bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐Molecular‐Weight Poly(tert‐butyl acrylate) by Nitroxide‐Mediated Polymerization: Effect of Chain Transfer to Solvent
Authors: Lessard Benoît , Tervo Christopher , Marić Milan 
Published: June 2009

AbstractTert‐Butyl acrylate (TBA) was polymerized by nitroxide‐mediated polymerization (NMP) using BlocBuilder initiator and 4.5 mol‐% additional SG1 (N‐tert‐butyl‐N‐[1‐diethylphosphono‐(2,2‐dimethylpropyl)] nitroxide) relative to BlocBuilder (2‐methyl‐2‐[N‐tert‐butyl‐N‐(diethoxylphosphoryl‐2,2‐(dimethylpropyl)aminooxy]propionic acid) at 115 °C in bulk and in various solvents. In all cases, number average molecular weight ($\overline M _{\rm n}$) increased linearly up to 35% conversion. kpK values (kp = propagation rate constant, K = equilibrium constant) for TBA agreed well with literature data. For higher target $\overline M _{\rm n}$ > 50 kg · mol−1, solution polymerizations used to reduce viscosity were problematic as chain transfer reactions became noticeable, particularly when block copolymers with styrene were desired. A better strategy to obtain high $\overline M _{\rm n}$ block copolymers involved a semi‐batch feeding in bulk of styrene monomer to a poly(TBA) macroinitiator which resulted in high $\overline M _{\rm n}$ gradient blocks with low polydispersity ($\overline M _{\rm n}$ = 54.7 kg · mol−1, $\overline M _{\rm w} /\overline M _{\rm n}$ = 1.3).magnified image
Non‐convex dual forms based on exponential intervening variables, with application to weight minimization
Authors: Wood Derren W. , Groenwold Albert A. 
Published: June 2009

AbstractWe study the weight minimization problem in a dual setting. We propose new dual formulations for non‐linear multipoint approximations with diagonal approximate Hessian matrices, which derive from separable series expansions in terms of exponential intervening variables. These, generally, nonconvex approximations are formulated in terms of intervening variables with negative exponents, and are therefore applicable to the solution of the weight minimization problem in a sequential approximate optimization (SAO) framework.Problems in structural optimization are traditionally solved using SAO algorithms, like the method of moving asymptotes, which require the approximate subproblems to be strictly convex. Hence, during solution, the nonconvex problems are approximated using convex functions, and this process may in general be inefficient. We argue, based on Falk's definition of the dual, that it is possible to base the dual formulation on nonconvex approximations. To this end we reintroduce a nonconvex approach to the weight minimization problem originally due to Fleury, and we explore certain convex and nonconvex forms for subproblems derived from the exponential approximations by the application of various methods of mixed variables. We show in each case that the dual is well defined for the form concerned, which may consequently be of use to the future code developers. Copyright © 2009 John Wiley & Sons, Ltd.
Potential particles for the modelling of interlocking media in three dimensions
Authors: Harkness J. 
Published: June 2009

AbstractA method is presented for the model creation and dynamic analysis of three‐dimensional interlocking media, such as locked sands or dry stone walls, in DEM simulations. A new form of discrete element is developed for this purpose, based on the concept of potential particles. A potential function is proposed for the modelling of spheres truncated by flats, and the mechanics of contacting particles is examined in some detail. In addition, suggestions are made to improve the convergence of the solver and accuracy of the solution for the contact point. Finally, some examples are presented, including a simulation of interlocked particles in a periodic shearbox. Copyright © 2009 John Wiley & Sons, Ltd.
Unilateral and bilateral upper extremity weight‐bearing effect on upper extremity impairment and functional performance after brain injury
Authors: Reistetter Timothy , Abreu Beatriz C. , Bear‐Lehman Jane , Ottenbacher Kenneth J. 
Published: June 2009

