Digital Commons Network^™

Anomalously Large Chiral Sensitivity In The Dissociative Electron Attachment Of 10-Iodocamphor, J. M. Dreiling, F. W. Lewis, J. D. Mills, Timothy J. Gay

Timothy J. Gay Publications

We have studied dissociative electron attachment (DEA) between low energy (≤ 0.6 eV) longitudinally polarized electrons and gas-phase chiral targets of 3-bromocamphor (C₁₀H₁₅BrO), 3-iodocamphor (C₁₀H₁₅IO), and 10-iodocamphor. The DEA rate depends on the sign of the incident electron helicity for a given target handedness, and it varies with both the atomic number (Z) and location of the heaviest atom in the molecule. While simple dynamic mechanisms can account for the asymmetry dependence on Z, they fail to explain the large asymmetry variation with the heavy atom location.

Shielded Radiography With A Laser-Driven Mev-Energy X-Ray Source, Shouyuan Chen, Grigory V. Golovin, Cameron Miller, Daniel Haden, Sudeep Banerjee, Ping Zhang, Cheng Liu, Jun Zhang, Baozhen Zhao, Shaun Clarke, Sara Pozzi, Donald Umstadter

Donald Umstadter Publications

We report the results of experimental and numerical-simulation studies of shielded radiography using narrowband MeVenergy X-rays from a compact all-laser-driven inverse-Compton-scattering X-ray light source. This recently developed Xray light source is based on a laser-wakefield accelerator with ultra-high-field gradient (GeV/cm). We demonstrate experimentally high-quality radiographic imaging (image contrast of 0.4 and signal-to-noise ratio of 2:1) of a target composed of 8-mm thick depleted uranium shielded by 80-mm thick steel, using a 6-MeV X-ray beam with a spread of 45% (FWHM) and 107 photons in a single shot. The corresponding dose of the X-ray pulse measured in front of the target …

The Impact Of Uncertainty, Threat, And Political Identity On Support For Political Compromise, Ingrid J. Haas

Department of Political Science: Faculty Publications

This work examines the impact of uncertainty and threat on support for political compromise. In Study 1, uncertainty, threat, and support for compromise were measured. Uncertainty increased support for compromise only when paired with positive or neutral affect. Studies 2 and 3 used an experimental design to examine the impact of incidental affect on support for political compromise as a function of political identification. Uncertainty was more likely to increase support for compromise in positive or neutral contexts and for political moderates and liberals. The combination of uncertainty and threat led conservatives to express reduced support for compromise.

Evaluating Categories Of Resistance In Soybean Genotypes From The United States And Brazil To Aphis Glycines (Hemiptera: Aphididae), Edison L. L. Baldin, Lia Marchi-Werle, Luiz E.R. Pannuti, Andre L. Lourencao, Tiffany M. Heng-Moss, Thomas E. Hunt

Department of Entomology: Faculty Publications

Aphis glycines Matsumura (Hemiptera: Aphididae), the soybean aphid, has become an important pest of soybeans, leading to significant yield losses in the United States. Host plant resistance is a viable alternative for managing A. glycines. The objectives of this study were to identify and categorize sources of resistance in soybean to A. glycines on genotypes from the United States and Brazil. An antixenosis assay was initially conducted with 8 genotypes to evaluate attractiveness to A. glycines. The selected soybean genotypes were further evaluated in a colonization assay to investigate the resistance of the genotypes at V1 (fully developed …

Ovipositional Preference, Fidelity, And Fitness Of Drosophila Suzukii In A Co-Occurring Crop And Non-Crop Host System, Lauren M. Diepenbrock, Katharine A. Swoboda-Bhattarai, Hannah Burrack

Department of Entomology: Faculty Publications

Drosophila suzukii (Matsumura) is a devastating pest of soft-skinned fruits including blackberries and raspberries. Management of this pest is focused on preventing infestation in crops, but non-crop hosts may play an important role in enabling D. suzukii to persist in the absence of cultivated hosts. Drosophila suzukii may also infest fruits of both crop and non-crop hosts concurrently. Our goals were to determine whether (1) D. suzukii prefers to oviposit in cultivated blackberry, Rubus L. subgenus rubus Watson, or American pokeweed, Phytolacca americana, a non-crop host commonly found along field edges, (2) D. suzukii prefers to oviposit into the same …

