Browsing by Subject "Plants"

Now showing 1 - 4 of 4
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    Bringing nature inside: improving the indoor experience
    (2024) Davidson, Maia
    In the modern world, United Stated people spend 90% of the day indoors, going against the innate desire all human beings possess to be connected with nature. Understanding how the connection to nature benefits individuals, and what this lost connection may be causing or negatively enhancing, is an important part of future design because improving the design of interior spaces will improve the health of those using it. Expanding and deepening the design toolkit to include tangible elements, such as using tall potted plants as a spatial divider, purposefully placed colorful plants as wayfinding elements, hanging plants as light diffusers, and many other design solutions, offers clear opportunity to add natural benefits, such as improved mental health, cleaner air, and expanded attention, to any project. This study reviewed the literature of nature-based benefits and major issues people are struggling with and determined that the disconnect between humans and the natural world is harming society, and that a change must occur. These findings were used to determine an equitable solution that could be incorporated into the design world. Realizing the issues affect those of all economic and social standing, an affordable, small-scale solution became the focus of this study. Offering opportunity for anyone to include potted plants in design makes this solution as attainable as it is effective. Encouraging design professionals and those who seek to do so on their own to incorporate plants into interior design is the first step towards a more impactful reconnection with nature.
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    Development of RNA Viral Vectors for Plant Genome Engineering
    (2022-02) Ellison, Evan
    Genetic variation is a key principle in the improvement of agricultural crops. For thousands of years, crop productivity, resilience and adaptability has been slowly improved by selection of favorable alleles. An increasing understanding of molecular genetics underlying key traits has contributed to the continuing progress in crop development. Dissecting and exploiting plant molecular genetics is greatly enhanced by the ability to precisely create genetic variation at pre-selected sites. Creating novel genetic variation through gene editing is reliant on technology that creates the desired modification at the target site and delivery of the reagents to plant cells. RNA guided endonucleases, such as CRISPR/Cas9, have enabled an unprecedented ability for site-specific genetic modification. Delivery of reagents, however, is still largely reliant on tissue culture regeneration to fix targeted genetic modifications in the genome. Tissue culture regeneration is a technically difficult process that can easily take several months or years to complete. The work described here outlines approaches to deliver genome editing reagents using RNA viruses. Chapter 1 discusses background information related to plant viruses and viral vectors. Chapter 2 describes a collaborative effort to develop a novel gene editing reagent delivery vector, Foxtail Mosaic Virus (FoMV), and its application in gene editing of monocot and dicot plant species. Genetic modifications obtained in chapter 2 only occurred in somatic cells, and still require laborious tissue-culture to fix in the germline. Chapter 3 describes my approaches to improve Tobacco Rattle Virus (TRV) for highly efficient heritable genome editing in the model species Nicotiana benthamiana. This work was improved further in chapter 4 by using viral vectors and an improved method for heritable genome editing in Solanum lycopersicum (tomato). Together, these improvements to RNA viral vectors provide an efficient and rapid means for delivery of genome engineering reagents. The time to generate targeted modifications that are fixed in the genome, for both model and crop species, is reduced from years to only a few months which enables genome editing at scale. The ease at which targeted genetic modifications can now be generated will enable important progress in crop improvement.
