Antarctic Ice Sheet mass balance and, hence, sea level change is affected by the floating extensions of outlet glaciers and ice streams that take up about 44% of the coastline (Drewry et al., 1982) and are referred to as "ice shelves". Ice sheet mass loss accelerates when these ice shelves...
Nitrification is the process within the global Nitrogen Cycle where ammonia (NH3) is oxidized to nitrate (NO₃⁻) and can be carried out by two distinct groups of bacteria. The ammonia-oxidizing bacteria (AOB) first oxidize NH₃ to nitrite (NO₂⁻), and second, the nitrite-oxidizing bacteria (NOB) oxidize NO₂⁻ to NO₃⁻. In aerobic...
Forest harvest persists as one of the most globally important industries, and crucially provides raw wood products for both building and fuel materials. Mechanistically complex abiotic and biotic processes curb ecosystem recovery following timber harvest and it is of great importance to understand the effects of this practice on biogeochemical...
Marine sediments are vast sources and reservoirs of methane, a potent greenhouse gas. Most of this methane is anaerobically oxidized by archaea before it can reach the overlying ocean, though the efficiency of this process often depends on methane fluxes and mechanisms of fluid transport. Anaerobic methanotrophic archaea, or ANME,...
Since a NanoSIMS high-resolution secondary ion mass spectrometry instrument was first used for cosmochemistry investigations over a decade ago, both interest in NanoSIMS and the number of instruments available have significantly increased. However, SIMS comes with a set of challenges that are of both technical and conceptual nature, particularly for...
The effect of the conjugation with cyclopropyl rings
on the activation parameters for the formation of
carbenes from the corresponding diazo compounds was
investigated using diisopropylcarbene (46), cyclopropyl-isopropylcarbene
(47), and dicyclopropylcarbene (48).
Each of these three carbenes was generated by the
thermolysis of the parent benzenesulfonylhydrazone
potassium salts using DMSO...
I used field experiments to study how plants in two grassland communities colonized
soil mounds made by the Camas pocket gopher, Thomomys bulbivorus (Richardson). I
identified potential mound colonizers in each source of colonization (buried propagule bank,
seed rain, and established vegetation) and then measured species specific rates of
colonization...
A flume study was conducted to investigate the influences of
changing hydraulic conditions on the bed morphology of a scoured pool.
During a simulated storm runoff event, responses of the pool were
tested under different conditions: clearwater flow, sediment supply at
steady rates, and two different sediment mixtures of the...
The Diels-Alder reaction represents a promising tool for use in
asymmetric synthesis. The reaction involves a rigid transition state
that facilitates the formation of one diastereomeric transition state
and is reversible. This satisfies two necessary criteria for
asymmetric synthesis.
The Diels-Alder reactions of 1,l-dialkylspiro[2.4]-4,6- heptadienes
with maleic anhydride and p-benzoquinone...