bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the sensitivity of interannual basin‐scale air‐sea CO2 fluxes to variability in atmospheric dust deposition using ocean carbon cycle models and atmospheric CO2 inversions
Authors: Patra Prabir K. , Moore J. Keith , Mahowald Natalie , Uematsu Mitsuo , Doney Scott C. , Nakazawa Takakiyo
Published: May 2007

Estimates of sources/sinks of carbon dioxide (CO2) at the Earth's surface are commonly made using atmospheric CO2 inverse modeling, terrestrial and oceanic biogeochemical modeling, and inventory‐based studies. In this study, we compare sea‐air CO2 fluxes from the Time‐Dependent Inverse (TDI) atmosphere model and the marine Biogeochemical Elemental Cycling (BEC) model to study the processes involved in ocean carbon cycling at subbasin scales. A dust generation and transport model, based on analyzed meteorology and terrestrial vegetation cover, is also used to estimate the interannual variability in dust and iron deposition to different ocean basins. Overall, a fairly good agreement is established between the TDI and BEC model results for the net annual patterns and seasonal cycle of sea‐air CO2 exchange. Sensitivity studies with the ocean biogeochemical model using increased or reduced atmospheric iron inputs indicate the relative sensitivity of air‐sea CO2 exchange. The simulated responses to changes in iron inputs are not instantaneous (peak response after ∼2−3 years). The TDI model derived seasonal cycles for the Southern Ocean (South Atlantic) are better matched by the BEC model by increasing (decreasing) iron inputs through atmospheric aerosols. Our results suggest that some of the interannual variability in TDI model air‐sea CO2 fluxes during the past decade may be explainable by dust variability that relaxes/increases iron limitation in high‐nitrate, low‐chlorophyll (HNLC) ocean regions.
Probability distributions of random electromagnetic fields in the presence of a semi‐infinite isotropic medium
Authors: Arnaut L. R.
Published: May 2007

Using a transverse electric/transverse magnetic decomposition for an angular plane wave spectrum of random electromagnetic waves and matched boundary conditions, we derive the probability density function for the energy density of the vector electric field in the presence of a semi‐infinite isotropic medium. The theoretical analysis is illustrated with calculations and results for good electric conductors and for a lossless dielectric half‐space. The influence of the permittivity and conductivity on the intensity, polarization state, statistical distribution, and standard deviation of the field is investigated, both for incident plus reflected fields and for refracted fields. External refraction is found to result in compression of the fluctuations of the random field. Several applications of the theory are discussed.
Predicting incipient motion, including the effect of turbulent pressure fluctuations in the bed
Authors: Vollmer Stefan , Kleinhans Maarten G.
Published: May 2007

Incipient motion of particles on a river bed can, in principle, be understood and predicted from a balance of the forces acting on the particles. On a natural river bed the exposure of particles to the flow is variable. The effect of exposure on the initiation of motion, including the case of deep embedding, is studied in this paper. So far, the turbulence‐induced lifting force has been derived exclusively from examinations of the surface flow. The understanding of destabilization processes of the riverbed is improved when turbulence‐induced vertical pressure gradients in the upper sediment layer are included. This is particularly important for particles that lie in the lee of larger ones. An analytical solution for the critical Shields parameter of spherical particles is found, including the effects of pressure fluctuations in the bed, macroscale flow structures, average bed slope, and shallow flow. Existing laboratory data designed to test the effect of exposure and roughness conditions are in excellent agreement with the new model.
Control of gene expression and mitochondrial biogenesis in the muscular adaptation to endurance exercise
Authors: Joseph Anna-Maria , Pilegaard Henriette , Litvintsev Anastassia , Leick Lotte , Hood David A.
Published: May 2007

Every time a bout of exercise is performed, a change in gene expression occurs within the contracting muscle. Over the course of many repeated bouts of exercise (i.e. training), the cumulative effects of these alterations lead to a change in muscle phenotype. One of the most prominent of these adaptations is an increase in mitochondrial content, which confers a greater resistance to muscle fatigue. This essay reviews current knowledge on the regulation of exercise-induced mitochondrial biogenesis at the molecular level. The major steps involved include, (i) transcriptional regulation of nuclear-encoded genes encoding mitochondrial proteins by the coactivator peroxisome-proliferator-activated receptor g coactivator-1, (ii) control of mitochondrial DNA gene expression by the transcription factor Tfam, (iii) mitochondrial fission and fusion mechanisms, and (iv) import of nuclear-derived gene products into the mitochondrion via the protein import machinery. It is now known that exercise can modify the rates of several of these steps, leading to mitochondrial biogenesis. An understanding of how exercise can produce this effect could help us decide whether exercise is beneficial for patients suffering from mitochondrial disorders, as well as a variety of metabolic diseases.
Lipid metabolism, exercise and insulin action
Authors: Bonen Arend , Dohm G. Lynis , van Loon Luc J.C.
Published: May 2007

