bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of low loss, high speed, and high isolation Ka‐band SPST pin switch in suspended stripline configuration
Authors: Kumar G. A. , Kumar Arun
Published: May 2012

This article describes the design of a low insertion loss, high speed, and high isolation reflective SPST switch at 36 GHz (Ka‐band).The switch is based on suspended stripline transmission line medium using PIN diodes in shunt configuration. The measured insertion loss for the switch is less than 1.1 dB with isolation greater than 30 dB over a bandwidth of 4 GHz. The measured switching speed for the switch is less than 5 ns. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1808–1810, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26964
A compact dual‐wideband antenna based on complementary split‐ring resonator
Authors: Cumhur Basaran S.
Published: May 2012

A dual‐wideband coplanar waveguide‐fed monopole antenna based on complementary split‐ring (CSR) resonators is introduced for wireless fidelity and worldwide interoperability for microwave access applications.The proposed CSR monopole antenna has a compact size and provides 31.5% and 9.4% impedance bandwidth at the respective bands. The antenna exhibits uniform radiation patterns at each frequency band. Analysis and design of the proposed antenna are performed by means of Ansoft HFSS. The measurement results of the fabricated antenna are in good agreement with the simulation results. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1917–1920, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26969
Switchable radar cross‐section evanescent waveguide antenna affiliation
Authors: Ludlow Peter , Fusco Vincent
Published: May 2012

We present a simple method of forming a switchable radar cross‐section (RCS) in evanescent waveguide.Here, the antenna can be selected to be matched to free space, or to act as an almost perfect reflector of incident energy via a single SPST switch located at the antenna aperture. With the aperture switch open, the antenna is matched over a measured bandwidth of 17.5%, from 2.35 to 2.8 GHz, for reflection coefficient <−10 dB, in 2.725 GHz cutoff waveguide. With the aperture switch closed, a minimum reflection coefficient of −2.5 dB across the bandwidth is observed, proving that the antenna has the capacity to be made RCS reconfigurable. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1849–1851, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26981
A Novel all‐fiber velocity interferometer based on optic‐feedback delay line
Authors: Hong Guangwei , Lin Peng , Xiao Qian
Published: May 2012

A novel all‐fiber velocity interferometer based on optic‐feedback delay line (NAFVISAR) is proposed and demonstrated.The configuration of the all‐fiber velocity interferometer system for any reflector removes the distributed phase modulation noise of the delay line essentially. In addition, the optic‐feedback delay line can double the phase sensitivity of the system compared with Levin's structure. With shaker vibration measurement experiment, it is shown that the NAFVISAR can successfully suppress the delay‐line‐induced noise with more than 30 dB. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1814–1817, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26982
Design and implementation of a 2.8‐dB insertion loss v‐band bandpass filter in 0.13‐μm cmos technology
Authors: Lin Chih‐Ying , Chang Jin‐Fa , Lin Yo‐Sheng
Published: May 2012

In this article, we demonstrate a low‐insertion‐loss V‐band bandpass filter with two finite transmission zeros by 0.13‐μm CMOS technology. The proposed filter architecture has the following feature: The low‐frequency transmission‐zero (ωz1) can be tuned individually by the series‐feedback capacitor Cs and the series capacitor C3. After ωz1 is determined by Cs and C3, the high‐frequency transmission zero (ωz2) can be tuned individually by the parallel‐feedback capacitor Cp. Besides, low‐insertion‐loss is achieved by adopting thick microstrip‐line with optimized ground‐plane pattern as the needed inductors to minimize the metal and substrate loss. This filter achieves insertion‐loss (1/S21) lower than 3 dB over the frequency range of 45–52 GHz, input return loss (S11) better than −10 dB over the frequency range of 41.2–57.8 GHz, and output return loss (S22) better than −10 dB over the frequency range of 39.5–55.9 GHz. The minimum insertion‐loss is 2.8 dB at 48 GHz, to the authors' knowledge, this is one of the best results ever reported for a V‐band CMOS bandpass filter in the literature. The chip area is only 0.295 × 0.21 mm2, i.e., 0.062 mm2, excluding the test pads and dummy metals for design rule requirement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2001–2006, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26984
Accurate computations of matrices with bidiagonal decomposition using methods for totally positive matrices
Authors: Barreras A. , Peña J. M.
Published: May 2012

A class of sign‐symmetric P‐matrices including all nonsingular totally positive matrices and their inverses as well as tridiagonal nonsingular H‐matrices is presented and analyzed. These matrices present a bidiagonal decomposition that can be used to obtain algorithms to compute with high relative accuracy their singular values, eigenvalues, inverses, or their LDU factorization. Copyright © 2012 John Wiley & Sons, Ltd.
A unified 3D‐based technique for plate bending analysis using scaled boundary finite element method
Authors: Man H. , Song C. , Gao W. , Tin‐Loi F.
Published: May 2012

