bluuebunny/crossref_metadata_2025 huggingface dataset:
Imaging and identifying defects in nitride semiconductor thin films using a scanning electron microscope
Authors: Naresh‐Kumar G. , Hourahine B. , Vilalta‐Clemente A. , Ruterana P. , Gamarra P. , Lacam C. , Tordjman M. , di Forte‐Poisson M. A. , Parbrook P. J. , Day A. P. , England G. , Trager‐Cowan C.
Published: January 2012

We describe the use of electron channelling contrast imaging (ECCI) – in a field emission scanning electron microscope (SEM) – to reveal and identify defects in nitride semiconductor thin films. In ECCI changes in crystallographic orientation, or changes in lattice constant due to local strain, are revealed by changes in grey scale in an image constructed by monitoring the intensity of backscattered electrons (BSEs) as an electron beam is scanned over a suitably oriented sample. Extremely small orientation changes are detectable, enabling small angle tilt and rotation boundaries and dislocations to be imaged. Images with a resolution of tens of nanometres are obtainable with ECCI. In this paper, we describe the use of ECCI with TEM to determine threading dislocation densities and types in InAlN/GaN heterostructures grown on SiC and sapphire substrates.
Excitonic signatures in the optical response of single‐wall carbon nanotubes
Authors: Voisin Christophe , Berger Sébastien , Berciaud Stéphane , Yan Hugen , Lauret Jean‐Sébastien , Cassabois Guillaume , Roussignol Philippe , Hone James , Heinz Tony F.
Published: January 2012

The optical properties of single‐wall carbon nanotubes (SWNTs) are dominated by the excitonic character of the transitions even at room temperature. The very peculiar properties of these excitons arise from both the one‐dimensional (1D) nature of carbon nanotubes and from the electronic properties of graphene from which nanotubes are made. We first propose a brief qualitative review of the structure of the excitonic manifold and emphasize the role of dark states. We describe recent experimental investigations of this excitonic structure by means of temperature dependent PL measurements. We investigate the case of upper sub‐bands and show that high‐order optical transitions remain excitonic for large diameter nanotubes. A careful investigation of Rayleigh scattering spectra at the single nanotube level reveals clear exciton–phonon side‐bands and Lorentzian line profiles for all semi‐conducting nanotubes. In contrast, metallic nanotubes show an ambivalent behavior which is related to the reduced excitonic binding energy.

magnified image

Schematic of the exciton manifold in single‐wall carbon nanotubes.
Spin fluctuations and 3D itinerant magnetism in NaxCoO2: Slave‐boson mean‐field study
Authors: Tang Huai‐Bao , Li Guang , Sun Jin , Ma Yong‐Qing
Published: January 2012

The in‐plane ferromagnetic (FM) fluctuations and three‐dimensional (3D) itinerant magnetism on the 3D triangular lattice of NaxCoO2 are studied based on a single‐band Hubbard model using the Kotliar–Ruckenstein (KR) slave‐boson mean‐field (SBMF) technique. By analyzing the instabilities of the FM and layer‐type antiferromagnetic (AFM) susceptibilities, the in‐plane FM fluctuations in NaxCoO2 with x < 0.63 are identified as the effects of both the strong Coulomb repulsion and the frustration on the Co ion triangular lattice. The saddle‐point solutions suggest that the experimental layer‐type AFM state is favorable for x > 0.75 due to the band top edge van Hove singularity arising from the next‐nearest‐neighbor (NNN) hopping. We also discuss the potential connection between the Curie–Weiss metallic behavior and the crossover from the weak FM phase to the layer‐type AFM phase at 0.63 < x < 0.75. Our results reveal the crucial role of the modified effects of the Coulomb interactions with doping x.
Statistical analysis of data from dilution assays with censored correlated counts
Authors: Quiroz Jorge , Wilson Jeffrey R. , Roychoudhury Satrajit
Published: January 2012

Frequently, count data obtained from dilution assays are subject to an upper detection limit, and as such, data obtained from these assays are usually censored. Also, counts from the same subject at different dilution levels are correlated. Ignoring the censoring and the correlation may provide unreliable and misleading results. Therefore, any meaningful data modeling requires that the censoring and the correlation be simultaneously addressed. Such comprehensive approaches of modeling censoring and correlation are not widely used in the analysis of dilution assays data. Traditionally, these data are analyzed using a general linear model on a logarithmic‐transformed average count per subject. However, this traditional approach ignores the between‐subject variability and risks, providing inconsistent results and unreliable conclusions. In this paper, we propose the use of a censored negative binomial model with normal random effects to analyze such data. This model addresses, in addition to the censoring and the correlation, any overdispersion that may be present in count data. The model is shown to be widely accessible through the use of several modern statistical software. Copyright © 2012 John Wiley & Sons, Ltd.
Essential Oil of Pinus koraiensis Leaves Exerts Antihyperlipidemic Effects via Up‐regulation of Low‐density Lipoprotein Receptor and Inhibition of Acyl‐coenzyme A: Cholesterol Acyltransferase
Authors: Kim Ji‐Hyun , Lee Hyo‐Jung , Jeong Soo‐Jin , Lee Min‐Ho , Kim Sung‐Hoon
Published: January 2012

