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The Depositional Environment of the Triassic Cow Branch Formation, Dan River Basin of Virginia and North Carolina Through Petrographic Study and Geochemical Analysis, and in Relation to Taphonomic Processes and Vertebrate Morphology
No full textThe Upper Triassic Cow Branch Formation of the Dan River Basin, located in southern Virginia and northern North Carolina, has long captivated generations of geoscientists. Since the 1970s, researchers have sought to unravel the mystery surrounding the depositional environment of this ancient lake system. This world-class lagerstätte hosts a diverse assemblage of fossil fauna and flora, with a notable preservation bias toward fossil vertebrates, most prominently the archosauromorph, Tanytrachelos ahynis. The geology of the Cow Branch strata continues to evoke a persistent question: Are these sediments representative of a shallow or deep lake?
I undertook a petrographic and geochemical study of the Cow Branch Formation to examine the unique depositional environment that led to this remarkable fossil assemblage. The petrographic study was done on rock samples collected from road and railway cuts around the Cow Branch depositional center. Samples were also analyzed for total organic carbon (TOC) percentages and examined for 87Sr/86Sr isotope ratio values to test hypotheses of a shallow or depth lake depositional environment relative to the preservation of these remarkable fossils.
The rock samples collected from Cow Branch Formation contain angular clasts, possible fragile detrital muscovite grains, highly chemically weathered quartz grains, remnants of highly altered feldspar, and possible glauconite – all of which are likely indicative of an immature sediment source feeding a deep lake with steepening slopes. Geochemical analysis indicates high levels of organic carbon (14.73% – 12.23%) within the black shales of the Solite Quarry in the Cow Branch Formation, which preserves most of the fossils, while the organic carbon in underlying strata is significantly less (0.15% – 0.46%), indicating a deepening anoxic lake. Geochemical results show relatively high levels of 87Sr/86Sr isotope ratios, indicating an isolated freshwater lake without connection to marine saline waters of the proto-Atlantic Ocean, within a region influenced by continental uplift. My research supports that the Cow Branch Formation consisted of a deep lake environment, geographically isolated and situated within the steep topography of the Appalachian Mountains. This suggests a unique environment for an aquatic fauna of reptiles, indicating a possible alpine reptilian fauna in the warmer climates of the Triassic
Design and Ground Testing of a Zero-Discharge Plant Growth System for Microgravity Applications
No full textPlant-based bioregenerative life-support systems play an essential role for long-duration space missions, offering a renewable source of fresh, nutritious food and psychological benefits for crew members. As human space missions extend further and last longer, developing efficient technologies for space agriculture becomes increasingly critical. In microgravity, altered fluid dynamics change water, nutrient, and gas distribution within the root-zone, potentially limiting plant growth. The Utah Reusable Root Module (URRM) system housed within NASA’s Ohalo III Crop Production System addresses these challenges through five root modules equipped with automated fertigation, redundant moisture sensors, and media containment materials. Designed to support repetitive harvests of pick-and-eat vegetables with minimal crew intervention, the URRM advances water and nutrient management strategies for space-based agriculture. Preliminary ground tests with Mizuna (Brassica rapa var. nipposinica) demonstrated that the URRM maintained optimal root-zone conditions and uniform resource distribution, yielding more than 1 kg of fresh biomass over 17 days. The use of different top cover designs and materials across root modules affected plant establishment and yield, as well as evapotranspiration, whereas Water use efficiency (WUE) exceeded 2 g L⁻¹ across the system. These findings highlight the URRM’s ability to support crop production using automated state-of-the-art technologies, strengthening the feasibility of long-term human space exploration
A Machine Learning Model to Predict Wildfire Burn Severity for Pre-Fire Risk Assessments, Utah, USA
No full textBackground
High-severity burned areas can have lasting impacts on vegetation regeneration, carbon dynamics, hydrology, and erosion. While landscape models can predict erosion from burned areas using the differenced normalized burn ratio (dNBR), post-fire erosion modeling has predominantly focused on areas that have recently burned. Here, we developed and validated a predictive burn severity model that produces continuous dNBR predictions for recently unburned forest land in Utah. Results
