Both “illness and temptation of the enemy”: melancholy, the medieval patient and the writings of King Duarte of Portugal (r. 1433–38)

Recent historians have rehabilitated King Duarte of Portugal, previously maligned and neglected, as an astute ruler and philosopher. There is still a tendency, however, to view Duarte as a depressive or a hypochondriac, due to his own description of his melancholy in his advice book, the Loyal Counselor. This paper reassesses Duarte's writings, drawing on key approaches in the history of medicine, such as narrative medicine and the history of the patient. It is important to take Duarte's views on his condition seriously, placing them in the medical and theological contexts of his time and avoiding modern retrospective diagnosis. Duarte's writings can be used to explore the impact of plague, doubt and death on the life of a well-educated and conscientious late-medieval ruler

Conspecific sperm precedence is a reproductive barrier between free-spawning marine mussels in the northwest atlantic mytilus hybrid zone.

Reproductive isolation at the gamete stage has become a focus of speciation research because of its potential to evolve rapidly between closely related species. Conspecific sperm precedence (CSP), a type of gametic isolation, has been demonstrated in a number of taxa, both marine and terrestrial, with the potential to play an important role in speciation. Free-spawning marine invertebrates are ideal subjects for the study of CSP because of a likely central role for gametic barriers in reproductive isolation. The western Atlantic Mytilus blue mussel hybrid zone, ranging from the Atlantic Canada to eastern Maine, exhibits characteristics conducive to the study of CSP. Previous studies have shown that gametic incompatibility is incomplete, variable in strength and the genotype distribution is bimodal-dominated by the parental species, with a low frequency of hybrids. We conducted gamete crossing experiments using M. trossulus and M. edulis individuals collected from natural populations during the spring spawning season in order to detect the presence or absence of CSP within this hybrid zone. We detected CSP, defined here as a reduction in heterospecific offspring from competitive fertilizations in vitro compared to that seen in non-competitive fertilizations, in five of the twelve crosses in which conspecific crosses were detectable. This is the first finding of CSP in a naturally hybridizing population of a free-spawning marine invertebrate. Our findings support earlier predictions that CSP can promote assortative fertilization in bimodal hybrid zones, further advancing their hypothesized progression towards full speciation. Despite strong CSP numerous heterospecific fertilizations remain, reinforcing the hypothesis that compatible females are a source of hybrid offspring in mixed natural spawns

Results from competition crosses.

<p>Significance of G-statistics and exact binomial test results (*<i>P</i><0.05; **<i>P</i><0.01; ***<i>P</i><0.001) were assessed using Bonferroni-adjusted alpha values.</p><p>Results from competition crosses.</p

Patterns of CSP variation.

<p>Predicted proportion (filled bars) and observed proportion (open bars) of conspecific offspring sired in each competition cross. Asterisks mark cases of CSP that are significant (G-test): ***<i>P</i><0.001.</p

Linear regression analyses of results from non-competitive crosses.

<p>All females are <i>M. edulis</i> and males are <i>M. edulis</i> (E) and <i>M. trossulus</i> (T).</p>†<p>The value is provided because the regression is significant, but F20 in this cross is biologically unrealistic (i.e. it exceeds the concentration of dry sperm).</p><p>F₂₀ are in sperm/ml, <i>a</i> =  the intercept, <i>b</i> =  the regression coefficient, and <i>F</i> =  the F-value (*<i>P</i><0.05; **<i>P</i><0.01; ***<i>P</i><0.001).</p><p>Linear regression analyses of results from non-competitive crosses.</p