Journal of Sciences, Islamic Republic of Iran
Volume:21 Issue: 2, Spring 2010

The incidence of pre-lingual hearing loss (HL) is about 1 in 1000 neonates. More than 60% of cases are inherited. Non-syndromic HL (NSHL) is extremely heterogeneous: more than 130 loci have been identified so far. The most common form of NSHL is the autosomal recessive form (ARNSHL). In this study, a cohort of 36 big ARNSHL pedigrees with 4 or more patients from 7 provinces of Iran was investigated. All of the families were examined for the presence of GJB2 and GJB6 (del D13S1830 and del D13S1854) mutations using direct sequencing and multiplex PCR methods, respectively. The negative pedigrees for the above-named genes were then tested for the linkage to 5 known loci including DFNB3 (MYO7A), DFNB4 (SLC26A4), DFNB7/11 (TMC1), DFNB21 (TECTA) and DFNB59 (PJVK) by genotyping the corresponding STR markers using PCR and PAGE. Six families had GJB2 mutations. No GJB6 mutation was found. Totally, 3 families showed linkage to DFNB4, 1 family to DFNB7/11 and 1 family to DFNB21. No family was linked to DFNB59. GJB2 included 16.6% of the causes of ARNSHL in our study. In the remaining negative families, DFNB4 accounted for 10% of the causes. Other loci including DFNB7/11 and DFNB21 were each responsible for 3.3% of the etiology. Thus, DFNB1(GJB2) and DFNB4 are the main causes of ARNSHL in our study and GJB6 mutations (del D13S1830, del D13S1854), DFNB3 and DFNB59 were absent. Totally, 30.5% of the ARNSHL etiology was found in this study.

VO2+ and its complexes with ethylenediamine (en), acetylacetonate (acac), 2, 2’-bipyridine(bpy) ligands, immobilized within nanoreactors of Al-MCM-41 designated as VO2+/Al-MCM-41 or VOL2/Al-MCM-41, were prepared and characterized by X-ray powder diffraction (XRD), FT-IR, BET nitrogen adsorption-desorption and chemical analysis techniques. VO2+/Al-MCM-41 and VOL2/Al-MCM-41 were found to catalyze the epoxidation of trans-stilbene, norbornene, and geraniol with aqueous hydrogen peroxide (H2O2) in refluxing acetonitrile with 30-80% conversion and up to 98% selectivity toward the formation of the corresponding epoxides. On the other hand, under similar conditions, these alkenes underwent epoxidation with 50 to 99% conversion and up to 100 % selectivitiy in the presence of VO(acac)2/Al-MCM-41with tert-butylhydroperoxide (TBHP) as oxidant.

Substituted Schiff bases (hydrazones) 5a-j have been prepared from the starting material 2-chloro pyridine-3-carboxylic acid 1 by a sequence of reactions like reaction with 2-amino-6-nitro benzothiazole (Ullamann condensation), thionyl chloride, hydrazine hydrate and different aromatic aldehydes. On cyclocondensation of 5a-j with thioglycolic acid in dry 1,4-dioxane furnished desired compounds 4-thiazolidinones 6a-j. The structures of all the synthesized compounds have been assigned on the basis of IR, 1H NMR, 13C NMR spectral data and elemental analyses. All the newly synthesized compounds were tested for their in vitro antimicrobial activity against several microbes. Some of the compounds showed significant antibacterial as well as antifungal activity.

Members of the family Laccophyllidae are small, solitary rugose corals with stratigraphic ranges from Silurian to Permian. Among the laccophyllids, axial ends of major septa are united in an aulos and dissepiments may be absent or present. Minor septa can be contratingent and sometimes are small or in some genera are absent. Septa and aulos may be thick or thin. In this study, Famennian rugose corals of the Khoshyeilagh Formation in the north of Meyghan village (35 km NE Shahrood, Eastern Alborz) have been investigated for the first time. All the studied corals share their common characteristics with family Laccophyllidae. Convincingly, based on comparison of the presence of some key features among the collected samples with characteristics of existed subfamilies of laccophyllids, establishing a new subfamily can be essential. The Alborziphyllinae (new subfamily) encompasses a Late Devonian laccophyllid lineage. The new subfamily described here includes a new genus, Alborziphyllum and two new species, Alborziphyllum ferdowsiense and Alborziphyllum lonsdaleiforme.

