Two new species of an Arbacioid echinoid, genus Goniopygus, are reported for the first time from Aptian sediments of Baghin area, Kerman, Iran. The main features of the species lie in apical disc and peristome diameter. In Goniopygus triangularis sp. nov., the periperoct is triangular in shape with three small, sunken tubercles, located alternatively adjacent to the periperoct, while Goniopygus...

We describe a generalization of the asymptotic calculation of the tidal torques experienced by a massive star as a result of a companion in circular orbit originally considered by Zahn (1975,1977) to the case of a rotating star when the forcing frequency is small and in the inertial regime, that is it is less than twice the rotation frequency in magnitude. The results confirm the presence of a ...

The hepatitis delta virus genome is a small circular RNA, similar to viroids. Although HDV contains a gene, the protein produced (HDAg) is encoded by less than half the genome and possesses no RNA polymerase activity. Because of this limited coding capacity, HDV relies heavily on host functions and on structural features of the viral RNA-very much like viroids. The virus' use of host RNA editin...

Background: Accurate small radiation field dosimetry is essential in modern radiotherapy techniques such as stereotactic radiosurgery (SRS) and intensity modulated radiotherapy (IMRT). Precise measurement of dosimetric parameters such as beam profile, percentage depth doses and output factor of these beams are complicated due to the electron disequilibrium and the steep dose gradients. In the p...

During year 2008–11, some infected leaves of eucalypt trees (Eucalyptus camaldulensis Dehnh.) having blight and spot symptoms were collected in Golestan province (N Iran). The necrotic spots were appeared on both surfaces of the leaves and were circular to irregular, single to confluent, medium brown to light brown with red brown margin (Fig. 1A & B). In some cases, young leaves have been sever...

The present work mainly studies the free vibration of circular magneto-electro-elastic (MEE) nano-plates based on the Kirchhoff’s plate theory within the framework of nonlocal elasticity theory to account for the small scale effect. The MEE nano-plate studied here is considered to be fully clamped and subjected to the external magnetic and electric potentials. Using nonlocal constitutive relati...