Spherical pipe joint delivers loads equally to mating flange

Oxidizer inlet duct with a ball joint pipe fitting incorporating two spherical bearing races and balls in contact with centering cage springs transmits an evenly distributed load to the mating flange. This design should find application in piping systems where unequal load distributions exist

Spherical shield Patent

Flexible bellows joint shielding sleeve for propellant transfer pipeline

Cross-spectral analysis of physiological tremor and muscle activity. I. Theory and application to unsynchronized EMG

We investigate the relationship between the extensor electromyogram (EMG) and tremor time series in physiological hand tremor by cross-spectral analysis. Special attention is directed to the phase spectrum and the effects of observational noise. We calculate the theoretical phase spectrum for a second order linear stochastic process and compare the results to measured tremor data recorded from subjects who did not show a synchronized EMG activity in the corresponding extensor muscle. The results show that physiological tremor is well described by the proposed model and that the measured EMG represents a Newtonian force by which the muscle acts on the hand.Comment: 9 pages, 6 figures, to appear in Biological Cybernetic

Engineering cyanobacteria for use as photosynthetic chemical factories

Finding a sustainable alternative for today’s petrochemical industry is a major challenge facing chemical engineers and society at large. To be sustainable, routes for converting carbon dioxide and light into organic compounds for use as both fuels and chemical building blocks must be identified, understood, and engineered. Furthermore, these routes must be economically competitive with current and future fossil fuel sources and not irreversibly deplete other natural resources (e.g. food, water). Terrestrial lignocellulosic biomass (e.g. agricultural wastes, energy crops, and forestry reserves) has been the subject of extensive R&D for use as a renewable carbon feedstock for producing biofuels and displacing petrochemicals. Despite this significant effort, many challenges to commercialization remain. These problems include cultivation costs, transportation, processing, and a mismatch between available supply and current petrochemical demand. A possible alternative and/or supplement is the use of aquatic phototrophs such as eukaryotic algae or prokaryotic cyanobacteria to directly produce chemicals and biofuels, skipping the biomass middle-man. In this talk, I will describe my group\u27s efforts to develop Synechococcus sp. strain PCC7002 as a model phototroph for chemical production from sunlight and carbon dioxide. PCC7002 is attractive because it is one of the fastest growing photoautotrophs, halotolerant, naturally transformable, and well represented in the literature. Our initial attempts to apply metabolic engineering in this strain failed miserably due to a lack of reliable genetic and synthetic biology tools (e.g. segregation drivers, controllable promoters, terminators). To address this problem, we assembled a toolbox for working with PCC7002 and have applied the tools to engineer strains capable of producing lysine, lactate, and glycogen. In this talk, I will describe our toolbox development (promoters, CRISPRi, CRISPR genome editing), our ongoing metabolic engineering studies, and the remaining obstacles to deploying cyanobacterial biorefineries. Biosketch: Brian received his bachelor’s degree in Chemical Engineering from Cornell University in 2000. and earned his PhD in Chemical Engineering in 2005 from the University of California-Berkeley under the supervision of Jay Keasling. Brian’s thesis research focused on developing methods of controlling gene expression in bacteria that could be applied to enhancing the biosynthesis of pharmaceuticals. After graduating, he accepted a postdoctoral fellowship in the laboratory of David Sherman at the University of Michigan, where he studied how six Bacillus anthracis enzymes assemble a natural product essential for iron acquisition and pathogenesis. Brian is currently the Walter J. and Cecile Hunt-Hougen Faculty Scholar and Associate Professor of Chemical and Biological Engineering with appointments in Biomedical Engineering, the Microbiology Doctoral Training Program, and the graduate program in Cell and Molecular Biology. Brian’s research has been recognized with young investigator awards from 3M, NSF (CAREER), DOE (Early Career), the Air Force Office of Scientific Research (AFOSR-YIP), Biotechnology and Bioengineering (Daniel IC Wang Award), the Vilas Trust (Early Career and Vilas Associate Awards) and Purdue University (Mellichamp lectureship). Brian also received the Benjamin Smith Reynolds teaching award from the UW-Madison College of Engineering for his efforts to introduce undergraduates to biotechnology

