Countering Misinformation on Social Networks Using Graph Alterations

We restrict the propagation of misinformation in a social-media-like environment while preserving the spread of correct information. We model the environment as a random network of users in which each news item propagates in the network in consecutive cascades. Existing studies suggest that the cascade behaviors of misinformation and correct information are affected differently by user polarization and reflexivity. We show that this difference can be used to alter network dynamics in a way that selectively hinders the spread of misinformation content. To implement these alterations, we introduce an optimization-based probabilistic dropout method that randomly removes connections between users to achieve minimal propagation of misinformation. We use disciplined convex programming to optimize these removal probabilities over a reduced space of possible network alterations. We test the algorithm's effectiveness using simulated social networks. In our tests, we use both synthetic network structures based on stochastic block models, and natural network structures that are generated using random sampling of a dataset collected from Twitter. The results show that on average the algorithm decreases the cascade size of misinformation content by up to $70\%$ in synthetic network tests and up to $45\%$ in natural network tests while maintaining a branching ratio of at least $1.5$ for correct information.Comment: 10 pages, 6 figure

Pilgrims to the Eurozone: How far, how fast?

Cataloged from PDF version of article.In our analysis, we re-examine the nominal and real convergence of all recent 10 European Union (EU) members to EU standards. Testing for monetary convergence has significant implications for interim optimal exchange rate and monetary policies before a formal and permanent link to the euro, while real convergence is the ultimate objective of economic integration. Novel features of the paper include broader measures of real convergence in both euro as well as local currencies, an examination of inflation and interest rate convergence with respect to the Maastricht benchmarks, and employment of more appropriate tests of convergence allowing for structural breaks. The results indicate slow but steady per-capita real income convergence towards EU standards. On the other hand, evidence indicates significant strong inflation and interest rate convergence. Policy implications of the paper are also discussed. © 2006 Elsevier B.V. All rights reserved

Relationship Design for Socially-Aware Behavior in Static Games

Autonomous agents can adopt socially-aware behaviors to reduce social costs, mimicking the way animals interact in nature and humans in society. We present a new approach to model socially-aware decision-making that includes two key elements: bounded rationality and inter-agent relationships. We capture the interagent relationships by introducing a novel model called a relationship game and encode agents' bounded rationality using quantal response equilibria. For each relationship game, we define a social cost function and formulate a mechanism design problem to optimize weights for relationships that minimize social cost at the equilibrium. We address the multiplicity of equilibria by presenting the problem in two forms: Min-Max and Min-Min, aimed respectively at minimization of the highest and lowest social costs in the equilibria. We compute the quantal response equilibrium by solving a least-squares problem defined with its Karush-Kuhn-Tucker conditions, and propose two projected gradient descent algorithms to solve the mechanism design problems. Numerical results, including two-lane congestion and congestion with an ambulance, confirm that these algorithms consistently reach the equilibrium with the intended social costs

Effect of micronized zeolite addition to lamb concentrate feeds on growth performance and some blood chemistry and metabolites

This study was conducted to determine the effects of the addition of micronized zeolite (MZ) on the fattening performance, blood parameters, faecal ash and nitrogen levels of lambs fed concentrate feeds intensively. For two months 25 four-month-old Merino x Ile de France crossbred male lambs (21.1 ± 1.32 kg live weight) were fed 100 g alfalfa hay and a mixed concentrate diet containing 0%, 1%, 2% or 3% additional MZ. At the end of the study, bodyweight gain and feed consumption were not affected by the treatments. Similarly, the addition of up to 2% MZ to the diet did not affect slaughter weight, hot carcass or cold carcass weights, but they decreased at 3% MZ inclusion. No differences were observed between the groups in terms of blood urea nitrogen, plasma glucose, serum creatinine, triglyceride, sodium, potassium and chlorine concentration. However, serum total protein, calcium and phosphorus concentrations were affected by MZ supplementation. The addition of MZ to the ration did not affect the faecal dry matter content and total nitrogen level, yet it increased the ash content of the faeces. Consequently, it was demonstrated that the addition of up to 2% MZ to lamb grower feed does not have a negative impact on performance and carcass yield of the animals, but affects serum total protein, calcium and phosphorus concentrations

