bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Input–Output Linearization Minimum Sliding Mode Error Feedback Control for Synchronization of FitzHugh–Nagumo Neurons
Authors: Cao Lu , Chen Xiaoqian
Published: November 2015

A novel input–output linearization minimum sliding mode error feedback control (I/OMSMEFC) is proposed for the synchronization between two uncoupled FitzHugh–Nagumo (FHN) neurons with different ionic currents and external electrical stimulations. To estimate and offset the system uncertainties and external disturbances, the concept of equivalent control error is introduced, which is the key to utilization of I/OMSMEFC. A cost function is formulated on the basis of the principle of minimum sliding mode covariance constraint; then the equivalent control error is estimated and fed back. It is shown that the proposed I/OMSMEFC can compensate various kinds of system uncertainties and external disturbances. Meanwhile, it can reduce the steady-state error more than the conventional sliding mode control (SMC). In addition, the sliding mode after the I/OMSMEFC will tend to be the ideal SMC, resulting in improved control performance and quantity. Sufficient conditions are given based on the Lyapunov stability theorem and numerical simulations are performed to verify the effectiveness of presented I/OMSMEFC for the chaotic synchronization accurately.
Microstructure and Mechanical Performance of Cold Metal Transfer Spot Joints of AA6061-T6 to Galvanized DP590 Using Edge Plug Welding Mode
Authors: Lei Haiyang , Li Yongbing , Carlson Blair E. , Lin Zhongqin
Published: November 2015

Dissimilar joining of aluminum to steel poses a challenge for arc welding. In this study, aluminum AA6061-T6 and hot dipped galvanized DP590 steel were joined using the Fronius cold metal transfer (CMT) welding process applying an edge plug welding mode (EPW). The correlation of the welding parameters, weld characteristics, and weld strength was systematically investigated. It was found that the EPW mode created a zinc-rich zone at the weld root along the Al–steel faying interface which transitioned to a continuous and compact intermetallic compounds (IMC) layer in the middle portion of the joint. The fracture propagation in lap-shear specimens was affected by this increase of IMC layer thickness. At a wire feed speed (wfs) of 5.6 m/min, the fracture initiated along the zinc-rich layer at the faying interface and then, upon meeting the compact IMC layer, propagated into the aluminum weld nugget. Propagation followed a path within the weld nugget along the boundary between columnar and equiaxed grains leading to weld nugget pullout upon fracture. For IMC layer peak thicknesses below 10 μm, the strength increased as a function of weld nugget diameter. However, larger heat inputs resulted in IMC layer thicknesses greater than 10 μm and interfacial fracture.
Modeling of Friction Self-Piercing Riveting of Aluminum to Magnesium
Authors: Ma YunWu , Li YongBing , Hu Wei , Lou Ming , Lin ZhongQin
Published: November 2015

In recent years, higher requirements on vehicle performance and emission have been posing great challenges to lightweighting of vehicle bodies. Mixed use of lightweight materials, e.g., aluminum alloys and magnesium alloys, is one of the essential methods for weight reduction. However, the joining of dissimilar materials brings about new challenges. Self-piercing riveting (SPR) is a feasible process to mechanically join dissimilar materials, however, when magnesium alloy sheet is put on the bottom layer, cracks occur inevitably due to the low ductility of the magnesium alloy. Friction self-piercing riveting (F-SPR) process is a newly proposed technology, which combines the SPR with friction stir spot welding (FSSW) and has been validated being capable of eliminating cracks and improving joint performance. However, in the F-SPR process, the generation of the transient friction heat and its effect on interaction between the rivet and the two sheets are still unclear. In this paper, a three-dimensional thermomechanical-coupled finite-element (FE) model of F-SPR process was developed using an ls-dyna code. Temperature-dependent material parameters were utilized to calculate the material yield and flow in the joint formation. Preset crack failure method was used to model the material failure of the top sheet. The calculated joint geometry exhibited a good agreement with the experimental measurement. Based on the validated model, the transient formation of F-SPR mechanical joint, stress distribution, and temperature evolution were further investigated.
Automatic Generation of Anisotropic Patterns of Geometric Features for Industrial Design
Authors: Andrade Diego , Vyas Ved , Shimada Kenji
Published: November 2015

While modern computer aided design (CAD) systems currently offer tools for generating simple patterns, such as uniformly spaced rectangular or radial patterns, these tools are limited in several ways: (1) They cannot be applied to free-form geometries used in industrial design, (2) patterning of these features happens within a single working plane and is not applicable to highly curved surfaces, and (3) created features lack anisotropy and spatial variations, such as changes in the size and orientation of geometric features within a given region. In this paper, we introduce a novel approach for creating anisotropic patterns of geometric features on free-form surfaces. Complex patterns are generated automatically, such that they conform to the boundary of any specified target region. Furthermore, user input of a small number of geometric features (called “seed features”) of desired size and orientation in preferred locations could be specified within the target domain. These geometric seed features are then transformed into tensors and used as boundary conditions to generate a Riemannian metric tensor field. A form of Laplace's heat equation is used to produce the field over the target domain, subject to specified boundary conditions. The field represents the anisotropic pattern of geometric features. This procedure is implemented as an add-on for a commercial CAD package to add geometric features to a target region of a three-dimensional model using two set operations: union and subtraction. This method facilitates the creation of a complex pattern of hundreds of geometric features in less than 5 min. All the features are accessible from the CAD system, and if required, they are manipulable individually by the user.
Designing and Harnessing the Metastable States of a Modular Metastructure for Programmable Mechanical Properties Adaptation
Authors: Harne R. L. , Wu Z. , Wang K. W.
Published: November 2015

