bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of preceding lead-alone and lag-alone click trains on the buildup of echo suppression
Authors: Bishop Christopher W. , Yadav Deepak , London Sam , Miller Lee M.
Published: August 2014

Spatial perception in echoic environments is influenced by recent acoustic history. For instance, echo suppression becomes more effective or “builds up” with repeated exposure to echoes having a consistent acoustic relationship to a temporally leading sound. Four experiments were conducted to investigate how buildup is affected by prior exposure to unpaired lead-alone or lag-alone click trains. Unpaired trains preceded lead-lag click trains designed to evoke and assay buildup. Listeners reported how many sounds they heard from the echo hemifield during the lead-lag trains. Stimuli were presented in free field (experiments 1 and 4) or dichotically through earphones (experiments 2 and 3). In experiment 1, listeners reported more echoes following a lead-alone train compared to a period of silence. In contrast, listeners reported fewer echoes following a lag-alone train; similar results were observed with earphones. Interestingly, the effects of lag-alone click trains on buildup were qualitatively different when compared to a no-conditioner trial type in experiment 4. Finally, experiment 3 demonstrated that the effects of preceding click trains on buildup cannot be explained by a change in counting strategy or perceived click salience. Together, these findings demonstrate that echo suppression is affected by prior exposure to unpaired stimuli.
Acoustic analysis of the directional information captured by five different hearing aid styles
Authors: Durin Virginie , Carlile Simon , Guillon Pierre , Best Virginia , Kalluri Sridhar
Published: August 2014

This study compared the head-related transfer functions (HRTFs) recorded from the bare ear of a mannequin for 393 spatial locations and for five different hearing aid styles: Invisible-in-the-canal (IIC), completely-in-the-canal (CIC), in-the-canal (ITC), in-the-ear (ITE), and behind-the-ear (BTE). The spectral distortions of each style compared to the bare ear were described qualitatively in terms of the gain and frequency characteristics of the prominent spectral notch and two peaks in the HRTFs. Two quantitative measures of the differences between the HRTF sets and a measure of the dissimilarity of the HRTFs within each set were also computed. In general, the IIC style was most similar and the BTE most dissimilar to the bare ear recordings. The relative similarities among the CIC, ITC, and ITE styles depended on the metric employed. The within-style spectral dissimilarities were comparable for the bare ear, IIC, CIC, and ITC with increasing ambiguity for the ITE and BTE styles. When the analysis bandwidth was limited to 8 kHz, the HRTFs within each set became much more similar.
Prediction of negative radiation forces due to a Bessel beam
Authors: Azarpeyvand Mahdi
Published: August 2014

The mechanism of generating backward dragging forces on objects standing in the path of a single, translationally invariant, symmetric acoustic Bessel beam is studied. This paper aims to provide mechanical and structural conditions for the emergence of negative axial forces based on the elastodynamic response of acoustically penetrable objects and beam's nonparaxiality parameter. An extensive numerical study has been performed for various liquid and solid elastic cases to illustrate the validity of the proposed eigenfrequency-based conditions. Results have revealed the existence of a complex but interpretable link between the emergence of negative radiation forces on spheres illuminated by zero-order Bessel beams and the eigenfrequencies of the particle. Considerable progress has been made in elucidating these relationships, which may lead to the development of predictable and robust single-beam acoustic handling devices.
A depth-dependent formula for shallow water propagation
Authors: Özkan Sertlek Hüseyin , Ainslie Michael A.
Published: August 2014

In shallow water propagation, the sound field depends on the proximity of the receiver to the sea surface, the seabed, the source depth, and the complementary source depth. While normal mode theory can predict this depth dependence, it can be computationally intensive. In this work, an analytical solution is derived in terms of the Faddeeva function by converting a normal mode sum into an integral based on a hypothetical continuum of modes. For a Pekeris waveguide, this approach provides accurate depth dependent propagation results (especially for the surface decoupling) without requiring complex calculation methods for eigenvalues and corresponding eigenfunctions.
Autofocusing circular synthetic aperture sonar imagery using phase corrections modeled as generalized cones
Authors: Marston Timothy M. , Kennedy Jermaine L. , Marston Philip L.
Published: August 2014

Circular synthetic aperture sonar (CSAS) is a coherent aperture synthesis technique that utilizes backscattered acoustic information from an encircled scene to generate information rich, high-resolution imagery. The aperture length required for image synthesis is much longer than in its linear synthetic aperture sonar counterpart and can result in challenging phase delay and navigation estimation constraints. Residual uncorrected phase errors manifest as focus aberrations in reconstructed CSAS imagery. This paper demonstrates that phase error in image patches can be approximated as an aspect variant linear phase shift representable as a generalized cone in wave-number space. If the geometry of the generalized cone is known, it can be applied as the spectral phase of an inverse filter for aberration correction. A method is derived for reconstructing the error cone geometry from independent estimates of its local curvatures, which are found via a series of one-dimensional line searches that maximize the focus of CSAS sub-aperture images. This approach is applied to real and simulated CSAS data containing aperture distortions, and the results successfully demonstrate estimation and correction of the underlying focus aberrations.
Partial dereverberation used to characterize open circuit scuba diver signatures
Authors: Gemba Kay L. , Nosal Eva-Marie , Reed Todd R.
Published: August 2014

