A known carcinogen, arsenic is elevated in many areas through natural and human causes. Its persistence in the environment and toxicity at low levels impacts both human health and ecosystem integrity. In humans, arsenic has been linked to cancers of the skin, lung, and bladder. Phytoremediation is a cost-effective, eco-friendly technology that uses the natural ability of plants to remediate pollutants, such as arsenic, from contaminated soils. We are investigating whether endophytes, mutualistic microbes colonizing the internal tissues of plants, can improve this process. Endophytes 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. Willow (Salix ssp.) are fast growing, high biomass plants, with deep roots, and have demonstrated tolerance to arsenic. In this research, eight willow varieties were screened for arsenic uptake from hydroponic solution in order to establish the best candidates for the phytoremediation of arsenic-contaminated soils. The plants were exposed to arsenic for ten days, then the dried tissues were separated (root/shoot), digested in concentrated nitric acid, and assessed for total arsenic via ICP-OES. Four species, S. scouleriana, S. discolor, S. vimanalis x S. miyabeana, and S. sachalinensis x S. miyabena accumulated the highest level of arsenic in their shoots. Because the purpose of phytoremediation is to remove pollutants from the site, ideal candidates will translocate higher proportions of arsenic into their above ground tissues. These four species will be used in further phytoremediation trials. 

Hot flashes (HF) are acute vasomotor disturbances that cause facial flushing and sweating. They commonly occur in menopausal women as a result of a decreased production of estradiol from the aging ovary, which triggers an acute malfunction in the brain’s control of body temperature. However, the molecular and cellular mechanisms that generate HF are poorly understood. Recent studies suggest that super-activation of KNDy neurons in the hypothalamus, which occurs in response to either reduced levels of estradiol or artificial stimulation, can disrupt thermoregulatory centers in the brain. To test this, we are developing an optogenetic animal model for HF aimed at understanding their physiological origins and enabling preclinical testing of potential therapeutics. We have created a transgenic mouse that has a light-sensitive membrane channel (channelrhodopsin-2) inserted into KNDy neurons, which can be activated with a fiber optic probe inserted into the brain. Selective activation of KNDy neurons and the subsequent behavioral response of the animal along a thermal gradient allow us to explore the role of KNDy neurons in thermoregulation. We hypothesize that following activation of KNDy neurons, the thermoregulatory set-point for excess heat perception will be lowered, so the animal will move to a cooler place along the gradient. We have preliminary evidence to suggest that when activated with a different technology (Designer Receptor Exclusively Activated by Designer Drugs) animals do, in fact move to cooler temperatures. Testing this hypothesis is our primary objective. We believe development of an animal model for hot flashes will aid our understanding of their neurobiological basis and foster development of better and safer therapeutic options for treatment.
 

 Glioblastoma multiforme (GBM) is the most common and deadliest cancer of the central nervous system. The existence of stem-like cells within GBM tumors - Glioblastoma stem cells (GSCs) - may explain some of the malignant features of Glioblastoma multiforme (GBM) owing to their rapid self renewal and diffuse migratory behavior. Increasingly apparent is the role ion channels play in many cancer cell properties, including regulation of cell cycle progression and proliferation, tumor cell motility and invasion, and regulation of metabolic rate. We hypothesize that ion channel dysregulation contributes to GSC malignancy, including increased viability, proliferation, and migration. To test this, multiple GSC isolates derived from human GBM tumors were maintained in culture over many passages while retaining stem cell properties. RNA-seq expression profiles revealed ion channel families that were highly enriched in GSC samples. Real-time qPCR was next used to confirm increased expression of voltage gated calcium, sodium, and potassium channels, ionotropic glutamate channels and inwardly-rectifying potassium channels. Identifying ion channels uniquely enriched in GSCs led to functional analyses to determine how ion channel blockers affected their proliferative and migratory properties. We performed MTT cell viability assays to assess how ion channel blockers altered the viability of GSCs compared to a control neural stem cell line. We were able to show a significant decrease in cell viability across GSC lines compared to control at a variety of drug concentrations. Utilizing live-image cell tracking, we determined decreased migratory behavior and rates of these GSC lines with the same blockers. Finally, to elucidate the role of the extrinsic tumour microenvironment on the proliferation and migration of GSCs, unique coculture models involving GSCs cultured on mouse organotypic brain slices were utilized, and showed the affects of stimulating and inhibitory DREADD receptors to modulate local neuronal activity.

