2013 MU theses - Freely available online
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Item Zooarchaeological analysis of material excavated in 2009 from the 76 draw site (la 156980), Luna County, New Mexico(University of Missouri--Columbia, 2013) McCarthy, Elizabeth M.; Lyman, R. LeeThe 76 Draw site is located in southwestern New Mexico, several kilometers south of Deming. Evidence such as thick abode walls oriented on a North-South axis, Ramos polychrome ceramic sherds and El Paso sherds, suggests that the site is associated with the Casas Grandes culture to the south as well as the Jornada-Mogollon culture to the north. The site is an Animas Phase settlement, occupied during 1200-1450 AD and is generally considered a borderlands site between the two cultures because it contains artifacts and adobe architecture associated with both the Casas Grandes and Jornada-Mogollon cultures. Faunal materials from the 2009 field school excavation season were analyzed to answer the following questions: 1) Was the assemblage created by anthropogenic or natural processes? 2) What were the prehistoric environmental conditions, how do they compare to the modern setting, and how were prehistoric people interacting with their environment? and, 3) If male and female jackrabbits can be differentiated from archaeological materials, does this further our understanding of ethnographically recorded rabbit drives? To understand the accumulation processes of the assemblage, taphonomic characteristics such as burning, butchery marks, worked bone, spiral fractures, and general weathering of the remains were recorded. Several fragments were cut and a single element was worked by humans. As much as 40% of the fragments were charred or calcined and about 10% of the remains were spiral fractured. These taphonomic modifications are considered to be caused by anthropogenic factors, and the taxa identified with these modifications were assumed to be consumed by humans. Weathering of the exterior surface of the bone, root etching, and gnaw marks from rodents and carnivores are evidence of natural processes. The lagomorph and artiodactyl indices were used to estimate past environmental conditions and hunting behaviors. The human behavioral ecology (HBE) theoretical paradigm used here makes the Prey choice and Central-place foraging models central to the discussion. Prey choice was utilized to estimate which prey item would be taken if the hunter was behaving efficiently. The central place foraging model put the prey choices and the location of the site into context. In conjunction with the HBE models, two abundance indices were calculated. The lagomorph index calculates the proportion of cottontails to all of the identified leporid remains, which can be used to estimate the general vegetation coverage and prehistoric environment. Jackrabbits were significantly more abundant than cottontails, indicating local vegetation was sparse and similar to the modern day. The artiodactyl index measures the proportion of large mammals (such as deer) among the abundance of large plus small mammals (such as rabbits). Large bodied mammals were sparse in the assemblage, indicating the inhabitants of the site may be exploiting the local environment and not traveling long distances to procure large mammals in nearby mountain ranges. To determine the sex of jackrabbit remains from the 76 Draw site, a variety of measurements were taken from known sex individuals from the American Southwest and northern Mexico region. No statistically significant differences in the measurements taken from males and females were detected. Based on the skeletal material examined, the sex of Southwestern jackrabbits cannot be determined. Thus whether or not occupants of the 76 Draw site drove jackrabbits cannot be determined based on sex demography of the remains.Item Foaming properties of whey protein isolate and [lambda]-carrageenan mixed systems(University of Missouri--Columbia, 2013) Wang, Zhengshan; Vardhanabhuti, Bongkosh, 1967-Heating protein with polysaccharide under a net negative condition can induce the formation of soluble complex with improved functional properties. Studies on foaming properties of whey protein isolate (WPI) with polysaccharide mostly focused on the effects of polysaccharide on native WPI or heated WPI, while little has been done on heated WPI-polysaccharide soluble complex. The objective of our research was to investigate effects of different [lambda]-carrageenan ([lambda]C) concentrations and pH on foaming properties of heated WPI and [lambda]C soluble complex. Three WPI and [lambda]C systems were prepared: 1) heated WPI and [lambda]C soluble complex (h-cpx), (2) heated WPI with added [lambda]C (pWPI - [lambda]C), and (3) unheated WPI with [lambda]C (WPI-[lambda]C). Foams were generated by beating the solution using a KitchenAid mixer. Foamability and foam stability were determined by measuring the foam overrun and drainage 1/5 life, respectively. Foam rheological properties were determined using a Kinexus Pro Rheometer, while foam microstructures were visualized by confocal laser scanning microscopy (CLSM). For native WPI and [lambda]C mixed system, [lambda]C was needed in order for 5% WPI to form measurable foams. In all three WPI- [lambda]C systems at neutral pH, increasing [lambda]C concentration led to improved foamability which increased with increasing [lambda]C concentration until a certain concentration before it decreased. Interestingly, despite their higher viscosity, both heated systems (pWPI-[lambda]C and h-cpx) showed significantly better foamability and foam stability compared to WPI-[lambda]C. Results