The use of passive acoustics to detect self-contained underwater breathing apparatus (SCUBA) divers is useful for nearshore and port security applications. While the performance of a detector can be optimized by understanding the signal's spectral characteristics, anechoic recording environments are generally not available or are cost prohibitive. A practical solution is to obtain the source spectra by equalizing the recording with the inverse of the channel's impulse response. This paper presents a dereverberation method for signal characterization that is subsequently applied to four recorded SCUBA configurations. The inverse impulse response is computed in the least-square sense, and partial dereverberation of SCUBA is performed over the 6–18 kHz band. Results indicate that early reflections and late reverberation added as much as 6.8 dB of energy. Mean unadjusted sound pressure levels computed over the 0.3–80 kHz band were 130 ± 5.9 dB re 1 μPa at 1 m. Bubble noise carries a significant amount of the total energy and masks the regulator signatures from 1.3 to 6 kHz, depending on the regulator configuration. While the dereverberation method is applied here to SCUBA signals, it is generally applicable to other sources if the impulse response of the recording environment can be obtained separately.
The role of spectro-temporal fine structure cues in lexical-tone discrimination for French and Mandarin listeners
Authors: Cabrera Laurianne , Tsao Feng-Ming , Gnansia Dan , Bertoncini Josiane , Lorenzi Christian
Published: August 2014

The role of spectro-temporal modulation cues in conveying tonal information for lexical tones was assessed in native-Mandarin and native-French adult listeners using a lexical-tone discrimination task. The fundamental frequency (F0) of Thai tones was either degraded using an 8-band vocoder that reduced fine spectral details and frequency-modulation cues, or extracted and used to modulate the F0 of click trains. Mandarin listeners scored lower than French listeners in the discrimination of vocoded lexical tones. For click trains, Mandarin listeners outperformed French listeners. These preliminary results suggest that the perceptual weight of the fine spectro-temporal modulation cues conveying F0 information is enhanced for adults speaking a tonal language.
Scattering from a finite cylinder near an interface
Authors: Fawcett John A.
Published: August 2014

In this paper, a Boundary Integral Equation Method (BIEM) is described for the computation of scattering from a finite, rigid, cylinder near a pressure release interface. The cylinder lies parallel or tilted with respect to the interface plane so that the azimuthal symmetry of the problem is destroyed. The scattering solution is first described in terms of an azimuthally symmetric free space solution. The multiple interactions of the scattered field with the interface are accounted for by an azimuthal-conversion matrix. In Sec. III, the method of this paper is benchmarked using wavefield superposition for a sphere near a pressure-release surface. Computed scattered spectra are shown for a finite cylinder, parallel and tilted with respect to the interface, and for a variety of source/receiver geometries. The differences resulting from not including multiple target/interface interactions (single scatter solution) and from including all interactions are presented. The problem of irregular frequencies for the single-scatter and the fully coupled BIEM are discussed and numerically examined.
Laboratory-scale experiment to study nonlinear N-wave distortion by thermal turbulence
Authors: Salze Édouard , Yuldashev Petr , Ollivier Sébastien , Khokhlova Vera , Blanc-Benon Philippe
Published: August 2014

The nonlinear propagation of spark-generated N-waves through thermal turbulence is experimentally studied at the laboratory scale under well-controlled conditions. A grid of electrical resistors was used to generate the turbulent field, well described by a modified von Kármán model. A spark source was used to generate high-amplitude (∼1500 Pa) and short duration (∼50 μs) N-waves. Thousands of waveforms were acquired at distances from 250 to 1750 mm from the source (∼15 to 100 wavelengths). The mean values and the probability densities of the peak pressure, the deviation angle, and the rise time of the pressure wave were obtained as functions of propagation distance through turbulence. The peak pressure distributions were described using a generalized gamma distribution, whose coefficients depend on the propagation distance. A line array of microphones was used to analyze the effect of turbulence on the propagation direction. The angle of deviation induced by turbulence was found to be smaller than 15°, which validates the use of the parabolic equation method to model this kind of experiment. The transverse size of the focus regions was estimated to be on the order of the acoustic wavelength for propagation distances longer than 50 wavelengths.
Seafloor sound-speed profile and interface dip angle characterization by the image source method
Authors: Pinson S. , Holland C. W.
Published: August 2014

The image source method is an efficient way to perform a sound-speed tomography for seafloor characterization. To date, however, it has been limited by a locally range-independent approximation. In other words, the layer boundary had to be parallel and flat within the Fresnel zone of the measurement system. Here the method is extended to take into account realistic variations of interface dip angles. To do so, the elliptical wavefront shape approximation of the reflected waves is used. This permits a fairly simple equation relating travel time to the sine of the dip angle, and consequently to an equation for the equivalent medium sound speed. The Radon transform is exploited to extract the dip angle. Simulations with varying layer dip angles and curvature provide insight into the strengths and limitations of the method.
Perceptual weights for loudness judgments of six-tone complexes
Authors: Jesteadt Walt , Valente Daniel L. , Joshi Suyash N. , Schmid Kendra K.
Published: August 2014