A Forest Vulnerability Index Based On Drought And High Temperatures, David Mildrexler, Zhiqiang Yang, Warren B. Cohen, David M. Bell

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Increasing forest stress and tree mortality has been directly linked to combinations of drought and high temperatures. The climatic changes expected during the next decades – large increases in mean temperature, increased heat waves, and significant long-term regional drying in the western USA – will likely increase chronic forest stress and mortality. The aim of this research is to develop and apply a new forest vulnerability index (FVI) associated with drought and high temperatures across the Pacific Northwest region (PNW; Oregon and Washington) of the USA during the MODIS Aqua era (since 2003). Our technique incorporates the alterations to canopy …

Contributing Factors For Drought In United States Forest Ecosystems Under Projected Future Climates And Their Uncertainty, Charles H. Luce, James M. Vose, Neil Pederson, John Campbell, Connie Millar, Patrick Kormos, Ross Woods

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Observations of increasing global forest die-off related to drought are leading to more questions about potential increases in drought occurrence, severity, and ecological consequence in the future. Dry soils and warm temperatures interact to affect trees during drought; so understanding shifting risks requires some understanding of changes in both temperature and precipitation. Unfortunately, strong precipitation uncertainties in climate models yield substantial uncertainty in projections of drought occurrence. We argue that disambiguation of drought effects into temperature and precipitation-mediated processes can alleviate some of the implied uncertainty. In particular, the disambiguation can clarify geographic diversity in forest sensitivity to multifarious drivers …

Diseases Of Trees In The Great Plains, Aaron D. Bergdahl, Alison Hill, Gerard C. Adams, Rachel A. Allison, John A. Appel, John Ball, James T. Blodgett, Kelly S. Burns, Whitney Cranshaw, Kelsey L. Dunnell, Mark L. Gleason, Mark O. Harrell, Thomas C. Harrington, Marcus B. Jackson, William R. Jacobi, Jennifer Juzwik, Megan M. Kennwlly, Les Koch, Jared M. Leboldus, Phillip A. Mason, Douglas L. Mcnew, Judith O'Mara, Hayley M. Nelson, Nicole Opbroek, Michael E. Ostry, Scott C. Redlin, Glen R. Stanosz, Laurie J. Stepanek, Ned Tisserat, Timothy C. Todd, James A. Walla, James J. Worrall, Simeon Wright

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Hosts, distribution, symptoms and signs, disease cycle, and management strategies are described for 84 hardwood and 32 conifer diseases in 56 chapters. Color illustrations are provided to aid in accurate diagnosis. A glossary of technical terms and indexes to hosts and pathogens also are included.

Scope

The purpose of this handbook is to assist users in diagnosing tree diseases and reducing their impact. Included are the most damaging diseases, along with some that are the subject of frequent inquiry although of minor importance. The diseases included were those encountered primarily on trees in conservation plantings such as windbreaks, farmstead plantings, …

Test–Retest, Retest, And Retest: Growth Curve Models Of Repeat Testing With Immediate Post-Concussion Assessment And Cognitive Testing (Impact), Arthur C. Maerlender, Caitlin J. Masterson, Tiffany D. James, Jonathan Beckwith, Per Gunner Brolinson, Joe Crisco, Stefan Duma, Laura A. Flashman, Rick Greenwald, Steven Rowson, Beth Wilcox, Tom W. Mcallister

Department of Psychology: Faculty Publications

Computerized neuropsychological testing has become an important tool in the identification and management of sports-related concussions; however, the psychometric effect of repeat testing has not been studied extensively beyond test–retest statistics. The current study analyzed data from Division I collegiate athletes who completed Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) baseline assessments at four sequential time points that varied over the course of their athletic careers. Administrations were part of a larger National Institutes of Health (NIH) study. Growth curve modeling showed that the two memory composite scores increased significantly with successive administrations: Change in Verbal Memory was best represented …

Dysphagia Management And Research In An Acute-Care Military Treatment Facility: The Role Of Applied Informatics, Nancy Pearl Solomon, Angela M. Dietsch, Katie E. Dietrich-Burns, Edda L. Styrmisdottir, Christopher S. Armao

Department of Special Education and Communication Disorders: Faculty Publications

Purpose: This report describes the development and preliminary analysis of a database for traumatically injured military service members with dysphagia.

