abd al-rah?m?n al-s??f? is a well-known astronomer who has some works in astronomy, mathematics and alchemy. the importance of his s?uwar al-kaw?kib (book about the constellations) caused that researchers don’t practice his other works. four treatises on astrolabe are ascribed to al-s??f?, any one of them is in persian. attribution of the three arabic treatises among these four to him is certai...

The Abdominal-B (Abd-B) gene is one of three genes in the bithorax complex, a cluster of homeotic genes in Drosophila. During embryogenesis Abd-B is expressed in a complex pattern, producing four different transcript classes, each of which exhibits a unique spatial pattern of expression. Proper regulation of the class A transcripts is required for appropriate development of the fifth through ei...

The three homeotic genes of the bithorax complex (BX-C), Ubx, abd-A and Abd-B control the identity of the posterior thorax and all abdominal segments. Large segment-specific cis-regulatory regions control the expression of Ubx, abd-A or Abd-B in each of the segments. These segment-specific cis-regulatory regions span the whole 300 kb of the BX-C and are arranged on the chromosome in the same or...