Journal of the Persian Gulf (Marine Science)
Volume:6 Issue: 22, Winter 2015

Distribution and growth of plant species is affected by many factors including abiotic (topography, altitude and soil) and biotic (root symbiosis) factors. In light of global warming, recent findings advocate microhabitats and micro-conditions of the root zone and canopy ambiance as determining factors in sustaining of plant populations. Although, occurrence of ectomycorrhizal (ECM) and non-mycorrhizal plants in forests south of the Caspian Sea have been studied extensively, stress response of tree species in relation to altitude and soil (texture and contents of heavy metals) has not been investigated much. This research investigated the antioxidant stress response of three dominant tree species (Alnus subcordata C.A.Mey, Acer velutinum Boiss. and Carpinus betulus L.) of three selected hyrcanian forests south of the Caspian Sea (Javaherdeh, Dalkhani and onekabon) at 4 altitudes (sea level, 500, 1000 and 1500 m above sea level). Results showed some onenzymatic antioxidants, such as flavonoids and anthocyanins contents correlated with ectomycorrhizal root colonization, differed amongst trees in corresponding altitudes and was generally greater in upper altitudes. Activity of antioxidant enzymes like catalase and peroxidase and total protein content were affected by soil physicochemical factors. A.velutinum grew better in sandy soils while A.subcordata dominanted clay soils. Although, nutrient status of the soil was different within each soil type, cation competition between Ca and Mg and high concentration of Fe in soil most likely affected root performance and consequentially pigment content in leaves, particularly in upper altitudes where temperatures were low and UV radiation was strong. UV radiation induces anthocyanin biosynthesis which mainly protects the DNA from damage. In this research, Chllorophyll/ Carotenoid ratio reduced with increasing altitude perhaps because of photoprotection.

In this paper, results extracted from a set of stress analyses performed on 46 FE models for unstiffened gap tubular KT-joints are presented and discussed. The main objective of the FE analyses, validated against experimental data, was to run a parametric investigation on the effects of geometrical characteristics of the joint on the values of the stress concentration factors (SCFs). The SCF is a key input parameter in the fatigue analysis and design of tubular joints commonly found in steel offshore structures such as jacket-type and jack-up platforms. Chord-side SCFs of central and outer braces were studied individually under four different types of out-of-plane bending (OPB) moment loads. After investigating the geometrical effects, a set of nonlinear parametric equations were developed for the computation of SCFs. Proposed equations, assessed according to the criteria recommended by the UK Department of Energy, can be reliably used for the fatigue calculations.

The aim of the current study was to investigate the histological and histochemical characteristics of large and small intestines of sea snake, Hydrophis cyanocinctus. Six adult sea snakes were collected from Minab beaches, located near the sea of Oman, in November, euthanized with chloroform, dissected and alimentary canal removed, tissues preparaed for sectioning and staining with Hematoxylin and Eosin (H&E) and Periodic Acid Schiff's (PAS) methods, and observed with a light microscope equipped with a dinolite lens. Histological evaluation showed that the walls of each organ was formed of mucosa, submucosa, muscularis and serosa. The wall of the small intestine has numerous circular folds with zigzag patterns. Epithelium of small intestine is composed of simple long columnar and goblet PAS positive cells. The epithelial layer of large intestine was formed of long simple columnar cells with acidophilic cytoplasm. Also, PAS positive goblet cells were found scattered in epithelial tissue. In histometry, the epithelial length and width in primary of small intestine was larger than other parts. Goblet cells with 15.36 ± 1.12 were more frequent in the large intestine. Thickness of both internal and external muscular layers were the most at the end of small intestine (p ≤ 0.05).

The recent studies show that the past researches may have significantly underestimated earthquake and tsunami hazard in the Makran Subduction Zone (MSZ) and this region is potentially capable of producing major earthquakes. In this study, the worst case possible earthquake scenarios of the MSZ are simulated using fully nonlinear boussinesq model to investigate tsunami hazards on the Jask Port, one of the most important southern coastal areas of Iran. The 9.1Mw and 8.7Mw earthquakes which respectively, represent the rupture of about full and half length of the MSZ plate boundary, have been considered in the modeling. The global and local numerical simulation were conducted based on 1-minute and 3-arc sec resolution bathymetry data, respectively, in order to capture tsunami generation, propagation and inundation at the Jask Port. Results show the water subsidence is firstly obsereved along the Jask Port coastlines just after the earthquake occurrence, which can alert residents as a natural warning sign. Model results also reveal that due to the 9.1Mw earthquake and the 8.7Mw western Makran earthquake, the most coastal areas around the Jask Port are inundated by tsunami waves. However, the tsunami run-up is not observed when the 8.7Mw earthquake occurs at the eastern segment of the MSZ because the tsunami waves almost propagate in the north-south direction, perpendicular to the Makran fault and it causes a little effect of the tsunami attack on the western coast of Makran. Therefore, the most crucial factor that determines the tsunami risk at the Jask Port is the location of earthquake focal points in the Makran region.

A Serpulidaepolychaetae, Spirobranchuskraussii, was newly recorded in the Persian Gulf, Iran. It is the first record of Serpulidae species in Iran. Serpulidaeforms dense aggregations in rocky shores in Bandar Abbas. This research investigated the biological structure and the effect of temperature on embryonic stages of S. kraussii. Sampling was conducted with a quadrant of 10×10 cm2, in rocky shores from January to May. The largest specimen of S. kraussiimeasured to a total body length of 36.4 mm, body width of 2.3 mm, total tube length of 48mm, and body wet weight of 0.11mg. Outer surface of tube is white and triangular in cross-section, inner surface colored blue or violet. Body color in ventral surface of thorax is dark violet, blue and pink. The sex ratio in S. kraussii was 1:2 and 1:0.81 in winter and spring respectively. Length-weight relationship was exponential and growth seems to be allometric for S. kraussii. A linear relationship was found between total length and other parameters. Correlation coefficients between parameters were positive and significant (p

In recent years, the Indian Ocean (IO) has been discovered to have a much larger impact on climate variability than previously thought. This paper reviews processes in which the IO is, or appears to be, actively involved. We begin the mathematical model with a pattern for summer monsoon winds. Three dimensional temperature and velocity fields are calculated analytically for the ocean forced by wind stress and surface heat flux. A basic thermal state involving a balance of lateral and vertical heat diffusion is assumed. The wind stress is chosen such that a tropical mass transport gyre is generated. An effect of nonlinear heat advection is calculated by a perturbation method. The zero order temperature field gives a rough overall representation of oceanic thermocline. A baroclinic eastward flow in the upper part, with a westward return flow below is associated with this field.This circulation is closed through thin up and downwelling layers at the sides. Superimposed, there is a barotropic wind driven circulation, with a transport field of the type described by Munk. The interior temperature field to the next order is affected, not only by interior heat advection but also by heat advection in the Ekman layer, in the up and downwelling layers and in the main western boundary current.

increased salinity stress because of rising temperature as a result of global warming. High salinity enhances plants photorespiration and affects its physiology, but Salicornia europaea L. in Urmia Lake has adapted to grow, propagate and occupy increasingly exposed saline habitats. Plant and soil samples were collected in triplicate plots from different sites of retreated beds of Urmia Lake in fall, 2015. Salinity stress physiology of S.europaea L. populations were investigated in Urmia Lake through determining: (a) leaf cell membrane lipid peroxidation (Malondialdehyde production, MDA); (b) antioxidant enzymes activities (peroxidase, catalase and Phenylalanine Ammonia Lyase (PAL) and (3) changes in contents of non-enzymatic antioxidants (flavonoid and anthocyanin). Analysis of variance (ANOVA), Duncan Post-hoc tests and correlation tests were performed using the SPSS.21 statistical program when significant differences occurred at 5% level. Results showed that peroxidase activity reduced and MDA content remained constant which indicates intact integrity of leaf cell membrane and the ability of cells to scavenge Reactive Oxygen Species (ROS). Increase in catalase activity and anthocyanin and total flavonoid contents correlated strongly with increased salinity at all stations located along the exposed and drying bed of the Urmia Lake. It is concluded that S.europaea tolerates salinity stress and subsequent ill-effects of ROSs produced through, (1) regulating vacuolar water exchanges, (2) managing peroxisome activity and (3) developing a complex system of antioxidants. Therefore, S.europaea can be cultivated in retreated Urmia Lake bed for animal feed or other uses.