bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improper analysis of trials randomised using stratified blocks or minimisation
Authors: Kahan Brennan C. , Morris Tim P. 
Published: December 2011

AbstractMany clinical trials restrict randomisation using stratified blocks or minimisation to balance prognostic factors across treatment groups. It is widely acknowledged in the statistical literature that the subsequent analysis should reflect the design of the study, and any stratification or minimisation variables should be adjusted for in the analysis. However, a review of recent general medical literature showed only 14 of 41 eligible studies reported adjusting their primary analysis for stratification or minimisation variables. We show that balancing treatment groups using stratification leads to correlation between the treatment groups. If this correlation is ignored and an unadjusted analysis is performed, standard errors for the treatment effect will be biased upwards, resulting in 95% confidence intervals that are too wide, type I error rates that are too low and a reduction in power. Conversely, an adjusted analysis will give valid inference. We explore the extent of this issue using simulation for continuous, binary and time‐to‐event outcomes where treatment is allocated using stratified block randomisation or minimisation. Copyright © 2011 John Wiley & Sons, Ltd.
Output characteristics model for an a‐Si ISFET pH sensor
Authors: Hashim Yasir , Sidek Othman 
Published: December 2011

AbstractA mathematical model for the calculation of the output characteristics of amorphous silicon hydrogenated (a‐Si:H) ion‐sensitive field‐effect transistors (ISFET) is developed, which depends on the integration of the conductivity channel versus gate voltage curve at fixed drain voltage. Single curve integration was changed to integration with many simple lines to obtain the ID − VD characteristics using computer programming. The results of this model were tested with those of experiments. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Reoptimization of the minimum spanning tree
Authors: Paschos Stratos A. , Paschos Vangelis Th. 
Published: December 2011

AbstractWe implement a fast reoptimization algorithm for MIN SPANNING TREE under vertex insertions, initially proposed and analyzed in the work of Boria and Paschos [Boria N, Paschos VTh. Fast reoptimization for the minimum spanning tree problem. J Discrete Algor 2010, 8:296–310] and study its experimental approximation behavior in randomly generated graphs. The reoptimization setting can briefly be formulated as follows: given an instance of the problem for which we already know some optimal solution, and given some ‘small’ perturbations on this instance, is it possible to compute a new (optimal or at least near‐optimal) solution for the modified instance without computation from scratch? We focus in this article on the most popular modification: vertex‐insertion. WIREs Comput Stat 2012, 4:211–217. doi: 10.1002/wics.204This article is categorized under:

Algorithms and Computational Methods > Dynamic Programming
Interactions of nanomaterials with the immune system
Authors: Hussain Salik , Vanoirbeek Jeroen A. J. , Hoet Peter H. M. 
Published: December 2011

AbstractEvaluation of the immunomodulatory potentials of nanomaterials is essential for developing safe and consumer‐friendly nanotechnology. Various nanomaterials interact with the immune system, in a beneficial or deleterious way, but mechanistic details about such interactions are scarce. A lack of agreed‐upon guidelines for evaluating the immunotoxicity of nanoparticles (NPs) adds to the complexity of the issue. Various review articles have summarized the immune system interactions of biodegradable NPs (with pharmaceutical uses), but such information is largely lacking for nonbiodegradable NPs. Here we give an overview of interactions of nonbiodegradable, persistent NPs with the immune system. Particular emphases include key factors that shape such interactions, cell‐specific responses, allergy and immune‐sensitive respiratory disorders. WIREs Nanomed Nanobiotechnol 2012, 4:169–183. doi: 10.1002/wnan.166This article is categorized under:

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials
Ionothermal Synthesis of a NaCl‐type Topological Network Based on Trinuclear Cobalt(II) Clusters as Nodes
Authors: Liang Yan‐Fang , Zhang Ya‐Ru , Han Zheng‐Bo 
Published: December 2011

