Scaling in public transport networks

We analyse the statistical properties of public transport networks. These networks are defined by a set of public transport routes (bus lines) and the stations serviced by these. For larger networks these appear to possess a scale-free structure, as it is demonstrated e.g. by the Zipf law distribution of the number of routes servicing a given station or for the distribution of the number of stations which can be visited from the chosen one without changing the means of transport. Moreover, a rather particular feature of the public transport network is that many routes service common subsets of stations. We discuss the possibility of new scaling laws that govern intrinsic features of such subsets.Comment: 9 pages, 4 figure

Entropic equation of state and scaling functions near the critical point in scale-free networks

We analyze the entropic equation of state for a many-particle interacting system in a scale-free network. The analysis is performed in terms of scaling functions which are of fundamental interest in the theory of critical phenomena and have previously been theoretically and experimentally explored in the context of various magnetic, fluid, and superconducting systems in two and three dimensions. Here, we obtain general scaling functions for the entropy, the constant-field heat capacity, and the isothermal magnetocaloric coefficient near the critical point in scale-free networks, where the node-degree distribution exponent $\lambda$ appears to be a global variable and plays a crucial role, similar to the dimensionality $d$ for systems on lattices. This extends the principle of universality to systems on scale-free networks and allows quantification of the impact of fluctuations in the network structure on critical behavior.Comment: 8 pages, 4 figure

Public transport networks: empirical analysis and modeling

We use complex network concepts to analyze statistical properties of urban public transport networks (PTN). To this end, we present a comprehensive survey of the statistical properties of PTNs based on the data of fourteen cities of so far unexplored network size. Especially helpful in our analysis are different network representations. Within a comprehensive approach we calculate PTN characteristics in all of these representations and perform a comparative analysis. The standard network characteristics obtained in this way often correspond to features that are of practical importance to a passenger using public traffic in a given city. Specific features are addressed that are unique to PTNs and networks with similar transport functions (such as networks of neurons, cables, pipes, vessels embedded in 2D or 3D space). Based on the empirical survey, we propose a model that albeit being simple enough is capable of reproducing many of the identified PTN properties. A central ingredient of this model is a growth dynamics in terms of routes represented by self-avoiding walks.Comment: 19 pages, 23 figure

Close relationships: A study of mobile communication records

Mobile phone communication as digital service generates ever-increasing datasets of human communication actions, which in turn allow us to investigate the structure and evolution of social interactions and their networks. These datasets can be used to study the structuring of such egocentric networks with respect to the strength of the relationships by assuming direct dependence of the communication intensity on the strength of the social tie. Recently we have discovered that there are significant differences between the first and further "best friends" from the point of view of age and gender preferences. Here we introduce a control parameter $p_{\rm max}$ based on the statistics of communication with the first and second "best friend" and use it to filter the data. We find that when $p_{\rm max}$ is decreased the identification of the "best friend" becomes less ambiguous and the earlier observed effects get stronger, thus corroborating them.Comment: 11 pages, 7 figure

Ground truth? Concept-based communities versus the external classification of physics manuscripts

Theoretical Physic

2-Amino-4,6,7,8-tetrahydrothiopyrano[3,2-b]pyran-3-carbonitrile 5,5-dioxide VP-4535 as an antimicrobial agent selective toward methicillin‐resistant Staphylococcus aureus

The antibacterial activity of 2-amino-4,6,7,8-tetrahydrothiopyrano[3,2-b]pyran-3-carbonitrile 5,5-dioxide toward five key ESKAPE pathogenic bacteria, methicillin‐resistant Staphylococcus aureus (ATCC 43300), Escherichia coli (ATCC 25922), Klebsiella pneumonia (ATCC 700603), Acinetobacter baumannii (ATCC 19606), and Pseudomonas aeruginosa (ATCC 27853) was evaluated. The antifungal activity was studied­ towards pathogenic fungal strains Candida albicans (ATCC 90028) and Cryptococcus neoformans var. Grubii (ATCC 208821). Compound VP-4535 bearing 5-methylindolin-2-one motif possessed the highest antibacterial activity and excellent selectivity toward methicillin‐resistant Staphylococcus aureus but was inactive against non-resistant Staphylococcus aureus strain. The compound in therapeutic concentration was safe to human red blood cells, human lymphocytes, HaCaT, Balb/c 3T3 and HEK-293 cells

Bactericidal, protistocidal, nematodicidal properties and chemical composition of ethanol extract of Punica granatum peel

We have studied the chemical composition and antibacterial profile of ethanolic extract of Punica granatum L. (Lythraceae) on strains of microorganisms in vitro. Analysis using GC-MS showed 5-hydroxymethylfurfural (36.6%), D-sucrose (23.2%), sorbitol (6.7%), palmitic acid β-monoglyceride (5.6%), 2-furancarboxaldehyde (3.5%) and β-D-glucopyranose (3.3%) as the major components of the title extract. The experiment revealed a positive antibacterial effect of extracts obtained from P. granatum on 14 strains specifically Enterobacteriaceae microorganisms (Escherichia coli, Enterobacter aegorenеs, Proteus vulgaris, Serratia marcescens, Klebsiella pneumonia), Listeriaceae (Listeria ivanovi, L. іnnocua, L. monocytogenes) and yeasts from the family Saccharomycetaceae (Candida albicans). Our study showed that in many cases these extracts more intensively affect multi-resistant strains of microorganisms than macrolide antibiotic azithromycin and is therefore a source of molecules to be exploited in medicine or by the pharmaceutical industry. The investigated extracts of P. granatum can be recommended for further in-depth research against poly-resistant strains of the above-mentioned microorganisms. Effective drugs perform a leading role in providing stable veterinary well-being of livestock and healthcare of the population. The present study showed that the studied plant species more intensively affects multi-resistant strains of microorganisms than sodium salt of azithromycin. Lethal concentration (LC50) of ethanol extract from pomegranate for Paramecium caudatum Ehr. equaled 0.3%. Death of 100% of nematode larvae of Strongyloides papillosus (Ihle) was recorded during 24 h exposition in 20% extract of P. granatum peel