bluuebunny/crossref_metadata_2025 huggingface dataset:
MRI evaluation of axonal reorganization after bone marrow stromal cell treatment of traumatic brain injury
Authors: Jiang Quan , Qu Changsheng , Chopp Michael , Ding Guang Liang , Davarani Siamak P. Nejad‐ , Helpern Joseph A. , Jensen Jens H. , Zhang Zheng Gang , Li Lian , Lu Mei , Kaplan David , Hu Jiani , Shen Yimin , Kou Zhifeng , Li Qingjiang , Wang Shiyang , Mahmood Asim
Published: March 2011

We treated traumatic brain injury (TBI) with human bone marrow stromal cells (hMSCs) and evaluated the effect of treatment on white matter reorganization using MRI. We subjected male Wistar rats (n = 17) to controlled cortical impact and either withheld treatment (controls; n = 9) or inserted collagen scaffolds containing hMSCs (n = 8). Six weeks later, the rats were sacrificed and MRI revealed selective migration of grafted neural progenitor cells towards the white matter reorganized boundary of the TBI‐induced lesion. Histology confirmed that the white matter had been reorganized, associated with increased fractional anisotropy (FA; p < 0.01) in the recovery regions relative to the injured core region in both treated and control groups. Treatment with hMSCs increased FA in the recovery regions, lowered T2 in the core region, decreased lesion volume and improved functional recovery relative to untreated controls. Immunoreactive staining showed axonal projections emanating from neurons and extruding from the corpus callosum into the ipsilateral cortex at the boundary of the lesion. Fiber tracking (FT) maps derived from diffusion tensor imaging confirmed the immunohistological data and provided information on axonal rewiring. The apparent kurtosis coefficient (AKC) detected additional axonal remodeling regions with crossing axons, confirmed by immunohistological staining, compared with FA. Our data demonstrate that AKC, FA, FT and T2 can be used to evaluate treatment‐induced white matter recovery, which may facilitate restorative therapy in patients with TBI. Copyright © 2011 John Wiley & Sons, Ltd.
A statistical method for verifying mesh convergence in Monte Carlo simulations with application to fragmentation
Authors: Bishop J. E. , Strack O. E.
Published: March 2011

A novel method is presented for assessing the convergence of a sequence of statistical distributions generated by direct Monte Carlo sampling. The primary application is to assess the mesh or grid convergence, and possibly divergence, of stochastic outputs from non‐linear continuum systems. Example systems include those from fluid or solid mechanics, particularly those with instabilities and sensitive dependence on initial conditions or system parameters. The convergence assessment is based on demonstrating empirically that a sequence of cumulative distribution functions converges in the Linfty norm. The effect of finite sample sizes is quantified using confidence levels from the Kolmogorov–Smirnov statistic. The statistical method is independent of the underlying distributions.

The statistical method is demonstrated using two examples: (1) the logistic map in the chaotic regime, and (2) a fragmenting ductile ring modeled with an explicit‐dynamics finite element code. In the fragmenting ring example the convergence of the distribution describing neck spacing is investigated. The initial yield strength is treated as a random field. Two different random fields are considered, one with spatial correlation and the other without. Both cases converged, albeit to different distributions. The case with spatial correlation exhibited a significantly higher convergence rate compared with the one without spatial correlation. Copyright © 2011 John Wiley & Sons, Ltd.
A three‐dimensional hybrid meshfree‐Cartesian scheme for fluid–body interaction
Authors: Yu P. , Yeo K. S. , Shyam Sundar D. , Ang S. J.
Published: March 2011

A numerical method based on a hybrid meshfree‐Cartesian grid is developed for solving three‐dimensional fluid–solid interaction (FSI) problems involving solid bodies undergoing large motion. The body is discretized and enveloped by a cloud of meshfree nodes. The motion of the body is tracked by convecting the meshfree nodes against a background of Cartesian grid points. Spatial discretization of second‐order accuracy is accomplished by the combination of a generalized finite difference (GFD) method and conventional finite difference (FD) method, which are applied to the meshfree and Cartesian nodes, respectively. Error minimization in GFD is carried out by singular value decomposition. The discretized equations are integrated in time via a second‐order fractional step projection method. A time‐implicit iterative procedure is employed to compute the new/evolving position of the immersed bodies together with the dynamically coupled solution of the flow field. The present method is applied on problems of free falling spheres and tori in quiescent flow and freely rotating spheres in simple shear flow. Good agreement with published results shows the ability of the present hybrid meshfree‐Cartesian grid scheme to achieve good accuracy. An application of the method to the self‐induced propulsion of a deforming fish‐like swimmer further demonstrates the capability and potential of the present approach for solving complex FSI problems in 3D. Copyright © 2011 John Wiley & Sons, Ltd.
A higher order compact finite difference algorithm for solving the incompressible Navier–Stokes equations
Authors: Tian Zhenfu , Liang Xian , Yu Peixiang
Published: March 2011

