In this paper, Runge-Kutta methods are discussed for numerical solutions of conservative systems. For the energy of conservative systems being as close to the initial energy as possible, a modified version of explicit Runge-Kutta methods is presented. The order of the modified Runge-Kutta method is the same as the standard Runge-Kutta method, but it is superior in energy-preserving to the standard one. Comparing the modified Runge-Kutta method with the standard Runge-Kutta method, numerical experiments are provided to illustrate the effectiveness of the modified Runge-Kutta method.
The phylogenetic relationships of the subgenera Polyommatus and Plebicula, within the Palaearctic butterfly genus Polyommatus, were inferred from a combined analysis of the nuclear marker ITS2 and the barcoding section of the mitochondrial gene COI. Eight major clades were recovered within Polyommatus s. l., which correspond closely to subgenera based on traditional systematics and are of late Pliocene to early Pleistocene origin. Extraordinary chromosomal evolution occurred independently in three of these clades. The disputed position of several species formerly placed in the subgenus Plebicula is clarified. A group of Central Asian species (Bryna) was recovered as a monophyletic clade within Polyommatus s. str. The Kurdistanian endemic P. buzulmavi appears as a sister species to P. icarus. P. celina replaces P. icarus in NW Africa and the Canary Islands, and split from the last common ancestor with P. icarus back in the early Pleistocene.
Uric acid is the final product of human purine metabolism. It was pointed out that this compound acts as an antioxidant and is able to react with reactive oxygen species forming allantoin. Therefore, the measurement of allantoin levels may be used for the determination of oxidative stress in humans. The aim of the study was to clarify the antioxidant effect of uric acid during intense exercise. Whole blood samples were obtained from a group of healthy subjects. Allantoin, uric acid, and malondialdehyde levels in plasma and erythrocytes were measured using a HPLC with UV/Vis detection. Statistical significant differences in allantoin and uric acid levels during short-term intense exercise were found. Immediately after intense exercise, the plasma allantoin levels increased on the average of 200 % in comparison to baseline. Plasma uric acid levels increased slowly, at an average of 20 %. On the other hand, there were no significant changes in plasma malondialdehyde. The results suggest that uric acid, important antioxidant, is probably oxidized by reactive oxygen species to allantoin. Therefore allantoin may be suitable candidate for a marker of acute oxidative stress., R. Kanďár, X. Štramová, P. Drábková, J. Křenková., and Obsahuje bibliografii
We consider the quotient categories of two categories of modules relative to the Serre classes of modules which are bounded as abelian groups and we prove a Morita type theorem for some equivalences between these quotient categories.
nfective nymphal stages of the family Sebekidae Sambon, 1922 are reported from four species of fish in Australian waters for the first time. Infected fish were collected from locations in Western Australia, the Northern Territory and north Queensland. The infective nymphs of Alofia merki Giglioli in Sambon, 1922 and Sebekia purdieae Riley, Spratt et Winch, 1990 are reported and described for the first time. The remaining specimens were identified as belonging to the genus Sebekia Sambon, 1922 based on the combination of buccal cadre shape, shape and size of hooks, and overall body size, but could not be attributed to any of the other species of Sebekia already reported due to missing required morphological features. DNA sequences of members of the family Sebekidae are presented for the first time. The lack of knowledge on the pentastome fauna of wild crocodiles, and any potential intermediate hosts, in northern Australia, is also outlined., Diane P. Barton, Jess A.T. Morgan., and Obsahuje bibliografii
A combined study of morphology, stem anatomy and isozyme patterns was used to reveal the identity of sterile plants from two rivers on the Germany/France border. A detailed morphological examination proved that the putative hybrid is clearly intermediate between Potamogeton natans and P. nodosus. The stem anatomy had characteristics of both species. The most compelling evidence came from the isozyme analysis. The additive “hybrid” banding patterns of the six enzyme systems studied indicate inheritance from P. natans and P. nodosus. In contrast, other morphologically similar hybrids were excluded: P. ×gessnacensis (= P. natans × P. polygonifolius) by all the enzyme systems, P. ×fluitans (= P. lucens × P. natans) by AAT, EST and 6PGDH, and P. ×sparganiifolius (= P. gramineus × P. natans) by AAT and EST. All samples of P. ×schreberi are of a single multi-enzyme phenotype, suggesting that they resulted from a single hybridization event and that the present-day distribution of P. ×schreberi along the Saarland/Moselle border was achieved by means of vegetative propagation and long-distance dispersal. Neither of its parental species occur with P. ×schreberi or are present upstream, which suggests that this hybrid has persisted vegetatively for a long time in the absence of its parents. The total distribution of this hybrid is reviewed and a detailed account of the records from Germany is given. P. ×schreberi appears to be a rare hybrid. The risk of incorrect determination resulting from the identification of insufficiently developed or inadequately preserved plant material is discussed.
