bluuebunny/crossref_metadata_2025 huggingface dataset:
On the realization of current transfer function using voltage amplifiers
Authors: Raut R.
Published: April 2006

Current transfer function is a feature of current‐mode filters. Current‐mode filters have so far been realized principally using current amplifiers and current conveyors. Some current‐mode filter architecture using operational amplifiers have also been reported. In this article it is shown that by using the principles of transposed network and nullor model for the active device, a current transfer function can be realized in a very simple way using a voltage amplifier, i.e. operational amplifier (OA). The key concept is the knowledge that each ideal (i.e. infinite gain) controlled source is exactly equivalent to a nullor. Thus, a voltage‐mode filter implemented using an ideal three terminal (output, input and ground) OA can be very easily converted to a current‐mode filter using the same OA. The principle has been illustrated by considering single‐OA‐ and multi‐OA‐based second‐order voltage‐mode filters. SPICE simulation results are provided to validate the theoretical concept. Copyright © 2006 John Wiley & Sons, Ltd.
DX5+NKT cells induce the death of colitis‐associated cells: involvement of programmed death ligand‐1
Authors: Hornung Matthias , Farkas Stefan A. , Sattler Christine , Schlitt Hans J. , Geissler Edward K.
Published: April 2006

NKT cells are activated by CD1d and show an immune regulating function. Here, we investigated whether DX5+NKT cells could be used to reduce colitis in a chronic colitis mouse model and studied the potential immunological mechanisms involved. Chronic colitis was induced either by transfer of enriched CD62L+CD4+ T cells to severe‐combined‐immunodeficient mice or by feeding dextran sodium sulfate to immune competent mice. DX5+NKT cells were transferred to mice with chronic colitis. Co‐transfer of DX5+NKT cells, but not CD8+ control cells, prevented the onset of colitis, and the immune regulatory effect of DX5+NKT cells was completely abrogated by injecting CD1d blocking antibody. Moreover, DX5+NKT cells reduced established colitis in both chronic colitis models. In vitro, DX5+NKT cells induced cell death of colon‐infiltrating lymphocytes isolated from diseased mice. This effect was inhibited in the presence of either anti‐CD1d or anti‐programmed death ligand‐1 (PD‐L1) blocking antibodies. The specific potency of DX5+NKT cells in regulating chronic colitis in two mouse models is demonstrated. In vitro testing suggests that DX5+NKT cells activated by CD1d induce cell death of colitis‐inducing lymphocytes, which is mediated through PD‐L1. Therefore, DX5+NKT cells could be important in the regulation of immune responses associated with chronic colitis.
On the Escape Transition of a Tethered Gaussian Chain; Exact Results in Two Conjugate Ensembles
Authors: Skvortsov Alexander M. , Klushin Leonid I. , Leermakers Frans A. M.
Published: April 2006

Summary: Upon compression between two pistons an end‐tethered polymer chain undergoes an abrupt transition from a confined coil state to an inhomogeneous flower‐like conformation that is partially escaped from the gap. In the thermodynamic limit the system demonstrates a first‐order phase transition. A rigorous analytical theory of this phenomenon for a Gaussian chain is presented in two ensembles: a) the H‐ensemble, in which the distance H between pistons plays the role of the control parameter, and b) the conjugate f‐ensemble in which the external compression force f is the independent parameter. A loop region for 〈f(H)〉 with negative compressibility exists in the H‐ensemble, while in the f‐ensemble 〈H(f)〉 is strictly monotonic. The average lateral forces taken as functions of H (or 〈H〉, respectively) have distinctly different behavior in the two ensembles. This result is a clear counterexample of the main principles of statistical mechanics stating that all ensembles are equivalent in the thermodynamic limit. Another theorem states that the thermodynamic potential as a function of volume must be concave everywhere. We demonstrated that the exact free energy in the H‐ensemble contradicts this statement. Inapplicability of these fundamental theorems to a macromolecule undergoing the escape transition is clearly related to the fact that phase coexistence in the present system is strictly impossible. This is a direct consequence of the tethering and the absence of global translational degrees of freedom of the polymer chain.
Proteomic analysis of liver tissues subjected to early ischemia/reperfusion injury during human orthotopic liver transplantation
Authors: Vascotto Carlo , Cesaratto Laura , D'Ambrosio Chiara , Scaloni Andrea , Avellini Claudio , Paron Igor , Baccarani Umberto , Adani Gian Luigi , Tiribelli Claudio , Quadrifoglio Franco , Tell Gianluca
Published: April 2006