Methods: A multidimensional database was developed to capture clinical variables related to swallowing. Data were derived from clinical records and instrumental swallow studies, and ranged from demographics, injury characteristics, swallowing biomechanics, medications, and standardized tools (e.g.. Glasgow Coma Scale, Penetration-Aspiration Scale). Bayesian Belief Network modeling was used to analyze the data at intermediate points, guide data collection, and predict outcomes. Predictive models were validated with independent data via receiver operating characteristic curves.

Results: The first iteration of …

Students At Enrollment Into Communitybased Systems Of Care: Characteristics And Predictors Of Functioning In School, Stacy-Ann A. January, Matthew C. Lambert, Michael Epstein, Mary Spooner, Tesfayi Gebreselassie

Department of Special Education and Communication Disorders: Faculty Publications

Community-based systems of care (SOC) provide a range of services to students with significant emotional and behavioral difficulties and their families. However, little is known about the educational characteristics and functioning of students at enrollment in SOC. The purpose of this study was to replicate and extend previous research by examining the educational characteristics and predictors of school functioning for students referred to SOC using a large and diverse national data source. Participants were 5,628 students ages 6 to 18 years who were enrolled in community-based SOC across 45 U.S. states, districts, and territories. Students’ grades, discipline, and attendance (as …

Differential Effects Of Cdh23753a On Auditory And Vestibular Functional Aging In C57bl/6j Mice, Bruce E. Mock, Sarath Vijayakumar, Jessica Pierce, Timothy A. Jones, Sherri M. Jones

Department of Special Education and Communication Disorders: Faculty Publications

The C57BL/6J (B6) mouse strain carries a cadherin 23 mutation (Cdh23^753A, also known as Ahl), which affects inner ear structures and results in age-related hearing loss. The B6.CAST strain harbors the wild type Cdh23 gene, and hence, the influence of Ahl is absent. The purpose of the present study was to characterize the effect of age and gender on gravity receptor function in B6 and B6.CAST strains and to compare functional aging between auditory and vestibular modalities. Auditory sensitivity declined at significantly faster rates than gravity receptor sensitivity for both strains. Indeed, vestibular functional aging was …

Real-Time Classification Of Patients With Balance Disorders Vs. Normal Subjects Using A Low-Cost Small Wireless Wearable Gait Sensor, Bhargava Teja Nukala, Taro Nakano, Amanda Rodriguez, Jerry Tsay, Jerry Lopez, Tam Q. Nguyen, Steven Zupancic, Donald Y. C. Lie

Department of Special Education and Communication Disorders: Faculty Publications

Gait analysis using wearable wireless sensors can be an economical, convenient and effective way to provide diagnostic and clinical information for various health-related issues. In this work, our custom designed low-cost wireless gait analysis sensor that contains a basic inertial measurement unit (IMU) was used to collect the gait data for four patients diagnosed with balance disorders and additionally three normal subjects, each performing the Dynamic Gait Index (DGI) tests while wearing the custom wireless gait analysis sensor (WGAS). The small WGAS includes a tri-axial accelerometer integrated circuit (IC), two gyroscopes ICs and a Texas Instruments (TI) MSP430 microcontroller and …

Understanding Differences In Hiv/Hcv Prevalence According To Differentiated Risk Behaviors In A Sample Of Pwid In Rural Puerto Rico, Roberto Abadie, Melissa L. Welch-Lazoritz, Camila Gelpi- Acosta, Juan Carlos Reyes, Kirk Dombrowski

Department of Sociology: Faculty Publications

Background: Blood contained in needles and injection equipment has been identified as a vector for HIV and HCV transmission among people who inject drugs (PWID). Yet, there is often a wide discrepancy in prevalence for both viruses. While microbiological differences between viruses influence prevalence, other variables associated with the way drugs are acquired and used, also play a role.

