The world’s future energy needs will almost certainly require extensive use of renewable sources of energy. Organic photovoltaics are a particularly lucrative source of energy due to their cheap materials and ease of production compared to inorganic solar cells. However, organic photovoltaics (OPVs) currently suffer several drawbacks: they have an efficiency of, at most, around 10% and they are unstable – they may begin to degrade within five to seven years. This project aims to alleviate these defects by gaining a greater understanding of the chemical interaction between interfaces within the solar cell. This project is a comprehensive study of the interactions between phenyl-C₆₁-butyric acid methyl ester (PCBM) and calcium. PCBM is an extensively researched molecule which acts as an electron acceptor in OPV devices. PCBM is typically paired with an electron donor such as poly-(3-hexylthiophene) in a working device, and calcium has energetic properties which allow for very good electron transfer at the cathode of such a device. We use adsorption micro-calorimetry under ultra-high vacuum conditions to study the reaction at the interface between calcium and PCBM, and surface analytical techniques to determine growth modes and chemical binding of calcium and PCBM. These experiments will elucidate the mechanisms of interface formation of this understudied but important OPV system.

The purpose of our research is to better understand older adults’ perceptions about fall detection devices. When an older adult experiences a fall, the results can be dramatically life altering or even fatal compared to an individual in a different age group. This led us to question what views older adults have about existing measures in place to monitor and analyze falls, such as fall detection devices or other technologies, as well as what demographic factors may influence these views. Using data from a parent study, we are currently in the process of analyzing focus group transcripts to compare perceptions of older adults from high and low socio-economic status using qualitative descriptive methods. We are analyzing transcripts for common themes that may lead to the identification of areas for further study. By studying older adults’ perceptions of fall detection devices, we hope to gain a better understanding of their needs and preferences when it comes to such devices. We hope exploring and understanding demographic or other factors that affect these perceptions may lead to more open conversations on falls, and thus better our ability to customize fall detection devices and their features, and fall prevention plans for older adults.

Traumatic Brain Injury (TBI) is an issue that seriously affects people of all ages; older adults with TBI have the highest rates of hospitalization and death. Additionally the overall recovery is significantly poorer than a younger person with a similar TBI. With normal aging, there is a reduction in the number of white blood cells (WBCs). However, in certain chronic diseases with an inflammatory component that are more common with older age, such as diabetes, there may be an ongoing activation of available WBCs which could affect viability in response to injury. This investigation used data from an ongoing parent study of the immune response following TBI in order to examine the number of and viability of peripheral blood mononuclear cells (PBMCs) within 24 hours of TBI in both older and younger adults as well as non-injured controls (N=133). Older age was defined as 55 and older for the purposes of this study. Whole blood was collected and processed for plasma and WBCs from subjects using Ficoll technique (separation of blood components). Cells were manually counted and viability of cells was determined using the trypan blue method (type of stain to observe cells). Data analysis is underway. Descriptive statistics were performed along with ANOVA to assess for group differences in cell count and viability. Time from blood draw to processing will be used as a covariate. The results of this study will enable us to determine if lower cell counts or cell viability differ by age and injury status. This will provide support for or refute the hypothesis that the immune response following injury is different in older adults which could impact patient outcomes. By understanding this relationship, we can implement clinical changes to potentially help change the immune response and improve the outcomes older adults experience post injury.

