Electrical propulsion is becoming an increasingly popular method of spacecraft and satellite propulsion, as it is much more efficient than rockets for vessels outside of the atmosphere. The various methods classified under electrical propulsion all work on the same principal: a material (usually solid or gas fuel) is energized to an ionic plasma state so it will react to an electric charge or magnetic field. These charged particles are then expelled by the field to create thrust. This is advantageous in that it requires significantly less fuel mass than a rocket, and draws its energy from electrical power, which can be produced onboard. In a High-Power Helicon (HPH) system, this is accomplished by ionizing a gas, such as argon, krypton, or xenon, and moving it through a series of coaxial solenoid magnets. The purpose of the HPH Cluster Experiment is to move away from standard single thruster testing and observe the effects of interacting HPH thrusters. This focuses on determining the effectiveness of shared components, such as power supplies and magnets, between the otherwise separate thrusters. The experiment itself consists of testing various thruster angles, magnetic orientations, and magnetic field strengths, for optimization of the shared systems. We hypothesize that by sharing downstream magnets, known as magnetic nozzles, the separate plasma streams will be able to converge into one larger beam. This reduces the necessary system mass and required power for the thruster, but should not significantly reduce the generated thrust. Our first stage of testing has been to compare right and left helical antennas, which are theoretically identical but have different performance experimentally. The final cluster design will serve as a proof of concept for the creation of larger, space-ready propulsion systems, which will be able to operate on deep space missions more efficiently than conventional propulsion methods.

The objective of this project is to develop an affordable (optimally less than $200 to manufacture), 4G/LTE touchscreen mobile phone in the shape of a circle. This will be accomplished by learning how to gather and assemble phone parts, design and solder printed circuit boards (PCBs), and program and test a custom phone. We will thereby apply concepts of communications, embedded systems, software programming, and PCB design. So far, we have built three different phones with various types of screens, processors, speakers, microphones, antennae, and more to compare the prices and performance of each phone and part. The ultimate intended outcome of the project is to build a circular phone that has all the features of a rectangular phone and more in terms of hardware, software, appearance, and usability. The desired performance specifications for the phone are that it can make and receive calls, create and receive SMS messages, and provide notifications via a speaker, buzzer, or any combination thereof. The idea for this project was originally conceived by dTOOR’s founders (prior to incorporation of the company) after they had grown frustrated with the bulkiness rectangular phones. They observed that rectangular phones had become the norm, but such phones were impossible to fit comfortably into women’s pockets and they all tended to look the same. As a result, dTOOR’s Cyrcle phone came into development. The uniquely-shaped Cyrcle phone is devoid of those troublesome corners that rectangular phones have, thus making it easier to carry around, much like an accessory. The prototypes for the phone are definitely brighter and more fun to carry around than other phones and they have successfully attracted a non-rectangular market. These prototypes use traditional, rectangular PCBs and so now, the next challenge is to build the Cyrcle with custom, circular PCBs.

The purpose of this research is to generate immersive, natural-looking environments from geoengineering data that can be viewed on hardware-constrained virtual and mixed-reality platforms. Current mixed and virtual-reality technologies, such as the Microsoft HoloLens, are constrained by limited hardware resources. These constraints set limits on the realism and quality of immersion of virtual reality environments. Thus, no software previously existed to intelligently render immersive 3D terrain on hardware-constrained virtual and mixed reality devices. Through research in terrain generation and 3D rendering, the Viewpoint Generator application was created that can accurately and realistically render 3D environments. To render the terrain, 3D environments generated in Unity, a game rendering software, are pre-processed on a host machine. The 3D terrain is sliced into a grid containing individual slices. For each slice of terrain, a set of concentric panoramas and a skybox are generated. These static components require relatively little power to render. Performance was benchmarked through simulations in Unity and on-device with a Microsoft HoloLens, with a minimum frames-per-second (fps) requirement of 60 fps to prevent nausea induced by slow rendering. These components form the Viewpoint Generator application that can be deployed to hardware-constrained devices, which allows users to explore areas of a 3D environment not previously possible on hardware constrained devices. Applications for the Viewpoint Generator include uses in civil engineering and environmental restoration and visualization. Large-scale environmental projects too large to convey through static 3D renderings or by human imagination can now be explored in an accurate and realistic virtual environment. As the Viewpoint Generator is designed to operate on compact devices, it is easily deployed to remote environments. The Viewpoint Generator sets the foundation for development in procedural environment generation based on geoengineering data, allowing new visual insight into civil engineering and environmental restoration projects.

