bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling tropical cyclone intensity with quantile regression
Authors: Jagger Thomas H. , Elsner James B. 
Published: December 2008

AbstractWind speeds from tropical cyclones (TCs) occurring near the USA are modeled with climate variables (covariates) using quantile regression. The influences of Atlantic sea‐surface temperature (SST), the Pacific El Niño, and the North Atlantic oscillation (NAO) on near‐coastal TC intensity are in the direction anticipated from previous studies using Poisson regression on cyclone counts and are, in general, strongest for higher intensity quantiles. The influence of solar activity, a new covariate, peaks near the median intensity level, but the relationship switches sign for the highest quantiles. An advantage of the quantile regression approach over a traditional parametric extreme value model is that it allows easier interpretation of model coefficients (parameters) with respect to changes to the covariates since coefficients vary as a function of quantile. It is proven mathematically that parameters of the Generalized Pareto Distribution (GPD) for extreme events can be used to estimate regression coefficients for the extreme quantiles. The mathematical relationship is demonstrated empirically using the subset of TC intensities exceeding 96 kt (49 m/s). Copyright © 2008 Royal Meteorological Society
Analysis of an ensemble of present day and future regional climate simulations for Greece
Authors: Zanis P. , Kapsomenakis I. , Philandras C. , Douvis K. , Nikolakis D. , Kanellopoulou E. , Zerefos C. , Repapis C. 
Published: December 2008

AbstractThis study investigates the simulated changes in temperature and precipitation over Greece from nine Regional Climate Models (RCMs) for the period 2071–2100 under the A2 emission scenario and evaluates their performance during the control period 1961–1990 using Greek gridded datasets of temperature and precipitation. In winter, most RCMs show a bias towards warmer and dryer conditions and a bias towards higher inter‐annual temperature variability and lower inter‐annual variability of precipitation than the Greek gridded datasets during the control period 1961–1990. In summer, all RCMs show a cold bias for the maritime sub‐regions and generally all sub‐regions show very small biases in precipitation. Concerning the future projections of the RCMs for Greece the mean change of the nine RCMs for the mean air temperature, T2mean, between the future period and the control period for the integrated Greek domain is 3.4 °C for winter and 4.5 °C for summer with the changes being larger in continental than in the marine sub‐regions. The inter‐annual temperature variability in the future simulations generally increases in summer and decreases in winter almost for all RCMs with these changes being larger in the continental sub‐regions than in maritime sub‐regions of Greece. Almost all RCMs simulate a decrease of the precipitation for the future climate for both winter and summer with the inter‐annual variability of summer precipitation decreasing for the majority of RCMs. The reported future climatic changes will have important impacts for the region of Greece in vital sectors such as water resources, agriculture, tourism, forest fire risk and energy demand. Copyright © 2008 Royal Meteorological Society
Surface layer climate and turbulent exchange in the ablation zone of the west Greenland ice sheet
Authors: van den Broeke Michiel , Smeets Paul , Ettema Janneke 
Published: December 2008

AbstractA comprehensive description is presented of the surface layer (SL) wind, temperature and humidity climate and the resulting sensible and latent heat exchange in the ablation zone of the west Greenland ice sheet. Over a four‐year period (August 2003–August 2007), data were collected using three automatic weather stations (AWS) located along the 67°N latitude circle at 6, 38 and 88 km from the ice sheet margin at elevations of 490, 1020 and 1520 m asl. In the lower ablation zone, surface momentum roughness peaks in summer, which enhances the mechanical generation of turbulence in the stable SL. The SL is stably stratified throughout the year: in summer, the surface temperature is maximised at the melting point and therefore remains colder than the overlying air, in winter the surface is cooled by a radiation deficit. The resulting downward directed sensible heat flux cools the SL air. Humidity gradients between surface and air are small in winter, in response to low temperatures, but peak in spring, when the surface is not yet melting and can freely increase its temperature. This is especially true for the lower ablation zone, where winter accumulation is small so that the dark ice surface is already exposed at the onset of spring, allowing significant convection and sublimation. During summer, when the surface is melting, the sensible heat flux becomes directed towards the surface and sublimation changes into deposition in the lower ablation zone. The SL wind climate is dominated by katabatic forcing, with high directional constancy in summer and winter. The katabatic forcing is important to maintain turbulent exchange in the stable Greenland SL. Copyright © 2008 Royal Meteorological Society
Determination of avoparcin in animal tissues and milk using LC‐ESI‐MS/MS and tandem‐SPE
Authors: Inoue Koichi , Mizuno Yasuomi , Yoshimi Yukiko , Nunome Mari , Hino Tomoaki , Tsutsumiuchi Kaname , Oka Hisao 
Published: December 2008

