bluuebunny/crossref_metadata_2025 huggingface dataset:
NEW VEHICLE DETECTION ALGORITHM USING SYMMETRY SEARCH AND GA-BASED SVM
Authors: TRUONG QUOC BAO , PHAM VAN HUY , LEE BYUNG RYONG
Published: March 2013

In this paper, we present a two-stage vision-based approach to detect front and rear vehicle views in road scene images. The first stage is hypothesis generation (HG), in which potential vehicles are hypothesized. During the HG step, we use a vertical, horizontal edge map, and different colors between road background and the lower part of vehicle to determine the bottom position of the vehicle. Next, we apply vertical symmetry axis detection into contour edge images to build the potential regions where vehicles may be presented. The second stage is hypothesis verification (HV). In this stage, all hypotheses are verified by Decision Tree (DT) training combined with a modified Genetic Algorithm (GA) to find the best features subset based on Haar-like feature extraction and an appropriate parameters set of Support Vector Machine for classification, which is robust for front and rear views of vehicle detection and recognition problems.
GIVING FUZZINESS TO SPATIAL CLUSTERS: A NEW INDEX FOR CHOOSING THE OPTIMAL NUMBER OF CLUSTERS
Authors: GREKOUSIS GEORGE
Published: March 2013

Choosing the optimal number of clusters is a key issue in cluster analysis. Especially when dealing with more spatial clustering, things tend to be more complicated. Cluster validation helps to determine the appropriate number of clusters present in a dataset. Furthermore, cluster validation evaluates and assesses the results of clustering algorithms. There are numerous methods and techniques for choosing the optimal number of clusters via crisp and fuzzy clustering. In this paper, we introduce a new index for fuzzy clustering to determine the optimal number of clusters. This index is not another metric for calculating compactness or separation among partitions. Instead, the index uses several existing indices to give a degree, or fuzziness, to the optimal number of clusters. In this way, not only do the objects in a fuzzy cluster get a membership value, but the number of clusters to be partitioned is given a value as well. The new index is used in the fuzzy c-means algorithm for the geodemographic segmentation of 285 postal codes.
CRITICAL HEEGAARD SURFACES OBTAINED BY SELF-AMALGAMATION
Authors: E QIANG , LEI FENGCHUN
Published: March 2013

Critical surfaces can be regarded as topological index 2 minimal surfaces which was introduced by David Bachman. In this paper, we give a sufficient condition and a necessary condition for self-amalgamated Heegaard surfaces to be critical.
GEOMETRICAL RAY-BUNDLE REVERBERATION MODELING
Authors: LEE KEUNHWA , CHU YOUNGMIN , SEONG WOOJAE
Published: March 2013

The classical ray approach for monostatic ocean boundary reverberation has been re-examined based on a geometrical ray-bundle concept. In this new formulation, the impulse response for the averaged scattering intensity is expressed by a simple function consisting of continuous ray-bundle quantities with respect to the time, and which can be regarded as a generalized function for ray-based reverberation in a boundary cell. To numerically evaluate this impulse response, a zeroth- and a first-order polynomial interpolation method are respectively applied to approximate the ray-bundle quantities. Then, the impulse function is reduced to the forms of the delta function and the rectangular function either with or without linear amplitude modulation linear in time. These basic functions are used to develop an explicit numerical scheme for the monostatic reverberation, which originates in the split-step marching algorithm for the range. This numerical scheme provides a considerable accuracy even with larger range steps and gives reasonable results for numerical examples of ocean waveguides with isovelocity, summer, and winter sound-speed profiles.
OPERATOR CALCULUS AND INVERTIBLE CLIFFORD APPELL SYSTEMS: THEORY AND APPLICATION TO THE n-PARTICLE FERMION ALGEBRA
Authors: SCHOTT RENÉ , STAPLES G. STACEY
Published: March 2013

Motivated by evolution equations on Clifford algebras and illustrated with the n-particle fermion algebra, a theory of invertible left- and right-Appell systems is developed for Clifford algebras of an arbitrary quadratic form. This work extends and clarifies the authors' earlier work on Clifford Appell systems, operator calculus, and operator homology/cohomology. A direct connection is also shown between blade factorization algorithms and the construction of Appell systems in these algebras.
ESTIMATES FOR EIGENVALUES OF $\mathfrak L$ OPERATOR ON SELF-SHRINKERS
Authors: CHENG QING-MING , PENG YEJUAN
Published: March 2013

In this paper, we study eigenvalues of the closed eigenvalue problem of the differential operator [Formula: see text], which is introduced by Colding and Minicozzi in [Generic mean curvature flow I; generic singularities, Ann. Math.175 (2012) 755–833], on an n-dimensional compact self-shrinker in R n+p. Estimates for eigenvalues of the differential operator [Formula: see text] are obtained. Our estimates for eigenvalues of the differential operator [Formula: see text] are sharp. Furthermore, we also study the Dirichlet eigenvalue problem of the differential operator [Formula: see text] on a bounded domain with a piecewise smooth boundary in an n-dimensional complete self-shrinker in R n+p. For Euclidean space R n, the differential operator [Formula: see text] becomes the Ornstein–Uhlenbeck operator in stochastic analysis. Hence, we also give estimates for eigenvalues of the Ornstein–Uhlenbeck operator.
STATIC FERROMAGNETIC MATERIALS: FROM THE MICROSCOPIC TO THE MESOSCOPIC SCALE
Authors: BIDÉGARAY-FESQUET BRIGITTE , JOUET QUENTIN , LABBÉ STÉPHANE
Published: March 2013

