Brand-name prescription drug manufacturers use various strategies to extend their market exclusivity periods by delaying generic or biosimilar competition. Recent Congressional legislation has targeted four such tactics. We analyze these proposals and assess their likely effect on competition in the U.S. drug market.

This article proposes an observer design for two important variables in the studies of single-leg hopping robot (SLHR), the apex height, and the vertical velocity of SLHR during its stance phase. At first, the Euler–Lagrange (EL) dynamics of SLHR are obtained and apex height is identified in the state-space representation of the EL dynamics. Apex height is the state variable that represents the robot body’s height at the top point, which keeps on changing as the robot functions. Vertical velocity is the velocity of the robot in the vertical direction. An observer design is presented in this article which will estimate these variables when required. The quality of the estimation is validated by the simulation results where the estimation error is zero which means the model output is correct and observer performance is good.

In this article, a novel mechanism for planar one-legged hopping robots is proposed. The robot consists of a flat foot which is pinned to the leg and a reciprocating mass which is connected to the leg via a prismatic joint. The proposed mechanism performs the hopping by transferring linear momentum between the reciprocating mass and its main body. The nonlinear equations of the motion of the robot are derived using the Euler–Lagrange equations. To accomplish a stable jump, appropriate trajectories have been planned. To guarantee a stable response for this nonlinear system, a sliding-mode controller is implemented. The performance of the hopping robot is investigated through numerical simulations. The results confirm the stability of the hopping robot through the jump cycle on a flat surface and in climbing up and down ramp and stairs.

We have studied the variable range hopping (VRH) mechanism for polarons in DNA structures using an exponential density of states. Due to the electron-phonon interaction localized polarons are formed in the DNA helix. The unwinding of DNA increases molecular orbital overlap between bases while decreasing the base-to-base distance. These types of vibrations create phonons. We consider that DNA has a band tail which has an exponential density of states and we have calculated the temperature- and the electric field dependence of the conductivity. We compare our model with the experiments of the electrical conductivity of samples of double-stranded H5N1 genes of avian Influenza virus DNA. Our theory is able to explain their data.