AbstractA new metal‐organic network [Co3(tbip)3(H2O)4]·2H2O (1) (H2tbip = 5‐tert‐butyl‐isophthalic acid) was synthesized through the ionothermal reaction of H2tbip, cobalt nitrate, and [bmim]Br ionic liquid ([bmim]Br = 1‐butyl‐3‐methylimidazolium bromide). It exhibits a three‐dimensional (3D) framework with NaCl topology based on trinuclear cobalt(II) clusters as nodes. The magnetic studies show that there exist antiferromagnetic interactions between the CoII ions.
Physicochemical Properties and Adhesion Performance of Canola Protein Modified with Sodium Bisulfite
Authors: Li Ningbo , Qi Guangyan , Sun Xiuzhi Susan , Stamm Michael J. , Wang Donghai 
Published: December 2011

AbstractThe objective of this research was to study the adhesion properties of sodium bisulfite (NaHSO3)‐modified canola protein. Protein was extracted from canola meal through alkali solubilization and acid precipitation methods, then modified with different concentrations of NaHSO3 (0–15 g/L) during the isolation process. As NaHSO3 concentration increased, canola protein purities decreased. Amino acid profiles showed that the hydrophobic amino acids in canola protein constituted only 27% of total protein, indicating that canola protein is mostly hydrophilic. The reducing effects of NaHSO3 were exerted on canola protein through the breaking of disulfide bonds in both its cruciferin and napin components, as reflected by the protein electrophoresis profile, DSC data, and morphological images. The wet protein isolates were used as adhesives. The greatest wet shear strength of canola protein adhesive without modification was 3.97 MPa with 100% wood cohesive failure (WCF), observed at a curing temperature of 190 °C. NaHSO3 had slight weakening effects on the adhesion performance of canola protein. Canola protein modified with 3 g/L NaHSO3 exhibited wet shear strength similar to the control at 190 °C and higher strength at 150 and 170 °C. The NaHSO3 modification significantly improved handling and flowability of canola protein adhesives.
Air-induced inverse Chladni patterns
Authors: van Gerner Henk Jan , van der Weele Ko , van der Hoef Martin A. , van der Meer Devaraj 
Published: December 2011

AbstractWhen very light particles are sprinkled on a resonating horizontal plate, inverse Chladni patterns are formed. Instead of going to the nodal lines of the plate, where they would form a standard Chladni pattern, the particles are dragged to the antinodes by the air currents induced by the vibration of the plate. Here we present a detailed picture of the mechanism using numerical simulations involving both the particles and the air. Surprisingly, the time-averaged Eulerian velocity, commonly used in these type of problems, does not explain the motion of the particles: it even has the opposite direction, towards the nodal lines. The key to the inverse Chladni patterning is found in the averaged velocity of a tracer particle moving along with the air: this Lagrangian velocity, averaged over a vibration cycle, is directed toward the antinodes. The Chladni plate thus provides a unique example of a system in which the Eulerian and Lagrangian velocities point in opposite directions.
On the theory of a shock wave driven by a corrugated piston in a non-ideal fluid
Authors: Bates J. W. 
Published: December 2011

AbstractIn the context of an Eulerian fluid description, we investigate the dynamics of a shock wave that is driven by the steady impulsively initiated motion of a two-dimensional planar piston with small corrugations superimposed on its surface. This problem was originally solved by Freeman (Proc. Royal Soc. A, vol. 228, 1955, pp. 341–362), who showed that piston-driven shocks are unconditionally stable when the fluid medium through which they propagate is an ideal gas. Here, we generalize Freeman’s mathematical framework to account for a fluid characterized by an arbitrary equation of state. We find that a sufficient condition for shock stability is $\ensuremath{-} 1\lt h\lt {h}_{c} $, where $h$ is the D’yakov parameter and ${h}_{c} $ is a critical value less than unity. For values of $h$ within this range, linear perturbations imparted to the front by the piston at time $t= 0$ attenuate asymptotically as ${t}^{\ensuremath{-} 3/ 2} $. Outside of this range, the temporal behaviour of perturbations is more difficult to determine and further analysis is required to assess the stability of a shock front under such circumstances. As a benchmark of the main conclusions of this paper, we compare our generalized expression for the linearized shock-ripple amplitude with an independent Bessel-series solution derived by Zaidel’ (J. Appl. Math. Mech., vol. 24, 1960, pp. 316–327) and find excellent agreement.
On the relationship between efficiency and wake structure of a batoid-inspired oscillating fin
Authors: Dewey Peter A. , Carriou Antoine , Smits Alexander J. 
Published: December 2011

