bluuebunny/crossref_metadata_2025 huggingface dataset:
INFORMATION FILTERING VIA CLUSTERING COEFFICIENTS OF USER–OBJECT BIPARTITE NETWORKS
Authors: GUO QIANG , LENG RUI , SHI KERUI , LIU JIAN-GUO
Published: January 2012

The clustering coefficient of user–object bipartite networks is presented to evaluate the overlap percentage of neighbors rating lists, which could be used to measure interest correlations among neighbor sets. The collaborative filtering (CF) information filtering algorithm evaluates a given user's interests in terms of his/her friends' opinions, which has become one of the most successful technologies for recommender systems. In this paper, different from the object clustering coefficient, users' clustering coefficients of user–object bipartite networks are introduced to improve the user similarity measurement. Numerical results for MovieLens and Netflix data sets show that users' clustering effects could enhance the algorithm performance. For MovieLens data set, the algorithmic accuracy, measured by the average ranking score, can be improved by 12.0% and the diversity could be improved by 18.2% and reach 0.649 when the recommendation list equals to 50. For Netflix data set, the accuracy could be improved by 14.5% at the optimal case and the popularity could be reduced by 13.4% comparing with the standard CF algorithm. Finally, we investigate the sparsity effect on the performance. This work indicates the user clustering coefficients is an effective factor to measure the user similarity, meanwhile statistical properties of user–object bipartite networks should be investigated to estimate users' tastes.
AGE-RELATED PREFERENTIAL SELECTION CAN PROMOTE COOPERATION IN THE PRISONER'S DILEMMA GAME
Authors: WANG ZHEN , WANG ZHEN , YANG YUAN-HAN , YU MING-XING , LIAO LI-GUO
Published: January 2012

In this paper, we introduce an age-related preferential selection mechanism into the prisoner's dilemma game. Under this mechanism, players can select a source of strategy imitation from their neighbors in a biased way proportional to their ages. Tuned by a selection parameter α, the impact of aging on the evolution of cooperation can be very different. The numerical results show that the cooperation will be effectively promoted by adjusting the value of α. By examining the evolution process and spatial patterns for different values of α, it is found that larger α will effectively promote the formation of large scale of cooperator clusters. In addition, the impact of noise K on the spreading process of cooperation strategy is studied. We find that small K can make cooperation monotonously increase with α, while large K guarantees the optimal existence of cooperation for an intermediate α.
AN EMPIRICAL ANALYSIS OF THE EFFECT OF MULTIMARKET CONTACTS ON US AIR CARRIERS' PRICING BEHAVIORS
Authors: MURAKAMI HIDEKI , ASAHI RYOTA
Published: January 2012

A number of empirical studies have shown that multimarket contacts facilitate collusive behaviors between full-service carriers (FSCs) in the US airline industry. This paper empirically investigates the effects of multimarket contacts on air carriers' pricing behaviors and highlights those of low-cost carriers (LCCs) and FSCs as well as those among LCCs. Simultaneous demand and price (pseudo-supply) equations are estimated to derive these impacts of multimarket contacts in the top 30 air markets in the US multimarket contacts among FSCs do lead to collusive setting of high airfares. However, the effect of multimarket contacts is lower among LCCs, and the degree depends on the number of LCCs in a market. The airfares of LCCs remain low, even though there are multimarket contacts among LCCs. These results suggest that the behaviors of LCCs are not affected by multimarket contacts.
A THEORETICAL FRAMEWORK FOR THE EVALUATION OF COMPETITION BETWEEN CONTAINER TERMINAL OPERATORS
Authors: YAP WEI YIM , LAM JASMINE SIU LEE , CULLINANE KEVIN
Published: January 2012

This paper presents a conceptual framework for analyzing the outcomes of potential competitive strategies and their expected payoffs for container terminal operators in the container handling industry. The framework is based on the integration of Bowley's linear model of aggregate demand of product differentiation with Porter's "Diamond" model. It focuses on the number of containers handled, prices charged, and profits earned to analyze a variety of strategies that could be employed by container terminal operators to enhance their competitive position. The findings suggest that strategies to build complementary relationships and stimulate greater demand are more desirable than alternatives because they generate benefits that accrue to the entire container port cluster. Conversely, strategies that are intended to raise entry barriers, employ strategic pricing mechanisms, and/or involve collusion are found to lead to the formation of insular clusters and retard competitive advantage in the long-run.
DOES ELECTRONIC TOLL COLLECTION TECHNOLOGY MATTER TO ECONOMIC AND FINANCIAL VIABILITY OF ROADS?
Authors: KRAMBERGER TOMAZ , CURIN ANDREJA
Published: January 2012

The provision and management of transport infrastructure is extremely important for economic development and economic competitiveness as facilitators of trade. However, it is becoming increasingly difficult for governments to publicly fund transport infrastructures given the current economic uncertainty. Revenues from road tolls are thus an important financial source for road investment and management. Financial sustainability in an era of scarce financial resources requires authorities or concessions (under some form of Public–Private Partnership) to adopt some form of maximization of potential toll revenues as well as to benefit the national economy. The role of technology is often overlooked as it can affect financial and economic viability of road infrastructure investment. This paper explores the role and impact of technology such as GNSS and DSRC on cost-benefit outcomes. The results suggest that DSRC technology has the edge in efficient technology in toll collection.
ASTROPHYSICAL UNCERTAINTIES ON DIRECT DETECTION EXPERIMENTS
Authors: GREEN ANNE M.
Published: January 2012