Subjects with normal hearing (NH) and with sensorineural hearing loss (SNHL) judged the overall loudness of six-tone complexes comprised of octave frequencies from 0.25 to 8 kHz. The level of each tone was selected from a normal distribution with a standard deviation of 5 dB, and subjects judged which of two complexes was louder. Overall level varied across conditions. In the “loudness” task, there was no difference in mean level across the two stimuli. In the “sample discrimination” task, the two complexes differed by an average of 5 dB. For both tasks, perceptual weights were derived by correlating the differences in level between matched-frequency tones in the complexes and the loudness decision on each trial. Weights obtained in the two tasks showed similar shifts from low to high frequency components with increasing overall level. Simulation of these experiments using a model of loudness perception [Moore and Glasberg (2004), Hear Res. 188, 70–88] yielded predicted weights for these stimuli that were highly correlated with predicted specific loudness, but not with the observed weights.
Calmodulin and PI(3,4,5)P
3
cooperatively bind to the Itk pleckstrin homology domain to promote efficient calcium signaling and IL-17A production
Authors: Wang Xinxin , Boyken Scott E. , Hu Jiancheng , Xu Xiaolu , Rimer Ryan P. , Shea Madeline A. , Shaw Andrey S. , Andreotti Amy H. , Huang Yina H.
Published: August 2014

Calcium and lipids stimulate the kinase Itk through the same domain to promote proinflammatory T cell signaling.
How Do Fingers Know Where to Grow?
Authors: Purnell Beverly A.
Published: August 2014

Modeling and experiments reveal how limb digits are patterned by three components.
Getting the Right Receptors to the Synapse
Authors: Gough Nancy R.
Published: August 2014

Long and short isoforms of Punctin serve as landmarks for proper clustering of postsynaptic excitatory and inhibitory receptors on muscle cells.
Complex Roles for Hedgehog Signaling in Pancreatic Cancer
Authors: Berndt Jason D.
Published: August 2014

Inhibition of Hedgehog signaling enhances the growth of pancreatic cancer in genetic mouse models.
Agmatine-Containing Poly(amidoamine)s as a Novel Class of Antiviral Macromolecules: Structural Properties and
In Vitro
Evaluation of Infectivity Inhibition
Authors: Donalisio Manuela , Ranucci Elisabetta , Cagno Valeria , Civra Andrea , Manfredi Amedea , Cavalli Roberta , Ferruti Paolo , Lembo David
Published: August 2014

Poly(amidoamine)s (PAAs) are multifunctional
tert
-amine polymers endowed with high structural versatility. Here we report on the screening of a minilibrary of PAAs against a panel of viruses. The PAA AGMA1 showed antiviral activity against herpes simplex virus, human cytomegalovirus, human papillomavirus 16, and respiratory syncytial virus but not against human rotavirus and vesicular stomatitis virus. The results suggest the contribution of both a polycationic nature and side guanidine groups in imparting antiviral activity.
Redefining Multidrug-Resistant Tuberculosis Based on Clinical Response to Combination Therapy
Authors: Gumbo Tawanda , Pasipanodya Jotam G. , Wash Peter , Burger André , McIlleron Helen
Published: August 2014

In tuberculosis treatment, susceptibility is defined by a critical concentration of 1.0 mg/liter for rifampin and 0.2 or 1.0 mg/liter for low- and high-level isoniazid resistance on the basis of an epidemiologic cutoff method that uses the distribution of the MICs for isolates. However, pharmacokinetics-pharmacodynamics-based clinical trial simulations suggested that the breakpoints should be 0.0625 mg/liter for rifampin and 0.0312 or 0.125 mg/liter for isoniazid. We examined the outcomes of 36 patients with drug-susceptible tuberculosis whose rifampin and isoniazid MICs were determined, whose plasma drug concentrations were also measured, and who were part of a prospective cohort study in Western Cape, South Africa. We performed classification and regression tree analysis to identify clinical and laboratory factors that predicted 2-month sputum conversion rates and long-term clinical outcomes. Poor long-term clinical outcomes were defined as microbiological failure, relapse, or death within a 2-year follow-up period. Peak drug concentrations and areas under the concentration-time curve were most predictive of outcomes and constituted the primary node, similar to our findings on the larger cohort. However, rifampin and isoniazid MICs improved the predictive capacity of the primary decision node by 20 and 17%, respectively, for these 36 patients. The rifampin MIC cutoff above which there was therapy failure was 0.125 mg/liter, while that of isoniazid was 0.0312 mg/liter; these are similar to those derived in clinical trial simulations. The critical concentrations used to define multidrug resistance for clinical decision making should take clinical outcomes into account.
The Combined Anti-HIV-1 Activities of Emtricitabine and Tenofovir plus the Integrase Inhibitor Elvitegravir or Raltegravir Show High Levels of SynergyIn Vitro
Authors: Kulkarni Rima , Hluhanich Rebecca , McColl Damian M. , Miller Michael D. , White Kirsten L.
Published: August 2014

Highly active antiretroviral therapy (HAART) involves combination treatment with three or more antiretroviral agents. The antiviral effects of combinations of emtricitabine (FTC) plus tenofovir (TFV) plus antiretroviral agents of all the major drug classes were investigated. Combinations of FTC and TFV with a nonnucleoside reverse transcriptase inhibitor (NNRTI) (efavirenz or rilpivirine) or with a protease inhibitor (PI) (atazanavir, lopinavir, or darunavir) showed additive to synergistic anti-HIV-1 activity. FTC-TFV with an HIV-1 integrase strand transfer inhibitor (INSTI) (elvitegravir or raltegravir) showed the strongest synergy. Anti-HIV-1 synergy suggests enhancement of individual anti-HIV-1 activities within cells that may contribute to potent treatment efficacy and open new areas of research into interactions between reverse transcriptase (RT) and integrase inhibitors.
Identification of Highly Conserved Residues Involved in Inhibition of HIV-1 RNase H Function by Diketo Acid Derivatives
Authors: Corona Angela , Di Leva Francesco Saverio , Thierry Sylvain , Pescatori Luca , Cuzzucoli Crucitti Giuliana , Subra Frederic , Delelis Olivier , Esposito Francesca , Rigogliuso Giuseppe , Costi Roberta , Cosconati Sandro , Novellino Ettore , Di Santo Roberto , Tramontano Enzo
Published: August 2014

