Results are presented from our ongoing studies of Titan using ALMA during the period 2012-2015, including a confirmation of the previous detection of vinyl cyanide (C2H3CN), as well as the first spatial map for this species on Titan. Simultaneous mapping of HC3N, CH3CN and C2H5CN reveal characteristic abundance patterns for each species that provide insight into their individual photochemical lifetimes, and help inform our understanding of Titan’s unique, time-variable atmospheric chemistry and global circulation. A time-sequence of HC3N maps covering 38 months reveals a dramatic change in the distribution of this gas consistent with high-altitude photochemical production followed by advection towards the southern (winter) pole, combined with rapid loss in the north after Titan’s 2009 seasonal equinox. The 2015 C2H3CN and C2H5CN maps show abundance peaks in Titan’s southern hemisphere, similar to those observed for the short-lived HC3N molecule. The longer-lived CH3CN, on the other hand, remains more concentrated in the north.

Over an eight-year period, harvesting methods based on simple mechanical aids (blade and shear) were evaluated against hand harvesting on mature morphologically contrasting tea clones in Southern Tanzania. The effects of shear step height (5–32 mm) and the harvest interval (1.8–4.2 phyllochrons) were also examined. Except in the year following pruning, large annual yields (5.7–7.9 t dry tea ha−1) were obtained by hand harvesting at intervals of two phyllochrons. For clones K35 (large shoots) and T207 (small shoots), the mean harvested shoot weights were equivalent to three unfurled leaves and a terminal bud. The proportions of broken shoots (40–48 %) and coarse material (4–6 %) were both relatively high. Using a blade resulted in similar yields to hand harvesting from K35 but larger yields from T207 (+13 %). The yield increase from clone T207 was associated with the harvest of more shoots and heavier shoots, smaller increases in canopy height, and a higher proportion (7–9 %) of coarse material compared to hand harvesting. On bushes, which had been harvested by hand for two years following pruning, using flat shears (no step) supported on the tea canopy resulted, over a three year period, in yields 8–14 % less than those obtained by hand harvesting and, for clone K35, a reduction in the leaf area index to below 5. The development of a larger leaf area index is made possible by adding a step to the shear. However, since annual yields were reduced by 40–50 kg ha−1 per mm increase in step height, the step should be the minimum necessary to maintain long-term bush productivity. As mean shoot weights following shear harvesting were about 13 % below those obtained by hand harvesting, there is scope, when using shears, to extend the harvest interval from 2 to 2.5 phyllochrons.

In this paper I argue that Panegyric VIII (V) was delivered on 25 July 311, at the completion of the celebration of Constantine’s Quinquennalia, and that Constantine always regarded 25 July as his dies imperii.

The purpose of Panegyric VIII (V) is to thank the Emperor Constantine for benefactions to the speaker’s civitas Autun. It adheres closely to its theme, offering few allusions to events unconnected with these benefactions, unlike, for example, Mamertinus’ Panegyrics II (X) and III (XI), which retail the recent achievements of his Emperors. What is the occasion and date of its delivery? The answers to these questions will be seen to have a wider significance.