Multiple shoot regeneration of cotton (Gossypium hirsutum L.) via shoot apex culture system

Induction of multiple shoots of cotton (Gossypium hirsutum L.) plant in two commercial varieties (Sahel and Varamin) using shoot apex was done. Explants were isolated from 3 - 4 days old seedlings, then they were cultured on a shoot induction media, modified MS nutrient agar with combinations: 1- Kinetin (0.0, 0.5, 1.0, 1.5 mg l-1) and 6-benzyaminopurine (BAP) (0.0, 0.1, 0.5, 1.0, 1.5 mg l-1), 2- α- naphthaleneacetic acid (NAA) (0.0, 0.1, 1.0 mg l-1) and BAP (0.0, 0.1, 0.5, 1.0, 1.5 mg l-1). After 1.5 - 2 months, multiple shoot induction medium with 0.1 mg l-1 NAA and 0.1 mg l-1 BAP resulted in the highest number of regenerated shoots per explant (3 - 4 shoots per explant) for the two cultivars. Elongation of multiple shoots was obtained on modified MS nutrient agar without any phytohormone. In vitro shoots were rooted on half-strength agar-solidified MS basal medium supplied with 0.1 mg l-1 Iidole-3-butyric acid (IBA) and MS vitamins.Key words: Cotton, Shoot apex, multiple shoot

Measurement of B(D+ -> mu+ nu) and the pseudoscalar decay constant f_D at CLEO

The analysis of 60 1/pb data collected on the psi(3770) resonance with the CLEO-c detector has produced the first statistically significant signal for D+ -> mu+ nu decay and led to the measurement of the decay branching fraction B(D+ -> mu+ nu) = (3.5 +- 1.4 +- 0.6) x 10-4 and the pseudoscalar decay constant f_D = (202 +- 41 +- 17) MeV.Comment: Talk presented at the 1st Meeting of the APS Topical Group on Hadronic Physics (Fermilab, Oct. 24-26, 2004). LaTeX 4 pages, 2 figure

Anomalous rotational-alignment in N=Z nuclei and residual neutron-proton interaction

Recent experiments have demonstrated that the rotational-alignment for the $N=Z$ nuclei in the mass-80 region is considerably delayed as compared to the neighboring $N \ne Z$ nuclei. We investigate whether this observation can be understood by a known component of nuclear residual interactions. It is shown that the quadrupole-pairing interaction, which explains many of the delays known in rare-earth nuclei, does not produce the substantial delay observed for these $N=Z$ nuclei. However, the residual neutron-proton interaction which is conjectured to be relevant for $N=Z$ nuclei is shown to be quite important in explaining the new experimental data.Comment: 4 pages, 3 figures, final version accepted by Phys. Rev. C as a Rapid Communicatio

Study of Giant Pairing Vibrations with neutron-rich nuclei

We investigate the possible signature of the presence of giant pairing states at excitation energy of about 10 MeV via two-particle transfer reactions induced by neutron-rich weakly-bound projectiles. Performing particle-particle RPA calculations on $^{208}$Pb and BCS+RPA calculations on $^{116}$Sn, we obtain the pairing strength distribution for two particles addition and removal modes. Estimates of two-particle transfer cross sections can be obtained in the framework of the 'macroscopic model'. The weak-binding nature of the projectile kinematically favours transitions to high-lying states. In the case of (~^6He, \~^4He) reaction we predict a population of the Giant Pairing Vibration with cross sections of the order of a millibarn, dominating over the mismatched transition to the ground state.Comment: Talk presented in occasion of the VII School-Semina r on Heavy Ion Physics hosted by the Flerov Laboratory (FLNR/JINR) Dubna, Russia from May 27 to June 2, 200