bluuebunny/crossref_metadata_2025 huggingface dataset:
PIC‐Simulation Resolved Period‐Doubling Route to Chaos in the Classical Pierce Diode
Authors: Kočan M. , Kuhn S. , Tskhakaya D.
Published: April 2006

The classical Pierce diode [J. R. Pierce, J. Appl. Phys. 15, 721 (1944)] is a one‐dimensional, electrostatic plasma‐filled system bounded by an emitter and a collector separated by a distance d and externally connected by a short circuit. A mono‐energetic electron beam is emitted from the emitter with a constant current density j 0 = –en 0u 0, where n 0 and u 0 are the initial electron density (corresponding to the plasma frequency ωpe = √n 0e 2/(ε 0me ) and velocity, respectively. The immobile ions form a uniform neutralising background. In this work we use Particle‐in‐Cell (PIC) simulations performed with the BIT1 code [D. Tskhakaya jr. and S. Kuhn, Contrib. Plasma Phys. 42, 302 (2002)] to investigate the evolution of slightly perturbed uniform equilibria into the related non‐linear attractor states for a broad range of α values, where α = ωped /u 0 is the diode control parameter. First, to demonstrate the suitability of our code, the period‐doubling route to chaos for α below 3π was re‐investigated in detail. In both the linear and non‐linear regimes, excellent agreement was found with the results obtained previously by Godfrey [Phys. Fluids 30, 1553 (1987)] from numerical integration of a genuine fluid model, and by Hörhager and Kuhn [Phys. Fluids B 2, 2741 (1990)] from a three‐harmonic fluid analysis. Having thus established that our method is perfectly adequate for these investigations, we present analogous results for linear and non‐linear oscillations in α domains in which these phenomena have not been considered in detail before. The present kinetic approach to small‐amplitude oscillations in a bounded system can be extended to more complex bounded plasma systems, e.g., for PIC simulations of turbulent fusion plasmas, in which small‐amplitude oscillations are known to give rise to anomalous transport. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Genetic vaccines against Ep‐CAM break tolerance to self in a limited subset of subjects: Initial identification of predictive biomarkers
Authors: Elia Leonardo , Mennuni Carmela , Storto Mariangela , Podda Silvia , Calvaruso Francesco , Salucci Valentina , Aurisicchio Luigi , Scarito Alessia , Ciliberto Gennaro , Monica Nicola La , Palombo Fabio
Published: April 2006

The epithelial cell adhesion molecule, Ep‐CAM, has been historically considered a target of passive immunotherapy using monoclonal antibodies, and more recently, of a first Pox‐vector‐based cancer vaccine Phase I trial in colorectal cancer patients. To shed further light on the use of this antigen, we isolated the mouse and rhesus homologues of human Ep‐CAM and explored different genetic vaccination modalities based on the use of adenoviral vectors as well as DNA electroporation (DNA‐EP). Immune responses to Ep‐CAM were measured by IFN‐γ ELISPOT and intracellular staining assays using overlapping sets of peptides covering the entire coding regions. We found the most powerful vaccination regimen to be constituted by DNA‐EP‐prime/Adeno‐boost mixed‐modality protocols. Vaccination in rhesus macaques resulted in breakage of immunological tolerance in a minority of cases. Similarly, a low frequency of responders was observed with the mouse Ep‐CAM vaccine in outbred CD1 mice. When immunized CD1 mice were analyzed for MHC haplotype and TCR expression levels, we observed that immune responders all had the same q/q MHC class I haplotype and showed higher expression levels of the TCRVβ4 and TCRVβ8 T cell receptors. Our results underscore the current limitations in our capacity to induce efficient cancer vaccines against self antigens like Ep‐CAM, but also represent a first effort to identify predictive biomarkers of response.

See accompanying commentary: http://dx.doi.org/10.1002/eji.200636085
Geometrical isomerisation of double bonds in acid‐catalysed preparation of fatty acid methyl esters
Authors: Mjøs Svein A. , Meier Sonnich , Grahl‐Nielsen Otto
Published: April 2006

Acid‐catalysed methylation is frequently applied for the preparation of fatty acid methyl esters used for gas chromatographic analysis of fatty acids. A series of artefacts were observed in hydrochloric acid‐catalysed direct methylation of herring (Clupea harengus L.) muscle. The artefacts were identified as trans isomers of eicosapentaenoic and docosahexaenoic acid, and their levels increased with reaction time. The isomers were not found after methylation of a lipid extract of the herring muscle, even after extreme reaction times. In general, the trans isomers are only observed after methylation of certain marine tissues, indicating catalytic activity in these samples. Based on these results, it is recommended that direct methylation procedures are thoroughly validated with each matrix type analysed, and that reaction times should not be longer than necessary to complete the methylation.
Effects of processing on the quality and stability of three unconventional Sudanese oils
Authors: Mariod Abdalbasit , Matthäus Bertrand , Eichner Karl , Hussein Ismail H.
Published: April 2006