Thanks to averaging processes and Γ-convergence techniques, we are able to link a microscopic description of ferromagnetic materials based on spin lattices and their mesoscopic description in the static framework for the three fundamental contributions: exchange, magnetostatics and external. The results are in accordance with the classical continuous description of ferromagnetic phenomena and justifies it. This work is a seed towards a dynamic description of ferromagnetic materials.
T-DUALITY AND DIFFERENTIAL K-THEORY
Authors: KAHLE ALEXANDER , VALENTINO ALESSANDRO
Published: March 2013

We give a precise formulation of T-duality for Ramond–Ramond fields. This gives a canonical isomorphism between the "geometrically invariant" subgroups of the twisted differentialK-theory groups associated to certain principal torus bundles. Our result combines topological T-duality with the Buscher rules found in physics.
DEFORMATIONS OF LEVI FLAT STRUCTURES IN SMOOTH MANIFOLDS
Authors: DE BARTOLOMEIS PAOLO , IORDAN ANDREI
Published: March 2013

We study intrinsic deformations of Levi flat structures on a smooth manifold. A Levi flat structure on a smooth manifold L is a couple (ξ, J) where ξ ⊂ T(L) is an integrable distribution of codimension 1 and J : ξ → ξ is a bundle automorphism which defines a complex integrable structure on each leaf. A deformation of a Levi flat structure (ξ, J) is a smooth family {(ξt, Jt)}t∈]-ε,ε[ of Levi flat structures on L such that (ξ0, J0) = (ξ, J). We define a complex whose cohomology group of order 1 contains the infinitesimal deformations of a Levi flat structure. In the case of real analytic Levi flat structures, this cohomology group is [Formula: see text] where (𝒵*(L), δ, {⋅,⋅}) is the differential graded Lie algebra associated to ξ.
CIRCULAR ARC SEGMENTATION BY CURVATURE ESTIMATION AND GEOMETRIC VALIDATION
Authors: PAL SHYAMOSREE , DUTTA RAHUL , BHOWMICK PARTHA
Published: March 2013

A novel algorithm to detect circular arcs from a digital image is proposed. The algorithm is based on discrete curvature estimated for the constituent points of digital curve segments, followed by a fast geometric analysis. The curvature information is used in the initial stage to find the potentially circular segments. In the final stage, the circular arcs are merged and maximized in length using the radius and center information of the potentially circular segments. Triplets of longer segments are given higher priorities; doublets and singleton arcs are processed at the end. Detailed experimental results on benchmark datasets demonstrate its efficiency and robustness.
A MUTATION PARTICLE SWARM OPTIMIZATION ALGORITHM FOR MULTILAYER PERCEPTRON TRAINING WITH APPLICATIONS
Authors: CHEN ZENGHAI , WU JING , CHI ZHERU
Published: March 2013

Particle swarm optimization (PSO), a prevalent optimization algorithm, has been successfully applied to various fields of science and engineering. However, PSO still suffers from some problems such as premature convergence. To solve these problems, we propose a mutation PSO (MPSO) in this paper. Compared with the traditional PSO, there are two main improvements of the proposed MPSO. First, a new particle update rule is explored. The new rule updates a particle's position according to not only its best known position and the global best known position of the swarm, but also a number of other particles' best known positions. The second improvement is that a mutation operator is employed. Mutation operator is used to avoid premature convergence. The MPSO is utilized to train a multilayer perceptron (MLP). The MLP trained by MPSO is finally applied to two classification problems: Iris flower classification and scene classification. For comparison purposes, traditional PSO, genetic algorithm (GA), and back-propagation (BP) are also investigated. Experimental results demonstrate the superior performance of the proposed MPSO for MLP training.
LIFE CYCLE ASSESSMENT (LCA) AND ENVIRONMENTAL PRODUCT DECLARATION (EPD) OF AN IMMUNOLOGICAL PRODUCT FOR BOAR TAINT CONTROL IN MALE PIGS
Authors: DE MORAES PAULO J. U. , ALLISON JIM , ROBINSON JOSEPH A. , BALDO GIAN LUCA , BOERI FABRIZIO , BORLA PAOLA
Published: March 2013

Recently, a leading manufacturer of veterinary medicines applied the LCA approach to the production and use of an immunological product for male pigs for the reduction of boar taint. The LCA study involved the facilities where the immunological product is manufactured, a sample at global level of farms where it is used and where the standard method of physical castration for boar taint reduction is adopted to define a benchmark and, finally, a sample of abbattoirs where the final product (pork) is produced for human consumption. The analysis was carried out for two doses of immunological product that is necessary to reduce boar taint in the male pig and, additionally, for the unit mass of pig (so called "live-weight), pig carcass and boneless/fatless pork meat (so called "lean meat"). The saving of carbon footprint respect to the physically castrated pig system is 3.7% in terms of kg live-weight. All the other life-cycle impact indicators show a reduction relative to the benchmark system (physical castration) as well. Scope of this paper is to present the results of this LCA study; complete results are also reported in the publicly available Environmental Product Declaration ( http://www.environdec.com )
AN INTEGRATED FRAMEWORK FOR INFORMING COASTAL AND MARINE ECOSYSTEM MANAGEMENT DECISIONS
Authors: REITER MICHAEL A. , MATLOCK GARY C. , GENTILE JOHN H. , HARWELL MARK A. , KELTY RUTH , BARKO JOHN W. , BAKER SUSAN , SCOTT GEOFF
Published: March 2013

