bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical characterization of dispersion coefficients by meshless‐based inverse analysis
Authors: Sheu Guang Y.
Published: March 2010

This study presents the preliminary development of a meshless‐based indirect inverse analysis. Two goals are desired to be attained: (a) identifying fewer quantities in an indirect inverse analysis and (b) getting the interpolation results of spatial variation of a quantity insensitive to the replacement of one or few interpolation points with other points. This idea is illustrated by modifying a meshless local Petrov‐Galerkin (MLPG) formulation of a two‐dimensional (2D) contaminant transport problem under the concept of boundary control. Thus, dispersion coefficients to be identified are solved from measured or prescribed pollutant concentrations.

A field problem is introduced to test the performance of resulting meshless‐based indirect inverse analysis procedure. This test finds a major motive and a minor one for performing a meshless‐based indirect inverse analysis. The major motive is attaining the aforementioned Goal (b), while the above‐mentioned Goal (a) is the minor motive. In conclusion, the development of a meshless‐based indirect inverse analysis procedure can be a valuable application of the MLPG method. Copyright © 2010 John Wiley & Sons, Ltd.
Fully coupled poromechanical back analysis of the pulse test by inverse method
Authors: Giot Richard , Giraud Albert , Auvray Christophe , Homand Françoise , Guillon Théophile
Published: March 2010

In this paper, we investigate the pulse test, which is usually considered as efficient for measuring the permeability of weakly permeable porous media. The pulse is first analyzed and we show that it is a fully poromechanical coupled problem. Owing to those couplings, the problem is 2D‐axisymmetrical, rather than 1D as is usually considered to be the case. As a consequence, the 1D solutions, for example under constant mean stress hypothesis, although giving good approximates of permeability and storage coefficient, are not rigorous and an enhanced back analysis of the test requires 2D solutions. Therefore, no analytical solution exists, and the problem has to be solved using 2D‐axisymmetrical numerical modelings of the pulse test. The finite element method is considered in this paper. We then proceed to formulate the pulse test back analysis as a parameter identification problem, and we focus on intrinsic permeability, Biot coefficient, drained Young's modulus and reservoir compressibility levels. This parameter identification problem is solved by an inverse method consisting of the minimization of a cost‐functional, through a gradient‐based algorithm. This new method of interpretation of the pulse test is finally applied to laboratory tests on Meuse/Haute–Marne argillite and is shown to give encouraging results. Copyright © 2010 John Wiley & Sons, Ltd.
A partial characterization of the optimal ordering/rationing policy for a periodic review system with two demand classes and backordering
Authors: Chen Shaoxiang , Xu Jianjun , Feng Youyi
Published: March 2010

We consider a finite horizon periodic review, single product inventory system with a fixed setup cost and two stochastic demand classes that differ in their backordering costs. In each period, one must decide whether and how much to order, and how much demand of the lower class should be satisfied. We show that the optimal ordering policy can be characterized as a state dependent (s,S) policy, and the rationing structure is partially obtained based on the subconvexity of the cost function. We then propose a simple heuristic rationing policy, which is easy to implement and close to optimal for intensive numerical examples. We further study the case when the first demand class is deterministic and must be satisfied immediately. We show the optimality of the state dependent (s,S) ordering policy, and obtain additional rationing structural properties. Based on these properties, the optimal ordering and rationing policy for any state can be generated by finding the optimal policy of only a finite set of states, and for each state in this set, the optimal policy is obtained simply by choosing a policy from at most two alternatives. An efficient algorithm is then proposed. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010
Effects of motion and b‐matrix correction for high resolution DTI with short‐axis PROPELLER‐EPI
Authors: Aksoy Murat , Skare Stefan , Holdsworth Samantha , Bammer Roland
Published: March 2010

Short‐axis PROPELLER‐EPI (SAP‐EPI) has been proven to be very effective in providing high‐resolution diffusion‐weighted and diffusion tensor data. The self‐navigation capabilities of SAP‐EPI allow one to correct for motion, phase errors, and geometric distortion. However, in the presence of patient motion, the change in the effective diffusion‐ encoding direction (i.e. the b‐matrix) between successive PROPELLER ‘blades’ can decrease the accuracy of the estimated diffusion tensors, which might result in erroneous reconstruction of white matter tracts in the brain. In this study, we investigate the effects of alterations in the b‐matrix as a result of patient motion on the example of SAP‐EPI DTI and eliminate these effects by incorporating our novel single‐step non‐linear diffusion tensor estimation scheme into the SAP‐EPI post‐processing procedure. Our simulations and in‐vivo studies showed that, in the presence of patient motion, correcting the b‐matrix is necessary in order to get more accurate diffusion tensor and white matter pathway reconstructions. Copyright © 2010 John Wiley & Sons, Ltd.
Wafer reuse for repeated growth of III–V solar cells
Authors: Bauhuis G. J. , Mulder P. , Haverkamp E. J. , Schermer J. J. , Bongers E. , Oomen G. , Köstler W. , Strobl G.
Published: March 2010

