Analysis of the distribution of pollen grains of various species contained in surface layer deposits, especially peat bogs and lake sediments, from which a record of past climate may be inferred. Because the lake sediments accumulate over time, a core of the mud will show that the mud at the bottom will be the oldest and the mud at the top will be
Few of these folkloric claims have been clinically evaluated at the level of large, randomized, double-blind studies. Some in-vitro or rat model studies are available in published biomedical literature. The composition of propolis is variable, depending on season, bee species and geographic location, so caution must be applied in extrapolating resu
