Mononucleosis, commonly called mono, is an illness caused by the Epstein-Barr virus. Although it's rarely serious, mono can cause bothersome symptoms that last several weeks.
Complex systems. Complex systems present problems both in mathematical modelling and philosophical foundations. The study of complex systems is an approach to science that investigates how relationships between parts give rise to the collective behaviors of a system and how the system interacts and forms relationships with its environment.
Our first theory is called structural-functional theory. This approach views society as a complex, but interconnected system, where each part works together as a functional whole. A metaphor for the structural-functional approach is the human body. You have arms, legs, a heart, a brain, and so on.ymbolic interactionism views larger society as a byproduct of the interactions among millions of individuals. In other words, this theory focuses more on tiny groups of two or three people, talking to each other and interacting, and says that society is really just millions of these tiny groups occurring over time.