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  1. Abstract

    HIV-1 viral transcription persists in patients despite antiretroviral treatment, potentially due to intermittent HIV-1 LTR activation. While several mathematical models have been explored in the context of LTR-protein interactions, in this work for the first time HIV-1 LTR model featuring repressed, intermediate, and activated LTR states is integrated with generation of long (env) and short (TAR) RNAs and proteins (Tat, Pr55, and p24) in T-cells and macrophages using both cell lines and infected primary cells. This type of extended modeling framework allows us to compare and contrast behavior of these two cell types. We demonstrate that they exhibit unique LTR dynamics, which ultimately results in differences in the magnitude of viral products generated. One of the distinctive features of this work is that it relies on experimental data in reaction rate computations. Two RNA transcription rates from the activated promoter states are fit by comparison of experimental data to model predictions. Fitting to the data also provides estimates for the degradation/exit rates for long and short viral RNA. Our experimentally generated data is in reasonable agreement for the T-cell as well macrophage population and gives strong evidence in support of using the proposed integrated modeling paradigm. Sensitivity analysis performed using Latin hypercube sampling method confirms robustness of the model with respect to small parameter perturbations. Finally, incorporation of a transcription inhibitor (F07#13) into the governing equations demonstrates how the model can be used to assess drug efficacy. Collectively, our model indicates transcriptional differences between latently HIV-1 infected T-cells and macrophages and provides a novel platform to study various transcriptional dynamics leading to latency or activation in numerous cell types and physiological conditions.

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  2. Today, saying Additive Manufacturing (AM) is changing our world is an understatement. Current applications include additively manufactured shoes, jewelry, prosthetics, and food products. In this study, a steering rack extension for Tennessee Tech’s Formula SAE (FSAE) car was replaced with various 3D printed alternatives. Numerous beta testing studies were performed to measure its sustainability. Utilization of a Steering Rack Extension is made to adapt a quick ratio steering rack to interface with the steering system designed for the TTU Motorsports FSAE car. The current study reports the design, analysis, and manufacturing studies performed to replace the steering rack extension with a 3D printed component. Various tests and 3D printing operations have been performed to show the improvements made to replace the currently used piece. This presentation will report the design, printing and testing studies performed for the newer steering rack extension. Student feedback received from the FSAE team and engineering students will be also presented. 
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  3. During the 2017 Engineering-a-Future activities at Tennessee Tech University, a set of 3D Pen activities has been organized for the female Middle School Students (5th and 6th grades) so that they learn more about the engineering fields and their practices in daily life. Various Additive Manufacturing technologies have been presented to students, and students have toured the lab facilities. During the 45-minute timeframe, students were grouped and constructed 3D art objects (butterfly, necklace, bird, and glasses) using the available 3D Pens. It was observed that the students had high enthusiasm about the new technology. This study will present the utilization of 3D Printing Pens in various practices, and report the current advantageous and disadvantageous of 3D Pen exercises detected through recent studies. 
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