Hyperlipidemia is an important factor to induce metabolic syndrome such as obesity, diabetes and cardiovascular diseases. Recently, some antihyperlipidemic agents from herbal medicines have been in the spotlight in the medical science field. Thus, the present study evaluated the antihyperlipidemic activities of the essential oil from the leaves of Pinus koraiensis SIEB (EOPK) that has been used as a folk remedy for heart disease. The reverse transcription polymerase chain reaction (RT‐PCR) revealed that EOPK up‐regulated low density lipoprotein receptor (LDLR) at the mRNA level as well as negatively suppressed the expression of sterol regulatory element‐binding protein (SREBP)‐1c, SREBP‐2, 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase (HMGCR), fatty acid synthase (FAS) and glycerol‐3‐phosphate acyltransferase (GPAT) involved in lipid metabolism in HepG2 cells. Also, western blotting showed that EOPK activated LDLR and attenuated the expression of FAS at the protein level in the cells. Consistently, EOPK significantly inhibited the level of human acylcoenzyme A: cholesterol acyltransferase (hACAT)1 and 2 and reduced the low‐density lipoprotein (LDL) oxidation activity. Furthermore, chromatography‐mass spectrometry (GC‐MS) analysis showed that EOPK, an essential oil mixture, contained camphene (21.11%), d‐limonene (21.01%), α‐pinene (16.74%) and borneol (11.52%). Overall, the findings suggest that EOPK can be a potent pharmaceutical agent for the prevention and treatment of hyperlipidemia. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of isobaric amino‐sulfonamides without prior separation
Authors: Barry Samantha J. , Wolff Jean‐Claude
Published: January 2012

RATIONALE

Direct analysis mass spectrometry (DAMS) techniques offer increased speed of analysis without the need for sample preparation or prior separation. A feature of these techniques is that all ionisable species will typically be analysed at the same time which makes the ability to distinguish between isobaric compounds increasingly important.

METHODS

Investigations have been carried out to distinguish isomeric compounds by mass spectrometry only, without the use of any separation technique, in order to further understand the capabilities of DAMS techniques. The work focused on commercially available isomeric amino‐sulfonamides, i.e. sulfalene, sulfameter, sulfamethoxypyridazine, sulfamonomethoxine, sulfadoxine, sulfadimethoxine, sulfisomidine, sulfamethazine, sulfamerazine, sulfaperine, sulfadiazine and sulfapyrazine.

RESULTS

All the isomeric compounds investigated could be distinguished from each other based on their tandem mass (MS/MS) spectrum or failing that, based on their MS3 spectrum. Common fragmentation patterns/pathways were observed for groups of the sulfonamides and a rationale for the fragmentations observed is proposed. For the sulfonamides which contain a methoxy group on the pyrimidinyl, pyridazynil, or pyrazinyl ring, the fragmentation‐directing feature is the positioning of the methoxy group in the ortho position of the ring with respect to the sulfonamide bond. The presence of an ortho substituent precludes the formation of the product ion resulting from the loss of aniline.

CONCLUSIONS

This work has demonstrated the usefulness of MSn fragmentation data in identifying and distinguishing isobaric structural isomers without the need for separation by high‐performance liquid chromatography (HPLC), allowing the identification of compounds by DAMS techniques. This work has also highlighted patterns in the product ion data which has led to a postulation of how the protonation preference of a molecule can affect the product ions observed and how the presence of ortho substituents can affect this initial protonation preference. Copyright © 2012 John Wiley & Sons, Ltd.
Micro‐chemical surface investigation of brittle carthaginian and roman silver artefacts
Authors: Mezzi A. , De Caro T. , Riccucci C. , Angelini E. , Faraldi F. , Grassini S.
Published: January 2012

Brittle Carthaginian and Roman silver artefacts, such as bracelets, coins, small jewels and cups, were found in extremely brittle condition during archaeological excavations in different Italian archaeological sites. Some of these silver objects are accidentally easily broken with little applied force and with only small deformation. In order to identify the origin of brittleness, fresh fractured surfaces have been investigated by means of the combined use of surface and micro analytical techniques such as X‐ray photoelectron spectroscopy, scanning electron microscopy (SEM) and field‐emission SEM (FESEM) equipped with an energy dispersive X‐ray spectrometer, optical microscopy and X‐ray diffraction. The overall experimental findings show that the main external brittleness agents are chloride ions that come from the soil of the excavation sites and attack the silver artefacts along the grain boundaries forming a thin layer or islands of silver chloride. Copyright © 2012 John Wiley & Sons, Ltd.
Calculation of layer thickness on nanotube surfaces from XPS intensity data
Authors: Mohai M. , Bertóti I.
Published: January 2012

Surface modification of nanomaterials is the subject of numerous recent investigations. Quantitative characterisation of such modifications is of great theoretical and practical interest. As a first step, our attention is focussed on carbon nanotubes because of their unique morphology and physicochemical properties, having many potential advantages in nanotechnology, electronics, optics and other fields of material science. Surface modification or coating of the nanotubes is essential in several applications, using them as drug carriers, reinforcing component in polymeric matrices or hi‐tech structural ceramics to create reactive surface groups or protection for efficient processing. Applying the simple planar approach to cylindrical‐shaped samples, as known, leading to overestimated layer thickness values because the effective thickness of the layers (seen from the direction of analyser) varies from point to point along the convex surface of the tubes of essentially cylindrical geometry. In case of nanotubes, and any type of nano‐objects, however, a further significant difference is that they have no ‘bulk‐like’ core material because they are usually thin enough to be transparent by the photoelectrons evolving in the XPS measurements. In a step forward for quantitative characterisation, in this article, a special model was developed to calculate the thickness of the modified layer on nanotubes, taking into account that several rows of the tubes are randomly piled on each other. The applicability of the model was tested for quantitative characterisation on multiwall carbon nanotubes (MWCNT), which were treated in d.c.‐biased RF N2 plasma for covalent attachment of nitrogen to their outer shells. This model will be implemented, and thus the calculations would be conveniently performed in the latest versions (from 7.0) of the XPS MultiQuant program. Copyright © 2012 John Wiley & Sons, Ltd.
Hierarchical Bayesian formulations for selecting variables in regression models
Authors: Rockova Veronika , Lesaffre Emmanuel , Luime Jolanda , Löwenberg Bob
Published: January 2012

