However, it is plausible that it might be contributing, for example by raising blood pressure or by disturbing people's sleep.
In a few patients systemic causes may contribute, for example hyperthyroidism, but for the most part no underlying cause is isolated other than individual susceptibility.
But though both biology and engineering contributed, for example, to the development of prosthetics, biology wasn't really approached from an engineer's perspective until recently.
Teachers, nongovernmental organizations (NGOs), and government agencies contributed, for example, to standardization in the shape and style of the classroom, types of curricula, and goals for school enrollments.
It is also a technology story, with superb BBC research and development contributing for example to digital broadcasting, to the computer games industry through the impact of the BBC Micro, and increasingly to online technologies.
Platforms, publishers and advertisers need to collaborate to ensure that we can all tackle the consequences of when these expectations are not met, contributing for example to the recent growth in ad blocking.
Results can contribute, for example, to the design and construction of instruments needed for the detection and identification of plastic anti-personnel landmines, explosives hidden in airline baggage and cargo containers via hydrogen contents as an indicator of their presence.
Michelle Mitchell, the Charity Director General of Age UK said: "As a society we need to change our ideas about older people and what they have to contribute; for example, encouraging employers to look at the maturity and experience that an older worker can bring to the workplace.
So they can contribute, for example, to NoiseTube, which monitors sound levels via mobile phones to combat the problem of noise pollution.
Data from the tissue bank contributed, for example, to a new prognostic indicator for melanoma recurrence, developed by Yale investigator David Rimm and his colleagues.
