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.
White lines running across nails. White spots or streaks are normal and nothing to worry about, but parallel white lines that extend all the way across the nails, known as Muehrcke's lines, are a sign of low levels of protein in the blood. In contrast to Beau's lines (see above), they're not grooved.