University Of Massachusetts Amherst

NSF Awards · FY 2024 · 2024-07

Quantum information science (QIS), at the intersection of physics, mathematics, and computer science, is pioneering new frontiers in computing and communication, promising unprecedented capabilities. However, the multidisciplinary complexity of QIS demands expert knowledge in diverse areas, from cutting-edge experimental physics to theoretical computer science. This project develops an open-source ecosystem of modeling tools for quantum hardware that bridges the gap between these extremes. The project novelties are founded upon creating user-friendly tools that allow researchers to model quantum systems without mastering a vast array of underlying techniques. Among the project impacts are enabling a network scientist to test the performance of a networking protocol on realistic hardware models without having intricate knowledge of quantum simulation algorithms or, conversely, a hardware engineer to optimize their hardware sitting at the bottom of a full-stack network application modeled for them. As a whole, these tools will democratize access to quantum technology, foster innovation, and accelerate the growth of QIS. The project revolves around the development of a symbolic algebra system for backend-agnostic modeling of quantum systems, capable of marshaling multiple backend simulators for different formalisms, seamlessly translating symbolic representations into numerics. The most appropriate simulation methods is automatically selected for each scenario. The investigators employ recent advances in scientific machine learning and auto-differentiation (even over discrete random functions) to provide the necessary foundation for constructing simulator systems of unprecedented sophistication. Emphasizing the importance of co-design, the project incorporates cutting-edge optimization and digital twin tooling, allowing for holistic optimization of quantum hardware and network dynamics. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NSF Awards · FY 2024 · 2024-07

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Richard Vachet, Professor Vincent Rotello, and their groups at the University of Massachusetts Amherst are developing new methods to measure polymeric nanomaterials in biological tissues. Nanomaterials are used in a wide range of products and technologies, including consumer goods, industrial applications, and medicine. To properly understand the biological consequences of such nanomaterials, new methods are needed that can track their distribution and biochemical effects, especially for newly emerging precision therapies based on RNA. Professors Vachet and Rotello are developing new imaging approaches that can simultaneously reveal the locations and effects of polymeric nanomaterials in tissues. The proposed imaging methods rely on new chemical tagging strategies and sophisticated laser-based mass spectrometry tools that will enable nanomaterials to be quantified in tissues. The ability to quantify these nanomaterials and the therapies that they carry has the potential to help guide the design of safer and more effective therapeutic delivery systems. In addition, new computational tools will be developed that may be extendible to other applications that require high resolution and site-specific molecular information. A diverse group of undergraduate and graduate students will be involved in the project, and these students will obtain training in cutting-edge mass spectrometry and nanotechnology. This collaborative study from the Vachet and Rotello groups will develop new molecular mass tags that when combined with laser ablation inductively-coupled plasma mass spectrometry (LA-ICP MS) and matrix-assisted laser desorption/ionization MS (MALDI MS) is expected to yield quantitative spatial information about nanomaterials, their therapeutic cargo, and their biochemical effects in tissues. Moreover, these molecular tags will enable a multiplexed imaging approach that allows multiple polymeric nanomaterial designs to be imaged simultaneously in mice, facilitating therapeutic optimization while avoiding overuse of mice. The new molecular tagging strategies will also facilitate the computational fusion of the mass spectrometry methods with fluorescence imaging methods, resulting in high-resolution, information-rich data that will provide unprecedented insight into the fate and effect of nanomaterial therapeutic delivery systems. The value of these new methods will be evaluated by using them to quantify distribution parameters for nanomaterial-enabled siRNA therapies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NSF Awards · FY 2024 · 2024-07

The goal of this project is to investigate Fluid-Structure Interactions (FSI) between a flexible structure and inertial-viscoelastic flow, by conducting a series of numerical simulations and synergistic experiments. Since the majority of the structures in FSI systems found in nature and in industry are in fact flexible, it is critical to understand the influence of viscoelasticity on flexible structures such as flags, sheets and cantilevered beams. The broader impacts of this project will extend to a possible new transformative suppression method for flow-induced oscillations of a host of different FSI systems used extensively in industry. The findings of this research will be disseminated at different levels by integrating the proposed research into the outreach programs for K-12 students and teachers, incorporating this research into undergraduate and graduate classes, increasing research opportunities for undergraduate and graduate students, and through a gallery exhibition based on the results of this project. This project will have a transformative impact on our understanding of FSI systems at simultaneously high Reynolds numbers and high Weissenberg numbers where the structures are flexible. A number of important canonical cases will be considered including the cases where the structure is a flexible sheet placed parallel to the incoming flow (the flapping flag problem), where wall-mounted flexible structures are placed in flow (terrestrial and aquatic plants), and where the structure with a circular or square cross section is placed in cross flow (VIV and galloping). The numerical simulations of these systems will be conducted in OpenFOAM by modifying the source code to account for the components of the polymeric stress tensor associated with viscoelastic flows, and by updating the OpenFOAM adapter which is used as a liaison between OpenFOAM and preCICE coupling library. The FENE-P constitutive model and its associated solvers will be introduced by integrating RheoTool into the computational environment. The viscoelasticity of the fluid will be systematically increased by modifying the rheological properties of the constitutive model to observe the influence of fluid elasticity on vortex formation and structural dynamics. In the experiments, the flexible structure’s motion will be recorded optically using a high-speed camera that will record the response of the entire structure. The flow field behavior will be studied using Particle Image Velocimetry. Through selective local injection of viscoelastic fluid ahead of these flexible structures, we will investigate a technique for suppressing or possibly enhancing the flow-induced motion of these flexible structures in real world applications. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2025 · 2024-07

Project Summary Abnormal nuclear shape is a diagnostic marker of disease progression and contributes to cellular dysfunction. Perturbations to major nuclear rigidity components, chromatin or lamins, results in a weaker nucleus that is deformed by external and/or internal forces to produce nuclear blebs and ruptures causing cellular dysfunction. Previously, we revealed that, independent of lamins, chromatin compaction via histone modification state (eu- /heterochromatin) determines nuclear mechanics, shape, rupture, and function. Changes in heterochromatin subtypes, transcription activity, and mitotic segregation are well-known to occur in diseases presenting abnormal nuclear morphology. The overall goal of my research program is to identify how nuclear rigidity, shape, and rupture are controlled to maintain proper genomic and cellular function. The central hypothesis is that chromatin rigidity via heterochromatin subtypes, chromatin motion via transcription activity, and chromatin organization during mitotic segregation drive the mechanisms underlying nuclear physical properties. This hypothesis addresses three knowledge gaps. First, what are the specific components that provide heterochromatin rigidity? Heterochromatin is composed of subtypes, constitutive vs. facultative, and their specific histone modifications that facilitate chromatin compaction and may have distinct impacts on rigidity. Second, is there another contributor to nuclear deformation? While actin compression and contraction provide an external nuclear deformation, transcription-driven chromatin motion represents a potential new internal nuclear deformation. Third, is there an alternative mechanism to cause abnormal nuclear shape? Mitotic segregation error represents a potential new mechanism of abnormal nuclear shape and rupture through chromatin disorganization during nuclear reformation. We are qualified to determine nuclear rigidity using our lab’s innovative micromanipulation single nucleus force-extension technique that has the unique ability to separate chromatin and lamin rigidity contributions. We will couple this with measuring nuclear shape/blebbing and rupture through tracking NLS-GFP via live cell microscopy. Our preliminary data show that heterochromatin histone modifications have distinct effects on nuclear shape while transcription inhibition suppresses nuclear blebbing and rupture independent of nuclear rigidity. Our preliminary data also show that miotic segregation errors cause both abnormal nuclear morphology and rupture. This work will provide a deeper understanding of the established interphase blebbing pathway by determining heterochromatin subtypes’ distinct physical contributions and a new contributor in transcription-driven deformation. This proposal will also identify a new mechanism for abnormal shape via mitotic segregation error. Identifying the role of heterochromatin subtypes, transcription activity, and mitotic segregation error to nuclear rigidity, shape, and rupture will enlighten the underlying causes of abnormal nuclear morphology and provide therapeutic targets for restoring nuclear shape and function in human disease.

