Browsing by Subject "Seminars"

Now showing 1 - 20 of 134
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    125-Day Spectral Record of the Bright Nova 2013 Delphini (V339 Del)(2014-09-11)
    (2014) Mooers, Howard; University of Minnesota Duluth. Department of Earth and Environmental Sciences
    Faculty seminar
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    3-D Printing of Anatomically-Accurate and Physiologically-Relevant Heart Models for Bioprosthetic Valve Testing (2020-01-31)
    (2020) Lai, Victor; University of Minnesota Duluth. Department of Chemistry and Biochemistry
    Transcatheter aortic valve replacement (TAVR) to treat severe aortic stenosis has exceeded the number of surgical aortic valve replacements done in the United States, because of its higher rates of success and lower risk of mortality, especially in older patients. While TAVR valves can achieve immediate relief of obstruction, complications such as aortic rupture and conduction abnormalities such as complete heart block may still occur, which require additional treatment. While it is believed that such valve complications may be exacerbated by pre-existing conditions, the underlying mechanisms causing such failures has not been well studied. In addition, there is currently no method to test the effectiveness of these valves under conditions that are specific to the patient. By applying a combination of Chemistry, Materials Science, and Engineering concepts, we want to develop a proof-of-concept of a 3-D printed heart model for bioprosthetic valve testing that is anatomically-accurate and physiologically-relevant to a patient and his/her underlying condition. The central hypothesis is that the effectiveness of such implants is influenced by the growth and remodeling of the surrounding native tissue in response to localized changes to the micromechanical and fluid flow environment due to the stented valve; understanding such changes to the cellular microenvironment will guide the design of TAVR implants to reduce the incidence of complications.
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    Accelerating Tuberculosis Drug Discovery by High Throughput Screening (2016-02-19)
    (2016) Arora, Kriti; University of Minnesota Duluth. Department of Biology
    Tuberculosis (TB) continues to be a leading killer of people worldwide infecting an estimated one-third of the world population and causing an 1.5 million deaths in 2014 alone. The current therapeutic regimen for drug-sensitive disease consists of 6-months of chemotherapy with agents that are associated with adverse events and toxicities leading to non-compliance. Additionally HIV-TB co-infection and the spread of drug-resistant TB underscores the need for discovery of new drugs that would shorten the course of chemotherapy. The Tuberculosis Drug Accelerator Program was born out of this urgent need and is a Gates Foundation funded collaborative effort between pharmaceutical companies and academic institutions. As part of this initiative we have conducted the largest global screening effort againstMycobacterium tuberculosis at the Tuberculosis Research Section (NIAID, NIH) in partnership with Merck, Bayer, AstraZeneca, EISAI, Pfizer and the University of Dundee. This screening campaign has generated several hit compounds which are currently progressing through our formal hit assessment cascade. The aim of the program is to increase early attrition rates so that only the best compounds move forward into preclinical development with the ultimate goal of declaring a new clinical candidate(s) by 2019 and a new regimen by 2024.
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    Active Vibratory Stimulation Enhances Functional Recovery After Brain Injury (2023-02-16)
    (2023) University of Minnesota Duluth. Medical School, Duluth Campus
    Yu Liu, MD, PhD, Associate Professor University of Tennessee, Department of Anatomy and Neurobiology, University of Tennessee Health Science Center
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    Advances in Ionic Liquid-Based Stationary Phases and Sorbent Materials for Chromatography and Sample Preparation (2020-02-07)
    (2020) Anderson, Jared; University of Minnesota Duluth. Department of Chemistry and Biochemistry
    Ionic liquids (ILs) can be designed to exhibit unique properties for their use in a number of applications in analytical and bioanalytical chemistry. This talk will focus on the design and synthesis of ILs, magnetic ionic liquids (MILs), and polymeric ionic liquids (PILs) as well as the use of these materials in a number of applications within multidimensional chromatography and sample preparation. A series of monocationic/dicationic ionic liquid-based and silver-containing stationary phases were evaluated as secondary columns in comprehensive two-dimensional gas chromatography (GCxGC) for the separation of aliphatic hydrocarbons from kerosene as well as the separation of olefins from paraffins. Finally, nucleic acids are biopolymers that constitute important diagnostic molecules for a broad range of applications from clinical testing to forensic analysis. A major challenge faced by DNA and RNA analysis techniques is the selective extraction of particular nucleic acid sequences using rapid and sensitve methodologies. It will be shown that ion-tagged oligonucleotides (ITOs) can be used in conjunction with MILs to efficiently capture DNA sequences from complex samples. The ITOs can be created through thio-lene "click" chemistry and the nature of the ion tag can influence the partitioning of the ITO to the hydrophobic MIL. This novel liquid-phase approach towards sequence-selective DNA capture provides superior extraction efficiencies to conventional magnetic bead technology as well as a platform for using external fields to manipulate the liquid droplets.