Knowledge of early molecular events occurring upon ischemia/reperfusion (I/R) during liver transplantation (LT) is of great importance to improve the therapeutic intervention of surgical treatment. However, nowadays, few data are available on early protein targets of I/R injury. To identify these proteins, we used a differential proteomics approach in the characterization human liver biopsies during I/R upon LT. Analyses were performed on nine donor livers during LT. By using 2‐DE and MALDI‐TOF MS, we identified 36 proteins which resulted significantly altered upon I/R injury. The majority of these proteins are functionally involved in lipid and energy metabolism, in different metabolic pathways, in redox signalling and in oxidative‐stress response. Our data represent the first global approach in the study of I/R injury in liver.
Dead Zones in LX‐17 and PBX 9502
Authors: Souers P. Clark , Andreski Henry G. , Batteux Jan , Bratton Brad , Cabacungan Chris , Cook Charles F. , Fletcher Sabrina , Garza Raul , Grimsley Denise , Handly Jeff , Hernandez Andy , McMaster Pat , Molitoris John D. , Palmer Rick , Prindiville Jim , Rodriguez John , Schneberk Dan , Wong Bradley , Vitello Peter
Published: April 2006

Pin and X‐ray corner turning data have been taken on ambient LX‐17 and PBX 9052, and the results are listed in tables as an aid to future modeling. The results have been modeled at 4 zones/mm with a reactive flow approach that varies the burn rate as a function of pressure. A single rate format is used to simulate failure and detonation in different pressure regimes. A pressure cut‐off must also be reached to initiate the burn. Corner turning and failure are modeled using an intermediate pressure rate region, and detonation occurs at high pressure. The TATB booster is also modeled using reactive flow, and X‐ray tomography is used to partition the ram‐pressed hemisphere into five different density regions. The model reasonably fits the bare corner turning experiment but predicts a smaller dead zone with steel confinement, in contradiction with experiment. The same model also calculates the confined and unconfined cylinder detonation velocities and predicts the failure of the unconfined cylinder at 3.75 mm radius. The PBX 9502 shows a smaller dead zone than LX‐17. An old experiment that showed a large apparent dead zone in Composition B was repeated with X‐ray transmission and no dead zone was seen. This confirms the idea that a variable burn rate is the key to modeling. The model also produces initiation delays, which are shorter than those found in time‐to‐detonation.
Atomic force microscopy and nanoindentation of cement pastes with nanotube dispersions
Authors: Sáez de Ibarra Y. , Gaitero J. J. , Erkizia E. , Campillo I.
Published: April 2006

Since their discovery in 1991 by Iijima [1], carbon nanotubes (CNTs) have probably become the most promising nanomaterials due to their unique mechanical, electronic and chemical properties. Our aim is to improve the mechanical properties of cement pastes by the addition of CNTs, giving rise to a new and higher‐performance composite material. To reach an efficient cement‐based composite with nanotubes, we have studied the addition of different CNT concentrations in the mix design in order to obtain enhanced mechanical properties with respect to plain cement pastes. We have measured the micro‐hardness and Young's modulus of the composites by nanoindenting with a sharp diamond three‐sided pyramidal tip mounted on an Atomic Force Microscope probe. These measurements have been correlated with the average macroscopic Young's modulus. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Continentalic acid from Aralia continentalis shows activity against methicillin‐resistant Staphylococcus aureus
Authors: Jeong Seung‐Il , Han Wan‐Soo , Yun Yeon‐Hee , Kim Kang‐Ju
Published: April 2006

In a continuing search for compounds with antibacterial activity against methicillin‐resistant Staphylococcus aureus (MRSA), a chloroform extract of roots of Aralia continentalis was found to contain continentalic acid (CA, C20H30O2), a diterpenic acid. This compound exhibited potent activity against standard methicillin‐susceptible Staphylococcus aureus (MSSA) as well as clinical isolates of methicillin‐resistant Staphylococcus aureus (MRSA). It was determined that continentalic acid had minimum inhibitory concentrations (MICs) of approximately 8–16 µg/mL against S. aureus, including the MSSA and MRSA standard strains. Therefore, the results obtained in this study suggest that continentalic acid might have potential as an adjunct in the treatment of antibiotic‐resistant bacteria. Copyright © 2006 John Wiley & Sons, Ltd.
Current Developments in Michael Addition‐Based Multicomponent Domino Reactions Involving 1,3‐Dicarbonyls and Derivatives
Authors: Liéby‐Muller Frédéric , Simon Céline , Constantieux Thierry , Rodriguez Jean
Published: April 2006

The aim of this mini‐review is to present an overview of the high synthetic potential of Multicomponent Reactions (MCRs) involving the specific reactivity of easily accessible 1,3‐dicarbonyl derivatives. The present contribution only focuses on sequences in which the first step consists of a Michael addition. Recent developments of these new useful methodologies valuable for the selective construction of highly functionalized heterocycles of high synthetic value are surveyed.
Avascular Necrosis of the Pisiform
Authors: GARCIA L. A. , VACA J. B.
Published: April 2006

Avascular necrosis of the pisiform bone is a very rare condition. This paper reports a case and discusses this pathology and its diagnosis.
ORDERED C$^\ast$-MODULES
Authors: BLECHER DAVID P. , WERNER WEND
Published: April 2006