Proton-coupled electron transfer (PCET) occurs in a variety of oxidation/reduction reactions. This thermodynamically-coupled transfer of an electron (e–) and a proton (H⁺) is important for many reactions, including catalysis and energy generation, and may occur through different mechanisms. Zinc oxide (ZnO) nanoparticles are useful for studying factors that influence the rates of PCET reactions in at metal-oxide surfaces. The ZnO nanoparticles used in this research have been well characterized and, as a colloidal solution, can be treated as molecule-like reactants in experiments. The ZnO nanoparticles described in these experiments are capped with dodecylamine (DDA), and then dispersed into air-free toluene, an aprotic solvent. The use of an aprotic solvent is important to ensure that the e–/H⁺ are transferred from the nanoparticle. When these nanoparticle solutions are irradiated with above-bandgap radiation, an electron is excited into the conduction band. This leaves a hole in the valence band that, from previously demonstrated research, is immediately quenched by EtOH left over from synthesis; EtOH provides both an electron and a proton, keeping the nanoparticle neutral. When the reduced and protonated ZnO nanoparticles are reacted with 2,4,6-tri-tert-butylphenoxyl (^tBu₃ArO·), an electron and a proton are transferred from the reduced ZnO nanoparticle to the ^tBu₃ArO·, yielding the corresponding phenol, ^tBu₃ArOH. The kinetics of this reaction are monitored using laser flash photolysis. The rates of PCET are affected by the reduction potentials and the pKa of the reactants. The reduction potentials of the nanoparticles may be tuned by changing the particle size. Initial results also show the concentration of the capping group affects the rate of PCET. We are investigating how these factors, reduction potential and capping group concentration, influence the rate of PCET from reduced and protonated ZnO nanoparticles.

The First World War (1914-1918) introduced the world to the horrors of warfare on an industrial scale. But it also gave rise to the one of the most dynamic and active anti-war movements of the 20th century. This research explores the activities of the local Pacific Northwest anti-war movement during World War I. National resistance to the militarist and imperialist policies of the United States peaked during the war period, and the Seattle anti-war movement provides a fascinating case study of how socialists, anarchists, labor unions and pacifists organized a robust anti-war movement. Using a wide variety of contemporary local newspapers, letters, activist memoirs and labor union meeting minutes, this study weaves together the story of Seattle’s radical and pacifist organizations during the First World War. This study finds that despite aggressive persecution from the Federal government, conservative labor unions and pro-war business interests, the Seattle anti-war coalition continued to offer active and radical resistance to militarist policies up until the end of the war.

The actions and attitudes of Roman imperial women have fascinated both ancient and modern historians alike, and many have used them in order to pose larger questions about the nature of Roman power and the lifestyle of the early Emperors. The representations of imperial and highborn women in the texts of Roman historians provide a unique and complex window into the lives of some of the most polarizing females of the early days of the Roman Empire. In this paper I seek to explore the manner in which the second century CE historian Tacitus, and the third century CE historian Cassius Dio, characterize and utilize these women within their narratives of the end of Augustus’ reign, and the reign of Tiberius (ca. 27 BCE-36 CE). Furthermore, I elucidate these authors’ reactions to notable women through the lens of female morality and virtues, especially those espoused by Augustus’ moral legislation. This series of laws regarding marriage, children and adultery were presented by Augustus as a return to ancient mores. This was in stark contrast to the reality of the Augustan state and the early Principate in which highborn women were often able to exercise large amounts of political power through their male relatives. A closer examination of high-placed imperial women, such as Livia, Agrippina the Elder, and Julia, through this lens of Augustan morality reveals that the sources, especially Tacitus, are very uneasy about women whose actions in the political sphere are completely unprecedented and “new”, but who adhere to the “old” standards of modesty and feminine virtue. In order to explain this interesting phenomenon I will explore the historians’ portrayals of “good” Roman women, “bad” Roman women, and women who are morally upright but suspect with regards to their engagement in political power.

Translation is a tricky business, especially when concerning religious texts. The problem of effectively communicating a culture's ingrained beliefs to another through a different language has potentially important implications for the original audience. An excellent example of this is the Septuagint, the Ancient Greek translation of the Old Testament Hebrew scriptures. My project focuses on the Greek version of the Hebrew Leviticus, a book which contains vital information about the Hebrew religion and sacrificial procedures. I examined the translation via a verse-by-verse, word-by-word comparison between the Greek and Hebrew versions, in particular noting the translator's accuracy, grammar, and communication of important Hebrew sacrificial terminologies and ideas into the Greek. By such a comparison and investigation of the translator's word usages, it is possible to reconstruct how the original non-Hebrew speaking audience understood and interpreted this text. The significance of this reconstruction lies in the fact that early Christianity used the Septuagint, including Leviticus, as a supportive foundation for its beliefs.

