounding soil. The soil is simplified as a homogenous linear viscoelastic material and the dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequency‐dependent coefficients corresponding to different degrees of freedom. The dynamic stiffness coefficients for the skirted foundation are evaluated using a three‐dimensional coupled boundary element/finite element model. Comparisons with known analytical and numerical solutions indicate that the static and dynamic behaviours of the foundation are predicted
accurately using the applied model. The analysis has been carried out for different combinations of the skirt length, Poisson's ratio of the subsoil and the ratio of the soil stiffness to the skirt stiffness. Copyright © 2007 John Wiley & Sons, Ltd.
Spherical sliding isolation bearings with adaptive behavior: Theory
Authors: Fenz Daniel M. , Constantinou Michael C.
Published: August 2007

The principles of operation and force–displacement relationships of three novel spherical sliding isolation bearings are developed in this paper. These bearings are completely passive devices, yet exhibit adaptive stiffness and adaptive damping. That is, the stiffness and damping change to predictable values at calculable and controllable displacement amplitudes. The primary benefit of adaptive behavior is that a given isolation system can be separately optimized for multiple performance objectives and/or multiple levels of ground shaking. With the devices presented here, this is accomplished using technology that is inherently no more complex than what is currently used by the civil engineering profession. The internal construction consists of various concave
surfaces and behavior is dictated by the different combinations of surfaces upon which sliding can occur over the course of motion. As the surfaces upon which sliding occurs change, the stiffness and effective friction change accordingly. A methodology is presented for determining which surfaces are active at any given time based on the effective radius of curvature, coefficient of friction and displacement capacity of each sliding surface. The force–displacement relationships and relevant parameters of interest are subsequently derived based on the first principles. Copyright © 2007 John Wiley & Sons, Ltd.
Simulating digital forecasting method of electromagnetic connectors' contacts durability
Authors: Wroblewski Zbigniew , Siwak Piotr
Published: August 2007

In this paper, a simulating method of forecasting durability of main contact assembly of electromagnetic connectors is presented on the basis of laboratory‐curtailed inspection. New multi‐parameter simulating model to forecasting the durability of contacts of electromagnetic connectors is presented. MATHCAD application was utilized during inspections. Copyright © 2007 John Wiley & Sons, Ltd.
Quantifying the effect of long‐term contract offered to pivotal suppliers on mitigating market power
Authors: Nam Young Woo , Park Jong‐Keun , Yoon Yong Tae , Song Kwang‐Jae
Published: August 2007

The market power by large suppliers remains to be problematic in establishing an efficient competitive market for electricity. The exercise of market power is often facilitated due to a few notable properties of electricity as a tradable commodity. The pivotal supplier whose capacity exceeds the market's surplus of capacity above inelastic demand can strategically withhold its capacity and cause an undesirable price spike. This paper presents a methodology for determining an adequate amount of mandatory long‐term contract to be used to mitigate the market power of the pivotal supplier and to eliminate the undesirable price spike. Using the Cournot model, the effect of mandatory long‐term contracts is measured with respect to market equilibrium for the pivotal monopoly in which there is only one pivotal supplier and for the pivotal duopoly in which two suppliers join together and become pivotal. Applying the methodology described in the paper, the market efficiency is assured as the pivotal supplier that no longer has the incentive to cause the undesirable price spike. Copyright © 2007 John Wiley & Sons, Ltd.
Fault‐tolerant operation of multicell‐inverters with a space phasor modulator
Authors: Correa Pablo , Pacas Mario , Rodríguez José
Published: August 2007

This paper presents a new space phasor modulation (SPM) scheme for the operation of the H‐bridge multicell inverter under fault conditions. The topology of this inverter consists of several single‐phase H‐bridge inverters which can be independently bypassed if a fault is detected. As this action may result in an asymmetrical inverter topology, a new method based on the SPM is proposed to avoid voltage unbalances. Simulations and experimental results obtained in a five‐level multicell inverter prototype validate the proposed fault‐tolerant method. Copyright © 2007 John Wiley & Sons, Ltd.
A randomised leader progression model for backflashover studies
Authors: Cotton Ian , Ab Kadir Mohd Zainal Abidin
Published: August 2007