NSF Awards · FY 2024 · 2024-07

Understanding how animals respond to temperature change is of increasing importance as climates become more variable and extreme weather events increase in frequency. Yet much debate exists about whether species will be able to respond to global change – and if so, how will they do it? Many animals living in temperate climates, like those across the northern U.S., already harbor the capacity to cope with temperature changes: they do so every time the seasons turn, and they even do so on shorter time scales, like from day to night. The birds at the local bird feeder are a great example of this. On a cold winter day, they turn up their internal engines to produce more heat, and they visit the feeder more often to fuel their engines. When the temperature warms up, they turn those internal heaters down to save energy. The ability to make these changes to their physiology may be especially beneficial when the weather turns rapidly, like when a winter storm hits, for example. But are some individuals better at changing this internal physiology than others? And if so, how do they do this? And what does this mean for their ability to withstand temperature changes? Using automated birdfeeders to track birds across the winter season, this project will make connections between an individual’s ability to change its physiology in response to temperature, its genetics, and its survival. These findings will then be incorporated into the National Audubon Society’s models with the goal of improving predicted responses to climatic change and informing conservation action. Accurately documenting the capacity for natural populations to respond to environmental variation is a core challenge of biology. When environmental fluctuations occur on short temporal scales relative to the lifetime of an individual, the ability to reversibly modify trait values can allow individuals to optimally match their phenotype to the environment. Determining the causes and consequences of variation in this phenotypic flexibility is critical to our understanding of individuals’ capacity to cope with accelerating global change and for realistic projections of species’ viabilities in the future. This pursuit necessarily requires linking genotype to phenotype to fitness, though such connections remain rare. Existing empirical evidence demonstrates that temperature variability drives spatial patterns of variation in physiological flexibility across the range of a small songbird, the Dark-eyed Junco (Junco hyemalis). This project will now quantify: (1) patterns of variation in junco physiological flexibility across a thermal variability gradient; (2) energetic costs of flexible phenotypic changes; (3) selection on physiological flexibility in the wild; and (4) spatial and temporal changes in allele frequencies for loci associated with physiological flexibility. These aims will be achieved using field mark-resight studies, repeated physiological assays, controlled laboratory experiments, and whole-genome resequencing to quantify the costs and benefits of flexibility and determine flexibility’s potential to evolve in response to environmental change. Taken together, this work will identify the adaptive benefit of junco physiological flexibility and provide a mechanistic understanding of the ability of natural populations to respond to global change. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2026 · 2024-07

PROJECT SUMMARY This proposal is responsive to NIA solicitation PAR-22-093/NOT-AG-21-048 for projects involving the development of digital technology for the early detection of Alzheimer’s disease. It is motivated by the need for novel low-cost and noninvasive digital biomarkers for Alzheimer’s disease that can flag early changes in at-risk individuals before cognitive symptoms surface. Changes in sleep patterns have been linked to a future dementia diagnosis in older adults. These changes can be tracked in a passive and unobtrusive way using a wide variety of low-cost consumer wearables. Our overarching objective is to deploy cutting-edge wearables for sleep, heart rate, and activity monitoring in an older adult cohort with elevated genetic susceptibility to Alzheimer’s disease from the Mass General Brigham Biobank in order to quantitatively evaluate each device, to develop artificial intelligence (AI) approaches for digital phenotyping of Alzheimer’s disease, and to perform hypothesis-driven statistical modeling for understanding the interplay between Alzheimer’s genetic risk, sleep, and Alzheimer’s pathophysiology. To capture early changes, this project will rely on a unique pool of older adult participants who have elevated polygenic risk of Alzheimer’s disease but are cognitively normal at baseline. We will acquire (i) electroencephalography (EEG) data using an EEG headband, (ii) heart rate, accelerometry, blood oxygenation, and temperature data using a smartwatch, (iii) heart rate variability data using a smart ring, (iv) plasma biomarker measures for amyloid, tau, and neurodegeneration (ATN), and (v) cognitive scores. The data will be collected longitudinally at two timepoints with a gap of 2-3 years from N=260 elderly participants at the highest genetic risk for Alzheimer’s disease and 40 low-risk controls based on their polygenic risk scores. We will rigorously validate all three wearables by benchmarking each against polysomnography (PSG), which is the established gold standard for sleep monitoring, and report their accuracies at measuring sleep and heart rate features. We will develop an AI model known as a transformer to learn composite features from EEG, heart rate, and accelerometry data that predict Alzheimer’s pathophysiology. Finally, we will use this data to test the hypothesis that pathway-specific polygenic risk for Alzheimer’s disease and sleep disruption associates or interacts with distinct sleep features to predict Alzheimer’s pathophysiological or cognitive endpoints. The project features an interdisciplinary investigative team with expertise in AI, human wearables studies, sleep genetics, sleep EEG quantitative analysis, preclinical Alzheimer’s neurology, PSG scoring, fluid biomarkers for Alzheimer’s disease, and biostatistics. We do not propose this technology as a substitute for lab-based approaches to detect Alzheimer’s pathophysiology or cognitive change. We envision that the combination of an unobtrusive wearable device, genetic risk assessment, and AI tools for wearables-based Alzheimer’s digital phenotyping could identify/flag at-risk individuals in the general population for clinical follow-up. Thus, this project could thus have broad clinical impact in the Alzheimer’s field.