My experience on a short term medical mission trip to Guatemala in 2010 left me with an uneasiness. In the face of the experience itself, much post-trip discourse has been centered largely on its value as social capital. The goal of my research is to begin to unravel the complex emotions that take place both at the site of contact in the third-world host country and after returning home. In the face of the ubiquity of short term mission trips, their increasing necessity for professional and educational development, and the vast amount of development literature, this emotional ambiguity is left out. I plan to unpack and illuminate this internal conflict as a way to understand the dual nature of its effects. As an overall objective, I hope that this project invites further discussion about short term volunteer programs and their complexities. Additionally, my research questions ask what evidence of this duality in their own experiences there might be in personal accounts of returnees. Additionally, I plan to address the source, context, and representation of this ambiguity, if it does in fact exist for others, as well. My methods consist of revisiting my experience through an autoethnography and collecting data from the trip. I also include personal narratives from several returned volunteers willing to share their experiences, as well as reviewing much of the academic literature about short term trips. I plan to present emergent broad themes and possible significance for others preparing to go on a short term volunteer trip. These themes include mixed feelings about the trip in the form of a duality, the manner in which relationships formed in the contact zone might affect personal beliefs about the work being done on the trip, and the ambiguity of short term mission trips in terms of their helpfulness or harm.

Compound I is the intermediate responsible for substrate oxidation in the catalytic cycles of a variety of heme-containing metalloenzymes, such as peroxidases, oxygenases, and importantly, cytochrome P450s. Cytochrome P450s, through compound I, oxidize approximately 75% of foreign substances that enter the body, such as pharmaceuticals and chemicals from the environment, so there is an interest in the mechanism by which this reaction occurs. The goal of this project is to probe the potential reversibility of Compound I formation, a step traditionally thought to be irreversible. Due to its stability and availability, horseradish peroxidase (HRP) was used as the model enzyme. In the case of HRP, hydrogen peroxide is reduced to water at the heme cofactor, while oxidizing a variety of substrates. In the presence of an oxidant and the absence of a substrate to oxidize, hydrogen peroxide coordinates to the iron of the heme, the O-O bond is cleaved, which forms water and compound I. A key experiment reacts HRP with unlabeled H₂O₂ in ¹⁸O-labeled water, and determines whether mixed-labled H₂O₂ is formed. The presence of mixed-labeled H₂O₂ indicates that there is reversibility of the O-O bond cleavage that forms compound I. The existence of mixed-labeled H₂O₂ is ascertained by first removing HRP by filtration, leaving the H₂O₂ in the filtrate. This is followed by the addition of a water soluble phosphine. In this case, the phosphine cannot be oxidized by Compound I, but can readily react with free hydrogen peroxide in solution to give the corresponding phosphine oxide. Mass spectroscopy is used to determine whether the phosphine oxide has incorporated the ¹⁸O label. Results show that when the experiment is performed in the presence of ¹⁸OH₂, there was no observable increase in the intensity of a peak corresponding to ¹⁸O-phosphine oxide, so reversibility of Compound I formation was not confirmed.