Vegetation productivity, elevation, and canopy fuels were the most important predictor variables in the model, highlighting the strong control of fuels and vegetation on burn severity in Utah. Final model out-of-bag R2 was 67.1%, residuals showed a correlation coefficient of 0.89 and classification accuracy into three classes was 85%. We demonstrated that dNBR can be empirically modeled relative to fuels and topography and found burn severity was highest in productive vegetation and at relatively cooler sites. Conclusions
We found that prediction accuracy was higher when fuel moisture was lower, suggesting drier weather conditions drive more consistent and predictable burn severity patterns across a range of burn severity, vegetation types, and geographic locations. Moreover, burn severity predictions from this model can be used to inform hydro-erosion models and subsequent management actions aimed at reducing burn severity and post-wildfire erosion risks
Plasmids Encode and can Mobilize Onion Pathogenicity in \u3cem\u3ePantoea agglomerans\u3c/em\u3e
No full textPantoea agglomerans is one of four Pantoea species reported in the USA to cause bacterial rot of onion bulbs. However, not all P. agglomerans strains are pathogenic to onion. We characterized onion-associated strains of P. agglomerans to elucidate the genetic and genomic signatures of onion-pathogenic P. agglomerans. We collected \u3e 300 P. agglomerans strains associated with symptomatic onion plants and bulbs from public culture collections, research laboratories, and a multi-year survey in 11 states in the USA. Combining the 87 genome assemblies with 100 high-quality, public P. agglomerans genome assemblies we identified two well-supported P. agglomerans phylogroups. Strains causing severe symptoms on onion were only identified in Phylogroup II and encoded the HiVir pantaphos biosynthetic cluster, supporting the role of HiVir as a pathogenicity factor. The P. agglomerans HiVir cluster was encoded in two distinct plasmid contexts: (i) as an accessory gene cluster on a conserved P. agglomerans plasmid (pAggl), or (ii) on a mosaic cluster of plasmids common among onion strains (pOnion). Analysis of closed genomes revealed that the pOnion plasmids harbored alt genes conferring tolerance to Allium thiosulfinate defensive chemistry and many harbored cop genes conferring resistance to copper. We demonstrated that the pOnion plasmid pCB1C can act as a natively mobilizable pathogenicity plasmid that transforms P. agglomerans Phylogroup I strains, including environmental strains, into virulent pathogens of onion. This work indicates a central role for plasmids and plasmid ecology in mediating P. agglomerans interactions with onion plants, with potential implications for onion bacterial disease management
Assessing Utah\u27s Agricultural Producer and Small Processor Interest in Value-Added Food Production
No full textIn 2024, Utah State University researchers conducted a study of Utah agricultural producers and food processors interested in value-added food production. This fact sheet provides an overview of the study’s results on respondents’ operational details, including years in business, number of employees, and annual sales, as well as their interest in and rationale for expanding into value-added food production. It also discusses their current or planned timeframe for processing operation implementation, the types of products and markets involved, processing locations, and sales projections. Finally, it highlights the resources, tools, information, and services respondents identified as most useful for their processing operations. These results will assist Extension faculty, policymakers, agricultural organizations, and local economic development agencies to more effectively target programs and resources that support value-added food production across Utah. By understanding producers’ needs, challenges, and resource gaps, these groups can develop tailored training, funding opportunities, and infrastructure investments that strengthen local food systems, enhance farm profitability, and promote rural economic growth
Nutrient Limitation and Seasonality Associated With Phytoplankton Communities and Cyanotoxin Production in a Large, Hypereutrophic Lake
