Composition of wax esters is linked to diapause behavior of Calanus finmarchicus in a sea loch environment

We studied the seasonal lipid dynamics of Calanus finmarchicus from Loch Etive, a semi-enclosed fjordic environment on the west coast of Scotland, in relation to the diapause behavior of this species. Levels of total lipid and triacylglycerol in individual copepodid stage V (CVs) exhibited clear seasonal trends, with highest levels in June and progressively decreasing through late summer to winter. Wax esters in CVs were more variable, but followed a similar pattern. An index of the level of unsaturation of wax esters, effectively an indicator of the levels of polyunsaturated fatty acids in the wax ester reserves, were highest in midsummer and declined progressively through autumn and winter. Fatty acid analysis of total lipid in the CVs confirmed that the amounts of polyunsaturated fatty acids in the wax esters decreased, while amounts of saturated and monounsaturated fatty acids remained comparatively stable. Polyunsaturated wax esters are selectively catabolized by C. finmarchicus during diapause. Previous studies have linked unsaturation of wax esters in calanoid copepods to the initiation of diapause and buoyancy control, and we hypothesize that selective catabolism of polyunsaturated wax esters is linked to the processes of diapause termination and ascent to surface waters

Emission at 1.3 microns from dysprosium-doped Ga:La:S glass

The potential for optical amplification at 1.3 µm is demonstrated in a dysprosium-doped gallium-lanthanum-sulphide based glass. Lifetimes of 59µs are observed for the 6H9/2 - 6H15/2 transition for which the emission peaks at 1.32µm. A radiative lifetime of 203µs is calculated by a Judd-Ofelt analysis, indicating a total radiative quantum efficiency of 29%. A pump absorption cross-section 20 times greater than Pr3+ suggests that shorter fibre devices may be possible