Since the seminal note published by M. Somos in 1989, a great deal of attention specialists number theory and adjacent areas are attracted nonlinear sequences that satisfy quadratic recurrence relation. At same time, special is paid to construction integer their Laurent property with respect initial values coefficients recurrence. In fundamental works Robinson, Fomin Zelevinsky Somos-k sequence...

we introduce a matricial toeplitz transform and prove that the toeplitz transform of a second order recurrence sequence is another second order recurrence sequence. we investigate the injectivity of this transform and show how this distinguishes the fibonacci sequence among other recurrence sequences. we then obtain new fibonacci identities as an application of our transform.

The ITS region including the 5.8S gene of rDNA of three desert truffle species were amplified using ITS4 and ITS1 primers. The ITS sequences were compared to those of other related authentic sequences obtained from GenBank. Among 12 specimens studied, seven isolates corresponded to Terfezia claveryi reported by other authors. Iranian T. claveryi specimens had an average similarity of 99.4% (ran...

Glutathione transferases are multifunctional proteins involved in several diverse intracellular events such as primary and secondary metabolisms, signaling and stress metabolism. These enzymes have been subdivided into eight classes in plants. The Phi class, being plant specific, is the most represented. In the present study, based on the sequences available at GenBank, different primers were d...