High-resolution spectral analysis

Analyzer extends the range and resolution of a digital spectrum analyzer without placing stringent stability requirements on the sampling rate. It compares an unknown signal with a stable frequency standard

Effects of high and low barometric pressures on susceptibility and resistance to infection Quarterly status report, 1 Apr. - 30 Jun. 1969

Effects of atmospheric pressure on susceptibility and resistance to infectio

Effects of high and low barometric pressures on susceptibility and resistance to infection Quarterly status report, 1 Oct. - 31 Dec. 1968

Effects of high and low barometric pressures on susceptibility and resistance to infection in mic

Shifting Perspective, Shifting Portrait

http://deepblue.lib.umich.edu/bitstream/2027.42/90990/1/lagillmo_1334769206.pd

Effects of high and low barometric pressures on susceptibility and resistance to infection Quarterly status report, 1 Jul. - 30 Sep. 1969

Atmospheric pressure effects on mice resistance to bacterial or virus infection

Potential effects of environmental change on mining wastes in a hyperarid climate

Three desert washes were sampled to evaluate the transport of contaminated sediments from abandoned mining sites to downwash environments. The area of concern is an extreme arid climate considered stable and not to pose pathways for contaminated sediments to impact downwash environments. Research of mine wastes in Nelson, Nevada has shown that residual geogenic and anthropogenic trace elements have been mobilized in surface sediments as a result of storm event. Cyanide and trace elements, especially mercury and lead, have transported to 6000 m downwash from source areas. Short term environmental impacts appear to be minimal because of present-day environmental conditions. However, climate shifts caused by the El Nino Southern Oscillations or even a dramatic climate shift might increase regional precipitation promoting a more rapid erosion of contaminated sediment. Currently, wash sediments do not contain levels of CN- or trace elements that pose threats to the environment; however, if erosion and transport of mining waste increased because of additional precipitation, then CN- and trace elements loading in storm water would increase, with their possibly delivery to Lake Mohave

An Analysis of Putative Roles for the CCR4-NOT Deadenylase-Complex Subunit Regena (NOT2) in microRNA-Mediated Gene Silencing in \u3cem\u3eDrosophila Melanogaster\u3c/em\u3e

microRNAs (miRNAs) are one class of small non-coding ribonucleic acid (RNA) molecules essential to development and homeostasis in plants and animals. miRNAs silence gene expression through complementary base pairing with target gene messenger RNAs and association with the miRNA-induced silencing complex (miRISC). The identification and characterization of cellular factors required for miRNA-mediated gene silencing is incomplete. A forward genetic screen was carried out in Drosophila melanogaster to generate flies defective for gene silencing. Silencing was assayed by expression of a Green Fluorescent Protein (GFP) reporter fused to the Brd gene 3’ UTR, which is regulated by miRNAs. Genetic analysis revealed that the CCR4-NOT deadenylase-complex subunit Regena (NOT2) is required for miRNA-mediated silencing of the reporter. In addition, perturbation of Regena function altered Drosophila eye development and resulting adult eye morphology. miRNAs are thought to silence target gene expression through a combination of translational repression and target mRNA degradation, though the detailed mechanism of this process is a matter of controversy. Novel genetic reagents to explore miRNA function in vivo have been generated and characterized. Ongoing efforts aim to explore whether Regena is required to silence other miRNA targets in vivo, and whether Regena is required for miRNA-mediated gene silencing at different stages of the Drosophila life cycle. Elucidation of the lesion in the Regena (NOT2) gene and the molecular nature of GFP reporter silencing will contribute to an understanding of the mechanism of miRNA-mediated gene silencing in vivo

Assessing the risk of sediment-associated nickel exposure to benthic marine biota in Southeast Asia and Melanesia

The Southeast Asia and Melanesia (SEAM) region has extensive nickel-rich lateritic regoliths formed from the tropical weathering of ultramafic rocks. As the global demand for nickel continues to rise, these lateritic regoliths are increasingly being exploited for their economic benefit. Mining of these lateritic regoliths contributes to the enrichment of coastal sediments in trace metals, especially nickel. A review of tropical estuarine and marine ecotoxicity data for nickel highlighted the absence of sediment ecotoxicity data, benthic test species and the associated sediment toxicity test methods required to assess the potential impacts of sediment nickel exposure to benthic biota of SEAM. The aim of this thesis was to use a multiple lines of evidence approach to provide a robust evidence-base and risk assessment tools applicable for informing environmental risk assessment of nickel-rich estuarine and marine sediments within the SEAM region. A whole sediment bioassay based on sub-lethal effects was adapted for use with the tropical benthic marine diatom Ceratoneis closterium (Chapter 3). Effects data relevant to the SEAM region were then derived for three nickel-spiked sediments and two field-contaminated sediments. No toxicity based on chlorophyll-a concentration was observed in the sediment with the highest total organic carbon content (5%) (72-h 10% effect concentration (EC10) \u3e4,300 mg/kg dilute-acid extractable concentration of nickel). The sediments without significant total organic carbon content (1%) were toxic above 950 mg/kg dilute-acid extractable nickel (72-h EC10). The tropical benthic snail Nassarius dorsatus was also investigated for its suitability for developing a whole-sediment bioassay but was found to be relatively tolerant to dissolved nickel exposure (juvenile 21-d lowest observable effect concentration (LOEC) based on scavenging ability endpoint of 380 g Ni/L). It was concluded that a species relevant to SEAM with greater sensitivity to nickel is required to provide greater confidence that using a whole-sediment bioassay as a line of evidence in sediment quality assessment will identify sediments likely to have adverse effects. This research highlighted the need for a more strategic approach for selecting species to develop new bioassays or alternative tools for investigating contaminated sediments in the absence of sensitive whole-sediment toxicity test methods relevant to the SEAM region