bluuebunny/crossref_metadata_2025_split huggingface dataset:
A branch‐and‐cut algorithm for partition coloring
Authors: Frota Yuri , Maculan Nelson , Noronha Thiago F. , Ribeiro Celso C. 
Published: December 2009

AbstractLet G = (V, E, Q) be a undirected graph, where V is the set of vertices, E is the set of edges, and Q = {Q1,…,Qq} is a partition of V into q subsets. We refer to Q1,…,Qq as the components of the partition. The partition coloring problem (PCP) consists of finding a subset V′ of V with exactly one vertex from each component Q1,…,Qq and such that the chromatic number of the graph induced in G by V′ is minimum. This problem is a generalization of the graph coloring problem. This work presents a branch‐and‐cut algorithm proposed for PCP. An integer programing formulation and valid inequalities are proposed. A tabu search heuristic is used for providing primal bounds. Computational experiments are reported for random graphs and for PCP instances originating from the problem of routing and wavelength assignment in all‐optical WDM networks. © 2009 Wiley Periodicals, Inc. NETWORKS, 2010
Longitudinal study on pediatric dyslipidemia in population‐based claims database
Authors: Li Jie , Motsko Stephen P. , Goehring Earl L. , Vendiola Ruby , Maneno Mary , Jones Judith K. 
Published: December 2009

AbstractPurposeTo examine the rate of lipid testing among children from a large US medical insurance claims database, describe the characteristics of pediatric dyslipidemia, and assess the sensitivity of the International Classification of Disease, Ninth Revision, Clinical Modification (ICD‐9‐CM) codes for identifying dyslipidemic children.MethodsThis retrospective cohort study used the claims data from the Integrated Healthcare Information Services (IHCIS), for the years 2003–2006. Two study cohorts consisted of children with laboratory‐defined and diagnosis/treatment‐defined dyslipidemia, respectively. They were compared to age‐ and gender‐matched children without dyslipidemia, with respect to co‐morbidities during the 6‐month prior to and 12‐month after the first dyslipidemic laboratory value or diagnosis/treatment.ResultsSeven per cent of the children who had laboratory values available in the database had a cholesterol test during the study period. Only 15% of laboratory‐defined children (n = 23 475) had a dyslipidemia diagnosis. Cholesterol‐modifying medications were rarely prescribed. Substantially more laboratory‐defined children than their comparators were obese (8 times), had diabetes mellitus (10 times), or had hypertension (5 times). These co‐morbidities were even higher among diagnosis/treatment‐defined children.ConclusionsThe rate of lipid testing among children was low. The ICD‐9‐CM diagnostic codes showed low sensitivity against laboratory definitions. Though only a small proportion of dyslipidemic children were diagnosed or treated with a medication, co‐morbidities associated with dyslipidemia were common. Copyright © 2009 John Wiley & Sons, Ltd.
Thermal and electrical behaviour of some hybrid polyimide films containing barium and titanium oxides
Authors: Hamciuc Corneliu , Hamciuc Elena , Olariu Marius , Ciobanu Romeo 
Published: December 2009

AbstractAromatic polyimides are high‐performance polymers used in applications demanding service at enhanced temperature while maintaining their structural integrity and excellent combination of chemical, physical and mechanical properties. The incorporation of various metallic additives into a polyimide matrix improves its properties, leading to materials required by specific applications. Hybrid polyimide films containing barium and titanium oxides having thicknesses in the range of tens of micrometres were prepared. These films were obtained using the sol–gel technique starting from a poly(amic acid) and a soluble precursor of metal oxides. They exhibited good thermal stability having an initial decomposition temperature above 460 °C, and a glass transition temperature in the range 217–238 °C. Two subglass transitions, γ and β, were evident from dynamic mechanical analysis and dielectric spectroscopy. A study of the thermal and electrical behaviour of some hybrid polyimide films containing barium and titanium oxides is presented. On increasing the concentration of metal oxides, an increase of dielectric constant and a decrease of thermal stability of the hybrid films were observed. The presence of metal oxides shifted the glass transition temperature and the temperature of the β transition to higher values. Copyright © 2009 Society of Chemical Industry
Preparation of molecularly imprinted polymers via atom transfer radical “bulk” polymerization
Authors: Zu Baiyi , Zhang Ying , Guo Xianzhi , Zhang Huiqi 
Published: December 2009