On the basis of the projection method, a higher order compact finite difference algorithm, which possesses a good spatial behavior, is developed for solving the 2D unsteady incompressible Navier–Stokes equations in primitive variable. The present method is established on a staggered grid system and is at least third‐order accurate in space. A third‐order accurate upwind compact difference approximation is used to discretize the non‐linear convective terms, a fourth‐order symmetrical compact difference approximation is used to discretize the viscous terms, and a fourth‐order compact difference approximation on a cell‐centered mesh is used to discretize the first derivatives in the continuity equation. The pressure Poisson equation is approximated using a fourth‐order compact difference scheme constructed currently on the nine‐point 2D stencil. New fourth‐order compact difference schemes for explicit computing of the pressure gradient are also developed on the nine‐point 2D stencil. For the assessment of the effectiveness and accuracy of the method, particularly its spatial behavior, a problem with analytical solution and another one with a steep gradient are numerically solved. Finally, steady and unsteady solutions for the lid‐driven cavity flow are also used to assess the efficiency of this algorithm. Copyright © 2011 John Wiley & Sons, Ltd.
Modification of novel bio‐based resin‐epoxidized soybean oil by conventional epoxy resin
Authors: Gupta A.P. , Ahmad Sharif , Dev Anshu
Published: March 2011

Conventional epoxy resin (DGEBA), in varying proportion, was used to modify epoxidized soybean oil (ESO) based systems, crosslinked by phthalic anhydride. The properties of DGEBA modified ESO systems were investigated by dynamic mechanical analysis, impact testing, tensile and flexural testing, scanning electron microscopy, and thermogravimetric analysis. Single loss factor tan δ peak was obtained for all of the modified systems. The results show the improvement in mechanical properties from their high crosslinking densities through the introduction of DGEBA with increase in initial degradation temperature, as obtained from thermogravimetric analysis. Results approaches to an ideal composition which gives the optimum property. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Optimization of powder injection molding of feedstock based on aluminum oxide and multicomponent water‐soluble polymer binder
Authors: Hausnerova Berenika , Marcanikova Lucie , Filip Petr , Saha Petr
Published: March 2011

Analyses crucial to optimize powder injection molding of feedstock based on aluminum oxide powder and multicomponent polymeric binder are provided with the aim to obtain defect‐free, high density parts. As the critical step of the process is the flow of highly filled (60 vol%) compound into a mold cavity, rheological properties supplemented by thermal and pressure‐volume‐temperature characteristics are measured and described. Upon shear deformation the feedstock undergoes structural changes, which are quantified in terms of yield stresses obtained using Herschel‐Bulkley and Casson methods. Further, the rheological model is developed to describe the flow behavior of the feedstock in the whole shear rate range measured. Thermogravimetric analysis is performed to optimize debinding step of the process, and two possible ways of the binder removal are proposed: purely thermal andcombined solvent/thermal. The quality of the final sintered parts is demonstrated on scanning electron microscopic images of their surfaces. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Microstructure, morphology, and mechanical properties of styrene‐butadiene rubber/organoclay nanocomposites
Authors: Díez J. , Barral L. , Bellas R. , Bouza R. , López J. , Marco C. , Ellis G.
Published: March 2011

Composites based on styrene‐butadiene rubber containing organophilic montmorillonite were produced by melt compounding and conventional sulfur curing. The samples were characterized by X‐ray diffraction and both transmission and scanning electron microscopy. The dispersion of the clay and the spacing between the silicate layers revealed the presence of intercalated, aggregated, and partially exfoliated structures. Infrared spectroscopy also provided clear evidence for clay exfoliation and migration of zinc stearate to the surface of the samples. The crosslink density, evaluated through swelling in toluene, decreased with increasing organoclay content. This behavior could be justified by the partial absorption of the curatives on the filler surface. The mechanical properties of nanocomposites significantly increased when compared with those of unfilled rubber. These enhanced properties were attributed to the intercalation/exfoliation of the organoclay. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Refractive materials for interlayer optical contacts with TiO2‐based organic/inorganic hybrids
Authors: Okaniwa Kaoru
Published: March 2011

Organic/inorganic hybrid materials were prepared by synthesizing from titanium tetraisopropoxide (TTIP), diethanolamine (DEOA), and water. Formulating the materials with thermosetting polymers, the composites were designed for refractive optical contacts with heat lamination of a film having >50 μm thickness. Inherent difficulties of TiO2 and sol‐gel reaction of TTIP, i.e. photocatalytic properties and prompt sol‐gel reaction to form large TiO2 particle, were avoided by stabilizing Ti with use of DEOA. The reactivity of the sol‐gel reaction and formation of TiO2 crystal structure were suppressed by DEOA. However, suppression of the photocatalytic properties was not enough and needed a use of anti‐oxidant agent, 2,6‐di‐t‐butyl‐p‐cresol (BHT). The titanium‐based organic/inorganic hybrid materials and its epoxy composites were transparent in visible wavelength region and gave in the range of 1.66 to 1.73 of refractive indices depending on stoichometric parameters of TTIP, water, and DEOA for the hybrid materials. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Styrene‐assisted melt‐free radical grafting of glycidyl methacrylate onto isotactic poly(1‐butene)
Authors: Zhou Yanfen , Zhao Yongxian , Yao Wei , Huang Baochen
Published: March 2011