Ecosystem management requires understanding society's goals for an ecosystem and managing for some optimal solution. Unlike terrestrial ecosystem managers, coastal and marine ecosystem management seldom integrates across sectors or scientific disciplines to achieve desired social benefits. An Integrated Ecosystem Assessment (IEA) considers the ecosystem (including humans) as a unit and can assist in setting goals, determining an ecosystem's ability to support ecological processes and society's desires, and predicting the outcome of alternatives. The use of Coupled Ecological-Societal Systems Models utilised within the Integrated Assessment and Ecosystem Management Protocol (IAEMP) allows managers to extend a graphical picture of risk hypotheses to forecast scenarios that can be analysed relative to management goals. Scenarios predicted to meet management goals are evaluated against management constraints to select the "optimal" option for a management action in an adaptive management process. The IAEMP thus helps characterise potential causes of environmental problems, select appropriate response options, and implement and evaluate the selected option, thereby either addressing the concern or improving the ecosystem model for future decisions.
DETERMINATION OF AMINOGLYCOSIDE ANTIBIOTICS BY A COLORIMETRIC METHOD BASED ON THE AGGREGATION OF GOLD NANOPARTICLES
Authors: WANG RUIYONG , FAN SHUMIN , WANG RUIQIANG , WANG RUI , DOU HUANJING , WANG LVJING
Published: March 2013

A sensitive and selective colorimetric biosensor for determination of gentamicin, amikacin and tobramycin was proposed with the unmodified gold nanoparticles (GNPs) as the sensing element. Gentamicin, amikacin and tobramycin can rapidly induce the aggregation of gold nanoparticles and is accompanied by a color change from red to blue. The concentration of gentamicin, amikacin and tobramycin can be determined by using UV-Vis spectrometer. The experimental parameters were optimized with regard to pH, incubation time and the concentration of the GNPs. Under optimal experimental conditions, the linear range of the colorimetric sensor for gentamicin/amikacin/tobramycin were 2.67–33.93 ng mL-1, 13.33–66.67 ng mL-1 and 20–180 ng mL-1, respectively. The corresponding limit of detection (3σ) was 0.354 ng mL-1, 0.999 ng mL-1 and 0.579 ng mL-1, respectively. This assay was simple and used to detect aminoglycoside antibiotics in milk and medicine products.
PHYSICAL PROPERTIES AND MICROSTRUCTURE PERFORMANCE OF LASER ALLOYING Zn MODIFIED AMORPHOUS-NANOCRYSTALS REINFORCED COATING
Authors: LI JIANQUAN , LIU HUASHI , LI JIANING , LI GUOZHONG
Published: March 2013

Zn was firstly used to improve wear resistance of a TA7 (Ti–5Al–2.5Sn) titanium alloy surface by mean of a laser alloying (LA) technique. The synthesis of the hard coating on a TA7 titanium alloy by LA of Co–Ti–Cr–TiB2–Zn–CeO2 pre-placed powders was investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). Experimental results indicated lot of the nanocrystals, such as Ti–B/CoZn13 and the amorphous phases were produced in such LA coating. The nucleation and growth of the amorphous phases were retarded by the nanocrystals in a certain extent during the crystallization process of the amorphous phases. Compared with a TA7 alloy substrate, an improvement of the wear resistance was obtained for such LA composite coating.
SYNTHESIS, PHASE TRANSFER AND SURFACE MODIFICATION OF HYDROPHOBIC QUANTUM DOTS FOR BIOAPPLICATIONS
Authors: ZHANG RUILI , ZHANG XIAO , LI XIAOYU , YANG PING
Published: March 2013

We review the preparation, phase transfer, surface modification and possible bioapplications of hydrophobic CdSe based quantum dots (QDs). CdSe cores with rod and spherical morphologies were prepared through adjusting preparation conditions. The photoluminescence (PL) of the QDs depended strongly on preparation conditions. The QDs were coated with semiconductor shells to improve their PL properties. Anisotropic growth occurred during shell coating. Core/shell QDs revealed tunable PL and high PL efficiencies up to 90%. The phase transfer of QDs from oil phase to water phase was carried out via polymer or a sol–gel process. The silanization of the QDs plays an important role for the sol–gel process. Because of a SiO2 coating, the surface modification of the QDs for bioapplications became easy. After transferring into water phase, the QDs still retained high PL efficiency. Because of their high PL, these biofunctional materials could provide a platform for various applications.
TRANSPORT PROPERTIES IN MISFIT-LAYERED Ca2Co2O5 COMPOUND
Authors: LAN JINLE , ZHAN BIN , LIN YUAN-HUA , NAN CE-WEN , LIU YAO-CHUN
Published: March 2013

The low temperature transport and magnetic properties were investigated in the misfit-layered Ca 2 Co 2 O 5 compound. The compound exhibits incommensurate spin-density-wave (SDW) state in the dχ-1/dT curve at 20 K, which is confirmed by the resistivity (ρ) characterization. The resistivity shows an upturn from metallic to insulating behavior at TM-I (130 K) and strong Fermi liquid behaviors with ρ ~ T2 relation between TM-I and T*(225 K ). The Seebeck coefficient shows abnormal temperature dependence at Tp (40 K), which is suggested to origin from the long order of atomic in [ Ca 2 CoO 3] sublayer and spin fluctuation of Co ions. Moreover, large Seebeck coefficient (120 μV/K) and low thermal conductivity (2.5 W/mK) were obtained at room temperature, indicating that it is a promising p-type thermoelectric material for energy conversion.
TUNABLE COMPLEMENT ACTIVATION BY PARTICLES WITH VARIABLE SIZE AND Fc DENSITY
Authors: PACHECO PATRICIA M. , LE BENJAMIN , WHITE DAVID , SULCHEK TODD
Published: March 2013

