bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Information on the Transition Moments in Poly(ethylene‐2,6‐naphthalene) by Polarization FT‐IR Spectroscopy
Authors: Scott Alex , Hakme Chady , Stevenson Isabelle , Voice Alison
Published: December 2005

Oriented poly(ethylene‐2,6‐naphthalate) (PEN) has been characterised by polarised FT‐IR spectroscopy to determine the structural angles of the transition moments to the molecular chain axis. The bands at 1130 cm−1, 1142 cm−1 and 1602 cm−1, which have been previously assigned as having their transition dipole moments parallel to the chain axis, are confirmed as parallel bands. Bands at 767 cm−1 and 831 cm−1 are confirmed as perpendicular bands. However the band at 1708 cm−1 which has previously been assigned as a perpendicular band, is shown here to have its transition moment at 72° to the molecular axis.
Spectroscopic Investigations of Polymer Nanocomposites
Authors: Bokobza Liliane , Diop Amadou Lamine , Fournier Vincent , Minne Jean‐Baptiste , Bruneel Jean‐Luc
Published: December 2005

The addition of an inorganic component to polymers leads to improvements in various physical and mechanical properties. Various examples on filled elastomeric networks will show that a mechanical characterization can be nicely combined with a spectroscopic investigation for a better understanding of the properties of the composite materials.
Solid‐State NMR Characterization of Biodegradable Shape‐Memory Polymer Networks
Authors: Bertmer Marko , Buda Alina , Blomenkamp‐Höfges Iris , Kelch Steffen , Lendlein Andreas
Published: December 2005

Copolymer networks synthesized from dilactide and diglycolide were characterized by solid‐state 13C CPMAS NMR in terms of composition, cross‐link density, and rate of cross‐linking by UV irradiation. The latter is directly evident by a signal at 44 ppm in the 13C NMR spectrum. Comparison of solid‐state NMR data with the determination of the gel content revealed that this NMR method is sensitive to the chemical cross‐link density whereas the gel content is also influenced by physical constraints such as entanglement. Furthermore, these copolymer networks show a shape‐memory effect, i.e. a temporary macroscopic shape can be programmed by heating the network above its glass transition temperature together with fixation during cooling. Reheating without fixation recovers the permanent shape. The recovery of the permanent shape could be followed by 1H DQ NMR buildup curves for a sample that was stretched by 80%.
Investigation of the Orientation in Composite Fibers of Polycarbonate with Multiwalled Carbon Nanotubes by Raman Microscopy
Authors: Fischer Dieter , Pötschke Petra , Brünig Harald , Janke Andreas
Published: December 2005

The superior association of the inherent good mechanical and electrical properties makes carbon nanotubes (CNT) exceptionally interesting for the production of composite fibers of thermoplastic polymers with CNT. Alignment of the CNT in the polymer fiber is important for improved mechanical properties. Especially the production of fibers makes it necessary to get a controlled orientation and/or alignment of the CNT. We applied transmission electron microscopy (TEM) and polarized Raman microscopy to quantify multiwalled carbon nanotubes (MWNT) orientation, alignment and crystallinity in polycarbonate (PC). The evaluation of the Raman measurements provided an improved alignment orientation of the MWNT in the fibers with increasing take‐up velocity during melt spinning and that the crystal structure of the MWNT is not changed through melt spinning.
Investigations on the Photoinitiator‐free Photopolymerization of Acrylates by Vibrational Spectroscopic Methods
Authors: Scherzer Tom , Knolle Wolfgang , Naumov Sergej , Prager Lutz
Published: December 2005

Photopolymerization of acrylates without photoinitiators was carried out by irradiation with short‐wavelength UV light from excimer lamps with an emission at 222 or 172 nm. Basic investigations on the reactivity of various acrylates and on the conditions under which they can be UV‐cured were performed by real‐time FTIR‐ATR spectroscopy. Depending on the molar extinction coefficients of a specific acrylate at the wavelength of irradiation, the absorption of the light within the coating leads to a pronounced intensity gradient which significantly influences polymerization rate and conversion. Accordingly, it limits the maximum thickness of the layer that can be cured (ranging from some hundreds of nanometres up to some micrometers). In addition to the basic studies, thin acrylate coatings were also cured on pilot scale. The actual conversion in the layer after UV irradiation was directly monitored by in‐line NIR reflection spectroscopy, and the resulting coatings were characterized by FTIR spectroscopy and hardness measurements.
Expression of peptidylarginine deiminase type 4 (PAD4) in various tumors
Authors: Chang Xiaotian , Han Jinxiang
Published: December 2005

Peptidylarginine deiminase type 4 (PAD4/PADI4) posttranslationally converts peptidylarginine to citrulline, in a process known as citrullination. Evidence suggests that PAD4 plays an essential role in pathogenesis of rheumatoid arthritis (RA). RA synovium has many features in common with tumor tissues, including abnormal cell proliferation, extensive fibrin deposition, high coagulation activity, and extreme angiogenesis. The purpose of the present study was to investigate expression of PAD4 in various tumor tissues. Immunohistochemistry indicated that PAD4 had significant expression in many tumor tissues, especially various adenocarcinoma. Western blotting with anti PAD4 antibody and immunostaining with anti citrulline antibody confirmed the expression of the enzyme in these tumors. Furthermore, our immunohistochemistry also detected co‐location of PAD4 with cytokeratin (CK), a well‐known tumor marker for oncological study in many tumors. Western blot analysis also detected citrulline signals in CK extracted from the tumors. In addition, CK 8, 18, and 19 following in vitro citrullination resisted to the digestion of caspase. The results further confirm the expression of PAD4 in the tumors and support that PAD4 may contribute to the disrupted apoptosis of tumors by caspase‐mediated cleavage of CK. Double immunofluorescent labeling detected co‐location of PAD4 with CD34, a cell marker of heamatopoietic progenitor cells (HPC) in bone marrow and other normal tissues, as well as in some fibroblast‐like cells at stroma region of tumors, but not in the tumor cells. The findings imply that PAD4 is initially expressed in CD34+ cells of bone marrow and then distributed in derives of the multi‐potent progenitor cells in diverse tissues. The development of tumor cells expressing PAD4 is possibly associated with abnormal proliferation of CD34+ stem cells. © 2005 Wiley‐Liss, Inc.
Differentiated rabbit prostatic stromal cells in primary culture display functional α1A‐adrenoceptors
Authors: Boulbès Delphine , Choquet Armelle , Barrère‐Lemaire Stéphanie , Costa Pierre , Soustelle Laurent , Nargeot Joël , Bali Jean‐Pierre , Hollande Frédéric , Magous Richard
Published: December 2005

Aims

BPH is characterized by uncontrolled proliferation and increased contractility of prostatic smooth muscle cells. The activation of α1‐adrenoceptors (α1‐AR) seems involved in the latter event, but the lack of in vitro models expressing these receptors has hampered a more specific characterization of their role. In order to do so, we attempted to develop a new model of rabbit cultured prostatic stromal cells (PSC) in a non‐proliferative and differentiated state.

Methods

The expression of cytoskeletal and stromal markers was confirmed by immunohistochemistry on primary cultured PSC. α1‐AR subtype expression was assessed by RT‐PCR, while receptor coupling to the ERK1/ERK2 and calcium pathways was studied by Western Blot and Fura‐2 calcium imaging, respectively.

Results

Cells grown under non‐proliferative conditions displayed a differentiated phenotype, with expression of contractile cytoskeletal and stromal proteins. Furthermore, the α1A‐AR was shown to activate ERK1/ERK2 as well as calcium signaling.

Conclusion

These results emphasize the interest of this model for the characterization of PSC adrenergic regulation, in particular through the little‐known α1A‐AR. Neurourol. Urodynam. © 2005 Wiley‐Liss, Inc.
A general strategic capacity planning model under demand uncertainty
Authors: Huh Woonghee Tim , Roundy Robin O. , Çakanyildirim Metin
Published: December 2005

Capacity planning decisions affect a significant portion of future revenue. In equipment intensive industries, these decisions usually need to be made in the presence of both highly volatile demand and long capacity installation lead times. For a multiple product case, we present a continuous‐time capacity planning model that addresses problems of realistic size and complexity found in current practice. Each product requires specific operations that can be performed by one or more tool groups. We consider a number of capacity allocation policies. We allow tool retirements in addition to purchases because the stochastic demand forecast for each product can be decreasing. We present a cluster‐based heuristic algorithm that can incorporate both variance reduction techniques from the simulation literature and the principles of a generalized maximum flow algorithm from the network optimization literature. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Black hole search in common interconnection networks
Authors: Dobrev S. , Flocchini P. , Královič R. , Ružička P. , Prencipe G. , Santoro N.
Published: December 2005

Mobile agents operating in networked environments face threats from other agents as well as from the hosts (i.e., network sites) they visit. A black hole is a harmful host that destroys incoming agents without leaving any trace. To determine the location of such a harmful host is a dangerous but crucial task, called black hole search. The most important parameter for a solution strategy is the number of agents it requires (the size); the other parameter of interest is the total number of moves performed by the agents (the cost). It is known that at least two agents are needed; furthermore, with full topological knowledge, Ω(n log n) moves are required in arbitrary networks. The natural question is whether, in specific networks, it is possible to obtain (topology‐dependent but) more cost efficient solutions. It is known that this is not the case for rings. In this article, we show that this negative result does not generalizes. In fact, we present a general strategy that allows two agents to locate the black hole with O(n) moves in common interconnection networks: hypercubes, cube‐connected cycles, star graphs, wrapped butterflies, chordal rings, as well as in multidimensional meshes and tori of restricted diameter. These results hold even if the networks are anonymous. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 47(2), 61–71 2006
A two‐dimensional stochastic algorithm for the solution of the non‐linear Poisson–Boltzmann equation: validation with finite‐difference benchmarks
Authors: Chatterjee Kausik , Poggie Jonathan
Published: December 2005

This paper presents a two‐dimensional floating random walk (FRW) algorithm for the solution of the non‐linear Poisson–Boltzmann (NPB) equation. In the past, the FRW method has not been applied to the solution of the NPB equation which can be attributed to the absence of analytical expressions for volumetric Green's functions. Previous studies using the FRW method have examined only the linearized Poisson–Boltzmann equation. No such linearization is needed for the present approach. Approximate volumetric Green's functions have been derived with the help of perturbation theory, and these expressions have been incorporated within the FRW framework. A unique advantage of this algorithm is that it requires no discretization of either the volume or the surface of the problem domains. Furthermore, each random walk is independent, so that the computational procedure is highly parallelizable. In our previous work, we have presented preliminary calculations for one‐dimensional and quasi‐one‐dimensional benchmark problems. In this paper, we present the detailed formulation of a two‐dimensional algorithm, along with extensive finite‐difference validation on fully two‐dimensional benchmark problems. The solution of the NPB equation has many interesting applications, including the modelling of plasma discharges, semiconductor device modelling and the modelling of biomolecular structures and dynamics. Copyright © 2005 John Wiley & Sons, Ltd.
Lower bound limit analysis of cohesive‐frictional materials using second‐order cone programming
Authors: Makrodimopoulos A. , Martin C. M.
Published: December 2005

The formulation of limit analysis by means of the finite element method leads to an optimization problem with a large number of variables and constraints. Here we present a method for obtaining strict lower bound solutions using second‐order cone programming (SOCP), for which efficient primal‐dual interior‐point algorithms have recently been developed. Following a review of previous work, we provide a brief introduction to SOCP and describe how lower bound limit analysis can be formulated in this way. Some methods for exploiting the data structure of the problem are also described, including an efficient strategy for detecting and removing linearly dependent constraints at the assembly stage. The benefits of employing SOCP are then illustrated with numerical examples. Through the use of an effective algorithm/software, very large optimization problems with up to 700 000 variables are solved in minutes on a desktop machine. The numerical examples concern plane strain conditions and the Mohr–Coulomb criterion, however we show that SOCP can also be applied to any other problem of lower bound limit analysis involving a yield function with a conic quadratic form (notable examples being the Drucker–Prager criterion in 2D or 3D, and Nielsen's criterion for plates). Copyright © 2005 John Wiley & Sons, Ltd.
A combined approach for goal‐oriented error estimation and adaptivity using operator‐customized finite element wavelets
Authors: Sudarshan R. , Amaratunga K. , Grätsch T.
Published: December 2005

We describe how wavelets constructed out of finite element interpolation functions provide a simple and convenient mechanism for both goal‐oriented error estimation and adaptivity in finite element analysis. This is done by posing an adaptive refinement problem as one of compactly representing a signal (the solution to the governing partial differential equation) in a multiresolution basis. To compress the solution in an efficient manner, we first approximately compute the details to be added to the solution on a coarse mesh in order to obtain the solution on a finer mesh (the estimation step) and then compute exactly the coefficients corresponding to only those basis functions contributing significantly to a functional of interest (the adaptation step). In this sense, therefore, the proposed approach is unified, since unlike many contemporary error estimation and adaptive refinement methods, the basis functions used for error estimation are the same as those used for adaptive refinement. We illustrate the application of the proposed technique for goal‐oriented error estimation and adaptivity for second and fourth‐order linear, elliptic PDEs and demonstrate its advantages over existing methods. Copyright © 2005 John Wiley & Sons, Ltd.
Analysis of adhesively bonded joints: a finite element method and a material model with damage
Authors: Schmidt Peter , Edlund Ulf
Published: December 2005

This paper deals with the derivation of a finite element (FE) method for an adhesively bonded joint which consists of two relatively thin bodies, joined by an even thinner adhesive layer. It is based on a model of the compound joint where the three bodies involved are described as material surfaces. A geometrically two‐dimensional model, where the middle surfaces of the upper and lower body are represented as geometrically coinciding surfaces, is obtained.

An elastic–plastic material model with damage is used for the adhesive layer, and an important implication is that the (quasi‐static) propagation of the local failure zone in the adhesive layer in a structure can be simulated. Consequently, the failure load is obtained as a computational result and no failure criterion is needed.

The problem is discretized, and a surface model, where only a single surface needs to be FE‐meshed, is obtained. A single‐lap joint is analysed and good agreement is obtained when compared to an analysis using a fine mesh with brick element. Furthermore, the failure load is computed and compared with experiments.

The derived FE method opens up the possibility to efficiently model and analyse the mechanical behaviour of large bonded structures. Copyright © 2005 John Wiley & Sons, Ltd.
Efficient return algorithms for associated plasticity with multiple yield planes
Authors: Clausen J. , Damkilde L. , Andersen L.
Published: December 2005

A new return method for implicit integration of linear isotropic yield criteria is presented. The basic idea is to perform all the manipulations in the principal stress space and thereby achieve very simple formulae for calculating the plastic corrector stresses, based on the constant gradient of such criteria. The return formulae are in closed form and no iteration is required. The method accounts for three types of stress return: return to a single yield plane, to a discontinuity line at the intersection of two yield planes and to a discontinuity point at the intersection between three or more yield planes. The infinitesimal and the consistent elastoplastic constitutive matrix are calculated for each type of stress return, as are the conditions to ascertain which type of return is required. The method is exemplified with the Mohr–Coulomb yield criterion. Copyright © 2005 John Wiley & Sons, Ltd.
Effect of intervention through a pharmaceutical care program on patient adherence with prescribed once‐daily atorvastatin
Authors: Vrijens Bernard , Belmans Ann , Matthys Katelijne , Klerk Erik de , Lesaffre Emmanuel
Published: December 2005

Aims

Correct execution of prescribed dosing regimen(s) is essential for patients to benefit from lipid lowering treatments. The objective of this study was to estimate the effect of a pharmaceutical care program on the adherence of once‐daily atorvastatin treatment in patients with elevated cholesterol levels.

