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Opportunistic Short‐Term Water Uptake Dynamics by Subalpine Trees Observed via In Situ Water Isotope Measurements
Get PDFAbstract Variations in tree water sources are important to understand in semi‐arid ecosystems because climatic shifts towards lower snowpack and increased drought affect water availability in subalpine forests of the western US. Here, we use daily in situ measurements of stable isotopes ( 2 H & 18 O) in soil and tree stem water, soil matric potential and sap flow to study tree water uptake dynamics. We instrumented three soil profiles down to 90 cm, as well as three aspen and engelmann spruce trees near Gothic, Colorado, in the East River watershed. We observed the fate of natural isotopic variations in rainfall, soil, and plants from June to October 2022, and in August 2023 we conducted a 2 H labeled irrigation experiment. Our observations showed that all studied aspen trees compensated for water scarcity in the shallow soil by shifting the dominant water source at 60(±20) cm to ⅔ of uptake from 90 cm within a few days of a dry period. Both species relied on snowmelt stored in the subsoil to sustain transpiration. Intense rainfall caused the plant water uptake to shift partially to top soil layers within 2 days. Spruce transpiration was lower and relied more on snowmelt, because rainfall infiltration was low in the spruce stand due to high canopy interception. Our findings highlight the important role of snowmelt stored in the deep soil layers for subalpine forest drought response and the dominant fate of monsoonal rainfall to become transpiration rather than recharging groundwater and streams in the Upper Colorado River.
Plain Language Summary There is a need to understand how trees in mountainous regions respond to dry conditions that lead to water scarcity, because climate projections suggest that such conditions will become more frequent in the future. Here we present a novel data set of measurements of daily stable isotopes of water across soil profiles and in tree stems of aspen and spruce. Our data show that when the upper soil dried out, aspen trees shifted to using water from deeper layers (beneath 60 cm) to keep transpiring. For spruce trees the uptake pattern is less clear, but both types of trees mainly used snowmelt stored in the deeper soil layers to survive the dry summer. After heavy rain, aspen and spruce trees switched to using water from the top 20 cm of soil. However, for spruce, only some rain reached the soil because the dense tree canopy intercepted it, so spruce trees stayed more dependent on snowmelt and used less water overall. This study shows how important deep snowmelt water is for helping forests survive dry periods and suggests that most summer rain is quickly used by trees rather than replenishing streams and groundwater in the headwaters of the Colorado River.
Key Points Tree water resources changed within a few days from snow dominated to higher share of rainfall as soils wetted up after a dry period Compensatory plant water uptake by aspen from the deep layer (90 cm), while uptake from soil depths that became drier (60 cm) declined Strong differences between water sources and availability beneath aspen and spruce, respectivel
AI-Driven MRI Biomarkers for Breast Cancer Risk and Treatment Response Assessment
Get PDFBreast cancer remains the most common malignancy in women worldwide, and quantitative biomarkers from breast MRI, including fibroglandular tissue (FGT) and background parenchymal enhancement (BPE), are emerging as important tools for risk assessment and treatment monitoring. To clarify the biological relevance of BPE, we analyzed screening MRI from 535 women stratified by lifetime risk and BRCA mutation status. After breast and FGT segmentation, six quantitative BPE measures were extracted, revealing strong associations with age, BMI, menopausal status, and breast density. Notably, BRCA1/2 carriers showed significantly lower enhancement than high-risk non-carriers after adjustment, suggesting a link between germline mutations and parenchymal physiology. Extending this work, we evaluated the predictive value of BPE for neoadjuvant chemotherapy (NAC) response in a multicenter cohort of 191 patients. Radiomics models combining tumor and BPE features achieved the best accuracy for predicting pathologic complete response, particularly in postmenopausal women and triple-negative cancers, highlighting the added value of BPE beyond tumor features alone. To enhance the reproducibility of breast MRI biomarkers, we developed an anatomy-aware loss function for deep learning–based FGT segmentation that integrates breast density information into the training process. Applied to 180 internal MRIs with independent evaluation on 40 held-out cases and an additional 100 external cases, this approach improved boundary accuracy and reduced biomarker estimation errors by approximately 10–15% compared with conventional loss functions, with the greatest benefit observed in fatty and scattered breasts. In conclusion, this work demonstrates that BPE is shaped by genetic and clinical risk factors, enhances prediction of treatment response, and can be more reliably quantified through anatomically informed segmentation, advancing its use as a robust imaging biomarker for breast cancer risk stratification and therapy monitoring
Evaluating the Additive Value of Machine Learning in Clinical Risk Prediction: A Comparative Study Across Three Patient Cohorts
