Current Status of the Northern Saw-whet Owl (Aegolius acadicus) in Arkansas

The secretive Northern Saw-whet Owl (Aegolius acadicus) is believed to be much more widespread during fall and winter than previously thought. Of the few places in the southern United States conducting research on this species, all have been successful at capturing birds. A total of 12 historic records existed for Arkansas until our work began in fall of 2014. The first confirmed record was in 1959 and the most recent, prior to this research, was in 2010. Over the course of two field seasons, we captured and banded 24 Northern Saw-whet Owls in rural Madison County. All birds were mist-netted along a trail, in woodland composed of pine and cedar with fairly dense undergrowth. Two were captured during our 2014 season after a late start and 22 were captured in 2015, likely the result of an earlier start. Comparing our data to that of several other banding operations in the south, it would appear that the peak of migration in Arkansas is late October through early November, with capture rates dropping by early December. Of the birds captured, all but one was female, the most common sex this far south. A variety of age classes were identified, with a fairly even distribution of hatch-year, second-year, and after-second-year birds. Exactly from where the saw-whets are migrating is unknown, although several foreign recoveries in Missouri and four recoveries in Arkansas suggest they are coming from the western Great Lakes region. Once considered a vagrant, based on this research, the saw-whet appears to be a fall migrant to the state of Arkansas

Doctor of Philosophy

dissertationStochastic weather generators (SWGs) are statistically-based point-scale models of meteorological data that are driven by random number generators. Commonly taking observational data or low-resolution global climate model data as input, they are useful tools for generating many realizations of possible climate scenarios for use in impacts studies. This dissertation presents the stochastic harmonic autoregressive parametric (SHArP) weather generator. SHArP is based on previous SWGs but it generates air temperature values directly instead of prescribing and removing the mean and standard deviations in advance and generating temperature residuals. In addition, in both the precipitation process and the temperature process, SHArP includes nonstationarity due to oceanic modes of variability. During frontal passage, the precipitation-responsive autocorrelated transitions result in more realistic temperatures. The multisite generalization of SHArP presents a challenge due to an exponential increase in the number of noise coefficient matrices as the number of sites increases, but empirical orthogonal function analysis is applied to the precipitation patterns over the domain in order to reduce the number of noise coefficient matrices to a reasonable number. For multisite precipitation simulation, a trend due to climate change is added. Even though they are statistically-based, SWGs are limited in their ability to capture meteorological extremes, including dry and wet spells. The second-order Markovian probabilities of precipitation at a single site are modified using the method of large deviations. This mathematically-based method is shown to accurately modify the probabilities of precipitation to produce binary precipitation occurrence time series that are extreme yet statistically consistent with the input data without needing to "wait to get lucky" for those extreme events to occur in very long simulations

Master of Science

thesisPrecipitation over the Wasatch Mountain Range of northern Utah, part of the Great Basin (GB) in the western United States, provides water for millions of people living along the Wasatch Front. Western US precipitation is known to be influenced by the El-Nin ̃o-Southern Oscillation (ENSO) as well as the Pacific Decadal Oscillation (PDO) in the North Pacific. Historical connectivity between GB precipitation and Pacific Ocean sea surface temperatures (SSTs) on interannual to multidecadal time scales is evaluated for 20 models that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5). While the majority of the models had realistic ENSO and PDO spatial patterns in the SSTs, the simulated influence of these two modes on GB precipitation tended to be too strong for ENSO and too weak for PDO. Few models captured the connectivity at a quasi-decadal period influenced by the transition phase of the Pacific quasi-decadal oscillation (QDO; a recently identified climate mode that regulates GB precipitation). Some of the discrepancies appear to stem from models not capturing the observed tendency for the PDO to modulate the sign of the ENSO-GB precipitation teleconnection. Of all of the models, CCSM4 most consistently captured observed connections between Pacific SST variability and GB precipitation on all time scales, suggesting that in future applications, its output represents a higher confidence for the future climate of this region. The utility of the assessment is illustrated by a brief statistical analysis of future western US precipitation under a high emissions scenario. Using the results from the assessment, the application portion of the study analyzes future precipitation data under a high emissions scenario (RCP 8.5) to determine what the future could potentially look like over the western US. The models are ranked based on their performance in capturing the connections between GB precipitation and Pacific Ocean modes of variability. The ranking then deter- mines which model would be appropriate to be applied to a stochastic framework and dynamical downscaling analyses. The results from the assessment were used to force a nonstationary, daily stochastic weather generator and produce precipitation occurrence output for a valley site and a mountain site located within the GB. With some considerations, the stochastic weather generator provides long-term data for any time period that statistically matches the input data

Classification System for the Natural Vegetation of Arkansas

We present a hierarchical classification system for existing natural vegetation of Arkansas based on the United Nations Educational, Scientific and Cultural Organization (UNESCO) system. It incorporates aspects of systems in use by the Nature Conservancy, Arkansas Natural Heritage Commission, Arkansas Game and Fish Commission, Society of American Foresters, and United States Forest Service, as well as data on potential vegetation from maps by E.E. Dale and A.W. Kuchler. A total of 18 physiognomic cover types are recognized for natural terrestrial cover, 6 for palustrine cover, and 4 each for lacustrine cover and riverine cover. Over 200 community types are recognized, grouped into 57 cover types and 90 intermediate groupings. This system is appropriate for use with remotely sensed data and the level of detail dealt with can be rationally adjusted by working at a higher or lower level of the hierarchy. We suggest that this system form the basis for future vegetation analyses and research within Arkansas

Trypanosoma brucei PRMT1 Is a Nucleic Acid Binding Protein with a Role in Energy Metabolism and the Starvation Stress Response.