The melt‐free radical grafting of glycidyl methacrylate (GMA) onto powered isotactic poly(1‐butene) (iPB‐1) using styrene (St) as a comonomer in a Haake mixer was studied. The effects of temperature, initial GMA, and peroxide concentration, as well as the addition of St comonomer, on the final grafting degree, grafting efficiency, and the melt flow rate of grafted polymer were studied. It was shown that the addition of St as a comonomer could significantly enhance the grafting degree of GMA on iPB‐1 and reduce the extent of degradation of iPB‐1 to some degree. It has been found that the grafting degree of dual‐monomer melt‐grafted iPB‐1 was about twice that of single‐monomer‐grafted iPB‐1 for the same monomer and peroxide concentrations. The grafting of GMA onto iPB‐1 remarkably accelerated the crystal form II → I transformation of iPB‐1. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Preparation and properties of amphoteric polyacrylamide by seeded dispersion polymerization in ammonium sulfate solution
Authors: Wang Chuanxing , Wang Xiaoxiang , Miao Chunbao , Wu Yumin
Published: March 2011

Amphoteric polyacrylamide (AmPAM) was prepared successfully through seeded dispersion polymerization with acrylamide, methacrylatoethyl trimethyl ammonium chloride and acrylic acid as comonomers in ammonium sulfate solution. It was characterized by 1H nuclear magnetic resonance (1H NMR) and elemental analysis. The particle morphology and apparent viscosity of polymer dispersion were obtained by optical microscope and rotary viscometer, respectively. AmPAM dispersion was obtained with low apparent viscosity. The process was smooth without high viscosity stage. The data of 1H NMR spectrum and elemental analysis indicated that all monomers had participated in the polymerization. The seeded reaction time and the mass ratio of two parts of monomers had significant effects on the dispersion polymerization. The best conditions were seeded reaction time 1.75h and the mass ratio 0.75. The apparent viscosity of AmPAM dispersion depended on the number of particles, particle size and low molecular weight polymer concentration in the continuous phase. AmPAM showed both anti‐polyelectrolyte effect and polyelectrolyte effect. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Effect of cyclotrimerization of bisphenol‐A dicyanate monomer on poly(ethylene terephthalate) chain extension
Authors: Zhang Yanjun , Zhang Chen , Li Hangquan , Du Zhongjie
Published: March 2011

The engineering application of poly(ethylene terephthalate) (PET) was limited by its low melt viscosity and strength. Numerous chain extenders were used to enlarge the molecular weight so as to overcome these shortcomings including bisphenol‐A dicyanate (BADCy), which was proven effective in one of our previous work. It was considered that tri‐mer of BADCy through cyclotrimerization might strengthen the effectiveness in chain extender for PET, and the effect of BADCy tri‐mer was studied in this work. With increasing the cyclotrimerization reaction temperature of BADCy monomer, the conversion to tri‐mers was increased. With a fraction of BADCy tri‐mer in the chain extender, the modified PET exhibited higher melt torque, intrinsic viscosity, melt modulus, and melt viscosity than those modified by BADCy monomer alone. BADCy tri‐mer had a positive effect on the chain extension of PET. However, the fraction of tri‐mers in the monomer/tri‐mer mixture should be limited to a certain value; otherwise, the chain extension would be weakened. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Crystallization and morphology studies of biodegradable poly(ϵ‐caprolactone)/polyhedral oligomeric silsesquioxanes nanocomposites
Authors: Pan Hong , Yu Jing , Qiu Zhaobin
Published: March 2011

Biodegradable poly(ε‐caprolactone) (PCL)/polyhedral oligomeric silsesquioxanes (POSS) nanocomposites at various POSS loadings were prepared via solution casting method in this work. Scanning electron microscopy observation indicates that POSS are homogeneously dispersed in the PCL matrix. The experiments show that the crystallization peak temperature is higher in the nanocomposites than in neat PCL during nonisothermal melt crystallization; moreover, the overall crystallization rate is faster in the nanocomposites than in neat PCL during isothermal melt crystallization. Both nonisothermal and isothermal melt crystallization studies suggest that the crystallization of PCL is enhanced by the presence of POSS and influenced by the POSS loading. The effect of POSS on the crystallization is twofold: the presence of POSS may provide heterogeneous nucleation sites for the PCL crystallization while the aggregates of POSS may restrict large crystal growth of PCL. However, the crystallization mechanism and crystal structure of PCL remain almost unchanged despite the presence of POSS in the nanocomposites. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Enhanced infrared transmission of GZO film by rapid thermal annealing for Si thin film solar cells
Authors: Jia Haijun , Matsui Takuya , Kondo Michio
Published: March 2011

Ga doped ZnO (GZO) films prepared by sputtering at room temperature were rapid thermal annealed (RTA) at elevated temperatures. With increasing annealing temperature up to 570°C, film transmission enhanced significantly over wide spectral range especially in infrared region. Hall effect measurements revealed that carrier density decreased from ∼8 × 1020 to ∼ 3 × 1020 cm−3 while carrier mobility increased from ∼15 to ∼28 cm2/Vs after the annealing, and consequently low film resistivity was preserved. Hydrogenated microcrystalline Si (µc‐Si:H) and microcrystalline Si1‐xGex (µc‐Si1‐xGex:H, x = 0.1) thin film solar cells fabricated on textured RTA‐treated GZO substrates demonstrated strong enhancement in short‐circuit current density due to improved spectral response, exhibiting quite high conversion efficiencies of 9.5% and 8.2% for µc‐Si:H and µc‐Si0.9Ge0.1:H solar cells, respectively. Copyright © 2011 John Wiley & Sons, Ltd.
17.9% Metal‐wrap‐through mc‐Si cells resulting in module efficiency of 17.0%
Authors: Lamers M. W. P. E. , Tjengdrawira C. , Koppes M. , Bennett I. J. , Bende E. E. , Visser T. P. , Kossen E. , Brockholz B. , Mewe A. A. , Romijn I. G. , Sauar E. , Carnel L. , Julsrud S. , Naas T. , de Jong P. C. , Weeber A. W.
Published: March 2011