AbstractA highly sensitive and selective method using LC‐ESI‐MS/MS and tandem‐SPE was developed to detect trace amounts of avoparcin (AV) antibiotics in animal tissues and milk. Data acquisition using MS/MS was achieved by applying multiple reaction monitoring of the product ions of [M + 3H]3+ and the major product ions of AV‐α and ‐β at m/z 637 → 86/113/130 and m/z 649 → 86/113/130 in ESI(+) mode. The calculated instrumental LODs were 3 ng/mL. The sample preparation was described that the extraction using 5% TFA and the tandem‐SPE with an ion‐exchange (SAX) and InertSep C18‐A cartridge clean‐up enable us to determine AV in samples. Ion suppression was decreased by concentration rates of each sample solution. These SPE concentration levels could be used to detect quantities of 5 ppb (milk), 10 ppb (beef), and 25 ppb (chicken muscle and liver). The matrix matching calibration graphs obtained for both AV‐α (r >0.996) and ‐β (r >0.998) from animal tissues and milk were linear over the calibration ranges. AV recovery from samples was higher than 73.3% and the RSD was less than 12.0% (n = 5).
Strong stability for a fluid–structure interaction model
Authors: Grobbelaar‐Van Dalsen Marié 
Published: December 2008

AbstractIn this paper we consider the question of stabilization of a fluid–structure model that describes the interaction between a 3‐D incompressible fluid and a 2‐D plate, the interface, which coincides with a flat flexible part of the surface of the vessel containing the fluid. The mathematical model comprises the Stokes equations and the equations for the longitudinal deflections of the plate with inclusion of the shear stress, which the fluid exerts on the plate. We show that the energy associated with the model decays strongly when the interface is equipped with a locally supported dissipative mechanism. Our main tool is an abstract resolvent criterion due to Tomilov. Copyright © 2008 John Wiley & Sons, Ltd.
A geometric‐based algebraic multigrid method for higher‐order finite element equations in two‐dimensional linear elasticity
Authors: Xiao Yingxiong , Shu Shi , Zhao Tuyan 
Published: December 2008

AbstractIn this paper, we will discuss the geometric‐based algebraic multigrid (AMG) method for two‐dimensional linear elasticity problems discretized using quadratic and cubic elements. First, a two‐level method is proposed by analyzing the relationship between the linear finite element space and higher‐order finite element space. And then a geometric‐based AMG method is obtained with the existing solver used as a solver on the first coarse level. The resulting AMG method is applied to some typical elasticity problems including the plane strain problem with jumps in Young's modulus. The results of various numerical experiments show that the proposed AMG method is much more robust and efficient than a classical AMG solver that is applied directly to the high‐order systems alone. Moreover, we present the corresponding theoretical analysis for the convergence of the proposed AMG algorithms. These theoretical results are also confirmed by some numerical tests. Copyright © 2008 John Wiley & Sons, Ltd.
Intumescent flame retardation and silane crosslinking of PP/EPDM elastomer
Authors: Wang Zhengzhou , Zhou Shun , Hu Yuan 
Published: December 2008

AbstractThis study deals with the silane crosslinking and intumescent flame retardation of polypropylene/ethylene‐propylene‐diene copolymer (PP/EPDM) elastomers. The effect of silane crosslinking on the flame retardancy of the PP/EPDM composites containing melamine phosphate (MP) and dipentaerythritol (DPER) was studied by limiting oxygen index, UL 94 and cone calorimetry tests. The chemical composition of the silane crosslinked and flame retarded PP/EPDM composites treated at different temperatures was studied by X‐ray photoelectron spectroscopy and real time Fourier transform infrared (FTIR) spectrometry. Thermal decomposition and crystallization behavior of the PP/EPDM composites were investigated using thermogravimetric analysis and differential scanning calorimetry, respectively. Moreover, the mechanical properties of the composites were also studied. It is found that the flame retardancy, mechanical properties, and thermal decomposition behavior of the composites are influenced by silane grafting and crosslinking. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of poly(γ‐glutamic acid) on the gelation of Pluronic F127
Authors: Lee Yen‐Hsien , Yang Ming‐Chien 
Published: December 2008

