bluuebunny/crossref_metadata_2025 huggingface dataset:
CORRELATION AMONG METALLIC IONS, PHENOLIC COMPOUNDS AND ANTIMICROBIAL ACTION IN MEDICINAL PLANTS EXTRACTS
Authors: DUCAT GISELI , TORRES YOHANDRA REYES , DALLA SANTA HERTA STUTZ , CAETANO ISIS KAMINSKI , KLEINUBING SIRLENE ADRIANA , STOCK DANIELE , TUSSOLINI LOYSE , JUSTO TAIS HOBOLD , QUINÁIA SUELI PÉRCIO
Published: October 2011

The extracts of three different medicinal plants –Calendula officinalis L., Maytenus ilicifolia Martius ex Reissek and Cymbopogon citratus (DC) Stapf – obtained with 70% and 95% v/v ethanol had their antimicrobial activity tested against five pathogenic microorganisms. A quantitative analysis of total phenols, flavonoids and mineral species was performed on the extracts using UV‐vis spectroscopy and atomic absorption spectroscopy. Klebsiella pneumoniae showed the greatest sensibility to the extracts tested. The mineral content of the medicinal herbs varied according to the type of plant (Cu = not detected to 10.90; Zn = 0.85 to 10.04; Na = 24.94 to 153.62; Al = 90.04 to 420.39; Mg = 9.62 to 1,129.15; Ca = 7.15 to 167.27 and K = 913.85 to 9,578.94 µg/g); however, the concentration of heavy elements (Pb, Cd and Cr) was null in the extracts. The concentrations of flavonoids ranged from 13.55 to 41.54 mg/g and 92.35 to 518.28 mg/g for phenolic acids.

PRACTICAL APPLICATIONS

The use of plants with pharmacological activities has increased significantly because of their functional properties in the diet for the promotion of human health and antimicrobial effects. Moreover, medicinal herbs play an important role in public health, especially in developing countries. In Brazil, the use of plant extracts in the treatment of certain diseases is very common. This habit can be explained, at least in part, by the belief that herbs with therapeutic effects do not have toxic effects on the organism. In this paper, ethanolic extracts of three medicinal plants, widely cultivated and used by the population of Brazil and worldwide, had their levels of metals ions and total phenolic compounds determined. Antimicrobial activity of the extracts was evaluated against foodborne pathogens or food spoilage organisms or clinically isolates microorganisms.
3D‐QSAR and Molecular Docking Studies on Substituted Isothiazole Analogs as Inhibitors Against MEK‐1 Kinase
Authors: Reddy Bandi Madhusudhan , Tanneeru Karunakar , Meetei Potshangbam Angamba , Guruprasad Lalitha
Published: October 2011

MEK‐1 and MEK‐2 are dual‐specificity kinases and important components in the mitogen‐activated protein kinase pathway. These enzymes are crucial for normal cell survival and are also expressed in several types of cancers, making them important targets for drug design. We have applied an integrated in silico approach that combines comparative molecular field analysis, comparative molecular similarity indices analysis, and molecular docking to study the structural determinants for the recognition of substituted isothiazole analogs as allosteric inhibitors against MEK‐1 kinase. The best 3D‐QSAR models for comparative molecular field analysis and comparative molecular similarity indices analysis were selected based on statistical parameters. 3D contour maps suggested that bulky or long‐chain substitutions at the X position on the core part decrease the inhibitory activity, and the presence of a hydrogen bond donor substitution enhances the activity. The bulky and electronegative substitutions at the Y position on the core part enhance the activity of the inhibitors. Molecular docking studies reveal a large and hydrophobic pocket that accommodates the Y substitution and a polar pocket that accommodates substitutions on the X position and forms hydrogen bonding interactions with MEK‐1 kinase. The results of the 3D‐QSAR analysis corroborate with the molecular docking results, and our findings will serve as a basis for further development of better allosteric inhibitors of MEK‐1 kinase against several cancers.
Organ‐Specific Responses to Circulatory Disturbances in Heart Failure: New Insights
Authors: Argulian Edgar , McPherson Craig , Kukin Marrick
Published: October 2011

Recent studies have provided new insights into the pathophysiology of congestive heart failure. Organ‐specific responses to circulatory disturbances may differ via a hypoperfusion state and a venous congestion state. The liver and the kidneys serve as a good example of a differential injury pattern based on the predominant circulatory insult. Cardiorenal syndrome appears to be a kidney‐specific response to predominantly right‐sided backward heart failure (“congestive state”), rather than forward heart failure. Despite significant progress in our understanding of cardiorenal interactions, there is no specific therapy for the cardiorenal syndrome, which is a marker of the severity of the heart failure state. ©2011 Wiley Periodicals, Inc.
Remineralization and acid resistance of enamel lesions after chewing gum containing fluoride extracted from green tea
Authors: Suyama E , Tamura T , Ozawa T , Suzuki A , Iijima Y , Saito T
Published: October 2011

Background:  The aim of this study was to evaluate enamel remineralization and the acquisition of acid resistance by using sugar‐free chewing gum containing fluoride extracted from green tea.