Electric propulsion is an area of increasing research as it offers increased efficiency and versatility in operation. Electric propulsion systems ionize solid propellant and accelerate plasma out the back of spacecraft at high velocities using electric and magnetic fields to create thrust. Pulsed plasma thrusters (PPT) are an example of how electric propulsion offers a lightweight and cost-effective source of in-space propulsion for small spacecraft with space and power limitations. Traditional solid propellants like Teflon provide adequate fuel for PPTs but are limited by space and weight thresholds for small spacecraft. The Advanced Propulsion Lab (APL) at the University of Washington is interested in exploring the use of dust as a fuel source in PPTs. Dust would prolong the life and therefore research capabilities of such spacecraft due to its universal availability. In addition to using planetary/asteroid dust, we are interested in de-orbiting and using particle-sized pieces of retired space debris as a source for fuel. We hypothesize favorable thrust values for small spacecraft can be obtained by igniting dust in a PPT. The dust thruster is mounted inside a small vacuum and operates by using high frequency vibrations to agitate micrometer-sized particles into a plume of very fine dust that is sparked via firing a PPT. We are experimenting with Martian regolith simulant (a synthetic manufactured Mars dust), lunar regolith simulant (synthetic lunar dust), and aluminum powder, but the dust thruster can utilize virtually any dust sample. This experiment will serve as a proof of concept that dust particles can be used as a main fuel source for PPTs. The dust thruster is a sustainable system that will allow for longer missions and thus increase research capabilities, while proposing a sustainable solution to space debris traffic.

The Tritium Recoil-Ion Mass Spectrometer (TRIMS) experiment is designed to measure the branching ratio of molecular tritium to the helium-tritium molecular ion after beta decay. Tritium emits very low-energy beta particles and is difficult to detect. My research seeks to measure the background levels of tritium contamination on laboratory and apparatus surfaces by using a gas flow proportional counter. This type of counter consists of a gas filled metal tube with a high voltage wire in the center. Beta particles from tritium decay ionize the gas, and the high electric field causes avalanche multiplication, which is picked up as a signal on the wire. The size of the signal is proportional to the energy of the original particle. This apparatus allows for surveys for tritium contamination initially and throughout the lifetime of the TRIMS experiment, with real time indication.

Our research project was to design, construct, and launch a high powered rocket with the intention of pushing its velocity significantly past the speed of sound while simultaneously collecting data from which to interpret the max achieved acceleration, velocity, and altitude. The rocket's body has a three inch inner diameter made to fit the 3-inch motor casing without any extra room. This minimum diameter design reduced its weight so that less force was required to achieve higher acceleration, and it provided a smaller cross sectional area than a traditional rocket, thereby reducing the amount of drag force impeding its acceleration. Atypical of most high powered rocket designs, our rocket features a metal tipped nose cone to provide resistance to the heat caused by friction when breaking the sound barrier. At the speeds achieved, unmodified rocket fins will vibrate at extreme rates due to turbulent flow. In order to combat this destructive effect the fins were reinforced with carbon fiber to significantly stiffen them and reduce any resonant effects during flight. The payload consists of a StratoLogger SL100 Altimeter to keep track of the maximum altitude and velocities of our flights as well triggering two separate parachute deployments, achieving a safe landing while also minimizing drift time due to winds at altitude. It is our hope that our research rocket will push the boundaries of velocity and altitude achieved by a junior college rocket team as well as provide insight into ways to optimize our rocket designs to maximize future results.

Europa is one of Jupiter’s moons which is covered in ice. Further research on Europa is needed to determine if the moon can sustain life. One of the barriers that has affected our understanding of the moon is the large velocity requirements to land on Europa, which make a soft landing on the surface too costly. To overcome this problem, research has being performed on penetrator technology that can withstand a hypervelocity impact. The initial system involves the study of the performance of a two-stage penetrator. The first stage would break the ice, making way for the second stage. The second stage of the penetrator would encounter weaker ice and therefore have a higher probability of surviving the impact. The electronics would be located in the second stage. Projectiles have been tested on impact qualities and post-impact properties. Further experimentation has been performed with various designs and materials that have varying densities. Density is expected to play an important role in the depth of penetration and the resulting deceleration forces on the system. Penetrators made of Lexan have been used along with wood as impact material. Seven inches of penetration has been achieved when fired at speeds close to 1 km/s. Smaller scale testing, at lower speeds, has been performed on larger Lexan projectiles fired into ice resulted in approximately 1.5 in. of penetration. Projectiles made of aluminum have been tested and fired into a bucket of ice. The ice was kept at -20° C, which is still significantly warmer that the surface conditions of the moon. Once the penetrators are optimized for these temperature conditions, additional testing would involve liquid nitrogen to cool the ice to colder temperatures. The penetrator system could lead to the discovery of new life, future missions to Europa and possible habitation or resource extraction.