This paper presents a unified technique for solving the plate bending problems by extending the scaled boundary finite element method. The formulation is based on the three‐dimensional governing equation without enforcing the kinematics of plate theory. Only the in‐plane dimensions are discretised into finite elements. Any two‐dimensional displacement‐based elements can be employed. The solution along the thickness is expressed analytically by using a matrix function. The proposed technique is consistent with the three‐dimensional theory and applicable to both thick and thin plates without exhibiting the numerical locking phenomenon. Moreover, the use of higher order spectral elements allows the proposed technique to better represent curved boundaries and to achieve high accuracy and fast convergence. Numerical examples of various plate structures with different thickness‐to‐length ratios demonstrate the applicability and accuracy of the proposed technique. Copyright © 2012 John Wiley & Sons, Ltd.
Impaired ubiquitin‐proteasome‐mediated PGC‐1α protein turnover and induced mitochondrial biogenesis secondary to complex‐I deficiency
Authors: Farhoud Murtada H. , Nijtmans Leo G. , Wanders Ronald J. A. , Wessels Hans J. C. T. , Lasonder Edwin , Janssen Antoon J. M. , Rodenburg Richard R. J. , van den Heuvel Lambert P. , Smeitink Jan A. M.
Published: May 2012

Most eukaryotic cells depend on mitochondrial OXidative PHOSphorylation (OXPHOS) in their ATP supply. The cellular consequences of OXPHOS defects and the pathophysiological mechanisms in related disorders are incompletely understood. Using a quantitative proteomics approach we provide evidence that a genetic defect of complex‐I of the OXPHOS system may associate with transcriptional derangements of mitochondrial biogenesis through stabilization of the master transcriptional regulator PPARγ co‐activator 1α (PGC‐1α) protein. Chronic oxidative stress suppresses the gene expression of PGC‐1α but concomitant inhibition of the ubiquitin–proteasome system (UPS) can stabilize this co‐activator protein, thereby inducing its downstream metabolic gene expression programs. Thus, mitochondrial biogenesis, which lays at the heart of the homeostatic control of energy metabolism, can be deregulated by secondary impairments of the protein turnover machinery.
Two steps forward—one step back: Advances in affinity purification mass spectrometry of macromolecular complexes
Authors: Oeffinger Marlene
Published: May 2012

Cellular functions are defined by the dynamic interactions of proteins within macromolecular networks. Deciphering these complex interplays is the key to getting a comprehensive picture of cellular behavior and to understanding biological systems, from a simple bacterial cell to highly regulated neuronal cells or cancerous tissue. In the last decade, affinity purification (AP) coupled to mass spectrometry has emerged as a powerful tool to comprehensively study interaction networks and their macromolecular assemblies. This review discusses recent advances in AP approaches, from cell lysis to the importance of sample preparation and the choice of AP matrix as well as the development of different epitope tags and strategies to study dynamic interactions, with an emphasis on RNA–protein interaction networks.
Combining many interaction networks to predict gene function and analyze gene lists
Authors: Mostafavi Sara , Morris Quaid
Published: May 2012

In this article, we review how interaction networks can be used alone or in combination in an automated fashion to provide insight into gene and protein function. We describe the concept of a “gene‐recommender system” that can be applied to any large collection of interaction networks to make predictions about gene or protein function based on a query list of proteins that share a function of interest. We discuss these systems in general and focus on one specific system, GeneMANIA, that has unique features and uses different algorithms from the majority of other systems.
An improved quantitative mass spectrometry analysis of tumor specific mutant proteins at high sensitivity
Authors: Ruppen‐Cañás Isabel , López‐Casas Pedro P. , García Fernando , Ximénez‐Embún Pilar , Muñoz Manuel , Morelli M. Pia , Real Francisco X. , Serna Antonio , Hidalgo Manuel , Ashman Keith
Published: May 2012

New disease specific biomarkers, especially for cancer, are urgently needed to improve individual diagnosis, prognosis, and treatment selection, that is, for personalized medicine. Genetic mutations that affect protein function drive cancer. Therefore, the detection of such mutations represents a source of cancer specific biomarkers. Here we confirm the implementation of the mutant protein specific immuno‐SRM (where SRM is selective reaction monitoring) mass spectrometry method of RAS proteins reported by Wang et al. [Proc. Natl. Acad. Sci. USA 2011, 108, 2444–2449], which exploits an antibody to simultaneously capture the different forms of the target protein and the resolving power and sensitivity of LC‐MS/MS and improve the technique by using a more sensitive mass spectrometer. The mutant form G12D was quantified by SRM on a QTRAP 5500 mass spectrometer and the MIDAS workflow was used to confirm the sequence of the targeted peptides. This assay has been applied to quantify wild type and mutant RAS proteins in patient tumors, xenografted human tissue, and benign human epidermal tumors at high sensitivity. The limit of detection for the target proteins was as low as 12 amol (0.25 pg). It requires low starting amounts of tissue (ca.15 mg) that could be obtained from a needle aspiration biopsy. The described strategy could find application in the clinical arena and be applied to the study of expression of protein variants in disease.
Ultra‐high intra‐spectrum mass accuracy enables unambiguous identification of fragment reporter ions in isobaric multiplexed quantitative proteomics
Authors: Pachl Fiona , Fellenberg Kurt , Wagner Corinna , Kuster Bernhard
Published: May 2012

