Journal of Sciences, Islamic Republic of Iran
Volume:21 Issue: 1, Winter 2010

Frequency of somaclonal variation in embryogenic calli and plants of Olea europaea L cv.Kroneiki derived from somatic embryogenesis were examined by randomly amplified polymorphic DNA (RAPD) analysis. Radicle and cotyledon (proximal part) of mature zygotic embryo were cultured in OMc medium supplemented with IBA (5 mgL-1) and 2-ip (0.5 mgL-1). Somatic embryogenesis was induced in calli of radicles (55%) and proximal part of cotyledons (8%) on OM medium without any hormones. After culturing the embryogenic calli on OM medium in the presence of BAP (2 mgL-1), regenerated plants were obtained. DNA sample from the leave of the mother plants, seedlings (germinated from zygotic embryo), plantlets (regenerated from somatic embryo), embryogenic calli, non-embryogenic calli and zygotic embryos were subjected to RAPD analysis. 20 arbitrary decamer primers produced polymorphic amplification products. These primers gave a total of 315 reproducible fragments from which 221 (71%) were useful as polymorphic bands with an average of twelve RAPD marks obtained for each primer. A dandogram, based on the unweighted pair group mean average (UPGMA) method of cluster analysis, were constructed using a similarity matrix derived from the RAPD amplification generated by all primers. The estimation of genetic similarity coefficient based on RAPD band sharing data indicated that regenerated plants were less than 75% similar to mother plants.

A thermodynamic study of copper ions by jack bean urease (JBU) was carried out at two temperatures of 27 and 37?C in Tris buffer (30 mM; pH=7.0) using an isothermal titration calorimetry. There is a set of twelve identical and non-interacting binding sites for copper ions. The intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 285 μM and? 15.2 kJ/mol at 27?C and 346 μM and? 14.6 kJ/mol at 37?C, respectively. The molar entropy of binding is? 17.2 J K-1 mol-1at 27?C and +19.1 J K-1 mol-1 at 37?C. Hence, the binding process of copper ion to JBU is not only enthalpy driven but also it is entropy driven, which the role of entropy driven should be more effective by increasing the temperature.

Agrobacterium tumefaciens mediated transformation may offer a better alternative than the biolistic gun for genetic transformation of maize plants. This gene delivery system results in a greater proportion of stable, low-copy number transgenic events than does the biolistic gun, and is highly efficient. In the present work, we studied maize transformation using A. tumefaciens by identifying some important factors that affect transformation efficiency subsequent tissue culture and regeneration of transgenic plants. Although, all genotypes produced embryogenic calli, S61 and A188 lines had higher percent (75% and 71% respectively) of regeneration than the other ones. Transformant events obtained when immature embryos (1.5-2 mm) were inoculated with A. tumefaciens LBA4404 harboring a standard binary vector pCAMBIA3301 after 72 h pretreatment culture of the embryos. Polymerase chain reaction (PCR) confirmed the presence of the gus and bar genes in the genome of regenerated plants. The transformation frequency (the number of independent, PCR-positive transgenic plants per 100 embryos infected) was 6.45% for S61 genotype. Therefore, our results identified suitable genotype (S61), embryo size (1.5-2 mm), A. tumefaciens strain (LBA4404), pretreatment culture, and appropriate antibiotic (Timentin) for Agrobacterium mediated transformation of Z. mays.

The Ultraviolet-visible (UV) spectra of toluene، ortho-bromo and para-bromo toluene in different solvents have been studied. The electric dipole moments and polarizabilities in the molecular excited electronic states were determined. It was found that the electric dipole moments for the excited states (μ*) and the ground states (μ) of these compounds are equal، and the change in dipole moment is zero. This implies، in part، little or no change in potential energy surfaces of the ground and the excited states. The negative values obtained for the change in polarizabilities (??) for the Lb state in various transitions indicate contraction in the excited state relative to the ground state، because the polarizability is proportional to the molecular volume.

