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Theses and Dissertations

2017

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Institution
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Articles 421 - 423 of 423

Full-Text Articles in Physical Sciences and Mathematics

Characterization Of The Suf Fe-S Pathway In Escherichia Coli, Naimah Bolaji Jan 2017

Characterization Of The Suf Fe-S Pathway In Escherichia Coli, Naimah Bolaji

Theses and Dissertations

Iron is an essential transition metal required by almost all organisms for use as a cofactor in many metabolic processes such as respiration and photosynthesis. Iron can be combined with elemental sulfur to form an iron-sulfur (Fe-S) cluster. In bacterial pathogens, Fe-S cluster cofactors carry out critical functions and the Fe-S cluster biogenesis pathway is essential for their survival. In E. coli, the Suf pathway assembles Fe-S clusters under conditions of iron starvation and oxidative stress. While some mechanistic details of the Fe-S cluster biogenesis have been well-characterized, the process of in vivo iron donation remains unclear. Iron storage proteins …


Polynomials Of Small Mahler Measure With No Newman Multiples, Spencer Victoria Saunders Jan 2017

Polynomials Of Small Mahler Measure With No Newman Multiples, Spencer Victoria Saunders

Theses and Dissertations

A Newman polynomial is a polynomial with coefficients in f0;1g and with constant term 1. It is known that the roots of a Newman polynomial must lie in the slit annulus fz 2C: f��1 1 such that if a polynomial f (z) 2 Z[z] has Mahler measure less than s and has no nonnegative real roots, then it must divide a Newman polynomial. In this thesis, we present a new upper bound on such a s if it exists. We also show that there are infinitely many monic polynomials that have distinct Mahler measures which all lie below f, have …


A Study Of Sediment Accretion Dynamics In Mature And Restored Tidal Freshwater Forested Wetlands In The James River Watershed Using Surface Elevation Tables And Marker Horizons, Ronaldo Lopez Jan 2017

A Study Of Sediment Accretion Dynamics In Mature And Restored Tidal Freshwater Forested Wetlands In The James River Watershed Using Surface Elevation Tables And Marker Horizons, Ronaldo Lopez

Theses and Dissertations

Sediment accretion and elevation change in tidal forests, and the corresponding ability of these wetlands to keep pace with sea-level rise (SLR), represent data gaps in our understanding of wetland sustainability. Surface Elevation Tables and marker horizons were installed in three mature tidal forests and a restored tidal marsh, allowing us to measure elevation change, accretion, and subsidence. Additionally, we measured predictor variables to test for their significance in explaining accretion and elevation change rates. Mean accretion at our sites was 11.67 +/- 3.01 mm yr-1 and mean elevation change was -20.22 +/- 8.10 mm yr-1, suggesting …