Methods

In both linguistic regions of Belgium, two districts were randomized between usual care and a supportive intervention program. Eligible patients included hyperlipemic subjects taking atorvastatin for at least 3 months. ‘Adherence’ was defined as the proportion of days during which the electronic device record showed that the patient had taken the daily dose. ‘Persistence’ quantifies how long the treatment is executed.

Results

A total of 392 patients from 35 pharmacies were included in the intent‐to‐treat (ITT) analysis of the data (194 patients received intervention and 198 in the control group). The intervention resulted in a 6.5% increase in post‐baseline adherence (p < 0.001) mainly driven by a 13% increase in persistence at 1 year (p = 0.002).

Conclusion

A supportive pharmaceutical care program consisting of review by patient and pharmacist of each patient's electronically compiled dosing history, plus educational reminders, improves patient adherence to the once‐daily atorvastatin dosing regimen, mainly by extending persistence. Copyright © 2005 John Wiley & Sons, Ltd.
What shields some can shackle others: the approach‐related consequences of threat categorisations vary by agreeableness
Authors: Robinson Michael D. , Meier Brian P. , Solberg Emily C.
Published: December 2005

It is common to think that threat categorisation tendencies (TCTs) should undermine a person's subjective well‐being. However, recent research has suggested that the hedonic impact of such tendencies varies considerably according to a person's traits. The present research seeks to extend such a perspective by considering potential interactions between TCTs and the trait of agreeableness. TCTs were measured through the use of choice reaction time tasks contrasting the threat and non‐threat categories. As expected, TCTs were not correlated with the trait of agreeableness, but interacted with this trait in predicting the dependent measures. Within three studies involving 184 undergraduates, TCTs were associated with the higher levels of approach‐related behaviour and positive emotion among disagreeable individuals, but lower levels of these same variables among agreeable individuals. The authors suggest that threat categorisation tendencies psychologically protect or burden the individual, depending on the levels of agreeableness. Copyright © 2005 John Wiley & Sons, Ltd.
Stereospecific polymerization of styrene with novel half‐sandwich titanium complexes—RCpTi(o‐MeOPhCPh2O)Cl2/methylaluminoxane
Authors: Chen Qihui , Huang Jiling
Published: December 2005

Two new half‐sandwich titanocene catalysts for the stereospecific polymerization of styrene, RCpTi(o‐MeOPhCPh2O)Cl2 (R = H (1); R = Me (2)), were prepared by reaction of the corresponding RCpTiCl3 complexes with o‐methoxyphenyldiphenylmethanol (o‐MeOPhCPh2OH) in the presence of triethylamine. Upon activation with excess methylaluminoxane (MAO), they showed high activities and high thermal stabilities for the stereospecific polymerization of styrene. The influences of polymerization temperature, Al/Ti molar ratio, solvent (aliphatic or aromatic) and time on the activity and syndiotacticity of the styrene polymerization were investigated. Copyright © 2006 Society of Chemical Industry
Synthesis of well‐defined polystyrene‐graft‐poly(methyl methacrylate)
Authors: Li Cuiping , Shi Yan , Fu Zhifeng
Published: December 2005

A well‐defined graft copolymer, polystyrene‐graft‐poly(methyl methacrylate), was synthesized in two steps. In the first step, styrene and p‐vinyl benzene sulfonyl chloride were copolymerized via reversible addition–fragmentation chain transfer polymerization (RAFT) in benzene at 60 °C with 2‐(ethoxycarbonyl)prop‐2‐yl dithiobenzoate as a chain transfer agent and 2,2′‐azobis(isobutyronitrile) as an initiator. In the second step, poly[styrene‐co‐p‐(vinyl benzene sulfonyl chloride)] was used as a macroinitiator for the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in toluene at 80 °C with CuCl as a catalyst and 2,2′‐bipyridine as a ligand. With sulfonyl chloride groups as the initiating sites for the ATRP of MMA, high initiation efficiencies were obtained. Copyright © 2006 Society of Chemical Industry
Theoretical study of carbon atom scrambling in benzenium ions with ethyl or isopropyl groups
Authors: Arstad Bjørnar , Kolboe Stein , Swang Ole
Published: December 2005

