bluuebunny/crossref_metadata_2025_split huggingface dataset:
A transmission problem with imperfect contact for an unbounded multiply connected domain
Authors: Castro L. P. , Pesetskaya E. 
Published: August 2009

AbstractAn analysis of the flux of certain unbounded doubly periodic multiply connected domains with circle disjoint components is performed. This is done under generalized non‐ideal contact conditions on the boundary between domain components, which include analytic given data. A formula for the flux that depends on the conductivity of components, their radii, centers, the conductivity of the matrix, and also certain values of special Eisenstein functions is derived. Existence and uniqueness of solution to the problem are obtained by using a transmission problem with imperfect contact for analytic functions in corresponding Hardy spaces. Copyright © 2009 John Wiley & Sons, Ltd.
Wavelets invariant under finite reflection groups
Authors: Bernardes G. , Bernstein S. , Cerejeiras P. , Kähler U. 
Published: August 2009

AbstractIn this paper we use approximate identities in the Dunkl setting in order to construct spherical Dunkl wavelets, which do not involve the knowledge of the intertwining operator, the Dunkl translation or of the Dunkl transform. The practicality of the proposed approach will be shown with the example of Abel‐Poisson wavelets. Copyright © 2009 John Wiley & Sons, Ltd.
Assessment of myocardial blood flow (MBF) in humans using arterial spin labeling (ASL): Feasibility and noise analysis
Authors: Zun Zungho , Wong Eric C. , Nayak Krishna S. 
Published: August 2009

AbstractArterial spin labeling (ASL) is a powerful tool for the quantitative measurement of tissue blood flow, and has been extensively applied to the brain, lungs, and kidneys. ASL has been recently applied to myocardial blood flow (MBF) measurement in small animals; however, its use in humans is limited by inadequate signal‐to‐noise ratio (SNR) efficiency and timing restrictions related to cardiac motion. We present preliminary results demonstrating MBF measurement in humans, using cardiac‐gated flow‐sensitive alternating inversion recovery (FAIR) tagging and balanced steady‐state free precession (SSFP) imaging at 3T, and present an analysis of thermal and physiological noise and their impact on MBF measurement error. Measured MBF values in healthy volunteers were 1.36 ± 0.40 ml/ml/min at rest, matching the published literature based on quantitative 13N‐ammonia positron emission tomography (PET), and increased by 30% and 29% with passive leg elevation and isometric handgrip stress, respectively. With thermal noise alone, MBF can be quantified to within ± 0.1 ml/ml/min with 85.5% confidence, for 3.09 cm3 regions averaged over 6 breath‐holds. This study demonstrates the feasibility of quantitative assessment of myocardial blood flow in humans using ASL, and identifies SNR improvement and the reduction of physiological noise as key areas for future development. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Spin‐locked balanced steady‐state free‐precession (slSSFP)
Authors: Witschey Walter R.T. , Borthakur Ari , Elliott Mark A. , Magland Jeremy , McArdle Erin L. , Wheaton Andrew , Reddy Ravinder 
Published: August 2009

AbstractA spin‐locked balanced steady‐state free‐precession (slSSFP) pulse sequence is described that combines a balanced gradient‐echo acquisition with an off‐resonance spin‐lock pulse for fast MRI. The transient and steady‐state magnetization trajectory was solved numerically using the Bloch equations and was shown to be similar to balanced steady‐state free‐precession (bSSFP) for a range of T2/T1 and flip angles, although the slSSFP steady‐state could be maintained with considerably lower radio frequency (RF) power. In both simulations and brain scans performed at 7T, slSSFP was shown to exhibit similar contrast and signal‐to‐noise ratio (SNR) efficiency to bSSFP, but with significantly lower power. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Robust quantification of contrast agent (CA) concentration with magnetic field correlation (MFC) imaging
Authors: Patil Vishal , Johnson Glyn , Jensen Jens H. 
Published: August 2009

