This model is based on the in vitro skin model Skin2 [5] which had been discontinued in October 1996. It was further proposed by industry to apply the model in a tiered strategy to identify those chemicals that are predicted to be likely to be phototoxic in the 3T3-NRU-PT but are negative in vivo [6].
401(k) contribution rules. On a pretax basis, employees can't contribute above certain limits. In 2015, for instance, the limit is $18,000; those 50 and older can make additional catch-up contributions of $6,000.This money is not counted toward income, and all gains are tax-deferred. The limits are the same for Roth 401(k)s, though the contributions do count toward income and all gains are tax-free.But employees can sock away a lot more retirement cash if their company plan offers an after-tax option in a traditional 401(k).he limits are the same for Roth 401(k)s, though the contributions do count toward income and all gains are tax-free. But employees can sock away a lot more retirement cash if their company plan offers an after-tax option in a traditional 401(k).
The maximum contributions for either the Roth 401k or the traditional 401k are the same -- $16,500 in 2010. If you contribute to both a Roth 401k and traditional 401k, the sum of your contributions can't exceed that limit.If an employer offers a Roth 401k, most likely it would provide the same matching contributions as for a traditional 401k.There are really two main reasons to consider investing your current and future contributions in a Roth 401k.f you contribute to the traditional 401k: Since you aren't paying income taxes on the $10,000, you can invest the full amount. At 5 percent annual investment returns, your $10,000 will grow to $16,289 (if you're mathematically inclined, that's $10,000 times 1.05**10).