bluuebunny/crossref_metadata_2025 huggingface dataset:
Pitch bending and higher-mode reed vibration in mechanically blown free reed instruments.
Authors: Cottingham James P.
Published: March 2010

Pitch bending in the harmonica, in which manipulation of vocal tract resonances plays an essential role, has long been a common practice. Pitch bending in free reed instruments with mechanically driven air supplies, such as the reed organ and the accordion, is a different matter. At least two methods of pitch bending in such instruments have been studied and demonstrated. The first, likely to be musically useful only in certain special circumstances, involves partial opening of the pallet valve combined with variations in blowing pressure. The second, recently described and implemented in the accordion by Tonon [J. Acoust. Soc. Am. 126, 2217 (2009)], involves modifying the construction to include a resonating chamber in addition to the standard reed chamber. It is also possible to construct air-blown free reed instruments in which the reed vibrates mainly in the second transverse mode. In one case the reed is coupled with a pipe resonator that provides a suitable mismatch in frequencies with the fundamental frequency of the reed. In another case the second or higher-mode vibration of the air-driven reed can be mechanically induced. The musical possibilities of these hypothetical reed-pipe instruments have yet to be explored.
Extended techniques of the contrabass.
Authors: Bullock Michael T.
Published: March 2010

Contrabass improvisers, composers, and performers of contemporary contrabass repertoire rely on a broad vocabulary of extended contrabass techniques. This vocabulary is continuously developed primarily through a kinesthetic engagement with the acoustics of the contrabass, and many new discoveries are made in the act of playing. This presentation will include live performance, by the presenter, of a series of extended techniques on the contrabass. Spectrograms and video clips will be used to illustrate how these techniques are related to the unique acoustic properties of that instrument. Principles demonstrated will include the following: (1) Overtone bowing and fingering: The low fundamental register of the contrabass means that each string has a many upper overtones within the audible range. Using various bowing and fingering techniques that exploit these upper partials, the timbre and pitch of a string can be radically altered and continuously transformed while playing. (2) Activating the contrabass body: Striking the contrabass body with hands and soft objects, rubbing the instrument’s back with the fingers, and manipulating feedback through amplification are ways to activate the complex resonances of the contrabass. [Thanks to Professor Jonas Braasch of the RPI School of Architecture.]
Transmission of acoustic-gravity waves through air-water interface.
Authors: Fuks Iosif M. , Godin Oleg A.
Published: March 2010

It was demonstrated recently that air-water interface, which is usually an almost perfect reflector of acoustic waves, becomes anomalously transparent and the power flux in the wave transmitted into air increases dramatically, when a compact sound source in water approaches the interface within a fraction of wavelength [O. A. Godin, Phys. Rev. Lett. 97, 164301 (2006)]. Powerful underwater explosions and certain natural sources, such as underwater landslides, generate very low-frequency waves in water and air, for which both fluid buoyancy and compressibility simultaneously serve as restoring forces. In this paper, analysis of sound transmission through air-water interface is extended to acoustic-gravity waves (AGWs). It is found that, as for sound, the interface becomes anomalously transparent for sufficiently shallow compact sources of AGWs. Depending on the source type, the increase in wave power flux into air due to diffraction effects can reach several orders of magnitude. Physical mechanisms responsible for the anomalous transparency are discussed. Excitation of an interface wave by an underwater source is shown to be an important channel of AGW transmission into atmosphere, which has no counterpart in the case of sound.
Constraining the acoustic energy radiated from collisions of polypropylene balls.
Authors: Riner Joshua , Petculescu Andi
Published: March 2010

Measurements of sound radiation from binary collisions of polypropylene balls were performed in order to study the collision dynamics and constrain the fraction of incident energy radiated as sound. In the experiments, one ball is released from directly above a stationary target ball. In the first experiment, the incident energy of the incident ball is varied by changing the drop height. The sound is recorded at an angle of 55 deg below the impact plane. Data from this experiment, fitted with a theoretical model, show a possible deviation from Hertzian behavior. The second experiment concens the radiation pattern of the collision process. The sound pressure was measured as a function of the polar angle θ. It is assumed that the problem is azimuthally symmetric, i.e., independent of the angle φ. The results are somewhat surprising: they show a dipole-like pattern that is asymmetric with respect to the impact line. The acoustic energy radiated during the impact, obtained by multiplying the collision time by the sound intensity integrated over a spherical surface centered at the impact point, is estimated as four orders of magnitude smaller than the incident energy. [The work was supported by the Louisiana Board of Regents.]
Acoustic behavior of large encapsulated gas bubbles with resonance frequencies in the 50–100 Hz range.
Authors: Wochner Mark S. , Hinojosa Kevin T. , Lee Kevin M. , Argo Theodore F. , Wilson Preston S. , Mercier Richard S.
Published: March 2010

