All seminars take place on Mondays from 4:00 pm - 5:00 pm in 2420 LEEP2, unless otherwise specified.
Speaker: Stevin Gehrke, Ph.D.
New Spring 2016 students only.
Speaker: Malcom Snead, D.D.S., Ph.D.
Professor, Ostrow School of Dentistry of USC, University of Southern California, Los Angeles, CA
Division Chair, Division of Biomedical Sciences, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA
"Cell to Matrix Interactions Suggests a Nanofabrication Paradigm for Enamel Regeneration"
The developing tooth is a model for epithelial-mesenchymal interactions during organogenesis used to identify reciprocal-signals exchanged between the ectoderm-derived epithelia (ameloblasts) and the neuroectoderm-derived mesenchyme (odontoblasts). The tooth is also a model for biomineralization, containing several unique bioceramic tissues, namely enamel, dentine and cementum, with each tissue being formed by a unique protein matrix that controls the crystallite habit of the mineral filler. Dentine and cementum are mesenchyme-derived tissues that depend largely on type I collagen to organize the matrix proteins. Enamel, in contrast, is the only ectodermal derived tissue to biomineralize and does so without collagen. Enamel formation has revealed several strategies used by biological systems to produce a tissue subjected to the stresses associated with food ingestion that must also last a lifetime in a wet, bacterial laden environment. Enamel formation is dependent upon protein self-assembly to fabricate a precursor protein matrix that is competent to direct the crystallite habit of its mineral phase. Cell to matrix interactions generate cellular signals that serve to continuously monitor matrix fabrication and the mineral conversion process. These interactions depend on amelogenin, the most abundant protein in the developing enamel matrix. We show how redesigning amelogenin protein results in disruptions to amelogenin self-assembly, which in turn results in cell to matrix interactions disturbances that alter enamel biomineralization. Knowledge from formation is used to inspire pathways for enamel regeneration through a nanofabricated artificial matrix. Here, we used gene targeting to replace native amelogenin with engineered proteins. This replacement led to changes to the enamel organization at the nanoscale level by altering protein-to-crystallite interactions and crystallite stacking, while at the mesoscale level, replacement by the engineered amelogenin protein diminished the ability of the ameloblast to maintain interactions with the secreted extracellular matrix. In another example, we demonstrate the application of an artificial matrix based upon peptide amphiphiles which undergo self-assembly into nanofibers can be used to support cell proliferation and differentiation. The surfaces of these nanofibers are engineered to present biological signals to direct ameloblast differentiation. Injection of these peptides into the enamel organ redirects cell differentiation to produce a small ectopic nodule of enamel. This biology inspired technology is used to regenerate enamel tissue.
Speaker: Yang Yi, Ph.D.
Assistant Professor, Electrical Engineering & Computer Science, University of Kansas
“Building Brain-Like Computing Small, Cool, and Robust: Novel Paradigm of Analog Neuron Circuit Design”
As semiconductor technologies continue to scale further into the nanometer regime, it is important to study how non-traditional computer architectures may be uniquely suited to take advantage of the novel behavior observed for many emerging technologies. Neuromorphic computing, which is inspired by the working mechanism of human brain, represents a type of non-traditional architecture encompassing evolutionary and holds great promise for many important engineering and scientific applications.
In this talk, I will present our work on energy efficient analog neuron integrated circuit (IC) design in neuromorphic computing systems and its exploration to emerging applications. Spike time dependent encoding efficiently maps a signal’s amplitude information into a spike time sequence that offers perfect recovery for band limited stimuli. The nonlinear node based delay feedback reservoir represents a class of dynamic processors that meet the requirements of high dimensionality and finite memory. Three dimensional (3D) integration with neuromorphic IC provides high system speed, high density, low power consumption, and small footprint. The layout design and performance analysis of proposed circuits will be demonstrated. Finally, I will show the application of the proposed design and methodology by looking at the problem of communicating over a multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) channel.
Speaker: Cathy Schwabauer & Janelle Whisler
Director & Assistant Director; Engineering Career Center, University of Kansas
PROFESSIONAL DEVELOPMENT SESSION:
How to build a skills based resume & be competitive in the job market
Speaker: Rita Patterson, Ph.D.
Professor, University of North Texas Health Science Center
“Wrist and Hand Functional Biomechanics”
Imagine tying your shoes or putting on a pair of pants while having limited use of one arm or hand. Now imagine the impact on your life if the limited use was permanent. Hand and wrist sprains are common and usually do not require surgical intervention. Cumulative injuries, however, can lead to abnormal mechanics, kinematics and eventually degenerative joint disease causing pain and the inability to perform activities of daily living.
Early work measured the load and contact distribution in the wrist and provided objective measures for evaluating surgical procedures for ligament and fracture injuries in the wrist. Our work showed that increased load and pressures in one portion of the joint lead to wear and tear of the cartilage and ultimately arthritis. Subsequent analysis of different surgical procedures to prevent joint arthritis identified which procedures were optimum to restore the wrist to optimal function. Because of this work, surgeons across the world adopted these surgical procedures and reported better clinical outcomes restoring joint balance.
Subsequent investigation of anatomical differences that affected the biomechanics of the wrist revealed new carpal shapes that were linked to patterns of arthritis that could not be found on standard x-rays. This resulted in the investigation of previously ignored anatomical sites during arthroscopic surgery that were found to have arthritic changes and therefore could subsequently be treated.
3D models and analysis of carpal kinematics added information to provide a comprehensive understanding of wrist function. 3D computer animations were created that helped health care professionals visualize motion of the wrist and how it is altered by ligament injury (sprains) or bony fracture. Again subsequent analysis of different surgical procedures identified which procedures were optimum to restore normal carpal kinematics.
Current work in the hand is supported by the above work and research experiences in the wrist. These include analysis of finger and hand kinematics. This work investigates the functional performance of the hand while interacting with everyday objects with the goal to improve rehabilitation after injury.
Qualifying Exam Review: All students (MS/PhD or PhD) who will be taking the qualifying exam this year or coming years are required to attend. If you are a MS only student or have already taken the exam, you are not required to attend.
Speaker: Lori Setton, Ph.D.
Professor of Biomedical Engineering, Washington University in St Louis
"Regenerative Medicine for Treating Intervertebral Disc Disorders"
Low back pain now ranks as #1 for disease impact in the USA, due in part to intervertebral disc disorders that contribute to pain and disability in millions of affected individuals. Pathological processes for resident cells of the intervertebral disc, the nucleus pulposus cells, contribute to a dysfunctional production of inflammatory cytokines and premature cell death that can drive loss of intervertebral disc height, tissue destruction and herniation. Inflammatory cytokines produced by resident cells and recruited monocytes are known to mediate the painful symptoms of intervertebral disc herniation, although systemic treatment with inflammatory antagonists (e.g., tumor necrosis factor “blockers”) has failed to date. Our laboratory has developed in situ forming drug depots for local delivery of “TNF blockers” and other inflammatory antagonists to increase drug residence time and bioactivity in the treatment of intervertebral disc herniation. Our laboratory has also advanced knowledge of environmental cues that are necessary to maintain healthy, biosynthetically active nucleus pulposus cells, factors that can be manipulated to attenuate inflammatory cytokine expression, promote matrix biosynthesis, and control progenitor cell differentiation. In this talk, we will describe our work with engineering substrates and protein-conjugated biomaterials to deliver cells to the disc, and drugs to the perineural space, for regeneration purposes.