bluuebunny/crossref_metadata_2025 huggingface dataset:
Laser welding of the synchronizer stop ring and the rear gear in a manual transaxle
Authors: Casalino G.
Published: June 2006

The focused laser beam is one of the highest power density sources available to industry today. When the “keyhole mode” is used for welding the result is characterized by a parallel-sided fusion zone, narrow width, and deep penetration. Therefore, a higher value of the joining efficiency (i.e., the reciprocal of the specific welding energy) is obtained and less energy is necessary for heating which generates a large heat affected zone and low mechanical distortion. This article focuses on the application of the CO2 seam laser welding of the stop ring of the synchronizer hub and the rear idle gear in a five-speed manual transaxle. This weld requires precision, repeatability, and welding efficiency. Unfortunately, stresses generated by the thermal cycle can produce cold cracks in the fused zone, which was highly stressed during the cooling phase. The different thermal expansion coefficients of the metals can also produce misalignment during the welding cycle. Here, the welding process was investigated with experimental tests and finite element numerical analysis. In particular a finite element model supported the decisional process of selecting parameters that minimize the crack risk and thermal induced misalignment during the welding process.
Characteristics of parallel irradiations in laser forming of stainless steel
Authors: Pennuto J. , Choi J.
Published: June 2006

The manufacturability of stainless steels has been extensively studied, but the spring back effect during material deformation continues to result in a costly trial and error tooling process. In an effort to develop a process free of dedicated tooling, this research seeks to study large radius deformation by laser forming. This is useful for shapes such as the lead edge of airfoils on airplane wings and rotor blades. Experimental testing was conducted to determine how the single pass output bend angle relates to the laser parameters of power, traverse velocity, and incident beam diameter. Experimentation was also performed to find the additive bend angle from successive parallel, evenly spaced laser irradiations. Using statistical analysis to develop an empirical model, this article will illustrate how the laser parameters affect the resultant bend angle. Suggestions for future study include researching the mechanical service effects of this thermomechanical process.
Femtosecond pulse stretching in microscope objectives used for micro/nanomachining
Authors: Tadepalli Nageswara Rao , Alexander Dennis , Doerr David , Li Jianchao , Zhang Haifeng
Published: June 2006

Femtosecond laser pulses are stretched when they pass through an optical microscope objective used for laser machining. The question that must be answered is how much does the pulse stretch passing through the objective. Stretching of pulses would be more prominent in the case of ultrashort laser pulses (∼9 fs). In this article, a study was performed to measure the final pulse duration for a 9 fs laser pulse passing through a microscope objective (Edmund Achromatic Objective Micro 60× DIN, 0.85 numerical aperture). Results indicate that a 9 fs pulse is stretched to 62 fs (i.e., a factor of 6) after passing through the microscope objective.
Pulsed laser welding of metal-polymer sandwich materials using pulse shaping
Authors: Gower H. L. , Pieters R. R. G. M. , Richardson I. M.
Published: June 2006

Increasing interest has been expressed in the application of hybrid metal/polymer materials for automotive applications, both to reduce weight and to improve performance. To date, the only joining methods available are mechanical fastening and adhesive bonding, both requiring an overlapping joint configuration to generate sufficient bond strength. This article describes how laser spot-welding and SHADOW™ (stepless high speed accurate and discrete one pulse welding) welding can be used to minimize degradation of the polymer while making fusion welds in the metal layers. The thickness of the external layers in metal polymer laminates is approximately 0.25 mm. Laser spot welds on such thin materials are very susceptible to cracking due to high cooling rates causing large stresses. These high cooling rates are necessary to avoid excessive thermal degradation of the central polymer layer. This article addresses a technique to provide such high cooling rates while preventing cracking in AA5182 thin sheet during pulsed laser welding.
Examination of laser hardened steel surfaces using interference microscopy
Authors: Pantsar Henrikki
Published: June 2006

A diode laser beam in the near-infrared region is absorbed more efficiently by a metal surface than a CO2 or a Nd:yttrium-aluminum-garnet laser beam. Diode laser transformation hardening without an absorptive coating is feasible even in an inert gas atmosphere. Absence of the absorptive coating, and the fact that the formation of an oxide layer is inhibited, makes it possible to study phase transformations occurring during hardening from the surface relief formed to the processed surface. In the present study diamond polished plain carbon and low alloy steel samples have been hardened in an inert gas atmosphere of argon using a high power diode laser. Surface reliefs caused by phase transformations during quenching have been examined using differential interference contrast (DIC) microscopy. Hardness of each sample was measured and the effect of the processing parameters on the surface hardness and microstructure has been established. DIC imaging was found to be a rapid and illustrative tool for examining microstructures in laser hardened surfaces. Extent of martensite, austenite grain size prior to quenching, and martensite lath size are visible in the DIC images.
Pit and rim formation during laser marking of acrylonitrile butadiene styrene plastic
Authors: Shin Yongjin , Kim Youngseop , Park Sohee , Jung Byungjo , Lee Jangwoen , Nelson J. Stuart
Published: June 2006