NIH Research Projects · FY 2025 · 2024-06

PROJECT SUMMARY This proposal is responsive to NIA solicitation PAR-22-094/NOT-AG-21-036 for projects involving the development of novel approaches to diagnose and study Alzheimer's Disease and Related Dementias (ADRD) with an emphasis on the need for biomarkers for dementia types other than Alzheimer’s disease in the ADRD spectrum, including frontotemporal dementia (FTD). In this project, we will leverage our MPI team’s expertise with MR-based accurate thalamic nuclei segmentation (TNS) and PET super-resolution (SR) to develop thalamic-nuclei-based measures of atrophy, connectivity, and hypometabolism as possible FTD biomarker candidates. FTD, the second most common cause of dementia in adults under 65 years of age after AD, is clinically, genetically, and pathologically heterogeneous. There is an urgent need for antemortem biomarkers for FTD that are sensitive across its different subtypes. Thalamic atrophy is a common feature of early disease pathogenesis for all FTD subtypes. We propose to develop an integrated MR and PET imaging framework for deriving quantitative imaging measures from the thalamic nuclei and validate in secondary-use multimodal imaging data. Our dataset will include both sporadic FTD and familial C9orf72+ FTD patients. We will use a more advanced variant of our TNS approach which, as per our preliminary results from an Alzheimer’s disease cohort, leads to significantly better discrimination between healthy and impaired groups than FreeSurfer’s Bayesian segmentation method, which is one of the current state-of-the-art TNS methods. We will develop and validate an SR PET platform that uses MR-based thalamic nuclei labels as additional inputs to the model to enhance thalamic nuclei contrast. To assess the clinical utility of the thalamic-nuclei-derived multimodal biomarker set for atrophy, connectivity, and hypometabolism, we will compute receiver operating characteristic curves for FTD subtype groups vs. cognitively normal subjects. We will also characterize our multimodal biomarker by establishing a temporal ordering via event-based modeling. To assess the sensitivity of our nuclei-derived atrophy and connectivity biomarkers, we will conduct cross-sectional spatiotemporal analyses in a larger cohort with MR-only data that can reveal the age of divergence of each biomarker in a diseased vs. control group. Finally, we will conduct longitudinal analyses to predict changes in clinical dementia rating and its behavioral and language subscores from changes in atrophy and connectivity measures from the thalamic nuclei. Unlike Alzheimer’s disease, for which the ATN research framework is well-developed for biomarker-based characterization of dementia, there is a pressing need for imaging biomarkers for FTD, which this project can address. We therefore envision that our proposed research will have high clinical impact on FTD characterization and could play a role in FTD drug development efforts.

NIH Research Projects · FY 2025 · 2024-05

PROJECT SUMMARY Cognition declines with age, and severe and prolonged use of alcohol (alcohol use disorder, AUD) could be accelerating and worsening these aging processes. The timing and magnitude of cognitive dysfunction correlates with the emergence of white matter loss in frontal and temporal lobes (frontotemporal intercortical myelinated axons), suggesting that myelin deficits may underlie these cognitive changes. However, the direct functional contribution these brain changes may (or may not) have on reduced cognitive abilities after alcohol in aged individuals is unknown, as are the underlying mechanisms. Thus, more direct empirical testing is greatly needed. The experiments of this proposal are designed to probe the mechanistic overlap of AUD and aging on white matter tracks by drilling down specifically on mechanisms involving myelinating cells of the central nervous system (oligodendrocytes, OLs). We use transgenic technology and cell fate mapping to track the birth and development of oligodendroglial populations involved in myelinating frontotemporal axons to learn about the cellular processes that lead to impaired remyelination capacity after alcohol exposure in older mice. We posit that in aged animals, alcohol induces delays in OL differentiation that prevents proper myelin ensheathment of intracortical axons and advances cognitive decline. Our experimental design tackles these research questions with precision, scaling from molecular—to phenotypic—to behavior. Manipulating these cellular processes allows for testing the direct link between myelin formation and cognitive functioning. Our comprehensive assessment of cognitive abilities as a function of age and sex also fills a critical gap by dissecting differential sensitivities that are clinically important for consideration. These essential first steps provide a solid foundation for a larger project on aging and alcohol interactions and whether reversal is possible with therapeutic targeting of cellular development in humans, opening new avenues for discovery of treatment strategies for alcohol and age- related cognitive dysfunction and dementia.

NIH Research Projects · FY 2026 · 2024-04

Project Summary/Abstract Hearing loss is the third most common chronic health condition affecting 37 million Americans. Untreated hearing loss is estimated to cost the United States two billion dollars in additional healthcare expenditure. Hearing aids are the primary treatment option for hearing loss, however only 30% of individuals who could benefit from a hearing aid use them. In an effort to improve the rates of hearing aid use, the Food and Drug Administration approved the sale of Over-the-Counter (OTC) Hearing Aids in October 2022. There is great expectation that OTC hearing aids will significantly improve the uptake of hearing aids among OTC hearing aid target populations. Unfortunately, only 16% of over 1000 consumers surveyed by our lab would consider using OTC hearing aids. One of the barriers that may hinder OTC hearing aid adoption is the inability to self- determine candidacy. Presently, the product information label (PIL) for OTC hearing aids is the only consumer- focused tool intended to help an individual self-determine if they an appropriate user. Unfortunately, preliminary work from our lab has shown that consumers do not attend to the PIL in its entirety, and it is often only made available to the consumer after purchase. Thus, we propose to supplement the PIL by developing an interactive mobile (m)health decision aid (HearEase) that will help guide consumers through the self-candidacy process for OTC hearing aids prior to their purchase. However, the development of HearEase will be critically dependent on thoughtful design and implementation. Thus, we will work with key stakeholders (manufacturers and retailers) to create an implementation plan that will ensure that HearEase will be adopted and implemented by manufacturers and retailers. These overall goals will be achieved by the following aims. Aim 1: To develop an interactive mHealth decision aid (HearEase) that will help potential consumers of OTC HA to self-determine candidacy. Aim 2: To develop the implementation plan for HearEase.

NIH Research Projects · FY 2026 · 2024-04

PROJECT SUMMARY/ABSTRACT To make full impact of organoid technology, it is key to build organoid disease models with regionalized and interconnected compartments. Such regional specificity and the associated inter-region communication are essential calibers for evaluating functional maturation and structural integrity of the organoid models. Besides the considerations of culturing yield and structural complexity, it is technically non-trivial to probe the functional connectivity and pathways among sub-regions of 3D-structured organoids with high spatiotemporal resolutions. While 3D electrophysiology platforms are suited for recording intact organoid activities, they are yet to combine with high-resolution, cell-type-specific circuit manipulation to fully examine interregional circuits under definitive stimulus patterns and substantiate the analysis of functional connectivity. To this end, optogenetic control over cell activity has been noted for its combined advantages of temporal precision, cell-type specificity, and bi- directionality over other ways of cell modulation. Optoelectronic probes assembled with light sources together with an MEA have emerged as a powerful tool to optogenetically modulate the cell activity in a variety of settings. In this project, we will tailor design one high-precision optogenetic probing system, based on monolithic integration of close-packed dual-color LEDs and MEA, to dissect inter-region communication within regionalized organoid disease models. Leveraging our efforts on optoelectronic probes and organoid patterning methods, we will investigate if our probes with scalable pixel counts/pitches could advance organoid disease modeling via cellular-precision, tissue-level optogenetic electrophysiology. The proposed work will establish a new set of organoid probing systems that enable cellular resolution bi- directional optogenetic control of inter-region circuits and electrophysiology across multiple regions and depths of the organoids, which cannot be achieved by existing RNA sequencing, 3D organoid electro-physiology, or cell imaging methods. Such capabilities will deepen our understandings on regional circuits, functional connectivity, and organoid disease models. Given their scalable form, these probes could also be applied to transplanted organoids, cortical spheroids, and assembloids. Moving forward, our technology may provide insight into functional maturation, developmental stages of diseases, and even tissue engineering via optogenetic control of gene expression in select regions of the organoids. In particular, this project is comprised of two research aims: Aim 1. Bi-directional optogenetic probing of region-specific, depth-dependent organoid dynamics. We will develop the probe structures with the LED/MEA pitches/counts tailor designed to optogenetically access depth-dependent activity in targeted regions of SCZ organoid disease models and its control group. Aim 2. Bi-directional optogenetic probing of inter-region communication within living organoids. We will develop multi-shank structured probes to access cell activities across multiple organoid regions, with the focus on identifying inter-region connectivity and pathways via bi-directional optogenetics.