This research details the design, construction, modeling, launch and post-flight analysis of a high-powered rocket through the Earth and Space Sciences’ Rockets and Instrumentation course at the University of Washington. The primary goal was to build and test a multistage cluster rocket, scheduled to launch March 2016 in Black Rock, NV. To exploit the exponentially decreasing drag at high altitudes the rocket was initially designed as a two-stage, with eight external motors and two internal motors providing 43 kN-s of total thrust with a max velocity of 750 m/s. Risk assessment shows three-stage ignition as a safer option, providing a ground launch of 10 kN-s of thrust. Once the main engine burns for 2 seconds, the external cluster motors will ignite, providing 19 kN-s of impulse before separating from the main stage at around 20,000 feet. The sustainer motor then ignites at a final impulse of 14 kN-s and will reach an apogee of approximately 47,000 feet. The recovery package was designed with two separate systems of dual deployment for drogue and main parachutes, as well as a GPS and an altimeter, using two different flight computers, one in each stage. Previously untested commercial telemetry instrumentation was chosen and simulated with electromagnetic software before launching. If the rocket performs as designed, it will be the highest rocket built and flown by a University of Washington student group.

The CubeSat form-factor is an increasingly popular design of small satellites utilized by a range of research orginizations. Consisting of stacks of 10x10x10cm cubes, CubeSats offer a compact and inexpensive means to place equipment and instrumentation into low-earth orbit, but suffer from limited or non-existent maneuvering capabilities. Currently available propulsion options for CubeSats may offer limited abilities to modify the shape of an orbit near to Earth, but suffer constraints on propellant efficiency, thrust duration, and thrust force. A new design of compact pulsed plasma thruster from the University of Washington for use on small satellites offers improved abilities to maneuver in not just low-Earth orbit but also in lunar insertion, lunar orbit, Earth escape trajectory, and a variety of trajectories reaching beyond. The orbital mechanics team has been responsible for studying the motion of PPT powered satellites in space and for the plotting of trajectories to potential mission targets. As the PPT has significantly different levels of thrust and efficiency from conventional liquid-fueled rockets, unique solutions to conventional problems must be found.

Studies suggest that Europa contains elements required to support life beneath its icy crust, but further data collection is required for verification. One of the largest issues in performing such a research expedition is the demanding cost of soft-landing an instrument on its surface to retrieve the data. To address this issue, research is currently being conducted for a new method involving a two-stage penetrator probe which would allow the hard-landing of the probe into the moon’s surface. The initial stage penetrator would weaken the ice and create a debris plume which would allow the second stage probe to decelerate and enter the surface intact. To optimize the system and further study its potential, the impact is being simulated in the ANSYS finite element analysis software. In working parallel with experimental data obtained from impact testing, the geometry and parameters within ANSYS were modeled to create a FEA explicit dynamics simulation of the impact. The analysis models the ice as concrete due to material properties of ice being difficult to obtain, and local mesh refinement methods were utilized to improve computational time. The focus of the simulation is to determine the optimal model in which the first stage penetrator has significant impact in the acceleration profile of the second stage probe. The impact pattern, the amount of material carved out, and the acceleration profile of the probe will be analyzed to relate the efficiency of various penetrator geometries at various speeds. Impacts involving the two stage system with various penetrator geometries show significant reductions in the acceleration profile of the probe. Future research will rely on refining the simulation parameters to derive a more accurate model of the impact.

