bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impacts of sand transport on flow variables and dissolved oxygen in gravel‐bed streams suitable for salmonid spawning
Authors: Ferreira Rui M.L. , Ferreira Lara M. , Ricardo Ana M. , Franca Mário J. 
Published: September 2009

AbstractIncreased sediment production resulting from the erosion of unprotected soil in a catchment may result in severe changes in the morphodynamics and hydrodynamics of mountain rivers. Sediment overfeeding can lead to the degradation of salmonids' spawning sites. The objective of this study is to evaluate the impacts of sand transport on flow hydrodynamics and on vertical dissolved oxygen (DO) distribution in gravel‐bed rivers. To accomplish the proposed objective, conditions similar to those found in nature, in what concerns flow and bed material, were reproduced in a laboratory flume and a theoretical model of the vertical distribution of DO was developed. Three laboratory tests simulated (i) an undisturbed openwork gravel bed; (ii) a framework‐supported gravel bed with a sand matrix and (iii) a framework‐supported gravel bed with imposed sand transport at near‐capacity conditions. Instantaneous velocity maps were obtained with Particle Image Velocimetry (PIV). The collected data were analysed and theoretically framed with double‐averaged methods (DAM). Mean Reynolds stresses were unaffected by reduced bed porosity or sediment transport even in the near‐bed region. Sediment transport affected longitudinal velocity profiles and eddy viscosity decreased. Numerical simulations of the vertical distribution of DO and of gaseous species were carried out under the hydrodynamic and sedimentological conditions of the flume work. The results of the numerical simulations show that, in the presence of sand transport, near‐bed concentrations of DO are strongly reduced, mostly due to the reduction of downward diffusive fluxes of gaseous oxygen and DO. Copyright © 2009 John Wiley & Sons, Ltd.
Linear mixed models for replication data to efficiently allow for covariate measurement error
Authors: Bartlett Jonathan W. , De Stavola Bianca L. , Frost Chris 
Published: September 2009

AbstractIt is well known that measurement error in the covariates of regression models generally causes bias in parameter estimates. Correction for such biases requires information concerning the measurement error, which is often in the form of internal validation or replication data. Regression calibration (RC) is a popular approach to correct for covariate measurement error, which involves predicting the true covariate using error‐prone measurements. Likelihood methods have previously been proposed as an alternative approach to estimate the parameters in models affected by measurement error, but have been relatively infrequently employed in medical statistics and epidemiology, partly because of computational complexity and concerns regarding robustness to distributional assumptions. We show how a standard random‐intercepts model can be used to obtain maximum likelihood (ML) estimates when the outcome model is linear or logistic regression under certain normality assumptions, when internal error‐prone replicate measurements are available. Through simulations we show that for linear regression, ML gives more efficient estimates than RC, although the gain is typically small. Furthermore, we show that RC and ML estimates remain consistent even when the normality assumptions are violated. For logistic regression, our implementation of ML is consistent if the true covariate is conditionally normal given the outcome, in contrast to RC. In simulations, this ML estimator showed less bias in situations where RC gives non‐negligible biases. Our proposal makes the ML approach to dealing with covariate measurement error more accessible to researchers, which we hope will improve its viability as a useful alternative to methods such as RC. Copyright © 2009 John Wiley & Sons, Ltd.
One‐Dimensional Composite Nanomaterials: Synthesis by Electrospinning and Their Applications
Authors: Lu Xiaofeng , Wang Ce , Wei Yen 
Published: September 2009

AbstractThis Review provides an overview of the synthesis of one‐dimensional (1D) composite nanomaterials by electrospinning and their applications. After a brief description of the development of the electrospinning technique, the transformation of an inorganic nanocomponent or polymer into another kind of polymer or inorganic matrix is discussed in terms of the electrospinning process, including the direct‐dispersed method, gas–solid reaction, in situ photoreduction, sol–gel method, emulsion electrospinning method, solvent evaporation, and coaxial electrospinning. In addition, various applications of such 1D composite nanomaterials are highlighted in terms of electronic and optical nanodevices, chemical and biological sensors, catalysis and electrocatalysis, superhydrophobic surfaces, environment, energy, and biomedical fields. An increasing number of investigations show that electrospinning has been not only a focus of academic study in the laboratory but is also being applied in a great many technological fields.magnified image
Chemically Responsive Gels Prepared from Microspheres Dispersed in Liquid Crystals
Authors: Pal Santanu Kumar , Agarwal Ankit , Abbott Nicholas L. 
Published: September 2009

