Schistosomiasis, also known as bilharzia (bill-HAR-zi-a), is a disease caused by parasitic worms. Infection with Schistosoma mansoni, S. haematobium, and S. japonicum causes illness in humans.Although schistosomiasis is not found in the United States, more than 200 million people are infected worldwide.chistosomiasis, also known as bilharzia (bill-HAR-zi-a), is a disease caused by parasitic worms. Infection with Schistosoma mansoni, S. haematobium, and S. japonicum causes illness in humans.
Part 2: How do Dry Snorkels Work? Dry snorkels have a mechanism at the top of the tube that closes when you submerge under water. It also has a covering at the top to prevent surface water from splashing into the top of tube. The dry snorkel has a valve/hinge mechanism at the top. When you submerge underwater, accidentally or purposely, the hinge reacts via a float mechanism and closes onto the top of the tube and seals it which prevents water from filling the tube.
In this shot, down-scanning sonar has revealed massive schools of herring. Scanning sonar works differently in two key ways. The primary difference is that the transducer broadcasts a very narrow beam, both straight down and side-to-side, instead of the traditional cone shape.This means the display is receiving a nearly two-dimensional signal, allowing for a much more detailed display image.n this shot, down-scanning sonar has revealed massive schools of herring. Scanning sonar works differently in two key ways. The primary difference is that the transducer broadcasts a very narrow beam, both straight down and side-to-side, instead of the traditional cone shape.