Children are most commonly infected. Estimated prevalence rates among children in various world regions are 4â28%. Ascariasis: Ascaris, or roundworm, infection is the common helminthic infection in humans, with an estimated worldwide prevalence of 1 billion. The causative organism, A lumbricoides, is cosmopolitan in distribution, being most abundant in tropical countries.
Definition of hollow. 1  1 : an unfilled space : cavity, hole in the hollow of a tree. 2  2 : a depressed or low part of a surface; especially : a small valley or basin.
Hollows, like those in Appalachia, are small valleys nestled between mountains or hills. Giant valleys, called rifts, are found where two pieces of Earth's crust are separated or split apart.One such example is the Great Rift Valley, a rift system stretching from the Middle East to southern Africa.he scars left behind are known by their shapes and where they lie. Some hang; others are hollow. They all take the form of a U or V.. Rivers and streams make most primary valley cuts, carving steep-walled sides and a narrow floor that from afar looks like the letter V..