Physical causes
2015 research by Johns Hopkins University has found that the brain tissue of combat veterans who have been exposed to improvised explosive devices (IEDs) exhibit a pattern of injury in the areas responsible for decision making, memory and reasoning. This evidence has led the researchers to conclude that shell shock may not only be a psychological disorder, since the symptoms exhibited by affected individuals from the First World War are very similar to these injuries. Immense pressure changes are involved in shell shock. Even mild changes in air pressure from weather have been linked to changes in behavior.There is also evidence to suggest that the type of warfare faced by soldiers would affect the probability of shell shock symptoms developing. First-hand reports from medical doctors at the time note that rates of such conditions decreased once the war was mobilized again during the 1918 German offensive, following the 1916–1917 period where the highest rates of shell shock can be found. This could suggest that it was trench warfare, and the experience of siege warfare specifically, that led to the development of these symptoms. Cowardice
Some men with shell shock were put on trial, and even executed, for military crimes including desertion and cowardice. While it was recognised that the stresses of war could cause men to break down, a lasting episode was likely to be seen as symptomatic of an underlying lack of character.
Roughly 95% of hookworms found in the southern region of the United States are N. americanus. This parasite is found in humans, but can also be found in pigs and dogs.Transmission of N. americanus infection requires the deposition of egg-containing feces on shady, well-drained soil and is favored by warm, humid (tropical) conditions. Therefore, infections worldwide are usually reported in places where direct contact with contaminated soil occurs. References


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