bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface functionalization with phosphazenes. V. Surface modification of plasma‐treated polyamide 6 with fluorinated alcohols and azobenzene derivatives through chlorinated phosphazene intermediates
Authors: De Jaeger Roger , Mazzah Ahmed , Gengembre Leon , Frere Martine , Jama Charafeddine , Milani Roberto , Bertani Roberta , Gleria Mario
Published: February 2008

In this article, we describe the synthesis and characterization of surface‐modified polyamide‐6, using polydichlorophosphazene and hexachlorocyclophosphazene as coupling agents. The solid surface of this polymer was modified first by the introduction of polar functions (CO, OH, OR, COOH, COOR, etc.) with a cold plasma technique, then by the treatment of the alcoholic groups on the surface with (NPCl2)n and (NPCl2)3 to graft these substrates through the formation of strong covalent POC bonds, and eventually by the substitution of the residual chlorines on the polyamide‐6 surface with different types of fluorinated alcohols (2,2,2‐trifluoroethanol and heptadecafluorononanol) and with 4‐hydroxyazobenzene. Contact‐angle measurements, together with X‐ray photoelectron spectroscopy and ultraviolet–visible spectroscopy techniques, support the occurrence of these surface‐functionalization reactions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Graft copolymerization of acrylamide onto konjac glucomannan via inverse emulsion polymerization and its thickening properties
Authors: Tian Dating , Xie Hong‐Quan
Published: February 2008

The graft copolymerization of acrylamide onto konjac glucomannan (KGM) was studied with inverse emulsion polymerization to obtain an effective thickener. The effects of the initiator concentration, emulsifier concentration, comonomer concentration, reaction temperature, and reaction time on the graft copolymerization were investigated. The results showed that the polymerization system retained good stability, and the graft efficiency of the graft copolymerization was almost 95% under optimum conditions. Moreover, both the water solubility and thickening properties of the KGM were improved evidently by grafting with polyacrylamide. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Chemical modification of polystyrene by low‐energy (<100 eV) electron irradiation studied by mass spectrometry
Authors: Massey S. , Cloutier P. , Bazin M. , Sanche L. , Roy D.
Published: February 2008

Dip‐coated thin films of polystyrene were chemically modified (degraded) by low‐energy electron irradiation (0–100 eV). The resulting degradation was studied by mass spectrometry with variable electron energy. In the negative‐ion mode, H− was observed and was associated with two phenomena. The resonant structure at 9.1 ± 0.4 eV was associated with dissociative electron attachment. The energy of the resonance peak agreed with the results obtained for organic molecules. At a higher energy, a monotonic rise of the emission yield was observed and was associated with nonresonant dipolar dissociation. More mass fragments were observed in the positive‐ion mode. The predominant ion was H+ at 100 eV of electron irradiation, and alkyl ions were detected at higher masses. Emission thresholds were measured for the most predominant positive ions. The shape of the emission curve showed that there was no resonant process in the formation of these ions. The energy threshold was measured at about 20 eV, and this meant that the carbon structure of the polymer broke with a recombination of the degradation products with hydrogen atoms before the emission occurred. Below 19 eV, there was only hydrogen loss; this implied that the possible degradation mechanisms did not break the general carbon structure of the material, leading to crosslinking. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of photopatternable epoxy hybrid materials for the fabrication of thick and thermally stable microstructures with a high aspect ratio
Authors: Jung Kyung Ho , Bae Byeong‐Soo
Published: February 2008

Photosensitive cycloaliphatic‐epoxy oligosiloxane was synthesized using a nonhydrolytic sol–gel reaction for the fabrication of thick and thermally stable microstructures with high aspect ratios. Its formation was confirmed by 29Si and 1H nuclear magnetic resonance spectroscopy, small‐angle neutron scattering, and Fourier transform infrared spectroscopy. Photocuring of cycloaliphatic‐epoxy oligosiloxane resin resulted in a thermally stable epoxy hybrid material (epoxy hybrimer). Micropatterns with a high aspect ratio (>5), an excellent sidewall shape, and low shrinkage were fabricated directly from these materials using a simple photolithographic process. The fabricated micropattern sustained temperatures of up to 250°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Five‐year followup of a cognitive–behavioral intervention for patients with recently‐diagnosed rheumatoid arthritis: Effects on health care utilization
Authors: Sharpe L. , Allard S. , Sensky T.
Published: February 2008

Objective

To investigate whether cognitive–behavioral therapy (CBT) administered early in the course of rheumatoid arthritis (RA) has long‐term effects on health care use.

Methods

We reviewed the files of 47 of the original 53 patients with early RA who volunteered for a randomized controlled trial comparing CBT with no psychological intervention. Occasions of service provision associated with RA were documented and health care use was compared between groups.

Results

The CBT group used fewer health care resources than the control group in the 5 years following intervention. Significant differences were observed for the number of inpatient nights, physiotherapy referrals, injections, and for total health care use. There was a trend that closely approached significance toward fewer episodes of surgery and orthopedic referrals in the CBT group.