HIV-1 reverse transcriptase (RT)-associated RNase H activity is an essential function in viral genome retrotranscription. RNase H is a promising drug target for which no inhibitor is available for therapy. Diketo acid (DKA) derivatives are active site Mg
2+
-binding inhibitors of both HIV-1 RNase H and integrase (IN) activities. To investigate the DKA binding site of RNase H and the mechanism of action, six couples of ester and acid DKAs, derived from 6-[1-(4-fluorophenyl)methyl-1
H
-pyrrol-2-yl)]-2,4-dioxo-5-hexenoic acid ethyl ester (RDS1643), were synthesized and tested on both RNase H and IN functions. Most of the ester derivatives showed selectivity for HIV-1 RNase H versus IN, while acids inhibited both functions. Molecular modeling and site-directed mutagenesis studies on the RNase H domain demonstrated different binding poses for ester and acid DKAs and proved that DKAs interact with residues (R448, N474, Q475, Y501, and R557) involved not in the catalytic motif but in highly conserved portions of the RNase H primer grip motif. The ester derivative RDS1759 selectively inhibited RNase H activity and viral replication in the low micromolar range, making contacts with residues Q475, N474, and Y501. Quantitative PCR studies and fluorescence-activated cell sorting (FACS) analyses showed that RDS1759 selectively inhibited reverse transcription in cell-based assays. Overall, we provide the first demonstration that RNase H inhibition by DKAs is due not only to their chelating properties but also to specific interactions with highly conserved amino acid residues in the RNase H domain, leading to effective targeting of HIV retrotranscription in cells and hence offering important insights for the rational design of RNase H inhibitors.
The competitiveness of Canadian softwood lumber: a disaggregated trade-flow analysis
Authors: Chang Wei-Yew , Gaston Chris
Published: August 2014

A recursive dynamic spatial equilibrium model is used to examine the global competitiveness of Canadian softwood lumber. To address the restrictive assumption of softwood lumber homogeneity, this study disaggregates softwood lumber into two product groups: (i) higher grade lumber that includes appearance, select structural-grade lumber, and Japanese J-grade lumber; and (ii) lower grade lumber that includes the United States dimension lumber that is commonly used in construction and utility- and economy-grade lumber. Factors that may affect global softwood lumber markets are simulated in the model to project global softwood lumber trade flows from 2012 to 2021. The results indicate that the reduced lumber supply in western Canada caused by the mountain pine beetle (Dendroctonus ponderosae Hopkins) infestation combined with demand increases in several regions of the world will contribute to a global increase in softwood lumber prices. Our results suggest that the global price increase will be greater for lower grade softwood lumber than for higher grade lumber. The United States and China will continue to be the top two markets for lower grade Canadian softwood lumber. Although Canadian exports of lower grade softwood lumber to the United States are expected to increase marginally over time in response to the recovery of American housing starts, softwood lumber exports to China are expected to drop significantly, and it is forecasted that exports from the Russian Federation will fill that void. These findings provide strong market signals for both forest managers and the forest-products industry to assess supply chain profitability and adjust production planning accordingly.
A financial analysis of establishing poplar plantations for carbon offsets using Alberta and British Columbia’s afforestation protocols
Authors: Anderson Jay A. , Long Amanda , Luckert M.K. (Marty)
Published: August 2014

Both Alberta and British Columbia allow the use of carbon offsets for meeting government greenhouse gas emission targets, but the provinces have different offset protocols. In British Columbia, afforested lands may be harvested yet still receive carbon offsets, whereas in Alberta, according to a yet-to-be-approved draft protocol, offsets could be contingent upon afforested lands being set aside as conservation easements. Our work considers the regulatory differences between the provincial carbon protocols as they impact the financial viability of afforestation projects in Alberta and British Columbia. Our results suggest that carbon prices would have to rise to approximately $150 per tonne of carbon dioxide equivalent (tCO2e) before conservation afforestation projects using balsam poplar would be financially viable in Alberta. However, afforesting and harvesting short-rotation hybrid poplar in British Columbia yields financially viable results under current carbon prices if stumpage prices for standing timber were to rise above $50·m–3. There may be other incentives such as the benefits from public relations associated with planting trees that may lead to the implementation of some afforestation carbon offset projects. However, it appears that financial considerations present a significant barrier, making it unlikely that afforestation of private land will play a significant role in generating carbon offsets for Alberta or British Columbia.
Analysis of the Tourism Locations of Chinese Provinces and Autonomous Regions: An Analysis Based on Cities
Authors: WANG Zheng , CHEN Lijuan
Published: August 2014

Based on the data collected from cities, this paper analyzes the conditions of tourism location of provinces and autonomous regions. For the method, this paper uses Geographic Information System (GIS) technology and statistical analysis methods to try to analyze tourism geographic conditions from the relationship of tourism industrial location and Chinese arterial highway location, so as to provide a reference for the development of regional tourism.
SmartMal: A Service-Oriented Behavioral Malware Detection Framework for Mobile Devices
Authors: Wang Chao , Wu Zhizhong , Li Xi , Zhou Xuehai , Wang Aili , Hung Patrick C. K.
Published: August 2014