Chemical Cascading Between Polymersomal Nanoreactor Populations

[EN] Harnessing interactions of functional nano-compartments to generate larger particle assemblies allows studying diverse biological behaviors based on their population states and can lead to the development of smart materials. Herein, thiol-functionalized polymersome nanoreactors are utilized as responsive organelle-like nano-compartments-with inherent capacity to associate into larger aggregates in response to change in the redox state of their environment-to study the kinetics of cascade reactions and explore functions of their collective under different population states. Two nanoreactor populations, glucose oxidase- and horseradish peroxidase-loaded polymersomes, are prepared, and the results of their cascading upon addition of glucose are investigated. The kinetics of resorufin production in associated polymersomes and non-associated polymersome populations are compared, observing a decreased rate upon association. For the associated populations, faster chemical cascading is found when the two types of nanoreactors are associated in a concerted step, as compared to sequential association. The addition of competing agents such as catalase impacts the communication between non-associated polymersomes, whereas such an effect is less pronounced for the associated ones. Altogether, the results showcase the impact of collective associations on enzymatic cascading between organelle-like nanoreactors.Y.A. and A.L.-L. contributed equally to this work. The authors would like to acknowledge the support from the Dutch Ministry of Education, Culture, and Science (Gravitation program 024.001.035 and Spinoza premium) and the ERC Advanced Grant (Artisym 694120).A.L.-L. acknowledges support from the MSCA Cofund project oLife, which has received funding from the European Union's Horizon 2020 research and innovation program under the Grant Agreement 847675; and the Maria Zambrano Program from the Spanish Government funded by NextGenerationEU from the European Union. Dr. Imke Pijpers is thanked for cryo-TEM imaging. Dr. Pascal Welzen is acknowledged for advice and useful discussion on polymer and polymersome preparation.Altay, Y.; Llopis-Lorente, A.; Abdelmohsen, LKEA.; Van Hest, JC. (2023). Chemical Cascading Between Polymersomal Nanoreactor Populations. Macromolecular Chemistry and Physics. 224(1):1-5. https://doi.org/10.1002/macp.20220026915224

Carbapenem Resistance in Klebsiella pneumoniae Not Detected by Automated Susceptibility Testing

Detecting β-lactamase–mediated carbapenem resistance among Klebsiella pneumoniae isolates and other Enterobacteriaceae is an emerging problem. In this study, 15 blaKPC-positive Klebsiella pneumoniae that showed discrepant results for imipenem and meropenem from 4 New York City hospitals were characterized by isoelectric focusing; broth microdilution (BMD); disk diffusion (DD); and MicroScan, Phoenix, Sensititre, VITEK, and VITEK 2 automated systems. All 15 isolates were either intermediate or resistant to imipenem and meropenem by BMD; 1 was susceptible to imipenem by DD. MicroScan and Phoenix reported 1 (6.7%) and 2 (13.3%) isolates, respectively, as imipenem susceptible. VITEK and VITEK 2 reported 10 (67%) and 5 (33%) isolates, respectively, as imipenem susceptible. By Sensititre, 13 (87%) isolates were susceptible to imipenem, and 12 (80%) were susceptible to meropenem. The VITEK 2 Advanced Expert System changed 2 imipenem MIC results from >16 μg/mL to <2 μg/mL but kept the interpretation as resistant. The recognition of carbapenem-resistant K. pneumoniae continues to challenge automated susceptibility systems

CLIC-LHC Based FEL-Nucleus Collider: Feasibility and Physics Search Potential

The feasibility of a CLIC-LHC based FEL-nucleus collider is investigated. It is shown that the proposed scheme satisfies all requirements of an ideal photon source for the Nuclear Resonance Fluorescence method. The tunability, monochromaticity and high polarization of the FEL beam together with high statistics and huge energy of LHC nucleus beams will give an unique opportunity to determine different characteristics of excited nuclear levels. The physics potential of the proposed collider is illustrated for a beam of Pb nuclei.Comment: 19 pages, 3 figure