The epitaxial lift‐off (ELO) technique can be used to separate a III–V solar cell structure from its underlying GaAs or Ge substrate. ELO from 4‐inch Ge wafers is shown and 2‐inch GaAs wafer reuse after lift‐off is demonstrated without degradation in performance of the subsequent thin‐film GaAs solar cells that were retrieved from it. Since a basic wet chemical smoothing etch procedure appeared insufficient to remove all the surface contamination, wafer re‐preparation is done by a chemo‐mechanical polishing procedure. Copyright © 2010 John Wiley & Sons, Ltd.
Optimal design of periodic surface texture for thin‐film a‐Si:H solar cells
Authors: Čampa Andrej , Isabella Olindo , van Erven Rob , Peeters Patrick , Borg Herman , Krč Janez , Topič Marko , Zeman Miro
Published: March 2010

Optical analysis of hydrogenated amorphous silicon (a‐Si:H) solar cells with a periodic texture applied to the interfaces was carried out by two‐dimensional optical simulator. The optical simulator solves the electromagnetic wave equations by means of finite element method using triangular elements for the discretization of space. The periodic texture with rectangular‐like shape acts as a diffraction grating which scatters light into selective angles and thus gives a potential for significant prolongation of optical paths in thin absorber layers of the cells. Optimization of the geometrical parameters (period, height and duty‐cycle) of the periodic texture was carried out in order to obtain the highest photocurrent from a‐Si:H solar cells. The a‐Si:H solar cell with the optimal periodic texture parameters (period of 300 nm, height of 300 nm and duty cycle of 50%) and the absorber layer thickness of 300 nm generates up to 35% more photocurrent in comparison to the cell with flat interfaces. The optical analysis demonstrates that the optimal periodic texture in the a‐Si:H solar cell results in the best trade‐off between the antireflection effect at front interfaces, light scattering efficiency and the absorption losses at realistic metal back contact. Copyright © 2010 John Wiley & Sons, Ltd.
Wire bonding as a cell interconnection technique for polycrystalline silicon thin‐film solar cells on glass
Authors: Gress Peter J. , Widenborg Per I. , Varlamov Sergey , Aberle Armin G.
Published: March 2010

The interconnection of solar cells is a critical part of photovoltaic module fabrication. In this paper, a high‐yield, low‐cost method for interconnecting polycrystalline silicon thin‐film solar cells on glass is presented. The method consists of forming adjacent, electrically isolated groves across the cells using laser scribing, and then forming wire bonds over each laser scribe, resulting in series interconnection of the individual solar cells. Wire bonds are also used to connect the first and last solar cell in the string to external (tabbing) leads, forming a mini‐module. A layer of white paint is then applied, which acts as both an encapsulation layer and an additional back surface reflector. Using this method, an 8·3% efficient mini‐module has been fabricated. By exploiting recent developments in wire bonding technology, it appears that this process can be automated and will be capable of forming solar cell interconnections on large‐area modules within relatively short processing times (∼10 min for a 1 m2 module). Copyright © 2010 John Wiley & Sons, Ltd.
Analysis of one‐axis tracking strategies for PV systems in Europe
Authors: Huld Thomas , Cebecauer Tomáš , Šúri Marcel , Dunlop Ewan D.
Published: March 2010

We present a method for estimating the energy output from one‐axis tracking non‐concentrating PV systems and compare the yields from different configurations. The method is based on the use of solar radiation and temperature databases and models for the performance of PV modules under given geographic conditions. In the resulting maps of energy yield for Europe it is found that there are two different one‐axis configurations that perform almost as well as a full two‐axis sun‐tracking system: one with a vertical axis and inclined modules, and the other with an inclined axis directed north–south and modules in the plane of the axis. When the inclination angles of the modules are optimized, these two configurations have an energy yield compared to an optimal fixed mounting that is approximately 30% higher in southern Europe, about 20–25% higher in central Europe, and up to 50% higher in northern Scandinavia. Compared to the two‐axis tracking, the yields are only 1–4% lower, making such one‐axis tracking systems very attractive in terms of performance relative to technical complexity and price. Copyright © 2010 John Wiley & Sons, Ltd.
Optimization of moth‐eye antireflection schemes for silicon solar cells
Authors: Boden Stuart A. , Bagnall Darren M.
Published: March 2010

Nanostructured moth‐eye antireflection schemes for silicon solar cells are simulated using rigorous coupled wave analysis and compared to traditional thin film coatings. The design of the moth‐eye arrays is optimized for application to a laboratory cell (air–silicon interface) and an encapsulated cell (EVA‐silicon interface), and the optimization accounts for the solar spectrum incident on the silicon interface in both cells, and the spectral response of both types of cell. The optimized moth‐eye designs are predicted to outperform an optimized double layer thin film coating by approximately 2% for the laboratory cell and approximately 3% for the encapsulated cell. The predicted performance of the silicon moth‐eye under encapsulation is particularly remarkable as it exhibits losses of only 0·6% compared to an ideal AR surface. Copyright © 2010 John Wiley & Sons, Ltd.
Modeling solar cells with the dopant‐diffused layers treated as conductive boundaries
Authors: Brendel Rolf
Published: March 2010