The objective of finding a parsimonious representation of the observed data by a statistical model that is also capable of accurate prediction is commonplace in all domains of statistical applications. The parsimony of the solutions obtained by variable selection is usually counterbalanced by a limited prediction capacity. On the other hand, methodologies that assure high prediction accuracy usually lead to models that are neither simple nor easily interpretable. Regularization methodologies have proven to be useful in addressing both prediction and variable selection problems. The Bayesian approach to regularization constitutes a particularly attractive alternative as it is suitable for high‐dimensional modeling, offers valid standard errors, and enables simultaneous estimation of regression coefficients and complexity parameters via computationally efficient MCMC techniques. Bayesian regularization falls within the versatile framework of Bayesian hierarchical models, which encompasses a variety of other approaches suited for variable selection such as spike and slab models and the MC3 approach. In this article, we review these Bayesian developments and evaluate their variable selection performance in a simulation study for the classical small p large n setting. The majority of the existing Bayesian methodology for variable selection deals only with classical linear regression. Here, we present two applications in the contexts of binary and survival regression, where the Bayesian approach was applied to select markers prognostically relevant for the development of rheumatoid arthritis and for overall survival in acute myeloid leukemia patients. Copyright © 2012 John Wiley & Sons, Ltd.
Thermodynamic Calculation and Experimental Investigation of Second Phase Particles in Low Carbon Nb Microalloyed Steels
Authors: Luo Yanzhao , Zhang Jiongming , Xiao Chao
Published: January 2012

Many experimental methods such as transmission electron microscopy (TEM) and X‐ray energy dispersive spectroscopy were used to study the precipitates of low carbon steel with niobium addition, the austenite/carbonitride equilibrium in FeNbCN system was performed in this paper. The equilibrium volume fraction, chemical driving force of carbonitride precipitation fraction of each element in austenite, and carbonitride at different temperature were calculated. The results show that the equilibrium mole fraction of carbonitride increases, mole fraction of each element dissolved in austenite are basically precipitated fully at low temperature, the chemical driving force is 2.072 × 103 J · mol−1 at 1050°C. It is found that Nb(CN) precipitated on grain boundaries by using TEM. The volume fraction of Nb(CN) precipitates increased with the temperature decrease, which is in good agreement with the value calculated by the model.
Radio‐sensitivity of some starches treated with accelerated electron beam
Authors: Nemtanu Monica R. , Brasoveanu Mirela
Published: January 2012

The paper presents the investigation of the sensitivity and degradation rate of corn, wheat, rice, and potato starches exposed to accelerated electron beam taking into consideration the paste apparent viscosity and MW distribution. The functional radiosensitivity of starch defined by analyzing the apparent viscosity behavior of its aqueous paste as a function of absorbed dose had the following order: potato>wheat>corn>rice. In a similar manner, the structural radiosensitivity of starch based on the degradation rate of the MW fractions was considered. Two slight different orders were found as (1) potato>wheat>corn>rice taking into account the number molecular fraction and (2) wheat>corn>potato>rice considering the weight molecular fraction, assigned to the different structural organization of the investigated starches.
Adaptive joint maximum‐likelihood detection and minimum‐mean‐square error with successive interference canceler over spatially correlated multiple‐input multiple‐output channels
Authors: Fan Lisheng , Zhang Yangyang , Jiang Yongquan , Fukawa Kazuhiko , Suzuki Hiroshi , Wong Kai‐Kit
Published: January 2012

We develop an efficient hard detector for multiple‐input multiple‐output (MIMO) channels, which adaptively combines maximum‐likelihood detection (MLD) and minimum‐mean‐square error with a successive interference canceler together. Unlike the conventional joint combination scheme, which may suffer from considerable degradation in bit‐error‐rate (BER) performance over correlated channels and where only one data stream is detected by MLD, our proposed scheme adaptively controls the number of data streams to be detected by MLD based on an analytical characterization of reliability for the detection. Simulation results illustrate that near‐optimal BER performance can be obtained at much lower computational complexity by the proposed method as compared with existing techniques, regardless of the spatial correlation of the MIMO channels. Copyright © 2012 John Wiley & Sons, Ltd.
Performance of joint transmit and receive antenna selection in dual hop amplify‐and‐forward relay network over Nakagami‐m fading channels
Authors: Yılmaz Ahmet , Kucur Oğuz
Published: January 2012