Pit and rim formation on the acrylonitrile butadiene styrene (ABS) plastic surface was evaluated after it was irradiated by CO2 and Nd:yttrium-aluminum-garnet (YAG) laser beams. Our results show that the thermal effect floor was well observed at the outer wall of the pit with CO2 laser irradiation while it was not the case with Nd:YAG laser irradiation. The volume and depth of the pit formation increase proportionally with laser irradiation energy while there are significant differences in the slope, width, and full width at half maximum of the pit formation with two different types of laser irradiations. This result shows that CO2 laser irradiation leads to a better cooling contraction effect while Nd:YAG laser irradiation induces a better recoil pressure effect during the interaction between ABS plastic and laser beam irradiation. The shape of the laser marking could vary significantly depending on the traveling path of molten plastic during injection molding of ABS plastic. Therefore, the selection of material and molding process can have a great impact on the laser micromachining of plastic.
Laser processing of polycrystalline diamond, tungsten carbide, and a related composite material
Authors: Harrison Paul M. , Henry Matthew , Brownell Michael
Published: June 2006

There are numerous industrial uses of superhard materials such as polycrystalline diamond, natural diamond, and tungsten carbide. These include tooling for mechanical processing as well as robust substrates for microelectronics in extreme environment applications. Processing these materials has presented a perennial problem for engineers. In this article cutting and milling of these materials is investigated using high average power nanosecond pulsed diode pumped solid-state lasers. The results are investigated with regard to developing models for nanosecond pulse laser milling. It is found that it is possible to process these materials at superior rates to conventional technologies, achieving comparable quality without the issues of tool wear and lubrication to contend with. It is also determined that this technology can both cut and mill these materials in concurrent processing—offering new flexibility for manufacturing design.
Fabrication of titanium microchannels using laser-assisted thermochemical wet etching
Authors: Son S. W. , Lee M. K. , Oh K. H. , Jeong S. H.
Published: June 2006

A fabrication method of titanium microchannels of an aspect ratio up to 16 and channel width of 10–30 μm is developed using laser-assisted thermochemical wet etching. For the fabrication of deep channel, the workpiece was repeatedly etched over the same path with the control of process parameters. The cross-sectional profile of the microchannel varied between a V shape and a U shape, depending largely upon the laser beam power and etchant concentration. Bubble formation characteristics that influence significantly on the surface quality and process stability are investigated. It is demonstrated that high-aspect-ratio metallic microchannels with different cross-sectional profiles and sizes can be fabricated by properly controlling the process parameters.
Laser helical drilling of silicon wafers with ns to fs pulses: Scanning electron microscopy and transmission electron microscopy characterization of drilled through-holes
Authors: Kaspar J. , Luft A. , Nolte S. , Will M. , Beyer E.
Published: June 2006

Electron microscopic methods (scanning electron microscopy and transmission electron microscopy) are used to characterize the precision and quality of microthrough-holes produced in 0.4 mm-thick silicon wafers by applying the pulsed laser helical drilling technique. The primary aim of the present work is to investigate how the mechanisms of material removal and redeposition change when the pulse width is systematically varied from nanosecond (ns) to femtosecond (fs) range (8 ns to 160 fs). Under the chosen processing conditions (Ti:sapphire laser, pulse energy: 0.3 mJ, beam spot diameter: 40 μm, resulting fluence: 24 J/cm2, processing time: 120 s) optimal drilling results, i.e., smooth holes being free of recast and free of thermally and mechanically driven structural damage, are achievable by using laser pulses with a width of 10 ps. On the contrary, drilling with ns pulses is associated with thick melt redepositions, high thermal load, and formation of microcracks, while processing with fs pulses suffers from detrimental mechanical effects causing defect generation, material degradation, and microroughness of the hole wall.
Finite element modeling of laser forming of aluminum matrix composites
Authors: Liu F. R. , Chan K. C. , Tang C. Y.
Published: June 2006

Much work has been done on modeling of laser forming over the past decades, but most of the models were developed for monolithic materials. In this article, a microstructure integrated finite element model is developed for the first time to predict the deformation behavior of composite materials in laser forming. A unit cell model is used to analyze the thermo-physical properties of an aluminum matrix composite. Spherical particles are assumed, and the particles are linearly elastic materials, whereas the matrix is an elastic-plastic material and the bonding between the particle and the matrix is perfect. A ten-node three-dimensional tetrahedral element has been employed to generate the meshes for unit cells and a 20-node brick element for the thermal and structural field in laser forming. The effective properties of the composite represented by the unit cells have been analyzed and compared with those obtained by the composite analytical models. The deformation behavior and bending angles of an aluminum matrix composite were simulated by the finite element model, and compared with the published experimental results. The distribution of the temperature field and the strain/stress field of the composite in laser forming are also analyzed, and the significance of the findings is discussed in this article.
Simultaneous wire- and powder-feed direct metal deposition: An investigation of the process characteristics and comparison with single-feed methods
Authors: Syed Waheed Ul Haq , Pinkerton Andrew J. , Li Lin
Published: June 2006

