Evaluating Posts on the Steemit Blockchain: Analysis on Topics Based on Textual Cues

Online Social Networking platforms (OSNs) are part of the people's everyday life answering the deep-rooted need for communication among humans. During recent years, a new generation of social media based on blockchain became very popular, bringing the power of the technology to the service of social networks. Steemit is one such and employs the blockchain to implement a rewarding mechanism, adding a new, economic, layer to the social media service. The reward mechanism grants virtual tokens to the users capable of engaging other users on the platform, which can be either vested in the platform for increased influence or exchanged for fiat currency. The introduction of an economic layer on a social networking platform can seriously influence how people socialize. In this work, we tackle the problem of understanding how this new business model conditions the way people create contents. We performed term frequency and topic modelling analyses over the written contents published on the platforms between 2017 and 2019. This analysis lets us understand the most common topics of the contents that appear in the platform. While personal mundane information still appears, along with contents related to arts, food, travels, and sport, we also see emerging a very strong presence of contents about blockchain, cryptocurrency and, more specifically, on Steemit itself and its users

Comparative analysis of four methods to extract DNA from paraffin-embedded tissues: effect on downstream molecular applications

<p>Abstract</p> <p>Background</p> <p>A large portion of tissues stored worldwide for diagnostic purposes is formalin-fixed and paraffin-embedded (FFPE). These FFPE-archived tissues are an extremely valuable source for retrospective (genetic) studies. These include mutation screening in cancer-critical genes as well as pathogen detection. In this study we evaluated the impact of several widely used DNA extraction methods on the quality of molecular diagnostics on FFPE tissues.</p> <p>Findings</p> <p>We compared 4 DNA extraction methods from 4 identically processed FFPE mammary-, prostate-, colon- and lung tissues with regard to PCR inhibition, real time SNP detection and amplifiable fragment size. The extraction methods, with and without proteinase K pre-treatment, tested were: 1) heat-treatment, 2) QIAamp DNA-blood-mini-kit, 3) EasyMAG NucliSens and 4) Gentra Capture-Column-kit.</p> <p>Amplifiable DNA fragment size was assessed by multiplexed 200-400-600 bp PCR and appeared highly influenced by the extraction method used. Proteinase K pre-treatment was a prerequisite for proper purification of DNA from FFPE. Extractions with QIAamp, EasyMAG and heat-treatment were found suitable for amplification of fragments up to 400 bp from all tissues, 600 bp amplification was marginally successful (best was QIAamp). QIAamp and EasyMAG extracts were found suitable for downstream real time SNP detection. Gentra extraction was unsuitable. Hands-on time was lowest for heat-treatment, followed by EasyMAG.</p> <p>Conclusions</p> <p>We conclude that the extraction method plays an important role with regard to performance in downstream molecular applications.</p

A multilayer social overlay for new generation DOSNs

Online Social Networking platforms (OSNs) have become part of the real life of people. This is the natural outcome of many centuries of "social media" development answering the deep-rooted need for communication among humans. Existing social media platforms give users the impression that they are in full control of their data. However, it is actually those companies providing those services that have sole authority over a person's information. The need of trusted environment and the privacy issues in OSNs have seen the rise of Decentralized Online Social Networks. However, all of these platforms are far from being useful in real life. Indeed, they fail to address the complexity of social structures, in which we change our roles fluently from one to another leading to different roles in several independent and interconnected contexts. The envision of a Next Generation Internet focused on people is the main topic of the new generation of Decentralized Online Social Networks, which takes into account the main characteristics of the previous generations. In this paper, we present a new idea to model a multilayer P2P Social Overlay which takes into account different actors and relationships to be included in smart environments. Moreover, it is organized in layers, where one layer represents a specific social context of the peer it models. We present a formal definition of the Heterogeneous Ego Network and we show how it works in a general scenario

Fourier transform photoluminescence excitation spectroscopy of medium-bandgap Hg1-xCdxTe and InSb.

