Flexible plants, fungi and sessile animals reconfigure in wind and water to reduce the drag acting upon them. In strong winds and flood waters, for example, leaves roll up into cone shapes that reduce drag compared with rigid objects of similar surface area. Less understood is how a leaf attached to a flexible leaf stalk will roll up stably in an unsteady flow. Previous mathematical and physica...

BACKGROUND The purpose of the present study was to analyse species-specific forms of behaviour (digging and swimming) and response to novelty in laboratory rats and their wild type counterparts at a very early stage of laboratorization. Three behavioural phenomena were taken into account: burrowing, spontaneous swimming, and neophobic behaviour. PRINCIPAL FINDINGS Wild-type rats and three str...

Ten North Temperate taxa representing diverse angiosperm lineages were analyzed for biogeographic histories using the dispersal-vicariance analysis method to gain insights into the origin and evolution of disjunct distributions in the Northern Hemisphere. Results indicate four general biogeographic patterns: (1) origin and speciation in eastern Asia with subsequent expansion into North America ...

Tinh dầu từ lá và thân rễ của loài Asarum geophyllum Merr., thu mẫu tại xã Đức Quang, Hạ Lang, Cao Bằng, được chưng cất bằng phương pháp lôi cuốn hơi nước có hồi lưu. Hàm lượng tinh đạt 0,16% 0,12% (theo nguyên liệu khô không khí). màu trắng, nặng hơn nước. Bằng sắc ký khí khối phổ (GC/MSD), 47 cấu tử chiếm 97,17% tổng đã xác định. Những thành phần chính gồm: β-caryophyllene (11,91%), 9-epi-β-c...