Skeletal muscle constitutes 40% of body mass and takes up 80% of a glucose load. Therefore, impaired glucose removal from the circulation, such as that which occurs in obesity and type 2 diabetes, is attributable in large part to the insulin resistance in muscle. Recent research has shown that fatty acids, derived from adipose tissue, can interfere with insulin signalling in muscle. Hence, insulin-stimulated GLUT4 translocation to the cell surface is impaired, and therefore, the rate of glucose removal from the circulation into muscle is delayed. The mechanisms provoking lipid-mediated insulin resistance are not completely understood. In sedentary individuals, excess intramyocellular accumulation of triacylglycerols is only modestly associated with insulin resistance. In contrast, endurance athletes, despite accumulating large amounts of intramyocellular triacylglycerols, are highly insulin sensitive. Thus it appears that lipid metabolites, other than triacylglycerols, interfere with insulin signalling. These metabolites, however, are not expected to accumulate in athletic muscles, as endurance training increases the capacity for fatty acid oxidation by muscle. These observations, and others in severely obese individuals and type 2 diabetes patients, suggest that impaired rates of fatty acid oxidation are associated with insulin resistance. In addition, in obesity and type 2 diabetes, the rates of fatty acid transport into muscle are also increased. Thus, excess intracellular lipid metabolite accumulation, which interferes with insulin signalling, can occur as a result of impaired rates of fatty acid oxidation and/or increased rates of fatty acid transport into muscle. Accumulation of excess intramyocellular lipid can be avoided by exercise, which improves the capacity for fatty acid oxidation.
Resistance training, insulin sensitivity and muscle function in the elderly
Authors: Dela Flemming , Kjaer Michael
Published: May 2007

Ageing is associated with a loss in both muscle mass and in the metabolic quality of skeletal muscle. This leads to sarcopenia and reduced daily function, as well as to an increased risk for development of insulin resistance and type 2 diabetes. A major part, but not all, of these changes are associated with an age-related decrease in the physical activity level and can be counteracted by increased physical activity of a resistive nature. Strength training has been shown to improve insulin-stimulated glucose uptake in both healthy elderly individuals and patients with manifest diabetes, and likewise to improve muscle strength in both elderly healthy individuals and in elderly individuals with chronic disease. The increased strength is coupled to improved function and a decreased risk for fall injuries and fractures. Elderly individuals have preserved the capacity to improve muscle strength and mass with training, but seem to display a reduced sensitivity towards stimulating protein synthesis from nutritional intake, rather than by any reduced response in protein turnover to exercise.
Microvascular dysfunction: causative role in the association between hypertension, insulin resistance and the metabolic syndrome?
Authors: Serné Erik H. , de Jongh Renate T. , Eringa Etto C. , Ijzerman Richard G. , de Boer Michiel P. , Stehouwer Coen D.A.
Published: May 2007

The metabolic syndrome defines a clustering of metabolic risk factors that confers an increased risk for type 2 diabetes and cardiovascular disease. The metabolic syndrome seems to have multiple etiological factors and microvascular dysfunction may be one potential factor explaining the clustering of multiple metabolic risk factors including hypertension, obesity, insulin resistance and glucose intolerance. Microvascular dysfunction may increase not only peripheral vascular resistance and blood pressure, but may also decrease insulin-mediated glucose uptake in muscle. The present article summarizes some of the data concerning the role of microvascular dysfunction in the metabolic syndrome.
Exercise, genetics and prevention of type 2 diabetes
Authors: Hu Gang , Rico-Sanz Jesús , Lakka Timo A. , Tuomilehto Jaakko
Published: May 2007

Type 2 diabetes is one of the fastest growing public health problems in both developed and developing countries. Cardiovascular disease is the most prevalent complication of type 2 diabetes. In the past decade, the associations of physical activity, physical fitness and changes in the lifestyle with the risk of type 2 diabetes have been assessed by a number of prospective studies and clinical trials. A few studies have also evaluated the joint associations of physical activity, body mass index and glucose levels with the risk of type~2 diabetes. The results based on prospective studies and clinical trials have shown that moderate or high levels of physical activity or physical fitness and changes in the lifestyle (dietary modification and increase in physical activity) can prevent type 2 diabetes.
Is the anti-inflammatory effect of regular exercise responsible for reduced cardiovascular disease?
Authors: Wilund Kenneth R.
Published: May 2007

Engaging in regular physical activity reduces the risk of developing CVD (cardiovascular disease), but it is not certain to what degree this may be due to the anti-inflammatory effects of exercise. Following acute exercise, there is a transient increase in circulating levels of anti-inflammatory cytokines, whereas chronic exercise reduces basal levels of pro-inflammatory cytokines. Exercise training also induces the expression of antioxidant and anti-inflammatory mediators in the vascular wall that may directly inhibit the development of atherosclerosis. Limited studies in humans and more comprehensive assessments in animal models have confirmed that exercise is atheroprotective and helped identify a number of the mechanisms to explain these effects. This review explores the relationship between systemic and vascular wall inflammation and the role that the anti-inflammatory effects of exercise have on the development and progression of CVD.
Information Literacy for Speech-Language Pathologists: A Key to Evidence-Based Practice
Authors: Nail-Chiwetalu Barbara J. , Ratner Nan Bernstein
Published: May 2007

Purpose

In this tutorial, we review the tenets of information literacy (IL) that parallel and intersect with new American Speech-Language-Hearing Association (ASHA) certification standards requiring clinicians to engage in evidence-based practice (EBP).

