علوم زیستی دریا
Seyyed Kiarash Jafari; Ahmad Savari; Faedeh Amini; Hosseim Mohammad Asgari
Abstract
The international Shadegan wetland is one the biggest ponds in Iran and located in Khouzestan province.This wetland is with more than 530 thousand hectares vast wetland registered in the international Ramsar Convention.Climate changes can make negative or passitive conditions by drought or wet periods ...
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The international Shadegan wetland is one the biggest ponds in Iran and located in Khouzestan province.This wetland is with more than 530 thousand hectares vast wetland registered in the international Ramsar Convention.Climate changes can make negative or passitive conditions by drought or wet periods on water quality and volume of this wetland.Today, concerns about the warming of the earth and damage to vital natural resources, have led researchers to study different periods of drought. Drought is a phenomenon adverse impact on all ecosystems, including wetlands. Because of it, new drought indices should be associated with specific time scales for monitoring and management of water resources. In the study area, data required by the Metrological Agency, water and power authority and by ocean-atmospheric data from NOAA satellites from 1950 to 2015 (65 years old) received. Changes in wetland on the downside and upside of drought and wet were studied by standardized precipitation evapotranspiration index (SPEI). The final model showed decaying and destroying the wetland each year goes by drought from year of 1998.
علوم زیستی دریا
Mahnosh Khosravizadeh; Laleh Roomiani
Abstract
In this study changes chemical compounds and textural, color and sensory properties were measured to investigate the shelf-life of the whole, gutted and filleted yellow fin Seabream (Acanthopagrus latus) in modified atmosphere packaging (MAP) (45% CO2, 50% N2 and 5% O2) during frozen condition in 4 months ...
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In this study changes chemical compounds and textural, color and sensory properties were measured to investigate the shelf-life of the whole, gutted and filleted yellow fin Seabream (Acanthopagrus latus) in modified atmosphere packaging (MAP) (45% CO2, 50% N2 and 5% O2) during frozen condition in 4 months storage. Results showed that no significant different in protein, ash and moisture contents were observed (p> 0.05). The lowest fat content (2.67 % ± 0.1%) was observed in sample containing the whole fish (p< 0.05). In all treatments the WHC was showed a significant decrease during storage time (p< 0.05) and the lowest value was found in gutted and filleted samples (22.1 % ± 0.39 and 22.34 % ± 0.34%, respectively). The results also showed a significant decrease in textural properties (including hardness, resilience, cohesiveness, gumminess and chewiness) compared with initial values (p< 0.05). However, the lowest values of these factors were found in whole fish samples. Evaluation of the color showed a significant increase in factor b* as well as decrease in factors a* and L* during storage. The results in all treatments revealed a significant decrease in sensory factors; however gutted and filleted fish in MAP packaging were judged to be more acceptable than whole fish samples. Considering of textural, color and sensory properties, it seems that filleting and gutting fish compared with whole fish samples resulted in better quality in MAP packing under frozen storage.
علوم زیستی دریا
khanomnaz ebadi; mandana zarei; ali mohammad sanati
Abstract
The aim of this study was to isolate and molecular identification of associated bacteria in sponges, with potential ability of biodegrading crude oil. Serial dilutions of homogenized Pachychalina sp. mesohyl were cultured in suitable medium for growth of marine microorganism. Obtained colonies were screened ...
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The aim of this study was to isolate and molecular identification of associated bacteria in sponges, with potential ability of biodegrading crude oil. Serial dilutions of homogenized Pachychalina sp. mesohyl were cultured in suitable medium for growth of marine microorganism. Obtained colonies were screened based on emulsification index and growth in medium containing 2% oil. Six strains which showed the highest growth rate and emulsification index were tested for the amount of oil removal in the minimal salt medium. Also the molecular identification was done Based on the 16SrRNA sequence and PCR. Removal of oil based on two methods; dry weight and absorption at 420 nm confirmed each other and both followed the same pattern. Accordingly KE5 and KE8 strains showed the highest degree of oil removing and molecular identification results revealed that they were most similar to strains of Staphylococcus aureus subsp. N31 and Luteimonas terricola BZ92r respectively. Also according to the results of bioinformatics analysis, it seems KE6 and KE7 respectively with 84% and 90% similarity with Exiguobacterium sp. AT1b and Pseudomonas rhodesiae CIP 104664 strains, have considerable potential for further molecular and biochemical studies .