Methods:  Forty‐five volunteers participated in a crossover, double‐blind study and wore intraoral appliances with human demineralized enamel. Subjects chewed fluoride chewing gum (FCG: 50 μg fluoride) or placebo gum. Remineralization and acid resistance were evaluated using the mineral change value (ΔZ, in vol%·μm). Fluoride concentrations in saliva and remineralized enamel were analysed.

Results:  The peak salivary fluoride concentration was 3.93 ± 1.28 ppm (mean ± SD). The elevated salivary fluoride concentration resulted in a higher fluoride concentration of 656 ± 95 ppm in the remineralized region versus 159 ± 26 ppm for placebo gum (p < 0.001). After remineralization, the ΔZ of the FCG group was higher than that of the placebo gum group. After an acid challenge, ΔZ of the FCG group was lower than the placebo gum group. Both ΔZ were statistically significant.

Conclusions:  FCG produced a superior level of remineralization and acid resistance, as compared to the placebo gum. The in situ results suggest that regular use of FCG is useful for preventing dental caries.
Dissociable neural systems for analogy and metaphor: Implications for the neuroscience of creativity
Authors: Vartanian Oshin
Published: October 2011

Two recent reviews of the neuroimaging literature on creativity have pointed to inconsistent findings across studies, calling into question the usefulness of the theoretical constructs motivating the search for its neural bases. However, it is argued that consistent patterns of neural activation do emerge when the cognitive process and the neuroimaging method are kept uniform across studies. To demonstrate this empirically, the activation likelihood estimation (ALE) method was used to conduct quantitative meta‐analyses of functional magnetic resonance imaging (fMRI) experiments of analogy and metaphor – two processes related to creativity and included in the recent reviews. The results demonstrated that analogy and metaphor reliably activate consistent but dissociable brain regions across fMRI studies. The implications of the findings for cognitive theories of analogy and metaphor are discussed. Furthermore, these results demonstrate that to the extent that creativity has heterogeneous sources, its neural instantiation will vary as a function of the underlying cognitive processes.
Service‐users’ experiences of an early intervention in psychosis service: An interpretative phenomenological analysis
Authors: Harris Katy , Collinson Christine , das Nair Roshan
Published: October 2011

Objectives. Previous research regarding Early Intervention in Psychosis (EIP) services has mainly adopted quantitative methodologies, in order to study the effectiveness of EIP services. Research studies that have explored service‐users’ experiences of EIP services are small in number. This research aimed to explore service‐users’ experiences of being in contact with an EIP service, its impact of their experience of psychosis and current life situation.

Design. Interpretative Phenomenological Analysis (IPA) was used to conduct an in‐depth qualitative study of a small sample of EIP service‐users, in order to explore their experiences of being in contact with the service.

Method. Flexibly guided interviews were conducted with eight service‐users who had been receiving a service from an EIP team for more than 2 years and were recruited using a purposive sampling method. Verbatim interview transcripts were analysed using IPA.

Results. Five super‐ordinate themes, developed from the analysis, are discussed in sections: Stigma, Relationships, Understanding the experiences, Sense of agency, and Impact on sense of self. Sub‐themes of these super‐ordinate themes are also discussed.

Conclusions. The themes developed from the analysis were envisioned as representing an overarching theme of ‘A personal journey of recovery’, which was influenced by participants’ involvement with the EIP service. Clinical implications include the need for EIP services, as with other mental health services, to find ways to promote recovery and create opportunities for agency and control. Future research directions are also discussed.
Transient Wax Gel Formation Model for Shut-In Subsea Pipelines
Authors: Ekweribe Chiedozie , Civan Faruk
Published: October 2011

Physics of wax gel formation during shut-in is analyzed and described over a cross-section of a typical subsea pipeline. Two regions are identified during this process: the liquid and gel regions. Phase transition is assumed to occur at the liquid-gel interface. Unsteady-state heat and mass transfer models are proposed for each region. Two diffusion streams are evaluated: the dissolved wax molecules moving from the pipe center toward the wall due to temperature gradient and subsequently concentration gradient and the wax molecules diffusing from the liquid-gel interface into the gel deposit. This model is essentially the modification of the model given by Bhat et al. [1] which considered transient heat transfer and neglected mass transfer of wax molecules through the gel deposit and the model by Singh et al. [2] which considered transient mass transfer of molecules with carbon numbers higher than the` critical carbon number (CCN) necessary for wax diffusion into gel deposit but did not consider transient heat transfer effects during the cooling process. This paper presents a transient-state formulation circumventing the limitations of these previous models and better represents the true cooling and gelation process occurring in a shut-in subsea pipeline filled with waxy crude.
Mask roughness challenges in extreme ultraviolet mask development
Authors: Naulleau Patrick , McClinton Brittany , Goldberg Kenneth A. , Mochi Iacopo , Rastegar Abbas
Published: October 2011

Despite significant progress in the commercialization of extreme ultraviolet (EUV) lithography, many challenges remain. Although availability of a reliable high power source is arguably the most daunting of these challenges, important mask issues are also of major concern. The issue of EUV phase roughness that can arise from either multilayer or capping layer roughness has recently become of increasing concern. The problem with mask phase roughness is that it couples to image plane speckle and thus line-edge roughness (LER). The coupling; however, depends on many factors including roughness magnitude, roughness correlation length, illumination partial coherence, aberrations and defocus, and numerical aperture. Analysis shows that only on the order of 50 pm multilayer roughness may be tolerable at the 22 nm half-pitch node. The analysis; however, also shows that the difficulty does not scale with future node reductions. Moreover, it is found that ruthenium is a particularly bad choice for capping layer from the perspective of phase roughness and that cleaning damage in such a multilayer could lead to unacceptable image-plane LER.
Fabrication of hybrid metal island/silicon single electron transistor
Authors: Lee Yen-Chun , Orlov Alexei O. , Snider Gregory L.
Published: October 2011