Modeling of transport and recombination of charge carriers in solar cells is useful for understanding and improving the device performance. We implement the fully coupled transport equations for electrons and holes into the finite‐element partial differential equation solverCOMSOL. The dopant‐diffused surface regions such as junctions, floating junctions, or back surface field layers are treated as conductive boundaries of the volume in which the semiconductor equations are solved. This so‐called conductive boundary (CoBo) model characterizes diffused layers by their sheet resistances and diode saturation current densities. Both are directly experimentally accessible. The CoBo model exhibits excellent numerical stability and enables two‐dimensional simulations on a laptop. We find agreement when testing the two‐dimensionalCOMSOLimplementation of the CoBo model for one‐dimensional devices against simulations using the code PC1D. We apply the CoBo model to elucidate how the sheet resistance of diffused vias impacts the power conversion efficiency of emitter wrap through solar cells. Copyright © 2010 John Wiley & Sons, Ltd.
High‐rate deposition of microcrystalline silicon in a large‐area PECVD reactor and integration in tandem solar cells
Authors: Parascandolo Gaetano , Bugnon Grégory , Feltrin Andrea , Ballif Christophe
Published: March 2010

We study the high‐rate deposition of microcrystalline silicon in a large‐area plasma‐enhanced chemical‐vapor‐deposition (PECVD) reactor operated at 40.68 MHz, in the little‐explored process conditions of high‐pressure and high‐silane concentration and depletion. Due to the long gas residence time in this process, the silane gas is efficiently depleted using moderate feed‐in power density, thus facilitating up‐scaling of the process to large surfaces. As observed in more traditional deposition processes, the deposition rate and performance of device‐quality material are limited by the inter‐electrode gap of the reactor. We significantly increase the cell performances by reducing this gap. X‐ray diffractometry (XRD) and secondary ion mass spectroscopy (SIMS) are used to characterize the microcrystalline material deposited in the modified reactor at a rate of 1 nm/s. Comparison with a microcrystalline process at a low deposition rate demonstrates that the crystallographic orientation of the absorbing layer of the cell and the concentrations of contaminants are strongly correlated and dependent on the process. We use microcrystalline cells with absorber layer grown at a rate of 1 nm/s integrated as bottom cells in amorphous‐microcrystalline (micromorph) tandem solar cells using the superstrate configuration. We report an initial efficiency of 10.8% (9.6% stabilized) for a tandem cell with 1.2 cm2surface. Copyright © 2010 John Wiley & Sons, Ltd.
A self‐calibrating led‐based solar test platform
Authors: Krebs Frederik C. , Sylvester‐Hvid Kristian O. , Jørgensen Mikkel
Published: March 2010

A compact platform for testing solar cells is presented. The light source comprises a multi‐wavelength high‐power LED (light emitting diode) array allowing the homogenous illumination of small laboratory solar cell devices (substrate size 50 × 25 mm) within the 390–940 nm wavelength range. The spectrum can be synthesized by independent tuning of the 18 different wavelengths to mimic AM1.5G as well as various indoor lamp spectra. The intensity can be controlled with a 214‐bit accuracy and intensities up to 3 suns are possible with an approximate AM1.5G spectral distribution. For several wavelengths intensities up to 10 suns is possible, and for a few wavelengths up to 30 suns can be reached. The setup is equipped with reference diodes and an optical fibre coupling enabling calibration, monitoring and control of the light impinging on the sample. Through a computer controlled interface, it is possible to perform all the commonly employed measurements on the solar cell at very high speed without moving the sample. In particular, the LED‐based illumination system provides an alternative to light‐biased incident photon‐to‐current efficiency measurement to be performed which we demonstrate. Both top and bottom contact is possible and the atmosphere can be controlled around the sample during measurements. The setup was developed for the field of polymer and organic solar cells with particular emphasis on enabling different laboratories to perform measurements in the same manner and obtain a common basis for comparing data. The use of the platform is demonstrated using a standard P3HT:PCBM polymer solar cell but is generally applicable to any solar cell technology with a spectral response in the 390–950 nm region. Copyright © 2010 John Wiley & Sons, Ltd.
Multijunction solar cell model for translating I–V characteristics as a function of irradiance, spectrum, and cell temperature
Authors: Domínguez César , Antón Ignacio , Sala Gabriel
Published: March 2010

We describe here a lumped diode model for concentrator multijunction solar cells, in which the temperature, irradiance and spectrum dependences are explicitly included. Moreover an experimental method based on it for the prediction of the I‐V curve under any irradiance‐spectrum‐temperature conditions from a single input measurement is proposed and applied to a set of commercial triple‐junction solar cells in order to demonstrate its validity. Component ‘isotype’ cells are used as reference cells for intensity and spectrum, sparing the measurement of light spectrum and cell spectral response. Finally, a mean RMS prediction error of 0.85% over a range of 100X‐25°C to 700X‐75°C is reported for the whole set when the model parameters inherent in the cell are assumed to be the same for every sample. If optimum parameters are extracted for every cell, the RMS error is reduced to 0.53%. Copyright © 2010 John Wiley & Sons, Ltd.
An observation study of reading instruction provided to elementary students with learning disabilities in the resource room
Authors: Swanson Elizabeth A. , Vaughn Sharon
Published: March 2010

This study documents the amount and quality of reading instruction provided to second‐ through fifth‐grade students with learning disabilities provided resource‐room services. Reading instruction provided by 10 special education resource‐room teachers was observed. Findings reveal that teachers and students were on task during instructional time that included phonological awareness, word study, comprehension, reading fluency, and vocabulary instruction of average to high average quality. Although class size was small overall, whole‐group instructional delivery was most common. Students made statistically significant gains in oral reading fluency but did not increase their standard scores on measures of comprehension or word reading. © 2010 Wiley Periodicals, Inc.
Identification of bioactive compounds from flowers of black elder (Sambucus nigra L.) that activate the human peroxisome proliferator‐activated receptor (PPAR) γ
Authors: Christensen Kathrine B. , Petersen Rasmus K. , Kristiansen Karsten , Christensen Lars P.
Published: March 2010