AbstractContrast‐enhanced perfusion studies of the brain by means magnetic resonance imaging (MRI) are used to estimate a number of important brain tissue parameters, including cerebral blood flow and volume. In order to calculate these parameters, the contrast agent (CA) concentration must first be estimated. This is usually accomplished by measurement of a nuclear magnetic resonance (NMR) relaxation rate with the assumption of a linear relationship between the rate and the CA concentration. However, such a linear relationship does not necessarily hold in biological tissues due to compartmentalization of the CA in either the intravascular or extracellular spaces. Here we propose an alternative MRI method of CA quantification based on measurement of the magnetic field correlation (MFC), which is theoretically predicted to have a robust quadratic dependence on the CA concentration even when the CA is compartmentalized. In this study, CA concentration estimation by means of MFC is shown to be more accurate than established methods based on relaxation rates in yeast cell suspensions. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Inductively coupled helmholtz coil on a dedicated imaging platform for the in vivo1H‐MRS measurement of intramyocellular lipids in the hind leg of rats
Authors: Neumaier Michael , Niessen Heiko G. , Kaulisch Thomas , Stiller Detlef 
Published: August 2009

AbstractSkeletal muscle triglycerides are markers for insulin resistance in type 2 diabetes. Recently, MR spectroscopy was adapted for in vivo measurement of triglycerides in animal models and for the characterization of new therapeutic approaches. Because of small MR spectroscopy voxel sizes used in skeletal muscles, surface coils are used for signal reception. Furthermore, to obtain well‐resolved and undistorted lipid spectra, muscle fibers must be aligned parallel to the magnetic field. Consequently, to achieve a high signal‐to‐noise ratio and spectral quality, a coil setup must combine high sensitivity with a reliable and reproducible positioning of muscle and voxel. These demands are difficult to match using surface coils. Here, a coil platform is described, which uses inductively coupled Helmholtz coil setup combined with a leg retainer system for rats. The new system allows for measurement of intramyocellular lipids with high signal‐to‐noise ratio and for significantly improved animal handling, positioning, and throughput. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
A branch‐and‐price‐based large neighborhood search algorithm for the vehicle routing problem with time windows
Authors: Prescott‐Gagnon Eric , Desaulniers Guy , Rousseau Louis‐Martin 
Published: August 2009

AbstractGiven a fleet of vehicles assigned to a single depot, the vehicle routing problem with time windows (VRPTW) consists of determining a set of feasible vehicle routes to deliver goods to a set of customers while minimizing, first, the number of vehicles used and, second, total distance traveled. A large number of heuristic approaches for the VRPTW have been proposed in the literature. In this article, we present a large neighborhood search algorithm that takes advantage of the power of branch‐and‐price which is the leading methodology for the exact solution of the VRPTW. To ensure diversification during the search, this approach uses different procedures for defining the neighborhood explored at each iteration. Computational results on the Solomo's and the Gehring and Homberge's benchmark instances are reported. Compared to the best known methods, the proposed algorithm produces better solutions, especially on the largest instances where the number of vehicles used is significantly reduced. © 2009 Wiley Periodicals, Inc. NETWORKS, 2009
Edge assembly‐based memetic algorithm for the capacitated vehicle routing problem
Authors: Nagata Yuichi , Bräysy Olli 
Published: August 2009

AbstractVehicle routing problems are at the heart of most decision support systems for real‐life distribution problems. In vehicle routing problem a set of routes must be determined at lowest total cost for a number of resources (i.e., fleet of vehicles) located at one or several points (e.g., depots, warehouses) to efficiently service a number of demand or supply points. In this article a new memetic algorithm is suggested for the standard capacitated vehicle routing problem. The proposed algorithm combines the edge assembly (EAX) crossover with well‐known local searches and allows for infeasible solutions with respect to capacity and route duration constraints after invoking the crossover. To address the constraint violation, an efficient modification algorithm is also suggested. Experimental tests on 47 standard benchmarks demonstrate that the suggested method is robust and competitive, finding new best‐known solution to 20 well‐studied instances and repeating the existing best‐known solution for 24 problems in a reasonable computing time. © 2009 Wiley Periodicals, Inc. NETWORKS, 2009
Computational methods for delay parabolic and time‐fractional partial differential equations
Authors: Rihan Fathalla A. 
Published: August 2009