A one-dimensional resonator technique was used to investigate the acoustic behavior of water containing large spherical and toroidal encapsulated air bubbles. Tethered balloons and inner tubes, respectively, were used to create the bubbles, which had effective spherical radii of approximately 5 cm. The number of balloons or inner tubes varied from 3 to 6, which resulted in void fractions from 1.5% to 5%. Effective mixture sound speeds for both shapes were inferred from the resonances of a water and bubble-filled waveguide 1.8 m in length. For the spherical bubbles, the Commander and Prosperetti (CP) model [J. Acoust. Soc. Am. 85, 732–746 (1989)] quantitatively described the measured sound speed dispersion approaching the individual bubble resonance frequency and qualitatively predicted the frequency range of high attenuation, even in this regime of high-void fractions and discrete bubble distribution within the waveguide. Qualitative agreement was found between the CP model and the toroidal bubble measurements. Finite-element simulations of both experiments were performed, which help explain the discrepancy between the CP model and the measurements. [Work supported by Shell.]
Sensorimotor maps and vowel development in English, Greek, and Korean: A cross-linguistic perceptual categorization study.
Authors: Munson Benjamin , Mnard Lucie , Beckman Mary E. , Edwards Jan , Chung Hyunju
Published: March 2010

Learning to speak involves learning the association between different articulatory maneuvers and their associated auditory-perceptual characteristics. These associations may change over the course of development as a consequence of the nonlinearities inherent in vocal-tract growth. A set of recent studies by Ménard and colleagues has examined these developmental changes by studying adults’ categorizations of synthesized vowels based on an articulatory model of the growing vocal tract. These have shown that vowels modeled on younger vocal tracts tend to be perceived as more front than those modeled on older vocal tracts. They have also shown language-specificity in the vowels that are identified in growing vocal tracts, with French listeners labeling fewer sounds as /u/ than English ones, presumably because the high-vowel space of French includes three vowels /i y u/, while English has only two. The current experiment expands on this by examining the perception of synthesized vowels based on seven vocal-tract growth stages by speakers of three languages with very different vowel systems, American English, Korean (seven vowels), and modern Greek (five vowels). Preliminary analyses show language-specific patterns in the perception of vowels in developing vocal tracts. [work supported by NIDCD 02932 and NSF grants BCS0729140 and BCS0729277]
Korean listeners’ sensitivity to language-specific phonetic details of children and adults’ vowel production in five different languages.
Authors: Chung Hyunju , Edwards Jan , Weismer Gary , Kong Eunjong , Munson Benjamin , Beckman Mary E.
Published: March 2010

Systematic differences in vowel production across languages have been demonstrated, even for so-called “shared” vowels. Starting from 10 months of age, language-specific vowel production patterns emerge in babbling [Boysson-Bardies et al. (1989)]. Vowel production data from a word repetition task in our laboratory also showed language-specific patterns emerging at 2 years of age. While there is research on adult and infant perception of non-native vowels produced by adults, there is little work on adult perception of children’s non-native vowels of different languages. The current study examined Korean adult listeners’ perception of vowels from five languages, Cantonese, English, Greek, Japanese, and Korean, produced by 2-, 5-year-old children, and adults. Consonant-vowel and vowel only stimuli were extracted from our vowel production data. Target vowels included /i/, /a/, and /u/, following velar and alveolar stops. Twenty native Korean adult listeners were asked to identify the vowels and rated their goodness. Results will be analyzed using both the formant frequencies and listeners’ judgments using a mixed effect model. [Supported by a Fulbright fellowship, NIDCD Grant 02932, and NSF Grant 0729140.]
The relationship between fundamental frequency and vowel quality.
Authors: Barreda Santiago , Nearey Terrance M.
Published: March 2010

There is disagreement over the role fundamental frequency (f0) plays in the determination of vowel quality. Some claim [e.g., D. Smith et al., J. Acoust. Soc. Am. 117, 305–318 (2005)] that changes in f0 do not affect vowel quality at all. Others claim there is relationship between f0 and vowel quality, whether direct or indirect [see T. M. Nearey and P. F. Assmann, in Experimental Approaches to Phonology, edited by M. J. Solé and P. S. Beddor (Oxford University Press, Oxford, 2007), pp. 246–269 for a review]. To test these theories, a series of experiments was carried out in which participants were asked to make simultaneous speaker and vowel quality judgments. Participants were presented with a synthetic vowel continuum spanning from [æ] to [ʌ] matched with several different f0s and higher formants. Participants were asked to rate vowel quality on a continuous scale ranging from completely [æ] to completely [ʌ] and to indicate the size and gender of the speaker. Results indicate that there is a complicated, indirect relationship between f0 and vowel quality, and that shifts in vowel quality caused by changes in f0 are a result of changes in assumed speaker properties.
Investigating within and between talker variability in the optical characteristics of American English vowels.
Authors: Auer Edward T. , Welch Laura
Published: March 2010

Previous research investigating vowel production provides evidence of substantial within and cross-talker variation in acoustic characteristics. The current study is designed to investigate whether similar within and cross-talker variation exists in the optical characteristics of American English vowels. Additionally, potential shared acoustic-optical variation across tokens will also be examined. Measures taken from three-dimensional motion data for a set of 13 markers positioned around the lips, cheeks, and chin sampled at 100 frames/s with millimeter spatial resolution along with simultaneous video (50 frames/s) and audio for each of ten repetitions of 11 vowels spoken by multiple talkers will be reported. Preliminary analysis of motion and acoustic data from12 repetitions of 11 vowels spoken by one male talker provides evidence of substantial within vowel variation in both vertical and horizontal lip separations measured at the midpoint of the vowel as determined by analysis of the acoustic signal. Correlations were observed between horizontal lip separation and second formant frequency (r = 0.48) and third formant frequency (r = 0.66) at the vowel midpoint. No correlations were obtained with vertical lip separation measure. Results will be discussed in terms of potential implications for talker intelligibility in visual only presentation conditions.
Glottal aperture monitoring with external lighting and sensing photoglottography.
Authors: Honda Kiyoshi , Maeda Shinji , Kitamura Tatsuya
Published: March 2010