Obesity is one of the predisposing factors for the development of overt Type 2 diabetes (T2D). T2D is caused by a combination of insulin resistance and β‐cell failure and can be treated with insulin sensitizing drugs that target the nuclear receptor peroxisome proliferator‐activated receptor (PPAR) γ. Extracts of elderflowers (Sambucus nigra) have been found to activate PPARγ and to stimulate insulin‐dependent glucose uptake suggesting that they have a potential use in the prevention and/or treatment of insulin resistance. Bioassay‐guided chromatographic fractionation of a methanol extract of elderflowers resulted in the identification of two well‐known PPARγ agonists; α‐linolenic acid and linoleic acid as well as the flavanone naringenin. Naringenin was found to activate PPARγ without stimulating adipocyte differentiation. However, the bioactivities of these three metabolites were not able to fully account for the observed PPARγ activation of the crude elderflower extracts and further studies are needed to determine whether this is due synergistic effects and/or other ligand‐independent mechanisms. Elderflower metabolites such as quercetin‐3‐O‐rutinoside, quercetin‐3‐O‐glucoside, kaempferol‐3‐O‐rutinoside, isorhamnetin‐3‐O‐rutinoside, isorhamnetin‐3‐O‐glucoside, and 5‐O‐caffeoylquinic acid were unable to activate PPARγ. These findings suggest that flavonoid glycosides cannot activate PPARγ, whereas some of their aglycones are potential agonists of PPARγ. Copyright © 2010 John Wiley & Sons, Ltd.
The cover time of random geometric graphs
Authors: Cooper Colin , Frieze Alan
Published: March 2010

We study the cover time of random geometric graphs. Let
$I(d)=[0,1]^{d}$
denote the unit torus in d dimensions. Let $D(x,r)$
denote the ball (disc) of radius r. Let $\Upsilon_d$
be the volume of the unit ball $D(0,1)$
in d dimensions. A random geometric graph $G=G(d,r,n)$
in d dimensions is defined as follows: Sample n points V independently and uniformly at random from $I(d)$. For each point x draw a ball $D(x,r)$
of radius r about x. The vertex set $V(G)=V$
and the edge set $E(G)=\{\{v,w\}: w\ne v,\,w\in D(v,r)\}$. Let $G(d,r,n),\,d\geq 3$
be a random geometric graph. Let $C_G$
denote the cover time of a simple random walk on G. Let $c>1$
be constant, and let $r=(c\log n/(\Upsilon_dn))^{1/d}$. Then whp the cover time satisfies

© 2010 Wiley Periodicals, Inc. Random Struct. Alg., 38, 324–349, 2011
Piercing random boxes
Authors: Tran Linh V.
Published: March 2010

Consider a set of n random axis parallel boxes in the unit hypercube in
${\bf R}^{d}$, where d is fixed and n tends to infinity. We show that the minimum number of points one needs to pierce all these boxes is, with high probability, at least $\Omega_d(\sqrt{n}(\log n)^{d/2-1})$
and at most $O_d(\sqrt{n}(\log n)^{d/2-1}\log \log n)$. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 38, 365–380, 2011
Mining and tracking evolving web user trends from large web server logs
Authors: Hawwash Basheer , Nasraoui Olfa
Published: March 2010

Recently, online organizations became interested in tracking users' behavior on their websites to better understand and satisfy their needs. In response to this need, web usage mining tools were developed to help them use web logs to discover usage patterns or profiles. However, since website usage logs are being continuously generated, in some cases, amounting to a dynamic data stream, most existing tools are still not able to handle their changing nature or growing size. This paper proposes a scalable framework that is capable of tracking the changing nature of user behavior on a website, and represent it in a set of evolving usage profiles. These profiles can offer the best usage representation of user activity at any given time, and they can be used as an input to higher‐level applications such as a web recommendation system. Our specific aim is to make the hierarchical unsupervised niche clustering (HUNC) algorithm more scalable, and to add integrated profile tracking and cluster‐based validation to it. Our experiments on real web log data confirm the validity of our approach for large data sets that previously could not be handled in one shot. Copyright © 2010 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 3: 106‐125, 2010
Modeling user reputation in wikis
Authors: Javanmardi Sara , Lopes Cristina , Baldi Pierre
Published: March 2010

Collaborative systems available on the Web allow millions of users to share information through a growing collection of tools and platforms such as wikis, blogs, and shared forums. By their very nature, these systems contain resources and information with different quality levels. The open nature of these systems, however, makes it difficult for users to determine the quality of the available information and the reputation of its providers. Here, we first parse and mine the entire English Wikipedia history pages in order to extract detailed user edit patterns and statistics. We then use these patterns and statistics to derive three computational models of a user's reputation. Finally, we validate these models using ground‐truth Wikipedia data associated with vandals and administrators. When used as a classifier, the best model produces an area under the receiver operating characteristic (ROC) curve (AUC) of 0.98. Furthermore, we assess the reputation predictions generated by the models on other users, and show that all three models can be used efficiently for predicting user behavior in Wikipedia. Copyright © 2010 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 3: 126‐139, 2010
Is inquiry possible in light of accountability?: A quantitative comparison of the relative effectiveness of guided inquiry and verification laboratory instruction
Authors: Blanchard Margaret R. , Southerland Sherry A. , Osborne Jason W. , Sampson Victor D. , Annetta Leonard A. , Granger Ellen M.
Published: March 2010