A novel process for silicon single electron transistors (Si-SET) is presented, combining chemical mechanical polishing (CMP) with the advantages of silicon processing. To eliminate effects caused by random distribution of dopants in the island, The Si-SET’s doped-Si island is replaced with an aluminum or tantalum island by integrating a metal CMP technique with our nano-encapsulation process. The fabricated hybrid Al-island Si-SET has ∼10 nm silicon on insulator lines as the source and drain leads. It shows characteristic Coulomb blockade oscillations with a charging energy of ∼4 meV. The fabrication results demonstrate the scalability of the SET island and the tunnel junction size in a manufacturable top-down approach.
Nanocoating zinc alkoxide (zincone) hybrid polymer films on particles using a fluidized bed reactor
Authors: Liang Xinhua , Jiang Ying-Bing , Weimer Alan W.
Published: October 2011

Ultrathin zinc alkoxide (zincone) hybrid polymer films were coated on large quantities of primary titania nanoparticles using molecular layer deposition (MLD) in a fluidized bed reactor. Diethyl zincand ethylene glycol were used as reactants at a reaction temperature of 80 or 120 °C. The composition and conformal zincone films were confirmed by x-ray photoelectron spectroscopy and TEM, respectively. The growth rate was higher at a lower reaction temperature. Primary nanoparticles were coated individually despite their strong tendency to aggregate during fluidization. Porous zinc oxide was formed by the oxidation of the hybrid zincone films in air at 400 °C. The surface area of the porous film itself was ∼40 m2/g for the MLD films after oxidation at 250 °C, and 31 m2/g for the films after oxidation at 400 °C. Methylene blue oxidation tests indicated that the zincone MLD film can reduce the photoactivity of TiO2 particles, but the passivation effect of the aged zincone films decreased due to the decomposition of zincone in the presence of water at room temperature to form a more stable composite containing zinc. The passivation effect of the oxidized zincone films further decreased due to the nonuniformity of the zinc oxide films after crystallization during the oxidation process.
Noise interferometry in an inhomogeneous environment in the geometric limit
Authors: Brown Michael G.
Published: October 2011

An approximation to the transient Green’s function G(xa|xb,t) between points xa and xb can be estimated by taking the time derivative of the correlation function Cab(t) of records of ambient noise measured at locations xa and xb. From the general relationship between Cab(t) and G(xa|xb,t) it is shown, using a stationary-phase-like argument, that in an inhomogeneous environment in the geometric limit Cab(t) consists of a superposition of signed step functions and two-sided logarithmic singularities that are delayed in time by the travel times of the rays connecting xa and xb.
Urban road traffic noise and annoyance: The effect of a quiet façade
Authors: Kluizenaar Yvonne de , Salomons Erik M. , Janssen Sabine A. , van Lenthe Frank J. , Vos Henk , Zhou Han , Miedema Henk M. E. , Mackenbach Johan P.
Published: October 2011

Road traffic noise in urban areas is a major source of annoyance. A quiet façade has been hypothesized to beneficially affect annoyance. However, only a limited number of studies investigated this hypothesis, and further quantification is needed. This study investigates the effect of a relatively quiet façade on the annoyance response. Logistic regression was performed in a large population based study (GLOBE, N∼18 000), to study the association between road traffic noise exposure at the most exposed dwelling façade (Lden) and annoyance in: (1) The subgroup with a relatively quiet façade (large difference in road traffic noise level between most and least exposed façade (Q > 10 dB); (2) the subgroup without a relatively quiet façade (Q < 10 dB). Questionnaire data were linked to individual exposure assessment based on detailed spatial data (GIS) and standard modeling techniques. Annoyance was less likely (ORQ >10 < ORQ < 10) in the subgroup with relatively quiet façade compared to the subgroup without relatively quiet façade. The difference in response between groups seemed to increase with increasing Q and Lden. Results indicate that residents may benefit from a quiet façade to the dwelling.
The relative effects of particles and turbulence on acoustic scattering from deep-sea hydrothermal vent plumes
Authors: Xu Guangyu , Di Iorio Daniela
Published: October 2011

Acoustic methods are applied to the investigation and monitoring of a vigorous hydrothermal plume within the Main Endeavor vent field at the Endeavor segment of the Juan de Fuca Ridge. Forward propagation and scattering from suspended particulates using Rayleigh scattering theory is shown to be negligible (log-amplitude variance σχ2~10-7) compared to turbulence induced by temperature fluctuations (σχ2~0.1). The backscattering from turbulence is then quantified using the forward scattering derived turbulence level, which gives a volume backscattering strength of sV = 6.5 × 10−8 m−1. The volume backscattering cross section from particulates can range from sV = 3.3 × 10−6 to 7.2 × 10−10 m−1 depending on the particle size. These results show that forward scatter acoustic methods in hydrothermal vent applications can be used to quantify turbulence and its effect on backscatter measurements, which can be a dominant factor depending on the particle size and its location within the plume.
Control of phonemic length contrast and speech rate in vocalic and consonantal syllable nuclei
Authors: Beňuš Štefan
Published: October 2011

