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The structural setting and the stratigraphy of the Early to Middle Triassic sedimentary succession exposed in the western part of the Aghdarband window (Kopeh Dag, NE Iran) is described. Six stratigraphic sections in the Sefid-Kuh Limestone, Nazar-Kardeh Formation and Sina Formation have been studied in the tectonic units 1a and 2. The lithostratigraphy is revised, with bio-chronostratigraphic constrain provided by conodonts and ammonoids. The new Olenekian ammonoid genus Megatirolitesis erected. It is based on species thus far known only in Mangyshlak (West Kazakhstan) but it is occurs also in the Sefid-Kuh Limestone.The evolution of the Lower Triassic carbonate ramp of the Sefid-Kuh Limestone, persisted in the Middle Anisian, with a three-stage development (Sefid-Kuh 1, 2 and 3 members) separated by drowning and onset of siliciclastics. The last stage is in part coeval with the Middle Anisian basinal Nazarkardeh Formation.The unconformity-bounded, three-stage development of the carbonate ramp documents that in the Aghdarband Basin the tectonic control over sedimentation started already in the Olenekian, since the onset of the marine transgression. The transgression of the Ladinian Sina Formation sealed a complex morphology resulting from the uplift and erosion of the Middle Anisian units. A new paleogeographic position along the southern Laurasia margin is propsed for the Triassic Aghdarband Basin. Based on the paleobiogeographic affinity of the Olenekian ammonoid occurences, we suggest that the Aghdarband Basin was located in a back-arc position in close connection with Mangyshlak (West Kazakhstan) and Tuarkyr (Turkmenistan), passing northwestward to a large epicontinental basin extending to the Donbass area. At least during the Olenekian the Aghdarband Basin had no direct connection with the Nakhlak Basin, which was proably located in a different intra-arc or more probably fore-arc region with respect to the Palaeotethys subduction-related Triassic arc., Rivista Italiana di Paleontologia e Stratigrafia (Research In Paleontology and Stratigraphy), V. 125 N. 1 (2019): In memory of Maurizio Gaetani

In the present study and research work, land suitability evaluation (qualitative and economic classification) has been determined for tea in an area including 5000 ha in sloping lands of Guilan province in Iran. In the study area, eight soil series and three orders (Inceptisols, Entisols and Alfisols) were identified. The simple limitation method, the limitation method regarding number and intensity and the parametric methods including the Square root and the Storie methods were used for qualitative land suitability evaluation. Results of first and second methods showed similar marginally suitability classes (S3). According to these methods, the most important limiting factors were climate, topography and physical soil characteristics. Moreover, results of Storie method showed unsuitable condition for tea cultivation (N2), except one land unit, which had non-suitable but correctable conditions (N1). In addition, results of Square root method showed unsuitable condition for one and non-suitable conditions but correctable for six land units and just one land unit had marginally suitable land classes. Economic land suitability evaluation showed that four land units had marginally suitability, three land units had moderately suitability (S2), and only one of them had the highest class (S1) and the best gross benefits. Sloping area in Guilan used to be covered by forest, but regarding to the highly destruction of plant cover and deforestation in order to tea cultivation, an intensive erosion in the area is predict to happen in future.

Mutations in the human hepatitis B virus (HBV) genome contribute to its escape from host immune surveillance and result in persistent infections. The aim of this study was to characterize the molecular variations of the surface gene and protein in chronically-infected patients from the southern part of Iran. The surface genes from 12 HBV chronic carriers were amplified, sequenced and subsequently aligned using international and national Iranian database. All strains belonged to genotype D, subgenotype D1 and subtype ayw2. Of all 30 mutations occurred at 22 nucleotide positions, 18 (60%) were missense (amino acid altering) and 12 (40%) were silent (no amino acid changing). The mean mutation frequency (missense to silent nucleotide ratio), was 1.5, indicating application of a high positive selection pressure on the surface proteins. At the amino acid level, of 17 substitutions, 15 (88%) occurred in different immune epitopes within surface protein, of which 7 (46.6%) in B cell epitopes in 5 residues; 7 (46.6%) in T helper epitopes in 6 positions; 1 (7%) in inside CTL epitopes in 1 residue. We therefore conclude that the distribution of 93.2% of amino acid mutations inside B and T helper immune epitopes as well as the ratio between silent and missense nucleotide mutations showed a positive, focused immune selection pressure on the surface protein, which led to the evolution and emergence of escape mutants in these patients. Copyright© Autumn 2013, Iran J Allergy Asthma Immunol. All rights reserved.

Salt stress is an abiotic stress that can effect the plant growth and physiological and biochemical activities such as photosynthesis activity and chlorophyll content. This study was conducted in order to evaluate effects of silicon (Si) on some physiological properties of maize (Zea mays) under salt stress. Selected seedlings were transplanted to plastic pots contained sterilized and non-saline sandy soil that continuously aerated full-strength Hoagland nutrient solution. The Si was added at four levels (0, 2, 4 and 6 mmol.L-1 ) from source potassium silicate (K2SiO3) and salt stress was applied at four levels (0, 3, 6 and 9 dS.m-1 ) from source sodium chloride (NaCl). A factorial experiment in a completely randomized design (CRD) with sixteen treatments and three replications was applied. Results indicated that salinity significantly decreased the fresh and dry weights of shoot and root, stem length, leaf area, chlorophyll content and relative water content (RWC) of maize plant and application of Si significantly increased them. Remarkable decrease observed in treatments with EC > 3 dS.m-1 , while, gradual increasing of Si increased physiological properties of maize. Therefore, proper Si nutrition can increase salt resistance in maize plant.