In a refining experiment, on a laboratory scale, crude oils from Sclerocarya birrea (SCO), sorghum bugs (SBO), water‐extracted melon bugs (MBO H2O) and solvent‐extracted melon bugs (MBO SOL) were processed by alkali refining. Quality changes were characterized by the determination of free fatty acids (FFA), peroxide value, tocopherols, sterols, phosphatides and stability against oxidation (Rancimat test). In addition, the fatty acid composition was determined. It is clear that the contents of phosphatides, peroxides, tocopherols, sterols as well as oxidative stability were reduced during processing, while FFA were nearly totally removed. The content of phosphorus was reduced in SCO, SBO, MBO H2O and MBO SOL by 26, 19, 12, and 78%, respectively, while complete oil processing removed 95, 99, 96 and 99% of the FFA in crude oils, respectively. The level of total tocopherols decreased during processing by 38.7, 83.8, 100, and 33.3%, respectively. The color decreased through the processing steps up to bleaching; then, in the deodorization step, it darkened sharply in all samples. No change in the fatty acid composition was observed. The order of oxidation stability was crude > degummed > deodorized > neutralized > bleached, in SCO; and crude > degummed > neutralized > bleached = deodorized, in MBO H2O; and crude > degummed > deodorized > neutralized > bleached in MBO SOL; while in SBO, the order of oxidative stability was deodorized > crude > degummed > neutralized = bleached. Total sterols decreased by 42–92% in the processed oils, compared with crude oils.
Book Review: Unraveling Lipid Metabolism with Microarrays edited by Alvin Berger and Matthew A. Roberts
Authors: Trajanoski Zlatko
Published: April 2006

No abstracts.
Reactivity in LaGaO3/Ni and CeO2/Ni Systems
Authors: Solak N. , Zinkevich M. , Aldinger F.
Published: April 2006

The reactivity in CeO2/Ni and LaGaO3/Ni systems, which are constituents of intermediate temperature solid oxide fuel cell (IT‐SOFC) anodes, has been investigated both computationally and experimentally. The CALPHAD‐method (CALculating of PHAse Diagrams), employing BINGSS and THERMOCALC software, was used to obtain a self‐consistent set of Gibbs energy functions describing the systems. Interactions in the LaGaO3/Ni system were predicted using a thermodynamic database developed for the La‐Ga‐Ni‐O system. Similarly, to analyze the CeO2/Ni system, the Ce‐Ni‐O ternary phase diagram was calculated using known thermodynamic data for binary Ce‐O, Ni‐O, and Ce‐Ni systems. The experimental work was designed based on the calculated phase diagrams. While the La‐Ga‐Ni‐O system experiments were conducted in air, the Ce‐Ni‐O system was also investigated in a reducing atmosphere. The calculated Ce‐Ni‐O diagram is in good agreement with the experimental results. It has been found that NiO does not react with CeO2. Extended solid solutions of La(Ga,Ni)O3, La2(Ni,Ga)O4, and La4(Ni,Ga)3O10 were found in the La‐Ga‐Ni‐O system. Additionally, the compound LaNiGa11O19, with magnetoplumbite‐type structure, has been found, which has not been reported in the literature so far. It is concluded that La2NiO4 is not chemically compatible, as a cathode material, with the LSGM electrolyte.
Influence of Microwave Irradiation on the Lipase‐Catalyzed Ring‐Opening Polymerization of ε‐Caprolactone
Authors: Kerep Patrick , Ritter Helmut
Published: April 2006

Summary: The microwave (MW)‐assisted lipase‐catalyzed ring‐opening polymerization of ε‐caprolactone in boiling solvents was investigated for the first time. In case of boiling toluene or benzene the MW‐assisted reaction proceeded significantly slower compared to oil bath heating. On the other hand, using boiling diethyl ether as solvent, an increase of the polymerization rate due to MW irradiation was found. Yield, molecular weight measurements, and MALDI‐TOF analysis supported the results.

Reactivity of the MW‐assisted ring‐opening polymerization of ε‐caprolactone compared with conventional thermal heating in different solvents.

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Reactivity of the MW‐assisted ring‐opening polymerization of ε‐caprolactone compared with conventional thermal heating in different solvents.
Submicron Polymer Gratings: Optical Diffraction and Spontaneous Brillouin Scattering
Authors: Cheng Wei , Fytas George , Kiyanova Anna V. , Efremov Mikhail Yu. , Nealey Paul F.
Published: April 2006

Summary: Brillouin light scattering (BLS) from submicron‐size patterned polyurethane (PU) films was found to display rich spectral features. Their identification allows the determination of the mechanical properties of the PU and the characterization of the periodicity and the coherence of the structure. A temperature‐dependent study demonstrates that BLS is a sensitive tool to monitor changes of the mechanical properties and/or of the morphology.

(a) Scheme of the sample structure and the scattering geometry, (b) SEM top view of the PU features.

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(a) Scheme of the sample structure and the scattering geometry, (b) SEM top view of the PU features.
Prediction of Polymer Properties from their Structure by Recursive Neural Networks
Authors: Duce Celia , Micheli Alessio , Starita Antonina , Tiné Maria Rosaria , Solaro Roberto
Published: April 2006

Summary: We propose a new approach for predicting polymer properties from structured molecular representations based on recursive neural networks. To this aim, a structured representation is designed for the modeling of polymer structures. This representation can also account for average macromolecule characteristics. Preliminarily, this model is applied to the calculation of the Tg of (meth)acrylic polymers with different stereoregularity.

