Bilingualism has been shown to have numerous cognitive benefits, ranging from improved executive function to possible protection against neurodegenerative diseases. Structurally, early childhood bilingualism correlates with expanded subcortical regions, specifically the basal ganglia (BG), an area most famously involved in functions such as motor control. In this project, we explore possible domain-general effects of infant and early childhood bilingualism. Specifically, we investigate the effect of early childhood language environments on motor skills in the form of rhythmically controlled babbling. Audio recordings were made in infants’ natural environments using the LENA system. Infants’ own utterances were captured and preprocessed. From these data, I first calculated the ratios of language use in the environment (English versus Spanish), and from these ratios, I categorized infants into monolingual English, monolingual Spanish, and bilingual groups. To determine the rhythmicity of babbling, I isolated subjects’ utterances from the audio data based on criteria that define canonical babbling (e.g., CV syllable structure where C is supraglottal, 4 or more syllables, and so on). For the purposes of this project, we defined the perceptual center as the peak intensity of each syllable and used it to determine the duration between syllables, or inter-syllable duration. The variation of syllable duration was subsequently calculated. We anticipate more rhythmic (i.e. lower variability across inter-syllable duration) babbling in bilingual subjects than in monolingual English and Spanish subjects. However, in accordance with previous findings on early childhood language development, we do not necessarily expect to see differences in whether or not infants are in the canonical babbling stage based on language group. We expect these findings to contribute to the theory of domain-general benefits of early life bilingualism through the quantification of language development milestones.

The expression of prosocial behavior holds significance across various species, and its disruption stands out as a characteristic symptom in numerous neurodevelopmental and neuropsychiatric disorders such as autism, schizophrenia, and depression. Neuronal activity in the nucleus accumbens, particularly modulated by the neurotransmitter- dopamine, plays a pivotal role in regulating reward-motivated behavior towards both food and social interaction. Although the influence of dopamine on social behavior is extensively researched, there exists a notable gap in our understanding of neuronal activity within the nucleus accumbens during social interactions. In this study, a viral vector was employed to induce the expression of a genetically encoded fluorescent calcium sensor, coupled with mini-scope imaging, to observe calcium dynamics in the nucleus accumbens. The recording of calcium dynamics occurred during an operant task where an experimental mouse pressed a lever to interact with a social partner or in separate sessions to receive a food reward. Our investigation revealed distinct subpopulations of neurons within the striatum that specifically encode food reward, as opposed to other discrete cues or actions associated with the task. The insights gained from this research contribute to a more comprehensive understanding of how signals related to general reward-motivated behavior and prosocial behavior may contribute to disruptions observed in social behavior, particularly in disorders characterized by impaired prosocial behavior.

As anthropogenic causes of species declines (i.e. habitat loss, climate change) worsen, many carnivoran species are threatened with extinction. These extinctions could also decrease the overall diversity of carnivorans, which have evolved diets as disparate as herbivorous pandas and carnivorous lions, and body shapes as different as elongate mustelids and robust bears. Because phylogeny and dietary ecology influence the evolution of skull shape, we used skull shape to quantify diversity in carnivorans. In this study, I will investigate whether carnivoran species at high risk of extinction have similar skull shapes to one another and whether their average skull shapes are distinct from the average skull shapes of species with other conservation statuses (i.e., least concern). If this is true, specific skull shapes could eventually cease to exist, decreasing skull diversity in carnivorans. I used 3D geometric morphometrics and phylogenetic principal component analysis to quantify skull shape diversity, and I used the International Union for Conservation of Nature (IUCN) Red List of Threatened Species to determine each species’ conservation status. In preliminary analyses, a phylogenetic ANOVA and pairwise comparisons of skull shape against conservation status indicated that there are significant differences in average skull shape among conservation statuses, specifically between vulnerable species and both least concern and near threatened species. This study will reveal new insights into the conservation of carnivorans and carnivoran morphological diversity.

