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.
An applicant must have worked within the 4 years preceding the filing of the examination application AND be within 4 years of his/her date of eligibility in order to sit for the NCLEX. For purposes of the NCLEX, the date of eligibility is defined as the issuance date for the initial Authorization to Test (ATT).