AbstractThe gelation of Pluronic F127 aqueous solution was investigated in the presence of sodium poly(γ‐glutamate) (PGA). The gelation temperature was determined based on the tube inversion technique. The gelation temperature increased greatly when the ratio of PGA to F127 was 0.2, and then decreased at higher ratios. The enthalpy of gelation (ΔHgel) was calculated based on the model of Eldridge and Ferry. A splitting in the model was observed when the PGA/F127 ratio was 0.2 which yielded both a maximum and a minimum of ΔHgel. These results indicate that PGA can significantly affect the gelation of F127. Copyright © 2008 John Wiley & Sons, Ltd.
Identification and quantification of proteins differentially secreted by a pair of normal and malignant breast‐cancer cell lines
Authors: Liang Xiquan , Huuskonen Jarkko , Hajivandi Mahbod , Manzanedo Raul , Predki Paul , Amshey Joseph R. , Pope R. Marshall 
Published: December 2008

AbstractSecreted proteins play a pivotal role in cellular functions. To better understand malignant behavior, we adapted stable isotopic labeling with amino acids in cell culture technology to identify and quantify proteins differentially released into the extracellular media by a pair of normal and malignant breast‐cancer cell lines. Approximately 380 non‐redundant proteins were quantified in serum‐free media. Of the assigned proteins, 62% are classified secreted in protein databases and an additional 25% are designated secreted in the literature. A number of growth factors were found differentially regulated. Tumor necrosis factor, pigment epithelial‐differentiating factor and stem‐cell growth factor precursor showed decreased expression in breast‐cancer cell line, whereas Inhibin beta and macrophage migration inhibitory factor show increased expression. Interestingly, protease inhibitors, including plasma protease (C1) inhibitor, PZP precursor, and SerpinE2 were significantly down‐regulated in cancer cell line as were angiostatic factors from extracellular matrix (ECM) such as endorepillin. Further, the C‐terminal fragment of type XVIII collagen, endostatin, a potent angiostatic factor, was down‐regulated as well whereas extracellular collagens and osteoblast‐specific factor 2 (OSF‐2), were up‐regulated. Differential expression and secretion of SerpinE2 and OSF‐2 were confirmed using Western blotting. These results corroborate models of invasive tumors sustained by elaborate coordination of stromal cells via chemokines and growth factors, while protease inhibitors remodel the ECM to stimulate angiogenesis.
Hepatocytes proteomic alteration and seroproteome analysis of HBV‐transgenic mice
Authors: Ding Chen , Wei Haiming , Sun Rui , Zhang Jian , Tian Zhigang 
Published: December 2008

AbstractHepatitis B is the most common and serious liver disease, especially in developing countries. Although HBV pathogenesis has been extensively investigated, the proteomic alteration of hepatocytes during HBV chronic infection is still unclear. Using the purified hepatocytes, we compared the protein profiles by 2‐DE and LC‐MS between HBV‐transgenic (Tg) and corresponding background mice. Twenty‐seven altered proteins were identified in hepatocytes from HBV‐Tg mice, among which 13 proteins were involved in mitochondrion metabolism pathway including tricarboxylic acid (TCA) cycle and oxidative response; four proteins (SELENBP, SCP2, RGN and PRDX1) were also dramatically changed in liver samples from HBV‐infected patients. Important genes (gpx, sod, ogg et al.) correlated to oxidative damage were up‐regulated in the liver of HBV‐Tg mice. Reactive oxygen species production was significantly increased while ATP production was decreased in liver mitochondria from HBV‐Tg mice. Moreover, hepatocytes of HBV‐Tg mice were more sensitive to hydrogen peroxide‐induced cell death than that of wild‐type control. Using 2‐D Western blotting analysis, eight hepatocyte proteins were found to react with sera of HBV‐Tg mice but not with that of background mice. Interestingly, two (Etfa and Dmgdh) of the eight reactive proteins were overexpressed in HBV‐Tg mice. We believe this study is the first proteomic and seroproteome analysis of HBV‐infected mammalian hepatocyte and provides insightful links between HBV infection and HBV‐induced liver diseases.
Clinical features, diagnosis and treatment of narcolepsy
Authors: Mathew Jose 
Published: December 2008

