Christopher M. Stevens results 173
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The nature of targets extracted through data-driven mineral prospectivity mapping (DD-MPM) is dependent on geodata annotation. However, geodata annotation is noisy because mineral systems are complex systems and the definition of positivity changes with annotator, jurisdiction and time. Consequently, historically annotated data (HAD), which are the exhaustive collection of labeled samples (sites) that have accumulated over the...
Using Eye Lens Stable Isotopes to Identify the Rearing Origin of Fall Age‐0 Walleye ( Sander vitreus )NARA Subscribed
Isotope values in fish eye lenses may be useful in differentiating rearing origins. We compared eye lens isotopic values of fall fingerling age‐0 walleye ( Sander vitreus ) reared in a hatchery pond, a recirculating aquaculture system (RAS), and a natural lake. Using 10 fish per rearing source, we delaminated layers from one eye lens per fish to assess temporal changes in carbon (δ 13 C) and nitrogen (δ 15 N) and pulverized th...
Interpretable deep learning reveals spatiotemporal MRI features of brain aging that align with neurodegenerationNARA Subscribed
Cortical thinning and atrophy are hallmarks of brain aging that have been characterized using magnetic resonance imaging (MRI). Brain aging involves many neuroanatomic features whose effects on brain structure remain unexplored. To address this challenge, we trained interpretable deep neural networks (DNNs) to estimate brain age (BA) from T 1 -weighted ( T 1 w) MRI. By identifying MRI features unapparent to humans, DNNs can fi...
Shortleaf Pine (Pinus echinata): Management Challenges, Knowledge Gaps, and Opportunities for an Unsung SpeciesNARA Subscribed
Shortleaf pine has the broadest range of the southern pine species, occurring in 22 states and extending north into New Jersey, Pennsylvania, and New York (Staten Island). Shortleaf pine has been understudied compared to loblolly pine and longleaf pine, typically favored for timber production and conservation value, respectively. The extensive range of shortleaf pine contributes to a high degree of variability within and among...
SNAPSHOT USA 2024: Year 6 of the Coordinated National Camera Trap Survey of the United StatesNARA Subscribed
Motivation SNAPSHOT USA is an annual, multi‐contributor camera trap survey of mammals across the United States. The growing SNAPSHOT USA dataset is intended for tracking the spatial and temporal responses of mammal populations to changes in land use, land cover and climate. These data will be useful for exploring the drivers of spatial and temporal changes in relative abundance and distribution, as well as the impacts of speci...
Biodiversity can enhance forest resistance to drought, but the forms of diversity involved and conditions under which diversity confers resistance remain unclear. We used Forest Inventory and Analysis (FIA) plot data to examine whether four variables—structural richness (variation in tree heights, stand density, canopy cover and/or spatial heterogeneity), species richness (number of tree species), structural evenness and speci...
Alzheimer’s disease (AD) disproportionately affects women and carriers of the apolipoprotein E ε4 allele (APOE4), yet little is known about how sex and APOE interact to influence white matter (WM) integrity during disease progression. We integrated diffusion MRI and matched blood transcriptomic data to investigate these interactions and their underlying biological mechanisms. WM microstructure was quantified using diffusion te...
Conservation genomics of the imperiled Leon springs pupfish, Cyprinodon bovinus, across temporal and spatial scalesNARA Subscribed
The Leon Springs pupfish, Cyprinodon bovinus , is federally listed as endangered and currently confined to spring-fed pools on the Diamond Y Spring Preserve in Pecos County, Texas, USA. A refuge population is maintained by U.S. Fish and Wildlife Service in Dexter, New Mexico, USA because of ongoing threats from hybridization with the introduced congener, the sheepshead minnow, C. variegatus. To inform continued conservation an...
Marine megafauna species are affected by a wide range of anthropogenic threats. To evaluate the risk of such threats, species’ vulnerability to each threat must first be determined. We build on the existing threats classification scheme and ranking system of the International Union for Conservation of Nature (IUCN) Red List of Threatened Species by assessing the vulnerability of 256 marine megafauna species to 23 at‐sea threat...
The Toxicology Investigators Consortium 2024 Annual ReportNARA Subscribed
Mapping blue carbon ecosystems from Earth observations at a national scale for Papua New GuineaOA Marine
National maps are essential to support the conservation, restoration, and sustainable management of blue carbon ecosystems (BCE). This is particularly important for nations in the Indo-Pacific region, including Papua New Guinea (PNG), that aspire to integrate these ecosystems into their nationally determined contributions (NDCs) for ecosystem accounting. This study focussed on mapping the extent of BCEs in PNG using Earth obse...
Bonefish Albula spp. in the Western Atlantic have historically been morphometrically and phenotypically indiscernible. We used biofluorescence in two sympatric, cryptic bonefish species, Albula goreensis and Albula vulpes , to develop a rapid and inexpensive in situ survey for species identification that can be used by managers and recreational anglers. Under ultraviolet (379–387 nm) and royal blue (440–457 nm) lights, the two...
National Aquatic Resource Surveys (NARS): the foundation for long-term aquatic monitoring data across the United StatesNARA Subscribed
There is a common saying in business that “what matters gets measured”. Environmental protection and sustainability certainly should qualify as important concerns for both businesses and governments. The 1970s marked the genesis of the modern environmental movement, with growing concern about water pollution in the United States (U.S.). In 1972, the U.S. enacted the Clean Water Act (CWA) “ to restore and maintain the chemical,...
Environmental and Geographic Conditions on the Breeding Grounds Drive Bergmannian Clines in NightjarsNARA Subscribed
Aim To evaluate (1) whether three migratory nightjar species (Family Caprimulgidae) adhere to Bergmann's rule, (2) whether environmental factors on the breeding or wintering grounds determine body size, and (3) which mechanistic hypotheses best explain Bergmannian patterns in body size. Location North and South America; Europe and Africa. Taxon Eastern whip‐poor‐will ( Antrostomus vociferus ), Common nighthawk ( Chordeiles min...
Cross‐Continental Analysis Shows That Disturbance Effects on Reptile Body Condition Do Not Predict Abundance ResponsesNARA Subscribed
Ecological disturbances are discrete events that alter or transform the physical, chemical, or biological characteristics of ecosystems. Disturbance can cause animal populations to decline and, according to the risk‐disturbance hypothesis and population collapse framework, these declines can be predicted by declines in animal body condition. However, no research has empirically examined the general relationship between body co...