A non-invasive photoglottographic method has been developed for monitoring glottal aperture changes during speech for the purpose of phonetic and clinical studies. The system includes light-source and sensor units both placed externally on the neck. An LED light source on the side of the neck illuminates the hypopharynx diffusely, and a photo-sensor unit on the front neck below the cricoid cartilage detects light passed through the glottis. An ambient light rejection circuit was newly added to avoid the effect of room light. The photoglottography (ePGG) system is free from interference due to tongue retraction and thus operational both in high- and low-vowel environments, while it is susceptible to articulatory movements of the jaw and larynx. We will present new ePGG/airflow data to explain why the apparent word-initial strengthening of glottal opening occurs in our ePGG, as often observed in other previous PGG data. [Work supported by ESAPVI/ANR and Kakenhi 21300071.]
Breathy phonation in Gujarati: An acoustic and electroglottographic study.
Authors: Khan Sameer ud Dowla
Published: March 2010

Recent electroglottographic research on Gujarati [Khan (2009)] reveals that speakers consistently distinguish breathy and modal vowels (e.g., /bar/ “twelve” vs /bAr/ “outside;” capitalization represents breathiness) by both closed quotient and closing velocity. Despite this interspeaker uniformity measured at the voice source, the acoustic correlates of the contrast measured in the speech output vary considerably across speakers. While some speakers mark breathiness with a larger H1-H2 difference, others use lower periodicity (CPP) or greater changes in intensity (rms energy). It is unclear how breathy vowels are contrasted with modal vowels following breathy consonants (e.g., /bAr/ “outside” vs /Bar/ “burden”) or to what extent the preceding consonant manner can affect the spectral acoustics of the vowel (e.g., /pAr/ “mountain” vs /vAn/ “vehicle”). To better capture the variation in both vowel and consonant phonations, the current study examines acoustic and electroglottographic data collected from naturalistic productions of near-minimal sets from a larger pool of Gujarati speakers, using a wider range of vowel and consonant types. Preliminary results suggest that while all speakers distinguish phonation types in both consonants and vowels based on electroglottographic measures, the acoustic cues in the output are far more complex. [Work supported by NSF.]
An acoustic analysis of pulmonic ingressive speech in the Shetland Islands.
Authors: Sundkvist Peter , Gao Man , Melchers Gunnel
Published: March 2010

The use of a pulmonic ingressive airstream mechanism in the pronunciation of certain discourse particles, typically variants of “yes” and “no,” is a well-known and salient feature of Scandinavian languages. It has been suggested, however, that this may be a more general North Atlantic phenomenon—occurring as far west as Newfoundland and New England—which spread via migration and trade routes. Unfortunately, there seem to be very few audio recordings available from areas other than Scandinavia and Newfoundland (perhaps partly attributable to various elicitation difficulties) and very little acoustic analysis has been presented [E. Thom, MA thesis, UCL (2005); R. Eklund, J. Int. Phonetic Assoc. 38, 235–325 (2008)]. This paper contains a study of ingressive discourse particles in the Shetland Islands, which have strong historical links to Scandinavia. A significant number of ingressives were found in field recordings from 1980–1982. This paper presents an acoustic pilot study of ingressive discourse particles, focusing on issues such as formant structure and voicing/phonation characteristics. A comparison is also made with previous analyses [E. Thom, MA thesis, UCL (2005); R. Eklund, J. Int. Phonetic Assoc. 38, 235–325 (2008)] as well as audio samples from other localities within the North Atlantic region.
The role of creaky voice quality in Cantonese tonal perception.
Authors: Lam Hiu-Wai , Yu Kristine M.
Published: March 2010

Vance (1976) found a response bias against Tone 4 (mid-low falling) in a tonal perception experiment in Cantonese where synthesized stimuli varied only in F0, and Vance (1977) explained this by suggesting that creaky voice quality is a redundant cue for Tone 4. Indeed, there is evidence that creaky voice quality plays a role in tonal perception: in Mandarin, a language where creak is well-known to be a redundant cue for one of the tones, Tone 3 (low fall-rise), Belotel-Grenié and Grenié (1994) found that creaky instances of Tone 3 were recognized faster than non-creaky instances. The effect of creaky voice quality on the perception of Tones 4 and 6 (mid-low level) in Cantonese will be investigated using a 2AFC identification task of natural stimuli that were elicited in isolation and in connected speech. Variability in creak in the realization of Tone 4 occurred naturally in the elicited stimuli. If creaky voice quality plays a role in tonal perception, we hypothesize that overtly audible creak, as well as low H1-H2, a spectral index of creak, will bias listeners toward identification as Tone 4, as measured by d′ scores, and may also speed Tone 4 recognition.
Perceptual similarities between native and non-native tones.
Authors: Wu Xianghua
Published: March 2010

