bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model‐based analysis of multishell diffusion MR data for tractography: How to get over fitting problems
Authors: Jbabdi Saad , Sotiropoulos Stamatios N. , Savio Alexander M. , Graña Manuel , Behrens Timothy E. J. 
Published: February 2012

AbstractIn this article, we highlight an issue that arises when using multiple b‐values in a model‐based analysis of diffusion MR data for tractography. The non‐monoexponential decay, commonly observed in experimental data, is shown to induce overfitting in the distribution of fiber orientations when not considered in the model. Extra fiber orientations perpendicular to the main orientation arise to compensate for the slower apparent signal decay at higher b‐values. We propose a simple extension to the ball and stick model based on a continuous gamma distribution of diffusivities, which significantly improves the fitting and reduces the overfitting. Using in vivo experimental data, we show that this model outperforms a simpler, noise floor model, especially at the interfaces between brain tissues, suggesting that partial volume effects are a major cause of the observed non‐monoexponential decay. This model may be helpful for future data acquisition strategies that may attempt to combine multiple shells to improve estimates of fiber orientations in white matter and near the cortex. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Spectral decomposition of susceptibility artifacts for spectral‐spatial radiofrequency pulse design
Authors: Yang Cungeng , Poser Benedikt A. , Deng Weiran , Stenger V. Andrew 
Published: February 2012

AbstractSusceptibility induced signal loss is a limitation in gradient echo functional MRI. The through‐plane artifact in axial slices is particularly problematic due to the inferior position of air cavities in the brain. Spectral‐spatial radiofrequency pulses have recently been shown to reduce signal loss in a single excitation. The pulses were successfully demonstrated assuming a linear relationship between susceptibility gradient and frequency, however, the exact frequency and spatial distribution of the susceptibility gradient in the brain is unknown. We present a spiral spectroscopic imaging sequence with a time‐shifted radiofrequency pulse that can spectrally decompose the through‐plane susceptibility gradient for spectral‐spatial radiofrequency pulse design. Maps of the through‐plane susceptibility gradient as a function of frequency were generated for the human brain at 3T. We found that the linear relationship holds well for the whole brain with an optimal slope of −1.0 μT/m/Hz. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
In Vitro Susceptibility of Important Skin and Wound Pathogens Against Low Temperature Atmospheric Pressure Plasma Jet (APPJ) and Dielectric Barrier Discharge Plasma (DBD)
Authors: Daeschlein Georg , Scholz Sebastian , Arnold Andreas , von Podewils Sebastian , Haase Hermann , Emmert Steffen , von Woedtke Thomas , Weltmann Klaus‐Dieter , Jünger Michael 
Published: February 2012

AbstractPlasma medicine has become an emerging field in medical sciences since cold plasma has demonstrated anti‐inflammatory, anti‐tumor as well as antimicrobial effects. In the light of increasing resistance of many pathogens like methicillin‐resistant Staphylococcus aureus (MRSA) to a multitude of antimicrobial therapies cold plasma therapy with complete different modes of action could constitute an alternative to conventional external antibiotic and antiseptic therapies. As plasma susceptibility data of human skin and wound pathogens are not available, the susceptibility of 105 typical isolates from dermatologic patients' wounds to low temperature atmospheric pressure plasma (APPJ device) and dielectric barrier discharge plasma device are tested in vitro. Plasma treatment proved to be highly effective in eradicating all (n = 105) strains including Escherichia coli, Pseudomonas aeruginosa, Klebsiella group (K. pneumoniae ssp. pneumoniae, K. oxytoca), S. aureus, hemolysing Lancefield Streptococci (group A and B), Proteus group (P. mirabilis, P. vulgaris), Acinetobacter spp., Stenotrophomonas spp., Enterococcus faecalis, Candida albicans and Staphylococcus epidermidis. In conclusion, cold plasma treatment exhibited strong and rapid antimicrobial effects against clinical most relevant skin and wound pathogens in vitro. Cold plasma may constitute an effective alternative to antiseptics in the attempt to eradicate skin and wound pathogens.magnified image
Growth and optical properties of gadolinium aluminum nitride thin films
Authors: Chen Yigang , Shi Xiaolei , Yang Jing , Chen Yiner 
Published: February 2012