AbstractLiquid‐crystalline materials are a promising class of stimuli‐responsive materials that have been demonstrated to undergo surface‐induced orientational ordering transitions that can be highly sensitive and specific to chemical species. However, past studies demonstrating surface‐induced transitions in liquid crystals (LCs) have employed thin films of low‐molecular‐weight LCs that are difficult to stabilize (due to dewetting of the LC on a surface). Here, it is reported that it is possible to prepare liquid‐crystalline gels using a mixture of polystyrene microspheres and nematic LCs that undergo changes in orientational order, and thus optical appearance, in response to exposure to specific chemical compounds. These colloid‐in‐liquid‐crystal (CLC) gels are mechanically stable and can be molded on chemically functionalized surfaces into thin films containing micrometer‐sized LC‐rich domains that span the two interfaces of the gels. In contrast to other reports of LC gels, where the presence of a polymeric or self‐assembled small‐molecule gelator network within a nematic LC frustrates ordering transitions from propagating through the gels over distances, it is demonstrated that thin films of CLC gels, when supported on chemically functionalized surfaces, do undergo easily visualized ordering transitions upon exposure to organophosphonate compounds. Because these optically responsive CLC gels are mechanically robust and can be molded, this class of composite LC material may be broadly useful for the design of chemically responsive LC devices.
BOLD MRI in sheep fetuses: a non‐invasive method for measuring changes in tissue oxygenation
Authors: Sørensen A. , Pedersen M. , Tietze A. , Ottosen L. , Duus L. , Uldbjerg N. 
Published: September 2009

AbstractObjectiveThe purpose of this descriptive study was to correlate changes in the blood oxygen level‐dependent (BOLD) magnetic resonance imaging (MRI) signal with direct measurements of fetal tissue oxygenation.MethodsSeven anesthetized ewes carrying singleton fetuses at 125 days' gestation (term 145 days) underwent BOLD MRI, covering the entire fetus in a multislice approach. The fetuses were subjected to normoxic, hypoxic and hyperoxic conditions by changing the O2/N2O ratio in the maternal ventilated gas supply. The partial pressure of oxygen (pO2) in the fetal liver was measured using an oxygen‐sensitive optode. Maternal arterial blood samples were simultaneously withdrawn for blood gas analysis. These measurements were compared with BOLD MRI signals in the fetal liver, kidney, spleen and brain.ResultsWe demonstrated a consistent increase in the BOLD MRI signal with increasing tissue pO2. For the fetal liver, spleen and kidney we observed a clear association between changes in maternal arterial blood pO2 and changes in BOLD MRI signal. Interestingly, we found that the BOLD signal of the fetal brain remained unchanged during hypoxic, normoxic and hyperoxic conditions.ConclusionsThis experimental study demonstrated that BOLD MRI is a reliable non‐invasive method for measuring changes in tissue oxygenation in fetal sheep. The unchanged signal in the fetal brain during altered maternal oxygen conditions is probably explained by the brain‐sparing mechanism. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Impact of Gender and Age on the Long‐Term Outcome of Laparoscopic Fundoplication
Authors: Beck Plauto E. , Watson David I. , Devitt Peter G. , Game Philip A. , Jamieson Glyn G. 
Published: September 2009

AbstractBackgroundIt has been suggested that gender and age could be factors that influence the likelihood of success following antireflux surgery, and our anecdotal impression has been that the outcome following Nissen fundoplication in older women is often disappointing. If correct, characterization of the extent of any differences in outcome might help patient selection and, hence, surgical outcomes. Therefore, in this study we investigated the impact of gender and age on longer‐term clinical outcomes following laparoscopic fundoplication.MethodsPerioperative and follow‐up data from patients undergoing laparoscopic fundoplication in our departments have been collected prospectively and stored in a database. From the database, patients who had undergone either an anterior 180° partial or 360° total laparoscopic fundoplication for gastroesophageal reflux and completed 5 years clinical follow‐up were identified. Patients were classified according to gender and age, and outcome data were analyzed to determine differences. Analog scales of 0–10 were used to determine symptoms of heartburn and dysphagia and overall satisfaction.ResultsSeven hundred three patients were studied (58% males). Females were less satisfied with the outcome (score = 7.8 ± 2.8 vs. 8.4 ± 2.5, P = 0.0036), and had higher scores for heartburn (2.0 ± 2.7 vs. 1.2 ± 2.2; P = 0.0001) and dysphagia for solid food (2.7 ± 2.9 vs. 2.0 ± 2.5, P = 0.0049) compared to males. Revisional procedures were undertaken more frequently in females (15.5% vs. 8.4%, P = 0.0038). Age had no impact on any clinical outcome.ConclusionsWhile the outcome for laparoscopic fundoplication is not influenced by age, the outcome for women is poorer than in males.
Magnetic Anisotropic Energy Gap and Strain Effect in Au Nanoparticles
Authors: Shih Po-Hsun , Wu ShengYun 
Published: September 2009

Abstract
We report on the observation of the size effect of thermal magnetization in Au nanoparticles. The thermal deviation of the saturation magnetization departs substantially from that predicted by the Bloch T3/2-law, indicating the existence of magnetic anisotropic energy. The results may be understood using the uniaxial anisotropy Heisenberg model, in which the surface atoms give rise to polarized moments while the magnetic anisotropic energy decreases as the size of the Au nanoparticles is reduced. There is a significant maximum magnetic anisotropic energy found for the 6 nm Au nanoparticles, which is associated with the deviation of the lattice constant due to magnetocrystalline anisotropy.
Ezetimibe Inhibits Expression of Acid Sphingomyelinase in Liver and Intestine
Authors: Cheng Yajun , Liu Fuli , Wu Jun , Zhang Yao , Nilsson Åke , Duan Rui‐Dong 
Published: September 2009

AbstractEzetimibe inhibits cholesterol absorption in the intestine. Sphingomyelin has strong interactions with cholesterol. We investigated the effects of ezetimibe on Sphingomyelinase (SMase) expression in intestine and liver. After feeding rats with ezetimibe (5 mg/kg per day) for 14 days, acid SMase activities in the liver and in the proximal part of small intestine were reduced by 34 and 25%, respectively. Alkaline SMase (alk‐SMase) was increased in the proximal part of the small intestine. Administration of lower doses of ezetimibe reduced acid SMase only in the liver by 14% (P < 0.05). In cell culture studies, ezetimibe decreased acid SMase activity in Hep G2 and Caco‐2 cells dose‐dependently. The reductions were more rapid for Hep G2 cells than for Caco‐2 cells. Western blot showed that acid SMase protein was decreased in both Hep G2 and Caco‐2 cells by 100 μM ezetimibe. The SM content was increased in Hep G2 cells but not Caco‐2 cells, and total cholesterol content was increased in both cell lines 24 h after stimulation with 100 μM ezetimibe. Mevastatin, the inhibitor of cholesterol synthesis, induced a mild increase in acid SMase activity in Hep G2 cells but not Caco‐2 cells. Following the reduction of acid SMase, ezetimibe at high dose slightly increased alk‐SMase activity. In conclusion, the study demonstrates an inhibitory effect of ezetimibe on acid SMase activity and expression in both liver and intestine.
Homology of some Artin and twisted Artin Groups
Authors: Clancy Maura , Ellis Graham 
Published: September 2009

AbstractWe begin the paper with a simple formula for the second integral homology of a range of Artin groups. The formula is derived from a polytopal classifying space. We then introduce the notion of atwisted Artin groupand obtain polytopal classifying spaces for a range of such groups. We demonstrate that these explicitly constructed spaces can be implemented on a computer and used in homological calculations.
Unstable sets, heteroclinic orbits and generic quasi-convergence for essentially strongly order-preserving semiflows
Authors: Yi Taishan , Li Qingguo 
Published: September 2009

AbstractWe present conditions guaranteeing the existence of non-trivial unstable sets for compact invariant sets in semiflows with certain compactness conditions, and then establish the existence of such unstable sets for an unstable equilibrium or a minimal compact invariant set, not containing equilibria, in an essentially strongly order-preserving semiflow. By appealing to the limit-set dichotomy for essentially strongly order-preserving semiflows, we prove the existence of an orbit connection from an equilibrium to a minimal compact invariant set, not consisting of equilibria. As an application, we establish a new generic convergence principle for essentially strongly order-preserving semiflows with certain compactness conditions.
Existence result for a class of nonlinear third-order two-point boundary-value problems
Authors: Wang Libo , Pei Minghe , Ge Weigao 
Published: September 2009