Isobaric tagging using reagents such as tandem mass tags (TMT) and isobaric tags for relative and absolute quantification (iTRAQ) have become popular tools for mass spectrometry based quantitative proteomics. Because the peptide quantification information is collected in tandem mass spectra, the accuracy and precision of this method largely depend on the resolution with which precursor ions can be selected for the fragmentation and the specificity of the generated reporter ion. The latter can constitute an issue if near isobaric ion signals are present in such spectra because they may distort quantification results. We propose a simple remedy for this problem by identifying reporter ions via the accurate mass differences within a single tandem mass spectrum instead of applying fixed mass error tolerances for all tandem mass spectra. Our results show that this leads to unambiguous reporter ion identification and complete removal of interfering signals. This mode of data processing is easily implemented in software and offers advantages for protein quantification based on few peptides.
Early changes in the liver‐soluble proteome from mice fed a nonalcoholic steatohepatitis inducing diet
Authors: Thomas Anja , Stevens Axel P. , Klein Matthias S. , Hellerbrand Claus , Dettmer Katja , Gronwald Wolfram , Oefner Peter J. , Reinders Jörg
Published: May 2012

Despite the increasing incidence of nonalcoholic steatohepatitis (NASH) with the rise in lifestyle‐related diseases such as the metabolic syndrome, little is known about the changes in the liver proteome that precede the onset of inflammation and fibrosis. Here, we investigated early changes in the liver‐soluble proteome of female C57BL/6N mice fed an NASH‐inducing diet by 2D‐DIGE and nano‐HPLC‐MS/MS. In parallel, histology and measurements of hepatic content of triglycerides, cholesterol and intermediates of the methionine cycle were performed. Hepatic steatosis manifested itself after 2 days of feeding, albeit significant changes in the liver‐soluble proteome were not evident before day 10 in the absence of inflammatory or fibrotic signs. Proteomic alterations affected mainly energy and amino acid metabolism, detoxification processes, urea cycle, and the one‐carbon/S‐adenosylmethionine pathways. Additionally, intermediates of relevant affected pathways were quantified from liver tissue, confirming the findings from the proteomic analysis.
Synthesis of syndiotactic‐rich star‐shaped poly(methyl methacrylate) by core‐first group transfer polymerization using N‐(trimethylsilyl)bis(trifluoromethanesulfonyl)imide
Authors: Chen Yougen , Takada Kenji , Fuchise Keita , Satoh Toshifumi , Kakuchi Toyoji
Published: May 2012

The N‐(trimethylsilyl)bis(trifluoromethanesulfonyl)imide‐catalyzed (Me3SiNTf2‐catalyzed) group transfer polymerization (GTP) of methyl methacrylate (MMA) has been studied for synthesizing stereospecific star‐shaped poly(methyl methacrylate)s (PMMAs). The catalytic property of Me3SiNTf2 for the GTP of MMA using 1‐methoxy‐1‐trimethylsilyloxy‐2‐methyl‐propene as the initiator was confirmed by a kinetic investigation and matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry measurement. The initiating efficiency (f) of Me3SiNTf2 was 0.94–1.00, which was estimated by the value of Mn(calcd)/Mn(SEC). The Me3SiNTf2‐catalyzed GTP of MMA was carried out using initiators possessing three, four, and six MTS groups (MTS3, MTS4, and MTS6, respectively) under the condition of [MMA]0/[MTS3, MTS4, or MTS6]0 = 120 at −55 °C. All the obtained PMMAs exhibited unimodal and narrow molecular weight distributions as Mw/Mns = 1.03–1.04 and the Mw(MALS)s of the 3‐, 4‐, and 6‐armed star‐shaped PMMAs (PMMA3, PMMA4, and PMMA6, respectively) were 12.9, 12.9, and 13.4 kgmol−1, respectively, which fairly agreed with the calculated Mw(calcd) values. The syndiotacticities, rrs, of PMMA3, PMMA4, and PMMA6 were in the range of 87–89%. The stereoblock synthesis of PMMA3, PMMA4, and PMMA6 was performed by the first and second polymerizations at −55 and 45 °C; the rrs of the first and second PMMA blocks were 87.0, 87.0, and 86.0% and 65.0, 65.0, and 64.0%, respectively. The glass transition temperatures (Tgs) were 118.1, 115.8, and 111.5 °C for the respective syndiotactic‐rich PMMA3, PMMA4, and PMMA6 and 111.5, 109.7, and 107.6 °C for the respective stereoblock ones. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Sensing the messenger: The diverse ways that bacteria signal through c‐di‐GMP
Authors: Krasteva Petya Violinova , Giglio Krista Michelle , Sondermann Holger
Published: May 2012

An intracellular second messenger unique to bacteria, c‐di‐GMP, has gained appreciation as a key player in adaptation and virulence strategies, such as biofilm formation, persistence, and cytotoxicity. Diguanylate cyclases containing GGDEF domains and phosphodiesterases containing either EAL or HD‐GYP domains have been identified as the enzymes controlling intracellular c‐di‐GMP levels, yet little is known regarding signal transmission and the sensory targets for this signaling molecule. Although limited in number, identified c‐di‐GMP receptors in bacteria are characterized by prominent diversity and multilevel impact. In addition, c‐di‐GMP has been shown to have immunomodulatory effects in mammals and several eukaryotic c‐di‐GMP sensors have been proposed. The structural biology of c‐di‐GMP receptors is a rapidly developing field of research, which holds promise for the development of novel therapeutics against bacterial infections. In this review, we highlight recent advances in identifying bacterial and eukaryotic c‐di‐GMP signaling mechanisms and emphasize the need for mechanistic structure–function studies on confirmed signaling targets.
Age‐dependent deamidation of glutamine residues in human γS crystallin: Deamidation and unstructured regions
Authors: Hooi Michelle Yu Sung , Raftery Mark J. , Truscott Roger John Willis
Published: May 2012