Methods: Respondent-driven sampling (RDS) methods recruited a sample of 315 current intravenous drug users in rural Puerto Rico. Information about type and frequency of use, HIV and HVC risk behaviors (sharing needles, cookers, cotton, and water), sexual behaviors, and alcohol use …

Current Rural Drug Use In The Us Midwest, Kirk Dombrowski, Devan M. Crawford, Bilal Khan, Kimberly A. Tyler

Department of Sociology: Faculty Publications

The nature and challenge of illicit drug use in the United States continues to change rapidly, evolving in reaction to myriad social, economic, and local forces. While the use of illicit drugs affects every region of the country, most of our current information about drug use comes from large urban areas. Data on rural drug use and its harms justify greater attention. Record overdose rates, unexpected outbreaks of HIV, and a dearth of treatment facilities point to a rapidly worsening health situation. While health sciences have made considerable progress in understanding the etiology of drug use and uncovering the link …

Applying Ecological Systems Theory To Sexual Revictimization Of Youth: A Review With Implications For Research And Practice, Samantha L. Pittenger, Terrence Z. Huit, David J. Hansen

Department of Psychology: Faculty Publications

This article reviews the literature on sexual revictimization, integrating findings from studies with adult and youth samples and organizing research evidence within a social ecological framework. Multiple victimization experiences are common among children, adolescents, and adults with histories of child sexual abuse; they are associated with negative cumulative effects on the individual and, through these negative sequelae, perpetuate a cycle of victimization. While much of the research has focused on individual factors that promote revictimization, there is emerging evidence that external influences on the individual may influence risk for subsequent victimization. Specifically, family, perpetrators, and engagement with helping professionals may …

The Double Standard At Sexual Debut: Gender, Sexual Behavior And Adolescent Peer Acceptance, Derek A. Kreager, Jeremy Staff, G. Robin Gauthier, Eva S. Lefkowitz, Mark E. Feinberg

Department of Sociology: Faculty Publications

A sexual double standard in adolescence has important implications for sexual development and gender inequality. The present study uses longitudinal social network data (N = 914; 11–16 years of age) to test if gender moderates associations between adolescents’ sexual behaviors and peer acceptance. Consistent with a traditional sexual double standard, female adolescents who reported having sex had significant decreases in peer acceptance over time, whereas male adolescents reporting the same behavior had significant increases in peer acceptance. This pattern was observed net of respondents’ own perceived friendships, further suggesting that the social responses to sex vary by gender of …

Plant Community Shifts Caused By Feral Swine Rooting Devalue Florida Rangeland, Brittany Bankovich, Elizabeth Boughton, Raoul Boughton, Michael L. Avery, Samantha M. Wisely

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species threaten agriculture by changing agroecosystem structure and function, reducing habitat value, decreasing biodiversity and ecosystem services and increasing management costs. Grazing lands in south central Florida are a mosaic of sown pastures, native grasslands, wetlands and woodlands that provide a variety of ecosystem services. Disturbance of these pastures and native grasslands by invasive feral swine (Sus scrofa) can have negative consequences for both economic productivity and biodiversity. In this study, we show that the effect of rooting on plant diversity depends on ecosystem type and initial levels of plant species diversity. For example, in native grassland pasture, rooting …

Chapter 8 Keeping Wildlife Out Of Your Food: Mitigation And Control Strategies To Reduce The Transmission Risk Of Food-Borne Pathogens, Alan B. Franklin, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

In this chapter, we provide a general framework for developing strategies to mitigate the contamination of agricultural operations with pathogens carried by wildlife. As part of this framework, we present adaptive management as a viable approach to developing these strategies to reduce the uncertainty over time as to whether management methods are being effective. We provide the general steps to developing an adaptive management strategies as well as generic mitigation methods that can be applied to agricultural operations as part of an adaptive management strategy.