Direct detection experiments are poised to detect dark matter in the form of weakly interacting massive particles (WIMPs). The signals expected in these experiments depend on the ultra-local WIMP density and velocity distribution. Firstly we review methods for modeling the dark matter distribution. We then discuss observational determinations of the local dark matter density, circular speed and escape speed, and the results of numerical simulations of Milky Way-like dark matter halos. In each case we highlight the uncertainties and assumptions made. We then overview the resulting uncertainties in the signals expected in direct detection experiments, specifically the energy, time and direction dependence of the event rate. Finally we conclude by discussing techniques for handling the astrophysical uncertainties when interpreting data from direct detection experiments.
PRODUCTION AND RESCATTERING OF STRANGE BARYONS AT ENERGIES AVAILABLE AT THE CERN SUPER PROTON SYNCHROTRON IN A TRANSPORT MODEL WITH HADRON POTENTIALS
Authors: LI QINGFENG , LI ZHUXIA
Published: January 2012

A mean-field potential version of the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model is used to investigate the production of strange (anti-)baryons, especially the Λs and [Formula: see text]s, from heavy ion collisions at SPS energies. It is found that, with the consideration of both formed and pre-formed hadron potentials in UrQMD, the transverse mass and longitudinal rapidity distributions of experimental data of both Λs and [Formula: see text]s can be quantitatively explained fairly well. Our investigation also shows the equal importance of both the production mechanism and the rescattering process of hadrons for the final yield of strange baryons.
HYDROGENIC IMPURITY BINDING ENERGY IN GaAs QUANTUM RINGS
Authors: WANG GUANG-XIN , ZHANG PENG
Published: January 2012

Using a variational approach within the effective-mass approximation, we investigate the ground-state binding energy of a donor impurity in the GaAs quantum rings (QR) in the infinite confinement potential. A trial wave function with two variational parameters is used in the calculation. The binding energy as a function of the QR structure parameters and the impurity position is investigated. The results indicate that the binding energy decreases gradually as the QR structure parameters increase in the infinite confinement potential. In addition, the binding energy of the impurity exhibits a maximum as the impurity position moves along the symmetry axis of the QR from the bottom of the QR to the top. The impurity binding energy firstly increases and then decreases as the impurity moves from the internal surface of the QR to the external surface, indicating that there is a maximum.
DYNAMIC RESPONSE RESEARCH OF U SHAPED PIPE WITH VISCOELASTIC DAMPING LAYER
Authors: GUO YAJUAN , MENG GUANG , LI HONGGUANG
Published: January 2012

The frequency dependency property of viscoelastic material leads to the dynamic analysis of compound structures which are complex and costly. Furthermore, using commercial finite element software, it is difficult to carry out the dynamic response analysis with this characteristic. Based on finite element iterative and modal strain energy (MSE) method, a mode superposition algorithm was proposed to solve the dynamic response of viscoelastic damping structure in this paper. Through iterative and MSE method, the modal frequency and loss factor for each mode can be obtained. Before calculating the next order modal frequency, the modal mode and corresponding load are extracted and the response of node was calculated at first in this algorithm. As a consequence, the node displacement response can be solved by summarizing the response results of each independent mode in the required frequency range. Numerical calculation of U shaped pipe with viscoelastic damping layer illustrates that the method is simple and practical. Moreover, the simulations with this method agree quite well with the experimental derived results. In the meantime, the damping layer parameters study shows that the position of the damping layer has an obvious effect of reducing the vibration response of U shaped pipe, but the width of the damping layer has little influence. The procedure proposed in this paper can be extended to analyze other more complex structures with viscoelastic material.
A SCHEME FOR QUANTUM DENSE CODING IN CAVITY QED
Authors: ZOU CHANG-LIN , CAO ZHUO-LIANG
Published: January 2012

Quantum mechanics allows one to encode the information in the superposition of a quantum state which embodies the nature of quantum nonlocality. Here we propose a realizable physical scheme for a multiparticle quantum dense coding (QDC) between two users in cavity quantum electrodynamics (QED). We also discuss the feasibility of our scheme within current technology.
CROSSOVER OF CRITICAL EXPONENTS INDUCED BY DILUTION VIA MONTE CARLO SIMULATIONS
Authors: MASROUR R. , HAMEDOUN M. , BENYOUSSEF A.
Published: January 2012

The crossover of dilution in the critical exponent associated with the thermodynamic properties in the magnetic materials via Monte Carlo simulations is observed. The obtained results of critical exponent associated with the magnetic susceptibility, specific heat and correlation length for the ZnCr 2x Al 2-2x S 4, Cd 1-y Cr 2-2x In y+2x Se 4 and Zn 1-x Mn x Te systems are comparable with those given by the experiment results.
EXCITON STATES IN A QUANTUM DOT WITH PARABOLIC CONFINEMENT
Authors: DOĞAN Ü. , SAKİROĞLU S. , YILDIZ A. , AKGÜNGÖR K. , EPİK H. , SÖKMEN İ. , SARI H. , ERGÜN Y.
Published: January 2012

