bluuebunny/crossref_metadata_2025 huggingface dataset:
Stochastic stability of extended filtering for non‐linear systems with measurement packet losses
Authors: Wang Gang , Chen Jie , Sun Jian
Published: October 2013

This study is concerned with stochastic stability of a new extended filtering for non‐linear systems subject to measurement packet losses. The measurements sensored are transmitted to the estimator through a packet‐dropping network. By introducing a time‐stamped packet arrival indicator sequence, the measurement loss process is modelled as an independent, identically distributed (i.i.d.) and therefore a Bernoulli process. The boundedness of estimation error covariance matrices is proved by showing the existence of a critical threshold for measurement packet arrival probability. It is also shown that, under appropriate assumptions, the estimation error remains bounded as long as the noise covariance matrices and the initial estimation error can be ensured small enough. Finally, simulation results validating the effectiveness of this proposed filtering framework are also presented.
r ‐consensus control for discrete‐time high‐order multi‐agent systems
Authors: Xin Youming , Cheng Zunshui
Published: October 2013

This study considers a consensus problem of discrete‐time high‐order multi‐agent systems with digraph. A concept r ‐consensus for discrete‐time multi‐agent systems is introduced, and consensus protocols are proposed for solving such problems. A sufficient and necessary condition for r ‐consensus is obtained using matrix theory. As a special case, criteria of r ‐consensus for third‐order systems are given, in which the exact relationship of feedback parameters is established. Finally, the effectiveness of the theoretical results is demonstrated through a numerical simulation.
Single DC source three‐phase multilevel inverter using reduced number of switches
Authors: Tsang Kai‐Ming , Chan Wai‐Lok
Published: October 2013

A novel pulse‐width modulation‐less three‐phase multilevel DC–AC inverter using only one DC source is presented in this study. The proposed approach enables multilevel output to be realised by a few cascaded H‐bridges and a three‐leg inverter using minimum number of power switches. As an illustration, a 19‐level three‐phase inverter has been implemented based on cascading four H‐bridges and a three‐leg inverter. Switching strategy has been derived for the proposed inverter such that a three‐phase power system with 19 output levels can be realised with proper capacitor voltage regulation and a single energy source. Only 22 power switches instead of 108 are required to achieve the objective. Experimental results are included to demonstrate the outstanding performance of the proposed inverter. Although only 50 Hz results are presented, the proposed inverter could be applied in aircraft systems by only changing the switching frequency.
Spectral characteristics of mixed micro‐Doppler time‐frequency data sequences in micro‐motion and inertial parameter estimation of radar targets
Authors: Wang Jun , Lei Peng , Sun Jinping , Hong Wen
Published: October 2013

Time variation of micro‐Doppler (mD) frequency is an important representation of target's micro‐motions and intrinsic attributes in radar signals. For free rigid targets consisting of multiple scatterers, mixed mD time‐frequency (TF) data sequences based on two‐dimensional TF distributions of mD signals demonstrates effectiveness and simplicity to estimate targets’ micro‐motion and inertial parameters. In this study the authors further explore the feasibility of the estimation method by studying the spectral characteristics of the mixed sequence. The construction of mixed mD TF data sequence is introduced, and then the analysis of its spectrum is conducted with the help of mathematical derivation and simulations. It is found that one of observation angles plays a leading role in relative amplitudes of spectral components, and could accordingly determine the optimal radar observation region for given micro‐dynamic targets. It could contribute to the proper placement of radar station, and help identify some desired spectral components accurately in the blind condition for the purpose of parameter estimation of micro‐dynamic targets.
Neural networks for local structure detection in polymorphic systems
Authors: Geiger Philipp , Dellago Christoph
Published: October 2013

The accurate identification and classification of local ordered and disordered structures is an important task in atomistic computer simulations. Here, we demonstrate that properly trained artificial neural networks can be used for this purpose. Based on a neural network approach recently developed for the calculation of energies and forces, the proposed method recognizes local atomic arrangements from a set of symmetry functions that characterize the environment around a given atom. The algorithm is simple and flexible and it does not rely on the definition of a reference frame. Using the Lennard-Jones system as well as liquid water and ice as illustrative examples, we show that the neural networks developed here detect amorphous and crystalline structures with high accuracy even in the case of complex atomic arrangements, for which conventional structure detection approaches are unreliable.
Quantum computer aided design simulation and optimization of semiconductor quantum dots
Authors: Gao X. , Nielsen E. , Muller R. P. , Young R. W. , Salinger A. G. , Bishop N. C. , Lilly M. P. , Carroll M. S.
Published: October 2013