AbstractThe purpose of the study was to investigate the effect of upper extremity (UE) weight bearing on UE impairment functional performance of persons with acquired brain injury (BI).A quasi‐experimental design was used to examine a convenience sample of 99 persons with acquired BI and 22 without BI (WBI) living in a community re‐entry centre. A computerized force‐sensing array pressure map system was used to determine the UE pressure during unilateral and bilateral conditions. Differences between groups were examined using t‐tests. Correlations were computed between UE weight bearing and hand function, and functional performance as measured by the Fugl‐Meyer scale and functional independence measure (FIM) scale.The group of people with BI exerted significantly lower UE weight bearing during unilateral conditions as compared with persons WBI [left: t (119) = 2.34, p = 0.021; right: t (119) = 4.79, p = 0.043). UE weight‐bearing measures correlated strongly with FIM motor scores with bilateral UE conditions yielded the highest significant correlation (bilateral left r = 0.487, p < 0.001; bilateral right r = 0.469, p < 0.01).The results indicated that UE weight‐bearing pressure differs in unilateral and bilateral conditions, between persons with and WBI and between persons with stroke and traumatic brain injury. These findings may have implications for occupational therapists that use unilateral versus bilateral motor training for rehabilitation.There is a need to replicate the study design with a randomized and stratified sample of persons with BI. Copyright © 2009 John Wiley & Sons, Ltd.
NSAID use and risk of leukaemia: a population‐based case‐control study
Authors: Bhayat F. , Das‐Gupta E. , Smith C. , Hubbard R. 
Published: June 2009

AbstractPurposeThe use of non‐steroidal anti‐inflammatory drugs (NSAIDs) is associated with a reduced risk of developing colorectal and lung cancer. Studies suggesting similar associations in leukaemia have been small and underpowered. We have conducted a large population‐based case‐control study to determine whether the use of NSAIDs is associated with a reduced risk of acute and chronic leukaemias, and whether their use has any impact on survival in these patients.MethodsWe identified all the incident cases of leukaemia in ‘The Health Improvement Network’ (THIN) general practice dataset, along with at least four matched controls per case. We used conditional logistic regression to determine odds ratios for NSAID prescription rates and the risk of developing several leukaemia sub‐types. We then used Cox regression to determine the association between NSAID prescription rate and risk of death in leukaemia. Hazard ratios were adjusted for gender, age at diagnosis, smoking status and Townsend Score.ResultsThe risk of leukaemia overall appears to increase marginally with increased use of NSAIDs prior to diagnosis. This is not seen when individual leukaemia sub‐types are examined, however, except perhaps in CLL where patients who had received 2–5 prescriptions/year are 34% more likely to be diagnosed with CLL than those who had not had any NSAID prescriptions (O.R. 1.34, p = 0.03, 95% C.I. 1.02–1.74). There was no statistically significant association between exposure to NSAIDs prior to leukaemia diagnosis and survival.ConclusionThe use of NSAIDs does not reduce the risk of developing leukaemia, nor do they improve survival. Copyright © 2009 John Wiley & Sons, Ltd.
Montelukast and psychiatric disorders in children
Authors: Wallerstedt Susanna M. , Brunlöf Gertrud , Sundström Anders , Eriksson Anna L. 
Published: June 2009

AbstractPurposeA signal has been raised concerning montelukast and adverse drug reactions (ADRs) in children. The purpose of the present study was to evaluate psychiatric ADRs during treatment with montelukast in children.MethodsWe analyzed all reports of psychiatric disorders during treatment with montelukast in children (<18 years) in the Swedish ADR database SWEDIS (1998–2007). The Bayesian Confidence Propagation Neural Network (BCPNN) method was used to screen for disproportional reporting rates of these reactions. An information component (IC) with a positive 95% lower confidence limit indicates a statistically significant disproportionality between the expected and the reported rate for a drug and an ADR.ResultsA total of 48 reports of psychiatric disorders in children during treatment with montelukast were found in SWEDIS. Reports appeared every year after registration. Psychiatric disorders reported more than once included nightmares (n = 15), unspecified anxiety (n = 11), aggressiveness (n = 11), sleep disorders (n = 10), insomnia (n = 3), irritability (n = 3), hallucination (n = 3), hyperactivity (n = 3), and personality disorder (n = 2). In 23 reports (48%), the child experiencing psychiatric ADRs was ≤3 years old. Time from exposure to ADR was indicated in 35 reports. In 28 of these (80%), the time from exposure to ADR was less than 1 week. A statistical signal for psychiatric disorders appeared in the fourth quarter of 1998 (three reports, IC‐value: 2.34, 95% lower confidence limit: 0.62).ConclusionsPsychiatric ADRs can occur during montelukast treatment in children, indicating that attention to this is essential. Further studies are needed to establish the magnitude of the problem. Copyright © 2009 John Wiley & Sons, Ltd.
Parkinson's Disease Society research conference
Authors: Archibald Neil 
Published: June 2009

