The Ultrabithorax (Ubx) gene of Drosophila specifies the third thoracic and first abdominal segments. Ubx expression is controlled by several mechanisms, including negative regulation by its own product. We show here that if Ubx expression levels are inappropriately elevated, overriding the auto-regulatory control, a permanent repression of Ubx is established. This continuous repression becomes...

canopy gaps are one of the most important structural features of forest ecosystems, and studying of them can have useful results and implications for forest management. the aim of this study is investigation of characteristics and regeneration within canopy gaps in an intact beech stand in the shastkalateh experimental forest of hyrcanian region, north of iran. all canopy gaps and related fores...

Traumatic injuries to permanent teeth are common, and dramatic episodes can occur during childhood. The aim of this paper is to present a report of severe trauma to the orofacial complex of an 8-year old girl that resulted in multiple injuries. The use of the term "dental polytrauma" (concomitant different dental traumatic injuries) is advocated in this case presentation.

The conventional method to evaluate earthquake induced permanent deformations of slopes is the one proposed by Newmark. In this paper, permanent displacement of slopes is studied using a combination of distinct element and finite difference methods and the results of these numerical evaluations are compared with those of the Newmark's approach. Several parameters involved, including peak ground...

nowadays, the status of regulations of securities exchange section in accordance with its huge transactions and its increasing role in countries’ economies has gained particular significance. on the other hand, taking into account that iran is presently an observer member of wto and the necessity of its becoming a permanent one in the near future, it is essential to revise and amend its rules a...