AbstractNarcolepsy is a lifelong condition characterised by excessive daytime sleepiness, cataplexy and other disorders of sleep that has wide‐ranging implications for sufferers. Here, Dr Mathew discusses the clinical features and diagnosis of narcolepsy and outlines the treatment options available. Copyright © 2008 Wiley Interface Ltd
Effects of correlation and missing data on sample size estimation in longitudinal clinical trials
Authors: Zhang Song , Ahn Chul 
Published: December 2008

AbstractIn longitudinal clinical trials, a common objective is to compare the rates of changes in an outcome variable between two treatment groups. Generalized estimating equation (GEE) has been widely used to examine if the rates of changes are significantly different between treatment groups due to its robustness to misspecification of the true correlation structure and randomly missing data. The sample size formula for repeated outcomes is based on the assumption of missing completely at random and a large sample approximation. A simulation study is conducted to investigate the performance of GEE sample size formula with small sample sizes, damped exponential family of correlation structure and non‐ignorable missing data. Copyright © 2008 John Wiley & Sons, Ltd.
Trace level impurity method development with high‐field asymmetric waveform ion mobility spectrometry: systematic study of factors affecting the performance
Authors: Champarnaud Elodie , Laures Alice M.‐F. , Borman Phil J. , Chatfield Marion J. , Kapron James T. , Harrison Mark , Wolff Jean‐Claude 
Published: December 2008

AbstractFor the determination of trace level impurities, analytical chemists are confronted with complex mixtures and difficult separations. New technologies such as high‐field asymmetric waveform ion mobility spectrometry (FAIMS) have been developed to make their work easier; however, efficient method development and troubleshooting can be quite challenging if little prior knowledge of the factors or their settings is available. We present the results of an investigation performed in order to obtain a better understanding of the FAIMS technology. The influence of eight factors (polarity of dispersion voltage, outer bias voltage, total gas flow rate, composition of the carrier gas (e.g. %He), outer electrode temperature, ratio between the temperatures of the inner and outer electrodes, flow rate and composition of the make‐up mobile phase) was assessed. Five types of responses were monitored: value of the compensation voltage (CV), intensity, width and asymmetry of the compensation voltage peak, and resolution between two peaks. Three types of studies were performed using different test mixtures and various ionisation modes to assess whether the same conclusions could be drawn across these conditions for a number of different types of compounds. To extract the maximum information from as few experiments as possible, a Design of Experiment (DoE) approach was used. The results presented in this work provide detailed information on the factors affecting FAIMS separations and therefore should enable the user to troubleshoot more effectively and to develop efficient methods. Copyright © 2008 John Wiley & Sons, Ltd.
Use of diagnostic neutral losses for structural information on unknown aromatic metabolites: an experimental and theoretical study
Authors: Bourcier Sophie , Hoppilliard Yannik 
Published: December 2008

AbstractThis work presents the use of neutral losses (NL) for the identification of compounds related to the metabolism of tyrosine. The mass spectra of all the studied compounds, recorded at several collision energies, are compared. The fragmentation mechanism of protonated molecules, MH+, is explained by combining collision‐induced dissociation (CID) mass spectra and density functional theory (DFT) calculations. The results show that the first fragmentation is the elimination from MH+ of a neutral molecule including a functional group of the linear chain. Three primary neutral losses are observed: 17 u (NH3), 18 u (H2O) and 46 u (H2O+CO) characterizing amino, hydroxyl and carboxylic functions on the linear chain. The presence and abundance of ions corresponding to these losses are dependent on (i) the position of the functional group on the linear chain, (ii) the initial localisation of the protonating hydrogen, and (iii) the substitution of the aromatic ring. For compounds including a functional group on the benzylic carbon atom, the investigation of the other functions requires the knowledge of secondary fragmentations. Among these secondary fragmentations we have retained the loss of NH3 from [MH–18u]+ and the loss of ketene from [MH–17u]+. Experimentally these fragmentations are detected using losses of 35 u and 59/73 u. In other words, NL35 identifies hydroxy and amino compounds and NL 46 and/or NL59/73 identify carboxylic acids. The search for characteristic neutral losses is used for the analysis of compounds in a mixture and the analysis of biological fluid. We show that selective search of several neutral losses allows also the unambiguous differentiation of isomers and gives the opportunity to identify compounds in biological fluids. Copyright © 2008 John Wiley & Sons, Ltd.
Mass spectrometric investigations of α‐ and β‐cyclodextrin complexes with ortho‐, meta‐ and para‐coumaric acids by negative mode electrospray ionization
Authors: Kralj Bogdan , Šmidovnik Andrej , Kobe Jože 
Published: December 2008