In this quantitative study, we compare the efficacy of Level 2, guided inquiry–based instruction to more traditional, verification laboratory instruction in supporting student performance on a standardized measure of knowledge of content, procedure, and nature of science. Our sample included 1,700 students placed in the classrooms of 12 middle school and 12 high school science teachers. The instruction for both groups included a week long, laboratory‐based, forensics unit. Students were given pre‐, post‐, and delayed posttests, the results of which were analyzed through a Hierarchical Linear Model (HLM) using students' scores, teacher, level of school, Reformed Teaching Observation Protocol (RTOP) scores, and school socioeconomic status. Overall, compared to students in traditional sections, students who participated in an inquiry‐based laboratory unit showed significantly higher posttest scores; had the higher scores, more growth, and long‐term retention at both the high school and middle school levels, if their teacher had stronger implementation of inquiry methods (as measured by RTOP scores); and tended to have better outcomes than those who learned through traditional methods, regardless of level of poverty in the school. Our findings suggest that Level 2 inquiry can be an effective teaching approach to support student learning as measured through standardized assessments. © 2010 Wiley Periodicals, Inc.Sci Ed94:577–616, 2010
Analysis of extreme drinking in patients with alcohol dependence using Pareto regression
Authors: Das Sourish , Harel Ofer , Dey Dipak K. , Covault Jonathan , Kranzler Henry R.
Published: March 2010

We developed a novel Pareto regression model with an unknown shape parameter to analyze extreme drinking in patients with Alcohol Dependence (AD). We used the generalized linear model (GLM) framework and the log‐link to include the covariate information through the scale parameter of the generalized Pareto distribution. We proposed a Bayesian method based on Ridge prior and Zellner'sg‐prior for the regression coefficients. Simulation study indicated that the proposed Bayesian method performs better than the existing likelihood‐based inference for the Pareto regression.

We examined two issues of importance in the study of AD. First, we tested whether a single nucleotide polymorphism withinGABRA2gene, which encodes a subunit of the GABAAreceptor, and that has been associated with AD, influences ‘extreme’ alcohol intake and second, the efficacy of three psychotherapies for alcoholism in treating extreme drinking behavior. We found an association between extreme drinking behavior andGABRA2. We also found that, at baseline, men with a high‐riskGABRA2allele had a significantly higher probability of extreme drinking than men with no high‐risk allele. However, men with a high‐risk allele responded to the therapy better than those with two copies of the low‐risk allele. Women with high‐risk alleles also responded to the therapy better than those with two copies of the low‐risk allele, while women who received the cognitive behavioral therapy had better outcomes than those receiving either of the other two therapies. Among men, motivational enhancement therapy was the best for the treatment of the extreme drinking behavior. Copyright © 2010 John Wiley & Sons, Ltd.
Graphene Oxide, Highly Reduced Graphene Oxide, and Graphene: Versatile Building Blocks for Carbon‐Based Materials
Authors: Compton Owen C. , Nguyen SonBinh T.
Published: March 2010

Isolated graphene, a nanometer‐thick two‐dimensional analog of fullerenes and carbon nanotubes, has recently sparked great excitement in the scientific community given its excellent mechanical and electronic properties. Particularly attractive is the availability of bulk quantities of graphene as both colloidal dispersions and powders, which enables the facile fabrication of many carbon‐based materials. The fact that such large amounts of graphene are most easily produced via the reduction of graphene oxide—oxygenated graphene sheets covered with epoxy, hydroxyl, and carboxyl groups—offers tremendous opportunities for access to functionalized graphene‐based materials. Both graphene oxide and graphene can be processed into a wide variety of novel materials with distinctly different morphological features, where the carbonaceous nanosheets can serve as either the sole component, as in papers and thin films, or as fillers in polymer and/or inorganic nanocomposites. This Review summarizes techniques for preparing such advanced materials via stable graphene oxide, highly reduced graphene oxide, and graphene dispersions in aqueous and organic media. The excellent mechanical and electronic properties of the resulting materials are highlighted with a forward outlook on their applications.
Levels of phosphodiesterase 4A and 4B are altered by chronic treatment with psychotropic medications in rat frontal cortex
Authors: Fatemi S. Hossein , Folsom Timothy D. , Reutiman Teri J. , Braun Natalie N. , Lavergne Luke G.
Published: March 2010