In this study the electronic eigenstructure of an exciton in a parabolic quantum dot (QD) has been calculated with a high accuracy by using Finite element method (FEM). We have converted the coordinates of electron–light-hole system to relative and center of mass coordinate, then placed the Spherical Harmonics into Schrödinger equation analytically and obtained the Schrödinger equation which depends only on the radial variable. Finally we used FEM with only radial variable in order to get the accurate numerical results. We also showed first 21 energy level spectra of exciton depending on confinement and Coulomb interaction parameters.
THERMOPHORESIS AND THE EFFECT OF HYDRODYNAMIC INTERACTIONS IN A LINEAR MODEL FOR COLLOIDS
Authors: NAJAFI ALI , POUSANEH FAEZEH
Published: January 2012

Thermal diffusion or Soret effect is the directed motion of colloidal particles in temperature gradient. In this article, by assuming local thermodynamic equilibrium, the drift velocity for a molecular system composed of two connected spheres is calculated. It is shown that for this system the positive Soret coefficient is given by: ST= (3/8)(a/l)(1/T), where l is the average linear size of the system, a is the radius of spheres and T is the local temperature. To investigate the hydrodynamic coupling in a dilute suspension of diffusers, we calculate the average drift velocity for two far diffusers. It is shown that due to the hydrodynamic interaction, an overall attraction between diffusers can be achieved.
ADAPTIVE GENERALIZED SYNCHRONIZATION OF HYPERCHAOS SYSTEMS
Authors: WANG XINGYUAN , WANG YAQIN
Published: January 2012

This paper studies the generalized synchronization of hyperchaos systems, and a new method, by which adaptive generalized synchronization of chaotic systems with a kind of linear and nonlinear relationship between the drive and response systems can be achieved, is proposed. This new method has more extensive application scope. Based on the Lyapunov stability theory, the correctness of the proposed scheme is strictly demonstrated. It is also illustrated by applications to hyperchaotic Chen system and hyperchaotic Lorenz system and the simulation results show the effectiveness of the proposed scheme.
A GENERAL METHOD FOR QUICK AND ACCURATE EVALUATION OF ESCAPE FACTOR
Authors: HE JIAN , ZHANG QINGGUO
Published: January 2012

A general method for quick and accurate evaluation of escape factor is presented, for any optical depths and any line profiles, using least square procedure. The principle of the least square procedure is discussed. As an example, the parameters are fitted when the optical depth is in the region of 0–1000, and the escape factors we obtained are in accordance with the theoretical formula.
ADAPTIVE FULL STATE HYBRID PROJECTIVE SYNCHRONIZATION OF UNIFIED CHAOTIC SYSTEM WITH UNKNOWN PARAMETERS
Authors: WANG XING-YUAN , ZHU LE-BIAO
Published: January 2012

This paper studies full state hybrid projective synchronization of the unified chaotic system with unknown parameters. Based on the Lyapunov stability theory, an adaptive controller is designed. It is proved theoretically that the controller can make the states of the dynamical system and the response system with unknown parameters asymptotically full state hybrid projective synchronized. Numerical simulations show the effectiveness of the scheme.
PIPPARD RELATIONS MODIFIED FOR THE RAMAN FREQUENCY SHIFTS CLOSE TO I–II PHASE TRANSITION IN S-TRIAZINE
Authors: YURTSEVEN H. , KURT M.
Published: January 2012

The pressure dependence of the frequency shifts 1/ω(∂ω/∂T)Pis calculated from the 1/ω(∂ω/∂P)Tfor the Raman modes I and IV according to the spectroscopic modifications of the Pippard relations. The observed Raman frequencies of those modes are used for this calculation close to the I–II phase transition in s-triazine. From the frequency shifts, the isothermal compressibility κTand the specific heat CPare also calculated as a function of pressure close to the I–II phase transition in s-triazine. Our calculated values of 1/ω(∂ω/∂T)PκTand CPcan be compared with the experimental measurements at various pressures in the phases I and II of s-triazine.
ON BLACK HOLE STABILITY IN CRITICAL GRAVITIES
Authors: LIU HAISHAN , LÜ H. , LUO MINGXING
Published: January 2012

We consider extended cosmological gravities with Ricci tensor and scalar squared terms in diverse dimensions. These theories admit solutions of Einstein metrics, including the Schwarzschild–Tangherlini AdS black holes, whose mass and entropy vanish at the critical point. We perform linearized analysis around the black holes and show that in general the spectrum consists of the usual spin-2 massless and ghost massive modes. We demonstrate that there is no exponentially-growing tachyon mode in the black holes. At the critical point, the massless spin-2 modes have zero energy whilst the massive spin-2 modes are replaced by the log modes. There always exist certain linear combination of massless and log modes that has negative energy. Thus the stability of the black holes requires that the log modes to be truncated out by the boundary condition.
NONSTATIC CHARGED BTZ-LIKE BLACK HOLES IN N+1 DIMENSIONS
Authors: GHOSH SUSHANT G.
Published: January 2012

We find an exact nonstatic charged BTZ-like solutions, in (N+1)-dimensional Einstein gravity in the presence of negative cosmological constant and a nonlinear Maxwell field defined by a power s of the Maxwell invariant, which describes the gravitational collapse of charged null fluid in an anti-de Sitter background. Considering the situation that a charged null fluid injects into the initially an anti-de Sitter spacetime, we show that a black hole form rather than a naked singularity, irrespective of spacetime dimensions, from gravitational collapse in accordance with cosmic censorship conjecture. The structure and locations of the apparent horizons of the black holes are also determined. It is interesting to see that, in the static limit and when N = 2, one can retrieve 2+1 BTZ black hole solutions.
ENFORCING RECIPROCITY IN NUMERICAL ANALYSIS OF ACOUSTIC RADIATION MODES AND SOUND POWER EVALUATION
Authors: PETERS HERWIG , KESSISSOGLOU NICOLE , MARBURG STEFFEN
Published: January 2012

By identifying the efficiently radiating acoustic radiation modes of a fluid loaded vibrating structure, the storage requirements of the acoustic impedance matrix for calculation of the sound power using the boundary element method can be greatly reduced. In order to compute the acoustic radiation modes, the impedance matrix needs to be symmetric. However, when using the boundary element method, it is often found that the impedance matrix is not symmetric. This paper describes the origin of the asymmetry of the impedance matrix and presents a simple way to generate symmetry. The introduction of additional errors when symmetrizing the impedance matrix must be avoided. An example is used to demonstrate the behavior of the asymmetry and the effect of symmetrization of the impedance matrix on the sound power. The application of the technique presented in this work to compute the radiated sound power of a submerged marine vessel is discussed.
NON-PERIODIC Γ-CONVERGENCE: APPLICATION TO A MAIN EXAMPLE OF A NON-FINER OSCILLATION OPERATOR IN HIGHER DIMENSION
Authors: PEDREGAL PABLO , SERRANO HELIA
Published: January 2012

We generalize, to a higher dimension, a main example of an operator that enjoys the NFO property introduced recently in [13]. It turns out that this issue is intimately connected to Γ-convergence of functionals in a non-periodic, general setting. Under a main structural assumption on the sequence of functionals, the Γ-convergence limit is computable. As a consequence of our analysis, we obtain the generalization just mentioned, opening thus the way to treat the existence for some nonlinear PDEs in divergence form.
Factors Impacting Cross-Cultural Knowledge Sharing Through Online Systems in Organisational Settings
Authors: Li Wei
Published: January 2012

The work reported in this paper has identified a research gap regarding the specific area of cross-cultural knowledge sharing through online systems in organisational settings, i.e. what are the factors impacting organisational members' online knowledge sharing behaviour in cross-cultural contexts? A survey of the relevant literature has recognised three main categories of potentially significant factors: organisational issues, national culture and computer-mediated communication. Although scholarly efforts have been taken in each of the three single areas, no previous study has integrated all three categories systematically. A review of the existing studies in all three areas shows that each areas is limited in some way, for understanding how and why people with different national cultural values, share or do not share knowledge through online systems within the same organisation. This paper explains the importance of identifying and addressing the research gaps, as well as suggests ways in which scholars can make use of new research methods that provide better explanations of why certain knowledge sharing behaviours exist.
ADVANCING WATERSHED CUMULATIVE EFFECTS ASSESSMENT AND MANAGEMENT: LESSONS FROM THE SOUTH SASKATCHEWAN RIVER WATERSHED, CANADA
Authors: NOBLE BRAM F. , SHEELANERE POORNIMA , PATRICK ROBERT
Published: January 2012

Watersheds are under increasing pressures from the cumulative environmental effects of human actions. Reviews of recent practice suggest that cumulative effects assessment and management (CEAM) has failed to capture the full range of stressors to Canada's watersheds. Indeed, the limitations to CEAM have been well documented; yet, there has been limited constructive evaluation to help explain why CEAM has failed to advance. In this paper we examine the underlying challenges to the assessment and management of cumulative effects in a watershed context. Based on lessons emerging from the South Saskatchewan watershed, Canada, challenges to CEAM in watersheds include stakeholder understanding and interpretation of cumulative effects; limitations in the scale of current EA practices in watersheds; data challenges; the lack of established thresholds for watershed effects; and lack of clarity regarding watershed science and regulatory capacity. The merits of a watershed-based approach to CEAM to help address these challenges to practice are explored.
A STRATEGIC APPROACH TO IMPROVE ENVIRONMENTAL POLICY-MAKING FOR END-OF-CYCLE PRODUCT MANAGEMENT
Authors: JONES SHARON A. , ROSE KEVIN , TULL KRISTEN
Published: January 2012

As they make decisions about collective goods, policy makers strive to apply objective standards to complex environmental issues. This challenge requires the use of analytic methods that can include the multiple dimensions of such complex problems. Life-cycle analysis is a physical model that is widely recognised for its utility in investigating and improving the environmental impacts across the supply chain. However, models such as environmental life-cycle analysis are insufficient by themselves for policy-making because they do not formally include the interdependent, dynamic, often socioeconomic choices that influence supply-chain firms, and thus affect environmental outcomes. We show that game theory can be applied to improve environmental policy-making for the end-of-cycle stages of supply chains by strategically considering environmental and economic incentives. These incentives are often dependant on previous life-cycle stages while affecting future life-cycle stages. We demonstrate these techniques with a case study of open-loop (out-of-network) pallet systems for shipping consumer goods while also discussing the remaining challenges.
TOWARDS A CULTURE OF LANDCARE: THE ARTS IN COMMUNITY CAPACITY BUILDING FOR NATURAL RESOURCES MANAGEMENT
Authors: CURTIS DAVID JOHN
Published: January 2012

