bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification and functional characterization of the promoter of the mouse sodium‐activated sodium channel Nax gene (Scn7a)
Authors: García‐Villegas Refugio , López‐Álvarez Luz E. , Arni Stephan , Rosenbaum Tamara , Morales Marco A. 
Published: March 2009

AbstractNax is a sodium channel, thought to be a descendant of the voltage‐gated sodium channel family. Nevertheless, Nax is not activated by voltage but rather by augmentation of extracellular sodium over 150 mM. In the brain, it is localized to the circumventricular organs, important regions for salt and water homeostasis in mammals, where it operates as a sodium‐level sensor of body fluid. Nax channel is expressed in lung, uterus, and heart, and it is also found in trigeminal and dorsal root ganglia and in nonmyelinating Schwann cells, where its physiological role remains unclarified. Here we identified the promoter and transcription start sites of Nax sodium channel in dorsal root ganglia neurons from mouse. We report a characterization of the basal TATA‐less promoter and the sequence requirements for promoter activity in Neuro 2A neuroblastoma cells and in dorsal root ganglia neurons, where basal promoter activity seems to require NGFI‐C and Ebox DNA elements. Finally, we provide evidence that a repression mechanism that inhibits Nax expression may be present in certain tissues. These findings provide the basis with which to understand tissue‐specific regulation of Nax sodium channel gene (Scn7a) expression. © 2009 Wiley‐Liss, Inc.
An Eulerian particle level set method for compressible deforming solids with arbitrary EOS
Authors: Mehmandoust B. , Pishevar A.‐R. 
Published: March 2009

AbstractIn this study, an Eulerian, finite‐volume method is developed for the numerical simulation of elastic–plastic response of compressible solid materials with arbitrary equation of state (EOS) under impact loading. The governing equations of mass, momentum, and energy along with evolution equations for deviatoric stresses are solved in Eulerian conservation law form. Since the position of material boundaries is determined implicitly by Eulerian schemes, the solution procedure is split into two separate subproblems, which are solved sequentially at each time step. First, the conserved variables are evolved in time with appropriate boundary conditions at the material interfaces. In the present work a fourth‐order central weighted essentially non‐oscillatory shock‐capturing method that was developed for gas dynamics has been extended to high strain rate solids problems. In this method fluxes are determined on a staggered grid at places where solution is smooth. As a result, the method does not rely on the solution of Riemann problems but enjoys the flexibility of using any type of EOS. Boundary conditions at material interfaces are also treated by a special ghost cell approach. Then in the second subproblem, the position of material interfaces is advanced to the new time using a particle level set method. A fifth‐order Godunov‐type central scheme is used to solve the Hamilton–Jacobi equation of level sets in two space dimensions. The capabilities of the proposed method are evaluated at the end by comparing numerical results with the experimental results and the reported benchmark solutions for the Taylor rod impact, spherical groove jetting, and void collapse problems. Copyright © 2009 John Wiley & Sons, Ltd.
Experimenting with organisational development in Bhutan: A tool for reform and the achievement of multi‐level goals?
Authors: O'Flynn Janine , Blackman Deborah 
Published: March 2009

AbstractIn this article we present a unique study of how a nation, Bhutan, is using a specific change management approach—organisational development—as the lever for system‐level change in pursuit of a complex, multi‐level suite of goals to, ultimately, enhance Gross National Happiness (GNH). We argue that this represents one of the first attempts at using OD for wide‐scale change, something hinted at decades ago, and flagged by recent work coming out of the United Nations Development Program and civil society organisations (CSOs). Conceptually, we point to a high level of fit between the Bhutanese development philosophy and OD, and argue there is great potential for using OD in the context. However, we raise a series of issues around the practical feasibility of this approach highlighting important points of tension which pose major challenges for the Bhutanese experiment. Copyright © 2009 John Wiley & Sons, Ltd.
A novel approach to prepare PBT nanocomposites with elastomer‐modified SiO2 particles
Authors: Zhang Ling , Hong Yuerong , Zhang Tianshui , Li Chunzhong 
Published: March 2009

