-It is widely held that sexual reproduction enhances the potential for evolution by expanding the range of variation on which selection can act. However, when nonadditive gene action contributes to the expression of traits under selection, sexual reproduction can also result in slippage of the mean genotypic value in the direction contrary to selection. We show how the magnitude of genetic slip...

It was thought previously that cardiac muscle gap junctions provide low-resistance connections between cells and permit the local-circuit current to flow. Some evidences show that myocardial cells may not require low-resistance connections for successful propagation of the action potential (AP). It seems that some other types of mechanisms must be involved in AP propagation. In this article, we...

the present study was undertaken to investigate the role of banana extract (be) on synchronous plantlet formation from seeds of dendrobium lituiflorum lindl. the seedlings formed on modified knudson c (kc) medium supplemented with 20% (v/v) be had significantly high fresh and dry weights. morphologically uniform plantlets with elongated leaves and well developed roots were formed on kc medium w...

Background: Lemon verbena (Lippia citriodora H.B.K.) is an aromatic and medicinal plant of family Verbenaceae, which cultivated in North region of Iran. Objective: Evaluation of phytochemical characters in Lippia citriodora H.B.K. plantlets affected by propagation methods (micro-propagation and stem cutting) cultivated in different soil type (peat moss and mixture soil). Methods: This study w...

Measurements of basin-scale acoustic transmissions made during the last four years by the Acoustic Thermometry of Ocean Climate (ATOC) program have allowed for the study of acoustic fluctuations of low-frequency pulse propagation at ranges of 1000 to 5000 km. Analysis of data from the ATOC Acoustic Engineering Test conducted in November 1994 has revealed new and unexpected results for the physi...