AbstractIn this study, c‐axis oriented AlN, GdxAl1‐xN and AlN/Gd0.05Al0.95N films have been successfully grown on both Si(100) and quartz glass substrates by DC magnetron reactive sputtering method. The XRD patterns show that the crystal structure of the film has changed after doping Gd3+. The optical constants were obtained by ellipsometry measurements. The high extinction coefficient k in the deep UV range is just in agreement with the low transmittance in the range of 250‐300 nm. The refractive index n increases as well with increasing Gd concentrations. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling and optimization of electric current spreading in III‐nitride LEDs
Authors: Suslov S. S. , Bougrov V. E. , Odnoblyudov M. A. , Romanov A. E. 
Published: February 2012

AbstractIn this work, we perform numerical simulations of a conventional GaN LED chip within the framework of the combined electrical/thermal/light approach. A GaN LED chip grown on a sapphire substrate is investigated. We calculate the dependencies of the forward voltage, light output power, wall‐plug efficiency, and uniformity of current spreading on the variations in the electrode geometry. Modelling is performed using a self‐developed software based on the Finite Volume method and the Monte Carlo ray tracing technique. The simulation results show that a well‐designed electrode pattern can provide more than 8% improvement in the wall‐plug efficiency. The implementation of contact optimization is required for designing highly efficient LED devices. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cd doping of AlN via ion implantation studied with perturbed angular correlation
Authors: Kessler P. , Lorenz K. , Miranda S. M. C. , Simon R. , Correia J. G. , Johnston K. , Vianden R. , the ISOLDE collaboration  
Published: February 2012

AbstractAlN with a wide bandgap of 6.2 eV is a promising candidate for ultraviolet light‐emitting diodes and laser diodes. However, the production of the required p‐type AlN is still challenging. As a possible dopant Cd was suggested among other Group II atoms (Be, Mg, and Zn). In this study the annealing condition of implanted Cd in AlN was investigated with the method of the perturbed angular correlation (PAC). Therefore radioactive 117Cd or 111mCd ions were implanted into thin AlN films on sapphire substrate with an energy of 30 keV and fluences in the range of 1011 ions/cm2.After thorough annealing with a proximity cap of the same material most of the Cd‐probes occupy substitutional lattice sites and almost all implantation damage can be annealed. This results in a distinct frequency in the PAC spectra which increases with temperature. In contrast to the formation of an indium nitrogen‐vacancy complex observed with the probe 111In on substitutional Al‐sites no defects are bound to substitutional Cd impurities. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural characterization of InN epilayers grown on r ‐plane sapphire by plasma‐assisted MBE
Authors: Lotsari A. , Dimitrakopulos G. P. , Kehagias Th. , Ajagunna A. O. , Iliopoulos E. , Georgakilas A. , Komninou Ph. 
Published: February 2012

AbstractThe structural properties of InN films grown on r ‐plane (1$\bar 1$02) sapphire by plasma‐assisted molecular beam epitaxy (PAMBE) using low temperature buffer layers are studied. Nonpolar a ‐plane (1$\bar 1$20) and semipolar s ‐plane (10$\bar 1$1) films were deposited depending on buffer layer and growth conditions. Single crystalline a ‐plane InN was grown using a GaN buffer layer following sapphire nitridation. Transmission electron microscopy (TEM) observations showed three‐dimensional growth and interactions of inclined threading dislocations emanating from the buffer layer. The defect interactions gradually reduced the threading dislocation density. Semipolar s ‐plane was grown when a thin InN buffer layer was employed. The epilayer was found to comprise two s ‐plane variants. Semipolar nucleation directly on the sapphire was observed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Complete controllability for abstract measure differential systems
Authors: Wan Xiaojun , Sun Jitao 
Published: February 2012