NIH Research Projects · FY 2026 · 2024-02

Project Summary HIV (human immunodeficiency virus) causes the acquired immune deficiency syndrome (AIDS). HIV/AIDS is one of the most serious public health challenges in the world. Early diagnosis of HIV can improve health outcome and reduce HIV transmission effectively. Currently nucleic acid amplification tests (NAAT) and enzyme-linked immunosorbent assays (ELISA) are the common methods for HIV detection. However, they can be only performed by professionals in a central laboratory. There is an essential need for development of point- of-care (POC) tools for early HIV detection. The p24 antigen is a protein biomarker that can be used for early detection. However, current POC testing tools have a poor limit of detection (LOD) toward p24 detection, which cannot be used for testing HIV within less than two weeks of post-infection The objective of this project is to develop a paper-based lateral flow strip (PLFS) for rapid, in-field detection of the p24 antigen in finger-prick whole blood samples. A plasmon-enhanced fluorescent sensor will be developed by utilizing a hierarchical three-dimensional nano-architecture. The chip-based fluorescent sensor and a plasma-separation unit will be integrated into a single paper-based microfluidic strip to enable blood sample pretreatment, fluid transport and analyte detection. The performance of the integrated PLFS will be tested in terms of limit of detection, sensitivity, selectivity and applicability to clinical patient samples. This need-driven work capitalizes on the expertise and skills of a multidisciplinary project team in device development, statistical modeling, medicine, HIV biology and clinical diagnosis. The discovery-driven research is novel because of the several appealing features. That is, incorporation of a blood plasma separation unit into the PLFS will eliminate the need of sample pretreatment in a central laboratory. The three-dimensional plasmonic nanostructure will enhance the sensitivity of the near-infrared fluorescence sensor. The PLFS can be read out by a commercial, battery-powered, hand-held fluorescence reader. The portable device can be employed as a POC tool for measuring p24 antigen in finger-prick (or heel-prick) blood samples in a minimally invasive way at home, in a clinic or other resource-limited settings. It can be used for self-testing by an untrained lay-person, and for early infant diagnosis. The data obtained from this portable device will assist early diagnosis of HIV within first two weeks of post-infection. Early detection of HIV infection will improve medical intervention outcome, and reduce HIV transmission, leading to substantial reduction in HIV/AIDS- related mortality and morbidity as well as economic costs.

NIH Research Projects · FY 2026 · 2023-12

Project Summary Mosquito-borne pathogens, including malaria, Zika, dengue, and chikungunya continue to be a major public health concern globally. As only older mosquitoes are infectious and represent a risk to human health, scientists have sought to age-grade mosquitoes based on this understanding; however, no reliable, cost effective and practical methods exist to age mosquitoes despite the tremendous epidemiological value of this approach. The overall objective of this R01 is to establish a novel approach to age-grade mosquitoes Aedes aegypti in the field. The approach we took is based on surface-enhanced Raman spectroscopy (SERS) to analyze the biomolecules from mosquito water extract that are bound with silver nanoparticles (AgNPs) and then the SERS spectra are used in modern machine learning models to age-grade the mosquitoes. Our central hypothesis is that AgNPs interact with specific biomolecules enabling SERS to generate unique and predictable spectral information for establishing modern machine learning models to determine the age of mosquitoes. Our prior work demonstrates the feasibility of SERS and Artificial Neuron Networks (ANNs) to determine the age of both lab (error <1 day) and field-collected (error < 2 days) mosquitoes Ae. aegypti. In the proposed work, we will establish robust lab and field-deployable protocols to produce reliable and repeatable SERS data of mosquito water extract. Then, we will manipulate the lab and field conditions to determine the impact of biotic (food and infection status) and abiotic (temperature) to SERS characteristics. Robust and accurate machine learning model based on modern ANNs and Domain Adoption (DA) strategies will be established and validated for age-grading mosquitoes in the field. In addition, we will explore the Multi-task Learning (MTL) strategies to simultaneously determine the age and infection status. Our long-term goal is to establish a rapid, cost-effective, and field-deployable system that enables real-time analysis and data sharing to facilitate epidemiological studies, risk assessment, vector control intervention monitoring and evaluation.

