A Brief Comparative History Analysis

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...

applying transitivity theory to gender analysis of efl textbook: : a comparative study.

efl/esl textbooks have been regarded as essential language teaching materials with which the learners spend about 70 up to 90 percent of their class time. the important role they play and their vast use make them not only influential in learning the language but also in shaping values and attitudes. put it another way, textbooks socialize learners using their contents (i.e. texts, illustrations...

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 ...