in order to adapt lasota strain of newcastle disease virus (ndv) on chick embryo fibroblast (cef) cells, 0.1 ml from lasota vaccine produced in razi vaccine and serum research institute inoculated to the cef cells and was passaged five times in the cef grown in eagle’s minimum essential medium (mem). first to third passages were blind but in fourth passage cytopathic effect of virus was observe...

Geoffrey A. Rubin, MD; Amar D. Desai, BS; Zilan Chai, MS; Aijin Wang, Qixuan Chen, PhD; Amy S. Cameron Kemal, Haajra Baksh, MBBS; Angelo Biviano, Jose M. Dizon, Hirad Yarmohammadi, MD, MPH; Frederick Ehlert, Deepak Saluja, David John P. Morrow, Uma Mahesh R. Avula, Jeremy Berman, Alexander Kushnir, Mark Abrams, Jessica Hennessey, Pierre Elias, Timothy J. Poterucha, Nir Uriel, Christine Kubin, P...

We obtain linearized oscillation theorems for the equation with distributed delays ẋ(t)+ m ∑ k=1 rk(t) ∫ t −∞ fk(x(s)) ds Rk(t, s) = 0. (1) The results are applied to logistic, Lasota–Wazewska and Nicholson’s blowflies equations with a distributed delay. In addition, the “Mean Value Theorem” is proved which claims that a solution of (1) also satisfies the linear equation with a variable concent...