Per- and polyfluoroalkyl substances (PFAS) contamination has become a prevalent problem due to their widespread accumulation in the environment and concerns over their public health implications. The US federal government has had a fragmented response to PFAS contamination; however, some states have adopted multifaceted policy approaches. The state of Maine has implemented several such interventions including education and outreach, labeling and registry requirements, prosecution, prohibitions, victim support, and remediation. We propose that Maine is at the leading edge of regulation of PFAS compounds with first-of-their-kind action thresholds in beef, dairy, and eggs as well as bans on spreading agricultural sludge. We summarize Maine’s existing regulatory landscape and articulate an integrated policy framework intended to generate improved environmental and human health outcomes. Since contamination does not recognize state lines; the nation needs protective, comprehensive, and consistent polices to effectively eliminate PFAS pollution and remediate the widespread contamination.
The co-pyrolysis of hazardous antibiotic sludge (AS) and waste tires is a promising valorization pathway; however, its implementation is hindered by high activation energy barriers, the release of toxic nitrogenous gases (e.g., HCN), and the formation of low-quality bio-oil. To address these challenges, this study synthesized a bimetallic hierarchical zeolite (Ni-Co/AZ) to modulate the co-pyrolysis pathways of AS with polyurethane/ rubber tires. Hydrogen spillover, generated from tire-derived radicals on the Ni-Co alloy surface, suppressed HCN formation and promoted aromatization. Thermokinetic analysis revealed that Ni-Co/AZ shifted the reaction mechanism from random chain scission (F1) to a three-dimensional diffusion-controlled model (D3), reducing the apparent activation energy by more than 50% (to approximately 28 kJ/mol). In-situ gas monitoring and liquid-phase analysis confirmed that this hydrogen spillover redirected toxic HCN precursors into gaseous NH3 and stable nitrogenous compounds (i.e., fatty nitriles and aromatic amines), achieving gas-liquid biphasic detoxification. Concurrently, the catalyst promoted deoxygenation via decarboxylation and hydrodeoxygenation, reducing the liquid-phase oxygenate content to 5.8%. The size-exclusion effect of the hierarchical zeolite network coupled with bimetallic active sites enabled microporous shape-selective aromatization, increasing the yields of monoaromatic hydrocarbons and light fuel gases while suppressing heavy polycyclic tars. Building upon these mechanistic insights, machine-learning-driven multi-objective optimization was employed to predict temperature and feedstock combinations that maximized co-pyrolysis efficiency and volatile product selectivity. This study provides molecular-level insights into metal-acid bifunctional catalysis, establishing an efficient and sustainable route for valorizing multiple solid waste streams.
With the rapid uptake of environmental DNA (eDNA) metabarcoding for a wide range of conservation and management uses, there is a growing need for guidance and best practices for species identification. A range of methodological and interpretive decisions influences taxa assignment. Here we provide a review and perspective of pitfalls and issues that can impact accurate taxonomic assignment across the full eDNA metabarcoding workflow: primer selection, lab handling, bioinformatics, taxonomic assignment, and communication of results. This paper addresses the complexities and challenges of the metabarcoding-based species identification process, offering recommendations for robust workflows and effective communication of findings. Accurate interpretation and communication of eDNA metabarcoding results requires an acknowledgment of methodological limitations such as incomplete reference databases, contamination risks, ambiguous sequences, and detection biases. Thus, we argue that transparency of methods and limitations, alongside proactive alignment of decisions with project objectives are critical for the successful application of eDNA metabarcoding in conservation and management decisions. We provide guidance for developing protocols that support species identification from eDNA metabarcoding sequences, and give recommendations on communication strategies for stakeholders and end users. To support these recommendations, we outline steps in the workflow that can impact species identification, with a discussion of the strengths and weaknesses at each stage. Ultimately, this guidance can improve the accuracy, reliability, and usability of eDNA and other metabarcoding and amplicon sequencing approaches to species identification while fostering trust and understanding among diverse end users.
Under recurring droughts, the southwestern U.S. loses a significant proportion of precipitation as evapotranspiration (ET), suggesting an opportunity to reduce ET via forest thinning. To better understand the potential impacts of thinning on the forest hydrologic cycle, we used sap flow sensors and Bowen ratio stations to measure ET in thinned and non-thinned ponderosa pine (Pinus ponderosa Douglas ex C. Lawson) stands in northern Arizona during the wet year of 2023, where thinning removed 42% of overstory basal area. Although our study site had experienced prolonged drought in previous years, heavy winter snowfall made 2023 a wet year. We correlated sap flow with environmental variables and used principal component analysis to identify the primary drivers of ponderosa pine water use in thinned and non-thinned stands. Results showed that after accounting for tree size, thinned stands had similar to 20% (similar to 5 L day(-1)) higher individual-tree water use at daily and weekly temporal scales than non-thinned stands. At the stand level, thinning decreased overstory ET (OET) but increased understory ET (UET), indicating a reallocation of outgoing water fluxes in the water balance. As a result, total ET (sum of OET and UET) decreased from 584 to 516 mm year(-1). In the semi-arid forest, this decrease in total ET of 68 mm year(-1) (similar to 12% reduction) indicates an ecohydrologically meaningful outcome of forest thinning. In both stands, tree water use was strongly regulated by environmental variables, primarily atmospheric variables such as air temperature and vapor pressure deficit. Overall, our results suggest that thinning can still promote an improved stand-level forest water balance during a wet year and thus may enhance forest resilience under projected increases in heat and aridity in the southwestern U.S.
The relationship between emotion regulation and functional impairment in youth is well-established in the extant literature on anxiety disorders, yet the specific mechanisms that underlie this relationship are less understood. Parental accommodation, a range of beliefs and behaviors intended to reduce anxiety in youth, consistently has emerged as a strong predictor of youth anxiety-related impairment. Parents of anxious youth may be more likely to engage in parental accommodation when their child demonstrates difficulties in emotion regulation. The present study sought to extend this literature by examining the association between emotion regulation and parental accommodation beliefs and behaviors. We hypothesized that difficulties in emotion regulation and multi-informant youth and parent impairment would be associated vis-à-vis parental accommodation beliefs and behaviors, over and above youth anxiety symptom severity. Participants included 280 youth seeking outpatient mental health treatment and their parents or caregivers. Parents reported on youth emotion regulation and impairment, as well as their own accommodation and impairment. Youth reported their own anxiety-related impairment and anxiety symptom severity. A path analysis model examined the indirect effect of emotion regulation on anxiety-related impairment through impact on parental accommodation beliefs and behaviors controlling for youth age, gender, and anxiety symptom severity. Only parental accommodation behaviors accounted for the link between youth emotion regulation and impairment. Findings provide preliminary support for the importance of addressing parental accommodation in response to difficulties in emotion regulation for clinically anxious youth.