This study investigated the effects of L1 and L2 experience on the perceptual assimilation of non-native tones by native Mandarin or Thai listeners. Of these, 32 had 0.5–1.5 years of L2 learning experience while 40 had none. All listeners participated in a tonal assimilation task in which they first identified which tone in Mandarin or Thai sounded most similar to the Thai or Mandarin tone they heard, and then rated its goodness on a five point Likert scale. Stimuli included four Mandarin tones (high level, rising, falling-rising, and falling tones) and five Thai tones (mid, low-, falling, high-, and rising tones) on four monosyllables: /tuo/, /fej/, /kha/, /siau/, and a hum. The Thai listeners, regardless of L2 experience, assimilated more L1 tone categories to L2 than did the Mandarin listeners. Nonetheless, the experienced listeners from the two languages showed a high degree of consistency in terms of which tones were assimilated. The perceived similarities between native and non-native tones were not always predictable from their acoustic similarities, and varied with L1 and L2 experience. Results will be discussed in terms of some well-known perceptual assimilation models, such as PAM. [Work supported by GIS.]
Production and perception of lexical tones in Beijing and Taiwan Mandarin.
Authors: Chang Chiung-Yun , Fox Robert Allen
Published: March 2010

The acoustic properties of four lexical tones between two regional varieties of Mandarin Chinese, Beijing Mandarin (Putonghua), and Taiwan Mandarin (Guoyu) were examined in terms of duration, pitch contours, and rms amplitude. Tokens included CV and V monosyllables, representing each of the four tones of Mandarin Chinese, and were produced in isolation and in sentence context by 15 adult native speakers. A different durational pattern of citation tones emerged for two dialect variety groups. In Taiwan Mandarin, it was T2>T1>T3>T4; whereas, it was T3>T2>T1>T4 in Beijing Mandarin [Deng et al. (2006)]. The durational discrepancy in isolated T3 may be related to different realization of T3 between two dialect groups. While T3 exhibited a falling-rising pitch contour in Beijing Mandarin, it was falling in Taiwan Mandarin. Such dialectal divergence in T3 contours shapes can be verified from the amplitude contours. Furthermore, pitch contours of other tones in two dialects will be compared to see if there is tonetic sound change in other Taiwan Mandarin tones. These surface acoustic variations in linguistically identical categories can result in perceptually ambiguous tones. A gating experiment was utilized to examine how native and non-native listeners adapt to speaker and dialect variability in the stimuli.
Temporal changes in Mandarin tone due to speaking rate variation.
Authors: Sereno Joan A. , Lee Hyunjung
Published: March 2010

The present research investigates the effects of variation in speaking rate on the production of Mandarin tone. Fourteen speakers (6M, 8F) produced 15 syllables, each with the four different Mandarin tones. Speakers produced these syllables at fast, normal, and slow speaking rates in isolation. To induce rate change, the 60 target words were presented on a computer screen at different tempos. Consonant, vowel, and syllable duration were measured as well as turning point (TP) for the contour tones, Tones 2 and 3. TP is the time interval from tone onset to the lowest f0 value. Duration data of each tone revealed significant ambiguity across tones due to speaking rate. Specifically, for the contour tones, results indicated significant overlap in terms of duration and, as speaking rate increased, the TP for Tone 2 decreased to a lesser extent as compared to Tone 3. Moreover, the TP values for Tones 2 and 3 showed a sizable range, with the ambiguous region of overlap observed not at the faster but at the slower speaking rates. These findings will be discussed in terms of the temporal adjustments that occur in production when speaking rate changes. [Research supported by NSF.]
Modeling diffuse and specular reflection surfaces and their effect on broadband interior sound field level and intensity flow.
Authors: Bliss Donald B. , Franzoni Linda P. , Michalis Krista A.
Published: March 2010

For steady-state broadband sound fields in enclosures, surfaces may be modeled as diffuse reflectors, specular reflectors, or some combination. Modeling of reflection surfaces when using energy-intensity based boundary elements is reviewed, and the proper energy-intensity source characteristics are derived. These characteristics depend on local correlation effects, the angular distribution of the incident field, and the angular dependence of reflection coefficient. Specular reflection surfaces subjected to fairly random reverberant sound fields exhibit behavior similar to diffuse reflection surfaces to lowest order. Simple solutions are obtained to illuminate the basic difference in interior sound fields caused by different reflection types. For example, random incidence sound propagating down a long corridor with non-absorbing walls exhibits different behavior depending on whether the surfaces are diffuse or specular reflectors. The diffuse case exhibits a spatial gradient in mean-square pressure along the corridor, whereas the specular case gives a uniform field. These solutions are also used to clarify the relationship between the flow of intensity and the gradient of mean-square pressure. This relationship has been represented simplistically and incorrectly in some energy based methods. The importance of benchmarking energy based methods against analytical solutions, rather than experimental data, is stressed.
Learning alters the coding capacity of single neurons and populations in the auditory forebrain.
Authors: Jeanne James , Sharpee Tatyana , Gentner Timothy
Published: March 2010