Conclusion

These results suggest that CBT administered early in the course of RA can reduce health care use for the first 5 years after treatment. This is a stringent test of the efficacy of a brief psychological intervention, and supports the fact that brief psychological treatments can have long‐term effects.
Responsiveness of six outcome assessment instruments in total shoulder arthroplasty
Authors: Angst Felix , Goldhahn Jörg , Drerup Susann , Aeschlimann André , Schwyzer Hans‐Kaspar , Simmen Beat R.
Published: February 2008

Objective

To assess the responsiveness (sensitivity to change) of 6 shoulder outcome instruments.

Methods

In a prospective cohort study of 153 total shoulder arthroplasties, outcome was measured by the Short Form 36 (SF‐36); Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH); Shoulder Pain and Disability Index (SPADI); American Shoulder and Elbow Surgeons questionnaire for the shoulder (ASES); and the Constant (Murley) Score (CS). Responsiveness was mainly quantified by effect sizes before and 6 months after operation. Sensitivity analysis of the effects by receiver operating characteristic (ROC) curves was performed to determine the instruments' ability to classify effects into global health change assessment categories.

Results

Effect sizes of the self‐assessment total scores were 0.71, 1.19, 2.10, and 2.13 for the SF‐36, DASH, SPADI, and ASES, respectively. The clinical ASES and the CS had effect sizes of 1.87 and 2.23, respectively. The SPADI (effect size 2.12) and the CS (effect size 2.72) were most responsive for pain. For functioning, the patient ASES (effect size 2.10), the CS (effect size 1.82), and the clinical ASES (effect size 1.85) were almost equal. The SF‐36 bodily pain scale and most scores of the condition‐specific instruments showed a significant area under the ROC of up to 0.77.

Conclusion

The SPADI and/or the CS are the most suitable for short, responsive, shoulder‐specific assessment. The more expensive patient ASES can be used for most responsive shoulder‐function assessment. For a comprehensive measurement of health and quality of life, the DASH and/or the SF‐36 should be added to the set.
Effects of postmenopausal hormone therapy on rheumatoid arthritis: The women's health initiative randomized controlled trials
Authors: Walitt Brian , Pettinger Mary , Weinstein Arthur , Katz James , Torner James , Wasko Mary Chester , Howard Barbara V. ,   Women's Health Initiative Investigators
Published: February 2008

Objective

To study the effects of postmenopausal hormone therapy (PHT) on the incidence and severity of rheumatoid arthritis (RA).

Methods

The Women's Health Initiative randomized controlled trials evaluated the effects of unopposed estrogen (E‐alone) and estrogen plus progestin (E+P) compared with placebo on a diverse set of health outcomes over 7.1 and 5.6 years, respectively. RA cases were identified using historical and medication data. The hazard of developing RA was estimated using Cox proportional hazards regression models. Disease symptom severity was estimated using the Short Form 36 (SF‐36) and self‐reported joint pain scores at baseline and after 1 year. Mean changes in severity were compared using linear regression models.

Results

Of the 27,347 participants, 63 prevalent cases and 105 incident cases of RA were identified. A nonsignificant reduction in the risk of developing RA (hazard ratio 0.74; 95% confidence interval [95% CI] 0.51, 1.10) was noted with PHT use. PHT use led to improved SF‐36 scores in unadjusted analyses (percent change 12.5%; 95% CI −24.45, −0.57) but not after adjustment for relevant covariates (P = 0.33). Nonsignificant improvements in joint pain scores were seen with PHT use (odds ratio [OR] 4.10; 95% CI 0.83, 20.20). PHT did not improve swelling (OR 1.27; 95% CI 0.08, 19.63) or prevent new joint pains (OR 0.72; 95% CI 0.11, 4.68) in RA participants.

Conclusion

There were no statistically significant differences in the risk of developing RA or the severity of RA between the PHT and placebo groups.
Coaching patients with early rheumatoid arthritis to healthy physical activity: A multicenter, randomized, controlled study
Authors: Brodin Nina , Eurenius Eva , Jensen Irene , Nisell Ralph , Opava Christina H. ,   Para Study Group
Published: February 2008

Objective

To investigate the effect of a 1‐year coaching program for healthy physical activity on perceived health status, body function, and activity limitation in patients with early rheumatoid arthritis.

Methods

A total of 228 patients (169 women, 59 men, mean age 55 years, mean time since diagnosis 21 months) were randomized to 2 groups after assessments with the EuroQol visual analog scale (VAS), Grippit, Timed‐Stands Test, Escola Paulista de Medicina Range of Motion scale, walking in a figure‐of‐8, a visual analog scale for pain, the Health Assessment Questionnaire disability index, a self‐reported physical activity questionnaire, and the Disease Activity Score in 28 joints. All patients were regularly seen by rheumatologists and underwent rehabilitation as prescribed. Those in the intervention group were further individually coached by a physical therapist to reach or maintain healthy physical activity (≥30 minutes, moderately intensive activity, most days of the week).

