Cancer Prevention Fellowship Program, Office of Preventive Oncology, National Cancer Institute, Bethesda, MD 20892-7105, USA. This article has been cited by other articles in PMC. Abstract. Causation is an essential concept in epidemiology, yet there is no single, clearly articulated definition for the discipline. From a systematic review of the literature, five categories can be delineated: production, necessary and sufficient, sufficient-component, counterfactual, and probabilistic.
Broad Valley. Broad Valley (63Â°22â²S 57Â°55â²W / 63.367Â°S 57.917Â°W / -63.367; -57.917Coordinates: 63Â°22â²S 57Â°55â²W / 63.367Â°S 57.917Â°W / -63.367; -57.917) is a descriptive name for the broad glacier-filled valley on the south side of Laclavere Plateau, Trinity Peninsula. The name was suggested by V.I.
The Central Valley (also called the Great Central Valley) is a very large valley in the middle of California, in the United States. About 42,000 square miles (108,779 square kilometers) in size, it is about the size of the state of Tennessee.It consists of two connected, differently named valleys, the Sacramento Valley and the San Joaquin Valley.bout 42,000 square miles (108,779 square kilometers) in size, it is about the size of the state of Tennessee. It consists of two connected, differently named valleys, the Sacramento Valley and the San Joaquin Valley.