Johnny was potty trained 2 years ago and for over a year he never had a bathroom accident. Over the last month Johnny has had accidents at least two to three times a week. A month ago is when his parents brought his new baby sister home from the hospital.

It is possible that Johnny would be experiencing what is called "regression". Regression is a behavior that occurs for more than a few weeks, when previously a child wouldn't have been having these issues anymore (such as when a child is already known to be potty trained but reverts back to having accidents fairly frequently). The most likely cause would be stress or a medical issue, in this case a young child may find the inclusion of a new sibling to be a stressful change in their lives. The question states that Johnny has been having accidents for the past month, and during that same time period his sister baby sister was brought home from the hospital. The stress of a schedule change for a young child could cause such issues. I hope this helps.

to prevent people from getting the ebola virus, countries around the world paid to doctors develop a new vaccine. now that the vaccine has been made, doctors will need to experiment on a large number of people to find out if it works safely.

what is the greatest limitation that scientists are dealing with as they try to figure out how to experiment with the ebola vaccine?

meditation is a practice of sitting still and quiet for minutes or even hours. it has been practiced for thousands of years and is even a part of religious practices for some people. carefully controlled, repeated measurements of brain activity have shown that meditation does increase certain chemicals in the brain and even grows the part of the brain that people connect with their current surroundings and activities.

are claims about the effects of meditation most likely scientific or pseudoscientific?

not pseudoscientific, because people have made claims about it but scientific observations have not been made

if this is true of false i think it would be true