Western Carolina University

Abstract. Photoacoustic spectroscopy (PAS) has become a common method for measuring aerosol absorption and is one of the few techniques capable of directly measuring absorption by suspended aerosol particles at ambient concentrations. When multiple wavelengths are used, PAS provides a way of measuring the absorption Ångström exponent (AAE) and, when combined with a scattering or extinction method, provides a measure of the aerosol single-scattering albedo (SSA), and both AAE and SSA are important parameters in climate models. Despite this utility, few commercial PAS instruments are available, and no multi-wavelength commercial instruments are currently available. Thus, most extant PAS instruments are custom-built and therefore come with considerable cost and development time and require access to machine shops capable of fabricating the needed components. The goal of this work was to provide a blueprint for a low-cost, multi-wavelength PAS for measurement of the aerosol AAE both in the laboratory and in the field. In an effort to create an instrument with a low barrier to entry, we aim to use low-cost, readily available components and use open-source options wherever possible. In this paper, we present the SiMPLE-PAS, a single-pass, multi-wavelength, portable, and low-expense photoacoustic spectrometer that uses low-cost electronics and a 3D-printed cell to meet these design goals. The instrument has a total bill-of-materials cost on the order of USD 500. The instrument is, to the best of our knowledge, the first 3D-printed PAS for aerosols and likely the lowest-cost PAS to date. The instrument performed well in laboratory validation experiments and showed good agreement with measurements of aerosol absorption by the previously developed MultiPAS-IV instrument when co-located at the second Georgia Wildland Fire Simulation Experiment (G-WISE 2) during April 2025. The instrument shows competitive detection limits of 0.63, 1.99, and 0.55 Mm−1 for the blue, green, and red channels (10 min, 2σ), respectively, which will allow it to measure both ambient and laboratory-generated aerosols. The SiMPLE-PAS therefore provides a low-cost, accessible photoacoustic spectrometer that offers to lower the barrier to entry for groups wishing to measure aerosol absorption, whether in the laboratory or in the field.

In this paper, we leverage insights from an MPA class in election administration at a mid-sized university to learn more about the practice of election administration as public administration in a crisis. Students interviewed election administrators in areas affected by Hurricane Helene. Substantively, the results demonstrate that election administrators are critical to a well-functioning democracy and can help mitigate problems introduced by disasters. In terms of curriculum design, the paper demonstrates that election administration courses have a great deal to offer MPA students and public affairs education. From a course design perspective, the success of the assignment and the insights gained about election administration as public administration shows the value of using place-based assignments to aide student learning in public administration courses.

ABSTRACT Teacher educators encounter significant challenges in preparing preservice teachers (PSTs) to teach writing, largely due to the limited availability of specialized writing methods courses in university curricula. Research indicates that dedicated coursework can enhance PSTs’ future teaching practices. This qualitative study investigates the development of noticing and naming as a social practice among early childhood (K-5) PSTs (n = 39) in response to a student’s writing sample over time within a writing methods course. Grounded in sociocultural theory and the concept of communities of practice, the purpose of this study was to examine how and in what ways PSTs developed their abilities to assess and provide guidance based on a student’s writing sample. We analyzed what PSTs noticed and named within a student’s opinion writing sample to explore their observations and the influence of these insights on their instructional decisions. Findings reveal that PSTs improved their ability to identify effective writing techniques, shifting their focus from editing mechanics to content-related elements as the semester progressed. These findings contribute to writing teacher education by underscoring the role of methods courses in fostering PSTs’ pedagogical skills in responding to student writing.

Micranthesvirginiensis (Saxifragaceae) is an herbaceous, flowering plant species native to eastern North America with a range extending from the Gulf of Mexico into Canada. This broad range, known from previous studies to contain individuals with varying chromosome numbers and morphological variation outside of the current formal description, indicates the need for a re-examination of the taxonomy of this species. Some populations in south-eastern Appalachia display intermediate traits between M.virginiensis and the peripatric congener M.careyana and have unresolved phylogenetic placement, raising the possibility of hybridisation. This study explored hypotheses of hybridisation and undescribed taxa within M.virginiensis, based on morphometric and chromosome data collected from samples across Eastern North America. Floral, fruit and leaf measurements were analysed to investigate morphological variation across the species’ range. Chromosome counts from south-eastern U.S.A. congener populations of M.careyana, M.palmeri and M.petiolaris all showed diploidy (2n = 20), representing the first known chromosome counts for these species. Tetraploidy and unique floral morphology in two populations of the Blue Ridge Escarpment of SC, where the distribution of M.virginiensis and M.careyana abut, indicate an undescribed species, possibly of hybrid origin. Other tetraploid populations in the south-eastern USA showed no morphological differences from diploid M.virginiensis, suggesting autopolyploidy. In addition, we document a trend of decreased reproductive investment with increasing elevation within M.virginiensis. Overall, the taxonomic boundaries across the broad range of M.virginiensis proved intact, aside from the escarpment tetraploid species. Here, we describe the new escarpment species, Micranthesscopularum Hall, Lanning & Mathews and provide a complete list of synonyms of M.virginiensis, in which we designate two lectotypes and one neotype.

Major morphological adaptations characterized the early evolutionary history of sarcopterygians during the Devonian (419-359Ma) and the Carboniferous (359-299Ma), punctuated by environmental changes and biodiversity crises. Here we present geometric morphometrics analyses of early sarcopterygian morphology to explore the impact of environmental and phylogenetic constraints on their morphology. Three analyses were performed by digitizing 2D landmarks and semi-landmarks on palaeontological reconstructions of the body shape, cheek, and skull roof. Major changes in shape seem associated with geological and biological changes from the Late Devonian and Early Carboniferous (Mississippian). An increase in shape diversity occurred during the Middle Devonian, when the first forests appeared, influencing freshwater and transitional environments, and when reef ecosystems were the most diversified. Skull roof and cheek disparity decrease during the end-Devonian mass extinction and recover during the Mid-Late Mississippian, with the reemergence of metazoan reefs and the rise of surviving groups such as actinistians. The skull roof disparity is associated primarily with shared ancestry and appears to be largely driven by the lack of an intracranial joint in dipnoans and tetrapods. The Devonian to Carboniferous environmental changes constitute a major turning point in early sarcopterygian history by having deeply impacted their morphological disparity.

This article will highlight how student choice in online asynchronous classes can offer personalized experiences for students. The choices provided for students increased their motivation, interest, personal connections, comprehension, and allowed them to apply the information to their current or future career goals. Instructors can design pathways for personal choice through content offered, options for discussing content, and avenues for applying acquired knowledge.