AbstractProgress: Advancing Parkinson's Research, the Parkinson's Disease Society research conference dedicated to showcasing the work of young Parkinson's disease researchers, was held in York in November 2008, attracting nearly 200 delegates. Neil Archibald, Parkinson's Disease Society Research Fellow, reports on some of the highlights of the conference, including stem cell and gene therapy research, the role of Lewy bodies in dementia and the use of deep brain stimulation in the treatment of Parkinson's disease. Copyright © 2009 Wiley Interface Ltd
Self‐Lubricating W–S–C Nanocomposite Coatings
Authors: Polcar Tomas , Evaristo Manuel , Cavaleiro Albano 
Published: June 2009

AbstractThis paper is aimed on a perspective low‐friction coatings, the W–S–C system deposited by magnetron sputtering, which exhibits extremely low‐friction coefficient together with high‐load‐bearing capacity. Special attention has been paid to the analysis of the frictional and wear mechanisms under different operating conditions, such as the contact pressure, the air humidity, and the temperature. The formation of a thin self‐lubricating WS2 tribolayer, which was observed regardless on the sliding conditions, is the driving force for the promising frictional properties of the coatings.magnified image
High Productive Deposited Mo Layers for Back Ohmic Contacts of Solar Cells
Authors: Heinß Jens‐Peter , Händel Frank , Meyer Toni , Würz Roland 
Published: June 2009

AbstractIn the paper, thin molybdenum (Mo) layers produced by magnetron sputtering [state of the art in production for photovoltaic applications (PV)] are compared with those produced by high‐rate electron beam (EB) deposition technology. Stainless steel and borofloat glass served as substrate materials. Mo layers deposited by DC‐magnetron sputtering were produced as a reference and investigated by analysis of structure and specific electrical resistance. Alternative layers prepared by high‐rate EB‐deposition with a rate up to 240 nm·s−1 were characterised by inquests of mechanical properties, sheet resistance and cell efficiency. A strong dependency of specific electrical resistance on residual gas conditions was determined. The specific electrical resistance dropped from 18 to 11 µΩ·cm. Compactness of Mo layers increased with implementation of plasma activation. The layer formation became denser and comparable to the magnetron sputtered Mo layers.
Development of Decorative and Corrosion Resistant Coatings for the Surface Refinement of Magnesium Alloys by Plasma‐based Methods
Authors: Hoche Holger , Groß Stefan , Foerster Rudolf , Schmidt Juergen , Adamitzki Wolfgang 
Published: June 2009

AbstractThis paper was amended in June 2013 because of a change of the author's names. The corrected author byline is presented on the last page of the pdf‐file.Within the presented study, the economic potential of PVD‐coatings for the surface refinement and protection of Mg‐alloys is fully examined. The research includes the introduction of new pre‐treatment methods by plasma and chemical polishing, followed by corrosion‐inhibiting PVD‐coating based on TiMgAlN and thin decorative PVD‐finish‐film consisting of Nb. Anodic oxidation of the PVD‐finish film guarantees the full colour palette by interference effects. It will be shown that chemical and plasma polishing can be applied for the surface pre‐treatment of magnesium alloys. The TiMgAlN coated magnesium alloys withstand the 96 h salt spray test without any significant corrosion damage.
Pressure‐induced structural transitions in multi‐walled carbon nanotubes
Authors: Shima Hiroyuki , Sato Motohiro 
Published: June 2009

AbstractWe demonstrate a novel cross‐sectional deformation, called the radial corrugation, of multi‐walled carbon nanotubes (MWNTs) under hydrostatic pressure. Theoretical analyses based on the continuum elastic approximation have revealed that MWNTs consisting of more than ten concentric walls undergo elastic deformations at critical pressure $p_{\rm c} \simeq {\rm 1}\,{\rm GPa}$, above which the circular shape of the cross‐section becomes radially corrugated. Various corrugation modes have been observed by tuning the innermost tube diameter and the number of constituent walls, which is a direct consequence of the core–shell structure of MWNTs.Cross‐sectional views of MWNT under high hydrostatic pressure: elliptic deformation with the mode index n = 2 (left), and radial corrugations with n = 5 (center), and n = 6 (right). The index n indicates the circumferential wave number of the deformed cross‐section.magnified image
Stimulation of glucose uptake by triterpenoids from Weigela subsessilis
Authors: Lee Myung Sun , Thuong Phuong Thien 
Published: June 2009

