bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lyapunov stability of periodic solutions of the quadratic Newtonian equation
Authors: Zhang Meirong , Chu Jifeng , Li Xiong 
Published: September 2009

AbstractWe will find a positive constant Σ2 such that for any 2π ‐periodic function h (t) with zero mean value, the quadratic Newtonian equation x ″ + x2 = σ + h (t) will have exactly two 2π ‐periodic solutions with one being unstable and another being twist (and therefore being Lyapunov stable), provided that the parameter σ is bigger than the first bifurcation value and is smaller than the constant Σ2. The construction of Σ2 is obtained by examining carefully the twist coefficients of periodic solutions (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interval oscillation criteria for second order super‐half linear functional differential equations with delay and advanced arguments
Authors: Zafer A. 
Published: September 2009

AbstractSufficient conditions are established for oscillation of second order super half linear equations containing both delay and advanced arguments of the formequation imagewhereϕδ(u) = |u|δ–1u;α> 0,β≥α, andγ≥αare real numbers;k,p,q,e,τ,σare continuous real‐valued functions;τ(t) ≤tandσ(t) ≥twith limt→∞τ(t) = ∞. The functionsp(t),q(t), ande(t) are allowed to change sign, provided thatp(t) andq(t) are nonnegative on a sequence of intervals on whiche(t) alternates sign.As an illustrative example we show that every solution ofequation imageis oscillatory provided that eitherm1orm2orr0is sufficiently large (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On spectral stability for the fractional Laplacian perturbed by unbounded obstacles
Authors: Demuth Michael , Hansmann Marcel 
Published: September 2009

AbstractIn this paper we give integral conditions for the stability of the absolutely continuous spectrum for the fractional Laplacian H0 = , where α ∈ (0, 2), perturbed by an unbounded obstacle Γ ⊂ Rd . We use the stochastic representation of the associated semigroups to derive conditions in terms of the capacity of certain subsets of Γ. In particular, obstacles with infinite capacity are allowed (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gâteaux derivatives and their applications to approximation in Lorentz spaces Γp,w
Authors: Ciesielski Maciej , Kamińska Anna , Płuciennik Ryszard 
Published: September 2009

AbstractWe establish the formulas of the left‐ and right‐hand Gâteaux derivatives in the Lorentz spaces Γp,w = {f: ∫0α (f **)p w < ∞}, where 1 ≤ p < ∞, w is a nonnegative locally integrable weight function and f ** is a maximal function of the decreasing rearrangement f * of a measurable function f on (0, α), 0 < α ≤ ∞. We also find a general form of any supporting functional for each function from Γp,w , and the necessary and sufficient conditions for which a spherical element of Γp,w is a smooth point of the unit ball in Γp,w . We show that strict convexity of the Lorentz spaces Γp,w is equivalent to 1 < p < ∞ and to the condition ∫0∞ w = ∞. Finally we apply the obtained characterizations to studies the best approximation elements for each function f ∈ Γp,w from any convex set K ⊂ Γp,w (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adolescents' perceptions of family communication patterns and some aspects of their consumer socialization
Authors: Kim Chankon , Lee Hanjoon , Tomiuk Marc A. 
Published: September 2009

AbstractThis study examined the effects of family communication patterns (FCP) on adolescent consumers' decision‐making styles and influence in family purchase decisions. Two underlying dimensions of FCP (concept‐orientation and socio‐orientation) were measured separately for mother–child communication and father–child communication and regressed on adolescents' use of the selected decision‐making styles and influence in purchase decisions involving durable products and nondurable products for their own use. Results show that only mother–child communication patterns have significant associations with adolescents' decision‐making styles and family purchase influence. Specifically, mothers' concept‐oriented communication was positively linked to children's use of utilitarian decision‐making styles (e.g., careful and deliberate decision making) and social/conspicuous decision‐making styles (e.g., recreational and hedonic decision making) as well as to children's influence in family purchase decisions involving both durable and nondurable products for themselves. On the other hand, mothers' socio‐oriented communication was linked positively to children's use of undesirable decision‐making styles (e.g., confusion by overchoice) and negatively to children's influence in family purchase decisions. This study also investigated the presence (or absence) of a same‐gender effect in the relationships between parent–child communication orientations and children's consumer socialization outcome. If present, a same‐gender effect would be indicated by a greater influence from the same‐sex parent's communication orientations on the adolescent's decision‐making styles and influence in family decisions relative to that of the opposite‐‐ sex parent's communication orientations. Comparisons of the two gender‐group regression results revealed no systematic pattern that suggests the presence of such an effect. © 2009 Wiley Periodicals, Inc.
Shaping online consumer choice by partitioning the Web
Authors: Martin Jolie M. , Norton Michael I. 
Published: September 2009

