Evaluation of lysosomal stability and red blood cell membrane fragility in mudskipper (Boleophthalmus dussumieri) as a biomarker of poly aromatic hydrocarbons

This research was carried out to study some physiological responses of mudskipper (i.e., Boleophthalmus dussumieri) as a biomarker Poly Aromatic Hydrocarbons (PAHs). Fish specimens were obtained 5 stations (Arvand, Jafari, Zangi, Samayeli, Bahrakan) along north western coast of the Persian Gulf (Khuzestan Coast). PAHs concentration was measured by HPLC method. Lysosomal membrane change was measured by NRR time method and stability of red blood cell membrane was evaluated by EOF test. Total PAH concentrations in the sediments and the liver tissue ranged between 113.50-3384.34 ng g-1dw, 3.99-46.64ng g-1 dw, respectively. Highest PAHs pollution was found at Jafari while the lowest was detected at Bahrakan, with significant between these 2 stations. Values of mean RT of the dye ranged from 34 (for the blood samples of mudskipper collected from Jafari site) to 78 minutes (for the blood samples of mudskipper collected from Bahrakan). Preliminary results showed a significant difference among stations except between Arvand and Zangi. Osmotic fragility curves indicated that erythrocytes collected from mudskippers at Jafari were the most fragile followed by Zangi> Arvand> Samayeli> and Bahrakan. The results suggest that lysosomal membrane change and red blood cell membrane stability in B. dussumieri could be extended as a biomarker of oil pollution in marine biomonitoring programs

The role of the tourist guide : a theoretical perspective

One can view tourism as a socio-cultural subsystem implanted in a particular society and which according to Jafari (1982), promotes the interaction of three cultures: the local culture, the tourist culture and the imported culture. This paper discusses the role of tourist guides in social mediation and cultural brokerage. Examples from the local scene are also given by the author to show the manipulative power tourist guides can wield.peer-reviewe

Gapless chiral excitons in thin films of topological insulators

In a nanoscopic thin film of a strong topological insulator (TI) the Coulomb interaction in the channel that exchanges the two electrons with the same chirality in two different planes of the slab takes advantage of the minus sign resulting from such "exchange" and gives rise to a bound state between the positive energy states in one surface and the negative energy states in the opposite surfaces. Therefore particle and hole pairs in the {\em undoped} Dirac cone of the TI thin film form an inter-surface spin-singlet state that lies below the continuum of free particle-hole pairs. This mode is similar to the excitons of semiconductors, albeit formed between the electron and hole pairs from two different two-dimensional surfaces. For low-momenta the dispersion relation characterizing this collective mode is linear. Experimental comparison of two slabs with different thicknesses can capture the exponential dependence of the present effect on the slab thickness.Comment: Comments are welcom

Mathematical modeling for cryptography using Jafari transformation method

Data protection is representing a huge trade in the modern era; the vast communication development gave this field increased attention from all sorts of parties (friends and foes); integral transforms have played a decent role in many methods that are proposed to be used in the cryptography field. In this work, the Jafari integral transform has been used as a part of a symmetric key system, by implementing a practical example in encryption and decryption; Jafari integral transform has proven its capability to be invested in cryptography and in the data security field in general

A Novel Third Order Numerical Method for Solving Volterra Integro-Differential Equations

In this paper we introduce a numerical method for solving nonlinear Volterra integro-differential equations. In the first step, we apply implicit trapezium rule to discretize the integral in given equation. Further, the Daftardar-Gejji and Jafari technique (DJM) is used to find the unknown term on the right side. We derive existence-uniqueness theorem for such equations by using Lipschitz condition. We further present the error, convergence, stability and bifurcation analysis of the proposed method. We solve various types of equations using this method and compare the error with other numerical methods. It is observed that our method is more efficient than other numerical methods