AbstractThis article is concerned with ϑ‐methods for delay parabolic partial differential equations. The methodology is extended to time‐fractional‐order parabolic partial differential equations in the sense of Caputo. The fully implicit scheme preserves delay‐independent asymptotic stability and the solution continuously depends on the time‐fractional order. Several numerical examples of interest are included to demonstrate the effectiveness of the method. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
Pointwise supercloseness of pentahedral finite elements
Authors: Liu Jinghong , Zhu Qiding 
Published: August 2009

AbstractThis article derives the weak estimate of the first type for pentahedral finite elements over uniform partitions of the domain for the Poisson equation. The estimate for the W1,1‐seminorm of the discrete derivative Green's function is also given. Using these two estimates, we obtain the pointwise supercloseness of derivatives of the pentahedral finite element approximation and the interpolant to the true solution. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
Comparison between variational iteration method and homotopy perturbation method for linear and nonlinear partial differential equations with the nonhomogeneous initial conditions
Authors: Ateş İnan , Yıldırım Ahmet 
Published: August 2009

AbstractIn this study, linear and nonlinear partial differential equations with the nonhomogeneous initial conditions are considered. We used Variational iteration method (VIM) and Homotopy perturbation method (HPM) for solving these equations. Both methods are used to obtain analytic solutions for different types of differential equations. Four examples are presented to show the application of the present techniques. In these schemes, the solution takes the form of a convergent series with easily computable components. The present methods perform extremely well in terms of efficiency and simplicity. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
Approximating solutions to the Dirichlet problem in Rn using one analytic function
Authors: Whitley R.J. , Hromadka T.V. , Horton S.B. 
Published: August 2009

AbstractA simpler proof is given of the result of (Whitley and Hromadka II, Numer Methods Partial Differential Eq 21 (2005) 905–917) that, under very mild conditions, any solution to a Dirichlet problem with given continuous boundary data can be approximated by a sum involving a single function of one complex variable; any analytic function not a polynomial can be used. This can be applied to give a method for the numerical solution of potential problems in dimension three or higher. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
A qualitative investigation into the donor lapsing experience
Authors: Nathan Amber , Hallam Leslie 
Published: August 2009

Abstract

Donor attrition is costing charities a fortune. Previous research has examined the relative importance of the antecedents to donor loyalty versus lapsing. This study qualitatively builds on this. It reports the results of workshops and interviews that took lapsers and donors back through their donor and lapser journeys. It drills down into and unpacks their experiences—inclusive of the (previously undocumented) lapsing experience itself. It reveals striking similarities between the cancellation of a direct debit and other more conventional purchase decisions. Most worryingly, it seems that most people stop supporting a given charity because they had never really had any loyalty to it in the first place. Charities are not meeting people's needs as donors. There is a distinct lack of understanding between charities and their donors, and donors are lapsing because charities give them little reason to stay. The authors conclude with practical recommendations for the management of attrition.

Copyright © 2009 John Wiley & Sons, Ltd.
Methoxy poly (ethylene glycol) thiosulfonate: new activated polymer derivatives for thiol‐specific modification
Authors: Zhao Yong‐Jiang , Zhai Yan‐qin , Su Zhi‐Guo , Ma Guang‐Hui 
Published: August 2009

AbstractThiol‐reactive methoxy poly (ethylene glycol) (mPEG) derivatives, mPEG methanethiosulfonate (mPEG‐MTS) and mPEG phenylthiosulfonate (mPEG‐PTS), were synthesized by one‐step S‐alkylation of mPEG‐halide with the corresponding sodium thiosulfonate. These functionalized polymers were fully characterized by 1H NMR, 13C NMR, GPC as well as MALDI‐TOF. To demonstrate the potential application of mPEG‐MTS and mPEG‐PTS, papain and recombinant human granulocyte colony‐stimulating factor (rhG‐CSF) were used as prototype protein for thiol‐selective PEGylation. The PEGylated products were verified by one or more of the following methods: SDS‐PAGE, HPLC, HPSEC as well as MALDI‐TOF. Compared with native rhG‐CSF, the PEGylated rhG‐CSF was further characterized by in vitro cell proliferative assay and preserved 59% biological activity. Furthermore, mPEG20k‐MTS was used to modify BSA nanoparticles coated with thiol groups. FT‐IR and ζ‐potential assay demonstrated that mPEG thiosulfonate can be effectively immobilized at the nanoparticles' surface via disulfide linkage to form hydrophilic and neutral corona. Therefore, we have demonstrated thiol‐selective PEG derivatives, endowed with unusual versatility, for practical use and potential exploitation. Copyright © 2009 John Wiley & Sons, Ltd.
Müller cell‐derived VEGF is a significant contributor to retinal neovascularization
Authors: Bai Yanyan , Ma Jian‐xing , Guo Junjing , Wang Juanjuan , Zhu Meili , Chen Ying , Le Yun‐Zheng 
Published: August 2009

