Design and performance of duct acoustic treatment

The procedure for designing acoustic treatment panels used to line the walls of aircraft engine ducts and for estimating the resulting suppression of turbofan engine duct noise is discussed. This procedure is intended to be used for estimating noise suppression of existing designs or for designing new acoustic treatment panels and duct configurations to achieve desired suppression levels

The effect of vegetation density on sampling volume by ultrasonic bat detectors (AnabatIIÆ) [abstract]

Abstract only availableFaculty Mentor: Dr. Rose-Marie Muzika, ForestryUltrasonic detectors are becoming more common as a means of sampling bat activity and abundance. Many factors must be taken into consideration when using ultrasonic detectors, however. The sensitivity and range of bat detectors are influenced by a variety of environmental conditions that should be well understood in order to correctly interpret data collected using this technology. Abiotic factors such as temperature and humidity are known to influence ultrasonic detection; and vegetation density, abundance, and structural complexity may also influence the detection. While abiotic factors have been studied to a limited extent, there are no data available to describe the effect of vegetation on ultrasonic detection. The purpose of this proposed project was to examine how varying vegetation cover influences detection of sounds by ultrasonic bat detectors. Ultrasonic emitters (bat chirpers) were placed at varying distances within three categories of vegetation density and the detection ability of the devices for the chirpers was monitored. Detection levels among all vegetation classes were very low, suggesting factors other than vegetation may have a greater influence on detectability of chirpers. Further tests suggested that improved alignment and other technical details would enhance accuracy in discernment among vegetation densities

TEMPORAL ALLOCATION ALTERNATIVES FOR SOUTHEASTERN RED DELICIOUS APPLES

This study examines the economic feasibility of storing southeastern U.S. Red Delicious apples under various circumstances. Circumstances encompassed type of storage, potential market share in the storage periods, perceived level of quality, and opportunity cost of storage. Reactive programming was used to allocate shipments throughout the harvest and storage periods. Except for apples harvested in August, storage was found to be economically feasible under all situations studied. The greatest economic benefit to producers was shown to come from the synergistic effect of storage and improvement in perceived quality.Crop Production/Industries,

Effects of Providing Novel Feedstuffs to Livestock on Production and Skeletal Muscle Growth

As the population increases and available land for food production decreases, it is necessary for livestock producers to continually work towards increasing livestock production efficiency. In livestock operations, feed accounts for the majority of input costs associated with raising livestock. As such, it is necessary to improve growth and production of livestock animals, while also optimizing feed utilization. Different feedstuffs can be included in the diet of livestock animals to maximize growth and production. However, the effects of some of these novel feedstuffs on growth and production of livestock animals has not been elucidated. As such, we investigated the effects of including two novel alfalfa products, ProLEAF MAX™ (a pellet composed of alfalfa leaves) and ProFiber Plus™ (alfalfa stems), in the diets of beef steers, dairy heifers, and lactating dairy cows. We hypothesized that inclusion of ProLEAF MAX™ and ProFiber Plus™ in the diet would result in improved growth and performance of beef steers, growth and development of dairy heifers, and milk yield and milk components of lactating dairy cows. We found that inclusion of ProFiber Plus™ in the diet of beef steers and dairy heifers decreases feed costs without affecting overall growth in steers, but decreases growth in dairy heifers and inclusion of the two novel alfalfa products in the diet of lactating dairy cows results in improved milk yield and milk components. Additionally, we examined the effects of supplementing murine myoblasts with polyamines and polyamine precursors to further investigate novel products that may be able to be utilized in the diets of livestock animals to increase growth. We hypothesized that supplementation of polyamines and their precursors would result in improved growth of skeletal muscle cells (myoblasts). Treatment of myoblasts with polyamines and their precursors improves proliferation rates and alters mRNA expression of genes involved in polyamine biosynthesis, cell proliferation, and protein synthesis. Collectively, our observations suggest that various novel feedstuffs, whether it be alfalfa processed differently or amino acid derivatives (polyamines), have the potential to improve various growth and/or production measures. However, additional research is required to fully understand the potential of including these products in the diet

Response of natural and artificial pin oak reproduction to mid- and understory removal in a bottomland hardwood forest

