Cohen-Boyer: A Brief History

a brief history of zero

it is generally recognised that ‘zero’ as we understand the concept today originated in two geographically separated cultures: the maya and indian. however, if zero merely signified a magnitude or a direction separator (i.e. separating those above the zero level from those below the zero level), the egyptian zero, nfr, dating back at least four thousand years, amply served these purposes. if ze...

Ontology – a Brief History

Tetrodotoxin —A brief history—

Tetrodotoxin (TTX), contained in puffer, has become an extremely popular chemical tool in the physiological and pharmacological laboratories since our discovery of its channel blocking action in the early 1960s. This brief review describes the history of discovery of TTX action on sodium channels, and represents a story primarily of my own work. TTX inhibits voltage-gated sodium channels in a h...

Brief history of mycology in Iran

The history of mycology in Iran is presented in five periods. In the first period (until 1860) there is no sign of Iranian fungi in scientific literature. In the second period (1860–1941) the study of Iranian fungi was started by foreign mycologists who did not visit Iran but worked on plant material collected by botanists. In the third period (1941–1963) the study of Iranian fungi was started ...

a brief history of human blood groups.

the evolution of human blood groups, without doubt, has a history as old as man himself. there are at least three hypotheses about the emergence and mutation of human blood groups. global distribution pattern of blood groups depends on various environmental factors, such as disease, climate, altitude, humidity etc. in this survey, the collection of main blood groups abo and rh, along with some ...