Sexual dimorphism describes the distinct characteristics between males and females of the same species. These different traits can be traced back to many external and internal factors. Here, we investigated how temperature and habitat influenced the evolution of sexual dimorphism in the mandible of mustelids. Mustelids are a great clade to study sexual dimorphism because of their mandibular diversity that is associated with their diverse diets, behavior, and ecological niches. We test two hypotheses: first, we examined if mustelids in high temperature environments exhibit higher degrees of dimorphism in their mandibles compared to those in lower temperature environments. Second, we test how the degree in dimorphism varies among mustelids inhabiting different habitats. To test our hypotheses, we quantified sexual dimorphism of mandibular size and shape using 3D geometric morphometrics. We then used phylogenetic ANOVAs to test how habitats influenced the degree of mandibular dimorphism and phylogenetic regressions to test how temperature influences the degree of mandibular dimorphism. We predict that mustelids in high temperature environments will exhibit a higher degree of sexual dimorphism than those in low temperature environments. Higher temperatures could correspond to a limited amount of resources which could lead to interspecies competition for food resources. As males and females use different strategies to survive, sexual dimorphism in mandibles size may occur. In our habitat analyses, we predict that mustelids in deserts will exhibit a higher degree of sexual dimorphism compared to those found in other habitats due to the same factors of resource availability and competition. Deserts tend to have scarce resources compared to forests and we believe that sexual dimorphism will reduce this competition. This research is impactful because as climate change is increasing temperatures all over the world, we should be aware of how that is directly affecting species.

Quadrupedal locomotion in leporids (rabbits and hares) relies on a unique appendicular skeleton that facilitates a propulsive gait. Long hindlimbs compared to forelimbs supports the pushing followed by a tucking motion that is characteristic of a rabbit hop. Leporids inhabit a range of habitats leading to a variety of specified anatomical needs to support propulsive gaits on different terrains. In this study, we investigated how habitat type influences the morphological diversity of the appendicular skeleton in rabbits and hares. We quantified the appendicular skeleton of different species using caliper measurements from osteological specimens held at the Burke Museum and other natural history museums. We then used phylogenetic comparative methods to test three predictions on how different habitats influenced the evolution of these skeletal traits . First, leporids inhabiting deserts or wetlands will exhibit adaptations in the limb bones that facilitate greater muscle attachment because jumping on softer ground requires more propulsive force than jumping on solid ground. Second, leporids inhabiting open grassile environments will have longer legs to support quickly escaping predators in search of limited vegetation for hiding. Third, more closely related leporids will exhibit more similar hind limb morphologies due to having a more recent common ancestor. Overall, this study elucidates the evolution of appendicular skeleton of leporids and informs us of a possible method to predict how the morphology of limbs evolve based on habitat type and close ancestry in mammals.

Body shape provides useful insight into the diversity and evolution of vertebrate body plans. Previous research revealed that body shape scales with body size in carnivoran mammals, but whether this trend occurs in other mammals remains unknown. Our goal is to examine the relationship between body shape and body size in Leporidae, which consists of rabbits and hares. Leporids exhibit a unique gradient of locomotion types between the smallest rabbits that are primarily saltatorial and the larger hares that are primarily cursorial. We quantified body shape using the head-body elongation ratio and body size using the geometric mean of all measured traits from osteological specimens held at the Burke Museum and other natural history museums. We tested the allometric relationship between body shape and size using a phylogenetic regression and also tested if these allometric relationships differed between saltatorial rabbits and cursorial hares using phylogenetic ANCOVAs. We predict that the differences in locomotory modes within the family could influence the correlation between body shape and allometry, possibly leading to different amounts of correlation in rabbits and hares. Specifically, we predict that larger body size corresponds with more elongate body shape. Elongate body shape would facilitate cursorial locomotion more common in larger leporids. More elongate and flexible bodies would allow the forelimbs to reach farther forward, enabling longer strides while running. This study informs allometric relationships of body shape and size of saltatorial and cursorial members of leporids and can lead to future research into the relationship between locomotion and body shape in other mammalian clades.

The mandible is a functionally important part of the mammalian skull. Various selective pressures shape mandibular morphology, with the impact of diet on mandibular evolution across mammals intriguing evolutionary biologists. In this study, we investigate whether diet influences mandibular evolution across a variety of primate species. The diets of primates vary greatly (e.g., omnivory, insectivory, frugivory, folivory, and gummivory) that are characterized by a range of different physical properties that include toughness, nutrient accessibility, and size. Therefore, we hypothesize that primates with different diets will have distinct mandibular morphologies, particularly traits associated with the relative length and width of the whole primate mandible as they may impact the speed and force transmission during biting. To test these hypotheses, we utilized a database of 3D scans of primate mandibles from natural history museums. We quantified the mandibular shape and size by placing landmarks and semilandmarks on digitized 3D models of primate mandibles. We then quantified primate diets by ranking the relative importance of food items found in primate species based on a literature review. We then used phylogenetic comparative methods to test the effect of dietary ranks on primate mandibular size and shape. We predict that different dietary categories and ranking of food items will influence mandibular evolution. For instance, primates feeding on gums by gouging or scraping would require a higher mechanical advantage, resulting in a relatively shorter and more robust mandible. Our research could be helpful for future primate and mammal studies focusing on the selective pressures on the evolution of the mandible.