NIH Research Projects · FY 2025 · 2023-09

Microenvironmental pH is a key factor in cell functioning and pathogenesis. To control the function and behavior of cells by modulating pH microenvironments is critical to advancing the development of cell biology and tissue engineering and enabling applications in drug delivery and regenerative medicine. However, pH-based cell control remains a challenge due to the lack of means to real-time, spatioselective modulation of microenvironmental pH. While pH microenvironments in cell systems are highly heterogeneous in time and space, known pH-modulation methods are through CO2/HCO3− buffering and H+ diffusion, which are slow, isotropic, and nonspecific. An urgent need, therefore, is to modulate pH microenvironments in a spatiotemporally specific manner. Failure to do so means that pH, an essential factor that determines cell fate and function, is not in good control. The PI’s long-term goal is microenvironmental pH–based closed-loop regulation of cell function, metabolism, and morphogenesis. The overall goal of this project, a critical step towards the long-term goal, is to control cells by real-time, spatioselective modulation of pH microenvironments. The hypothesis is that cell function and behavior can be regulated with ultra-high spatiotemporal resolutions (10–100 µm, <50 s), compared to conventional, diffusion-based methods (>103 µm, >103 s), in pH microenvironments that are modulated nanoelectrochemically by microelectrodes based on graphene, a two-dimensional nanomaterial with unique outstanding bio-transduction properties that address the primary challenge of on-chip pH modulation of living cell systems for typical microelectrode materials. The approach to test this hypothesis is to quantify real-time responses of model cell systems to arrayed pH microenvironment generated by an array of bidirectional graphene-microelectrode transducers that are optically transparent to allow microscopic characterization and communicate with cellular systems through electrical signal interrogation and rapid nanoelectrochemical microenvironmental-pH modulation. The following milestone goals will be reached in this project: (1) to create densely arrayed pH microenvironment by developing an array of bidirectional graphene-microelectrode transducers and (2) to control the function and behavior of model cell systems (cardiomyocytes and tumor cells) via spatiotemporal microenvironmental pH modulation using the graphene transducer array. The PI is uniquely positioned to conduct the project due to the ability of the PI’s lab to create graphene microelectrodes integrable in a fluidic device for interfacing cellular systems, interrogating electrical/chemical cell signals, and controlling cell behavior by generating microscale pH gradients. To harness and combine these techniques allows the development of arrays of bidirectional graphene transducers for selective, real-time pH-microenvironment modulation and cell control. The expected outcome of the project is pH-based cell-control tools with over two- orders-of-magnitude enhanced spatiotemporal resolutions compared to conventional methods. This outcome is to generate positive impact on bioengineering development, regenerative medicine, and synthetic morphology.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY One in six children aged 6-17 years had a behavioral health (BH) diagnosis in 2016 and rates have continued to increase. Limited access to BH services has long presented challenges for most children. Efforts to address the shortcomings of the specialty BH care system, such as integrating BH care into pediatric primary care settings, and state programs that offer telephonic psychiatry consultation to pediatricians, have helped improve care, but immense gaps in care persist. Accountable care organizations (ACOs) incentivize care integration and population health, which promotes community-health care linkages and care coordination. The innovative reform introduced by ACOs has the potential to improve BH care delivery, but their impact for pediatric populations is largely unknown. Studies of adult populations suggest that ACOs with certain organizational features (e.g., type of contract) may improve quality of care for chronic diseases but the few studies of the impact of ACOs on quality of care and outcomes for children have not focused on this large population of children with BH disorders. This study will be the first to address this critical gap in knowledge by taking advantage of the natural experiment taking place in Massachusetts (MA), a state with a high prevalence of children with BH diagnoses. In 2018, MA, launched 17 new Medicaid ACOs with heterogeneous organizational features (e.g., size; physician vs. hospital-led; age mix). We will leverage MA’s innovative Medicaid ACO ‘experiment’ to address the following aims using mixed methods: 1) Evaluate the impact of ACOs on BH care quality, outcomes, and disparities for Medicaid-insured children; 2) Discern how ACO heterogeneity modifies ACOs’ effects on BH quality and outcomes; 3) Determine the relationship between parent reported experience with their child’s BH care and organizational features of the Medicaid ACOs. Fundamental changes in healthcare are needed to address disparities in BH care quality and outcomes for children. Our innovative mixed methods approach to examining the association between exposure to a new heterogeneous group of Medicaid ACOs and BH care and outcomes uses state-level administrative claims and survey data and key informant interviews with ACO leaders and parents to begin to address this large gap in knowledge. This new information is expected to benefit providers, payers, and policy makers responsible for the care of children with BH disorders.

NIH Research Projects · FY 2025 · 2023-09

Stroke is the leading cause of disability in adults worldwide. Upper-limb paresis is the most common impairment post-stroke. The ultimate goal of stroke rehabilitation is to improve patients’ motor performance in their home and community settings (i.e., what patients actually do). However, current clinical standards to monitor patients’ recovery process are limited to assessing patients’ motor capacity observed in the clinic (i.e., what patients are capable of doing). Wrist-worn accelerometers have been considered as a potential solution but criticized for providing a limited view of upper-limb performance. Therefor, the research and clinical communities have emphasized the need for a technological solution to support a more comprehensive understanding of stroke survivors’ motor performance. In this work, we propose to develop a novel multi-modal sensing platform to monitor important elements of upper-limb motor performance: the amount, type, and quality of movements. To that end, we introduce a new kind of sensing technology, namely Body Channel Identification (BCID), that can accurately and reliably track human interactions with the environment and, thus, human behaviors. In our setting, everyday objects are instrumented with small, inexpensive, batteryless BCID tags that can be powered by and communicate with wrist-worn devices (so-called readers) by exploiting the human body as the signal transfer channel during tactile interactions. The system provides multi-modal data, including the object ID, binary time-series of interaction patterns (contact vs. no contact), kinetic data from an optional pressure sensor embedded in the tag, and kinematic data from the inertial measurement unit on the wrist-worn readers. Leveraging data obtained from 50 stroke survivors and ten healthy subjects, we propose to develop a unique set of machine learning algorithms to process these data to taxonomically identify important types of upper-limb movements relevant to stroke rehabilitation, which are further processed to assess the quality and amount of movements performed. Finally, we investigate the relationship between the motor capacity observed in the clinic vs. motor performance outside the clinic, a topic that has been deemed critical in stroke rehabilitation but infeasible due to technical limitations. We believe the proposed research will lay the technological groundwork to open up new research and clinical opportunities, leading to key scientific discoveries to transform current practices of stroke rehabilitation.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY / ABSTRACT Over the course of the development and into adulthood, the human brain builds neural circuits composed of thousands of types of neurons. As new neurons are born, they are incorporated into developing and existing circuits making connections to neurons that are nearby as well as neurons that are in distant parts of the brain. Many neurological conditions are related to the improper growth of networks in the brain. Yet, we lack a basic understanding of how neural circuits change as new neurons join. To address this question, this proposal uses a novel animal model, the mollusc, Berghia stephanieae, in which it is possible to construct a cellular- and synaptic-level wiring diagram of the entire brain at several juvenile stages as well as the adult. Using these whole brain connectomes, the project will track the changes in specific neurons, in neural circuits, and in whole brain networks as the number of neurons in the brain increases by over 40-fold. Neurons will be identified by intersectional labeling of gene expression using sets of up to five in situ hybridization chain reaction probes that label different mRNA sequences. Overlapping sets of probes will used so that individually identifiable neurons and neuron types can be distinguished based on their patterns of gene expression combined with their soma location and size. Additionally, in adult animals, neurons will be labeled using fluorescent tracers applied to nerves emanating from the brain. Machine learning (ML) will be employed to classify neuronal types based on all of these features. ML classifications of neurons across developmental stages will be corrected by humans to enhance the predictive power of the ML. A series of connectomes of the brains of an adult and juveniles from four stages will be constructed. The brain will be serially sectioned. Each of the 30 nm thick sections will be imaged using a 61 beam scanning electron microscope. The sections will be aligned and all neurons will be automatically reconstructed in 3D. The reconstructions will include all axons, dendrites, and synapses. Again, humans will proofread the results to correct the ML algorithm. The result will be five complete brain connectomes spanning from the early juvenile with 500 neurons to the mature adult with over 23,000 neurons. The developmental series will be analyzed to test hypotheses about the organization and development of neurons, neural circuits, and entire brain networks. Changes in neural structure of identified neurons will be tracked over development. Comparisons will be made between neural types as new neurons are added. Complete neural circuitry for visual, olfactory, and motor systems will be determined. Finally, the project will determine whether hubs develop around the oldest neurons or whether the network scales without concentrating connectivity at particular hubs. The results will provide an unprecedented look at how the synaptic networks of neurons across an entire brain change as new neurons are added.

