California State University Los Angeles

With wildfires occurring yearly in the United States, an increased risk of wildfire-induced microplastic contamination is common. Wildfires can generate microplastics from the thermal degradation of plastic materials found near urban areas, which then infiltrate soils as ash deposits. The contaminated soil’s geotechnical properties can differ depending on the contamination level compared to pure fine-grained soil. The effect of microplastics on clay particles and behavior is studied using a simple shear apparatus, with built-in bender element caps, at the California State University, Los Angeles. This paper examines the effects of polyethylene terephthalate (PET) contamination concentration of 10% by weight in kaolin clay samples. Introducing microplastics in the soil may result in changes in cohesion, friction angles, and shear modulus compared to kaolin samples, depending on the strain levels. By using the bender elements from the simple shear apparatus, the kaolin samples with microplastics showed higher stiffness at smaller strains.

Selenium contamination in arid agricultural basins remains a key ecological concern, yet the Wister Unit of the Imperial Wildlife Area has received comparatively little hydrochemical study. This investigation provides the most integrated assessment to date of selenium, salinity, nitrate, stable water isotopes (δ2H and δ18O), and selected redox-sensitive trace elements within the Wister Unit and its contributing open agricultural drains, with the goal of identifying controls on selenium concentrations and mobility. Water samples from open agricultural drains, shallow groundwater tile drains, canal project water, and tailwater return flow were analyzed for Total Dissolved Solids (TDS), major ions, nutrients, selenium, and stable water isotopes. A subset of samples was anlayzed for iron, manganese, and vanadium. Overall, 71% of open drain and tile drain samples collected in this study exceeded the U.S. Environmental Protection Agency aquatic-life criterion of 5 µg/L, indicating persistent ecological risk. All waters plotted along an evaporation trajectory originating from imported Colorado River irrigation water; however, isotopic enrichment did not scale directly with salinity. Pure evaporation models predicted much lower TDS values than observed, and the most evaporated samples were not the most saline or selenium-rich. These results demonstrate that simple soil water evaporation alone cannot explain the data. Instead, the broad isotopic range at similar salinities reflects a secondary process in which salts that accumulated in soils during dry or average years are later mobilized and flushed during periods of surplus water and heavy irrigation. Low dissolved iron, manganese, and vanadium concentrations in a subset of water samples indicate predominantly oxidizing conditions, under which selenium behaves conservatively during salt leaching, producing a strong correlation with TDS. Selenium levels measured in Wister Unit are generally lower than those reported in nearby areas during the 1990s–2000s, implying changes in salt accumulation, hydrologic routing, or agricultural practices. These results refine the conceptual model for the Wister Unit and motivate future work on selenium speciation, nitrate isotope tracing, time series monitoring, and soil-salt interactions.

Several factors may influence adherence to the recommended twice-weekly strength activity guideline. Currently, there is a paucity of literature examining the associations of socioeconomic status (SES) on meeting the strength activity guideline among adults with disabilities. The purpose of this analysis is to examine the associations of SES on meeting the strength activity guideline among people with disabilities. Using data from the 2017-2019 Behavioral Risk Factor Surveillance System, 14,425 adults with disabilities were classified as meeting or not meeting the strength activity guideline. Several SES variables, education, employment status, income level, household size, number of children, federal poverty level, partnered status, and homeownership were included in the analysis and served as independent variables. Separate unadjusted and adjusted logistic regression models were conducted to relate the effect of SES on meeting the strength activity guideline among people with disabilities. Among participants, 73.73% (95% CI [72.28, 75.15]) did not meet the guideline. Participants who were college or technical school graduates (aOR = 1.97, 95% CI [1.50, 2.57]) were more likely to meet the strength activity guideline, while other SES variables were found to be not statistically significantly associated with meeting the strength activity guideline (p > .05). Many SES factors were not associated with meeting the strength activity guideline among people with disabilities. Future targeted strategies may need to consider factors besides SES factors of people with disabilities to promote adherence to the strength activity guideline.