Mount Bidkhan stratovolcano is located in the central Iranian volcanic belt. It is composed of several types of pyroclastic deposits, lava flows and intrusive bodies. Textural and chemical characteristics of plagioclase phenocrysts from the eruptive products volcanic edifice, record complex magma mixing events over the lifetime of the volcano. Evidences such as xenocrystic high Al+Ti clinopyroxene and calcic cored plagioclase phenocrysts (An 75) in andesites, sieve-textured, dusty, and oscillatory zoned plagioclase together with clear normally zoned ones in the same sample and the wide compositional range of the plagioclase rims, show that magma mixing events have been playing an important role in the origin of Bidkhan eruptive products. Based on whole evidences, we propose a model for the evolution of Bidkhan parent magmas. According to the model, it is likely that mantle derived basic melts are injected into the lower crust, cause partial melting and produced acidic primitive melts. These two melts are then, mixed and resulted hybrid magmas, ascend toward the shallower reservoirs. Repeated magma injection gives rise to a second mixing event. Thus eruptive products at Mount Bidkhan have been originated from the mixing of intermediate hybrid magmas within shallow magma chambers. Sometimes, two melts have been erupted simultaneously as mingled melts. This model can be tested for other volcanic province of central Iranian volcanic belt.

Deformation pattern of the northeastern part of the Iranian-Arabian collision zone (i.e., mainly Sanandaj-Sirjan Belt or Zone) is the main concern of this paper. Here, we investigate the stress distribution and displacement pattern of Eghlid-Deh Bid area as affected by the position of Zagros suture using a three dimensional mechanical model. The modeled area is located between the Zagros Thrust Fault on the west and Deh Shir-Baft Fault in the east as its edges. The model is composed of 3 layers: the upper two layers represent the upper brittle and lower ductile crusts of the collided continent and the lowest layer represents lithospheric mantle. The bounding major faults are treated as vertical sides of the model. We introduced a discontinuity parallel with the Zagros Thrust Line at two different locations at the western margin and in the middle of the model to simulate Zagros suture to investigate its debated position and role on the deformation history in the area. Our results showed that stress and displacement patterns are fairly affected and disturbed by its position in the two cases. It could also have partitioned deformation across the study area particularly due to its marginal position. The modeled pattern of stress and displacement fields are both totally comparable with plate boundary shear zones demonstrating dextral transpression and more consistent with a suture zone located at or very close to the Zagros Thrust Line place. Such a conclusion is in agreement with recent field surveys including micro and macro-tectonic data.

Ad hoc networks are multi-hop wireless networks without a pre-installed infrastructure. Such networks are widely used in military applications and in emergency situations as they permit the establishment of a communication network at very short notice with a very low cost. Video is very sensitive for packet loss and wireless ad-hoc networks are error prone due to node mobility and weak links. High quality video transport under ad hoc network is a challenging task due to low bandwidth, high loss rate, unpredictable node mobility, and severe interference characteristics of such kind of network. End to end packet delivery often exhibits low performance due to one hop-by-hop routing failure and misinterpretation to such failures. Multi path routing has been used to increase the robustness for video over ad-hoc networks. The key idea of proposed schema is based on sending video packets over two disjoint paths beside using buffering technique in special nodes of network. In each of every path there is only one node selected as cache node. The main task of these nodes is to realizing different packet types, buffering some of important video packets, reducing forward traffic rate while detecting loss in network and local error management to overcome high loss rate of video packets. Selecting these nodes in network can be as an agreement between video sender and receiver or based on network topological status. The goal of this work is to reduce network end to end delay and increased quality of service over application layer.

The pupose of this paper is modeling of Partial Digest Problem (PDP) as a mathematical programming problem. In this paper we present a new viewpoint of PDP. We formulate the PDP as a continuous optimization problem and develope a method to solve this problem. Finally we constract a linear programming model for the problem with an additional constraint. This later model can be solved by the simplex method in which a restricted basis-entry-rule is defined.