Get PDFThis dissertation evaluates when and how machine learning (ML) adds value beyond traditional statistical methods for cardiovascular risk prediction across three electronic health record (EHR)-derived cohorts. It consists of three projects. Project 1 examined major adverse cardiovascular events (MACE) in 5,766 patients treated with immune checkpoint inhibitors (ICIs). MACE occurred in 19.6% of patients and was associated with traditional risk factors, cancer exposures, and treatment intensity. ML (XGBoost, AUROC 0.71) identified non-cardiovascular immune-related adverse events requiring prednisone as a novel, high-impact predictor. Project 2 investigated new-onset left ventricular systolic dysfunction (LVSD) after orthotopic liver transplantation in 956 patients. LVSD developed in approximately 7% of patients, typically early in the post-transplant course, and was often reversible. Risk markers included mineralocorticoid receptor antagonist use, lower pre-operative hemoglobin, intraoperative dialysis, and diastolic/pulmonary hemodynamic features; ML (XGBoost, AUROC 0.73) revealed important non-linear interactions among echocardiographic variables. Project 3 analyzed predictors of successful decannulation in veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Among 199 patients, successful decannulation occurred in 48.5%. ML (random forest, AUROC 0.94) and regression converged on higher mixed venous oxygen saturation as the dominant predictor.
Across these three projects, ML complemented logistic regression by uncovering novel predictors in Project 1, capturing complex interactions in Project 2, and isolating a single dominant predictor in Project 3. Together, the combined use of traditional statistical methods and ML enhanced risk stratification across diverse cohorts and provides a framework for future applications in cardiovascular prediction
Everyday Archiving in Chinese American Families: The Affects of Ordinary Things
Get PDFArchival practices historically emerged from work with government and organizational records. However, little research has examined archives and archival practices within domestic family contexts, especially those of ethnic and diasporic populations. To address this gap, this dissertation study investigates the everyday archiving practices of Chinese American families and examines how seemingly small and ordinary objects can carry deep emotional significance, shaping a sense of belonging and intergenerational connection.The study used a qualitative, multi-method research design, incorporating in-depth interviews of Chinese Americans from different generations, object elicitation and observation of family archives as its primary methods of inquiry.Findings indicate that the notion of “family” is fluid, shaped by family dynamics and shared experiences rather than being restricted to biological ties. These understandings influence imagined archival boundaries, determining who is included, excluded and represented. Family archives emerge at the intersection of incidental accumulation and intentional selection, guided by judgments about what is meaningful or worth preserving. Even if they are dispersed, they are also purposefully arranged within the home, with valued items placed in visible locations carrying affective and symbolic significance. The growing ease of documentation enabled by digital technology raises questions about how such convenience and associated abundance and wider distribution might influence the intentionality and perceived value of family archives. The study also identifies a latent gendered division of archival work: men, particularly the eldest son, often take responsibility for the custody of physical materials (material stewardship), while women are more often positioned as transmitters of family stories (narrative transmission). Grounded in the concept of archival pluralism, the study challenges conventional understandings, showing that archives can be changing rather than fixed, in use rather than archived away, interaction-centered rather than object-centered and reproducible rather than necessarily original. In doing so, it supports records continuum ideas of archives as ever-mutating, always evolving through continuous interactions between users and content. By foregrounding the affective dimensions of archival work, the study demonstrates how emotional connections can elevate ordinary things beyond their utilitarian functions—findings that, perhaps unsurprisingly, affirm much of what community archives scholarship has revealed. At the same time, it extends the newest scholarship on the role of affect by showing that family archives, at least in the Chinese American context, are distinctive: partly because of their object orientation, partly because of their intangible and affective qualities and partly because of how they reflect particular elements of Chinese culture.Based on these findings, the dissertation advocates for community-engaged archival practice that supports families in preserving their archives with sensitivity and emotional care. The research also points to several directions for further research, including targeted studies of specific subgroups to examine how distinct historical experiences shape Chinese Americans’ awareness of and attitudes toward archival preservation, as well as investigations into how digital and physical archives may differ in their roles in intergenerational transmission, including questions of ownership in digital archival legacies. 