Representation of poly(methyl methacrylate) as a chemical tree and unfolding of the encoding process through its structure.

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Representation of poly(methyl methacrylate) as a chemical tree and unfolding of the encoding process through its structure.
Cover Picture: Macromol. Symp. 237/2006
Authors: Mann Bernward A. , Kremer Kurt , Holm Christian
Published: April 2006

Cover: The 5th International Symposium “Molecular Mobility and Order in Polymer Systems” was held in June 2005 as part of the series of St. Petersburg IUPAC meetings organized by the Institute of Macromolecular Compounds of the Russian Academy of Sciences. These meetings are the most important international gathering of polymer scientists in Russia. Main attention was paid to problems of structure and dynamics of polymer systems which combine order and pronounced molecular mobility, i.e., systems with so‐called “soft” order. The figure shows a snapshot depicting the diamond lattice topology of the polyelectrolyte network (see article by B. A. Mann, K. Kremer, C. Holm).
Tuning aerosol‐assisted vapor phase processing towards low oxygen GaN powders
Authors: Janik J. F. , Drygaś M. , Stelmakh S. , Grzanka E. , Pałosz B. , Paine R. T.
Published: April 2006

Herein, are reported studies of various experimental conditions aimed at optimizing the Aerosol‐Assisted Vapor Phase Synthesis (AAVS) of GaN powders. In general, the process utilizes affordable oxygen‐bearing gallium precursors in aqueous/methanol solutions to initially prepare nano‐sized GaNx Oy powders of spheroidal morphology. Subsequent pyrolysis of the GaNx Oy intermediate in a NH3 atmosphere converts the powders to sub‐micron, crystalline GaN powders that usually contain some residual oxygen. The application of appropriate solvents, e.g. , methanol, in the aerosol powder generation stage and the use of pyrolysis temperatures in the range 900–1000 °C may improve both the extent of nitridation and, to certain degree, the control over average particle sizes. The characteristics of the AAVS‐produced materials are compared with those for bulk GaN powders obtained by direct nitridation of commercial gallium oxide. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mechanism for proteins destabilization at low temperatures
Authors: Marqués Manuel I.
Published: April 2006

Proteins undergo unfolding when lowering the temperature by means of a process known as cold denaturation. Pure cold denaturation (without denaturants) is obtained at high pressures. In this paper, a recent proposal to explain the cold denaturation process based on the high density liquid state of water [Phys. Rev. Lett. 91, 138103 (2003)] is described in detail. The correct understanding of this process may be useful to artificially implement activation and inactivation of proteins at room temperatures with direct applications into the word of nanobiotechnology machinery. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A study of the trypanocidal activity of triterpene acids isolated from Miconia species
Authors: Cunha Wilson Roberto , Crevelin Eduardo J. , Arantes Glenda M. , Crotti Antonio E. Miller , Silva Márcio L. Andrade e , Furtado Niege A. J. Cardoso , Albuquerque Sérgio , Ferreira Daniele da Silva
Published: April 2006

Triterpene acids, including ursolic acid (1), urjinolic acid (4) and oleanoic acid (5) along with a mixture of 2α‐hydroxyursolic acid (2) and maslic acid (3) were isolated from methylene chloride extracts of the Miconia sellowiana and M. ligustroides species and their activities against the trypomastigote blood forms of Trypanosoma cruzi were evaluated. The potassium salt derivative of ursolic acid (1a) was also tested. The in vitro assays showed that compounds 1, 5 and 1a were the most active (IC50 17.1 µm, 12.8 µm and 8.9 µm, respectively). In contrast, a mixture of 2 plus 3, that exhibit a hydroxyl at C‐2 and C‐3, is much less potent than a mixture of 1 and 5 (IC50 48.5 µm and 11.8 µm, respectively). In the same manner, compound 4, that differs from 5 by two additional hydroxyl groups (at C‐2 and C‐23) displayed weak trypanocidal activity (IC50 76.3 µm) when compared with the other triterpenes. These results suggest that the free hydroxyl at C‐3 and the polarity of C‐28 are the most influential structural features for determining the in vitro trypanocidal activity of triterpenes. In vivo assays were also undertaken for the most active compounds 1, 1a and the mixture of 1 plus 5. The most significant reduction in parasite number in the parasitemic peak were obtained for compound 1 and its salt derivative 1a (75.7% and 70.4%, respectively). Moreover, the survival time was increased for all the treated animals. Copyright © 2006 John Wiley & Sons, Ltd.
Butea superba Roxb. enhances Penile erection in rats
Authors: Tocharus Chainarong , Smitasiri Yuthana , Jeenapongsa Rattima
Published: April 2006

