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Regional Differences in Winter Diets of Bobcats in Their Northern Range
No full textWhen generalist predators have wide geographic ranges, diets may differ dramatically, largely as a result of differing prey communities. Bobcats (Lynx rufus) are widely distributed across southern North America, with their northern range edge occurring in southern Canada and in the northern US states. Within this northern range, bobcats are exposed to cold and snowy winters and a limited number of prey species, conditions that are atypical for most of the range of bobcats. We examined winter diets of bobcats in high elevation and very snowy forests in northwest Montana to determine how these generalist predators managed in these harsh conditions in comparison to elsewhere in the northern range. Bobcats consumed 5 major prey types: red squirrels (Tamiasciurus hudsonicus) and Cricetid rodents comprised >78% of the dietary biomass, whereas the larger snowshoe hares (Lepus americanus), deer (Odocoileus spp.), and grouse were consumed much less often. The standardized niche breadth of bobcat diets was 0.29; bobcats from across the northern range also routinely ate multiple prey species, although eastern bobcats appear to consume more lagomorphs than do western bobcats. These results indicate that bobcats remain generalists in difficult winter conditions while preying primarily on small-bodied prey, although bobcats have highly variable diets across their northern range
Metagenomic Vs 16s Dna Sequencing for Identifying Bacterial Populations
No full textNext Generation Sequencing (NGS) technology has launched immense growth of DNA sequence databases, paving the way to better categorize the genetic diversity of the biosphere. Bioinformaticians curate and analyze this massive amount of DNA sequence data for applications that range from science and medicine to forensics and commercial ancestry services. The DNA sequences provided by NGS can be analyzed to profile bacterial communities within environmental niches. Experimental approaches for assessing these communities vary widely between labs. Our goal was to compare two common methods to test for cohesion between these approaches’ results. We obtained DNA sequences from both metagenomic (“shotgun”) and bacterial 16S gene sequencing for five DNA samples (two soil and three human microbiome). We developed a custom software pipeline in conjunction with the program BLAST, processed hundreds of thousands of DNA sequence reads produced by each sequencing method (metagenomic or 16S) and, for each sample, compared the two resulting bacterial profiles. For all five samples, community taxonomic profiles produced from the two methods were distinctly different. Explanations for these disparities may include sampling bias in databases or the reliability of the 16S gene as a species identifier. These results highlight the importance of establishing a common methodology to accurately infer bacterial communities from DNA sequence data
Natural Infection in Honey Bee Hemocytes
No full textHoney bees act as the primary pollinators of plants including fruit, nut, and vegetable crops. Since 2006, however, viral and other pathogens have caused honey bee colony losses averaging 33% annually (Lee et al, 2015). In an effort to better understand how the immune system of honey bees works, especially honey bee antiviral responses, I am investigating natural infection in honey bee larvae and in isolated hemocytes, which are macrophage-like immune cells. It was discovered that fruit fly hemocytes remained uninfected in virus-infected larvae, since hemocytes are important in mediating antiviral responses (Tassetto et al., 2017). The goal of this research project was to determine if these cells may also remain free of viruses in otherwise infected honey bee larvae and, thus, play an important role in honey bee antiviral defense. RNA was extracted separately from larval carcasses and hemocytes and cDNA was made, which was then screened for eight different honey bee viruses to determine the presence of viruses in the hemocytes and in the cells that make up the carcass. I found that in naturally infected larvae, hemocytes are generally uninfected. Of 39 larvae, 13 had natural infections. Three of the eight viruses were responsible for these infections. Of these 13 infected larvae, the hemocytes of only one larva was infected with the same virus that had infected the larva. Further experimentation will include testing hemocytes and carcasses from a larger sample of naturally infected larvae and from adult honey bees that will be injected with flock house virus. This will help determine if adult honey bee hemocytes are similarly resistant to viruses as larval hemocytes. Should hemocytes remain uninfected in otherwise infected larvae or adult bees, they may be a useful model for studying infection and the resulting antiviral response in honey bees at a cellular level