We report for the first time on Fourier transform photoluminescence excitation spectroscopy in the mid-infrared covering the wavelength range between 1 and 5.5 Mym. By studying a medium-bandgap Hgsub0.66Cdsub0.34Te bulk crystal and InSb bulk material, direct evidence for the excitonic nature of the luminescence transitions has been found in both cases. In addition, the excitation spectra on MBE-grown Hgsub1minusxCdsubxTe superlattices show the step-like density of states of the confined two- dimensional system

The Contextual Ego Network P2P Overlay for the Next Generation Social Networks

Internet has completely evolved in recent years, and smart devices, such as mobile and IoT devices have become pervasive in the daily life of people. Internet is becoming more social, and Online Social Networking platforms (OSNs) have become part of the real life of people. Current Online Social Media platforms are centralized. Centralization presents several drawbacks, and during the last years several privacy issues have been arisen concerning the control of private data. Indeed, those platforms offer inadequate guarantees where it concerns the privacy of their users. These problems have been confronted by exploiting decentralized solutions. Decentralized Online Social Networks (DOSNs) guarantee more control over private data. Thanks to the definition of a Next Generation Internet focused on people, the need for a new generation of Decentralized Online Social Networks, which puts the user at the center of the system, has been arisen. The HELIOS project tackles this issue by introducing a new decentralized paradigm. In this paper, we present the Contextual Ego Network (CEN), a new P2P Social Overlay built by exploiting the real life of users. We propose a formal definition of the structure, the implementation of the structure in a Java library, and a preliminary analysis in order to evaluate the homophily of each context

Responsivity and Gain of InGaAs/GaAs-QWIPs and GaAs/AlGaAs-QWIPS: a Comparative Study

We experimentally compare the peak responsivity R, gain g, quantum efficiency, and detectivity of GaAs/AlGaAs-QWIPs with devices based on the competing material system InGaAs/GaAs. For this purpose we use a typical n-type GaAs/AlGaAs-QWIP and three n-type InGaAs/GaAs-QWIPs with varying doping densities. R and g of the GaAs/AlGaAs-QWIP show a typical negative differential behavior, while both quantities grow monotonously with increasing bias voltage in the case of the InGaAs/GaAs-QWIPs. For identical nominal doping densities and similar cutoff wavelengths between 8.9 micrometers and 9 micrometers , InGaAs/GaAs-QWIPs show much higher responsivities than GaAs/AlGaAs-QWIPs. The ratio between these responsivities is 2.5 at the bias voltage where the GaAs/AlGaAs-QWIP has its maximum. By making use of the different bias dependence of the responsivity in both types of QWIPs a further enhancement of this factor is achieved. Nevertheless, both types of QWIPs show comparable detectivities. This is due to the fact that the gain has a negligible influence on the detectivity. In conclusion, InGaAs/GaAs-QWIPs are promising if high responsivities and short integration times are required

The SUMO2/3 specific E3 ligase ZNF451-1 regulates PML stability

The small ubiquitin related modifier SUMO regulates protein functions to maintain cell homeostasis. SUMO attachment is executed by the hierarchical action of E1, E2 and E3 enzymes of which E3 ligases ensure substrate specificity. We recently identified the ZNF451 family as novel class of SUMO2/3 specific E3 ligases and characterized their function in SUMO chain formation. The founding member, ZNF451isoform1 (ZNF451-1) partially resides in PML bodies, nuclear structures organized by the promyelocytic leukemia gene product PML. As PML and diverse PML components are well known SUMO substrates the question arises whether ZNF451-1 is involved in their sumoylation. Here, we show that ZNF451-1 indeed functions as SUMO2/3 specific E3 ligase for PML and selected PML components in vitro. Mutational analysis indicates that substrate sumoylation employs an identical biochemical mechanism as we described for SUMO chain formation. In vivo, ZNF451-1 RNAi depletion leads to PML stabilization and an increased number of PML bodies. By contrast, PML degradation upon arsenic trioxide treatment is not ZNF451-1 dependent. Our data suggest a regulatory role of ZNF451-1 in fine-tuning physiological PML levels in a RNF4 cooperative manner in the mouse neuroblastoma N2a cell-line