NIH Research Projects · FY 2025 · 2023-09

Project Summary Reproduction in flowering plants depends on multiple male (pollen)-female (pistil) interactive steps to deliver sperm, which are non-motile and transported as cytoplasmic cargos by the pollen tube through several specialized pistil tissues to the female target for fertilization, leading to seed production. The proposed research addresses key cell-cell communicative events in three distinct prezygotic (i.e. prior to sperm-egg fusion) phases during the pollen/pollen tube journey in the pistil to enable fertilization. Long- term efforts in our lab have set discovery milestones for the field and recently elucidated key molecular players in each of these phases, providing critical advances and unprecedented opportunities for the mechanistic dissection proposed here. The pistil supports pollen germination on its receptive surface, the stigma, to produce a pollen tube that grows inside the transmitting tissue to reach the target egg-bearing chamber, the female gametophyte located inside an ovule. Once arriving at the female gametophyte, the pollen tube burst, releasing sperm for fertilization, producing seed. The pistil also set up barriers to ward off unwanted mates or invasive disease agents, and to effectively prevent multiple pollen tubes from penetrating the same female gametophyte to suppress polyspermy and ensure progeny health. We discovered three related signaling modules, each critical for one the three prezygotic phases. Phase 1 supports pollen germination on the stigma. Phase 2 achieves two goals, one ensuring pollen tube integrity until it reaches its target, the other ensuring single pollen tube entry into an ovule. Phase 3 occurs at the pollen tube/ovule and pollen tube/female gametophyte interfaces. Interactions here induce bursting of the first-arriving pollen tube in the female gametophyte and trigger a mechanism for a local polyspermy block to further ensure against supernumerary pollen tube entry into an already penetrated female gametophyte. These signaling modules are anchored by the pistil-expressed receptor kinase FERONIA or pollen-expressed homologs, each partnering with a GPI-anchored protein (GPI-AP) LORELEI (LRE) or LRE-like GPI-AP1,2,3 (LLG1,2,3) to serve as coreceptors for peptide ligands called RALFs (Rapid Alkalinization Factors). Here we propose experiments to elucidate how these signaling modules and additional regulatory factors impact the molecular interactions, biochemical processes and cellular conditions in pistillate cells to mediate success for these prezygotic phases, enabling fertilization, and to prevent unwanted intrusions. Plants have evolved but hidden in the most protected location these highly sophisticated cell-cell communication strategies to ensure their own proliferation. Our expertise positions us uniquely capable of achieving these goals, which will fill a complete mechanistic void, setting paradigms to guide studies in many ecologically and agriculturally important plants, and inform rational designs to safe-guard reproductive success, ensuring food security to provide for global nutritional needs.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY/ABSTRACT Next generation structural biology experiments look to move beyond static observations of structure to a dynamic, time-resolved understanding of function. These next-level experiments are enabled by serial crystallography at X-ray free-electron lasers (XFELs) and microfocus synchrotron beamlines but are limited by issues of sample consumption. The long-term goal of this project is to democratize studies of protein structural dynamics by developing robust fixed-target mounting strategies for light-, chemical-, and electrically-triggered time-resolved protein crystallography experiments while maximizing sample utilization. This effort leverages the expertise of the SLAC National Accelerator Laboratory and the BioCARS facility at the Advanced Photon Source for testing and validation of new mounting strategies. These relationships will also enable rapid translation of developed technologies to the larger structural biology community. We have four initial aims to do this: Aim 1: Develop fixed-target strategies to facilitate the study of macromolecular crystallography targets while maintaining biological activity. We will design and fabricate X-ray compatible sample holders that maintain the stability of protein crystals over time while also allowing for easy sample loading, robotic handling, and in situ spectroscopy. A particular focus will include enabling data collection in a fully anaerobic environment, and the technologies developed here will serve as a basis for efforts in subsequent Aims. Aim 2: Develop fixed-target platforms for photo-triggering of reactions for analysis via time-resolved serial crystallography. We will develop X-ray compatible sample holders that take advantage of hydrodynamic forces to create large-scale arrays of crystals for use in serial crystallography experiments. The polymer-based fabrication strategy will enable fast, low-cost device fabrication, as well as allowing for direct imaging of samples, in situ spectroscopy, and laser-based triggering of reactions for time-resolved X-ray crystallography studies. Aim 3: Develop fixed-target platforms for chemical triggering of reactions for time-resolved serial crystallography analysis. We will develop strategies to enable the controlled addition of a chemical species (i.e., substrate, pH change) to enable the chemical triggering of reactions in crystals. Aim 4: Utilize graphene-based devices to study structural dynamics based on high voltage triggering. We will integrate graphene-based circuitry into our microfluidic devices to enable the use of a voltage-jump as both a general strategy for triggering protein motions and to control electron transfer reactions. The team is well qualified, merging expertise in microfluidics, X-ray science, and structural biology, with an established history of developing new technology to address challenges within the structural biology community. The impact will be improvements in the ability to perform time-resolved studies of protein structural dynamics that will immediately enhance the research capabilities of a large base of NIH-supported and other researchers.

NIH Research Projects · FY 2024 · 2023-08

SUMMARY More than 6.5 million Americans suffer from Alzheimer’s Disease (AD), and by 2050 this number is expected to double. Yet the development of effective therapies remains an urgent unmet need. In a scenario of highly complex AD pathophysiology and costly and long drug development process, repurposing of drugs approved for other indications is an attractive complementary approach. The rationale for repurposing a drug initially relies on observational studies demonstrating that the cumulative drug exposure is correlated with either a reduction in the risk of developing AD dementia, or with a slowing of the rate of cognitive decline based on serial cognitive evaluations, or with milder AD neuropathological changes at autopsy examination, after adjusting for covariates including age, sex, education, family history of dementia and APOE genotype, and vascular and other modifiable risk factors. However, the vast majority of such published longitudinal studies have ignored the truncation or interval censoring associated with the covariate of interest (e.g., cumulative drug exposure), which is due to either termination of observation by death or non-continuous observation visits in longitudinal studies. Building upon our extensive prior work in the areas of truncation and censoring as well as AD, here we propose to develop methods to more appropriately treat these sampling and measurement problems to avoid bias. We will apply them in two case studies of drugs with opposite purported associations with AD risk -- statins (protective) and proton-pump inhibitors (PPIs, deleterious) -- but mixed findings from longitudinal studies. To this end, we will leverage the strengths of two high-quality publicly available longitudinal datasets: the National Alzheimer’s Coordinating Center (NACC) cohort study and the Harvard Aging Brain Study (HABS). In Aim 1, we propose analytic methods that remove biases arising due to covariate measurements that are truncated in AD studies, such as cumulative statin exposure, including inverse probability weighting, pseudo-observations and reverse regression approaches. In Aim 2, we develop pseudo-observation methods for time-to-event regression with interval-censored covariates. In Aim 3, we conduct and report analyses of NACC and HABS datasets using proposed methods, and develop publicly available R packages for implementation of our proposed methods. Successful completion of these specific aims will produce new statistical methodology that will eliminate the bias that may arise with truncated and interval-censored covariates, which are inherent to longitudinal cohort studies in AD and related dementias. Our proposed research is responsive to the NIA Notice of Special Interest (NOSI): Maximizing the Scientific Value of Secondary Analyses of Existing Cohorts and Datasets in Order to Address Research Gaps and Foster Additional Opportunities in Aging Research (NOT-AG-21-020).