In this first part of a study of ordered operator spaces, we develop the basic theory of 'ordered C*-bimodules'. A crucial role is played by 'open tripotents', a JB*-triple variant of Akemann's notion of open projection.
Langzeiteffekte einer Planungs- und Handlungskontrollintervention auf die körperliche Aktivität von Herzpatienten nach der Rehabilitation
Authors: Scholz Urte , Sniehotta Falko F.
Published: April 2006

Zusammenfassung. Personen, die Intentionen haben, körperlich aktiver zu werden, scheitern oft an der Umsetzung dieser Intentionen in Verhalten. Zur Überwindung dieser “Intentions-Verhaltens-Lücke“ bieten sich die volitionalen Konstrukte Ausführungsplanung, Bewältigungsplanung und Handlungskontrolle an. Die vorliegende Studie untersuchte die Effektivität einer Intervention zur Verbesserung der Ausführungsplanung, der Bewältigungsplanung und der Handlungskontrolle auf die körperliche Aktivität ein Jahr später im Vergleich zu einer Kontrollgruppe. Weiterhin sollte anhand von Mediatoranalysen ermittelt werden, welche der drei volitionalen Konstrukte die Wirksamkeit der Intervention maßgeblich beeinflussten. Teilnehmer der Studie waren 199 Herzpatienten, die nach Entlassung aus der Rehabilitation einen körperlich aktiven Lebensstil aufnehmen und aufrechterhalten sollten und die auch über eine entsprechende Intention berichteten. Die Ergebnisse zeigen, dass die Intervention die körperliche Aktivität der Teilnehmer, verglichen mit einer Kontrollgruppe, ein Jahr später positiv beeinflusst hat. Die Handlungskontrolle mediierte den Interventionseffekt auf die körperliche Aktivität. Implikationen für die Übertragung der Ergebnisse in die Praxis sowie für die weitere Forschung werden diskutiert.
Social Behaviors of Children With Language Impairment on the Playground
Authors: Fujiki Martin , Brinton Bonnie , Isaacson Ted , Summers Connie
Published: April 2006

Purpose:
This pilot study examined the social behaviors of children with language impairment (LI) and their typical peers on the playground.

Method:
Eight children with LI and their age-matched peers were videotape recorded for 45 minutes during morning and lunch recesses. Samples were divided into 5-second segments and coded according to the child’s behavior occurring during the segment. The behavior displayed during each interval was then coded into one of 37 subcategories. These subcategories were grouped into six general categories of (a) peer interaction, (b) adult interaction, (c) withdrawal, (d) aggression, (e) victimization, and (f) other.

Results:
Significant differences were observed in the categories of peer interaction and withdrawal. Typical children spent significantly more time interacting with peers than did children with LI. Conversely, children with LI demonstrated significantly more withdrawn behaviors than did their typical peers. Analyses of effect size using ω
2
indicated that group membership accounted for approximately 30% of the variability in both of these types of playground behavior. No other significant differences were observed. These findings support the conclusions of researchers using teacher interview procedures, indicating that children with LI are more withdrawn than their typical peers at school.

Clinical Implications:
Specific intervention targeting social language skills in playground contexts may be warranted to include children with LI in social interactions at recess.
Collaborating to Obtain Phonological Acquisition Data for Local Schools
Authors: Porter Judith Halvorsen , Hodson Barbara Williams
Published: April 2006

Purpose
: Twelve school-based speech-language practitioners enlisted the assistance of a university clinical phonologist to help them implement a collaborative research project for their school system in order to investigate phonological acquisition.

Method
: The school practitioners transcribed speech samples of 520 typically developing children between the ages of 2:6 and 8:0 (years:months). Responses were coded for syllable/word structures (e.g., final consonant deletion) and phoneme classes (e.g., velar deficiencies).

Results
: The 3-year-olds in this sample had acquired all major phoneme classes except liquids. For the older participants, /l/was acquired between 4 and 5 years of age and /r/between 5 and 6 years of age. Although the strident phoneme class had reached the criterion for acquisition by age 3 years, sibilant lisps were still common until the age of 7 years. Another finding was the rare occurrence of omissions.

Clinical Implications
: The practitioners resolved that when determining whether a preschooler would be eligible to receive treatment services as a part of their caseloads, consistent speech sound omissions appeared to be a critical indicator and should be considered a higher priority than substitutions and/or distortions.

Conclusion
: The collaborative effort between the university clinical phonologist and the school-based speech-language practitioners was considered to be a valuable experience and a model for future collaborative partnerships.
A Prospective Longitudinal Study of Phonological Development in Late Talkers
Authors: Williams A. Lynn , Elbert Mary
Published: April 2006

Purpose:This study involved prospective longitudinal data on 5 late talkers to provide information about the course of phonological development in order to identify possible predictors of delayed versus deviant development.