This study aimed to investigate the effects of ethanol extracts of Butea superba in increasing intracavernous pressure (ICP) in vivo. The extracts were prepared from fresh and dried root cores and fresh and dried root barks. Penile erection was induced in aged rats by electrical stimulation of the cavernous nerve. Cavernous smooth muscle relaxation was also observed in vitro in the presence of the extract, cGMP or isobutyl‐methylxanthine (IBMX) alone or the extract together with cGMP or IBMX. The dried root core extract from Phrae was the most effective in increasing the ICP. The dose‐response relationship study revealed a bell‐shape curve with the maximum effective dose at 1 mg/kg. The ICP of the control and 1 mg/kg extract‐treated animals were 45.3 ± 2.5 and 100.9 ± 14.0 mmHg, respectively. The extract, cGMP and IBMX alone induced dose dependent muscle relaxation. B. superba significantly enhanced the effects of cGMP and IBMX. The results suggest that ethanol extracts of B. superba are effective in enhancing penile erection. The dried root core extract from Phrae is the most effective part with a maximal dose of 1 mg/kg. The results also suggest that B. superba may act through cAMP/cGMP pathways. Copyright © 2006 John Wiley & Sons, Ltd.
Fatty acids profile and antiinflammatory activity of Nonea setosa R. et S.
Authors: Curini Massimo , Epifano Francesco , Genovese Salvatore , Menghini Alessandro , Altinier Gianmario , Tubaro Aurelia , Menghini Luigi
Published: April 2006

In order to verify the antiinflammatory properties of Nonea setosa R. et S. (Fam. Boraginaceae) and to identify the relevant active principles, aerial parts of this plant were extracted with increasing polarity solvents. The antiinflammatory activity was investigated by a bioassay‐oriented fractionation using the inhibition of the croton oil‐induced ear oedema in mice as an experimental model of inflammation. GC‐MS analysis of the most active fraction revealed the presence of high amounts of polyunsaturated fatty acids. Copyright © 2006 John Wiley & Sons, Ltd.
Anti‐influenza agents from plants and traditional Chinese medicine
Authors: Wang Xiaoyan , Jia Wei , Zhao Aihua , Wang Xiaorong
Published: April 2006

Influenza is a serious threat to health in all parts of the world. The control and treatment of influenza depends mainly on chemical or biochemical agents and, to date, some anti‐influenza agents have been isolated from plants as a result of chemical and pharmacological studies. These agents include a variety of polyphenols, flavonoids, saponins, glucosides and alkaloids. Traditional medicine focuses on the use of herbs and traditional Chinese medicine has performed well in clinical practice and shows a potential in the therapy of influenza and its symptoms. The present paper reviews some constituents and extracts from plants and traditional Chinese medicine with anti‐influenza activity. Copyright © 2006 John Wiley & Sons, Ltd.
Continuous Synthesis of Tri‐ and Tetrasubstituted Imidazoles via a Multicomponent Reaction under Microreactor Conditions
Authors: Acke Davy R. J. , Orru Romano V. A. , Stevens Christian V.
Published: April 2006

Using a modified Radziszewski reaction, a procedure has been optimized for the generation of tri‐ and tetrasubstituted imidazoles via microreactor technology. Optimization included the search for a suitable solvent mixture, temperature and reaction time. Finally, the generality of the optimized reaction was tested using different starting materials. It was possible to create a variety of tri‐ and tetrasubstituted imidazoles in moderate to good yields via a continuous procedure.
Expeditious Access to Diversely Substituted Indolizines Using a New Multi‐component Condensation
Authors: Bedjeguelal K. , Bienaymé H. , Poigny S. , Schmitt Ph. , Tam E.
Published: April 2006

Multi‐component condensations are among the most powerful tools in the arsenal of the modern medicinal chemist. Herein we disclose a new, highly efficient, three‐component synthesis of diversely substituted fused amino‐pyrrolo‐heterocycles by the condensation of activated methylene compounds, aldehydes and isonitriles.
SOME SELF-ADJOINT QUANTUM SEMIMARTINGALES
Authors: BELTON ALEXANDER C. R.
Published: April 2006

It is proved that the quantum stochastic gauge integral preserves self-adjointness of vacuum-adapted processes. This fact, together with bounded perturbations and the link between the Hudson–Parthasarathy calculus and vacuum-adapted theory, is used to produce many self-adjoint quantum semimartingales.
Indian Labour, Labour Standards, and Workers' Health in Burma and Malaya, 1900–1940
Authors: KAUR AMARJIT
Published: April 2006

Indian labour migration to Burma and Malaya in the late nineteenth century was an important dimension of British colonial rule in Southeast Asia and coincided with the region's greater integration into the international economy. Compared to the Chinese, Indians formed an important minority only in these states where they filled a critical need in the urban manufacturing sector (Burma) and the plantation sector (Malaya). Their importance declined after World War Two, both in absolute and comparative terms. There were fewer millionaires and traders among them and their emigration to these territories was largely regulated by law. Moreover, the specific political and economic relationship between the Colonial Office in London and these territories determined recruitment patterns and influenced employment relations and working conditions. In turn, these impacted on the living conditions and mortality suffered by workers and shaped the structure of health services.
The MOX Plant and IJzeren Rijn Disputes: Which Court Is the Supreme Arbiter?
Authors: LAVRANOS NIKOLAOS
Published: April 2006