No full textThough freshwater harmful algal blooms have been described and studied for decades, several important dynamics remain uncertain, including the relationships among nutrient concentrations, phytoplankton growth, and cyanotoxin production. To identify when and where nutrients limit phytoplankton, cyanobacteria, and cyanotoxins, we conducted in situ bioassay studies. We added nitrogen (N), phosphorus (P), or N + P across various seasons in water collected from three locations across Utah Lake, one of the largest freshwater lakes in the western U.S. This shallow, hypereutrophic lake provides a powerful testbed for quantifying nutrient-growthtoxin interactions. We assessed a range of parameters over time, including photopigment concentrations, phytoplankton abundance (cell counts), cyanotoxins, and nutrient concentrations. Despite high background nutrient concentrations in lake water, phytoplankton abundance and composition were strongly affected by nutrient addition. Phosphorus limitation was more common in the spring, with N limitation and N + P limitation becoming more common in the fall. Nutrient additions were positively associated with cyanobacteria (Microcystis, Aphanocapsa, Dolichospermum, Merismopedia, Aphanizomenon spp.), eukaryotes (Aulacoseira, Desmodesmus spp.), and two taxonomical categories of phytoplankton (i.e., unicellular and colonial green algae). When detected, anatoxin-a was positively associated with Aphanizomenon and negatively associated with Microcystis spp. However, overall cyanotoxin concentrations were not associated with cyanobacterial cell density but varied seasonally. These findings highlight the importance of considering seasonal nutrient availability dynamics and provide insights into specific nutrient targets, species, and cyanotoxins that play a significant role in the health and management of similar eutrophic lake environments around the world
Feeling a Goodness of Fit: Children Establishing Corporeal Comfort in STEM Learning
No full textAffect has long been of interest in early childhood education, where social and emotional dynamics are seen as critical dimensions of learning, intricately linked to embodied activity. As part of the special issue Centering Affect and Emotion Toward Justice and Dignity in Science Education, this paper conceptualizes affect through children\u27s bodily comfort. Data were collected in two Kindergarten classrooms participating in an integrated computer science-STEM curriculum that involved small groups of children engaging in floor-based activities. Focusing on body positioning, we use interaction analysis to explore how a focal child found a comfortable fit in her learning environment, highlighting the role of clothing in establishing a mundane sense of comfort. We found that fitting in the space and fitting in with others involved creating comfortable spaces, or comfort zones, in the classroom. For focal participant Theresa, a comfort zone involved physically positioning her body and negotiating norms of social comportment that govern how different bodies come to feel like some-body. We discuss ways in which some children perform extra physical and emotional labor to establish comfort zones in the classroom, and how this contributes to their felt sense of belonging and dignity, whereby all children are valued participants and feel that they fit. We conclude with pedagogical implications of creating spaces for embodied belonging, where children feel a goodness of fit in STEM
Refurbishing Used GPS Transmitters Improves Performance for Subsequent Deployments on Greater Sage-Grouse
No full textGlobal Positioning Systems (GPS) radio transmitters are increasingly used across taxa to monitor animal populations. However, GPS transmitters can be susceptible to malfunctions that may result in location errors or data loss causing potential inferential bias that can have important implications for monitored species. Research using GPS transmitters on greater sage-grouse (Centrocercus urophasianus; sage-grouse) has increased, but few sage-grouse studies have evaluated GPS performance. Because sage-grouse management has been subject to intense legal and political scrutiny with consequential economic implications, reliable data acquisition is central to informed decision-making for the species. We evaluated differences in the performance of 2 commonly used solar-powered GPS transmitters (Microwave Telemetry, Inc. [MTI], Columbia, MD, USA and GeoTrak, Inc., Apex, NC, USA) deployed on sage-grouse throughout Wyoming from 2011 to 2017 and Utah from 2013 to 2019. Our investigation of GPS performance included daily fix inefficiency, the number of 1-day fix gaps, and transmitter loss rate. We also evaluated transmitter functionality during the nesting period including daily nesting fix inefficiency, fix error distance mean and standard deviation (i.e., accuracy and precision), and mean fix error direction. New and refurbished MTI transmitters outperformed GeoTrak transmitters in daily fix inefficiency and day gaps during most seasons. Cumulatively redeployed MTI transmitters did not perform differently than GeoTrak transmitters. Transmitter loss, daily nesting fix inefficiency, and nest fix precision did not vary significantly between the 2 transmitters. GeoTrak performed better than MTI for nest fix accuracy across all latitudes (40–45° N). The mean error direction to the nest location ranged between 105° and 135° for GeoTrak and between 135° and 155° for MTI. We recommend refurbishing transmitters following deployment to retain higher fix efficiency than cumulatively redeploying transmitters
