Using electronic resources to support dialogue in undergraduate small‐group teaching: The ASTER project

Learning through dialogue is an important element of UK higher education, supported by tutorial, seminar and workshop classes. Since 1998, the ASTER project has been exploring how Information and Communication Technologies support learning in small groups (http://cti‐psy.york.acuk/aster/). Electronic resources are developed and used in courses to support a wide range of learning needs, from delivery of content to interactive teaching tools and assessment. The manner in which they are integrated into a course dictates the extent to which they support and extend learning. The ASTER survey has identified the use of a range of new technologies to support learning through dialogue in a variety of contexts. Many of the uses are common across disciplines, though we have observed some differences in the range of tools used, and how they are implemented in and beyond the classroom. These differences are partly determined by the subject content of resources, and by the activities that ICT tools support. Another factor influencing this variation seems to be traditions of academic discourse. The findings suggest that educational technology needs to support both generic education practice, and the special needs of particular disciplines

Synthesis, structure, and high-temperature thermoelectric properties of boron-doped Ba_8Al_(14)Si_(31) clathrate I phases

Single crystals of boron-doped Ba_8Al_(14)Si_(31) clathrate I phase were prepared using Al flux growth. The structure and elemental composition of the samples were characterized by single-crystal and powder X-ray diffraction; elemental analysis; and multinuclear ^(27)Al, ^(11)B, and ^(29)Si solid-state NMR. The samples' compositions of Ba_8B_(0.17)Al_(14)Si_(31), Ba_8B_(0.19)Al_(15)Si_(31), and Ba_8B_(0.32)Al_(14)Si_(310) were consistent with the framework-deficient clathrate I structure Ba_8Al_xSi_(42-3/4x)□_(4-1/4x) (X = 14, □ = lattice defect). Solid-state NMR provides further evidence for boron doped into the framework structure. Temperature-dependent resistivity indicates metallic behavior, and the negative Seebeck coefficient indicates that transport processes are dominated by electrons. Thermal conductivity is low, but not significantly lower than that observed in the undoped Ba_8Al_(14)Si_(31) prepared in the same manner

Tyrosine kinase inhibition produces specific alterations in axon guidance in the grasshopper embryo

Tyrosine kinase signaling pathways are essential for process outgrowth and guidance during nervous system development. We have examined the roles of tyrosine kinase activity in programming growth cone guidance decisions in an intact nervous system in which neurons can be individually identified. We applied the tyrosine kinase inhibitors herbimycin A and genistein to whole 40% grasshopper embryos placed in medium, or injected the inhibitors into intact grasshopper eggs. Both inhibitors caused interneuronal axons that normally would grow along the longitudinal connectives to instead leave the central nervous system (CNS) within the segmental nerve root and grow out toward the body wall muscles. In addition, herbimycin A produced pathfinding errors in which many longitudinal axons crossed the CNS midline. To study how this drug affected guidance decisions made by individual growth cones, we dye-filled the pCC interneuron, which normally extends an axon anteriorly along the ipsilateral longitudinal connective. In the presence of herbimycin A, the pCC growth cone was redirected across the anterior commissure. These phenotypes suggest that tyrosine kinase inhibition blocks a signaling mechanism that repels the growth cones of longitudinal connective neurons and prevents them from crossing the midline

The Influence of School Segregation on Students’ Educational Achievement

This literature review evaluates how race, geographical location, and socioeconomic status impacts a student’s educational achievement. These variables affect educational success, which is impacted by the history of housing and racial segregation in the United States. The discussion will include why schools are segregated and how this has an impact on a student’s education by looking at different studies and theories such as the Black Culture theory and the Acting White Hypothesis. Even in desegregated schools, “tracking” separates and further segregates races in the educational system. The literature review concludes with a summary of the findings, importance, and future research that can be done in this field including equal funding for public schools across Americ

Gene Expression Is Required for Correct Axon Guidance

AbstractAs axons form connections in the developing brain, they often change course before they reach their final target. An outstanding question concerning changes in axon guidance is whether autonomous gene expression directs axons to their targets. If autonomous gene expression is required during axon guidance, then at least some aspects of guidance may be irreversible. Once commissural axons cross the midline in the central nervous system (CNS), they usually make guidance decisions that differ from those made on the ipsilateral side. Here I explore whether a change in gene expression is involved in postcommissural axon guidance. Grasshopper serotonergic neurons were microinjected with a fluorescent tracer dye and either a translation blocker or a transcription blocker. After 24 hr of development, the guidance decisions of these microinjected axons were assayed. If the growth cones had already made a postcommissural guidance choice after crossing the midline, they continued growth even when gene expression was inhibited. If growth cones had just crossed the midline and not yet reached the choice point, they made a distinct guidance error when gene expression was inhibited. These results show that there is a discrete step in which gene expression plays a critical role in postcommissural axon guidance