Tutor and Freelance Writer. Science Teacher and Lover of Essays. Article last reviewed: 2020 | St. Rosemary Institution © 2010-2021 | Creative Commons 4.0

The Kalapalo Indians: Culture & Lifestyle

The Kalapalo Indians of Central Brazil are one of a few surviving indigenous cultures that is uniquely protected by a national reserve in lowland South America. Through no effort of their own, they have been isolated artificially from Brazilian social and economic influences that reach almost every other Indian tribe in Brazil. This unusual situation…

Diphtheria (Corynebacterium diphtheriae): History, Symptoms, Causes, Treatment

Corynebacteria are Gram-positive, aerobic, nonmotile, rod-shaped bacteria related to the Actinomycetes. They do not form spores or branch as do the actinomycetes, but they have the characteristic of forming irregular shaped, club-shaped or V-shaped arrangements in normal growth. They undergo snapping movements just after cell division which brings them into characteristic arrangements resembling Chinese letters.…

Huntington’s Disease: Causes, Symptoms, Testing

Huntington’s disease, or Huntngton’s chorea, is a genetic disease that causes selective neural cell death, which results in chorea, or irregular, jerking movements of the limbs caused by involuntary muscle contractions, and dementia.  It can cause a lack of concentration and depression.  It also may cause atrophy of the caudate nucleus, a part of the…

Obsessive-Compulsive Disorder: Causes & Treatment

“Compulsive” and “obsessive” have become everyday words. “I’m compulsive” is how some people describe their need for neatness, punctuality, and shoes lined up in the closets. “He’s so compulsive is shorthand for calling someone uptight, controlling, and not much fun. “She’s obsessed with him” is a way of saying your friend is hopelessly lovesick. That…