Engineering enzymes to control the chain-length selectivity of biosynthesized oleochemicals

Oleochemicals, a class of aliphatic molecules derived from lipids, are used in a range of applications including transportation fuels, consumer products (e.g. cosmetics, shampoo, cleaners), and industrial products (e.g. surface coatings, paints, lubricants, bioplastics). The most common oleochemicals are surfactants (e.g. sodium dodecyl sulfate) and biodiesel. Currently, the majority of oleochemicals are made from inexpensive lipid sources such as plant oils. Growing demand for oleochemicals, and in particular biodiesel, has led to an increased production of plant oil crops and raised concern about the sustainability and environmental impact of oil seed production. Consequently, interest in identifying alternative oleochemical feedstocks has grown. Many types of oleochemicals (e.g. free fatty acids, alcohols, methyl-ketones, olefins, alkanes, esters) have been produced in engineered microbes grown on a variety of carbon sources. That said, products made this way are not widely available. At least three major barriers remain — high feedstock costs, low yields, and a lack of selectivity towards desired molecules. In this talk, I will discuss the development of enzymes capable of targeting the highly valued medium chain length products. I will describe pathways for producing high-value commodity chemicals derived from fatty-acids and how my group and others have combined synthetic biology and systems biology to improve oleochemical production in bacteria using sustainable feedstocks. I will highlight the use of heterologous plant and bacterial enzymes to alter the chain length distribution of products from common long-chain molecules to higher-value medium-chain analogs. I will describe bioprospecting, structure-guided mutagenesis, and directed evolution approaches that have successfully increased the selectivity and/or activity of enzymes to produce eight-carbon chain-length products. I will conclude with commentary on the remaining barriers to commercializing these technologies and areas where further research investment could prove fruitful

(Un)Doing and (Un)Becoming: Temporality, Subjectivity, and Relationality in Twenty-First-Century German Literature and Film

This dissertation investigates how recent German-language literary and cinematic texts depict the interpellation of contemporary subjects under neoliberal capitalism. As I argue, the texts signal, reflect, and comment on the emergence of new types of subjectivities with precarious non-conforming identities, bodily desires, and pleasures struggling to persist under coercive social and economic systems. My core works express a sense of pessimism regarding both the present and future and foreground the ways in which bodies and minds are exposed to normative forces that act on, regulate, and resituate them. As I engage with questions of political agency, subjectivity, performativity, precarity, and neoliberalist capitalism in twenty-first-century German-language texts, I draw attention to how German-language texts specifically generate productive modes of inquiry when placed in conversation with queer and gender theory and vice versa. My analysis shows how these texts employ motifs of time and temporal patterns, rather than place and space more commonly emphasized in analyses since what has often been called the spatial turn, to explore the potential to engender reconfigurations of subjectivity. Tracing out-of-sync and non-teleological moments and momentums in the core texts, I show how the works uncover a temporary promise of breaking free from the dominant, restricting social structure, even as they make clear that this schism cannot and should not be permanent. These performative acts and discursive strategies of breaking free, I argue, extend the promise of (un)doing and (un)becoming, offering the prospect of developing and refining new strategies of queer world-making

“Show Me” Your Legal Status: A Constitutional Analysis of Missouri’s Exclusion of DACA Students from Postsecondary Educational Benefits

This Note discusses how Missouri’s exclusion of in-state tuition and state scholarship funding affects DACA students and concludes the Missouri legislature’s proposal violates the Fourteenth Amendment’s Equal Protection Clause. Part II explores the DACA program and its effects on both DACA individuals and society; it then lays out Missouri law on higher education benefits, both prior to and after the passage of HB 3 and SB 224. Next, Part III details the process used to evaluate equal protection claims based on immigration status. Part IV scrutinizes the legislation under equal protection case law, ultimately concluding in Part V that HB 3 and SB 224 violate the U.S. Constitution and deprive DACA students, such as Sanchez, of their right to equal protection of the law