Our laboratory has recently demonstrated altered expression of phosphodiesterase (PDE) 4A and 4B in subjects with autism, bipolar disorder, and schizophrenia, suggesting disrupted cAMP signaling in these diagnostic groups. In the current study, we measured expression of PDEs in rat frontal cortex (FC) following chronic treatment with clozapine, fluoxetine, haloperidol, lithium, olanzapine, valproic acid (VPA), or sterile saline for 21 days. Western blotting experiments showed decreased expression of PDE4A subtypes in FC following treatment with clozapine, haloperidol, lithium, and VPA. PDE4B subtypes were similarly reduced in FC following treatment with clozapine, fluoxetine, and lithium. We also measured levels of nine PDE subtypes via qRT‐PCR in FC and found significant upregulation of PDE1A and PDE8B following treatment with olanzapine, while treatment with lithium reduced expression of mRNA for PDE8B. Our results demonstrate altered expression of PDE4A and PDE4B in response to a variety of psychotropic medications suggesting potentially new therapeutic avenues for treatment of neuropsychiatric diseases. Synapse 64:550–555, 2010. © 2010 Wiley‐Liss, Inc.
Selective perturbation of the BAR domain of endophilin impairs synaptic vesicle endocytosis
Authors: Andersson Fredrik , Löw Peter , Brodin Lennart
Published: March 2010

The importance of the BAR domain of endophilin in synaptic vesicle endocytosis was tested in presynaptic microinjection experiments in the lamprey giant synapse. Antibodies as well as Fab fragments directed to the BAR domain caused a stimulus‐dependent decrease in the number of synaptic vesicles along with an accumulation of shallow clathrin coated pits in the periactive zone. Moreover, the isolated BAR domain protein also caused an accumulation of shallow‐coated pits in the periactive zone, in addition to appearance of narrow tubules in synaptic regions. The BAR domain of endophilin is thus required for efficient progression of the synaptic vesicle cycle. Synapse 64:556–560, 2010. © 2010 Wiley‐Liss, Inc.
Shaking table tests on China Pavilion for Expo 2010 Shanghai China
Authors: Yang Juhua , Chen Yun , Jiang Huanjun , Lu Xilin
Published: March 2010

Modern structural engineering tends to progress towards more novel high‐rise structures through gradually improved methods of design and wide use of new materials. The National Hall of China Pavilion for Expo 2010 Shanghai is such a building specially designed with a shape of an inverted trapezoid in elevation and local discontinuity of floor slabs in plan for aesthetic and functional considerations. The preliminary analysis shows that the fundamental vibration mode of this structure is a torsional mode due to the special shape, thus resulting in the period ratio between the first torsional mode and the first translational mode exceeding the limit value stipulated in Chinese code. Shaking table tests of a 1/27‐scale structural model were performed to observe the seismic response characteristics, and verify the seismic safety of the structure. This paper presents the results of the shaking table tests in terms of dynamic properties, global responses, as well as local responses. It was found that the torsional effects were not significant by the analysis of the ratio between the maximum displacement and the average displacement of floor and torsional angle. Finally, weak points were identified, and some corresponding suggestions were put forward to improve the overall seismic performance of this structure. Copyright © 2010 John Wiley & Sons, Ltd.
Collapse risk of tall steel moment frame buildings with viscous dampers subjected to large earthquakes
Authors: Miyamoto H. Kit , Gilani Amir S. J. , Wada Akira , Ariyaratana Christopher
Published: March 2010

The design approach for tall steel moment frame structures with viscous dampers entails sizing steel members per code‐level strength forces, and sizing viscous dampers to limit storey drifts. This method has been used extensively in new and retrofit applications. This methodology has resulted in structures that have longer periods than those using the code‐designed approach, are economically competitive and have excellent performance in design‐level earthquakes. However, the efficacy of this design in extreme events is not well understood because of the lack of limit states data for dampers and the absence of a field or analytical database of such structures subjected to large earthquakes. Mathematical modelling of viscous dampers with limit states was developed, correlated with experimental results and then used to analyse 10‐storey archetypes. This analysis showed that the design had satisfactory performance during extreme seismic events. There were significant improvements in reducing collapse hazard by using an enhanced damper design with an increased damper safety factor. Copyright © 2010 John Wiley & Sons, Ltd.
Diagrid tube structures composed of straight diagonals with gradually varying angles
Authors: Zhang Chonghou , Zhao Feng , Liu Yansheng
Published: March 2010

This paper presents preliminary design guidelines specifically for diagrid tube structures composed of straight diagonals with gradually changing angles. A graphic approach to configurating a diagrid of this type is introduced, with two basic geometric variables involved, i.e. the bottom and top diagonal angles. In terms of both stiffness and strength design criteria, a methodology for calculating diagonal member sizes is developed and applied to a set of diagrid tube structures with height‐to‐width aspect ratios ranging from 3.6 to 9. The diagrid tube structures are designed with various combinations of bottom and top angles in order to investigate the effects of bottom and top angles on the material usage. Based on the results, the optimal values of bottom and top angles are suggested, then, the optimal geometries for diagrid tube structures with different aspect ratios are determined. This paper attempts to help the designer arrange the structurally efficient diagrid layout conveniently and perform approximate calculations of the diagonal member sizes. Copyright © 2010 John Wiley & Sons, Ltd.
Moral psychology (ethics)
Authors: Andreou Chrisoula
Published: March 2010

This article examines a selection of currently lively debates in the quickly evolving, interdisciplinary field of moral psychology. Topics discussed include the possibility of amoralism, the nature of rationality, the (ir)rationality of emotions and intuitions, the psychology of cooperation and of (rational) commitment, weakness of will, free will, and the assignment of moral responsibility. Copyright © 2010 John Wiley & Sons, Ltd.