The complement system is an integral innate immune component that is made up of a cascade of enzymatic proteins that, once activated, results in lysis of invading pathogens, opsonization or recruitment of other innate and/or acquired immune responders, or some combination of the three. Due to the importance of the signal amplification and control points present in the cascade, complement is highly sensitive to subtle variations in initiation conditions, including nanoscale changes to molecular spacing. Using Fc-functionalized microparticles and nanoparticles, we find that activation requires a minimum threshold surface concentration of Fc of at least 20% surface coverage. This result indicates that a high surface density Fc is necessary for micro/nanoparticle complement activation through the classical pathway. In addition, the magnitude of the response was dependent on the size of the particle, with larger particles causing decreased activation. We hypothesize that a high density of Fc is needed to efficiently bind and closely appose molecular initiators of the complement cascade, from initiation to terminal complement complex formation. These fundamental studies of the interaction of microparticles and nanoparticles with the immune system suggest design rules for particle size and molecular density that impact immunostimulation through the complement system. Providing a therapeutic agent to modulate the complement response could aid a variety of treatment strategies. Engineered nanoparticles with controlled gaps between molecular activators could lead to new types of immunomodulatory agents.
The autonomic nervous system regulates postprandial hepatic lipid metabolism
Authors: Bruinstroop Eveline , la Fleur Susanne E. , Ackermans Mariette T. , Foppen Ewout , Wortel Joke , Kooijman Sander , Berbée Jimmy F. P. , Rensen Patrick C. N. , Fliers Eric , Kalsbeek Andries
Published: March 2013

The liver is a key organ in controlling glucose and lipid metabolism during feeding and fasting. In addition to hormones and nutrients, inputs from the autonomic nervous system are also involved in fine-tuning hepatic metabolic regulation. Previously, we have shown in rats that during fasting an intact sympathetic innervation of the liver is essential to maintain the secretion of triglycerides by the liver. In the current study, we hypothesized that in the postprandial condition the parasympathetic input to the liver inhibits hepatic VLDL-TG secretion. To test our hypothesis, we determined the effect of selective surgical hepatic denervations on triglyceride metabolism after a meal in male Wistar rats. We report that postprandial plasma triglyceride concentrations were significantly elevated in parasympathetically denervated rats compared with control rats ( P = 0.008), and VLDL-TG production tended to be increased ( P = 0.066). Sympathetically denervated rats also showed a small rise in postprandial triglyceride concentrations ( P = 0.045). On the other hand, in rats fed on a six-meals-a-day schedule for several weeks, a parasympathetic denervation resulted in >70% higher plasma triglycerides during the day ( P = 0.001), whereas a sympathetic denervation had no effect. Our results show that abolishing the parasympathetic input to the liver results in increased plasma triglyceride levels during postprandial conditions.
Aging accentuates alcohol-induced decrease in protein synthesis in gastrocnemius
Authors: Korzick Donna H. , Sharda Daniel R. , Pruznak Anne M. , Lang Charles H.
Published: March 2013

The present study sought to determine whether the protein catabolic response in skeletal muscle produced by chronic alcohol feeding was exaggerated in aged rats. Adult (3 mo) and aged (18 mo) female F344 rats were fed a nutritionally complete liquid diet containing alcohol (36% of total calories) or an isocaloric isonitrogenous control diet for 20 wk. Muscle (gastrocnemius) protein synthesis, as well as mTOR and proteasome activity did not differ between control-fed adult and aged rats, despite the increased TNF-α and IL-6 mRNA and decreased IGF-I mRNA in muscle of aged rats. Compared with alcohol-fed adult rats, aged rats demonstrated an exaggerated alcohol-induced reduction in lean body mass and protein synthesis (both sarcoplasmic and myofibrillar) in gastrocnemius. Alcohol-fed aged rats had enhanced dephosphorylation of 4E-BP1, as well as enhanced binding of raptor with both mTOR and Deptor, and a decreased binding of raptor with 4E-BP1. Alcohol feeding of both adult and aged rats reduced RagA binding to raptor. The LKB1-AMPK-REDD1 pathway was upregulated in gastrocnemius from alcohol-fed aged rats. These exaggerated alcohol-induced effects in aged rats were associated with a greater decrease in muscle but not circulating IGF-I, but no further increase in inflammatory mediators. In contrast, alcohol did not exaggerate the age-induced increase in atrogin-1 and MuRF1 mRNA or the increased proteasome activity. Our results demonstrate that, compared with adult rats, the gastrocnemius from aged rats is more sensitive to the catabolic effects of alcohol on protein synthesis, but not protein degradation, and this exaggerated response may be AMPK-dependent.
Bladder outlet obstruction triggers neural plasticity in sensory pathways and contributes to impaired sensitivity in erectile dysfunction
Authors: Malykhina Anna P. , Lei Qi , Chang Shaohua , Pan Xiao-Qing , Villamor Antonio N. , Smith Ariana L. , Seftel Allen D.
Published: March 2013

Lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) are common problems in aging males worldwide. The objective of this work was to evaluate the effects of bladder neck nerve damage induced by partial bladder outlet obstruction (PBOO) on sensory innervation of the corpus cavernosum (CC) and CC smooth muscle (CCSM) using a rat model of PBOO induced by a partial ligation of the bladder neck. Retrograde labeling technique was used to label dorsal root ganglion (DRG) neurons that innervate the urinary bladder and CC. Contractility and relaxation of the CCSM was studied in vitro, and expression of nitric oxide synthase (NOS) was evaluated by Western blotting. Concentration of the sensory neuropeptides substance P (SP) and calcitonin gene-related peptide was measured by ELISA. Partial obstruction of the bladder neck caused a significant hypertrophy of the urinary bladders (2.5-fold increase at 2 wk). Analysis of L6-S2 DRG sections determined that sensory ganglia received input from both the urinary bladder and CC with 5–7% of all neurons double labeled from both organs. The contractile responses of CC muscle strips to KCl and phenylephrine were decreased after PBOO, followed by a reduced relaxation response to nitroprusside. A significant decrease in neuronal NOS expression, but not in endothelial NOS or protein kinase G (PKG-1), was detected in the CCSM of the obstructed animals. Additionally, PBOO caused some impairment to sensory nerves as evidenced by a fivefold downregulation of SP in the CC ( P ≤ 0.001). Our results provide evidence that PBOO leads to the impairment of bladder neck afferent innervation followed by a decrease in CCSM relaxation, downregulation of nNOS expression, and reduced content of sensory neuropeptides in the CC smooth muscle. These results suggest that nerve damage in PBOO may contribute to LUTS-ED comorbidity and trigger secondary changes in the contraction/relaxation mechanisms of CCSM.
Proximal pulmonary arterial obstruction decreases the time constant of the pulmonary circulation and increases right ventricular afterload
Authors: Pagnamenta Alberto , Vanderpool Rebecca , Brimioulle Serge , Naeije Robert
Published: March 2013

The time constant of the pulmonary circulation, or product of pulmonary vascular resistance (PVR) and compliance (Ca), called the RC-time, has been reported to remain constant over a wide range of pressures, etiologies of pulmonary hypertension, and treatments. We wondered if increased wave reflection on proximal pulmonary vascular obstruction, like in operable chronic thromboembolic pulmonary hypertension, might also decrease the RC-time and thereby increase pulse pressure and right ventricular afterload. Pulmonary hypertension of variable severity was induced either by proximal obstruction (pulmonary arterial ensnarement) or distal obstruction (microembolism) eight anesthetized dogs. Pulmonary arterial pressures (Ppa) were measured with high-fidelity micromanometer-tipped catheters, and pulmonary flow with transonic technology. Pulmonary ensnarement increased mean Ppa, PVR, and characteristic impedance, decreased Ca and the RC-time (from 0.46 ± 0.07 to 0.30 ± 0.03 s), and increased the oscillatory component of hydraulic load (Wosc/Wtot) from 25 ± 2 to 29 ± 2%. Pulmonary microembolism increased mean Ppa and PVR, with no significant change in Ca and characteristic impedance, increased RC-time from 0.53 ± 0.09 to 0.74 ± 0.05 s, and decreased Wosc/Wtot from 26 ± 2 to 13 ± 2%. Pulse pressure increased more after pulmonary ensnarement than after microembolism. Concomitant measurements with fluid-filled catheters showed the same functional differences between the two types of pulmonary hypertension, with, however, an underestimation of Wosc. We conclude that pulmonary hypertension caused by proximal vs. distal obstruction is associated with a decreased RC-time and increased pulsatile component of right ventricular hydraulic load.
Interaction between cognitive and motor cortico-basal ganglia loops during decision making: a computational study
Authors: Guthrie M. , Leblois A. , Garenne A. , Boraud T.
Published: March 2013

In a previous modeling study, Leblois et al. (2006) demonstrated an action selection mechanism in cortico-basal ganglia loops based on competition between the positive feedback, direct pathway through the striatum and the negative feedback, hyperdirect pathway through the subthalamic nucleus. The present study investigates how multiple level action selection could be performed by the basal ganglia. To do this, the model is extended in a manner consistent with known anatomy and electrophysiology in three main areas. First, two-level decision making has been incorporated, with a cognitive level selecting based on cue shape and a motor level selecting based on cue position. We show that the decision made at the cognitive level can be used to bias the decision at the motor level. We then demonstrate that, for accurate transmission of information between decision-making levels, low excitability of striatal projection neurons is necessary, a generally observed electrophysiological finding. Second, instead of providing a biasing signal between cue choices as an external input to the network, we show that the action selection process can be driven by reasonable levels of noise. Finally, we incorporate dopamine modulated learning at corticostriatal synapses. As learning progresses, the action selection becomes based on learned visual cue values and is not interfered with by the noise that was necessary before learning.
Short- and long-latency interhemispheric inhibitions are additive in human motor cortex
Authors: Ghosh Soumya , Mehta Arpan R. , Huang Guan , Gunraj Carolyn , Hoque Tasnuva , Saha Utpal , Ni Zhen , Chen Robert
Published: March 2013