In this paper, performance of joint transmit and receive antenna selection in each hop of dual hop amplify‐and‐forward relay network is analyzed over flat and asymmetric Nakagami‐m fading channels. In the network, source, relay, and destination are equipped with multiple antennas. By considering relay location, we derive exact closed‐form cumulative distribution function, moment generating function, moments of end‐to‐end signal‐to‐noise ratio and closed form symbol error probability expressions for fixed and channel state information‐based relay gains. We also derive the asymptotical outage probability and symbol error probability expressions to obtain diversity order and array gain of the network. Analytical results are validated by the Monte Carlo simulations. Copyright © 2012 John Wiley & Sons, Ltd.
Density‐functional tight binding—an approximate density‐functional theory method
Authors: Seifert Gotthard , Joswig Jan‐Ole
Published: January 2012

In this paper, we review the foundations of the density‐functional tight‐binding (DFTB) method. The method is based on the density‐functional theory as formulated by Hohenberg and Kohn. It introduces several approximations: First, densities and potentials are written as superpositions of atomic densities and potentials. Second, many‐center terms are summarized together with nuclear repulsion energy terms in a way that they can be written as a sum of pairwise repulsive terms. For small distances, the nuclear repulsion dominates, whereas for large distances, these terms vanish. The Kohn–Sham orbitals are expanded in a set of localized atom‐centered functions. They are represented in a minimal basis of optimized atomic orbitals, which are obtained for spherical symmetric spin‐unpolarized neutral atoms self‐consistently. The whole Hamilton and overlap matrices contain one‐ and two‐center contributions only. Therefore, they can be calculated and tabulated in advance as functions of the distance between atomic pairs. In addition, we discuss a self‐consistent charge extension, the treatment of weak interactions, and a linear response scheme in connection with the DFTB method. Finally, some practical aspects are presented. © 2012 John Wiley & Sons, Ltd.

This article is categorized under:

Electronic Structure Theory > Semiempirical Electronic Structure Methods
Depth profiling of dopants implanted in Si using the synchrotron radiation based high‐resolution grazing emission technique
Authors: Kayser Y. , Banaś D. , Cao W. , Dousse J.‐Cl. , Hoszowska J. , Jagodziński P. , Kavčič M. , Kubala‐Kukuś A. , Nowak S. , Pajek M. , Szlachetko J.
Published: January 2012

We report on the surface‐sensitive grazing emission X‐ray fluorescence technique combined with synchrotron radiation excitation and high‐resolution detection to realize depth‐profile measurements of Al‐implanted Si wafers. The principles of grazing emission measurements as well as the benefits offered by synchrotron sources and wavelength‐dispersive detection setups are presented. It is shown that the depth distribution of implanted ions can be extracted from the dependence of the X‐ray fluorescence intensity on the grazing emission angle with nanometer‐scale precision provided that an analytical function describing the shape of the depth distribution is assumed beforehand. If no a priori assumption is made, except a bell shaped form for the dopant distribution, the profile derived from the measured angular distribution is found to reproduce quite satisfactorily the depth distribution of the implanted ions. Copyright © 2012 John Wiley & Sons, Ltd.
Determination of Pb, Zr, Ti, Sr, Cr, Nb and La in lead zirconate titanate ceramics by particle‐induced X‐ray emission
Authors: García Rafael Hernández , Behar Moni , Dias Johnny Ferraz , Tagle Margarita Edelia Villanueva , Rodríguez María Dolores Durruthy , de Paula Calderón Piñar Francisco , Alfonso Mario Simeón Pomares
Published: January 2012

A particle‐induced X‐ray emission (PIXE) technique has been used in the determination of the principal components Pb, Zr and Ti and the substituting elements Sr, Cr, Nb and La in lead zirconate titanate ceramics. In general, precision of analysis was concentration dependent from each element under study. For Pb, precision varied between 0.13% and 0.16%, at higher concentration of 59.32–64.5%. It was around 6–9% for Sr, Cr and Nb at concentrations of 1% or lower. Particular attention was devoted to the estimation of the analysis trueness. With this purpose, three methods were applied: (1) comparison of PIXE and inductively coupled plasma optical emission spectrometry concentrations, (2) recovery study and (3) comparison with a laboratory standard. Trueness of analysis was around 100 ± 10% for the evaluated elements Pb, Zr, Ti, Sr and Cr. The expected stoichiometry and elemental composition homogeneity of a wide group of produced ceramics were confirmed by the PIXE technique. Copyright © 2012 John Wiley & Sons, Ltd.
Searching for light higgsinos with b-jets and missing leptons
Authors: Bobrovskyi S. , Brümmer F. , Buchmüller W. , Hajer J.
Published: January 2012

Abstract

A recently proposed class of supersymmetric models predicts rather light and nearly mass-degenerate higgsinos, while the other superparticles are significantly heavier. In this paper we study the early LHC phenomenology of a benchmark model of this kind. If the squarks and gluinos, and in particular the lighter stop, are still light enough to be within reach, then evidence for our model can be found in hadronic SUSY searches. Moreover, with dedicated searches it will be possible to distinguish the light higgsino model from generic SUSY models with a bino LSP. Search channels with b-jets and with isolated leptons play a crucial role for model discrimination.
Clinicopathological significance of growth factors and their receptors as potential therapeutic targets for biliary tract carcinoma
Authors: Ojima Hidenori
Published: January 2012

