Bing Chen - US grants

Electrical Engineering (55)

This project is adapting and augmenting the TekBot mobile robot platform developed at Oregon State University in a vertically integrated fashion, using problem-based learning as a foundational strategy throughout the computer engineering and electronics engineering curriculum. The project objectives are to: 1) adapt and implement TekBot course materials around various course sequences in their curriculum; 2) adapt and implement problem-based learning strategies that complement and augment the TekBot course materials; 3) develop and implement an ongoing assessment methodology and tools to determine the effectiveness of the TekBot diffusion and impact on student learning; 4) disseminate the materials, practices, and results of the project, and (5) continue these new educational reforms beyond the scope of the project. In this curriculum model, students are actively engaged in the learning process through problem-solving scenarios that allow them to more deeply participate in their own learning. As a result, the anticipated outcomes include increased student success on selected course assignments and course grades, reduced course withdrawal and failure rates, and increased positive student perceptions of the curriculum and commitment to the program. An ongoing and collaborative partnership with Oregon State University will lead to continuing program improvements at both institutions. The TekBot learning modules and laboratory experiments developed in this project are being indexed on the project website with linkages freely available to other ECE departments. The investigators are planning on showcasing the TekBot technologies in summer institutes for high school mathematics and science teachers and students that target underrepresented women and minority students as well as students from rural areas. They also areplanning to disseminate their TekBot learning platform via workshops at engineering education and department head conferences and through journal and conference papers.

The "Silicon Prairie Initiative on Robotics in IT" (SPIRIT), a collaboration between the University of Nebraska and Omaha Public Schools, is a three-year Comprehensive ITEST Project for Students and Teachers. SPIRIT targets 105 science and mathematics teachers in grades 7-8, each of whom receives more than 100 hours of summer professional development and 50 hours of follow-up support in developing in-school curricular activities. More than 9,000 students are expected to participate through in-school and summer programs.

The centerpiece of the project is a unversity level TekBot (TM) learning platform that is being adapted to the middle school level. This platform can be used to demonstrate basic applications in wireless, video and signal processing, sensors, video displays, electronics, control systems, embedded systems, digital logic and introductory programming. The curriculum to be developed in the project employs TekBots as a fundamental strategy for problem-based instructional activities. It is adaptable, expandable and cost-effective, providing learning experiences that can extend into high school and college. Results will be disseminated through publications and presentations, teacher workshops, displays prepared for the Omaha Children's Museum and collaborations with other universities using robotics platforms. An interactive, dynamic website will be created with modules and tutorials, uploadable programs, chat rooms and links to robotics research.

Building on previous ITEST funding, the PI is designing and developing a set of curriculum materials centering on a revised version of the NSF funded TekBot robotics platform developed by Oregon State University. Having added to the TekBot, a new robot, called NUBot is being developed by the Technology Development Corporation of the Peter Keitit Institute of the University of Nebraska. These robots are substantially less expensive, than most major commercial kits and use off the shelf parts from local electronics suppliers.

The leadership team creates materials for grades 5-8 that address and assess STEM concepts through a robotics curriculum. The curriculum addresses STEM standards through such documents as the NCTM Focal Points and the Atlas of Science Literacy. There are three problem based ways in which students can use the TekBot: building, moving, and programming. The intent is to scale up to a cyber-infrastructure that supports the national distribution and implementation of the curriculum. The cyber-infrastructure provides for summer workshops, distance education, a means of permitting teachers to identify lesson plans based upon their educational objectives, and an internet on call technician as means of teacher professional development.

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. HIV-1 envelope glycoprotein gp41 undergoes large conformational changes to drive fusion of viral and target cell membranes, thereby exhibiting at least three distinct conformations during the viral entry process. Neutralizing antibodies against gp41 block HIV-1 infection by targeting its membrane proximal external region in a fusion-intermediate state. We have obtained biochemical and structural evidence that non-neutralizing antibodies, capable of binding with high affinity to an immunodominant segment adjacent to the neutralizing epitopes in the membrane-proximal region, only recognize a gp41 conformation when membrane fusion is complete. We propose that these non-neutralizing antibodies are induced in HIV-1 infected patients by gp41 antigens in a triggered, postfusion form and contribute to production of ineffective humoral responses. These results have important implications for gp41-based vaccine design by rational strategies.

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Ibalizumab is a humanized, anti-CD4 monoclonal antibody. It potently blocks HIV-1 infection and targets an epitope in the second domain of CD4 without interfering with immune functions mediated by interaction of CD4 with major histocompatibility complex (MHC) class II molecules. We have determined the crystal structure of ibalizumab Fab fragment in complex with the first two domains (D1-D2) of CD4 at 2.2 [unreadable] resolution. Ibalizumab grips CD4 primarily by the BC-loop (residues 121-125) of D2, sitting on the opposite side of gp120 and MHC-II binding sites. No major conformational change in CD4 accompanies binding to ibalizumab. Both monovalent and bivalent forms of ibalizumab effectively block viral infection, suggesting that it does not need to crosslink CD4 to exert antiviral activity. While gp120-induced structural rearrangements in CD4 are probably minimal, CD4 structural rigidity is dispensable for ibalizumab inhibition. These results could guide CD4-based immunogen design and lead to a better understanding of HIV-1 entry.