We obtained 17.9% cell efficiency on thin and large mc‐Si REC wafers using ECN's metal‐wrap‐through (MWT) concept. Optimization of several cell processing steps led to an increase of more than 2% absolute in cell efficiency. With these cells 36‐cell modules were manufactured at 100% yield in our industry scale module pilot line. The highest module efficiency obtained (as independently confirmed by JRC‐ESTI) was 17%. In this module the average cell efficiency was 17.8%; this shows a small difference between cell and module efficiency. Copyright © 2011 John Wiley & Sons, Ltd.
Photochemistry of a 6′‐cyanosubstituted spironaphthooxazine: photo‐induced decay of an open form
Authors: Nikolaeva Marina I. , Korolev Valeri V. , Pritchina Elena A. , Glebov Evgeni M. , Plyusnin Victor F. , Metelitsa Anatoly V. , Voloshin Nikolai A. , Minkin Vladimir I.
Published: March 2011

Photochemistry of three 6′‐cyanosubstituted spironaphthooxazines (SNO) in ethanol matrices at 77 K was studied by means of ultraviolet (UV) and erythrocyte sedimentation rate (ESR) spectroscopy and quantum chemistry. The quantum yield of the open form photolysis is found to be 0.01–0.02, which is high enough for 77 K. For one of the SNO, the formation of a merocyanine form radical was observed. The radicals were formed by an H atom abstraction from the solvent molecule to the light‐excited merocyanine isomers. The formation of a merocyanine radical represents a new specific channel of photochemically induced degradation of spirooxazines. Copyright © 2011 John Wiley & Sons, Ltd.
Kinetics and product distribution of p‐nitrophenyl phosphate dianion solvolysis in ternary DMSO/alcohol/water mixtures are compatible with metaphosphate formation
Authors: Lima F. S. , Chaimovich H. , Cuccovia I. M.
Published: March 2011

The rate of solvolysis of p‐nitrophenyl phosphate (PNPP) dianion in DMSO/water strongly decreases by increasing water concentration. Addition of linear alcohols (methanol, propanol, butanol, pentanol, and hexanol) at constant DMSO/water molar ratio produced an even sharper rate decrease. Alkyl phosphate formation, resulting from PNPP solvolysis in ternary DMSO/water/alcohol mixtures, increased with alcohol concentration and was essentially temperature independent. Methanol and hexanol were the poorest nucleophiles under all conditions. Activation energies and enthalpies for solvolysis in ternary mixtures were similar and entropies varied with alcohol concentration. Taken together these results can be best interpreted in terms of a dissociative mechanism with the intervention of metaphosphate. Copyright © 2011 John Wiley & Sons, Ltd.
‘Every Wednesday I Am Happy’: Childhoods in an Irish Asylum Centre
Authors: White Allen
Published: March 2011

In Ireland, asylum seekers are placed into a system of dispersed ‘direct provision’ reception centres across the country. This paper argues that the frequently contradictory and ambiguous positions created for children living within the Irish asylum system reflect the uncertainties and ambiguities surrounding them as immigrants (as part/not part of host societies), children (as child/not adult), and asylum seekers (as separated‐out populations in dispersal centres). Based on research in a specific asylum dispersal centre, this paper will explore the ways in which the spatialities of the children's lives reflect and constitute these contradictions and ambiguities in a host of different ways. Copyright © 2011 John Wiley & Sons, Ltd.
Electrical properties of (Na,Ce) doped Bi5Ti3FeO15 ceramics
Authors: Huang Zhen , Wang Gen‐Shui , Li Yu‐Chen , Liang Rui‐Hong , Cao Fei , Dong Xian‐Lin
Published: March 2011

Bi5Ti3FeO15 (BTF) doped with (Na,Ce) was prepared by solid‐state reaction sintering. Effects of (Na,Ce) doping on the structure, microstructure, and electrical properties of BTF were investigated. The Curie point decreased from 759 to 711 °C with increasing dopant amount. At low temperatures (50–400 °C), peaks of dielectric losses only can be seen for BTF, Bi4.95Na0.025Ce0.025Ti3FeO15, and Bi4.90Na0.05Ce0.05Ti3FeO15 ceramics. The highest piezoelectric constant d33 of 13.4 pC/N is achieved for Bi4.80Na0.10Ce0.10Ti3FeO15 ceramics. At an applied electric field of 200 kV/cm, the polarization–electrical field and the current–electrical field hysteresis loops of Bi4.90Na0.05Ce0.05Ti3FeO15 ceramics are shown. This composition also has the highest room‐temperature resistivity, about 8 × 1012 Ω · cm.
Pressure‐induced structural transition in CaF2 nanocrystals
Authors: Wang Jingshu , Hao Jian , Wang Qiushi , Jin Yunxia , Li Fangfei , Liu Bo , Li Quanjun , Liu Bingbing , Cui Qiliang
Published: March 2011