of rheological properties of foams made from treatments with 0.25% [lambda]C at neutral pH suggested that higher elasticity and viscous films were produced in h-cpx and pWPI-[lambda]C systems corresponding to better foam stability. Heating WPI and [lambda]C together to form heated soluble complex resulted in thicker and viscoelastic interfacial film surrounding the air bubbles and thus better foamItem Development and characterization of light weight laminated composite under impact loading(University of Missouri--Columbia, 2013) Tambvekar, Ajit Abaso; Khanna, Sanjeev K.Today, armor protection is one of the most important elements of survivability. So developing materials which can withstand all futuristic threats, including those from terrorism has therefore become very critical. Polymer matrix composites (PMCs) are attractive materials in this regard because they are lighter, stronger, and stiffer than unreinforced polymers. Along with PMCs, steel and aluminum alloys are also used in light weight armor materials against projectile impact. The laminated composite materials in which different layers of different materials are bonded together are becoming a key material for future lightweight military, marine, and aerospace hardware as they incorporate high hardness and sufficiently high toughness simultaneously. In this study a layered composite panel of steel and aluminum layers has been bonded with graphene reinforced polyurethane. Four types of laminated panels were fabricated with steel facing plate followed by a combination of various aluminum alloy layers. The average weight of a 7-layer laminated composite was 7 lb/ft² and that of 9-layer laminated composites was 10 lb/ft². Different tests, such as tensile test, lap shear strength test, and three-point bend test, have been conducted on the fabricated panels to determine their mechanical properties. The composite laminates' bending stiffness was modeled using ABAQUS finite element software and validated by experiments. The effect of a ballistic impact with armor piercing ammunition was also conducted to qualitatively measure their relative resistance to failure under ballistic loading.Item Evaluation of agrochemical interactions and application timings in corn and soybean(University of Missouri--Columbia, 2013) Solomon, Craig Bradley; Bradley, Kevin W. (Kevin Wayne), 1973-Due to the increase in glyphosate-resistant (GR) weeds, two agrochemical companies have developed soybeans with resistance to 2,4-D and dicamba in an effort to provide growers with new options for the control of problematic GR species. Due to the high sensitivity of non-transformed soybeans that may be grown in close proximity to 2,4-D- or dicamba-resistant crops, there is increasing concern about the potential for off-target movement of these herbicides through drift, volatility, and/or tank contamination. Traditionally, applications of fungicides have been made to corn between tasseling (VT) and silking (R1); however in recent years some pesticide manufacturers have promoted early-season fungicide coapplications with post-emergence (POST) herbicide treatments. Corn is also a nitrogen-demanding crop, where nitrogen uptake is often limited due to soil characteristics and environmental factors. The ability to co-apply agrochemicals allows growers the option of combining desirable products with a POST herbicide application at no additional application cost. The objectives of this research are to: 1) compare the relative soybean phytotoxicity of eight synthetic auxin herbicides to one another and 2) determine the effects of V5 herbicide, fungicide, and/or slow-release N co-applications on corn injury and yield. Results from these experiments suggest significant yield reductions can occur if proper application methods are not followed when applying synthetic auxin herbicides. Also, the addition of a fungicide and/or slow-release N fertilizer at V5 is not likely to increase corn grain yields in comparison to an herbicide treatment alone.Item Defining the therapeutic window in spinal muscular atrophy :(University of Missouri--Columbia, 2013) Robbins, Kate Lynn; Lorson, Christian L. (Christian Lawrence), 1969-Spinal muscular atrophy (SMA) is caused by the loss of a single gene, survival motor neuron-1 (SMN1), which results in the rapid deterioration of motor neuron integrity and function, most often leading to infantile death. Administration of self complementary adeno-associated virus expressing full-length SMN cDNA (scAAV-SMN) has proven an effective means to rescue the SMA phenotype in SMA mice, either by intravenous (IV) or intracerebroventricular (ICV) administration at very early time points. We have recently shown that ICV delivery of scAAV9- SMN is more effective than a similar dose of vector administered via an IV injection, thereby providing an important mechanism to examine a timeline for ameliorating the disease and determining the optimal therapeutic window. SMN[delta]7 mice were injected with scAAV9-SMN vector via ICV injection on a single day, from P2 through P8. At each delivery point from P2 through P7, scAAV9-SMN decreased disease severity, ranging from a near complete rescue (P2) to a significant, albeit lesser degree (P7) in which animals lived ̃130% longer. Our study demonstrates that a maximal benefit is obtained when treatment is delivered during a specified therapeutic window of the pre-symptomatic stages of SMA in the SMN[delta]7 mouse model. Although disease severity can be significantly decreased when SMN levels are increased at later stages of the disease, there is a time (after postnatal day 8) at which therapy is no longer effective.