We present the Quantum Computer Aided Design (QCAD) simulator that targets modeling multi-dimensional quantum devices, particularly silicon multi-quantum dots (QDs) developed for quantum bits (qubits). This finite-element simulator has three differentiating features: (i) its core contains nonlinear Poisson, effective mass Schrodinger, and Configuration Interaction solvers that have massively parallel capability for high simulation throughput and can be run individually or combined self-consistently for 1D/2D/3D quantum devices; (ii) the core solvers show superior convergence even at near-zero-Kelvin temperatures, which is critical for modeling quantum computing devices; and (iii) it interfaces directly with the full-featured optimization engine Dakota. In this work, we describe the capabilities and implementation of the QCAD simulation tool and show how it can be used to both analyze existing experimental QD devices through capacitance calculations and aid in the design of few-electron multi-QDs. In particular, we observe that computed capacitances are in rough agreement with experiment, and that quantum confinement increases capacitance when the number of electrons is fixed in a quantum dot. Coupling of QCAD with the optimizer Dakota allows for rapid identification and improvement of device layouts that are likely to exhibit few-electron quantum dot characteristics.
Inelastic collision selection procedures for direct simulation Monte Carlo calculations of gas mixtures
Authors: Zhang Chonglin , Schwartzentruber Thomas E.
Published: October 2013

A modification to existing phenomenological inelastic collision selection procedures suitable for modeling the internal energy exchange processes of gas mixtures in direct simulation Monte Carlo calculations is presented. The selection procedure does not depend on the relative order of rotational and vibrational relaxation processes and does not require the solution of a quadratic equation for every collision to determine the inelastic collision probability. The simulated relaxation process resulting from the selection procedure is analytically proven to be equivalent to the procedures of Haas et al. [“Rates of thermal relaxation in direct simulation Monte Carlo methods,” Phys. Fluids 6, 2191–2201 (1994)] and the modified procedure of Gimelshein et al. [“Vibrational relaxation rates in the direct simulation Monte Carlo method,” Phys. Fluids 14, 4452–4455 (2002)]. The implementation and computational efficiency of each of the procedures are discussed. The proposed selection procedure is verified to accurately simulate rotational and vibrational processes for gas mixtures through isothermal relaxation simulations compared with analytical solutions using the Jeans equation.
Flows around a cascade of flat plates with acoustic resonance
Authors: Yokoyama H. , Kitamiya K. , Iida A.
Published: October 2013

In order to better understand the effects of acoustic resonance on flows around a cascade of flat plates, fluid structures and acoustic fields were examined by aeroacoustic direct simulations and wind tunnel experiments. Computations and experiments were performed for the flows around five parallel plates with and without the acoustic resonance changing the freestream velocity. The aspect ratio of the plates, C/b, is 15.0, and the separation-to-thickness ratio, s/b, is 6.0. For the resonant condition of a freestream velocity of 44 m/s, the Reynolds number based on the plate thickness, b, and the freestream velocity is 5.8 × 103. The computational results revealed that large-scale vortices composed of fine-scale vortices are shed in the wake of the plates. Both experimental and computational results indicated that the shedding of the large-scale vortices is more synchronized in the spanwise direction for the resonant condition. Moreover, the shedding of the large-scale vortices from one plate and those from the neighboring plates become more synchronized in the resonant condition. The mode of this synchronization was found to be an anti-phase mode, in which the vortex is shed from the upper or lower face of one plate when the vortex is shed from the lower or upper faces of the neighboring plates. Computation of the flow around a single plate was also performed, and the radiation of the acoustic waves from the downstream edge due to vortex shedding from the plate was indicated. When acoustic resonance occurs in the flows around the cascade of flat plates, vortex shedding in the above-mentioned mode contributes to the intensification of the standing waves between the plates. Moreover, standing waves were demonstrated to induce new vortices around the upstream edges of the plates in synchronization.
No-insulation multi-width winding technique for high temperature superconducting magnet
Authors: Hahn Seungyong , Kim Youngjae , Keun Park Dong , Kim Kwangmin , Voccio John P. , Bascuñán Juan , Iwasa Yukikazu
Published: October 2013

We present a No-Insulation (NI) Multi-Width (MW) winding technique for an HTS (high temperature superconductor) magnet consisting of double-pancake (DP) coils. The NI enables an HTS magnet self-protecting and the MW minimizes the detrimental anisotropy in current-carrying capacity of HTS tape by assigning tapes of multiple widths to DP coils within a stack, widest tape to the top and bottom sections and the narrowest in the midplane section. This paper presents fabrication and test results of an NI-MW HTS magnet and demonstrates the unique features of the NI-MW technique: self-protecting and enhanced field performance, unattainable with the conventional technique.
The universality of β-hairpin misfolding indicated by molecular dynamics simulations
Authors: Shao Qiang , Wang Jinan , Shi Jiye , Zhu Weiliang
Published: October 2013

Previous molecular dynamics simulations showed that besides the experimentally measured folded structures, several β-structured polypeptides could also have misfolded “out-of-register” structures. Through the enhanced sampling molecular dynamics simulations on a series of polypeptides using either implicit or explicit solvent model, the present study systematically investigated the universality of β-hairpin misfolding and its determinants. It was observed that the misfolding could take place for almost all polypeptides under study, especially in the presence of weak side chain hydrophobicity. Moreover, the observed misfolded structures for various polypeptides share the following common features: (1) the turn length in misfolded structure is one-residue shorter than that in folded structure; (2) the hydrophobic side chains on the two strands are pointed to the opposite directions instead of packing in the same direction to form hydrophobic core cluster in the folded structure; and (3) the misfolded structure is one-residue-shifted asymmetric β-hairpin structure. The detailed analysis suggested that the misfolding of β-hairpin is the result of the competition between the formation of the alterable turn configurations and the inter-strand hydrophobic interactions. These predictions are desired to be tested by experiments.
Common behavior of the critical properties of the 2D and 3D square-well fluids
Authors: Reyes Yuri , Flores-Sandoval César A. , Orea Pedro
Published: October 2013

