Reactive immunization on complex networks

Epidemic spreading on complex networks depends on the topological structure as well as on the dynamical properties of the infection itself. Generally speaking, highly connected individuals play the role of hubs and are crucial to channel information across the network. On the other hand, static topological quantities measuring the connectivity structure are independent on the dynamical mechanisms of the infection. A natural question is therefore how to improve the topological analysis by some kind of dynamical information that may be extracted from the ongoing infection itself. In this spirit, we propose a novel vaccination scheme that exploits information from the details of the infection pattern at the moment when the vaccination strategy is applied. Numerical simulations of the infection process show that the proposed immunization strategy is effective and robust on a wide class of complex networks

An evolutionary game model for behavioral gambit of loyalists: Global awareness and risk-aversion

We study the phase diagram of a minority game where three classes of agents are present. Two types of agents play a risk-loving game that we model by the standard Snowdrift Game. The behaviour of the third type of agents is coded by {\em indifference} w.r.t. the game at all: their dynamics is designed to account for risk-aversion as an innovative behavioral gambit. From this point of view, the choice of this solitary strategy is enhanced when innovation starts, while is depressed when it becomes the majority option. This implies that the payoff matrix of the game becomes dependent on the global awareness of the agents measured by the relevance of the population of the indifferent players. The resulting dynamics is non-trivial with different kinds of phase transition depending on a few model parameters. The phase diagram is studied on regular as well as complex networks

Searching for multi-messenger signals with the Pierre Auger Observatory

The Pierre Auger Observatory [1], primarily designed for the detection of ultra-high energy (UHE) cosmic rays, has been proven to be also an excellent tool in multi-messenger searches. With its unprecedented exposure to UHE particles, it is exploited to set stringent upper limits on the diffuse flux of UHE photons and neutrinos and to look for neutral particles associated with steady sources and transient events, such as gravitational waves. All these searches can provide key information to investigate the most energetic phenomena in the Universe and answer some of the most important still-open questions in astrophysics

Hydrogeochemistry and sustainability of freshwater lenses in the Samborombón Bay wetland, Argentina

Freshwater lenses constitute one of the most vulnerable aquifer systems in the world, especially in coastal wetland areas. The objectives of this work are to determine the hydrogeochemical processes that regulate the quality of the freshwater lenses in a sector of the Samborombón Bay wetland, and to assess their sustainability as regards the development of mining activities. A hydrochemical evaluation of groundwater was undertaken on the basis of major ion, trace and environmental isotope data. The deterioration in time of the freshwater lenses in relation to mining was studied on the basis of the analysis of topographic charts, aerial photography and satellite imaging. The results obtained show that the CO2(g) that dissolves in the rainwater infiltrating and recharging the lenses is converted to HCO3-, which dissolves the carbonate facies of the sediment. The exchange of Ca2+ for Na+, the incongruent dissolution of basic plagioclase and the reprecipitation of carbonate produce a change of the Ca-HCO3 facies to Na-HCO3. In depth, the pH increases with the groundwater flow, and the volcanic glassis dissolved, releasing F-and As. Besides, the evapotranspiration processes cause the saline content to increase slightly. As the only sources of drinking water in the region are the freshwater lenses occurring in the shell ridges, mining operations have deteriorated this resource and decreased the freshwater reserves in the lenses. The study undertaken made it possible to develop some preservation, remediation and management guidelines aimed at the sustainability of the water resources in the region.Facultad de Ciencias Naturales y Muse

High Density Lipoproteins Inhibit Oxidative Stress-Induced Prostate Cancer Cell Proliferation

Recent evidence suggests that oxidative stress can play a role in the pathogenesis and the progression of prostate cancer (PCa). Reactive oxygen species (ROS) generation is higher in PCa cells compared to normal prostate epithelial cells and this increase is proportional to the aggressiveness of the phenotype. Since high density lipoproteins (HDL) are known to exert antioxidant activities, their ability to reduce ROS levels and the consequent impact on cell proliferation was tested in normal and PCa cell lines. HDL significantly reduced basal and H2O2-induced oxidative stress in normal, androgen receptor (AR)-positive and AR-null PCa cell lines. AR, scavenger receptor BI and ATP binding cassette G1 transporter were not involved. In addition, HDL completely blunted H2O2-induced increase of cell proliferation, through their capacity to prevent the H2O2-induced shift of cell cycle distribution from G0/G1 towards G2/M phase. Synthetic HDL, made of the two main components of plasma-derived HDL (apoA-I and phosphatidylcholine) and which are under clinical development as anti-atherosclerotic agents, retained the ability of HDL to inhibit ROS production in PCa cells. Collectively, HDL antioxidant activity limits cell proliferation induced by ROS in AR-positive and AR-null PCa cell lines, thus supporting a possible role of HDL against PCa progression