The MOX Plant and IJzeren Rijn disputes illustrate the growing problem of concurrent jurisdiction between international courts and tribunals and the ECJ. This article argues that in cases in which Community law is involved in a dispute between two EC member states, international courts and tribunals must accept the exclusive jurisdiction of the ECJ under Article 292 of the EC Treaty to decide these cases. However, only the UNCLOS arbitral tribunal in the MOX Plant case stayed the proceedings and requested that the parties first find out whether the ECJ had jurisdiction, whereas the OSPAR as well as the IJzeren Rijn arbitral tribunals rendered their awards despite the implications of Article 292. Thus it appears that every arbitral tribunal decides the issue of Article 292 as it sees fit. This situation, it is argued, requires the creation of some sort of hierarchy between the growing number of international courts and tribunals in order to co-ordinate and harmonize their decisions so as to avoid a fragmentation of international law.
Carl Stumpf, Oskar Pfungst, der Kluge Hans und eine geglückte Vernebelungsaktion
Authors: Gundlach Horst
Published: April 2006

Zusammenfassung. Das berühmte Buch des Oskar Pfungst Das Pferd des Herrn von Osten, Der Kluge Hans (1907) verfolgt einen bisher nicht erkannten Zweck, nämlich zu verbergen, dass Carl Stumpf lange Zeit höhere geistige Gaben des Pferdes annahm. Zweifel an der vollständigen Autorenschaft Pfungsts und Berichte aus Tageszeitungen führen zu der Hypothese, dass Stumpf erhebliche Teile des Buches abgefasst oder redigiert hat und seinen peinlichen Irrtum hinter dem Namen seines Studenten Pfungst verbirgt.
An Initial Investigation of Phonological Patterns in Typically Developing 4-Year-Old Spanish-English Bilingual Children
Authors: Goldstein Brian , Washington Patricia Swasey
Published: April 2006

Purpose:
This collaborative study investigated phonological patterns in 12 typically developing 4-year-old bilingual (Spanish-English) children.

Method:
A single-word phonological assessment with separate versions for English and Spanish was administered to each child. Analyses consisted of a phonetic inventory; percentage of consonants correct; percentage of consonants correct for voicing, place of articulation, and manner of articulation; and the percentage of occurrence for phonological processes.

Results:
The results indicated that there were no significant differences between the two languages on percentage of consonants correct; percentage of consonants correct for voicing, place of articulation, and manner of articulation; or percentage of occurrence for phonological processes. However, the children exhibited different patterns of production across the two languages and showed different patterns compared to monolingual children of either language.

Clinical Implications:
The preliminary findings suggest that the phonological system of bilingual (Spanish-English) children is both similar to and different from that of monolingual speakers of either language. Compared to monolingual speakers, bilingual children should be expected to exhibit different types of errors and different substitution patterns for target sounds.
Use of Enhanced Natural Gestures to Foster Interactions Between Children With Angelman Syndrome and Their Parents
Authors: Calculator Stephen N.
Published: April 2006

The acceptability and feasibility of a home-based gestural training program for nine children with Angelman syndrome (AS), deletion positive, and their parents were examined. Children with AS have been found to exhibit a variety of challenges, including severe communication disabilities for which different Augmentative and Alternative Communication (AAC) systems have been of limited use (Alvares & Downing, 1998). Parents in this study were taught to recognize and then enhance their children's use of natural gestures as enhanced natural gestures (ENGs). ENGs are intentional behaviors that are present in a child's motor repertoire or can be easily taught based on a child's extant motor skills. Unlike contact gestures, such as grabbing objects from partners or pulling partners toward preferred activities, ENGs do not require physical contact with entities or interactants and are readily understood by others in context.

Parents were taught to use four primary teaching techniques: environmental sabotage, mand-model, expectant delay, and molding/shaping, and then to use these techniques over a period of 16 to 18 weeks to foster their child's use of ENGs. A questionnaire Enhanced Natural Gestures-Acceptability Rating Form (ENG-ARF), was administered to sample parents' perceptions about the acceptability and feasibility of the ENG training program. With few exceptions, parents described this method as acceptable, effective, reasonable, and easy to teach others, with minor negative consequences and side effects. Implications for subsequent research are discussed.
Qualitative Research and Speech-Language Pathology
Authors: Damico Jack S. , Simmons-Mackie Nina N.
Published: April 2006

As an analytic paradigm, qualitative research offers much to clinical speech-language pathology. This paradigm has a long history of use in the social sciences, and it is well suited to address the complex issues of speech, language, and communication. As an introduction to this forum on qualitative research, this article provides an operational definition of qualitative research, discusses the primary distinguishing traits of this research paradigm, and describes six viable traditions of inquiry for our application. Additionally, numerous qualitative studies within our field are considered, and five potential reasons for the increased use of qualitative research studies in our discipline are discussed.
Challenges and Strategies for Conducting Survey and Focus Group Research With Culturally Diverse Groups
Authors: Huer Mary Blake , Saenz Terry Irvine
Published: April 2006

The professions represented by the American Speech-Language-Hearing Association are serving a wide range of populations as diversity in the United States continues to grow rapidly. This article offers tentative guidance for and invites an open dialogue with other researchers interested in culturally sensitive research issues. Specifically, as the professions adopt an increasingly global perspective, it is likely that researchers will need to acquire skills in conducting research within culturally diverse populations. Within this article, research scenarios are discussed, in particular, methods for survey, interview, and focus groups. Topics such as preparing a research instrument, gaining access to clients, and effectively utilizing interpreters are presented. In brief, this article is designed as a beginning conversation about an increasingly important topic: conducting culturally sensitive research in communication disorders.
Assessment of Phonology in Preschool African American Vernacular English Speakers Using an Alternate Response Mode
Authors: Laing Sandra P.
Published: April 2006