AbstractPoly(butylenes terephthalate) (PBT)/SiO2 nanocomposites with uniform dispersion, strong interfacial adhesion, and improved mechanical properties have been prepared by a novel approach. Ethylene‐methyl acrylate‐glycidyl methacrylate (E‐MA‐GMA) elastomer chains were first chemically grafted onto the surface of SiO2 nanoparticles. Fourier transform infrared spectra result shows that elastomer‐modified SiO2 nanoparticles exhibit absorption at 2963–2862 cm−1 of the stretching modes of CH, which suggests the reaction between the hydroxyl groups of SiO2 surface and epoxy groups of E‐MA‐GMA. And the binding energy of Si2p and O1s of the elastomer‐modified SiO2 shifts to lower binding energy, which further confirms the formation of SiOC bonds. This surface treatment allows SiO2 nanoparticles homogeneously dispersing in PBT matrix. The morphology with loose aggregates contains networked SiO2 particles with an interparticle distance ranging from 0 to 30 nm. As a result, the storage modulus and the tensile properties of PBT/E‐MA‐GMA‐SiO2 nanocomposites are higher than those of pure PBT and PBT with untreated SiO2. The incorporation of E‐MA‐GMA‐modified SiO2 particles increases the tensile strength and modulus to 58.4MPa and 2661MPa respectively, which is 8% and 16% higher than those of pure PBT. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers
Herbal products use during pregnancy: prevalence and predictors
Authors: Moussally Krystel , Oraichi Driss , Bérard Anick 
Published: March 2009

AbstractPurposes(1) Measure the prevalence of herbal product (HP) use, alone, and concomitantly with prescribed medications during pregnancy, (2) identify the most frequently consumed HP during gestation and (3) determine predictors of HP use at the beginning of pregnancy, and during the third trimester.MethodsA questionnaire was mailed to 8505 women selected from the Quebec Pregnancy Registry which was created by the linkage of three administrative databases: RAMQ, Méd‐Echo and ISQ. Women were eligible if they were continuously insured by the RAMQ drug plan for at least 12 months before the first day of gestation and during pregnancy, and if they gave birth to a live born between January 1998 and December 2003 in one of the Quebec's hospitals. Women with diabetes and psychoses, and women who delivered a baby with birth defects were selected first. Descriptive statistics and multivariate logistic regression models were used to analyse data.ResultsOf the 3354 women (39%) who answered the questionnaire, and were included in the study, nine per cent used HP during pregnancy. 69% of users took at least one prescribed medication concomitantly. Chamomile, green tea, peppermint and flax were the most frequently HP used. Multivariate analyses showed that body mass index (BMI), multivitamin use and one to three prescribed medications used before pregnancy were predictors of HP use at the beginning of pregnancy; adherent women, smokers and users of HP prior to pregnancy were predictors of HP use during the third trimester.ConclusionHP use alone and concomitantly with prescribed medications during pregnancy is common, and needs to be addressed by health professionals. Copyright © 2009 John Wiley & Sons, Ltd.
Grafting of glycidyl methacrylate onto swift‐nickel‐ions irradiated polypropylene films using chemical initiator
Authors: Chawla S. , Ghosh A.K. , Avasthi D.K. , Kulriya P.K. , Ahmad S. 
Published: March 2009

AbstractPolypropylene (PP) films were irradiated with swift nickel ions, (90 MeV Ni8+ ions) at different fluencies varying from 1010 to 3 × 1011 ions/cm2 and then grafted with glycidyl methacrylate (GMA) using benzoyl peroxide (BPO) as chemical initiator. It is shown that GMA could be grafted onto PP film. A comparison for the GMA grafting using BPO initiator in virgin as well as in the swift nickel ions irradiated PP films was given. The exposure of PP film to SHI results in a reduction in the effect of the BPO for graft copolymerization. Furthermore, as the fluency of swift nickel ions increased beyond an optimum value, the overlapping of the latent tracks reduced the grafting yield. Contact angle measurements and surface energy calculations showed an increasing hydrophilic nature in the direction from pure PP to grafted PP‐g‐GMA. These results are intended to benefit the synthesis and properties of a functional polymer. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Structural and electrical properties of V‐modified Pb(Fe0.5Nb0.5)O3 ceramics
Authors: Sahoo Subhadarsani , Choudhary R. N. P. , Mathur B. K. 
Published: March 2009