Insulation coordination models are an essential part of power system studies and are used to determine the risk of damage to plant during abnormal conditions such as those experienced when lightning strikes the power system. One model used to predict the performance of an overhead line when hit by lightning examines the likelihood of a backflashover; the breakdown of an insulator coordination gap due to a rise in tower potential in comparison to a phase conductor. A backflashover model has many components that must be accurately modelled including the lightning strike, the tower, the shield wire/phase conductors, the insulator coordination gaps and the tower earthing system. Of all of these, the only two significant challenges are the accurate modelling of the insulator coordination gaps and the tower earthing system (the soil ionisation mechanism in particular). This paper focuses on the simulation of the insulator coordination gap for which available models range from a simple voltage controlled switch to the more complex leader progression model (LPM). The paper details the use of experimental data to produce a modified LPM in which certain model parameters are randomly varied. The development of this model using laboratory data is detailed, as is the effect that using this model has on the results of two insulation coordination studies that relate to backflashovers. Copyright © 2007 John Wiley & Sons, Ltd.
One size does not fit all: Managing IT employees' employment arrangements
Authors: Prasad Jayesh , Enns Harvey G. , Ferratt Thomas W.
Published: August 2007

As alternative employment arrangements proliferate within the information technology (IT) function, it becomes increasingly important to understand the impact of these arrangements on IT employees. A prevalent notion in the IT literature is that these employees are homogeneous in their work values and that they prefer similar employment arrangements. Given the inefficiency of designing individual employment programs, we advocate a middle ground between the two extremes of individualized employment arrangements and “one size fits all.” We conducted two studies. The first study developed an individual's work values profile as a psychological construct. It used a national sample of IT employees to validate a simple, heuristic procedure that was successful in classifying about 80% of the sample into three work values profiles.The second study demonstrated the use of work values profiles for understanding how employment arrangements differentially influence employee satisfaction. It applied the validated procedure to a single organization in order to demonstrate the general applicability of the procedure and to show that it provides researchers and HR professionals with better insights than the assumption that all IT employees are alike. © 2007 Wiley Periodicals, Inc.
Firm‐specific human capital and compensation organizational tenure profiles: An archival analysis of salary data for it
Authors: Slaughter Sandra A. , Ang Soon , Fong Boh Wai
Published: August 2007

We examine determinants of IT compensation using archival salary data from 2,251 IT professionals in Singapore. Consistent with human capital theory, we find that professionals in IT jobs requiring more firm‐specific human capital are paid more than those in jobs requiring less firm‐specific human capital. Moreover, compensation increases with organizational tenure at an increasing rate for professionals in higher firm‐specific human capital IT jobs, but at a decreasing rate for those in lower firm‐specific human capital IT jobs. Our results reveal firm‐specific human capital as a primary determinant of compensation and a moderator of IT compensation‐organizational tenure profiles. © 2007 Wiley Periodicals, Inc.
Of races to run and battles to be won: Technical skill updating, stress, and coping of IT professionals
Authors: Tsai Hsing‐Yi , Compeau Deborah , Haggerty Nicole
Published: August 2007

The expectation on today's information technology (IT) professionals to remain technically competent constitutes a significant source of stress. We examine how IT professionals experience and cope with the threat of technical obsolescence. Interestingly, not all IT professionals consider technology change a threat to their technical competence; some viewed updating as enjoyable and pursued learning for its own sake. However, most viewed the relentless demand to update their technical skills as stressful and used a variety of coping strategies to address this threat. Using this cognitive approach to technical obsolescence, we describe implications for managerial practice and delineate a direction for future research. © 2007 Wiley Periodicals, Inc.
Managing human resources in information technology: Best practices of high performing supervisors
Authors: Major Debra A. , Davis Donald D. , Germano Lisa M. , Fletcher Thomas D. , Sanchez‐Hucles Janis , Mann Joan
Published: August 2007

Focus groups with information technology (IT) professionals and interviews with high‐performing IT supervisors were content‐analyzed to discover best supervisory practices.The focus is on how these best practices address challenges commonly confronted in the IT work environment. Consistent with classic leadership theory, best practices fell into two major categories: task‐focused (boundary spanning, performance management, employee involvement, training and development) and person‐focused (relationship building, mentoring, stress management, work‐family balance) practices. Results demonstrate that while leadership practices effective with other types of professionals also are appropriate for IT professionals, these practices can be tailored to address unique IT demands. © 2007 Wiley Periodicals, Inc.
Managing work‐life conflict among information technology workers
Authors: Messersmith Jake
Published: August 2007

As organizations continue to emphasize information technology (IT) to help them compete, IT professionals are being asked to overcome a growing list of challenges. This unrelenting emphasis on IT initiatives often results in longer working hours and around‐the‐clock support, placing IT workers at risk of suffering from work‐life conflict. Human resource managers must skillfully manage this issue, with a particular focus on mitigating the consequences associated with work‐life conflict. This article provides an analysis of the antecedents to work‐life conflict in the IT profession, as well as solutions that organizations may implement to increase the work‐life balance of IT professionals. © 2007 Wiley Periodicals, Inc.
Personal sun exposure and risk of non Hodgkin lymphoma: A pooled analysis from the Interlymph Consortium
Authors: Kricker Anne , Armstrong Bruce K. , Hughes Ann Maree , Goumas Chris , Smedby Karin Ekström , Zheng Tongzhang , Spinelli John J. , De Sanjosé Sylvia , Hartge Patricia , Melbye Mads , Willett Eleanor V. , Becker Nikolaus , Chiu Brian C.H. , Cerhan James R. , Maynadié Marc , Staines Anthony , Cocco Pierluigi , Boffeta Paolo ,   for the Interlymph Consortium
Published: August 2007

