Nanotechnologies continue to permeate a multitude of industries, with diverse applications ranging from pesticides to fuel additives. The unusual behavior of nanomaterials that drives their innovation also complicates the job of toxicologists tasked with assessing their potential environmental and public health impacts. This dissertation investigates the underlying reasons for uncertainty...
Bacterial cultures enriched from sheep rumen fluid have demonstrated the ability
to detoxify pyrrolizidine alkaloids (seneciphylline and jacobine) in tansy ragwort
(Senecio jacobaea). The microbes are difficult to isolate using classical anaerobic
techniques, therefore, microbes from two different enrichment cultures demonstrating
similar degradation activity were identified using their 16S ribosomal...
A dose related carcinogenic response was established for dimethylnitrosamine
administered in the diet of rainbow trout (Salmo gairdneri).
An equation was derived for the relationship between dose and hepatocellular
carcinoma incidence. From a published dose response study
using Porton rats as a test animal, a second equation was derived
An experiment was designed to simulate field conditions of tansy
ragwort poisoning in cattle and horses.
Four calves and four ponies were fed pelleted feed containing 5%
Senecio jacobaea and two ponies and two calves were used as controls.
The feeding continued for two months. Following this, the chronic
The pyrrolizidine alkaloids (PAs) and ergot alkaloids are known natural
toxicants found in livestock forage. These alkaloids contribute to large
economic losses in livestock throughout the world. An understanding of the
mechanisms of toxicity and development of better diagnostic tools for better
management practices was investigated.
Variability exists in the...
This research focused on anaerobic transformation of trichloroethene (TCE), a
groundwater contaminant. The mixed anaerobic Evanite culture (EV) was studied to determine community behavior and composition responses to different electron donors and chloroethene electron acceptors. The potential toxicity from high concentrations of TCE and its daughter product cis-1,2-dichloroethene (cDCE) was...
Reported here is an investigation to determine the in vitro and in vivo metabolism
of xanthohumol (XN). XN is the major prenylated flavonoid of the female
inflorescences (cones) of the hop plant (Humulus lupulus). It is also a constituent of
beer, the major dietary source of prenylated flavonoids. Recent studies...
In the environment, it is the unbound fraction of chemical (Cfree) which is able to diffuse across environmental interfaces and biological membranes. It is therefore Cfree which drives many important biological-environmental processes including contaminant transport, bioaccumulation and toxicity. Passive sampling devices (PSDs) offer a simplified and more accurate approach for...