A Flexible Network Approach to Privacy of Blockchain Transactions

For preserving privacy, blockchains can be equipped with dedicated mechanisms to anonymize participants. However, these mechanism often take only the abstraction layer of blockchains into account whereas observations of the underlying network traffic can reveal the originator of a transaction request. Previous solutions either provide topological privacy that can be broken by attackers controlling a large number of nodes, or offer strong and cryptographic privacy but are inefficient up to practical unusability. Further, there is no flexible way to trade privacy against efficiency to adjust to practical needs. We propose a novel approach that combines existing mechanisms to have quantifiable and adjustable cryptographic privacy which is further improved by augmented statistical measures that prevent frequent attacks with lower resources. This approach achieves flexibility for privacy and efficency requirements of different blockchain use cases.Comment: 6 pages, 2018 IEEE 38th International Conference on Distributed Computing Systems (ICDCS

Signaling through focal adhesion kinase

Integrin receptor binding to extracellular matrix proteins generates intracellular signals via enhanced tyrosine phosphorylation events that are important for cell growth, survival, and migration. This review will focus on the functions of the focal adhesion kinase (FAK) protein-tyrosine kinase (PTK) and its role in linking integrin receptors to intracellular signaling pathways. FAK associates with several di€erent signaling proteins such as Src-family PTKs, p130 Cas, Shc, Grb2, PI 3-kinase, and paxillin. This enables FAK to function within a network of integrin-stimulated signaling pathways leading to the activation of targets such as the ERK and JNK/mitogen-activated protein kinase pathways. Focus will be placed on the structural domains and sites of FAK tyrosine phosphorylation important for FAKmediated signaling events and how these sites are conserved in the FAK-related PTK, Pyk2. We will review what is known about FAK activation by integrin receptor-mediated events and also non-integrin stimuli. In addition, we discuss the emergence of a consensus FAK substrate phosphorylation sequence. Emphasis will also be placed on the role of FAK in generating cell survival signals and the cleavage of FAK during caspase-mediated apoptosis. An in-depth discussion will be presented of integrin-stimulated signaling events occurring in the FAK knockout ®broblasts (FAK � ) and how these cells exhibit de®cit

Construction Superintendent Skill Sets

This is the first of a series of articles reviewing the results of an ongoing qualitative research project designed to document construction superintendent skill sets and develop postsecondary curricula to support superintendent education. Varying views of the role of the superintendent and an historical perspective are presented in a review of literature. The research methodology for the entire project, as well as this first phase, is presented. Data have been coded and analyzed from the interviews with seven superintendents to date and the results of these analyses are provided. Themes that emerged in these interviews include people skills, understanding the work and sequencing, organizational and managerial skills, scheduling, estimating, cost control/awareness, work ethic, and learning from other people. Insights into how the role of the superintendent has changed and the preparation needed for future superintendents also are provided from these interviews. These preliminary results indicate there is a role for colleges and universities in developing these skill sets, and that construction superintendents now are doing tasks formerly thought to be the responsibility of project managers. The Technology Age coupled with our litigious society is forcing the construction superintendent into a new role

Statistical privacy-preserving message dissemination for peer-to-peer networks

Concerns for the privacy of communication is widely discussed in research and overall society. For the public financial infrastructure of blockchains, this discussion encompasses the privacy of transaction data and its broadcasting throughout the network. To tackle this problem, we transform a discrete-time protocol for contact networks over infinite trees into a computer network protocol for peer-to-peer networks. Peer-to-peer networks are modeled as organically growing graphs. We show that the distribution of shortest paths in such a network can be modeled using a normal distribution $\mathcal{N}(\mu,\sigma^2).$ We determine statistical estimators for $\mu,\sigma$ via multivariate models. The model behaves logarithmic over the number of nodes n and proportional to an inverse exponential over the number of added edges k. These results facilitate the computation of optimal forwarding probabilities during the dissemination phase for optimal privacy in a limited information environment.Comment: 6 figures, 19 pages, single colum

Range expansion of an endangered beetle: Alpine Longhorn Rosalia alpina (Coleoptera: Cerambycidae) spreads to the lowlands of Central Europe

Rosalia alpina is an endangered and strictly protected icon of saproxylic biodiversity throughout its range. Despite its popularity, information on its habitats and host-plants is insufficient, which may compromise the adoption of suitable conservation strategies. R. alpina has been considered as montane and associated with beech in central Europe, whereas in southern Europe R. alpina has often been reported from lowlands and its host spectrum is broader. We present evidence of an elm-feeding population ofR. alpina occurring in a lowland (beechfree) forest in the Czech Republic. This plus other information available suggest, that R. alpina spreads into central European lowland forests along large rivers, and that spectra of hosts and habitats exploited by R. alpina in Central Europe are wider than generally thought. Alteration of its habitat preference has either occurred in Central European populations, or lowland-inhabiting populations from the South are spreading northwards, possibly due to climate change

Site factors determining epiphytic lichen distribution in a dieback-affected spruce-fir forest on Whiteface Mountain, New York: stemflow chemistry

Epiphytic lichen diversity in a dieback-affected forest of red spruce (Picea rubens Sarg.) and balsam fir (Abies balsamea (L.) Mill.) on Whiteface Mountain, New York, U.S.A., was higher on dead compared with living trees and on fir compared with spruce. Diversity differed more between living and dead spruce than between living and dead fir. Cover of all lichen species that occurred on more than 50% of the sample trees, except for two species, decreased with increasing mean concentration of NO3– in stemflow. Concentrations of NO3– were higher on living spruce compared with dead spruce and with living and dead fir. The negative correlations between lichen cover and NO3– concentration may reflect either a decrease of lichen abundance caused by toxic effects of higher NO3– concentrations or a removal of NO3– from stemflow by epiphytic lichens. Experimental exposure of Hypogymnia physodes to NaNO3 reduced chlorophyll concentrations. This result, together with estimations of lichen and needle biomass, indicates that a dependence of lichen cover on NO3– concentrations in stemflow may be the cause for the negative correlations. The sulphur concentration in stemflow did not affect lichen abundance on Whiteface Mountain. The manganese concentration in stemflow may have an effect on single species