Nitrite Photochemistry in 2-Propanol/Water Solution

Nitrite ion, a component of nitrogen oxide pollution, is an important source of free radicals in the environment. N02- absorbs ambient ultraviolet light to break into NO and 0-, and in environmental conditions, 0- is converted to hydroxyl radical, OH. Hydroxyl radical reacts with a wide variety of environmental pollutants, including hydrocarbons and nitrogen oxides, so its sources are of interest to environmental chemists. In order to investigate the processes of nitrite photochemistry, nitrite ion was photolyzed at 366 nm in 2-propanol/water solution. This mixed solvent system allows investigation of the effects of varying the solvent cage composition and scavenger concentration on the photolysis process and OH production in particular. A secondary goal was to follow nitrite ion and OH scavenging product concentrations simultaneously. OH radicals were scavenged by 2-propanol to form acetone, which was quantified by derivatization with 2,4-dinitrophenylhydrazine followed by HPLC detection. Acetone yields were compared to nitrite disappearance quantified by ultraviolet spectroscopy for nitrite ion photolyses in 96/4, 98/2, and 100/0 mass/mass 2-propanol/water solutions. Acetone was formed at a higher rate in the 100% 2-propanol solvent, suggesting a shift in mechanism at much lower water concentrations

Wilson River Watershed Assessment : final report

The purpose of this watershed assessment is to provide an inventory and characterization of watershed conditions in the Wilson River watershed and to provide recommendations that address the issues of water quality, fisheries and fish habitat, and watershed hydrology

Miami River watershed assessment : final report

The purpose of this watershed assessment is to inventory and characterize watershed conditions of the Miami River watershed and to provide recommendations that address the issues of water quality, fisheries and fish habitat, and watershed hydrology. This assessment was conducted by reviewing and synthesizing existing data sets and some new data collected by the watershed council, following the guidelines outlined in the Oregon Watershed Enhancement Board (OWEB) watershed assessment manual (WPN 1999)

The Heat Shock Response of Mycobacterium Tuberculosis: Linking Gene Expression, Immunology and Pathogenesis

The regulation of heat shock protein (HSP) expression is critically important to pathogens such as Mycobacterium tuberculosis and dysregulation of the heat shock response results in increased immune recognition of the bacterium and reduced survival during chronic infection. In this study we use a whole genome spotted microarray to characterize the heat shock response of M. tuberculosis. We also begin a dissection of this important stress response by generating deletion mutants that lack specific transcriptional regulators and examining their transcriptional profiles under different stresses. Understanding the stimuli and mechanisms that govern heat shock in mycobacteria will allow us to relate observed in vivo expression patterns of HSPs to particular stresses and physiological conditions. The mechanisms controlling HSP expression also make attractive drug targets as part of a strategy designed to enhance immune recognition of the bacterium

The IceCube Neutrino Observatory: Instrumentation and Online Systems

The IceCube Neutrino Observatory is a cubic-kilometer-scale high-energy neutrino detector built into the ice at the South Pole. Construction of IceCube, the largest neutrino detector built to date, was completed in 2011 and enabled the discovery of high-energy astrophysical neutrinos. We describe here the design, production, and calibration of the IceCube digital optical module (DOM), the cable systems, computing hardware, and our methodology for drilling and deployment. We also describe the online triggering and data filtering systems that select candidate neutrino and cosmic ray events for analysis. Due to a rigorous pre-deployment protocol, 98.4% of the DOMs in the deep ice are operating and collecting data. IceCube routinely achieves a detector uptime of 99% by emphasizing software stability and monitoring. Detector operations have been stable since construction was completed, and the detector is expected to operate at least until the end of the next decade.Comment: 83 pages, 50 figures; updated with minor changes from journal review and proofin

Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences

The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics