bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partitioning of biweighted trees
Authors: Agnetis Alessandro , Mirchandani Pitu B. , Pacifici Andrea 
Published: October 2004

AbstractA districting problem is formulated as a network partitioning model where each link has one weight to denote travel time and another weight to denote workload. The objective of the problem is to minimize the maximum diameter of the districts while equalizing the workload among the districts. The case of tree networks is addressed and efficient algorithms are developed when the network is to be partitioned into two or three districts. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 143–158, 2002; DOI 10.1002/nav.10003
Minimum‐weight rooted not‐necessarily‐spanning arborescence problem
Authors: Rao V. Venkata , Sridharan R. 
Published: October 2004

AbstractIn this paper, we propose the problem of identifying a minimum‐weight rooted not‐necessarily‐spanning arborescence (MRA) in a directed rooted acyclic graph with weights on arcs. We show this problem to be NP‐hard and formulate it as a zero—one integer program. We develop a heuristic H to construct a rooted arborescence (RA) in a given graph G, giving an upper bound. We also formulate a Lagrangian problem, LMRA, by relaxing one set of constraints of the zero—one integer program. For a given set of Lagrange multipliers, LMRA can be easily solved to obtain a lower bound. Then, we propose a Lagrangian heuristic, L, that generates both a lower bound and an upper bound in each iteration. The above heuristics were tested with 50 test problems. We also compared the performance of L with a general‐purpose optimization package, CPLEX, using 12 test problems. The results show that L was able to identify an optimal solution in almost all cases. CPLEX found an optimal solution in all cases, but was not able to verify optimality in some instances. © 2002 Wiley Periodicals, Inc.
Deterministic radio broadcasting at low cost
Authors: Dessmark Anders , Pelc Andrzej 
Published: October 2004

AbstractWe consider distributed deterministic broadcasting in synchronous radio networks. A node receives a message in a given round if and only if exactly one of its neighbors transmits. The source message has to reach all nodes. We assume that nodes do not know the network topology or even their immediate neighborhood. (Such networks are calledad hoc.) We are concerned with two efficiency measures of broadcasting algorithms: their executiontime(number of rounds) and theircost(number of transmissions). We focus our study on the execution time of algorithms which have cost close to minimum. We consider two scenarios depending on whether nodes know or do not know global parameters of the network: the numbernof nodes and the eccentricityDof the source. Our main contribution is proving tight lower bounds on the time of low‐cost broadcasting which show sharp differences between these scenarios. In each case, we also give broadcasting algorithms whose performance matches these lower bounds. © 2002 Wiley Periodicals, Inc.
Rare and spatially segregated release sites mediate a synaptic interaction between two identified network neurons
Authors: Cabirol‐Pol Marie‐Jeanne , Combes Denis , Fénelon Valérie S , Simmers John , Meyrand Pierre 
Published: October 2004

AbstractLaser‐scanning confocal microscopy (LSCM), electron microcopy (EM), and cellular electrophysiology were used in combination to study the structural basis of an inhibitory synapse between two identified neurons of the same network. To achieve this, we examined the chemical inhibitory synapse between identified neurons belonging to the lobster (Homarus gammarus) pyloric network: the pyloric dilator (PD) and the lateral pyloric (LP) neurons. In order to visualize simultaneously these two neurons, we used intrasomatic injection of Lucifer Yellow (LY) in one and rhodamine/horseradish peroxydase (HRP) in the other. Under LSCM, we found only two zones of close apposition in a restricted part of the neuritic tree of the two network neurons. Then, within these two zones, the synaptic release sites were searched using EM. To this end, photoconversion of LY with immunogold and development of HRP with DAB were performed on the previously observed preparations. Structural evidence was found for only one release site per zone. To confirm this result, and because the zones of contact were always segregated in a restricted part of the dendrites, we used laser photoablation to selectively delete, either pre‐ or postsynaptically, the branches on which the release sites were located. In both cases, such restrictive ablation completely abolished the functional interaction between these neurons. Our results therefore demonstrate that an inhibitory synapse that is essential for the operation of a neural network relies on only very few sites of contact localized in a highly restricted part of each neuron's dendritic arbor. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 150–163, 2002; DOI 10.1002/neu.10023
Pain intensity and bioavailability of intramuscular asparaginase and a local anesthetic: A double‐blinded study
Authors: Albertsen Birgitte Klug , Hasle Henrik , Clausen Niels , Schrøder Henrik , Jakobsen Preben 
Published: October 2004

AbstractBackgroundTo evaluate if dissolution of asparaginase in lidocaine can relieve pain of an intramuscular injection in children without changes in bioavailability.ProcedureThe study was designed as a double‐blinded study, randomizing 12 children with acute lymphoblastic leukemia (ALL) to four different combinations of injections, including two injections where asparaginase was dissolved in a lidocaine solution and two in sterile water. Seventeen treatment courses of asparaginase, each consisting of four injections, were evaluated.Pain intensity (Pain Visual Analog Scale, VAS‐score) and pharmacokinetics of the drug was evaluated.ResultsThe pain scores showed a significant difference between the two solutions of asparaginase (±lidocaine) (P value < 0.0001). Lidocaine did not influence the pharmacokinetics of the drug.ConclusionsAsparaginase with addition of lidocaine significantly decreases the pain as measured by the visual analog scale without changing the bioavailability or the absorption rate of the enzyme. © 2004 Wiley‐Liss, Inc.
High‐dose ifosfamide in relapsed pediatric osteosarcoma: Therapeutic effects and renal toxicity
Authors: Berrak Su Gülsün , Pearson Margaret , Berberoğlu Semha , İlhan İnci Ergürhan , Jaffe Norman 
Published: October 2004

AbstractBackgroundSixteen pediatric osteosarcoma patients, previously treated with conventional chemotherapy (including ifosfamide (IFX), 9 g/m2) were retreated with high‐dose ifosfamide (HD‐IFX, 14 g/m2 per course), following relapse or development of a new bone tumor. The objective was to obtain responses and an improved event‐free survival (EFS).ProcedureHD‐IFX was administered as described by Patel SR: J Clin Oncol 1997;15:2378. Efficacy of treatment was assessed initially after two to four courses. The interval between the courses was 3 to 4 weeks. Provided a response was obtained after two to four courses, treatment was continued for an additional eight courses unless progressive disease or an untoward event, for example, renal failure occurred. Tumor sites were: lung, (10) bone (9), and bone and soft‐tissue (1).ResultsResponse after two to four courses was 62.5%: CR 6 and PR 4. A total of 84 courses were administered to the 16 patients: (range 2–10, median 5.5 per patient). Median interval between courses was 28.5 days (range 15–90). Five patients were disease free at 15+ to 63+ months after induction and maintenance therapy. Fever and neutropenia occurred in 12 courses. Nephrotoxicity was a major toxic event and was characterized by creatinine levels at or above three times the upper limit of normal. It was unpredictable and occurred in four patients: two were reversible. The other two patients developed full‐blown renal failure; one was treated with renal dialysis, but both eventually succumbed to osteosarcoma. Our past experience also indicated that two patients treated with IFX (9 g/m2/course) developed renal failure: one recovered and the other required a renal transplant.ConclusionsHD‐IFX is effective in patients who have failed conventional chemotherapy including IFX (9 g/m2). Improved disease‐free survival was achieved in 30% of patients. However, renal failure constitutes an important life‐threatening complication and its development is unpredictable. © 2004 Wiley‐Liss, Inc.
Parental perceptions of adverse educational outcomes among children diagnosed and treated for ADHD: A call for improved school/provider collaboration
Authors: LeFever Gretchen B. , Villers Margaret S. , Morrow Ardythe L. , Vaughn, E. Sidney 
Published: October 2004

AbstractAn Erratum has been published for this article in Psychology in the Schools 42(2) 2005, 227 [].This research utilized parent report to examine the prevalence of attention deficit hyperactivity disorder (ADHD), related treatment, and associated educational outcomes among elementary school children in southeastern Virginia. In a representative sample of elementary school children, 17% had been diagnosed with ADHD. The majority of diagnosed children had been medicated for ADHD (84%). More than one third of students taking medication had received no other interventions for ADHD. Over half of the diagnosed students received behavioral therapy and almost half received a combination of medical and behavioral interventions. Children diagnosed with ADHD were 3 to 7 times ( p values < 0.001) more likely than other children to receive special education, be expelled or suspended, and repeat a grade. Based on parental opinion, children diagnosed with ADHD are at high risk for school failure. Results are discussed in terms of distinctions between clinical efficacy/effectiveness and schoolwide and public health interventions implemented in the study region. © 2002 John Wiley & Sons, Inc.
Differential ability scales: Profiles of preschoolers with cognitive delay
Authors: Hughes Tammy L. , McIntosh David E. 
Published: October 2004

AbstractThis study examined the cluster profiles obtained using the Differential Ability Scale (DAS, Elliott, 1990a) for preschool children diagnosed with cognitive delay and for those without cognitive delay. Cluster analyses resulted in distinctive profiles for each group. Profiles for preschoolers diagnosed with cognitive delay were compared with DAS profile patterns previously reported for school‐aged children diagnosed with learning disabilities (McIntosh & Gridley, 1993). Cluster comparisons indicated profiles of cognitively delayed preschoolers were not the same as those found in school‐age children with learning disabilities. Implications for prediction of school‐age learning disabilities from preschool DAS cognitive cluster profiles are discussed. © 2002 John Wiley & Sons, Inc.
Relations of middle school students' perceptions of family and school contexts with academic achievement
Authors: Marchant Gregory J. , Paulson Sharon E. , Rothlisberg Barbara A. 
Published: October 2004

AbstractThe purposes of this study were to examine the relations of both family and school contexts on students' academic achievement and to explore the mediating effects of students' perceptions of their motivations and academic self‐competence between the family and school contexts and achievement. Participants were 230 fifth‐ and sixth‐grade students. Students' perceptions of parenting style (demandingness and responsiveness), parental involvement (parental values and involvement in school functions), teaching style (teacher control and responsiveness), and school atmosphere (school responsiveness and supportive social environment) significantly predicted their school achievement; however, students' motivations and self‐competence mediated the relations between students' contexts and their academic achievement. Furthermore, parental values, teacher responsiveness, school responsiveness, and supportive social environment predicted students' motivations and academic competence above and beyond parenting style, parental involvement, and teacher control. The importance of students' supportive relationships and the internalization of the messages conveyed to them underscore the need for a contextual view by school psychologists when consulting with parents and education staff regarding achievement concerns. © 2001 John Wiley & Sons, Inc.
Polymerization of sterically congested α‐alkylacrylates under high pressure
Authors: Rzayev Javid , Penelle Jacques 
Published: October 2004

AbstractA series of α‐alkylacrylates, including methyl ethacrylate (MEA), methyl α‐propylacrylate, methyl α‐isopropylacrylate (MiPA), methyl α‐butylacrylate (MnBA), and methyl α‐isobutylacrylate (MiBA), were successfully polymerized at 65 °C under high pressure (1–9 kbar). In contrast to results obtained at ambient pressure, all monomers yielded high molecular weight polymers (number‐average molecular weight = 4–18 × 104), except for MiPA (number‐average molecular weight = 8 × 103), probably because of the high steric hindrance of the isopropyl group. Polymerization kinetics under high pressure were obtained for MEA, MnBA, and MiBA. Overall activation volumes were estimated to be −14.9, −17.0, and −11.6 mL mol−1 for MEA (3–7 kbar), MnBA (3–7 kbar), and MiBA (5–9 kbar), respectively. Extrapolation to ambient pressure provided rates of polymerization for these monomers unaffected by the ceiling temperature effect. These values were further used to quantitatively assess the steric influence exerted by the α‐substituent on the polymerizability of these sterically congested acrylates with Meyer's steric parameter. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 836–843, 2002; DOI 10.1002/pola.10161
Analogy in adsorption behavior of homopolyelectrolyte mixtures as compared to analogous diblock polyampholytes
Authors: Mahltig B. , Gohy J.‐F. , Jérôme R. , Buchhammer H.‐M. , Stamm M. 
Published: October 2004

AbstractThe adsorption behavior of aqueous mixtures of the homopolyelectrolytes poly(methacrylic acid) (PMAA) and poly[(dimethylamino)ethyl methacrylate] (PDMAEMA) was investigated in comparison with the adsorption of the ampholytic diblock copolymer PMAA‐b‐PDMAEMA on silicon substrates. Ellipsometry was used to determine the amount of adsorbed homopolyelectrolyte and diblock polyampholyte. Furthermore, the topography of the adsorbed polymers was investigated with atomic force microscopy (AFM) and compared with the structures observed in aqueous solutions by dynamic light scattering (DLS). For all types of investigated polyelectrolytic mixtures or the single polyampholyte, the adsorption was strongly influenced by the pH of the polymer solution. Although single homopolyelectrolytes showed only one maximum in adsorption according to their charge, the mixtures made from these homopolyelectrolytes showed two or three maxima. The third maximum near the isoelectric point of the mixture was assigned to a new species formed by aggregation of the two homopolyelectrolytes. Altogether, the adsorption behavior of the polyelectrolytic mixtures was in between the behavior of the pure homopolyelectrolytes and the analogous polyampholytes and therefore understandable from both of these polymer species. © 2002 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 40: 338–345, 2002; DOI 10.1002/polb.10091
Time‐resolved backbone desolvation and mutational hot spots in folding proteins
Authors: Fernández Ariel 
Published: October 2004

AbstractA method is presented to identify hot mutational spots and predict the extent of surface burial at the transition state relative to the native fold in two‐state folding proteins. The method is based on ab initio simulations of folding histories in which transitions between coarsely defined conformations and pairwise interactions are dependent on the solvent environments created by the chain. The highly conserved mammalian ubiquitin is adopted as a study case to make predictions. The evolution in time of the chain topology suggests a nucleation process with a critical point signaled by a sudden quenching of structural fluctuations. The occurrence of this nucleus is shown to be concurrent with a sudden escalation in the number of three‐body correlations whereby hydrophobic units approach residue pairs engaged in amide‐carbonyl hydrogen bonding. These correlations determine a pattern designed to structure the surrounding solvent, protecting intramolecular hydrogen bonds from water attack. Such correlations are shown to be required to stabilize the nucleus, with kinetic consequences for the folding process. Those nuclear residues that adopt the dual role of protecting and being protected while engaged in hydrogen bonds are predicted to be the hottest mutational spots. Some such residues are shown not to retain the same protecting role in the native fold. This kinetic treatment of folding nucleation is independently validated vis‐a‐vis a Φ‐value analysis on chymotrypsin inhibitor 2, a protein for which extensive mutational data exists. Proteins 2002;47:447–457. © 2002 Wiley‐Liss, Inc.
Energy spectrum of extended Hubbard model with spin‐dependent hopping and related spin ladder model
Authors: Cheranovskii V. O. , Ezerskaya E. V. , Özkan I. 
Published: October 2004

AbstractWe studied the energy spectrum of the 1‐D extended Hubbard model with spin‐dependent hopping and related spin ladder system formed by two coupled XXZ spin 1/2 chains with the interchain interaction of Ising type. It was proved that the model excitation spectrum has no gap excepting some special values of z‐projection of the ground‐state total spin. The thorough analytic consideration of two‐magnon states was given. The existence up to five bound states at specified value of quasimomentum of the pair of inverted spins was shown. We also present the results of density matrix renormalization group calculations that showed nonadequacy of the pair approximation for n‐magnon bound states of the extended model with the strong electron–electron interactions. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Generic molecular mechanics as based on local quantum description of molecular electronic structure
Authors: Tokmachev A. M. , Tchougréeff A. L. 
Published: October 2004

AbstractMolecular mechanics (MM) is now widely used for modeling potential energy surfaces of large organic molecules. All MM schemes use ad hoc forms for the potential functions and parameters specially adjusted to fit experimental or quantum chemical data. In this work we attempt to deduce a generic MM scheme starting from a local quantum mechanical description of molecular electronic structure. The basis for this derivation is the trial electronic wave function in the form of antisymmetrized product of strictly localized geminals. The MM scheme obtained does not require adjusting any parameters. The quality of numerical estimates obtained by this scheme is analyzed. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Ab initio quantum chemical calculations of a cluster C8H12
Authors: Timokhina Helen N. , Ovchinnikov Alexander A. , Bozhenko Konstantin V. 
Published: October 2004

AbstractUsing unrestricted Hartree–Fock–Roothaan approximation and density functional theory on 6‐31G* basis, ab initio calculation cluster C8H12 has been carried out. It was shown as a result of calculations that a ground state for the conformation given is a septet state. This cluster can be used for investigation of the kinematic mechanism of magnetic exchange and magnetic ordering in polyradicals. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Metallomacrocycle (MacM) complex with cyanide as bridged ligand: Electronic structures of [MacMCN]n
Authors: Mendizabal Fernando , Olea‐Azar Claudio 
Published: October 2004

AbstractThe electronic structures of complexes and one‐dimensional metallomacrocycles with cyanide as bridged ligand, such as [MacM(CN)2]− and [MacM(CN)]n [Mac=phthalocyanine, tetrabenzoporphyrine; M=Co(III), Rh(III)] have been investigated using density functional theory. The results of this study show that the intrinsic semiconductivity properties depend on the frontier bands. The valence band is composed by the π‐macrocycle orbital. The conduction band for the cobalt polymers is a mixture of orbitals between this metal and the cyanide ligand along of the stacking direction. However, in the rhodium polymers such a band is exclusively composed of the π* system of the macrocycles. © 2002 John Wiley & Sons, Inc. Int J Quantum Chem, 2002
An analysis of labwork tasks used in science teaching at upper secondary school and university levels in several European countries
Authors: Tiberghien Andrée , Veillard Laurent , Le Maréchal Jean‐François , Buty Christian , Millar Robin 
Published: October 2004

AbstractThis article describes the results of a study of the similarities and differences in laboratory tasks used in science education at upper secondary school and university level, in the three main science subjects, in seven European countries. The data source for the study was a collection of 75 laboratory instruction sheets for use at school level in five countries, and 90 for use at university level in six countries, selected as being “typical” of practice in these countries. The tool used for analysis was a “map” (or classification system) for labwork tasks. Whilst some differences are noted between the science subjects and between educational levels, the dominant impression from this analysis is of similarity across educational levels, science subjects and countries. Some coding categories arise only very infrequently, suggesting that some possible designs of labwork task are very seldom used. The findings indicate the potential usefulness of this classificatory “map” as a tool for monitoring practice and for raising questions about the use of labwork in science education. © 2001 John Wiley & Sons, Inc. Sci Ed 85:483–508, 2001.
Infants with single ventricle: A population‐based epidemiological study
Authors: Steinberger Eileen K. , Ferencz Charlotte , Loffredo Christopher A. 
Published: October 2004

AbstractBackgroundSingle ventricle, a rare congenital cardiac defect, often occurs as part of a complex group of cardiovascular abnormalities. Little is known of its epidemiologic associations.MethodsUsing data from the Baltimore‐Washington Infant Study [BWIS], (1981–89), a population based case‐control study of cardiovascular malformations, infants with single ventricle were evaluated with respect to infant and family characteristics and maternal and paternal exposures. The cases were analyzed according to presence/absence of abnormal cardio‐visceral situs. Controls were 3,572 infants without heart defects randomly selected from the regional cohort of live births. Odds ratios and 95% confidence intervals were used as measures of association.ResultsSingle ventricle occurred in 1.25% of infants with congenital cardiovascular defects in the BWIS. Fifty‐five infants had single ventricle. In 48 families (87.3%) the parents were interviewed. Thirty‐three infants had normal situs and 15 had abnormal situs. Paternal alcohol consumption (OR = 2.0, 95% CI 1.1–3.9) and paternal cigarette smoking (OR = 2.4, 95% CI 1.1–5.1) were associated with all cases of single ventricle. These associations were even stronger in the subset of infants with abnormal situs. Maternal history of a previous induced abortion was also associated with infants born with abnormal situs (OR = 3.2, 95% CI 1.1–11.5). Paternal marijuana use was associated with cases of single ventricle in normal situs (OR = 2.2, 95% CI 1.0–5.2).ConclusionsPotential risk factors included paternal smoking and alcohol consumption, highlighting the need for future studies to consider environmental factors in the pathogenesis of this cardiac defect. Teratology 65:106–115, 2002. © 2002 Wiley‐Liss, Inc.