This paper presents SmartMal—a novel service-oriented behavioral malware detection framework for vehicular and mobile devices. The highlight of SmartMal is to introduce service-oriented architecture (SOA) concepts and behavior analysis into the malware detection paradigms. The proposed framework relies on client-server architecture, the client continuously extracts various features and transfers them to the server, and the server’s main task is to detect anomalies using state-of-art detection algorithms. Multiple distributed servers simultaneously analyze the feature vector using various detectors and information fusion is used to concatenate the results of detectors. We also propose a cycle-based statistical approach for mobile device anomaly detection. We accomplish this by analyzing the users’ regular usage patterns. Empirical results suggest that the proposed framework and novel anomaly detection algorithm are highly effective in detecting malware on Android devices.
CountablyQC-Approximating Posets
Authors: Mao Xuxin , Xu Luoshan
Published: August 2014

As a generalization of countablyC-approximating posets, the concept of countablyQC-approximating posets is introduced. With the countablyQC-approximating property, some characterizations of generalized completely distributive lattices and generalized countably approximating posets are given. The main results are as follows: (1) a complete lattice is generalized completely distributive if and only if it is countablyQC-approximating and weakly generalized countably approximating; (2) a posetLhaving countably directed joins is generalized countably approximating if and only if the latticeσcLopof allσ-Scott-closed subsets ofLis weakly generalized countably approximating.
Cognitive Radio-Based Vehicular Ad Hoc and Sensor Networks
Authors: Jalil Piran Mohammad , Cho Yongwoo , Yun Jihyeok , Ali Amjad , Suh Doug Young
Published: August 2014

Current advancements in vehicular networking lead to amplifying the issue of spectrum scarcity. Cognitive radio (CR) has emerged as the key technology that enables flexible, efficient, and reliable spectrum exploiting by unlicensed networks to use licensed spectrum bands in an opportunistic manner to alleviate the spectrum scarcity issue. We have already proposed vehicular ad hoc and sensor networks (VASNET) as a new networking paradigm for vehicular communication by utilizing wireless sensor nodes in two mobile and stationary modes. The nodes are employed to sense vehicles' activity, for example, car crashes. Like other unlicensed networks, VASNET is supposed to operate over unlicensed spectrum bands. However, due to emergency nature of accident alarms in VASNET that must be received in minimum period of time and avoiding packet loss, in this paper we investigate CR-based VASNET, named as CR-VASNET. Various challenges and issues are discussed in details. In order to save stationary nodes' power and enlarge the network lifetime, an optimization technique for relay node selection is proposed. Furthermore, for primary users (PU) protection, an energy detection-based scheme is suggested to calculate the probability of PU arrival. Our theoretical discussions and simulation results proved the efficient functionality of the proposed CR-VASNET as a promising vehicular networking paradigm.
Twenty Traditional Algerian Plants Used in Diabetes Therapy as Strong Inhibitors of α-Amylase Activity
Authors: Khacheba Ihcen , Djeridane Amar , Yousfi Mohamed
Published: August 2014

In the present work, we have studied the inhibitory effects of aqueous and alcoholic extracts of six Algerian medicinal plants known by their therapeutic virtues against diabetes. The total phenolic compounds content, assayed using Folin-Ciocalteu’s reagent, of the samples ranged from 0.183 mg/g to 43.088 mg/g and from 1.197 mg/g to 7.445 mg/g, expressed as gallic acid equivalent (GAE), for the, respectively, whereas the total flavonoids concentrations, detected using 2% of the aluminium chloride, ranged from 0.41 mg/g to 11.613 mg/g and from 0.0097 mg/g to 1.591 mg/g, expressed as rutin equivalents (RE), for the aqueous and methanolic extracts, respectively. The major plants were found to inhibit enzymatic activities of Aspergillus oryzae-amylase in a concentration dependent manner. The values of the inhibition constants (Ki) have been determined according to the Dixon and Lineweaver-Burk methods. The results showed that the Ki values were less than 55 ppm for the all extracts. A strong inhibition was found in the phenolic extract of Salvia officinalis with a Ki of 8 ppm.
Dynamics and Matter-Wave Solitons in Bose-Einstein Condensates with Two- and Three-Body Interactions
Authors: Chen Jing , Yang Jie , Zhang Lu
Published: August 2014

By means of similarity transformation, this paper proposes the matter-wave soliton solutions and dynamics of the variable coefficient cubic-quintic nonlinear Schrödinger equation arising from Bose-Einstein condensates with time-dependent two- and three-body interactions. It is found that, under the effect of time-dependent two- and three-body interaction and harmonic potential with time-dependent frequency, the density of atom condensates will gradually diminish and finally collapse.
Morphology and Magnetic Properties of Ferriferous Two-Phase Sodium Borosilicate Glasses
Authors: Naberezhnov Alexander , Porechnaya Nadezda , Nizhankovskii Viktor , Filimonov Alexey , Nacke Bernard
Published: August 2014

This contribution is devoted to the study of morphology and magnetic properties of sodium borosilicate glasses with different concentrations (15, 20, and 25 wt.%) ofα-Fe2O3in an initial furnace charge. These glasses were prepared by a melt-quenching method. For all glasses a coexistence of drop-like and two-phase interpenetrative structures is observed. The most part of a drop structure is formed by self-assembling iron oxides particles. All types of glasses demonstrate the magnetic properties and can be used for preparation of porous magnetic matrices with nanometer through dendrite channel structure.
Some Insights to the Reuse of Dredged Marine Soils by Admixing with Activated Steel Slag
Authors: Chan Chee-Ming , Abdul Jalil Ainun Nazhirin
Published: August 2014

