bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of sequential data assimilation methods for the Kuramoto–Sivashinsky equation
Authors: Jardak M. , Navon I. M. , Zupanski M. 
Published: February 2009

AbstractThe Kuramoto–Sivashinsky equation plays an important role as a low‐dimensional prototype for complicated fluid dynamics systems having been studied due to its chaotic pattern forming behavior. Up to now, efforts to carry out data assimilation with this 1‐D model were restricted to variational adjoint methods domain and only Chorin and Krause (Proc. Natl. Acad. Sci. 2004; 101(42):15013–15017) tested it using a sequential Bayesian filter approach. In this work we compare three sequential data assimilation methods namely the Kalman filter approach, the sequential Monte Carlo particle filter approach and the maximum likelihood ensemble filter methods. This comparison is to the best of our knowledge novel. We compare in detail their relative performance for both linear and nonlinear observation operators. The results of these sequential data assimilation tests are discussed and conclusions are drawn as to the suitability of these data assimilation methods in the presence of linear and nonlinear observation operators. Copyright © 2009 John Wiley & Sons, Ltd.
Spending on new drug development1
Authors: Adams Christopher Paul , Brantner Van Vu 
Published: February 2009

AbstractThis paper replicates DiMasi et al. (J. Health Econ. 2003; 22: 151–185; Drug Inf. J. 2004; 38: 211–223) estimates of expenditure on new drug development using publicly available data. The paper estimates that average expenditure on drugs in human clinical trials is around $27m per year, with $17m per year on drugs in Phase I, $34m on drugs in Phase II and $27m per year on drugs in Phase III of the human clinical trials. The paper's estimated expenditure on new drug development is somewhat greater than suggested by the survey results presented in DiMasi et al. (J. Health Econ. 2003; 22: 151–185; Drug Inf. J. 2004; 38: 211–223). The paper combines a 12‐year panel of research and development expenditure for 183 publicly traded firms in the pharmaceutical industry with panel of drugs in human clinical trials for each firm over the same period. The paper estimates drug expenditure by estimating the relationship between research and development expenditure and the number of drugs in development for 1682 company/years (183 firms multiplied by the number of years for which we have financial and drug development information). The paper also estimates expenditure on drugs in various therapeutic categories. Copyright © 2009 John Wiley & Sons, Ltd.
Statistical implications of utility weighted and equally weighted HRQL measures: an empirical study
Authors: Wilke Caitlyn T. , Pickard A. Simon , Walton Surrey M. , Moock Joern , Kohlmann Thomas , Lee Todd A. 
Published: February 2009

AbstractThe utility‐based approach to health measurement, exemplified by EQ‐5D and Health Utilities Index (HUI), has been challenged on a theoretical basis, but the statistical implications of such an approach have received little attention. To empirically investigate this issue, psychometric properties and statistical efficiency of the EQ‐5D and HUI Mark 3 (HUI3) classifiers were compared when scored using preference weighted (WPS) and equally weighted summary scores using two longitudinal datasets (nstroke=124; nrehabilitation=264). Test–retest reliability, construct validity, responsiveness, and relative efficiency (RE) ratios (with bootstrapped 95% confidence intervals) were examined. WPS had slightly lower test–retest reliability, particularly for EQ‐5D (intraclass correlation coefficient=0.61 vs 0.72). For known‐groups comparisons, WPS had greater inferential power for both EQ‐5D and HUI3 (RE>1). No significant differences in sensitivity to change were observed for EQ‐5D [0.71 (95% CI: 0.29,1.33)≤RE≤0.96(95% CI: 0.69,1.32)] or HUI3 [0.97 (95% CI: 0.89,1.03)≤RE≤1.23 (95% CI: 0.98,1.72)]. Implications of weighted scoring will depend on whether the weights are greater or less than equal weights where patients fall along the health state classifier continuum. Because utility weights can affect the statistical properties and significance of results, the summary score selected should be appropriate to the purpose of the study and population of interest. Copyright © 2009 John Wiley & Sons, Ltd.
Central nervous system dissemination in immunocompetent patients with aggressive lymphomas: incidence, risk factors and therapeutic options
Authors: Ferreri Andrés J. M. , Assanelli Andrea , Crocchiolo Roberto , Ciceri Fabio 
Published: February 2009