Autism Spectrum Disorder (ASD) is a prevalent neurodevelopmental condition affecting approximately 1% of the world population. Characterized by impaired social interactions, the precise etiology of ASD remains elusive, but emerging research suggests deficits in the mesostriatal pathway may contribute to deficits in social reward processing. In order to better understand the role of the mesostriatal pathway in social reward processing, I performed in vivo microscopy coupled with viral delivery of genetically encoded fluorescent sensors to record nucleus accumbens (NAc) neuronal ensemble activity during an operant task in which mice were trained to press a lever in order to gain access to a social partner mouse. I found distinct populations of neurons that were more active or less active during the social reward task at discrete time points. Understanding the neurobiological mechanisms involved in social reward may pave the way for novel medications and treatments for ASD.

Primates are known to have relatively larger brains for their body sizes (i.e., encephalization) when compared to other mammals. Previous studies have examined the relationship between food scarcity and endocast volumes in Old World Monkeys, specifically looking at the Cognitive Buffer Hypothesis –which states that greater rates of encephalization are correlated to living in more variable environments. In this study, we examine whether and how the cognitive requirements of social interactions (Social Brain Hypothesis, SBH) and investment from parents (Parental Investment Hypothesis, PIH) influence the evolution of encephalization in primates at the macroevolutionary scale. Social interactions stimulate the brain, causing it to produce more neural connections and as a result, greater encephalization. A higher degree of parental investment renders a safer space for infants to mature and their brain to develop, providing the capability of reaching larger sizes. To test these hypotheses, we first quantified encephalization as the ratio of endocranial volume to estimated body mass. Our data was collected using CT scans of primate crania from the Natural History Museum, London, United Kingdom. We quantified endocranial volume in 3D Slicer. We then used phylogenetic comparative methods to test how encephalization relates to social factors such as group size, social complexity, gestation length, and litter size across various primate species. Group size and social complexity serves to quantify the social interaction variable stipulated in the SBH, while gestation length and litter size correspond to determining the scale of parental investment per offspring. If the SBH and PIH are supported, then each of the four factors will exhibit a positive relationship with encephalization. Our findings will elucidate how social interactions and parental investment influence the evolution of brain sizes in primates.

Carnivorans display a wide array of adaptations in their mandibular morphology, potentially influenced by various evolutionary factors like sexual selection and niche divergence. The Mustelidae family encompasses a diverse range of carnivorous mammals such as otters, badgers, and ferrets. Although mustelids are predominantly carnivorous, there is significant variability in dietary habits, with weasels exhibiting strictly carnivorous behaviors, badgers tending towards omnivory, and otters adopting piscivorous diets. This study explores the relationship between ecomorphological differences in mandibular shape and different dietary groups within the Mustelidae family. We will investigate variations in the breadth and length of the coronoid process, a mandibular element associated with biting performance. We hypothesize that carnivorous mustelids will exhibit shorter mandibles and larger coronoid processes compared to their omnivorous and insectivorous counterparts within the family. We predict these morphological adaptations aid carnivorous species by enhancing bite force and optimizing prey processing efficiency. We will use geometric morphometrics on mandible scans from various mustelid species with different dietary habits using 3D Slicer. Additionally, shape variation and allometry will be assessed using phylogenetic regression and phylogenetic ANOVAs to determine the effectiveness of diet as a predictor of mandibular feature variation within the Mustelidae family. This study will reveal new insights on how diet influences mandibular shape and size in mustelids, which can be applied to all carnivoran families. 

Traumatic spinal cord injury (tSCI) is a devastating condition that causes sensory and motor dysfunction and permanently impairs normal life. Spasticity is one of the most common complications associated with tSCI that limits independent functional abilities. Spasticity is defined as a velocity-dependent increase in muscle tone, in response to passive movement and it is accompanied by pain and stiffness. Unfortunately, current treatments provide only transient and often incomplete relief of spasticity and individuals often experience long-term adverse effects. Through a collaborative project between three labs, we aim to develop a durable non-invasive electrical stimulation treatment to alleviate spasticity. I participated in preparing the model of spasticity by performing spinal surgeries on the cervical spine of rats. To evaluate spasticity, we studied the loss of Rate-Dependent Depression (RDD) of the H-reflex which is considered the electrophysiological hallmark of spasticity. To do so, I fabricated an electrode nerve cuff that was implanted on the median nerve of the rodent’s forearm to study the H-reflex of the affected muscle in the rat’s forelimb. I then recorded and analyzed the temporal development and change of spasticity. H-reflex results validated the spasticity model by showing RDD reduction in injured rats compared to the uninjured rats. The developed treatment shows promising modulation of the H-reflex and recovery of RDD in injured animals. Additionally, to measure velocity-dependent muscle tone, we developed a robotic device that passively moves the rodent’s forearm at different velocities. Employing this robotic behavioral assessment allows me to objectively assess the effect of stimulation on spasticity in the rodent forelimb. Obtained data reveals the muscle resistance to be three times higher in the injured rodent. This novel therapeutic stimulation protocol could potentially be used for clinical use as a non-invasive therapy, to help patients with spasticity in the hand after suffering from cervical tSCI.