 In silicon photonics, light propagation along a narrow silicon waveguide at the nanoscale produces an electromagnetic field that extends beyond the waveguide surface. Microrings can “couple” light from an incident waveguide at certain wavelengths. Silicon microring resonators can detect changes in the effective refractive index at the sensor’s surface by producing minute shifts in the peak resonance frequency. For biosensing applications, this resonance frequency shift is utilized to quantify the binding of biological analytes to the microring surface. Combined with a microfluidic platform for directing chemical and biological reagents over the microring resonators, silicon photonics offer a promising method of determining the concentrations and binding activities of analytes of interest in biological assays. However, protein fouling- the non-specific accumulation of protein molecules on a surface- in blood samples presents a significant challenge in the translation of these assays toward clinical adoption. Ongoing research has aimed to significantly reduce non-specific adsorption by coating the chip surface with polymer chains, resulting in a hydrated surface which resists protein fouling. In this study, charged polymer layers were grown on the chip surface by atom-transfer radical polymerization (ATRP), producing a coating of polymer brushes of high density and uniform length. Microring sensors were then functionalized by conjugating biological capture elements using standard carbodiimide chemistry to the terminal carboxylic acid residues of a surface-grafted polymer. The polymerization reaction conditions were optimized to minimize the thickness of the polymer layer while maintaining the non-fouling properties of the surface as a whole. Non-fouling properties were observed in the residual resonance shift following plasma and buffer rinse flows via a microfluidic platform. By minimizing the surface polymer thickness, we increase the physical limit of analyte detection on the microring surface, thereby maximizing the sensitivity of the biosensor while reducing “biological noise” due to non-specific protein adsorption.

Cancer diagnostic immunoassays are widely used for the detection of disease in vitro, but low antigen concentrations may not be detected in an early stage or confused for baseline noise, leading to false negative or positive diagnoses. Poly(carboxybetaine methacrylate) (PCB) is a zwitterionic polymer that strongly resists biofouling while allowing simple functionalization and effective bioconjugation to proteins. Coating this polymer on iron oxide nanoparticles via a DOPA attachment group allows for easy antibody immobilization, to realize low nonspecific binding and high signal-to-noise ratio in one platform. Methods for nanoparticle construction include synthesis of MNPs (magnetic nanoparticles) coated with PCB-DOPA and PCB-DOPA2. The coated particles are functionalized with FITC-BSA and FITC-streptavidin using EDC/NHS chemistry to optimize conjugation parameters. A model antibody (ALCAM antibody) is then conjugated to test the platform’s sensitivity for immunoassays. The functionalized nanoparticles are characterized with Dynamic Light Scattering (DLS), fluorescence spectroscopy, flow cytometry, and Surface Plasmon Resonance (SPR). Control groups with bare beads, functionalized beads with no polymer coating, or no functionalization are also processed in the experiment to compare with experimental groups. In preliminary tests, the functionalized magnetic nanoparticles have a high level of immobilization of each tested protein or antibody (FITC-BSA, FITC-streptavidin, and ALCAM antibody). In the plasma stability test, the PCB-coated and beads show low nonspecific binding even with high levels of functionalization. The experimental immunoassay can detect a low concentration of the ALCAM cancer biomarker in bovine serum, with less baseline noise than a commercial immunoassay (Luminex MagPlex®). The functionalized magnetic nanoparticles have a low detection limit to an early-stage cancer biomarker and a high signal-to-noise ratio due to reduced nonspecific binding. This platform could be extended to many clinical immunoassays in which either false negative or false positive diagnostic readings are problem.

An inborn genetic disorder, phenylketonuria (PKU) is characterized by elevated phenylalanine (Phe) concentrations that interfere with neurodevelopment, leading to irreversible symptoms such as mental retardation and motor developmental delays if left undetected. Most countries, including the United States, implement PKU testing in newborn screening programs, in order to provide treatment to prevent the onset of irreversible damage. Current methods of detection include tandem mass spectrometry, high performance liquid chromatography, and fluorometric immunoassay. However, these methods require highly technical equipment and trained personnel that do not allow for the tests to be implemented in low resource settings. Thus there is a need for a fully disposable, easy to use, and cost-efficient device for the detection of Phe that can be implemented in areas that lack current Phe detection strategies. My project proposes to develop an enzymatic colorimetric assay for the detection of Phe in a simple paper-based disposable, such that an untrained user can perform and read the test results. Critical to this the incorporation of dry reagents on card. The assay requires a two-step reaction: 1) the conversion of nicotinamide adenine dinucleotide (NAD+) to its reduced form (NADH) in the presence of Phe and catalyzed by phenylalanine dehydrogenase (PheDH), and 2) the conversion of the tetrazolium salt, nitroblue tetrazolium (NBT), into a purple formazan dye due to the presence of NADH and the coenzyme phenazine methozulfate (PMS). Reagent drying protocols have been evaluated for PheDH, NAD+, NBT and PMS for short-term reagent stability. Preliminary data shows NBT and PMS should be stored separately, to avoid autoproduction, while PheDH should be stored with a low concentrated sugar. NAD+ stores well without added stabilizers.