Regular dredging is necessary for the development of coastal regions and the maintenance of shipping channels. The dredging process dislodges sediments from the seabed, and the removed materials, termed dredged marine soils, are generally considered a geowaste for dumping. However, disposal of the dredged soils offshores can lead to severe and irreversible impact on the marine ecosystem, while disposal on land often incurs exorbitant costs with no guarantee of zero-contamination. It is therefore desirable to reuse the material, and one option is solidification with another industrial waste, that is, steel slag. This paper describes the exploratory work of admixing dredged marine soil with activated steel slag for improvement of the mechanical properties. An optimum activation concentration of NaOH was introduced to the soil-slag mixture for uniform blending. Specimens were prepared at different mix ratios then left to cure for up to 4 weeks. The unconfined compressive strength test was conducted to monitor the changes in strength at predetermined intervals. It was found that the strength does not necessarily increase with higher steel slag content, indicating an optimum slag content required for the maximum solidification effect to take place. Also, regardless of the slag content, longer curing time produces greater strength gain. In conclusion, steel slag addition to dredged sediments can effectively strengthen the originally weak soil structure by both the “cementation” and “filler” effects, though the combined effects were not distinguished in the present study.
The Photocatalytic Oxidation of 4-Chlorophenol Using Bi2WO6 under Solar Light Irradiation
Authors: Madriz Lorean , Tatá José , Vargas Ronald
Published: August 2014

This report discusses the effects of the initial concentration of 4-chlorophenol (4-CP) on its solar light photoinduced oxidation/mineralization kinetics on Bi2WO6 catalyst. Photocatalytic degradation followed the Langmuir-Hinshelwood (L-H) mechanism. From the kinetic data the Langmuir adsorption equilibrium constant of 4-CP on the Bi2WO6 surface and the L-H maximum reaction rate for 4-CP oxidation have been evaluated. Chromatographic and spectroscopy studies show the presence of p-benzoquinone and maleic acid as the main reaction products; these compounds first increase and then decay until they disappear. Chemical oxygen demand (COD) and produced CO2 measurement show that photocatalytic mineralization of the phenolic compound was readily possible in a wide concentration range.
A Facile and Waste-Free Strategy to Fabricate Pt-C/TiO2Microspheres: Enhanced Photocatalytic Performance for Hydrogen Evolution
Authors: Li Hui , Zhang Xiaoyan , Cui Xiaoli
Published: August 2014

A facile and waste-free flame thermal synthesis method was developed for preparing Pt modified C/TiO2microspheres (Pt-C/TiO2). The photocatalysts were characterized with X-ray diffraction, field emission scanning electron microscopy, transmission electron microscope, ultraviolet-visible (UV-vis) diffuse reflectance spectra, X-ray photoelectron spectroscopy, and thermogravimetry analysis. The photocatalytic activity was evaluated by hydrogen evolution from water splitting under UV-vis light illumination. Benefitting from the electron-hole separation behavior and reduced overpotential of H+/H2, remarkably enhanced hydrogen production was demonstrated and the photocatalytic hydrogen generation from 0.4 wt% Pt-C/TiO2increased by 22 times. This study also demonstrates that the novel and facile method is highly attractive, due to its easy operation, requiring no post treatment and energy-saving features.
A Negotiation-Based TDMA Scheduling with Consecutive Slots Assignment for Wireless Sensor Networks
Authors: Zeng Bo , Dong Yabo , Liu Zhidan
Published: August 2014

TDMA protocols are recognized to save energy consumption by avoiding unnecessary idle listening and communication collision. As sensor nodes are usually equipped with limited resource supply, they are thus desirable to improve network capacity and energy efficiency by adopting TDMA scheduling for wireless sensor networks (WSNs). This paper proposes a TDMA scheduling approach, which reuses time slots among sensor nodes, for WSNs. Specifically, with the idea of consecutive slots assignment, our approach can reduce both the time and energy cost of establishing nodes' schedule. Furthermore, the energy of node's switching is also reduced. To avoid the transmission of a node's result interference to all irrelevant receivers within its interference range, we develop a slot negotiation mechanism for slot assignment. We perform extensive simulations in NS-2 to evaluate our proposed approach. The results show that our approach outperforms existing TDMA scheduling in terms of time and energy overhead.
RSM Based Optimization of Chemical and Enzymatic Transesterification of Palm Oil: Biodiesel Production and Assessment of Exhaust Emission Levels
Authors: Mumtaz Muhammad Waseem , Mukhtar Hamid , Anwar Farooq , Saari Nazamid
Published: August 2014