Prosocial behavior is important to many species and its disruption is a hallmark symptom of many diseases and disorders such as autism. Previous research has shown that the mesostriatal network, which consists in part of neurons located in the midbrain that make the neurotransmitter dopamine and release it downstream in the nucleus accumbens, plays an important role in prosocial behavior. Dopamine neurons express the potassium ion channel Kv7.3 and mutant variants of Kv7.3 have been identified in individuals with autism spectrum disorder (ASD). Here we investigate how the Kv7.3-R2C variant found in ASD patients impacts social behavior and dopamine release in mice. We use viral strategies to express human Kv7.3-R2C in mouse dopamine neurons and a genetically encoded dopamine sensor (dLight1.3) in the nucleus accumbens during a social operant task. We found that while Kv7.3-R2C expression decreased social reward in an operant task rewarded with social behavior, dopamine release was similar between groups. Findings from this study help improve our understanding of how deficits in the mesostriatal pathway may lead to decreased social interaction in patients with ASD.

As our relationship with public space continues to grow, pedestrianization remains an important tool for reclaiming our space for public social function. Pedestrianization of The Ave is both academically and statistically supported, yet there remains little movement in its favor. Through the lens of placemaking, this project examines the best practices for campaigning the pedestrianization of The Ave in a way that fosters community ownership. Incorporating insight from historical reviews and stakeholder surveys, this research identifies preferred engagement strategies for community stakeholders. Utilizing these findings this research conducts a pilot study and creative visioning that centers community culture. This will result in concepts of a pedestrianization that will best gain public support and feelings of community ownership. These strategies and materials will be compiled as a “campaign” that has the potential to be implemented in the near future. As community planning in the University District seems to be very disconnected from its stakeholders, this project is rooted in community empowerment, seeking to connect people to systems.

This study presents a design research project to create high-fidelity prototypes for culturally inclusive and responsible Indigenous e-publications, specifically targeting the Cherokee community. The initiative addresses the issue of knowledge transmission, which has traditionally relied on oral traditions, by leveraging digital platforms to record and organize traditional ecological knowledge. Using Cherokee Earth Dwellers (Teuton & Shade Family, UW Press, 2023), a comprehensive book on Cherokee culture, as a primary source, the project integrates audio and video with text from the print book to craft a multimodal educational resource. The methodology is grounded in 10 usability heuristics and participatory design principles, involving members from the Cherokee community in the design process to ensure the final e-publication meets their needs and expectations. Drawing on previous research in Indigenous studies, co-design workshops, participatory sciences, and human-computer interaction, the project aims to produce an interactive e-publication as a vital resource for Cherokee educators and youth, enhancing access to Cherokee culture for educational purposes through digital mediums, thus fostering language revitalization and cultural education. Anticipated outcomes include design guidelines for research towards Culturally-inclusive, Relational and Responsible web design.

Science is rapidly evolving, yet its advances do not enter classrooms at the same rate. Systems Education Experiences (SEE) is a program in the Baliga Lab at the Institute for Systems Biology (ISB) that accelerates the transfer of scientific knowledge and practices to classrooms. One active area of Baliga Lab research is elucidating the level of resilience organisms have, when faced with complex environmental changes. My role is to design laboratory experiments that investigate this with the model organism Halobacterium salinarum (Halo) and to connect this to broader rules governing natural systems for use in high school classrooms. My first experiment probes the resiliency of Halo with the introduction of a combination of stressors (salt and hydrogen peroxide) and its recovery after population collapse. The second measures the long term phenotypic changes in the population. I wanted to see if after being exposed to a new environment if there was an advantage to having gas vesicles and if it is an irreversible trait that allows Halo to be resilient across a variety of environmental conditions. This relates to broadly applicable rules governing resilience across many systems. This project serves as a model for how all organisms respond to stress. Combinations of stressors in human lives can make us less resilient. However, strategies to quickly prepare, respond, and react can improve outcomes for individuals and the overall population. This project connects to a goal of K-12 science education which is to not just teach academic concepts but to equip students with knowledge that can be applied to all parts of life. Our knowledge on the mechanisms that control how organisms respond to stress is extremely limited. By understanding the biological stress response we can promote resilience in the earth's most vulnerable systems in the wake of climate change.

