Decrypting distributed ledger design—taxonomy,classification and blockchain community evaluation

More than 1000 distributed ledger technology (DLT) systems raising $600 billion in investment in 2016 feature the unprecedented and disruptive potential of blockchain technology. A systematic and data-driven analysis, comparison and rigorous evaluation of the different design choices of distributed ledgers and their implications is a challenge. The rapidly evolving nature of the blockchain landscape hinders reaching a common understanding of the techno-socio-economic design space of distributed ledgers and the cryptoeconomies they support. To fill this gap, this paper makes the following contributions: (i) A conceptual architecture of DLT systems with which (ii) a taxonomy is designed and (iii) a rigorous classification of DLT systems is made using real-world data and wisdom of the crowd. (iv) A DLT design guideline is the end result of applying machine learning methodologies on the classification data. Compared to related work and as defined in earlier taxonomy theory, the proposed taxonomy is highly comprehensive, robust, explanatory and extensible. The findings of this paper can provide new insights and better understanding of the key design choices evolving the modeling complexity of DLT systems, while identifying opportunities for new research contributions and business innovation.

     

Conformational requirements for molecular recognition of acetylcholine receptor main immunogenic region (MIR) analogues by monoclonal anti-MIR antibody: A two-dimensional nuclear magnetic resonance and molecular dynamics approach

The conformational properties of two [D -A⁷⁰, A⁷⁶] and [Aib⁷⁰, A⁷⁶] analogues of the α67–76 Torpedo acetylcholine receptor fragment, with low binding capacity for the anti main immunogenic region (MIR) antibodies, were studied in DMSO by two-dimensional nmr techniques and molecular dynamics simulations. The results were compared to the free and bound conformations of the [A⁷⁶] analogue, which has twice more affinity for the anti-MIR monoclonal antibody 6 (mAb6), than the natural Torpedo sequence. It appeared that a single substitution of the A⁷⁰, at a crucial position, by the D -A⁷⁰ or Aib⁷⁰, could modify completely the conformational behavior of the peptide and reduced its recognition by the anti-MIR antibody. The WNPADY rigid structure at the N-terminal part was essential for antibody recognition. The adjacent more flexible C-terminal sequence (GGIK) gives additional stability to the monoclonal antibody–peptide complex probably due to an adequate orientation of the peptide side chains in the complex, by setting them in close contact with the antibody. © 1993 John Wiley & Sons, Inc.     

Application of the fourth universal definition of myocardial infarction in clinical practice

Abstract

Purpose: The Fourth Universal Definition of Myocardial Infarction (MI) has highlighted the different pathophysiological mechanisms that may lead to ischaemic and non-ischaemic myocardial injury and has emphasised that the diagnosis of myocardial infarction requires the presence of acute myocardial ischaemia in the setting of acute myocardial injury. This case based review intends to illustrate basic principles on how to apply this new, revised definition in clinical practice.

Methods and Results: The distinction between different types of MIs (type 1 or type 2) and the delineation of MI from acute non-ischaemic myocardial injury may be challenging in individual patients, which is illustrated by presenting and discussing real-life routine cases.

Conclusions: Type 1?MI is a consequence of coronary plaque rupture or erosion with intracoronary thrombus formation that is usually apparent on coronary angiography. Plausible triggering mechanisms causing myocardial oxygen supply/demand mismatch must be identified for the diagnosis of type 2?MI and its treatment should focus initially on management of the underlying disease attributable to acute myocardial ischaemia.     

