Janet Harwood

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The metapopulation concept provides a very powerful tool for analysing the persistence of spatially-disaggregated populations, in terms of a balance between local extinction and colonization. Exactly the same approach has been developed by epidemiologists, in order to understand patterns of diseases persistence. There is great scope for further(More)
We compared concentrations of organochlorines in the blubber of common seals (Phoca vitulina) found dead during the 1988 phocine distemper epizootic with levels in animals which survived it. There were highly significant differences between the live and dead animals, and between sample sites. These were not fully accounted for by seasonal and(More)
This paper uses simple mathematical models to examine the long-term dynamic consequences of the 1988 epizootic of phocine distemper virus (PDV) infection in Northern European common seal populations. In a preliminary analysis of single outbreaks of infection deterministic compartmental models are used to estimate feasible ranges for the transmission rate of(More)
The 1 mg dexamethasone suppression test (DST) was carried out in patients with a major depressive illness in order to establish whether the results of this test, given before antidepressant or ECT treatment, could predict eventual therapeutic outcome. No significant difference could be detected in overall therapeutic improvement between those patients with(More)
The 'time, place, individual' approach, widely used in characterising human epidemics, was applied to the 1988 phocine distemper virus (PDV) epizootic affecting North Sea seals. Estimates of time of death from 157 (69%) of the 228 dead seals necropsied in 1988 indicated that the number of carcasses which were found more than 14 days post mortem increased as(More)
The death of tens of thousands of common seals (Phoca vitulina) around the coast of Europe in 1988 provoked wide interest in the popular press, but it also raised questions about the importance of mass mortality in the dynamics of marine mammal populations. Here, we summarize published information on the occurrence of mass mortalities among marine mammals(More)
A comparison is made between two fluorimetric techniques for the determination of total and free plasma tryptophan. Comparison is also made between methods for the separation of the unbound and bound fraction of plasma tryptophan using ultrafiltration, Centricones and small-scale equilibrium dialysis.
The concentration of kynurenine in plasma from depressed patients and control subjects has been measured using a sensitive and specific method. The levels of kynurenine in the plasma of depressed patients and controls are not significantly different and are not influenced by age or sex. The severity of affective disturbance was not related to plasma(More)
The prevalence of an abnormal response to the dexamethasone suppression test (DST) was examined in 119 in-patients suffering from a major depressive disorder and in 79 normal controls. Only 11 per cent of controls showed an abnormal DST as against 70 per cent of depressed patients. The specificity of the DST was examined by testing patients with other(More)
The dexamethasone suppression test (DST) was carried out on 143 patients with a major depressive disorder, who were classified into those with a history of weight loss (n = 89) and those without (n = 54). Seventy-three per cent of patients with weight loss and 61% of patients without had an abnormal DST; this difference was not statistically significant. Of(More)