Azarbaijan Shahid Madani University

About: Azarbaijan Shahid Madani University is a education organization based out in Tabriz, Iran. It is known for research contribution in the topics: Graphene & Nanocomposite. The organization has 1477 authors who have published 3186 publications receiving 30278 citations. The organization is also known as: Azarbaijan University.

Signed Roman edge domination numbers in graphs

Abstract: The closed neighborhood $$N_G[e]$$NG[e] of an edge $$e$$e in a graph $$G$$G is the set consisting of $$e$$e and of all edges having a common end-vertex with $$e$$e. Let $$f$$f be a function on $$E(G)$$E(G), the edge set of $$G$$G, into the set $$\{-1, 1, 2\}$${-1,1,2}. If $$ \sum _{x\in N[e]}f(x) \ge 1$$?x?N[e]f(x)?1 for every edge $$e$$e of $$G$$G and every edge $$e$$e for which $$f (e) = -1$$f(e)=-1 is adjacent to at least one edge $$e'$$e? for which $$f (e')= 2$$f(e?)=2, then $$f$$f is called a signed Roman edge dominating function of $$G$$G. The minimum of the values $$\sum _{e\in E(G)} f(e)$$?e?E(G)f(e), taken over all signed Roman edge dominating functions $$f$$f of $$G$$G, is called the signed Roman edge domination number of $$G$$G and is denoted by $$\gamma _{sR}'(G)$$?sR?(G). In this note we initiate the study of the signed Roman edge domination in graphs and present some (sharp) bounds for this parameter.

Recent loss of the Dim2 DNA methyltransferase decreases mutation rate in repeats and changes evolutionary trajectory in a fungal pathogen.

Abstract: DNA methylation is found throughout all domains of life, yet the extent and function of DNA methylation differ among eukaryotes. Strains of the plant pathogenic fungus Zymoseptoria tritici appeared to lack cytosine DNA methylation (5mC) because gene amplification followed by Repeat-Induced Point mutation (RIP) resulted in the inactivation of the dim2 DNA methyltransferase gene. 5mC is, however, present in closely related sister species. We demonstrate that inactivation of dim2 occurred recently as some Z. tritici isolates carry a functional dim2 gene. Moreover, we show that dim2 inactivation occurred by a different path than previously hypothesized. We mapped the genome-wide distribution of 5mC in strains with or without functional dim2 alleles. Presence of functional dim2 correlates with high levels of 5mC in transposable elements (TEs), suggesting a role in genome defense. We identified low levels of 5mC in strains carrying non-functional dim2 alleles, suggesting that 5mC is maintained over time, presumably by an active Dnmt5 DNA methyltransferase. Integration of a functional dim2 allele in strains with mutated dim2 restored normal 5mC levels, demonstrating de novo cytosine methylation activity of Dim2. To assess the importance of 5mC for genome evolution, we performed an evolution experiment, comparing genomes of strains with high levels of 5mC to genomes of strains lacking functional dim2. We found that presence of a functional dim2 allele alters nucleotide composition by promoting C to T transitions (C→T) specifically at CpA (CA) sites during mitosis, likely contributing to TE inactivation. Our results show that 5mC density at TEs is a polymorphic trait in Z. tritici populations that can impact genome evolution.

Testicular expression of TDRD1, TDRD5, TDRD9 and TDRD12 in azoospermia

Abstract: Tudor domain-containing proteins (TDRDs) play a critical role in piRNA biogenesis and germ cell development. piRNAs, small regulatory RNAs, act by silencing of transposons during germline development and it has recently been shown in animal model studies that defects in TDRD genes can lead to sterility in males. Here we evaluate gene and protein expression levels of four key TDRDs (TDRD1, TDRD5, TDRD9 and TDRD12) in testicular biopsy samples obtained from men with obstructive azoospermia (OA, n = 29), as controls, and various types of non-obstructive azoospermia containing hypospermatogenesis (HP, 28), maturation arrest (MA, n = 30), and Sertoli cell-only syndrome (SCOS, n = 32) as cases. One-way ANOVA test followed by Dunnett’s multiple comparison post-test was used to determine inter-group differences in TDRD gene expression among cases and controls. The results showed very low expression of TDRD genes in SCOS specimens. Also, the expression of TDRD1 and TDRD9 genes were lower in MA samples compared to OA samples. The expression of TDRD5 significantly reduced in SCOS, MA and HP specimens than the OA specimens. Indeed, TDRD12 exhibited a very low expression in HP specimens in comparison to OA specimens. All these results were confirmed by Western blot technique. TDRDs could be very important in male infertility, which should be express in certain stages of spermatogenesis.

New mixed stacked multicell converter with interesting advantages

Abstract: Multilevel converters are very interesting alternatives for medium and high-power applications. This study presents a new configuration of multicell converters. The main advantages of the proposed converter, in comparison with conventional flying capacitor multicell (FCM) and stacked multicell (SM) converters, are doubling the number of output voltage levels and the root mean square (RMS), improving the output voltage frequency spectrum and lowering the number and rating of components and decreasing the converter losses. Furthermore, the stored energy and rating of flying capacitors will be decreased to half in this topology in comparison with FCM and SM converters. These improvements are achieved by adding only four low-frequency switches to the conventional SM converters configuration. In this topology, the number of high-frequency switches is decreased while the voltage ratings of them during a full cycle are kept constant. Also, a modified phase shifted pulse-width-modulation-based control method has been applied to the proposed topology, which can decrease the harmonic distortions and THD. The circuit is simulated using PSCAD/EMTDC software and simulation results are presented to validate the effectiveness and advantages of the proposed configuration. In addition, the experimental results of proposed configuration prototype have been presented to examine its practicability.