To control adaptive behaviors, vertebrate neural systems must extract information from large numbers of diverse, physically complex signals in the natural world. Sensory experience helps neural systems to meet this challenge by evoking long-lasting changes that bias cortical circuits toward representations of behaviorally relevant signals. Such circuits may encode stimuli using highly selective individual neurons or by larger populations of neurons, thereby greatly expanding coding capacity. I will describe studies investigating the representation of a complex acoustic communication signal, birdsong, across multiple forebrain regions that are analogous to secondary auditory cortices in mammals. I will show that single neurons and populations of neurons in these regions are tuned to the complex spectro-temporal features in songs that birds have learned to recognize. These results demonstrate that learning mechanisms can act and different organizational levels in the brain, and provide biological support for specific population coding schemes.
Structural and mechanical assessment of trabecular bone by in vivo magnetic resonance imaging.
Authors: Wehrli Felix
Published: March 2010

Bone is a complex composite material whose strength is determined by a combination of the material’s intrinsic mechanical properties, its overall volume fraction, and architecture at the macro-, micro- and ultrastructural levels. Trabecular bone, the type of bone prevalent in the vertebrae and ends of long bones, is particularly prone to fracture in osteoporosis. It consists of a network of interconnected plates and struts of about 100-μm thickness immersed in a matrix of marrow. Advances in magnetic resonance imaging technology, including development of high-field magnets and radiofrequency coil technology, along with improved image processing and analysis techniques, now allow acquisition of images from which the three-dimensional (3D) microarchitecture can be retrieved, at least at peripheral skeletal locations such as the distal radius and tibia. From these data measures of topology, scale and orientation of the trabecular network, all contributing to the bone’s mechanical competence, can be derived with high-serial reproducibility. The processed images can also be used to create 3-D meshes and mechanical parameters such as elastic and shear moduli computed by micro-finite-element analysis. The translation of this technology to clinical medicine is highlighted with examples from recent drug intervention studies, allowing direct assessment of structural and mechanical consequences of treatment.
Acousto-optic monitoring of high-intensity focused ultrasound lesion formation in optically diffuse tissue.
Authors: Lai Puxiang , McLaughlan James R. , Draudt Andrew B. , Murray Todd W. , Cleveland Robin O. , Roy Ronald A.
Published: March 2010

Tissue heating by high-intensity focused ultrasound (HIFU) is a promising modality for minimally invasive therapy. However, real-time treatment monitoring still poses significant challenges, particularly at the lower exposure levels where stable cavitation and/or boiling does not result. Bubble--free HIFU lesions offer little acoustic contrast; however, one does observe significant contrast in both optical scattering and absorption. We employ acousto-optic (AO) imaging to sense, in real time, optical changes induced by lesion formation. By using a transducer to simultaneously heat a tissue volume and pump the AO interaction, lesions generated in excised chicken breast are monitored in real time. The change in AO response with time is linearly related to the time-dependent lesion volume, provided the diameter of the lesion does not exceed the width of the optical beam. Therefore, AO sensing can be used to both determine the onset of lesion formation and the resulting volume of the necrosed region. The feasibility of using the observed change AO signal amplitude as the criteria to guide HIFU exposure in real time is demonstrated. [Work supported by the Center for Subsurface Sensing and Imaging Systems, NSF ERC Award No. EEC-9986821.]
Posterior-based attributes in machine recognition of speech.
Authors: Hermansky Hynek
Published: March 2010

Current ASR uses two main sources of information, the top-down prior knowledge in the form of a statistical language and the bottom-up information from acoustic speech signal. The information from acoustic signal is presented in so called speech attributes that are derived from the signal. Any information that gets lost during attribute extraction cannot be recovered. Any preserved information that is irrelevant to the ASR task could complicate further processing. Attributes in conventional ASR are derived by some transformation of the short-term spectrum of speech that represents magnitude frequency components of a short segment of the signal. Origins of this representation can be traced to speech vocoding. For a past decade, we are working on attributes that are derived from posterior probabilities of speech sounds that are estimated by multilayer perceptron trained on large amounts of labeled data. This speech representation is now used in most leading state-of-the-art experimental systems. The talk will describe several research issues that influence the effectiveness of these posterior-based attributes. These issues include the choice of classes of speech sounds, input evidence for the posterior estimation, architecture and training of the posterior probability estimator, and post-processing of posterior estimates for use with conventional GMM-HMM ASR.
Margin based discriminative training techniques for automatic speech recognition.
Authors: Sha Fei , Cheng Chih-Chieh , Saul Lawrence
Published: March 2010

Recently, large margin techniques have gained popularity for discriminative training of continuous-density hidden Markov models. These techniques are motivated by statistical learning theory, aiming to strike a balance between model complexity and generalization error. When used in speech recognition, these techniques separate discriminant scores from the correct transcriptions from all incorrect recognizer outputs. The parameters of acoustic models are adjusted to maximize the separation—margin—that is proportional to recognition errors. Many of such techniques have been successfully applied to large vocabulary speech recognition tasks and have improved the performance of existing systems with traditional approaches for parameter estimation. In this talk, I will review some of the work that my collaborators and I have undertaken in this direction. I will also describe a few new advances, including online learning of large margin separation as well as applying margin based techniques to adaptively transform acoustic features jointly with acoustic models.
On the use of instantaneous acoustic intensity for the classification of defects in air-filled pipes.
Authors: Horoshenkov Kirill , Bin Ali Tareq , Tait Simon , Tolstoy Alexandra
Published: March 2010