Transcranial magnetic stimulation (TMS) of the human primary motor cortex (M1) at suprathreshold strength results in inhibition of M1 in the opposite hemisphere, a process termed interhemispheric inhibition (IHI). Two phases of IHI, termed short-latency interhemispheric inhibition (SIHI) and long-latency interhemispheric inhibition (LIHI), involving separate neural circuits, have been identified. In this study we evaluated how these two inhibitory processes interact with each other. We studied 10 healthy right-handed subjects. A test stimulus (TS) was delivered to the left M1, and motor evoked potentials (MEPs) were recorded from the right first dorsal interosseous (FDI) muscle. Contralateral conditioning stimuli (CCS) were applied to the right M1 either 10 ms or 50 ms prior to the TS, inducing SIHI and LIHI, respectively, in the left M1. The effects of SIHI and LIHI alone, and SIHI and LIHI delivered together, were compared. The TS was adjusted to produce 1-mV or 0.5-mV MEPs when applied alone or after CCS. SIHI and LIHI were found to be additive when delivered together, irrespective of the strength of the TS. The interactions were affected neither by varying the strength of the conditioning stimulus producing SIHI nor by altering the current direction of the TS. Small or opposing interactions, however, may not have been detected. These results support previous findings suggesting that SIHI and LIHI act through different neural circuits. Such inhibitory processes may be used individually or additively during motor tasks and should be studied as separate processes in functional studies.
Tuberculous Pyomyositis: A Rare but Serious Diagnosis
Authors: Krishnasamy Vikram , Joseph Matthew
Published: March 2013

Tuberculous pyomyositis is a rare clinical entity with serious consequences if a diagnosis is not established early. A 53-year-old female with a past medical history of sarcoidosis and pulmonary fibrosis presented from an outside hospital with persistent fevers and a rash. She had been hospitalized multiple times at an outside hospital without any improvement in her symptoms. On examination, she was noted to have a large area of left upper lower extremity (LUE) tenderness with superimposed erythema. Laboratory data revealed a white blood cell count of 22,300. Computed tomography (CT) scans of the LUE, chest, and left lower extremity (LLE) showed multiple intramuscular abscesses in those regions without evidence of osteomyelitis. Subsequent drainage of the abscesses and resulting cultures revealedMycobacterium tuberculosis. The patient was started on therapy with rifampin, isoniazid, pyrazinamide, and ethambutol. However, the patient developed hepatitis on these agents and subsequently went into septic shock with multiorgan failure. Care was eventually withdrawn as a result of a poor prognosis. This case illustrates the severe consequences of TB pyomyositis if not diagnosed promptly. While tuberculosis is uncommon in the United States, it should be an important consideration in the differential diagnosis of immunocompromised patients.
Hybrid Multiphase CFD Solver for Coupled Dispersed/Segregated Flows in Liquid-Liquid Extraction
Authors: Wardle Kent E. , Weller Henry G.
Published: March 2013

The flows in stage-wise liquid-liquid extraction devices include both phase segregated and dispersed flow regimes. As a additional layer of complexity, for extraction equipment such as the annular centrifugal contactor, free-surface flows also play a critical role in both the mixing and separation regions of the device and cannot be neglected. Traditionally, computional fluid dynamics (CFD) of multiphase systems is regime dependent—different methods are used for segregated and dispersed flows. A hybrid multiphase method based on the combination of an Eulerian multifluid solution framework (per-phase momentum equations) and sharp interface capturing using Volume of Fluid (VOF) on selected phase pairs has been developed using the open-source CFD toolkit OpenFOAM. Demonstration of the solver capability is presented through various examples relevant to liquid-liquid extraction device flows including three-phase, liquid-liquid-air simulations in which a sharp interface is maintained between each liquid and air, but dispersed phase modeling is used for the liquid-liquid interactions.
Fast Far Field Computation of Single and Dual Reflector Antennas
Authors: Arias-Acuña Marcos , García-Pino Antonio , Rubiños-López Oscar
Published: March 2013

The physical optics (PO) method has been widely used for the analysis of the electromagnetic behavior of single and dual reflector antennas. An extensive work has been done by the authors of this paper in order to increase the speed for obtaining far field patterns from single and dual geometries and also in order to increase the accuracy of the method. This paper reviews these contributions and improves the existing published work with the physical interpretation of the radiation from a single patch and the computer implications when using acceleration techniques such as OpenMP.
Rapid, Low-Cost, and Ecofriendly Approach for Iron Nanoparticle Synthesis Using Aspergillus oryzae TFR9
Authors: Tarafdar Jagadish Chandra , Raliya Ramesh
Published: March 2013

Development of reliable and ecofriendly green approach for synthesis of metallic nanoparticles biologically is an important step in the field of application of nanoscience and nanotechnology. The present paper reports the green approach for iron nanoparticle synthesis using Aspergillus oryzae TFR9 using FeCl3 as a precursor metal salt. Valid characterization techniques employed for biosynthesized iron nanoparticles including dynamic light scattering (DLS), transmission electron microscopy (TEM), and high resolution-transmission electron microscopy (HR-TEM) for morphological study. X-ray energy dispersive spectroscopy (EDS) spectrum confirmed the presence of elemental iron signal in high percentage. Apart from ecofriendliness and easy availability, low-cost biomass production will be more advantageous when compared to other chemical methods. Biosynthesis of iron nanoparticles using fungus has greater commercial viability that it may be used in agriculture, biomedicals and engineering sector.
Strong Convergence Theorems for a Common Fixed Point of a Family of Asymptoticallyk-Strict Pseudocontractive Mappings
Authors: Zegeye H. , Shahzad N.
Published: March 2013

