International Journal of Science
Volume:3 Issue: 2, 2002

Synechococcus sp., the hypersaline Cyanobacterium form, produces extracellular products under high salinity and high intensity of light. The excretion of large amounts of extracellular material caused an additional increase in brine viscosity. An experiment was undertaken using twelve aquaria filled with brine. Measurements were made ofsalinity, viscosity and the amount of organic materials at the high and low light intensity. Relative viscosity and the amount of organic materials were higher in conditions of high salinity and high light intensity, because under these conditions Synechococcus producedmore extracellular products. Therefore these can decrease the quality and quantity of salt produced in solar salt field which is economically important to understand the effect of these extracellular materials in these environments.

Synechococcus sp., the hypersaline Cyanobacterium form, producesextracellular products under high salinity and high intensity of light.The excretion of large amounts of extracellular material caused an additional increase in brine viscosity. An experiment was undertaken using twelve aquaria filled with brine. Measurements were made ofsalinity, viscosity and the amount of organic materials at the high and low light intensity. Relative viscosity and the amount of organic materials were higher in conditions of high salinity and high light intensity, because under these conditions Synechococcus producedmore extracellular products. Therefore these can decrease the quality and quantity of salt produced in solar salt field which is economically important to understand the effect of these extracellular materials in these environments.

In Xenopus embryos, primordial germ cells (PGC), located ventrally in the endoderm, migrate into dorsal endodermal crest where they exit from the endoderm and migrate into genital ridges. The aim of this study was to investigate the nature of PGC movement from ventral to dorsal endoderm. A grafting experiment was planned in which theventral part of one of three endodermal regions - anterior, middle or posterior endoderm labelled with fluorescein dextran amine (FDA) from stage 28 donor embryos was grafted to a similar position in unlabelled host embryos of the same stage. The grafted embryos were allowed to develop until stage 40 and 46 when they were examinedhistologically for presence of FDA positive cells. Regardless of some slight local distortion (especially in the anterior graft), labelled endodermal cells appeared as a cohesive group in the ventral region adherent to the ventral lateral plate mesoderm. In all cases there weresharp, straight, anterior, posterior and dorsal boundaries between the donor labelled cells and host endoderm. These results suggest that, there are no early endodermal cell movements, either as single cells or as a group of cells, involved in morphogenesis of the endoderm, indicating that the PGC could move actively through the endoderm.

Compound [1,4-di (4-methylphenyl) 1,4-Diazabutadiene] Zinc (II) Chloride (1) was obtained by reaction of zinc chloride with N, N’–bis (p-tolyl) ethylendiimine. X-ray crystallography shows the molecule to possess distorted tetrahedral geometry and together with NMR data it suggests to be a unique example of 1 complex. The crystal are monoclinic, spacegroup P21/n, with a =11.4859(1), b=7.5185(5), c=20.2110 (25)Å,? â=106.23(°), V=1675 (3), Dc=1.474 gcm-3 and Z=4.1525 unique observed reflections [Fo>3s (Fo)] have been used to solve and refine the structure down to R = 0.0439

Zarrin granite intrusion is located in the Central Iran, to west of Chapedoni and Posht-e-Badam faults. It consists of three separate outcrops situated at the northern end of a long mountain range, which is comprised of Mesozoic rocks. Lithologically the intrusion contains granites as well as, gneisses (?) and aplites. Petrographic and geochemical evidence strongly suggest that they are cogenetic. High aluminum contents and other characteristics of these rocks, as well as petrographic evidence, indicate that the granite is ²S-type². Moreover, on the basis of geochemical evidence it is suggested that this granite intrusion may be classified as a Post-Orogenic Granite (POG) and Within Plate Granite (WPG). It is also suggested that the intrusion occurred in a relatively quietperiod of the final stage of an orogeny.Lamprophyric dykes cutting Zarrin granite have similar orientations and are parallel to the major faults zone. It appears that their genesis is related to the deep faults, which extend down to the upper mantle. Due to the activities of these faults, the upper mantle melted and consequently caused, the crustal rocks melt at a higher level earlier than expected, and formed granite magma which moved upward along these faults.Gold mineralization occurred in the north eastern part of the intrusion. The mineralization is most frequent, where lamprophyric dykes are greater in number. It appears that hydrothermal fluids, which developed after lamprophyre intrusion, has leached the gold present in dykes and emplaced it in the surrounding rocks.

The present study has focused on Palmatolepis, the biostratigraphically most important conodont genus in the Late Devonian. The studied materials produced from the both stratotype section of the Shishtu Formation, eastern Iran, in the Ozbak-Kuh Mountains and sections at Howz-e-Dorah and from the intervening Niaz area. Thirty species and subspecies of Palmatolepis have been produced: nine from the Ozbak-Kuh Mountains, thirteen from the Howz-e-Dorah section, and twenty two from small sections in the intervening Niaz area. Only Famennian forms of Palmatolepis were encountered in theOzbak-Kuh Mountains, but the other two areas produced both Frasnian and Famennian species of Palmatolepis.

The objective of this study is a modeling in artificial neural networks (ANN) and its generalization to predict reliable porosity values from log data obtained from three wells in Khangiran gas field located in northeast of Iran. We used a back-propagation ANN method (BP-ANN) to predict porosity. The ANN for porosity is a simple three-layer network which uses sonic, density and resistivity logs for input. Porosity predictions were then compared with log porosity which had been derived from density and neutron logs. The results confirmed the capability of using ANN.

The palynological assemblage of the Akli Lignite in Barmer District of Rajasthan contains a rich variety of microforaminiferal linings.Three types of microforaminiferal linings belonging to benthic communities occur. Two main occurring morphotypes: trochospiral and singlechambered types are most common in the assemblage. These linings are less abundant than spores, pollen grains and dinoflagellates.The paleoecological and paleoenvironmental significance of these microforaminiferal linings suggesting their deposition in low salinityconditions and at a relatively shallow depths in an embayment of an epicontinental sea of Paleocene-Eocene age in Barmer Basin.

This paper outlines the organic petrology and geochemistry of potential hydrocarbon source rocks from southern Caspian Basin. Coals and associated beds from Kalaris member of the Shemshak Formation in the southern Caspian Basin were analyzed megascopically,petrologically and geochemically. Maceral analyses reveal a dominance of duroclarite to clarodurite subgroups. The synthesis of source rock characteristics emphatically surmises that in the Kalaris member, organic matter is ubiquitously of terrestrial origin.This member displays poor to good and occasionally very good generative potential. The kerogens are predominantly of type III but sometimes type II-III kerogen has also been identified. Such occurrences envisage predominance of gas prone and occasional oilprone source rocks. Vitrinite reflectance values (mostly 0.6 to 1.2% VRo) indicate that the coals are thermally mature.The depositional environment is interpreted as a peat swamp with a variable density of herbaceous vegetation situated in an upper delta plain.

The palynological assemblage of the Akli Lignite in Barmer District ofRajasthan contains a rich variety of microforaminiferal linings.Three types of microforaminiferal linings belonging to benthic communities occur. Two main occurring morphotypes: trochospiral and singlechambered types are most common in the assemblage. These linings are less abundant than spores, pollen grains and dinoflagellates.The paleoecological and paleoenvironmental significance of these microforaminiferal linings suggesting their deposition in low salinityconditions and at a relatively shallow depths in an embayment of an epicontinental sea of Paleocene-Eocene age in Barmer Basin.