Results

The retention rates after 1 year were 82% in the intervention group and 85% in the control group. The percentages of individuals in the intervention and control groups fulfilling the requirements for healthy physical activity were similar before (47% versus 51%;P> 0.05) and after (54% versus 44%;P> 0.05) the intervention. Analyses of outcome variables indicated improvements in the intervention group over the control group in the EuroQol VAS (P= 0.025) and muscle strength (Timed‐Stands Test;P= 0.000) (Grippit;P= 0.003), but not in any other variables assessed.

Conclusion

A 1‐year coaching program for healthy physical activity resulted in improved perceived health status and muscle strength, but the mechanisms remain unclear, as self‐reported physical activity at healthy level did not change.
Glycerol fermentation by (open) mixed cultures: A chemostat study
Authors: Temudo Margarida F. , Poldermans Rolf , Kleerebezem Robbert , van Loosdrecht Mark C.M.
Published: February 2008

Glycerol is an important byproduct of bioethanol and biodiesel production processes. This study aims to evaluate its potential application in mixed culture fermentation processes to produce bulk chemicals. Two chemostat reactors were operated in parallel, one fed with glycerol and the other with glucose. Both reactors operated at a pH of 8 and a dilution rate of 0.1 h−1. Glycerol was mainly converted into ethanol and formate. When operated under substrate limiting conditions, 60% of the substrate carbon was converted into ethanol and formate in a 1:1 ratio. This product spectrum showed sensitivity to the substrate concentration, which partly shifted towards 1,3‐propanediol and acetate in a 2:1 ratio at increasing substrate concentrations. Glucose fermentation mainly generated acetate, ethanol and butyrate. At higher substrate concentrations, acetate and ethanol were the dominant products. Co‐fermentations of glucose–glycerol were performed with both mixed cultures, previously cultivated on glucose and on glycerol. The product spectrum of the two experiments was very similar: the main products were ethanol and butyrate (38% and 34% of the COD converted, respectively). The product spectrum obtained for glucose and glycerol fermentation could be explained based on the general metabolic pathways found for fermentative microorganisms and on the metabolic constraints: maximization of the ATP production rate and balancing the reducing equivalents involved. Biotechnol. Biotechnol. Bioeng. 2008;100: 1088–1098. © 2008 Wiley Periodicals, Inc.
The Identification and Characterization of Fusogenic Domains in Herpes Virus Glycoprotein B Molecules
Authors: Galdiero Stefania , Vitiello Mariateresa , D'Isanto Marina , Falanga Annarita , Cantisani Marco , Browne Helena , Pedone Carlo , Galdiero Massimiliano
Published: February 2008

The molecular mechanism of entry of herpes viruses requires a multicomponent fusion system. Virus entry and cell–cell fusion of Herpes simplex virus (HSV) requires four glycoproteins: gD, gB and gH/gL. The role of gB remained elusive until recently, when the crystal structure of HSV‐1 gB became available. Glycoprotein B homologues represent the most highly conserved group of herpes virus glycoproteins; however, despite the high degree of sequence and structural conservation, differences in post‐translational processing are observed for different members of this virus family. Whereas gB of HSV is not proteolytically processed after oligomerization, most other gB homologues are cleaved by a cellular protease into subunits that remain linked through disulfide bonds. Proteolytic cleavage is common for activation of many other viral fusion proteins, so it remains difficult to envisage a common role for different herpes virus gB structures in the fusion mechanism. We selected bovine herpes virus type 1 (BoHV‐1) and herpes simplex virus type 1 (HSV‐1) as representative viruses expressing cleaved and uncleaved gBs, and have screened their amino acid sequences for regions of highly interfacial hydrophobicity. Synthetic peptides corresponding to such regions were tested for their ability to induce the fusion of large unilamellar vesicles and to inhibit herpes virus infection. These results underline that several regions of the gB protein are involved in the mechanism of membrane interaction.
Spectroscopic studies of oligomers containing 2,5‐trans furanoid sugar amino acids
Authors: Edwards Alison A. , Alexander Bruce D. , Fleet George W. J. , Tranter George E.
Published: February 2008

Sugar amino acids and their oligomers, known as carbopeptoids, are commonly studied as foldamers. However, study of their conformational preference is often challenging when the adopted conformations are extended and/or disordered. This study is the first to explore the disordered nature of such carbopeptoids by utilizing a family of 2,5‐trans carbopeptoids. An array of spectroscopic techniques has been used to investigate the conformational preference of these carbopeptoids. However, using this data alone it has not been possible to assign conformational preference as an ordered extended conformation or as a disordered family of closely related conformations. Computational methods need to be employed to achieve reliable interpretation of the spectroscopic data. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Dendritic crystal growth, differential circular scattering, and the origin of biomolecular homochirality
Authors: Kahr Bart , Freudenthal John H.
Published: February 2008