The sound pressure in an air-filled pipe has been measured using six pairs of matched microphones. These data have then been analyzed to determine the six vectors of instantaneous particle velocity and acoustic intensity. The acoustic intensity vectors have been processed coherently using the matched field processing (MFP) technique to study the effect of changes such as blockages and cracks on the ambiguity surface. The results show that the technique is sensitive to very small changes in the pipe cross-section and the boundary conditions on the pipe wall. It enables us to locate a defect to within 1% of the measurement range. It also enables us to discriminate between blockages and wall cracks using the spectral characteristics of the ambiguity surface predicted via the MFP. This technique does not require acoustic modeling of the sound field in the pipe, but it relies on the sound pressure data recorded on three or more microphones in the absence and presence of a defect.
Gain-of-Function Enhancement of IP
3
Receptor Modal Gating by Familial Alzheimer’s Disease–Linked Presenilin Mutants in Human Cells and Mouse Neurons
Authors: Cheung King-Ho , Mei Lijuan , Mak Don-On Daniel , Hayashi Ikuo , Iwatsubo Takeshi , Kang David E. , Foskett J. Kevin
Published: March 2010

By altering IP
3
receptor gating, presenilin mutations associated with familial Alzheimer’s disease increase Ca
2+
release from the endoplasmic reticulum.
Choosing Which Way to Turn
Authors: Adler Elizabeth M.
Published: March 2010

Fly macrophages prioritize migratory cues during development.
Dancing with AMPARs
Authors: Stern Peter
Published: March 2010

A synaptic protein that regulates postsynaptic AMPA receptor responses has been cloned and functionally characterized.
Mutant Prevention Concentrations of Four Carbapenems against Gram-Negative Rods
Authors: Credito Kim , Kosowska-Shick Klaudia , Appelbaum Peter C.
Published: March 2010

We tested the propensities of four carbapenems to select for resistant
Escherichia coli
,
Klebsiella pneumoniae
,
Pseudomonas aeruginosa
, and
Acinetobacter baumannii
mutants by determining the mutant prevention concentrations (MPCs) for 100 clinical strains with various ß-lactam phenotypes. Among the members of the
Enterobacteriaceae
family and
A. baumannii
strains, the MPC/MIC ratios were mostly 2 to 4. In contrast, for
P. aeruginosa
the MPC/MIC ratios were 4 to ≥16. The MPC/MIC ratios for β-lactamase-positive
K. pneumoniae
and
E. coli
isolates were much higher (range, 4 to >16 μg/ml) than those for ß-lactamase-negative strains.
Novel Synthetic, Salt-Resistant Analogs of Human Beta-Defensins 1 and 3 Endowed with Enhanced Antimicrobial Activity
Authors: Scudiero Olga , Galdiero Stefania , Cantisani Marco , Di Noto Rosa , Vitiello Mariateresa , Galdiero Massimiliano , Naclerio Gino , Cassiman Jean-Jacques , Pedone Carlo , Castaldo Giuseppe , Salvatore Francesco
Published: March 2010

Human beta-defensins (hBDs) are antimicrobial peptides of human innate immunity. The antibacterial activities of hBDs 1, 2, and 4 but not the activity of hBD3 are impaired by high salt levels. We have designed and synthesized seven novel hBD analogs, constituted by different domains of hBD1 (which is constitutively expressed in humans) and of hBD3 (which is induced by microorganisms and inflammatory factors in humans), that would maintain and potentially increase the wild-type antimicrobial activities and be salt resistant. We have compared the antibacterial, antiviral, and chemotactic activities of the analogs with those of hBD1 and hBD3. We show that the hBD1 internal region and the hBD3 C-terminal region are critical for antibacterial activity also at high salt concentrations, whereas deletion of the N-terminal region of hBD3 results in an increase in antibacterial activity. All analogs inhibited herpes simplex virus; antiviral activity was enhanced by the hBD1 internal region and the hBD3 C-terminal region. Wild-type and analog peptides were chemotactic for granulocytes and monocytes, irrespective of the salt concentrations. These new peptides may have therapeutic potential.
Susceptibility of Recently Collected Spanish Pneumococci Nonsusceptible to Oral Penicillin from Serotypes Not Included in the 7-Valent Conjugate Vaccine
Authors: Fenoll Asunción , Aguilar Lorenzo , Giménez María-José , Vicioso María-Dolores , Robledo Olga , Granizo Juan-José , Coronel Pilar
Published: March 2010

The susceptibilities of pneumococci recently collected (up to June 2009) in Spain (500 isolates nonsusceptible to oral penicillin and 150 susceptible isolates) from serotypes not included in the conjugate vaccine were determined. Most nonsusceptible isolates (53.6%) belonged to serotype 19A. Susceptibility rates in serotype 19A penicillin-intermediate (
n
= 201)/penicillin-resistant (
n
= 67) isolates were <33%/≤6.0% (erythromycin and oral cephalosporins with defined breakpoints), 85.1%/11.9% (amoxicillin), and 96.0%/52.2% (cefotaxime), respectively. Low susceptibility to common oral β-lactams was also found in serotypes 11A (95.5% susceptibility to cefotaxime and erythromycin) and 35B.
Systematic Review and Meta-Analysis of the Tolerability and Hepatotoxicity of Antifungals in Empirical and Definitive Therapy for Invasive Fungal Infection
Authors: Wang Jiun-Ling , Chang Chia-Hsuin , Young-Xu Yinong , Chan K. Arnold
Published: March 2010

