Economists have never had a consistent definition of "entrepreneur" or "entrepreneurship" (the word "entrepreneur" comes from the French verbentreprendre, meaning "to undertake"). Though the concept of an entrepreneur existed and was known for centuries, the classical andneoclassical economistsleft entrepreneurs out of their formal models: They assumed that perfect information would be known to fully rational actors, leaving no room for risk-taking or discovery. It wasn't until the middle of the 20th century that economists seriously attempted to incorporate entrepreneurship into their models.

11 Does aciclovir prevent the chances of developing herpes zoster (shingles) when given during primary infection?

12 How long does it take after vaccination to become immunized against chickenpox and therefore safe to work in infectious areas?

13 Is meticillin-resistant Staphylococcus aureus (MRSA) the only major hospital-acquired infection?

14 Do you have to have antibiotics to get Clostridium difficile infection?

15 Why do some patients with rheumatic fever later progress to chronic rheumatic heart disease?

16 What is the World Health Organization recommendation for the prophylaxis of rheumatic fever after a streptococcal throat infection?

17 Does rheumatic fever have an infectious or an immunological aetiology?

18 Why is migratory polyarthritis found in rheumatic heart disease?

19 Are penicillins still the drug of choice in streptococcal infections (particularly Strep. Pneumoniae)?

20 1. How long can the antistreptolysin-O (ASO) titre remain positive after a streptococcal infection? 2. What is the effect of a suitable antibiotic on the ASO titre, if any?