Recent studies on periodic metamaterial systems have shown that remarkable properties adaptivity and versatility are often the products of exploiting internal, coexisting metastable states. Motivated by this concept, this research develops and explores a local-global design framework wherein macroscopic system-level properties are sought according to a strategic periodic constituent composition and assembly. To this end and taking inspiration from recent insights in studies of multiphase composite materials and cytoskeletal actin networks, this study develops adaptable metastable modules that are assembled into modular metastructures, such that the latter are invested with synergistic features due to the strategic module development and integration. Using this approach, it is seen that modularity creates an accessible pathway to exploit metastable states for programmable metastructure adaptivity, including a near-continuous variation of mechanical properties or stable topologies and adjustable hysteresis. A model is developed to understand the source of the synergistic characteristics, and theoretical findings are found to be in good agreement with experimental results. Important design-based questions are raised regarding the modular metastructure concept, and a genetic algorithm (GA) routine is developed to elucidate the sensitivities of the properties variation with respect to the statistics amongst assembled module design variables. To obtain target multifunctionality and adaptivity, the routine discovers that particular degrees and types of modular heterogeneity are required. Future realizations of modular metastructures are discussed to illustrate the extensibility of the design concept and broad application base.
Folding Behavior of a Foldable Prismatic Mast With Kresling Origami Pattern
Authors: Jianguo Cai , Xiaowei Deng , Yuting Zhang , Jian Feng , Ya Zhou
Published: November 2015

The folding behavior of a prismatic mast based on Kresling origami pattern is studied in this paper. The mast consists of identical triangles with cyclic symmetry. Bar stresses and necessary external nodal loads of the mast during the motion are studied analytically. The results show that the mechanical behaviors are different when the initial height of the mast is different. Then the numerical analysis is used to prove the accuracy of the analytical results. The influence of the geometry and the number of sides of the polygon on the folding behavior of the basic segment is also investigated. The folding process of the mast with multistories was discussed. The effect of the imperfection based on the eigenvalue buckling modes on the folding behavior is also studied. It can be found that when the number of sides of the polygon is small, the imperfection in the axial direction affects the energy seriously by changing the folding sequence of the mast. When the number of sides of the polygon is larger, the imperfection in the horizontal plane has significant effect on the folding pattern, which leads to the sudden change of energy curve.
Long-Term Extreme Load Prediction of Spar and Semisubmersible Floating Wind Turbines Using the Environmental Contour Method
Authors: Karmakar D. , Bagbanci Hasan , Guedes Soares C.
Published: November 2015

The prediction of extreme loads for the offshore floating wind turbine is analyzed based on the inverse reliability technique. The inverse reliability approach is in general used to establish the design levels associated with the specified probability of failure. The present study is performed using the environmental contour (EC) method to estimate the long-term joint probability distribution of extreme loads for different types of offshore floating wind turbines. The analysis is carried out in order to predict the out-of-plane bending moment (OoPBM) loads at the blade root and tower base moment (TBM) loads for a 5 MW offshore floating wind turbine of different floater configuration. The spar-type and semisubmersible type offshore floating wind turbines are considered for the analysis. The FAST code is used to simulate the wind conditions for various return periods and the design loads of various floating wind turbine configurations. The extreme and operation situation of the spar-type and semisubmersible type offshore floating wind turbine are analyzed using one-dimensional (1D) and two-dimensional (2D)-EC methods for different return periods. The study is useful to predict long-term design loads for offshore wind turbines without requiring excessive computational effort.
Single Degree-of-Freedom Rigidly Foldable Cut Origami Flashers
Authors: Lang Robert J. , Magleby Spencer , Howell Larry
Published: November 2015

We present the design for a family of deployable structures based on the origami flasher, which are rigidly foldable, i.e., foldable with revolute joints at the creases and planar rigid faces. By appropriate choice of sector angles and introduction of a cut, a single degree-of-freedom (DOF) mechanism is obtained. These structures may be used to realize highly compact deployable mechanisms.
Optimal Design of Cable-Driven Manipulators Using Particle Swarm Optimization
Authors: Bryson Joshua T. , Jin Xin , Agrawal Sunil K.
Published: November 2015

The design of cable-driven manipulators is complicated by the unidirectional nature of the cables, which results in extra actuators and limited workspaces. Furthermore, the particular arrangement of the cables and the geometry of the robot pose have a significant effect on the cable tension required to effect a desired joint torque. For a sufficiently complex robot, the identification of a satisfactory cable architecture can be difficult and can result in multiply redundant actuators and performance limitations based on workspace size and cable tensions. This work leverages previous research into the workspace analysis of cable systems combined with stochastic optimization to develop a generalized methodology for designing optimized cable routings for a given robot and desired task. A cable-driven robot leg performing a walking-gait motion is used as a motivating example to illustrate the methodology application. The components of the methodology are described, and the process is applied to the example problem. An optimal cable routing is identified, which provides the necessary controllable workspace to perform the desired task and enables the robot to perform that task with minimal cable tensions. A robot leg is constructed according to this routing and used to validate the theoretical model and to demonstrate the effectiveness of the resulting cable architecture.
Force Distribution With Pose-Dependent Force Boundaries for Redundantly Actuated Cable-Driven Parallel Robots
Authors: Yuan Han , Courteille Eric , Deblaise Dominique
Published: November 2015