This paper investigates the mechanisms controlling the phonemic quantity contrast and speech rate in nonsense p1Np2a words read by five Slovak speakers in normal and fast speech rate. N represents a syllable nucleus, which in Slovak corresponds to long and short vowels and liquid consonants. The movements of the lips and the tongue were recorded with an electromagnetometry system. Together with the acoustic durations of p1, N, and p2, gestural characteristics of three core movements were extracted: p1 lip opening, tongue movement for (N)ucleus, and p2 lip closing. The results show that, although consonantal and vocalic nuclei are predictably different on many kinematic measures, their common phonological behavior as syllabic nuclei may be linked to a stable temporal coordination of the consonantal gestures flanking the nucleus. The functional contrast between phonemic duration and speech rate was reflected in the bias in the control mechanisms they employed: the strategies robustly used for signaling phonemic duration, such as the degree of coproduction of the two lip movements, showed a minimal effect of speech rate, while measures greatly affected by speech rate, such as p2 acoustic duration, or the degree of p1-N gestural coproduction, tended to be minimally influenced by phonemic quantity.
Limitations of the equivalence between spatial and ensemble estimators in the case of a single-tone excitation
Authors: Monsef Florian , Cozza Andrea
Published: October 2011

The ensemble-average value of the mean-square pressure is often assessed by using the spatial-average technique, underlying an equivalence principle between spatial and ensemble estimators. Using the ideal-diffuse-field model, the accuracy of the spatial-average method has been studied theoretically forty years ago in the case of a single-tone excitation. This study is revisited in the present work on the basis of a more realistic description of the sound field accounting for a finite number of plane waves. The analysis of the spatial-average estimator is based on the study of its convergence rate. Using experimental data from practical examples, it is shown that the classical expression underestimates the estimator uncertainty even for frequencies greater than Schroeder’s frequency, and that the number of plane waves may act as lower bound on the spatial-average estimator accuracy. The comparison of the convergence rate with an ensemble-estimator shows that the two statistics cannot be regarded as equivalent in a general case.
Psychoacoustic evaluation of multichannel reproduced sounds using binaural synthesis and spherical beamforming
Authors: Song Wookeun , Ellermeier Wolfgang , Hald Jørgen
Published: October 2011

The binaural auralization of a 3D sound field using spherical-harmonics beamforming (SHB) techniques was investigated and compared with the traditional method using a head-and-torso simulator (HATS). The new procedure was verified by comparing simulated room impulse responses with measured ones binaurally. The objective comparisons show that there is good agreement in the frequency range between 0.1 and 6.4 kHz. A listening experiment was performed to validate the SHB method subjectively and to compare it to the HATS method. Two musical excerpts, pop and classical, were used. Subjective responses were collected in two head rotation conditions (fixed and rotating) and six spatial reproduction modes, including phantom mono, stereo, and surround sound. The results show that subjective scales of width, spaciousness, and preference based on the SHB method were similar to those obtained for the HATS method, although the width and spaciousness of the stimuli processed by the SHB method were judged slightly higher than the ones using the HATS method in general. Thus, binaural synthesis using SHB may be a useful tool to reproduce a 3D sound field binaurally, while saving considerably on measurement time because head rotation can be simulated based on a single recording.
Nonlinear shear wave interaction at a frictional interface: Energy dissipation and generation of harmonics
Authors: Meziane A. , Norris A. N. , Shuvalov A. L.
Published: October 2011

Analytical and numerical modeling of the nonlinear interaction of shear wave with a frictional interface is presented. The system studied is composed of two homogeneous and isotropic elastic solids, brought into frictional contact by remote normal compression. A shear wave, either time harmonic or a narrow band pulse, is incident normal to the interface and propagates through the contact. Two friction laws are considered and the influence on interface behavior is investigated: Coulomb’s law with a constant friction coefficient and a slip-weakening friction law which involves static and dynamic friction coefficients. The relationship between the nonlinear harmonics and the dissipated energy, and the dependence on the contact dynamics (friction law, sliding, and tangential stress) and on the normal contact stress are examined in detail. The analytical and numerical results indicate universal type laws for the amplitude of the higher harmonics and for the dissipated energy, properly non-dimensionalized in terms of the pre-stress, the friction coefficient and the incident amplitude. The results suggest that measurements of higher harmonics can be used to quantify friction and dissipation effects of a sliding interface.
Time reversal communication in a time-varying sparse channel
Authors: Song H. C.
Published: October 2011

Recently time reversal (TR) communications has been extended to time-varying channels. The basic idea is to implement it on a block-by-block basis such that within each block the channel remains time-invariant and subsequently is updated using detected symbols (decision-directed mode). Using experimental data (12–20 kHz) collected in shallow water, this letter investigates three different block-based TR approaches: (1) without explicit phase tracking, (2) with phase tracking, and (3) exploiting channel sparsity. The TR approaches then are compared to a conventional adaptive multichannel equalizer. It is found that approach (3) generally provides the best performance and robustness.
A note about insensitivity to pitch-change direction
Authors: Mathias Samuel R. , Bailey Peter J. , Semal Catherine , Demany Laurent
Published: October 2011

