This introduction addresses some key issues and questions in the study of negation and polarity. Focussing on negative polarity and negative indefinites, it summarizes research trends and results.

Dr. Irwin Arias, emeritus senior scientist at the National Institutes of Health (NIH) and a renowned doctor in the field of hepatology, the study of the liver, emphasized the importance of studying ...

Plant polarity refers to the asymmetric distribution of cellular components along a particular axis within a cell, and is essential for processes such as intercellular communication, cell division, ...

Some 41,000 years ago, a complete and rapid reversal of the geomagnetic field occured. Magnetic studies on sediment cores from the Black Sea show that during this period, during the last ice age, a ...

Every so often—every 250,000 years on average—the Earth's magnetic poles reverse polarity. If such a reversal happened today, compass needles would point south rather than north. Here, view a computer ...