In Trypanosoma brucei and related kinetoplastid parasites, transcription of protein coding genes is largely unregulated. Rather, mRNA binding proteins, which impact processes such as transcript stability and translation efficiency, are the predominant regulators of gene expression. Arginine methylation is a posttranslational modification that preferentially targets RNA binding proteins and is, therefore, likely to have a substantial impact on T. brucei biology. The data presented here demonstrate that cells depleted of T. brucei PRMT1 (TbPRMT1), a major type I protein arginine methyltransferase, exhibit decreased virulence in an animal model. To understand the basis of this phenotype, quantitative global proteomics was employed to measure protein steady-state levels in cells lacking TbPRMT1. The approach revealed striking changes in proteins involved in energy metabolism. Most prominent were a decrease in glycolytic enzyme abundance and an increase in proline degradation pathway components, changes that resemble the metabolic remodeling that occurs during T. brucei life cycle progression. The work describes several RNA binding proteins whose association with mRNA was altered in TbPRMT1-depleted cells, and a large number of TbPRMT1-interacting proteins, thereby highlighting potential TbPRMT1 substrates. Many proteins involved in the T. brucei starvation stress response were found to interact with TbPRMT1, prompting analysis of the response of TbPRMT1-depleted cells to nutrient deprivation. Indeed, depletion of TbPRMT1 strongly hinders the ability of T. brucei to form cytoplasmic mRNA granules under starvation conditions. Finally, this work shows that TbPRMT1 itself binds nucleic acids in vitro and in vivo, a feature completely novel to protein arginine methyltransferases.IMPORTANCETrypanosoma brucei infection causes human African trypanosomiasis, also known as sleeping sickness, a disease with a nearly 100% fatality rate when untreated. Current drugs are expensive, toxic, and highly impractical to administer, prompting the community to explore various unique aspects of T. brucei biology in search of better treatments. In this study, we identified the protein arginine methyltransferase (PRMT), TbPRMT1, as a factor that modulates numerous aspects of T. brucei biology. These include glycolysis and life cycle progression signaling, both of which are being intensely researched toward identification of potential drug targets. Our data will aid research in those fields. Furthermore, we demonstrate for the first time a direct association of a PRMT with nucleic acids, a finding we believe could translate to other organisms, including humans, thereby impacting research in fields as distant as human cancer biology and immune response modulation. Copyright © 2018 Kafková et al

Numerical simulations of the flow and sediment transport regimes surrounding a short cylinder

Author Posting. © IEEE, 2007. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in IEEE Journal of Oceanic Engineering 32 (2007): 249-259, doi:10.1109/JOE.2007.890986.The 3-D flow field and bed stress surrounding a short cylinder in response to combined wave and mean-flow forcing events is examined. Model simulations are performed with a 3-D nonhydrostatic computational fluid dynamics model, FLOW-3D. The model is forced with a range of characteristic tidal and wave velocities as observed in 12–15 m of water at the Martha's Vineyard Coastal Observatory (MVCO, Edgartown, MA). The 2.4-m-long and 0.5-m diameter cylinder is buried 10% of the diameter on a flat, fixed bed. Regions of incipient motion are identified through local estimates of the Shields parameter exceeding the critical value. Potential areas of sediment deposition are identified with local estimates of the Rouse parameter exceeding ten. The model predictions of sediment response are in general in agreement with field observations of seabed morphology obtained over a one-week period during the 2003–2004 MVCO mine burial experiment. Both observations and simulations show potential transport occurring at the ends of the mine in wave-dominated events. Mean flows greater than 10 cm/s lead to the formation of larger scour pits upstream of the cylinder. Deposition in both cases tends to occur along the sides, near the center of mass of the mine. However, the fixed-bed assumption prohibits the prediction of full perimeter scour as is observed in nature. Predicted scour and burial regimes for a range of wave and mean-flow combinations are established.This work was supported in part by the U.S. Office of Naval Research under the mine burial project N00014-00-1-0570. The work of K. A. Hatton was supported by the National Science Foundation Graduate Research Fellowship

Harmful Algae Bloom Identification Laboratory for Virginia Shellfish Hatcheries and Nurseries

HAB Identification Laboratory Training Module This laboratory is one part of a collaborative effort funded by NOAA Sea Grant to deliver timely and practical shellfish culture information to the commercial industr

Adolescent and Young Adult Perceptions of Hookah and Little Cigars/Cigarillos: Implications for Risk Messages

Use of hookah and little cigars/cigarillos (LCCs) is high among adolescents and young adults. Although these products have health effects similar to cigarettes, adolescents and young adults believe them to be safer. This study examined adolescent and young adult perceptions of hookah and LCCs to develop risk messages aimed at discouraging use among users and at-risk nonusers. Ten focus groups with 77 adolescents and young adults were conducted to explore their perceptions about the perceived risks and benefits of hookah and LCC use. Participants were users of other (non-cigarette) tobacco products (n=47) and susceptible nonusers (n=30). Transcripts were coded for emergent themes on participants’ perceptions of hookah and LCCs. Participants did not perceive health effects associated with hookah and LCC use to be serious or likely to happen given their infrequency of use and perceptions that they are less harmful than cigarettes. Participants generally had positive associations with smoking hookah and LCCs for several reasons, including that they are used in social gatherings, come in various flavors, and can be used to perform smoke tricks. Because adolescents and young adults underestimate and discount the long-term risks associated with hookah and LCC use, effective messages may be those that focus on the acute/immediate health and cosmetic effects