We have analyzed the behavior of the critical properties and second virial coefficient of the square well fluids in two (2D) and three dimensions (3D) as a function of the interaction range. In both systems, the critical density shows an oscillating-like behavior as the interaction range increases. The second virial coefficient evaluated at the critical temperature as a function of the interaction range shows a general behavior for both cases, and quite surprisingly, there is a minimum of this parameter, for the 2D and 3D fluids, located approximately at the same interaction range. These findings are discussed in terms of the structure of the fluids, via the analysis of the radial distribution function evaluated at the critical point.
Excited exciton and biexciton localised states in a single quantum ring
Authors: Kim H. D. , Kyhm K. , Taylor R. A. , Nicolet A. A. L. , Potemski M. , Nogues G. , Je K. C. , Lee E. H. , Song J. D.
Published: October 2013

We observe excited exciton and biexciton states of localised excitons in an anisotropic quantum ring, where large polarisation asymmetry supports the presence of a crescent-like localised structure. We also find that saturation of the localised ground state exciton with increasing excitation can be attributed to relatively fast dissociation of biexcitons (∼430 ps) compared to slow relaxation from the excited state to the ground state (∼1000 ps). As no significant excitonic Aharonov-Bohm oscillations occur up to 14 T, we conclude that phase coherence around the rim is inhibited as a consequence of height anisotropy in the quantum ring.
Effects of boron dopants of Si (001) substrates on formation of Ge layers by sputter epitaxy method
Authors: Tsukamoto Takahiro , Hirose Nobumitsu , Kasamatsu Akifumi , Mimura Takashi , Matsui Toshiaki , Suda Yoshiyuki
Published: October 2013

The formation of Ge layers on boron-doped Si (001) substrates by our sputter epitaxy method has been investigated. The surface morphology of Ge layers grown on Si substrates depends on the substrate resistance, and flat Ge layers are obtained on Si substrates with 0.015 Ω cm resistivity. Highly boron-doped Si substrates cause a transition in the dislocation structure from complex dislocations with 60° dislocation glide planes to 90° pure-edge dislocations, resulting in the formation of flat Ge layers. Furthermore, we have found that the surface morphology of the Ge layers improves with increasing Ge layer thickness. Ge atoms migrating on the deposited Ge layers tend to position themselves at the reactive sites, where the reactivity is related to the number of bonding contacts between the Ge atom and the surface. This modifies the surface morphology, resulting in a flatter surface. Boron dopants together with the sputter epitaxy method effectively suppress the growth of Ge islands and result in the formation of flat Ge layers.
Magnetic phase separation and exchange bias in off-stoichiometric Ni-Mn-Ga alloys
Authors: Han Z. D. , Qian B. , Wang D. H. , Zhang P. , Jiang X. F. , Zhang C. L. , Du Y. W.
Published: October 2013

The magnetic phase separation and exchange bias effect in off-stoichiometric Ni2Mn1.4Ga0.6 alloy were reported. Spontaneous exchange bias after zero-field cooling was observed in this alloy. The magnetic nature of ground state was characterized as phase separation with non-percolated ferromagnetic domains in spin glass matrix due to the spatial composition fluctuation and competing ferromagnetic and antiferromagnetic interactions. A mechanism of field-induced growth of ferromagnetic domains changing from non-percolating to percolating state was proposed for the appearance of spontaneous exchange bias.
Wnt/Rspondin/β-catenin signals control axonal sorting and lineage progression in Schwann cell development
Authors: Grigoryan Tamara , Stein Simone , Qi Jingjing , Wende Hagen , Garratt Alistair N. , Nave Klaus-Armin , Birchmeier Carmen , Birchmeier Walter
Published: October 2013

Significance

Schwann cells (SCs) are the glial cells of the peripheral nervous system essential for nerve ensheathment and myelination. Deregulation in SC development is often associated with diseases in humans. Around birth, immature SCs segregate axons, a process called “axonal radial sorting.” Here we unravel the mechanism of Wnt/β-catenin signaling in axonal sorting of SCs in mice. Loss- and gain-of-function mutations of
β-catenin
in SCs impede and accelerate radial sorting of axons, respectively. Moreover, down- or up-regulated Wnt/β-catenin signaling inhibits or promotes cell spreading and lamellipodia formation of cultured SCs. Our research contributes to a better understanding of the mechanisms of SC development and disease.
Does sex-ratio selection influence nest-site choice in a reptile with temperature-dependent sex determination?
Authors: Mitchell Timothy S. , Maciel Jessica A. , Janzen Fredric J.
Published: October 2013