Human aging is associated with the deterioration of long‐lived proteins. Gradual cumulative modifications to the life‐long proteins of the lens may ultimately be responsible for the pronounced alterations to the optical and physical properties that characterize lenses from older people. γS crystallin, a major human lens protein, is known to undergo several age‐dependent changes. Using proteomic techniques, a site of deamidation involving glutamine 92 has been characterized and its time course established. The proportion of deamidation increased from birth to teen‐age years and then plateaud. Deamidation at this site increased again in the eighth decade of life. There was no significant difference in the extent of deamidation between cataract and age‐matched normal lenses. Gln92 is located in the linker region between the two domains, and the introduction of a negative charge at this site may alter the interaction between the two regions of the protein. Gln170, which is located in another unstructured part of γS crystallin, showed a similar deamidation profile to that of Gln92. As the other Gln residues in β‐sheet regions of γS crystallin appear to remain as amides, modification of Gln92 and Gln170 thus conforms to a pattern whereby deamidation is localized to the unstructured regions of long‐lived proteins.
Piperlongumine induces rapid depletion of the androgen receptor in human prostate cancer cells
Authors: Golovine Konstantin V. , Makhov Peter B. , Teper Ervin , Kutikov Alexander , Canter Daniel , Uzzo Robert G. , Kolenko Vladimir M.
Published: May 2012

BACKGROUND

Androgen receptor (AR) signaling is regarded as the driving force in prostate carcinogenesis, and its modulation represents a logical target for prostate cancer (PC) prevention and treatment. Natural products are the most consistent source of small molecules for drug development. In this study, we investigate the functional impact of piperlongumine (PL), a naturally occurring alkaloid present in the Long pepper (Piper longum), on AR expression in PC cells and delineate its mechanism of action.

METHODS

Expression and transcriptional activity of AR was examined by western blotting and luciferase reporter assay, respectively. CellTiter Blue assay was utilized to quantify cell proliferation. Reactive oxygen species (ROS) generation was examined by staining cells with a ROS indicator CM‐H2DCFDA, followed by flow cytometry analysis.

RESULTS

The results of our experiments demonstrate that PL rapidly reduces AR protein levels in PC cells via proteasome‐mediated ROS‐dependent mechanism. Moreover, PL effectively depletes a modified AR lacking the ligand‐binding domain, shedding light on a new paradigm in the treatment approach to prostatic carcinoma that expresses mutated constitutively active AR. Importantly, PL effectively depletes AR in PC cells at low micromolar concentrations, while concurrently exerting a significant inhibitory effect on AR transcriptional activity and proliferation of PC cells.

CONCLUSIONS

Our investigation demonstrates for the first time that PL induces rapid depletion of the AR in PC cells. As such, PL may afford novel opportunities for both prevention and treatment of prostatic malignancy. Prostate 73: 23–30, 2013. © 2012 Wiley Periodicals, Inc.
Optical and photoluminescence properties of BiFeO3 thin films grown on ITO‐coated glass substrates by chemical solution deposition
Authors: Chen Xinman , Zhang Hu , Wang Tao , Wang Feifei , Shi Wangzhou
Published: May 2012

The optical and photoluminescence properties of the pure bismuth ferrite (BiFeO3) thin films deposited on ITO‐coated glass substrates by chemical solution deposition methods were investigated. The optical bandgap of obtained BiFeO3 thin films annealed at 500 and 600 °C were confirmed to be 2.75 and 2.71 eV, respectively. The dependence of bandgap on annealing was discussed in terms of coarsening grain sizes as well as the existence of amorphous phases in the films. Furthermore, the evident photoluminescence of BiFeO3 thin films is observed. The near‐band‐edge emission located at 455.4 and 457.9 nm were identified for BiFeO3 thin films annealed at 500 and 600 °C, respectively, while the identical defect emission at 468.7 and 492.3 nm were confirmed for both BiFeO3 thin films, which were tentatively attributed to the defect states related with Bi3+ level and oxygen deficiencies inside the bandgap. However, more investigations are needed to classify the origin of BiFeO3 thin‐film emission for further application.
Cubic materials in different auxetic regions: Linking microscopic to macroscopic formulations
Authors: Brańka A. C. , Heyes D. M. , Maćkowiak Sz. , Pieprzyk S. , Wojciechowski K. W.
Published: May 2012

A number of basic features of the mechanical properties of a cubic symmetry solid material are identified and discussed within the framework of the XY‐plane approach, where X = G/K, Y = G/W, K is the bulk modulus and G, W are shear moduli. An anisotropic part of the Debye temperature is analysed, which was found to be weakly dependent on X and is mainly determined by Y which quantifies the material elastic anisotropy. The anisotropic part has a considerable effect on the Debye temperature of partially auxetic materials. An empirical ductility‐brittleness criterion is considered, which indicates that many auxetics may deform in a brittle manner. A possible correlation between directional tensile deformation and the surface of the most extreme Poisson's ratio (PR) values is suggested. Finally, the reasons for the paucity of cubic materials in the part of the XY‐plane with low Y values is investigated using static microscopic models in which the particles interact with nearest and next nearest neighbours only. An example of a type of microscopic model system located in this ‘empty’ region has been found, which consists of a system under tension, where the interparticle interaction decays with distance in an oscillatory way. The results obtained suggest that a rather unconventional form of the interparticle interaction set and thermodynamic conditions may therefore be required to develop a solid material with these mechanical properties.
Statistical Inference on Constant Stress Accelerated Life Tests under Generalized Gamma Lifetime Distributions
Authors: Fan Tsai‐Hung , Yu Chia‐Hsiang
Published: May 2012