Carbon atom scrambling is observed in benzenium ions in the mass spectrometer and in isotopic labeling experiments in the methanol‐to‐hydrocarbons reaction over acidic zeolites. We have shown plausible scrambling mechanisms in ethyl‐ and isopropylbenzenium ions and various intramolecular interconversion reactions that may take place in alkylbenzenium ions. Quantum chemical Density Functional Theory (DFT) modeling at the B3LYP/cc‐pVTZ//B3LYP/6‐311G(d,p) level of theory has been carried out to investigate carbon atom scrambling reactions in ethyl‐ and isopropyl(methyl)benzenium ions. A total of 85 stationary points have been calculated (48 minima and 37 transition states). The carbon atom scrambling reactions start with an initial ring expansion of the benzenium ions to a seven‐membered ring. The seven‐membered ring may rearrange and at a later stage re‐contract to the original benzenium species, albeit with some atoms interchanged, i.e. there has been atom scrambling. Copyright © 2005 John Wiley & Sons, Ltd.
Gel effect in the bulk reversible addition–fragmentation chain transfer polymerization of methyl methacrylate: Modeling and experiments
Authors: Peklak A. David , Butté Alessandro , Storti Giuseppe , Morbidelli Massimo
Published: December 2005

A model for the evaluation of the kinetics and the chain length distribution in living/controlled radical polymerization mediated by reversible addition–fragmentation chain transfer (RAFT) in bulk is presented. Using the free volume theory, the model accounts for the diffusion limitations over both termination and RAFT exchange reactions. Model predictions are compared to experimental results of methyl methacrylate polymerization with cumyl dithiobenzoate as a RAFT agent. It is shown that the polymerization retardation observed in living systems at large conversions is well predicted. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1071–1085, 2006
Epoxy resin containing polyphenylsilsesquioxane: Preparation, morphology, and thermomechanical properties
Authors: Ni Yong , Zheng Sixun
Published: December 2005

Polyphenylsilsesquioxane (PPSQ) was incorporated into an epoxy resin to prepare organic–inorganic composites, and two strategies were adopted to afford composites with different morphologies. Phase separation induced by polymerization occurred in the physical blending system. However, nanostructured composites were obtained when a catalytic amount of aluminum triacetylacetonate was added to mediate the reaction between PPSQ and diglycidyl ether of bisphenol A (DGEBA). The intercomponent reaction significantly suppressed the phase separation on the micrometer scale. Organic–inorganic composites with different morphologies displayed quite different thermomechanical properties. Both differential scanning calorimetry and dynamic mechanical analysis showed that the nanostructured composites possessed higher glass‐transition temperatures than the phase‐separated composites with the same loading of PPSQ, although the intercomponent reaction between PPSQ and DGEBA reduced the crosslinking density of the epoxy matrix. This result was ascribed to the presence of nanosized PPSQ domains in the nanostructured composites, which acted as physical crosslinking sites and thus reinforced the epoxy networks. The nanoreinforcement of the PPSQ domains afforded the enhanced dynamic storage modulus for the nanostructured composites in comparison with the phase‐separated composites with a PPSQ concentration less than 15 wt %. In terms of thermogravimetric analysis, the organic–inorganic composites displayed improved thermal stability and flame retardancy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1093–1105, 2006
Further study of the viscoelastic phase separation of cyanate ester modified with poly(ether imide)
Authors: Zhan Guozhu , Yu Yingfeng , Tang Xiaolin , Tao Qingsheng , Li Shanjun
Published: December 2005

In this study, the viscoelastic phase separation process was studied further by time‐resolved light scattering, differential scanning calorimetry, and scanning electron microscopy in the system of poly(ether imide)‐modified bisphenol‐A dicyanate. It was observed that the evolution time of phase structure and relaxation time of diffusion flow of the bisphenol‐A dicyanate were similar with the phase diagram of curing conversion versus content of PEI. The results suggested that the viscoelastic phase separation was affected by the curing conversion of the system at the onset point of phase separation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 517–523, 2006
Warming of permafrost in the Arctic National Wildlife Refuge, Alaska
Authors: Osterkamp T. E. , Jorgenson J. C.
Published: December 2005

Permafrost borehole temperatures were measured in 1985, 1998, and 2004 on Barter Island near the village of Kaktovik and in the Arctic National Wildlife Refuge (Arctic NWR) north of the Brooks Range. These measurements indicate that the century‐long warming documented for the central and western Arctic has also occurred in the region near Barter Island and in the northern Arctic NWR. At Kaktovik, the warming occurred during the second quarter of the 20th century or earlier and its magnitude exceeded 0.8°C. A more recent warming (since the mid to late 1980s) similar to that in the central and western Arctic is also occurring on Barter Island and in the northern Arctic NWR. Near Kaktovik, the permafrost warmed about 2 to 3°C from 1985 to 2004. In the northern Arctic NWR, on a line extending southward from Tapkaurak Point, it warmed about 1.5 to 2°C from 1985 to 1998. If air temperatures warm 5°C over the next century, as predicted, some of the permafrost in the northern Arctic NWR would be expected to thaw. Copyright © 2005 John Wiley & Sons, Ltd.
Expression of prothymosin alpha is correlated with development and progression in human prostate cancers
Authors: Suzuki Shugo , Takahashi Satoru , Takahashi Seishiro , Takeshita Kentaro , Hikosaka Atsuya , Wakita Toshiaki , Nishiyama Naoki , Fujita Tamio , Okamura Takehiko , Shirai Tomoyuki
Published: December 2005

BACKGROUND

Our previous study clearly demonstrated that decreased expression of prothymosin alpha (PTMA) was associated with inhibition of rat prostate carcinogenesis by isoflavones. The purpose of the present investigation was to provide a better understanding of the role of PTMA in human prostate cancers.