Evolutionary theory predicts that dioecious species should produce a balanced primary sex ratio maintained by frequency-dependent selection. Organisms with environmental sex determination, however, are vulnerable to maladaptive sex ratios, because environmental conditions vary spatio-temporally. For reptiles with temperature-dependent sex determination, nest-site choice is a behavioural maternal effect that could respond to sex-ratio selection, as mothers could adjust offspring sex ratios by choosing nest sites that will have particular thermal properties. This theoretical prediction has generated decades of empirical research, yet convincing evidence that sex-ratio selection is influencing nesting behaviours remains absent. Here, we provide the first experimental evidence from nature that sex-ratio selection, rather than only viability selection, is probably an important component of nest-site choice in a reptile with temperature-dependent sex determination. We compare painted turtle (
Chrysemys picta
) neonates from maternally selected nest sites with those from randomly selected nest sites, observing no substantive difference in hatching success or survival, but finding a profound difference in offspring sex ratio in the direction expected based on historical records. Additionally, we leverage long-term data to reconstruct our sex ratio results had the experiment been repeated in multiple years. As predicted by theory, our results suggest that sex-ratio selection has shaped nesting behaviour in ways likely to enhance maternal fitness.
Genetic diversity and virulence properties of Streptococcus dysgalactiae subsp. equisimilis from different sources
Authors: Gherardi Giovanni , Imperi Monica , Palmieri Claudio , Magi Gloria , Facinelli Bruna , Baldassarri Lucilla , Pataracchia Marco , Creti Roberta
Published: October 2013

A recent increase in virulence of pathogenic Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been widely proposed. Such an increase may be partly explained by the acquisition of new virulence traits by horizontal gene transfer from related streptococci such as Streptococcus pyogenes (GAS) and Streptococcus agalactiae (GBS). A collection of 54 SDSE strains isolated in Italy in the years 2000–2010 from different sources (paediatric throat carriage, invasive and non-invasive diseases) was characterized by emm typing and pulsed-field gel electrophoresis (PFGE) analysis. The virulence repertoire was evaluated by PCR for the presence of GAS superantigen (spe) genes, the streptolysin S (sagA) gene, the group G fibronectin-binding protein (gfbA) gene and GAS–GBS alpha-like protein family (alp) genes; moreover, the ability to invade human epithelial cells was investigated. Resistance to tetracycline, erythromycin and clindamycin was assessed. The combined use of emm typing and PFGE proved to be a reliable strategy for the epidemiological analysis of SDSE isolates. The most frequent emm types were the same as those more frequently reported in other studies, thus indicating the diffusion of a limited number of a few successful emm types fit to disseminate in humans. The speG gene was detected in SDSE strains of different genetic backgrounds. Erythromycin resistance determined by the erm(T) gene, and the unusual, foggy MLSB phenotype, observed in one and seven strains, respectively, have never previously, to our knowledge, been reported in SDSE. Moreover, a new member of the alp family was identified. The identification of new antibiotic and virulence determinants, despite the small size of the sample analysed, shows the importance of constant attention to monitoring the extent of lateral gene transfer in this emerging pathogen.
Ethanolamide Oxylipins of Linolenic Acid Can Negatively Regulate Arabidopsis Seedling Development
Authors: Keereetaweep Jantana , Blancaflor Elison B. , Hornung Ellen , Feussner Ivo , Chapman Kent D.
Published: October 2013

N-Acylethanolamines (NAEs) are fatty-acid derivatives with potent biological activities in a wide range of eukaryotic organisms. Polyunsaturated NAEs are among the most abundant NAE types in seeds of Arabidopsis thaliana, and they can be metabolized by either fatty acid amide hydrolase (FAAH) or by lipoxygenase (LOX) to low levels during seedling establishment. Here, we identify and quantify endogenous oxylipin metabolites of N-linolenoylethanolamine (NAE 18:3) in Arabidopsis seedlings and show that their levels were higher in faah knockout seedlings. Quantification of oxylipin metabolites in lox mutants demonstrated altered partitioning of NAE 18:3 into 9- or 13-LOX pathways, and this was especially exaggerated when exogenous NAE was added to seedlings. When maintained at micromolar concentrations, NAE 18:3 specifically induced cotyledon bleaching of light-grown seedlings within a restricted stage of development. Comprehensive oxylipin profiling together with genetic and pharmacological interference with LOX activity suggested that both 9-hydroxy and 13-hydroxy linolenoylethanolamides, but not corresponding free fatty-acid metabolites, contributed to the reversible disruption of thylakoid membranes in chloroplasts of seedling cotyledons. We suggest that NAE oxylipins of linolenic acid represent a newly identified, endogenous set of bioactive compounds that may act in opposition to progression of normal seedling development and must be depleted for successful establishment.
Crystal structure and packing energy calculations of (+)-6-aminopenicillanic acid
Authors: Saouane Sofiane , Buth Gernot , Fabbiani Francesca P. A.
Published: October 2013