AbstractCentral nervous system (CNS) dissemination is a rare (4–5%) but usually fatal complication of aggressive lymphomas. Prophylaxis modalities to prevent CNS dissemination in aggressive lymphomas cannot be widely applied to every lymphoma patient since it is associated with increased risk of neurotoxicity. Therefore, identification of high‐risk patients as the best candidates to receive CNS prophylaxis constitutes a major endpoint in the management of these malignancies. Various risk factors and models for CNS recurrence have been described. Parameters reflecting the extent and proliferation of the disease, like elevated serum lactate dehydrogenase levels, involvement of multiple extranodal sites, advanced stage and high age‐adjusted International Prognostic Index (IPI) score, as well as the involvement of specific anatomic sites, like testes, orbit, paranasal sinuses, have been identified and confirmed as important to predict CNS dissemination. Management of this complication in aggressive lymphomas with conventional‐dose chemotherapy is associated with disappointing results, while some preliminary but encouraging experiences suggest a potential role of high‐dose chemotherapy and stem cell transplantation. The analysis of recent clinical studies could lead to advancement in the prognosis of aggressive lymphomas, but several questions regarding the optimum chemotherapy combination, the best conditioning regimen and the role of radiation therapy and intrathecal chemotherapy remain still unanswered. The purposes of the present review are to critically analyse current data on the risk of CNS dissemination in aggressive lymphomas, the clinical presentation of secondary CNS lymphomas and the efficacy of CNS prophylaxis as well as to discuss the available therapeutic options for this devastating event. Copyright © 2009 John Wiley & Sons, Ltd.
Modeling the adhesion of human embryonic stem cells to poly(lactic‐co‐glycolic acid) surfaces in a 3D environment
Authors: Gao Steven Y. , Lees Justin G. , Wong Jennifer C. Y. , Croll Tristan I. , George Peter , Cooper‐White Justin J. , Tuch Bernard E. 
Published: February 2009

AbstractHuman embryonic stem cells (hESCs) have previously been cultured on three dimensional (3D) biodegradable polymer scaffolds. Although complex structures were formed from the hESCs, very little is known about the mechanism of adhesion of these cells to the surfaces of the scaffolds. In this study, we achieved the efficient adhesion of pluripotent hESCs to 3D poly(lactic‐co‐glycolic acid) (PLGA) scaffolds based on our data from a novel two dimensional (2D) model that imitates the surface properties of the scaffolds. In the 2D model, single cell preparations of pluripotent hESCs adhered efficiently and predominantly to PLGA surfaces coated with laminin in comparison to collagen I, collagen IV, or fibronectin‐coated surfaces. Flow cytometry analysis revealed that almost all of the pluripotent single cells expressed the integrin α6, with a small percentage also expressing α3ß1, which facilitates adhesion to laminin. This data was then translated into the 3D environment, with the efficient binding of single pluripotent hESCs to PLGA scaffolds coated with laminin. The utility of this system was shown by the directed differentiation of single hESCs seeded within laminin‐coated scaffolds toward the endoderm lineage. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Recombinant retrovirus‐like particle forming DNA vaccines in prime‐boost immunization and their use for hepatitis C virus vaccine development
Authors: Desjardins Delphine , Huret Christophe , Dalba Charlotte , Kreppel Florian , Kochanek Stefan , Cosset François‐Loïc , Tangy Frédéric , Klatzmann David , Bellier Bertrand 
Published: February 2009