Biliary tract carcinoma (BTC) has a poor prognosis. However, no standard chemotherapy regimens have been established for inoperable cases or cases of recurrence after surgical resection. Recent molecular biological analysis has shown that epidermal growth factor receptor, human epidermal growth factor receptor 2, vascular endothelial growth factor, hepatocyte growth factor, c‐Met and transforming growth factor‐beta could be potential targets for therapy of BTC. It is considered that these molecules are involved in the carcinogenesis, invasion, and progression of BTC. Furthermore, immunohistochemical overexpression of these targets is associated with several clinicopathological factors. This article reviews the clinicopathological significance of these growth factors and their receptors.
Mucopolysaccharidosis: Cardiologic features and effects of enzyme‐replacement therapy in 24 children with MPS I, II and VI
Authors: Brands Marion M. M. G. , Frohn‐Mulder Ingrid M. , Hagemans Marloes L. C. , Hop Wim C. J. , Oussoren Esmee , Helbing Wim A. , van der Ploeg Ans T.
Published: January 2012

We determined the cardiologic features of children with MPS I, II and VI, and evaluated the effect of enzyme‐replacement therapy (ERT) on cardiac disease. Twenty‐four children aged 1‐18 years with MPS I, II or VI were prospectively evaluated with echocardiogram and electrocardiogram from the start of enzyme‐replacement therapy up to 6 years of treatment. At start of therapy, 66% had abnormal cardiac geometric features. Left‐ventricular mass index (LVMI) was increased in half of the patients, due mainly to concentric hypertrophy in MPS I and II and to eccentric hypertrophy in MPS VI. Regurgitation was most severe in a subgroup of young MPS VI patients (<5 years) at the mitral valve. At baseline, all patients had abnormal valves. The ECG showed no clear rhythm or conduction abnormalities; neither, in most patients, did it reflect the hypertrophy. After ERT, the LVMI Z‐score normalized in 70% of the patients who had a Z‐score > 2. LVMI Z‐scores decreased significantly in patients with MPS I and MPS II (p = 0.04 and p = 0.032). Despite ERT, valve regurgitation increased in 60% of the patients. We conclude that all our MPS patients have cardiac abnormalities. The most severe cardiac disease was observed in a subgroup of young MPS VI patients. While ERT had an effect on LVMI and IVSd, it apparently had little or none on valve regurgitation.
Triacylglycerols Oxidation in Oils and Fats Monitored by Easy Ambient Sonic‐Spray Ionization Mass Spectrometry
Authors: Simas R. C. , Barrera‐Arellano D. , Eberlin M. N. , Catharino R. R. , Souza V. , Alberici R. M.
Published: January 2012

Oxidation is the major cause of fat and oil deterioration which produces rancid and unpleasant flavors that drastically reduces their quality and nutritional value. The primary oxidation products are triacylglycerols (TAG) containing unsaturated fatty acyl hydroperoxides formed by a chain process occurring through free radical intermediates. The Rancimat method is currently the gold standard for measuring the oxidative stability of oils and fats. In this report, easy ambient sonic‐spray ionization mass spectrometry (EASI‐MS) is demonstrated to function as a direct (no pre‐separation or sample preparation steps), fast and accurate method to monitor oils and fats oxidation, providing detailed overviews of the most immediate TAG hydroperoxide products. The EASI‐MS results were compared to those obtained via the classical Rancimat test.
Ethanol Production from Soybean Fiber, a Co‐product of Aqueous Oil Extraction, Using a Soaking in Aqueous Ammonia Pretreatment
Authors: Karki Bishnu , Maurer Devin , Box Shannon , Kim Tae Hyun , Jung Stephanie
Published: January 2012

The effectiveness of soaking in aqueous ammonia (SAA) as a pretreatment method for the conversion of soybean fiber to ethanol via simultaneous saccharification and fermentation (SSF) was investigated. Insoluble fiber is a co‐product from oil and protein extraction using two‐stage, countercurrent, enzyme‐assisted, aqueous extraction processing of full‐fat soybean flakes (FFSF) and extruded FFSF. The fiber fractions were soaked in 15 wt% aqueous ammonia at 1:10 solid‐to‐liquid ratio. The effects of operating variables, including treatment times (6, 12, and 24 h), treatment temperatures (60 and 80 °C), and cellulase loadings (15 and 60 FPU/g‐glucan) on the degree of enzymatic hydrolysis were determined. The best SAA conditions were 80 °C for 12 h followed by an enzyme loading of 15 FPU/g‐glucan, which produced a 152‐mg/g glucose yield after 48 h of hydrolysis. This was 8.7 times the amount produced from the same fiber not pretreated with SAA. The glucose yield increased to 381 mg/g when fiber obtained from extruded FFSF was submitted to SAA. SAA (80 °C, 12 h) on extruded fiber subjected to SSF increased ethanol yield from 0.06 g of ethanol/g [40% of theoretical yield] (for non SAA pretreated fiber) to 0.25 g of ethanol/g [92% of theoretical yield]. The combination of extrusion and SAA was an efficient means for converting the fiber‐rich soybean fraction into ethanol.
Religious Diversity in Mexico: Socioeconomic Attainment and Family Structure
Authors: Heaton Tim , Knowlton David , England Lynn
Published: January 2012

Mexico has experienced dynamic changes in its religious landscape, but relatively little is known about the ways in which the affiliates of the diverse religious groups differ in their socioeconomic and family characteristics. This paper examines religious group differences in key demographic indicators of socioeconomic status and family structure using the 2000 Mexican Census. The changing patterns of religious affiliation in Mexico signal increasing religious, socioeconomic and familial diversity. Non-Christians and Mormons stand out for having higher scores on education and the wealth index relative to other religious groups. Most groups have lower rates of consensual unions and higher rates of marriage than do Catholics. These same groups also tend to have larger families and lower divorce/separation. These trends seem inconsistent with the Catholic teachings about marriage, divorce and contraception. Apparently, new groups are attracting adherents who have family orientations that differ from main-stream Mexican society.
Relaxation and coalescence of two equal-sized viscous drops in a quiescent matrix
Authors: Vannozzi Carolina
Published: January 2012