The purpose of this study was to determine whether an adapted stimulus elicitation format would reduce the amount of final consonant absence in African American Vernacular English (AAVE) speakers and to determine the extent to which the adapted and standard response formats would differ in their predictions of membership in a delayed and a typical group. Findings revealed that the alternate response mode resulted in statistically significant decreases in the use of final consonant absence and that it was less likely than the standard response mode to penalize the AAVE speaker to a degree that was clinically significant.
Effects of Intensive Voice Treatment (the Lee Silverman Voice Treatment [LSVT]) on Ataxic Dysarthria
Authors: Sapir Shimon , Spielman Jennifer , Ramig Lorraine O. , Hinds Stephanie L. , Countryman Stefanie , Fox Cynthia , Story Brad
Published: April 2006

In the November 2003 issue of
AJSLP
, an incorrect reference was included in the article, "Effects of Intensive Voice Treatment (the Lee Silverman Voice Treatment [LSVT]) on Ataxic Dysarthria: A Case Study," by Shimon Sapir, Jennifer Spielman, Lorraine O. Ramig, Stephanie L. Hinds, Stefanie Countryman, Cynthia Fox, and Brad Story.

The following reference, on p. 398, is incorrect:
Liotti, M., Vogel, D., Ramig, L., New, P., Cook, C., & Fox, P.
(2003). Functional reorganization of speech-motor function in Parkinson disease following LSVT: A PET study.
Neurology, 60
, 432–440.

The correct reference is:
Liotti, M., Ramig, L. O., Vogel, D., New, P., Cook, C. I., Ingham, R. J., Ingham, J. C., & Fox, P. T.
(2003). Hypophonia in Parkinson’s disease: Neural correlates of voice treatment revealed by PET.
Neurology, 60
, 432–440.
Effect of Phonemic Perception Training on the Speech Production and Phonological Awareness Skills of Children With Expressive Phonological Delay
Authors: Rvachew Susan , Nowak Michele , Cloutier Genevieve
Published: April 2006

Children with expressive phonological delays often possess poor underlying perceptual knowledge of the sound system and show delayed development of segmental organization of that system. The purpose of this study was to investigate the benefits of a perceptual approach to the treatment of expressive phonological delay. Thirty-four preschoolers with moderate or severe expressive phonological delays received 16 treatment sessions in addition to their regular speech-language therapy. The experimental group received training in phonemic perception, letter recognition, letter-sound association, and onset-rime matching. The control group listened to computerized books. The experimental group showed greater improvements in phonemic perception and articulatory accuracy but not in phonological awareness in comparison with the control group.
Working Memory in Aphasia
Authors: Wright Heather Harris , Shisler Rebecca J.
Published: April 2006

Recently, researchers have suggested that deficits in working memory capacity contribute to language-processing difficulties observed in individuals with aphasia (e.g., I. Caspari, S. Parkinson, L. LaPointe, & R. Katz, 1998; R. A. Downey et al., 2004; N. Friedmann & A. Gvion, 2003; H. H. Wright, M. Newhoff, R. Downey, & S. Austermann, 2003). A theoretical framework of working memory can aid in our understanding of a disrupted system (e.g., after stroke) and how this relates to language comprehension and production. Additionally, understanding the theoretical basis of working memory is important for the measurement and treatment of working memory. The literature indicates that future investigations of measurement and treatment of working memory are warranted in order to determine the role of working memory in language processing.
Connexin 26 as a Cause of Hereditary Hearing Loss
Authors: McGuirt Wyman T. , Smith Richard J.H.
Published: April 2006

Connexin 26 (Cx26) is an inner ear protein that forms part of the potassium recycling pathway used to maintain the osmotic balance essential for normal auditory function. Mutations in the
GJB2
gene, which encodes for the Cx26 protein, recently have been implicated as the cause of up to 50% of hereditary prelingual severe-to-profound nonsyndromic hearing loss. A single mutation that results in the loss of a guanosine nucleotide at position 35, the 35delG mutation, is involved in approximately 97% of cases of Cx26-related deafness. In persons with prelingual severe-to-profound nonsyndromic hearing loss, genetic testing for Cx26-related deafness can establish a diagnosis and obviate the need for a more expensive evaluation. However, if this type of testing is considered, appropriate genetic counseling must be provided and the nuances and limitations of genetic testing must be understood.
Effects of Noise and Reverberation on the Precedence Effect in Listeners With Normal Hearing and Impaired Hearing
Authors: Roberts Richard A. , Koehnke Janet , Besing Joan
Published: April 2006