SUMMARYIn this paper, we investigate the complete controllability for abstract measure differential systems. Firstly, we introduce several new concepts about complete controllability for abstract measure differential systems. Then, on the basis of the Sadovskii fixed‐point theorem, we give sufficient conditions for complete controllability for a class of abstract measure differential systems. The compactness of the semigroup generated by some operator is unnecessary in this paper, and we show that our results, dealing with complete controllability problem for an ordinary differential system in infinite‐dimensional Banach space, are also less conservative than that in the previous literature. Copyright © 2012 John Wiley & Sons, Ltd.
Tuning Electron Transport in Graphene‐Based Field‐Effect Devices using Block Co‐polymers
Authors: Guo Shirui , Ghazinejad Maziar , Qin Xiangdong , Sun Huaxing , Wang Wei , Zaera Francisco , Ozkan Mihrimah , Ozkan Cengiz S. 
Published: February 2012

AbstractGraphene possesses many remarkable properties and shows promise as the future material for building nanoelectronic devices. For many applications such as graphene‐based field‐effect transistors (GFET), it is essential to control or modulate the electronic properties by means of doping. Using spatially controlled plasma‐assisted CF4doping, the Dirac point shift of a GFET covered with a polycrystalline PS‐P4VP block co‐polymer (BCP) [poly(styrene‐b‐4‐vinylpyridine)] having a cylindrical morphology can be controlled. By changing the chemical component of the microdomain (P4VP) and the major domain (PS) with the CF4plasma technique, the doping effect is demonstrated. This work provides a methodology where the Dirac point can be controlled via the different sensitivities of the PS and P4VP components of the BCP subjected to plasma processing.
Air‐Grid Surface Patterning Provided by Superhydrophobic Surfaces
Authors: Chen Li , Yang Gao , Wang Shutao 
Published: February 2012

AbstractRecently, several unique studies on surface patterning have been developed based on superhydrophobic surfaces, where air was introduced as the separating barrier for the surface pattern. This new type of surface patterning approach is called “air‐grid surface patterning.” Traditional technologies of surface patterning always utilize the solid or liquid phase as the separating barrier, for example, a 2D chemical molecular barrier in soft lithography, a 3D solid barrier in photolithography, or a liquid barrier in microfluidic, laminar flow patterning methods. These recent studies reveal that air can act as a gas‐phase separating barrier. This concept is expected to open up a new branch of applications of superhydrophobic surfaces, and it exhibits promising potential for functional micropatterning of various materials, from nanomaterials to crystals to cells.
Intermediate transverse stiffeners in plate girders
Authors: Sinur Franc , Beg Darko 
Published: February 2012

AbstractThe aim of this paper is to study the design requirements for rigid intermediate transverse stiffeners in longitudinally stiffened plate girders. Firstly, two representative design codes, AASHTO and EN 1933‐1‐5, are discussed and compared. Then the results of two tests on 1.5 m deep plate girders and the results of the extensive numerical parametric study are presented. The analysis of the results shows that the axial force in the stiffener due to tension field action is overestimated in the design codes and that all the design requirements for rigid transverse stiffeners can be covered by defining a minimum required second moment of area.
Ligand‐specific differential regulation of 5‐hydroxytryptamine receptors: functional selectivity in serotonergic signaling
Authors: Stroth Nikolas , Svenningsson Per 
Published: February 2012

AbstractPharmacological theory has recently undergone an important revision. It is now clear that certain ligands can exert differential regulation of the effector mechanisms that are coupled to their cognate receptors, enabling functional selectivity in the control of distinct cellular outputs. Ligands at receptors for the biogenic amine serotonin (5‐hydroxytryptamine, 5‐HT) have provided convincing examples of functional selectivity, and key experiments from this area are the subject of the present review. Given that signaling through 5‐HT receptors is implicated in many diseases, functionally selective modulation of such signaling may be a promising avenue for the development of improved therapeutics. WIREs Membr Transp Signal 2012, 1:453–466. doi: 10.1002/wmts.39For further resources related to this article, please visit the WIREs website.
Diverse functional networks of Tbx3 in development and disease
Authors: Washkowitz Andrew J. , Gavrilov Svetlana , Begum Salma , Papaioannou Virginia E. 
Published: February 2012