AbstractThe first application of atom transfer radical “bulk” polymerization (ATRBP) in molecular imprinting is described, which provides molecularly imprinted polymers (MIPs) with obvious imprinting effects towards the template, very fast binding kinetics, and an appreciable selectivity over structurally related compounds. In comparison with the MIP prepared via the normally used traditional “bulk” free radical polymerization (BFRP), the MIPs obtained via ATRBP showed somewhat lower binding capacities and apparent maximum numbers Nmax for high‐affinity sites as well as quite similar binding association constants Ka for high‐affinity sites and high‐affinity site densities, in contrast with the previous reports (e.g., nitroxide/iniferter‐mediated “bulk” polymerization provided MIPs with improved properties). This is tentatively ascribed to the occurrence of rather fast gelation process in ATRBP, which greatly restricted the mobility of the chemical species, leading to a heavily interrupted equilibrium between dormant species and active radicals and heterogeneous polymer networks. In addition, the general applicability of ATRBP was also confirmed by preparing MIPs for different templates. This work clearly demonstrates that applying controlled radical polymerizations (CRPs) in molecular imprinting not always benefits the binding properties of the resultant MIPs, which is of significant importance for the rational use of CRPs in generating MIPs with improved properties. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 532–541, 2010
Effect of chain entanglements on plastic deformation behavior of ultra‐high molecular weight polyethylene
Authors: Bartczak Zbigniew 
Published: December 2009

AbstractSamples of ultra‐high molecular weight polyethylene, in which the chain topology within the amorphous component was altered using two‐stage processing, including crystallization at high pressure in the first step, were produced and their deformation behavior in the plane‐strain compression was studied. Deformation and recovery experiments demonstrated that the state of the molecular network governed by entanglement density is one of the primary parameters controlling the response of the material on the imposed strain, especially at moderate and high strains. Any change in the concentration of entanglements markedly influences the shape of the true stress–true strain curve. The strain hardening modulus decreases while the onset of strain hardening increases with a decrease of the entanglement density within the amorphous component. Density of entanglements also influences the amount of rubber‐like recoverable deformation and permanent plastic flow. In material of the reduced concentration of entanglements permanent flow appears easier and sets in earlier than in the material with a higher entanglement density, becoming a favorable deformation mechanism at moderate strains. As a result, strong strain hardening is postponed to higher strain when compared with the samples of equilibrium entanglement density. In the samples of an increased entanglement density the molecular network becomes stiffer, with a reduced ability of strain induced disentangling of chains. Consequently, there is a less permanent flow and strain hardening begins earlier than in the reference material of an unaltered chain topology. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 276–285, 2010
Pseudomonas aeruginosa serological analysis in young children with cystic fibrosis diagnosed through newborn screening
Authors: Hayes D. , Farrell P.M. , Li Z. , West S.E. 
Published: December 2009

