Bio-separator Design Improvements for Removal of Petroleum Hydrocarbons from Runoff

A number of methods exist for removing petroleum hydrocarbons from water to lower the risk to the environment. Firefighting training generates a unique case of immiscible-phase hydrocarbons with intermittent flow, high total petroleum hydrocarbon (TPH) concentrations, and strict regulations. The available treatment options for this contaminated water have a number of disadvantages that include: expense, waste disposal, fluctuating effectiveness, and intensive manual maintenance that make it unsuitable for firefighting training centers. Thus, a bio-separator was designed for remediating the impacts of immiscible-phase hydrocarbon using horizontal flow through a layer of mulch and a layer of aggregate in series. Free-phase hydrocarbon is retained in a fuel storage reservoir while remediated water flows out of an inverted siphon. This research 1) completes a comprehensive literature review on methods for removing petroleum hydrocarbons from runoff and the performance of wood mulch for stormwater pollutant removal, 2) elucidates on the physical and biological removal processes of the bio-separator, and 3) investigates and tests design options for the bio-separator. Using the results from the tests, multiple regression analysis was performed and predictive equations for immiscible-phase hydrocarbon breakthrough time and concentration reduction were found. A case study bio-separator was designed for the Oklahoma State University (OSU) Fire Service Training Center. The results suggest that further work testing the bio-separator at a larger scale is needed before widespread implementation.Biosystems & Agricultural Engineerin

Intraneuronal ApoE in Human Visual Cortical Areas Reflects the Staging of Alzheimer Disease Pathology

Alzheimer disease (AD) is marked by progressive loss of cortical neurons with associated cognitive decline. Multiple genetic and environmental factors likely contribute to this progressive loss. Such genetic factors include the polymorphic locus (APOE) that encodes apolipoprotein E (apoE). In order to investigate a possible correspondence between cellular localization of apoE and the neuropathology of AD, we examined the distribution of apoE-immunoreactive neurons in visual cortical areas with different apparent susceptibility to AD neuropathology (areas 17-primary sensory, 18-secondary sensory, and inferior temporal-association cortex) at different stages of AD pathology as described by Braak and Braak. We found that intraneuronal apoE was present at all these stages, however, only in visual cortical regions known to be vulnerable to AD. In the late stages, the laminar distribution of apoE-immunoreactivity matched the distribution of other markers of AD pathology, especially modified tau. These data support previous findings that intraneuronal apoE in neocortex is common in aged, nondemented controls and demonstrate that it may be more common in regions at risk for AD pathology. Thus, intraneuronal accumulation of apoE may be an attribute of cortical neurons that are more vulnerable to age-related injury with the presence of apoE antedating the classical indices of late-onset AD patholog