| In general, Tb's showed a marked circadian cycle in phase with photoperiod. |
| For enzymatic activities and sugar determinations, samples were collected at the middle of the photoperiod. |
| Exposure of male edible dormice all year round to an unvarying photoperiod and warm temperature disrupted their biological cycles. |
| Preliminary observations indicate an impact of the photoperiod on the regulation of the reproductive cycle. |
| Summary of 10 studies examining the effect of increased photoperiod on milk yield in lactating cows. |
| The initiation of reproduction in the beach flea, Orchestia gammarellus, is affected by temperature, but not by changes in photoperiod or salinity. |