AbstractPolycrystalline samples of Pb(Fe0.5Nb0.5–x Vx)O3, x = 0, 0.05, 0.10, 0.15 were synthesized by a mixed oxide technique. Preliminary structural analysis suggests that the compounds have been formed in single‐phase monoclinic crystal system. Incorporation of V+5 in place of Nb+5 significantly reduces the sintering temperature of the compounds. Scanning electron micrographs of the compounds show that the grains are uniformly and densely distributed over the entire surface of the samples. Detailed studies of dielectric properties (dielectric constant and tangent loss) as a function of frequency (103–106 Hz) and temperature (50–300) °C suggest that Pb(Fe0.5Nb0.5–x Vx)O3 x = 0.0, 0.05 undergoes a ferroelectric–paraelectric phase transition. The phase transition in these compositions has been confirmed with the polarisation measurement. For the composition x = 0.10 and 0.15 ferroelectric phase transition vanishes due the grain size reduction. The presence of loss anomaly at high temperature in all V‐doped Pb(Fe0.5Nb0.5)O3 is related to the charge hopping relaxation. On increase in vanadium content in PFN the grain size reduces below the critical value for ferroelectricity to vanish. The ac conductivity of the compounds was found to increase on increasing temperature suggesting NTCR behavior of the materials. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Casimir force between two parallel semiconductor slabs: Magnetic field effects in the Voigt geometry
Authors: García‐Serrano R. , Martínez G. , Hernández P. H. , Palomino‐Ovando M. , Cocoletzi Gregorio H. 
Published: March 2009

AbstractWe investigate the Casimir force F between two parallel semiconductor slabs taking into account magnetoplasmon effects. For our calculations we consider an external magnetic field applied in the Voigt geometry. Studies are carried out using the formula of F, which is written in terms of the reflectivities of the incident electromagnetic (EM) waves onto the surfaces of the semiconductor slabs, in the vacuum gap between slabs. Results show that the Casimir force depends strongly on the slab thickness as well as on the magnetic‐field strength (or equivalently on the cyclotron frequency). At a constant cyclotron frequency and for small slab thickness F/F0 (F0 is the ideal force) displays a dip at small separation distances L between slabs. F/F0 increases with L up to saturation as the slab thickness increases. The curve with the strongest value of F/F0 corresponds to the semi‐infinite medium geometry. For a constant slab thickness and small cyclotron frequency, F/F0 as a function of L shows a monotonic increase as L increases, and eventually reaches saturation. At high cyclotron frequency F/F0 displays a dip. The curve of F/F0 with no applied external field corresponds to the one with the strongest Casimir force. Therefore, magnetoplasmon effects, with an applied magnetic field in the Voigt geometry may inhibit the Casimir force. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The most probable structures of platinum nitride as a function of composition
Authors: Soto Gerardo , Moreno‐Armenta Maria G. 
Published: March 2009

AbstractSo far two methods have been successful for the production of platinum nitride. One is the laser ablation method, the other the high‐temperature high‐pressure method. Spectroscopic examinations of films produced by the first method reveal that nitrogen is in interstitial sites of platinum as N1 units. In contrast, the accepted configuration for the material grown by the second method is that nitrogen is as N2 units in a pyrite‐like PtN2 structure. To elucidate these conflicting results we carried out density functional calculations to correlate composition with nitrogen sites in PtNx . We found that for dilute nitrogen concentrations, x < 0.2, nitrogen is in six‐fold coordinated sites (octahedral interstices) as N1 units. For 0.2 < x < 1.5, nitrogen is in tetrahedral interstices as N1 units. Only for x > 1.5 is the N2 configuration in octahedral sites attained. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Room‐temperature ferromagnetism of Cu‐doped ZnO films deposited by helicon magnetron sputtering
Authors: Ran Fan‐Yong , Imaoka Masao , Tanemura Masaki , Hayashi Yasuhiko , Herng Tun‐Seng , Lau Shu‐Ping 
Published: March 2009

