A thermodynamic view of networks

Networks can be described by the frequency distribution of the number of links associated with each node (the degree of the node). Of particular interest are the power law distributions, which give rise to the so-called scale-free networks, and the distributions of the form of the simplified canonical law (SCL) introduced by Mandelbrot, which give what we shall call the Mandelbrot networks. Many dynamical methods have been obtained for the construction of scale-free networks, but no dynamical construction of Mandelbrot networks has been demonstrated. Here we develop a systematic technique to obtain networks with any given distribution of the degrees of the nodes. This is done using a thermodynamic approach in which we maximise the entropy associated with degree distribution of the nodes of the network subject to certain constraints. These constraints can be chosen systematically to produce the desired network architecture. For large networks we therefore replace a dynamical approach to the stationary state by a thermodynamical viewpoint. We use the method to generate scale-free and Mandelbrot networks with arbitrarily chosen parameters. We emphasise that this approach opens the possibility of insights into a thermodynamics of networks by suggesting thermodynamic relations between macroscopic variables for networks.     

Does the liposuction method influence the phenotypic characteristic of human adipose-derived stem cells?

Adipose-derived stem cells (ASCs) possess a high differentiation and proliferation potential. However, the phenotypic characterization of ASCs is still difficult. Until now, there is no extensive analysis of ASCs markers depending on different liposuction methods. Therefore, the aim of the present study was to analyse 242 surface markers and determine the differences in the phenotypic pattern between ASCs obtained during mechanical and ultrasound-assisted liposuction. ASCs were isolated from healthy donors, due to mechanical and ultrasound-assisted liposuction and cultured in standard medium to the second passage. Differentiation potential and markers expression was evaluated to confirm the mesenchymal nature of cells. Then, the BD LyoplateTM Human Cell Surface Marker Screening Panel was used. Results shown that both population of ASCs are characterized by high expression of markers specific for ASCs: cluster of differentiation (CD)9, CD10, CD34, CD44, CD49d, CD54, CD55, CD59, CD71 and low expression of CD11a, CD11c and CD144. Moreover, we have noticed significant differences in antigen expression in 58 markers from the 242 studied. Presented study shows for the first time that different liposuction methods are not a significant factor which can influence the expression of human ASCs surface markers.     

Foraging Behavior Patterns of Sheep and Horses Under a Mixed Species Grazing System

The research objective was to assess the behavior patterns of the Polish Konik horse breed and the Uhruska variety of the Polish Lowland Sheep breed under a mixed-grazing system, and their relationship with climatic factors. The observation included 4 adult horses, 27 ewes with lambs and 10 primiparous ewes. The behavior of the animals and the weather conditions were recorded at 60-min intervals. Horses and sheep displayed similarities in both species-specific behavioral patterns and timing of grazing activity, and the duration of foraging sessions was mostly influenced by time of day, lower temperature and relative humidity. In addition, the two species showed more interest in the watering place in the afternoon, and drinking frequency was mainly dependent on air temperature. The animals that pastured together gradually began to mix, but at first, they remained within their species group. Both animal species can be used for environmental protection and landscape conservation making rational use of pastures within protected areas.