This paper addresses the force distribution of redundantly actuated cable-driven parallel robots (CDPRs). A new and efficient method is proposed for the determination of the lower-boundary of cable forces, including the pose-dependent lower-boundaries. In addition, the effect of cable sag is considered in the calculation of the force distribution to improve the computational accuracy. Simulations are made on a 6DOF CDPR driven by eight cables to demonstrate the validity of the proposed method. Results indicate that the pose-dependent lower-boundary method is more efficient than the fixed lower-boundary method in terms of minimizing the motor size and reducing energy consumption.
Controlling the Movement of a TRR Spatial Chain With Coupled Six-Bar Function Generators for Biomimetic Motion
Authors: Plecnik Mark M. , Michael McCarthy J.
Published: November 2015

This paper describes a synthesis technique that constrains a spatial serial chain into a single degree-of-freedom mechanism using planar six-bar function generators. The synthesis process begins by specifying the target motion of a serial chain that is parameterized by time. The goal is to create a mechanism with a constant velocity rotary input that will achieve that motion. To do this, we solve the inverse kinematics equations to find functions of each serial joint angle with respect to time. Since a constant velocity input is desired, time is proportional to the angle of the input link, and each serial joint angle can be expressed as functions of the input angle. This poses a separate function generator problem to control each joint of the serial chain. Function generators are linkages that coordinate their input and output angles. Each function is synthesized using a technique that finds 11 position Stephenson II linkages, which are then packaged onto the serial chain. Using pulleys and the scaling capabilities of function generating linkages, the final device can be packaged compactly. We describe this synthesis procedure through the design of a biomimetic device for reproducing a flapping wing motion.
An Accelerated Method for Creep Prediction From Short Term Stress Relaxation Tests
Authors: Guo J. Q. , Li F. , Zheng X. T. , Shi H. C. , Meng W. Z.
Published: November 2015

With the development of ultrasupercritical power generation technology, creep strength of high-temperature materials should be considered for safety evaluation and engineering design. However, long-time creep testing should be conducted by traditional creep assessment methods. This paper established a high-efficient prediction method for steady creep strain rate and creep strength based on short-term relaxation tests. Equivalent stress relaxation time and equivalent stress relaxation rate were defined according to stress relaxation characteristics and the Maxwell equation. An accelerated creep prediction approach from short-term stress relaxation tests was proposed by defining the equivalent relaxation rate as the creep rate during the steady stage. Stress relaxation and creep tests using high-temperature material 1Cr10NiMoW2VNbN steel were performed to validate the proposed model. Results showed that the experimental data are in good agreement with those predicted solutions. This indicates that short-term stress relaxation tests can be used to predict long-term creep behavior conveniently and reliably, and the proposed method is suitable for creep strength design and creep life prediction of 9–12%Cr steel used in ultrasupercritical unit at 600 °C.
Effects of birth weight and growth on childhood wheezing disorders: findings from the Born in Bradford Cohort
Authors: Mebrahtu Teumzghi F , Feltbower Richard G , Parslow Roger C
Published: November 2015

Objectives

To examine the effects of birth weight and childhood growth on childhood wheezing disorders. We hypothesised that low birth weight and fast growth during early age would increase the risk of wheezing disorders.

Setting

Observational secondary analysis of data from the Born in Bradford cohort.

Participants

All children who were born at the Bradford Royal Infirmary hospital between March 2007 and December 2010 were eligible for the study. A total of 13 734 and 1598 children participated in the analyses of the effects of birth weight and growth on wheezing disorders, respectively.

Primary and secondary outcome measures

Wheezing disorders diagnosis (diagnosed as asthma or had wheezing symptom) during the ages of 0–7 years were the primary outcome measures. Diagnosis of asthma and occurrence of wheezing during the same period were secondary outcome measures. Birth weight was classified as normal (2.5–4.0 kg), low (<2.5 kg) and high (>4.0 kg). Growth mixture models were used to drive growth pattern outcomes which were classified as ‘normal’, ‘fast’ and ‘slow’ growth based on their velocities between birth and 36 months.

Results

The adjusted relative risks (RRs) of wheezing disorders diagnosis for the low and high birthweight children were 1.29 (95% CI 1.12 to 1.50; p=0.001) and 0.91 (95% CI 0.79 to 1.04; p=0.17), respectively. The adjusted RRs of wheezing disorders diagnosis were 1.30 (95% CI 0.56 to 3.06; p=0.54) and 0.60 (95% CI 0.16 to 2.18; p=0.44), respectively, for the ‘fast’ and ‘slow’ growth as compared with the ‘normal’ growth.

