Special Education and Massachusetts Charter Schools: Examining Issues and Practices Associated with Enrollment, Placement and Compliance

Over the last ten years, charter schools have become a viable choice for parent’s seeking an alternative to traditional public schools. However, research shows this is not the case for students with disabilities. The purpose of this dissertation was to examine special education in charter schools and traditional public schools located in Massachusetts. I examined three key areas specific to special education; enrollment, placement and compliance, to determine if differences exist between charter schools and traditional public schools located in the state. Logistic regression analyses were conducted to examine differences between Massachusetts charter schools and public schools with respect to enrollment for each disability category. Multiple regression was used to examine differences in placement for special education students. Lastly, descriptive statistics were used to analyze the Massachusetts Department of Elementary and Secondary Education Coordinated Program Review (CPR) reports to determine if charter schools are compliant with state and federal regulations under the Individuals with Disabilities Education Act (IDEA). Findings revealed charter schools disproportionately under-enrolled students with disabilities, specifically severe disabilities, and placed students in full inclusion placements more frequently than public schools throughout the state. Charter schools also struggled to comply with state and federal regulations under the IDEA, specifically in areas related to direct services and supports to students with disabilities

Surface Stress, Morphological Development, and Dislocation Nucleation During SixGe1-x Epitaxy

Utilizing Ge marker layer experiments combined with atomic number contrast (Z-contrast) imaging, we have studied the evolving surface morphology of SixGe1-x alloys during growth by molecular beam epitaxy. The marker layers map out the instability transition between planar two-dimensional (2D) growth and three-dimensional (3D) growth. The transition occurs via the gradual formation of a surface ripple as anticipated from instability theory. However, these undulations rapidly develop into crack-like surface instabilities which we simulate and explain by the mechanism of stress-driven surface diffusion. Finally, we model the large stresses associated with these features within a fracture mechanics formalism. This analysis demonstrates that crack-like instabilities provide ideal candidate sites for the nucleation of misfit dislocations

Subclinical Aphasia Following Closed Head Injury: A Response to Sarno, Buonaguro, and Levita

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Determination of reference values for optical properties of liquid phantoms based on Intralipid and India ink

A multi-center study has been set up to accurately characterize the optical properties of diffusive liquid phantoms based on Intralipid and India ink at near-infrared (NIR) wavelengths. Nine research laboratories from six countries adopting different measurement techniques, instrumental set-ups, and data analysis methods determined at their best the optical properties and relative uncertainties of diffusive dilutions prepared with common samples of the two compounds. By exploiting a suitable statistical model, comprehensive reference values at three NIR wavelengths for the intrinsic absorption coefficient of India ink and the intrinsic reduced scattering coefficient of Intralipid-20% were determined with an uncertainty of about 2% or better, depending on the wavelength considered, and 1%, respectively. Even if in this study we focused on particular batches of India ink and Intralipid, the reference values determined here represent a solid and useful starting point for preparing diffusive liquid phantoms with accurately defined optical properties. Furthermore, due to the ready availability, low cost, long-term stability and batch-to-batch reproducibility of these compounds, they provide a unique fundamental tool for the calibration and performance assessment of diffuse optical spectroscopy instrumentation intended to be used in laboratory or clinical environment. Finally, the collaborative work presented here demonstrates that the accuracy level attained in this work for optical properties of diffusive phantoms is reliable

Influence of mismatch on the defects in relaxed epitaxial InGaAs/GaAs(100) films grown by molecular beam epitaxy

Thick (∼3 μm) films of InxGa1−xAs grown on GaAs(100) substrates, across the whole composition range, have been examined by transmission electron microscopy and double‐crystal x‐ray diffraction. The results were compared with the observed growth mode of the material determined by in situ reflection high‐energy electron diffraction in the molecular beam epitaxy growth system. The quality of the material degraded noticeably for compositions up to x∼0.5 associated with an increased density of dislocations and stacking faults. In contrast, improvements in quality as x approached 1.0 were correlated with the introduction of an increasingly more regular array of edge dislocations