AbstractThis research explores how partitioning attributes in online search interfaces changes the valuations of those attributes—and impacts subsequent choice—such that attributes that are displayed as separate categories tend to receive greater decision weight than attributes grouped under umbrella categories. Across several choice domains—cars, dates, and hotels—we show that different attribute partitions impact the importance assigned to attributes (Studies 1 and 2), as well as consumer choices (Studies 3 and 4). We argue that these effects are due in part to users' willingness to use the implicit recommendations of interface designers to determine the importance of attributes, a willingness that extends to following explicit recommendations of online agents based on those attributes (Study 5). © 2009 Wiley Periodicals, Inc.
Perfectly Controlled Lamella Thickness and Thickness Distribution: A Morphological Study on ADMET Polyolefins
Authors: Hosoda S. , Nozue Y. , Kawashima Y. , Utsumi S. , Nagamatsu T. , Wagener K. , Berda E. , Rojas G. , Baughman T. , Leonard J. 
Published: September 2009

AbstractSummary: Lamella thickness distribution (LTD) plays a critical role in determining the mechanical properties of polyethylene. LTD is predominantly governed by the intermolecular chemical composition distribution, but intrachain heterogeneity also results in a broadened LTD. Polyethylene synthesized by acyclic diene metathesis (ADMET) contains pristine microstructures free from inter and intrachain heterogeneity and therefore represent ideal models to investigate these phenomena. The crystalline structures of ADMET polyethylene with ethyl or n‐hexyl branches every 21st backbone carbon (EB21and EO21, respectively) were characterized by transmission electron microscopy (TEM), small X‐ray scattering and wide angle X‐ray diffraction (SAXS and WAXD), and differential scanning calorimetry (DSC). The samples were crystallized for various periods at temperatures near the DSC crystallization peak temperatures: 10 °C for EB21 and 0 °C for EO21. TEM observation exhibited that EB21 displays straight lamellar crystals with axialitic organization and an average thickness of about 55 Å. This corresponds to twice the ethylene sequence length between branches, suggesting that one lamellar stem spans three branches and includes one ethyl branch within the lamella. The lamella thickness distribution was very narrow compared with that of the cross‐fraction of ethylene/1‐butene copolymer prepared via Ziegler‐Natta polymerization. Similarly it was found from the same characterization methods that EO21 also displays a narrow lamella thickness distribution albeit with thinner lamellae, averaging 25–26Å thick. Judging from this lamella thickness, EO21 is considered to have a lamella stem composed of a single ethylene sequence between two braches, suggesting that the n‐hexyl branch is entirely excluded from a crystalline phase.
New Routes to High Resolution and Automated Polymer Morphology Microscopy via Scanning Electron Microscopy
Authors: Bar G. , Tocha E. , Garcia‐Meitin E. , Todd C. , Blackson J. 
Published: September 2009

AbstractSummary: Polymer morphologies are traditionally studied by transmission electron microscopy (TEM). With the use of appropriate contrast enhancing heavy metal stains, direct images of the morphology as well as of the lamellar structure of semi‐crystalline polymers can be obtained. Despite its clear strengths, this approach faces several challenges and difficulties: the laborious nature of ultra‐thin section preparation, high capital investment, and no obvious routes to high‐throughput. We propose an alternative approach to cover the major morphology imaging needs based on a new generation of high resolution scanning electron microscopes (SEM) that have been developed in recent years, and that does not rely on the need for ultra‐thin section preparation. The proposed approach is capable of not only determining the general phase morphology, but also to image details such as the lamellar structure with sufficient resolution. Our approach is based on the use of backscattered electron imaging at low accelerating voltages. The backscattered electron images show high contrast and information content that is comparable to TEM. The main advantage of our SEM based approach is the ability to examine a polished surface, which requires less demanding sample preparation than producing ultra‐thin sections. This opens the door to automated workflows where automated imaging, substantial productivity increases and high speed characterization options can be successfully realized. The successful approach is demonstrated for various polyolefin and engineering plastics samples.
Estimating Slow Crack Growth Performance of Polyethylene Resins from Primary Structures such as Molecular Weight and Short Chain Branching
Authors: DesLauriers Paul J. , Rohlfing David C. 
Published: September 2009