Creating a Reciprocationg Air Compressor using a Single Degree of Freedom Spring Mass Damper Resonant System
No full textTheoretically, a reciprocating air compressor should work with a single degree of freedom spring mass damper resonant (1D-SMD) design. The following steps were used to demonstrate how the system could be applied to an air compressor. Once a mathematical model was created, the calculated results determined the parameters for the solid model using SolidWorks. The model included a design that was based around an off-the-shelf air compressor. These parts were either 3d printed, ordered, or machined and assembled. Finally, the system was tested as an air compressor. Several design iterations were performed to improve the system. The application of this project resulted in a newly built air compressor, which suggests this is an efficient way to compress ai
Enhanced Reductive Defluorination of 6:2 Fluorotelomer Alcohol Using Bio-Electrochemical Systems
No full textCurrent research on the biological degradation of poly- and perfluorinated alkyl substances (PFASs) is still challenged by two limitations: 1) Poor feasibility: successful biodegradation is limited to a small number of perfluoroalkyl acid precursors such as fluorotelomer alcohols (FTOHs); 2) Lack of means to precisely study the mechanism: conventional biological methods can only create an anaerobic (vs. aerobic) environment, which cannot pinpoint whether the mechanism is oxidative or reductive.This study uses Bio-Electrochemical Systems (BES) to precisely accomplish and enhance reductive PFAS degradation. BES is a platform technology where bacteria directly exchange electrons with solid electrodes to catalyze biochemical reactions. It has great potential for studying and enhancing PFAS degradation because it can: 1) Enhance bio-reactions by utilizing electric power; 2) Precisely separate oxidation and reduction reactions given the fuel-cell-like setup. This study monitored the reductive defluorination of 6:2 fluorotelomer alcohol (6:2 FTOH) for over two months in BES. The results indicated that BES significantly increased (p-value<0.05) the rate of F- release under -0.55V poised potentials (vs. AgCl), and decreased the accumulation of 6:2 fluorotelomer carboxylic acid (6:2 FTCA), an intermediate degradation product (Fig 1). This study was the first time that reductive PFAS bio-degradation was precisely achieved, and the first report of successful BES-driven PFAS degradation. The findings provided the proof of concept needed to further explore whether enhanced defluorination can be accomplished with BES on more recalcitrant PFAS classes (e.g., perfluoroalkyl acids), and develop a new remediation technology
Is Time Resolved Infrared Radiometry an Alternative of Positron Annihilation Lifetime Spectroscopy for Defect Detection in Metals: An Experimental Approach and a Model Development
No full textTime resolved infrared radiometry (TRIR) and positron annihilation lifetime spectroscopy (PALS) are both defect detection methods used in different materials for more than 40 years. Interestingly, both of the methods are similar in many ways, such as non-invasive testing procedures and follow a decay scheme. Both of the methods are successfully applied to metals, polymers, and composites materials. However, the methods are different in application mechanism and principle. TRIR is a thermography technique that measures temperature decay with time of the investigated material whereas PALS uses positronium decay with time of the tested material. In PALS, two-state trapping model is mostly used. Two state trapping model is a positronium trapping model used to describe positron diffusion inside the material. According to the trapping model, high energy positron beam is emitted from radioactive nuclei, diffused into the material, and trapped in a defect caused emissions of comparatively lower energy γ (gamma) rays. We develop a model to describe the similarity between time resolved infrared radiometry and positron annihilation lifetime spectroscopy. In the model, we describe the heat transfer and diffusion mechanism in the investigated material in time resolved infrared radiometry. The model also describes an experimental development for time resolved infrared radiometry researc
Knockout of Elp3 Gene in Candida Albicans
No full textamilial Dysautonomia (FD) is a devastating neurodegenerative childhood disease characterized by diminished polarized growth of autonomic neurons. FD results from a mutation in the ELP1 gene and reduced levels of the corresponding protein ELP1, a scaffolding protein that assembles a multi-subunit complex called Elongator. Elongator functions in the modification of tRNAs that mediate efficient translation of AA- and AG-ending codons. The Elongator complex also includes the ELP3 protein, a catalytic subunit of the complex. We are using hyphal growth in the fungus Candida albicans to model the role of Elongator in polarized growth. In this study C. albicans was genetically modified to knockout the ELP3 gene. As with the ELP1 gene, the absence of the ELP3 is expected to eliminate Elongator function. We have found that knocking out ELP3 mitigates the polarized growth of hyphal filaments under certain growth condition