Method:Five children (3 boys, 2 girls) were identified as late talkers and divided into a younger group and an older group. Each child was followed monthly for 10 to 12 months (22–33 months for the younger group and 30–42 months for the older group). Two types of monthly language samples (free play and elicited) were obtained to describe the individual courses of phonological development for each child. Independent and relational analyses were completed at each age to describe word-initial and word-final phonetic inventories, syllable structure, syllable diversity, percentage of consonants correct (PCC), sound variability, and error patterns.

Results:The results indicated that 3 of the children resolved their late onset of speech by 33 to 35 months of age. In addition to quantitative factors, (e.g., limited phonetic inventory, lower PCC, and more sound errors), qualitative variables (e.g., atypical error patterns, greater sound variability, and slower rate of resolution) also were identified as potential markers of long-term phonological delay.

Clinical Implications:This study provides information to clinicians so they can identify those children who are less likely to resolve their late onset of phonological development without direct intervention. Procedures are described for assessing early linguistic behaviors that incorporate independent and relational analyses on more extensive speech samples (elicited and free play). From these analyses, clinicians can examine quantitative and qualitative variables to differentiate phonological delay from deviance.
Evidence-Based Practice in Schools
Authors: Meline Timothy , Paradiso Teri
Published: April 2006

This article examines the clinician/researcher relationship, suggests directions for improving the relationship, and discusses avenues for transferring information from research to clinical practice. An eight-step model for transferring research studies to practice is adopted, and three of the eight steps are targeted for discussion and illustration. To illustrate the use and interpretation of effect size measures for practical significance, as well as the transfer of research results to practice (evidence-based practice [EBP]), a case study from the contemporary literature is presented. Speech-language pathologists in schools and other work settings were surveyed to evaluate barriers to EBP. The survey suggested several possible barriers to EBP. For example, the speech-language pathologists surveyed agreed that there is not enough time on the job for research and other EBP activities. Collaborations between clinicians and researchers are recommended as a good avenue for applied research. The methods illustrated for critically evaluating research are useful for engaging EBPs. Further, clinicians in schools are encouraged to adopt EBPs with active involvement in research collaboration whenever possible.
Treatment of Voice Disorders in Children
Authors: Hooper Celia R.
Published: April 2006

Children with voice disorders do respond to treatment, with vocal hyperfunction being the predominant disorder on the caseload of the pediatric voice clinician. This article reviews the literature in describing what is known about these children and typical disorders, prevention of voice disorders, the need for treatment, the referral patterns of teachers and others, and typical management programs and their settings. Good online resources are offered and brief highlights about voice therapy with children are reviewed.
Serving English Language Learners in Public School Settings
Authors: Roseberry-McKibbin Celeste , Brice Alejandro , O’Hanlon Laureen
Published: April 2006

Purpose
: In 1990, 1,145 public school speech-language pathologists (SLPs) across the United States were surveyed regarding service delivery to English language learner (ELL) students (C. A. Roseberry-McKibbin & G. E. Eicholtz, 1994). In 2001, the survey was replicated with a larger national sample (
N
= 1,736). The first purpose of the current study was to conduct an in-depth analysis of the 2001 survey results in terms of relationships between variables in respondents’ backgrounds (e.g., region of the United States and coursework in service delivery to ELL students) and perceived problems in providing service delivery to ELL students. The second purpose of the current study was to compare answers from the 1990 and 2001 surveys in terms of similarities and differences.

Method:
Six thousand surveys were mailed out to a randomly and independently selected sample of public school SLPs across the United States. One thousand seven hundred thirty-six surveys were returned and analyzed.

Results
: Results indicated both similarities and differences between answers from the 1990 and 2001 surveys. Results from an in-depth analysis of the current survey found that respondents from the West had the most coursework in service delivery to ELL students. Respondents from the West and the Southwest regions of the United States perceived all service delivery problems with ELL students as occurring less frequently than did their counterparts from other regions. Respondents with more university coursework perceived "lack of appropriate less biased assessment instruments" as a more frequently occurring problem than did respondents with less university coursework.

Clinical Implications:
Universities need to offer coursework regarding service delivery to ELL students. A particularly important area that courses should address is less biased assessment of ELL students. Other implications and directions for future research are discussed.
Intervention With Linguistically Diverse Preschool Children
Authors: Kohnert Kathryn , Yim Dongsun , Nett Kelly , Kan Pui Fong , Duran Lillian
Published: April 2006

Purpose:
This article addresses a series of questions that are critical to planning and implementing effective intervention programs for young linguistically diverse learners with primary language impairment (LI). Linguistically diverse learners in the United States include children whose families speak languages such as Spanish, Korean, Cantonese, Hmong, Vietnamese, or any language other than, or in addition to, English.

Method:
A narrative review of the relevant literature addresses clinical questions including (a) Why support the home language when it is not the language used in school or the majority community? (b) Does continued support for the home language undermine attainment in a second language? (c) Should we support the home language when it includes the code switching or mixing of two traditionally separate languages? and (d) What are some strategies that can be used to support the home language when it is a language that the speech-language pathologist (SLP) does not speak?