The X-ray single-crystal structure of (2S,5R,6R)-6-amino-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid, commonly known as (+)-6-aminopenicillanic acid (C8H12N2O3S) and a precursor of a variety of semi-synthetic penicillins, has been determined from synchrotron data at 150 K. The structure represents an ordered zwitterion and the crystals are nonmerohedrally twinned. The crystal structure is composed of a three-dimensional network built by three charge-assisted hydrogen bonds between the ammonium and carboxylate groups. The complementary analysis of the crystal packing by thePIXELmethod brings to light the nature and ranking of the energetically most stabilizing intermolecular interaction energies. In accordance with the zwitterionic nature of the structure,PIXELlattice energy calculations confirm the predominance of the Coulombic term (−379.1 kJ mol−1) ahead of the polarization (−141.4 kJ mol−1), dispersion (−133.7 kJ mol−1) and repulsion (266.3 kJ mol−1) contributions.
A well-resolved cyclic water tetramer in a dinuclear CuIIcoordination complex based on 1,2-bis(pyridin-3-yloxy)ethane and capped by pyridine-2,6-dicarboxylic acid
Authors: Ge Jing-Yuan , Wang Peng , Ma Jian-Ping , Liu Qi-Kui , Dong Yu-Bin
Published: October 2013

μ-1,2-Bis(pyridin-3-yloxy)ethane-κ2N:N′-bis[aqua(pyridine-2,6-dicarboxylato-κ3O2,N,O6)copper(II)] tetrahydrate, [Cu2(C7H3NO4)2(C12H12N2O2)(H2O)2]·4H2O, (I), is a C-shaped molecule based on 1,2-bis(pyridin-3-yloxy)ethane (L) and CuIIin the presence of pyridine-2,6-dicarboxylic acid (H2pydc). The two five-coordinated CuIIcentres are chelated by terminal pydc2−ligands and bridged by anLspacer. The molecules are arranged in a two-dimensional sheetvia15 O—H...O hydrogen bonds, and C—H...O interactions further bridge neighbouring sheets into a three-dimensional supermolecular architecture. The structure includes a well-resolved cyclic water tetramer, which acts as a subunit to form a larger aggregate. A thermogravimetric analysis of complex (I) was also carried out.
Achieving Integration in Mixed Methods Designs—Principles and Practices
Authors: Fetters Michael D. , Curry Leslie A. , Creswell John W.
Published: October 2013

Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs—exploratory sequential, explanatory sequential, and convergent—and through four advanced frameworks—multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods.
Single‐nucleotide polymorphism discovery in Leptographium longiclavatum, a mountain pine beetle‐associated symbiotic fungus, using whole‐genome resequencing
Authors: Ojeda Dario I. , Dhillon Braham , Tsui Clement K. M. , Hamelin Richard C.
Published: October 2013

Single‐nucleotide polymorphisms (SNPs) are rapidly becoming the standard markers in population genomics studies; however, their use in nonmodel organisms is limited due to the lack of cost‐effective approaches to uncover genome‐wide variation, and the large number of individuals needed in the screening process to reduce ascertainment bias. To discover SNPs for population genomics studies in the fungal symbionts of the mountain pine beetle (MPB), we developed a road map to discover SNPs and to produce a genotyping platform. We undertook a whole‐genome sequencing approach of Leptographium longiclavatum in combination with available genomics resources of another MPB symbiont, Grosmannia clavigera. We sequenced 71 individuals pooled into four groups using the Illumina sequencing technology. We generated between 27 and 30 million reads of 75 bp that resulted in a total of 1, 181 contigs longer than 2 kb and an assembled genome size of 28.9 Mb (N50 = 48 kb, average depth = 125x). A total of 9052 proteins were annotated, and between 9531 and 17 266 SNPs were identified in the four pools. A subset of 206 genes (containing 574 SNPs, 11% false positives) was used to develop a genotyping platform for this species. Using this roadmap, we developed a genotyping assay with a total of 147 SNPs located in 121 genes using the Illumina® Sequenom iPLEX Gold. Our preliminary genotyping (success rate = 85%) of 304 individuals from 36 populations supports the utility of this approach for population genomics studies in other MPB fungal symbionts and other fungal nonmodel species.
Impacts of bioturbation on temporal variation in bacterial and archaeal nitrogen‐cycling gene abundance in coastal sediments
Authors: Laverock B. , Tait K. , Gilbert J. A. , Osborn A. M. , Widdicombe S.
Published: October 2013

In marine environments, macrofauna living in or on the sediment surface may alter the structure, diversity and function of benthic microbial communities. In particular, microbial nitrogen (N)‐cycling processes may be enhanced by the activity of large bioturbating organisms. Here, we study the effect of the burrowing mud shrimp Upogebia deltaura upon temporal variation in the abundance of genes representing key N‐cycling functional guilds. The abundance of bacterial genes representing different N‐cycling guilds displayed different temporal patterns in burrow sediments in comparison with surface sediments, suggesting that the burrow provides a unique environment where bacterial gene abundances are influenced directly by macrofaunal activity. In contrast, the abundances of archaeal ammonia oxidizers varied temporally but were not affected by bioturbation, indicating differential responses between bacterial and archaeal ammonia oxidizers to environmental physicochemical controls. This study highlights the importance of bioturbation as a control over the temporal variation in nitrogen‐cycling microbial community dynamics within coastal sediments.
Transepithelial elimination in sarcoidosis: a frequent finding
Authors: Ismail Aimen , Beckum Kathleen , McKay Kristopher
Published: October 2013

Background

Transepithelial elimination is a process by which dermal materials are expelled through an active epithelial‐dermal connective tissue interaction. It has been described as a regular or sporadic occurrence in a variety of dermatologic conditions, including sarcoidosis.