مهندسی دریا
Vida Atashi; Mehdi GHomeshi
Abstract
In this paper, the effect of in phase or out of phase fluctuation of two tandem circular cylinders with PTC on FIM is investigated. Flow-Induced Motion (FIM) is a phenomenon that frequently occurs when slender structures are subjected to a transverse fluid flow.VIV and galloping are the most common phenomena ...
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In this paper, the effect of in phase or out of phase fluctuation of two tandem circular cylinders with PTC on FIM is investigated. Flow-Induced Motion (FIM) is a phenomenon that frequently occurs when slender structures are subjected to a transverse fluid flow.VIV and galloping are the most common phenomena in FIM which occurs due to interaction between shear layers and wakes of upstream cylinders. In this paper, the effect of tandem spacing on FIM of two circular cylinders with PTC is investigated by visualization. The power harness graphs for upstream, downstream and synergy was extracted with VIVACE. The VIVACE consists of a rigid bluff body that is mounted on an elastic base and exposed to fluid flow. The mechanical energy from the cylinder vibration is also transmitted by a PTO to a generator. Normally, the harness power in galloping region increases with increasing in flow velocity and Reynolds number. Unlike what was expected, drops and jumps in Power harness in the velocity range of 0.9
علوم غیرزیستی دریا
hakime moosazad; mohammad akbari nasab; Hossin Mashayekh Poul
Abstract
Three forcing processes can provide residual current: Tidal forces, wind forces, and density differences. Tidal residual current are created by tidal wave interaction with the structure of topography. In this study, two-dimensional model VOM-SW2d is applied In the barotropic and fully nonlinear to Pozm ...
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Three forcing processes can provide residual current: Tidal forces, wind forces, and density differences. Tidal residual current are created by tidal wave interaction with the structure of topography. In this study, two-dimensional model VOM-SW2d is applied In the barotropic and fully nonlinear to Pozm Bay in the northern coast of Oman to simulate the tidal residual currents. In this study aimed to investigate the effects of substrate unevenness, removed topography slope using high-pass filter. Regular computational grid has been used with a resolution of 150 m, in direction x and y. The results obtain the maximum current velocity of 0.05 m/s near the mouth of the Gulf of Pozm. Tidal residual current was observed of topographic features near the headland of Pozm Bay, headland at Pozm Bay and also in coastal areas due to the slope of the coast. Also the model results shows several eddies in different sizes and some Circulation in various scales. Tidal residual currents in the Pozm Bay, as depicted by Lagrangian trajectories reveal a stationary flow whit several eddies. Each eddy can be identified with a topographic obstacle. This confirms that the tidal residual flow field is strongly influenced by the nonlinear interaction of the tidal wave with the bottom relief which, in turn, is deformed by figure hills and valleys beneath the seabed
علوم زیستی دریا
babak lvhnd; Hassan Zare Maivan; Mona Sorahinobar; Mehri Seyed Hashtroudi
Abstract
Gene expression studies could provide insight into the physiological mechanisms and strategies used by plants under stress conditions. Selection of suitable internal control gene(s) is essential to accurately assess gene expression levels. For the mangrove plant, Avicennia marina, reliable reference ...
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Gene expression studies could provide insight into the physiological mechanisms and strategies used by plants under stress conditions. Selection of suitable internal control gene(s) is essential to accurately assess gene expression levels. For the mangrove plant, Avicennia marina, reliable reference genes to normalize real-time quantitative PCR data has not been previously investigated. In this study, the expression stabilities of four candidate reference genes [Actin 2 (ACT2),Serine/threonine-protein phosphatase 2A subunit A3 (PP2AA3),TIP-Like (TIP), polyubiquitin 10 (UBQ)] were determined in leaves and roots of A. marina treated by different level of oils contamination . Three software programs (Bestkeeper, NormFinder and geNorm) were employed to analyze and rank the tested genes. Results showed that ACT2 was the most suitable reference gene in A. marina and the combination of two or three genes was recommended for greater accuracy. Identification of A. marina reference genes in a wide range of experimental samples will provide a useful reference in future gene expression studies in this species, particularly involving similar stresses.