An Improved Understanding of Population Dynamics Using Count Data - Insights from Elk in Western Montana
No full textnderstanding the dynamics of ungulate populations is a crucial goal for managers given their ecological and economic importance. In particular, the ability to evaluate the evidence for potential drivers of variation in population trajectories is important for informed management. However, the routine use of age ratio data (e.g., juveniles:100 adult females) to evaluate variation in population dynamics is hindered by a lack of statistical power and difficult interpretation. Here, we show that the use of a population model fueled by count, classification and harvest data can dramatically improve the understanding of population dynamics compared to a model using age ratio data by: 1) increasing the power to assess potential sources of variation in key vital rates, and 2) providing easily interpretable vital rates (e.g., per capita recruitment rates and population growth rates) that are useful to managers. Using a time series of spring count data (2004 to 2016) and fall harvest data from hunting districts in western Montana, we constructed a population model to assess the effects of a series of environmental covariates and indices of predator abundance on the per capita recruitment rates of elk calves. Results from this modeling approach suggest per capita recruitment rates decline in association with wet springs, dry summers and severe winters, and in interactions between predator communities and the environment. In contrast, the analysis of age ratio data failed to detect these relationships. We recommend using count data and a population modeling approach rather than interpreting estimated age ratio data as a substantial improvement in understanding population dynamics
Keeping the Crown of the Continent Connected - A Report on Highway 2 Near Glacier National Park (Poster)
No full textThe US Highway 2 corridor separates Glacier National Park from the Bob Marshall Wilderness complex to the south. With increasing vehicle traffic, recreation, and high train traffic, resource managers in the region are concerned that Highway 2 is slowly becoming a barrier to north-south wildlife movement in the Crown of the Continent Ecosystem, and thus, this corridor has been identified as a priority for wildlife connectivity planning. While there have been a number of efforts to understand wildlife connectivity across this corridor, they have tended to be narrowly focused and temporally disjointed. Over the last year, an interagency group of local researchers and managers met in two workshops to evaluate existing research and data sources, identify knowledge gaps, and establish a research framework to increase understanding of wildlife use of the US2 corridor. The long-term goal is to identify explicit management options for preserving trans-highway movements, seasonal migrations, and dispersal movements of animals, plants, and ecological processes. This report builds on previous efforts to understand and plan for terrestrial wildlife connectivity across this inter-jurisdictional corridor by beginning a multi-agency conversation for collaborative research and management
Short-Term Response of Snowshoe Hares to Western Larch Restoration and Seasonal Needle Drop
No full textOld-growth western larch has been degraded throughout much of its historic range due to extensive timber harvest and fire suppression. We examined the effects of a restoration treatment of western larch on snowshoe hares, a denizen of the boreal forest serving as a focal animal species to indicate the health of the restored ecosystem. In western Montana, we implemented a restoration treatment using “doughnut thinning” to accelerate development of old-growth attributes in larch stands and simultaneously examined the short-term effects on snowshoe hare density, survival and movement. Although typical forest management activities tend to have adverse effects on hares especially in the short-term, we found that the restoration treatment did not affect hare density or survival in the short-term. In addition, despite significant decreases in cover coinciding with the larch needle drop, we found evidence of year-round immigration into larch stands by hares suggesting larch stands are suitable year-round hare habitat. Taken together, our findings suggest that a larch restoration treatment designed to accelerate the development of old-growth attributes can be implemented so as to have no measurable short-term detrimental effects on hares