METHODS AND RESULTS

PTMA expression in 68 prostate cancer cases and in prostate cancer cell lines was examined by immunohistochemistry and immunoblotting, and its levels were increased with progression from normal epithelium, through prostatic intraepithelial neoplasia (PIN) to carcinomas, correlating with the Gleason's pattern. All cell lines studied (LNCaP, 22Rv1, DU145, and PC3) showed high PTMA expression compared with prostate epithelial cells (PrEC). Knockdown of PTMA expression in PC3 cells by RNAi resulted in the inhibition of both cell growth and invasion in vitro.

CONCLUSIONS

The present study clearly demonstrated that PTMA expression is intimately involved in the differentiation and progression of human prostate cancers, and could be a target for therapy and diagnostic purposes. © 2005 Wiley‐Liss, Inc.
Quantum chemical model study of the acyl migration in 2′(3′)‐formylnucleosides
Authors: Rangelov Miroslav A. , Vayssilov Georgi N. , Petkov Dimiter D.
Published: December 2005

This work reports a density functional study of the mechanism of acyl migration between vicinal OH groups in monoformylated cis‐tetrahydrofuran‐3,4‐diol as a model system for the acyl migration in amino‐acylated tRNA. In addition, migration toward the ionized hydroxyl group was modeled, which simulates the process in the presence of basic reagents. The polarized continuum model (PCM) for four solvents evaluated the solvent effect on the reaction energetics. The computational results suggest that the stepwise mechanism via an orthoester intermediate is preferred by 45–48 kJ/mol over the concerted mechanism where migration of the formyl group, and the proton from the vicinal OH group occurs simultaneously via a four‐atom transition state. The conformational constrains of the THF ring could increase the energy of the transition states by ∼24 and 37 kJ/mol for the stepwise and concerted reaction paths, respectively. The calculated lowest activation energy of the reaction both in vacuum and in solvents is rather high, at 188 and 172–182 kJ/mol, respectively. These results suggest that in real systems, the process is most likely catalyzed by preliminary deprotonation of the vicinal OH group. In this case, the formyl group migration proceeds spontaneously, and the intermediate formed is 15–30 kJ/mol more stable than the initial anion of the monoformylated diol. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Multiobjective Tabu Search method used in chemistry
Authors: Rusu T. , Bulacovschi V.
Published: December 2005

The use of a combined artificial intelligence method in macromolecular chemistry design is described. This method implies a Back‐Propagation (BP) Neural Network, modified for two‐dimensional input data and for a system composed of a genetic algorithm extended by a Tabu Search operator used to incorporate high‐level chemical knowledge: thermodynamic polymer properties. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Polynomial time perfect sampling algorithm for two‐rowed contingency tables
Authors: Kijima Shuji , Matsui Tomomi
Published: December 2005

This paper proposes a polynomial time perfect (exact) sampling algorithm for 2 ×ncontingency tables. The algorithm is based on monotone coupling from the past (monotone CFTP) algorithm. The expected running time is bounded by O(n3lnN) wherenis the number of columns andNis the total sum of all entries. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006
Degree distribution of the greatest common divisor of polynomials over 𝔽q
Authors: Gao Zhicheng , Panario Daniel
Published: December 2005

We study the degree distribution of the greatest common divisor of two or more random polynomials over a finite field 𝔽q. We provide estimates for several parameters like number of distinct common irreducible factors, number of irreducible factors counting repetitions, and total degree of the gcd of two or more polynomials. We show that the limiting distribution of a random variable counting the total degree of the gcd is geometric and that the distributions of random variables counting the number of common factors (with and without repetitions) are very close to Poisson distributions when q is large. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006
MAXk‐CUT and approximating the chromatic number of random graphs
Authors: Coja‐Oghlan Amin , Moore Cristopher , Sanwalani Vishal
Published: December 2005

We consider the MAXk‐CUT problem on random graphsGn,p. First, we bound the probable weight of a MAXk‐CUT using probabilistic counting arguments and by analyzing a simple greedy heuristic. Then, we give an algorithm that approximates MAXk‐CUT in expected polynomial time, with approximation ratio 1 +O((np)‐1/2). Our main technical tool is a new bound on the probable value of Frieze and Jerrum's semidefinite programming (SDP)‐relaxation of MAXk‐CUT on random graphs. To obtain this bound, we show that the value of the SDP is tightly concentrated. As a further application of our bound on the probable value of the SDP, we obtain an algorithm for approximating the chromatic number ofGn,p, 1/n≤p≤ 0.99, within a factor ofO((np)1/2) in polynomial expected time, thereby answering a question of Krivelevich and Vu. We give similar algorithms for random regular graphs. The techniques for studying the SDP apply to a variety of SDP relaxations of further NP‐hard problems on random structures and may therefore be of independent interest. For instance, to bound the SDP we estimate the eigenvalues of random graphs with given degree sequences. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006
The degree sequences and spectra of scale‐free random graphs
Authors: Jordan Jonathan
Published: December 2005

