Turn on 2-Step Verification. When you enable 2-Step Verification (also known as two-factor authentication), you add an extra layer of security to your account. You sign in with something you know (your password) and something you have (a code sent to your phone). Go to the 2-Step Verification page. You might have to sign in to your Google Account.
Lung function will also be affected by, or co-vary, with other factors, such as smoking and chronic respiratory diseases. However, the relationships between these variables are not always obvious as some smokers never develop symptoms and lung function decline, while some never smokers become ill, etc [1, 2].
Density-independent factors are environmental factors affecting a population regardless of size, such as temperature and oxygen supply. One Density-independent factors would be the impacts of an earthquake on a pack of wild dogs. The number of dogs does not affect the result of the earthquake upon the dog population. In contrast, drought is a density-dependent factor because more dogs will cause greater competition for limited water resources.