There are two models of protein folding that are currently being confirmed: 1  The diffusion collision model, in which a nucleus is formed, then the secondary structure is formed, and finally these secondary structures are collided together and pack tightly together.
ATT Validity Dates. 1  Each ATT is valid for a period of time specified by the BON/RB (the average length of an ATT is 90 days). 2  Once the BON/RB has declared you eligible to test and you receive your ATT, you must test within the validity dates on the ATT.
1 If you have registered with Pearson/Vue, the BON will deem you eligible to take the NCLEXÂ®. 2  Then Pearson/Vue will send you an email verification giving you the authorization to test (ATT) and instructions on scheduling the test. 3  Upon receiving the ATT, you will have 75 days to take the exam.