ABSTRACT Research Question/Issue This study examines the role of government as a major customer in influencing corporate social responsibility (CSR) initiatives among supplier firms. Specifically, it investigates whether firms that rely on government customers are more likely to engage in substantive CSR practices to meet government expectations and maintain strong business relationships. Research Findings/Insights Our findings indicate that supplier firms with greater reliance on government customers exhibit a higher propensity to adopt CSR‐related executive compensation plans, establish CSR committees within their boards of directors, and voluntarily disclose climate change risks in their SEC filings. These effects are more pronounced for firms operating in states governed by Democrats and for smaller firms. To address endogeneity concerns, we employ instrumental variable analysis, difference‐in‐differences estimation, and entropy balancing, all of which reinforce the robustness of our results. Theoretical/Academic Implications This study contributes to the literature on CSR and stakeholder theory by highlighting the government's role as an influential stakeholder in shaping firms' CSR engagement through supply chain relationships. It also extends research on political economy by demonstrating how political leadership at the state level moderates firms' CSR responsiveness to government customers. Practitioner/Policy Implications Our findings suggest that policymakers can leverage government procurement policies to incentivize broader CSR adoption among supplier firms, thereby fostering positive social externalities. Firms seeking to establish or maintain government contracts should consider aligning their CSR strategies with government expectations to enhance their business relationships and long‐term sustainability.

Circadian rhythms generated by molecular clocks time a diverse array of physiological cycles in many organisms. Cyanobacteria are currently the only prokaryotic system with a robust and rigorously tested circadian clock, which is carried out by KaiA, KaiB, and KaiC core oscillator proteins. This KaiABC oscillator drives global rhythms in gene expression, compaction of the chromosome, natural transformation, and timing of cell division in the model organism Synechococcus elongatus PCC 7942. The oscillator proteins have been previously shown to undergo changes in their subcellular localization patterns, where KaiA and KaiC are diffuse throughout the cell during the day and localize to or near one pole of the cell at night. However, functional fluorescent fusions of KaiB to track subcellular localization could not be obtained. More recently, we have described the identification of Rbp2 as a member of the extended clock network that associates with KaiC in a localized state. However, the subcellular localization patterns of KaiB and Rbp2 remain uncharacterized, and the mechanism driving the dynamic localization of circadian proteins remains undescribed. Here, we describe the patterns of KaiB and Rbp2 subcellular localization over the course of the day. Specifically, we demonstrate that KaiB and Rbp2 form polar foci and co-localize with KaiC at night using both traditional fusions to fluorescent proteins and endogenously expressed antibodies. We show that the RNA-binding activity of Rbp2 is necessary for the robust formation of Rbp2 foci. We propose a model by which Rbp2 drives circadian protein localization via its RNA binding activity.IMPORTANCECircadian rhythms driven by a circadian clock are required to time a wide range of physiological and metabolic processes. In cyanobacteria, the circadian clock is required for optimal fitness in environmental cycles. Where the clock proteins are located within the cell and how this helps them to synchronize with the environment and time rhythmic behaviors is incompletely understood. Here, we demonstrate that recently identified extended clock protein Rbp2 and core oscillator protein KaiB localize to the cell poles at night and co-localize with other members of the clock complex. We also demonstrate that the RNA binding activity of Rbp2 is necessary for the polar localization of Rbp2. Moreover, the use of endogenously expressed antibodies introduces a new and robust method for imaging challenging proteins in bacteria that is applicable across various fields.

Implementing enterprise risk management (ERM) helps organizations identify, assess, and manage emerging risks. As global ecosystems face intensifying environmental, social and governance (ESG) pressures—including climate risks, regulatory demands for sustainability reporting and stakeholder expectations for ecosystem protection —the internal audit function (IAF) plays an increasingly critical role in helping organizations monitor and respond to these risks. Internal auditors’ expertise supports risk identification and assessment, though management maintains responsibility for risk management and control. Using the Committee of Sponsoring Organizations’ (COSO) ERM framework, we review 77 studies across 23 journals published between 2004 and 2024. Prior research primarily examines internal audit’s assurance and consulting roles, with considerably less attention given to activities that compromise independence. While evidence suggests that internal audit quality enhances risk management effectiveness, uncertainty remains about boundaries for consulting activities and technology-enabled assurance. Our synthesis highlights limited empirical insight into internal audit’s strategic partnership role in ERM and identifies future research opportunities for scholars, practitioners and standard setters.