We provide an iterative process which converges strongly to a common fixed point of finite family of asymptoticallyk-strict pseudocontractive mappings in Banach spaces. Our theorems improve and unify most of the results that have been proved for this important class of nonlinear operators.
Multiphysics Model Development and the Core Analysis for In Situ Breeding and Burning Reactor
Authors: Si Shengyi
Published: March 2013

The in situ breeding and burning reactor (ISBBR), which makes use of the outstanding breeding capability of metallic pellet and the excellent irradiation-resistant performance of SiCf/SiC ceramic composites cladding, can approach the design purpose of ultralong cycle and ultrahigh burnup and maintain stable radial power distribution during the cycle life without refueling and shuffling. Since the characteristics of the fuel pellet and cladding are different from the traditional fuel rod of ceramic pellet and metallic cladding, the multiphysics behaviors in ISBBR are also quite different. A computer code, named TANG, to model the specific multiphysics behaviors in ISBBR has been developed. The primary calculation results provided by TANG demonstrate that ISBBR has an excellent comprehensive performance of GEN-IV and a great development potential.
Various Heteroclinic Solutions for the Coupled Schrödinger-Boussinesq Equation
Authors: Jiang Murong , Dai Zhengde
Published: March 2013

Various closed-form heteroclinic breather solutions including classical heteroclinic, heteroclinic breather and Akhmediev breathers solutions for coupled Schrödinger-Boussinesq equation are obtained using two-soliton and homoclinic test methods, respectively. Moreover, various heteroclinic structures of waves are investigated.
Superficial Collagen Fibril Modulus and Pericellular Fixed Charge Density Modulate Chondrocyte Volumetric Behaviour in Early Osteoarthritis
Authors: Tanska Petri , Turunen Siru M. , Han Sang Kuy , Julkunen Petro , Herzog Walter , Korhonen Rami K.
Published: March 2013

The aim of this study was to investigate if the experimentally detected altered chondrocyte volumetric behavior in early osteoarthritis can be explained by changes in the extracellular and pericellular matrix properties of cartilage. Based on our own experimental tests and the literature, the structural and mechanical parameters for normal and osteoarthritic cartilage were implemented into a multiscale fibril-reinforced poroelastic swelling model. Model simulations were compared with experimentally observed cell volume changes in mechanically loaded cartilage, obtained from anterior cruciate ligament transected rabbit knees. We found that the cell volume increased by 7% in the osteoarthritic cartilage model following mechanical loading of the tissue. In contrast, the cell volume decreased by 4% in normal cartilage model. These findings were consistent with the experimental results. Increased local transversal tissue strain due to the reduced collagen fibril stiffness accompanied with the reduced fixed charge density of the pericellular matrix could increase the cell volume up to 12%. These findings suggest that the increase in the cell volume in mechanically loaded osteoarthritic cartilage is primarily explained by the reduction in the pericellular fixed charge density, while the superficial collagen fibril stiffness is suggested to contribute secondarily to the cell volume behavior.
FISH Detection ofPML-RARAFusion in ins(15;17) Acute Promyelocytic Leukaemia Depends on Probe Size
Authors: Campbell Lynda J. , Oei Paul , Brookwell Ross , Shortt Jake , Eaddy Nicola , Ng Ashley , Chew Edward , Browett Peter
Published: March 2013

The diagnosis of acute promyelocytic leukaemia (APL) is usually confirmed by cytogenetics showing the characteristic t(15;17), but a minority of patients have a maskedPML/RARAfusion. We report ten patients with APL and no evidence of the t(15;17), in whom the insertion ofRARAintoPMLcould not be demonstrated by initial FISH studies using a standard dual fusion probe but was readily identified using smaller probes. Given the need for rapid diagnosis of APL, it is important to be aware of the false negative rate for largePML/RARAFISH probes in the setting of masked rearrangements.
Amortized Fairness for Drive-Thru Internet
Authors: Li Zhi , Sun Limin , Zhou Xinyun
Published: March 2013

The drive-thru Internet is an effective mean to provide Internet access service for wireless sensor networks deployed on vehicles. In these networks, vehicles often experience different link qualities due to different relative positions to the access point. This makes fair and efficient system design a very challenging task. In traditional approaches, the network efficiency has to be greatly sacrificed to provide the fair share for vehicles with low link quality. To address this issue, we propose a novel amortized fairness MAC protocol. The basic idea is that vehicles with lower link quality can defer their fairness requests and let the lost fairness be “amortized” in the future when their links become the high quality. The amortized fairness MAC requires predictions of future link quality. For this, we fully exploit the inner and inter-AP correlations revealed from our extensive field studies and design a link quality prediction algorithm. Based on the predicted link quality, we formulate the optimal amortized fairness MAC as a convex programming problem, which can be solved with the desired precision in polynomial time. Extensive simulation on real traces shows that the amortized fairness MAC scheme is more efficient than the existing fairness schemes in terms of efficiency and fairness.
State Estimation for Fractional-Order Complex Dynamical Networks with Linear Fractional Parametric Uncertainty
Authors: Li Hongjie
Published: March 2013

This paper deals with state estimation problem for a class of fractional-order complex dynamical networks with parametric uncertainty. The parametric uncertainty is assumed to be of linear fractional form. Firstly, based on the properties of Kronecker product and the stability of fractional-order system, a sufficient condition is derived for robust asymptotic stability of linear fractional-order augmented system. Secondly, state estimation problem is then studied for the same fractional-order complex networks, where the purpose is to design a state estimator to estimate the network state through available output measurement, the existence conditions of designing state estimator are derived using matrix's singular value decomposition and LMI techniques. These conditions are in the form of linear matrix inequalities which can be readily solved by applying the LMI toolbox. Finally, two numerical examples are provided to demonstrate the validity of our approach.
Low Diastolic Blood Pressure as a Risk for All-Cause Mortality in VA Patients
Authors: Tringali Steven , Oberer Charles William , Huang Jian
Published: March 2013