Head-on collisions of two equal-sized viscous drops in a biaxial extensional flow were simulated using the boundary integral method in the Stokes flow limit, for capillary numbers of the order of $1{0}^{\ensuremath{-} 4} $–$1{0}^{\ensuremath{-} 1} $, typical of flow-induced coalescence experiments. At a certain point in time, during the drainage process, the flow was abruptly stopped and the time-dependent dynamics of drop deformation (relaxation) was followed to discern whether the pair of drops would eventually coalesce. The concept of coalescence probability was used to study the evolution of probable collisions. The polymeric system of polybutadiene (PBd) drops undergoing head-on collisions in a polydimethylsiloxane (PDMS) matrix, previously well-characterized both experimentally and numerically by Yoon et al. (Phys. Fluid, vol. 19, 2007, 102102), in which both fluids were Newtonian under the experimental conditions, was used as our reference. Film shapes, velocity profiles and pressure distributions were studied for initially parabolic or dimpled thin film shapes. It was shown that micrometre-sized drops undergoing relaxation can coalesce in the capillary number range studied, which also included cases of hindered coalescence and cases in which the flow interaction time for the collision was smaller than the drainage time; thus, this phenomenon could influence the final drop size distribution of blends. Further, these findings could be of interest in interpreting stop–strain experiments, in the case of a sudden change in flow conditions and in population balance studies of drops in blends.
ULTRAPOWERS OF ℓ1-MUNN ALGEBRAS AND THEIR APPLICATION TO SEMIGROUP ALGEBRAS
Authors: SOROUSHMEHR MAEDEH
Published: January 2012

In this work, we study and investigate the ultrapowers of ℓ1-Munn algebras. Then we show that the class of ℓ1-Munn algebras is stable under ultrapowers. Finally, applying this result to semigroup algebras, we show that for a semigroup S, ultra-amenability of ℓ1(S) and amenability of the second dual ℓ1(S)′′ are equivalent.
ON THE CLASS NUMBER AND THE FUNDAMENTAL UNIT OF THE REAL QUADRATIC FIELD
Authors: KIM JAE MOON , RYU JADO
Published: January 2012

For a real quadratic field $k=\mathbb {Q}(\sqrt {pq})$, let tk be the exact power of 2 dividing the class number hk of k and ηk the fundamental unit of k. The aim of this paper is to study tk and the value of Nk/ℚ(ηk). Various methods have been successfully applied to obtain results related to this topic. The idea of our work is to select a special circular unit ℰk of k and investigate C(k)=〈±ℰk 〉. We examine the indices [E(k):C(k)] and [C(k):CS (k)] , where E(k) is the group of units of k, and CS (k) is that of circular units of k defined by Sinnott. Then by using the Sinnott’s index formula [E(k):CS (k)]=hk, we obtain as much information about tk and Nk/ℚ (ηk) as possible.
THE MODULUS OF WEAKLY COMPACT MULTIPLIERS ON THE BANACH ALGEBRA L1(𝒢)** OF A LOCALLY COMPACT GROUP
Authors: MEHDIPOUR MOHAMMAD JAVAD
Published: January 2012

In this paper we give a necessary and sufficient condition under which the answer to the open problem raised by Ghahramani and Lau (‘Multipliers and modulus on Banach algebras related to locally compact groups’, J. Funct. Anal. 150 (1997), 478–497) is positive.
Treatment with Selemax®, a selenium-enriched yeast, ameliorates experimental arthritis in rats and mice
Authors: Vieira Angélica T. , Silveira Kátia D. , Arruda Maria C. C. , Fagundes Caio T. , Gonçalves Juliana L. , Silva Tarcília A. , Neves Maria J. , Menezes Maria A. B. C. , Nicoli Jacques R. , Teixeira Mauro M. , Martins Flaviano S.
Published: January 2012

Rheumatoid arthritis (RA) is a chronic inflammatory disease that mainly targets the synovial membrane, cartilage and bone. It affects 1 % of the population and is associated with significant morbidity and increased mortality. Se is an essential trace element with antioxidant properties and the ability to modulate the immune responses. Selemax® is an inactive yeast (Saccharomyces cerevisiae) enriched with organic Se. The aim of the present study was to investigate the effects of Selemax® administration in models of an antigen-induced arthritis (AIA) in C57BL/6 mice, and of an adjuvant-induced arthritis (AdIA) in Holtzman rats. As control, the animals were treated with the same inactivated yeast species that was not enriched for Se. In the AIA model, treatment with different doses of Selemax® (0·01, 0·1, 1 and 10 % added to food) significantly decreased the number of inflammatory cells recruited to the knee cavity, essentially by reducing the number of neutrophils. Levels of proinflammatory cytokines, including TNF-α, IL-1β and chemokine (C-X-C motif) ligand 1/keratinocyte chemoattractant (CXCL1/KC), were also reduced in the peri-articular tissue of mice treated with Selemax® at the tested dose (1 %). In the AdIA model in rats, Selemax® treatment decreased paw oedema and hypernociception. This reduction was associated with inhibition of the influx of proinflammatory cells. Therefore, treatment with Selemax® is associated with amelioration of several inflammatory and functional parameters in models of arthritis, suggesting that this Se-enriched yeast should be evaluated further in patients with RA.
Supplementation of xanthophylls decreased proinflammatory and increased anti-inflammatory cytokines in hens and chicks
Authors: Gao Yu-Yun , Xie Qing-Mei , Jin Ling , Sun Bao-Li , Ji Jun , Chen Feng , Ma Jing-Yun , Bi Ying-Zuo
Published: January 2012