Phthalic acid rapidly crystallizing in thin aqueous films is deposited radially and rhythmically as dendritic banded spherulites that have heterochiral meso‐textures in hemi‐circles. The chiral fields differentially scatter left and right circularly polarized light. A scenario for chiral amplification and the origin of biomolecular homochirality is thus proposed that combines the influences of crystals and light. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
SyGMa: Combining Expert Knowledge and Empirical Scoring in the Prediction of Metabolites
Authors: Ridder Lars , Wagener Markus
Published: February 2008

Predictions of potential metabolites based on chemical structure are becoming increasingly important in drug discovery to guide medicinal chemistry efforts that address metabolic issues and to support experimental metabolite screening and identification. Herein we present a novel rule‐based method, SyGMa (Systematic Generation of potential Metabolites), to predict the potential metabolites of a given parent structure. A set of reaction rules covering a broad range of phase 1 and phase 2 metabolism has been derived from metabolic reactions reported in the Metabolite Database to occur in humans. An empirical probability score is assigned to each rule representing the fraction of correctly predicted metabolites in the training database. This score is used to refine the rules and to rank predicted metabolites. The current rule set of SyGMa covers approximately 70 % of biotransformation reactions observed in humans. Evaluation of the rule‐based predictions demonstrated a significant enrichment of true metabolites in the top of the ranking list: while in total, 68 % of all observed metabolites in an independent test set were reproduced by SyGMa, a large part, 30 % of the observed metabolites, were identified among the top three predictions. From a subset of cytochrome P450 specific metabolites, 84 % were reproduced overall, with 66 % in the top three predicted phase 1 metabolites. A similarity analysis of the reactions present in the database was performed to obtain an overview of the metabolic reactions predicted by SyGMa and to support ongoing efforts to extend the rules. Specific examples demonstrate the use of SyGMa in experimental metabolite identification and the application of SyGMa to suggest chemical modifications that improve the metabolic stability of compounds.
Design optimization of switched reluctance machines for starter/generator of hybrid electric vehicle by genetic algorithm
Authors: Faiz Jawad , Moayed‐zadeh K.
Published: February 2008

A switched reluctance machine for starter/generator of a hybrid electric vehicle is designed to optimize two objective functions: (1) high starting torque over low speed and (2) high efficiency over high speed. For static modeling of flux‐linkage, a quick analytical model is used and its accuracy is verified by comparison with the finite element results. In addition, a suitable technique is adopted to estimate the losses. Comparison of the optimal design between a conventional technique and genetic algorithm shows that the genetic algorithm enables to optimize the proposed objective functions over whole range of the speed. Copyright © 2008 John Wiley & Sons, Ltd.
Investigation of suppressing PD white noise by compound information of complex wavelet transform
Authors: Tang Ju , Xu Zhongrong , Sun Caixin
Published: February 2008

According to the distinct properties between the complex wavelet coefficients of partial discharge (PD) signals and white noises, this paper presents the specific compound information (CI) of WTRInseries for complex wavelet transform (CWT), which are utilized to suppress white noises. Through the simulation case, the influence of n‐index value on denoising effect is discussed and the optimal CI of corresponding to different PD waveforms is analyzed by the simulation investigation. The parameters of variable tendency parameter (VTP), normalized correlation coefficient (NCC), and signal‐to‐noise ratio (SNR) are defined to synthetically evaluate the denoising effect. The db4 complex wavelet is constructed to suppress the white noise in ultra high frequency (UHF) PD detection system. The results indicate that the denoising effect of the CI for CWT is better than the simple information (SI) for CWT and the CI of WTRInseries have the optimal denoising effect to suppress white noise for UHF PD signals. Copyright © 2008 John Wiley & Sons, Ltd.
Decentralized decision on operating reserve considering insurance and penalty policies
Authors: Chan C. Y. , Shi L. B. , Ni Y. X.
Published: February 2008

In power markets, operating reserve procurement is usually centrally handled according to certain reliability rules and aiming at minimizing the total procurement cost. In this approach, there are no customer choices, no incentives for the independent system operator (ISO) to minimize the social cost or for reserve suppliers to commit promised reserve capacity. It may lead to inefficiency. In this paper, we propose a decentralized approach for operating reserve procurement. In the approach, gencos try to maximize their own expected profits and consumers try to minimize their own expected cost with certain market information announced by the ISO. Insurance theory is applied to the approach. With the insurance policy, consumers are able to transfer their financial risk of loss of supply to the ISO. The claim defined in the insurance policy induces incentive for the ISO to manage the reserve capacity in an efficient manner. A penalty system is introduced as well. Under the penalty system, a genco is required to pay a high penalty if it does not commit the reserve capacity provision, which enforces the liability of gencos to provide operating reserve. A detailed math model and a solution procedure are presented. It is shown that with a properly defined reserve market rule, the decentralized approach can yield same optimal solution as its centralized counterpart aiming at maximizing social welfare in reserve markets. Numerical test results illustrate the effectiveness of the suggested approach. Copyright © 2008 John Wiley & Sons, Ltd.
The role of Poynting's vector in polyphase power calculations
Authors: Faria J. A. Brandão
Published: February 2008

