The disease may have been closely linked with humans and likely predated civilization. Spirochete infections have also been linked to dementia. Optimism may also be linked to health. Potential energy is closely linked with forces. Bonds has also been linked to steroids. These allergens are also linked with asthma. Nor are they directly linked proportional to reserves. It is also often linked to pulmonary ailments. The project is closely linked with Tullow Oil. This has been theoretically linked to increased impulsivity. Isotretinoin has also been linked to psychosis. These rings can be linked together into polypyrrole molecules. Creative destruction has also been linked to sustainable development. Endometriosis has been linked to ovarian cancers. Polymorphism has been linked with migratory behaviour.