Bioconversion of levulinic acid to methyl-ethyl ketone via a novel catabolic pathway

Levulinic acid (LA) is a common degradation by-product of acid-catalyzed hydrolysis of lignocellulosic biomass. Under the right conditions, LA can instead be made as the dominant hydrolysis product. For this reason, LA was identified as a key renewable building block and motivated development of chemical upgrading strategies for producing value-added chemicals from a renewable feedstock. Biological upgrading of LA has been limited to natural microbial products, mainly polyhydroxyalkanoates (PHA), due to a lack of understanding about the LA catabolic pathway. Recently, we discovered and characterized an enzymatic pathway from Pseudomonas putida KT2440 that enables growth on LA in both P. putida and when heterologously expressed Escherichia coli LS5218. The pathway, described in Rand et al., Nature Microbiology (2017), activates LA as a CoA-thioester, reduces 4-keto-moiety, and isomerizes the resulting hydroxyl via a unique ATP-dependent mechanism. The 3- hydroxypentanoyl-CoA generated by the pathway can be incorporated into PHA or further oxidized by the native enzymes of beta-oxidation to enable growth and energy generation. In this talk, we will describe the transposon (traditional and TN-seq) experiments used to identify essential genes in the pathway and the genetic and biochemical studies used to associate each enzyme in a five gene operon (lvaABCDE) to roles in the pathway. We will also describe our efforts to evolve E. coli for utilization of LA as a sole carbon source. The evolved strains were derived from E. coli LS5218, which contains specific mutations for overexpression of β-oxidation (fadR) and short chain fatty acid degradation genes [atoC(Con)]. Genome sequencing of the evolved mutants and parent led to the isolation of two key function deletions required for robust growth on LA as well as several other differences away from its presumed E. coli parent. Reconstitution of the isolated mutations in wild type LS5218 revealed one to be necessary, fadE, and one to confer a beneficial growth phenotype, atoC. In this talk, we will describe the genome of LS5218 (Rand et al., Metabolic Engineering Communications (2017), and how it may be an advantageous strain for metabolic engineering of organic acid biosynthesis. Lastly, we will describe how we engineered a strain of E. coli to perform a bioconversion of LA to the common industrial solvent methyl-ethyl ketone (MEK). Here, we overexpressed an acetoacetyl-CoA transferase (AtoDA) and heterologously expressed an acetoacetate decarboxylase (ADC) to enable flux to MEK. Through genome scale metabolic modeling of the pathway, we identified growth coupling strategies to force cells to perform the bioconversion in order to generate energy (and grow). The resulting strains convert LA to MEK at unit conversion with appreciable rates. In this talk, we will present the unpublished metabolic engineering, modeling, and fed-batch optimization of the process

Syntax or Experience: What Should Determine If Sex Trafficking Qualifies as a Crime of Violence?

This Note analyzes the Fourth Circuit’s opinion in United States v. Fuertes, ultimately concluding that, contrary to the decision in Fuertes, sex trafficking should be considered a crime of violence under 18 U.S.C. § 924(c). Part II of this Note details the acts of German Ventura, a defendant charged with sex trafficking and possession of a gun during a crime of violence. Part III explores the purpose of § 924(c) and courts’ interpretations of “crime of violence”; it then considers federal circuit courts’ bases for finding sex trafficking under the TVPA to be a violent crime under a variety of statutes. Part IV summarizes the Fourth Circuit’s decision to depart from established precedent. Part V scrutinizes the court’s theory that sex trafficking cannot be a violent crime, ultimately resolving that, while sex trafficking should be considered a crime of violence, Congress must change the statute to expressly reflect the violent nature of sex trafficking