This paper is a tutorial contribution to the clarification of the role played by Poynting's vector (PV) in power calculations. In polyphase power systems, the standard computation of the instantaneous power is usually performed by using a summation of voltage–current products. We show analytically how such a result can be deduced directly from Maxwell's equations together with the evaluation of the PV flux. A simple application example is provided to illustrate the issue under discussion. Copyright © 2008 John Wiley & Sons, Ltd.
Optimal Control of Rigid‐Link Manipulators by Indirect Methods
Authors: Callies Rainer , Rentrop Peter
Published: February 2008

The present paper is a survey and research paper on the treatment of optimal control problems of rigid‐link manipulators by indirect methods. Maximum Principle based approaches provide an excellent tool to calculate optimal reference trajectories for multi‐link manipulators with high accuracy. Their major drawback was the need to explicitly formulate the complicated system of adjoint differential equations and to apply the full apparatus of optimal control theory. This is necessary in order to convert the optimal control problem into a piecewise defined, nonlinear multi‐point boundary value problem. An accurate and efficient access to first‐ and higher‐order derivatives is crucial. The approach described in this paper allows it to generate all the derivative information recursively and simultaneously with the recursive formulation of the equations of motion. Nonlinear state and control constraints are treated without any simplifications by transforming them into sequences of systems of linear equations. By these means, the modeling of the complete optimal control problem and the accompanying boundary value problem is automated to a great extent. The fast numerical solution is by the advanced multiple shooting methodJANUS. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lie Theory for Quantum Control
Authors: Dirr G. , Helmke U.
Published: February 2008

One of the main theoretical challenges in quantum computing is the design of explicit schemes that enable one to effectively factorize a given final unitary operator into a product of basic unitary operators. As this is equivalent to a constructive controllability task on a Lie group of special unitary operators, one faces interesting classes of bilinear optimal control problems for which efficient numerical solution algorithms are sought for. In this paper we give a review on recent Lie‐theoretical developments in finite‐dimensional quantum control that play a key role for solving such factorization problems on a compact Lie group. After a brief introduction to basic terms and concepts from quantum mechanics, we address the fundamental control theoretic issues for bilinear control systems and survey standard techniques fromLie theory relevant for quantum control. Questions of controllability, accessibility and time optimal control of spin systems are in the center of our interest. Some remarks on computational aspects are included as well. The idea is to enable the potential reader to understand the problems in clear mathematical terms, to assess the current state of the art and get an overview on recent developments in quantum control‐an emerging interdisciplinary field between physics, control and computation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Daily precipitation observations over Emilia‐Romagna: mean values and extremes
Authors: Pavan V. , Tomozeiu R. , Cacciamani C. , Di Lorenzo M.
Published: February 2008

Daily precipitation data from a dense observational network covering Emilia‐Romagna, a region of Northern Italy, are described and analysed. Data are available for all stations for the period 1951–2004 and for a selected group of stations located over the Reno hydrological basin for the period 1925–2004. Indices describing seasonal values of mean precipitation and frequency of extreme events are computed starting from daily data and are used to describe the temporal and spatial variability of precipitation over the region.

Data referring to the period 1951–2004 are used to describe trends of relevant precipitation indices over the same period in all seasons, and the relation between the variability of these indices and major Euro‐Atlantic large‐scale circulation indices over winter.

Data referring to the period 1925–2004 are used to analyse the decadal and long‐term variability over the Reno Basin and its relation with the winter daily discharge of the river. This analysis allows identifying the presence of a clear decadal periodicity in river discharge, strongly related with the decadal variability in both total precipitation and frequency of intense events. Copyright © 2008 Royal Meteorological Society
Organizational networks of collaboration for community‐based living
Authors: Poole Dennis L.
Published: February 2008

This exploratory study of the Texas Community Awareness and Relocation Services (CARS) Project examines organizational networks of collaboration for community‐based living. A high degree of collaboration in these networks is needed to help nursing facility residents negotiate the complex process of moving to community‐based settings. Social network analysis reveals considerable variations in local organizational networks of collaboration among lead nonprofit providers before and after implementation of the CARS Project in five test sites. These variations probably affected their collaborative capacity of each site and, ultimately, the project's outcomes.
Two Fast Marching Methods for Hamilton–Jacobi Equations
Authors: Cristiani Emiliano , Falcone Maurizio
Published: February 2008

We introduce and analyze two new Fast Marching (FM) methods based on a semi‐Lagrangian (SL) approximation (see [2] for a more complete presentation). The Characteristics driven Fast Marching method accepts more than one node at every iteration using a dynamic condition which leads to a faster convergence. The Buffered Fast Marching method allows to deal with convex and non–convex Hamilton–Jacobi equations including anisotropic front propagation and differential games. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Haptotaxis Model with Age and Spatial Structure and Nonlinear Age‐Boundary Conditions
Authors: Walker Christoph
Published: February 2008