AbstractFour ursane‐type triterpenoids, corosolic acid (1), ilekudinol B (2), ursolic acid (3) and pomolic acid (4), were isolated from an EtOAc‐soluble extract of the leaves of Weigela subsessilis. These bioactive compounds were evaluated for their glucose uptake activity and produced moderate to strong enhancement both in basal‐ and insulin‐stimulated L6 muscle cells. In particular, corosolic acid exhibited the most potent activity, increasing uptake by basal‐ and insulin‐stimulated myotubes by 2.63‐ and 3.33‐fold, respectively; ilekudinol B produced 1.6‐ and 2.9‐fold, ursolic acid produced 1.84‐ and 2.64‐fold, and pomolic acid produced 1.6‐ and 2.8‐fold increases. No cytotoxicities were observed for corosolic acid, ursolic acid and ilekudinol B in myoblasts, while pomolic acid at doses of 25 and 50 µm reduced cell viability by 19% and 21.8% upon 24 h treatment and by 48.6% and 54.1% upon 48 h treatment, respectively. These results suggest that ursane‐type triterpenoids from W. subsessilis might enhance glucose uptake by acting as insulin mimics and as insulin sensitizers and that they could be useful as nontoxic diabetes treatment agents. Copyright © 2009 John Wiley & Sons, Ltd.
Sensitivity of a modelled life cycle of a mesoscale convective system to soil conditions over West Africa
Authors: Gantner Leonhard , Kalthoff Norbert 
Published: June 2009

AbstractCloud‐resolving real‐case simulations initialized with European Centre for Medium‐range Weather Forecasts (ECMWF) analysis data were performed to investigate the sensitivity of a mesoscale convective system (MCS) to soil properties. Four scenarios were investigated: original ECMWF soil moisture (MOI); ECMWF soil moisture reduced by 35% (CTRL), which better fits with the satellite observations; homogeneous soil type and soil moisture (HOM); and homogeneous soil type with a north–south oriented drier band of two degrees width (BAND).Initiation of convection was observed in all experiments. The initiation area was characterised by very low convective inhibition (CIN) and high convective available potential energy (CAPE). The simulations showed some evidence that convection was initiated in the vicinity of orography and along soil moisture inhomogeneities. Except for the MOI run, MCSs developed in all experiments. In CTRL, a weakening of the system was observed when approaching an area with reduced total water content and enhanced CIN. In BAND, convection developed almost simultaneously in the original initiation area and inside the dry band, where convergence, generated by thermally‐induced circulation and supported by downward mixing of momentum from the African Easterly Jet, triggered convection. When the mature MCS approached the band from the east it weakened, caused by increasing CIN ahead of the band. Triggering of convection on this day was favoured by drier surfaces and/or soil moisture inhomogeneities, while a mature system weakened in the vicinity of a drier surface. Thus a positive feedback between soil moisture and convection existed for a mature system whereas a negative feedback was found for triggering of convection. Copyright © 2009 Royal Meteorological Society
Application of wavelet denoising to improve OFDM‐based signal detection and classification
Authors: Klein Randall W. , Temple Michael A. , Mendenhall Michael J. 
Published: June 2009

AbstractThe developmental emphasis on improving wireless access security through various OSI PHY layer mechanisms continues. This work investigates the exploitation of RF waveform features that are inherently unique to specific devices and that may be used for reliable device classification (manufacturer, model, or serial number). Emission classification is addressed here through detection, location, extraction, and exploitation of RF [fingerprints] to provide device‐specific identification. The most critical step in this process is burst detection which occurs prior to fingerprint extraction and classification. Previous variance trajectory (VT) work provided sensitivity analysis for burst detection capability and highlighted the need for more robust processing at lower signal‐to‐noise ratio (SNR). The work presented here introduces a dual‐tree complex wavelet transform (DT‐ℂWT) denoising process to augment and improve VT detection capability. The new method's performance is evaluated using the instantaneous amplitude responses of experimentally collected 802.11a OFDM signals at various SNRs. The impact of detection error on signal classification performance is then illustrated using extracted RF fingerprints and multiple discriminant analysis (MDA) with maximum likelihood (ML) classification. Relative to previous approaches, the DT‐ℂWT augmented process emerges as a better alternative at lower SNR and yields performance that is 34% closer (on average) to [perfect] burst location estimation performance. Copyright © 2009 John Wiley & Sons, Ltd.
eRIPP‐FS: Enforcing privacy and security in RFID
Authors: Conti Mauro , Di Pietro Roberto , Mancini Luigi V. , Spognardi Angelo 
Published: June 2009