Conservatively estimated, about one in every ten youth experiences severe depression during adolescence. This is concerning because depression is known to be responsive to prevention as well as to early interventions when accessible to youth. Those who experience early onset depression are at increased risk for other negative outcomes including substance use and suicidal behavior. The effects of depression carry over into young adulthood and are linked with psychiatric and medical hospitalizations, suicidal behavior, and lower educational accomplishments. Youth identified as academically at-risk are particularly susceptible to experiencing depression as well as other co-occurring health risks. Research reveals that family processes serve as a protective influence on the development of depression. Few studies, however, have examined the role of familial risk and protective factors in the development or progression of depression for academically at-risk youth. This research was designed to investigate patterns of depression across time and the influence of family-level risk (family conflict, authoritative parenting style and parental substance use) and protective factors (parental involvement/monitoring and family support) on these patterns. These factors will be compared in terms of their strength of influence on depression. This predictive study is based on survey data collected from a randomly selected, ethnically diverse sample (n=149) of students from two Washington State school districts who were subsequently followed from middle into high school (8th-10th grade). The sample includes youth randomly assigned to the control condition in a school-based prevention study. Depression is expected to be positively associated with family risk factors and negatively associated with protective factors. We anticipate distinguishing differences in the relative influence of family factors on adolescent depression. This detailed examination of key factors influencing adolescent depression will contribute to designing new interventions that are more clearly and specifically targeted, and thus more meaningful, for vulnerable youth and their families.

Porous membrane-based lateral flow assays have become commonplace in the diagnosis of a wide range of conditions. Attributes of these assays vary greatly depending upon the application. Many commercially available lateral flow tests (LFTs) employ a 'sandwich' format, where the target molecule is effectively sandwiched between a surface anchored antibody and a labeled antibody. Because small molecules lack multiple epitopes (antibody binding sites), they cannot support the binding of two antibodies simultaneously, and thus cannot be detected using a sandwich format. Competition format assays offer a solution to this problem, but fall short in two key areas: they generally rely on a counterintuitive, inverted user read-out, where a darker signal translates to lower concentration, and are not compatible with chemical signal amplification. My work seeks to improve upon current competition methods by investigating assay formats that generate a colorimetric signal proportional to the concentration of small molecule analyte in a sample. Amplification chemistries have been utilized to improve the limit of detection for small molecules in this new format. Potential future applications of a robust small molecule assay include: rapid detection of cortisol to diagnose post-traumatic stress disorder or Cushing's disease, and field-use testing for active drug components like Δ9 THC in marijuana. Such an assay would have tremendous utility at the point-of-care, and would provide an efficient and effective alternative to expensive lab-based testing.

Magnetic microbeads are a common tool used in biological assay purification, however, they don’t diffuse quickly nor do they have a high surface area, which results in low binding efficiency. Magnetic nanoparticles have more total surface area and can diffuse quickly, but cannot be separated magnetically as individual particles. The research I do uses magnetic nanoparticles (MNPs) coupled with pNIPAAm (p(N-isopropylacrylamide)) as a temperature-responsive reagent system to purify solutions for diagnostic tests in order to increase the sensitivity and specificity. This works by combining MNPs coated with pNIPAAm and free pNIPAAM-antibody conjugates. The antigen binds to the antibody and when heated to the cloud point temperature (around 37°C for pNIPAAm), the polymers aggregate, allowing the MNPs and the antibody conjugates to be magnetically separated together. The conjugates are synthesized using NHS chemistry and purified through HPLC. The separation efficiency of these conjugates is determined though ELISA and can reach near 100% and the total aggregation and capture time for this system is less than 4 minutes. This is useful because it can rapidly concentrate and purify samples to reduce false positives and allow for a lower limit of detection. This can be incorporated into a multitude of point-of-care tests to deliver earlier, faster, and more accurate results.

