Follow-up study of eighty-five veterans with epilepsy.

Thesis (Ed.M.)—Boston Universit

Wood As a Bimodular Material

Wood is usually considered to be a material with equal stiffness in tension and compression, but this supposition is not uniformly supported by experimental evidence. On the basis of data in the literature, the authors believe that there is sufficient evidence to conclude that some woods, particularly hardwoods, exhibit bimodular behavior. For the hardwood data analyzed here, the ratio of Young's modulus in tension to Young's modulus in compression (Et/Ec) averaged 1.08 and ranged as high as 1.28. Comparisons with composite materials with known bimodular behavior suggest that fiber displacement around rays (and the resulting fiber curvature) might be one cause of this behavior. Some data also indicate that the equality of the tension and compression moduli may be affected by the moisture content. There are similarities with synthetic fibers which suggest that wood fibers might also be bimodular, but the question of whether bimodular behavior can be ascribed to both undelignified fibers and solid wood remains unanswered

Using questionnaires as a tool for comparative linguistic field research: Two case studies on Javanese

In this paper, we discuss how written questionnaires for targeted constructions can be a beneficial tool for comparative linguistic field research through two case studies on Javanese (Austronesian; Indonesia). The first case study is based on a questionnaire designed to elicit how a language or a dialect expresses the semantic meaning of modality (Vander Klok 2014); we show how it can be implemented in three different ways for comparative linguistic field research. The second case study is based on a questionnaire which investigates the morphosyntax of polar questions across four Javanese dialects; we show how items can be designed to maximize direct comparison of features while still allowing for possible lexical, phonological, or morphosyntactic variation. Based on these two studies, we also address methodological challenges that arise in using questionnaires in comparative linguistic field research and offer best practices to overcome these challenges.National Foreign Language Resource Cente

Evaluation of the voice visualizer as an aid in teaching voice improvement.

Thesis (Ed.D.)--Boston University

Expression of neurogenin3 reveals an islet cell precursor population in the pancreas

Differentiation of early gut endoderm cells into the endocrine cells forming the pancreatic islets of Langerhans depends on a cascade of gene activation events controlled by transcription factors including the basic helix-loop-helix (bHLH) proteins. To delineate this cascade, we began by establishing the position of neurogenin3, a bHLH factor found in the pancreas during fetal development. We detect neurogenin3 immunoreactivity transiently in scattered ductal cells in the fetal mouse pancreas, peaking at embryonic day 15.5. Although not detected in cells expressing islet hormones or the islet transcription factors Isl1, Brn4, Pax6 or PDX1, neurogenin3 is detected along with early islet differentiation factors Nkx6.1 and Nkx2.2, establishing that it is expressed in immature cells in the islet lineage. Analysis of transcription factor-deficient mice demonstrates that neurogenin3 expression is not dependent on neuroD1/BETA2, Mash1, Nkx2.2, Nkx6.1, or Pax6. Furthermore, early expression of neurogenin3 under control of the Pdx1 promoter is alone sufficient to drive early and ectopic differentiation of islet cells, a capability shared by the pancreatic bHLH factor, neuroD1/BETA2, but not by the muscle bHLH factor, MyoD. However, the islet cells produced in these transgenic experiments are overwhelmingly α cells, suggesting that factors other than the bHLH factors are required to deviate from a default α cell fate. These data support a model in which neurogenin3 acts upstream of other islet differentiation factors, initiating the differentiation of endocrine cells, but switching off prior to final differentiation. The ability to uniquely identify islet cell precursors by neurogenin3 expression allows us to determine the position of other islet transcription factors in the differentiation cascade and to propose a map for the islet cell differentiation pathway

Matching Variables for Research Involving Youth with Down Syndrome: Leiter-R versus PPVT-4

Much of what is known about the cognitive profile of Down syndrome (DS) is based on using either receptive vocabulary (e.g., PPTV-4) or nonverbal ability (e.g., Leiter-R) as a baseline to represent cognitive developmental level. In the present study, we examined the relation between these two measures in youth with DS, with non-DS intellectual disability (ID) and with typical development (TD). We also examined the degree to which these two measures produce similar results when used as a group matching variable. In a cross-sectional developmental trajectory analysis, we found that the relation between PPVT-4 and Leiter-R was largely similar across groups. However, when contrasting PPVT-4 and Leiter-R as alternate matching variables, the pattern of results was not always the same. When matched on Leiter-R or PPVT-4, the group with DS performed below that of the groups with ID and TD on receptive grammar and below the group with TD on category learning. When matched on the PPVT-4, the group with ID performed below that of the group with TD on receptive grammar and category learning, but these differences between the groups with ID and TD were not found when matched on the Leiter-R. The results of the study suggest that the PPVT-4 and Leiter-R are interchangeable at least for some outcome measures for comparing youth with DS and TD, but they may produce different results when comparing youth with ID and TD