Some listeners are insensitive to the direction of pure-tone frequency changes when the standard frequency is roved widely over trials, but less so when the standard frequency is fixed and trial-by-trial feedback is provided. The present experiment tested the hypothesis that fixing the standard frequency and providing feedback is advantageous for direction-impaired listeners because under these conditions the listeners can learn to respond correctly without genuinely perceiving frequency-change direction. This hypothesis was ruled out by the experiment. It appears instead that direction-impaired listeners find it difficult to ignore the irrelevant frequency changes introduced by roving.
Range aliasing in frequency coherent geoacoustic inversion
Authors: Yardim Caglar , Gerstoft Peter , Hodgkiss William S.
Published: October 2011

This paper discusses the effects of frequency selection on source localization and geoacoustic inversion methods that use frequency coherent objective functions. Matched-field processors based on frequency-coherent objective functions often have rapidly fluctuating range ambiguity surfaces. Insufficient sampling in frequency domain results in range aliasing terms that affect geoacoustic inversion. Range aliasing and its effects on source localization and environmental parameter inversion are demonstrated on data collected during the MAPEX2000 experiment. Guidance for frequency selection to avoid range aliasing is provided.
Cross-language perceptual similarity predicts categorial discrimination of American vowels by naïve Japanese listeners
Authors: Strange Winifred , Hisagi Miwako , Akahane-Yamada Reiko , Kubo Rieko
Published: October 2011

Current speech perception models propose that relative perceptual difficulties with non-native segmental contrasts can be predicted from cross-language phonetic similarities. Japanese (J) listeners performed a categorical discrimination task in which nine contrasts (six adjacent height pairs, three front/back pairs) involving eight American (AE) vowels [iː, ɪ, ɛ, æː, ɑː, ʌ, ʊ, uː] in /hVbə/ disyllables were tested. The listeners also completed a perceptual assimilation task (categorization as J vowels with category goodness ratings). Perceptual assimilation patterns (quantified as categorization overlap scores) were highly predictive of discrimination accuracy (rs = 0.93). Results suggested that J listeners used both spectral and temporal information in discriminating vowel contrasts.
Perception of interrupted speech: Effects of dual-rate gating on the intelligibility of words and sentences
Authors: Shafiro Valeriy , Sheft Stanley , Risley Robert
Published: October 2011

Perception of interrupted speech and the influence of speech materials and memory load were investigated using one or two concurrent square-wave gating functions. Sentences (Experiment 1) and random one-, three-, and five-word sequences (Experiment 2) were interrupted using either a primary gating rate alone (0.5−24 Hz) or a combined primary and faster secondary rate. The secondary rate interrupted only speech left intact after primary gating, reducing the original speech to 25%. In both experiments, intelligibility increased with primary rate, but varied with memory load and speech material (highest for sentences, lowest for five-word sequences). With dual-rate gating of sentences, intelligibility with fast secondary rates was superior to that with single rates and a 25% duty cycle, approaching that of single rates with a 50% duty cycle for some low and high rates. For dual-rate gating of words, the positive effect of fast secondary gating was smaller than for sentences, and the advantage of sentences over word-sequences was not obtained in many dual-rate conditions. These findings suggest that integration of interrupted speech fragments after gating depends on the duration of the gated speech interval and that sufficiently robust acoustic-phonetic word cues are needed to access higher-level contextual sentence information.
Experimental validation of flow models for a rigid vocal tract replica
Authors: Hirtum Annemie Van , Pelorson Xavier , Estienne Olivier , Bailliet Hélène
Published: October 2011

Flow through the vocal tract is studied through an in vitro rigid replica for different geometrical configurations and steady flow conditions with bulk Reynolds numbers Re < 15 000. The vocal tract geometry is approximated by two consecutive obstacles, representing “tongue” and “tooth,” in a rectangular channel of fixed length. For the upstream tongue obstacle with fixed constriction degree (81%) the streamwise position is varied and for the downstream obstacle the constriction degree is varied from 0% up to 96%. Different upstream pressures are considered for each geometrical configuration. Point pressure measurements at three fixed locations along the channel are experimentally assessed. In addition, the volume airflow rate is measured. The pressure distribution is estimated with a one-dimensional flow model, and the effects of different corrections to a laminar irrotational flow are assessed. The model outcome is validated against experimental data. Depending on the geometrical configuration, the best model accuracy is obtained by accounting for viscosity (needed for constriction degrees at the tooth that are small, i.e.,≤ 58%, or very large, i.e., ≥ 96%), a sudden constriction (large gap between both constrictions), or a bending geometry (narrow gap between both constrictions). Best overall model errors vary between 4% and 30% for all assessed geometrical configurations in cases where a tongue obstacle is present.
Ear and pitch segregation in Deutsch’s octave illusion persist following switch from stimulus alternation to repetition
Authors: Brancucci Alfredo , Lugli Victor , Santucci Alessandra , Tommasi Luca
Published: October 2011

