University of North Carolina Wilmington

Crowdsourced location networks turn billions of consumer devices into a global sensor grid for locating lost items, but the same reach enables two systemic abuses: (i) location tracking via beacons that masquerade as “lost tags,” and (ii) data exfiltration by embedding short secrets in Bluetooth Low Energy (BLE) advertisements that are relayed forward without inspection. Using Apple’s Find My as a case study, we show that covert beacons reliably reach the cloud and then the attacker within minutes due to relay density. We also find that basic single-layer countermeasures such as packet dropping, TCP ACK/RST injection, fixed-delay insertion, or traffic flooding fail under realistic operational conditions. We contribute the first end-to-end experimental evaluation of deployable mitigations that require no vendor changes. Our defense-in-depth design combines: endpoint controls that correlate OS location-service access with immediate BLE advertising and enforce per-process advertising limits; a hybrid perimeter detector that correlates on-host BLE advertisement counts with outbound traffic to crowd-location backends; and physical controls for high-security areas, including exclusion zones of 35 m indoors and 200 m outdoors (line of sight), optionally supported by selective, low-duty RF jamming. For the longer term, we outline protocol changes that vendors can adopt, such as basic beacon admission control and authentication, shorter helper-retention timers, and helper-side quotas. While evaluated on Find My , these findings generalize to crowdsourced location systems built under similar design assumptions.

ABSTRACT This paper reexamines foundational liquidity factors in light of modern market dynamics, focusing on liquidity across thinly versus actively traded securities. Specifically, we explore whether the liquidity gap identified by the SEC is a byproduct of trading volume or a more complex response to evolving market factors such as market fragmentation, adverse selection, inventory costs, and competition. We find that modern liquidity components have asymmetric effects, with thinly traded securities facing significantly higher execution costs, latency, and temporal fragmentation compared to actively traded stocks. Market fragmentation, in particular, exacerbates these inefficiencies for low‐activity stocks, as liquidity becomes more fragmented and execution times increase. Furthermore, we show that competition among exchanges benefits high‐activity stocks but has a detrimental impact on the execution quality of low‐activity stocks, leading to larger quoted spreads and slower executions. Our findings suggest that liquidity disparities are not simply a function of trading volume but also reflect the impact of modern market dynamics. This has important implications for market design and regulatory policy, particularly for ensuring that thinly traded stocks are not unduly disadvantaged by fragmentation‐induced inefficiencies.

Orbitrap based Isotope Ratio MS is preferable to classical IRMS techniques for measuring PFAS compounds for a verity of reasons. The powerful new Thermo Scientific™ Orbitrap Exploris™ Isotope Solutions workflow harnesses the combination of electrospray ionization (ESI) and high-resolution accurate mass to enable the detection of isotopologues that were previously inaccessible. ESI allows ionization of PFAS directly from the solution without the necessity of converting it to a gas. ESI also has the advantage of performing “soft” ionization, which produces intact molecular ions. These intact molecules can be fragmented within the Orbitrap mass spectrometer to gain intramolecular information on site specific isotope ratios. Here we present the analytical improvements we have developed specifically for investigating the isotopic composition and structure of PFAS. This including sample introduction to enhance the accuracy and reliability of the isotope ratio analysis, buffers, tuning and optimization of ionization and Orbitrap MS parameters, and focusing on fine-tuning of critical parameters such as AGC target and resolution to achieve optimal performance. We will also explore data acquisition strategies for acquiring high-quality data in isotope analysis, including setting up full scan and fragmentation experiments, and data processing techniques to ensure precise and accurate results.

Reverse engineering remains a critical yet time-consuming task, increasingly strained by sophisticated code-obfuscation techniques. Although modern decompilers offer strong baseline capabilities, their outputs often lack readability and semantic accuracy when analyzing obfuscated binaries. In this research, we evaluate decompilation capabilities, showing high efficacy on simple binaries (95% functional similarity) but revealing critical shortcomings when faced with obfuscation techniques such as control-flow flattening and virtualization. We propose LLM4Deobfuscate, a framework for training LLMs on synthetically generated obfuscation-deobfuscation pairs, leveraging datasets like ExeBench and automated obfuscation pipelines. Our results underscore the need for a hybrid static-dynamic analysis architecture and context-aware modeling to advance LLM-driven reverse engineering.

