Edward Sapir

Edward Sapir was an American anthropologist-linguist, who is widely considered to be one of the most important figures in the development of the discipline of linguistics in the United States. Sapir was born in German Pomerania, in what is now northern Poland. His family emigrated to the United States of America when he was a child. He studied Germanic linguistics at Columbia, where he came under the influence of Franz Boas, who inspired him to work on Native American languages.

Lesbian, Gay, Bisexual, and Transgender

LGBT is an initialism that stands for "lesbian, gay, bisexual, and transgender". In use since the late 1980s, the initialism, as well as some of its common variants, functions as an umbrella term for marginalized sexualities and gender identities. 
LGBT is an adaptation of LGB, which in the mid-to-late 1980s began to replace the term gay (or gay and lesbian) in the broader LGBT community. The LGBT label is not universally agreed to by everyone that it is generally intended to include.

Heart Rate Variability

Heart rate variability (HRV) is the physiological phenomenon of variation in the time interval between heartbeats. It is measured by the variation in the beat-to-beat interval. Other terms used include "cycle length variability", "R–R variability" (where R is a point corresponding to the peak of the QRS complex of the ECG wave; and RR is the interval between successive Rs), and "heart period variability".