The structural transition of CaF2 nanocrystals was studied by in situ high pressure synchrotron radiation X‐ray diffraction measurements up to about 46.5 GPa at ambient temperature. A pressure‐induced fluorite structure (Fm3m) to orthorhombic PbCl2‐type structure (Pnma) transition starts at 14.0 GPa, and phase transition is sluggish. The orthorhombic phase of nanocrystalline CaF2 is stable up to 46.5 GPa. The enhancement of transition pressure in CaF2 nanocrystals as compared with the corresponding bulk material is mainly caused by the surface energy difference between the phases involved.
Pressure dependence of Raman modes at the interface of a CIGS/CdS/ZnO solar cell
Authors: Choi I. H.
Published: March 2011

CuInSe2/CdS/ZnO and CuInGaSe2/CdS/ZnO heterojunction solar cells have been prepared and the Raman scattering spectra from the interface between CdS buffer and CIS absorber layer have been measured as a function of hydrostatic pressure. CuInSe2 absorber layers were prepared by the metal organic chemical vapour deposition (MOCVD) technique on Mo coated soda lime glass. The CdS buffer layer and ZnO window layer were deposited by chemical bath deposition (CBD) and R. F. magnetron sputtering, respectively. The pressure coefficient of the A1(Γ1) peak of the CIS layer in the solar cell was measured to be ${\partial} \omega /{\partial} P = 3.84\pm 0.13\;{\rm cm}^{{-} 1} /{\rm GPa}$, slightly smaller than the value obtained for a thin film of CIS only, which was ${\partial} \omega /{\partial} P = 4.0\pm 0.12\;{\rm cm}^{{-} 1} /{\rm GPa}$. The measured pressure coefficient of the A1(Γ1) peak of the CdS layer in the solar cell, ${\partial} \omega /{\partial} P = 5.31\pm 0.27\;{\rm cm}^{{-} 1} /{\rm GPa}$, is much larger than that obtained with the CdS thin film grown on a GaAs substrate, which was ${\partial} \omega /{\partial} P = 4.99\pm 0.20\;{\rm cm}^{{-} 1} /{\rm GPa}$. The pressure coefficient of the A1(Γ1) peak in the CuIn0.7Ga0.3Se2 thin film is ${\partial} \omega /{\partial} P = 3.81\pm 0.15\;{\rm cm}^{{-} 1} /{\rm GPa}$, which is lower than that of the CuInSe2 thin film.
High pressure phase transitions in Mg1–xCaxO: Theory
Authors: Srivastava Anurag , Chauhan Mamta , Singh R. K. , Padegaonker Rishikesh
Published: March 2011

We have analysed a B1 → B2 structural phase transitions in Mg1–xCaxO solid solutions and their ground state properties by using first principle density functional theory and charge transfer interaction potential (CTIP) approach. The effects of exchange‐correlation interactions are handled by the generalized gradient approximation with Perdew–Burke–Ernzerhof type parameterization. CTIP approach includes the long range modified Coulomb with charge transfer interactions and short range part of this model includes the van der Waals as well as Hafemeister Flygare type overlap repulsive interactions. The study observes a linear variation of calculated transition pressure, bulk modulus and lattice parameter of Mg1−xCaxO as a function of Ca composition. The observed results for the end point members are in agreement to their experimental counterparts and the deviations have been discussed.
Complexities in the climate of the subpolar North Atlantic: a case study from the winter of 2007
Authors: Moore G. W. K. , Pickart R. S. , Renfrew I. A.
Published: March 2011

As a result of its high topography, Greenland significantly distorts the atmospheric flow affecting local as well as remote weather systems and, via air–sea interaction processes, the coupled climate system. During February and March 2007, a field campaign was carried out to investigate this as part of the international Greenland Flow Distortion Experiment (GFDex). The observational programme occurred during anomalous conditions, relative to the climatological mean, that favoured the formation of barrier flow along the southeastern coast of Greenland and easterly tip jets at Cape Farewell, Greenland's southernmost point, while inhibiting the formation of westerly tip jets in the same region. The North Atlantic Oscillation (NAO) index was positive, indicating a deep Icelandic Low. However, there was a southeastward shift in the low's centre and a more zonally oriented storm track that we propose to be the result of the concurrent positive phase of the East Atlantic (EA) teleconnection. Unlike the usual situation for an NAO positive state, there was also a warming in the lower troposphere over the Labrador Sea that we argue was the result of a relatively weak Canadian Polar Trough over the eastern Canadian Arctic. It is shown that consideration of the strength of the Canadian Polar Trough in conjunction with information on the phases of the NAO and EA provides for a qualitatively better representation of the state of the atmosphere over the subpolar North Atlantic during the winter of 2007, and by inference in general, than is possible via the NAO alone. Copyright © 2011 Royal Meteorological Society
Linz—Urfahr railway and road bridge — a 110‐year‐old structure severely damaged by corrosion
Authors: Fink Josef , Aigner Francesco
Published: March 2011

At the very end of the 1890s, the rural district of Urfahr was connected to the town of Linz, Austria, by means of a seven‐span, 393.94 m long steel bridge. Serious problems regarding its durability arose from the use of the bridge for road traffic due to the application of de‐icing salt, which began in the mid‐1960s and caused severe corrosion damage. In 1981 the bridge was improved by restoring the anti‐corrosion protection and by replacing the old deck construction with a new one. Since that time, restoration works and repairs have been carried out continuously. This paper deals with the present reliability of the main spans with a special focus on the structural behaviour under traffic and wind loads, quantified by means of modern standards.
Active management of the early innovation phases in steel application research for the construction sector
Authors: Nuesse Gregor , Wieland Hans‐Joachim , Limbachiya Mukesh , Herr Roland
Published: March 2011