The purpose of this study was to determine the effects of reverberation and noise on the precedence effect in listeners with hearing loss. Lag burst thresholds (LBTs) for 4-ms noise bursts were obtained for 2 groups of participants: impaired hearing and normal hearing. Data were collected in reverberant and anechoic environments in quiet and noise, at sensation levels of 10, 20, 30, 40, and 50 dB. Results indicated a significant effect of reverberation on LBTs for both participant groups. LBTs increased with sensation level in the reverberant environment and decreased with increasing sensation level in the anechoic environment. There was no effect of hearing loss on LBTs. When the change in LBT due to noise was compared, the effect of noise depended on group and environment, with a greater effect of noise on the performance of listeners with impaired hearing. It is likely that the ability to fuse direct sounds and early reflections is degraded in listeners with impaired hearing and that this contributes to the difficulties experienced by these listeners in reverberation and noise.
An Investigation of List Equivalency of the Northwestern University Auditory Test No. 6 in Interrupted Broadband Noise
Authors: Stuart Andrew
Published: April 2006

The equivalency of Lists 1 to 4 of the Northwestern University Auditory Test No. 6 (NU-6; T. W. Tillman & R. Carhart, 1966) was investigated in interrupted broadband noise. Forty-eight young adults with normal hearing participated. All lists were administered at 50 dB sensation level re: listener spondee recognition thresholds at signal-to-noise ratios (S/Ns) of 10, 5, 0, –5, –10, –15, –20, –25, and –30 dB. Significant differences in listener performance were observed only at S/Ns ranging from 10 to –10. Significant mean list differences varied from 5.8% to 12.0%. These findings support the notion that caution should be exercised in the interpretation of listener performance differences with NU-6 stimuli presented in a background of interrupted noise.
Clinical Guide for Audiologic Tinnitus Management I
Authors: Henry James A. , Zaugg Tara L. , Schechter Martin A.
Published: April 2006

Purpose:This article is the first of 2 that present basic guidelines for audiologists to provide clinical management of tinnitus. The method, termed audiologic tinnitus management (ATM), was developed to incorporate management strategies that can be implemented most efficiently by audiologists.

Method:Development of ATM has been drawn from the clinical and research experience of the authors and numerous audiologists. Certain elements of ATM are adapted from the methods of tinnitus masking and tinnitus retraining therapy. Procedures are described in the present article for performing the intake assessment, while the companion article (J. A. Henry, T. L. Zaugg, & M. A. Schechter, 2005) describes treatment methodology.

Results:Development of ATM has resulted in defined procedures to conduct a basic tinnitus assessment that includes written questionnaires, an intake interview, audiologic evaluation, and a psychoacoustic assessment of tinnitus perceptual characteristics. If patients report a sound tolerance problem (hyperacusis), loudness discomfort levels are measured at audiometric frequencies. There are special procedures for selecting hearing aids, ear-level noise generators, combination devices (noise generator and hearing aid combined), and personal listening devices (i.e., portable radios and tape, CD, and MP3 players).

Conclusions:This article explains each of these assessment components in detail. Adoption of the ATM assessment protocol by audiologists can contribute to the establishment of uniform procedures for the clinical management of tinnitus patients.
Acoustic Comparison of Vowel Articulation in Normal and Reverse Phonation
Authors: Robb Michael P. , Chen Yang , Gilbert Harvey R. , Lerman Jay W.
Published: April 2006

Acoustic characteristics of the vowels /i,u,α/ produced by adult females and males during normal phonation were compared with the same vowels produced on deliberate ingressive airflow (i.e., "reverse" phonation). Results of the analysis revealed the average fundamental frequency (F
0
) of reverse phonation to be significantly higher than the corresponding normal phonations. There were no significant differences noted in the vocal tract resonance (F1 and F2 frequency) values for /i/ during normal and reverse phonation. However, the F1 values for /α/ were significantly lower, and the F2 values for /u/ significantly higher, during reverse phonation. The results are discussed with regard to differences in the articulatory control of the speech mechanism during reverse phonation as compared to normal expiratory phonation. Also discussed are the implications of using reverse phonation as a voice management technique.
Mechanisms of Discourse Comprehension Impairment After Right Hemisphere Brain Damage
Authors: Tompkins Connie A. , Lehman-Blake Margaret T. , Baumgaertner Annette , Fassbinder Wiltrud
Published: April 2006

This study examined the generality of a previous finding indicating that difficulty suppressing or inhibiting context-inappropriate interpretations is an important predictor of narrative discourse comprehension for adults with right brain damage RBD) (C. A. Tompkins, A. Baumgaertner, M. T. Lehman, & W. Fassbinder, 2000). Forty adults with RBD and 39 without brain damage listened to two-sentence stimuli and judged whether a probe word fit with the overall stimulus meaning. An ambiguous initial sentence elicited both dominant and less preferred inferences, and the second sentence resolved the ambiguity toward the initially less-likely interpretation. Probes represented the dominant inference for the first sentence and were presented at two poststimulus intervals.