AbstractVascular endothelial growth factor (VEGF‐A) is a major pathogenic factor and a therapeutic target for age‐related macular degeneration, diabetic retinopathy, and retinopathy of prematurity. Despite intensive effort in the field, the cellular mechanisms of VEGF action remain virtually uninvestigated. This situation makes it difficult to design cellular target‐based therapeutics for these diseases. In light of the recent finding that VEGF is a potential neurotrophic factor, revealing the cellular mechanisms of VEGF action becomes necessary to preserve its beneficial effect and inhibit its pathological function in long‐term anti‐VEGF therapeutics for ocular vascular diseases. We therefore generated conditional VEGF knockout mice with an inducible Cre/lox system and determined the significance of Müller cell‐derived VEGF in retinal development and maintenance and ischaemia‐induced neovascularizartion and vascular leakage. Retinal development in the conditional VEGF knockout mice was analysed by examining retinal and choroidal vasculatures and retinal morphology and function. Ischaemia‐induced retinal neovascularization and vascular leakage in the conditional VEGF knockout mice were analysed with fluorescein angiography, quantification of proliferative neovascular cells, immunohistochemistry, and immunoblotting using an oxygen‐induced retinopathy model. Our results demonstrated that disruption of Müller cell‐derived VEGF resulted in no apparent defects in retinal and choroidal vasculatures and retinal morphology and function, significant inhibition of the ischaemia‐induced retinal neovascularization and vascular leakage, and attenuation of the ischaemia‐induced breakdown of the blood‐retina barrier. These results suggest that the retinal Müller cell‐derived VEGF is a major contributor to ischaemia‐induced retinal vascular leakage and pre‐retinal and intra‐retinal neovascularization. The observation that a significant, but not complete, reduction of VEGF in the retina does not cause detectable retinal degeneration suggests that appropriate doses of anti‐VEGF agents may be important to the safe treatment of retinal vascular diseases. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The p53‐mediated sensitivity of cancer cells to chemotherapeutic agents is conditioned by the status of the retinoblastoma protein
Authors: Derenzini Massimo , Brighenti Elisa , Donati Giulio , Vici Manuela , Ceccarelli Claudio , Santini Donatella , Taffurelli Mario , Montanaro Lorenzo , Treré Davide 
Published: August 2009

AbstractDespite the well‐established function of p53 in determining cell cycle arrest and/or apoptosis in response to cytostatic/cytotoxic stresses, the role of the p53 status in the response to chemotherapeutic agents in human cancers has been not clearly defined. We wondered whether this was due to the fact that the p53‐mediated response to chemotherapy drugs might be conditioned by the status of the retinoblastoma protein (pRb), a downstream factor of the pathway activated by p53 stabilization, which is frequently disrupted in cancer. The dependence of p53‐mediated chemosensitivity on pRb status was first investigated in a prospective study on the prognostic relevance of p53 in breast cancer patients treated with adjuvant chemotherapy (5‐fluorouracil, methotrexate and cyclophosphamide). Univariate analysis of disease‐free survival (DFS) indicated that the p53 status, immunohistochemically evaluated, had no predictive value if considered independently of the pRb status. However, in patients with cancer with pRb neither lost nor hyperphosphorylated, p53 was significantly associated with the prognosis and, in a multivariate analysis of DFS including the established clinical and histopathological prognostic parameters, was found to be the only factor predicting the progression of the disease. We then studied the role of pRb status in the p53‐mediated response to 5‐fluorouracil and methotrexate or doxorubicin treatment in three human cancer cell lines. We found that in these cells the chemosensitivity was strictly dependent on the p53 status. However, either RB1 silencing or pRb hyperphosphorylation, caused by p16(INK4a) silencing, strongly reduced the p53‐mediated response to chemotherapeutic agents. These results demonstrated that: (a) the p53‐mediated response to chemotherapeutic agents induces a cytostatic/cytotoxic effect only in cancers with unaltered pRb pathway; and (b) the p53 status can actually predict the clinical outcome in this group of cancer patients. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Cholinergic switch associated with morphological differentiation in neuroblastoma
Authors: Bourdeaut Franck , Janoueix‐Lerosey Isabelle , Lucchesi Carlo , Paris Régine , Ribeiro Agnès , de Pontual Loïc , Amiel Jeanne , Lyonnet Stanislas , Pierron Gaëlle , Michon Jean , Peuchmaur Michel , Delattre Olivier 
Published: August 2009