With ~34 million people infected with human immunodeficiency virus (HIV), researchers are actively trying to decipher the evasive nature of the virus--primarily its high mutation rate that allows it to escape immune recognition. We are thus analyzing evolutionary distances between viral DNA sequences and applying them to other aspects of HIV pathogenesis such as the highly variable course of infection. There is typically an initial short period of flu-like symptoms as the virus begins to destroy CD4+ T-cells, which are crucial to the immune system, then seroconversion, when the body produces cytotoxic T-lymphocytes that suppress and stabilize viral levels, and virus-specific antibodies. An asymptomatic period that varies greatly in length then follows. However, viral levels eventually increase again and T-cell levels drop and/or the immune system can no longer control opportunistic infections, the patient is diagnosed with Acquired Immunodeficiency Syndrome (AIDS). However, the majority of research focuses on HIV-infected men, despite intriguing evidence suggesting that there are gender-specific differences in the progression to AIDS. In this comprehensive longitudinal study of HIV-1 in eight different women, we are investigating the patterns of viral genetic diversity and divergence, from the time of seroconversion to the development of AIDS or until disease progression was halted by antiretroviral drugs. We amplified the conserved group specific antigen (gag) gene and the variable envelope gene (env) of various time points of each infected woman by performing Multiplex Polymerase Chain Reactions. Sequencher and Geneious programs were used to determine and align the DNA sequences after they were sent out for Sanger sequencing. We will investigate the patterns of diversity and divergence over the time course of an infection in each patient using phylogenetic trees of their DNA sequences. Results from this work will be presented, as well as a comparison to similar measures from men.

Finding threads of commonality among stories from multiple gallery participants, "Intersections" takes intimate memories and brings them to life. Participants sit alone in a secluded room and share real and imagined stories while navigating through a series of prompts. Speech is recorded in fragments and also converted to text to drive the compositional process. Important words, as determined through parts-of-speech and repetition analysis of the text, are entered in a Flickr tag search. Images thoroughly tagged and described by Flickr users, which often capture personal experiences, are then saved. In the public gallery space, three video monitors display a dynamic sequence of these images while two speakers (with left, right, and center channels) play back the speech fragments. Neurobiological principles of memory consolidation provide an underlying functional framework that determines probabilities and sequences of the image and speech output. Images and speech associated with frequently used words have a higher probability of occurrence and a greater longevity inside the system. Patterns emerge over time as commonly shared memories achieve a monopoly on the output. Ultimately this system functions as a collective mind where shared memories are fragmented and juxtaposed to form narrative re-appropriations of the original stories. In the end viewers are left with remnants of the original speech and continuously changing visual representations. The new system of memory is constantly in flux and becomes a new form in itself, a collective reminiscence.

HIV-1 positive patients on antiretroviral therapy (ART) who agreed to donate their bodies to science are the sampling population for this study. All patients had low or undetectable virus levels in the blood at or near time of death. DNA was extracted from each of the patient tissues and then using nested PCR, envelope and polymerase genes from single viral templates were amplified and the sequences determined. We used this data to determine whether any tissues harbored virus reservoir- or compartment-like qualities. This is the study of patient HV00103 who had been treated ART for the last 4.5 years of his life and had a viral load of less than 50 cps/ml, indicating successful suppression of virus. Despite this control, he died of multiple organ failure. We found that large intestine seemed to exhibit reservoir like properties but more samples would need to be examined before any conclusive claims can be made. We also found that 80% of his HIV-infected cells were derived from the proliferation of a single cell, as evidenced by the identical viral sequences found throughout his tissues. This represents the most extreme example to date that infected cell proliferation is an important contributor to the persisting population of infected cells under ART.