Probe judgment response times indicated that neither group suppressed the eventually inappropriate inferences in the time intervals studied. However, multiple regression analysis demonstrated that for individual participants with RBD, the extent of suppression from one interval to the next was a significant predictor of performance on a specialized measure of inference comprehension. The discussion evaluates these findings and identifies directions for future research.
Psycholinguistic Models of Speech Development and Their Application to Clinical Practice
Authors: Baker Elise , Croot Karen , McLeod Sharynne , Paul Rhea
Published: April 2006

This article presents an introduction to psycholinguistic models of speech development. Two specific types of models are addressed:
box-and-arrow
models and
connectionist
or
neural network
models. We review some historical and some current models and discuss recent applications of such models to the management of speech impairment in children. We suggest that there are two ways in which a psycholinguistic approach can influence clinical practice: by directly supplementing a speech-language pathologist’s repertoire of assessment and treatment approaches and by offering a new way to conceptualize speech impairment in children.
The Relationship Between Perception and Acoustics for a High-Low Vowel Contrast Produced by Speakers With Dysarthria
Authors: Bunton Kate , Weismer Gary
Published: April 2006

This study was designed to explore the relationship between perception of a high-low vowel contrast and its acoustic correlates in tokens produced by persons with motor speech disorders. An intelligibility test designed by Kent, Weismer, Kent, and Rosenbek (1989a) groups target and error words in minimal-pair contrasts. This format allows for construction of phonetic error profiles based on listener responses, thus allowing for a direct comparison of the acoustic characteristics of vowels perceived as the intended target with those heard as something other than the target. The high-low vowel contrast was found to be a consistent error across clinical groups and therefore was selected for acoustic analysis. The contrast was expected to have well-defined acoustic measures or correlates, derived from the literature, that directly relate to a listeners' responses for that token. These measures include the difference between the second and first formant frequency (F2-F1), the difference between F1 and the fundamental frequency (F0), and vowel duration. Results showed that the acoustic characteristics of tongue-height errors were not clearly differentiated from the acoustic characteristics of targets. Rather, the acoustic characteristics of errors often looked like noisy (nonprototypi-cal) versions of the targets. Results are discussed in terms of the test from which the errors were derived and within the framework of speech perception theory.
Balancing Bilinguals II
Authors: Kohnert Kathryn J. , Bates Elizabeth
Published: April 2006

The present study investigated developmental changes in lexical comprehension skills in early sequential bilinguals, in both Spanish (L1) and English (L2), exploring the effects of age, years of experience, and basic-level cognitive processing (specifically the ability to maintain performance during mixed vs. single-language processing) within a timed picture-word verification task. Participants were 100 individuals, 20 at each of five different age levels (ages in years, 5–7, 8–10, 11–13, 14–16, and adults). All had learned Spanish as a first language in the home, with formal English experience beginning at 5 years. Gains (as indexed by increased response speed) were made in both languages across age, although these gains were greater in English than in Spanish. The youngest participants were relatively "balanced" in their crosslinguistic performance. By middle childhood, performance was better in English. There were no response decrements at any age between the mixed and single-language processing conditions. These results are compared to those from a previous study that investigated basic-level lexical production in developing Spanish-English bilinguals. Both studies show a move toward English dominance in middle childhood, but the transition occurs earlier in comprehension. The production study showed differences between mixed and single-language processing (reflecting potential interlanguage interference) that are not evident in comprehension.
Interaction of Speech Coders and Atypical Speech II
Authors: Jamieson Donald G. , Parsa Vijay , Price Moneca C. , Till James
Published: April 2006

We investigated how standard speech coders, currently used in modern communication systems, affect the quality of the speech of persons who have common speech and voice disorders. Three standardized speech coders (GSM 6.10 RPELTP, FS1016 CELP, and FS1015 LPC) and two speech coders based on subband processing were evaluated for their performance. Coder effects were assessed by measuring the quality of speech samples both before and after processing by the speech coders. Speech quality was rated by 10 listeners with normal hearing on 28 different scales representing pitch and loudness changes, speech rate, laryngeal and resonatory dysfunction, and coder-induced distortions. Results showed that (a) nine scale items were consistently and reliably rated by the listeners; (b) all coders degraded speech quality on these nine scales, with the GSM and CELP coders providing the better quality speech; and (c) interactions between coders and individual voices did occur on several voice quality scales.
Electroglottographic Evaluation of Gender and Vowel Effects During Modal and Vocal Fry Phonation
Authors: Chen Yang , Robb Michael P. , Gilbert Harvey R.
Published: April 2006

Two unique characteristics of vocal fry register are the occurrence of multiple opening and closing phases occurring within one vibratory cycle and a similar vocal fundamental frequency (F
0
) between women and men. The present study tested the hypothesis that significant differences in glottal cycle symmetry exist between women and men during modal phonation, with no significant differences during vocal fry phonation. Consistent with previous studies of modal phonation, it was also hypothesized that a vowel effect would be apparent during vocal fry phonation. Five women and 5 men sustained modal and vocal fry phonations in four vowel contexts (/agr;, æ, u, i/). Vocal F
0
, duration of opening and closing phase, and contact symmetry (speed quotient) were derived from electroglottographic (EGG) waveforms. Both female and male speakers demonstrated significantly higher SQ values in vocal fry register than in their modal register, indicating a longer opening-phase duration per glottal cycle. Women demonstrated a significantly greater increase in SQ during vocal fry phonations than men, indicating greater asymmetry between opening and closing durations. The results confirmed that gender differences in vocal fold contact behavior not only exist during modal register but also during vocal fry register. No vowel effects on vocal fold contact behavior as inferred using the SQ measure were found for either modal or vocal fry registers. Possible contributing factors to multiple opening and closing phases occurring within a vibratory cycle are discussed.