The present study investigated the effects of xanthophylls (containing 40 % of lutein and 60 % of zeaxanthin) on proinflammatory cytokine (IL-1β, IL-6, interferon (IFN)-γ and lipopolysaccharide-induced TNF-α factor (LITAF)) and anti-inflammatory cytokine (IL-4 and IL-10) expression of breeding hens and chicks. In Expt 1, a total of 432 hens were fed diets supplemented with 0 (as the control group), 20 or 40 mg/kg xanthophylls (six replicates per treatment). The liver, duodenum, jejunum and ileum were sampled at 35 d of the trial. The results showed that both levels of xanthophyll addition decreased IL-1β mRNA in the liver and jejunum, IL-6 mRNA in the liver, IFN-γ mRNA in the jejunum and LITAF mRNA in the liver compared to the control group. Expt 2 was a 2 × 2 factorial design. Male chicks hatched from 0 or 40 mg/kg xanthophyll diet of hens were fed a diet containing either 0 or 40 mg/kg xanthophylls. The liver, duodenum, jejunum and ileum were collected at 0, 7, 14 and 21 d after hatching. The results showed thatin ovoxanthophylls decreased proinflammatory cytokine expression (IL-1β, IL-6, IFN-γ and LITAF) in the liver, duodenum, jejunum and ileum and increased anti-inflammatory cytokine expression (IL-4 and IL-10) in the liver, jejunum and ileum mainly at 0–7 d after hatching.In ovoeffects gradually vanished and dietary effects began to work during 1–2 weeks after hatching. Dietary xanthophylls modulated proinflammatory cytokines (IL-1β, IL-6 and IFN-γ) in the liver, duodenum, jejunum and ileum and anti-inflammatory cytokine (IL-10) in the liver and jejunum mainly from 2 weeks onwards. In conclusion, xanthophylls could regulate proinflammatory and anti-inflammatory cytokine expression in different tissues of hens and chicks.
Sources of dietary protein and risk of hypertension in a general Dutch population
Authors: Altorf-van der Kuil Wieke , Engberink Mariëlle F. , Geleijnse Johanna M. , Boer Jolanda M. A. , Monique Verschuren W. M.
Published: January 2012

Evidence suggests a small beneficial effect of dietary protein on blood pressure (BP), especially for plant protein. We examined the relationship between several types of dietary protein (total, plant, animal, dairy, meat and grain) and the risk of hypertension in a general population of 3588 Dutch adults, aged 26–65 years, who were free of hypertension at baseline. Measurements were done at baseline and after 5 and 10 years of follow-up. Hazard ratios (HR), with 95 % CI, for incident hypertension were obtained in tertiles of energy-adjusted protein, using time-dependent Cox regression models. Models were adjusted for age, sex, BMI, education, smoking, baseline systolic BP, dietary confounders and protein from other sources (if applicable). Mean BP was 118/76 mmHg at baseline. Protein intake was 85 (sd22) g/d (approximately 15 % of energy) with 62 % originating from animal sources. The main sources of protein were dairy products (28 %), meat (24 %) and grain (19 %). During the follow-up, 1568 new cases of hypertension were identified (44 % of the participants). Energy-adjusted intake of total protein, plant protein and animal protein was not significantly associated with hypertension risk (all HR approximately 1·00,P>0·60). Protein from grain showed a significant inverse association with incident hypertension, with a HR of 0·85 (95 % CI 0·73, 1·00,Ptrend = 0·04) for the upper tertile ( ≥ 18 g/d)v.the lower tertile ( < 14 g/d), whereas dairy protein and meat protein were not associated with incident hypertension. In conclusion, higher intake of grain protein may contribute to the prevention of hypertension, which warrants confirmation in other population-based studies and randomised controlled trials.
INTERACTION BETWEEN HIV AWARENESS, KNOWLEDGE, SAFE SEX PRACTICE AND HIV PREVALENCE: EVIDENCE FROM BOTSWANA
Authors: RAY RANJAN , SINHA KOMPAL
Published: January 2012

This paper makes methodological and empirical contributions to the study of HIV in the context of Botswana, a country with high HIV prevalence. Comparable evidence is presented from India to put the Botswana results in perspective. The results point to the strong role played by affluence and education in increasing HIV knowledge, promoting safe sex and reducing HIV prevalence. The study presents African evidence on the role played by the empowerment of women in promoting safe sex practices such as condom use. The lack of significant association between HIV prevalence and safe sex practice points to the danger of HIV-infected individuals spreading the disease through multiple sex partners and unprotected sex. This danger is underlined by the finding that females with multiple sex partners are at higher risk of being infected with HIV. These results take on special policy significance in the context of Botswana, where the issue of multiple sex partners has not been adequately addressed in the programme to contain the spread of HIV.
THE HIV–POVERTY THESIS RE-EXAMINED: POVERTY, WEALTH OR INEQUALITY AS A SOCIAL DETERMINANT OF HIV INFECTION IN SUB-SAHARAN AFRICA?
Authors: FOX ASHLEY M.
Published: January 2012

