Generating Robust and Efficient Networks Under Targeted Attacks

Much of our commerce and traveling depend on the efficient operation of large scale networks. Some of those, such as electric power grids, transportation systems, communication networks, and others, must maintain their efficiency even after several failures, or malicious attacks. We outline a procedure that modifies any given network to enhance its robustness, defined as the size of its largest connected component after a succession of attacks, whilst keeping a high efficiency, described in terms of the shortest paths among nodes. We also show that this generated set of networks is very similar to networks optimized for robustness in several aspects such as high assortativity and the presence of an onion-like structure

Exotic Smoothness and Quantum Gravity

Since the first work on exotic smoothness in physics, it was folklore to assume a direct influence of exotic smoothness to quantum gravity. Thus, the negative result of Duston (arXiv:0911.4068) was a surprise. A closer look into the semi-classical approach uncovered the implicit assumption of a close connection between geometry and smoothness structure. But both structures, geometry and smoothness, are independent of each other. In this paper we calculate the "smoothness structure" part of the path integral in quantum gravity assuming that the "sum over geometries" is already given. For that purpose we use the knot surgery of Fintushel and Stern applied to the class E(n) of elliptic surfaces. We mainly focus our attention to the K3 surfaces E(2). Then we assume that every exotic smoothness structure of the K3 surface can be generated by knot or link surgery a la Fintushel and Stern. The results are applied to the calculation of expectation values. Here we discuss the two observables, volume and Wilson loop, for the construction of an exotic 4-manifold using the knot $5_{2}$ and the Whitehead link $Wh$. By using Mostow rigidity, we obtain a topological contribution to the expectation value of the volume. Furthermore we obtain a justification of area quantization.Comment: 16 pages, 1 Figure, 1 Table subm. Class. Quant. Grav

Brown adipocytes can display a mammary basal myoepithelial cell phenotype in vivo

This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB13030000) and the CAS-Novonordisk Foundation, as well as grants from the ‘1000 talents’ recruitment program, and a ‘Great-wall professorship’ from the CAS-Novonordisk Foundation all to JRS. We are grateful to all the members of Molecular Energetics Group for their support and discussion of the results. We would like to thank the Center for Biological Imaging from Institute of Biophysics Chinese Academy of Sciences and Professor Zhaohui Wang's Lab from Institute of Genetics and Developmental Biology Chinese Academy of Sciences for confocal microscopy and the Center for Developmental Biology from Institute of Genetics and Developmental Biology Chinese Academy of Sciences and Dr. Jai from Core Facility for Protein Research from Institute of Biophysics Chinese Academy of Sciences for flow cytometry. We are grateful to Dr. Kuang from Purdue University and Dr. Zhu from Chinese Academy of Medical Sciences Peking Union Medical College for the kind donation of Myf5-Cre mice and Dr. Wolfrum from the Institute of Food Nutrition and Health at the ETH Zurich for the kind donation of the Ucp1-DTR mice. Xun Huang provided valuable comments on previous versions of the manuscript.Peer reviewedPublisher PD

Application of CE-MS to examination of black inkjet printing inks for forensic purposes.

The potential of capillary electrophoresis coupled to mass spectrometry with electrospray ion source and time of flight analyser (CE-ESI-TOF-MS) in the analysis of inkjet inks was investigated. The developed and validated method allowed reliable and repeatable analysis of black inkjet inks extracted from printouts. Over a dozen inkjet printouts printed on various printer models from different manufacturers were analysed under selected conditions to determine the variation of chemical composition of inks between different brands and types. It was ascertained that the developed method is capable of revealing qualitative differences between ink samples. For most of the investigated inks, the studies showed the presence of a characteristic mass spectrum originating from the surfactant or polymer. The mass distribution of the additive is distinctive for some inkjet ink producers, and allows for group identification of inks. The results showed the strength of the CE-ESI-TOF-MS method as an effective technique for forensic purposes, requiring a small amount of inkjet ink samples and giving analytical information that is useful in the identification of compounds

Topological quantum D-branes and wild embeddings from exotic smooth R^4

This is the next step of uncovering the relation between string theory and exotic smooth R^4. Exotic smoothness of R^4 is correlated with D6 brane charges in IIA string theory. We construct wild embeddings of spheres and relate them to a class of topological quantum Dp-branes as well to KK theory. These branes emerge when there are non-trivial NS-NS H-fluxes where the topological classes are determined by wild embeddings S^2 -> S^3. Then wild embeddings of higher dimensional $p$-complexes into S^n correspond to Dp-branes. These wild embeddings as constructed by using gropes are basic objects to understand exotic smoothness as well Casson handles. Next we build C*-algebras corresponding to the embeddings. Finally we consider topological quantum D-branes as those which emerge from wild embeddings in question. We construct an action for these quantum D-branes and show that the classical limit agrees with the Born-Infeld action such that flat branes = usual embeddings.Comment: 18 pages, 1 figur

Diversity of vertebrate remains from the Lower Gogolin Beds (Anisian) of southern Poland

Middle Triassic (Muschelkalk) limestones and dolostones of southern Poland contain vertebrate remains, which can be used for palaeoecological and palaeogeographical analyses. The results presented concern vertebrate remains uncovered at four localities in Upper Silesia and one on Opole Silesia, a region representing the south-eastern margin of the Germanic Basin in Middle Triassic times. The most abundant remains in this assemblage are fish remains, comprising mostly actinopterygian teeth and scales. Chondrichthyan and sauropsid remains are less common. Reptilian finds include vertebrae, teeth and fragments of long bones, belonging to aquatic or semi-aquatic reptiles, such as nothosaurids, pachypleusorosaurids, and ichthyosaurids. Also, coprolites of possibly durophagous and predacious reptiles occur. In the stratigraphic column of Mikołów, actinopterygian remains are the most numerous and no distinct changes of the taxonomic composition occur. Although this assemblage differs from those described at other localities (Ząbkowice with numerous chondrichthyans, Żyglin, and Płaza with common sauropsid fossils), sampling bias has to be considered

Spin polarization of exciton-polariton condensate in a photonic synthetic effective magnetic field

We investigate the spin polarization of localized exciton-polariton condensates. We demonstrate the presence of an effective magnetic field leading to the formation of elliptically polarized condensates. We show that this synthetic field has an entirely photonic origin, which we believe is unique for the CdTe-based microcavities. Moreover, the degree of spin polarization of localized polariton condensates in samples with magnetic ions depends on the excitation power or polarization of the non-resonant excitation laser. In an external magnetic field, the semimagnetic condensate spontaneously builds up strong spin polarization. Based on the magnetic field behavior of the condensate in the presence of magnetic ions, we apply a model that allows us to estimate the polariton-polariton interaction strength in a CdTe-system to approx. 0.8 $\mu \text{eV}\!\cdot\!\mu \text{m}^2$