As a response to the NASA Cubesat initiative, the UW ESS department started the effort to design and build a 3U Cubesat by the students from various technical backgrounds. 3U Cubesat is made of 3 units vertically stacked onto each other with each unit at 10x10x11.35cm. This team is assembled within the UW Cubesat project to work on the structure system of the Cubesat and is responsible for solving problems in structure system. Recent progress regarding the CAD modeling of the body, designing and manufacturing of the hinges, deployers, solar panel mounting and ideas about fixed solar array and launcher possibilities are discussed. Various models have been proposed and tested and the overall capability of the hinges is improved to better suit the mission. For getting the maximum exposure of sunlight and keeping the whole system optimal, different solar panel solutions were assessed. Deployer design to release the Cubesat from the launching system and to release the solar panels from the Cubesat body was studied. Before machining the deployer and hinge system at its actual size, multiple tests have been done on the enlarged 3D-printed versions of the deployer and hinge system to make sure the design works properly. Among our team members, the tasks to design and implement each section are collaborative and everybody made sizable contributions to the progress. The current results produced include a design of the full body CAD model for the 3U Cubesat and its major components, a preliminary design of the deployer and hinge system undergoing its initial testing stage, a decision to use existing design of PPOD launcher and a design of the location and dimensions of the solar panels. Multiple models and their respective numerical estimations have been used in multiple presentations and will be presented at the day of the Symposium.

Auditory-motor adaptation is a form of sensorimotor learning in which human subjects gradually (i.e., over several trials) adjust the movements of their speech articulators when experiencing experimentally manipulated auditory feedback. For example, it is well documented that subjects lower their formant frequencies (i.e., acoustic output resonant frequencies that are determined by the articulators’ positions) in response to a real-time upward shift of these formants in the perceived auditory feedback. Our long-term goal of translating such auditory-motor learning protocols into clinical applications for individuals with speech disorders requires an understanding of the central nervous system’s tolerance for feedback delays. Indeed, one potential problem for efficient sensorimotor learning arises when movement-related feedback is delayed: perceiving the consequences of one’s own actions with a delay results in this sensory information being processed similar to externally-generated, rather than self-generated, sensory input. In the present study, we follow up on recent work in which we found that auditory-motor learning in speech is completely abolished with feedback delays of 100 ms or more. Here, we tested whether shorter delays also have a negative impact on speech auditory-motor learning. Twelve adult subjects read out loud monosyllabic words while a digital vocal processor applied a 2.5 semitones upward shift to all formants in the auditory feedback signal that was presented through insert earphones. In separate conditions, this feedback was delayed by 0, 33, 66, or 100 ms. Measurements of the subjects’ extent of auditory-motor learning across all conditions will be presented and interpreted in the context of current models of sensorimotor learning.
 

Human immunodeficiency virus (HIV) infection is an important health issue worldwide and consists of two main types, HIV-1 and HIV-2. In the fight against HIV, integrase strand transfer inhibitors (INSTIs) are a relatively newer class of antiretroviral drugs aimed at blocking viral replication. FDA-approved first generation INSTIs include raltegravir (RAL) and elvitegravir while the second generation includes dolutegravir and cabotegravir (CTG). The high mutation rate of HIV often results in resistance to antiretrovirals and leads to treatment failure. However, the mechanisms and mutations that confer INSTI resistance in HIV-2 are not completely understood, despite the growing importance of INSTIs for HIV-2 treatment. The purpose of my research is to identify and characterize genetic changes responsible for INSTI resistance in HIV-2. Specifically, I engineered mutations that have been reported in sequences from patients receiving INSTI treatment into a laboratory strain of HIV-2, and tested the mutants for resistance to RAL and CTG in culture. Initial results indicate that a mutation at integrase position 263 (R263K) does not confer resistance to either RAL or CTG. However, a second variant encoding the mutations G140S+Q148H+N155H is highly resistant to both drugs, with 50% effective concentrations (EC₅₀ values) that were at least 1000-times greater than the wild-type strain. Experiments with additional HIV-2 integrase mutants are in progress. In the future, the mutant HIV-2 clones produced in this study will serve as a reference library for evaluating the resistance profiles of newer integrase inhibitors, thus helping to identify therapeutic strategies for HIV-2 patients that harbor drug-resistant virus.

Working in small groups, our studio collectively studied various residential projects, focusing on conceptual design, human scale, programmatic relationships, and the buildings' relationship to the site. Our group was assigned the Floodplain House designed by Paul Hirzel Architects. In order to gain a better understanding of the project, our group created 1/4" = 1' basswood section model. The Floodplain House was built to provide a live/work space for the client’s 70 acre winery. The live and work areas are housed in the main body, while a bedroom rests within a grove of cottonwood trees as its own private wing that flanks the main structure. The house sits on the edge of Potlach River to maximize the land for the vineyard, as well as provide an immersive experience for its owner and their guests. At 184 feet in length, a steel Howe truss rests on four thick concrete piers, allowing the house to cantilever above the river similar to a bridge. The structure is elevated at a height above the ‘500 year flood plane’ and to prevent rattlesnake infestations. Building on such a challenging site, the exoskeletal structure doubled as scaffolding during the construction to keep initial costs low. The external structural system allows the walls to be placed and angled freely in order to frame views and suggest movement. Paul Hirzel Architects' Floodplain House effectively incorporates the clients' needs and is responsive to the existing site conditions.