Hubble Constant and Strong Gravitational Lensing
Get PDFThe persistent tension between early and late universe measurements of the Hubble constant (H0) represents one of the most significant challenges in modern cosmology, with implications for our understanding of fundamental physics. Strong gravitational lensing of variabl
Fluorescent and bioluminescent methods to quantify protein levels in the endoplasmic reticulum lumen
No full textFluorescence and bioluminescence complementation assays have been commonly used to examine protein subcellular localization or behavior. This work outlines parallel fluorescence and bioluminescence complementation systems used in the assessment of any protein-of-interest’s (POI) translocation to the ER lumen. The fluorescence system, ERTrap, consists of one ER membrane “trapping” protein with a red fluorescent marker (Trap2) with translocation benchmarked against two control constructs: a cytosolic mNG11-mTagBFP construct (CytoBait) or an ER lumen mNG11-mTagBFP (ERBait). The bioluminescence system, BLERA, consists of orthogonal bioluminescent constructs to ERTrap. AMPK, a serine/threonine kinase promoting catabolic processes like autophagy, reportedly phosphorylates proteins with localization to the ER lumen like angiotensin-converting enzyme 2 (ACE2) and programmed death-ligand 1 (PD-L1). AMPK phosphorylation sites on PD-L1 (S195) and ACE2 (S680) are on the proteins’ extracellular domains, which would be accessible to AMPK if it was within the secretory pathway or extracellular. With no available studies on AMPK translocation and ER lumen substrate phosphorylation, ERTrap was developed to clarify if AMPK’s catalytic (α) or regulatory (β) subunit could enter the ER.No significant translocation of AMPKα or β subunit was observed, marked by low colocalization with ERTrap. Considering that AMPKα and β subunit entry may be in low amounts to escape fluorescent detection, the BLERA system with enhanced sensitivity was designed to allow for further testing of luminal AMPK translocation. Although our assays showed no significant luminal entry of AMPK, both tools could be used to quantify translocation or abundance of other POIs in the secretory pathway
Mexperimental Music: Reimagining Roots, Identity and Singing
Get PDFMexperimental Music: Reimagining Roots, Identity and Singing is a creative research project that was born from the need to explore the ongoing question "Who am I?” and the desire to research and express my identity. Within a context of experimentation, improvisation, and composition of arrangements – and as a process led by intention, care, respect, historical awareness, and acceptance – the project engages with Mexican traditional musics that had been my companions since childhood thorough my family’s musical heritage. These musics include ranchera song, modern mariachi, bolero, son jarocho, son istmeño, son de artesa, and corrido, and have become strong references for my musical taste, vocal techniques, and expressive idioms. In this paper I aim to share the motives behind this project and the creative process, as well as the challenges I faced while creating the experimental arrangements that composed the Mexperimental Music concert performed on April 6th, 2025
Color glass condensate meets high twist expansion
Get PDFWe establish the correspondence between two well-known frameworks for quantum chromodynamics (QCD) multiple scattering in nuclear media: the color glass condensate (CGC) and the high-twist (HT) expansion formalism. We argue that a consistent matching between both frameworks, in their common domain of validity, is achieved by incorporating the subeikonal longitudinal momentum phase in the CGC formalism, which mediates the transition between coherent and incoherent scattering. We perform a detailed calculation and analysis of direct photon production in proton-nucleus scattering as a concrete example to establish the matching between HT and CGC up to twist-4, including initial- and final-state interactions, as well as their interferences. The techniques developed in this work can be adapted to other processes in electron-nucleus and proton-nucleus collisions, and they provide a potential avenue for a unified picture of dilute-dense dynamics in nuclear media