AbstractThe morphology of malignant cells distinguishes between undifferentiated, poorly differentiated and differentiating neuroblastomas and constitutes a strong prognostic factor. Spontaneous or treatment‐induced maturation characterizes a subset of neuroblastomas. It constitutes the basis of retinoic acid treatment to improve survival in aggressive neuroblastomas. However, the molecular events that drive differentiation are poorly understood. In the present study we have investigated the relationships between gene expression profiles and differentiation criteria in stroma‐poor neuroblastomas. This study included three undifferentiated (UN), 20 poorly differentiated (PDN) and 11 differentiating (DN) neuroblastomas. These groups could be clearly separated using unsupervised clustering methods, which further enabled a major classification impact of genes involved in neural development, differentiation and function to be identified. UNs are characterized by highASCL1, highPHOX2B, lowGATA2, lowTHand lowDBHexpressions. Most PDNs harbour a clear adrenergic phenotype, even in the presence of missensePHOX2Bmutations. Finally, all DN tumours demonstrate cholinergic features. Depending upon their association with adrenergic characteristics, this enables dual ‘cholinergic/adrenergic’ and ‘fully cholinergic’ neuroblastomas to be defined. This suggests that the cholinergic switch, a final specification process that occurs physiologically in a minority of sympathetic neurons, is a critical step of differentiation in some neuroblastic tumours. This switch is associated with a down regulation ofDBHthat is apparently not strictly dependent uponPHOX2B. Conversely,GATA2andTFAP2Bmay play critical roles in maintaining adrenergic features in poorly differentiated tumours. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Veno‐occlusive disease as a complication of preoperative chemotherapy for Wilms tumor: A clinico‐pathological analysis
Authors: Jagt Charissa T. , Zuckermann Michelle , Ten Kate Fibo , Taminiau Jan A.J.M. , Dijkgraaf Marcel G.W. , Heij Hugo , De Kraker Jan , Verschuur Arnauld C. 
Published: August 2009

AbstractBackgroundVincristine (VCR) and actinomycin D (ACD) form the backbone of chemotherapeutic regimens of Wilms tumor treatment. Veno‐occlusive disease (VOD) is a potentially life‐threatening complication of ACD.ObjectivesTo investigate the incidence of VOD after preoperative chemotherapy and assess the effect of dose and frequency of administrating ACD on the occurrence of VOD.MethodsA single‐center retrospective study of patients where liver biopsies were performed after 4 or 8 weeks of preoperative chemotherapy. Patients had localized or metastatic Wilms tumor and were treated according to SIOP 9, 93‐1, or 2001 protocol. A correlation was analyzed between histologically confirmed VOD, laboratory parameters, and mode and frequency of ACD administration. Long‐term hepatic toxicity was assessed 5 years after the end of therapy.ResultsNinety‐one patients were included in this analysis. Forty‐one patients (45.1%) had histological evidence of VOD. The incidence of histologically proven VOD was significantly correlated with single administration of 45 µg/kg ACD (SIOP 2001 protocol) as compared to repeated dosing of l5 µg/kg (P = 0.003). Fifty‐two percent of all patients had mild‐to‐severe abnormal liver enzymes 5 years after accomplishing therapy.ConclusionDespite short‐course preoperative chemotherapy regimen, patients are at risk of developing histological VOD. This risk is higher when ACD is administered in a 1‐day 45 µg/kg regimen as compared to 3 days l5 µg/kg. Pediatr Blood Cancer 2009; 53:1211–1215. © 2009 Wiley‐Liss, Inc.