As a response to the NASA Cubesat initiative, students of the Advanced Propulsion Lab at the University of Washington’s Department of Earth and Space Sciences initiated development of the 3U Cubesat to produce the first 3U CubeSat to feature a pulsed plasma thruster (PPT) and a reflect array communications system by March 2018. 3U Cubesats are microsatellites made of 3 cubes stacked vertically on top of each other with each cube measuring 100 by 100 by 113.5 mm. This is a systems-engineering project requiring interdisciplinary research among various fields and technical backgrounds. As part of the program, the structures team specializes in designing the structural components of the Cubesat using computer aided design (CAD) software such as SolidWorks as well as testing the vibrational and thermal resistances of the chassis using engineering analysis software such as ANSYS. To ensure mission viability, the structures team is also responsible for developing the hinges and a release mechanism for the solar panel deployment and actuation system. Finally, the structures team is responsible for developing a thermal model of the entire assembly as well as conducting vibration tests on the shake table. The current results produced includes a complete CAD model of the 3U Cubesat chassis with all its components, a prototype of the release mechanism and the hinges, and results received from preliminary thermal models and structural analysis. Multiple models of the 3U Cubesat components were improvised repeatedly and their respective numerical estimations have been used in multiple presentations. The purpose of this project is to demonstrate the survivability of the chassis throughout its projected lifetime using the selected truss design while ensuring compatibility with volatile propulsion systems such as the PPT.

When constructing supersonic rockets, builders must pay close attention to their design and construction methods to ensure that the rocket is capable of withstanding the dramatic pressure changes associated with breaking the sound barrier. This phenomenon is well understood and modeled by aeronautical engineers; however, it can be helpful to understand how pressure impacts individual rocket components for particular builds. Amateur rocket construction at the University of Washington consists of five key components relevant to all rockets — a nose cone, payload section, coupler, motor section, and fins. Our team constructed a single stage, three-inch rocket capable of flying above thirty thousand feet and speeds well in excess of Mach one, to better understand how each of these components experiences stress. A network of five pressure sensors is employed to study the change in pressure in the nose cone, on the fins, inside and outside the payload section, and between the coupler and motor compartment. Upon launch and recovery of our rocket, we calibrated an Arduino, an open-source electronic prototyping platform, to pass a constant voltage to a piezoelectric sensor, which gathers and analyze the high-resolution stress data. We then carefully model the dynamics of stress on each component throughout the flight and determine exactly how strong each particular part must be to achieve successful flight. The findings of this project can serve to improve future engineering of amateur university rockets as a more specialized understanding of stress on rocket components. This can be used to optimize materials and design to improve rocket performance while maintaining a safe level of durability. Perhaps more importantly, this project compares the stress experienced by student-built rockets to verified research to check for congruency in the predicted levels of stress used in simulating rocket performance prior to construction.

Current weight loss therapies are largely unsuccessful stressing the urgent need to develop new and effective strategies to treat the growing obesity epidemic. Oxytocin (OT) is a downstream target of the adiposity signal, leptin, and is an attractive therapeutic target to treat obesity in humans because it reduces body weight (BW) in diet-induced obese (DIO) rodents even in the face of an impaired ability of leptin to reduce food intake. Recent findings from our lab indicate that, while reductions in food intake contribute to OT’s ability to elicit prolonged weight loss in DIO rodents and nonhuman primates, mounting evidence implicates a role of increased energy expenditure (EE) through sympathetic nervous system (SNS) outflow to interscapular brown adipose tissue (IBAT) as contributing to weight loss. OT neurons in the parvocellular paraventricular nucleus are positioned to control SNS outflow to IBAT through either direct projections to the spinal cord or indirectly via the hindbrain nucleus of the solitary tract. Thus, these circuits are potential targets for pharmacological therapies to reverse the deleterious metabolic effects of central leptin resistance. We hypothesized that OT-induced stimulation of SNS outflow to IBAT contributes to its ability to elicit weight loss in DIO rodents. To test this, we determined the effect of exogenous fourth ventricular (4V) OT administration on IBAT temperature, BW, and body composition in DIO rats. We found that 4V OT increased IBAT temperature, reduced BW and body adiposity. Acute 4V administration of OT increased IBAT temperature during the test period relative to vehicle-treated controls (45 min measurement: vehicle: 37.2 ± 0.03 vs. OT: 38 ± 0.2°C; P<0.05). Collectively, these studies implicate a role for SNS outflow to IBAT in the mechanism by which OT increases EE and elicits BW loss in DIO rats.