AbstractSummary: Molecular weight and short chain branching (SCB) data experimentally obtained by SEC‐FTIR are combined into a single, primary structural parameter (PSP2) and used to rapidly screen the slow crack growth resistance of a variety of polyethylene resins. Our results show that PSP2 values obtained for resins made using different catalysts (both dual and single catalyst systems) and hence, different polymer architectures, correlate well with results obtained from several short‐term tensile tests. The development of PSP2, as well as the qualitative and quantitative predictive ability of this parameter are presented and discussed.
In situ Polymerization of Nanocomposites by TpTiCl2(Et) System: UHMWPE Filled with Carbon Nanotubes
Authors: Sánchez Y. , Albano C. , Karam A. , Perera R. , Casas E. 
Published: September 2009

AbstractSummary: Nanocomposites of ultra‐high molecular weight polyethylene (UHMWPE) filled with multi‐walled carbon nanotubes (CNT) were obtained by in situ polymerization of ethylene by TpTiCl2Et. This novel catalytic complex activated with polymethylaluminoxane (P‐MAO) (Al:Ti = 200) allowed to incorporate the CNT at different compositions (0,1‐1 w/w %) into the UHMWPE matrix. The filler addition produced an important enhancement of the catalytic activity when it was compared to that of homogeneous ethylene polymerization carried out under the same experimental conditions (30 min; 1bar; 25 °C). This fact was attributed to in situ support of TpTiCl2Et onto the CNT surface, which not only could induce the stabilization of the catalytic system but also allowed the growing of polymeric chains around the CNT structures. The characterization of these nanocomposites was carried out by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Thermal analysis showed that the incorporation of CNT (at the tested concentrations) did not produce changes in the polymer thermal stability, as revealed by the initial degradation temperature values. However, the CNT produced a nucleating effect in the crystallization of UHMWPE as observed by DSC, independently of the filler content. The crystallization temperature of the obtained nanocomposites increased and the crystallinity degree slightly increased as well.
Non‐coaxial elasto‐plasticity model and bifurcation prediction of shear banding in sands
Authors: Huang Maosong , Lu Xilin , Qian Jiangu 
Published: September 2009

AbstractNumerous constitutive models built on coaxial theory and validated under axi‐symmetric condition often describe the stress–stain relationships and predict the inceptions of shear banding in sands inaccurately under true triaxial condition. By adopting an elaborated Mohr–Coulomb yield function and using non‐coaxial non‐associated flow rule, a 3D non‐coaxial elasto‐plasticity model is proposed and validated by a series of true triaxial tests on loose sands. The bifurcation analysis of true triaxial tests on dense sands predicts the influence of the intermediate principal stress ratio on the onset of shear band accurately. The failure of soils is shown to be related to the formation of shear band under most intermediate principal stress ratio conditions except for those which are close to the axi‐symmetric compression condition. Copyright © 2009 John Wiley & Sons, Ltd.
Sacrocolpopexy using xenogenic acellular collagen in patients at increased risk for graft‐related complications
Authors: Claerhout Filip , De Ridder Dirk , Van Beckevoort Dirk , Coremans Georges , Veldman Joan , Lewi Paul , Deprest Jan 
Published: September 2009