AbstractWurtzite structure ZnO films doped with 0.5 and 1.7 at% Cu were deposited by helicon magnetron sputtering. The prepared films exhibited room‐temperature (RT) ferromagnetism (FM). Maximum RT saturation magnetization of 2 emu/cm3 (∼0.3μB/Cu) was observed for ZnO film with 1.7 at% Cu. Cu ions were in a bivalent state as identified by X‐ray photoelectron spectroscopy (XPS). In photoluminescence spectra, the green emission peak increased and redshifted due to the incorporation of Cu or defects induced by Cu incorporation. Since Cu and Cu‐related oxides are not RT ferromagnetic, and no trace of ferromagnetic contamination was detected in XPS results, the observed FM is considered to be an intrinsic property of Cu‐doped ZnO films. The FM was thought to originate from defect‐related mechanisms. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Propensity scores and M‐structures
Authors: Sjölander Arvid 
Published: April 2009

AbstractIn a recent issue of Statistics in Medicine, Ian Shrier [Statist. Med. 2008; 27(14):2740–2741] posed a question regarding the use of propensity scores [Biometrika 1983; 70(1):41–55]. He considered an ‘M‐structure’ illustrated by the directed acyclic graph (DAG) in Figure 1. In Figure 1, z is a binary exposure, r is a response of interest, x is a measured covariate, and u1 and u2 are two unmeasured covariates. Shrier stated that for the M‐structure, ‘... it remains unclear if the propensity method described by Rubin would introduce selection bias or not’. In the same issue, Donald Rubin [Statist. Med. 2002; 27(14):2741–2742] replied by clarifying several key points in the use of propensity scores. He did not, however, discuss the original question posed by Shrier. Given the popularity of both propensity score methods and graphical models, I think any confusion regarding the appropriateness of these methods deserves serious attention and I would therefore like to answer Shrier's question here. The short answer is that for the M‐structure, propensity score methods do indeed induce a bias. Below, I will clarify this statement. I will first briefly review the basic idea of propensity scores and then explain why the idea does not apply to the M‐structure. I will use a notation which is consistent with Rosenbaum and Rubin [Biometrika 1983; 70(1):41–55]. Copyright © 2009 John Wiley & Sons, Ltd.
Non‐inferiority tests for clustered matched‐pair data
Authors: Nam Jun‐mo , Kwon Deukwoo 
Published: March 2009

AbstractNon‐inferiority tests for matched‐pair data where pairs are mutually independent may not be appropriate when pairs are clustered. The tests may require an adjustment to account for the correlation within a cluster. We consider the adjusted score and Wald‐type tests, and a modification of Obuchowski's method for non‐inferiority and compare them with the non‐inferiority test based on a method of moments estimate in terms of Type 1 error rate and power by simulations for a small cluster size under various correlation structures. In general, the score test adjusted by an inflation factor and the modified Obuchowski's method perform as good as the test based on moments estimate in the accuracy of Type 1 error rates. The latter does not provide reasonably close Type 1 error rates to the nominal level when the number of clusters is 25 or smaller and a positive response rate for the standard procedure is 20 per cent or lower. The adjusted score test, the method based on moments estimate and the modified test are comparable in power. The adjusted Wald‐type test is too anti‐conservative and we should caution use of the test. Since number of clusters is strongly related to the accuracy of empirical Type 1 error rate and power, it is very important to have a sufficiently large number of clusters in designing a clustered matched‐pair study for non‐inferiority. Published in 2009 by John Wiley & Sons, Ltd.
Three‐dimensional sonographic calculation of the volume of intracranial structures in growth‐restricted and appropriate‐for‐gestational age fetuses
Authors: Benavides‐Serralde A. , Hernández‐Andrade E. , Fernández‐Delgado J. , Plasencia W. , Scheier M. , Crispi F. , Figueras F. , Nicolaides K. H. , Gratacós E. 
Published: March 2009