Human immunodeficiency virus (HIV) infection is a global health issue and consists of two main types, HIV-1 and HIV-2. As the backbone of all first-line treatments of HIV, nucleoside reverse transcriptase inhibitors (NRTI) have a critical role in antiretroviral therapy. EFdA (4´-ethynyl-2-fluoro-2´-deoxyadenosine; MK-8591; Merck & Co.) is an investigational NRTI that blocks HIV-1 replication in culture with 50% effective concentrations (EC₅₀) in the low nanomolar to picomolar range. However, studies evaluating the activity of EFdA against HIV-2 and against NRTI-resistant mutants of HIV-2 are lacking. As a result, HIV-1 and HIV-2 isolates from antiretroviral-naïve individuals were tested against EFdA in single-cycle infections of a human cell line (MAGIC-5A cells). Site-directed mutants of HIV-2 reverse transcriptase were generated in a full-length plasmid clone and were evaluated for EFdA resistance in the single-cycle assay. EFdA inhibited HIV-2 infection of MAGIC-5A cells with mean EC₅₀ values (± SD) of 0.55 ± 0.17 nM for 8 HIV-2 group A isolates and 0.50 ± 0.12 nM for 6 HIV-2 group B isolates (range = 0.25–0.76 nM for all 14 HIV-2 strains tested). In contrast, the mean EC₅₀ for 10 HIV-1 isolates, including group M (subtype A, B, C, D and F) and group O isolates, was 2.56 ± 0.56 nM (range = 1.96–3.78 nM; p<.0001 for HIV-1 versus HIV-2, Welch’s t-test). EFdA is the most potent inhibitor of HIV-2 replication described to date and is more active against HIV-2 than against HIV-1 in culture. EFdA also inhibits multi-NRTI–resistant HIV-2 mutants with single-cycle EC₅₀ values <12 nM. Our data indicate that EFdA should be evaluated in clinical studies involving HIV-2-infected individuals.

Youth with T1D, although encouraged to exercise as part of their treatment plan, are not implementing recommendations to adjust insulin around exercise. Little is known as to whether insulin delivery method impacts these behaviors. Our aim was to compare behaviors surrounding exercise between youth on insulin pump therapy and those on insulin injections, specifically focusing on evening behaviors after exercise. We recruited 50 youth aged 10-18 years with T1D who completed the Type 1 Diabetes Report of Exercise Practices Survey (T1D-REPS), a questionnaire designed to assess specific practices around insulin management, nutrient intake, and glucose monitoring. 30 were on insulin pump therapy and 20 on injection therapy. We measured frequency of glucose checks and hemoglobin A1C (HbA1c). HbA1c measures average blood glucose level over the preceding 3 months. Higher HbA1c indicates worse blood glucose levels. Pump users were more likely to be male (73%), had lower HbA1c (8.5% ±1.3 v. 9.8% ±2.7, p<.05), and reported more glucose checks per day (5.1±3.0 v. 3.2±1.9, p<.05). Pump users were less likely to check their blood glucose prior to exercise (37% of pump users reported often or always checking v. 60% of non-pump users; p=.07). Pump users were also less likely to adjust insulin for bedtime snacks following exercise (8% of pump users v. 31% of non-pump users, p<.05).  Overall, pump users reported less glucose monitoring before exercise and were less likely to implement interventions to prevent overnight hypoglycemia, though they displayed more frequent monitoring around exercise. Understanding populations at risk for glycemic excursions around exercise will allow for the development of intervention strategies to improve adherence to these recommendations.

Many inherited diseases are attributed to monogenic mutations; however, some human disorders and conditions are genetically complex, requiring mutations at multiple loci. One of the research goals at the Waterston Lab is to identify genetic interactions that could affect developmental pathways related to human disease. Using the small nematode, Caenorhabditis elegans, as a model organism, we have developed a high-throughput approach to look for interactions. RNAi bacteria were grown separately for knockdown of forty different transcription factor (TF) genes on pooled populations composed of 38 mutated and fully sequenced strains of C. elegans from the Million Mutation Project (MMP). After growth for several generations, the abundance of strains in each condition was compared by targeting strain-specific single nucleotide variants with Molecular Inversion Probes and sequencing on an Illumina MiSeq system. From ~115,000 possible screened genetic interactions, we identified a number of candidate interactions and focused our efforts on a positive interaction between the strain VC20424 and the TF gene B0261.1. While most strains had poor growth on the B0261.1 RNAi, VC20424 had a much higher abundance. We confirmed this candidate interaction by re-testing VC20424 alone and against a control strain on B0261.1 RNAi. We then genetically mapped the VC20424 interaction to a region on chromosome X. In this region we identified a deletion in C25A11.2 which shows similar expression patterns as B0261.1, suggesting a good interaction candidate. We will test additional MMP strains that share the same allele of C25A11.2 on B0261.1 RNAi to look for a similar interaction. We also plan to use CRISPR/Cas-9 to induce the mutation into a control strain and look for conferred resistance to B0261.1, which would further validate our results. Broadly, studying the nature of genetic interactions and potential roles of transcription factors may contribute to the elucidation of human development and complex disease.

