DSpace Community: K-State Electronic Theses, Dissertations, and Reports

STAND OFF BOMB DETECTION USING NEUTRON INTERROGATION

Wed, 27 Aug 2008 18:08:58 GMT

Title: STAND OFF BOMB DETECTION USING NEUTRON INTERROGATION

Authors: Lowrey, Justin

Abstract: One of the most pressing threats facing the United States is the increasingly effective use of improvised explosive devices or IEDs. Many commonly used techniques to detect explosives involve imaging. The primary drawback of imaging is that it requires interpretation of one or more images from each target. Human interpretation requires extensive training and is subject to the chance of false-negatives due to human fatigue. To counter the threat posed by IEDs, the signature-based radiation scanning (SBRS) technology has been developed. The goal of this project is to create an automated system, with minimal operator assistance, that is capable of detecting at least a gallon-sized explosive sample from at least one meter away. It is hoped that this can be accomplished quickly, in less than 30 seconds, with high sensitivity and specificity. The SBRS technique is based on the fact that many classes of materials have similar stoichiometries. For example, many common explosives have characteristic concentrations of hydrogen, carbon, nitrogen and oxygen. As neutrons interact with a material, unique gamma rays are created based on the composition of the material. Specifically, in this work, the gamma rays from inelastically scattered neutrons and from thermal neutron capture are investigated. Two neutron detectors are also used, whose responses depend on neutron thermalization in and around the target. Response templates are created based on gamma-ray and neutron responses that are collected from targets that contain explosives,. These templates are developed under different conditions for many different explosive materials to create a library of templates. The collection of responses from an unknown target is compared to a subset of the library of templates using a figure of merit to distinguish benign from explosive targets. Preliminary experiments were performed at Kansas State University. A high-purity germanium detector (HPGe) was used to detect the gamma rays. Two neutron detectors, one covered with cadmium, were used to detect back-streaming neutrons. A 252Cf radioisotope source as well as a Triga Mk III reactor were used as neutron sources.

Porcine Innate Antiviral Immunity: Host Defense Peptides and Toll-Like Receptors

Tue, 26 Aug 2008 14:27:35 GMT

Title: Porcine Innate Antiviral Immunity: Host Defense Peptides and Toll-Like Receptors

Authors: Yongming, Sang

Abstract: The immediate antiviral defense residing in the innate immune system of multicellular organisms critically determines the outcome of viral infection. This dissertation presents a study of the “effectors” and “receptors” of porcine innate immunity in infection caused by porcine reproductive and respiratory syndrome virus (PRRSV), which is the most devastating pathogen impacting the swine industry. In the first investigation, eleven novel porcine host defense peptides (HDPs), β-defensins (pBDs), were identified and characterized. All of these peptides have a consensus β-defensin motif and phylogenetically are similar to orthologs from other species. A differential expression pattern for these 11 newly identified genes was found. For example, pBD-2 and pBD-3 were expressed in bone marrow, lung, skin and other lymphoid tissues. pBD-2 and pBD-3 were further characterized for their gene structure, and antimicrobial activity of synthetic peptides. The second study was conducted to evaluate PRRSV-induced differential expression of porcine HDPs and direct antiviral activity of selected HDPs against PRRSV. In vitro incubation of PRRSV with synthetic pBD-3 or protegrin-4 (PG-4) significantly inhibited viral infectivity. Using nine protegrin-derived peptides, it was determined that cyclization of PG-4 increased anti-PRRSV activity and mutation of some residues in PG-4 diminished some of the activity. These findings suggest the potential role of porcine HDPs as a group of innate antiviral effectors. In the third and fourth investigations, porcine Toll-like receptor (TLR) 3 and TLR7 were identified and functionally expressed. Increased expression of TLR3 was observed in PRRSV-infected porcine lungs. Stimulation of porcine alovelar macrophages with poly (I:C), a synthetic TLR3 ligand, increased expression of interferon-β and suppressed PRRSV infectivity. Activation of porcine TLR3 overexpressed in a PRRSV-sensitive cell line, elicited antiviral responses to PRRSV infection. Partial silencing of TLR3 in PAMs resulted in increased PRRSV infection. In summary, these data provide molecular information on porcine TLR3 and TLR7, and their involvement in PRRSV pathogenesis, which may elicit new strategies to prevent this costly swine disease.

Blue search in Kansas river database

Thu, 21 Aug 2008 20:00:20 GMT

Title: Blue search in Kansas river database

Authors: Sama, Haritha Reddy

Abstract: Students who are Research Assistants under Dr. Craig Paukert, Division of Biology Kansas State University have problems storing/retrieving their field data directly from database. There data is generally related to fishes in Kansas River. All this data is entered in the data sheets during the research in field. They enter fish related data like tag numbers (each fish caught is given a tag and after noting the data related to the fish it is left back in the river) and other information like size of the fish, place the fish was caught (stations) and information about the shore habitats, water temperature, depth etc. They also need data to recognize the aging in a recaptured fish (fish caught with a tag). The data from these data sheets is manually entered into the database. Each student has their information on the database entered (wherein they actually have to work on a single database). There is inconsistency of data. Also the database doesn't show the concentration of the fishes or location of the fishes right away. For which they require lot of analysis on the data. The main objective of this project is to provide a solution for this problem. The solution is an interface to store data and retrieve data and show the data on Maps for easy analysis and also have centralized data. The interface is user friendly which removes the hassle from entering the data manually into the database.

Factors affecting whole grain consumption: primary focus health factors

Thu, 21 Aug 2008 12:41:23 GMT

Title: Factors affecting whole grain consumption: primary focus health factors

Authors: Scott, Willie Henry Jr.

Abstract: We designed a mail survey to investigate consumer choices between whole-grain and regular grain products. Consumption of whole-grain foods has been linked to numerous health benefits including reduced risk of heart disease, diabetes and obesity. The prevalence of obesity has increased in recent decades and has been shown to be negatively correlated with education levels and income. Data from the survey are used to investigate correlations between the likelihood of choosing whole-grain alternatives and various demographic and behavioral characteristics including an individual's Body Mass Index (BMI). We also investigate the impact on consumer choices of providing information about the health benefits of whole-grain foods. Results indicate that education level and the use of food labels are both positively correlated with the likelihood of choosing whole-grain foods. Provision of information about health benefits also had a positive impact on the likelihood of choosing a whole-grain over a conventional grain product, but given a low sample size in this study the effect was not statistically significant. Choices were found to be largely insensitive to changes in relative prices, and no correlation was found between BMI and the likelihood of choosing a whole-grain product.