AbstractBackgroundWith newborn screening (NBS) for cystic fibrosis (CF), eradication of Pseudomonas aeruginosa (PA) is possible if PA detection occurs early. A serological response to infection likely precedes culture positivity in CF patients, so PA serological testing is very appealing in this population. However, controversies continue to exist about serology testing, titer cutoffs for enzyme‐linked immunosorbent assay (ELISA) antibody tests, and their value in children with CF.MethodsThis longitudinal, prospective study collected respiratory secretions as oropharyngeal swabs or expectorated sputum for culture and also sera over 6 years in 69 patients diagnosed by NBS. Serology assessed PA antibody titers against cell lysate, exotoxin A, and elastase. A novel statistical approach with weighted receiver operating characteristic (ROC) curves was used to determine best antibody titer cutoff values to predict subsequent PA positive cultures.ResultsUsing these weighted ROC curves, the order of sensitivity was found to be cell lysate, exotoxin A, and then elastase while age‐specific cutoffs were better than fixed cutoffs previously used. Age‐specific serological cutoffs both predict and detect PA respiratory infections with a higher sensitivity and specificity. Serological responses to the PA antigens determined that a response to cell lysate occurs significantly earlier than culture positivity.ConclusionsAge‐specific serological cutoffs rather than fixed values against common PA antigens improve early PA identification in infants and young children diagnosed with NBS. Regular serological assessment with age‐specific cutoffs in these children appears to be a worthy diagnostic tool. Pediatr Pulmonol. 2010; 45:55–61. © 2009 Wiley‐Liss, Inc.
New delay‐dependent stability analysis and synthesis of T–S fuzzy systems with time‐varying delay
Authors: Yang Zhong , Yang Yu‐Pu 
Published: December 2009

AbstractIn this paper, a new method is proposed for stability analysis and synthesis of Takagi–Sugeno (T–S) fuzzy systems with time‐varying delay. Based on a new Lyapunov–Krasovskii functional (LKF), some less conservative delay‐dependent stability criteria are established. In the derivation process, some additional useful terms, ignored in previous methods, are considered and new free‐weighting matrices are introduced to estimate the upper bound of the derivative of LKF for T–S fuzzy systems with time‐varying delay. The proposed stability criterion and stabilization condition are represented in terms of linear matrix inequalities. Numerical examples are given to demonstrate the effectiveness and the benefits of the proposed method. Copyright © 2009 John Wiley & Sons, Ltd.
Improving model understanding using statistical screening
Authors: Taylor Timothy R. B. , Ford David N. , Ford Andrew 
Published: December 2009

AbstractSystem dynamics models are often constructed to improve system performance by identifying and modifying feedback mechanisms that drive system behavior. Once identified, these feedback mechanisms can be used to design and test policies for system performance improvement. A preliminary step in developing policies is the identification of high‐leverage parameters and structures, the influential model sections that drive system behavior. The current work clarifies and extends the use of statistical screening as a tool to improve model understanding, explanation, and development with a six‐step process. Statistical screening adds rigor to model analysis by objectively identifying high‐leverage model parameters and structures for further analysis. Statistical screening offers system dynamicists a user‐friendly tool that can be used to help explain how model structure drives behavior. Copyright © 2009 John Wiley & Sons, Ltd.
Additive survival least‐squares support vector machines
Authors: Van Belle V. , Pelckmans K. , Suykens J. A. K. , Van Huffel S. 
Published: December 2009

AbstractThis work studies a new survival modeling technique based on least‐squares support vector machines. We propose the use of a least‐squares support vector machine combining ranking and regression. The advantage of this kernel‐based model is threefold: (i) the problem formulation is convex and can be solved conveniently by a linear system; (ii) non‐linearity is introduced by using kernels, componentwise kernels in particular are useful to obtain interpretable results; and (iii) introduction of ranking constraints makes it possible to handle censored data. In an experimental setup, the model is used as a preprocessing step for the standard Cox proportional hazard regression by estimating the functional forms of the covariates. The proposed model was compared with different survival models from the literature on the clinical German Breast Cancer Study Group data and on the high‐dimensional Norway/Stanford Breast Cancer Data set. Copyright © 2009 John Wiley & Sons, Ltd.
Comparative cultural cognition
Authors: Price Elizabeth E. , Caldwell Christine A. , Whiten Andrew 
Published: December 2009