AbstractBackgroundThe expression of Moloney murine leukemia virus (Mo‐MLV) gag proteins is sufficient to generate retrovirus‐like particles (retroVLPs) that can be used as antigen‐display platforms by pseudotyping with heterologous envelope proteins or by insertion of epitopes in structural constituents. To circumvent the in vitro production of such retroVLPs, we used DNA plasmids generating recombinant retroVLPs (plasmo‐retroVLPs) as immunogens. We previously demonstrated that plasmo‐retroVLPs induce significantly better antigen‐specific T cell responses and antiviral immune protection than plasmids bearing a single mutation preventing retroVLPs assembly. In the present study, we investigated the possibility of using such plasmo‐retroVLPs in prime‐boost immunization strategies for hepatitis C virus (HCV) vaccine development.MethodsTo define the best immunization regimen with plasmo‐retroVLPs and serotype 5 recombinant adenovirus vectors (rAd5), we used standardized methodologies measuring immune responses to the GP33–41 ‘gold standard’ antigen. The protective efficacy of these immunization schedules was also evaluated in mice after tumor challenge. We then applied the optimal prime‐boost immunization strategy using vectors expressing HCV‐E1/E2 envelope glycoproteins.ResultsUsing vectors expressing the model antigen, we demonstrated that rAd5GP33–41/plasmo‐retroVLPGP33–41 regimen induced significantly higher cellular immune responses than plasmo‐retroVLPGP33–41/rAd5GP33–41. Consequently, HCV‐specific plasmo‐retroVLPs (plasmo‐retroVLPE1E2) were used as boost in mice primed with rAd5E1E2 and we observed that plasmo‐retroVLPE1E2 significantly increased E1/E2‐specific interferon‐γ cellular responses and E2‐specific antibody generation. By contrast, plasmids unable to form E1/E2‐pseudotyped retroVLPs had no boosting effect, revealing the importance of presenting E1/E2 in a particulate form.ConclusionsAltogether, combining plasmo‐retroVLPs that represent a new class of genetic vaccines in a heterologous prime‐boost vaccination strategy appears to be a promising strategy for HCV vaccine development. Copyright © 2009 John Wiley & Sons, Ltd.
HPLC methods for the purification of [11C]‐labelled radiopharmaceuticals: reversal of the retention order of products and precursors
Authors: Lehel Szabolcs , Madsen Jacob , Gillings Nic 
Published: February 2009

AbstractPreparative HPLC methods have been developed for a number of [11C]‐methylated PET tracers, which enable elution of the labelled compounds prior to their precursors, thus reducing the overall synthesis time and avoiding contamination of the final product with precusor. This reversal of retention order has been achieved for [11C]DASB, [11C]raclopride, [11C]FLB 457, [11C]carfentanil, and 2‐fluoro‐[N‐methyl‐11C]apomorphine, enabling collection of the purified radiopharmaceuticals from the HPLC system after 5–7 min. Furthermore, by using ethanol as the organic modifier, residual solvent analysis prior to human injection could be avoided and three of the radiopharmaceuticals could be injected directly following simple dilution and sterile filtration. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and biodistribution of novel 99mTc‐nitrido methylpiperidine dithioformate derivatives as potential brain imaging agents
Authors: Lu Jie , Xu Mingyan , Jia Hongmei , Xi Shuxia , Wang Yimeng , Wang Xuebin 
Published: February 2009

AbstractThree dithioformate ligands with methyl substituted on the piperidine rings, potassium 1‐(2‐methylpiperidine‐1‐yl)‐dithioformate (2‐mp), potassium 1‐(3‐methylpiperidine‐1‐yl)‐dithioformate (3‐mp) and potassium 1‐(4‐methylpiperidine‐1‐yl)‐dithioformate (4‐mp) were synthesized. The corresponding 99mTc‐nitrido complexes were prepared in high yield (>95%) through the [99mTcN] intermediate and characterized by thin layer chromatography and high‐performance liquid chromatography. All the neutral 99mTc‐nitrido complexes were stable under physiological conditions and lipophilic with log P values between 1.40 and 1.58. In vivo biodistribution results showed that all the 99mTc‐nitrido complexes displayed high brain uptakes and long retention times. Among them, 99mTcN‐4mp, demonstrated the best properties for brain imaging with the brain uptake 3.40±0.24, 3.22±0.31, 2.72±0.28 and 2.22±0.18% ID/g at 5, 30, 60 and 120 min p.i., respectively. Moreover, the influence of stereochemistry of the 99mTcN complexes with methyl substitution on ortho, meta and para positions on piperidine ring on the biodistribution properties were investigated with B3LYP/6‐31G*(LANL2DZ for Tc) method using the Gaussian 03 program package. Copyright © 2009 John Wiley & Sons, Ltd.
Structure of male accessory glands of Bolivarius siculus (fischer) (Orthoptera, Tettigoniidae) and protein analysis of their secretions
Authors: Marchini Daniela , Brundo Maria Violetta , Sottile Lorenzo , Viscuso Renata 
Published: February 2009