The Fu lab, in collaboration with the Yager and Lutz labs, develops low cost disposable diagnostic assays, much like the common pregnancy strip, but capable of performing more complex sample processing. Our paper-based assays are capable of automatically sending multiple reagents over a detection zone in sequence. These assays have been developed to perform the detection of markers for diseases such as dengue fever and malaria. My project is to further expand the capability of these assays by providing methods to passively control the flow rate through the detection zone. By optimizing the flow rate for each reagent delivery step, the time to result of the assay can be reduced without sacrificing signal strength. Devices are designed in AUTOCAD and fabricated from nitrocellulose and cellulose using a CO2 laser system. Flow speed within a device is quantified using a fluid marking system, in conjunction with custom video tracking software composed in MATLAB. Our experiments demonstrate several preliminary designs, in which flow is modulated by modifying the geometry of the assay substrate. In one design, a steady flow rate eventually transitions to a secondary, slower steady flow. A second design performs the opposite, where a steady flow rate eventually transitions to a secondary faster steady flow. The third preliminary design incorporates both these results to have a slow steady flow, which eventually transitions to a faster steady flow, and then finally falls back to a slower steady flow again. These flow profiles are well tailored for common protocols currently in use, where fast flowing rinse steps alternate in between slow flowing reagent binding steps.

This study is using Hamilton Search (HS) memory task and Set breaking (SB) task to assess working memory, cognitive flexibility and inhibition control of a variety of domestic dog breeds reflecting differences in evolutionary lineage. HS and SB have been tested on young pigtail macaque monkeys as well as other species. The HS task consisted of each dog searching 4 containers side by side to find a randomly placed food reward in 5 sessions of 16 trials each. SB followed HS and the location of the food was fixed based on performance in the HS trials. Trials continued until a dog reached criterion, establishing that they had learned the position of the food. The latency and search pattern was recorded to determine performance of the task. Results compared to pigtail macaque monkeys as well as across dog breeds. The primary variables analyzed were number of containers examined, probability of selecting an outer container and right/left side bias. Preliminary results show that dogs in general are approaching this task in a remarkably systematic manner, searching from one end to the other, which is considerably different than the performance of macaques. This approach leads to few recheck errors that, rather than indicating perfect memory, actually reflects an efficient alternative to memory. Results of this study can be used to establish the validity of these tasks, and provide interesting new perspectives on both optimal foraging strategy models and the refinement of training techniques.  

Public health concern in the U.S and across the world regarding the impact of environmental hazards on human health is becoming more evident as we develop tools to see disparities in exposure and health outcome. Pollutants in the air and water can have lifelong consequences for the quality of lives of many people. Therefore, our toxicology laboratory is examining the result of pesticide exposure and toxicity in children, and how it may cause harm to normal development. Our research centers on studying exposure using blood, urine, and oral buccal samples obtained as part of a Children’s Health study on Yakima Valley. We have determined blood pesticide, urinary metabolite concentrations, cholinesterase activity, paraoxonase activity, and genome wide variation in 200 families. We have analyzed buccal samples from farmworker and non-farmworker families that were collected during different pesticide spray seasons. We are studying these buccal swab samples of children and their parents to identify bacteria present within them. We are utilizing targeted 16S ribosomal polymerase chain reaction (PCR) to determine the phylogenetic composition of the microbiome in saliva samples. The microbiome refers to the vast colonization of microbes within the body. There are more bacterial cells in our bodies than human cells even though they are only about 10% of the total mass. We hope to find a difference in microbe composition and metabolism for samples from agricultural seasons (pesticide use and non-spray seasons), and for child and adult samples. We have already analyzed pilot samples and found consistent results. Recently, we have begun PCR-based analysis and sequencing the remainder of the cohort buccal samples to characterize the diversity of oral microbiomes. If a link is found between the microbiome, pesticides, metabolic traits, and host genotype then we can more fully describe risk and metabolic biomarkers for exposed populations. 

