Publications by Colleges and Departments (MSU - Bozeman)
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Item A Deeper Look into eFEDS AGN Candidates in Dwarf Galaxies with Chandra(American Astronomical Society, 2024-10) Sanchez, Adonis A.; Reines, Amy E.; Bogdán, Ákos; Kraft, RalphThe ability to accurately discern active massive black holes (BHs) in nearby dwarf galaxies is paramount to understanding the origins and processes of "seed" BHs in the early Universe. We present Chandra X-ray Observatory observations of a sample of three local dwarf galaxies (M* ≤ 3 × 109M⊙, z ≤ 0.15) previously identified as candidates for hosting active galactic nuclei (AGN). The galaxies were selected from the NASA-Sloan Atlas with spatially coincident X-ray detections in the eROSITA Final Equatorial Depth Survey. Our new Chandra data reveal three X-ray point sources in two of the target galaxies with luminosities between log(L2−10 keV [erg s−1]) = 39.1 and 40.4. Our results support the presence of an AGN in these two galaxies and an ultraluminous X-ray source (ULX) in one of them. For the AGNs, we estimate BH masses of MBH ∼ 105−6M⊙ and Eddington ratios on the order of ∼10−3.Item Cross-State Validation of a Tool Supporting Implementation of Rural Kinship Navigator Programs(MDPI AG, 2024-09) Routh, Brianna; McKibbin, Christine L.; Wihry, David; Crittenden, Jennifer; Foluso, Ayomide A.; Jain, JenniferWhile kinship care is prevalent and preferred over out-of-family care, there are relatively few measurement tools validated for use with this audience. The Title IV-E Clearinghouse, used to rate Families First Prevention Services such as Kinship Navigator Programs, requires valid tools. Such families face a myriad of needs in supporting children in their care. Previous research has established the significant challenges faced by rural families. Accurate assessment of these needs, particularly for rural families, is an essential component of kinship navigation services. In this study, we examined the face validity of the Family Needs Scale for use with kinship caregivers in rural programs. Methods: The evaluation teams with each respective kinship program conducted four virtual focus groups comprising kinship caregivers (n = 18) in three rural states. Participants were recruited from outside an ongoing Kinship Navigator Program Evaluation sample but had previously received program support as kinship caregivers. All states received IRB approval from their respective universities. Verbal consent was obtained at the time of the focus group. Focus groups lasted approximately 60–90 min and participants received a gift card incentive. Data were transcribed and qualitatively coded by question set and individual questions to identify phenomenological trends. Findings: Across four focus groups, we found four themes: (1) Broad agreement regarding the face validity of most assessment items; (2) Lack of clarity and shared understanding of several terms used within the tool, (3) Responses change with Ages and Stages of kinship family, and (4) Perspective considerations varying when completing the assessment. Discussion: Findings indicate that most assessment items had strong face validity, where there are a few opportunities to clarify key concepts relevant to rural kinship families and assess additional needs to understand the situational scope of the kinship experience. Overall, the needs assessment tool appears to have validity in assessing current kinship needs and outcomes within Kinship Navigator program evaluation.Item Development and Preliminary Validation of the Complicated and Adaptive Grief Inventory for Native Americans(SAGE Publications, 2024-08) Gameon, Julie A.; FireMoon, Paula; Skewes, Monica C.Grief research among American Indian (AI) and Alaska Native (AN) people has been limited to studies on historical trauma and elevated mortality rates among AI/ANs. A lack of validated measures is one barrier to grief research with AI/ANs. Therefore, we conducted three studies to develop and validate a culturally congruent measure of grief. In Study 1, interviews were conducted with 12 AI reservation-based community members to understand perspectives on grief. In Study 2, AI/AN community members (n = 10) and professionals (n = 7) provided feedback on measure items adapted or developed in Study 1. In Study 3, exploratory and confirmatory factor analyses using separate randomly selected samples from a web-based survey of 600 AI/ANs were conducted to identify the factor structure of the Complicated and Adaptive Grief Inventory for Native Americans (CAGI-NA). Findings suggest that the resulting 30-item CAGI-NA is valid, reliable, and suitable for use in research with AI/AN people.Item Casual language and statistics instruction: evidence from a randomized experiment(International Association for Statistical Education, 2024-08) Hill, Jennifer; Perrett, George; Hancock, Stacey; Win, Le; Bergner, YoavMost current statistics courses include some instruction relevant to causal inference. Whether this instruction is incorporated as material on randomized experiments or as an interpretation of associations measured by correlation or regression coefficients, the way in which this material is presented may have important implications for understanding causal inference fundamentals. Although the connection between study design and the ability to infer causality is often described well, the link between the language used to describe study results and causal attribution typically is not well defined. The current study investigates this relationship experimentally using a sample of students in a statistics course at a large western university in the United States. It also provides (non-experimental) evidence about the association between statistics instruction and the ability to understand appropriate causal attribution. The results from our experimental vignette study suggest that the wording of study findings impacts causal attribution by the reader, and, perhaps more surprisingly, that this variation in level of causal attribution across different wording