Although health is generally believed to improve with higher wealth, research on HIV in sub-Saharan Africa has shown otherwise. Whereas researchers and advocates have frequently advanced poverty as a social determinant that can help to explain sub-Saharan Africa's disproportionate burden of HIV infection, recent evidence from population surveys suggests that HIV infection is higher among wealthier individuals. Furthermore, wealthier countries in Africa have experienced the fastest growing epidemics. Some researchers have theorized that inequality in wealth may be more important than absolute wealth in explaining why some countries have higher rates of infection and rapidly increasing epidemics. Studies taking a longitudinal approach have further suggested a dynamic process whereby wealth initially increases risk for HIV acquisition and later becomes protective. Prior studies, conducted exclusively at either the individual or the country level, have neither attempted to disentangle the effects of absolute and relative wealth on HIV infection nor to look simultaneously at different levels of analysis within countries at different stages in their epidemics. The current study used micro-, meso- and macro-level data from Demographic and Health Surveys (DHS) across 170 regions within sixteen countries in sub-Saharan Africa to test the hypothesis that socioeconomic inequality, adjusted for absolute wealth, is associated with greater risk of HIV infection. These analyses reveal that inequality trumps wealth: living in a region with greater inequality in wealth was significantly associated with increased individual risk of HIV infection, net of absolute wealth. The findings also reveal a paradox that supports a dynamic interpretation of epidemic trends: in wealthier regions/countries, individuals with less wealth were more likely to be infected with HIV, whereas in poorer regions/countries, individuals with more wealth were more likely to be infected with HIV. These findings add additional nuance to existing literature on the relationship between HIV and socioeconomic status.
Dissociable patterns of medial prefrontal and amygdala activity to face identityversusemotion in bipolar disorder
Authors: Keener M. T. , Fournier J. C. , Mullin B. C. , Kronhaus D. , Perlman S. B. , LaBarbara E. , Almeida J. C. , Phillips M. L.
Published: January 2012

Background

Individuals with bipolar disorder demonstrate abnormal social function. Neuroimaging studies in bipolar disorder have shown functional abnormalities in neural circuitry supporting face emotion processing, but have not examined face identity processing, a key component of social function. We aimed to elucidate functional abnormalities in neural circuitry supporting face emotion and face identity processing in bipolar disorder.

Method

Twenty-seven individuals with bipolar disorder I currently euthymic and 27 healthy controls participated in an implicit face processing, block-design paradigm. Participants labeled color flashes that were superimposed on dynamically changing background faces comprising morphs either from neutral to prototypical emotion (happy, sad, angry and fearful) or from one identity to another identity depicting a neutral face. Whole-brain and amygdala region-of-interest (ROI) activities were compared between groups.

Results

There was no significant between-group difference looking across both emerging face emotion and identity. During processing of all emerging emotions, euthymic individuals with bipolar disorder showed significantly greater amygdala activity. During facial identity and also happy face processing, euthymic individuals with bipolar disorder showed significantly greater amygdala and medial prefrontal cortical activity compared with controls.

Conclusions

This is the first study to examine neural circuitry supporting face identity and face emotion processing in bipolar disorder. Our findings of abnormally elevated activity in amygdala and medial prefrontal cortex (mPFC) during face identity and happy face emotion processing suggest functional abnormalities in key regions previously implicated in social processing. This may be of future importance toward examining the abnormal self-related processing, grandiosity and social dysfunction seen in bipolar disorder.
Lifetime co-morbidity of DSM-IV disorders in the US National Comorbidity Survey Replication Adolescent Supplement (NCS-A)
Authors: Kessler R. C. , Avenevoli S. , McLaughlin K. A. , Green J. Greif , Lakoma M. D. , Petukhova M. , Pine D. S. , Sampson N. A. , Zaslavsky A. M. , Merikangas K. Ries
Published: January 2012

Background

Research on the structure of co-morbidity among common mental disorders has largely focused on current prevalence rather than on the development of co-morbidity. This report presents preliminary results of the latter type of analysis based on the US National Comorbidity Survey Replication Adolescent Supplement (NCS-A).

Method

A national survey was carried out of adolescent mental disorders. DSM-IV diagnoses were based on the Composite International Diagnostic Interview (CIDI) administered to adolescents and questionnaires self-administered to parents. Factor analysis examined co-morbidity among 15 lifetime DSM-IV disorders. Discrete-time survival analysis was used to predict first onset of each disorder from information about prior history of the other 14 disorders.

Results

Factor analysis found four factors representing fear, distress, behavior and substance disorders. Associations of temporally primary disorders with the subsequent onset of other disorders, dated using retrospective age-of-onset (AOO) reports, were almost entirely positive. Within-class associations (e.g. distress disorders predicting subsequent onset of other distress disorders) were more consistently significant (63.2%) than between-class associations (33.0%). Strength of associations decreased as co-morbidity among disorders increased. The percentage of lifetime disorders explained (in a predictive rather than a causal sense) by temporally prior disorders was in the range 3.7–6.9% for earliest-onset disorders [specific phobia and attention deficit hyperactivity disorder (ADHD)] and much higher (23.1–64.3%) for later-onset disorders. Fear disorders were the strongest predictors of most other subsequent disorders.

Conclusions

Adolescent mental disorders are highly co-morbid. The strong associations of temporally primary fear disorders with many other later-onset disorders suggest that fear disorders might be promising targets for early interventions.