Precedent Model Study (Fall 2015): the primary objective of the 2-week long project is to foster the ability to see and create architectural spaces that are sensitive to human needs and requirements in terms of materiality, scale, and use. Students work in teams to investigate a building, which is selected for its particular architectural language and relationship with its site. Students research, analyze and then create a 1/2" = 1'-0" section model of their building precedent. Then,they develop an evocative section perspective that communicates qualities of the building uncovered during their research, analysis, and model construction. Our group researched Glenn Murcutt's Marika-Alderton House, which was selected by our mentor for its particular architectural language and relationship with its site. Glenn Murcutt’s Marika-Alderton House stands as an attempt to apply modernism and bring about peace in the midst of the tense cultural and uniquely volatile natural landscape of far Northern Australia. His structure was created as a home for Aboriginal artist Banduk Marika and her family, drawing upon both the inspiration of the native people of Australia in their curved-bark long houses, and the inspiration of the European settlers, with their raised corrugated metal woolsheds. It is most essentially the interpretation of structure as elevated, shaded platform. The house “floats” on the air, raised on stilts with a permeable membrane of open windows, allowing the tropical winds to permeate the walls and floor and sweep upward through holes in the roof. The corrugated metal roof with deep eaves protects the house from the sun and heavy monsoon rains. It is intrinsically local, made of natural timber with a steel frame and built using unskilled labor. Glenn Murcutt’s Marika-Alderton House is an example of a structure dictated by the complex cultural and natural web into which it is placed.

The model is a project from our architectural design studio. In this project, groups of students were assigned an existing building and tasked to build a scale model of it while making a section cut that helped give a better understanding of the building as a whole. Each was built primarily of basswood at 1/4" - 1' 0" scale. In doing so, we were able to compare and contrast the different forms and structures effectively. The building we had been assigned to was the Palmyra House in Maharashtra, India by Studio Mumbai, which was completed in 2007. Studying the house and its model gave us a better understanding of its relationship to its environment. Local craftsmen who had knowledge of traditional construction methods like interlocking joinery were employed for the House’s construction. Focusing on building by hand avoided the need for heavy machinery, which would have damaged part of the existing coconut plantation it is located in. The louvers help bring in air from the Arabian Sea or the plantation, cooling the interior spaces. They also prevent direct sunlight from reaching these rooms while still keeping them well lit with natural light. These characteristics let the Palmyra House naturally fit its site and also leave it undisturbed.

Many genetic diseases are currently explained by monogenic mutations; however, a number of human disorders and conditions are genetically complex and cannot be attributed to a single mutation. One of the main research goals at the Waterston Lab is to identify genetic interactions that may give rise to disease, such as synergistic, alleviating, or epistatic interactions that could affect important pathways. By using the small nematode worm, Caenorhabditis elegans, as a model, we have developed a high-throughput approach to look for interactions. Forty different transcription factor (TF) genes were separately knocked down using RNAi bacteria on pooled populations composed of 38 mutated and fully sequenced strains of C. elegans. After growth for several generations in the presence of the RNAi, the abundance of strains in each population was compared by targeting strain-specific single nucleotide variants (SNVs) with Molecular Inversion Probes (MIPS) and sequencing on an Illumina MiSeq system. After growth for over 12 generations and screening for ~115,000 possible genetic interactions, two negative and two positive interactions were detected. Strains that quickly fell out of the population on a given RNAi indicate possible negative interactions. We observed this negative interaction between the strain VC20123 and RNAi for the gene K11D2.4, as well as VC20128 and F22D6.2. Strains that did significantly better than other strains on a given RNAi indicates possible positive genetic interactions. We observed these interactions between VC20424 and B0261.1 as well as VC20514 and let-607. To confirm these candidate interactions, we are growing the specific strains against a control strain. To identify the interactions at the gene level, we are using genetic mapping. Broadly, studying the nature of genetic interactions and potential roles of transcription factors may contribute to the elucidation of human development and complex diseases.