conditions seems to pale in comparison to the variation across study contexts. More research, however, is needed to better understand how to tailor statistics instruction to make students sufficiently wary of unwarranted causal interpretation.Item Hybrid Radial-Axial Flow for Enhanced Thermal Performance in Packed Bed Energy Storage(Wiley, 2024-10) Al-Azawii, Mohammad M. S.; Anderson, RyanIn this work, a hybrid radial-axial (HRA) system is used to store thermal energy in a packed bed. The heat transfer fluid (HTF) is delivered via a perforated radial pipe placed at the center of the packed bed along the axial length. Hot fluid flows from the center toward the wall through the holes (like other radial systems), but then leaves via the traditional axial flow exit, creating the HRA flow configuration. A computational fluid dynamics (CFD) model is used to analyze the thermal performance of the packed bed during the charging process utilizing the new HRA system. Alumina beads of 6 mm were filler materials and air was HTF with inlet temperature of 75°C for proof of concept. The present paper focuses on two aims: (1) utilizing CFD models to analyze flow and temperature profiles in the packed bed; (2) comparing the model results to experimental results published in a previous HRA flow study and to traditional axial flow. Two HRA configurations were considered based on previous experimental designs, one with uniform holes in the central pipe (R1) and one with gradients in the hole sizes to promote even flow from the central pipe into the bed (R2). The numerical results agree with the experimental results in both cases. The HRA system performance depends on the flow profile created by the hole designs, and it can perform better than the axial flow depending on the design of the radial pipe. Design R2, which promotes even flow from the central pipe into the bed, has higher charging efficiency than standard axial flow methods. For HRA design R2 at 0.0048 m3/s (7 SCFM, standard cubic feet per minute), numerical results for charging efficiency were 75.5% versus 73.8% for traditional axial flow. For HRA design R2 at 0.0061 m3/s (9 SCFM), numerical charging efficiency was 80.5% versus 78.1% for traditional axial flow. These results are consistent with experimental data.Item A Review on Recent Progress of Biodegradable Magnetic Microrobots for Targeted Therapeutic Delivery: Materials, Structure Designs, and Fabrication Methods(ASME International, 2024-08) Cao, Yang; Nunez Michel, Karen; Alimardani, Farzam; Wang, YiTargeted therapeutic delivery employs various technologies to enable precise delivery of therapeutic agents (drugs or cells) to specific areas within the human body. Compared with traditional drug administration routes, targeted therapeutic delivery has higher efficacy and reduced medication dosage and side effects. Soft microscale robotics have demonstrated great potential to precisely deliver drugs to the targeted region for performing designated therapeutic tasks. Microrobots can be actuated by various stimuli, such as heat, light, chemicals, acoustic waves, electric fields, and magnetic fields. Magnetic manipulation is well-suited for biomedical applications, as magnetic fields can safely permeate through organisms in a wide range of frequencies and amplitudes. Therefore, magnetic actuation is one of the most investigated and promising approaches for driving microrobots for targeted therapeutic delivery applications. To realize safe and minimally invasive therapies, biocompatibility and biodegradability are essential for these microrobots, which eliminate any post-treatment endoscopic or surgical removals. In this review, recent research efforts in the area of biodegradable magnetic microrobots used for targeted therapeutic delivery are summarized in terms of their materials, structure designs, and fabrication methods. In the end, remaining challenges and future prospects are discussed.Item MetaCDP: Metamorphic Testing for Quality Assurance of Containerized Data Pipelines(IEEE, 2024-06) ur Rehman, Faqeer; Umbreen, Sidrah; Rehman, MudasserIn the ever-evolving world of technology, companies are investing heavily in building and deploying state-of-the-art Machine Learning (ML) based systems. However, such systems heavily rely on the availability of high-quality data, which is often prepared/generated by the Extract Transform Load (ETL) data pipelines; thus, they are critical components of an end-to-end ML system. A low-performing model (trained on buggy data) running in a production environment can cause both financial and reputational losses for the organization. Therefore, it is of paramount significance to perform the quality assurance of underlying data pipelines from multiple perspectives. However, the computational complexity, continuous change in data, and the integration of multiple components make it challenging to test them effectively, ultimately causing such solutions to suffer from the Oracle problem. In this research paper, we propose MetaCDP, a Metamorphic Testing approach that can be used by both researchers and practitioners for quality assurance of modern Containerized Data Pipelines. We propose 10 Metamorphic Relations (MRs) that target the robustness and correctness of the data pipeline under test, which plays a crucial role in providing high-quality data for developing a clustering-based anomaly detection model. To show the applicability of the proposed approach, we tested a data pipeline (from the E-commerce domain) and uncovered several erroneous behaviors. We also present the nature of issues identified by the proposed MRs, which can better help/guide software engineers and researchers to use best coding practices for maintaining and improving the quality of their data pipelines.Item Osteoarthritis Year in Review 2024: Molecular biomarkers of osteoarthritis(Elsevier BV, 2024-10) Welhaven, Hope D.; Welfley, Avery H.; June, Ronald K.Objective. To provide a comprehensive and insightful summary of studies on molecular biomarkers at the gene, protein, and metabolite levels across different sample types