Moving embedded lattice solitons

It was recently proved that isolated unstable "embedded lattice solitons" (ELS) may exist in discrete systems. The discovery of these ELS gives rise to relevant questions such as the following: are there continuous families of ELS?, can ELS be stable?, is it possible for ELS to move along the lattice?, how do ELS interact?. The present work addresses these questions by showing that a novel differential-difference equation (a discrete version of a complex mKdV equation) has a two-parameter continuous family of exact ELS. The numerical tests reveal that these solitons are stable and robust enough to withstand collisions. The model may apply to the description of a Bose-Einstein condensate with dipole-dipole interactions between the atoms, trapped in a deep optical-lattice potential.Comment: 13 pages, 11 figure

The nature of GRB-selected submillimeter galaxies: hot and young

We present detailed fits of the spectral energy distributions (SEDs) of four submillimeter (submm) galaxies selected by the presence of a gamma-ray burst (GRB) event (GRBs 980703, 000210, 000418 and 010222). These faint ~3 mJy submm emitters at redshift ~1 are characterized by an unusual combination of long- and short-wavelength properties, namely enhanced submm and/or radio emission combined with optical faintness and blue colors. We exclude an active galactic nucleus as the source of long-wavelength emission. From the SED fits we conclude that the four galaxies are young (ages <2 Gyr), highly starforming (star formation rates ~150 MSun/yr), low-mass (stellar masses ~10^10 MSun) and dusty (dust masses ~3x10^8 MSun). Their high dust temperatures (Td>45 K) indicate that GRB host galaxies are hotter, younger, and less massive counterparts to submm-selected galaxies detected so far. Future facilities like Herschel, JCMT/SCUBA-2 and ALMA will test this hypothesis enabling measurement of dust temperatures of fainter GRB-selected galaxies.Comment: 9 pages, 2 figures, submitted to ApJ, for SED templates, see http://archive.dark-cosmology.dk

Commenting on Political Topics Through Twitter: Is European Politics European?

The aim of this study was to explore social media, and specifically Twitter's potential to generate a European demos. Our use of data derived from social media complements the traditional use of mass media and survey data within existing studies. We selected two Twitter hashtags of European relevance, #schengen and #ttip, to test several theories on a European demos (non-demos, European democracy, or pan-European demos) and to determine which of these theories was most applicable in the case of Twitter topics of European relevance. To answer the research question, we performed sentiment analysis. Sentiment analysis performed on data gathered on social media platforms, such as Twitter, constitutes an alternative methodological approach to more formal surveys (e.g., Eurobarometer) and mass media content analysis. Three dimensions were coded: (1) sentiments toward the issue public, (2) sentiments toward the European Union (EU), and (3) the type of framing. Among all of the available algorithms for conducting sentiment analysis, integrated sentiment analysis (iSA), developed by the Blog of Voices at the University of Milan, was selected for the data analysis. This is a novel supervised algorithm that was specifically designed for analyses of social networks and the Web 2.0 sphere (Twitter, blogs, etc.), taking the abundance of noise within digital environments into consideration. An examination and discussion of the results shows that for these two hashtags, the results were more aligned with the demoicracy and "European lite identity" models than with the model of a pan-European demos

Mediastinal mass presenting as an ST-elevation MI

Background: MINOCA is defined as a clinical syndrome in which there is myocardial ischemia in the setting of normal coronary arteries. Different causes include coronary spasms, SCAD, or external compression, e.g., by a mediastinal mass. CT or MRI would show presence of the mass, deferring any need for coronary angiography. Case: The patient is a 57-year-old lady with a past medical history of hypertension who presented to the ED complaining of shortness of breath associated with chest pain. Upon evaluation her vitals were BP 126/76, HR 94, RR 18, O2 98% on room air. Physical exam was unremarkable. Troponin peaked at 0.62. Chest x-ray showed no acute findings. EKG showed ST-elevation MI in leads V1-V3. She was immediately taken to the catheterization lab and was found to have normal coronary arteries without any evidence of coronary artery disease. CT angiography was done to rule out pulmonary embolism which showed an anterior mediastinal mass with invasion to the anterior cardiac wall consistent with malignancy. Interventional radiology was consulted, and she underwent CT guided biopsy of the mass. The patient remained stable with no further symptomatology and was discharged home. Biopsy results showed mass consistent with diffuse large B-cell lymphoma, activated B-cell type, with an exceedingly high proliferative fraction. She was started on chemotherapy regimen. Discussion: Primary mediastinal B-cell lymphomas are aggressive entities that can expand around the mediastinum and compromise the heart. Due to its cardiac invasion patients can present with an ACS picture. Coronary angiography would show no abnormalities. Aggressive chemotherapy regimen is pertinent in these patients due to the risk of myocardial rupture. Our case highlights the importance of viewing STEMI as a clinical syndrome with different etiologies and not just an EKG finding

