Electrophoretic heterogeneity in preparations of arabis mosaic virus (AMV) was due to differences in net surface charge among the sedimenting components. Bottom component migrated more rapidly than top component in polyacrylamide gels and on cellulose acetate strips. When nucleic acid was removed from bottom component the nucleic acid-free protein shell showed sedimentation and electrophoretic ...

JCB • VOLUME 214 • NUMBER 2 • 2016 122 Growing up in the Boston area, Cliff Brangwynne was a kid with distinct interests. He recalls performing one of his fi rst experiments after watching a TV program on quantum mechanics: spending an afternoon bouncing a tennis ball off a wall in an attempt to observe quantum tunneling. Through high school, he read pop-science books about the weirdness of the...

Ibn Sina is generally known as one of the most important philosophers and physicians, one whose contributions to science and philosophy have attracted numerous studies. This article provides an outline of his philosophy of science which determined the framework for his understanding of natural philosophy. Rather than being of historical interest, the article argues, Ibn Sina's philosophy of sci...

During the 1020s Ibn Sı̄nā wrote a commentary in Arabic on the logical works of Aristotle, as part of his encyclopedia Al-Šifā’ (The Cure). The commentary runs to some 2180 pages in the recent Cairo edition; this figure includes his commentary Madk ̄ al on Porphyry’s Eisagōgē, which he counted as an introduction to Aristotle’s work. Apart from the Madk ̄ al which was translated into Latin in the 1...

Ibn Sina is regarded as one of the greatest physicians, thinkers and medical scholars in the history of medicine. Ibn Sina, a Persian scholar in the medieval era, wrote a famous book of medicine, the Canon of Medicine. The book was adopted as the main textbook of medicine in most Western and Persian universities. In the present critique, we analyzed the functional and anatomic descriptions of t...

BACKGROUND The distribution and abundance of plants is controlled by the availability of seeds and of sites suitable for establishment. The relative importance of these two constraints is still contentious and possibly varies among species and ecosystems. In alpine landscapes, the role of seed limitation has traditionally been neglected, and the role of abiotic gradients emphasized. METHODOLO...