We investigate the degree sequences of scale‐free random graphs. We obtain a formula for the limiting proportion of vertices with degreed, confirming non‐rigorous arguments of Dorogovtsev, Mendes, and Samukhin (Phys Rev Lett 85 (2000), 4633). We also consider a generalization of the model with more randomization, proving similar results. Finally, we use our results on the degree sequence to show that for certain values of parameters localized eigenfunctions of the adjacency matrix can be found. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006
Bayesian decision procedures for dose‐escalation based on evidence of undesirable events and therapeutic benefit
Authors: Whitehead John , Zhou Yinghui , Stevens John , Blakey Graham , Price Jim , Leadbetter Joanna
Published: December 2005

In this paper, Bayesian decision procedures are developed for dose‐escalation studies based on bivariate observations of undesirable events and signs of therapeutic benefit. The methods generalize earlier approaches taking into account only the undesirable outcomes. Logistic regression models are used to model the two responses, which are both assumed to take a binary form. A prior distribution for the unknown model parameters is suggested and an optional safety constraint can be included. Gain functions to be maximized are formulated in terms of accurate estimation of the limits of a ‘therapeutic window’ or optimal treatment of the next cohort of subjects, although the approach could be applied to achieve any of a wide variety of objectives. The designs introduced are illustrated through simulation and retrospective implementation to a completed dose‐escalation study. Copyright © 2006 John Wiley & Sons, Ltd.
Application of reliability coefficients in cDNA microarray data analysis
Authors: He Wenqing , Bull Shelley B. , Gokgoz Nalan , Andrulis Irene , Wunder Jay
Published: December 2005

Gene expression microarray technology has been widely used in areas such as human cancer research to identify molecular characteristics of sample specimens. The microarray study, however, is a very complicated procedure which involves numerous sources of variability that may be either systematic or random. Systematic variation is often eliminated by applying normalization procedures, but at present there are no standard criteria available to evaluate the performance of a particular normalization approach. In this paper, we propose a reliability‐type coefficient as a criterion to assess the effectiveness of normalization procedures in eliminating systematic variation. Simulation studies show that this criterion performs reasonably well in a range of settings. The proposed method is illustrated using a subset of an ongoing microarray study of soft‐tissue sarcoma. Copyright © 2005 John Wiley & Sons, Ltd.
Shared random effects analysis of multi‐state Markov models: application to a longitudinal study of transitions to dementia
Authors: Salazar Juan C. , Schmitt Frederick A. , Yu Lei , Mendiondo Marta M. , Kryscio Richard J.
Published: December 2005

Multi‐state models are appealing tools for analysing data about the progression of a disease over time. In this paper, we consider a multi‐state Markov chain with two competing absorbing states: dementia and death and three transient non‐demented states: cognitively normal, amnestic mild cognitive impairment (amnestic MCI), and non‐amnestic mild cognitive impairment (non‐amnestic MCI). The likelihood function for the data is derived and estimates for the effects of the covariates on transitions are determined when the process can be viewed as a polytomous logistic regression model with shared random effects. The presence of a shared random effect not only complicates the formulation of the likelihood but also its evaluation and maximization. Three approaches for maximizing the likelihood are compared using a simulation study; the first method is based on the Gauss‐quadrature technique, the second method is based on importance sampling ideas, and the third method is based on an expansion by Taylor series. The best approach is illustrated using a longitudinal study on a cohort of cognitively normal subjects, followed annually for conversion to mild cognitive impairment (MCI) and/or dementia, conducted at the Sanders Brown Center on Aging at the University of Kentucky. Copyright © 2005 John Wiley & Sons, Ltd.
Modelling menstrual status during and after adjuvant treatment for breast cancer
Authors: Szwarc Suzanne E. , Bonetti Marco
Published: December 2005

Failure time data may consist of the observation of an event whose cause is unknown due to the censoring or lack of a second event that could identify the cause of the first event. Standard competing‐risks methodology does not apply to this setting because the cause of the event is not always identifiable. Moreover, one cannot assume that the entire population will eventually experience the event of interest, and the observation is potentially censored for all patients. The model that we describe in this article is motivated by a breast cancer clinical trial conducted by the International Breast Cancer Study Group (IBCSG). Because some breast cancer adjuvant treatments for premenopausal patients who have undergone surgery cause the interruption of menses, or amenorrhoea, it is of interest to describe the process by which menses discontinue and resume after treatment is completed. The process is complicated by the fact that natural menopause also occurs in the patient population, and that treatment‐induced amenorrhoea is not distinguishable from menopause unless menses are observed to resume after treatment completion. We discuss a parametric model for the time to amenorrhoea and for the time to the recovery of menses, also accounting for the presence of censoring and for the possibility that treatment causes an anticipation of natural menopause. Copyright © 2005 John Wiley & Sons, Ltd.
A mixed‐effects model for cognitive decline with non‐monotone non‐response from a two‐phase longitudinal study of dementia
Authors: Shen Changyu , Gao Sujuan
Published: December 2005