Global existence and uniqueness of solutions is shown for a system of nonlinear pde's modeling tumor invasion into tissue. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sparse direct factorizations through unassembled hyper‐matrices
Authors: Bientinesi Paolo , Eijkhout Victor , Kurtz Jason , van de Geijn Robert
Published: February 2008

We set out to efficiently compute the solution of a sequence of linear systems Aixi = bi, where the matrix Ai is tightly related to matrix Ai –1. In the setting of an hp ‐adaptive Finite Element Method, the sequence of matrices Ai results from successive local refinements of the problem domain. At any step i > 1, a factorization already exists and it is the updated linear system relative to the refined mesh for which a factorization must be computed in the least amount of time. This observation holds the promise of a tremendous reduction in the cost of an individual refinement step. We argue that traditional matrix storage schemes, whether dense or sparse, are a bottleneck, limiting the potential efficiency of the solvers. We propose a new hierarchical data structure, the Unassembled Hyper‐Matrix (UHM), which allows the matrix to be stored as a tree of unassembled element matrices, hierarchically ordered to mirror the refinement history of the physical domain. The factorization of such an UHM proceeds in terms of element matrices, only assembling nodes when they need to be eliminated. Efficiency comes in terms of both performance and space requirements. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Image analysis using p ‐Laplacian and geometrical PDEs
Authors: Kuijper A.
Published: February 2008

Minimizing the integral ∫Ω1/p |∇L |p d Ω for an image L under suitable boundary conditions gives PDEs that are well‐known for p = 1, 2, namely Total Variation evolution and Laplacian diffusion (also known as Gaussian scale space and heat equation), respectively. Without fixing p, one obtains a framework related to the p ‐Laplace equation. The partial differential equation describing the evolution can be simplified using gauge coordinates (directional derivatives), yielding an expression in the two second order gauge derivatives and the norm of the gradient. Ignoring the latter, one obtains a series of PDEs that form a weighted average of the second order derivatives, with Mean Curvature Motion as a specific case. Both methods have the Gaussian scale space in common. Using singularity theory, one can use properties of the heat equation (namely. the role of scale) in the full L (x, t) space and obtain a framework for topological image segmentation. In order to be able to extend image analysis aspects of Gaussian scale space in future work, relations between these methods are investigated, and general numerical schemes are developed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Acoustics of gas‐saturated foams: Modelling comparisons
Authors: Steeb Holger
Published: February 2008

We show results obtained by Biot's equations and a simple Theory of Porous Media‐based hybrid model describing acoustical waves in a gas‐saturated high‐porous foam. The resulting dispersion relations for the longitudinal mode and phase velocities vs. porosity show the extraordinary effect of waves in gas‐saturated porous media. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resonance in viscous film flow over topography
Authors: Heining Christian , Wierschem Andreas , Bontozoglou Vasilis , Aksel Nuri , Uecker Hannes
Published: February 2008

We study viscous gravity‐driven films flowing over periodically undulated substrates. Linear analysis describes resonance in steady flow along small bottom corrugations for films of arbitrary thickness. Depending on the dimensionless film thickness we find different regimes for the resonance, which is associated with the interaction of the undulated film with capillarygravity waves traveling against the flow. Nonlinear resonance produces higher harmonics and bistable resonance. The higher harmonics are due to higher harmonics resonance and due to the nonlinear coupling to lower harmonics. For the bistable resonance we derive a minimum model showing that the bistability corresponds essentially to that of the driven Duffing oscillator. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surfactant‐driven instability in two‐fluid pipe and channel flows
Authors: Blyth M.G. , Luo H. , Pozrikidis C.
Published: February 2008

Recent work on the stability of two‐layer channel flow, with either smooth or corrugated walls, and core‐annular flow is discussed with the emphasis on the potentially destabilising effect of an insoluble surfactant. Linearised normal mode analyses are conducted to identify unstable parametric conditions, and these are followed up by computer simulations which confirm the linear results and, furthermore, reveal a rich array of dynamical behaviour in the nonlinear regime. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Retrieving knowledge from auditing log‐files for computer and network forensics and accountability
Authors: Takahashi Daisuke , Xiao Yang
Published: February 2008

This paper analyzes and simulates the complexity of searching a particular database called a computer or network auditing log database. In order to observe behaviors of users in a computer or a computer network, system authorities in a particular domain first keep logs of all the actions conducted by the users. In general, we can grasp the users' actions by analyzing their actions in a computer system, or messages in a computer network, especially analyzing headers of packets in a particular network protocol. From this bunch of data (database), we can retrieve particular knowledge according to some requirements for computer and network forensics and accountability. For example, in a computer or network system, if at some point the fact that the content of a secret file is leaking has been already known, to figure out the reasons of the leaking, we can search partial or entire log‐files to find out direct or indirect accesses to the file; since a user who accessed the secret before may send messages containing the secret to other users (the secret is leaking due to indirect accesses) via packets in a computer network, or via pipe/FIFO/Message‐Queue in a computer system, finding the reasons of the leaking is not a trivial task. In this paper, we analyze and simulate the complexity of retrieving knowledge from the computer and network auditing log database for forensics and accountability. Copyright © 2008 John Wiley & Sons, Ltd.
An efficient data structure for network anomaly detection
Authors: Fan Jieyan , Wu Dapeng , Lu Kejie , Nucci Antonio
Published: February 2008

