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.
RIO GRANDE VALLEY. RIO GRANDE VALLEY. The Rio Grande valley is a complex economic and perceptual region. What Texans call the Valley centers on Starr, Cameron, Hidalgo, and Willacy counties in the lower Rio Grande region and extends from the mouth of the Rio Grande up the river for a distance of some 100 miles.