The northeastern quadrant of Washington State is an area of vast public lands. It includes 2-3 National Forests, three State Forests, three Indian Reservations, five Wildlife Areas, and 28 Sno-Parks that contain a wide variety of recreational amenities, including kayaking, rafting, horseback riding, snowshoeing, skiing, camping, and backpacking, among others. This area is also part of the Okanogan Dry Forest and Canadian Rockies Mountains ecoregions, which are characterized by dense coniferous forests that are easily ignitable. As a result, the region is regularly impacted by devastating wildfires, which are accompanied by heavy smoke and pose significant threats to local air quality, small town economies, and natural resources. The purpose of this project is to understand how smoke and fire impact two important resources serving tourists in the area: outdoor recreational amenities, and the production of apples and wine. To investigate these impacts, I reviewed data on recent fires that caused damage to orchard and vineyard land, tribal land, recreational land, and private real estate, looking at the cost of this damage in terms of lives and property lost and the particular impacts of smoke hazards. This data was augmented with interviews of local real estate agents, business owners, and members of the Washington State Department of Natural Resources. The final results I'm expecting from this research is on how recreational amenties are impacted by mega-fires that causes devestating damage towards the forest, recreation amenties, local tribes, people lives,property, public health and the community. By doing this reserch it help me get better understanding how we should managed fire on recreational areas in the Okanogan Highlands area by following proper fire suppression tactics and resources. The results of this project help us better understand the growing effects of fire and smoke on this region in general, and on recreational and tourist activity in particular.

Joubert syndrome (JS) is a rare, congenital neurodevelopmental condition diagnosed by the appearance of the “molar tooth sign” on axial brain magnetic imaging (MRI). Patients typically display hypotonia, abnormal eye movements, and ataxia. Substantial progress has been made on identifying the genetic causes of JS, which typically displays recessive inheritance. Nonetheless, the cause still cannot be identified in ~27% of our cohort of JS-affected families and the contribution of causal variants that impact RNA splicing remains unknown. Canonical splice variants impact RNA splicing by disrupting the splice site directly, whereas noncanonical splice variants affect it through alternative mechanisms, which must be validated by RNA analysis. Our goal is to evaluate the role of noncanonical splice variants in the pathogenesis of JS. We previously identified genetic causes in 582 of 714 families with JS. To identify additional causes, we used SpliceAI, a deep learning-based tool to identify variants with predicted splicing effects (SpliceAI score >0.5) for functional validation. We extracted RNA from patient cell lines then used polymerase chain reaction (PCR) and evaluated amplicons using gel electrophoresis and Sanger sequencing. Five families with candidate noncanonical splice variants that may confirm their genetic cause provided skin biopsies for further splice analysis. We confirmed the pathogenicity of three of these variants by demonstrating abnormal splicing in JS genes, AHI1 and MKS1, bringing the total contribution of aberrant splicing up to 77/714 families. The final two variants did not render conclusive results after 10+ attempts of PCR-based assays and may therefore be candidates for other methods of investigation such as mini-gene assays or long-read sequencing. By extrapolation from our data in JS, splice variants may contribute ≥11% to the genetic causes of conditions. A precise genetic diagnosis informs prognosis, avoids unnecessary work-up, guides monitoring for associated complications, and opens the door to gene-specific treatments.

As the climate changes, we are beginning to see the impacts on a global scale. In order to understand how our landscapes will change with future warming, we can look back to see how landscapes were impacted by past warm, variable climates. This project looks to understand how climate variability in the Middle Miocene is expressed in terrestrial sedimentary records. Using X-ray fluorescence (XRF) analysis, we created a high-resolution elemental geochemical profile of sediment samples from Clarkia, ID (~16 Ma). From XRF, elemental concentrations for a host of elements, including Ca, Fe, K, Mn, Sr, Ti, Zn, and Zr, were calculated. Some elements, notably Ca, showed long-term trends but also sections of shorter-term cyclic variability. It is possible that this variability reflects changes in basin weathering rates of Ca-bearing minerals as a function of climate change occurring on timescales of tens to hundreds of thousands of years. Alternatively, Ca concentrations may reflect changes to precipitation of Ca-bearing minerals within the ancient lake, responding to algal productivity. These hypotheses are tested using X-ray diffraction (XRD) to identify minerals and their crystalline structures as well as characterizing the elemental trends from an additional site, Clarkia’s P-40. Understanding the depositional history of the Clarkia lakebeds aids our understanding in how climate impacts Miocene landscapes.