Deutsch’s octave illusion occurs when two tones that are spaced an octave apart are repeatedly presented in alternation; the sequence is presented to both ears simultaneously but offset by one tone, so that two dichotic chords are repeatedly presented in alternation. The most common illusory percept consists of an intermittent high tone in one ear alternating with an intermittent low tone in the other ear. The aim of this study was to investigate whether, once the illusory percept has emerged, the illusion will persist when the original sequence is followed by another sequence consisting of the repeated presentation of one of the two dichotic chords. Forty naïve subjects were tested with stimuli consisting first of a priming sequence containing dichotic octaves alternating between ears followed immediately by a test sequence consisting of a single dichotic octave presented repeatedly. The durations of the priming and test sequences were manipulated. The findings showed that the illusory percept is maintained after the switch from alternation to repetition and that the relative length of the priming and test sequences has a negligible influence on the persistence of the illusory percept.
Estimating speech spectra for copy synthesis by linear prediction and by hand
Authors: Remez Robert E. , Dubowski Kathryn R. , Davids Morgana L. , Thomas Emily F. , Paddu Nina U. , Grossman Yael S. , Moskalenko Marina
Published: October 2011

Linear prediction is a widely available technique for analyzing acoustic properties of speech, although this method is known to be error-prone. New tests assessed the adequacy of linear prediction estimates by using this method to derive synthesis parameters and testing the intelligibility of the synthetic speech that results. Matched sets of sine-wave sentences were created, one set using uncorrected linear prediction estimates of natural sentences, the other using estimates made by hand. Phoneme restrictions imposed on linguistic properties allowed comparisons between continuous and intermittent voicing, oral or nasal and fricative manner, and unrestricted phonemic variation. Intelligibility tests revealed uniformly good performance with sentences created by hand-estimation and a minimal decrease in intelligibility with estimation by linear prediction due to manner variation with continuous voicing. Poorer performance was observed when linear prediction estimates were used to produce synthetic versions of phonemically unrestricted sentences, but no similar decline was observed with synthetic sentences produced by hand estimation. The results show a substantial intelligibility cost of reliance on uncorrected linear prediction estimates when phonemic variation approaches natural incidence.
Resonances and wave propagation velocity in the subglottal airways
Authors: Lulich Steven M. , Alwan Abeer , Arsikere Harish , Morton John R. , Sommers Mitchell S.
Published: October 2011

Previous studies of subglottal resonances have reported findings based on relatively few subjects, and the relations between these resonances, subglottal anatomy, and models of subglottal acoustics are not well understood. In this study, accelerometer signals of subglottal acoustics recorded during sustained [a:] vowels of 50 adult native speakers (25 males, 25 females) of American English were analyzed. The study confirms that a simple uniform tube model of subglottal airways, closed at the glottis and open at the inferior end, is appropriate for describing subglottal resonances. The main findings of the study are (1) whereas the walls may be considered rigid in the frequency range of Sg2 and Sg3, they are yielding and resonant in the frequency range of Sg1, with a resulting ∼ 4/3 increase in wave propagation velocity and, consequently, in the frequency of Sg1; (2) the “acoustic length” of the equivalent uniform tube varies between 18 and 23.5 cm, and is approximately equal to the height of the speaker divided by an empirically determined scaling factor; (3) trachea length can also be predicted by dividing height by another empirically determined scaling factor; and (4) differences between the subglottal resonances of males and females can be accounted for by height-related differences.
Use of parabolic reflector to amplify in-air signals generated during impact-echo testing
Authors: Dai Xiaowei , Zhu Jinying , Tsai Yi-Te , Haberman Michael R.
Published: October 2011

The impact-echo method is a commonly used nondestructive testing technique for elastic plates in civil engineering. The impact-echo mode corresponds to the frequency at zero group velocity of S1 Lamb mode. Recent development of the air-coupled impact-echo (ACIE) method introduces the possibility for rapid scanning of large structures and increases the practicality of in situ measurements. However, sensors used in ACIE are susceptible to ambient noise, which complicates in situ ACIE measurements. This letter presents the results of ACIE measurements taken using a parabolic reflector together with standard measurement microphones to increase the signal to noise ratio for ACIE measurements. The signal gain and effects of sensor location with respect to impact location are discussed.
Nonlinear optoacoustic transformation in the system of dielectric substrate/submicron metal coating/liquid
Authors: Kopylova Daria S. , Pelivanov Ivan M.
Published: October 2011

The optoacoustic method has been shown to be an accurate technique for the measurement of the properties of submicron metal coatings deposited on a dielectric substrate, i.e., mirrors. The method has been previously theoretically described in terms of a linear model of optoacoustic transformation in a system substrate/coating/liquid. The goal of the present work was to determine the limits at which the linear model is still applicable. The modification of the laser induced acoustic signal profiles and transfer functions of optoacoustic transformation versus the laser fluence was studied for two liquids: ethanol and water.
ENHANCING NETWORK PERFORMANCE BY EDGE ADDITION
Authors: JIANG ZHONGYUAN , LIANG MANGUI , GUO DONGCHAO
Published: October 2011

