I discuss several issues concerning the use of string models as unified theories of all interactions. After a short review of gauge coupling unification in the string context, I discuss possible motivations for the construction of SU (5) and SO(10) String-GUTs. I describe the construction of such String-GUTs using different orbifold techniques and emphasize those properties which could be gener...

Toxicokinetic-toxicodynamic models (TKTD models) simulate the time-course of processes leading to toxic effects on organisms. Even for an apparently simple endpoint as survival, a large number of very different TKTD approaches exist. These differ in their underlying hypotheses and assumptions, although often the assumptions are not explicitly stated. Thus, our first objective was to illuminate ...

Gauge-Yukawa Unification (GYU) is a renormalization group invariant functional relation among gauge and Yukawa couplings which holds beyond the unification point in Grand Unified Theories (GUTs). Here, GYU is obtained by requiring finiteness and reduction of couplings to all orders in perturbation theory. We examine the consequences of GYU in various supersymmetric GUTs and in particular the pr...

compounds obtained from marine organisms have been isolated due to their anti-bacterial and antifungal activities. in this study, the antifungal activity of aqueous-methanol, methanol, chloroform and n-hexane extracts of body wall, guts and white strings of sea cucumber (holothuria leucospilota) collected from chabahar bay in 100 to 2000 μg/ml concentrations is discussed. the antifungal test on...