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Power County Resource Guide - Idaho
Get PDFCounty level and region-specific resource guides focused on mental health and substance use
Grays Harbor County Resource Guide - Washington
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Whitman County Resource Guide - Washington
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King Seattle County Resource Guide - Washington
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Pacific County Resource Guide - Washington
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KANGAROO RAT BURROW BIOFILMS TO IMPROVE SOIL STABILITY BIOFILM-INDUCED CEMENTATION AND MICROBIAL MECHANISMS
Get PDFKangaroo rats (Dipodomys deserti) construct complex burrow systems in loose desert sand that remain stable under extreme environmental conditions due to the cementation effects of biofilms. Burrow biofilms, through their extracellular polymeric substances and filamentous structures, bind sand particles together and increase soil mechanical strength. Utilizing biofilm formations for soil improvement presents an environmentally sustainable alternative to traditional methods that rely on cement and chemical additives. As such, I investigated the mechanisms behind biofilm-induced cementation in kangaroo rat burrows and their application in soil improvement. This work included (1) characterizing microbial communities in kangaroo rat burrow sand and studying the influence of kangaroo rats on the burrow microbiome, (2) identifying the microbial species that are likely responsible for biofilm-induced cementation and assessing their potential contributions to mechanical strength of burrow sand. We collected samples from burrow ceilings of occupied burrows, abandoned burrows, and proximal surface sand in the Sonoran Desert, Yuma, AZ. The results of the first objective revealed that burrow sand exhibited greater bacterial richness and diversity compared to surface sand, with higher abundance of bacterial genera associated with nitrogen fixation, nitrification, and urea hydrolysis. The correspondence of bacterial taxa between burrows and kangaroo rats suggested that kangaroo rats influence the microbial composition of their burrow environment by introducing organic material and waste, resulting in increased species richness and bacterial diversity in the burrows. The second objective explored how different biofilms formed by different microbial species contribute to the strength in burrow sand. To address this, we quantified the tensile strength of pure and mixed biofilm cultures of burrow sand microbiota using the microcantilever technique to assess the potential influence of different species and their combinations on burrow sand tensile strength. The study identified key abundant microbial species, including the fungus Aspergillus tamarii and four bacterial species: Peribacillus frigoritolerans, Paenibacillus ehimensis, Bacillus sp., and Neobacillus niacini for testing. The tensile strength of mono-species biofilms varied, with A. tamarii exhibiting the highest tensile strength (67.3 ± 13.6 kPa) and N. niacini the lowest (9.45 ± 4.84 kPa). Dual-species biofilms exhibited synergistic or antagonistic effects depending on microbial combinations. Increasing species diversity in biofilms to five species resulted in a decline in tensile strength. These findings demonstrate that biofilms formed by different species can contribute to varying degrees of tensile strength in biofilm-induced cemented burrow sand, depending on species composition and interactions. Collectively, this dissertation improves our understanding of biofilm-induced cementation, drawing inspiration from naturally formed biocementation processes in kangaroo rat burrows and translating these insights into practical insights for soil improvement in engineering
Dataset and code for "State-dependent and social modulation of circulating glucocorticoids in a nomadic songbird, the Red Crossbill (Loxia curvirostra)"
No full textData and code for Vernasco et al. "State-dependent and social modulation of circulating glucocorticoids in a nomadic songbird, the Red Crossbill (Loxia curvirostra)" Integrative Organismal Biology https://doi.org/10.1093/iob/obaf047</p
SCALABLE GEOSPATIAL ALGORITHMS FOR FLOW MODELING
Get PDFAs remote sensing technology produces increasingly fine-resolution digital elevation models (DEMs), traditional hydrologic algorithms face computational bottlenecks. Amid rising frequencies of natural disasters due to global warming, efficiently processing this abundant topographical data has become critical. We investigate whether exploiting the structural regularities inherent in topography, such as continuity, local homogeneity, and consistent gradients, can improve computational efficiency.This thesis introduces two works that enable scalable hydrologic modeling by adapting to the inherent topographical structure. First, we present Scalable Terrain-Aware Adaptive Resolution Framework for Flow Modeling (STAAR-FM), which introduces an irregular, terrain-aware mesh that dynamically allocates computational resolution based on topographic complexity. This approach preserves hydrologic fidelity while substantially reducing computational overhead in flow accumulation, achieving 77.69% streamline matching at 30% data reduction.