Conclusion:
SLPs should provide services to linguistically diverse preschool-age children with LI in a manner that effectively supports the development of the home language. Parent and paraprofessional training along with peer-mediated models of intervention are presented as two possible methods for facilitating the home language in children with LI.
Assessment of Phonological Representations in Children With Speech Impairment
Authors: Sutherland Dean , Gillon Gail T.
Published: April 2006

Purpose:
This study explored the use of assessment tasks to examine underlying phonological representations in preschool children with speech impairment. The study also investigated the association between performance on phonological representation tasks and phonological awareness development.

Method:
The performance of 9 children (aged 3;09 [years;months] to 5;03) with moderate or severe speech impairment and 17 children of the same age with typical speech development was investigated on a range of novel receptive-based assessment tasks designed to tap underlying phonological representations.

Results:
Preschool children with speech impairment experienced more difficulty judging correct and incorrect speech productions of familiar multisyllable words and showed inferior performance in the ability to learn nonwords as compared to children without speech impairment. Performance on these tasks was moderately correlated with phonological awareness ability.

Clinical Implications:
Factors such as the precision and accessibility of underlying phonological representations of spoken words may contribute to problems in phonological awareness and subsequent reading development for young children with speech impairment. Receptive-based assessments that examine underlying phonological representations provide clinically relevant information for children with speech impairment.
Backward and Simultaneous Masking Measured in Children With Language-Learning Impairments Who Received Intervention With Fast ForWord or Laureate Learning Systems Software
Authors: Marler Jeffrey A. , Champlin Craig A. , Gillam Ronald B.
Published: April 2006

The developers of a computer-assisted language intervention program called Fast ForWord (FFW) have claimed that their software changes temporal processing abilities as a result of specialized modifications to the acoustic and temporal properties of the speech signal within the program. This pilot study compared changes in auditory temporal processing in children who received FFW training and in children who received training with computer-assisted language intervention programs that were not designed to improve auditory perceptual skills. Four boys with Language-Learning Impairments (LLI) and 3 boys with typical language participated. Two of the boys with LLI received the FFW program, and the other 2 received a bundle of computer-assisted instruction (CAI) programs published by Laureate Language Systems (LLS). The FFW and LLS programs were presented on the same schedule.

To assess temporal processing, signal thresholds in backward and simultaneous masking conditions were evaluated just before, during, and immediately after language training. The boys with typically developing language received no training. Children with typical language produced signal thresholds in the backward masking condition that were markedly lower than those in the simultaneous masking condition. This disparity is indicative of normal temporal processing. Conversely, 3 of 4 children with LLI failed to demonstrate a simultaneous-backward difference during baseline. The lack of a difference implies that temporal processing was not normal in these children. The fourth child with LLI had signal thresholds that paralleled those of the children with normal language development. This child also had the mildest form of LLI.

Of the 3 children whose temporal processing was abnormal, 2 boys showed decreased signal thresholds in the backward masking condition. However, the improvement was sudden, occurring relatively early in the training sequence, and observed with both treatment programs. The third child with abnormal temporal processing failed to show a change in backward masking at any time during treatment. Over the course of the experiment, signal thresholds for
all
listeners decreased by similar amounts in both backward and simultaneous masking. Taken together, these results do not support the presence of a program-specific improvement in temporal processing. In addition to the temporal processing deficits revealed by backward masking, group differences in response patterns implicate auditory memory involvement or differences in maintaining attention.
Use of Speech by Children From Total Communication Programs Who Wear Cochlear Implants
Authors: Geers Ann , Spehar Brent , Sedey Allison
Published: April 2006

This study examined whether children who are deaf acquire usable speech or continue to rely primarily on manual communication when they are enrolled in a total communication setting following receipt of a cochlear implant. Furthermore, it considered whether the use of speech post-implant is associated with other outcomes such as better speech perception skills, English language competence, speech intelligibility, and educational mainstreaming. Language samples were elicited from twenty- seven 8- and 9-year-olds who had received a Nucleus 22-channel cochlear implant before age 5 and were enrolled in a total communication program for at least the first 3 years following implantation. Samples were transcribed by mode of production (i.e., speech or sign) and scored for lexical diversity, syntax, utterance length, and use of bound morphemes. Results revealed a wide range of mode preference, with some children using primarily speech, some primarily sign, and some using both modes to varying extents. Not only did speech users achieve higher auditory speech perception scores and speech intelligibility ratings, but they also demonstrated better comprehension and use of English syntax than did children who used little or no speech. After 3 years with an implant, speech users were more likely than children who used little or no speech to be placed in mainstream educational programs.
Characteristics of Vietnamese Phonology
Authors: Hwa-Froelich Deborah , Hodson Barbara W. , Edwards Harold T.
Published: April 2006