Many direct laser deposition processes utilize metallic powders to obtain near net shape objects. Wire feeding has also been used in many laser-cladding and other material-addition applications. Each feeding method has its own advantages and disadvantages: wire feeding laser deposition typically has higher deposition rate and higher material usage rate than the powder feeding deposition process, while powder feeding gives better geometry control. In this study a new approach is investigated by combining wire and powder feeding to achieve higher build rate and higher material usage efficiency while maintaining the geometry accuracy. Multilayer parts are produced from 316L stainless steel by powder feeding, wire feeding, and the combined process, together with a diode laser at powers of between 1 and 1.5 kW. The tracks are compared and the results analyzed in terms of deposition efficiency, surface roughness, and microstructure. Results show that by combining wire and powder an increased overall deposition rate can be achieved. Sample surface roughness is increased, but remains constant for all the calculated parameters, and microstructure remains essentially the same for all three deposition methods. The differences between the processes and reasons for the final sample characteristics are discussed.
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laser beam cutting of steels: Material issues
Authors: Manohar Murali
Published: June 2006

Laser beam cutting and its advantages along with its relevance to worldwide trends in manufacturing are introduced. Results of efforts to identify material-related factors that render steel suitable for laser cutting are described. Key material requirements for both hot-strip and discrete plate products have been summarized using data collected over several years based on anecdotal information as well as experimental results. It has become clear that near-zero residual stresses and a minimum level of residual elements (Cu, Ni, and Cr) are necessary to obtain clean pierces and consistent cut quality in thick (20–25 mm) plates, in both as-rolled and as-shot-blasted conditions using conventional CO2 laser cutting. A mechanism to explain why the presence of residual elements results in improved cut quality is proposed. Further work required to develop a better understanding of laser cutting has been highlighted and recent process developments that could significantly impact this technology have been outlined.
A high power diode laser-based technique for the bonding of composite patches to aluminium alloys on various military aircraft
Authors: Lawrence J.
Published: June 2006

A rapid, effective, and repeatable technique for repairing the damaged skins of various military aircraft, both fixed and rotary winged, using high power diode laser (HPDL) radiation is described herein. The HPDL beam was traversed across the surface of an APC-2 repair patch, thereby melting a thermoplastic adhesive placed inbetween the repair patch and an Alclad substrate, consequently bonding the repair patch to the Alclad substrate. When subjected to single lap shear tests, the shear strength of the bond generated with the HPDL radiation was 47.8±4.7 MPa, compared to 32.4±3.7 MPa for the induction welded samples. When subjected to the Boeing wedge test, the HPDL samples had a 1 h crack growth rate that was rated as very good (1.9±0.5 mm/h); for the induction welded samples the 1 h crack growth rate that was rated as good (2.7±1.2 mm/h). Of great significance was processing time achieved with the HPDL, which was reduced from 11.75 min when employing induction welding to 2.75 min with the HPDL. Moreover, the use of HPDL radiation has been shown in this work to be an effective means for bonding that is superior to its contemporary counterparts.
In-process monitoring and adaptive control for prevention of through-holes in full-penetration lap welds of aluminum alloy sheets
Authors: Kawahito Yousuke , Katayama Seiji
Published: June 2006

The availability of adaptive control for microspot lap welding of A3003 aluminum alloy sheets of 0.1 mm in thickness with a pulsed fundamental yttrium-aluminum-garnet laser beam was investigated with the objective of the stable production of sound full-penetration spot welds without through-holes. Two full-penetration welds with through-holes were produced among 20 samples subjected to a normal pulse laser beam. The in-process monitoring results of the reflected light and heat radiation signals showed that the minimum value of the reflected light intensity was lower and the maximum variations in rate of change of the heat radiation were higher due to the generation of a through-hole. Therefore, the laser power was controlled at 0.15 ms intervals in order to maintain both the reflected light intensity and the variation of heat radiation within the levels for the formation of normal full-penetration welds. Consequently, sound fully penetrated welds were consistently produced in all the 20 samples, owing to the stable growth of a molten area under the adaptive control of a pulsed laser power.
Laser ablation of silicon wafer with a water microdrop
Authors: Shimizu Kouki , Takahashi Kunimitsu , Morikazu Hiroshi , Ogoshi Nobumori , Takeyama Koichi , Wakayama Yoji , Obara Tetsuro
Published: June 2006

We have developed a new laser ablation process using a water-microdrop with a diameter of 70 μm. The shapes of the debris were investigated at various delay times. A Q-switched Nd:yttrium-aluminium-garnet laser of 25 ns pulse width and 532 nm wavelength was used. The spattering of debris was remarkably reduced by using the water microdrop. The debris pattern was dependent on the shape of the microdrop on the wafer, which in turn was dependent on the surface condition of the wafer and the delay time. The use of a smaller microdrop would result in laser dicing with a small ridge at the rim of the ablation point and no debris. The flexural stress of 720 MPa was obtained near the blade dicing.
Marking of lines on clay brick pavers by vitrification with a Nd:YAG laser
Authors: Restrepo J. W. , Fernández-Pradas J. M. , Gómez M. A. , Serra P. , Morenza J. L.
Published: June 2006