AbstractThe T‐box transcription factor Tbx3 plays multiple roles in normal development and disease. In order to function in different tissues and on different target genes, Tbx3 binds transcription factors or other cofactors specific to temporal or spatial locations. Examining the development of the mammary gland, limbs, and heart as well as the biology of stem cells and cancer provides insights into the diverse and common functions that Tbx3 can perform. By either repressing or activating transcription of target genes in a context‐dependent manner, Tbx3 is able to modulate differentiation of immature progenitor cells, control the rate of cell proliferation, and mediate cellular signaling pathways. Because the direct regulators of these cellular processes are highly context‐dependent, it is essential that Tbx3 has the flexibility to regulate transcription of a large group of targets, but only become a active on a small cohort of them at any given time or place. Moreover, Tbx3 must be responsive to the variety of different upstream factors that are present in different tissues. Only by understanding the network of genes, proteins, and molecules with which Tbx3 interacts can we hope to understand the role that Tbx3 plays in normal development and how its aberrant expression can lead to disease. Because of its myriad functions in disparate developmental and disease contexts, Tbx3 is an ideal candidate for a systems‐based approach to genetic function and interaction. WIREs Syst Biol Med 2012. doi: 10.1002/wsbm.1162This article is categorized under:

Developmental Biology > Developmental Processes in Health and Disease
Developmental Biology > Stem Cell Biology and Regeneration
Nutrition issues in Codex: health claims, nutrient reference values and WTO agreements: a conference report
Authors: Aggett Peter J. , Hathcock John , Jukes David , Richardson David P. , Calder Philip C. , Bischoff-Ferrari Heike , Nicklas Theresa , Mühlebach Stefan , Kwon Oran , Lewis Janine , Lugard Maurits J. F. , Prock Peter 
Published: February 2012

Abstract

Background
Codex documents may be used as educational and consensus materials for member governments. Also, the WTO SPS Agreement recognizes Codex as the presumptive international authority on food issues. Nutrient bioavailability is a critical factor in determining the ability of nutrients to provide beneficial effects. Bioavailability also influences the quantitative dietary requirements that are the basis of nutrient intake recommendations and NRVs.

Health claims
Codex, EFSA and some national regulatory authorities have established guidelines or regulations that will permit several types of health claims. The scientific basis for claims has been established by the US FDA and EFSA, but not yet by Codex. Evidence-based nutrition differs from evidence-based medicine, but the differences are only recently gaining recognition. Health claims on foods may provide useful information to consumers, but many will interpret the information to mean that they can rely upon the food or nutrient to eliminate a disease risk.

Nutrient reference values
NRVs are designed to provide a quantitative basis for comparing the nutritive values of foods, helping to illustrate how specific foods fit into the overall diet. The INL-98 and the mean of adult male and female values provide NRVs that are sufficient when used as targets for individual intakes by most adults.

World Trade Organization agreements
WTO recognizes Codex as the primary international authority on food issues. Current regulatory schemes based on recommended dietary allowances are trade restrictive. A substantial number of decisions by the EFSA could lead to violation of WTO agreements.
Unravelling the dynamics of organisms in a changing world using ecological modelling
Authors: Amano Tatsuya 
Published: February 2012

AbstractUnderstanding and predicting the dynamics of organisms is a central objective in ecology and conservation biology, and modelling provides a solution to tackling this problem. However, the complex nature of ecological systems means that for a thorough understanding of ecological dynamics at hierarchical scales, a set of modeling approaches need to be adopted. This review illustrates how modelling approaches can be used to understand the dynamics of organisms in applied ecological problems, focussing on mechanistic models at a local scale and statistical models at a broad scale. Mechanistic models incorporate ecological processes explicitly and thus are likely to be robust under novel conditions. Models based on behavioural decisions by individuals represent a typical example of the successful application of mechanistic models to applied problems. Considering the data‐hungry nature of such mechanistic models, model complexity and parameterisation need to be explored further for a quick and widespread implementation of this model type. For broad‐scale phenomena, statistical models play an important role in dealing with problems that are often inherent in data. Examples include models for quantifying population trends from long‐term, large‐scale data and those for comparative methods of extinction risk. Novel statistical approaches also allow mechanistic models to be parameterised using readily obtained data at a macro scale. In conclusion, the complementary use and improvement of multiple model types, the increased use of novel model parameterisation, the examination of model transferability and the achievement of wider biodiversity information availability are key challenges for the effective use of modelling in applied ecological problems.
The pros and cons of Confucian values in transport infrastructure development in China
Authors: de Jong Martin 
Published: February 2012