This article reports on how the steel industry in Germany can systematically improve the early phases of its cooperative pre‐competitive application research in the construction sector. The aim of this work is to increase innovation success through a targeted lead‐in to the innovation processes. It makes use of various models from industrial innovation management, experience in research management for a current project on the sustainability of steel in the construction sector and the results from a survey of the research institutes participating in the project. As a result, a model for the systematic management of the early innovation phases in steel application research for the construction industry is presented. The model supports the participants from industry and the academic sector in finding, formulating and implementing new innovation ideas.
Concise Review: Adipose-Derived Stromal Vascular Fraction Cells and Stem Cells: Let's Not Get Lost in Translation
Authors: Gimble Jeffrey M. , Bunnell Bruce A. , Chiu Ernest S. , Guilak Farshid
Published: March 2011

Subcutaneous fat has emerged as an alternative tissue source for stromal/stem cells in regenerative medicine. Over the past decade, international research efforts have established a wealth of basic science and preclinical evidence regarding the differentiation potential and regenerative properties of both freshly processed, heterogeneous stromal vascular fraction cells and culture expanded, relatively homogeneous adipose-derived stromal/stem cells. The stage has been set for clinicians to translate adipose-derived cells from the bench to the bedside; however, this process will involve “development” steps that fall outside of traditional “hypothesis-driven, mechanism-based” paradigm. This concise review examines the next stages of the development process for therapeutic applications of adipose-derived cells and highlights the current state of the art regarding clinical trials. It is recommended that the experiments addressing these issues be reported comprehensively in the peer-review literature. This transparency will accelerate the standardization and reproducibility of adipose-derived cell therapies with respect to their efficacy and safety.
Anterior Hox Genes Interact with Components of the Neural Crest Specification Network to Induce Neural Crest Fates
Authors: Gouti Mina , Briscoe James , Gavalas Anthony
Published: March 2011

Hox genes play a central role in neural crest (NC) patterning particularly in the cranial region of the body. Despite evidence that simultaneous loss of Hoxa1 and Hoxb1 function resulted in NC specification defects, the role of Hox genes in NC specification has remained unclear due to extended genetic redundancy among Hox genes. To circumvent this problem, we expressed anterior Hox genes in the trunk neural tube of the developing chick embryo. This demonstrated that anterior Hox genes play a central role in NC cell specification by rapidly inducing the key transcription factors Snail2 and Msx1/2 and a neural progenitor to NC cell fate switch characterized by cell adhesion changes and an epithelial-to-mesenchymal transition (EMT). Cells delaminated from dorsal and medial neural tube levels and generated ectopic neurons, glia progenitors, and melanocytes. The mobilization of the NC genetic cascade was dependent upon bone morphogenetic protein signaling and optimal levels of Notch signaling. Therefore, anterior Hox patterning genes participate in NC specification and EMT by interacting with NC-inducing signaling pathways and regulating the expression of key genes involved in these processes.
Differentiation Potential of Human Postnatal Mesenchymal Stem Cells, Mesoangioblasts, and Multipotent Adult Progenitor Cells Reflected in Their Transcriptome and Partially Influenced by the Culture Conditions
Authors: Roobrouck Valerie D. , Clavel Carlos , Jacobs Sandra A. , Ulloa-Montoya Fernando , Crippa Stefania , Sohni Abhishek , Roberts Scott J. , Luyten Frank P. , Van Gool Stefaan W. , Sampaolesi Maurilio , Delforge Michel , Luttun Aernout , Verfaillie Catherine M.
Published: March 2011

Several adherent postnatal stem cells have been described with different phenotypic and functional properties. As many of these cells are being considered for clinical therapies, it is of great importance that the identity and potency of these products is validated. We compared the phenotype and functional characteristics of human mesenchymal stem cells (hMSCs), human mesoangioblasts (hMab), and human multipotent adult progenitor cells (hMAPCs) using uniform standardized methods. Human MAPCs could be expanded significantly longer in culture. Differences in cell surface marker expression were found among the three cell populations with CD140b being a distinctive marker among the three cell types. Differentiation capacity towards adipocytes, osteoblasts, chondrocytes, and smooth muscle cells in vitro, using established protocols, was similar among the three cell types. However, only hMab differentiated to skeletal myocytes, while only hMAPCs differentiated to endothelium in vitro and in vivo. A comparative transcriptome analysis confirmed that the three cell populations are distinct and revealed gene signatures that correlated with their specific functional properties. Furthermore, we assessed whether the phenotypic, functional, and transcriptome features were mediated by the culture conditions. Human MSCs and hMab cultured under MAPC conditions became capable of generating endothelial-like cells, whereas hMab lost some of their ability to generate myotubes. By contrast, hMAPCs cultured under MSC conditions lost their endothelial differentiation capacity, whereas this was retained when cultured under Mab conditions, however, myogenic capacity was not gained under Mab conditions. These studies demonstrate that hMSCs, hMab, and hMAPCs have different properties that are partially mediated by the culture conditions. STEM CELLS 2011;29:871–882
Effect of spectrum analyzer's impulse bandwidth on the measurement of EM waves emitted from partial discharges in multipath‐rich environment
Authors: Murayama Tetsuya , Kawada Masatake , Isaka Katsuo
Published: March 2011