Background. A paradoxical increase in cardiovascular events has been reported with intensively lowering diastolic blood pressure (DBP). This J-curve phenomenon has challenged the aggressive lowering of blood pressure, especially in patients with coronary artery disease.Objective. Our objective was to study the effects of low DBP on mortality and determine a threshold for which DBP should not be lowered beyond.Methods. We evaluated a two-year cross-section of primary care veteran patients, from 45 to 85 years of age. Receiver operating characteristics (ROC) were employed to establish an optimal cut-off point for DBP. Propensity-score matching and multivariate logistic regression were used to control for confounders. All-cause mortality was the primary outcome.Results. 14,270 patients were studied. An ROC curve found a threshold value of DBP 70 mmHg had the greatest association with mortality (P<0.001). 49% of patients had a DBP of 70 mmHg or less. Using a propensity-matched multivariate logistic regression, odds ratio for all-cause mortality in subjects with a DBP less than 70 mmHg was 1.5 (95% CI 1.3–1.8).Conclusions. Reduction of DBP below 70 mmHg is associated with increased all-cause mortality. Hypertension guidelines should include a minimum blood pressure target.
Development of an HPLC-UV Method for the Analysis of Drugs Used for Combined Hypertension Therapy in Pharmaceutical Preparations and Human Plasma
Authors: Kepekci Tekkeli Serife Evrim
Published: March 2013

A simple, rapid, and selective HPLC-UV method was developed for the determination of antihypertensive drug substances: amlodipine besilat (AML), olmesartan medoxomil (OLM), valsartan (VAL), and hydrochlorothiazide (HCT) in pharmaceuticals and plasma. These substances are mostly used as combinations. The combinations are found in various forms, especially in current pharmaceuticals as threesome components: OLM, AML, and HCT (combinationI) and AML, VAL, and HCT (combinationII). The separation was achieved by using an RP-CN column, and acetonitrile-methanol-10 mmol orthophosphoric acid pH 2.5 (7 : 13 : 80, v/v/v) was used as a mobile phase; the detector wavelength was set at 235 nm. The linear ranges were found as 0.1–18.5 μg/mL, 0.4–25.6 μg/mL, 0.3–15.5 μg/mL, and 0.3–22 μg/mL for AML, OLM, VAL, and HCT, respectively. In order to check the selectivity of the method for pharmaceutical preparations, forced degradation studies were carried out. According to the validation studies, the developed method was found to be reproducible and accurate as shown by RSD ≤6.1%, 5.7%, 6.9%, and 4.6% and relative mean error (RME) ≤10.6%, 5.8%, 6.5%, and 6.8% for AML, OLM, VAL, and HCT, respectively. Consequently, the method was applied to the analysis of tablets and plasma of the patients using drugs including those substances.
Dynamically Weighted Clique Evolution Model in Clique Networks
Authors: Li Zhang-Wei , Yang Xu-Hua , Jiang Feng-Ling , Chen Guang , Weng Guo-Qing , Zhu Mei
Published: March 2013

This paper proposes a weighted clique evolution model based on clique (maximal complete subgraph) growth and edge-weight driven for complex networks. The model simulates the scheme of real-world networks that the evolution of networks is likely to be driven by the flow, such as traffic or information flow needs, as well as considers that real-world networks commonly consist of communities. At each time step of a network’s evolution progress, an edge is randomly selected according to a preferential scheme. Then a new clique which contains the edge is added into the network while the weight of the edge is adjusted to simulate the flow change brought by the new clique addition. We give the theoretical analysis based on the mean field theory, as well as some numerical simulation for this model. The result shows that the model can generate networks with scale-free distributions, such as edge weight distribution and node strength distribution, which can be found in many real-world networks. It indicates that the evolution rule of the model may attribute to the formation of real-world networks.
Self‐Propagating Reactive Fronts in Compacts of Multilayered Particles
Authors: Sraj Ihab , Vohra Manav , Alawieh Leen , Weihs Timothy P. , Knio Omar M.
Published: March 2013

Reactive multilayered foils in the form of thin films have gained interest in various applications such as joining, welding, and ignition. Typically, thin film multilayers support self‐propagating reaction fronts with speeds ranging from 1 to 20 m/s. In some applications, however, reaction fronts with much smaller velocities are required. This recently motivated Fritz et al. (2011) to fabricate compacts of regular sized/shaped multilayered particles and demonstrate self‐sustained reaction fronts having much smaller velocities than thin films with similar layering. In this work, we develop a simplified numerical model to simulate the self‐propagation of reactive fronts in an idealized compact, comprising identical Ni/Al multilayered particles in thermal contact. The evolution of the reaction in the compact is simulated using a two‐dimensional transient model, based on a reduced description of mixing, heat release, and thermal transport. Computed results reveal that an advancing reaction front can be substantially delayed as it crosses from one particle to a neighboring particle, which results in a reduced mean propagation velocity. A quantitative analysis is thus conducted on the dependence of these phenomena on the contact area between the particles, the thermal contact resistance, and the arrangement of the multilayered particles.