Observation

Our patient demonstrated a rare presentation of sarcoidosis involving the genital region, with histopathologic evidence of transepithelial elimination of granulomas. This prompted us to conduct the first case series documenting the frequency of transepithelial elimination in sarcoidosis.

Methods

Slides of skin biopsies from patients (n = 50) with cutaneous sarcoidosis from the University of Alabama at Birmingham were evaluated for transepithelial elimination. Transepithelial elimination was defined as epithelial channel formation with a sarcoidal‐type granuloma completely surrounded by squamous epithelium on the section examined.

Results

Transepithelial elimination was found in 9 of 50 cases (18%).

Conclusion

This is the first report of transepithelial elimination in a lesion of sarcoidosis localized to the vulvar area, and one of only six reports in the English literature documenting cutaneous sarcoidosis with histopathologic evidence of transepithelial elimination. These reports are reviewed herein. Surprisingly, the results from this case series indicate that transepithelial elimination is more common in cutaneous sarcoidosis than one may surmise from the current literature.
Increasing conflict in times of retrenchment? Attitudes towards healthcare provision in Europe between 1996 and 2002
Authors: Naumann Elias
Published: October 2013

Public opinion is considered a major obstacle to changing the status quo of welfare state policies. Yet some far‐reaching reforms and gradual changes of European welfare states prompt the reverse question: Have increased reform pressures and restructuring efforts led to changes in individual attitudes? In line with previous research, I found that the strong support for a public provision of healthcare remains unchanged. But what about the structure of attitudes? Testing core assumptions of the new politics theory and power resources theory, I looked at conflict lines within society and how they change in times of retrenchment. Analysing individual attitudes in 14 European countries between 1996 and 2002, I moved beyond static comparisons across countries to provide a dynamic account of trends over time. Observing stability, not change, I found no evidence that the relevance of old cleavages is in decline. Both old and new cleavages shape individual attitudes.
The EU in the Horn of Africa: Building Resilience as a Distant Form of Governance
Authors: Joseph Jonathan
Published: October 2013

The EU has recently got involved in resilience building. This article concentrates on the SHARE project relating to resilience building in the Horn of Africa. It suggests that resilience is best understood as part of a particular approach to governance. By employing the concept of governmentality it is suggested that the resilience project is part of a broader strategy that seeks to govern from a distance. It is argued that this is consistent with two other developments. First it fits with new approaches to development and global governance, something that is shown through a comparison with the work of USAID. And it fits with the EU's own internal processes both in the field of risk and disaster preparedness, and in relation to things like the open method of co‐ordination. Resilience has emerged as an important new approach and this will be at the heart of internal and external EU relations.
The Receding Tide of Medical Malpractice Litigation: Part 1—National Trends
Authors: Paik Myungho , Black Bernard , Hyman David A.
Published: October 2013

The United States has experienced three medical malpractice (med mal) crises in the past 40 years. In response, 31 states now have caps on noneconomic or total damages. Researchers have studied the impact of these caps, relative to control states without caps, but have not studied trends in no‐cap states or overall national trends. We find that the per‐physician rate of paid med mal claims has been dropping for 20 years and in 2012 was less than half the 1992 level. Lawsuit rates, in the states with available data, are also declining, at similar rates. “Small” paid claims (payout < $50,000 in 2011 dollars) have been dropping for the full period; “large” paid claims (payout ≥ $50,000) have been dropping since 2001. Payout per large paid claim was roughly flat. Payouts per physician have been dropping since 2003, and by 2012 were 48 percent below their 1992 level. The “third wave” of damage cap adoptions over 2003–2006 contributed to this trend, but there are also large declines in no‐cap states.
Early impairment in brain metabolism detected by MR spectroscopy antedates structural changes in mouse models of spinocerebellar ataxias
Authors: Mlynárik Vladimír , McKenna Mary C.
Published: October 2013

Read the full article ‘Non‐invasive detection of neurochemical changes prior to overt pathology in a mouse model of spinocerebellar ataxia type 1’ on doi: 10.1111/jnc.12435.
Knowledge creation capability, absorptive capacity, and product innovativeness
Authors: Su Zhongfeng , Ahlstrom David , Li Jia , Cheng Dejun
Published: October 2013

This study focuses on the impact of knowledge creation capability and absorptive capacity on product innovativeness. Capabilities contribute through their uniqueness, their integration into effective configurations, and their deployment in response to external environment changes. Therefore, this study examines the individual (uniqueness) and interactive (integration) effects of knowledge creation capability and absorptive capacity on product innovativeness as well as how these effects vary in differing technologically turbulent contexts (deployment). Based on a survey of 212 Chinese firms, this study finds that in addition to their individually positive effects, knowledge creation capability and absorptive capacity have a synergistic effect on product innovativeness. Moreover, the individual effect of knowledge creation capability and the synergistic effect become stronger as technological turbulence increases, whereas the impact of absorptive capacity tends to be dampened by technological turbulence.
Passive revolution: A church‐military partnership in the Philippines
Authors: Moxham Christopher , Grant Miriam
Published: October 2013