Transmission efficiency and robustness are two important properties of various networks and a number of optimization strategies have been proposed recently. We propose a scheme to enhance the network performance by adding a small fraction of links (or edges) to the currently existing network topology, and we present four edge addition strategies for adding edges efficiently. We aim at minimizing the maximum node betweenness of any node in the network to improve its transmission efficiency, and a number of experiments on both Barabási–Albert (BA) and Erdös–Rényi (ER) networks have confirmed the effectiveness of our four edge addition strategies. Also, we evaluate the effect of some other measure metrics such as average path length, average betweenness, robustness, and degree distribution. Our work is very valuable and helpful for service providers to optimize their network performance by adding a small fraction of edges or to make good network planning on the existing network topology incrementally.
EXPLORING THE EFFORT OF GENERAL SOFTWARE PROJECT ACTIVITIES WITH DATA MINING
Authors: HAAPIO TOPI , MENZIES TIM
Published: October 2011

Software project effort estimation requires high accuracy, but accurate estimations are difficult to achieve. Increasingly, data mining is used to improve an organization's software process quality, e.g. the accuracy of effort estimations. Data is collected from projects, and data miners are used to discover beneficial knowledge. This paper reports a data mining experiment in which we examined 32 software projects to improve effort estimation. We examined three major categories of software project activities, and focused on the activities of the category which has got the least attention in research so far, the non-construction activities. The analysis is based on real software project data supplied by a large European software company. In our data mining experiment, we applied a range of machine learners. We found that the estimated total software project effort is a predictor in modeling and predicting the actual quality management effort of the project.
PG-TRUST: A SELF-ADAPTIVE AND SCALABLE TRUST COMPUTING MODEL FOR LARGE-SCALE PEER-TO-PEER GRID COMPUTING
Authors: LI XIAOYONG , ZHOU FENG
Published: October 2011

Peer-to-peer Grid (PG) is a new, promising approach for distributed computation that takes advantage of the huge amount of resources in grid computing. The purpose of PG is to support cooperative work between large-scale grid domains. In order to protect each domain's privilege and security, an efficient trust management mechanism is essential. Focusing on the requirement of large-scale PG computing, PG-Trust, a novel trust model is proposed based on trust relationships across domains. Firstly, a self-adaptive overall trust quantified framework is proposed based on the historical interaction records between participants, which not only can improve system efficiency, but also can solve trust computing problem when the direct evidence is sparse. Furthermore, the direct trust computing method based on attenuation function and the feedback trust mechanism based on direct trust tree (DTT) are introduced, which makes our model have a higher self-adaptability and a better scalability than previous studies. Through performance analyzing, the proposed model exhibits a strong self-adaptability in handling various dynamic behaviors of peers, and has a remarkable enhancement in the accuracy of trust evaluation.
A DFT STUDY ON THE HYDROLYSIS MECHANISM OF THE NAMI-A-TYPE ANTITUMOR COMPLEX (HL)[trans-RUCl4L(dmso-S)](L=4-amino-1,2,4-triazole)
Authors: CHEN LAN MEI , CHEN JIN CAN , LUO HUI , LIAO SI YAN , ZHENG KANG CHENG
Published: October 2011

The hydrolysis process of Ru (III) complex (HL)[trans- RuCl4L(dmso-S)] (L=4-amino-1,2,4-triazole) (1), a potential antitumor complex similar to the well-known antitumor agent (ImH)[trans- RuCl4(dmso-S)(Im)](NAMI-A), was investigated using density functional theory (DFT) with the conductor-like polarizable continuum model (CPCM). The structural characteristics and the detailed energy profiles for the hydrolysis processes of this complex were obtained. For the first hydrolysis step, complex 1 with 4-amino-1,2,4-triazole ligand shows much faster aquation than NAMI-A with imidazole ligand and complex 2 with 4H-1,2,4-triazole ligand, and such a calculated result is in good agreement with the experimental one. For the second hydrolysis step, the formation of cis-diaqua products is found to be thermodynamically preferred over the trans isomers. In addition, on the basis of the analysis of electronic characteristics of species in the hydrolysis process, the trend in abilities (A) of hydrolysis products attacked nucleophilicly by pertinent biomolecules is revealed. These theoretical results will help in understanding the action mechanism of this potential Ru (III) drug with pertinent biomolecular targets.
MULTISCALE BORN-OPPENHEIMER THEORY OF COLLECTIVE ELECTRON-NUCLEAR DYNAMICS IN NANOSYSTEMS
Authors: SHREIF ZEINA , ORTOLEVA PETER
Published: October 2011

Born-Oppenheimer theory is based on the separation in timescales between the nuclear and electron dynamics implied by the electron-to-nuclear mass ratio. This makes it naturally fit into a multiscale analysis. It is shown that a fully dynamical Born-Oppenheimer theory follows from a multiscale ansatz on the wave function and a Taylor expansion in the mass ratio. Allowing for a larger spatial scale of electron motion yields an understanding of boson, fermion, and more complex excitations that involve quasi-particles with an effective mass not equal to that of the electron. The theory involves a unified asymptotic expansion in a mass and length scale ratio, and preserves all many-body effects via accounting for the full strength of the interparticle forces. A novel mean-field theory emerges based on the fact that long-scale migration allows each electron to interact with many others on the space-time scale relevant to the coarse-grained equation. Implications for computational methods and applications to quantum nanosystems such as quantum dots, nanowires, superconducting nanoparticles, and liquid He droplets are discussed.
MECHANISM AND KINETICS OF THE CH3CH2C(O)OCH2CH3 + OH REACTION: A THEORETICAL STUDY
Authors: HOU CONG , CI CHENG-GANG , JIN TONG-YIN , WANG YONG-XIA , LIUM JING-YAO
Published: October 2011

