What research method is used in order to establish what causes a behavior? an experiment What is the first step of the scientific method? pose a question In the science of human development, &quot;nurture&quot; refers to: environmental influences.
Vertical lines on one's nails, like those the writer seems to have, are a common phenomenon that often get more pronounced with age. There are many reasons for ridged nails but the most common is aging, says Dr. Phoebe Rich, M.D., FAAD, clinical adjunct professor of dermatology at Oregon Health Science University.
Q: Dear Dr. Mao, My toenails have fine white lines running in a horizontal direction, although my fingernails are fine. Do you know what could be the cause of this condition?eesâ lines, horizontal lines of discoloration, can indicate arsenic poisoning, Hodgkinâs disease, congestive heart failure, leprosy, malaria, chemotherapy, carbon monoxide poisoning, or other systemic traumas.