In the Philippines, a Catholic social movement for local development and broad structural transformation, referred to as Basic Ecclesial Communities, offers a counter‐narrative to state development. Predicated on the power of networked local groups, the Diocese of San Carlos has taken the original concept and rescaled it, operating a variety of social‐action programmes at the diocese level. The focus of this paper is a unique partnership between the diocese and the Armed Forces of the Philippines, which has produced a number of measurable positive changes in under‐serviced areas. We remain uncertain, however, about the extent to which the church is cooperating with, or being co‐opted by, the military as it enters into partnership, and many members of the clergy share our scepticism. In this paper we draw upon Gramsci's concept of passive revolution (1971) as a means to conceptualize both the efforts of the church to reform society from within, and the reaffirmation of the hegemonic discourse that seems inevitable.
Incidence and risk factors for herpes zoster following heart transplantation
Authors: Koo S. , Gagne L.S. , Lee P. , Pratibhu P.P. , James L.M. , Givertz M.M. , Marty F.M.
Published: October 2013

Background

Data on the incidence, timing, and risk factors for herpes zoster (HZ) in heart transplant (HT) recipients are limited.

Methods

We determined HZ incidence rates and actuarial estimates of time to first HZ episode in 314 HT recipients at our institution from 1995 to 2010. We developed Cox models to assess potential risk factors for HZ in HT.

Results

Median age at HT was 54 (range, 17–71) years; 237 (76%) were male. There were 60 episodes of HZ in 51 patients, with an overall incidence rate of 31.6 cases (95% confidence interval [CI], 23.5–41.6)/1000 person‐years. Although most cases occurred during the first post‐HT year, cumulative HZ incidence was 0.078 at 1, 0.15 at 5, and 0.20 at 10 years. Many patients had substantial HZ morbidity, including 14% with HZ ophthalmicus and 45% with post‐herpetic neuralgia. Adjusting for age, gender, and acute cellular rejection episodes, exposure to mycophenolate mofetil (MMF) was an independent risk factor for HZ (adjusted hazard ratio [HR] 2.18; 95% CI, 1.20–3.96; P = 0.01), while ganciclovir‐based cytomegalovirus prophylaxis reduced HZ risk (adjusted HR 0.09; 95% CI, 0.01–0.71; P = 0.02). Although age and female gender increased HZ risk, the magnitude of their effect was not statistically significant in Cox models.

Conclusions

HZ is common and morbid after HT, particularly with MMF exposure. Ganciclovir prophylaxis is effective in reducing the short‐term risk of HZ, but the steady incidence of cases for years post HT makes long‐term HZ prevention challenging. Augmenting varicella zoster virus immunity post HT with vaccines warrants further exploration.
A Unified Continuum Damage Mechanics Model for Predicting the Stress Relaxation Behavior of High-Temperature Bolting
Authors: Guo J. Q. , Zheng X. T. , Zhang Y. , Shi H. C. , Meng W. Z.
Published: October 2013

Two stress relaxation constitutive models have been developed to predict the stress relaxation behavior for high-temperature bolting according to continuum damage mechanics, Kachanov–Robatnov (K–R), and Othman–Hayhurst (O–H) creep constitutive equations as well as stress relaxation strain equations. To validate the effectiveness of constitutive equations, the predicted results were compared with the experimental data of uniaxial isothermal stress relaxation tests using 1Cr10NiMoW2VNbN steel. The results show that the results obtained by the stress relaxation constitutive model based on the K–R creep equation overestimates the stress relaxation behavior, while the model deduced by the O–H creep equation is more in agreement with the experimental data. Moreover, the stress relaxation damage predicted increases with the increment of initial stress significantly. These indicate that the new models can predict the stress relaxation behavior of high-temperature bolting well.
Health Physics and Radiological Health, 4th Edition.
Authors: Pfeiffer Douglas
Published: October 2013

Health Physics and Radiological Health, 4th Edition. Johnson Thomas E., Birky Brian K., Lippincott Williams & Wilkins, a Walter Kluwer business, Baltimore, Maryland, 2012, $205.99. ISBN: 9781609134198, 1288 pp. (hardcover)
Articulatory and acoustic characteristics of English /l/ in children’s speech production
Authors: Oh Sunyoung , Gick Bryan
Published: October 2013

English /l/ is one of the later-developing sounds in language acquisition. It has syllable-based allophones (e.g., light l in initial, dark l in final) and comprises multiple articulatory gestures (e.g., tongue tip fronting and raising, tongue dorsum backing, lateral dipping) with different coordination in timing and magnitude in syllable position (e.g., synchronicity in initial, tongue tip delay in final with greater reduction in magnitude). Using ultrasound, this study examined how articulatory characteristics of /l/ are presented in children’s speech production. Replicating previous articulatory studies in adult speech production, /l/ words in isolation and combination were collected from eight monolingual children aged 3;11 to 5;9. Although some children produced more similar to adult /l/, children produced /l/ using different articulatory properties. /l/ was produced with less detail and more variations than in the adults’ speech as movements of the tongue were simplified or modified. While articulatory performance varied across subjects as well as syllable positions, acoustic analysis of formants (F1, F2, F3) of sample tokens showed similar patterns for all subjects. This study suggests that the tendency toward late acquisition of /l/ is due directly to the articulatory as well as motor complexity.
A comparison of mine counter measure performance models
Authors: Holden Andrew
Published: October 2013