Abstract Marine bivalve mortality events cause substantial economic losses in aquaculture and threaten global food security. While pathogenic Vibrio species are frequently implicated, growing evidence suggests that loss of beneficial microbes can increase host susceptibility to disease. We previously observed that Vibrio mediterranei was consistently isolated from healthy oysters but systematically disappeared prior to mortality events, coinciding with proliferation of pathogenic Vibrio species. Here, we test whether this pattern reflects a protective functional role. Pre-colonization with V. mediterranei strain Vm02 increased Crassostrea virginica oyster larval survival from 10-19% (pathogen-only controls) to 94-97% when challenged with V. harveyi or V. coralliilyticus , representing near-complete protection from pathogen-induced mortality. Protection was maintained at both ambient (28°C) and thermal stress (32°C) temperatures where pathogen virulence is enhanced, rapid (effective from co-inoculation), and durable (maintained for >96 hours). Fluorescence microscopy confirmed stable colonization of larval digestive tissues by fluorescently-tagged Vm02. Larval colonization by eleven V. mediterranei strains revealed three distinct phenotypes – protective, pathogenic, and intermediate – corresponding to monophyletic clades with 97.1-97.8% average nucleotide identity between protective and pathogenic lineages. Pangenome analysis identified 230 protective-specific versus 80 pathogenic-specific orthogroups. Protective strains encode unique regulatory systems, stress tolerance mechanisms, and metabolic versatility while lacking Type I and Type VI secretion system variants associated with pathogenicity. Together, these findings demonstrate that beneficial versus pathogenic phenotypes are phylogenetically constrained within distinct V. mediterranei lineages. This supports reports that V. mediterranei acts as both a pathogen and potential symbiont in marine hosts and reveals a clade that provides robust protection against oyster pathogens. Importance Aquaculture disease management has traditionally emphasized either prophylactic treatment using antibiotics to avoid disease and dysbiosis or has focused entirely on pathogen detection. Both of these approaches have overlooked the potential contributions of beneficial microbes to host defense and grow-out performance. Developing beneficial probiotic tools for disease prevention represents an emerging opportunity for sustainable aquaculture management. This study demonstrates that specific lineages of Vibrio mediterranei function as protective symbionts capable of rescuing oyster larvae from near-complete pathogen-induced mortality. By integrating field observations of microbial succession during mortality events with experimental validation and comparative genomics, we show that protective versus pathogenic phenotypes are phylogenetically constrained within V. mediterranei clades separated by 97.1-97.8% average nucleotide identity. This resolution of strain-level functional variation provides fundamental insights into how host-microbe mutualisms evolve within species complexes that also harbor pathogens. The unique genomic markers identified here enable reliable screening for protective symbionts, while the temperature-stable and durable protection demonstrated in this study highlights the potential for biological control strategies in shellfish hatcheries increasingly affected by warming oceans and Vibrio -driven mortality events.

Recreational therapists work in a broad field with numerous service settings for individuals with disabilities. Students' learning may be enhanced by providing opportunities during class time to implement services for more unfamiliar populations. Therefore, the purpose of this study was to investigate students' reflections from a class time fieldwork experience (CTFE) in a recreational therapy (RT) class with adolescents who engage in health-risk behaviors. A retrospective, qualitative content analysis of 111 RT students' perspectives was used for this study, and two main themes emerged: exposure to an unfamiliar community population and identifying personal biases and judgments. Implications are identified for RT educators and practitioners to apply these findings to future CTFEs, internships, and employment opportunities.

• Erosion rates show varying relationships with topographic metrics in the Himalaya • Climate-driven erosional efficiency differs by lithology • Erosional efficiency from metasedimentary rocks correlates with extreme rainfall • Extreme precipitation on tectonically active, steep slopes drives high efficiency Although climate can strongly influence erosional efficiency (i.e., erosion rate for a given topography), demonstrating its impact in tectonically active areas has been challenging due to other confounding controlling factors, such as lithology. Here, we show that 10 Be-derived erosion rates and efficiencies in the Himalayan orogen exhibit distinct relationships with climatic factors depending on lithology. We compile 173 10 Be-derived, basin-averaged erosion rates across the orogen, including 12 newly measured rates from the Dibang and Lohit valleys in the easternmost Himalaya, regions characterized by high precipitation magnitudes and variability. We group basins based on lithologies separated by orogen-scale thrust faults and quantify erosional efficiency coefficients based on the relationships between erosion rates and topographic metrics. Our results show that erosion rates and erosional efficiency from sedimentary and metasedimentary rocks along the Himalayan range front display a positive, nonlinear correlation with climatic factors, such as the number of extreme rainfall events and mean annual precipitation rates. In contrast, erosion rates from crystalline lithologies in the hanging wall of the Main Central thrust show a strong correlation with fluvial topography, whereas erosional efficiency shows no statistically significant correlation with climatic factors. Rapid erosion rates and high erosional efficiencies in the eastern Himalayan range front are likely driven by extreme precipitation on tectonically active, steep slopes composed of mechanically weak metasedimentary rocks. Our findings highlight the importance of the interplay between controlling factors, which include tectonics, lithology, and climate, that drive surface erosion and influence the topographic evolution of orogenic systems.

Soil erosion and sedimentation, intensified by climate change, pose significant ecological and socioeconomic challenges globally. This study investigates the hydrological and ecological impacts of sedimentation in Ethiopia’s Burji-Kelale Sediment-Dammed Lake, formed at the confluence of the Haro, Upper Segen, and Turkute Rivers. The lake’s formation and ongoing degradation are closely linked to severe soil erosion driven by deforestation, unsustainable agriculture, and vegetation loss in the surrounding watershed. The primary objective is to quantify long-term soil erosion rates and assess their impact on lake sustainability and agricultural productivity. Using the Revised Universal Soil Loss Equation (RUSLE) integrated with Geographic Information Systems (GIS) and remote sensing, the study analyzes soil erosion patterns from 2002 to 2023. Results indicate an average annual soil loss of 8.2 t ha−1 yr−1, with maximum losses reaching 1694 t ha−1 yr−1. The watershed experiences an estimated total soil loss of approximately 3.06 million tons annually. A notable sedimentation event occurred in 2012/13, when accelerated erosion led to excessive deposition, obstructing river flow and forming the sediment-dammed lake. The findings underscore a rising trend in erosion, correlating with expanding cultivation and diminishing vegetation cover. To address these challenges, the study recommends erosion control strategies such as interconnected pond systems, large-scale reforestation, and integrating modern and Indigenous land management practices. These approaches are essential to enhance ecosystem resilience and ensure the long-term sustainability of the Burji-Kelale Sediment-Dammed Lake and its surrounding watershed.