AbstractAimsWe studied the long‐term anatomical and functional outcome following sacrocolpopexy for apical vaginal prolapse using xenogenic grafts in a population at increased risk for graft‐related complications (GRCs).MethodsTwenty‐two consecutive patients with symptomatic apical prolapse were scheduled for laparoscopic sacrocolpopexy (LSC) with porcine grafts because they were presumed to be at risk for GRC, because of pre‐existing vaginal ulcerations (n = 4), concomitant vaginal prolapse repair (n = 15), total hysterectomy (n = 1), or intra‐operative abdominal contamination due to accidental laceration of the vagina, bowel perforation (n = 1) or the presence of infection (n = 1). Either small intestinal submucosa (n = 8) or dermal collagen (n = 14) was used. Outcome measures were GRCs, anatomical cure (≤Stage I at any compartment), subjective cure, impact on bowel, bladder, and sexual function measured by a standardized interview.ResultsAt study closure 20 (91%) patients were available for functional evaluation and 16 (73%) for anatomical evaluation at a mean follow‐up period of 27.4 months. The GRC rate was 25% (n = 4) prompting reintervention in half, and including two patients with spondylodiscitis. The anatomical cure rate was 31.5%. Failures at the vault, anterior, and posterior compartments occurred in, respectively, 31%, 18.8%, and 50% of patients. The subjective cure rate was 60% and three patients (15%) underwent redo‐LSC.ConclusionThe strategy of using xenografts in patients at risk for GRC, did not prevent these to occur and was associated with a high anatomical and functional failure rate as well as reoperation rate. Neurourol. Urodynam. 29:563–567, 2010. © 2009 Wiley‐Liss, Inc.
Melting and spread of polymers in fire with the particle finite element method
Authors: Oñate Eugenio , Rossi Riccardo , Idelsohn Sergio R. , Butler Kathryn M. 
Published: September 2009

AbstractA new computational procedure for analysis of the melting and flame spread of polymers under fire conditions is presented. The method, termed particle finite element method (PFEM), combines concepts from particle‐based techniques with those of the standard finite element method (FEM). The key feature of the PFEM is the use of an updated Lagrangian description to model the motion of nodes (particles) in the thermoplastic material. Nodes are viewed as material points that can freely move and even separate from the main analysis domain representing, for instance, the effect of melting and dripping of polymer particles. A mesh connects the nodes defining the discretized domain where the governing equations are solved as in the standard FEM. An incremental iterative scheme for the solution of the non‐linear transient‐coupled thermal‐flow problem, including loss of mass by gasification, is used. Examples of the possibilities of the PFEM for the modeling and simulation of the melting and flame spread of polymers under different fire conditions are described. Numerical results are compared with experimental data provided by NIST. Published in 2009 by John Wiley & Sons, Ltd.
A possible case of ‘poll‐evil’ in an early Scythian horse skull from Arzhan 1, Tuva Republic, Central Asia
Authors: Bendrey R. , Cassidy J. P. , Bokovenko N. , Lepetz S. , Zaitseva G. I. 
Published: September 2009

AbstractOccipital bone lesions on an Iron Age horse cranium from the burial mound of Arzhan 1, Tuva, Central Asia, are described and interpreted. Cavitations around the nuchal ligament attachment site on the skull are interpreted as foci of inflammation and necrosis following local infection. It is suggested that the pathology represents a case of ‘poll‐evil’, most likely due to a bacterial infection. The significance of such an interpretation is discussed, including its implications for disease ecology and the possible infection risks to contiguous animal and human communities of the first millennium BC in Central Asia. Copyright © 2009 John Wiley & Sons, Ltd.
Behavioral and emotional problems in children with sickle cell disease and healthy siblings: Multiple informants, multiple measures
Authors: Hijmans Channa T. , Grootenhuis Martha A. , Oosterlaan Jaap , Last Bob F. , Heijboer Harriët , Peters Marjolein , Fijnvandraat Karin 
Published: September 2009

