Katherine A. Mitchell

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Mercury use in small-scale gold mining is ubiquitous across Ghana but little is known about the extent to which such activities have contaminated community residents and miners. Here, occupational exposures to elemental mercury (via urine sampling) and dietary exposures to methylmercury (via hair sampling) were assessed among 120 participants recruited from(More)
I tulipifera L. Dark res iration rate varied by leaf canopy position and was higher i leaves collected from high-l ight environments. When exp .essed on an area basis, dark respiration rate (Rdtaa, pmol COs (kg leaf dry area)-’ s-‘) showed a strong linear relat ionship w: th the predictor variables leaf nitrogen (N,,, g N (m leaf area)-*) and leaf structure(More)
We examined latitudinal variation in adult and larval heat tolerance in Drosophila melanogaster from eastern Australia. Adults were assessed using static and ramping assays. Basal and hardened static heat knockdown time showed significant linear clines; heat tolerance increased towards the tropics, particularly for hardened flies, suggesting that tropical(More)
The distribution of insects can often be related to variation in their response to thermal extremes, which in turn may reflect differences in plastic responses or innate variation in resistance. Species with widespread distributions are expected to have evolved higher levels of plasticity than those from restricted tropical areas. This study compares adult(More)
Among-population variation in chill-coma onset temperature (CTmin ) is thought to reflect natural selection for local microclimatic conditions. However, few studies have investigated the evolutionary importance of cold tolerance limits in natural populations. Here, using a common-environment approach, we show pronounced variation in CTmin (± 4 °C) across(More)
There is a need to further our understanding of the role that the equine hindgut ecosystem plays in digestive processes and diseases. The aim of the present study was to utilise the real-time PCR technique to determine the abundance of candidate cellulolytic (Ruminococcus flavefaciens; Fibrobacter succinogenes) and non-cellulolytic (Streptococcus bovis)(More)
Ontogenetic variation in plasticity is important to understanding mechanisms and patterns of thermal tolerance variation. The Bogert effect postulates that, to compensate for their inability to behaviourally thermoregulate, less-mobile life stages of ectotherms are expected to show greater plasticity of thermal tolerance than more-mobile life stages. We(More)
Dispersal and phenotypic plasticity are two main ways for species to deal with rapid changes of their environments. Understanding how genotypes (G), environments (E), and their interaction (genotype and environment; G × E) each affects dispersal propensity is therefore instrumental for predicting the ecological and evolutionary responses of species under(More)
OBJECTIVES This study aimed to compare costs of caring for people with dementia in domiciliary and residential settings, central England. METHODS A cohort of people with dementia was recruited during a hospital stay 2008-2010. Data were collected by interview at baseline, and 6- and 12-month follow-up, covering living situation (own home with or without(More)
Community health workers (CHWs) have demonstrated effectiveness in improving health outcomes and addressing health inequities. Statewide CHW coalitions are supporting expansion of the CHW workforce and influencing health policy. Evaluations can play a key role in sustaining coalitions. This article discusses how evaluation has informed the development,(More)