AbstractCultural learning is an adaptive mechanism which can lead to changes in behavior and cognition much faster than naturally selected genetic change. Although social learning is prevalent in many species, the capacity for significant cumulative culture remains restricted to humans. This capacity has been a driving force behind the evolution of complexity in our technologies and societies, and has allowed us to become the most widespread mammal on earth. The comparative study of cultural cognition assesses where important differences lie between species. A combination of observational studies in the wild, experimental studies in captivity, and field experiments together provide the most comprehensive methods with which to tackle the question. Copyright © 2009 John Wiley & Sons, Ltd.This article is categorized under:Cognitive Biology > Evolutionary Roots of Cognition
Fully nonlinear electrostatic waves in electron–positron plasmas
Authors: LU GAIMIN , LIU YUE , WANG YOUMEI , STENFLO L. , POPEL S. I. , YU M. Y. 
Published: December 2009

AbstractFully nonlinear electrostatic waves in a plasma containing electrons, positrons, and ions are investigated by solving the governing equations exactly. It is found that both smooth and spiky quasistationary waves exist, and large-amplitude waves necessarily have large-phase velocities, but small-amplitude waves can be both fast and slow.
Ion-acoustic solitons in plasmas with two adiabatic constituents
Authors: VERHEEST FRANK , HELLBERG MANFRED A. 
Published: December 2009

AbstractLarge amplitude ion-acoustic solitons are treated by a Sagdeev pseudopotential analysis, in a plasma with two adiabatic constituents, with the full inclusion of inertial and pressure effects for both. The sign of the supersonic species determines the polarity of the solitons, which are compressive in both constituents. Emphasis is placed on the determination of the soliton existence domains in compositional parameter space, allowing correct Sagdeev pseudopotential graphs to be easily generated, and offering insight into why limitations occur. Soliton velocities are bounded from below by the true acoustic velocity in the plasma model, and from above by the breakdown of the description when the supersonic ions reach their sonic point. Increases in the mass density ratio and the soliton velocity or decreases in the temperature ratio lead to increases in soliton amplitudes and decreases of the widths. Applications include hydrogen and electron–positron plasmas, and various kinds of dusty plasmas.
Permo-Triassic arthropod trace fossils from the Beardmore Glacier area, central Transantarctic Mountains, Antarctica
Authors: Briggs Derek E.G. , Miller Molly F. , Isbell John L. , Sidor Christian A. 
Published: December 2009

AbstractPermian and Triassic lacustrine and fluvial-system deposits in the Beardmore Glacier area of the Transantarctic Mountains preserve a superb record of continental environments and evidence of life on extensive bedding plane exposures. They yielded the first invertebrate trackways reported from continental Permo-Triassic deposits of Antarctica, here assigned to the ichnogenera Diplichnites and Diplopodichnus, which were probably produced by myriapodous arthropods. A resting trace is compared to Orbiculichnus and interpreted as generated by a jumping insect. Plant life is represented by leaf impressions, fossil forests and peat, vertebrates by body and trace fossils, and invertebrate shallow infauna by near surface burrows. The small number and diversity of trackways recovered from the large bedding plane exposures suggest that trackway-producing arthropods were rare at these high southern palaeolatitudes.
Evaluation of myocardial function using the Tei index in patients with Kawasaki disease
Authors: Ajami Gholamhossein , Borzouee Mohammad , Amoozgar Hamid , Ashnaee Feridoon , Kashef Sara , Nesar Mir Sabina , Nesar Mir Soleh 
Published: December 2009

