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Title
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A LONGITUDINAL EXAMINATION OF IMITATION RECOGNITION IN CHILDREN WITH AUTISM SPECTRUM DISORDER
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Creator
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Pomales Ramos, Anamiguel
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Date
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2021
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Collection
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Electronic Theses & Dissertations
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Description
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Children with autism spectrum disorder (ASD) have significant difficulties engaging in imitative behaviors, which can have cascading developmental effects on subsequent social communication skills. Although there is a substantial body of research on imitation in children, research on imitation recognition is extremely limited, despite its theoretical significance. The current study examined the longitudinal trajectory of imitation recognition during a period of contingent imitation by an...
Show moreChildren with autism spectrum disorder (ASD) have significant difficulties engaging in imitative behaviors, which can have cascading developmental effects on subsequent social communication skills. Although there is a substantial body of research on imitation in children, research on imitation recognition is extremely limited, despite its theoretical significance. The current study examined the longitudinal trajectory of imitation recognition during a period of contingent imitation by an adult in a sample of 51 children with ASD over a 9-month period. Results indicated that rates of implicit and explicit imitation recognition as well as the proportion of explicit imitation increased over time, consistent with their developmental emergence in children without ASD. Multilevel modeling indicated a main effect of implicit imitation recognition on receptive language and expressive vocabulary, suggesting the relationship between these skills in children with ASD. In addition, there was a marginally significant time by explicit imitation recognition interaction in predicting receptive language, indicating that children who demonstrated higher rates of explicit imitation recognition at baseline made greater gains in receptive language over time than those with lower rates of explicit imitation recognition. The clinical implications of these results suggest that early interventions that target imitation recognition may support the development of language skills in children with ASD.
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Title
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A FARM-BASED BIOREFINERY FOR CHEMICAL PRODUCTION FROM AGRICULTURAL RESIDUES
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Creator
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Frost, Henry James
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Date
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2021
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Collection
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Electronic Theses & Dissertations
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Description
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The purpose of this study is to investigate a new process of chemical production from agricultural residues. The studied system reduces the environmental impacts and power requirements of current chemical production methods. The feedstocks, corn stover and swine manure, are utilized by a three-step biological and physical conversion process to produce value-added chemicals lactic acid and chitin. Anerobic co-digestion was applied on the feedstocks to produce biogas and generate carbohydrate...
Show moreThe purpose of this study is to investigate a new process of chemical production from agricultural residues. The studied system reduces the environmental impacts and power requirements of current chemical production methods. The feedstocks, corn stover and swine manure, are utilized by a three-step biological and physical conversion process to produce value-added chemicals lactic acid and chitin. Anerobic co-digestion was applied on the feedstocks to produce biogas and generate carbohydrate-rich solid digestate. The solid digestate was then processed by a mechano-biocatalytic one-pot hydrolysis to release mono-sugars.Rhizopus Oryzae, a fungus, was used to convert mono-sugars into lactic acid and chitin. Under the steady state, anaerobic co-digestion produced 249±71 mL biogas/g volatile solids loading/day with a methane content of 62% (v/v). The mechano-biocatalytic process produced hydrolysate with high titers of glucose, xylose and acetic acid (32.90, 21.35, 4.06 g/L, respectively). The liquid hydrolysate was then fermented by R. oryzae to produce lactic acid (14.23 g/L) and mixed biomass (119 g dry matter) with a chitin content of 18% (w/w). A mass and energy balance on a farm-based biorefinery concluded that 199 m3 of biogas, 22 kg of lactic acid and 34 kg chitin per day can be produced by processing 1,000 kg dry feedstock per day. The energy balance showed that a positive net energy output of 2,200 MJ/1,000 kg dry feedstock was achieved by proposed process. Therefore, the studied system not only addressed the environmental challenges of agricultural residues handling and disposal but also produces value-added chemicals to generate revenues from the residues.
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Title
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A COMPREHENSIVE STUDY OF PREDATOR DIETS IN LAKE HURON
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Creator
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Kierczynski, Katie Elline
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Date
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2022
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Collection
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Electronic Theses & Dissertations
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Description
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Lake Huron has a history of overfishing, habitat degradation, and introductions of non-native species that have resulted in a dynamic ecosystem with a prey base of primarily non-native species. In the mid-2000s, a massive shift in the ecosystem occurred when Alewife and Chinook Salmon populations collapsed. This led to an increase in native Lake Trout and Walleye populations, despite the continued low prey biomass. Alternative prey such as non-native Round Goby and Rainbow Smelt have...
Show moreLake Huron has a history of overfishing, habitat degradation, and introductions of non-native species that have resulted in a dynamic ecosystem with a prey base of primarily non-native species. In the mid-2000s, a massive shift in the ecosystem occurred when Alewife and Chinook Salmon populations collapsed. This led to an increase in native Lake Trout and Walleye populations, despite the continued low prey biomass. Alternative prey such as non-native Round Goby and Rainbow Smelt have supported predator foraging, but it is unclear if current prey biomass levels can support the continued expansion of Lake Trout and Walleye populations. I conducted a comprehensive diet study of angler-caught predators in 2017 and 2018 to evaluate current spatial and temporal trends in the diets of the major predators of Lake Huron within the context of historical foraging conditions. I observed several prominent spatiotemporal trends for the majority of Lake Huron predator diets, including a shift in consumption from Round Goby to Rainbow Smelt between spring and summer, and an overall reduced consumption of Round Goby in Saginaw Bay compared to the main basin. I also found an increased reliance on Round Goby by native Walleye and Lake Trout compared to previous studies while Chinook Salmon continued to rely upon Rainbow Smelt and Alewife. Evidence from gut fullness indices and size distributions of consumed prey indicate that forage conditions in Lake Huron continue to decline. Overall, the predator community continues to be reliant on non-native prey, and forage conditions may be indicative of prey limitation for the foreseeable future.
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Title
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3D printed antennas : metalized plastic
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Creator
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Mohd Ghazali, Mohd Ifwat
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Date
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2014
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Collection
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Electronic Theses & Dissertations
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Description
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This thesis introduces the use of 3D printed plastic structures for the fabrication of antenna structures. Use of 3D printing technology allows for a simple fabrication technique that is faster and low cost compared with traditional microfabrication approaches. Two Vivaldi antenna designs are studied first: i) a simple notch antenna with a radiating slot line cavity and ii) a corrugated Vivaldi with a partially covered cavity. The corrugations help increase the bandwidth and gain of the...
Show moreThis thesis introduces the use of 3D printed plastic structures for the fabrication of antenna structures. Use of 3D printing technology allows for a simple fabrication technique that is faster and low cost compared with traditional microfabrication approaches. Two Vivaldi antenna designs are studied first: i) a simple notch antenna with a radiating slot line cavity and ii) a corrugated Vivaldi with a partially covered cavity. The corrugations help increase the bandwidth and gain of the Vivaldi antenna. The antennas show an extremely wide bandwidth of approximately 13 GHz and have a gain maximum of approximately 12dB. Further modifications were made by adding bilateral pieces and dielectric focal lens at the radiating end. A larger bandwidth and higher gain was attained. The dielectric guiding structure in the aperture helps to further improve the gain both at the lower frequency and higher frequency regions. The integration of dielectrics in the antenna design is readily achieved using 3D printing. Apart from the above Vivaldi antenna designs, three other antenna designs were also studied. This includes a dielectric loaded monopole antenna, a patch antenna and a reconfigurable Lego-like antenna. Complex 3D antenna structures and novel antenna designs that use a combination of dielectric and metal regions are studied and these structures can readily be fabricated using 3D printing.
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