Conclusions

Low birth weight is associated with an increased risk of wheezing disorders; however, there is a weak evidence that suggests high birthweight children have a reduced risk in this birth cohort. Low birth weight coupled with a slower growth until 3 months and a sharp growth between 3 and 12 months has an increased risk of wheezing disorders diagnosis.
Effect of hemodynamics on outcome of subtotally occluded paraclinoid aneurysms after stent-assisted coil embolization
Authors: Liu Jian , Jing Linkai , Wang Chao , Paliwal Nikhil , Wang Shengzhang , Zhang Ying , Xiang Jianping , Siddiqui Adnan H , Meng Hui , Yang Xinjian
Published: November 2015

Background

Endovascular treatment of paraclinoid aneurysms is preferred in clinical practice. Flow alterations caused by stents and coils may affect treatment outcome.

Objective

To assess hemodynamic changes following stent-assisted coil embolization (SACE) in subtotally embolized paraclinoid aneurysms with residual necks that were predisposed to recanalization.

Methods

We studied 27 paraclinoid aneurysms (seven recanalized and 20 stable) treated with coils and Enterprise stents. Computational fluid dynamic simulations were performed on patient-specific aneurysm geometries using virtual stenting and porous media technology.

Results

After stent placement in 27 cases, aneurysm flow velocity decreased significantly, the reduction gradually increasing from the neck plane (11.9%), to the residual neck (12.3%), to the aneurysm dome (16.3%). Subsequent coil embolization was performed after stent placement and the hemodynamic factors decreased further and significantly at all aneurysm regions except the neck plane. In a comparison of recanalized and stable cases, univariate analysis showed no significant differences in any parameter before treatment. After stent-assisted coiling, only the reduction in area-averaged velocity at the neck plane differed significantly between recanalized (8.1%) and stable cases (20.5%) (p=0.016).

Conclusions

Aneurysm flow velocity can be significantly decreased by stent placement and coil embolization. However, hemodynamics at the aneurysm neck plane is less sensitive to coils. Significant reduction in flow velocity at the neck plane may be an important factor in preventing recanalization of paraclinoid aneurysms after subtotal SACE.
Investigation of NdxY0.25–xZr0.75O1.88 inert matrix fuel materials made by a co-precipitation synthetic route
Authors: Hayes John R. , Grosvenor Andrew P.
Published: November 2015

Yttria-stabilized zirconia (YSZ) is a material that is being considered for use as an inert matrix fuel in nuclear reactors, but a complete characterization of these materials is required for them to be licensed for use. A series of NdxY0.25–xZr0.75O1.88 materials have been synthesized using a co-precipitation method, and the thermal stability of these materials has been studied by annealing them at 1400 and 1500 °C. (Nd was used as surrogate for Am.) The long-range and local structures of the materials were characterized via powder X-ray diffraction, scanning electron microscopy, wavelength dispersive spectroscopy, and X-ray absorption spectroscopy at the Zr K- and Y K-edges. These results were compared with the previous characterization of Nd-YSZ materials synthesized using a ceramic method. The results indicated that the ordering in the local metal–oxygen polyhedral remains relatively unaffected by the synthetic method, but there was increased long-range disorder in the materials prepared by the co-precipitation method. Further, it was found that the materials produced by the co-precipitation method were unexpectedly unstable when annealed at high temperature. This study highlights the importance of determining the effect of synthetic method on material properties and demonstrates how the co-precipitation route could be used to produce inert matrix fuels.
Numerical study of an innovative fish ladder design for perched culverts
Authors: Duguay Jason M. , Lacey R.W. Jay
Published: November 2015

A fish ladder designed to facilitate fish passage at the outlet end of perched culverts is investigated with a 3D computational fluid dynamics model. The fish ladder consists of a series of alternating arch baffles with geometries providing options for fish passage over varying flow and debris conditions within the ladder. At high flows, the baffle’s protruding center arch increases pool depth, reducing the volumetric bulk turbulence of the pools and improving fish habitat. The arch baffle is compared to a standard baffle design currently in use and demonstrates potential advantages for fish passage. A recirculation zone of low velocity occupies a large volume of the pool believed to provide appropriate hydraulic habitat for resting and staging jump attempts upstream. This numerical study provides an acceptable design for future physical prototype testing in the laboratory or field to verify hydraulics and evaluate fish passage effectiveness.
Life cycle assessment of low-rise office building with different structure–envelope configurations
Authors: Alshamrani Othman Subhi
Published: November 2015

This paper presents life cycle assessment approach to study the impact of structure and envelope types on the energy consumption and environmental impact of an office building in New York City, USA. In addition, the future costs of environmental impact for various structure and envelope options are assessed according to the current practice and market price of CO2. Eight structure and envelope types for the low-rise office building are investigated, which include concrete and steel structures with various combinations of envelopes. The parameters such as life cycle energy use, global warming potential, and water, air and land emissions are analyzed. The energy simulation is performed by using eQUEST software while the environmental impact is assessed by using ATHENA® impact estimator. The building with concrete frame is proved to have lower environmental impact compared to that with steel frame. The precast concrete building is found to be the most economical alternative due to the minimal environmental impact cost. This study is expected to enable the decision makers and building owners to select the best alternative with respect to energy use, and environmental and economic constraints.
A simple semi-relativistic hypercentral constituent quark model for light baryons
Authors: Aslanzadeh M. , Rajabi A.A.
Published: November 2015

