Recurrent Dynamic Message Passing with Loops for Epidemics on Networks

Several theoretical methods have been developed to approximate prevalence and threshold of epidemics on networks. Among them, the recurrent dynamic message-passing (rDMP) theory offers a state-of-the-art performance by preventing the echo chamber effect in network edges. However, the rDMP theory was derived in an intuitive ad-hoc way, lacking a solid theoretical foundation and resulting in a probabilistic inconsistency flaw. Furthermore, real-world networks are clustered and full of local loops like triangles, whereas rDMP is based on the assumption of a locally tree-like network structure, which makes rDMP potentially inefficient on real applications. In this work, for the recurrent-state epidemics, we first demonstrate that the echo chamber effect exits not only in edges but also in local loops, which rDMP-like method can not avoid. We then correct the deficiency of rDMP in a principled manner, leading to the natural introduction of new higher-order dynamic messages, extending rDMP to handle local loops. By linearizing the extended message-passing equations, a new epidemic threshold estimation is given by the inverse of the leading eigenvalue of a matrix named triangular non-backtracking matrix. Numerical experiments conducted on synthetic and real-world networks to evaluate our method, the efficacy of which is validated in epidemic prevalence and threshold prediction tasks. In addition, our method has the potential to speed up the solution of the immunization, influence maximization, and robustness optimization problems in the networks.Comment: Submitted, 14 pages, 7 figure

Mobile payment and subjective well-being in rural China

We explore the impact of mobile payment usage on the subjective well-being (S.W.B.) of rural residents in China using unique data from the China Household Finance Survey (C.H.F.S.). The estimated results show that using mobile payment has increased the S.W.B. of rural residents, and this finding still holds through several robust checks. The mechanism analysis suggests that the positive effect of mobile payment is partially explained by the reduction in transaction costs, the promotion in consumption upgrade, and the increase in social networks. Additionally, the inclusive financial attributes of mobile payment are verified through several heterogeneity analyses. Results show that the positive impact of mobile payment on S.W.B. is more pronounced in socially vulnerable groups such as the elderly, people with lower income, or lower education. Our study enriches the research on the fields of happiness effect of rural financial convenience and function of inclusive finance and has practical significance for other developing countries

Alum sludge as an efficient sorbent for hydrogen sulfide removal: Experimental, mechanisms and modeling studies

International audienceThis paper firstly reported a systematic study of using alum sludge (waterworks residue) for H2S adsorption. Various trials were performed at ambient temperature in a fixed bed column to study the effects of H2S flow rate, sorbent bed depth on the alum sludge adsorption efficiency of H2S. The Breakthrough Curves were simulated by the Thomas model, Bed Depth Service Time model and Yoon-Nelson models. The mechanisms of H2S adsorption onto alum sludge was examined by different physiochemical characterizations of exhausted and raw alum sludge. Moreover, the mass transfer coefficients were determined from mathematical descriptions of breakthrough curves. The alum sludge adsorption capacity was determined to be 374.2 mg of H2S/g, slightly decreasing with the increasing flow rate and increasing with the increasing bed depth. All the three models successfully predict breakthrough curves which could be used for scaling-up purposes. The microporous structure, alkaline pH and the inherent metal species of the alum sludge promoted the formation of metal sulphate species. This study demonstrated that alum sludge could be used as cost-effective, largely available, and efficient sorbent for H2S removal

New low-cost wastewater treatment system pioneered in Ireland

A pilot scheme in Ireland is treating agricultural wastewater using waste alum sludge from water-treatment works. Akin Babatunde and Yaqian Zhao from University College Dublin report on what could become the world's low-cost wastewater-treatment system of choice, particularly in remote areas

Anaerobic co-digestion of food waste and FOG with sewage sludge – realising its potential in Ireland

International audienceThe severe environmental pollution in many countries is caused by indiscriminate discharge of large quantities of food waste (FW), fat oil and grease (FOG) and sewage sludge (SS) to the environment. There are many possible treatment routes, but anaerobic digestion (AD) is now well accepted for treating several kinds of organic wastes. But AD of FW alone presents some operational challenges because of substrates and variability. Anaerobic co-digestion of two or more substrates is better than single substrate digestion. This can use a plant’s unused capacity, in line with the trend to renewable energy. Co-digestion technology, although well established in many European countries, is still in its infancy in Ireland. There are problems with different regulatory arrangements. They should be resolved. The paper reviews anaerobic co-digestion technology is reviewed, with special focus on possible application in Ireland

On the Migration Origin of the Hercules Moving Group with GAIA, LAMOST, APOGEE, and GALAH Surveys

Using Gaia DR3 data and the wavelet transformation technique, we study the substructures of the Hercules moving group (HMG): Hercules 1 (H1) and Hercules 2 (H2). Spectroscopic survey data from LAMOST, APOGEE, and GALAH are used to obtain metallicities and ages of stars belonging to the HMG. Our analysis leads to several key findings as follows: ($a$) the HMG is on average richer in metallicity than the Galactic disk, with H2 being metal richer than H1; ($b$) the HMG likely has a radial metallicity gradient distinct from that of the disk; ($c$) the HMG is on average older than the disk, with H2 being older than H1; ($d$) the HMG likely has a radial age gradient distinct from that of the disk; and ($e$) the metallicity and age distributions of the HMG depend mainly on the Galactic radius but show no dependence on the azimuthal velocity. Taken all together, we conclude that the HMG is composed primarily of stars undergoing radial migration. We suggest that the HMG is associated with a higher-order dynamical resonance of the bar of the Galaxy.Comment: 15 pages, 6 figures. Accepted by Ap