We will discuss the reliability analysis of the constant stress accelerated life tests when a parameter in the generalized gamma lifetime distribution is linear in the stress level. Statistical inference on the estimation of the underlying model parameters as well as the mean time to failure and the reliability function will be addressed on the basis of the maximum likelihood approach. Large sample theory will be derived for the goodness of fit of the data. Some simulation study and an illustrative real example will be presented to show the appropriateness of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.
Multicriteria Model for Selection of Preventive Maintenance Intervals
Authors: de Almeida Adiel Teixeira
Published: May 2012

Selecting preventive maintenance intervals is a problem addressed in the literature in which several different models are used according to the context and other issues. This article presents a multicriteria decision model to support decision makers in choosing the best maintenance interval based on the combination of conflicting criteria, such as reliability and cost. A procedure is proposed for using the model, which is based on multiattribute utility theory (MAUT). Moreover, a numerical application illustrates the use of the procedure, based on a real case study. The discussion of the results addresses theoretical issues and practical managerial implications related to the model proposed. This study shows that a multicriteria decision model is important for the maintenance and reliability community when a context of service production systems is to be accounted for due to interruptions caused by failures in this kind of production system. Copyright © 2012 John Wiley & Sons, Ltd.
Designing offshore fish cages using systems engineering principles
Authors: Shainee Mohamed , Haskins Cecilia , Ellingsen Harald , Leira Bernt J.
Published: May 2012

The human population reached 7 billion at the end of October 2011, accentuating the challenge to increase food production to meet the demand. Offshore mariculture, which does not depend on wild fish harvest, has the potential to become a primary food source to meet this demand. Despite an overall interest and justification in investments in offshore aquaculture, there are very few offshore cage designs suitable for use today. The goal of the current paper is to describe a research project that applied systems engineering principles to develop and document a set of requirements and identify the relevant technical components that are needed to design a sustainable offshore cage system. Requirements from the sector should be met by a robust environmentally friendly cage system ensuring the welfare of the fish and capable of producing a quality fish product demanded by the consumer. Future design work will build on the proposed preliminary architecture to satisfy these requirements. © 2012 Wiley Periodicals, Inc. Syst Eng
Unified theories of cognition
Authors: Byrne Michael D.
Published: May 2012

Unified theories of cognition (UTCs) offer an alternative to the modal ‘divide and conquer’ methodology within cognitive science and attempt to address the full range of cognitive activity within a single theoretical framework. These theories, also termed ‘cognitive architectures’ are generally computational in nature and are intended to model, at some degree of fidelity, human cognition in a broad range of tasks. This style of research has numerous advantages, not the least of which being that the actual human cognitive system is itself an integrated system and many important tasks require bringing integrated capabilities to bear. There are also drawbacks, particularly dealing with the incompleteness of the knowledge base in cognitive science and the difficulty of evaluating such theories. Three architectures are profiled, each one representing a different ‘home’ discipline: from AI, Soar; from cognitive psychology, Adaptive Control of Thought‐Rational; and from neuroscience, Leabra. Future directions for UTCs include expansion into branches of cognition not already well represented, such as spatial cognition, and increasing attention to cognitive moderators such as emotion and fatigue. Overall, this is a powerful research strategy that is likely to remain an important part of cognitive science for the foreseeable future. WIREs Cogn Sci 2012, 3:431–438. doi: 10.1002/wcs.1180

This article is categorized under:

Computer Science > Neural Networks
The Barium Oxotellurate(IV) Bromides Ba6Te10O25Br2 and Ba3Te3O8Br2 with Channel Structures
Authors: Stöger Berthold , Weil Matthias
Published: May 2012

Two new barium oxotellurate(IV) bromides with sum formula Ba6Te10O25Br2 and Ba3Te3O8Br2 were obtained under hydrothermal conditions and were characterized by single‐crystal X‐ray diffraction. In the crystal structures of both compounds a three‐dimensional Ba/Te/O network is perforated by channels, into which the lone pairs E of the TeIV atoms protrude and in which the Br– anions are located. Ba6Te10O25Br2 {Aea2, Z = 8, a = 11.4707(9) Å, b = 31.140(2) Å, c = 18.3216(14) Å, 9331 F2 data, 392 variable parameters, R[F2 > 2σ(F2)] = 0.0376} can be described as a fourfold super structure derived from an idealized basic structure in space group Pmmn. The main building blocks of the super structure are nine crystallographically independent [TeO3+1] units and one trigonal‐pyramidal [TeO3] unit, which share corners and edges to form wavy layers parallel to (001) that are connected by seven independent Ba2+ ions. The three independent Br– anions are situated in channels parallel to [100], leading to overall coordination numbers of the cations ranging from eight to eleven. In the crystal structure of Ba3Te3O8Br2 {Pnma, Z = 4, a = 12.6226(8) Å, b = 5.9663(4) Å, c = 18.1112(12) Å, 5897 F2 data, 88 variable parameters, R[F2 > 2σ(F2)] = 0.0260} the oxotellurate(IV) anions consist of an isolated [TeO3] unit and a condensed [Te2O5]2– group. They coordinate to the three independent Ba2+ ions to form channels extending parallel to [010]. The overall coordination number of all cations is eight whereby each of them is bonded at least to one of the two independent Br– anions in the channels in the form of distorted coordination polyhedra.
Strengthening Mechanisms in NiAl Bronze: Hot Deformation by Rolling and Friction-Stir Processing
Authors: Menon Sarath K. , Pierce Frank A. , Rosemark Brian P. , Oh-Ishi Keiichiro , Swaminathan Srinivasan , McNelley Terry R.
Published: May 2012