In this work, baryons as a three-body bound system have been investigated in a semi-relativistic approach. Our model, like all constituent quark models, contains a dominant SU(6)-invariant part accounting for the average multiplet energies, and a perturbative SU(6)-violating interaction for the splitting within the multiplets, a structure that is inspired by lattice QCD calculations. Introducing a spin-independent relativistic description for the SU(6)-invariant part of the spectrum, we presented the exact analytical solution of the three-particle Klein–Gordon equation, through which the average energy values of the nonstrange resonances are reproduced. To describe the hyperfine structure of the baryon, the splittings within the SU(6) multiplets are produced by the spin- and isospin-dependent SU(6)-violating interaction, which have been treated as perturbative terms. For the SU(6)-invariant potential, we have added a quadratic term to the popular “Coulombic-plus-linear” potential. The resulting description of the baryon spectrum is comparable with those obtained by other calculations and experimental spectrum.
Indirect reach of heavy MSSM Higgs bosons by precision measurements at future lepton colliders
Authors: Kakizaki Mitsuru , Kanemura Shinya , Kikuchi Mariko , Matsui Toshinori , Yokoya Hiroshi
Published: November 2015

In the Minimal Supersymmetric Standard Model (MSSM), the bottom Yukawa coupling of the Higgs boson can considerably deviate from its Standard Model prediction due to nondecoupling effects. We point out that the ratio of the Higgs boson decay branching fraction to a bottom quark pair and that to a W-boson pair from the same production channel is particularly sensitive to large additional MSSM Higgs boson mass regions at future electron–positron colliders. Based on this precision measurement, we explicitly show the indirect discovery reach of the additional Higgs bosons according to planned programs of the International Linear Collider.
Relativistic geometric quantum phases from the Lorentz symmetry violation effects in the CPT-even gauge sector of Standard Model Extension
Authors: Bakke K. , Belich H.
Published: November 2015

We discuss the appearance of geometric quantum phases for a Dirac neutral particle in the context of relativistic quantum mechanics based on possible scenarios of the Lorentz symmetry violation tensor background in the CPT-even gauge sector of Standard Model Extension. We assume that the Lorentz symmetry breaking is determined by a tensor background given by [Formula: see text], then, relativistic analogues of the Anandan quantum phase [J. Anandan, Phys. Lett. A 138, 347 (1989)] are obtained based on the parity-even and parity-odd sectors of the tensor [Formula: see text].
Multi-Stage Planning of Distribution Networks with Application of Multi-Objective Algorithm Accompanied by DEA Considering Economical, Environmental and Technical Improvements
Authors: Oskuee Mohammad Reza Jannati , Babazadeh Elnaz , Najafi-Ravadanegh Sajad , Pourmahmoud Jafar
Published: November 2015

The regards to widespread impact of distribution networks and ever increasing demand for electricity, some strategies must be devized in order to well operate the distribution networks. In this paper, to enhance the accountability of the power system and to improve the system performance parameters, simultaneous placement of renewable energy generation (REG) sources (e.g., wind, solar and dispatchable distributed generators (DGs)) and capacitors are investigated in a modified radial distribution network with considering ZIP loads. To enhance all network parameters simultaneously to the best possible condition multi-objective functions are proposed and solved using non-dominated sorting genetic algorithm (NSGA II). The employed objectives contain all economical, environmental and technical aspects of distribution network. One of the most important advantages of the proposed multi-objective formulation is that it obtains non-dominated solutions allowing the system operator (decision maker) to exercise his/her personal preference in selecting each of those solutions based on the operating conditions of the system and the costs. It is clear that the implementation of each non-dominated solution needs related costs according to the technology used and the system performance characteristics. However, there is a paucity of objective methodologies for ranking the obtained non-dominated solutions considering economical, environmental and technical aspects. So, in this paper, data envelopment analysis (DEA) is suggested for this purpose. In other words, in this paper, first NSGA II is applied to the siting and sizing problem, and then the obtained non-dominated solutions are prioritized by DEA. The significant advantage of using DEA is that there is no need to impose the decision maker’s idea into the model and ranking is done based on the efficiencies of the non-dominated solutions. The most efficient solution is the one which has improved network parameters considerably and has lowest costs. So, using DEA gives a realistic view of solutions and the provided results are for all, not for a specific decision maker. To validate the effectiveness of the proposed scheme, the simulations are carried out on a modified test case 33-bus radial distribution network.
Soft Core Processor Generated Based on the Machine Code of the Application
Authors: Ziebinski Adam , Swierc Stanwlaw
Published: November 2015