To evaluate the tolerability and liver safety profiles of the systemic antifungal agents commonly used for the treatment of invasive fungal infection, we conducted a systematic review and meta-analysis of randomized controlled trials published before 31 August 2009. Two reviewers independently applied selection criteria, performed quality assessment, and extracted data. We used the beta-binomial model to account for variation across studies and the maximum likelihood method to estimate the pooled risks. We identified 39 studies with more than 8,000 enrolled patients for planned comparisons. The incidence rates of treatment discontinuation due to adverse reactions and liver injury associated with antifungal therapy ranged widely. The pooled risks of treatment discontinuation due to adverse reactions were above 10% for amphotericin B formulations and itraconazole, whereas they were 2.5% to 3.8% for fluconazole, caspofungin, and micafungin. We found that 1.5% of the patients stopped itraconazole treatment due to hepatotoxicity. Furthermore, 19.7% of voriconazole users and 17.4% of itraconazole users had elevated serum liver enzyme levels, although they did not require treatment discontinuation, whereas 2.0% or 9.3% of fluconazole and echinocandin users had elevated serum liver enzyme levels but did not require treatment discontinuation. The results were similar when we stratified the data by empirical or definitive antifungal therapy. Possible explanations for antifungal agent-related hepatotoxicity were confounded by antifungal prescription to patients with a high risk of liver injury, the increased chance of detection of hepatotoxicity due to prolonged treatment, or the pharmacological entity.
Telbivudine Exhibits No Inhibitory Activity against HIV-1 Clinical Isolates
In Vitro
Authors: Lin Kai , Karwowska Sylwia , Lam Eric , Limoli Kay , Evans Thomas G. , Avila Claudio
Published: March 2010

Most approved drugs with activity against hepatitis B virus (HBV) have activity against human immunodeficiency virus type 1 (HIV-1), which precludes their use in patients who are coinfected with HBV and HIV-1 and who are not receiving antiretroviral therapy due to the risk of inducing resistance. The activity of telbivudine, a highly selective HBV inhibitor, against temporally and geographically distinct wild-type and multidrug-resistant HIV-1 clinical isolates was evaluated
in vitro
. No inhibition was observed with up to 600 μM drug, which supports further exploration of telbivudine as a therapeutic option for the treatment of HBV infections in patients coinfected with HIV-1.
Effects of Inoculum, pH, and Cations on the
In Vitro
Activity of Fidaxomicin (OPT-80, PAR-101) against
Clostridium difficile
Authors: Babakhani F. , Seddon J. , Robert N. , Shue Y.-K. , Sears P.
Published: March 2010

The effects of the inoculum, pH, cation concentrations, and different lots of commercial media on the
in vitro
susceptibility of
Clostridium difficile
to fidaxomicin were examined. Of the factors evaluated, only pH alterations influenced the activity of fidaxomicin against
C. difficile
, noticeably reducing its activity at higher pH (≥7.9).
Type IV Secretion Machinery Promotes Ton-Independent Intracellular Survival of
Neisseria gonorrhoeae
within Cervical Epithelial Cells
Authors: Zola Tracey A. , Strange Heather R. , Dominguez Nadia M. , Dillard Joseph P. , Cornelissen Cynthia N.
Published: March 2010

Survival of
Neisseria gonorrhoeae
within host epithelial cells is expected to be important in the pathogenesis of gonococcal disease. We previously demonstrated that strain FA1090 derives iron from a host cell in a process that requires the Ton complex and a putative TonB-dependent transporter, TdfF. FA1090, however, lacks the gonococcal genetic island (GGI) that is present in the majority of strains. The GGI in strain MS11 has been partially characterized, and it encodes a type IV secretion system (T4SS) involved in DNA release. In this study we investigated the role of iron acquisition and GGI-encoded gene products in gonococcal survival within cervical epithelial cells. We demonstrated that intracellular survival of MS11 was dependent on acquisition of iron from the host cell, but unlike the findings for FA1090, expression of the Ton complex was not required. Survival was not dependent on a putative TonB-like protein encoded in the GGI but instead was directly linked to T4SS structural components in a manner independent of the ability to release or internalize DNA. These data suggest that expression of selected GGI-encoded open reading frames confers an advantage during cervical cell infection. This study provides the first link between expression of the T4SS apparatus and intracellular survival of gonococci.
AdpC Is aPrevotella intermedia17 Leucine-Rich Repeat Internalin-Like Protein
Authors: Iyer Divya , Anaya-Bergman Cecilia , Jones Kevin , Yanamandra Sai , Sengupta Dipanwita , Miyazaki Hiroshi , Lewis Janina P.
Published: March 2010