Superheterodyne spectrum analyzer (SA) has been widely used for receiving EM waves emitted from partial discharge (PD) because of its high sensitivity. Generally, resolution bandwidth is shown as a measurement parameter because the pulse response depends on the receiver's bandwidth. In this paper, we measure the impulse bandwidth of SA and describe the effect of the impulse bandwidth of SA on the measurement of EM waves emitted from PD in multipath‐rich environment. The results showed that the field strength of the EM waves emitted from PD is proportional to the impulse bandwidth higher than about 200 kHz and signal‐to‐noise ratio (SNR) increases with the impulse bandwidth as in the measurement of pulsed RF signals. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Expected security cost‐based FACTS device allocation using hybrid PSO
Authors: Seto Wibowo Rony , Yorino Naoto , Eghbal Mehdi , Zoka Yoshifumi , Sasaki Yutaka
Published: March 2011

This paper presents FACTS device allocation for market‐based power systems. The purpose of the FACTS installation is to provide benefit for all entities. Therefore, we use a concept of minimizing expected security cost (ESC), implying to maximize social welfare, to minimize operating reserve, and to minimize load interruption in annual basis. The FACTS device investment cost is also taken into account. The ESC considers operating cost under normal state and contingencies along with their associated probabilities to occur. Annual basis bid data is used to compute ESC as well as the cost data for load interruption and reserve procurement. This paper also considers control actions among multiple FACTS device to achieve minimum ESC. To solve the overall problem, particle swarm optimization is utilized to obtain optimal FACTS device allocation as main problem while sequential quadratic programing is used to solve optimal power flow as suboptimization problem. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Autoregressive processes
Authors: Brockwell P. J.
Published: March 2011

In this article, the definition, properties, and applications of linear autoregressive processes (or autoregressions) are reviewed. These form an important subset of the class of autoregressive moving‐average (ARMA) processes which are widely used as stationary models for time series data. Particular attention is paid to the problem of selecting and estimating appropriate autoregressions to describe empirically observed time series. WIREs Comp Stat 2011 3 316–331 DOI: 10.1002/wics.163

This article is categorized under:

Applications of Computational Statistics > Computational Mathematics

Applications of Computational Statistics > Signal and Image Processing and Coding

Data: Types and Structure > Time Series, Stochastic Processes, and Functional Data
RNA nucleotide methylation
Authors: Motorin Yuri , Helm Mark
Published: March 2011

Methylation of RNA occurs at a variety of atoms, nucleotides, sequences and tertiary structures. Strongly related to other posttranscriptional modifications, methylation of different RNA species includes tRNA, rRNA, mRNA, tmRNA, snRNA, snoRNA, miRNA, and viral RNA. Different catalytic strategies are employed for RNA methylation by a variety of RNA‐methyltransferases which fall into four superfamilies. This review outlines the different functions of methyl groups in RNA, including biophysical, biochemical and metabolic stabilization of RNA, quality control, resistance to antibiotics, mRNA reading frame maintenance, deciphering of normal and altered genetic code, selenocysteine incorporation, tRNA aminoacylation, ribotoxins, splicing, intracellular trafficking, immune response, and others. Connections to other fields including gene regulation, DNA repair, stress response, and possibly histone acetylation and exocytosis are pointed out. WIREs RNA 2011 2 611–631 DOI: 10.1002/wrna.79

This article is categorized under:

RNA Processing > RNA Editing and Modification
RITS—connecting transcription, RNA interference, and heterochromatin assembly in fission yeast
Authors: Creamer Kevin M. , Partridge Janet F.
Published: March 2011

In recent years, a bevy of evidence has been unearthed indicating that ‘silent’ heterochromatin is not as transcriptionally inert as once thought. In the unicellular yeast Schizosaccharomyces pombe, the processing of transcripts derived from centromeric repeats into homologous short interfering RNA (siRNA) is essential for the formation of centromeric heterochromatin. Deletion of genes required for siRNA biogenesis showed that core components of the canonical RNA interference (RNAi) pathway are essential for centromeric heterochromatin assembly as well as for centromere function. Subsequent purification of the RNA‐induced initiation of transcriptional gene silencing (RITS) complex provided the critical link between siRNAs and heterochromatin assembly, with RITS acting as a physical bridge between noncoding RNA scaffolds and chromatin. Here, we review current understanding of how RITS promotes heterochromatin formation and how it participates in transcription‐coupled silencing. WIREs RNA 2011 2 632–646 DOI: 10.1002/wrna.80

This article is categorized under:

RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications

Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs

Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action
Uridine insertion/deletion editing in trypanosomes: a playground for RNA‐guided information transfer
Authors: Aphasizhev Ruslan , Aphasizheva Inna
Published: March 2011

RNA editing is a collective term referring to enzymatic processes that change RNA sequence apart from splicing, 5′ capping or 3′ extension. In this article, we focus on uridine insertion/deletion mRNA editing found exclusively in mitochondria of kinetoplastid protists. This type of editing corrects frameshifts, introduces start and stops codons, and often adds much of the coding sequence to create an open reading frame. The mitochondrial genome of trypanosomatids, the most extensively studied clade within the order Kinetoplastida, is composed of ∼50 maxicircles with limited coding capacity and thousands of minicircles. To produce functional mRNAs, a multitude of nuclear‐encoded factors mediate interactions of maxicircle‐encoded pre‐mRNAs with a vast repertoire of minicircle‐encoded guide RNAs. Editing reactions of mRNA cleavage, U‐insertions or U‐deletions, and ligation are catalyzed by the RNA editing core complex (RECC, the 20S editosome) while each step of this enzymatic cascade is directed by guide RNAs. These 50–60 nucleotide (nt) molecules are 3′ uridylated by RET1 TUTase and stabilized via association with the gRNA binding complex (GRBC). Remarkably, the information transfer between maxicircle and minicircle transcriptomes does not rely on template‐dependent polymerization of nucleic acids. Instead, intrinsic substrate specificities of key enzymes are largely responsible for the fidelity of editing. Conversely, the efficiency of editing is enhanced by assembling enzymes and RNA binding proteins into stable multiprotein complexes. WIREs RNA 2011 2 669–685 DOI: 10.1002/wrna.82