Despite the rapid advance in networking technologies, detection of network anomalies at high‐speed switches/routers is still far from maturity. To push the frontier, two major technologies need to be addressed. The first one is efficient feature‐extraction algorithms/hardware that can match a line rate in the order of Gb/second; the second one is fast and effective anomaly detection schemes. In this paper, we focus on design of efficient data structure and algorithms for feature extraction. Specifically, we propose a novel data structure that extracts the so‐called two‐directional (2D) matching features, which are shown to be effective indicators of network anomalies. Our key idea is to use a Bloom filter array (BFA) to trade‐off a small amount of accuracy in feature extraction, for much less space and time complexity, so that our data structure can catch up with a line rate in the order of Gb/second. Different from the existing work, our data structure has the following properties: (1) it dynamic Bloom filter, (2) combination of a it sliding window with Bloom filter, and (3) using an insertion–removal pair to enhance Bloom filter with a removal operation. Our analysis and simulation demonstrate that the proposed data structure has a better space/time trade‐off than conventional algorithms. For example, for a fixed time complexity, the conventional algorithm (i.e., hash table [1—8]) requires a memory of 1.01 Gbits while our data structure requires a memory of only 62.9 Mbits, at the cost of losing 1% accuracy in feature extraction. Copyright © 2008 John Wiley & Sons, Ltd.
Propofol Decreases Early Postoperative Nausea and Vomiting in Patients Undergoing Thyroid and Parathyroid Operations
Authors: Gauger Paul G. , Shanks Amy , Morris Michelle , Greenfield Mary Lou V. H. , Burney Richard E. , O’Reilly Michael
Published: February 2008

Background

As the practice of parathyroid and thyroid surgery shifts toward short stay and outpatient treatment, the occurrence and management of postoperative nausea and vomiting (PONV) increases in importance due to its potential to delay discharge. PONV also may contribute negatively to the patient’s experience and thus their level of satisfaction. The purpose of this study was to determine whether anesthetic technique based on propofol decreases the incidence of PONV and, consequently, improves patient satisfaction with their care.

Methods

A prospective, randomized trial included patients undergoing thyroidectomy and parathyroidectomy under general anesthetic with (75 patients) or without (73 patients) propofol. Occurrences of nausea, vomiting, and the resultant treatment were tracked during the perioperative period. Repeated questionnaires at multiple time points determined patient expectations and experiences related to PONV after their operation. Statistical analyses compared differences between the propofol and non‐propofol groups.

Results

PONV was significantly less likely in the propofol group at the early time points (in the operating room and postanesthesia care unit) but not at later time points (postoperative day 1 or 2). Patients were largely satisfied with different aspects of their management despite the specifics of their anesthetic regimen.

Conclusions

A propofol‐based anesthetic decreases PONV immediately after the operation but this influence does not persist throughout the episode of care or significantly contribute to patient perceptions of satisfaction.
The inability to ignore: distractibility in women with restricting anorexia nervosa
Authors: Dickson H. , Brooks S. , Uher R. , Tchanturia K. , Treasure J. , Campbell I. C.
Published: February 2008

Background

Attentional difficulties reported in individuals with anorexia nervosa (AN) may be due to preferential processing of disease-salient stimuli at a pre-attentive or at a conscious level or to a general problem in attention. Attentional difficulties may be associated with duration of illness.

Method

Female participants with AN (restricting subtype;n=24) and healthy comparison women (n=24) were randomly allocated to subliminal or supraliminal exposure to visual stimuli (food, neutral and aversive images) while performing the 1-back and 2-back working-memory tasks.

Results

Participants with AN made fewer errors than the healthy comparison group in the subliminal condition but significantly more errors in the supraliminal condition [condition×group interaction,F(1, 44)=6.82,p<0.01]: this was irrespective of stimulus type (food, neutral and aversive) and task (1-back or 2-back). The total number of errors made correlated positively with the duration of the AN for both the 1-back task (rs=0.46,p<0.05) and for the 2-back task (rs=0.53,p<0.01).