Laser marking of architectural materials is nowadays an attractive technique for industrial and decorative applications. We report the clay brick pavers marking by vitrification with a continuous-wave Nd:YAG laser (λ=1.064 μm), at different output powers and scan speeds of the laser beam. The marked lines resulted in a dark green glassy phase. The width, depth, and cross-section area of the lines grow with the impinging laser energy density. It was found that the energy density determines the volume per length unit of glassy phase formed. However, the width and depth of the lines can present small differences depending on the particular combination of power and speed.
Mycobacterium tuberculosis secreted protein ESAT-6 interacts with the human protein syntenin-1
Authors: Schumann Gisbert , Schleier Susanne , Rosenkrands Ida , Nehmann Nina , Hälbich Steffi , Zipfel Peter , Jonge Marien , Cole Stewart , Munder Thomas , Möllmann Ute
Published: June 2006

In order to study the function of the Mycobacterium tuberculosis protein ESAT-6 in the infection process, we searched for host proteins that interact with this secreted mycobacterial protein. Using a yeast two-hybrid system we identified the rat syntenin-1 protein as a candidate to interact with ESAT-6. This interaction was confirmed in vitro by protein overlay and by surface plasmon resonance using recombinant ESAT-6 and human syntenin-1, and by co-purification analysis of the mycobacterial expressed ESAT-6 and macrophage derived syntenin-1. The interaction domains were localized by two-hybrid studies using truncated derivatives of both proteins and by peptide spot analysis. Two domains of each protein mediate the ESAT-6/syntenin-1 interaction. The C-terminus of ESAT-6 binds to the PDZ-domains of syntenin-1 and the N-terminus of ESAT-6 binds to the N-terminus of syntenin-1. Thus, the host protein syntenin-1 represents a possible cellular receptor for the mycobacterial protein ESAT-6.
The protective effects of selenoorganic compounds against peroxynitrite-induced changes in plasma proteins and lipids
Authors: Nowak Paweł , Saluk-Juszczak Joanna , Olas Beata , Kołodziejczyk Joanna , Wachowicz Barbara
Published: June 2006

Many selenoorganic compounds play an important role in biochemical processes and act as antioxidants, enzyme inhibitors or drugs. The effects of a new selenocompound — bis(2-aminophenyl)-diselenide on oxidative/nitrative changes in human plasma proteins induced by peroxynitrite (ONOO−) were studied in vitro and compared with the those of ebselen, a well-known antioxidant. We also studied the role of the tested selenocompounds in peroxynitrite-induced plasma lipid peroxidation. Exposure of the plasma to peroxynitrite (0.1 mM) resulted in an increase in the level of carbonyl groups and nitrotyrosine residues in plasma proteins (estimated using the ELISA method and Western blot analysis). In the presence of different concentrations (0.025–0.1 mM) of the tested selenocompounds, 0.1 mM peroxynitrite caused a distinct decrease in the level of carbonyl group formation and tyrosine nitration in plasma proteins. Moreover, these selenocompounds also inhibited plasma lipid peroxidation induced by ONOO−1 (0.1 mM). The obtained results indicate that in vitro bis(2-aminophenyl)-diselenide and ebselen have very similar protective effects against peroxynitrite-induced oxidative/nitrative damage to human plasma proteins and lipids.
Identification of microsatellite markers in the rye genome
Authors: Bolibok Hanna , Rakoczy-Trojanowska Monika , Wyrzykowska Małgorzata , Radecka Magdalena , Orczyk Wacław
Published: June 2006

The rye genomic library, which consists of DNA fragments in the range of 0.5–1.1 kb, was screened for the presence of tri-and tetranucleotide and compound microsatellites. Of the 1,600,000 clones analysed, 102 clones were positive and 41 were suitable for SSR primer pair design. Twenty-six primer pairs amplified specific products, and six of them were capable of detecting polymorphism among 30 rye accessions of different genetic backgrounds. Using a set of Chinese Spring-Imperial wheat-rye addition lines, it was possible to locate 3 newly identified microsatellites on chromosomes 3R, 4R and 7R.
Translating Self-Determination Concepts into Support for Adults with Severe Disabilities
Authors: Bambara Linda M. , Cole Christine L. , Koger Freya
Published: June 2006

Enhancing self-determination is an ongoing process that involves the development of skills, interaction with the environment, and the support of others. In this report we translate the concepts of self-determination into action strategies for support providers who work with adults with severe disabilities. Specifically, this report (a) describes several barriers to self-determination, (b) describes ways to translate the four components of self-determination into practice, (c) provides an example of how support for self-determination was implemented for one woman, and (d) discusses some of the unresolved challenges in making self-determination a reality for adults with severe disabilities.
Teaching Children with Severe Disabilities to Utilize Nonobligatory Conversational Opportunities: An Application of High-Probability Requests
Authors: Davis Carol A. , Reichle Joe , Southard Kristin , Johnston Susan
Published: June 2006