Microstructures produced by isothermal hot rolling of a NiAl bronze material were evaluated by quantitative microscopy methods and parameters describing the contributions of precipitate dispersions, grain size, solute content, and dislocation density to the yield strengths of the individual constituents of microstructure were determined. Models for the strengths of the individual constituents were combined to predict the temperature dependence of the yield strength as a function of hot rolling temperature, and the prediction was found to be in good agreement with measured yield strengths. The models were applied to microstructures in a stir zone produced by multipass friction-stir processing (FSP) and, again, found to predict measured yield strengths with high accuracy. Such models may aid in assessing the role of microstructure gradients produced during FSP and other processes.
Forgetting mechanisms for scalable collaborative filtering
Authors: Vinagre João , Jorge Alípio Mário
Published: May 2012

Collaborative filtering (CF) has been an important subject of research in the past few years. Many achievements have been made in this field, however, many challenges still need to be faced, mainly related to scalability and predictive ability. One important issue is how to deal with old and potentially obsolete data in order to avoid unnecessary memory usage and processing time. Our proposal is to use forgetting mechanisms. In this paper, we present and evaluate the impact of two forgetting mechanisms—sliding windows and fading factors—in user-based and item-based CF algorithms with implicit binary ratings under a scenario of abrupt change. Our results suggest that forgetting mechanisms reduce time and space requirements, improving scalability, while not significantly affecting the predictive ability of the algorithms.
Microspherule protein 2 associates with ASK1 and acts as a negative regulator of stress‐induced ASK1 activation
Authors: Xu Mafei , Zhang Fang , Da Liang , Li Tsaiping , Zhao Mujun
Published: May 2012

ASK1
and
MCRS2
colocalize by fluorescence microscopy (
View interaction
)
The “see and treat” strategy for identifying cytologic high‐grade precancerous cervical lesions among low‐income Brazilian women
Authors: Nogara Paula R.B. , Manfroni Luís A.R. , da Silva Mariana C. , Consolaro Marcia E.L.
Published: May 2012

Objective

To evaluate the strategy of “see and treat” by loop electrosurgical excision procedure (LEEP) for cytologic high‐grade precancerous cervical lesions (squamous intraepithelial lesions; HSIL) and post‐LEEP recurrence among low‐income Brazilian women.

Methods

In a retrospective survey of women who underwent LEEP for cytologic HSIL without prior cervical biopsy between January 2004 and March 2008 at CISVALI, União da Vitória, Paraná, Brazil, LEEP sample histology and patient follow‐up by Papanicolaou smear were assessed.

Results

Among 117 women treated, 24% had no lesions, 67.5% had cervical intraepithelial neoplasia (CIN) grade 2/3, and 5.2% had squamous cell carcinoma or adenocarcinoma on LEEP histology. Among patients with follow‐up, recurrences occurred in those with no lesions (16.7%) and CIN 2/3 (25%) (P > 0.05). HSIL was the most frequent type of recurrence (87%) (P < 0.001). In total, 6.3% of patients had positive ectocervical (ecto‐positive) and endocervical (endo‐positive) margins, 3.8% had ecto‐positive, and 33.0% had endo‐positive margins. Recurrences occurred in women with endo‐positive (26.3%), no margin (17.4%), and cautery artifact margin (25.0%) involvement (P > 0.05).

Conclusion

For cytologic HSIL, the benefits of the strategy of “see and treat” by LEEP outweighed the risk of overtreatment. Patients with both positive and negative margins on LEEP should be followed carefully.
Comparison of intrapartum outcome among immigrant women from Ethiopia and the general obstetric population in Israel
Authors: Salim Raed , Mfra Ali , Garmi Gali , Shalev Eliezer
Published: May 2012

Objective

To compare intrapartum outcome between ethnic Ethiopian women and the general obstetric population in Israel.

Methods

In a retrospective study, computerized data from all Ethiopian women who delivered between January 2004 and August 2011 at a university teaching hospital in Afula, Israel, were assessed. The control group comprised non‐Ethiopian Israeli women, who were matched at a ratio of 1:2 on the basis of deliveries that took place immediately before and after delivery by an Ethiopian woman. The primary outcome was incidence of operative delivery.

Results

During the study period, 576 Ethiopian women delivered along with 1152 matched control women. Ethiopian women had a higher incidence of pre‐eclampsia (6.8% versus 4.0%, P = 0.01) and early postpartum hemorrhage (4.3% versus 1.6%, P = 0.003) than control women. After adjustment for potential confounders, the incidence of vacuum or cesarean delivery was significantly higher among Ethiopian than among control women (odds ratio, 1.68; 95% confidence interval, 1.28–2.20; P = 0.002). The incidence of composite major perinatal morbidity, including Erb palsy and cord pH less than 7.1, tended to be higher among Ethiopian women than among control women (2.3% versus 1.1%; P = 0.053).