Development of an ERT‐Based Framework for Bentonite Buffers Monitoring From Laboratory Tests: 2. Quantitative Moisture Dynamics Estimation Model
Get PDFAbstract The long‐term containment of high‐level radioactive waste in geological disposal repositories relies on Engineered Barrier Systems (EBS), with bentonite clay emerging as a candidate material due to its unique properties. Understanding moisture dynamics within bentonite buffers is crucial for EBS performance, as it directly influences the material's swelling capacity, thermal and hydraulic conductivity, mechanical properties, and long‐term evolution under complex thermal‐hydrological‐mechanical (THM) processes. This study develops an advanced Electrical Resistivity Tomography (ERT)‐based framework to quantitatively monitor moisture dynamics under THM conditions. Our framework extends the Waxman‐Smits model to incorporate the coupled effects of temperature, water content, fluid chemistry, and mechanical changes on bentonite's electrical properties. Utilizing HotBENT‐Lab data from our companion paper, which includes electrical conductivity, CT density, and thermocouple measurements, this study offers a novel methodological framework bridging different scales of the model. Our results show that the extended model can estimate water content from ERT data, capturing spatial and temporal variations in moisture distribution within bentonite columns. However, the model tends to overestimate water content compared to CT density‐derived measurements. We address this discrepancy by incorporating a simplified swelling effect model, which improves agreement between ERT and CT density‐based water content estimates. We also discuss model limitations, including simplified treatment of swelling and micropore effects, and propose a conceptual framework for transitioning from laboratory to field applications, addressing challenges such as parameter scalability, field validation methods, and integration of diverse data sources. This ERT‐based framework can potentially advance real‐world moisture monitoring of bentonite‐based EBS in nuclear waste repositories.
Plain Language Summary Safely containing high‐level radioactive waste depends on barriers made from materials like bentonite clay, which is effective because it swells and seals in the waste. To ensure these barriers work well over time, it's important to understand how moisture moves through the clay. Our study developed a new method using ERT to monitor moisture levels in bentonite under conditions that mimic those in actual storage sites, including changes in temperature, water content, and mechanical stress. This study improved an existing model to better account for how these factors affect the clay, allowing us to create more accurate moisture maps. Initially, the proposed model overestimated the amount of water in the clay, but its accuracy was improved by factoring in how the clay swells when wet. This study also identified some limitations of the model and suggested ways to adapt it for use in real‐world waste storage sites. This new approach could lead to better monitoring and safety checks for nuclear waste storage systems, helping to ensure long‐term containment.
Key Points This work develops an ERT‐based framework extending the Waxman‐Smits model to monitor bentonite moisture dynamics during coupled THM processes The extended model accurately estimates water content from Electrical Resistivity Tomography data, incorporating swelling effects to improve precision This work proposes a conceptual framework for transitioning from laboratory to field applications, advancing EBS monitoring in nuclear waste repositorie
Dynamics of E6 chiral gauge theories
Get PDFWe present exact nonperturbative vacuum solutions to chiral gauge theories based on the gauge group and several matter fermions in the fundamental -dimensional representation. They are obtained when supersymmetric versions are perturbed by small supersymmetry breaking by anomaly mediation. The universality classes obtained are very different from what can be conjectured by the tumbling hypothesis. In particular, the case with three may have an unbroken SU(3) symmetry with massless composite fermions in of SU(3). For this case, we employed numerical techniques to obtain the exact ground state