Current study presents RSM based optimized production of biodiesel from palm oil using chemical and enzymatic transesterification. The emission behavior of biodiesel and its blends, namely, POB-5, POB-20, POB-40, POB-50, POB-80, and POB-100 was examined using diesel engine (equipped with tube well). Optimized palm oil fatty acid methyl esters (POFAMEs) yields were depicted to be47.6±1.5, 92.7±2.5, and95.4±2.0% for chemical transesterification catalyzed by NaOH, KOH, and NaOCH3, respectively, whereas for enzymatic transesterification reactions catalyzed by NOVOZYME-435 and A. n. lipase optimized biodiesel yields were94.2±3.1and62.8±2.4%, respectively. Distinct decrease in particulate matter (PM) and carbon monoxide (CO) levels was experienced in exhaust emissions from engine operating on biodiesel blends POB-5, POB-20, POB-40, POB-50, POB-80, and POB-100 comparative to conventional petroleum diesel. Percentage change in CO and PM emissions for different biodiesel blends ranged from −2.1 to −68.7% and −6.2 to −58.4%, respectively, relative to conventional diesel, whereas an irregular trend was observed for NOx emissions. Only POB-5 and POB-20 showed notable reductions, whereas all other blends (POB-40 to POB-100) showed slight increase in NOx emission levels from 2.6 to 5.5% comparative to petroleum diesel.
A New Approach for Resolving Conflicts in Actionable Behavioral Rules
Authors: Su Peng , Zhu Dan , Zeng Daniel
Published: August 2014

Knowledge is considered actionable if users can take direct actions based on such knowledge to their advantage. Among the most important and distinctive actionable knowledge are actionable behavioral rules that can directly and explicitly suggest specific actions to take to influence (restrain or encourage) the behavior in the users’ best interest. However, in mining such rules, it often occurs that different rules may suggest the same actions with different expected utilities, which we call conflicting rules. To resolve the conflicts, a previous valid method was proposed. However, inconsistency of the measure for rule evaluating may hinder its performance. To overcome this problem, we develop a new method that utilizes rule ranking procedure as the basis for selecting the rule with the highest utility prediction accuracy. More specifically, we propose an integrative measure, which combines the measures of the support and antecedent length, to evaluate the utility prediction accuracies of conflicting rules. We also introduce a tunable weight parameter to allow the flexibility of integration. We conduct several experiments to test our proposed approach and evaluate the sensitivity of the weight parameter. Empirical results indicate that our approach outperforms those from previous research.
Community Analysis of Arbuscular Mycorrhizal Fungi in Roots ofPoncirus trifoliataandCitrus reticulataBased on SSU rDNA
Authors: Wang Peng , Wang Yin
Published: August 2014

Morphological observation of arbuscular mycorrhizal fungi (AMF) species in rhizospheric soil could not accurately reflect the actual AMF colonizing status in roots, while molecular identification of indigenous AMF colonizing citrus rootstocks at present was rare in China. In our study, community of AMF colonizing trifoliate orange (Poncirus trifoliataL. Raf.) and red tangerine (Citrus reticulataBlanco) were analyzed based on small subunit of ribosomal DNA genes. Morphological observation showed that arbuscular mycorrhizal (AM) colonization, spore density, and hyphal length did not differ significantly between two rootstocks. Phylogenetic analysis showed that 173 screened AMF sequences clustered in at least 10 discrete groups (GLO1~GLO10), all belonging to the genus ofGlomusSensu Lato. Among them, GLO1 clade (clustering with uncultured Glomus) accounting for 54.43% clones was the most common in trifoliate orange roots, while GLO6 clade (clustering withGlomus intraradices) accounting for 35.00% clones was the most common in red tangerine roots. Although, Shannon-Wiener indices exhibited no notable differences between both rootstocks, relative proportions of observed clades analysis revealed that composition of AMF communities colonizing two rootstocks varied severely. The results indicated that native AMF species in citrus rhizosphere had diverse colonization potential between two different rootstocks in the present orchards.
Optimal Energy‐Efficient Sensing and Power Allocation in Cognitive Radio Networks
Authors: Wu Xia , Xu Jin-Ling , Chen Ming , Wang Junbo
Published: August 2014

We consider a joint optimization of sensing parameter and power allocation for an energy‐efficient cognitive radio network (CRN) in which the primary user (PU) is protected. The optimization problem to maximize the energy efficiency of CRN is formulated as a function of two variables, which are sensing time and transmit power, subject to the average interference power to the PU and the target detection probability. During the optimizing process, the quality of service parameter (the minimum rate acceptable to secondary users (SUs)) has also been taken into consideration. The optimal solutions are analyzed and an algorithm combined with fractional programming that maximizes the energy efficiency for CRN is presented. Numerical results show that the performance improvement is achieved by the joint optimization of sensing time and power allocation.
Diversity and Antimicrobial Activities of Actinobacteria Isolated from Tropical Mangrove Sediments in Malaysia
Authors: Lee Learn-Han , Zainal Nurullhudda , Azman Adzzie-Shazleen , Eng Shu-Kee , Goh Bey-Hing , Yin Wai-Fong , Ab Mutalib Nurul-Syakima , Chan Kok-Gan
Published: August 2014