AbstractMyocarditis is a well-recognized component of Kawasaki disease, with left ventricular dysfunction occurring in more than half of the patients during the acute phase of the disease. The purpose of our study was to evaluate myocardial function in these patients using the myocardial performance index, also known as the Tei index. In a prospective study, 14 patients underwent echocardiographic evaluation, first at the time of diagnosis of the disease, in its acute phase before treatment with intravenous immunoglobulin and then 2 weeks later after treatment with immunoglobulin. We assessed the Tei-index, the ejection fraction, shortening fraction, and the presence of valvar regurgitation, pericardial effusion, or coronary arterial involvement. As a control, we also assessed 22 healthy children, matched for age and sex with the study population. Of the patients, half had an increased left ventricular Tei-index in the acute phase, as compared with the data obtained after treatment, the index changing from 0.43 ± 0.08 to 0.35 ± 0.06 (p equal to 0.003). An increased index for the right ventricle was found in 5 patients (36%), values being 0.30 ± 0.05 as opposed to 0.26 ± 0.04 (p equal to 0.009). Of the patients, 5 (35.7%) also had decreased ejection fractions and proportional shortening fractions during the acute phase, confirming left ventricular dysfunction. We concluded that the Tei-index, which measures combined systolic and diastolic function, is a simple, sensitive, and accurate tool for estimating global myocardial dysfunction in patients with Kawasaki disease.
Comparative community genomics in the Dead Sea: an increasingly extreme environment
Authors: Bodaker Idan , Sharon Itai , Suzuki Marcelino T , Feingersch Roi , Shmoish Michael , Andreishcheva Ekaterina , Sogin Mitchell L , Rosenberg Mira , Maguire Michael E , Belkin Shimshon , Oren Aharon , Béjà Oded 
Published: December 2009

Abstract
Owing to the extreme salinity (∼10 times saltier than the oceans), near toxic magnesium levels (∼2.0 m Mg2+), the dominance of divalent cations, acidic pH (6.0) and high-absorbed radiation flux rates, the Dead Sea represents a unique and harsh ecosystem. Measures of microbial presence (microscopy, pigments and lipids) indicate that during rare bloom events after exceptionally rainy seasons, the microbial communities can reach high densities. However, most of the time, when the Dead Sea level is declining and halite is precipitating from the water column, it is difficult to reliably measure the presence of microorganisms and their activities. Although a number of halophilic Archaea have been previously isolated from the Dead Sea, polar lipid analyses of biomass collected during Dead Sea blooms suggested that these isolates were not the major components of the microbial community of these blooms. In this study, in an effort to characterize the perennial microbial community of the Dead Sea and compare it with bloom assemblages, we performed metagenomic analyses of concentrated biomass from hundreds of liters of brine and of microbial material from the last massive Dead Sea bloom. The difference between the two conditions was reflected in community composition and diversity, in which the bloom was different and less diverse from the residual brine population. The distributional patterns of microbial genes suggested Dead Sea community trends in mono- and divalent cation metabolisms as well as in transposable elements. This may indicate possible mechanisms and pathways enabling these microbes to survive in such a harsh environment.
Chiral porphyrazine near-IR optical imaging agent exhibiting preferential tumor accumulation
Authors: Trivedi Evan R. , Harney Allison S. , Olive Mary B. , Podgorski Izabela , Moin Kamiar , Sloane Bonnie F. , Barrett Anthony G.M. , Meade Thomas J. , Hoffman Brian M. 
Published: December 2009

A chiral porphyrazine (pz), H2[pz(trans-A2B2)] (247), has been prepared that exhibits preferential in vivo accumulation in the cells of tumors. Pz 247 exhibits near-infrared (NIR) emission withλ > 700 nm in the required wavelength range for maximum tissue penetration. When MDA-MB-231 breast tumor cells are treated with 247, the agent shows strong intracellular fluorescence with an emission maximum, 704 nm, which indicates that it localizes within a hydrophobic microenvironment. Pz 247 is shown to associate with the lipophilic core of LDL and undergo cellular entry primarily through receptor-mediated endocytosis accumulating in lysosomes. Preliminary in vivo studies show that 247 exhibits preferential accumulation and retention in the cells of MDA-MB-231 tumors subcutaneously implanted in mice, thereby enabling NIR optical imaging with excellent contrast between tumor and surrounding tissue. The intensity of fluorescence from 247 within the tumor increases over time up to 48 h after injection presumably due to the sequestration of circulating 247/LDL complex by the tumor tissue. As the need for cholesterol, and thus LDL, is elevated in highly proliferative tumor cells over nontumorigenic cells, 247 has potential application for all such tumors.