This paper argues that the new generation of community based natural resources management (CBNRM) should involve the arts, and particularly the community arts, to better enable success in engaging communities in land rehabilitation and ecological sustainability. The paper is based on insights gained from a five-year research project which examined the role of the arts in affecting environmental behaviour. About 200 informant interviews were undertaken, and eight case studies were analysed to provide qualitative and quantitative data. The case studies presented in this paper show that a culture of landcare is gradually evolving and there is a general overlap, and perhaps even convergence, between the community arts and community environmental initiatives such as Landcare. There are now many community arts events that have an environmental focus, and increasingly CBNRM is using the arts to encourage greater community involvement in the issues and to provide an artistic voice of those involved in CBNRM.
SUPERVISED CLASSIFICATION OF WHITE BLOOD CELLS BY FUSION OF COLOR TEXTURE FEATURES AND NEURAL NETWORK
Authors: JIJI G. WISELIN , SELVARAJ HENRY , SUJI G. EVELIN
Published: January 2012

Nucleus segmentation is one of important steps in the automatic white blood cell differential counting. In this paper, we proposed a technique to segment images of the nucleus. We analyze a set of white-blood-cell-nucleus-based features using color fuzzy texture spectrum (Base 5). We applied artificial neural network for classification. We compared the results with moment based features. The classification performances are evaluated by class wise classification rates. The results show that the features using nucleus alone could be utilized to achieve a classification rate of 99.05% on the test sets.
COMPARISON OF FROST AND DEFROST PERFORMANCE BETWEEN MICROCHANNEL COIL AND FIN-AND-TUBE COIL FOR HEAT PUMP SYSTEMS
Authors: PADHMANABHAN SANKAR , CREMASCHI LORENZO , FISHER DANIEL
Published: January 2012

This paper presents a comparison of frost and defrost cycling performance between a microchannel heat exchanger with louvered fin and a fin-and-tube heat exchanger with straight fins employed as outdoor coils of a 14 kW (48 000 Btu/h) heat pump system. In addition to temperature, pressure and flow rate measurements taken at various locations of the systems, the fin-base and tube wall surface temperature were also recorded by using fine-gauge precalibrated thermocouples on the coils. Further, load cells were used to measure the mass of frost accumulation during heating tests. Data showed that the frosting time of the microchannel heat exchanger is more than 50% shorter than for the fin-and-tube heat exchanger, which is chosen as the baseline system. The average heating capacity and system performance over a frost–defrost cycle are also lower for the system with microchannel heat exchangers. Higher frost growth rate was mainly due to augmented temperature difference between air and the surface of the heat exchanger, and preferential frost nucleation sites on the louvered fins and microchannel tubes. Removal of residual water in the microchannel heat exchanger did not improve the frost performance significantly. Blowing nitrogen on the microchannel coil after defrost removed any visible water retained in the coil after the defrost cycle but the cycle time increased only by 4% with respect to wet and frost conditions. The cycle time of the same microchannel coil starting with dry conditions was about 60% longer than the cycle time in wet and frost conditions.
EVALUATION OF WIND ENVIRONMENT AROUND THE BUILDING IN THE EARLY DESIGN STAGES USING BIM-BASED CFD SIMULATION
Authors: LEE SU-MI , SONG DOOSAM
Published: January 2012

Drastic urbanization and Manhattanization are causing various problems in the wind environments of urban areas. This study suggests a computational fluid dynamics (CFD) simulation method to evaluate the wind environment around urban buildings in the early design stages. The CFD simulation method suggested in this study is not a traditional in-depth simulation, but a method to immediately evaluate the wind environment for each design alternative and provide guidelines for design modification. The CFD simulation approach suggested in this study is based on the building information model. In addition, previous criteria for evaluating wind environments around buildings in urban areas are reviewed and criteria applicable to the proposed CFD simulation method are identified. Furthermore, a proper mesh generation method and appropriate CPU time were investigated to allow generation of a meaningful CFD simulation result in a limited time.
Potential interaction of brain natriuretic peptide with hyperadiponectinemia in preeclampsia
Authors: Masuyama Hisashi , Nobumoto Etsuko , Inoue Seiji , Hiramatsu Yuji
Published: January 2012

Adiponectin was reported recently to have roles in the pathophysiology of preeclampsia. Moreover, elevation of adiponectin and brain natriuretic peptide (BNP) has been observed in preeclampsia. We examined the possible links between adiponectin and BNP in the pathophysiology of preeclampsia. We performed a cross-sectional study in 56 preeclampsia patients and 56 controls matched for gestational age and body mass index. The BNP, leptin, and adiponectin levels were measured by ELISA, and their mRNA expressions were evaluated in omental adipose tissue by real-time PCR. The effects of BNP on adiponectin and leptin mRNA expression and secretion were investigated in primary cultures of adipocytes from obese and normal-weight women. The BNP, adiponectin, and leptin levels were significantly higher in preeclampsia patients compared with controls. The adiponectin level was increased significantly in normal-weight preeclampsia patients compared with overweight preeclampsia patients. Adiponectin mRNA expression was increased significantly in adipose tissues of preeclampsia patients compared with controls and was also increased significantly in normal-weight preeclampsia patients compared with overweight preeclampsia patients, whereas leptin was not. BNP and adiponectin showed significant positive correlations in both normal-weight and overweight preeclampsia patients. BNP had a significantly weaker effect on adiponectin in overweight compared with normal-weight preeclampsia patients. Moreover, BNP had a weaker effect on adiponectin production in adipocytes from overweight women compared with adipocytes from normal-weight women using primary culture of human adipocytes. These data suggested that BNP may play a role in hyperadiponectinemia of preeclampsia patients. The weaker effect of BNP on adiponectin production may participate in the pathophysiology of overweight preeclampsia patients.
Short-interval intracortical inhibition blocks long-term potentiation induced by paired associative stimulation
Authors: Elahi Behzad , Gunraj Carolyn , Chen Robert
Published: January 2012