AbstractIn RFID systems addressing security issues, many authentication techniques require the tag to keep some sort of synchronization with the reader. In particular, this is true in those proposals that leverage hash chains. When the reader and the tag get de‐synchronized, possibly by an attacker, this paves the way to several denial of service (DoS) attacks, as well as threatening privacy (e.g.,viathetiming attack). Even if de‐synchronization happens for non‐malicious causes, this event has a negative effect on performances (for instance, slowing down the authentication process).In this paper, we provide a solution to cope with the de‐synchronization between the tag and the reader when hash chains are employed. In particular, our solution relies on mutual reader‐tag authentication, achievedviahash traversal and Merkle tree techniques. We show that this techniques applied to an existing security protocol for RFID systems, such as RIPP‐FS, make timing attacks hard to succeed. Moreover, the proposed solutions can be transparently and independently adopted by similar security protocols as well to thwart timing attack and/or to provide reader‐tag mutual authentication.Finally, extensive simulations show that our proposal introduces a negligible overhead to recover de‐synchronization. Copyright © 2009 John Wiley & Sons, Ltd.
An end‐to‐end approach to secure routing in MANETs
Authors: Dabideen Stephen , Smith Bradley R. , Garcia‐Luna‐Aceves J. J. 
Published: June 2009

AbstractProviding secure routing in mobile ad hoc networks (MANETs) is far more difficult than establishing secure routing in wired networks or static wireless networks. Node mobility and the relative scarcity of bandwidth render prior solutions ineffective. Solutions based on securing link or path information do not work well in MANETs because the dynamic nature of links requires extensive use of flooding to establish effective countermeasures. On the other hand, solutions based on hop‐by‐hop exchanges of distance information are easily compromised. Instead of trying to secure the ordering of nodes, we argue that secure routing in MANETs must be based on the end‐to‐end verification of physical‐path characteristics aided by the exploitation of path diversity to increase the probability of finding secure paths. We apply this approach to the design of the Secure Routing through Diversity and Verification (SRDV) protocol, a secure routing protocol that we show to be as efficient as unsecured on‐demand or proactive routing approaches in the absence of attacks. We prove that the countermeasures used in SRDV can defend against a variety of known attacks to routing protocols, including attacks involving collusion, and the fabrication and modification of routing packets. We also show the effectiveness of the end‐to‐end mechanisms via simulations. Copyright © 2009 John Wiley & Sons, Ltd.
Implementation of Global Software Development: a structured approach
Authors: Casey Valentine , Richardson Ita 
Published: June 2009

AbstractThe analysis of a 3‐year in‐depth case study on virtual team operation in a globally distributed software development resulted in the identification of ten key factors for Global Software Development (GSD). These ten factors have been utilised as the basis for the development of the GSD Implementation Model. The objective of the creation and presentation of this model is to provide a practical and systematic approach to address the key activities, infrastructure and support which are required to facilitate effective distributed software development. This approach is inspired by the IDEALsm model and divided into five specific phases which are classified as Initiating, Provisioning, Establishing, Managing and Leveraging. The goal of the Initiating phase is to clearly determine why, if and how the distributed development strategy is to be selected and undertaken. The implementation of the Provisioning phase is to ensure that the required infrastructure, processes and support to facilitate successful distributed software development are identified and put in place. The focus of the Establishing phase is to ensure that the development teams are effectively established. The Managing phase addresses the day‐to‐day requirements of operating efficiently in a distributed environment. The Leveraging phase concentrates on the need to ensure that the structures and procedures are in place so that lessons learned can be documented and leveraged in existing and future projects. Copyright © 2009 John Wiley & Sons, Ltd.