Currently embedded system designs aim to improve areas such as speed, energy efficiency and the cost of an application. Application-specific instruction set extensions on reconfigurable hardware provide such opportunities. The article presents a new approach for generating soft core processors that are optimized for specific tasks. In this work, we describe an automatic method for selecting custom instructions for generating software core processors that are based on the machine code of the application program. As the result, a soft core processor will contain the logic that is absolutely necessary. This solution requires fewer gates to be synthesized in the field programmable gate arrays (FPGA) and has a potential to increase the speed of the information processing that is performed by the system in the target FPGA. Experiments have confirmed the correct operation of the method that was used. After the reduction mechanism was enabled, the total number of slices blocks that were occupied decreased to 47% of its initial value in the best case for the Xilinx Spartan3 (xc3s200) and the maximum frequency increased approximately 44% in the best case for Xilinx Spartan6 (xc6slx4).
On Gromov’s conjecture for totally non-spin manifolds
Authors: Bolotov Dmitry , Dranishnikov Alexander
Published: November 2015

Gromov’s conjecture states that for a closed [Formula: see text]-manifold [Formula: see text] with positive scalar curvature, the macroscopic dimension of its universal covering [Formula: see text] satisfies the inequality [Formula: see text] [9]. We prove that for totally non-spin [Formula: see text]-manifolds, the inequality [Formula: see text] implies the inequality [Formula: see text]. This implication together with the main result of [6] allows us to prove Gromov’s conjecture for totally non-spin [Formula: see text]-manifolds whose fundamental group is a virtual duality group with [Formula: see text].

In the case of virtually abelian groups, we reduce Gromov’s conjecture for totally non-spin manifolds to the problem whether [Formula: see text]. This problem can be further reduced to the [Formula: see text]-stability conjecture for manifolds with free abelian fundamental groups.
Severity of Fetal Brain Abnormalities in Congenital Heart Disease in Relation to the Main Expected Pattern of in utero Brain Blood Supply
Authors: Masoller Narcís , Sanz-Cortés Magda , Crispi Fàtima , Gómez Olga , Bennasar Mar , Egaña-Ugrinovic Gabriela , Bargalló Núria , Martínez Josep María , Gratacós Eduard
Published: November 2015

Objectives: We evaluated the hypothesis that in fetuses with congenital heart disease (CHD) there is a correlation between the expected pattern of in utero brain blood supply and the severity of neurodevelopmental impairment. Methods: A total of 58 fetuses with CHD and 58 controls underwent a Doppler ultrasound and fetal MRI at 36-38 weeks. Fetuses with CHD were divided into two functional classes: class A with an expected severe reduction in oxygenated brain blood supply (left outflow tract obstruction and transposition of great vessels) and class B with theoretically near-normal or mildly impaired oxygenated brain blood supply (other CHD). Head biometry and cerebroplacental Doppler were assessed by ultrasound, and brain volumetry, cortical development and metabolism by MRI. Results: Both class A and B CHD fetuses had significant differences in head biometry, brain perfusion, cortical development and brain metabolism compared with controls. However, there was a significant linear tendency for head biometry, cerebral Doppler, volumes, cortical sulcation and metabolic ratios across the three clinical groups, with signs of more severe brain alterations in type A CHD fetuses. Conclusions: All fetuses with CHD showed significant brain developmental changes, but differences were more pronounced in CHD associated with an expected severe reduction in oxygenated blood supply to the brain.
Iron in Frontotemporal Lobar Degeneration: A New Subcortical Pathological Pathway?
Authors: Gazzina Stefano , Premi Enrico , Zanella Isabella , Biasiotto Giorgio , Archetti Silvana , Cosseddu Maura , Scarpini Elio , Galimberti Daniela , Serpente Maria , Gasparotti Roberto , Padovani Alessandro , Borroni Barbara
Published: November 2015

Introduction: Brain iron homeostasis dysregulation has been widely related to neurodegeneration. In particular, human haemochromatosis protein (HFE) is involved in iron metabolism, and HFE H63D polymorphism has been related to the risk of amyotrophic lateral sclerosis and Alzheimer's disease. Recently, iron accumulation in the basal ganglia of frontotemporal lobar degeneration (FTLD) patients has been described. Objective: To explore the relationship between HFE genetic variation and demographic, clinical and imaging characteristics in a large cohort of FTLD patients. Methods: A total of 110 FTLD patients underwent neuropsychological and imaging evaluation and blood sampling for HFE polymorphism determination. HFE H63D polymorphism was considered in the present study. Two imaging approaches were applied to evaluate the effect of HFE genetic variation on brain atrophy, namely voxel-based morphometry and region of interest-based probabilistic approach (SPM8; Wellcome Trust Centre for Neuroimaging). Results: FTLD patients carrying the D* genotype (H/D or D/D) showed greater atrophy in the basal ganglia, bilaterally, compared to H/H carriers (x, y, z: -22, -4, 0; T = 3.45; cluster size: 33 voxels, x, y, z: 24, 4, -2; T = 3.38; cluster size: 36 voxels). The former group had even more pronounced behavioural symptoms, as defined by the Frontal Behavioural Inventory total scores. Conclusions: Our data suggest that H63D polymorphism could represent a disease-modifying gene in FTLD, fostering iron deposition in the basal ganglia. This suggests a new possible mechanism of FTLD-associated neurodegeneration.
Evaluating the Ability of the Bedside Index for Severity of Acute Pancreatitis Score to Predict Severe Acute Pancreatitis: A Meta-Analysis
Authors: Yang Yu-Xia , Li Li
Published: November 2015