M dwarfs are small stars with masses between 10 and 50% that of the Sun. They are also the most common, making up about 70% of the stars in our galaxy, and are noted for their high levels of magnetic activity. Stellar flares are a dramatic manifestation of this activity, and occur frequently on M dwarfs. Flares are explosive events resulting from rearranging magnetic fields on the stellar surface. We used data from the Kepler satellite to search for flares from a binary M dwarf system, named GJ 1245. With more than 8 months of continuous imaging, taken every 1-minute, we detected over 3,000 flare events from these twin stars. We conducted a by-eye search of this data to validate our automatic flare-finding code. We present the energy distribution and morphology for flares on these stars, and compare them to other well studied flare stars from Kepler. The long term goal is to train the automatic flare-finding code to run without the need for human validation, and thus to study tens of thousands of stars. By studying the statistical properties of flares on many M dwarfs, we will further our understanding of stellar magnetic activity and how flares are affected by the internal magnetic dynamo.

The development of drug-resistant HIV variants is an important cause of virologic failure. In order to choose effective regimens, assays for diagnosing resistance are essential. Pol gene mutations within the HIV retrovirus, which are associated with drug failure and phenotypic resistance, can be used as the assay targets. Current diagnostic assays include various genotypic and phenotypic assays, recombinant virus assays and other commercial assays. However, these assays are time consuming. To address this issue, we are applying engineering principles to convert the oligonucleotide ligation assay (OLA), developed by Frenkel et al., for point-of-care (POC) diagnostics, to significantly reduce the timeframe for diagnosing drug resistance, leading to regimen decisions. In order to detect the HIV pol gene using OLA, nucleic acid (NA) from bodily fluids need to be extracted and purified. Current extraction methods are time consuming, and require complex procedures, instrumentation, and expensive reagents unavailable in low-resource settings. We are developing novel approaches to capture NA without instrumentation through the use of stimuli-responsive polymers. These polymers are capable of responding to specific changes in their environments, such as temperature variations, resulting in a change of their physical properties; our polymer becomes cationic and aggregating. Magnetic nanoparticles (mNPs) can be utilized in conjunction with these polymers for biomolecule separation by applying a stimulus and a magnetic field. The new NA extraction strategy starts from complexing cationic stimuli-responsive polymers with NA, and then magnetically separating NA from solution via the co-aggregation with mNPs and heating (characterized using standard agarose gel protocol). This extraction method utilizes 2 reagents and takes about 20 minutes, which will reduce cost and enable POC diagnostics in low-resource settings. The extracted NA can then be amplified, tested for the presence of the mutant pol gene, and used to better diagnose HIV drug-resistance and determine patient regimens.

By detecting interesting subatomic particles, physicists can understand fundamental constituents of the natural world. In detection processes, however, unwanted particles can mingle with those which are targets of investigations, and thus in any experiment it becomes necessary to extract the data corresponding to the wanted particles from the rest of the measurement results. In my research project, I analyzed data that were known to come from neutrons and those from alphas, both of which were obtained in a subterranean detector located in eastern Canada. Specifically, I tested the efficacy of a proposed method to discriminate the two types of particles. When detected, each particle gave rise to an electrical pulse. Based on the hypothesis that the shapes of the pulses are qualitatively different for different particles, I have mathematically analyzed the pulses by performing integrals on the pulse shapes and finding the numerical difference between each pair of the pulses. As a result, I found that about only 25% of neutrons could be clearly distinguished from alphas, but the others were indistinguishable, solely on the basis of this pulse shape analysis. Since this result is not satisfying, my goal of the next phase of this project is to devise an improved method that can distinguish the particles more efficiently.