A Transient Expression of Prospero Promotes Cell Cycle Exit of Drosophila Postembryonic Neurons through the Regulation of Dacapo

Cell proliferation, specification and terminal differentiation must be precisely coordinated during brain development to ensure the correct production of different neuronal populations. Most Drosophila neuroblasts (NBs) divide asymmetrically to generate a new NB and an intermediate progenitor called ganglion mother cell (GMC) which divides only once to generate two postmitotic cells called ganglion cells (GCs) that subsequently differentiate into neurons. During the asymmetric division of NBs, the homeodomain transcription factor PROSPERO is segregated into the GMC where it plays a key role as cell fate determinant. Previous work on embryonic neurogenesis has shown that PROSPERO is not expressed in postmitotic neuronal progeny. Thus, PROSPERO is thought to function in the GMC by repressing genes required for cell-cycle progression and activating genes involved in terminal differentiation. Here we focus on postembryonic neurogenesis and show that the expression of PROSPERO is transiently upregulated in the newly born neuronal progeny generated by most of the larval NBs of the OL and CB. Moreover, we provide evidence that this expression of PROSPERO in GCs inhibits their cell cycle progression by activating the expression of the cyclin-dependent kinase inhibitor (CKI) DACAPO. These findings imply that PROSPERO, in addition to its known role as cell fate determinant in GMCs, provides a transient signal to ensure a precise timing for cell cycle exit of prospective neurons, and hence may link the mechanisms that regulate neurogenesis and those that control cell cycle progression in postembryonic brain development

Sentiment analysis on predicting presidential election: Twitter used case

© Springer Nature Switzerland AG 2020. Twitter is a popular tool for social interaction over the Internet. It allows users to share/post opinions, social media events, and interact with other political and ordinary people. According to Statista web site 2019 statistical report, it estimated that the number of users on Twitter had grown dramatically over the past couple of years to research 300 million users. Twitter has become the largest source of news and postings for key presidents and political figures. Referring to the Trackalytics 2019 report, the recent president of the USA had posted 4,000 tweets per year, which indicates an average of 11–12 tweets per day. Our research proposes a technique that extracts and analyzes tweets from blogs and predicts election results based on tweets analysis. It assessed the people’s opinion and studied the impact that might predict the final results for the Turkey 2018 presidential election candidates. The final results were compared with the actual election results and had a high accuracy prediction percentage based on the collected 22,000 tweets

New insights on the molecular recognition of imidacloprid with Aplysia californica AChBP: a computational study

The binding of imidacloprid (IMI), the forerunner of neonicotinoid insecticides, with the acetylcholine binding protein (AChBP) from Aplysia californica, the established model for the extracellular domain of insects nicotinic acetylcholine receptors, has been studied with a two-layer ONIOM partition approach (M06-2X/6-311G(d):PM6). Our calculations allow delineating the contributions of the key residues of AChBP for IMI binding. In particular, the importance of Trp147 and Cys190-191, through weak CH...pi interactions and both van der Waals and hydrogen-bond (H-bond) interactions, respectively, are highlighted. Furthermore, H-bonds between hydroxyl groups of both Ser189 and Tyr55 and the IMI nitro group are pointed out. The participation of Ile118, whose main chain NH and carbonyl group are hydrogen-bonded with the IMI pyridinic nitrogen through a water molecule, is characterized. Our simulations also indicate the presence of a significant contribution of this residue through van der Waals interactions. The various trends obtained by the calculations of the pairwise interaction energies are confirmed through a complementary noncovalent interaction (NCI) analysis of selected IMI-AChBP amino acid pairs. Indeed, the contribution of a halogen-bond interaction between IMI and AChBP, recently proposed in the literature, is corroborated by our NCI analysis

Are Darknets All The Same? On Darknet Visibility for Security Monitoring

Darknets are sets of IP addresses that are advertised but do not host any client or server. By passively recording the incoming packets, they assist network monitoring activities. Since packets they receive are unsolicited by definition, darknets help to spot misconfigurations as well as important security events, such as the appearance and spread of botnets, DDoS attacks using spoofed IP address, etc. A number of organizations worldwide deploys darknets, ranging from a few dozens of IP addresses to large/8 networks. We here investigate how similar is the visibility of different darknets. By relying on traffic from three darknets deployed in different contintents, we evaluate their exposure in terms of observed events given their allocated IP addresses. The latter is particularly relevant considering the shortage of IPv4 addresses on the Internet. Our results suggest that some well-known facts about darknet visibility seem invariant across deployments, such as the most commonly contacted ports. However, size and location matter. We find significant differences in the observed traffic from darknets deployed in different IP ranges as well as according to the size of the IP range allocated for the monitoring