: difficult in a way that is usually interesting or enjoyable. Thesaurus: All synonyms and antonyms for challenging Nglish: Translation of challenging for Spanish speakers Britannica English: Translation of challenging for Arabic speakers.
To illustrate the tremendous indirect impact of emerging zoonotic diseases on public health policy and structures and on public perception of health risks, the authors provide a number of examples, including that of the Ebola virus, avian influenza, monkeypox and bovine spongiform encephalopathy.
Economist Jeffrey Goldstein provided a current definition of emergence in the journal Emergence. Goldstein initially defined emergence as: the arising of novel and coherent structures, patterns and properties during the process of self-organization in complex systems.