Method

A review of the literature on EBP in medical and allied health areas was conducted through an online database search. The
Information Literacy Competency Standards for Higher Education
(American Library Association, 2004) are used as a framework for outlining IL practices that will aid in EBP.

Results

Current strategies are contrasted with more desirable strategies. Potential barriers to the utilization of information-literate procedures in locating sources of reliable clinical evidence are discussed together with potential solutions.

Conclusion

Suggestions for more efficient information searches by clinicians, as well as a proposed discipline-wide agenda for increasing clinicians' IL skills during and after entry-level graduate training, are provided.
Structural Development of the Fictional Narratives of African American Preschoolers
Authors: Price Johanna R. , Roberts Joanne E. , Jackson Sandra C.
Published: May 2007

Purpose

This study examined the structural development of African American preschoolers' narratives. It also investigated the effect of background variables (e.g., gender, maternal education, stimulation and responsiveness of the home environment, and whether or not the child lived in poverty) on the children’s narratives.

Method

Sixty-five children completed a story-retelling task at age 4 and again at kindergarten entry. Narratives were then coded for story grammar elements.

Results

Four-year-olds narrated some attempts to solve the problem and some elements of the story ending. At kindergarten entry, children had higher total narrative scores and included more of every type of story grammar element except relationship. Overall, narratives were not related to background variables.

Clinical Implications

The Bus Story Language Test (C. Renfrew, 1991) appears to be an assessment tool that is sensitive to structural growth in African American children’s narratives from 4 years to kindergarten entry.
Contributions of Mother–Child Storybook Telling and Joint Writing to Literacy Development in Kindergartners With Hearing Loss
Authors: Aram Dorit , Most Tova , Mayafit Hanny
Published: May 2007

Purpose

This study investigated mother–child storybook telling and joint writing as predictors of early literacy among kindergartners with hearing loss.

Method

Participants were 30 Israeli kindergartners with hearing loss and their mothers. Early literacy assessments tapped children’s alphabetic skills (e.g., word writing, word recognition, and letter knowledge) and linguistic skills (e.g., phonological awareness, general knowledge, and receptive vocabulary). Each mother told her child the story of a wordless book and helped her child write words. Both interactions were videotaped and analyzed.

Results

Our major findings showed that maternal storybook telling correlated with linguistic skills, and maternal writing mediation correlated with basic alphabetic skills. A series of 3-step hierarchical regression analyses revealed that beyond children’s age, children’s degree of hearing loss, and joint writing, storybook telling predicted children’s phonological awareness (22%), general knowledge (28%), and receptive vocabulary (18%). Beyond children’s age, children’s degree of hearing loss, and storybook telling, joint writing predicted word writing (15%), word recognition (31%), and letter knowledge (36%).

Implications

Recommendations focused on encouraging parent and teacher awareness about the differential contributions of storybook telling and writing mediation to early literacy. We also advocated enhancing parents' skills for promoting children’s literacy.
Evidence-Based Practice, Response to Intervention, and the Prevention of Reading Difficulties
Authors: Justice Laura M.
Published: May 2007

Purpose

This article provides an evidence-based perspective on what school communities can do to lower the prevalence of reading difficulties among their pupils through preventive interventions. It also delineates the roles that speech-language pathologists (SLPs) might play in these interventions.

Method

This article is organized to first provide a broad overview of current directions in research, practice, and policy in educational interventions, with an emphasis on how the three are increasingly integrated to respond to evidence showing that American school children are underperforming in reading. Next, the concept of response to intervention (RTI) is described. RTI is an educational policy and practice that is grounded in the accumulated literature that focuses on how schools might better organize themselves to deliver multitiered reading interventions to reduce children’s risk for reading disability. Last, this article provides three organizational principles that school-based professionals, including SLPs, might follow to deliver RTI interventions.

Implications

This article provides an important and timely description of key concepts in the prevention of reading difficulties through proactive multitiered interventions. SLPs can draw on the suggestions presented here to inform their local efforts in implementing preventive literacy programs that are consistent with an RTI paradigm.
Epilogue: Some Final Thoughts on EBP
Authors: Kamhi Alan G.
Published: May 2007

Purpose

In this afterward, I will offer some final thoughts on this clinical forum by considering a central question of EBP—how experimental validation is defined—to illustrate the difficulty involved in implementing EBP.

Method

The comments draw on critical reviews I have received on my article in this forum and conversations I have had with professional colleagues about EBP.