The hydrogen abstraction reaction of CH 3 CH 2 C(O)OCH 2 CH 3 + OH has been studied theoretically by dual-level direct dynamics method. Six H-abstraction channels were found for this reaction. The required potential energy surface information for the kinetic calculations was obtained at the MCG3-MPWB//M06-2X/aug-cc-pVDZ level. The rate constants were calculated by the improved canonical variational transition-state theory with small-curvature tunneling correction (ICVT/SCT) approach in the temperature range of 200–2000 K. It is shown that the "methylene H-abstraction" from the alkoxy end of the ester CH 3 CH 2 C(O)OCH 2 CH 3 is the dominant channel at lower temperature (< 400 K), while the other channels from the acetyl end should be taken into account as the temperature increases and become the competitive ones at higher temperature. The calculated global rate constants are in good agreement with the experimental ones in the measured temperature range and exhibit a negative temperature dependence below 500 K. A four-parameter rate constant expression was fitted from the calculated kinetic data between 200–2000 K.
OPEN INNOVATION NETWORKS: THE ROLE OF INNOVATIVE MARKETPLACES FOR SMALL AND MEDIUM ENTERPRISES' VALUE CREATION
Authors: NDOU VALENTINA , VECCHIO PASQUALE DEL , SCHINA LAURA
Published: October 2011

The article is focused on the explanation of the benefits of an open innovation approach in order to drive small and medium enterprises within the actual dynamic environment. In particular, the article gives evidence of the capability of the new paradigm in enabling innovative patterns of growth and development, especially for the small segment, not able to overpass a lot of constraints for achieving high performance by itself.

We argue that firms' innovation can be carried out through open innovation platforms, in which they will grasp the most important benefits and opportunities in order to catch the value creation.
COMPARING TWO CORPUS-BASED METHODS FOR EXTRACTING PARAPHRASES TO DICTIONARY-BASED METHOD
Authors: HO CHUKFONG , MURAD MASRAH AZRIFAH AZMI , KADIR RABIAH ABDUL , DORAISAMY SHYAMALA
Published: October 2011

Paraphrase extraction plays an increasingly important role in language-related research and applications in areas such as information retrieval, question answering and automatic machine evaluation. Most of the existing methods extract paraphrases from different types of corpora by using syntactic-based approaches. Since a syntactic-based approach relies on the similarity of context to identify and capture paraphrases, other than paraphrases, other terms which tend to appear in a similar context such as loosely related terms and functionally similar yet unrelated terms tend to be extracted. Besides, different types of corpora suffer from different kinds of problems such as limited availability and domain biased. This paper presents a solely semantic-based paraphrase extraction model. This model collects paraphrases from multiple lexical resources and validates those paraphrases semantically in three ways; by computing domain similarity, definition similarity and word similarity. This model is benchmarked with two outstanding syntactic-based approaches. The experimental results from a manual evaluation show that the proposed model outperforms the benchmarks. The results indicate that a semantic-based approach should be applied in paraphrase extraction instead of a syntactic-based approach. The results further suggest that a hybrid of these two approaches should be applied if one targets strictly precise paraphrases.
Neutron Production in Thick Targets Irradiated with High-Energy Ions
Authors: Hashemi-Nezhad S. R. , Zamani-Valasiadou M. , Krivopustov M. I. , Brandt R. , Ensinger W. , Odoj R. , Westmeier W.
Published: October 2011

The neutron production in thick targets irradiated with 1 GeV protons was studied experimentally, and results are well understood with model calculations, including MCNPX 2.7a. However, one observes very large neutron production rates in the interaction of 44 GeV12C onto thick Cu-, Pb-, and U-targets beyond calculated rates. The experimental spallation product yield curve in a 20 cm thick Cu target irradiated with 72 GeV40Ar also cannot be reproduced by several model codes, including MCNPX 2.7a. This may be due to secondary fragments produced in high energy ( GeV) heavy-ion interactions which destroy target nuclei more effectively than primary ions. These observed experimental facts constitute “unresolved problems” from a fundamental point of view. It may have an impact on radiation protection issues for future heavy-ion accelerators.
Numerical Investigation into CO2 Emission, O2 Depletion, and Thermal Decomposition in a Reacting Slab
Authors: Makinde O. D. , Chinyoka T. , Lebelo R. S.
Published: October 2011

The emission of carbon dioxide (CO2) is closely associated with oxygen (O2) depletion, and thermal decomposition in a reacting stockpile of combustible materials like fossil fuels (e.g., coal, oil, and natural gas). Moreover, it is understood that proper assessment of the emission levels provides a crucial reference point for other assessment tools like climate change indicators and mitigation strategies. In this paper, a nonlinear mathematical model for estimating the CO2 emission, O2 depletion, and thermal stability of a reacting slab is presented and tackled numerically using a semi‐implicit finite‐difference scheme. It is assumed that the slab surface is subjected to a symmetrical convective heat and mass exchange with the ambient. Both numerical and graphical results are presented and discussed quantitatively with respect to various parameters embedded in the problem.