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    An Integrated Approach to Assessing Multiple Stressors for Coastal Lake Superior
    (2011) Niemi, Gerald J; Reavie, Euan; Peterson, Gregory S; Kelly, John R; Johnston, Carol A; Johnson, Lucinda B; Howe, Robert W; Host, George; Hollenhorst, Thomas; Danz, Nick; Ciborowski, Jan H; Brown, Terry; Brady, Valerie; Axler, Richard P
    This peer-reviewed article summarizes research conducted under the Great Lakes Environmental Indicators (GLEI) project initiated by the authors in 2001. The authors assessed the status of Lake Superior’s coastal ecosystem relative to over 200 environmental variables collected from GIS data sets for the enture US Great Lakes basin. These were assessed using gradients including atmosphereic deposition, agriculture, human population and development, land cover, point source pollution, soils and a cumulative stress index. Relationships of biological assemblages of birds, diatoms, fish and invertebrates, wetland plants, soils and stable isotopes to these gradients were then assessed. Key findings are extracted and reproduced below. Biological indicators can be used both to estimate ecological condition and to suggest plausible causes of ecosystem degradation across the U.S. Great Lakes coastal region. Here we use data on breeding bird, diatom, fish, invertebrate, and wetland plant communities to develop robust indicators of ecological condition of the U.S. Lake Superior coastal zone. Sites were selected as part of a larger, stratified random design for the entire U.S. Great Lakes coastal region, covering gradients of anthropogenic stress defined by over 200 stressor variables (e.g. agriculture, altered land cover, human populations, and point source pollution). A total of 89 locations in Lake Superior were sampled between 2001 and 2004 including 31 sites for stable isotope analysis of benthic macroinvertebrates, 62 sites for birds, 35 for diatoms, 32 for fish and macroinvertebrates, and 26 for wetland vegetation. A relationship between watershed disturbance metrics and 15N levels in coastal macroinvertebrates confirmed that watershed-based stressor gradients are expressed across Lake Superior’s coastal ecosystems, increasing confidence in ascribing causes of biological responses to some landscape activities. Several landscape metrics in particular—agriculture, urbanization, human population density, and road density—strongly influenced the responses of indicator species assemblages. Conditions were generally good in Lake Superior, but in some areas watershed stressors produced degraded conditions that were similar to those in the southern and eastern U.S. Great Lakes. The following indicators were developed based on biotic responses to stress in Lake Superior in the context of all the Great Lakes: (1) an index of ecological condition for breeding bird communities, (2) diatom-based nutrient and solids indicators, (3) fish and macroinvertebrate indicators for coastal wetlands, and (4) a non-metric multidimensional scaling for wetland plants corresponding to a cumulative stress index. These biotic measures serve as useful indicators of the ecological condition of the Lake Superior coast; collectively, they provide a baseline assessment of selected biological conditions for the U.S. Lake Superior coastal region and prescribe a means to detect change over time.” Key points: “In general, the U.S. Great Lakes coastal region of Lake Superior shows greater overall stress in the southern regions compared with relatively low overall stress in the northern regions. These patterns are primarily due to agricultural land use, higher human population densities, and point sources in the eastern and western portions on the south shore, while the north shore at the western end of Lake Superior is primarily forested with relatively sparse human population densities. Coastal regions of Lake Superior can be found at each of the extremes of the disturbance gradients. This includes relatively pristine watersheds in the northern regions with low human population densities and little agriculture that contrast with regions of relatively high populations with industrial activity such as Duluth-Superior in Minnesota-Wisconsin and Sault Ste. Marie Michigan at the other end of the gradient. The U.S. Lake Superior coastal region varies widely in the degree of human-related stress; generally, levels of stress decrease from south to north but with considerable variation, especially along the southern shore due to local agricultural activity and the presence of several population and industrial centers. In spite of a lack of latitudinal variation, there is human-induced, watershed scale variability across the Lake Superior coast. Compared to the other Great Lakes, Lake Superior coastal fish communities had more generally intolerant fish and more turbidity intolerant fish. Coastal fish community composition reflected the higher levels of suspended solids associated with human alteration to watersheds. The most disturbed sites on Lake Superior had greater proportions of non-native species and fewer bottom-feeding taxa.
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    Wetland Mitigation in Abandoned Gravel Pits
    (Minnesota Department of Transportation, 2010-03) Johnson, Kurt W.
    It is becoming increasingly difficult to provide on-site mitigation for wetland impacts due to road construction in northeastern Minnesota counties that retain greater than 80 percent of their pre-settlement wetlands. Abandoned gravel pits are one of the few remaining areas that can serve as wetland mitigation sites. The overall goal of the project is to develop cost-effective methods for creating functional mitigation wetlands on abandoned gravel pit sites to compensate for wetland impacts due to road construction. Two approximately 1-hectare wetland creation demonstration sites were established in adjacent abandoned gravel pits within the U.S. Trunk Highway 53 reconstruction corridor to evaluate techniques for wetland establishment. Wet meadow and shrub swamp wetlands were attempted on one site, and wooded swamp and bog wetlands on the other. Wetland seed mixes provided both positive and negative effects on the developing plant communities on both sites initially but their effect was limited to the first year. Alder thicket and bog donor soil applications had positive effects but not until the third year of the study. Hardwood willow cuttings were effective for establishing a shrub component. Conifer seedlings did not survive unless planted on soil mounds. Fertilizer proved ineffective for promoting wetland plant growth during the study period. The use of straw mulch is questionable on saturated wetland sites such as those in this study.