Estimates Of Small Indian Mongoose Densities: Implications For Rabies Management, Shylo R. Johnson, Are R. Berentsen, Christine Ellis, Amy Davis, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

The small Indian mongoose (Herpestes auropunctatus) is an invasive species and rabies reservoir in Puerto Rico. In the continental United States, terrestrial wildlife rabies is primarily managed by the National Rabies Management Program (NRMP) of the United States Department of Agriculture through oral rabies vaccination (ORV); the distribution of the vaccine baits is influenced by the population density of the target species. TheNRMPuses a density index for estimating raccoon (Procyon lotor) population density to guide bait distribution. In Puerto Rico, a wildlife rabies vaccination program does not exist and vaccination of domestic animals is limited and not compulsory. …

Bait Preference Of Free-Ranging Feral Swine For Delivery Of A Novel Toxicant, Nathan P. Snow, Joseph M. Halseth, Michael J. Lavelle, Thomas E. Hanson, Chad R. Blass, Justin A. Foster, Simon T. Humphrys, Linton D. Staples, David G. Hewitt, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive feral swine (Sus scrofa) cause extensive damage to agricultural and wildlife resources throughout the United States. Development of sodium nitrite as a new, orally delivered toxicant is underway to provide an additional tool to curtail growth and expansion of feral swine populations. A micro-encapsulation coating around sodium nitrite is used to minimize detection by feral swine and maximize stability for the reactive molecule. To maximize uptake of this toxicant by feral swine, development a bait matrix is needed to 1) protect the micro-encapsulation coating so that sodium nitrite remains undetectable to feral swine, 2) achieve a high …

Evaluation Of Harvest Indices For Monitoring Cougar Survival And Abundance, Michael L. Wolfe, Eric M. Gese, Pat Terletzky, David C. Stoner, Lise M. Aubry

United States Department of Agriculture Wildlife Services: Staff Publications

Harvest indices are used by state wildlife management agencies to monitor population trends and set harvest quotas for furbearer species. Although harvest indices may be readily collected from hunters, the reliability of harvest indices for monitoring demography and abundance of the harvested species is rarely examined, particularly amongst large carnivores. The overall objective of this study was to assess whether cougar (Puma concolor) harvest statistics collected by wildlife managers were correlated with changes in cougar demography, mainly survival rates and abundance. We estimated key demographic parameters for 2 cougar populations in Utah over 17 years during which we monitored 235 …

Cholecalciferol Plus Diphacinone Baits For Vole Control: A Novel Approach To A Historic Problem, Roger A. Baldwin, Ryan Meinerz, Gary W. Witmer

United States Department of Agriculture Wildlife Services: Staff Publications

Combination baits containing cholecalciferol plus an anticoagulant are effective against commensal rodents resistant to anticoagulants, and they likely pose less risk than anticoagulant-only rodenticides due to lower concentrations of active ingredients and shorter time to death. However, these combination baits have not been tested for agricultural rodent pests. Therefore, we established a study to test the efficacy of cholecalciferol plus diphacinone artichoke bract and pellet baits to determine their ability to manage California voles Microtus californicus in artichokes, where resistance to anticoagulants is known to occur. Field tests using radiocollared voles indicated that bract baits were highly efficacious (85 %), …

Defending Against Disparate Marine Turtle Nest Predators: Nesting Success Benefits From Eradicating Invasive Feral Swine And Caging Nests From Raccoons, Richard M. Engeman, David Addison, J. C. Griffin

United States Department of Agriculture Wildlife Services: Staff Publications

Nest predation can threaten marine turtle nesting success, and having to address dissimilar predator species complicates nest protection efforts. On Florida’s Keewaydin Island predation by raccoons Procyon lotor and invasive feral swine Sus scrofa are disparate, significant threats tomarine turtle nests. Using 6 years of nesting data (mostly for loggerhead marine turtles Caretta caretta) we examined the impacts of swine predation on nests and the benefits of swine eradication, caging nests to protect them from raccoon predation, and the effects of nest caging on swine predation. Nest predation by swine began in mid nesting season 2007, after which swine …

Evaluation Of An Avian Radar System In A Midwestern Landscape, Michael B. Gerringer, Steven L. Lima, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Bird strikes in aviation are an increasing threat to both aircraft and human safety. Management efforts have focused largely on the immediate airport environment. Avian radar systems could potentially be useful in assessing bird strike threats at greater distances from the airport, at higher altitudes, and at night, but few studies have been conducted to assess the capabilities of avian radar systems. Thus, our goal was to assess the detection and tracking abilities of a commercially available avian radar system in an airport environment in Indiana, USA, during October 2011–March 2012. Transits by free-flying birds allowed us to assess radar …