AbstractBackgroundBehavioral and emotional problems in children with sickle cell disease (SCD) may be related to disease factors, or to socio‐demographic factors. The aim of this study was to investigate the prevalence of behavioral and emotional problems in children with SCD living in a Western European country, compared to healthy siblings (who were comparable in age, gender, ethnicity, and socio‐economic status—SES), and to a Dutch norm population.MethodsThe Child Behavior Checklist (CBCL), Teacher Report Form (TRF) and Disruptive Behavior Disorders rating scale (DBD) were distributed among caregivers and teachers of 119 children with SCD aged 6–18 years and among caregivers and teachers of 38 healthy siblings.ResultsQuestionnaires were returned by caregivers and/or teachers of 106 children with SCD and 37 healthy siblings. According to caregivers and teachers, children with SCD had more severe internalizing problems than healthy siblings and the norm population. According to teachers, subgroups of both children with SCD and healthy siblings had more severe externalizing problems than the norm population. Children with SCD had more difficulties than healthy siblings in terms of school functioning, showed less competent social behavior and tended to have more attention deficits.ConclusionsChildren with SCD are at increased risk of developing internalizing problems as a result of their disease. Subgroups of children with SCD are at increased risk of developing severe externalizing problems, which may either be related to socio‐demographic factors, or to disease factors, such as neurocognitive deficits associated with cerebral infarction. Pediatr Blood Cancer 2009; 53:1277–1283. © 2009 Wiley‐Liss, Inc.
Interactions between antiepileptic and chemotherapeutic drugs in children with brain tumors: Is it time to change treatment?
Authors: Ruggiero Antonio , Rizzo Daniela , Mastrangelo Stefano , Battaglia Domenica , Attinà Giorgio , Riccardi Riccardo 
Published: September 2009

AbstractEpileptic seizures are a common clinical problem in children with brain tumors. The conventional antiepileptic drugs (AEDs) permit a good seizure control in most of these children. An emerging problem is the possible interactions between AEDs and chemotherapeutic drugs, because many of these drugs are metabolized by the cytochrome P450. The aim of this article is to propose a novel therapeutic approach for new‐onset epilepsy in children with brain tumors. Among the new AEDs not metabolized by the P450 system, levetiracetam seems to be a promising AED owing to its pharmacokinetic features, efficacy, and safety. Pediatr Blood Cancer 2010;54:193–198. © 2009 Wiley‐Liss, Inc.
Development of poly(acrylamide)‐hydroxyapatite composites as bone substitutes: Study of mechanical and blood compatible behavior
Authors: Bajpai A.K. , Bundela H. 
Published: September 2009

AbstractThe Hydroxyapatite (HAp) serves as potential biomaterial in various biomedical applications. This study is a continuing attempt to design the biomimetic bone‐like composite materials. The authors have tried to develop HAp/Polyacrylamide (PAm) composites with different weight ratios through a suspension polymerization method. The prepared composite materials were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy, optical microscopy techniques, and compressive strength tests. The composites were also studied for water sorption capacity and the water sorption data were used to evaluate network parameters revealing the internal chemical architecture of the composite. In vitro tests were carried out to study water uptake and dissolution profiles of HAp/PAm composites. Furthermore, in vitro blood compatibility of the composites was also judged using protein adsorption, percentage haemolysis, blood clot formation, and platelet adhesion tests. The results obtained fairly support the objectives of the study to meet physiochemical and biological concerns for a bone‐like material. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers
Gene expression in chorionic villous samples at 11 weeks of gestation in women who develop preeclampsia later in pregnancy: implications for screening
Authors: Farina Antonio , Morano Danila , Arcelli Diego , De Sanctis Paola , Sekizawa Akihiko , Purwosunu Yuditiya , Zucchini Cinzia , Simonazzi Giuliana , Okai Takashi , Rizzo Nicola 
Published: September 2009

AbstractObjectivesTo determine the gene expression profile in chorionic villous samples (CVS) of women destined to develop preeclampsia.MethodcDNA microarray technology was employed. Ten singleton fetuses of women who subsequently developed preeclampsia where compared with a pool of 50 controls. The mRNA expression of some of the genes previously found to be up‐ or down‐regulated were validated by RT‐PCR in peripheral blood from 23 pregnant women at term affected with preeclampsia and 23 controls.ResultsAltered expression was found among several genes including those involved in invasion of human trophoblasts (Titin), in inflammatory stress (Lactotransferrin), endothelial aberration (Claudin 6), angiogenesis (Vasohibin 1), blood pressure control (Adducin 1). Also the peripheral blood from preeclampsia patients showed significant differences for all the genes studied.ConclusionCVS show an aberrant gene profile prior to preeclampsia onset that may be predictive of the disease. Copyright © 2009 John Wiley & Sons, Ltd.