This article is categorized under:

RNA Processing > RNA Editing and Modification

RNA Processing > Processing of Small RNAs
A descriptive study evaluating the circumstances of medical treatment for acute pancreatitis before publication of the new JPN guidelines based on the Japanese administrative database associated with the Diagnosis Procedure Combination system
Authors: Murata Atsuhiko , Matsuda Shinya , Mayumi Toshihiko , Yokoe Masamichi , Kuwabara Kazuaki , Ichimiya Yukako , Fujino Yoshihisa , Kubo Tatsuhiko , Fujimori Kenji , Horiguchi Hiromasa
Published: March 2011

Purpose

To examine the circumstances of medical treatment for acute pancreatitis before publication of the new Japanese (JPN) guidelines using the Japanese administrative database associated with the Diagnosis Procedure Combination system.

Methods

We collected data from 7,193 patients with acute pancreatitis in 2008 and examined the recommended medical treatment in the new JPN guidelines [from recommendations B (considered to be recommended treatments) to D (considered to be unacceptable treatments)] according to severity of acute pancreatitis. Patients were divided into two groups: mild cases (n = 6,520) and severe cases (n = 673).

Results

Enteral nutrition for severe cases without ileus (recommendation B) was uncommon (13.5%). In contrast, prophylactic antibiotics were administered in a large number (80.4%) of mild cases without acute cholangitis (recommendation D). Furthermore, administration of H2 receptor antagonists, except for cases of upper gastrointestinal bleeding (recommendation D), were performed in many patients with both mild and severe cases (66.8 vs. 78.6%).

Conclusions

This study demonstrated a discrepancy between actual medical treatment performed and the new JPN guidelines with regard to some of the medical treatments. Future studies are required after publication of the new JPN guidelines to determine how they affect medical treatments.
Effect of penicillin G on the biliary excretion of cholephilic compounds in rats
Authors: Fukami Masako , Tanka Atsushi , Takikawa Hajime
Published: March 2011

Aim

Penicillin G is reported to increase bile flow by increasing biliary glutathione excretion, as well as the biliary excretion of penicillin G itself. In order to study the effect of penicillin G on the hepatic excretory pathway, the effect of colchicine and genipin on the increase of biliary glutathione excretion induced by penicillin G was studied in rats. The effect of penicillin G on the biliary excretion of sulfobromophthalein and erythromycin was also studied, together with the effect of penicillin G on cholestasis induced by estradiol‐17β‐glucuronide.

Methods

After bile duct cannulation, penicillin G was administered to rats at the rate of 0.5 μmol/min/100 g. The effect was examined of colchicine pretreatment (0.2 mg/100 g) and genipin administration (0.5 μmol/min/100 g) on biliary glutathione excretion increased by penicillin G infused at the rate of 0.5 μmol/min/100 g. The effect of penicillin G on the biliary excretion of sulfobromophthalein and erythromycin (0.2 and 0.1 μmol/min/100 g for 90 min, respectively) was studied, together with the effect of penicillin G on cholestasis induced by estradiol‐17β‐glucuronide (0.075 μmol/min/100 g for 20 min).

Results

Penicillin G increased bile flow and biliary glutathione excretion, which were not inhibited by colchicine or genipin. Biliary penicillin G excretion was markedly reduced in Eisai hyperbilirubinemic rats (EHBR) and Mrp2‐deficient rats. Biliary sulfobromophthalein and erythromycin excretion was unchanged by penicillin G. Cholestasis induced by estradiol‐17β‐glucuronide was not relieved by penicillin G.

Conclusions

It was shown that colchicine‐sensitive vesicular transport has no role on the penicillin G‐induced insertion of Mrp2 into the canalicular membrane, as has been observed with genipin. Although the choleresis of penicillin G is thought to be due to the increased biliary excretion of glutathione and penicillin G itself by Mrp2, the mechanism of Mrp2 insertion by penicillin G is thought to be partly different from that by genipin.
From political economy to sociology: Francis Galton and the social-scientific origins of eugenics
Authors: RENWICK CHRIS
Published: March 2011

Having coined the word ‘eugenics’ and inspired leading biologists and statisticians of the early twentieth century, Francis Galton is often studied for his contributions to modern statistical biology. However, whilst documenting this part of his work, historians have frequently neglected crucial aspects of what motivated Galton to establish his eugenics research programme. Arguing that his work was shaped more by social than by biological science, this paper addresses these oversights by tracing the development of Galton's programme, from its roots in a debate about political economy to his appeals for it to be taken up by sociologists. In so doing, the paper not only returns Galton's ideas to their original context but also provides a reason to reflect on the place of the social sciences in history-of-science scholarship.