31 research outputs found

    Popularity versus Similarity in Growing Networks

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    Popularity is attractive -- this is the formula underlying preferential attachment, a popular explanation for the emergence of scaling in growing networks. If new connections are made preferentially to more popular nodes, then the resulting distribution of the number of connections that nodes have follows power laws observed in many real networks. Preferential attachment has been directly validated for some real networks, including the Internet. Preferential attachment can also be a consequence of different underlying processes based on node fitness, ranking, optimization, random walks, or duplication. Here we show that popularity is just one dimension of attractiveness. Another dimension is similarity. We develop a framework where new connections, instead of preferring popular nodes, optimize certain trade-offs between popularity and similarity. The framework admits a geometric interpretation, in which popularity preference emerges from local optimization. As opposed to preferential attachment, the optimization framework accurately describes large-scale evolution of technological (Internet), social (web of trust), and biological (E.coli metabolic) networks, predicting the probability of new links in them with a remarkable precision. The developed framework can thus be used for predicting new links in evolving networks, and provides a different perspective on preferential attachment as an emergent phenomenon

    Relativistic K shell decay rates and fluorescence yields for Zn, Cd and Hg

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    In this work we use the multiconfiguration Dirac-Fock method to calculate the transition probabilities for all possible decay channels, radiative and radiationless, of a K shell vacancy in Zn, Cd and Hg atoms. The obtained transition probabilities are then used to calculate the corresponding fluorescence yields which are compared to existing theoretical, semi-empirical and experimental results

    Renal amyloidosis in children

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    Renal amyloidosis is a detrimental disease caused by the deposition of amyloid fibrils. A child with renal amyloidosis may present with proteinuria or nephrotic syndrome. Chronic renal failure may follow. Amyloid fibrils may deposit in other organs as well. The diagnosis is through the typical appearance on histopathology. Although chronic infections and chronic inflammatory diseases used to be the causes of secondary amyloidosis in children, the most frequent cause is now autoinflammatory diseases. Among this group of diseases, the most frequent one throughout the world is familial Mediterranean fever (FMF). FMF is typically characterized by attacks of clinical inflammation in the form of fever and serositis and high acute-phase reactants. Persisting inflammation in inadequately treated disease is associated with the development of secondary amyloidosis. The main treatment is colchicine. A number of other monogenic autoinflammatory diseases have also been identified. Among them cryopyrin-associated periodic syndrome (CAPS) is outstanding with its clinical features and the predilection to develop secondary amyloidosis in untreated cases. The treatment of secondary amyloidosis mainly depends on the treatment of the disease. However, a number of new treatments for amyloid per se are in the pipeline

    Solution of a rational difference equation

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    In this work a solution for the following difference equation x n +1 = 1+xn ?5 x n ?11 was investigated, where x ? 11, x ? 10, x ? 9, x ? 8, x ? 7, x ? 6, x ? 5, x ? 4, x ? 3, x ? 2, x ? 1, x0 ? (0, ?). Copyright c 2019 Watam Pres

    No relation between colorectal cancer and concentrations of calcium in serum.

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    A very long foreign body in the bladder.

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    We report on a 58-year-old man in whom a very long rubber catheter was self-inserted for the purpose of increasing rigidity during erection. Eight years elapsed between insertion of the catheter and its retrieval. The foreign body was removed from the bladder by endoscopy

    Diyarbakir Bölgesindeki Sahipsiz Köpeklerde Toxoplasmosis, Leishmaniasis ve Listeriozisin Seroprevalansi.

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    The aim of this study was to determine the prevalence of toxoplasmosis, listeriosis and leishmaniasis in dogs in Diyarbakir region, Turkey. A total of 100 sera were collected from healthy dogs and tested for toxoplasmosis, leishmaniasis and listeriosis by the Sabin-Feldman Dye Test (SFDT), Indirekt Florescence Antikor Test (IFAT) and, Osebold Agglutination Test (OAT), respectively. Among these 100 dogs, 94 (94%) were seropositive for toxoplasmosis and and 17 (17%), for listeriosis. All of them were found to be seronegative for leishmaniasis. No statistically significant differences were observed between male and female dogs in the seroprevalence of toxoplasmosis and listeriosis. As a result, the presence of anti-Toxoplasma gondii and Listeria monocytogenesis specific antibodies in dogs in the region of Diyarbakir was determined
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