Conclusion

Like most scientific constructs, EBP is open to different interpretations. At their worst, these differences have the potential to polarize clinical practice. The hope, however, as Kent and Fey have expressed, is that articles and commentaries such as these will serve as the basis for discussion and even argument among clinicians and researchers as we attempt to define a philosophy and implementation of EBP suited to our profession.
Characteristics of Speech Errors Produced by Children With and Without Delayed Phonological Awareness Skills
Authors: Rvachew Susan , Chiang Pi-Yu , Evans Natalia
Published: May 2007

Purpose

The purpose of this study was to examine the relationship between the types of speech errors that are produced by children with speech-sound disorders and the children’s phonological awareness skills during their prekindergarten and kindergarten years.

Method

Fifty-eight children with speech-sound disorders were assessed during the spring of their prekindergarten year and then again at the end of their kindergarten year. The children’s responses on the Goldman–Fristoe Test of Articulation (R. Goldman & M. Fristoe, 2000) were described in terms of match ratios for the features of each target sound and the type of error produced. Match ratios and error type frequencies were then examined as a function of the child’s performance on a test of phonological awareness.

Results

Lower match ratios for +distributed and higher frequencies of typical syllable structure errors and atypical segment errors were associated with poorer phonological awareness test performance. However, no aspect of the children’s error patterns proved to be a reliable indicator of which individual child would pass or fail the test. The best predictor of test performance at the end of the kindergarten year was test performance 1 year earlier. Children who achieved age-appropriate articulation skills by the end of kindergarten also achieved age-appropriate phonological awareness skills.

Conclusion

Children who enter kindergarten with delayed articulation skills should be monitored to ensure age-appropriate acquisition of phonological awareness and literacy skills.
Understanding Alexithymia and Language Skills in Children: Implications for Assessment and Intervention
Authors: Way Ineke , Yelsma Paul , Van Meter Adelia M. , Black-Pond Connie
Published: May 2007

Purpose

This article reviews the construct of alexithymia and its relationship to language impairment.

Method

The article includes a review of the literature on emotional competence, trauma effects, alexithymia, and language impairment; summarizes tools to assess alexithymia; and provides an intervention framework.

Implications

Understanding the relationship of emotional competence and language impairment may provide a new perspective for speech-language pathologists who are serving children with language and socioemotional impairments.
The Stuttering Treatment Research Evaluation and Assessment Tool (STREAT): Evaluating Treatment Research as Part of Evidence-Based Practice
Authors: Davidow Jason H. , Bothe Anne K. , Bramlett Robin E.
Published: May 2007

Purpose

This article presents, and explains the issues behind, the Stuttering Treatment Research Evaluation and Assessment Tool (STREAT), an instrument created to assist clinicians, researchers, students, and other readers in the process of critically appraising reports of stuttering treatment research.

Method

The STREAT was developed by combining and reorganizing previously published recommendations about the design and conduct of stuttering treatment research.

Conclusions

If evidence-based practice is to be widely adopted as the basis for stuttering assessment and treatment, procedures must be developed and distributed that will allow students, clinicians, and other readers without specialized knowledge of research design to critically appraise treatment research reports. The STREAT is intended to be such an instrument: It represents the consensus of previous methodological recommendations; it is consistent with and complements existing recommendations in evidence-based medicine and in the broader science of treatment outcome evaluation; and it is formatted into a single instrument for ease of use.
Speech Characteristics of Patients With Pallido-Ponto-Nigral Degeneration and Their Application to Presymptomatic Detection in At-Risk Relatives
Authors: Liss Julie M. , Krein-Jones Kari , Wszolek Zbigniew K. , Caviness John N.
Published: May 2007

Purpose

This report describes the speech characteristics of individuals with a neurodegenerative syndrome called pallido-ponto-nigral degeneration (PPND) and examines the speech samples of at-risk, but asymptomatic, relatives for possible preclinical detection.

Method

Speech samples of 9 members of a PPND kindred were subjected to perceptual characterization. Speech deterioration patterns were reported for 2 participants followed longitudinally at 6-month intervals. Cross-sectional findings were reported for 3 participants at various stages of disease. Longitudinal and cross-sectional findings were used to guide the examination of 4 at-risk, but asymptomatic, participants.

Results

Results revealed a progressive mixed dysarthria with hypokinetic, spastic, and flaccid features. It was characterized primarily by vocal tremor and high-frequency vocal flutter, speaking rate abnormalities most often in the direction of slowing, and a tendency toward monopitch. Dysarthria progression was marked by exacerbation and increasing severity of early features, progressive decrease in spontaneous speech output, verbal perseverations, and eventual mutism. Results for at-risk participants revealed preclinical speech abnormalities that preceded other motor signs. Speech results were examined in light of available autopsy findings for site of lesion associations.

Conclusion

The dysarthria of PPND is an early harbinger of disease onset. It has a mixed presentation, with hypokinetic, spastic, and flaccid features.
Clinical Relevance of Discourse Characteristics After Right Hemisphere Brain Damage
Authors: Lehman Blake Margaret
Published: May 2007

Purpose

Discourse characteristics of adults with right hemisphere brain damage are similar to those reported for healthy older adults, prompting the question of whether changes are due to neurological lesions or normal aging processes. The clinical relevance of potential differences across groups was examined through ratings by speech-language pathologists.