Development Of Artificial Bait For Brown Treesnake Suppression, Bruce A. Kimball, Scott A. Sterling, Thomas W. Mcauliffe, Randal S. Stahl, Rafael A. Garcia, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

The brown treesnake (Boiga irregularis) was accidentally introduced to Guam in the 1940s from the Admiralty Islands. A native of Australia, Papua New Guinea, and the Solomon Islands, the brown treesnake (BTS) continues to threaten the economy and ecology of Guam and is currently the subject of a cooperative program to control snake populations on the island and prevent its spread throughout the Pacific Rim. Delivery of toxic baits is a primary component of population suppression efforts. While many food items tested as baits for toxicant delivery provide relevant food prey cues leading to investigatory behaviors in BTS, …

Retention Time Of Chlorophacinone In Black-Tailed Prairie Dogs Informs Secondary Hazards From A Prairie Dog Rodenticide Bait, Gary W. Witmer, Nathan P. Snow, Rachael S. Moulton

United States Department of Agriculture Wildlife Services: Staff Publications

BACKGROUND: Secondary toxicity in mammals and birds that consume animals containing residues of anticoagulant rodenticides represents a persistent conflict between conservation, agriculture and environmental contamination. Chlorophacinone residues in black-tailed prairie dogs (Cynomys ludovicianus) represent a secondary exposure hazard to predatory and scavenging avian and mammalian species in the Central Plains of the United States, especially considering efforts to re-establish black-footed ferrets (Mustela nigripes). Rozol® Prairie Dog Bait (chlorophacinone 0.005%) is registered to control black-tailed prairie dogs in ten states throughout themidwestern and western United States.

RESULTS:We fed Rozol Prairie Dog Bait to captive black-tailed prairie dogs …

Susceptibility Of Rock Doves To Low-Pathogenic Avian Influenza A Viruses, Susan A. Shriner, J. Jeffrey Root, Nicole L. Mooers, Jeremy W. Ellis, Scott R. Stopak, Heather J. Sullivan, Kaci K. Vandalen, Alan B. Franklin

United States Department of Agriculture Wildlife Services: Staff Publications

Following a 2008 outbreak of North American low-pathogenic H5N8 influenza A virus at an upland gamebird farm, we sero-sampled rock doves (pigeons, Columba livia) at the outbreak site and conducted experimental inoculations of wild-caught pigeons using the H5N8 virus and another low-pathogenic virus (H4N6). While 13 % of pigeons at the outbreak site were seropositive, none were positive for exposure to H5, and one was positive for N8. Challenged pigeons exhibited low susceptibility and limited viral RNA excretion for both viruses tested, but at least one individual had RNA loads indicative of the potential for viral transmission to other …

Fishing Diseased Abalone To Promote Yield And Conservation, Tal Ben-Horin, Kevin D. Lafferty, Gorka Bidegain, Hunter S. Lenihan

United States Geological Survey: Staff Publications

Past theoretical models suggest fishing disease-impacted stocks can reduce parasite transmission, but this is a good management strategy only when the exploitation required to reduce transmission does not overfish the stock. We applied this concept to a red abalone fishery so impacted by an infectious disease (withering syndrome) that stock densities plummeted and managers closed the fishery. In addition to the non-selective fishing strategy considered by past disease- fishing models, we modelled targeting (culling) infected individuals,which is plausible in red abalone because modern diagnostic tools can determine infection without harming landed abalone and the diagnostic cost is minor relative to …

Coherent Late-Holocene Climate-Driven Shifts In The Structure Of Three Rocky Mountain Lakes, Jeffrey R. Stone, Jasmine E. Saros, Gregory T. Pederson

United States Geological Survey: Staff Publications

Large-scale atmospheric pressure centers, such as the Aleutian and Icelandic Low, have a demonstrated relationship with physical lake characteristics in contemporary monitoring studies, but the responses to these phenomena are rarely observed in lake records. We observe coherent changes in the stratification patterns of three deep (>30 m) lakes inferred from fossil diatom assemblages as a response to shifts in the location and intensity of the Aleutian Low and compare these changes with similar long-term changes observed in the ¹⁸O record from the Yukon. Specifically, these records indicate that between 3.2 and 1.4 ka, the Aleutian Low shifted …