Paired associative stimulation (PAS) of the motor cortex leads to increased motor evoked potential (MEP) amplitudes in the stimulated hand muscles. We hypothesized that evoking GABAA receptor-mediated short-interval intracortical inhibition (SICI) simultaneously with excitatory PAS would depress long-term potentiation plasticity in motor cortex. Four different PAS paradigms were tested, standard PAS (PAS25) and three conditioned PAS protocols (CS2-PAS25, CS2-PAS25adj, and CS10-PAS25adj). A subthreshold conditioning stimulus 2 ms (CS2) or 10 ms (CS10) before the test stimuli was added to the conditioned PAS protocols. Since CS2 has inhibitory and CS10 has facilitatory effect on cortical excitability, in the CS2-PAS25adj and CS10-PAS25adj protocols, TS intensity was adjusted to produce a 1-mV MEP in the presence of CS2 or CS10 to control for the degree of corticospinal excitation. As expected, MEP amplitudes after PAS25 were higher compared with that at baseline, but importantly, MEP amplitudes did not change after PAS was induced in the presence of SICI in either the CS2-PAS25 or CS2-PAS25adj condition. Furthermore, the CS10-PAS25adj protocol showed significantly increased MEP amplitude at 60 min after PAS compared with baseline. These results show that SICI blocked the induction of long-term potentiation-like plasticity in the motor cortex, indicating that GABAergic circuits play an important role in the regulation of cortical plasticity. The study demonstrates a noninvasive and nonpharmacological way to achieve focal modulation of plasticity.
Contributions of excitation and suppression in shaping spatial frequency selectivity of V1 neurons as revealed by binocular measurements
Authors: Ninomiya Taihei , Sanada Takahisa M. , Ohzawa Izumi
Published: January 2012

Neurons in the early visual cortex are generally highly sensitive to stimuli presented to the two eyes. However, the majority of studies on spatial and temporal aspects of neural responses were based on monocular measurements. To study neurons under more natural, i.e., binocular, conditions, we presented sinusoidal gratings of a variety of spatial frequencies (SF) dichoptically in rapid sequential flashes and analyzed the data using a binocular reverse correlation technique for neurons in cat area 17. The resulting set of data represents a frequency-domain binocular receptive field from which detailed selectivities, both monocular and binocular, could be obtained. Consistent with previous studies, the responses could generally be explained by linear summation of inputs from the two eyes. Suppressive responses were also observed and were delayed typically by 5–15 ms relative to excitatory responses. However, we have found more diverse nature of suppressive responses than those reported previously. The optimal suppressive frequency could be either higher or lower than that of the excitatory responses. The bandwidth of SF tuning of the suppressive responses was usually broader than that of the excitatory responses. Cells with lower optimal SFs for suppression tended to show high optimal SFs and sharp tuning curves. The dynamic shift of optimal SF from low to high SF was accompanied by suppression with earlier onset and higher peak SF or later onset and lower peak SF than excitation. These results suggest that the suppression plays an essential role in generating the temporal dynamics of SF selectivity.
Spectral, NLO, Fluorescence, and Biological Activity of Knoevenagel Condensate of β-Diketone Ligands and Their Metal(II) Complexes
Authors: Sumathi S. , Anitha C. , Tharmaraj P. , Sheela C. D.
Published: January 2012

Transition metal complexes of various acetylacetone-based ligands of the type ML (where M=  Cu(II), Ni(II), Co(II); L=  3-(aryl)-pentane-2,4-dione) have been synthesized. The structural features have been derived from their elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, H1NMR, mass and ESR spectral studies. Conductivity measurements reveal that all the complexes are nonelectrolytic in nature. Spectroscopic and other analytical data of the complexes suggest square planar geometry for copper(II), cobalt(II), and nickel(II) complexes of 3-(3-phenylallylidene)pentane-2,4-dione and octahedral geometry for other metal(II) complexes. The redox behaviors of the copper(II) complexes have been studied by cyclic voltammetry. The free ligands and their metal complexes have been screened for their in vitro biological activities against bacteria and fungus. The metal(II) complexes are found to possess increased activities compared to those of the free ligands. All synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG) efficiency of the ligands was found to have considerable effect compared to that of urea and KDP.
Monocular Vision-Based Robot Localization and Target Tracking
Authors: Wu Bing-Fei , Lu Wang-Chuan , Jen Cheng-Lung
Published: January 2012