Conclusion

Although prepartum and intrapartum care are standardized, Ethiopian women had a less favorable intrapartum outcome.
Risk factors for human papillomavirus infection among women in Portugal: The CLEOPATRE Portugal Study
Authors: Pista Angela , de Oliveira Carlos F. , Cunha Maria J. , Paixao Maria T. , Real Odete
Published: May 2012

Objective

To investigate demographic, socioeconomic, lifestyle, and medical factors that might predispose women to cervical human papillomavirus (HPV) infection.

Method

A cross‐sectional population‐based study was performed. Women aged 18–64 years who attended selected obstetrics and gynecology or sexually transmitted disease (STD) clinics in mainland Portugal between February 2008 and March 2009 were recruited, according to an age‐stratified sampling strategy. Liquid‐based cytology samples were analyzed centrally for HPV genotype and for cytologic features. Univariate and multivariate logistic regression analyses identified risk factors for HPV infection.

Results

Among the 2326 women evaluated, the crude prevalence of HPV infection was 19.4%. Lifetime number of sexual partners was a strong predictor of HPV infection (odds ratio 5.44 for 5–10 partners versus 1 partner; P < 0.001). Other risk factors were young age (particularly among women aged 20–24 years; P < 0.001); country of birth other than mainland Portugal (P = 0.002); education up to secondary school level (P = 0.010); smoking history (≤ 10 years; P = 0.004); and any STD in the past 12 months (P = 0.052).

Conclusion

Data from the present study may aid identification of women at increased risk of HPV infection and target prevention strategies.

Trial registration: National Commission of Data Protection (CNPD) registration number 5346/2007; Sanofi Pasteur MSD study number HPV‐E05.
Neotectonic crustal uplifts as a consequence of mantle fluid infiltration into the lithosphere
Authors: Artyushkov E.V.
Published: May 2012

As evidenced by plentiful data, most of the large recent positive topographic features formed as a result of a dramatically accelerated crustal uplift in the Pliocene–Quaternary after a relatively stable period (∼100 Myr in most of the regions). The methods used are illustrated by the well-studied large neotectonic crustal uplifts on the Tibetan Plateau and in the Himalayas. Farther north, neotectonic uplifts with amplitudes of several hundred meters to several kilometers spread over a vast area from Central and Northeast China in the south to the Taimyr Peninsula and Northeastern Asia in the north. They are often attributed to the India–Asia plate collision which began ∼50 Ma.

Most of the uplifts in these regions have formed only during the last few Myr, unaccompanied by significant crustal shortening. Therefore, the large neotectonic crustal uplifts can be explained by a decrease in the lithospheric density. One of the causes was the rapid convective replacement of the lower part of the denser mantle lithosphere by the asthenosphere or mantle plume. This became possible owing to a drastic weakening of the mantle lithosphere under the influence of asthenospheric fluids. In some areas, a considerable asthenospheric top uplift is evidenced by seismic tomography data.

The lower mantle lithosphere (∼50–100 km thick) was replaced by the asthenosphere underneath the neotectonic crustal uplifts of ∼1.0 km in Central Asia. Areas with a thick lithosphere were affected by relatively small neotectonic uplifts, strongly nonuniform in space. They point to metamorphism with mafic-rock expansion in the lower crust upon the infiltration of an asthenospheric fluid. The large crustal uplifts which formed on the continents in the Pliocene and Pleistocene indicate large-scale quasi-synchronic supply of the mantle fluid to their lithosphere.
Non-normal dynamics of time-evolving co-rotating vortex pairs
Authors: Mao X. , Sherwin S. J. , Blackburn H. M.
Published: May 2012

Transient energy growth of disturbances to co-rotating pairs of vortices with axial core flows is investigated in an analysis where vortex core expansion and vortex merging are included by adopting a time-evolving base flow. The dynamics of pairs are compared with those of individual vortices in order to highlight the effect of vortex interaction. Three typical vortex pair cases are studied, with the pairs comprised respectively of individually inviscidly unstable vortices at the streamwise wavenumber that maximizes the individual instabilities, viscously unstable vortices also at the streamwise wavenumber maximizing the individual instabilities and asymptotically stable vortices at streamwise wavenumber zero. For the inviscidly unstable case, the optimal perturbation takes the form of a superposition of two individual helical unstable modes and the optimal energy growth is similar to that predicted for an individual inviscid unstable vortex, while where the individual vortices are viscously unstable, the optimal disturbances within each core have similar spatial distributions to the individually stable case. For both of these cases, time horizons considered are much lower than those required for the merger of the undisturbed vortices. However, for the asymptotically stable case, large linear transient energy growth of optimal perturbations occurs for time horizons corresponding to vortex merging. Linear transient disturbance energy growth exhibited by pairs in this stable case is two to three orders of magnitude larger than that for a corresponding individual vortex. The superposition of the perturbation and the base flow shows that the perturbation has a displacement effect on the vortices in the base flow. Direct numerical simulations of stable pairs seeded by optimal initial perturbations have been carried out and acceleration/delay of vortex merging associated with a dual vortex meandering and vortex breakup related to axially periodic acceleration and delay of vortex merging are observed. For axially invariant cases, the sign of perturbation has an effect, as well as magnitude; the sign dependence relates to whether or not the perturbation adds to or subtracts from the swirl of the base flow. For a two-dimensional perturbation that adds to the swirl of the base flow, seeding with the linear optimal disturbance at a relative energy level $1\ensuremath{\times} 1{0}^{\ensuremath{-} 4} $ induces the pair to move towards each other and approximately halves the time required for merger. Direct numerical simulation shows that the optimal three-dimensional perturbation can induce the vortex system to break up before merging occurs, since the two-dimensional nature of vortex merging is broken by the development of axially periodic perturbations.
Spatial modes of capillary jets, with application to surface stimulation
Authors: Guerrero J. , González H. , García F. J.
Published: May 2012