Method

A thinking-out-loud task was used to elicit discourse from 8 individuals with right brain damage and 8 healthy older adults. Speech-language pathologists rated discourse transcripts on content and quantity variables and then classified them as belonging to a participant with or without brain damage. Subjective ratings were validated against corroborating measures.

Results

Discourse produced by adults with right brain damage was rated as more tangential and egocentric than that from healthy older adults. Extreme verbosity or paucity of speech was attributed to people with right brain damage. One third of the speech-language pathologists accurately classified discourse samples according to group, whereas the others displayed biases toward one group or the other.

Conclusions

Tangentiality, egocentrism, and extremes of quantity are clinically relevant characteristics of discourse produced by adults with right brain damage. Speech-language pathologists must be aware of potential biases that influence their perception of “normal” discourse production.
Comparison of Context-Based Interaction Patterns of Mothers Who Are Homeless With Their Preschool Children
Authors: O’Neil-Pirozzi Therese M.
Published: May 2007

Purpose

The primary purpose of this exploratory study was to examine the influence of context on interaction patterns used by mothers who are homeless with their preschool children during book-reading and game-playing activities. The impact of mothers’ previously determined language functioning on their contextual use of facilitating language utterances was also examined.

Method

Using a prospective, nonrandomized, comparison group design, mothers read a book and played a game with their preschool children. Facilitating language utterances produced by the mothers in 16 mother–child dyads during each activity were analyzed.

Results

Regardless of their language functioning, no significant contextual differences in percentage use of facilitating language utterances were found across mothers. Overall maternal use of facilitating utterances was less than 50%. Across both contexts, mothers used few different types of facilitating language utterances.

Conclusions

This exploratory study provides initial evidence of overall consistency of facilitating language utterance use by mothers who are homeless during interactions with their preschool children across contexts, regardless of maternal language functioning. This study provides an initial framework for future research investigating the interactions of families who are homeless and discusses possible language interventions for these at-risk families.
Measuring Communicative Participation: A Review of Self-Report Instruments in Speech-Language Pathology
Authors: Eadie Tanya L. , Yorkston Kathryn M. , Klasner Estelle R. , Dudgeon Brian J. , Deitz Jean C. , Baylor Carolyn R. , Miller Robert M. , Amtmann Dagmar
Published: May 2007

Purpose

To assess the adequacy of self-report instruments in speech-language pathology for measuring a construct called communicative participation.

Method

Six instruments were evaluated relative to (a) the construct measured, (b) the relevance of individual items to communicative participation, and (c) their psychometric properties.

Results

No instrument exclusively measured communicative participation. Twenty-six percent (n= 34) of all items (N= 132) across the reviewed instruments were consistent with communicative participation. The majority (76%) of the 34 items were associated with general communication, while the remaining 24% of the items were associated with communication at work, during leisure, or for establishing relationships. Instruments varied relative to psychometric properties.

Conclusions

No existing self-report instruments in speech-language pathology were found to be solely dedicated to measuring communicative participation. Developing an instrument for measuring communicative participation is essential for meeting the requirements of our scope of practice.
Stuttering Treatment Research 1970–2005: II. Systematic Review Incorporating Trial Quality Assessment of Pharmacological Approaches
Authors: Bothe Anne K. , Davidow Jason H. , Bramlett Robin E. , Franic Duska M. , Ingham Roger J.
Published: May 2007

Purpose

To complete a systematic review, incorporating trial quality assessment, of published research about pharmacological treatments for stuttering. Goals included the identification of treatment recommendations and research needs based on the available high-quality evidence.

Method

Multiple readers reviewed 31 articles published between 1970 and 2005, using a written data extraction instrument developed as a synthesis of existing standards and recommendations. Articles were then assessed using 5 methodological criteria and 4 outcomes criteria, also developed from previously published recommendations.

Results

None of the 31 articles met more than 3 of the 5 methodological criteria (
M =
1.74). Four articles provided data to support a claim of short-term improvement in social, emotional, or cognitive variables. One article provided data to show that stuttering frequency was reduced to less than 5%, and 4 additional articles provided data to show that stuttering may have been reduced by at least half. Among the articles that met the trial quality inclusion criterion for the second stage of this review, none provided uncomplicated positive reports.

Conclusions

None of the pharmacological agents tested for stuttering have been shown in methodologically sound reports to improve stuttering frequency to below 5%, to reduce stuttering by at least half, or to improve relevant social, emotional, or cognitive variables. These findings raise questions about the logic supporting the continued use of current pharmacological agents for stuttering.
Complexity in the Treatment of Naming Deficits
Authors: Kiran Swathi
Published: May 2007

Purpose

This article discusses a novel approach for treatment of lexical retrieval deficits in aphasia in which treatment begins with complex, rather than simple, lexical stimuli. This treatment considers the semantic complexity of items within semantic categories, with a focus on their featural detail.