The goal of this project is to design a faster and more efficient motion controller for the leaf collimator that is used to shape a neutron beam around a tumor for use in intensity modulated neutron radiation therapy. The system currently in operation was developed in the 80’s and is too slow for new treatment techniques we plan to support. We started with familiarizing ourselves with the Galil motion controller and the Experimental Physics and Industrial Control System (EPICS) software to control 40 motors that will adjust the position of the collimator leaves within an accuracy of 2 mm. Because we augmented an existing system, there are some system aspects that could not change and needed to be worked into our design: the 40 motors need to be driven manually with analog feedback and the overall mechanical setup should remain mostly the same. Additionally, we rewired the system to accommodate bipolar power supplies in order to half the number of wires used in the gantry, allowing us to save on space and increase the ease of future system maintenance. This was accomplished by configuring diodes in parallel with relays that allows us to control the direction of the current, which in turn controls the rotation of the motors. Since our system’s internal components are heavily exposed to radiation, we implemented the diodes on a printed circuit board to ensure that the system upkeep and component replacement is manageable. Finally, we updated the existing Extensible Display Manager (EDM) user interface so the radiation therapists and technicians can see real-time leaf locations and interact with our motion control system. The final deliverable is a complete installation of our new fully tested system inside the the gantry.

Arsenic, a known carcinogen, has been linked to numerous cancers, and its toxicity and persistence in the environment at low levels impact both human health and ecosystem integrity. Due to natural and anthropogenic factors, the concentration of arsenic has elevated in many areas. Phytoremediation is a cost-effective, eco-friendly technology that uses the natural ability of plants to remediate pollutants, such as arsenic, from contaminated soils. Endophytes, mutualistic microbes colonizing the internal tissues of plants, have been shown to increase host-plant tolerance to a wide range of environmental stressors, and we hypothesize that arsenic-tolerant endophytes may improve the tolerance of their host plants to arsenic. The arsenic-tolerant isolate PD12R, identified as Rahnella aquatilis, has been shown to grow at a higher concentration in the presence of arsenic, than it does without. We hypothesis that this unexpected result may have to do with its ability to form a protective biofilm. This biofilm is made up of a matrix of extracellular polymeric substances (EPS) which bacteria use as a protection against environmental stressors. EPS may be protecting PD12R from arsenic either by slowing diffusion to the cells, or by chemically chelating the arsenic in the EPS matrix. This has an important application in plants because it may indirectly help reduce free arsenic in planta by promoting plant tolerance, thereby enhancing the process of phytoremediation. We are currently testing PD12R, and two other isolates, to determine whether biofilm production is correlated with arsenic concentration in the media, and whether arsenic is bound by the EPS matrix by using a 96-well plate set up to test optical density and colony forming units. The results will then be compared to the EPS data which will be quantified using a crystal violet assay.

A large body of research has examined the association between disadvantage and crime in neighborhoods, usually finding a strong positive association between neighborhood disadvantage and crime. Neighborhood disadvantage is associated to crime via a variety of pathways, including, but not limited to, reduced educational opportunities and reduced collective efficacy (i.e., the ability of residents to control or influence the behavior of other individuals and groups in the neighborhood). However, research that links neighborhood disadvantage to crime has not examined the effects of clustering, better understood as grouping, of neighborhoods on the relationship between neighborhood disadvantage and crime. In metropolitan areas, predominantly minority-occupied, disadvantaged neighborhoods are often grouped together into specific areas. In other words, poor neighborhoods are adjacent to other poor neighborhoods compounding the disadvantage that inhabitants of these neighborhoods face. This is important to understand because it means that segregation of neighborhoods may be helping to drive high crime rates within neighborhoods. I extend this body of research by considering the role of clustering in the relationship between neighborhood disadvantage and crime. I use data from the National Neighborhood Crime Study, which includes tract, city, and metropolitan level variables to analyze crime and spatial inequality. The poverty and spatial proximity data is provided by the Neighborhood Change Database, which includes tract level data for impoverished neighborhoods as well as longitude and latitude of said neighborhoods. I use these two data sets to analyze the effects of neighborhood clustering through various data analyses. Preliminary data analyses show a statistically positive relationship between spatial proximity and number of murders. From this, it is expected that spatial proximity will also have a statistically positive relationship with overall crime.