Objective: To evaluate the diagnostic performance of the bedside index for severity in acute pancreatitis (BISAP) score in predicting severe acute pancreatitis (SAP). Materials and Methods: A systematic search was conducted using PubMed, Cochrane library and EMBASE databases up to May 2014, and 9 related studies, including 1,972 subjects, were reviewed. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnosis of odds ratio (DOR) and hierarchic summary receiver-operating characteristic (HSROC) curves, as well as the area under the HSROC curve (AUC), were assessed using the HSROC and bivariate mixed effects models. Moreover, a subgroup analysis stratified by cutoff value was performed to measure the effect of the diagnostic threshold on the performance of the BISAP score. Finally, publication bias was assessed using Deeks' funnel plot asymmetry test. Statistical analyses were performed using the STATA 12.0 software. Results: The pooled sensitivity, specificity, PLR, NLR and DOR of the BISAP for predicting SAP were 64.82% (95% CI: 54.47-73.74%), 83.62% (95% CI: 70.03-91.77%), 3.96 (95% CI: 2.27-6.89), 0.42 (95% CI: 0.34-0.52) and 9.41 (95% CI: 5.38-16.45), respectively. The AUC was 0.77 (95% CI: 0.73-0.80). Moreover, the subgroup analysis results demonstrated that the BISAP cutoff point at 3 had a higher specificity and greater accuracy than at 2 to predict SAP. No significant publication bias was detected across the studies (p = 0.359). Conclusion: The BISAP score showed low sensitivity but high specificity for assessing the severity of acute pancreatitis.
Effects of FGFR Signaling on Cell Proliferation and Differentiation of Apert Dental Cells
Authors: Lu Changming , Huguley Samuel , Cui Chun , Cabaniss Lauren B. , Waite Peter D. , Sarver David M. , Mamaeva Olga A. , MacDougall Mary
Published: November 2015

The Apert syndrome is a rare congenital disorder most often arising from S252W or P253R mutations in fibroblast growth factor receptor (FGFR2). Numerous studies have focused on the regulatory role of Apert FGFR2 signaling in bone formation, whereas its functional role in tooth development is largely unknown. To investigate the role of FGFR signaling in cell proliferation and odontogenic differentiation of human dental cells in vitro, we isolated dental pulp and enamel organ epithelia (EOE) tissues from an Apert patient carrying the S252W FGFR2 mutation. Apert primary pulp and EOE cells were established and shown to exhibit normal morphology and express alkaline phosphatase under differentiation conditions. Similar to control cells, Apert dental pulp and EOE cells expressed all FGFRs, with highest levels of FGFR1 followed by FGFR2 and low levels of FGFR3 and FGFR4. However, Apert cells had increased cell growth compared with control cells. Distinct from previous findings in osteoblast cells, gain-of-function S252W FGFR2 mutation did not upregulate the expression of epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor (PDGFRα), but elevated extracellular signal-regulated kinase (ERK) signaling in cells after EGF stimulation. Unexpectedly, there was little effect of the S252W mutation on odontogenic gene expression in dental pulp and EOE cells. However, after inhibition of total FGFR signaling or ERK signaling, the expression of odontogenic genes was upregulated in both dental cell types, indicating the negative effect of whole FGFR signaling on odontogenic differentiation. This study provides novel insights on FGFR signaling and a common Apert FGFR2 mutation in the regulation of odontogenic differentiation of dental mesenchymal and epithelial cells.
Acquired Congenital Malalignment of the Great Toenails
Authors: Decker Ashley , Scher Richard K. , Avarbock Andrew
Published: November 2015

Congenital malalignment is the lateral deviation of the nail plate along the longitudinal axis due to the lateral rotation of the nail matrix. The nail plate grows out in ridges caused by repeated microtrauma to the nail. Common complications include onychomycosis, Pseudomonas infection and acute or chronic paronychia. Treatment options range from conservative management to surgical options including realignment and nail matrixectomy. Congenital malalignment usually presents in infancy or childhood, but we present two cases of acquired malalignment occurring in the teenage years.
Classification of Dopamine Receptor Genes in Vertebrates: Nine Subtypes in Osteichthyes
Authors: Yamamoto Kei , Fontaine Romain , Pasqualini Catherine , Vernier Philippe
Published: November 2015

Dopamine neurotransmission regulates various brain functions, and its regulatory roles are mediated by two families of G protein-coupled receptors: the D1 and D2 receptor families. In mammals, the D1 family comprises two receptor subtypes (D1 and D5), while the D2 family comprises three receptor subtypes (D2, D3 and D4). Phylogenetic analyses of dopamine receptor genes strongly suggest that the common ancestor of Osteichthyes (bony jawed vertebrates) possessed four subtypes in the D1 family and five subtypes in the D2 family. Mammals have secondarily lost almost half of the ancestral dopamine receptor genes, whereas nonmammalian species kept many of them. Although the mammalian situation is an exception among Osteichthyes, the current classification and characterization of dopamine receptors are based on mammalian features, which have led to confusion in the identification of dopamine receptor subtypes in nonmammalian species. Here we begin by reviewing the history of the discovery of dopamine receptors in vertebrates. The recent genome sequencing of coelacanth, gar and elephant shark led to the proposal of a refined scenario of evolution of dopamine receptor genes. We also discuss a current problem of nomenclature of dopamine receptors. Following the official nomenclature of mammalian dopamine receptors from D1 to D5, we propose to name newly identified receptor subtypes from D6 to D9 in order to facilitate the use of an identical name for orthologous genes among different species. To promote a nomenclature change which allows distinguishing the two dopamine receptor families, a nomenclature consortium is needed. This comparative perspective is crucial to correctly interpret data obtained in animal studies on dopamine-related brain disorders, and more fundamentally, to understand the characteristics of dopamine neurotransmission in vertebrates.
Gingipains: Critical Factors in the Development of Aspiration Pneumonia Caused by Porphyromonas gingivalis
Authors: Benedyk Małgorzata , Mydel Piotr Mateusz , Delaleu Nicolas , Płaza Karolina , Gawron Katarzyna , Milewska Aleksandra , Maresz Katarzyna , Koziel Joanna , Pyrc Krzysztof , Potempa Jan
Published: November 2015