AbstractIn Tettigoniidae (Orthoptera), male reproductive accessory glands are involved in the construction of a two‐part spermatophore; one part, the spermatophylax, is devoid of sperm and considered a nuptial gift. The morphology, ultrastructure, and secretion protein content of the male reproductive accessory glands from Bolivarius siculus were investigated. Two main groups of gland tubules open into the ejaculatory duct: the “first‐order” glands, a number of large anterior tubules, and the “second‐order” glands, smaller and more numerous tubules positioned posteriorly. Along with a further subdivision of the gland tubules, we here describe for the first time an additional gland group, the intermediate tubules, which open between first and second‐order glands. The mesoderm‐derived epithelium of all glands is a single layer of microvillated cells, which can be either flattened or cylindric in the proximal or distal region of the same gland. Epithelial cells, very rich in RER and Golgi systems, produce secretions of both electron‐dense granules and globules or electron‐transparent material, discharged into the gland lumen by apocrine or merocrine mechanisms, respectively. With one exception, a unique electrophoresis protein profile was displayed by each of the gland types, paralleling their unique morphologies. To assess the contribution of different types of accessory glands to the construction of the spermatophore, the protein patterns of the gland secretions were compared with those of the extracts from the two parts of the spermatophore. All samples showed bands distributed in a wide range of molecular weight, including proteins of very low molecular mass. However, one major high molecular weight protein band (>180 kDa) is seen exclusively in extracts from the first‐order glands, and corresponds to an important protein component of the spermatophylax. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.
Morphological characterization of the testicular cells and seminiferous epithelium cycle in six species of Neotropical bats
Authors: Beguelini Mateus R. , Moreira Paula R.L. , Faria Karina C. , Marchesin Sandra R.C. , Morielle‐Versute Eliana 
Published: February 2009

AbstractWe know little about the process of spermatogenesis in bats, a great and diverse clade of mammals that presents different reproductive strategies. In the present study, spermatogenesis in six species of Neotropical bats was investigated by light microscopy. On the basis of chromatin condensation, nuclear morphology, relative position to the basal membrane and formation of the flagellum, three types of spermatogonia were recognized: dark type A (Ad), pale type A (Ap), and type B; the development of spermatids was divided into seven steps. With the exception of Myotis nigricans, the seminiferous epithelium cycle of the other five species studied was similar to those of other mammals, showing gradual stages by the tubular morphology method. Asynchrony was observed in the seminiferous epithelium cycle of M. nigricans, shown by overlapping stages and undefined cycles. The frequencies found in the three phases of the cycle were variable with the greatest frequency occurring in the postmeiotic phase (>50%) and the least in the meiotic phase (<10%). The similarities observed in the five species of Phyllostomidae appeared to be related to their phylogenetic relationship and shorter divergence times, whereas the differences in M. nigricans appeared to be related to its greater phylogenetic distance because the Vespertilionidae family diverged earlier. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.
Regional climate model simulation of winter climate over Central–Southwest Asia, with emphasis on NAO and ENSO effects
Authors: Syed F. S. , Giorgi F. , Pal J. S. , Keay Kevin 
Published: February 2009

AbstractWe present a regional climate modeling study of the winter climate of Central–Southwest Asia (CSWA), focusing on the mean model climatology of temperature and precipitation, the simulated storm characteristics and the effects of El‐Nino Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) on storm activity and precipitation. Forty‐three winter seasons are simulated with the model RegCM3 driven by ERA40 reanalysis fields over a region encompassing CSWA and the Mediterranean sector. The model shows a good performance in reproducing the observed mean surface climate of the region as well as the characteristics of the western disturbances affecting CSWA. Observations show that both the NAO and ENSO have a substantial influence on the CSWA climate, particularly in the region of Northern Pakistan, Afghanistan and Tajikistan, where precipitation increases (decreases) during the positive (negative) NAO phase and warm (cold) ENSO phase. The model captures well the observed signals and a detailed storm analysis shows that they are mostly associated with an intensification of western disturbances originating in the Eastern Mediterranean and Middle East regions and moving eastward across a 500 hPa trough situated over the CSWA during the positive NAO and warm ENSO phases. The NAO and ENSO signals are reinforced by enhanced moisture sources from the Mediterranean, Caspian and Arabian Seas. Our study provides encouraging indications towards the use of the model RegCM3 for climate simulations over CSWA. Copyright © 2009 Royal Meteorological Society
Thermoelastic rolling contact problem with temperature dependent friction
Authors: Chudzikiewicz Andrzej , Myslinski Andrzej 
Published: February 2009