The aim of this study was to isolate and identify Actinobacteria from Malaysia mangrove forest and screen them for production of antimicrobial secondary metabolites. Eighty-seven isolates were isolated from soil samples collected at 4 different sites. This is the first report to describe the isolation ofStreptomyces, Mycobacterium, Leifsonia, Microbacterium, Sinomonas, Nocardia, Terrabacter, Streptacidiphilus, Micromonospora, Gordonia, andNocardioidesfrom mangrove in east coast of Malaysia. Of 87 isolates, at least 5 isolates are considered as putative novel taxa. NineStreptomycessp. isolates were producing potent antimicrobial secondary metabolites, indicating thatStreptomycesisolates are providing high quality metabolites for drug discovery purposes. The discovery of a novel species,Streptomyces pluripotenssp. nov. MUSC135Tthat produced potent secondary metabolites inhibiting the growth of MRSA, had provided promising metabolites for drug discovery research. The biosynthetic potential of 87 isolates was investigated by the detection of polyketide synthetase (PKS) and nonribosomal polyketide synthetase (NRPS) genes, the hallmarks of secondary metabolites production. Results showed that many isolates were positive for PKS-I (19.5%), PKS-II (42.5%), and NRPS (5.7%) genes, indicating that mangroveActinobacteriahave significant biosynthetic potential. Our results highlighted that mangrove environment represented a rich reservoir for isolation ofActinobacteria, which are potential sources for discovery of antimicrobial secondary metabolites.
Seroepidemiology of Hepatitis B and C Viruses in the General Population of Burkina Faso
Authors: Tao Issoufou , Compaoré Tegwindé R. , Diarra Birama , Djigma Florencia , Zohoncon Theodora M. , Assih Maléki , Ouermi Djeneba , Pietra Virginio , Karou Simplice D. , Simpore Jacques
Published: August 2014

Objectives. In Burkina Faso, few studies reported the prevalence of HBV and HCV in the general population. This study aimed to evaluate the prevalence of hepatitis B and C viruses in the general population and to determine the most affected groups in relation to the risk factors associated with the infection. Method. A voluntary testing opened to anyone interested was held at Saint Camille Medical Centre in Ouagadougou. Rapid tests were carried out on 995 persons who voluntarily answered a range of questions before the venous blood sampling. Results. The results revealed that the antigen HBs carriers in the general population represented 14.47% (144/995) and the prevalence of HCV was 1.00% (10/995). The difference between HBV’s prevalence in men (18.58%) and that in women (11.60%) was statistically significant (P = 0.002). The most affected groups were undergraduated students (19.57%) and persons working in the informal sector (15.98%). The least affected group was high level students (8.82%). Conclusion. Burkina Faso is a country with a high prevalence of HBV, while the incidence of HCV is still low in the general population. Therefore, more campaigns on the transmission routes of HBV and HCV are needed to reduce the spread of these viruses in sub-Saharan Africa.
Effects ofHelicobacter pyloriand Heat Shock Protein 70 on the Proliferation of Human Gastric Epithelial Cells
Authors: Tao Liping , Zou Hai , Huang Zhimin
Published: August 2014

Infection ofHelicobacter pylori (H. pylori)changed the proliferation of gastric epithelial cells and decreased the expression of heat shock protein 70 (HSP70). However, the effects ofH. pylorion the proliferation of gastric epithelial cells and the roles of HSP70 during the progress need further investigation.Objective.To investigate the effects ofHelicobacter pylori (H. pylori)and heat shock protein 70 (HSP70) on the proliferation of human gastric epithelial cells.Methods. H. pyloriand a human gastric epithelial cell line (AGS) were cocultured. The proliferation of AGS cells was quantitated by an MTT assay, and the expression of HSP70 in AGS cells was detected by Western blotting. HSP70 expression in AGS cells was silenced by small interfering RNA (siRNA) to investigate the role of HSP70. ThesiRNA-treated AGS cells were cocultured withH. pyloriand cell proliferation was measured by an MTT assay.Results.The proliferation of AGS cells was accelerated by coculturing withH. pylorifor 4 and 8 h, but was suppressed at 24 and 48 h. HSP70 expression was decreased in AGS cells infected byH. pylorifor 48 h. The proliferation in HSP70-silenced AGS cells was inhibited after coculturing withH. pylorifor 24 and 48 h compared with the control group.Conclusions.Coculture ofH. pylorialtered the proliferation of gastric epithelial cells and decreased HSP70 expression. HSP70 knockdown supplemented the inhibitory effect ofH. pylorion proliferation of epithelial cells. These results indicate that the effects ofH. pylorion the proliferation of gastric epithelial cells at least partially depend on the decreased expression of HSP70 induced by the bacterium.
AdenosineA2AReceptors Modulate Acute Injury and Neuroinflammation in Brain Ischemia
Authors: Pedata Felicita , Pugliese Anna Maria , Coppi Elisabetta , Dettori Ilaria , Maraula Giovanna , Cellai Lucrezia , Melani Alessia
Published: August 2014

The extracellular concentration of adenosine in the brain increases dramatically during ischemia. AdenosineA2Areceptor is expressed in neurons and glial cells and in inflammatory cells (lymphocytes and granulocytes). Recently, adenosineA2Areceptor emerged as a potential therapeutic attractive target in ischemia. Ischemia is a multifactorial pathology characterized by different events evolving in the time. After ischemia the early massive increase of extracellular glutamate is followed by activation of resident immune cells, that is, microglia, and production or activation of inflammation mediators. Proinflammatory cytokines, which upregulate cell adhesion molecules, exert an important role in promoting recruitment of leukocytes that in turn promote expansion of the inflammatory response in ischemic tissue. Protracted neuroinflammation is now recognized as the predominant mechanism of secondary brain injury progression.A2Areceptors present on central cells and on blood cells account for important effects depending on the time-related evolution of the pathological condition. Evidence suggests thatA2Areceptor antagonists provide early protection via centrally mediated control of excessive excitotoxicity, whileA2Areceptor agonists provide protracted protection by controlling massive blood cell infiltration in the hours and days after ischemia. Focus on inflammatory responses provides for adenosineA2Areceptor agonists a wide therapeutic time-window of hours and even days after stroke.