Species co-occurrence: the case of congeneric species and a causal approach to patterns of species association

Aim To test whether congeneric species are significantly associated with one another in space, either positively or negatively. Also, to provide a framework for a causal investigation of co‐occurrence patterns by a parallel comparison of interactions in geographical and ecological data matrices. Location For the analysis of congeneric species’ co‐occurrences we used 30 matrices covering a wide range of taxa and geographical areas, while for the causal investigation we used the distribution of 50 terrestrial isopod species on 20 islands and 264 sampling stations in the central Aegean archipelago, as well as a number of ecological variables for each sampling station. Methods We developed a software program (cooc ) that incorporates the species‐by‐species approach to co‐occurrence analysis using EcoSim's output of prior null model analysis of co‐occurrence. We describe this program in detail, and use it to investigate one of the most common assembly rules, namely, the decreased levels of co‐occurrence among congeneric species pairs. For the causal analysis, we proceed likewise, cross‐checking the results from the geographical and the ecological matrices. There is only one possible combination of results that can support claims for direct competition among species. Results We do not get any strong evidence for widespread competition among congeneric species, while most communities investigated do not show significant patterns of species associations. The causal analysis suggests that the principal factors behind terrestrial isopod species associations are of historical nature. Some exceptional cases are also discussed. Main conclusions Presence/absence data for a variety of taxa do not support the assembly rule that congeneric species are under more intense competition compared to less related species. Also, these same data do not suggest strong interactions among species pairs, regardless of taxonomic status. When significant species associations can be seen in such matrices, they mainly reflect the effects of history or of habitat requirements.     

Between-island compositional dissimilarity of avian communities

Compositional dissimilarity patterns of biotic communities can vary among different types of insular systems and among taxa with different dispersal abilities. In this work we examined compositional dissimilarity patterns of four avian groups, namely birds of prey, waterbirds, seabirds and landbirds, in various insular systems around the world. Compositional dissimilarity of avian communities was calculated for 25 presence-absence matrices compiled from the literature. We used generalized linear mixed-effects models to check for differences in between-island compositional dissimilarity among the aforementioned avian groups that differ in their dispersal abilities, as well as between two different types of insular systems, oceanic and continental shelf. In agreement with our original hypothesis, landbirds which have relatively poorer dispersal abilities than birds of prey and waterbirds, exhibit higher between-island compositional dissimilarity compared to these two avian groups. On the contrary, seabirds present a deviation from the expected pattern, since they show higher between-island compositional dissimilarity compared to landbirds, even though they also have better dispersal abilities than landbirds, which can be explained by the relatively irregular occurrence of proper breeding habitats among islands for this avian group. Island type (oceanic or continental shelf) does not appear to affect between-island compositional dissimilarity of avian communities. Distance, area and elevation differences among islands are positively related to compositional dissimilarity. In conclusion, compositional dissimilarity of avian communities differs between avian groups but cannot always be associated with differences in the dispersal ability among these groups.     

A qualitative and quantitative study of mites in similar alfalfa fields in Greece

The present study investigated the mite fauna and the relative abundance of mites present in foliage and litter of two adjacent and similar alfalfa fields, differing only in the number of cuttings, in Kopais Valley (Central Greece) through 2008–2010. We also examined the relationship between assemblage patterns of Mesostigmata, Oribatida and Prostigmata by comparing their population fluctuation, population density, species richness and diversity. Spatial distribution of common dominant and influent mite species was also estimated. Our results showed that both fields supported a very rich and similar mite fauna with eight new species records for alfalfa of Greece, although these species have been previously reported from other habitats in Greece. The pattern of population fluctuation in foliage was similar in both fields, unlike the fluctuation in litter. Population density significantly differed between fields, being higher in the less harvested field, except Prostigmata. Species richness in litter was higher in the less harvested field, whereas it was higher in the foliage of the more harvested field, apart from that of prostigmatic mites in litter, which was higher in the more harvested field, and that of oribatid mites in foliage, which was higher in the less harvested field. The diversity of mites was higher in the more harvested field, with the exception of prostigmatic mites. The spatial distribution of mites in foliage and litter was aggregated in both fields. Our results indicate that despite the considerable similarity of the study fields, the different harvesting frequency might have disturbed differently the mite communities hosted in foliage and litter.