AbstractA mechanical representation of batoid-like propulsion using a flexible fin with an elliptical planform shape is used to study the hydrodynamics of undulatory propulsion. The wake is found to consist of a series of interconnected vortex rings, whereby leading and trailing edge vortices of subsequent cycles become entangled with one another. Efficient propulsion is achieved when leading and trailing edge vortices coalesce at the spanwise location where most of the streamwise fluid momentum is concentrated in the wake of the fin. Both the Strouhal number and the wavelength are found to have a significant effect on the wake structure. In general, a decrease in wavelength promotes a wake transition from shedding a single vortex per half-oscillation period to shedding a pair of vortices per half-oscillation period. An increase in Strouhal number causes the wake to bifurcate a finite distance downstream of the trailing edge of the fin into a pair of jets oriented at an acute angle to the line of symmetry. The bifurcation distance decreases with increasing Strouhal number and wavelength, and it is shown to obey a simple scaling law.
Sediment-laden fresh water above salt water: linear stability analysis
Authors: Burns P. , Meiburg E. 
Published: December 2011

AbstractWhen a layer of particle-laden fresh water is placed above clear, saline water, both Rayleigh–Taylor and double diffusive fingering instabilities may arise. For quasi-steady base profiles, we obtain linear stability results for such situations by means of a rational spectral approximation method with adaptively chosen grid points, which is able to resolve multiple steep gradients in the base state density profile. In the absence of salinity and for a step-like concentration profile, the dominant parameter is the ratio of the particle settling velocity to the viscous velocity scale. As long as this ratio is small, particle settling has a negligible influence on the instability growth. However, when the particles settle more rapidly than the instability grows, the growth rate decreases inversely proportional to the settling velocity. This damping effect is a result of the smearing of the vorticity field, which in turn is caused by the deposition of vorticity onto the fluid elements passing through the interface between clear and particle-laden fluid. In the presence of a stably stratified salinity field, this picture changes dramatically. An important new parameter is the ratio of the particle settling velocity to the diffusive spreading velocity of the salinity, or alternatively the ratio of the unstable layer thickness to the diffusive interface thickness of the salinity profile. As long as this quantity does not exceed unity, the instability of the system and the most amplified wavenumber are primarily determined by double diffusive effects. In contrast to situations without salinity, particle settling can have a destabilizing effect and significantly increase the growth rate. Scaling laws obtained from the linear stability results are seen to be largely consistent with earlier experimental observations and theoretical arguments put forward by other authors. For unstable layer thicknesses much larger than the salinity interface thickness, the particle and salinity interfaces become increasingly decoupled, and the dominant instability mode becomes Rayleigh–Taylor-like, centred at the lower boundary of the particle-laden flow region.
Characterization of the flow past a truncated square cylinder in a duct under a spanwise magnetic field
Authors: Dousset Vincent , Pothérat Alban 
Published: December 2011

AbstractWe study the flow of an electrically conducting fluid past a truncated square cylinder in a rectangular duct under the influence of an externally applied homogeneous magnetic field oriented along the cylinder axis. Our aim is to bridge the gap between the non-magnetic regime, where we previously found a complex set of three-dimensional recirculations behind the cylinder (Dousset & Pothérat,J. Fluid Mech., vol. 653, 2010, pp. 519–536) and the asymptotic regime of dominating Lorentz force analysed by Hunt & Ludford (J. Fluid. Mech., vol. 33, 1968, pp. 693–714). The latter regime is characterized by a remarkable structure known asHunt’s wakein the magnetohydrodynamics community, where the flow is deflected on either side of a stagnant zone, right above the truncated cylinder as if the latter would span the full height of the duct. In steady flows dominated by the Lorentz force, with negligible inertia, we provide the first numerical flow visualization of Hunt’s wake. In regimes of finite inertia, a thorough topological analysis of the steady flow regimes reveals how the Lorentz force gradually reorganizes the flow structures in the hydrodynamic wake of the cylinder as the Hartmann number$\mathit{Ha}$(which gives a non-dimensional measure of the magnetic field) is increased. The nature of the vortex shedding follows from this rearrangement of the steady structures by the magnetic field. As$\mathit{Ha}$is increased, we observe that the vortex street changes from a strongly symmetric one to the alternate procession of counter-rotating vortices typical of the non-truncated cylinder wakes.
Design of viscometers corresponding to a universal molecular simulation method
Authors: Dayal Kaushik , James Richard D. 
Published: December 2011