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on August 27, 2007)Includes bibliographical references.Thesis (M.S.) University of Missouri-Columbia 2006.Dissertations, Academic -- University of Missouri--Columbia -- Forestry.This study was conducted to determine whether mid- and understory removal in combination with ground flora vegetation control would result in a sufficient increase in light to foster the development of pin oak (Quercus palustris Muenchh.) advance reproduction without releasing non-oak competitors. Implementation of three artificial regeneration treatments (direct seeding pin oak acorns, planting 1-0 pin oak bareroot seedlings, and planting pin oak RPMP®P seedlings) was also conducted on these same bottomland forest sites in southeastern Missouri. The mid- and understory removal treatment increased the amount of photosynthetically active radiation reaching the understory from 3 percent of full sunlight to 16 percent of full sunlight. This increase in light led to an increase in the proportion of pin oak advance reproduction present in the understory from 1.5 percent of all advance reproduction in control areas to 28.1 percent in removal treatment areas. Ground flora control had a negative influence on the proportion of advance reproduction as well as on survival and growth of all reproduction types. After three years, the highest survivals were observed in RPMP®P and bareroot seedlings. The greatest basal diameter growth rates were observed in direct-seeded and natural seedlings and the greatest height growth rates were observed in direct seeded seedlings. RPMP®P and bareroot seedlings were, however, considerably larger than were the natural and direct seeded seedlings

The effect of alternative permutation testing strategies on the performance of multifactor dimensionality reduction

<p>Abstract</p> <p>Background</p> <p>Multifactor Dimensionality Reduction (MDR) is a novel method developed to detect gene-gene interactions in case-control association analysis by exhaustively searching multi-locus combinations. While the end-goal of analysis is hypothesis generation, significance testing is employed to indicate statistical interest in a resulting model. Because the underlying distribution for the null hypothesis of no association is unknown, non-parametric permutation testing is used. Lately, there has been more emphasis on selecting all statistically significant models at the end of MDR analysis in order to avoid missing a true signal. This approach opens up questions about the permutation testing procedure. Traditionally omnibus permutation testing is used, where one permutation distribution is generated for all models. An alternative is <it>n</it>-locus permutation testing, where a separate distribution is created for each <it>n</it>-level of interaction tested.</p> <p>Findings</p> <p>In this study, we show that the false positive rate for the MDR method is at or below a selected alpha level, and demonstrate the conservative nature of omnibus testing. We compare the power and false positive rates of both permutation approaches and find omnibus permutation testing optimal for preserving power while protecting against false positives.</p> <p>Conclusion</p> <p>Omnibus permutation testing should be used with the MDR method.</p

Evaluation of calling algorithms for array-CGH

Copy number variation (CNV) detection has become an integral part many of genetic studies and new technologies promise to revolutionize our ability to detect and link them to disease. However, recent studies highlight discrepancies in the genome wide CNV profile when measured by different technologies and even by the same technology. Furthermore, the change point algorithms used to call CNVs can have substantial disagreement on the same data set. We focus this article on comparative genomic hybridization (CGH) arrays because this platform lends itself well to accurate statistical modeling. We describe some newer methodological developments in local statistics that are well suited for CNV detection and calling on CGH arrays. Then we use both simulation studies and public data to compare these new local methods with the global methods that currently dominate literature. These results offer suggestions for choosing a particular method and provide insight to the lack of reproducibility that has been seen in the field so far

Analysis, design, and test of acoustic treatment in a laboratory inlet duct

A suppression prediction program based on the method of modal analysis for spinning mode propagation in a circular duct was used in the analytical design of optimized, multielement, Kevlar bulk-absorber treatment configurations for an inlet duct. The NASA-Langley ANRL anechoic chamber using the spinning mode synthesizer as a sound source was used to obtain in-duct spinning mode measurements, radial mode measurements, and far-field traverses, as well as aerodynamic measurements. The measured suppression values were compared to predicted values, using the in-duct, forward-traveling, radial-mode content as the source for the prediction. The performance of the treatment panels was evaluated from the predicted and measured data. Although experimental difficulties were encountered at the design condition, sufficient information was obtained to confirm the expectation that it is the panel impedance components which are critical to suppression at a single frequency, not the particular construction materials. The agreement obtained between measurement and prediction indicates that the analytical program can be used as an accurate, reliable, and useful design tool

Importance of a Dietary Cation-Anion Difference in Peripartum Dairy Cows

At calving, nutrient requirements of dairy cows increase to support milk synthesis. Energy and protein requirements are increased at the initiation of lactation (Moore et al., 2000). Additionally, calcium requirements increase tremendously to meet the demands of lactation (Moore et al., 2000). Calving and subsequent milk synthesis can cause calcium concentrations in the blood to drop. When the demand for calcium exceeds the cow’s ability to mobilize calcium, hypocalcemia (low blood calcium) occurs, which can negatively impact production. This fact sheet reviews hypocalcemia in dairy cows and how to implement hypocalcemia prevention strategies