Cameron P McIntyre

Learn More
The Deepwater Horizon blowout is the largest offshore oil spill in history. We present results from a subsurface hydrocarbon survey using an autonomous underwater vehicle and a ship-cabled sampler. Our findings indicate the presence of a continuous plume of oil, more than 35 kilometers in length, at approximately 1100 meters depth that persisted for months(More)
Quantitative information regarding the endmember composition of the gas and oil that flowed from the Macondo well during the Deepwater Horizon oil spill is essential for determining the oil flow rate, total oil volume released, and trajectories and fates of hydrocarbon components in the marine environment. Using isobaric gas-tight samplers, we collected(More)
The effect of convulsive stimulations on the dissipation of tolerance to the anticonvulsant effect of diazepam was investigated using the kindled-convulsion model. Amygdala-kindled rats were rendered tolerant to diazepam's anticonvulsant effect by 25 "bidaily" (one/48 h) diazepam injections (2.5 mg/kg), each followed 1 h later by a convulsive stimulation.(More)
Northern high-latitude rivers are major conduits of carbon from land to coastal seas and the Arctic Ocean. Arctic warming is promoting terrestrial permafrost thaw and shifting hydrologic flowpaths, leading to fluvial mobilization of ancient carbon stores. Here we describe (14)C and (13)C characteristics of dissolved organic carbon from fluvial networks(More)
Improved testing and remediation procedures for sites contaminated with petroleum hydrocarbons are a priority in remote cold regions such as Antarctica, where costs are higher and remediation times are longer. Isoprenoid/n-alkane ratios are commonly used to determine the extent of biodegradation at low levels but are not useful once the n-alkanes have been(More)
Fire-derived, pyrogenic carbon (PyC), sometimes called black carbon (BC), is the carbonaceous solid residue of biomass and fossil fuel combustion, such as char and soot. PyC is ubiquitous in the environment due to its long persistence, and its abundance might even increase with the projected increase in global wildfire activity and the continued burning of(More)
Humans have interacted with fire for thousands of years, yet the utilization of fossil fuels marked the beginning of a new era. Ubiquitous in the environment, pyrogenic carbon (PyC) arises from incomplete combustion of biomass and fossil fuels, forming a continuum of condensed aromatic structures. Here we develop and evaluate 14C records for two(More)
The retention time shown in Figure 1 is incorrect. In this case, the gas chromatograph was run using constant pressure conditions (25 psi) rather than with the constant flow conditions (1.2 mL/min) detailed in the methods section. As a result, the peaks eluted around 15 min later. Figure 2 shows the correct retention times for the constant flow method(More)
A gas chromatograph-combustion (GC-C) system is described for the introduction of samples as CO(2) gas into a (14)C accelerator mass spectrometry (AMS) system with a microwave-plasma gas ion source. Samples are injected into a gas chromatograph fitted with a megabore capillary column that uses H(2) as the carrier gas. The gas stream from the outlet of the(More)
  • 1