AbstractWe present conceptual designs of viscometers corresponding to our new exact molecular simulation method (Dayal & James, J. Mech. Phys. Solids, vol. 58 (2), 2010, pp. 145–163). The molecular simulation method is a generalization of the method of Lees & Edwards (J. Phys. C: Solid State Phys., vol. 5, 1972, p. 1921), and includes a three-parameter family of incompressible flows, as well as compressible flows and unsteady flows exhibiting vortex stretching. All fluids are allowed. The method gives a way to simulate these flows using relatively few molecules, in the absence of a constitutive relation describing the fluid. This paper presents conceptual designs for viscometers that produce large families of these flows. The basic theme of this paper is that the flows discussed here are a better way to characterize the properties of complex fluids than the currently available methods, such as those based on viscometric flows.
Oxidised fish oil does not influence established markers of oxidative stress in healthy human subjects: a randomised controlled trial
Authors: Ottestad Inger , Vogt Gjermund , Retterstøl Kjetil , Myhrstad Mari C. , Haugen John-Erik , Nilsson Astrid , Ravn-Haren Gitte , Nordvi Berit , Brønner Kirsti W. , Andersen Lene F. , Holven Kirsten B. , Ulven Stine M. 
Published: December 2011

Intake of fish oil reduces the risk of CHD and CHD deaths. Marine n-3 fatty acids (FA) are susceptible to oxidation, but to our knowledge, the health effects of intake of oxidised fish oil have not previously been investigated in human subjects. The aim of the present study was to investigate markers of oxidative stress, lipid peroxidation and inflammation, and the level of plasma n-3 FA after intake of oxidised fish oil. In a double-blinded randomised controlled study, healthy subjects (aged 18–50 years, n 54) were assigned into one of three groups receiving capsules containing either 8 g/d of fish oil (1·6 g/d EPA+DHA; n 17), 8 g/d of oxidised fish oil (1·6 g/d EPA+DHA; n 18) or 8 g/d of high-oleic sunflower oil (n 19). Fasting blood and morning spot urine samples were collected at weeks 0, 3 and 7. No significant changes between the different groups were observed with regard to urinary 8-iso-PGF2α; plasma levels of 4-hydroxy-2-hexenal, 4-hydroxy-2-nonenal and α-tocopherol; serum high sensitive C-reactive protein; or activity of antioxidant enzymes in erythrocytes. A significant increase in plasma level of EPA+DHA was observed in both fish oil groups, but no significant difference was observed between the fish oil groups. No changes in a variety of in vivo markers of oxidative stress, lipid peroxidation or inflammation were observed after daily intake of oxidised fish oil for 3 or 7 weeks, indicating that intake of oxidised fish oil may not have unfavourable short-term effects in healthy human subjects.
Increasing the folic acid content of maternal or post-weaning diets induces differential changes in phosphoenolpyruvate carboxykinase mRNA expression and promoter methylation in rats
Authors: Hoile Samuel P. , Lillycrop Karen A. , Grenfell Leonie R. , Hanson Mark A. , Burdge Graham C. 
Published: December 2011

