A disease is any condition which results in the disorder of a structure or function in a living organism that is not due to any external injury. The study of disease is called pathology, which includes the study of cause. Disease is often construed as a medical condition associated with specific symptoms and signs. It may be caused by external factors such as pathogens or by internal dysfunctions, particularly of the immune system, such as an immunodeficiency, or by a hypersensitivity, including allergies and autoimmunity.
The horseman on the white horse was clad in a showy and barbarous attire. [...] While his horse continued galloping, he was bending his bow in order to spread pestilence abroad. At his back swung the brass quiver filled with poisoned arrows, containing the germs of all diseases.
Vicente Blasco Ibáñez, The Four Horsemen of the Apocalypse (1916), (ch V).
Solar power is potentially an almost limitless resource. The sun provides enough energy in one minute to supply the world’s energy needs for one year. But turning this resource into affordable electricity is difficult – silicon-based solar cells still suffer from a decline in their effectiveness over time. Through her ERC-funded SOLARX project, Professor Hele Savin, of Aalto University in Finland, is investigating a possible route to solving this problem.