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.
Horizontal Fingernail Ridges. Horizontal fingernail ridges are usually but not always, a sign of a medical condition. Horizontal ridges run across the nail from one side to another. Ridges that include white lines may be a sign of arsenic poisoning. Horizontal dents, on the other hand are a sign of beau lines. Beau lines occur due to malnutrition, uncontrolled diabetes or circulatory diseases. Vitamin Deficiencies. B vitamins are a group of vitamins with key functions including cell growth. Vitamin B-12 of the B vitamin complex strengthens nail growth; therefore, a deficiency in B vitamins may cause fingernail ridges.