The oral bacteriumPrevotella intermediaattaches to and invades gingival epithelial cells, fibroblasts, and endothelial cells. Several genes encoding proteins that mediate both the adhesion and invasion processes are carried on the genome of this bacterium. Here, we characterized one such protein, AdpC, belonging to the leucine-rich repeat (LRR) protein family. Bioinformatics analysis revealed that this protein shares similarity with theTreponema pallidumLRR (LRRTP) family of proteins and contains six LRRs. Despite the absence of a signal peptide, this protein is localized on the bacterial outer membrane, indicating that it is transported through an atypical secretion mechanism. The recombinant form of this protein (rAdpC) was shown to bind fibrinogen. In addition, the heterologous host strainEscherichia coliBL21 expressing rAdpC (V2846) invaded fibroblast NIH 3T3 cells at a 40-fold-higher frequency than controlE. coliBL21 cells expressing a shamP. intermedia17 protein. Although similar results were obtained by using human umbilical vein endothelial cells (HUVECs), only a 3-fold-increased invasion of V2846 into oral epithelial HN4 cells was observed. Thus, AdpC-mediated invasion is cell specific. This work demonstrated that AdpC is an important invasin protein ofP. intermedia17.
Functional Characterization of the IlpA Protein of
Vibrio vulnificus
as an Adhesin and Its Role in Bacterial Pathogenesis
Authors: Lee Kyung-Jo , Lee Na Yeon , Han Yang-Soo , Kim Juri , Lee Kyu-Ho , Park Soon-Jung
Published: March 2010

Vibrio vulnificus
is a Gram-negative bacterium that causes a fatal septicemia. One of its virulence factors is a membrane-bound lipoprotein, IlpA, which can induce cytokine production in human immune cells. In the present study, the role of IlpA as an adhesion molecule was investigated. An
ilpA
-deleted
V. vulnificus
mutant showed significantly decreased adherence to INT-407 human intestinal epithelial cells, which in turn resulted in reduced cytotoxicity. The
ΔilpA
mutant recovered the adherence ability of the wild type by complementation in
trans
with the intact
ilpA
gene. In addition, pretreatment of
V. vulnificus
with anti-IlpA polyclonal antibodies resulted in a significant reduction of bacterial adherence. To localize the domain of IlpA required for cytoadherence, three truncated recombinant IlpA polypeptides were constructed and tested for the ability to adhere to human cells by a ligand-binding immunoblot assay and fluorescence microscopy. The polypeptide containing the carboxy (C)-terminal hydrophilic domain exhibited direct binding to INT-407 cells. Therefore, the C-terminal domain of IlpA allows this protein to be an adhesion molecule of
V. vulnificus
.
Metabolic changes associated with growth of soybean as affected by pre-emergence application of metribuzin
Authors: Gabr M. A. , Shakeeb M. A. , Zid I. M.
Published: March 2010

Pre-emergence application of metribuzin stimulated the accumulation of nitrogen, especially in the form of protein. The application of metribuzin induced marked suppression of carbohydrates. The soluble sugars and polysaccharides in nontreated control plants declined throughout the experimental period. The inhibitory effect of metribuzin on carbohydrates was concomitant with changes in photosynthetic efficiency, biosynthesis of pigments (chlorophyll), and the nucleic acid contents. The chlorophyll a/b ratio was not affected by metribuzin application.
Penetration and colonization of resistant and susceptible Apium graveolens by Fusarium oxysporum f.sp. apii race 2: callose as a structural response
Authors: Jordan C. M. , Endo R. M. , Jordan L. S.
Published: March 2010

Root apices of Apium graveolens L. resistant and susceptible to race 2 of Fusarium oxysporum f.sp. apii (R. Nels. & Sherb.) were studied at various times after inoculation, using light and electron microscopy to determine structural response(s) of the hosts during penetration and colonization by the pathogen. Penetration was intercellular and intracellular and involved mechanical and enzymatic mechanisms. At the onset of penetration, the host cell walls manifested fluorescence, induced with either aniline blue or sirofluor, at the point of penetration. The fluorescent area was more intense and larger in the resistant host. Fluorescence disappeared with time. After incubation with β-1,3 glucanase fluorescence disappeared, indicating β-1,3 polysaccharide (probably callose) presence. Callose deposits were 2 and 3 times greater in the epidermis and 4 and 9 times greater in the cortex of the resistant than in two susceptible hosts, respectively. Hyphal counts in the cortex of the resistant host were 50% fewer than in the susceptible hosts. Increased callose deposition on host cell walls was associated with reduced colonization. Callose formed in vascular tissue as the fungus colonized it. Callose detection with sirofluor was more sensitive; background fluorescence common with aniline blue without periodic acid – Schiff's reagent pretreatment was absent.
Observations on tissue morphology and spore ultrastructure of Colostoma junghuhnii (Gasteromycetes)
Authors: Miller Jr. Orson K. , Cotter H. Van T.
Published: March 2010

Fresh specimens of Colostoma junghuhnii (Schl. & Müll.) Massee, collected in Nepal, are described. The ultrastructure of the basidiospore wall is compared with that in the three North American species of Colostoma. The spore wall of C. junghuhnii is ornamented with pyramidal warts; that of C. cinnabarina Desvaux, the type species of the genus, is pitted. The ultrastructure of the spore wall in the two species is similar. The distinctive stoma and other features distinguish C. junghuhnii from the other species of Colostoma but do not warrant recognition as a second genus in the Calostomataceae.