1,498 research outputs found

    Determination of heavy metals content in Astacus leptodactylus caspicus in Anzali Lagoon

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    With attention to different human activities around Anzali lagoon and entrance different pollutants containing heavy metals into this aquatic ecosystem and alterante absorption and accumulation of heavy metals in shell and muscle of Astacus leptodactylus which is native species of Anzali lagoon and having food and economic importance. Sampling of water and sediments from 18 stations and also shell and muscle of Astacus leptodactylus from 5 stations have been conducted. After biometric evaluation of Astacus leptodactylus, the chemical analysis of the samples were done by using international standard methods and then their heavy metals content was determined by Atomic Absorption Spectrophotometer (A.A.S). Result of the analysis stated that: There wasn't significant difference between weight and size of Astacus leptodactylus with their absorption and accumulation of heavy metals; but there was a significant difference and correlation coefficient between heavy metals content in water and sediments, and also in sediments with shell and muscle of Astacus leptodactylus in Anzali lagoon

    Parareal in time 3D numerical solver for the LWR Benchmark neutron diffusion transient model

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    We present a parareal in time algorithm for the simulation of neutron diffusion transient model. The method is made efficient by means of a coarse solver defined with large time steps and steady control rods model. Using finite element for the space discretization, our implementation provides a good scalability of the algorithm. Numerical results show the efficiency of the parareal method on large light water reactor transient model corresponding to the Langenbuch-Maurer-Werner (LMW) benchmark [1]

    Chiral nature of magnetic monopoles in artificial spin ice

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    Micromagnetic properties of monopoles in artificial kagome spin ice systems are investigated using numerical simulations. We show that micromagnetics brings additional complexity into the physics of these monopoles that is, by essence, absent in spin models: besides a fractionalized classical magnetic charge, monopoles in the artificial kagome ice are chiral at remanence. Our simulations predict that the chirality of these monopoles can be controlled without altering their charge state. This chirality breaks the vertex symmetry and triggers a directional motion of the monopole under an applied magnetic field. Our results also show that the choice of the geometrical features of the lattice can be used to turn on and off this chirality, thus allowing the investigation of chiral and achiral monopoles.Comment: 10 pages, 4 figure

    Study of mycoflora in cultured Indian white shrimp (Penaeus indicus) in Abadan, Iran

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    The development of the commercial culture of penaeid shrimps has been accompanied by the occurrence of infectious and noninfectious diseases. The most important penaeid diseases are caused by organisms that are part of the normal microflora of penaeids. In 1998, the samples were collected from five farms in Ghofase area (Ahadan) 2-5 ponds in each farm. The shrimps of these ponds were preserved in full hygienic conditions, from each pond, at least 5 samples were collected and then transferred to the Aquatic Diseases Laboratory of Khouzestan Fisheries Research Center. The main tissues of Gill, Hemolymph, Hepatopancreas and cuticle of live-shrimps were studied in the laboratory. In this research, a total of 40 fungal species were isolated from different tissues with high abundance in Hepatopancrease (19 species) and Hemolymph (12 species). Aspergillus niger was identified as the most abundant species

    Chronic effects of aerobic exercise on gene expression of LOX-1 receptor in the heart of rats fed with high fat diet

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    Objective(s): Lectin-like low density lipoprotein receptor (LOX-1) has pivot role in vascular complications, which is upregulated in numerous pathological conditions. Since exercise has beneficial effects in prevention of hyperlipidemic complications, present study examined protective effects of aerobic exercise through reduction of LOX-1 expression in heart during dyslipidemia. Materials and Methods: Four groups of rats were used (N=25): Normal, Normal and exercise, High fat and High fat and exercise. High fat diet (HFD) was made by adding 10 animal oil, 2 cholesterol and 0.5 colic acid to standard rodent chow. Exercise protocol consisted of swimming 1 hr/day, and 5 days/week for 8 weeks. Plasma lipids were evaluated at the end of experiment, 48 hr after final session of exercise. At the end, rats were sacrificed and heart was removed for determination of malondialdehyde (MDA) content, and LOX-1 expression. Results: HFD meaningfully changed lipid profile (>50), but chronic exercise had no significant effects on lipid profile. LOX-1 expression was significantly increased in heart of rats fed with HFD, while swimming exercise considerably reduced gene expression of LOX-1. MDA content was significantly enhanced in rats fed with HFD (4.37±0.6 nmol/mg, P<0.01) compared to normal group (1.56±0.48 nmol/mg), whereas swimming exercise decreased MDA level of heart in rats fed with HFD (2.28±0.32, P<0.01). Conclusion: Findings indicated that swimming exercise is able to diminish heart expression of LOX-1 receptor concomitant reduction of oxidative stress. Since these parameters are involved in generation of dyslipidemic complications, swimming exercise is a good candidate to reduce these complications. Copyright 2015, Mashhad University of Medical Sciences , All Rights Reserved
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