AbstractThe upper and lower solutions method and Leray–Schauder degree theory are employed to establish the existence result for a class of nonlinear third-order two-point boundary-value problems with a sign-type Nagumo condition.
Leading coefficients and cellular bases of Hecke algebras
Authors: Geck Meinolf 
Published: September 2009

AbstractLet H be the generic Iwahori–Hecke algebra associated with a finite Coxeter group W. Recently, we have shown that H admits a natural cellular basis in the sense of Graham and Lehrer, provided that W is a Weyl group and all parameters of H are equal. The construction involves some data arising from the Kazhdan–Lusztig basis {Cw} of H and Lusztig's asymptotic ring J}. We attempt to study J and its representation theory from a new point of view. We show that J can be obtained in an entirely different fashion from the generic representations of H, without any reference to {Cw}. We then extend the construction of the cellular basis to the case where W is not crystallographic. Furthermore, if H is a multi-parameter algebra, we see that there always exists at least one cellular structure on H. Finally, the new construction of J may be extended to Hecke algebras associated with complex reflection groups.
Genetic influence on the kinetics and associated pathology of the early stage (intestinal-hepatic) migration ofAscaris suumin mice
Authors: DOLD C. , CASSIDY J. P. , STAFFORD P. , BEHNKE J. M. , HOLLAND C. V. 
Published: September 2009

SUMMARYThe generative mechanism(s) of aggregation and predisposition toAscaris lumbricoidesandA. suuminfections in their host population are currently unknown and difficult to elucidate in humans and pigs for ethical/logistical reasons. A recently developed, optimized murine model based on 2 inbred strains, putatively susceptible (C57BL/6j) and resistant (CBA/Ca) to infection, was exploited to elucidate further the basis of the contrasting parasite burdens, most evident at the pulmonary stage. We explored the kinetics of early infection, focusing on the composite lobes of the liver and lung, over the first 8 days in an effort to achieve a more detailed understanding of the larval dispersal over time and the point at which worm burdens diverge. Larval recoveries showed a heterogenous distribution among the lobes of the lungs, being higher in the right lung of both strains, and in the susceptible strain larvae accumulating preferentially in 2 (caudal and middle) of the 4 lobes. Total larval burdens in these 2 lobes were largely responsible for the higher worm burdens in the susceptible strain. While total lung larval recoveries significantly differed between mouse strains, a difference in liver larval burdens was not observed. However, an earlier intense inflammatory response coupled with more rapid tissue repair in the hepatic lobes was observed in CBA/Ca mice, in contrast to C57BL/6j mice, and it is possible that these processes are responsible for restricting onward pulmonary larval migration in the resistant genotype.
RNA interference in schistosomes: machinery and methodology
Authors: KRAUTZ-PETERSON GREICE , BHARDWAJ RITA , FAGHIRI ZAHRA , TARARAM CIBELE A. , SKELLY PATRICK J. 
Published: September 2009

SUMMARYRNA interference (RNAi) is a potent gene silencing process that is playing an increasingly important role in investigations of gene function in schistosomes. Here we review what is known about the process in these parasites and provide an update on the methodology and machinery of RNAi. Data are presented to demonstrate that: (1) not all schistosome genes can be suppressed to the same extent, using the methods employed here; (2) while there is variation in the level of suppression achieved for one target gene (SmAP) in adult parasites, all individuals exhibit robust (>80%) suppression; (3) short interfering RNAs (siRNAs) can effect suppression when delivered by soaking (and not just via electroporation, as reported previously); (4) Male/female adult pairs need not be separated prior to siRNA delivery by electroporation for effective gene suppression in both genders and (5) electroporation of siRNAs in medium is as efficient as in commercial electroporation buffer. Regarding the machinery of RNAi in schistosomes, a homologue of theC. elegansmulti-membrane spanning, RNA importing protein SID-1 is identifiedin silico. The gene encoding this protein contains 21 exons and spans over 50 kb to potentially encode a 115,556 Mr protein (SmSID-1). These analyses, and a review of the literature, permit us to derive and present here a draft of potential RNAi pathways in schistosomes.
Unemployment as an Institutional Construct? Structural Differences in Non-Employment between Selected European Countries and the United States
Authors: ERLINGHAGEN MARCEL , KNUTH MATTHIAS 
Published: September 2009