The number of individuals in the United States whose native language is Vietnamese has increased dramatically during the past decade. To work effectively with Vietnamese speakers, speech-language practitioners need to understand basic aspects of the Vietnamese language, especially the sound system, and how it differs from English. The purpose of this report is to provide basic information that can be used by practitioners to understand not only the differences between Vietnamese and English phonology, but also the influence of dialects. Characteristics of Vietnamese phonology and speech samples of three native speakers, representing the northern, central, and southern dialects, are used to illustrate information from the literature in this tutorial. Clinical Implications include considerations for assessment and intervention with Vietnamese individuals who may have a phonological disorder.
Effect of Communication Disability on Satisfaction With Health Care
Authors: Hoffman Jeanne M. , Yorkston Kathryn M. , Shumway-Cook Anne , Ciol Marcia A. , Dudgeon Brian J. , Chan Leighton
Published: April 2006

Purpose:
To examine the prevalence and characteristics of community-dwelling Medicare beneficiaries reporting a communication disability and the relationship between that disability and dissatisfaction with medical care.

Method:
A total of 12,769 Medicare Current Beneficiary Survey respondents age 65 and older in 2001 were categorized by level of communication disability. Sampling weights were used to make inferences about the entire Medicare population.

Results:
Over 16 million beneficiaries reported a communication disability. Hearing problems were most commonly reported (41.99%). The association between dissatisfaction and communication disability was statistically significant (
p
≤ .05) for 8 of 10 items.

Conclusions:
Prevalence of dissatisfaction among those with a communication disability varied, ranging from 3.43% to 19.34%. Respondents with a communication disability reported much more dissatisfaction when compared with those respondents without a communication disability.
English Past Tense Use in Bilingual Children With Language Impairment
Authors: Jacobson Peggy F. , Schwartz Richard G.
Published: April 2006

Grammatical measures that distinguish language differences from language disorders in bilingual children are scarce. This study examined English past tense morphology in sequential bilingual Spanish/English-speaking children, age 7;0–9;0 (years;months). Twelve bilingual children with language impairment (LI) or history of LI and 15 typically developing (TD) bilingual children participated. Thirty-six instances of the past tense including regular, irregular, and novel verbs were examined using an elicited production task. By examining English past tense morphology in sequential bilinguals, we uncovered similarities and differences in the error patterns of TD children and children with LI. The groups differed in the overall accuracy of past tense use according to verb type, as well as the characteristic error patterns. Children with LI performed lower than their TD peers on all verb categories, with an interaction between verb type and group. TD children were better at producing regular verbs and exhibited more productive errors (e.g., overregularization). Conversely, children with LI performed relatively better on irregular verbs and poorest on novel verbs, and they exhibited more nonproductive errors (e.g., bare stem verbs). The results have important clinical implications for the assessment of morphological productivity in Spanish-speaking children who are learning English sequentially.
Area-Under-the-Curve Measure of the Auditory Middle Latency Response (AMLR) From Birth to Early Adulthood
Authors: Pynchon Kara A. , Tucker Denise A. , Ruth Roger A. , Barrett Katherine A. , Herr David G.
Published: April 2006

The area-under-the-curve (AUC) measure of the auditory middle latency response (AMLR) waveform was derived and analyzed from recordings in 50 subjects with normal hearing. The AUC metric is believed to represent the total amount of neural energy contributing to the evoked response. This proposed method of measure, therefore, may provide an alternative method of quantifying the response. The subjects were divided into five age groups (
n
= 10 for each group): infants, children, preteens, teens, and adults. Ipsilateral and contralateral recordings of the AMLR were obtained at two stimulus levels (70 and 40 dB nHL) and at two stimulus rates (11.3 and 3.3/s). AUC measures were obtained for each recording at 70 and 40 dB nHL and at 3.3 and 11.3 clicks/s. These area measurements were compared among the five age groups for significant differences due to age. According to the results, no significant differences in the AUC of the AMLR waveform existed as a function of age.
Predicted Gain and Functional Gain With Transcranial Routing of Signal Completely-in-the-Canal Hearing Aids
Authors: Fagelson Marc A. , Noe Colleen M. , Murnane Owen D. , Blevins Jennifer S.
Published: April 2006

Transcranial routing of signal (TCROS) was accomplished using completely-in-the-canal (CIC) hearing aids in 5 profoundly unilaterally hearing-impaired individuals. The functional gain realized by the participants far exceeded the gain predicted by measuring the acoustic output and real ear aided response of the hearing aids. The difference between predicted and functional gain increased with signal frequency and was attributed at least in part to mechanical vibration of the hearing aid in the external canal. Implications for fitting unilateral hearing loss using TCROS amplifying systems are discussed.
Durational, Proportionate, and Absolute Frequency Characteristics of Disfluencies
Authors: Throneburg Rebecca Niermann , Yairi Ehud
Published: April 2006