This paper presents a vision-based technology for localizing targets in 3D environment. It is achieved by the combination of different types of sensors including optical wheel encoders, an electrical compass, and visual observations with a single camera. Based on the robot motion model and image sequences, extended Kalman filter is applied to estimate target locations and the robot pose simultaneously. The proposed localization system is applicable in practice because it is not necessary to have the initializing setting regarding starting the system from artificial landmarks of known size. The technique is especially suitable for navigation and target tracing for an indoor robot and has a high potential extension to surveillance and monitoring for Unmanned Aerial Vehicles with aerial odometry sensors. The experimental results present “cm” level accuracy of the localization of the targets in indoor environment under a high-speed robot movement.
A Time Course for Susceptibility to Staphylococcus aureus Respiratory Infection during Influenza in a Swine Model
Authors: Smith Elizabeth A. , Kumar Sandeep R. P. , Deventhiran Jagadeeswaran , Cecere Thomas E. , LeRoith Tanya , McGilliard Mike , Elankumaran Subbiah , Mullarky Isis Kanevsky
Published: January 2012

Bacterial superinfections following influenza A virus (IAV) are predominant causes of morbidity in humans. The recent emergence of methicillin-resistant Staphylococcus aureus (MRSA) and highly virulent IAV strains has reduced treatment options. Development of an appropriate animal model to study secondary S. aureus infections may provide important information regarding disease pathogenesis. Pigs are natural hosts to both IAV and S. aureus and have respiratory physiology and immune response comparable to humans. To establish a time course of susceptibility to S. aureus after IAV infection, nursery pigs infected intranasally with IAV were challenged with MRSA at different time points. Lung pathology scores and MRSA CFU were evaluated in dual-infected animals after IAV infection. Flow cytometric analysis of bronchoalveolar lavage fluid indicated differences between treatments. These results demonstrate the appropriateness of an intranasal challenge model in nursery pigs for studying the pathogenesis of IAV and S. aureus coinfection and provide insights into the timeframe for susceptibility of IAV-infected pigs to secondary S. aureus infection.
Statistical Portfolio Estimation under the Utility Function Depending on Exogenous Variables
Authors: Hamada Kenta , Wei Ye Dong , Taniguchi Masanobu
Published: January 2012

In the estimation of portfolios, it is natural to assume that the utility function depends on exogenous variable. From this point of view, in this paper, we develop the estimation under the utility function depending on exogenous variable. To estimate the optimal portfolio, we introduce a function of moments of the return process and cumulant between the return processes and exogenous variable, where the function means a generalized version of portfolio weight function. First, assuming that exogenous variable is a random process, we derive the asymptotic distribution of the sample version of portfolio weight function. Then, an influence of exogenous variable on the return process is illuminated when exogenous variable has a shot noise in the frequency domain. Second, assuming that exogenous variable is nonstochastic, we derive the asymptotic distribution of the sample version of portfolio weight function. Then, an influence of exogenous variable on the return process is illuminated when exogenous variable has a harmonic trend. We also evaluate the influence of exogenous variable on the return process numerically.
A Single Dose of Oral BCG Moreau Fails to Boost Systemic IFN-γResponses to Tuberculin in Children in the Rural Tropics: Evidence for a Barrier to Mucosal Immunization
Authors: Vaca Maritza , Moncayo Ana-Lucia , Cosgrove Catherine A. , Chico Martha E. , Castello-Branco Luiz R. , Lewis David J. , Cooper Philip J.
Published: January 2012

Immune responses to oral vaccines are impaired in populations living in conditions of poverty in developing countries, and there is evidence that concurrent geohelminth infections may contribute to this effect. We vaccinated 48 children living in rural communities in Ecuador with a single oral dose of 100 mg of BCG Moreau RDJ and measured the frequencies of tuberculin-stimulated peripheral blood mononuclear cells expressing IFN-γbefore and after vaccination. Vaccinated children had active ascariasis(n=20)or had been infected but received short-(n=13)or long-term(n=15)repeated treatments with albendazole prior to vaccination to treat ascariasis. All children had a BCG scar from neonatal vaccination. There was no evidence of a boosting of postvaccination IFN-γresponses in any of the 3 study groups. Our data provide support for the presence of a barrier to oral vaccination among children from the rural tropics that appeared to be independent of concurrent ascariasis.
Ecto- and Endoparasitic Fungi on Ants from the Holarctic Region
Authors: Espadaler Xavier , Santamaria Sergi
Published: January 2012

The ant-specific fungiAegeritella, Laboulbenia, Rickia, Hormiscium,andMyrmicinosporidiumin the Holarctic region—nine species—are reviewed. Present knowledge is highly biased geographically, as shows the single record for Holarctic Asia, and this is to solve. The phylogenetic position ofAegeritella, Hormiscium, andMyrmicinosporidiumis unknown. Hosts seem to be also skewed phylogenetically although this may be a true pattern.
Dynamical Analysis of Long Fiber-Reinforced Laminated Plates with Elastically Restrained Edges
Authors: Nallim Liz G. , Bellomo Facundo J. , Quinteros Ricardo D. , Oller Sergio
Published: January 2012

This paper presents a variational formulation for the free vibration analysis of unsymmetrically laminated composite plates with elastically restrained edges. The study includes a micromechanics approach that allows starting the study considering each layer as constituted by long unidirectional fibers in a continuous matrix. The Mori-Tanaka method is used to predict the mechanical properties of each lamina as a function of the elastic properties of the components and of the fiber volume fraction. The resulting mechanical properties for each lamina are included in a general Ritz formulation developed to analyze the free vibration response of thick laminated anisotropic plates resting on elastic supports. Comprehensive numerical examples are computed to validate the present method, and the effects of the different mechanical and geometrical parameters on the dynamical behavior of different laminated plates are shown. New results for general unsymmetrical laminates with elastically restrained edges are also presented. The analytical approximate solution obtained in this paper can also be useful as a basis to deal with optimization problems under, for instance, frequency constraints.
Genetic Algorithm Optimized CCEM for Complex Topology
Authors: Xu Ye , Wang Zhuo
Published: January 2012