AbstractThe paper is concerned with the numerical solution of a thermoelastic rolling contact problem with wear. The friction between the bodies is governed by Coulomb law. A frictional heat generation and heat transfer across the contact surface as well as Archard's law of wear in contact zone are assumed. The friction coefficient is assumed to depend on temperature. In the paper quasistatic approach to solve this contact problem is employed. This approach is based on the assumption that for the observer moving with the rolling body the displacement of the supporting foundation is independent on time. The original thermoelastic contact problem described by the hyperbolic inequality governing the displacement and the parabolic equation governing the heat flow is transformed into elliptic inequality and elliptic equation, respectively. In order to solve numerically this system we decouple it into mechanical and thermal parts. Finite element method is used as a discretization method. Numerical examples showing the influence of the temperature dependent friction coefficient on the temperature distribution and the length of the contact zone are provided. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability calculation of travelling waves in a simplified brake model
Authors: Steindl Alois 
Published: February 2009

AbstractWe consider a system composed of an elastic tube, which is fixed at the outer boundary and in frictional contact with a rigid cylinder, rotating inside the tube about the common axis.Using a 1–mode Galerkin ansatz in radial direction, a non–smooth PDE for the tangential and radial deformations at the contact between the two bodies is obtained. It has been shown ([1]) that different types of travelling stick–slip–separation waves exist, but these waves are unstable for most parameter values. In this investigation we first enlarge the model by viscuous damping and second we introduce a larger number of nodes in radial direction for the numerical analysis. The influence of these two effects on the shape and stability of the travelling waves is studied. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Weight Functions Method in Stability Study of Systems
Authors: Stroe Ion , Parvu Petrisor 
Published: February 2009

AbstractA new method for systems stability analysis is presented. This method is called weight functions method and it replaces the problem of Liapunov function finding with a problem of finding a number of functions (weight functions) equal to the number of first order differential equations describing the system. It is known that there are not general methods for finding Liapunov functions. The weight functions method is simpler than the classical method since one function at a time has to found. Conditions of solution stability for linear and nonlinear systems and some examples are presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Zum Einfluss von Fahrzeugparametern auf die Schädigung von Straßen
Authors: Vogt Heike , Seemann Wolfgang 
Published: February 2009

AbstractBedingt durch erhöhte Transportnachfragen und höhere Achslasten hat in den vergangenen Jahren die Belastung der Straßen stetig zugenommen. Unter diesem Aspekt ist es wichtig, die grundlegenden Mechanismen, die zur Schädigung der Straße beitragen, zu verstehen, um Verbesserungsmöglichkeiten aufzuzeigen. Während schon seit längerem experimentelle Arbeiten durchgeführt werden, sind grundlegende analytische Untersuchungen bisher eher rar (siehe beispielsweise [1]).In dieser Arbeit werden deshalb die Wechselwirkungen zwischen Straße und Fahrzeug genauer betrachtet. Die Straße wird dabei als viskoelastische Schicht modelliert, während als Fahrzeugmodell ein Einmassenschwinger gewählt wird.Der Einfluss unterschiedlicher Parameter auf die Verformung der Straße wird untersucht. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamic response analysis of the two stators hybrid transducer type piezoelectric ultrasonic motor using finite element simulation
Authors: Nantawatana Weerayuth , Seemann Wolfgang 
Published: February 2009

AbstractThis paper presents the finite element simulation with an aim to analyse the dynamic response of the two stators hybrid transducer type piezoelectric ultrasonic motor. The three dimensional–model which includes the effects of piezoelectric coupling are formulated. The dynamic behaviours of a motor stator are calculated and later compared to the experimental results measured from the prototype of this motor. The impedance characteristic of the complete stator is validated using HP4294A precision impedance analyzer. In addition to the electrical measurements, the mechanical displacement and the mechanical velocity of the stator are measured directly using a single point laser Doppler vibrometer. This is to verify that finite element modelling is an appropriate approach to analyse the dynamic behaviour of this piezoelectric ultrasonic motor. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)