1,512 research outputs found

    Static noise tests on augmentor wing jet STOL research aircraft (C8A Buffalo)

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    Results are presented for full scale ground static acoustic tests of over-area conical nozzles and a lobe nozzle installed on the Augmentor Wing Jet STOL Research Aircraft, a modified C8A Buffalo. The noise levels and spectrums of the test nozzles are compared against those of the standard conical nozzle now in use on the aircraft. Acoustic evaluations at 152 m (500 ft), 304 m (1000 ft), and 1216 m (4000 ft) are made at various engine power settings with the emphasis on approach and takeoff power. Appendix A contains the test log and propulsion calculations. Appendix B gives the original test plan, which was closely adhered to during the test. Appendix C describes the acoustic data recording and reduction systems, with calibration details

    Remote sensing applied to land-use studies in Wyoming

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    Impending development of Wyoming's vast fuel resources requires a quick and efficient method of land use inventory and evaluation. Preliminary evaluations of ERTS-1 imagery have shown that physiographic and land use inventory maps can be compiled by using a combination of visual and automated interpretation techniques. Test studies in the Powder River Basin showed that ERTS image interpretations can provide much of the needed physiographic and land use information. Water impoundments as small as one acre were detected and water bodies larger than five acres could be mapped and their acreage estimated. Flood plains and irrigated lands were successfully mapped, and some individual crops were identified and mapped. Coniferous and deciduous trees were mapped separately using color additive analysis on the ERTS multispectral imagery. Gross soil distinctions were made with the ERTS imagery, and were found to be closely related to the bedrock geology. Several broad unstable areas were identified. These were related to specific geologic and slope conditions and generally extended through large regions. Some new oil fields and all large open-cut coal mines were mapped. The most difficult task accomplished was that of mapping urban areas. Work in the urban areas provides a striking example of snow enhancement and the detail available from a snow enhanced image

    Some illustrations of the advantages of improved resolution in geologic studies

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    There are no author-identified significant results in this report

    ZEBRAFISH FETAL ALCOHOL SYNDROME: EFFECTS OF ETHANOL ON MICRO-TUBULES

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    poster abstractFetal alcohol syndrome is the most frequent preventable birth defect, re-sulting from excessive maternal alcohol consumption during pregnancy. Pre-vious studies showed that a variety of species, including humans, exhibit de-velopmental abnormalities when embryos are exposed to ethanol. Zebrafish embryos treated with a pathophysiological concentration of ethanol (100 mM) causes a range of defects that recapitulate some developmental defects seen in fetal alcohol syndrome (FAS) patients. The Marrs lab and others pre-viously showed that zebrafish embryos exposed to ethanol show reduced epiboly cell movements in early embryogenesis. Microtubule cytoskeleton, especially within the large yolk cell of the zebrafish embryo, participates in the epiboly process. To understand these epiboly defects, the effect of etha-nol on embryonic microtubules was investigated. Zebrafish embryos at the 2hr cell stage were exposed to100 mM ethanol or control media for various times, fixed, and then, stained using anti-tubulin antibodies. Embryos were also stained to detect E-cadherin, actin cytoskeleton, and nuclei. These ex-periments showed that ethanol induced tubulin cytoskeleton redistribution in the yolk cell, which was associated with E-cadherin redistribution. Despite the redistribution of the tubulin cytoskeleton, we did not detect large differ-ences in the microtubule staining intensity, indicating that the microtubule cytoskeleton redistributes without significant fluctuation in the amount of microtubule filament. Microtubule cytoskeleton and E-cadherin defects may contribute to epiboly defects observed in the early embryo

    Ethanol-Induced Defects on Zebrafish Retinal Development: Rescue by Nutritional Supplements

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    poster abstractFetal Alcohol Spectrum Disorder (FASD), a result of prenatal alcohol exposure, produces a wide range of developmental defects including severe ocular defects that include microphthalmia, optic nerve hypoplasia, scotopic vision loss and coloboma. The zebrafish FASD model recapitulates many defects seen in human patients. Ethanol exposure (100 and 150 mM) during early development (midblatula transition through somitogenesis, 2-24 hours post fertilization, hpf) produced severe ocular defects including microphthalmia, optic nerve hypoplasia and photoreceptor differentiation defect. Examining specific terminal differentiation markers showed ethanol-induced defects in differentiation of most retinal cell types. Ethanol exposure altered gene expression of critical transcription factors. Increased cell death accounted for the small eye phenotype, and the retina responds with increased proliferation in the outer nuclear layer, inner nuclear layer, and ciliary marginal zone (CMZ). Ethanol treated retinas showed an expanded CMZ and cell cycle exit defects of the photoreceptor cells. In order to examine progenitor cell populations and differentiation defects in the ethanol treated retinal cells, specific markers for retinal stem, precursor and progenitor cell populations were examined. While control retinas showed terminally differentiated photoreceptors at 72 hpf, ethanol treated retinas expressed immature and nascent photoreceptor markers in cell populations undergoing proliferation. Nutrient co-supplement with retinoic acid (RA) or folic acid (FA) with ethanol during 2-24 hpf rescued photoreceptor differentiation and optic nerve defects. Competitive inhibition of RA synthesis by ethanol was hypothesized by Duester (1991), and rescue of ethanol-induced retinal defects suggest an effect on RA levels in the developing retina. Treatment with RA inhibitors produced retinal defects similar to ethanol-treated embryos. Interestingly, RA supplementation (24-48 hpf and 48-72 hpf) following ethanol treatment (2-24 hpf) restored photoreceptor differentiation suggesting RA provides a critical signal for precursor cell differentiation. In contrast, post-treatment with FA, did not restore retinal cell differentiation. FA functions as a critical component of one-carbon metabolism and can influence histone- and DNA-methyl transferase activities. Molecular mechanisms underlying disruption of cell cycle exit and FA rescue of ethanol-induced defects are being actively studied

    Modeling the Example Life-Cycle in an Online Classification Learner

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    Abstract. An online classification system maintained by a learner can be subject to latency and filtering of training examples which can impact on its classification accuracy especially under concept drift. A life-cycle model is developed to provide a framework for studying this problem. Meta data emerges from this model which it is proposed can enhance online learning systems. In particular, the definition of the time-stamp of an example, as currently used in the literature, is shown to be problematic and an alternative is proposed

    Myosin II Light Chain Phosphorylation Regulates Membrane Localization and Apoptotic Signaling of Tumor Necrosis Factor Receptor-1

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    Activation of myosin II by myosin light chain kinase (MLCK) produces the force for many cellular processes including muscle contraction, mitosis, migration, and other cellular shape changes. The results of this study show that inhibition or potentiation of myosin II activation via over-expression of a dominant negative or wild type MLCK can delay or accelerate tumor necrosis factor-α (TNF)-induced apoptotic cell death in cells. Changes in the activation of caspase-8 that parallel changes in regulatory light chain phosphorylation levels reveal that myosin II motor activities regulate TNF receptor-1 (TNFR-1) signaling at an early step in the TNF death signaling pathway. Treatment of cells with either ionomycin or endotoxin (lipopolysaccharide) leads to activation of myosin II and increased translocation of TNFR-1 to the plasma membrane independent of TNF signaling. The results of these studies establish a new role for myosin II motor activity in regulating TNFR-1-mediated apoptosis through the translocation of TNFR-1 to or within the plasma membrane
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