Answer:
There were an estimated 18 million Native Americans living north of Mexico at the beginning of the European invasion. Prior to the arrival of the Europeans, American Indians were remarkably free of serious diseases. People did not often die from diseases. As the European explorers and colonists began to arrive, this changed and the consequences were disastrous for Native American people. The death tolls from the newly introduced European diseases often reached 80-90 percent. Entire groups of people vanished before the tidal wave of disease.
Explanation:
The diseases brought to this continent by the Europeans included bubonic plague, chicken pox, pneumonic plague, cholera, diphtheria, influenza, measles, scarlet fever, smallpox, typhus, tuberculosis, and whooping cough. The diseases introduced in the Americas by the Europeans were crowd diseases: that is, individuals who have once contracted the disease and survived become immune to the disease. In a small population, the disease will become extinct. Measles, for instance, requires a population of about 300,000 to survive. If the population size drops below this threshold, the virus can cause illness and death, but after one epidemic, the virus itself dies out.
Another important factor in the European diseases was the presence of domesticated animals. The source of many of the infections was the domesticated animals which lived in close proximity with the humans.
Overall, hundreds of thousands of Indians died of European diseases during the first two centuries following contact. In terms of death tolls, smallpox killed the greatest number of Indians, followed by measles, influenza, and bubonic plague.
Activation of the <u>Serotonin </u>neurons of the forebrain would be expected to <u>suppress </u>aggressive attack.
Numerous studies link elevated impulsive and aggressive behaviors with reduced serotonin metabolites. The opposing association has been substantiated by therapies targeted at directly reducing serotonin cell activity, despite the fact that pharmaceutical reduction of serotonin is linked to an increase in aggression.
Furthermore, it is unclear whether any of the relationships observed may be caused by changed serotonin activity during development. Here, we used two Pharmacogenetic techniques to selectively and reversibly decrease the firing of serotonin neurons in behaving animals in transgenic mice.
A persistent reduction in serotonin neuron firing was linked to increased aggression, as demonstrated by conditional over expression of the serotonin 1A receptor (Htr1a) in serotonin neurons.
To learn more about Serotonin here
brainly.com/question/9793167
#SPJ4
It is a period from the 14th to 17th CE the bridge between the Middle ages and the modern history.
Answer:
A. Selective.
Explanation:
This could be looked at in the sense of a little disorder from little Andrew, though the act is selective, it could also come up as mutuism. Some adults with selective mutism are fully capable of speech and understanding language but are physically unable to speak in certain situations, though speech is expected of them.
The behaviour may be perceived as shyness or rudeness by others. A child with selective mutism may be completely silent at school for years but speak quite freely or even excessively at home. There is a hierarchical variation among people with this disorder: some people participate fully in activities and appear social but do not speak, others will speak only to peers but not to adults, others will speak to adults when asked questions requiring short answers but never to peers, and still others speak to no one and participate in few, if any, activities presented to them.