Aspiration pneumonia is a life-threatening infectious disease often caused by oral anaerobic and periodontal pathogens such as Porphyromonas gingivalis. This organism produces proteolytic enzymes, known as gingipains, which manipulate innate immune responses and promote chronic inflammation. Here, we challenged mice with P. gingivalis W83 and examined the role of gingipains in bronchopneumonia, lung abscess formation, and inflammatory responses. Although gingipains were not required for P. gingivalis colonization and survival in the lungs, they were essential for manifestation of clinical symptoms and infection-related mortality. Pathologies caused by wild-type (WT) P. gingivalis W83, including hemorrhage, necrosis, and neutrophil infiltration, were absent from lungs infected with gingipain-null isogenic strains or WT bacteria preincubated with gingipain-specific inhibitors. Damage to lung tissue correlated with systemic inflammatory responses, as manifested by elevated levels of TNF, IL-6, IL-17, and C-reactive protein. These effects were unequivocally dependent on gingipain activity. Gingipain activity was also implicated in the observed increase in IL-17 in lung tissues. Furthermore, gingipains increased platelet counts in the blood and activated platelets in the lungs. Arginine-specific gingipains made a greater contribution to P. gingivalis-related morbidity and mortality than lysine-specific gingipains. Thus, inhibition of gingipain may be a useful adjunct treatment for P. gingivalis-mediated aspiration pneumonia.
Early Glucose Derangement Detected by Continuous Glucose Monitoring and Progression of Liver Fibrosis in Nonalcoholic Fatty Liver Disease: An Independent Predictive Factor?
Authors: Schiaffini Riccardo , Liccardo Daniela , Alisi Anna , Benevento Danila , Cappa Marco , Cianfarani Stefano , Nobili Valerio
Published: November 2015

Background: Glucose derangement has been reported to increase oxidative stress, one of the most important factors underlying the progression of hepatic fibrosis in adults with nonalcoholic fatty liver disease (NAFLD). To date, careful evaluation of the glucose profile in pediatric NAFLD has not been performed. Methods: A total of 30 severely obese children (15 males; mean age 12.87 ± 2.19 years) with biopsy-proven NAFLD were enrolled in this study from September to December 2013. All patients underwent anthropometric and laboratory evaluation, including the oral glucose tolerance test (OGTT) and continuous glucose monitoring (CGM). Results: Our study reveals some differences between OGTT and CGM in detecting NAFLD children with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). OGTT showed 2 (6.67%) patients with IFG and 1 (3.34%) with IGT, while CGM showed 5 (16.67%) patients with IFG and 6 (20%) with IGT. The daily blood glucose profile positively correlated with the baseline blood glucose (r = 0.39, p = 0.04) and the homeostatic model assessment (r = 0.56, p = 0.05). A positive correlation between hyperglycemia and liver fibrosis was found (r = 0.65, p < 0.05). Mean glucose values (F3-F4 group: 163.2 ± 35.92 mg/dl vs. F1 group: 136.58 ± 46.83 mg/dl and F2 group: 154.12 ± 22.51 mg/dl) and the difference between the minimum and maximum blood glucose levels (F3-F4 group: 110.21 ± 25.26 mg/dl vs. F1 group: 91.67 ± 15.97 mg/dl and F2 group: 92 ± 15.48 mg/dl) were significantly (p < 0.05) higher in the F3-F4 group compared to the F1 and F2 groups. Conclusion: Glucose profile derangement as detected by CGM is associated with the severity of hepatic fibrosis in children with NAFLD.
The Genetic and Environmental Factors Underlying Hypospadias
Authors: Bouty Aurore , Ayers Katie L. , Pask Andrew , Heloury Yves , Sinclair Andrew H.
Published: November 2015

Hypospadias results from a failure of urethral closure in the male phallus and affects 1 in 200-300 boys. It is thought to be due to a combination of genetic and environmental factors. The development of the penis progresses in 2 stages: an initial hormone-independent phase and a secondary hormone-dependent phase. Here, we review the molecular pathways that contribute to each of these stages, drawing on studies from both human and mouse models. Hypospadias can occur when normal development of the phallus is disrupted, and we provide evidence that mutations in genes underlying this developmental process are causative. Finally, we discuss the environmental factors that may contribute to hypospadias and their potential immediate and transgenerational epigenetic impacts.