Key Virulence Factors Responsible for Differences in Pathogenicity Between Clinically Proven Live-Attenuated Japanese Encephalitis Vaccine SA\u3csub\u3e14\u3c/sub\u3e-14-2 And Its Pre-Attenuated Highly Virulent Parent SA\u3csub\u3e14\u3c/sub\u3e
No full textJapanese encephalitis virus (JEV), a neuroinvasive and neurovirulent orthoflavivirus, can be prevented in humans with the SA14-14-2 vaccine, a live-attenuated version derived from the wild-type SA14 strain. To determine the viral factors responsible for the differences in pathogenicity between SA14 and SA14-14-2, we initially established a reverse genetics system that includes a pair of full-length infectious cDNAs for both strains. Using this cDNA pair, we then systematically exchanged genomic regions between SA14 and SA14-14-2 to generate 20 chimeric viruses and evaluated their replication capability in cell culture and their pathogenic potential in mice. Our findings revealed the following: (i) The single envelope (E) protein of SA14-14-2, which contains nine mutations (eight in the ectodomain and one in the stem region), is both necessary and sufficient to render SA14 non-neuroinvasive and non-neurovirulent. (ii) Conversely, the E protein of SA14 alone is necessary for SA14-14-2 to become highly neurovirulent, but it is not sufficient to make it highly neuroinvasive. (iii) The limited neuroinvasiveness of an SA14-14-2 derivative that contains the E gene of SA14 significantly increases (approaching that of the wild-type strain) when two viral nonstructural proteins are replaced by their counterparts from SA14: (a) NS1/1’, which has four mutations on the external surface of the core β-ladder domain; and (b) NS2A, which has two mutations in the N-terminal region, including two non-transmembrane α-helices. In line with their roles in viral pathogenicity, the E, NS1/1’, and NS2A genes all contribute to the enhanced spread of the virus in cell culture. Collectively, our data reveal for the first time that the E protein of JEV has a dual function: It is the master regulator of viral neurovirulence and also the primary initiator of viral neuroinvasion. After the initial E-mediated neuroinvasion, the NS1/1’ and NS2A proteins act as secondary promoters, further amplifying viral neuroinvasiveness
Extensive Admixture Among Karst-Obligate Salamanders Reveals Evidence of Recent Divergence and Gene Exchange Through Aquifers
No full textKarst ecosystems often contain extraordinary biodiversity, but the complex underground aquifers of karst regions present challenges for assessing and conserving stygobiont diversity and investigating their evolutionary history. We examined the karst-obligate salamanders of the Eurycea neotenes species complex in the Edwards Plateau region of central Texas using population genomics data to address questions about population connectivity and the potential for gene exchange within the underlying aquifer system. The E. neotenes species complex has historically been divided into three nominal species, but their status, and spatial extent of species ranges, have remained uncertain. We discovered evidence of extensive admixture among species within the complex and with adjacent lineages. We observed relatively low levels of differentiation among all sampling localities which supports the hypothesis of recent divergence. Nominal taxonomy, aquifer region and geography each accounted for a modest amount of the overall population genomic variation; however, these predictors were largely confounded and difficult to disentangle. Importantly, current taxonomy of the three nominal species does not reflect the admixture apparent in clustering analyses. Inference of migration events revealed a complex pattern of gene exchange, suggesting that Eurycea salamanders have a dynamic history of dispersal through the aquifer system. These results highlight the need for greater understanding of how stygobiont populations are connected via dispersal and gene exchange through karst aquifers. These results also highlight the applicability of population genomics data as a powerful lever for investigating connectivity among populations in systems where direct detection of dispersal paths is difficult, as in underground, aquatic systems