Cambrian sedimentary facies are exposed throughout north part of Kerman region. Trilobites’ faunas are the most common invertebrate fossils within the Cambrian strata. The section is made of 217 m of sandstone, shale, limestone and dolomite. In this study, 153 trilobite samples including seven species and genera were identified from the Dahu section 12 Km. east of Zarand. This trilobite’s assemblage including Redlichia sp. Redlichia neotlingi, Kermanella kuhbananensis, Kermanella lata minuta, Kermanella lata lata, Paragraulos, Kermanella sp. identified of this strata. Based on trilobite fauna the section, divided in to 2 biozone including; Redlichia neotlingi and Kermanella kuhbananensis biozones. The Redlichia neotlingi biozone indicated late Early Cambrian age while Kermanella kuhbananensis biozone suggests Middle – early Late Cambrian time interval.

A new species of cassiduloid echinoids, Pygaulus baghinensis is reported for the first time from Aptian sediments of Baghin area, west of Kerman, Iran. The diagnostic features of the species are centrally positioned of the apical disc and approximately low profile of the test. Variation in gonopore size in different individuals allows to conclude that P. baghinensis is sexually dimorphic. Specimens with large gonopores can be considered to be females, while other specimens whose gonopores diameter is small, can be considered to be males. One of the specimens has one large and three small gonopores on its apical disc. This difference may be due to hermaphroditic feature of the specimen.

The study area is situated in the Middle part of the Tabas Block. It contains outcrops of rocks that formed along longitudinal faults in Early Cimmerian orogenic phase. The basin subsided along these faults from the Late Triassic to Early Cretaceous, which include two sedimentary cycles. A sedimentary cycle, related to Upper Triassic to Bajocian is known as Shemshak group. Another sedimentary cycle, related to Bathonian to Upper Jurassic, is known as MAGU group. The Cretaceous rock units include red coarse-grained sandstone, at the base changing upward into red gypsifferous marl, rudist limestone and conglomerate, which deposited in a shallow marine environment. Subsidence analysis is applied to geologically disconnected objects in a manner that departs from its traditional use in basin analysis. However, as it introduces quantified data on the behavior of the crust in response to tectonics, it was shown to be an efficient tool in sorting out the major events amongst various local evidences for crustal instability. Based on the subsidence curves plotted for tectonic domain of the Tabas Block, the major obtained results include: - subsidence curves shown a relatively high subsidence rate in the Upper Triassic to the Middle Cretaceous, that coupled with rifting environment in this time; - this rifting was rapidly ceased in the Late Cretaceous to form Aulacogen(Failed Rift) and caused to generate oceanic crust and overriding of Sabzevar-Nain-Baft Ophiolites in this time; - subsidence rate in this part of Tabas Block was increasing towards the west and the north.

A 1993 result of J. Llibre, and M. Misiurewicz, (Theorem A [5]), states that if a continuous map f of a graph into itself has an s-horseshoe, then the topological entropy of f is greater than or equal to logs, that is h(f)? logs. Also a 1980 result of L.S. Block, J. Guckenheimer, M. Misiurewicz and L.S. Young (Lemma 1.5 [3]) states that if G is an A-graph of f then h(G)? h(f). In this paper we generalize Theorem A and Lemma 1.5 for continuous functions on forests. Let F be a forest and f: F?F be a continuous function. By using the adjacency matrix of a graph, we give a lower bound for the topological entropy of f.

Field Ion Microscopy (FIM) and Scanning Tunneling Microscopy (STM) have found a wide application in nanotechnology. These microscopes use a metallic nanotip for image acquisition. Resolution of FIM and STM images depends largely on the radius of nanotip apex; the smaller the radius the higher the resolution. In this research, for tungsten nanotip fabrication, electrochemical etching of tungsten wire was used in which a 0.3 mm diameter tungsten wire, a graphite tube, and KOH solution in deionized water was applied as anode, cathode, and electrolyte respectively. The most important parameters that govern the nanotip fabrication process are the time delay in turning off the voltage at the end of tip fabrication process, electrolyte concentration, immersion length of the tungsten wire, inner diameter of the cathode tube, and the process voltage. In this research, the effects of these parameters on the radius of nanotip apex were investigated by using Taguchi method. It was found that the process parameters can be ranked in terms of their impact on the radius of nanotip apex as process voltage, electrolyte concentration, wire immersion length, and inner diameter of the cathode tube, respectively. By setting the process parameters on the optimum level, the radius of the nanotip apex was decreased by 5 times in comparison to the mean value of the experimental results. The radius of the nanotip apex was improved down to about 10 nm under the optimum conditions.