Coordination complexes of niobium and tantalum pentahalides with a bulky NHC ligand

The 1 : 1 molar reactions of niobium and tantalum pentahalides with the monodentate NHC ligand 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (Ipr), in toluene (or benzene) at ca. 80 °C, afforded the complexes NbX5(Ipr) (X = F, 2; Br, 3) and TaX5(Ipr) (X = F, 4; Cl, 5; Br, 6), in generally good yields. Complexes 2–6 represent uncommon cases of stable NHC adducts of metal halides with the metal in an oxidation state higher than +4, and also rare examples of Nb–NHC and Ta–NHC bonding systems. In particular, the X-ray molecular structure determined for 6 provides the unprecedented crystallographic characterization of a tantalum compound with a monodentate NHC ligand. DFT results indicate that the metal–carbon bond in 2–6 is a purely σ one. According to NMR studies (1H, 13C, 93Nb), the formation of 3, 5, 6, as well as the previously communicated NbCl5(Ipr), 1, proceeded with the intermediacy of [MX6]− salts, presumably due to steric reasons. On the other hand, the intermediate formation of MF6− in the pathways to 2 and 4 was not observed, according to 19F (and 93Nb in the case of 2) NMR. DFT calculations were carried out in order to shed light on structural and mechanistic aspects, and allowed to trace possible reaction routes

Hydrogeochemical and isotopic signature of surface and groundwater in a highly industrialized sector of the Rio de la Plata coastal plain (Argentina)

The coastal plain of the middle estuary of the Río de la Plata is a highly industrialized area and is densely populated by sectors. The main human activity in the sector encompassed between the cities of Ensenada and Berisso is associated with the petrochemical industry. In this work, hydrogeochemical and isotopic characteristics of surface and groundwater in the impacted area are analyzed and the results are contrasted with those obtained in an undisturbed protected area. Major and trace elements were determined using standardized methods while the stable isotopes δ18O y δ2H were analyzed by mass spectroscopy. Human impact is evidenced by the occurrence of large variations in the major chemical composition of water, and also by the elevated concentrations of some trace elements that are not contributed from natural sources. These results may contribute to the understanding of chemical processes and pollutants distribution in highly industrialized coastal plain areas.Centro de Investigaciones Geológica

The Use of New Mobile and Gaming Technologies for the Assessment and Rehabilitation of People with Ataxia: a Systematic Review and Meta-analysis

There are no currently available disease-modifying pharmacological treatments for most of the chronic hereditary ataxias; thus, effective rehabilitative strategies are crucial to help improve symptoms and therefore the quality of life. We propose to gather all available evidence on the use of video games, exergames, and apps for tablet and smartphone for the rehabilitation, diagnosis, and assessment of people with ataxias. Relevant literature published up to June 8, 2020, was retrieved searching the databases PubMed, ISI Web of Science, and the Cochrane Database. Data were extracted using a standardized form, and their methodological quality was assessed using RoB and QUADAS-2. Six studies of 434 retrieved articles met the predefined inclusion/exclusion criteria. Two of them were diagnostic, while 4 were experimental studies. Studies included participants ranging from 9 to 28 in trials and 70 to 248 in diagnostic studies. Although we found a small number of trials and of low methodological quality, all of them reported an improvement of motor outcomes and quality of life as measured by specific scales, including the SARA, BBS, DHI, and SF-36 scores. The main reason for such low quality in trials was that most of them were small and uncontrolled, thus non-randomized and unblinded. As video games, exergames, serious games, and apps were proven to be safe, feasible, and at least as effective as traditional rehabilitation, further and more high-quality studies should be carried out on the use of these promising technologies in people with different types of ataxia