Environmental exposures throughout the life course, including nutrition, may induce phenotypic and epigenetic changes. There is limited information about how timing affects the nature of such effects induced by a specific nutritional exposure. We investigated the effect of increased exposure to folic acid before birth or during the juvenile–pubertal period in rats on the epigenetic regulation of glucose homeostasis. Rats were fed either a folic acid-adequate (AF; 1 mg/kg feed) or a folic acid-supplemented (FS; 5 mg/kg feed) diet from conception until delivery and then an AF diet during lactation. Juvenile rats were fed either the AF or the FS diet from weaning for 28 d and then an AF diet. Liver and blood were collected after a 12 h fast between postnatal days 84 and 90. Maternal FS diet increased plasma glucose concentration significantly (P < 0·05) in females, but not in males. Post-weaning FS diet decreased glucose concentration significantly in females, but increased glucose concentration in males. There were no effects of the FS diet on phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression in males, while the pattern of expression was related to plasma glucose concentration in females. The FS diet induced specific changes in the methylation of individual CpG in females, but not in males, which were related to the time of exposure. Methylation of CpG − 248 increased the binding of CCAAT-enhancer-binding protein β to the PEPCK promoter. Together, these findings show that both the period during the life course and sex influence the effect of increased exposure to folic acid on the epigenetic regulation of PEPCK and glucose homeostasis.
Predicting urinary creatinine excretion and its usefulness to identify incomplete 24 h urine collections
Authors: De Keyzer Willem , Huybrechts Inge , Dekkers Arnold L. M. , Geelen Anouk , Crispim Sandra , Hulshof Paul J. M. , Andersen Lene F. , Řehůřková Irena , Ruprich Jiří , Volatier Jean-Luc , Van Maele Georges , Slimani Nadia , van't Veer Pieter , de Boer Evelien , De Henauw Stefaan 
Published: December 2011

Studies using 24 h urine collections need to incorporate ways to validate the completeness of the urine samples. Models to predict urinary creatinine excretion (UCE) have been developed for this purpose; however, information on their usefulness to identify incomplete urine collections is limited. We aimed to develop a model for predicting UCE and to assess the performance of a creatinine index usingpara-aminobenzoic acid (PABA) as a reference. Data were taken from the European Food Consumption Validation study comprising two non-consecutive 24 h urine collections from 600 subjects in five European countries. Data from one collection were used to build a multiple linear regression model to predict UCE, and data from the other collection were used for performance testing of a creatinine index-based strategy to identify incomplete collections. Multiple linear regression (n458) of UCE showed a significant positive association for body weight (β = 0·07), the interaction term sex × weight (β = 0·09, reference women) and protein intake (β = 0·02). A significant negative association was found for age (β = − 0·09) and sex (β = − 3·14, reference women). An index of observed-to-predicted creatinine resulted in a sensitivity to identify incomplete collections of 0·06 (95 % CI 0·01, 0·20) and 0·11 (95 % CI 0·03, 0·22) in men and women, respectively. Specificity was 0·97 (95 % CI 0·97, 0·98) in men and 0·98 (95 % CI 0·98, 0·99) in women. The present study shows that UCE can be predicted from weight, age and sex. However, the results revealed that a creatinine index based on these predictions is not sufficiently sensitive to exclude incomplete 24 h urine collections.
An Information War Waged by Merchants and Missionaries at Canton: The Society for the Diffusion of Useful Knowledge in China, 1834–1839
Authors: CHEN SONGCHUAN 
Published: December 2011

AbstractThis paper explores the efforts and impact of the Society for the Diffusion of Useful Knowledge in China (1834–1839), which existed during the five years before the First Opium War. It contends that the Society represented a third form of British engagement with the Chinese, alongside the diplomatic attempts of 1793 and 1816, and the military conflict of 1839–1842. The Society waged an ‘information war’ to penetrate the information barrier that the Qing had established to contain European trade and missions. The foreigners in Canton believed they were barred from further access to China because the Chinese had no information on the true character of the Europeans. Thus, they prepared ‘intellectual artillery’ in the form of Chinese language publications, especially on world geography, to distribute among the Chinese, in the hope that this effort would familiarize the Chinese with the science and art of Westerners and thereby cultivate respect and a welcoming atmosphere. The war metaphor was conceived, and the information war was waged, in the periphery of the British informal empire in Canton, but it contributed to the conceptualization of war against China, both in Canton and in Britain, in the years before actual military action. Behind the rhetoric of war and knowledge diffusion in Canton, lay a convergence of interests between merchants and missionaries, which drove both to employ information and military power to further their shared aim of opening China up for trade and proselytizing.