Conclusions

Decreased ability to concentrate in the presence of explicit distracters is a feature of AN and is associated with longer duration of illness. This phenomenon could be addressed in psychological interventions.
Choice and Values: Individualised Rational Action and Social Goals
Authors: TAYLOR-GOOBY PETER
Published: February 2008

For excellent reasons, in response to pressures from social, economic and political changes, welfare states are undergoing reform. A central theme in the new policies, particularly influential in the UK, is the use of incentives through activation programmes and reforms to public sector management to promote rational responsible choices by both service users and providers. The theoretical underpinning of this approach relies on a model of people as plural in their values, but holding values that are independent from social context and institutional framework. Policy seeks to harness those values to produce desired behaviour. This article focuses on two relevant literatures. Analyses of rational action at an individual level by economic psychologists, evolutionary biologists and game theorists indicate that the context in which choices are framed influences responses. Further work by economic sociologists and social psychologists suggests that the values that guide behaviour have an important social element as normative systems embodied in institutional frameworks. The norms appropriate to market interactions typically differ from welfare norms, so that different value frameworks and responses apply. The implication is that the transition to quasi-market and individualised incentive systems risks damaging the norms that sanction support for distant but vulnerable groups. The article falls into three sections: reviewing the background to reform and the emergence of an emphasis on individualised rational choice, considering each of the literatures mentioned above and discussing policy consequences.
Social Policy Digest Online
Authors: Bennett Fran , Jones Ken
Published: February 2008

The Social Policy Digest went online in the summer of 2003. This means that the Digest, which used to be printed as part of the Journal of Social Policy, is now only available via the web.
The Koizumi Revolution
Authors: Kabashima Ikuo , Steel Gill
Published: February 2008

On September 11, 2005, Koizumi Junichiro and his Liberal Democratic
Party (LDP) achieved a stunning victory in the 44th House of
Representatives election. In stark contrast with the previous election,
just two years earlier, in which the LDP had only managed 237 seats, the
LDP captured an impressive 296 seats. This meant that together with their
coalition partner, the Komeito, the LDP now controlled two thirds of the
seats in the House of Representatives (the more powerful of the two houses
that comprise Japan's Diet, or parliament).
The Future of Scholarly Book Publishing in Political Theory
Authors: Thatcher Sanford G.
Published: February 2008

In 1995, I wrote an article for the Chronicle of Higher
Education outlining the problems of publishing scholarly books in
literary criticism and explaining why the Penn State University Press
could no longer afford to remain active in this field. Of the 150 books
about literature the Press had put out in the previous decade, 65% had
sold fewer than 500 copies, 91% fewer than 800 copies, and only 3% more
than 1,000. The pattern of sales in this discipline had eroded to the
point where a press without much of a subsidy from its parent university
could not sustain a publishing program in it anymore. It seemed clear even
then that what we scholarly publishers have come to call the problem of
“endangered species” would be spreading to other disciplines
over time. Five years later, in an article I wrote for the newsletter of
APSA's Organized Section on Comparative Politics (2000), I analyzed
data that seemed to show that field to be heading in the same direction as
literary studies, and I concluded with not a great deal of hope for the
future. Recently, at the invitation of the Association for Political
Theory, I turned my attention to the subfield of political theory and
offered this paper as background for the session on book publishing at the
conference in November 2006. While many of the same pressures remain in
place to bedevil university presses, and it would be premature surely to
claim that we are out of the woods yet, there have been some significant
changes that give reason to think the future may not be quite as gloomy as
it appeared back at the turn of the millennium. This article was initially prepared as a background paper for
the Association for Political Theory conference plenary session, November
4, 2006.
APSA Investment Practices
Authors: Ross Loren D.
Published: February 2008

In order to keep members informed about APSA financial pratices, the
APSA Trust and Development Board, which is charged by the APSA
Constitution to oversee Association assets, reports from time to time on
Association investment practices.

APSA's investments are managed professionally by Mr. Loren Ross
of Cedarpoint Capital Management, Inc., New York, with oversight by the
APSA Trust and Development Board. The following is a statement of
investment philosophy circulated by Cedarpoint Capital Management on
APSA's behalf. The holdings in APSA's Trust and Congressional
Fellowship Portfolios, as of June 2006, are also listed.

March 15, 2006
2006 Workshop for Department Chairs—Planning for Assessment
and Accountability Issues
Authors: Rajaee Bahram M.
Published: February 2008

The 2006 Workshop for Department Chairs, held at the Annual Meeting in
Philadelphia, focused on the theme of “Planning for Assessment and
Accountability Issues.” Moderated by Stephen Majeski, chair,
department of political science, University of Washington, and of the APSA
Departmental Services Committee, the session included presentations by
four speakers with notable experience on this topic: Kerstin Hamann,
University of Central Florida; Michelle Deardorf, Jackson State
University; Ken Campbell, University of Delaware; Linda Suskie, Middle
States Commission on Higher Education.
Internationalizing the Undergraduate Curriculum: Opening
Commentary
Authors: Barber Benjamin R.
Published: February 2008

The excellent papers in this symposium warrant our close attention for
the cardinal reason that they teach citizenship in the global world. They
arm us with ideas, concrete techniques, and specialized skill sets to
reach this goal. The simple importance of learning to function well in a
global society belies the complexity of achieving it. These papers give us
tools as well as provide motivation to confront this challenge.
Internationalizing Political Theory Courses
Authors: Leslie Isis
Published: February 2008

On March 28, 2006, the following televised exchange took place between
two professors at Al-Azhar University in Egypt and the station newscaster
for Kuwaiti Al-Rai TV on the subject of female circumcision.