Surface stimulation of any physical origin (electrohydrodynamic, thermocapillary, etc.) has the goal of generating localized perturbations on the free surface or the velocity field of a capillary jet. Among these perturbations, only the axisymmetric ones are determinant for the jet breakup. Often, the stimulation is weak enough for a linear model to be applicable. Then, the stimulation can be described by means of the Green functions for stresses, both normal and tangential to the interface, the calculations of which are, in addition, uncoupled from the hydrodynamic variables. If a harmonic forcing is applied, these Green functions are combinations of the spatial modes whose associated poles lie inside the appropriate integration contour of the complex wavenumber plane. This is the motivation for a comprehensive enumeration and description of the spatial modes, which has not been done up to now. Modes familiar from a temporal analysis, the dominant and subdominant capillary modes and the hydrodynamic modes, are present, along with modes specific to a spatial analysis. Most of the latter have already been mentioned in the literature for inviscid jets, but not analysed. A mode not previously found is reported. In addition, a description of the velocity field associated with each mode is provided, as a tool to understand their physical origin and behaviour. The relative importance of each mode in both normal- and tangential-stress stimulations is discussed. Finally, the well-known merging of poles below a critical jet velocity, leading to absolute instability, is analysed in the light of the modal description.
Internationalisation with the use of Arctic indigeneity: the case of the Republic of Sakha (Yakutia), Russia
Authors: Maj Emilie
Published: May 2012

Over a period of 70 years, the lifestyles and belief systems of indigenous Siberian peoples were transformed by Soviet policy, based on the idea of assimilation and homogenisation of the peoples in its territory, in compliance with the idea of a ‘people's friendship’. The fall of the Soviet Union has given people the opportunity to rebuild their identity, as well as to provide a means of cultural revival for each ethnic community. The case study of the Republic of Sakha (Yakutia) in northern Siberia shows a new relationship, already started during perestroika and developing between the Russian Federation and its peoples. This relationship favours the development of each people's culture within the broader context of their integration into Russian society. The issue of the instrumentalisation of indigenous peoples’ cultural and religious heritage is part of a broader picture of a global affirmation of peoples’ indigenousness. The identification of ethnic Sakha (Yakuts) with other northern peoples is a means of entering the international political arena, pushing far away the geopolitical and cultural boundaries imposed by the Russian Federation and highlighting the idea of a circumpolar civilisation.
Highly skilled migration in the urban Arctic: a Norwegian case study on skilled migrant labour market integration
Authors: Fossland Trine Medby
Published: May 2012

Arctic Norway is a region with a shortage of highly skilled professionals and international expertise, in many work sectors. Fast growing cites attract people from other regions and also high skilled migrants. It is a paradox that skilled migrants often fail to get qualified work in the local labour market. To understand this and to capture the complexity of labour market participation, this article draws on interviews with recruitment agencies and highly skilled migrants, attending a recruitment programme initiated by the ‘Confederation of Norwegian Business and Industry in Norway’. This paper draws on recent literature on highly skilled migration and analyses the complex and relational sides of labour market integration for skilled migrants in an urban Arctic town.
Gibbs and equilibrium measures for some families of subshifts
Authors: MEYEROVITCH TOM
Published: May 2012

For subshifts of finite type (SFTs), any equilibrium measure is Gibbs, as long as$f$has$d$-summable variation. This is a theorem of Lanford and Ruelle. Conversely, a theorem of Dobrušin states that for strongly irreducible subshifts, shift-invariant Gibbs measures are equilibrium measures. Here we prove a generalization of the Lanford–Ruelle theorem: for all subshifts, any equilibrium measure for a function with$d$-summable variation is ‘topologically Gibbs’. This is a relaxed notion which coincides with the usual notion of a Gibbs measure for SFTs. In the second part of the paper, we study Gibbs and equilibrium measures for some interesting families of subshifts:$\beta $-shifts, Dyck shifts and Kalikow-type shifts (defined below). In all of these cases, a Lanford–Ruelle-type theorem holds. For each of these families, we provide a specific proof of the result.
Homoclinic points, atoral polynomials, and periodic points of algebraic -actions
Authors: LIND DOUGLAS , SCHMIDT KLAUS , VERBITSKIY EVGENY
Published: May 2012

Cyclic algebraic ${\mathbb {Z}^{d}}$-actions are defined by ideals of Laurent polynomials in $d$ commuting variables. Such an action is expansive precisely when the complex variety of the ideal is disjoint from the multiplicative $d$-torus. For such expansive actions it is known that the limit of the growth rate of periodic points exists and is equal to the entropy of the action. In an earlier paper the authors extended this result to ideals whose variety intersects the $d$-torus in a finite set. Here we further extend it to the case where the dimension of intersection of the variety with the $d$-torus is at most $d-2$. The main tool is the construction of homoclinic points which decay rapidly enough to be summable.