Two children with severe disabilities who used electronic communication aids were taught to extend conversations as a result of implementation of an intervention strategy based on high-probability request sequences. Both participants had been selected as a result of the discrepancy between their propensity to respond to obligatory conversational bids (e.g., a question such as “What did you do at recess?”) and their propensity to refrain from responding to nonobligatory conversational bids (e.g., comments such as “I played kickball at recess”). Both learners' conversational maintenance skills improved as a result of the procedure. Educational implications are discussed.
Self-Efficacy Beliefs and the Education of Students with Severe Disabilities
Authors: Soto Gloria , Goetz Lori
Published: June 2006

The purpose of this article is to examine the contributions made by the teacher efficacy literature to the study of teaching students with severe disabilities. The description and measurement of the self-efficacy construct are first explained, followed by a brief overview of problems in self-efficacy research. Findings on the relationship between perceived self-efficacy of teachers and variables including perceptions of student abilities, classroom practices, adoption of innovations, and collaboration with others are then summarized. Implications of this literature for practice, staff development, and personnel training programs are then discussed. Finally, strategies to guide future research are offered.
Participatory Research: New Approaches to the Research to Practice Dilemma
Authors: Meyer Luanna H. , Park Hyun-Sook , Grenot-Scheyer Marquita , Schwartz Ilene , Harry Beth
Published: June 2006

The dissemination of research into practice presents an enduring challenge to the social sciences. Despite intervention research focused on individuals with disabilities and their families that reveals clear pathways to improving practice, researchers and practitioners alike express concern regarding limited and slow implementation of the results of research in typical school and community settings. This article reviews three widely disparate literatures concerned with the gap between research and practice, highlighting suggestions for narrowing the gap through the incorporation of elements of practice into the research process. For each of the steps in our research on the social relationships of children and youth, we present examples of participatory research approaches to decision making designed to increase the relevance and validity of findings for everyday practice. We conclude with criteria that might be applied to the design of effective interventions for research validation to increase the likelihood that the results of intervention research will be adopted by school and community constituencies.
Enhancing Choice and Participation for Adults with Severe Disabilities in Community-Based Instruction
Authors: Cooper Karena J. , Browder Diane M.
Published: June 2006

Three adults with severe disabilities received instructional support to make purchases in fast food restaurants. During baseline and intervention, participants received discrete, systematic prompting and feedback to perform the steps of the purchasing task analysis. During intervention, participants were prompted to make five distinct choices during the community routine. This prompting resulted not only in increased choicemaking, but also in collateral increases in the performance of the purchasing task analysis.
Service Learning: A Creative Strategy for Inclusive Classrooms
Authors: Gent Pamela J. , Gurecka Louis E.
Published: June 2006

The movement for full inclusion is often hindered by the lack of creative and alternative teaching methodologies in regular classrooms. Service learning not only offers an alternative to traditional classroom teaching methods, it is also a vehicle to provide inclusive community based instruction, to promote the development of communities, and to provide functional skills training. This paper defines service learning and its components while also discussing applicability of service learning for all students.
Parents' Perceptions of Siblings' Interactions with Their Brothers and Sisters Who are Deaf-Blind
Authors: Heller Kathryn Wolff , Gallagher Peggy A. , Fredrick Laura D.
Published: June 2006

This study surveyed parents' perceptions of relationships between siblings and their brothers and sisters with deaf-blindness. Parents' responses to a questionnaire were used to examine parents' perceptions of the types of interactions and interaction difficulties found between siblings and their brothers and sisters with deaf-blindness. In addition, parents shared their perceptions in the areas of communication, visual and auditory adaptations, orientation and mobility, and inclusion. The data indicate that relationships between siblings in this study consisted of unequal roles between siblings and their brothers and sisters with deaf-blindness, with siblings primarily taking on a helping role. According to parents, unique modifications needed to effectively interact with individuals who are deaf-blind were not typically being implemented by the siblings in this study.
Pivotal Response Intervention I: Overview of Approach
Authors: Koegel Lynn Kern , Koegel Robert L. , Harrower Joshua K. , Carter Cynthia Marie
Published: June 2006

The purpose of this article is to present an overview of several pivotal response interventions. Our research at the University of California, Santa Barbara, has been focused on attempting to identify pivotal areas that, when changed, result in concomitant positive changes in other areas. Pivotal areas that are discussed include responsivity to multiple cues, motivation to initiate and respond appropriately to social and environmental stimuli, and self-regulation of behavior, including self-management and self-initiations. The trend to streamline intervention by targeting behaviors that will have widespread effects on development, rather than targeting individual behaviors one at a time, is discussed.
The Effects of Peer Delivered Self-Monitoring Strategies on the Participation of Students with Severe Disabilities in General Education Classrooms
Authors: Gilberts Guy H. , Agran Martin , Hughes Carolyn , Wehmeyer Michael
Published: June 2006

This study investigated the effects of self-monitoring instruction delivered by peer tutors on the occurrence of academic survival skills displayed by five middle school students with severe disabilities. We employed a multiple baseline across subjects design. Instruction was provided in general education content classes. The students were taught to indicate on a self-recording sheet if they performed each of 11 skills. Data revealed an increase in the percentages of occurrence of survival skills across all students. Also, their general education teachers indicated that they observed a positive change for four of the five students. All students indicated that they believed that they were part of the class and reported an increase in their classroom participation. The implications of these findings are discussed.
Continuing to Describe the Natural Support Process
Authors: Ohtake Yoshihisa , Chadsey Janis G.
Published: June 2006