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    Adventures in Mineral Reactivity Characterization: How Silicate Mineral Dissolution Brought Me Across Two Continents and into the Private Sector (2019-10-10)
    (2019) Diedrich, Tamara; University of Minnesota Duluth. Department of Earth and Environmental Sciences
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    The Affordable Care Act and Your Business (2013-12-13)
    (2013) University of Minnesota Duluth. Center for Economic Development; Branshaw, Pamela
    The majority of the Affordable Care Act (ACA) will be implemented by January 1st, 2014. This workshop provides valuable information needed to make educated healthcare decisions for your business.
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    Anji'bide: Research as a transformative tool to improve community well-being (2022-11-16)
    (2022) University of Minnesota Duluth. Medical School, Duluth Campus
    Brenna Greenfield, PhD, LP, Associate Professor, Department of Family Medicine & Biobehavioral Health, UMN Medical School, Duluth Campus ; Amy Redcloud, Mental Health Clinical Treatment Director for Red Lake Nation
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    Applications of Synthetic Chemistry: From Biomaterials and Environmental Science to Molecular Electronics (2021-10-08)
    (2021) Banks, Surya; University of Minnesota Duluth. Department of Chemistry and Biochemistry
    The extent of synthetic organic chemistry is pervasive in every aspect of our society today. However, this applied science is no longer exclusive to one laboratory and has evolved into an exciting multidisciplinary and collaborative quest of our material environment. This talk touches upon some of the interdisciplinary collaborative research projects ranging from a viable proof of chemically modified alginate microcapsules as controlled drug delivery mediums, to search for structure activity relationships on rectification ratios of self-assembled monolayers of benzalkylsilanes on SiO2 substrate. Projects on use of chemically modified biopolymers for environmental chemistry and organometallic oligomers/polymers with potential optoelectronic applications will also be highlighted.
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    Approaching the Reality: Personal Experience with use of Scientific Education (2019-09-19)
    (2019) Shmagin, Boris; University of Minnesota Duluth. Department of Earth and Environmental Sciences
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    Aqueous Photochemistry of Polyolefins (2020-02-28)
    (2020) Mundhenke, Thomas; University of Minnesota Duluth. Department of Chemistry and Biochemistry
    Polypropylene (PP) and polyethylene (PE) are commonly used polyolefins in a variety of applications, which have resulted in their accummulation in the environment. Once in the environment, these polymers undergo various chemical and physical transformations as the result of environmental stressors such as sunlight. During photodegradation, PP and PE undergo reactions such as oxidation, crosslinking, and chain scission that are induced from UV light; yet, there are key gaps in knowledge on the phototransformations that occur under aqueous conditions. Therefore, it is the goal of this project to characterize the phototransformations of PP and PE in simulated natural water conditions. This presentation focuses on 25 µm thick PP films. The polymer films were irradiated with 254 nm and 350 nm UV light in air, ultra-pure water, and solutions of dissolve organic matter (DOM) (10 mgC/L Suwanee River natural organic matter) to simulate natural systems. For comparison, the films were subjected to natural weathering over the course of Summer 2019 in Duluth, Minnesota. Irradiated plastics were then evaluated for a variety of chemical transformations. It was observed using Fourier Transform Infrared Spectroscopy (FTIR) that oxidation occurred both in air and aqueous environments, with oxidation in aqueous environments happening at a slower rate. Using gel fraction analysis crosslinking was observed to occur in both air and aqueous environments with a lower crosslinking fraction occurring in aqueous environments. Polymer crystallinity was also monitored using FTIR. An increase in crystallinity was observed for all samples indicating that the polymer matrix was rearranged during photodegradation. Through this work, we have gained a more clear perspective on the chemical weathering of materials found in aquatic plastic debris, which will allow us to predict the behavior of these materials, including the breakdown into microplastics.
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    Assessing the Degradation of Munitions Compounds by Compound Specific Isotope Analysis in Natural and Engineered Environments (2021-11-19)
    (2021) Berens, Matthew; University of Minnesota Duluth. Department of Chemistry and Biochemistry
    Iron-bearing minerals are important reductants in the contaminated subsurface, but their availability for the reduction of anthropogenic pollutants is often limited by competition with other electron acceptors including microorganisms and poor accessibility to Fe(II) in complex hydrogeologic settings. The supply of external electron donors through in situ chemical reduction (ISCR) has been proposed as one remediation approach, but the quantification of pollutant transformation is complicated by the perturbations introduced to the subsurface by ISCR. Here, we evaluate the application of compound specific isotope analysis (CSIA) for monitoring the reduction of 2,4-dinitroanisole (DNAN), a component of insensitive munitions formulations, by mineral-bound Fe(II) generated through ISCR of subsurface material from two field sites. Electron balances from laboratory experiments in batch and column reactors showed that 3.6% to 11% of the total Fe in the sediments was available for the reduction of DNAN and its partially reduced intermediates after dithionite treatment. The extent of DNAN reduction was successfully quantified from its N isotope fractionation measured in the column effluent based on the derivation of a N isotope enrichment factor, ?N, derived from a comprehensive series of isotope fractionation experiments with numerous Fe(II)-bearing minerals as well as dithionite-reduced subsurface materials. Our observations illustrate the utility of CSIA as a robust approach to evaluate the success of in situ remediation through abiotic contaminant reduction.
