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References 1 J. C. Fetzer. The Chemistry and Analysis of the Large Polycyclic Aromatic Hydrocarbons , John Wiley, New York (2000). 2 10.1002/cber.19640970226 , K. F. Lang, J. Kalowy, H. Buffleb. Chem. Ber. Recl. 97 , 494 (1964). 3 10.1002/cber.19620950438 , K. F. Lang, J. Kalowy, H. Buffleb. Chem. Ber. Recl. 95 , 1052 (1962). 4 10.1038/380227a0 , D. J. Cook, S. Schlemmer, N. Balucani, D. R. Wagner, B. Steiner, R. J. Saykally. Nature 380 , 227 (1996). 5 10.1002/jlac.19123940202 , R. Scholl, C. Seer. Justus Liebigs Ann. Chem. 394 , 111 (1912). 6 10.1002/cber

DOI 10.1515/jmc-2015-0013 | J. Math. Cryptol. 2015; 9 (3):161–167 Research Article Matvei Kotov and Alexander Ushakov Analysis of a certain polycyclic-group-based cryptosystem Abstract:We investigate security properties of the Anshel–Anshel–Goldfeld commutator key-establishment protocol [1] used with certain polycyclic groups described by Eick and Kahrobaei [3]. We show that despite low success of the length based attack shown by Garber, Kahrobaei and Lam [5] the protocol can be broken by a deterministic polynomial-time algorithm. Keywords: Cryptography

Introduction Polycyclic-fused quinolines are an important group of compounds in medicinal chemistry [1–3] and are ubiquitous substructures associated with biologically active natural products such as Luotomins ( 1 , Figure 1 ) [4] and Calothrixin B ( 2 , Figure 1 ) [5]. Studies have shown that planar polycyclic-fused quinoline systems can cleave DNA [6] and exhibit significant biological properties such as antitumoral [7], anti-cancer [8], anti-inflammatory [9], antibacterial, and antituberculosis activities [10]. For example, owing to their aromatic character

Zagreb and the general multiplicative Zagreb indices for Polycyclic Aromatic Hydrocarbons (PAH n ). Section 3 contains similar results for a jagged-rectangle Benzenoid system ( B m,n ). 2 Results for Polycyclic Aromatic Hydrocarbons In this section, we focus on the molecular graph structure of the family of Polycyclic Aromatic Hydrocarbons, denoted PAH n . These graphs of hydrocarbon molecules are defined recursively as follows. The 6-cycle with leaves at each vertex is PAH 1 (C 6 H 6 , benzene). The next element in the family, PAH 2 , is given by deleting the leaves

groups are polycyclic, and therefore they admit a polycyclic presentation (see [ 7 ]). One can thus select τ 2 {\tau_{2}} -groups by randomly specifying polycyclic presentations P , making sure that the P ’s are chosen in a way that the resulting groups are τ 2 {\tau_{2}} -groups, and that any τ 2 {\tau_{2}} -group can be chosen this way. The following result, which we prove in Section 4 , allows one to do so. One would like to extend this approach to the class of all (torsion-free) f.g. nilpotent groups, but, as far as we know, all reasonable generalizations

References Lee LM, Novotny VM, Bartle DK. Analytical Chemistry of Polycyclic Aromatic Compounds. New York (NY): Academic Press; 1981. World Health Organization (WHO). Regional Office for Europe. Air Quality Guidelines for Europe. 2 nd ed. Copenhagen: WHO; 2000. International Agency for Research on Cancer (IARC). Environmental Carcinogens: Selected Methods of Analysis. Vol. 3. Analysis of Polycyclic Aromatic Hydrocarbons in Environmental Samples. Lyon: IARC; 1979. Beak SO, Goldstone ME, Kirk PWW, Lester IN, Perry R. Concentrations of particulate and gaseous


The Anshel–Anshel–Goldfeld (AAG) key-exchange protocol was implemented and studied with the braid groups as its underlying platform. The length-based attack, introduced by Hughes and Tannenbaum, has been used to cryptanalyze the AAG protocol in this setting. Eick and Kahrobaei suggest to use the polycyclic groups as a possible platform for the AAG protocol. In this paper, we apply several known variants of the length-based attack against the AAG protocol with the polycyclic group as the underlying platform. The experimental results show that, in these groups, the implemented variants of the length-based attack are unsuccessful in the case of polycyclic groups having high Hirsch length. This suggests that the length-based attack is insufficient to cryptanalyze the AAG protocol when implemented over this type of polycyclic groups. This implies that polycyclic groups could be a potential platform for some cryptosystems based on conjugacy search problem, such as non-commutative Diffie–Hellman, El Gamal and Cramer–Shoup key-exchange protocols. Moreover, we compare for the first time the success rates of the different variants of the length-based attack. These experiments show that, in these groups, the memory length-based attack introduced by Garber, Kaplan, Teicher, Tsaban and Vishne does better than the other variants proposed thus far in this context.

were the suggested platform for both protocols, other classes of groups can be employed. In general, groups suitable for use in non-commutative cryptography must be well known and possess the following properties: a solvable word problem, a computationally difficult group-theoretic problem, a “fast” word growth rate, and the namesake non-commutativity [ 33 ]. In 2004, Eick and Kahrobaei [ 10 ] investigated the algorithmic properties of polycyclic groups. In particular, they explored how the time complexity of the word and conjugacy problems varied with respect to a

analytical methods remains necessary. Polycyclic aromatic hydrocarbons (PAHs) are a class of common and persistent environmental pollutants containing three or more benzene rings, and they are toxic to aquatic animals and humans [ 4 ]. PAHs are frequently found in the soil, air and water, where they can negatively impact human health [ 5 ]. Therefore, the rapid and sensitive determination of PAH compounds in environmental samples is urgently needed [ 6 , 7 , 8 , 9 ]. However, the traditional liquid–liquid [ 10 ] and solid-phase (SPE) [ 11 , 12 ] methods for extraction

Polycyclic Aromatic Hydrocarbon Degradation by Biosurfactant-Producing Pseudomonas sp. IR1 Manoj Kumara,b,*, Vladimir Leona, Angela De Sisto Materanoa, Olaf A. Ilzinsa, Ivan Galindo-Castroa, and Sergio L. Fuenmayora a Unidad de Biotecnologı́a del Petróleo, Centro de Biotecnologı́a, Fundación Instituto de Estudios Avanzados (IDEA), Apartado 17606 Caracas 1015 A, Venezuela b Present address: Synthesis and Biotics Division, Indian Oil Corporation, Research and Development Center, Faridabad-121007, Haryana, India. Fax: +91-129-2286221. E-mail: manojupreti