This study extends previous research by continuing to describe the natural support process. Specifically, we focus on the roles that co-workers and job coaches assume in supporting a worker with a disability. First, we discuss research related to co-worker involvement in work settings and provide a rationale for considering various roles for co-workers and job coaches. Second, we propose a framework for a continuum of six support strategies for co-workers and job coaches and show how prior research supports these strategies. Third, we offer suggestions for selecting an appropriate support strategy in a particular work setting. Finally, we discuss research areas that are still needed to clarify the natural support process.
Evaluating Special Education Services for Learners from Ethnically Diverse Groups: Getting it Right
Authors: Bevan-Brown Jill
Published: June 2006

One of the greatest challenges in evaluating special education services for ethnically diverse groups is obtaining accurate, valid, reliable, and relevant information. This can be achieved by the right person asking the right questions of the right people in the right way at the right place and time. These deceptively simple requirements are discussed in the context of research studies evaluating special education services for indigenous Maori children in New Zealand. Examples of cross-cultural misunderstanding and miscommunication are described and strategies to avoid them are discussed.
A Strategy for Students with Moderate Disabilities When Lost in the Community
Authors: Taber Teresa A. , Alberto Paul A. , Hughes Melissa , Seltzer Allison
Published: June 2006

This study examined the acquisition of cell phone use by middle school students with moderate cognitive disabilities. While in school and community settings, students were taught to identify when they were lost and follow a set of procedures for using a cell phone to call for assistance. Through the use of a five-level prompting system in conjunction with total task presentation, students acquired these new safety skills. A series of concurrent multiple-probe designs across groups was used to evaluate cell phone use and to permit generalization from school to community settings. For four participants, generalization was also made to a second phone call recipient. Results indicated that all students successfully acquired the skills of identifying when they were lost and then using a cell phone to call for assistance.
An Analysis of Legal Hearings and Cases Related to Individualized Education Programs for Children with Autism
Authors: Etscheidt Susan
Published: June 2006

Developing appropriate programs for students with autism has been an increasingly complex task for parents, schools, and other stakeholders. Parents of students with autism have challenged the appropriateness of proposed school district programs, and these disputes represent the fastest growing and most expensive area of litigation in special education. In this article, 68 hearings and cases were reviewed. The article discusses the outcomes of administrative and judicial decisions related to appropriate programs for children with autism. Three primary factors were identified: Individualized education program (IEP) goals must be matched to evaluation data, IEP team members must be qualified to develop programs, and the methodology selected must be able to assist the students in achieving identified IEP goals. Implications for school teams are discussed.
“Scientifically Based Research” and Qualitative Inquiry
Authors: Giangreco Michael F. , Taylor Steven J.
Published: June 2006

Not everything that can be counted counts, and not everything that counts can be counted. (Anonymous, often attributed to Albert Einstein; Calaprice, 2000)
Parent Perception of the Impacts of Inclusion on Their Nondisabled Child
Authors: Peck Charles A. , Staub Debbie , Gallucci Chrysan , Schwartz Ilene
Published: June 2006

We studied parents' perceptions of the effects of their nondisabled child's participation in a classroom in which a child with severe disabilities was enrolled full time. Survey responses from 389 parents indicated that they generally perceived their nondisabled child to have benefited from this experience. A minority of parents held negative views of inclusion after their child's participation. Analysis of narrative comments on surveys returned by some of these parents indicated that concerns about behavioral disruption and loss of teacher time allocated to their child were the major source of their dissatisfaction. Survey comments suggested in some cases that parents did not view academic and social learning experiences to be highly related. Implications of this and other viewpoints expressed by these parents are considered in terms of priorities for teacher education and for subsequent research.
The Importance of Choice-Making Skills for Students with Severe Disabilities
Authors: Shevin Mayer , Klein Nancy K.
Published: June 2006

Making choices is an essential part of functioning independently as an adult in society. Activities specifically directed toward helping students learn to make choices, however, are typically neglected in educational programs for students with severe disabilities. This paper presents a rationale for the inclusion of choice-making as an important skill area for persons with severe disabilities. Behavioral approaches that present useful means of conceptualizing choice-making in the school life of severely disabled students are identified. Procedures are suggested for teaching choice-making skills, for integrating opportunities for exercising those skills throughout the course of the student's school life, and for fostering choice-making skills through the use of logical consequences.
Peer-Mediated Conversational Repair in Students with Moderate and Severe Disabilities
Authors: Weiner Jan S.
Published: June 2006

Conversation skills are critical to learning and the development of social relationships. Some students with severe disabilities have a difficult time conversing with their nondisabled classmates because of their unintelligible verbalizations or an inability to correct or repair a message that may have been misunderstood by their conversational partner. For intervention purposes, extant literature strongly suggests that typical similar-age peers are effective change agents. In a study using a multiple baseline design with generalization probes, nine typical peers were taught to request repairs in response to unintelligible verbalizations. Three peers were assigned to each of the three target students. Teaching peers to request repair resulted in increased repaired messages and frequency of turns taken during conversation.
Toward a Technology of “Nonaversive” Behavioral Support
Authors: Horner Robert H. , Dunlap Glen , Koegel Robert L. , Carr Edward G. , Sailor Wayne , Anderson Jacki , Albin Richard W. , O'Neill Robert E.
Published: June 2006