Method and Results

Previous work on training items within animate categories (S. Kiran & C. K. Thompson, 2003b) and preliminary work aimed at items within inanimate categories are discussed in this article. Both these studies indicate that training atypical category items that entail features inherent in the category prototype as well as distinctive features that are not characteristic of the category prototype results in generalization to untrained typical examples which entail only features consistent with the category prototype. Conversely, training typical examples does not result in generalization to untrained atypical examples. In this article, it is argued that atypical items are more complex than typical items within a category, and a theoretical framework for this dimension of semantic complexity is discussed. Then, evidence from treatment studies that support this complexity hierarchy is presented. Potential patient- and stimulus-specific factors that may influence the success of this treatment approach are also discussed.

Conclusions

The applications of semantic complexity to treatment of additional semantic categories and functional applications of this approach are proposed.
Phonological Priming in Young Children Who Stutter: Holistic Versus Incremental Processing
Authors: Byrd Courtney T. , Conture Edward G. , Ohde Ralph N.
Published: May 2007

Purpose

To investigate the holistic versus incremental phonological encoding processes of young children who stutter (CWS;N= 26) and age- and gender-matched children who do not stutter (CWNS;N= 26) via a picture-naming auditory priming paradigm.

Method

Children named pictures during 3 auditory priming conditions: neutral, holistic, and incremental. Speech reaction time (SRT) was measured from the onset of picture presentation to the onset of participant response.

Results

CWNS shifted from being significantly faster in the holistic priming condition to being significantly faster in the incremental priming condition from 3 to 5 years of age. In contrast, the majority of 3- and 5-year-old CWS continued to exhibit faster SRT in the holistic than the incremental condition.

Conclusion

CWS are delayed in making the developmental shift in phonological encoding from holistic to incremental processing, a delay that may contribute to their difficulties establishing fluent speech.
Effects of an Extended Version of the Lee Silverman Voice Treatment on Voice and Speech in Parkinson’s Disease
Authors: Spielman Jennifer , Ramig Lorraine O. , Mahler Leslie , Halpern Angela , Gavin William J.
Published: May 2007

Purpose

The present study examined vocal SPL, voice handicap, and speech characteristics in Parkinson’s disease (PD) following an extended version of the Lee Silverman Voice Treatment (LSVT), to help determine whether current treatment dosages can be altered without compromising clinical outcomes.

Method

Twelve participants with idiopathic PD received the extended treatment version (LSVT-X), similar to LSVT except that it was administered twice a week in 1-hr sessions over 8 weeks and required substantially more home practice. Recordings were made in a sound-treated booth immediately before and after treatment, and again 6 months later. Vocal SPL was measured for 4 different tasks and compared with data from a previous study, in which participants with PD received traditional LSVT 4 times a week for 4 weeks. Listener ratings were conducted with audio samples from both studies, using sentence pairs from a standard passage. LSVT-X participants completed the Voice Handicap Index (VHI) before each set of recordings.

Results

Participants receiving LSVT-X significantly increased vocal SPL by 8 dB after treatment and maintained increased vocal SPL by 7.2 dB at 6 months. VHI scores improved for 25% of the LSVT-X participants following treatment, and listener ratings indicated audible improvement in speech.

Conclusions

LSVT-X successfully increased vocal SPL (which was consistent with improvements following traditional LSVT), decreased perceived voice handicap, and improved functional speech in individuals with PD. Further large-scale research is required to truly establish LSVT-X efficacy.
Speech and Language Skills of Parents of Children With Speech Sound Disorders
Authors: Lewis Barbara A. , Freebairn Lisa A. , Hansen Amy J. , Miscimarra Lara , Iyengar Sudha K. , Taylor H. Gerry
Published: May 2007

Purpose

This study compared parents with histories of speech sound disorders (SSD) to parents without known histories on measures of speech sound production, phonological processing, language, reading, and spelling. Familial aggregation for speech and language disorders was also examined.

Method

The participants were 147 parents of children with SSD (58 fathers and 89 mothers) who were directly tested and interviewed for family history of disorders.

Results

Thirty-six parents (18 mothers and 18 fathers) reported enrollment in speech therapy as children for SSD. Parents with a history of speech therapy obtained lower scores on the Multisyllabic Word Repetition, Nonword Repetition, and Tongue Twister tasks than parents without such histories. These parents also had poorer reading, spelling, and receptive language skills. Parents with histories of SSD and additional language impairments (LI) performed worse than parents with isolated SSD on all measures except Pig Latin and oral motor skills. Familial aggregation for SSD and LI was supported. In addition, the likelihood of SSD in a family member increased by a factor of 1.9 over rates of SSD found in individuals without additional family members with SSD, and the odds of LI increased by a factor of 4.1 over rates of LI found in individuals without additional family members with LI for each additional family member with SSD or LI, respectively.

Conclusions

The results documented both residual effects in adulthood of childhood SSD and familial aggregation for SSD. These residual difficulties do not appear to affect educational and occupational outcomes.
The Use of Ultrasound in Remediation of North American English /r/ in 2 Adolescents
Authors: Adler-Bock Marcy , Bernhardt Barbara May , Gick Bryan , Bacsfalvi Penelope
Published: May 2007

Purpose

Ultrasound can provide images of the tongue during speech production. The present study set out to examine the potential utility of ultrasound in remediation of North American English /r/.