In 2004–2007 4 independent case‐control studies reported evidence that sun exposure might protect against NHL; a fifth, in women only, found increased risks of NHL associated with a range of sun exposure measurements. These 5 studies are the first to examine the association between personal sun exposure and NHL. We report here on the relationship between sun exposure and NHL in a pooled analysis of 10 studies participating in the International Lymphoma Epidemiology Consortium (InterLymph), including the 5 published studies. Ten case‐control studies covering 8,243 cases and 9,697 controls in the USA, Europe and Australia contributed original data for participants of European origin to the pooled analysis. Four kinds of measures of self‐reported personal sun exposure were assessed at interview. A two‐stage estimation method was used in which study‐specific odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for potential confounders including smoking and alcohol use, were obtained from unconditional logistic regression models and combined in random‐effects models to obtain the pooled estimates. Risk of NHL fell significantly with the composite measure of increasing recreational sun exposure, pooled OR = 0.76 (95% CI 0.63–0.91) for the highest exposure category (p for trend 0.01). A downtrend in risk with increasing total sun exposure was not statistically significant. The protective effect of recreational sun exposure was statistically significant at 18–40 years of age and in the 10 years before diagnosis, and for B cell, but not T cell, lymphomas. Increased recreational sun exposure may protect against NHL. © 2007 Wiley‐Liss, Inc.
Viral load of episomal and integrated forms of human papillomavirus type 33 in high‐grade squamous intraepithelial lesions of the uterine cervix
Authors: Khouadri Soraya , Villa Luisa L. , Gagnon Simon , Koushik Anita , Richardson Harriet , Matlashewski Greg , Roger Michel , Ferenczy Alex S. , Franco Eduardo L. , Coutlée François
Published: August 2007

The association between total and integrated HPV‐33 DNA loads and high‐grade squamous intraepithelial lesions (HSIL) of the uterine cervix was investigated. Of 5,347 women recruited in 4 studies, 89 (64 without SIL, 7 low‐grade SIL (LSIL), 15 HSIL, 3 unknown grade) were infected by HPV‐33. HPV‐33 E6, HPV‐33 E2 and β‐globin DNA were measured with real‐time PCR that allowed to assess total (E6), episomal (E2) and integrated (E6–E2) HPV‐33 viral loads. HPV‐33 E6/E2 ratios ≥≥2.0 suggesting the presence of integrated HPV‐33 were obtained for 28.6% (n = 18) of women without SIL and 21.4% (n = 3) of women with HSIL (p = 0.74). Although median viral loads were similar, there was a trend toward having a greater proportion of women with HSIL in the fourth quartile (≥≥106.69 copies/μg DNA) of total HPV‐33 viral loads compared to normal women. Controlling for age, site, ethnicity and LCR polymorphism by logistic regression, HPV‐33 total loads in the fourth quartile {odds ratio (OR) 4.5 [95% confidence interval (CI) 1.2–17.3]; p = 0.03} and episomal loads in the fourth quartile (≥≥106.64 copies/μg DNA) [OR 3.9 (95% CI 1.1–13.2); p = 0.05] but not integrated HPV‐33 load in the fourth quartile [OR 1.0 (95% CI 0.3–3.3); p = 0.50] were associated with HSIL. Controlling for age, study site and SIL grade, HPV‐33 episomal load [OR 0.2 (95% CI 0.1–0.5), p = 0.0004] was associated with the presence of HPV‐33 integration. High episomal loads in HSIL and the presence of integration in women without SIL are likely to weaken the usefulness of HPV load of integrated forms in clinical practice. © 2007 Wiley‐Liss, Inc.
Influence of education level on breast cancer risk and survival in Sweden between 1990 and 2004
Authors: Hussain Shehnaz K. , Altieri Andrea , Sundquist Jan , Hemminki Kari
Published: August 2007

