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Some of the students felt initially that they would have a difficult time due to their lack of computer knowledge , but perhaps due to the unobtrusive nature of the iLab on the classroom dynamics they became comfortable and some noted learning computer skills as an outcome . All women had a known date of when they became HIV-positive ( seroconversion ) . Students may use the NIU catalog which was in effect when they became freshmen at their original school or any later NIU catalog , providing they were enrolled during catalog year of their choice , but they can not choose an NIU catalog which was in effect more than three years before their admission to NIU . Biodefense scientists say they became aware that such an innovation could be applied to germ-warfare powders with deadly effect , especially deadly because charged particles are more prone to lodge in the lung . As time went on , however , they became thicker and of poorer quality .