AbstractObjectivesTo evaluate the feasibility and reproducibility of volume segmentation of fetal intracranial structures using three‐dimensional (3D) ultrasound imaging, and to estimate differences in the volume of intracranial structures between intrauterine growth‐restricted (IUGR) and appropriate‐for‐gestational age (AGA) fetuses.MethodsTotal intracranial, frontal, thalamic and cerebellar volumes were measured using 3D ultrasound imaging and Virtual Organ Computer‐aided AnaLysis (VOCAL) in 39 IUGR and 39 AGA fetuses matched for gestational age, at 28–34 weeks of gestation. Volumes of, and ratios between, structures were estimated, and differences between IUGR and AGA fetuses were calculated. Volume measurements were performed by two observers, and interobserver and intraobserver intraclass correlation coefficients (ICCs) were calculated for each structure.ResultsVolumes were satisfactorily obtained in all fetuses. All net volumes except those for the thalamus (P = 0.23) were significantly smaller (P = 0.001) in IUGR fetuses. After adjusting volumes for biparietal diameter the frontal volume was significantly smaller (P = 0.02) and the thalamic volume significantly greater (P = 0.03) in IUGR fetuses than in AGA fetuses. Significant intergroup differences in the ratios between structures were found only in those involving the frontal region. Interobserver ICCs were as follows: total intracranial 0.97 (95% CI, 0.92–0.98), cerebellar 0.69 (95% CI, 0.44–0.75), frontal 0.66 (95% CI, 0.42–0.79) and thalamic 0.54 (95% CI, 0.37–0.72).ConclusionsIUGR fetuses show differences in the volume of intracranial structures compared with AGA fetuses, with the largest difference found in the frontal region. These differences might be explained by in‐utero processes of neural reorganization induced by chronic hypoxia. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Analysis of paintings from the nineteenth century Brazilian painter Rodolfo Amoedo using EDXRF portable system
Authors: Calza Cristiane , Pedreira Andrea , Lopes Ricardo Tadeu 
Published: March 2009

AbstractThe pigments used in four of the most representative paintings of the Brazilian artist Rodolfo Amoedo were characterized by means of the EDXRF technique. The analyzed paintings were ‘The Last Tamoyo’ (1883), ‘Study of a Woman’ (1884), ‘Bust of Mrs. Amoedo’ (1892) and ‘Bad News’ (1895). EDXRF measurements were carried out with a portable system developed by the Nuclear Instrumentation Laboratory, consisting of an x‐ray tube Oxford TF3005 with a W anode, operating at 25 kV and 100 µA, and a Si‐PIN XR‐100CR detector from Amptek. Several spectra were obtained in each color and distinct hue of the paint layer, with an acquisition time of 300 s and a beam collimation of 2 mm. Some pigments used by the artist were zinc white, lead white, ochre, umber, vermilion, Prussian blue, cobalt blue, cadmium yellow, black iron oxide and manganese violet. In the painting ‘The Last Tamoyo’, titanium white was identified in some alteration areas, which were restored during the twentieth century. These results—together with computed radiography analyses—will be used to create a database about the nineteenth‐century collection of the National Museum of Fine Arts, in order to assist restorers, conservators, art students and researchers in the field of archeometry. Copyright © 2009 John Wiley & Sons, Ltd.
Cortisol and antisocial behavior in early adolescence: The role of gender in an economically disadvantaged sample
Authors: Kobak Roger , Zajac Kristyn , Levine Seymour 
Published: April 2009

AbstractThis study examines the relation between adolescents' antisocial behaviors and adrenocortical activity during a laboratory visit in a sample of economically disadvantaged families (N= 116, ages 12–14, 51% female). Pretask cortisol levels indexed adolescents' prechallenge response to the lab visit, whereas adolescents' response to a conflict discussion with their caregivers was indexed with residualized change in pre- to postconflict cortisol levels. A trait measure of antisocial behavior (derived from parent, teacher, and self-reports) was associated with lower pretask cortisol levels but greater cortisol response to the conflict discussion. Gender moderated antisocial adolescents' cortisol response to the conflict discussion with girls who reported more covert risky problem behaviors showing an increased cortisol response. The findings suggest that, although antisocial adolescents had lower pretask cortisol levels, conflict discussions with caregivers present a unique challenge to antisocial girls compared with antisocial boys.
Entropic Landscape: the method to predict folding patterns and regional stability of proteins
Authors: Onizuka Kentaro 
Published: March 2009

AbstractI propose a new method to calculate the entropy of a given protein sequence fragment. The set of fragment entropies over all possible fragments of the given sequence shows which region of the sequence is statistically stable and which region has a strong desire to fold into particular conformations. Here are three methods to calculate fragment entropy, the results from each of which represent entropies of different stage of protein folding.