On account of limited recent data regarding the role of education in breast cancer risk and prognosis, we conducted this study to assess the association between education level and in situ and invasive breast cancer risk and invasive breast cancer survival, using the 2006 update of the Swedish Family‐Cancer Database. Cox's proportional hazards models were used to calculate the hazard ratio (HR) and 95% confidence interval (CI) adjusted for age, time‐period, parity, age at first birth, county of residence, and family history of breast cancer. Compared to women completing less than 9 years of education, university graduates were more likely to be diagnosed with in situ (HR = 1.44, 95% CI: 1.28–1.63) and invasive (HR = 1.28, 95% CI: 1.20–1.36) breast cancer, and the lack of homogeneity between these two HRs was statistically significant, p = 0.007. Further stratification revealed that the lack of homogeneity was greatest for breast cancers diagnosed before age 50. Compared to women completing less than 9 years of education, university graduates were associated with the highest survival following a breast cancer diagnosis (lowest fatality hazard ratio), HR = 0.68, 95% CI: 0.61–0.75. Further research is warranted to elucidate possible behaviors or characteristics associated with education that could explain the differences in incidence and survival, such as compliance with cancer screening. © 2007 Wiley‐Liss, Inc.
ANXA7 expression represents hormone‐relevant tumor suppression in different cancers
Authors: Srivastava Meera , Torosyan Yelizaveta , Raffeld Mark , Eidelman Ofer , Pollard Harvey B. , Bubendorf Lukas
Published: August 2007

Tumor suppressor function of ubiquitously expressed Annexin‐A7, ANXA7 (10q21) that is involved in exocytosis and membrane fusion was based on cancer prone phenotype in Anxa7(+/−) mice as well as ANXA7 role in human prostate and breast cancers. To clarify ANXA7 biomarker and tumor suppressor function, we analyzed its expression pattern in comparison to the prostate‐specific biomarker NKX3.1. Immunohistochemistry‐based ANXA7 and NKX3.1 protein expression was analyzed on human tissue microarrays of 4,061 specimens from a wide spectrum of the histopathologically well‐characterized tumors in different stages compared to corresponding normal tissues. Decreased ANXA7 expression was mostly associated with high invasive potential in multiple tumors. Although some metastases retained relatively high ANXA7 rates compared to primary cancer tissues, the lymph node metastases from different sites (including prostate and breast) had decreased ANXA7 expression in comparison to the intact lymphatic tissues. Major ANXA7 downregulation pattern was deviated in tumors of glandular (especially neuroendocrine) origin. ANXA7 and NKX3.1 proteins were synexpressed in the male urogenital system and adrenal gland. Gene expression profiling in prostate and breast cancers (SMD) revealed distinct hormone‐related profiles for NKX3.1 and ANXA7, where ANXA7 expression correlated with steroid sulfatase which has a pivotal role in steroidogenesis. Abundant protein presence in adrenal gland and its loss in hormone‐refractory prostate cancer indicated that ANXA7 can be relevant to steroidogenesis and androgen sensitivity in particular. With tumor suppressor pattern validated in different tumors, ANXA7 can be an attractive diagnostic and therapeutic target associated with the hormone and/or neurotransmitter‐mediated modulation of tumorigenesis. © 2007 Wiley‐Liss, Inc.
Fibrillin‐rich microfibrils: Structural determinants of morphogenetic and homeostatic events
Authors: Ramirez Francesco , Dietz Harry C.
Published: August 2007

Fibrillin‐rich microfibrils are specialized extracellular matrix assemblies that endow connective tissues with mechanical stability and elastic properties, and that participate in the regulation of organ formation, growth and homeostasis. Their physiological importance is underscored by the complex spectrum of clinical manifestations associated with mutations of fibrillin‐1 and fibrillin‐2 in Marfan syndrome (MFS) and congenital contractural arachnodactyly, respectively. Early evidence suggested that fibrillin‐1 mutations in MFS lead to loss of tissue integrity by perturbing microfibril assembly and function. Recent studies in genetically targeted mice have however revealed that fibrillin‐1 and fibrillin‐2 mutations perturb signaling events mediated by TGF‐β superfamily members. As such, these studies have established a new biological paradigm whereby fibrillin‐rich microfibrils are structural networks that specify the local concentration and timely release of signaling molecules during morphogenesis and tissue remodeling. This review summarizes our current understanding of the role of fibrillin‐rich microfibrils in development and disease, as well as exciting new applications in the clinical management of MFS and related connective tissue disorders. J. Cell. Physiol. 213: 326–330, 2007. © 2007 Wiley‐Liss, Inc.
DNA methylation: The nuts and bolts of repression
Authors: Miranda Tina Branscombe , Jones Peter A.
Published: August 2007

DNA methylation is an epigenetic modification which plays an important role in chromatin organization and gene expression. DNA methylation can silence genes and repetitive elements through a process which leads to the alteration of chromatin structure. The mechanisms which target DNA methylation to specific sites in the genome are not fully understood. In this review, we will discuss the mechanisms which lead to the long‐term silencing of genes and will survey the progression that has been made in determining the targeted mechanisms for de novo DNA methylation. J. Cell. Physiol. 213: 384–390, 2007. © 2007 Wiley‐Liss, Inc.