Nonaversive behavior management is an approach to supporting people with undesirable behaviors that integrates technology and values. Although this approach has attracted numerous proponents, more adequate definition and empirical documentation are still needed. This article presents an introduction to the nonaversive approach. Important definitions are suggested, and three fundamental elements are presented: (a) an emerging set of procedures for supporting people with severe challenging behavior; (b) social validation criteria emphasizing personal dignity; and (c) a recommendation for prohibition or restriction of certain strategies. These elements are defined in hopes of stimulating further discussion and empirical analyses of positive behavioral support.
Non‐random associations and vascular fields in neurofibromatosis 1: A pathogenetic hypothesis
Authors: Lubinsky Mark S.
Published: June 2006

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with highly variable expression generally ascribed to random factors. However, evidence is presented for patterns suggesting non‐stochastic processes as follows: (1) We have seen a MZ twin pair concordant for renal vascular hypertension, and another for unilateral ptosis. Other concordances have been reported, including both malformations and tumors, and combinations as well. (2) Four children were seen with a distinct ipsilateral association of glaucoma or iris anomaly, optic glioma, plexiform neurofibromas arising from the trigeminal nerve and its branches, and sphenoid dysplasia. Other cases in the literature support milder forms of this association. (3) We saw six children with apparent gynecomastia or premature thelarche without endocrine abnormalities. Tissue samples from four of these showed an unusual fibrous plexiform neurofibroma. Interestingly, five of the six cases were African Americans, and constitutional factors affecting fibrous reactions may also be involved here.

A tentative hypothesis is presented suggesting vascular fields involving defined areas that can: (1) Support tumor growth. They would be the “soil” determining the ability and the extent of growth. There would, however, still be a need for a “second hit” tumor transformation. (2) Affect blood supply to organs, creating structural anomalies. NF1 involves a vasculopathy, and would predispose to vulnerabilities of such fields. Genetic factors could induce superimposed susceptibilities of specific fields, leading to twin concordances. “Hits” affecting specific fields would increase the likelihood of multiple abnormalities that could include both tumors and structural findings. Finally, tumors may follow the contours of existing fields. The breast is an area normally primed for growth, and the observation of clitoromegally secondary to tumor involvement suggests that such fields exist elsewhere. © 2006 Wiley‐Liss, Inc.
Novel mutations in dihydrolipoamide dehydrogenase deficiency in two cousins with borderline‐normal PDH complex activity
Authors: Cameron Jessie M. , Levandovskiy Valeriy , MacKay Neviana , Raiman Julian , Renaud Deborah L. , Clarke Joe T.R. , Feigenbaum Annette , Elpeleg Orly , Robinson Brian H.
Published: June 2006

We have diagnosed dihydrolipoamide dehydrogenase (DLD) deficiency in two male second cousins, who presented with markedly different clinical phenotypes. Patient 1 had a recurrent encephalopathy, and patient 2 had microcephaly and lactic acidosis. Their presentation is unusual, in that the DLD subunit deficiency had little effect on pyruvate dehydrogenase complex activity, but caused a severe reduction in the activities of other enzymes that utilize this subunit. We have identified two mutations in the DLD gene in each patient. The second cousins have one novel mutation in common resulting in a substitution of isoleucine for threonine (I47T), which has not been previously reported in the literature. Patient 1 has a second mutation that has been reported to be common in the Ashkenazi Jewish population, G229C. Patient 2 has a second mutation, E375K, which has also been previously reported in the literature. Enzyme kinetic measurements on patient fibroblasts show that under certain conditions, one heteroallelic mutation may have a higher Km. This may account for the differing clinical phenotypes. These findings have important repercussions for other patients with similar clinical phenotypes, as DLD activity is not normally measured in cases with normal PDHc activity. © 2006 Wiley‐Liss, Inc.
Congenital diaphragmatic hernia associated with duplication of 11q23‐qter
Authors: Klaassens M. , Scott D.A. , van Dooren M. , Hochstenbach R. , Eussen H.J. , Cai W.W. , Galjaard R.J. , Wouters C. , Poot M. , Laudy J. , Lee B. , Tibboel D. , de Klein A.
Published: June 2006