NIH Research Projects · FY 2023 · 2023-08

Abstract Age is the major risk factor for AD, which affects ~5.8 million Americans. Increasing physical activity (PA) could decrease the prevalence of Alzheimer’s Disease (AD) and AD Related Dementias by 11%. Yet, the majority of older adults (54%) remain physically inactive. Traditional PA interventions do not reduce excessive sitting in middle-aged or older adults. In particular, sitting continuously for ≥20 min (prolonged sitting) can acutely reduce frontoparietal (FP) brain function and attentional control. Thus, habitually high levels of prolonged sitting in middle-aged and older adults (5 h/day) may contribute to the declining efficiency of the FP brain function with age, negatively affecting attentional control and consolidation of episodic memories. Accordingly, PA interventions to enhance FP and cognitive function in older adults should also target reducing prolonged sitting. However, no effective PA interventions designed to reduce prolonged sitting and improve FP brain function, attentional control, and episodic memory exist. To be effective such interventions should target the mechanisms underlying PA effects on brain function. A single bout of PA is thought to enhance FP brain function by stimulating phasic release of cerebral norepinephrine from the locus coeruleus. Specifically, PA stimulates vagus nerve in the periphery by increasing levels of peripheral catecholamines. Capitalizing on PA intensity as the major limiting factor in peripheral catecholamine increase, we propose a pilot randomized crossover feasibility trial to compare 2 conditions lasting 3.5 h each: sitting interrupted every 30 min by 6-min of HIIT, and sitting interrupted by 6-min of light-intensity interval training (LIIT) to address 3 aims: (i) assess feasibility, acceptability, fidelity, and safety of HIIT breaks to improve neurocognitive function; (ii) quantify the differences between conditions in the change in P3b amplitude and latency; (iii) explore the differences between conditions in attentional control, episodic memory, and functional connectivity (FC) of the FP and default mode networks. We will administer the conditions in a counterbalanced order to 54 middle-aged and older adults (40-75 years). We will use the P3b component of an event-related potential as a primary outcome because it is a known marker of frontoparietal brain function, and an index of phasic shifts (e.g., in response to PA) in cerebral norepinephrine release. It is also reliably modulated by exercise. Next, we will measure FC in the frontoparietal and default mode brain networks because they are modulated by cerebral norepinephrine, and support attentional control and episodic memory, respectively. Furthermore, FC in these networks can be improved with a single bout of PA but declines with age. These results will reveal if short bouts of HIIT can be used as a model to regularly enhance brain function and cognition, by probing cerebral norepinephrine release in a chronic intervention. Our long-term objective is to test the chronic effects of HIIT breaks on the integrity of the locus coeruleus, FP function, and cognitive functions affected by aging and AD in cognitively healthy and cognitively impaired middle-aged and older adults.

NIH Research Projects · FY 2026 · 2023-08

Project Summary/Abstract Human milk provides significant health benefits for infants. Beyond nutrients, breastmilk contains antibodies for immunity, growth factors associated with gut epithelial maturation, bacteria for establishment of the gut microbiome, and metabolites that modulate inflammation. These important elements of human milk support strong immune system development within the infant gut and better infant health. Unfortunately, many parents aiming to breastfeed will supplement or wean earlier than planned and frequently report perceived low milk supply as the reason. Increased mammary epithelium permeability (IMEP), as indicated by elevated milk sodium, is a physiologic condition that could have significant implications for milk secretion, composition and infant health. Lactation physiology studies have established that closed paracellular pathways, i.e., low permeability, are essential for the establishment and maintenance of adequate milk secretion. Human studies on permeability have focused on the period of secretory activation and persistent mammary epithelium permeability at day 7 postpartum has been associated with perceived low milk supply. However, little is known about IMEP during established lactation. We recently reported that IMEP among US women is more common across lactation than previously recognized. Longitudinal US studies are needed to quantify mammary epithelium permeability during established lactation and to investigate the extent to which increased permeability influences lactation insufficiency. Our overall goal is to establish a clinically relevant robust IMEP threshold, based on our analysis of sodium as a continuous variable, and determine the extent to which IMEP is associated with suboptimal lactation outcomes and reduced infant health. We propose that IMEP is associated with low milk supply and earlier than desired weaning. We also posit that IMEP results in altered milk nutrient content, shifted inflammatory profiles and milk microbiome composition impacting the infant gut immune profile and microbiome. We will enroll a diverse cohort of 400 mother-infant dyads from New Mexico and Massachusetts. Participants will provide bilateral milk and infant fecal samples at four timepoints spanning transitional, early and mature milk. Understanding the extent of IMEP linkage to suboptimal lactation outcomes and infant intestinal health is of major importance because IMEP can be measured, treated and prevented. Interventions to limit IMEP could include behavioral and dietary changes, as well as medications or supplements. This will be the first study to determine the prevalence of IMEP and associated changes in milk throughout the first five months postpartum, and the only large US cohort study of IMEP. Results from this study could lead to a major change in clinical practice. Assessment of IMEP in milk could become routine, especially among women seeking lactation counseling, and this may lead to improved outcomes. We expect that our geographically and ethnically diverse cohorts will provide novel data on differences in risk factors for IMEP with implications for lactation outcomes.