AbstractChina’s economic growth and the high pace with which it plans and constructs its infrastructure networks have led to a renewed interest in its decision-making models and the Confucian values which are believed to underlie it. This article makes an attempt to show what these Confucian values entail, through what mechanisms they influence organisational and decision-making processes, what their positive and negative sides are, to what extent they permeate transport infrastructure planning in China and why it is not easy or straightforward to emulate these policy practices elsewhere. Adopting certain features imbued with Confucian values, such as aspects of collectivism, conceptions of the common good, moral reflection and empathy are not pointless in a non-Asian context, but the specific context of such ‘other’ institutional environments must always be taken into account. Asian countries have grown stronger by selectively learning Western lessons; Western countries could reinforce the performance of their planning and policy-making processes in the future by looking eastwards and drawing inspiration from them while acknowledging vital differences.
Erratum: Black reefs: iron-induced phase shifts on coral reefs
Authors: Kelly Linda Wegley , Barott Katie L , Dinsdale Elizabeth , Friedlander Alan M , Nosrat Bahador , Obura David , Sala Enric , Sandin Stuart A , Smith Jennifer E , Vermeij Mark J A , Williams Gareth J , Willner Dana , Rohwer Forest 
Published: February 2012

Abstract
Correction to: The ISME Journal (2012) 6, 638–649; doi:10.1038/ismej.2011.114; published online 1 September 2011 Since the publication of this article, the authors have noticed an omission in the acknowledgements section: This work was carried under a permit from the Palmyra Atoll National Wildlife Refuge, US Fish and Wildlife Service at the Department of the Interior.
Crystal structure and functional characterization of a glucosamine-6-phosphate N-acetyltransferase from Arabidopsis thaliana
Authors: Riegler Heike , Herter Thomas , Grishkovskaya Irina , Lude Anja , Ryngajllo Malgorzata , Bolger Marie E. , Essigmann Bernd , Usadel Björn 
Published: February 2012

GlcNAc (N-acetylglucosamine) is an essential part of the glycan chain in N-linked glycoproteins. It is a building block for polysaccharides such as chitin, and several glucosaminoglycans and proteins can be O-GlcNAcylated. The deacetylated form, glucosamine, is an integral part of GPI (glycosylphosphatidylinositol) anchors. Both are incorporated into polymers by glycosyltransferases that utilize UDP-GlcNAc. This UDP-sugar is synthesized in a short pathway comprising four steps starting from fructose 6-phosphate. GNA (glucosamine-6-phosphate N-acetyltransferase) catalyses the second of these four reactions in the de novo synthesis in eukaryotes. A phylogenetic analysis revealed that only one GNA isoform can be found in most of the species investigated and that the most likely Arabidopsis candidate is encoded by the gene At5g15770 (AtGNA). qPCR (quantitative PCR) revealed the ubiquitous expression of AtGNA in all organs of Arabidopsis plants. Heterologous expression of AtGNA showed that it is highly active between pH 7 and 8 and at temperatures of 30–40°C. It showed Km values of 231 μM for glucosamine 6-phosphate and 33 μM for acetyl-CoA respectively and a catalytic efficiency comparable with that of other GNAs characterized. The solved crystal structure of AtGNA at a resolution of 1.5 Å (1 Å=0.1 nm) revealed a very high structural similarity to crystallized GNA proteins from Homo sapiens and Saccharomyces cerevisiae despite less well conserved protein sequence identity.