This article is categorized under:

Philosophy > Action
Profound biotinidase deficiency: a rare disease among native Swedes
Authors: Ohlsson Annika , Guthenberg Claes , Holme Elisabeth , von Döbeln Ulrika
Published: March 2010

Biotinidase deficiency is an autosomal recessive metabolic disorder included in many newborn screening programmes. Prior to the introduction of screening for biotinidase deficiency in Sweden in 2002, the disorder was almost unknown, with only one case diagnosed clinically. Biotinidase activity was measured in dried blood spots with a semiquantitative method using biotin‐6‐amidoquinoline as substrate. The cutoff value was set at 25% (later lowered to 20%) of the mean activity of all samples measured on that day. The disorder was confirmed by quantitative determination of biotinidase activity in plasma and DNA analyses. Over a period of 6 years, 13 patients were identified among 637,452 screened newborns and 5,068 adoptive/immigrant children. None of the patients had clinical symptoms at the time of diagnosis. Six patients had profound biotinidase deficiency, with an activity of 0–5% of normal in plasma. Four of these patients were born to parents who were first cousins of Middle Eastern or African origin. Eighteen gene alterations were identified, nine of which have not previously been described: seven mutations p.L83S (c.248T > C), p.R148H (c.443G > A), p.N202I (c.605A > T), p.I255T (c.764T > C), p.N402S (c.1205A > G), p.L405P (c.1214T > C), p.G445R (c.1333G > A) and two silent mutations p.L71L (c.211C > T) and p.L215L (c.645C > T). The predicted severity of the novel mutations was analyzed by sorting intolerant from tolerant (SIFT) and polymorphism phenotyping (PolyPhen), predicting p.L83S, p.L405P and p.G445R as severe mutations. Due to the high rate of immigrants since 1990 from non‐Nordic countries, the incidence of biotinidase deficiency is similar to that found in many other Western countries.
Coacervates as a Modern Delivery System of Hand Dishwashing Liquids
Authors: Wasilewski Tomasz
Published: March 2010

Hand dishwashing liquids can be produced in a coacervate form. Such a delivery system can be readily mixed with water and, in the initial dilution stage, may exhibit a high viscosity. This makes it feasible to formulate concentrated products which can be diluted by consumers. The surfactant concentration in the starting formulation is found to affect the possibility of producing hand dishwashing liquids in coacervate form. Hand dishwashing liquids in coacervate form are produced by the separation of the upper phase under the effect of sodium chloride, whose concentration is a key parameter. An increase in the concentration of anionic surfactants in the starting formulation, requires a slight increase in the concentration of sodium chloride to start coacervation and this results in an increase in coacervate volume. The properties of the coacervate, i.e. viscosity, washability, emulsifying power and foamability, are reported and found to be similar to those of typical commercial products.
Structural basis for a PABPN1 aggregation‐preventing antibody fragment in OPMD
Authors: Impagliazzo Antonietta , Tepper Armand W. , Verrips Theo C. , Ubbink Marcellus , van der Maarel Silvère M.
Published: March 2010

Oculopharyngeal muscular dystrophy is caused by small alanine expansions in polyadenylate binding protein nuclear 1 (PABPN1) protein resulting in its intranuclear accumulation in skeletal muscle. 3F5 llama antibody specifically interferes with the PABPN1 aggregation process in vitro and in vivo. To understand the structural basis for its epitope recognition we mapped the binding interface of 3F5 with PABPN1 and provide a structural model of the 3F5‐PABPN1 complex. We show that 3F5 complementarity determining regions create a cavity in which PABPN1 α‐helix domain resides by involving critical residues previously implicated in the aggregation process. These results may increase our understanding of the PABPN1 aggregation mechanism and the therapeutic potential of 3F5.
Magnetic Nanotechnology for Biodetection
Authors: Han Shu-Jen , Wang Shan
Published: March 2010

A highly sensitive biodetection technology using nanomagnetic sensors and magnetic nanoparticles (NPs) was developed. Absorption of magnetic NPs by the hybridized DNA alters the sensor resistance and generated electrical signals that can be directly measured with the off-die or on-die circuitry. Assays with DNA concentration down to sub-10 pM with a dynamic range of three orders of magnitude were demonstrated. The proposed biochip can be applied to other bioreaction detections, for example, protein assay, through different surface modifications.
Superhydrophilic Surfaces for Antifoqging and Antifouling Microfluidic Devices
Authors: Patel Pragneshkumar , Choi Chang K. , Meng Dennis Desheng
Published: March 2010

Superhydrophilic surfaces are investigated for their potential to provide antifogging and antifouling properties for microfluidic devices. Two types of exemplary superhydrophilic surfaces are prepared, including polyester films treated by oxygen plasma and indium tin oxide-coated glasses treated by an electrochemical method. The superhydrophilicity of the treated surfaces presented herein is confirmed by their near-zero water contact angles. Their corresponding antifogging and antifouling capability is examined. The fluorescence microscopic study has confirmed the significantly reduced adhesion of the fluorescein and fluorescent proteins after the surfaces are treated to be superhydrophilic, indicating their potential for antifouling applications. The degradation of the superhydrophilicity under different humidity conditions is also investigated.
Gold Nanoparticle-Based Biodetection for Chip-Based Portable Diagnosis Systems
Authors: Li Shifeng , Goluch Edgar , Liu Chang , Szegedi Sandra , Shaikh Kashan , Ahmed Faysal , Hu Alan , Zhao Shenshen
Published: March 2010