Congenital diaphragmatic hernia (CDH) is a relatively common birth defect with a high mortality. Although little is known about its etiology, there is increasing evidence for a strong genetic contribution. Both numerical and structural chromosomal abnormalities have been described in patients with CDH. Partial trisomy 11q and partial trisomy 22 associated with the common t(11;22) has been reported in several cases of CDH. It has been assumed that the diaphragmatic defect seen in these individuals was primarily due to duplication of material from chromosome 22q11. However, in this report we describe a family with a t(11;12) in which one of two brothers with partial trisomy 11q has a left sided posterolateral CDH. This is the second case of CDH in partial trisomy 11q due to an unbalanced translocation other than t(11;22). Using array‐based comparative genomic hybridization and fluorescent in situ hybridization, we mapped the breakpoints in both brothers and their mother who is a balanced translocation carrier. Our results suggest that duplication of one or more genes on a ∼19 Mb region of 11q23.3‐qter predisposes to the development of CDH. These effects may be the primary cause of CDH in individuals t(11;22) or may be additive to effects from the duplication of chromosome 22 material. We also conclude that the partial trisomy 11q syndrome has a variable phenotype and that CDH should be added to the spectrum of anomalies that can be present in this syndrome. © 2006 Wiley‐Liss, Inc.
Constitutional UPD for chromosome 11p15 in individuals with isolated hemihyperplasia is associated with high tumor risk and occurs following assisted reproductive technologies
Authors: Shuman Cheryl , Smith Adam C. , Steele Leslie , Ray Peter N. , Clericuzio Carol , Zackai Elaine , Parisi Melissa A. , Meadows Anna T. , Kelly Thaddeus , Tichauer David , Squire Jeremy A. , Sadowski Paul , Weksberg Rosanna
Published: June 2006

Isolated hemihyperplasia (IH) refers to a distinct diagnosis involving asymmetric overgrowth of single or multiple organs or regions of the body and can result from various genomic changes including molecular alterations of 11p15; these are paternal uniparental disomy (UPD), and alterations of methylation at two imprinting centers at 11p15: IC1 (H19) and IC2 (KCNQ1OT1). As little information is available on the molecular basis of tumor development in IH, or on the frequency of tumors in children with different molecular subtypes of IH, molecular testing was undertaken on 51 patients with IH and revealed: 8 (16%) with UPD, 3 (6%) with hypomethylation at KCNQ1OT1, and 0 with hypermethylation at H19. Of the 8 patients with UPD, 4 had tumors (3 hepatoblastomas, 1 Wilms tumor); 0/3 patients with hypomethylation at KCNQ1OT1 had a tumor; of the remaining 40 with no molecular alterations, 6 had tumors (3 Wilms tumors, 2 neuroblastomas, 1 adrenocortical adenoma). The 50% tumor frequency in patients with IH and UPD was statistically significantly higher than the 15% tumor frequency in those with IH and no molecular alteration detected (Fisher's exact test P = 0.047, OR 5.67). This is the first demonstration that UPD at 11p15 in patients with IH confers a higher tumor risk than in patients with IH without this molecular change. Of note, two of the eight patients with UPD and IH were conceived using assisted reproductive technologies (ART), thus raising the question whether ART might impact the rate of somatic recombination during embryonic development. © 2006 Wiley‐Liss, Inc.
Chromosome 3p25 deletion in mother and daughter with minimal phenotypic effect
Authors: Takagishi Jennifer , Rauen Katherine A. , Drumheller Timothy , Kousseff Boris , Sutcliffe Maxine
Published: June 2006

3p25 deletion syndrome is characterized by mental retardation, growth retardation, hypotonia, microcephaly, ptosis, and micrognathia. Of the 42 persons with this deletion syndrome cited in the literature, only 2 patients, a mother–daughter pair, have previously been reported without apparent clinical consequence. We present a second mother–daughter dyad with a terminal 3p25.3–3pter deletion, who present with only mild clinical effects. In addition to cytogenetic analysis, array CGH was performed to determine the breakpoints at the molecular level. Our data show that the 3p25 deletion syndrome may, therefore, reflect a much broader phenotypic spectrum than previously recognized. © 2006 Wiley‐Liss, Inc.
Molecular cytogenetic analysis of de novo dup(5)(q35.2q35.3) and review of the literature of pure partial trisomy 5q
Authors: Chen Chih‐Ping , Lin Shuan‐Pei , Lin Chyi‐Chyang , Chen Yann‐Jang , Chern Schu‐Rern , Li Yueh‐Chun , Hsieh Lie‐Jiau , Lee Chen‐Chi , Pan Chen‐Wen , Wang Wayseen
Published: June 2006

An 11‐year‐old girl presented with the phenotype of microcephaly, moderate mental retardation, motor retardation, short stature, strabismus, brachydactyly, and facial dysmorphism. She had undergone surgery for inguinal hernias. Detailed examinations of the heart and other internal organs revealed normal findings. Her karyotype was 46,XX,dup(5)(q35.2q35.3) de novo. Molecular cytogenetic analysis showed a paternally derived 5q35.2 → q35.3 direct duplication and led to a correlation between the particular genotype and phenotype. This is the first description of a direct duplication of 5q35.2 → q35.3. Our case represents the smallest distal duplication of chromosome 5q that is not associated with congenital heart defects. Our case also represents the smallest distal duplication of chromosome 5q that is associated with short stature and microcephaly. Mutations or deletions of the NSD1 gene, mapped to 5q35.2 → q35.3, has been known to cause Sotos syndrome with cerebral gigantism, macrocephaly, advanced bone age and overgrowth. Our case provides evidence that the gene dosage effect of the NSD1 gene causes a reversed phenotype of microcephaly and short stature. © 2006 Wiley‐Liss, Inc.