To evaluate how much two different complex topologies are similar to each other in a quantitative way is an essential procedure in large‐scale topology researches and still remains an NP problem. Cross‐correlation evaluation model (CCEM) together with Genetic Algorithm (GA) is introduced in this paper trying to solve this issue. Experiments have proved that SLS (Signless Laplacian Spectra) is capable of identifying a topology structure and CCEM is capable of distinguishing the differences between corresponding topology SLS eigenvectors. CCEM used in GA is recommended at last since a way of not finding the optimum solution in GA is a good way to reduce computing complexity.
Bound Maxima as a Traffic Feature under DDOS Flood Attacks
Authors: Xue Jie , Li Ming , Zhao Wei , Chen Sheng-Yong
Published: January 2012

This paper gives a novel traffic feature for identifying abnormal variation of traffic under DDOS flood attacks. It is the histogram of the maxima of the bounded traffic rate on an interval‐by‐interval basis. We use it to experiment on the traffic data provided by MIT Lincoln Laboratory under Defense Advanced Research Projects Agency (DARPA) in 1999. The experimental results profitably enhance the evidences that traffic rate under DDOS attacks is statistically higher than that of normal traffic considerably. They show that the pattern of the histogram of the maxima of bounded rate of attack‐contained traffic greatly differs from that of attack‐free traffic. Besides, the present traffic feature is simple in mathematics and easy to use in practice.
A Dynamic Stiffness Element for Free Vibration Analysis of Delaminated Layered Beams
Authors: Erdelyi Nicholas H. , Hashemi Seyed M.
Published: January 2012

A dynamic stiffness element for flexural vibration analysis of delaminated multilayer beams is developed and subsequently used to investigate the natural frequencies and modes of two-layer beam configurations. Using the Euler-Bernoulli bending beam theory, the governing differential equations are exploited and representative, frequency-dependent, field variables are chosen based on the closed form solution to these equations. The boundary conditions are then imposed to formulate the dynamic stiffness matrix (DSM), which relates harmonically varying loads to harmonically varying displacements at the beam ends. The bending vibration of an illustrative example problem, characterized by delamination zone of variable length, is investigated. Two computer codes, based on the conventional Finite Element Method (FEM) and the analytical solutions reported in the literature, are also developed and used for comparison. The intact and defective beam natural frequencies and modes obtained from the proposed DSM method are presented along with the FEM and analytical results and those available in the literature.
Tunable Lowpass Filter with RF MEMS Capacitance and Transmission Line
Authors: Saha Shimul C. , Hanke Ulrik , Sagberg Håkon , Fjeldly Tor A. , Sæther Trond
Published: January 2012

We have presented an RF MEMS tuneable lowpass filter. Both distributed transmission lines and RF MEMS capacitances were used to replace the lumped elements. The use of RF MEMS capacitances gives the flexibility of tuning the cutoff frequency of the lowpass filter. We have designed a low-pass filter at 9–12 GHz cutoff frequency using the theory of stepped impedance transmission lines. A prototype of the filter has been fabricated using parallel plate capacitances. The variable shunt capacitances are formed by a combination of a number of parallel plate RF MEMS capacitances. The cutoff frequency is tuned from C to X band by actuating different combinations of parallel capacitive bridges. The measurement results agree well with the simulation result.
Global Existence of Classical Solutions to a Three‐Species Predator‐Prey Model with Two Prey‐Taxes
Authors: Li Chenglin , Hong Zhangguo
Published: January 2012

We are concerned with three‐species predator‐prey model including two prey‐taxes and Holling type II functional response under no flux boundary condition. By applying the contraction mapping principle, the parabolic Schauder estimates, and parabolic Lp estimates, we prove that there exists a unique global classical solution of this system.
Analytical Model Based on a Cylindrical Geometry to Study RF Ablation with Needle‐Like Internally Cooled Electrode
Authors: López Molina Juan A. , Rivera María J. , Berjano Enrique
Published: January 2012

Radiofrequency (RF) ablation with internally cooled needle‐like electrodes is widely used in medical techniques such as tumor ablation. The device consists of a metallic electrode with an internal liquid cooling system that cools the electrode surface. Theoretical modeling is a rapid and inexpensive way of studying different aspects of the RF ablation process by the bioheat equation, and the analytical approach provides an exact solution to the thermal problem.
Our aim was to solve analytically the RF ablation transient time problem with a needle‐like internally cooled cylindrical electrode while considering the blood perfusion term. The results showed that the maximal tissue temperature is reached ≈3 mm from the electrode, which confirms previous experimental findings. We also observed that the temperature distributions were similar for three coolant temperature values (5 ∘C, 15 ∘C, and 25 ∘C). The differences were only notable in temperature very close to the probe. Finally, considering the 50 ∘C line as a thermal lesion mark, we found that lesion diameter was around 2 cm, which is exactly that observed experimentally in perfused hepatic tissue and slightly smaller than that observed in nonperfused (ex vivo) hepatic tissue.