Second, we develop TopoFlowGNN, a Graph Neural Network (GNN) framework that learns hydrologic dynamics on adaptive DEM-derived graphs, demonstrating the broader potential of topology-guided GNNs. TopoFlowGNN extends the concept of an adaptive grid to a more flexible representation. By embedding physical flow directionality as an inductive prior, the model efficiently learns the dynamics of flux transfer. We demonstrate its efficacy on the task of predicting flood depth, achieving Nash-Sutcliffe Efficiency of 0.728 versus 0.224 for baseline methods with real-time inference speeds of 11.68 batches/second. This addresses a problem that has historically been intractable for real-world applications due to the computational cost of numerical solvers, making flood forecasting operationally feasible where physics-based solvers require hours to days. Together, these works demonstrate the potential of adaptive terrain-aware representations for hydrologic modeling
LEADING FROM THE MIDDLE: PRINCIPAL PERSPECTIVES ON NAVIGATING COMPETING PRIORITIES
Get PDFPrincipals are uniquely positioned to impact the climate and culture of the school through leadership focused on continuous school improvement. Principals are held accountable for student outcomes and are responsible for supervising and supporting teachers while engaging families and community members. While principals are leaders of the school, they hold a middle leadership position within the school district. One significant challenge facing school principals is navigating competing school-level and district-level priorities. This qualitative study explored the lived experiences of five principals as they describe navigating competing school-based improvement efforts and district office expectations. Findings highlight four important considerations for principals and district leaders: competing priorities are a common occurrence; leadership identities and experience influence actions; and principals use the tools of strategic prioritization and communication when navigating the challenges of competing priorities. The findings indicate that this is a recurring, pervasive, complex, and challenging dilemma facing principals. Implications for practice, policy, and future research focus on preparing principals and district office leaders to work more collaboratively to create coherence through system alignment and shared accountability
ADVANCES IN TARGETED DRUG DELIVERY FOR CANCER: OVERCOMING RESISTANCE AND ENHANCING THERAPEUTIC EFFICACY
Get PDFConventional chemotherapy remains a cornerstone of cancer treatment but is hindered by poor tumor selectivity, dose-limiting toxicity, and the development of multidrug resistance. These challenges, coupled with the complexity of the tumor microenvironment, underscore the need for the development of targeted drug delivery platforms that improve therapeutic index and reduce off-target effects. This dissertation explores the design and evaluation of targeted and resistance- responsive delivery platforms through a progression of mechanistic and translational studies. The first chapter provides a comprehensive overview of current strategies in targeted drug delivery, highlighting advances in prodrug design, efflux modulation, and nanocarrier systems aimed at overcoming intrinsic and acquired resistance. Subsequent chapters present experimental work investigating efflux-mediated resistance and transporter-guided drug activation using imidazoquinoline-based immunostimulants and small-molecule prodrugs. These studies establish the mechanistic basis for exploiting efflux transporters such as P-glycoprotein to enhance immune signaling and therapeutic selectivity. Dendrimer-based drug delivery systems were designed to improve solubility, stability, and intracellular release of potent chemotherapeutics. In triple-negative breast cancer, a non-targeted dendrimer-camptothecin conjugate exhibited strong cytotoxic and apoptotic activity through controlled release and synergistic interactions with DNA damage repair inhibitors. In parallel, PSMA-targeted dendrimer conjugates for prostate cancer achieved receptor-mediated uptake, enhanced cytotoxicity, and inhibition of angiogenic and hypoxia-associated resistance mechanisms. Collectively, these studies integrate enzyme- activated and efflux-modulated prodrug design with receptor-targeted dendrimer therapeutics, establishing complementary strategies to overcome major barriers in cancer treatment. The findings demonstrate how rationally engineered delivery systems can improve solubility, selectivity, and intracellular activation while mitigating efflux-driven resistance. By combining mechanistic insight with translational relevance, this work provides a framework for developing next-generation targeted therapeutics that achieve durable and selective responses across diverse cancer models