The Bilateral State of Nature: Bargaining Power, Social Contract, and the Death Penalty

Article published in the Michigan State University School of Law Student Scholarship Collection

Development and Validation of an Analogue Lumbar Spine Model and its Integral Components

There is a large need for an anatomically and mechanically correct model of the human lumbar spine. Such a model could have widespread use in the development of new implants and surgical procedures designed to remediate low back pain. Previous work has already been completed on such a model, and the purpose of this study is to approach release of the first generation model to the public. In order to reach this milestone significant work went into the development of a synthetic vertebral cancellous bone model, as well as analysis and development of the overall spine model itself. This work is being completed with Pacific Research Laboratories (Sawbones) who will ultimately manufacture and sell the product. Foam theory was utilized to analyze solid materials that could serve as effective cancellous bone models. These materials were readily available to PRL, and their supply secured for the indefinite future. Following four point bend tests, one material was deemed acceptable for use in a cancellous bone model. Analysis showed that a synthetic model manufactured from this material would require 85% of human bone's relative density to obtain similar stiffness, and 111% of human bone's relative density to obtain adequate strength. Synthetic foams were prepared, mechanically characterized, and compared to the literature. Overall, the model behaved quite similarly to human bone, with mechanical properties slightly higher than the reported literature. The model had stiffness of 375 MPa, strength of 4.33 MPa, and post yield ductility of .51%.Future work will serve to further refine this model, and incorporate it into the vertebral body of the Analogue Spine Model. At the beginning of this study, the Analogue Spine Model was behaving too stiffly, and aberrant behaviors were noticeable in axial rotation. Stiffness was approximately 1 Nm/° higher than the literature in all modes of bending. Aberrant behavior was most notable in axial rotation. In this mode of bending, a "stair step" behavior was observed in what should have been a smooth sigmoid curve. Work was conducted on locating the source of these limitations, and altering them to improve model performance. This was conducted with the use of a systematic dissection, allowing identification of the interactions and elements responsible for the model's behavior and stiffness. After identifications, alterations were made to the manufacturing process, and to specific soft tissues. Once completed, the model now has appropriate neutral zone stiffness in all modes of bending (flexion - 1.82 Nm/°, extension - 2.01 Nm/°, lateral bending - .85 Nm/°, axial rotation - 2.47 Nm/°), extension zone stiffness in three of four modes of bending (flexion - 3.09 Nm/°, lateral bending - 5.30 Nm/°, axial rotation - 11.25 Nm/°), but high neutral zone range of motion in all modes of bending and high extension zone stiffness in extension (9.15 Nm/°). Future work is centered on reduction of neutral zone range of motion, and extension zone stiffness in extension. This model's performance will be compared to cadaveric specimens tested using the experimental setup utilized in this study. Following validation, the model will be released into the market, and become accessible to researchers and companies alike

Absence of manganese superoxide dismutase delays p53-induced tumor formation.

BACKGROUND: Manganese superoxide dismutase (MnSOD) is a mitochondrial antioxidant enzyme that is down-regulated in a majority of cancers. Due to this observation, as well as MnSOD\u27s potent antioxidant enzymatic activity, MnSOD has been suggested as a tumor suppressor for over 30 years. However, testing this postulate has proven difficult due to the early post-natal lethality of the MnSOD constitutive knock-out mouse. We have previously used a conditional tissue-specific MnSOD knock-out mouse to study the effects of MnSOD loss on the development of various cell types, but long-term cancer development studies have not been performed. We hypothesized the complete loss of MnSOD would significantly increase the rate of tumor formation in a tissue-specific manner. RESULTS: Utilizing a hematopoietic stem cell specific Cre-recombinase mouse model, we created pan-hematopoietic cell MnSOD knock-out mice. Additionally, we combined this MnSOD knock-out with two well established models of lymphoma development: B-lymphocyte specific Myc over-expression and conditional pan-hematopoietic cell p53 knock-out. Mice were allowed to age unchallenged until illness or death had occurred. Contrary to our initial hypothesis, the loss of MnSOD alone was insufficient in causing an increase in tumor formation, but did cause significant life-shortening skin pathology in a strain-dependent manner. Moreover, the loss of MnSOD in conjunction with either Myc overexpression or p53 knock-out did not accelerate tumor formation, and in fact delayed lymphomagenesis in the p53 knock-out model. CONCLUSIONS: Our findings strongly suggest that MnSOD does not act as a classical tumor suppressor in hematological tissues. Additionally, the complete loss of MnSOD may actually protect from tumor development by the creation of an unfavorable redox environment for tumor progression. In summary, these results in combination with our previous work suggest that MnSOD needs to be tightly regulated for proper cellular homeostasis, and altering the activity in either direction may lead to cellular dysfunction, oncogenesis, or death

Lokal, regional, national: Rezension zu "Rechtes Denken, rechte Räume? Demokratiefeindliche Entwicklungen und ihre räumlichen Kontexte" von Lynn Berg und Jan Üblacker (Hg.)

Lynn Berg / Jan Üblacker (Hg.): Rechtes Denken, rechte Räume?: Demokratiefeindliche Entwicklungen und ihre räumlichen Kontexte. Bielefeld: transcript 2020. 978-3-8376-5108-

Practice Resources for Administrative, Zoning, and Tax Appeals

This article provides practice tips on appealing administrative rulings, zoning determinations, and tax assessments

Food and Fertile Ground: Improving Chinese Food Safety through Environmental Regulation

This paper explores the historical development of food safety regulation in China and highlights how the bifurcation of urban and rural populations leaves a regulatory gap that limits the efficacy of food safety regulation

Development and Simulation of a Novel Guidance System for Quadrotors Flying in a Contested Environment

Due to their accessibility, quadrotors are used as testbeds for guidance, navigation, and control systems and have been used for a wide variety of applications. These applications range from commercial aerial photography to military surveillance. In the latter case, the vehicle can be exposed to danger if opposing agents are present. The vehicle is incentivized to take cover among obstacles in order to protect it during surveillance operations. However, current research seeks only to avoid obstacles. This thesis develops a guidance system capable of generating tactical flight of a quadrotor. This guidance system consists of three complementary subsystems. The first is fast model predictive control (FMPC). This algorithm uses the dynamics of the system to plan several time steps into the future. Using this plan, the algorithm communicates the optimal action to take and repeats the process. FMPC is advantageous due to its fast computation subject to the system dynamics and customizable cost functions that can be used to enforce tactical behavior. However, it is not designed to work in non-convex environments and is vulnerable to locally optimal points that are not the goal position. The convexity issue is mitigated by using quadratic discrimination to find a locally convex region. Local optima are avoided by employing a global pathfinding algorithm built off of the motion primitive library. Flight test results demonstrating the capabilities of the resultant guidance system are presented