AbstractA comparison of unemployment rates in Germany, the Netherlands, France, Denmark, the UK and the United States suggests poor performance by the German labour market. The present study endeavours to show that a more sophisticated picture of unemployment can be drawn by taking into account additional forms of non-employment (such as incapacity, retirement or labour reserve). For this purpose, data from the ‘European Social Survey’ (ESS) and the survey ‘Citizenship, Involvement and Democracy’ collected in 2004 and 2005 have been analysed. While ‘unemployment’ plays a dominant role in Germany, people with comparable demographic characteristics and similar health status are more likely to identify themselves as ‘permanently sick or disabled’ and hence are classified thus in other countries. The results of this study underline that an international comparison of labour market performance, particularly a comparison of the effectiveness of labour market and social policy reforms, should not rely only on employment and unemployment rates. Taking alternate forms of non-employment into account can enhance one's knowledge and understanding of the functional differences between the labour markets in Europe and the United States.
Developing a National Consensus on the Accessibility Needs of Older Adults with Concurrent and Chronic, Mental and Physical Health Issues: A Preliminary Framework Informing Collaborative Mental Health Care Planning
Authors: Horgan Salinda , LeClair Ken , Donnelly Martha , Hinton Geri , MacCourt Penny , Krieger-Frost Sarah 
Published: September 2009

RÉSUMÉLe Canada fait face à un défi important, soit de répondre aux besoins en soins de santé des personnes âgées manifestant des problèmes physiques et mentaux complexes. Les études montrent que les services de santé mentale en collaboration sont efficaces en ce qui concerne les divers besoins de santé de ce groupe. Cependant, un aspect négligé, néanmoins important, de la planification de la prestation de services pour cette population est de s’assurer que les personnes âgées ont suffisamment accès aux services de pratiques d’excellence offerts. Cet article présente un exercice national de réalisation de consensus mené par l’Initiative canadienne de collaboration en santé mentale – Seniors Working Group. L’objectif de la réalisation de consensus est de développer, à l’aide de renseignements provenant de tout le paysQ1: Ok, oui c bon je comprends. si ton cadre conceptuel est nationally informed, c’est que forcément il reçoit de l'info de partout dans le pays. C’est pourquoi je l’ai traduit comme ça. Pour rester plus proche de l'anglais, on pourrait mettre kekchose comme obtenant des renseignements sur le plan national..?, un cadre conceptuel sur les besoins d’accessibilité des personnes âgées relatifs aux soins de santé mentale en collaboration. Le cadre conceptuel a pour but de fournir aux planificateurs, administrateurs et fournisseurs les éléments nécessaires pour comprendre les besoins uniques des personnes âgées en matière d’accessibilité, en fonction de trois priorités (l’élément personnel, systémique, et les prestataires de soins), et de leur permettre d’implanter des stratégies pour résoudre ces problèmes, à l’intérieur d’initiatives collaboratives de santé mentale mises en place sur le terrain.
The Canadian Longitudinal Study on Aging (CLSA)
Authors: Raina Parminder S. , Wolfson Christina , Kirkland Susan A. , Griffith Lauren E. , Oremus Mark , Patterson Christopher , Tuokko Holly , Penning Margaret , Balion Cynthia M. , Hogan David , Wister Andrew , Payette Hélène , Shannon Harry , Brazil Kevin 
Published: September 2009

RÉSUMÉLes Canadiens vivent plus longtemps et les personnes plus âgées composent une part croissante de la population (14% en 2006, projeté d’atteindre 20% d’ici 2021). L’Étude longitudinale canadienne sur le vieillissement (ÉLCV) est une étude longitudinale nationale portant sur le développement adulte et le vieillissement qui recrutera 50 000 Canadien(ne)s âgé(e)s de 45 à 85 ans et qui les suivra pendant au moins 20 ans. Tous les participants fourniront un ensemble d’informations communes sur plusieurs aspects de la santé et du vieillissement, et 30 000 passeront un examen approfondi couplé au don de spécimens biologiques (sang et urine). L’ÉLCV deviendra une source de données riches pour l’étude d’inter-relations complexes entre les facteurs biologiques, physiques, psychosociaux et sociaux qui affectent le vieillissement en santé.