Most longitudinal studies of elderly are characterized by substantial drop‐out due to death and many other factors beyond the control of the investigators. In a two‐phase longitudinal study of dementia, subjects with cognitive impairment skip the first phase survey in the next follow‐up, leading to intermittent missing variables measured in that phase. In the context of analysing pre‐dementia cognitive decline in an elderly population, both of the two causes of non‐response can potentially be informative in the sense that the missingness is dependent on the unobserved outcome. To take these factors into account, mixed‐effects models are constructed to allow the outcome and the multiple causes of missing values to share the same ‘random parameter’ or random effect. The crucial assumption of our model is that the random effects of the model for the outcome and that of the model for the missing‐data indicators are linked in a deterministic manner. It can be thought of as an approximation of a more general and realistic situation, in which the two models have distinct, yet dependent, random effects. We conduct a simulation study to investigate possible deviations of the estimates under such a scenario. A second simulation illustrates the magnitude of the bias in estimating the difference of decline rate between two groups when the random effects are linked in different manners for the two groups. Copyright © 2005 John Wiley & Sons, Ltd.
Exploring cultural dimensions of gender and management in the Middle East
Authors: Metcalfe Beverly Dawn
Published: December 2005

This study analyzes the experiences of female professionals working in three case study countries in the Middle East: Bahrain, Jordan, and Oman. Data were gleaned while conducting management and cultural training for female managers. Results highlight the importance of women to economic development and the complexity of the interrelations between gender, organization, and Islamic values. The study reveals that women have advanced in management in the Middle East but have career and development constraints due to strong gender roles in Islamic culture. The study suggests strategies for HR and for gender and development to support international business. © 2006 Wiley Periodicals, Inc.
Wet clutch transmission fluid for AWD differentials: base fluid influence on friction characteristics
Authors: Mäki Rikard , Ganemi Bager , Olsson Richard
Published: December 2005

During the past few years several electronically controllable automotive transmission systems, where wet clutches are used as intelligent differentials, have emerged in the market. In this type of application the anti‐shudder properties of the lubricants are of vital importance. This paper investigates the influence of base fluids on the anti‐shudder properties of transmission fluids for wet clutches in all‐wheel‐drive systems. The investigated all‐wheel‐drive system featuring a wet multi‐plate clutch with a sintered brass‐based friction material is described. The test equipment used to determine the frictional characteristics of the transmission fluid is described. The parameters studied include base fluid type and base fluid viscosity. It is shown that the choice of base fluid has no impact on torque capacity, but that the base fluid influences the temperature dependence of the dynamic friction and the anti‐shudder properties. It is also shown that the major effect on the friction characteristics is caused by additive effects rather than base fluid effects. Copyright © 2006 John Wiley & Sons, Ltd.
Abraham's Bosom, the Place Where he Belonged: A Short Note on απενεχθηναι in Luke 16.22
Authors: VAN DER HORST PIETER W.
Published: December 2005

In the story of the rich man and the poor Lazarus in Luke 16, the usual translation of v. 22 is: ‘The poor man died and was carried away by the angels to be with Abraham’, or ‘he was carried by the angels to the bosom of Abraham’ (εγενετο δε αποθανειν τον πτωχον και απενεχθηναι αυτον υπο των αγγελων εις τον κολπον Αβρααμ). None of the dozens of existing translations of Luke and commentaries on his Gospel that I have consulted offer anything other than this. There is nothing wrong with this translation, except that the verb used here for carrying away, αποϕερειν, can have a semantic aspect that is not captured in this rendering, an aspect which I strongly suspect is present here. I submit as a translation of the verse the following free rendition: ‘The poor man died and the angels carried him away to the bosom of Abraham, the place where he belonged (or: his well-deserved place)’.
Lateralized deficit of response inhibition in early-onset schizophrenia
Authors: BELLGROVE MARK A. , CHAMBERS CHRISTOPHER D. , VANCE ALASDAIR , HALL NICOLE , KARAMITSIOS MARY , BRADSHAW JOHN L.
Published: December 2005

Background. The ability to inhibit inappropriate or unwanted actions is a key element of executive control. The existence of executive function deficits in schizophrenia is consistent with frontal lobe theories of the disorder. Relatively few studies have examined response inhibition in schizophrenia, and none in adolescent patients with early-onset schizophrenia (EOS).

Methods. Twenty-one adolescents with the onset of clinically impairing psychosis before 19 years of age and 16 matched controls performed a stop-signal task to assess response inhibition. The patients with EOS were categorized as paranoid (n=10) and undifferentiated subtypes (n=11). The undifferentiated group had higher levels of negative symptomatology. Stop-signal reaction time (SSRT) and go-signal reaction time (Go-RT) were analysed with respect to hand of response.

Results. The undifferentiated early-onset patients had significantly longer SSRTs, indicative of poor response inhibition, for the left hand compared to the paranoid early-onset patients and control participants. No differences existed for inhibitory control with the right hand. The three groups did not differ in Go-RT.

Conclusions. Our results indicate a specific lateralized impairment of response inhibition in patients with undifferentiated, but not paranoid, EOS. These findings are consistent with reports of immature frontostriatal networks in EOS and implicate areas such as the pre-motor cortex and supplementary motor area (SMA) that are thought to play a role in both voluntary initiation and inhibition of movement.