The main objective of this study was to investigate developmental aspects of disfluencies over time as stuttering persists or ameliorates for 2 groups of preschool age children who stutter. Results indicated that the frequency, type, and duration of disfluencies remained relatively constant instead of increasing as expected in the persistent group over a 3-year period. In contrast, the recovered group's initially higher frequency of disfluency decreased over time, as did their number of repetition units and proportion of disrhythmic phonations, while the duration of silent intervals between repetition units and proportion of monosyllabic word repetitions increased.
Quantification of Static and Dynamic Supraglottic Activity
Authors: Stager Sheila V. , Bielamowicz Steven , Gupta Ashmit , Marullo Shannon , Regnell Joan R. , Barkmeier Julie
Published: April 2006

For estimating supraglottic compression in disordered voice production, categorical rating scales of true vocal fold coverage by supraglottic structures are the current standard. Quantification of change in the position of supraglottic structures compared to no supraglottic activity would be a better method for distinguishing between and within voice-disordered groups. This study developed a method for quantifying static supraglottic activity and extent of false vocal fold (FVF) motion during dynamic supraglottic activity. Twelve control participants and 12 individuals with voice disorders (6 with complaints of vocal fatigue and 6 with vocal fold nodules) were enrolled in the study. These individuals participated in a transnasal fiberoptic laryngeal examination in which various speech tasks were recorded. Single-frame images were selected to represent the positions of minimum and maximum supraglottic compression for each speech task. Two individuals rated these single-frame images using a categorical rating scale. Two other individuals measured the anterior-to-posterior (A-P) distance, vocal fold length, and vocal fold area. A-P and FVF compression were derived from these three measures.

Reliability was demonstrated between judges for the ratings and between and within judges for the measures. Significant differences in normalized static supraglottic compression measures corresponded to the rating scale categories. Significant differences in normalized dynamic supraglottic compression measures corresponded to the differences in category ratings between minimum and maximum compression.

Using the normalized measures, the voice-disordered groups demonstrated significantly greater static A-P compression (
t
test,
p
<.03) than did the control participants. These results suggest that static supraglottic activity may be diagnostic of voice disorder. Normalized dynamic FVF compression ratios were not significantly different between groups. This supports a previous hypothesis that dynamic supraglottic activity serves as an articulatory function at the level of the larynx and is part of the linguistic/phonemic system, rather than evidence of disordered laryngeal function.
An Acoustic Analysis of Excellent Female Esophageal, Tracheoesophageal, and Laryngeal Speakers
Authors: Bellandese Mary H. , Lerman Jay W. , Gilbert Harvey R.
Published: April 2006

Acoustic data for female esophageal speakers is sparse, particularly with regard to characteristics of female tracheoesophageal speakers. This study quantified and compared six acoustic characteristics of excellent female tracheoesophageal (TE), standard esophageal (SE), and laryngeal (LA) speakers. Results indicated there were no significant differences between TE and SE speakers with regard to mean F
0
of sustained /α/, mean F
0
(reading), signal-to-noise ratio, total duration of passage read, number of pauses, or syllables per minute. Significant differences were found between LA speakers and both alaryngeal groups for all variables, with the exception of mean F
0
(reading).
Kinematic Strategies for Hyoid Movement in Rapid Sequential Swallowing
Authors: Chi-Fishman Gloria , Sonies Barbara C.
Published: April 2006

Past videofluoroscopic and EMG evidence has shown that rapid sequential swallowing differs from discrete swallows, but our knowledge of the control strategies remains incomplete. This study examined in detail the interrelationships among kinematic variables to discern the strategies for deglutitive hyoid motion during discrete (5 cc, 10 cc, 20 cc, 30 cc) and rapid sequential (120 cc) swallowing tasks. Submental ultrasound was conducted with head and transducer stabilization on 30 healthy subjects (15 males, 15 females) in three age groups (20–39, 40–59, 60–79 yrs). Frame-by-frame changes in hyoid position were tracked from digitized images of 236 discrete and 318 rapid sequential swallows. Repeated-measures analyses of variance were conducted on a number of kinematic variables with corrections for multiple tests and comparisons. The main effect of task was significant for all variables except
forward peak velocity
. Per post hoc contrasts, rapid sequential swallows had significantly reduced
maximal amplitude
(maximal displacement),
total distance, backward peak velocity, at-max
and
total durations
, and
time to backward peak velocity
in comparison with discrete swallows of any volume. Amplitude "down-scaling" was the prominent kinematic strategy used to accomplish rapid sequential swallows in a shorter time while keeping
forward peak velocity
essentially unchanged. In contrast, amplitude "up-scaling" was the strategy for accommodating largervolume discrete swallows. Our results confirm built-in flexibility in the functional range of deglutitive hyoid motion.
Grammatical Morphology and Perception of Synthetic and Natural Speech in Children With Specific Language Impairments
Authors: Evans Julia L. , Viele Kert , Kass Robert E. , Tang Feng
Published: April 2006

