National security, unlocked. Each Thursday, host Mary Louise Kelly and a team of NPR correspondents discuss the biggest national security news of the week. With decades of reporting from battlefields ...

Computational models are mathematical models used to numerically study the behaviour of complex systems by means of a computer simulation. A computational model can be used to make predictions of the ...

Abiotic factors are non-living chemical and physical elements in the environment, which affect individual organisms as well as ecosystems. Examples are UV, IR and visible light, radiation, temperature ...