Method

The participants were 2 Canadian English-speaking adolescents who had not yet acquired /r/. The study included an initial period without ultrasound and 13 treatment sessions, each 1 hr long, using ultrasound. Speech samples were recorded at screening and immediately before and after treatment. Samples were analyzed acoustically and with listener judgments. Ultrasound images were obtained before, during, and after the treatment period.

Results

Three speech-language pathologists unfamiliar with the participants rated significantly more posttreatment tokens as accurate [r]s in single words and some phrases. Acoustic analyses showed an expected lowering of the third formant after treatment. A qualitative observation of posttreatment ultrasound images for accurate [r] tokens showed tongue shapes to be more similar to those of typical adults than had been observed before treatment. Participants needed continued practice of their newly acquired skills in sentences and conversation.

Conclusion

Two-dimensional dynamic ultrasound appears to have potential utility for remediation of /r/ in speakers with residual /r/ impairment. Further research is needed with larger numbers of participants to establish the relative efficacy of ultrasound in treatment.
Genetic Etiology in Cases of Recovered and Persistent Stuttering in an Unselected, Longitudinal Sample of Young Twins
Authors: Dworzynski Katharina , Remington Anna , Rijsdijk Frühling , Howell Peter , Plomin Robert
Published: May 2007

Purpose

The contribution of genetic factors in the persistence of and early recovery from stuttering was assessed.

Method

Data from the Twins Early Development Study were employed. Parental reports regarding stuttering were collected at ages 2, 3, 4, and 7 years, and were used to classify speakers into recovered and persistent groups. Of 12,892 children with at least 2 ratings, 950 children had recovered and 135 persisted in their stutter.

Results

Logistic regressions showed that the rating at age 2 was not predictive of later stuttering, whereas ratings at ages 3 and 4 were. Concordance rates were consistently higher for monozygotic than for dizygotic twin pairs (with the exception of girls at age 3). At 3, 4, and 7 years, the liability to stuttering was highly heritable (h2 estimates of between .58 and .66). Heritability for the recovered and persistent groups was also high but did not differ from each other.

Conclusion

Stuttering appears to be a disorder that has high heritability and little shared environment effect in early childhood and for recovered and persistent groups of children, by age 7. The clinical implications of the findings are discussed.
Peer Conflict Explanations in Children, Adolescents, and Adults: Examining the Development of Complex Syntax
Authors: Nippold Marilyn A. , Mansfield Tracy C. , Billow Jesse L.
Published: May 2007

Purpose

Expository discourse, the use of language to convey information, requires facility with complex syntax. Although expository discourse is often employed in school and work settings, little is known about its development in children, adolescents, and adults. Hence, it is difficult to evaluate this genre in students who have language disorders. This study examined syntactic complexity in expository discourse in an effort to begin to establish a normative database.

Method

Speakers with typical development whose mean ages were 11, 17, and 25 years old (
n
= 60) participated in a peer conflict resolution (PCR) task designed to elicit expository discourse. The results were compared with an additional measure of expository discourse, the favorite game or sport (FGS) task, reported in a previous study that included these same participants (M. A. Nippold, L. J. Hesketh, J. K. Duthie, & T. C. Mansfield, 2005).

Results

The PCR task elicited expository discourse from speakers in all 3 groups. Older speakers packed more information into their utterances than did younger ones, and the PCR task elicited greater syntactic complexity than did the FGS task.

Conclusions

The PCR task is potentially a useful tool for examining expository discourse. Research is needed to expand the database and administer the task to clinical groups.
Test–Retest Reliability of In Situ Unaided Thresholds in Adults
Authors: Smith-Olinde Laura , Nicholson Nannette , Chivers Courtney , Highley Patricia , Williams D. Keith
Published: May 2007

Purpose

The purpose of this study was to examine test–retest reliability of in situ unaided thresholds measured using a handheld hearing aid programmer coupled to a hearing aid transducer in adults with normal hearing.

Method

Randomized in situ thresholds at 4 octave frequencies were established in 1 ear of 43 adults twice using the Widex Diva SP3 device with the stimulus generated by and transduced through a Widex Diva SD-9 behind-the-ear hearing aid. Insert earphone tips were used in each of the measures to couple the hearing aid/transducer to the ear canal.

Results

Mean decibel differences between the test and retest thresholds were less than 1 dB at each frequency. Using an 80% statistical test criterion, results revealed test–retest reliability within 5 dB for all frequencies: 98% at 500 Hz, 100% at 1000 and 2000 Hz, and 93% at 4000 Hz.