Mine counter measure (MCM) sonar systems perform the task of detection and classification of marine mines that are typically laid in shallow water environments. Currently, there are several MCM performance models in use that can predict the performance of MCM sonars. This paper gives a brief description of some these models and gives a comparison of their performance predictions for several shallow water scenarios. All the models examined are self contained packages that can model the entire problem—the sonar, the environment, and the target. They are considered to be energy models in that only the intensity of sound received from various parts of the environment is modeled while phase calculations are ignored. The results show that the models can give good agreements with each other for some scenarios. In some other scenarios the agreement is not so good and reasons are given to show why this happens.
Estimating loudness in animals
Authors: Dent Micheal L.
Published: October 2013

Although auditory acuity experiments in animals are valuable, this is not how animals typically encounter real world sounds. It is also important to know how animals respond to stimuli at more ‘‘realistic’’ intensities. The perception of above-threshold level sounds has been well documented in humans, but is much less studied in animals, where acoustic communication is important for survival. In humans, equal loudness contours are used to show that loudness does not increase with intensity equally at all frequencies. Loudness is a subjective experience, however, and much harder to measure in animals. Reaction time is one untrained response that can be used to gauge how different or similar two stimuli are: high intensities yield short and low intensities yield long reaction times. Comparing reaction times across frequencies (equal latency contours) in birds and mammals show results that are similar to equal loudness contours obtained in humans. At low SPLs equal-latency contours closely parallel threshold curves, while at high SPLs the contours flatten and all frequencies are perceived as being about the same loudness. These results in animals should be considered when thinking about aspects of acoustic communication such as sound transmission, vocal signals designs, and sound-attenuating properties of the environment.
Coupled vibration and sound radiation from a fluid-filled and submerged or embedded vascular tube with internal turbulent flow due to a constriction
Authors: Yazicioglu Yigit , Royston Thomas J. , Spohnholtz Todd , Martin Bryn , Loth Francis , Bassiouny Hisham
Published: October 2013

The vibration of a thin-walled cylindrical, compliant viscoelastic tube with internal flow and an axisymmetric constriction that results in turbulent fluid flow is studied theoretically and experimentally. Vibration of the tube is considered with internal fluid-coupling only and with coupling to internal flowing fluid and external stagnant fluid or external tissue-like viscoelastic material. The theoretical analysis includes the adaptation of a model for turbulence in the internal fluid and its vibratory excitation of and interaction with the tube wall and surrounding viscoelastic medium. Theoretical predictions are compared with experimental measurements conducted on a flow model system using laser Doppler vibrometry to measure tube vibration and the vibration of the surrounding viscoelastic medium, as well as miniature hydrophones to measure fluid pressure in the tube. Discrepancies between theory and experiment and the coupled nature of the fluid-structure interaction are highlighted. This study is relevant to and may provide further incite into vascular patency and mechanisms of failure, as well as diagnostics via noninvasive acoustic measurements. [Work supported by NIH EB002511 and HL55296, and Whitaker Foundation BME RG 01-0198.]
The violin octet and bowed string instrument design
Authors: Bissinger George
Published: October 2013

Modal analyses were combined with room-averaged acoustic measurements of a complete octet to assess Schellengs fundamental scaling design assumptions: similarity of shape and flat plate scaling. The scaling employed only the two lowest strongly radiating violin resonances, the main air A0 and main wood comprised of the first corpus bending modes B1− and B1+. A0 fell below the desired pitch placement (1.5× lowest string pitch), while the B1 complex generally straddled the desired placement at 2.25×. Difficulties in properly scaling A0 derived partly from an unreliable theory that failed to incorporate A0 coupling to A1 (first length-wise cavity mode), and partly from inability to incorporate cavity wall compliance. Wall compliance dropped A1 into main wood region even though larger instruments were designed successively shorter; the A1/A0 frequency ratio rose from ∼1.5 to ∼2.0 (smallest to largest). Modern models sensitive to cavity shape predict A0 and A1 within ∼10% over the octet, ranging over ∼4.5:1 in length, ∼10:1 in f-hole area, ∼3:1 in top plate thickness, and ∼128:1 in volume. A0 radiates strongly over the octet, while surprisingly A1 is the dominant radiator in the main wood region for the large bass even though A1 was never included in the scaling.
The acoustics of hammered dulcimers
Authors: Peterson David R.
Published: October 2013

The hammered dulcimer, a stringed instrument played with two wooden hammers, probably originated in the Middle East, but it has become part of the musical culture of many countries. In the U. S., the folk revivial in the 1970’s sparked renewed interest in the hammered dulcimer as a concert instrument. Today, despite some consolidation in the retail market, there are still hundreds of builders, mostly amateurs, who experiment with the basic design. The most important design parameters will be discussed from a practical and acoustical point of view: soundboard size, shape, and composition, internal bracing, bridge shape, string arrangement and composition, hardness of bridge caps, hammer weight and stiffness, instrument resonances due to the unique string splitting and stiffness of the body, and soundboard modes.