NIH Research Projects · FY 2025 · 2023-08

PROJECT SUMMARY After decades of using implantable neural probes with implantable multielectrode arrays for medical studies, the exact failure mechanisms of these implants still remain to be fully understood. However, more and more studies have shown that minimizing the mismatches between the soft biological tissue and bioelectronic devices would be a key to achieving long-term, accurate, real-time, and large-scale neural recordings and stimulations without inflammatory immune responses. To mitigate the mechanical mismatch found in hard metal or silicon probes, soft neural probes that are both flexible and stretchable have been developed in recent years. However, bioelectronics on current soft probes has fundamental limits in the stability of their electrochemical impedance under physiological conditions, resulting in a compromise between electronic performance and mechanical matching. The long-term goal is to create a next-generation brain-computer interface (BCI) for advancement in biology, neuroscience, biomedical engineering, and regenerative medicine. The overall objective of this application is to elucidate the design rules to enable electronic-tissue interfaces with reliable electrochemical impedance, tunable mechanical stiffness, using an approach that combines two unique material types – nontoxic liquid metals and biocompatible elastomers. The central hypothesis is that a combination of low-melting-point nontoxic gallium-based liquid metals and intrinsically stretchable polymers will synergistically enhance the electrical, and mechanical interfacial properties in the biological environment and provide unified interfaces for multifunctional integrated systems with embodied intelligence. The successful completion of this research will result in significant advances in the methodology of liquid-metal-embedded soft neural probes. The rationale underlying the proposed research is that the successful development of a truly stretchable and reliable probe-tissue interface offers neuroscientists an unprecedented platform technology to design specific neural probes to investigate fundamental life science questions that were unexplorable before, such as “how neuronal circuits are formed during brain development” where high-density high-resolution stretchable neural probes are needed as a mammalian brain may grow more than 100% in size and add vast amounts of new tissue and resulting new functions. The proposed research is innovative, because it departs from both the conventional and existing neuroscientific instrumentations and introduces a new framework for next-generation neural probe systems using low-melting-point metals and soft polymers. The proposed research is transformative because it will enable “invisible” brain-computer interfaces (BCI) to provide fundamental insights into the underlying physics of brain circuitry formation and functionality. Ultimately, such knowledge paves the way for us to understand the brain and ourselves better, offers new opportunities for finding the origin of intelligence, and invites new solutions for the development of innovative therapies to treat brain disorders.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY Sleep is critical for infant physical and cognitive development and yet understanding sleep time and timing is a source of stress to parents and families. Thus a better understanding of when infants sleep, specifically the transition from two to one naps, will support infant cognitive development and contribute to guidance for families. The objective of the proposed research is to examine, longitudinally, the role of multiple sleep bouts in memory consolidation across the triphasic to biphasic sleep transition in infancy. The overarching hypothesis is that naps maintain their usefulness across these transitions, but that multiple naps become less essential to the preservation of memories as infants naturally transition to one nap per day. More specifically, it is predicted that memories can be held longer without interference as the child develops across this age range, making the morning nap less essential to memory while the afternoon nap remains essential. Participants will be 100 infants, who will complete 2 sessions, a sleep and a wake session, every three months (9, 12, and, 15 months). A deferred imitation task will be used to assess nap-related changes in memory consolidation. Actigraphy will be used to objectively assess nap habituality. Polysomnography will be used to understand the physiological mechanism underlying memory benefits and it will also provide a proxy for brain development. Collectively, the work will (1) assess memory consolidation over morning and afternoon nap intervals across the triphasic to biphasic sleep transition in infants; (2) examine the mechanism supporting declarative memory consolidation in infancy; and (3) establish the developmental trajectory of key sleep physiology features within naps across this developmental age range. An exploratory aim will examine whether changes in estimated brain development predict the triphasic to biphasic sleep transition. The outcomes have theoretical significance. These results will be significant for the field of sleep research, providing critical insight into development of sleep regulation processes and longitudinal changes in sleep patterns. Additionally, results will be informative to developmental scientists, suggesting that the timing of studies will contribute to performance. The outcomes also have translational significance. A better understanding of nap transitions will inform pediatricians and parents as they make recommendations and decisions about infant sleep and allow for identification of infants with abnormal sleep development trajectories.

NIH Research Projects · FY 2025 · 2023-07

The 26S proteasome is a massive, intricately regulated ATP-dependent protease responsible for the degradation of most cellular proteins. The goal of this research program is to determine how degradation by the 26S proteasome is regulated by deubiquitinases. Since misregulation of protein degradation is a hallmark of many human cancers and neurological disorders, the results of these studies can be used to design new drugs that target key regulators of the 26S proteasome. A major focus of this research program will be on the deubiquitinase UCHL5/UCH37, which is recruited to the proteasome by the ubiquitin-binding receptor ADRM1/RPN13. Deficiencies in UCH37 leads to embryonic lethality in mice and overexpression of UCH37 along with RPN13 is associated with poor prognoses in several cancers. A combination of x-ray crystallography, NMR, in vitro biochemistry, protein engineering, and cell-based approaches will be used to understand how UCH37 selects its ubiquitin chain targets, why the cleavage of those targets is necessary for promoting proteasomal degradation, and which proteins in a cellular proteome require UCH37 activity for efficient degradation. We will also develop a set of single-chain antibodies (referred to as nanobodies) capable of interfering with distinct activities of UCH37. These new tools will be instrumental in defining the function of UCH37 in different biochemical pathways such as the cell cycle and the cellular response to oxidative stress and DNA damage. Considering the tumor suppressor BAP1 shares a similar sequence with the catalytic domain of UCH37, our tools and approaches can also be used to better understand its role outside of histone deubiquitination. The molecular insights that will result from the proposed studies will provide a foundation for the development of new therapeutic agents that target cancers requiring excessive proteasome activity for survival.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY This proposal seeks to develop a targeted tri-agonist “super adjuvant” nanoparticle platform for in situ cancer vaccination. Vaccines consist of 2 components: a tumor-specific antigen that is recognized by CD8+ cytotoxic T cells (CTLs) and an adjuvant that provides the necessary costimulatory cytokine signals to antigen-presenting cells (APCs) to prime and activate a CTL response. In complex diseases like cancer, however, a single- adjuvant vaccine may not be fully effective to mitigate the myriad immunosuppressive effects of a heterogeneous aggressive tumor microenvironment (TME) such as that of triple-negative breast cancer (TNBC). Co-delivery of multiple adjuvants in a rationally designed “super adjuvant” formulation can harness multiple pattern recognition receptor pathways simultaneously to drive a proinflammatory synergistic cytokine response that has both breadth and depth. Further, compared to standard vaccination, where a preselected antigen and adjuvant are delivered to lymph nodes, in situ vaccination, where only the adjuvant is delivered directly to the tumor, has clear advantages. In an in situ approach, the tumor itself provides the antigen in the form of neoantigens shed from dying tumor cells. This approach captures patient heterogeneity on a personalized basis and does not require prior knowledge of tumor antigens. Current in situ approaches, including free agonists, free cytokines, and immunogenic viruses, rely heavily on direct intratumoral injection to minimize off-target toxicity and are cancer type-specific. Intratumoral delivery itself also has serious limitations in both delivery and efficacy. Supported by our recent publications and additional preliminary data, this high- risk proposal seeks to address these shortcomings by designing a “super adjuvant” immunomodulatory nanoparticle (immuno-NP) platform that coencapsulates 3 synergistic Type I interferon-driving innate immune agonists on the same NP using lipid-based materials and microfluidics. Specifically, 60-nm PEGylated immuno-NPs will be designed to be delivered safely in the systemic blood circulation to co-deliver agonists of the STING, TLR4, and TLR9 pathways to tumors. They will also be targeted to multiple specific types of cells in the TME, including APCs, activated endothelial cells, and tumor cells, to orchestrate a concerted multi-cellular response that may be necessary to eliminate heterogeneous aggressive tumors. We hypothesize that targeted tri-agonist “super adjuvant” immuno-NPs will drive a synergistic Type I interferon-mediated APC response that activates CTLs for tumor clearance in multiple mouse models of TNBC. Specific Aim 1 will identify immuno-NP design parameters required for optimal function in terms of promoted cytokine breadth and depth. Specific Aim 2 will establish immuno-NP targeting schemes for effective TME homing and therapeutic efficacy. These studies will effectively address the delivery, efficacy, and safety challenges that severely limit current approaches. As a platform technology, successful development of this “super adjuvant” immuno-NP also has wide-ranging applications in standard lymph node-directed vaccination for both cancer and infectious disease.