AbstractThe mass spectrometric characterization of aqueous solutions of α‐ and β‐cyclodextrins (CDs) and o‐, m‐ and p‐coumaric acids (CAs) by negative ion electrospray ionization (ESI) indicates that the [CD+CA]− ions were sourced from the inclusion complex present in solution and from the anion attached to CD molecules formed in the spray processes. The anion adducts formed in the spray process contribute significantly to the signal intensity of an ionized inclusion complex thus overestimating the calculated stability constant (K) of solution‐phase complexes by one to two orders of magnitude. The relative intensities of anion adducts in mass spectra depend on the concentration ratio of the anion and the CD in spray droplets, while the relative intensity of the ionized inclusion complex depends on CD and CA concentrations in solutions and the value of K. Ion Mobility Spectrometry Mass Spectrometry [IMS‐MS] measurements show that the collision cross‐section (Ω) values of the [CD+CA]− or [(CD)2+CA]2− and [CD+CA] complex ions are 5–6% larger than or equal to CD− or [CD], respectively. Therefore, in the gas phase the anion adducts [CD+CA−] on cyclodextrin molecules possess the same conformations as the ionized inclusion complexes [CD+CA]−. Copyright © 2008 John Wiley & Sons, Ltd.
Robustness assessment via stability radii in delay parameters
Authors: Michiels Wim , Fridman Emilia , Niculescu Silviu‐Iulian 
Published: December 2008

AbstractThis paper focuses on the robust stability analysis of a class of linear systems including multiple delays subjected to constant or time‐varying perturbations. The approach considered makes use of appropriate stability radius concepts (dynamic, static) and relies on a feedback interconnection interpretation of the uncertain system. Various computable bounds on stability radii are obtained that exploit the structure of the problem. Systems including perturbations on both system matrices and delays are also dealt with. Copyright © 2008 John Wiley & Sons, Ltd.
Age‐ and size‐related reference ranges: A case study of spirometry through childhood and adulthood
Authors: Cole T. J. , Stanojevic S. , Stocks J. , Coates A. L. , Hankinson J. L. , Wade A. M. 
Published: December 2008

AbstractAge‐related reference ranges are useful for assessing growth in children. The LMS method is a popular technique for constructing growth charts that model the age‐changing distribution of the measurement in terms of the median, coefficient of variation and skewness. Here the methodology is extended to references that depend on body size as well as age, by exploiting the flexibility of the generalised additive models for location, scale and shape (GAMLSS) technique. GAMLSS offers general linear predictors for each moment parameter and a choice of error distributions, which can handle kurtosis as well as skewness. A key question with such references is the nature of the age‐size adjustment, additive or multiplicative, which is explored by comparing the identity link and log link for the median predictor.There are several measurements whose reference ranges depend on both body size and age. As an example, models are developed here for the first four moments of the lung function variables forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC in terms of height and age, in a data set of 3598 children and adults aged 4 to 80 years. The results show a strong multiplicative association between spirometry, height and age, with a large and nonlinear age effect across the age range. Variability also depends nonlinearly on age and to a lesser extent on height. FEV1and FVC are close to normally distributed, while FEV1/FVC is appreciably skew to the left. GAMLSS is a powerful technique for the construction of such references, which should be useful in clinical medicine. Copyright © 2008 John Wiley & Sons, Ltd.