Conclusions

Test–retest reliability of in situ unaided thresholds using the SP3/SD-9 device is equivalent to that of currently accepted audiometric procedures.
An Adaptive Clinical Test of Temporal Resolution
Authors: Lister Jennifer J. , Roberts Richard A. , Shackelford Jennifer , Rogers Catherine L.
Published: May 2007

Purpose

It has been recommended that diagnostic and screening test batteries for auditory processing disorder (APD) include a measure of temporal gap detection using broadband noise stimuli. Although psychophysical laboratory procedures exist for the measurement of temporal resolution, none are clinically feasible. This study was designed to obtain preliminary data on a new clinical measure of gap detection, the Adaptive Test of Temporal Resolution (ATTR).

Method

The ATTR, a currently available clinical test (Random Gap Detection Test), and a standard psychophysical laboratory procedure were used to measure gap detection thresholds (GDTs) from a group of 30 young adults with normal hearing.

Results

Mean ATTR GDTs were 2.2 ms, consistent with GDTs measured using the psychophysical laboratory procedure (3.2 ms) and significantly smaller than those measured using the Random Gap Detection Test (7.0 ms).

Conclusions

Because it incorporates standard adaptive psychophysical methodology in a computer application that can be used on any desktop computer but does not depend on specialized hardware for application, the ATTR promises to be a clinically feasible addition to the APD test battery.
Effects of Artifact Rejection and Bayesian Weighting on the Auditory Brainstem Response During Quiet and Active Behavioral Conditions
Authors: Sanchez Jason Tait , Gans Donald
Published: May 2007

Purpose

To evaluate the effects of 2 noise reduction techniques on the auditory brainstem response (ABR).

Method

ABRs of 20 normal hearing adults were recorded during quiet and active behavioral conditions using 2 stimulus intensity levels. Wave V amplitudes and residual noise root-mean-square values were measured following the offline application of artifact rejection and Bayesian weighting. Repeated measures analysis of variance and Bonferroni adjusted pairwise
t
tests were utilized to evaluate significant main effects and interactions between the 2 noise reduction techniques.

Results

ABRs recorded during the quiet behavioral condition resulted in minimal differences in wave V amplitude and noise reduction improvement, suggesting that the 2 techniques were equally effective under ideal recording situations. During the active behavioral condition, however, the techniques differed significantly in the ability to preserve the evoked potential and reduce noise. Consequently, strict artifact rejection levels resulted in an inherent underestimation of wave V amplitudes when compared with the Bayesian approach.

Conclusion

Artifact rejection had a detrimental effect on waveform morphology of the ABR. This could lead to difficulty in ABR interpretation when patients are active and ultimately result in diagnostic errors.
The Production of Finite and Nonfinite Complement Clauses by Children With Specific Language Impairment and Their Typically Developing Peers
Authors: Owen Amanda J. , Leonard Laurence B.
Published: May 2007

The purpose of this study was to explore whether 13 children with specific language impairment (SLI; ages 5;1–8;0 [years;months]) were as proficient as typically developing age- and vocabulary-matched children in the production of finite and nonfinite complement clauses. Preschool children with SLI have marked difficulties with verb-related morphology. However, very little is known about these children’s language abilities beyond the preschool years. In Experiment 1, simple finite and nonfinite complement clauses (e.g.,The count decided that Ernie should eat the cookies;Cookie Monster decided to eat the cookies) were elicited from the children through puppet show enactments. In Experiment 2, finite and nonfinite complement clauses that required an additional argument (e.g.,Ernie told Elmo that Oscar picked up the box; Ernie told Elmo to pick up the box) were elicited from the children. All 3 groups of children were more accurate in their use of nonfinite complement clauses than finite complement clauses, but the children with SLI were less proficient than both comparison groups. The SLI group was more likely than the typically developing groups to omit finiteness markers, the nonfinite particleto,arguments in finite complement clauses, and the optional complementizerthat. Utterance-length restrictions were ruled out as a factor in the observed differences. The authors conclude that current theories of SLI need to be extended or altered to account for these results.
The Relationship of Vocal Loudness Manipulation to Prosodic F0 and Durational Variables in Healthy Adults
Authors: Watson Peter J. , Hughes Deanna
Published: May 2007

This investigation was motivated by observations that when persons with dysarthria increase loudness their speech improves. Some studies have indicated that this improvement may be related to an increase of prosodic variation. Studies have reported an increase of fundamental frequency (F0) variation with increased loudness, but there has been no examination of the relation of loudness manipulation to specific prosodic variables that are known to aid a listener in parsing out meaningful information. This study examined the relation of vocal loudness production to selected acoustic variables known to inform listeners of phrase and sentence boundaries: specifically, F0 declination and final-word lengthening. Ten young, healthy women were audio-recorded while they read aloud a paragraph at what each considered normal loudness, twice-normal loudness, and half-normal loudness. Results showed that there was a statistically significant increase of F0 declination, brought about by a higher resetting of F0 at the beginning of a sentence and an increase of final-word lengthening from the half-normal loudness condition to the twice-normal loudness condition. These results suggest that when some persons with dysarthria increase loudness, variables related to prosody may change, which in turn contributes to improvement in communicative effectiveness. However, until this procedure is tested with individuals who have dysarthria, it is uncertain whether a similar effect would be observed.