Mixed membership stochastic blockmodels

Observations consisting of measurements on relationships for pairs of objects arise in many settings, such as protein interaction and gene regulatory networks, collections of author-recipient email, and social networks. Analyzing such data with probabilisic models can be delicate because the simple exchangeability assumptions underlying many boilerplate models no longer hold. In this paper, we describe a latent variable model of such data called the mixed membership stochastic blockmodel. This model extends blockmodels for relational data to ones which capture mixed membership latent relational structure, thus providing an object-specific low-dimensional representation. We develop a general variational inference algorithm for fast approximate posterior inference. We explore applications to social and protein interaction networks.Comment: 46 pages, 14 figures, 3 table

Potential mechanism of action of cyclosporin a in human dermal fibroblasts—Transcriptomic analysis of CYPs

Effect of cyclosporin A (CsA) in a therapeutic concentration, on the expression of cytochrome P450 genes (CYPs), was investigated in normal human dermal fibroblast cells. The expression of 57 genes, encoding cytochrome P450 isoforms, was estimated using the microarray method. Amongst 396 normalized fluorescence signals related to cytochrome P450 activity, only 91 were strictly connected to CYPs and were analyzed using two methods: a self-organizing feature map of artificial neural networks and typical statistical analysis with significance level at p ≤ 0.05. Comparing the samples from fibroblasts cultured with CsA and those cultured without, up-regulated changes of CYP19A1, 1B1, 7A1, 7F1, 17A1 and down-regulated 2D6 gene expression were observed. The mRNAs with increased changes were in the same neuron of the self-organizing feature map. All distinguished CYPs encode monooxygenases, which plays an important role in steroids biosynthesis and metabolism. Based on the obtained results, we can conclude that CsA in therapeutic concentration changes the expression profile of CYPs in human dermal fibroblasts, especially affecting genes linked to steroids synthesis and/or metabolism. It shows the potential mechanism of action of CsA in human dermal fibroblast cell

The biotechnology of higher fungi - current state and perspectives

This review article concisely describes methodology of biotechnological processes with the use of cultures of higher fungi, their application in bioremediation and to obtain biologically active preparations. Advantages and disadvantages of biotechnological methods used to cultivate mushrooms are analyzed. This paper contains overview of higher fungi species most commonly used in biotechnological processes, of cultivation methods applied to produce fungal biomass, of enzymes and bioactive metabolites and of the strategies for submerged cultivation of the mycelial cultures. The problems of optimization of strains and biotechnological processes are briefly discussed.Niemniej pomimo trudności, producenci substancji leczniczych pochodzenia grzybowego (Lentinan, LEM, Grifon-D, PSK, PSP), suplementów diety oraz enzymów grzybowych, wprowadzają metody biotechnologiczne do produkcji. Zgodnie ze stosowanym od dawna w biotechnologii przemysłowej (np. przez producentów antybiotyków) zwyczajem, warunki procesu rzadko są opisywane w publikacjach, a czasami nie są nawet patentowane - co ułatwia zachowanie ich w tajemnicy. W latach 90-tych XX wieku pojawiły się pierwsze informacje o możliwości stosowania metod rekombinowanego DNA dla grzybów wyższych. Współcześnie, liczne publikacje donoszą o opracowaniu metod transformacji oraz o uzyskaniu modyfikowanych genetycznie grzybów jadalnyc