Studies investigating the relationship between the use of inflectional morphology and speech-perception abilities in children with SLI traditionally have employed synthetic speech stimuli. The purpose of this study was to replicate the findings reported in Leonard, McGregor, and Allen (1992) with an older group of children with SLI and to determine if the pattern of deficits seen for synthetic speech extends to perception of natural speech stimuli. The speech-perception abilities of 27 children between the ages of 6;11 and 8;11 (15 SLI and 12 NL) were compared using natural and synthetic versions of the [das]-[da∫], [dabiba]-[dabuba], and [i]-[u] contrast pairs originally used in Leonard et al. The findings reported by Leonard et al. were replicated with synthetic speech but not for the natural speech. Use of inflectional morphology in obligatory contexts by the children with SLI was not significantly correlated with their perception abilities for any of the natural or synthetic speech-contrast pairs. Further, although both groups' ability to maintain the target contrast in memory declined over the span of the trials for all target contrasts for both natural and synthetic speech, the rate of decline did not differ significantly between the SLI and NL groups. Findings are discussed with respect to possible deficits in linking phonological representations to grammatical representations in children with SLI.
A Comparison of the Speech Understanding Provided by Acoustic Models of Fixed-Channel and Channel-Picking Signal Processors for Cochlear Implants
Authors: Dorman Michael F. , Loizou Philipos C. , Spahr Anthony J. , Maloff Erin
Published: April 2006

Vowels, consonants, and sentences were processed by two cochlear-implant signal-processing strategies—a fixed-channel strategy and a channel-picking strategy—and the resulting signals were presented to listeners with normal hearing for identification. At issue was the number of channels of stimulation needed in each strategy to achieve an equivalent level of speech recognition in quiet and in noise. In quiet, 8 fixed channels allowed a performance maximum for the most difficult stimulus material. A similar level of performance was reached with a 6-of-20 channel-picking strategy. In noise, 10 fixed channels allowed a performance maximum for the most difficult stimulus material. A similar level of performance was reached with a 9-of-20 strategy. Both strategies are capable of providing a very high level of speech recognition. Choosing between the two strategies may, ultimately, depend on issues that are independent of speech recognition—such as ease of device programming.
Epidemiology of Stuttering in the Community Across the Entire Life Span
Authors: Craig Ashley , Hancock Karen , Tran Yvonne , Craig Magali , Peters Karen
Published: April 2006

A randomized and stratified investigation was conducted into the epidemiology of stuttering in the community across the entire life span. Persons from households in the state of New South Wales, Australia, were asked to participate in a telephone interview. Consenting persons were given a brief introduction to the research, and details were requested concerning the number and age of the persons living in the household at the time of the interview. Interviewees were then given a description of stuttering. Based on this description, they were asked if any person living in their household stuttered (prevalence). If they answered ‘yes,’ a number of corroborative questions were asked, and permission was requested to tape over the telephone the speech of the person who stutters. Confirmation of stuttering was based on (a) a positive detection of stuttering from the tape and (b) an affirmative answer to at least one of the corroborative questions supporting the diagnosis. Results showed that the prevalence of stuttering over the whole population was 0.72%, with higher prevalence rates in younger children (1.4–1.44) and lowest rates in adolescence (0.53). Male-to-female ratios ranged from 2.3:1 in younger children to 4:1 in adolescence, with a ratio of 2.3:1 across all ages. The household member being interviewed was also asked whether anyone in the household had ever stuttered. If the answer was ‘yes,’ the same corroborative questions were asked. These data, along with the prevalence data, provided an estimate of the incidence or risk of stuttering, which was found to range from 2.1% in adults (21–50 years) to 2.8% in younger children (2–5 years) and 3.4% in older children (6–10 years). Implications of these results are discussed.
Speaking Clearly for Children With Learning Disabilities
Authors: Bradlow Ann R. , Kraus Nina , Hayes Erin
Published: April 2006

This study compared the speech-in-noise perception abilities of children with and without diagnosed learning disabilities (LDs) and investigated whether naturally produced clear speech yields perception benefits for these children. A group of children with LDs (
n
=63) and a control group of children without LDs (
n
=36) were presented with simple English sentences embedded in noise. Factors that varied within participants were speaking style (conversational vs. clear) and signal-to-noise ratio (–4 dB vs. –8 dB); talker (male vs. female) varied between participants. Results indicated that the group of children with LDs had poorer overall sentence-in-noise perception than the control group. Furthermore, both groups had poorer speech perception with decreasing signal-to-noise ratio; however, the children with LDs were more adversely affected by a decreasing signal-to-noise ratio than the control group. Both groups benefited substantially from naturally produced clear speech, and for both groups, the female talker evoked a larger clear speech benefit than the male talker. The clear speech benefit was consistent across groups; required no listener training; and, for a large proportion of the children with LDs, was sufficient to bring their performance within the range of the control group with conversational speech. Moreover, an acoustic comparison of conversational-to-clear speech modifications across the two talkers provided insight into the acoustic-phonetic features of naturally produced clear speech that are most important for promoting intelligibility for this population.