We review the past development of highly sensitive and selective gold nanoparticle (AuNP)-based assays of protein and DNA biomarkers for chip-based detection systems. The microfluidic systems, various assays, and preliminary laboratory results are shown. AuNP-based biodetection assays provide low detection threshold, offering promises for multiplexed diagnostics of many forms of disease markers.
Carbon Nanopipettes for Cell Surgery
Authors: Schrlau Michael G. , Bau Haim H.
Published: March 2010

Carbon nanopipettes (CNPs), nanoprobes that integrate carbon nanotubes (CNTs) into larger easily maneuverable devices, provide a viable means of performing cell surgery with carbon-based nanostructures. Taking advantage of the nanoscopic tubular geometry and unique material properties of CNTs, CNPs facilitate minimally invasive cell probing, low-volume intracellular fluid injection, sensitive electrical measurements of cell signals, and other unique analytical abilities not possible with traditional glass-based cell probing technology. In this technology review, we highlight the cell probing applications where CNPs were used as nanoneedles for intracellular injection and nanoelectrodes for cell electrophysiology. Besides summarizing the proven capabilities of CNPs, the intent of this review is to encourage further development of CNT-based devices and related nanotechnology for novel cell probing and bioanalytical applications.
Stabilizing Biomacromolecules in Nontoxic Nano-Structured Materials
Authors: Domach Michael M. , Walker Lynn M.
Published: March 2010

Increases in the use of protein-based pharmaceuticals require the development of cost-effective methods of storage and transport of sensitive biomolecules. In this article, we review the general problems of protein stabilization, aspects specific to antibodies, and a proposed method for protecting proteins based on nanostructured hydrogels. This review is not intended to be comprehensive, but instead to provide the reader with specific examples that capture some of the key challenges and opportunities of the field.
The effect of the year of wheat variety release on productivity and stability of performance on two organic and two non-organic farms
Authors: JONES H. , CLARKE S. , HAIGH Z. , PEARCE H. , WOLFE M.
Published: March 2010

Nineteen wheat cultivars, released from 1934 to 2000, were grown at two organic and two non-organic sites in each of 3 years (2004–05, 2005–06 and 2006–07). Assessments included grain yield, grain protein concentration, protein yield, disease incidence and green leaf area (GLA). The superiority of each cultivar (the sum of the squares of the differences between its mean in each environment and the mean of the best cultivar there, divided by twice the number of environments; CS) was calculated for yield, grain protein concentration and protein yield, and ranked in each environment. The yield and grain protein concentration CS were more closely correlated with cultivar release date at the non-organic sites than at organic sites. This difference may be attributed to higher yield levels with larger differences among cultivars at the non-organic sites, rather than to improved stability (i.e. similar ranks) across sites. The significant difference in the correlation of protein yield CS and cultivar age between organic and non-organic sites would support evidence that the ability to take up mineral nitrogen (N) compared to soil N has been a component of the selection conditions of more modern cultivars (released after 1989). This is supported by assessment of GLA, where more modern cultivars in the non-organic systems had greater late-season GLA, a trend that was not identified in organic conditions. This effect could explain the poor correlation between age and protein yield CS in organic compared to non-organic conditions where modern cultivars are selected to benefit from later nitrogen (N) availability which includes the spring nitrogen applications tailored to coincide with peak crop demand. Under organic management, N release is largely based on the breakdown of fertility-building crops incorporated (ploughed-in) in the previous autumn. The release of nutrients from these residues is dependent on the soil conditions, which includes temperature and microbial populations, in addition to the potential leaching effect of high winter rainfall in the UK. In organic cereal crops, early resource capture is a major advantage for maximizing the utilization of nutrients from residue breakdown. It is concluded that selection of cultivars under conditions of high agrochemical inputs selects for cultivars that yield well under maximal conditions in terms of nutrient availability and pest, disease and weed control. The selection conditions for breeding have a tendency to select cultivars which perform relatively better in non-organic compared to organic systems.
Changes in surgical consent practices for common otolaryngology procedures: impact of Modernising Medical Careers
Authors: Puwanarajah P , McDonald S E
Published: March 2010

Objectives:

To assess elective surgery consent practices amongst senior house officers from a selection of UK ENT departments, and to compare results with similar surveys in 2002 and 2005.

Methods:

A telephone survey of senior house officers in 40 UK ENT departments was conducted to assess departmental consent policies and knowledge of complications of common ENT operations.

Results:

A total of 77.5 per cent of responding senior house officers were responsible for consenting, reduced from 92.5 per cent in 2002 (p = 0.06). There had been a significant improvement in the use of patient information sheets, from 25 per cent of departments in 2002 to 65 per cent in 2008 (p = 0.0002). There had been no improvement in training or in the use of standard National Health Service consent forms, and the senior house officers' knowledge of specific complications remained poor. Of the senior house officers surveyed, 37.5 per cent were foundation trainees.

Conclusions:

There has been some improvement in information delivery to patients during the consent process, in accordance with General Medical Council, Department of Health and Modernising Medical Careers guidelines. However, most senior house officers are still required to obtain patient consent without appropriate training.