The anadromous Rutilus kutum Kamenskii, 1901is the most important fish in north of Iran with the highest economic value. Ignoring the natural process of reproduction due artificial propagation, catching some migrating broodstocks from the sea (not from the estuaries) and mixing the produced fingerlings in culture ponds within restocking programs in the last 30 years have caused an uncertainty about homing success and population differentiation in the fish. A 13-landmark morphometric truss network system was used to investigate the hypothesis of homeward migration success and population differentiation, while the previous studies revealed low genetic variability among the fish populations. A total of 504 adult specimens were caught from four localities along the southern Caspian Sea in the reproductive period. Univariate analysis of variance showed significant differences among the four groups for 78 standardized morphometric measurements. In linear discriminant function analysis (DFA), the overall assignments of individuals into their original groups were 73.3 % and 80.3 % in males and females, respectively. The principal component analysis (PCA) and clustering analysis based on Euclidean square distances showed that the 504 examined specimens grouped into distinct areas. The results showed that each sampling site represents independent population which confirmed the success of homeward migration. The high grouping ranges suggests that almost all populations return to their birthplace river to breed, which results in high inbreeding. The results can be interesting for management and conservation programs of this valuable species in the Caspian Sea.
Modern organizations tend to constitute of communities of practice to cover the side effect of standardization and centralization of knowledge. The distributed nature of knowledge in groups, teams and other departments of organization and complexity of this tacit knowledge lead us to use community of practice as an environment to share knowledge. In this paper we propose an agent mediated community of a practice system using MAS-CommonKADS methodology. We support the principle of autonomy since every single agent, even those in the same community, needs its own autonomy in order to model an organization and its individuals correctly, using this approach, the natural model for an agent based on knowledge sharing system has been resulted. We presented all models of MAS-CommonKADS methodology required for developing the multi-agent system. We found MAS-CommonKADS useful to design Knowledge Management applications. Because of detailed description of agents, a resulted design model could be simply implemented. We modeled our system using Rebeca and verified it to show that by use of our system, knowledge sharing can be satisfied.
In this paper, we propose a new economic dispatch model with random wind power, demand response and carbon tax. The specific feature of the demand response model is that the consumer's electricity demand is divided into two parts: necessary part and non-essential part. The part of the consumer's participation in the demand response is the non-essential part of the electricity consumption. The optimal dispatch objective is to obtain the minimum total cost (fuel cost, random wind power cost and emission cost) and the maximum consumer's non-essential demand response benefit while satisfying some given constraints. In order to solve the optimal dispatch objective, a multi-subpopulation bat optimization algorithm (MSPBA) is proposed by using different search strategies. Finally, a case of an economic dispatch model is given to verify the feasibility and effectiveness of the established mathematical model and proposed algorithm. The economic dispatch model includes three thermal generators, two wind turbines and two consumers. The simulation results show that the proposed model can reduce the consumer's electricity demand, reduce fuel cost and reduce the impact on the environment while considering random wind energy, non-essential demand response and carbon tax. In addition, the superiority of the proposed algorithm is verified by comparing with the optimization results of CPLEX+YALMIP toolbox for MATLAB, BA, DBA and ILSSIWBA.
Finding reducts is one of the key problems in the increasing applications of rough set theory, which is also one of the bottlenecks of the rough set methodology. The population-based reduction approaches are attractive to find multiple reducts in the decision systems, which could be applied to generate multi-knowledge and to improve decision accuracy. In this paper, we design a multi-swarm synergetic optimization algorithm (MSSO) for rough set reduction and multi-knowledge extraction. It is a multi-swarm based search approach, in which different individual trends to be encoded to different reduct. The approach discovers the best feature combinations in an efficient way to observe the change of positive region as the particles proceed throughout the search space. The performance of our approach is evaluated and compared with Standard Particle Swarm Optimization (SPSO) and Genetic Algorithms (GA). Empirical results illustrate that the approach can be applied for multiple reduct problems and multi-knowledge extraction effectively.