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    "Assessing the Impact of Climate Change on High Mountain Glacial Watersheds of the Cordillera Blanca in Peru" by Dr. Daene C. McKinney (2014-04-11)
    (2014) University of Minnesota Duluth. Water Resources Science Graduate Program; McKinney, Daene C; Cunningham, W A. (Bill)
    His research focuses on sustainable management of water resources, especially the integration of engineering, economic, environmental and political considerations in transboundary basins, including work in Peru, Nepal, Aral Sea, the Rio Grande-Rio Bravo basin in Texas/Mexico, Lebanon, and Kuwait.
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    Asymmetrical Boron-Based Light-Emitting Compounds Based on Aromatic Diamine Frameworks (2022-04-08)
    (2022) Ploeger, Ethan; University of Minnesota Duluth. Department of Chemistry and Biochemistry
    In recent years OLED technology has become very popular for its vibrant colors. The use of OLED allows users to create fluorescent organic compounds without the use of heavy metals. Our work explores chelating ligand frameworks of the kind HO••N that are based on asymmetrical aromatic diamine frameworks that are attached to boron fragments such as BF2 and PPh2. The ligand synthesis is done through condensation reactions and the further reaction with diphenylborinic acid or with BF3 by reaction with BF3•Et2O leads to the final boron-containing products. The final boron derivatives are characterized by NMR, LC-MS, and UV-Vis. The status of current findings in synthesis and characterization as well as light emission data will be presented as well as future plans outlined.
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    Biogeochemical and food web studies in lakes large and small (2019-10-11)
    (2019) Ozersky, Ted; University of Minnesota Duluth. Department of Biology
    My lab studies the ecology and biogeochemistry of lake ecosystems. In this talk I will highlight three research projects that my students, collaborators and I have been pursuing over the past five years. First, I will discuss our work on the way invasive zebra and quagga (dreissenid) mussels affect thebiogeochemistry of invaded lakes and how the impacts of dreissenids change with environmental setting. I will also describe our work on uncovering the seldom-studied ecological processes that occur during the winter in small and large ice-covered lakes. The third project I will present examines environmental controls on growth of benthic algae in large lake ecosystems, including the Laurentian Great Lakes and Russia’s Lake Baikal. I will finish by discussing my plans for future research.
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    "The Biogeochemical Habitat of Wild Rice" (2014-09-16)
    (2014) Pastor, John; Johnson, Nathan; Craig, Timothy P
    “The Biogeochemical Habitat of Wild Rice” by John Pastor, Ph.D., Professor, UMD Biology and Nathan Johnson, Ph.D, UMD Civil Engineering
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    Biology and Biochemistry in Craft Beverage Distilling (2023-03-03)
    (2023) Vikre, Emily; University of Minnesota Duluth. Department of Chemistry and Biochemistry
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    Biomineralization Along a Manganese Depositing Hot Spring in Yellowstone National Park (2020-03-05)
    (2020) Smythe, Wendy; University of Minnesota Duluth. Department of Earth and Environmental Sciences
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    Breakdown of Plastics in the Environment: The Impact of Weathering on the Fate and Transformations of Aquatic Plastic Debris (2020-10-09)
    (2020) Maurer-Jones, Melissa; University of Minnesota Duluth. Department of Chemistry and Biochemistry
    Plastics are a ubiquitous part of everyday life and a central challenge in the environment. Environmental stresses such as sunlight, temperature fluctuations, wet/dry cycling or microbial forces affect the longevity or degradation of plastics. Assessing the fate of plastics under these stresses allows us to accurately predict the service lifetime of plastics used in infrastructure (e.g., power cabling/solar panels) or evaluate the extent of the plastic pollution problem. This talk details the work of quantifying photochemical and thermal degradation mechanisms of plastics commonly found in aquatic plastic debris: polyethylene, polypropylene and polyethylene terephthalate. In this talk, I will focus on the development of a methodological framework for characterization of the rates and yields of the chemical transformations within polymers, moving beyond traditional materials characterization techniques. Additionally, we quantified the formation of microplastics upon photochemical weathering, applying our understanding of the chemical photo-transformations. Beyond the transformations of the plastics, we also began to unravel the role plastics and plastic weathering play on the ecosystem health by monitoring the sorption of model micropollutants to weathered plastics and the toxicity of nanoplastics to a model bacterium. Ultimately, this work strives to quantify the transformations and fate of plastics so as to design a predictive model of plastic behavior in the environment, which has implications for accurately assessing the burden of plastics on the environment but also allows for new polymer design.