and joints affected by osteoarthritis (OA). Methods. A literature search using the PubMed database for publications on OA biomarkers published between April 1, 2023 and April 30, 2024 was performed. Publications were then screened, examined at length, and summarized in a narrative review. Results. Out of the 364 papers initially identified, 44 publications met inclusion criteria, were relevant to OA, and were further examined for data extraction and discussion. These studies included 1 genomic analysis, 22 on protein markers, 6 on metabolite markers, 9 on inflammatory mediators, and 6 integrating multiple molecular levels. Conclusions. Significant advancements have been made in identifying molecular biomarkers for OA, encompassing various joints, sample types, and molecular levels. Despite this progress, gaps remain, particularly in the need for validation, larger sample sizes, the integration of more clinical data, and consideration of covariates. For early detection and improved treatment of OA, continued efforts in biomarker identification are needed. This effort should seek to identify effective biomarkers that advance early detection, support prevention, evaluate interventions, and improve patient outcomes.Item Functional attributes of conifers expanding into temperate semi-arid grasslands modulate carbon and nitrogen fluxes in response to prescribed fire(Springer Science and Business Media LLC, 2024) Gay, Justin D.; Currey, Bryce; Davis, Kimberley T.; Brookshire, E. N. JackFire exclusion is a key factor driving conifer expansion into temperate semi-arid grasslands. However, it remains unclear how reintroducing fire affects the aboveground storage of carbon (C) and nitrogen (N) in the expanding tree species and belowground in soils. To assess the impacts of fire reintroduction C and N pools and fluxes in areas of conifer expansion we targeted a region of the Northern Great Plains that has experienced extensive woody plant expansion (WPE) of two species: ponderosa pine (Pinus ponderosa) and juniper (Juniperus spp). We quantified tree mortality of both species to estimate the amount of dead biomass C and N produced by a recent prescribed fire, in addition to changes in soil C, pyrogenic C (PyC), and N concentrations across a woody-cover gradient using a before/after/control experimental design. Post-fire soil chemical analysis revealed a 2 year increase in mineral soil C, PyC and N, suggesting the return of fire led to the transfer of partially combusted plant organic matter back to the soil. Further, we found that functional trait differences between the two species influenced the distribution of living conifer biomass-N prior to fire. Despite junipers having 41% less total aboveground biomass than ponderosa, they contained two times more aboveground N. Prescribed fire resulted in 88% mortality of all mature juniper stems and increased fire severity correlated with greater pre-fire juniper cover. Ponderosa mortality varied by size class, with > 40 cm stem diameter class having only 28% mortality. High mortality and greater aboveground N storage in juniper biomass, compared to ponderosa, led to 77% of the total conifer biomass N lost. Consequently, the functional attributes of expanding trees differentially contribute to fluxes of C and N after the return of fire, with junipers acting as conduits for N movement due to their relatively higher N content in less fire-resistant tissues and ponderosa serving as important and more stable storage pools for C. Together, these findings highlight the importance of considering species-specific traits when planning WPE management strrategies at landscape-scales, particularly when goals include C storage or soil nutrient status.Item Spatial Risk Effects From Lions Compound Impacts of Prey Depletion on African Wild Dogs(Wiley, 2024-10) Goodheart, Ben; Creel, Scott; Schuette, Paul; Droge, Egil; Becker, Justine A.; Banda, Kambwiri; Kusler, Anna; Matsushima, Stephi; Banda, Kachama; Kabwe, Ruth; Donald, Will; Reyes de Merkle, Johnathan; Kaluka, Adrian; Chifunte, Clive; Becker, Matthew S.Prey depletion threatens many carnivore species across the world and can especially threaten low-density subordinate competitors, particularly if subordinates are limited to low densities by their dominant competitors. Understanding the mechanisms that drive responses of carnivore density to prey depletion is not only crucial for conservation but also elucidates the balance between top-down and bottom-up limitations within the large carnivore guild. To avoid predation, competitively subordinate African wild dogs typically avoid their dominant competitors (lions) and the prey rich areas they are associated with, but no prior research has tested whether this pattern persists in ecosystems with anthropogenically-reduced prey density, and reduced lion density as a result. We used spatial data from wild dogs and lions in the prey-depleted Greater Kafue Ecosystem to test if wild dogs continue to avoid lions (despite their low density), and consequently avoid habitats with higher densities of their dominant prey species. We found that although lion density is 3X lower than comparable ecosystems, wild dogs continue to strongly avoid lions, and consequently avoid habitats associated with their two most important prey species. Although the density of lions in the GKE is low due to prey depletion, their competitive effects on wild dogs remain strong. These effects are likely compounded by prey-base homogenization, as lions in the GKE now rely heavily on the same prey preferred by wild dogs. These results suggest that a reduction in lion density does not necessarily reduce competition, and helps explain why wild dogs decline in parallel with their dominant competitors in ecosystems suffering from anthropogenic prey depletion. Protecting prey populations within the few remaining strongholds for wild dogs is vitally important to avoid substantial population declines. Globally, understanding the impacts of prey depletion on carnivore guild dynamics should be an increasingly important area of focus for conservation.